1 //===--- Sema.h - Semantic Analysis & AST Building --------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines the Sema class, which performs semantic analysis and
11 // builds ASTs.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_CLANG_SEMA_SEMA_H
16 #define LLVM_CLANG_SEMA_SEMA_H
17 
18 #include "clang/AST/Attr.h"
19 #include "clang/AST/DeclarationName.h"
20 #include "clang/AST/Expr.h"
21 #include "clang/AST/ExprObjC.h"
22 #include "clang/AST/ExternalASTSource.h"
23 #include "clang/AST/MangleNumberingContext.h"
24 #include "clang/AST/NSAPI.h"
25 #include "clang/AST/PrettyPrinter.h"
26 #include "clang/AST/TypeLoc.h"
27 #include "clang/Basic/ExpressionTraits.h"
28 #include "clang/Basic/LangOptions.h"
29 #include "clang/Basic/Module.h"
30 #include "clang/Basic/OpenMPKinds.h"
31 #include "clang/Basic/Specifiers.h"
32 #include "clang/Basic/TemplateKinds.h"
33 #include "clang/Basic/TypeTraits.h"
34 #include "clang/Sema/AnalysisBasedWarnings.h"
35 #include "clang/Sema/DeclSpec.h"
36 #include "clang/Sema/ExternalSemaSource.h"
37 #include "clang/Sema/IdentifierResolver.h"
38 #include "clang/Sema/LocInfoType.h"
39 #include "clang/Sema/ObjCMethodList.h"
40 #include "clang/Sema/Ownership.h"
41 #include "clang/Sema/Scope.h"
42 #include "clang/Sema/ScopeInfo.h"
43 #include "clang/Sema/TypoCorrection.h"
44 #include "clang/Sema/Weak.h"
45 #include "llvm/ADT/ArrayRef.h"
46 #include "llvm/ADT/Optional.h"
47 #include "llvm/ADT/SetVector.h"
48 #include "llvm/ADT/SmallPtrSet.h"
49 #include "llvm/ADT/SmallVector.h"
50 #include "llvm/ADT/TinyPtrVector.h"
51 #include <deque>
52 #include <memory>
53 #include <string>
54 #include <vector>
55 
56 namespace llvm {
57   class APSInt;
58   template <typename ValueT> struct DenseMapInfo;
59   template <typename ValueT, typename ValueInfoT> class DenseSet;
60   class SmallBitVector;
61   class InlineAsmIdentifierInfo;
62 }
63 
64 namespace clang {
65   class ADLResult;
66   class ASTConsumer;
67   class ASTContext;
68   class ASTMutationListener;
69   class ASTReader;
70   class ASTWriter;
71   class ArrayType;
72   class AttributeList;
73   class BlockDecl;
74   class CapturedDecl;
75   class CXXBasePath;
76   class CXXBasePaths;
77   class CXXBindTemporaryExpr;
78   typedef SmallVector<CXXBaseSpecifier*, 4> CXXCastPath;
79   class CXXConstructorDecl;
80   class CXXConversionDecl;
81   class CXXDestructorDecl;
82   class CXXFieldCollector;
83   class CXXMemberCallExpr;
84   class CXXMethodDecl;
85   class CXXScopeSpec;
86   class CXXTemporary;
87   class CXXTryStmt;
88   class CallExpr;
89   class ClassTemplateDecl;
90   class ClassTemplatePartialSpecializationDecl;
91   class ClassTemplateSpecializationDecl;
92   class VarTemplatePartialSpecializationDecl;
93   class CodeCompleteConsumer;
94   class CodeCompletionAllocator;
95   class CodeCompletionTUInfo;
96   class CodeCompletionResult;
97   class Decl;
98   class DeclAccessPair;
99   class DeclContext;
100   class DeclRefExpr;
101   class DeclaratorDecl;
102   class DeducedTemplateArgument;
103   class DependentDiagnostic;
104   class DesignatedInitExpr;
105   class Designation;
106   class EnableIfAttr;
107   class EnumConstantDecl;
108   class Expr;
109   class ExtVectorType;
110   class ExternalSemaSource;
111   class FormatAttr;
112   class FriendDecl;
113   class FunctionDecl;
114   class FunctionProtoType;
115   class FunctionTemplateDecl;
116   class ImplicitConversionSequence;
117   class InitListExpr;
118   class InitializationKind;
119   class InitializationSequence;
120   class InitializedEntity;
121   class IntegerLiteral;
122   class LabelStmt;
123   class LambdaExpr;
124   class LangOptions;
125   class LocalInstantiationScope;
126   class LookupResult;
127   class MacroInfo;
128   typedef ArrayRef<std::pair<IdentifierInfo *, SourceLocation>> ModuleIdPath;
129   class ModuleLoader;
130   class MultiLevelTemplateArgumentList;
131   class NamedDecl;
132   class ObjCCategoryDecl;
133   class ObjCCategoryImplDecl;
134   class ObjCCompatibleAliasDecl;
135   class ObjCContainerDecl;
136   class ObjCImplDecl;
137   class ObjCImplementationDecl;
138   class ObjCInterfaceDecl;
139   class ObjCIvarDecl;
140   template <class T> class ObjCList;
141   class ObjCMessageExpr;
142   class ObjCMethodDecl;
143   class ObjCPropertyDecl;
144   class ObjCProtocolDecl;
145   class OMPThreadPrivateDecl;
146   class OMPClause;
147   class OverloadCandidateSet;
148   class OverloadExpr;
149   class ParenListExpr;
150   class ParmVarDecl;
151   class Preprocessor;
152   class PseudoDestructorTypeStorage;
153   class PseudoObjectExpr;
154   class QualType;
155   class StandardConversionSequence;
156   class Stmt;
157   class StringLiteral;
158   class SwitchStmt;
159   class TemplateArgument;
160   class TemplateArgumentList;
161   class TemplateArgumentLoc;
162   class TemplateDecl;
163   class TemplateParameterList;
164   class TemplatePartialOrderingContext;
165   class TemplateTemplateParmDecl;
166   class Token;
167   class TypeAliasDecl;
168   class TypedefDecl;
169   class TypedefNameDecl;
170   class TypeLoc;
171   class TypoCorrectionConsumer;
172   class UnqualifiedId;
173   class UnresolvedLookupExpr;
174   class UnresolvedMemberExpr;
175   class UnresolvedSetImpl;
176   class UnresolvedSetIterator;
177   class UsingDecl;
178   class UsingShadowDecl;
179   class ValueDecl;
180   class VarDecl;
181   class VarTemplateSpecializationDecl;
182   class VisibilityAttr;
183   class VisibleDeclConsumer;
184   class IndirectFieldDecl;
185   struct DeductionFailureInfo;
186   class TemplateSpecCandidateSet;
187 
188 namespace sema {
189   class AccessedEntity;
190   class BlockScopeInfo;
191   class CapturedRegionScopeInfo;
192   class CapturingScopeInfo;
193   class CompoundScopeInfo;
194   class DelayedDiagnostic;
195   class DelayedDiagnosticPool;
196   class FunctionScopeInfo;
197   class LambdaScopeInfo;
198   class PossiblyUnreachableDiag;
199   class TemplateDeductionInfo;
200 }
201 
202 // FIXME: No way to easily map from TemplateTypeParmTypes to
203 // TemplateTypeParmDecls, so we have this horrible PointerUnion.
204 typedef std::pair<llvm::PointerUnion<const TemplateTypeParmType*, NamedDecl*>,
205                   SourceLocation> UnexpandedParameterPack;
206 
207 /// Sema - This implements semantic analysis and AST building for C.
208 class Sema {
209   Sema(const Sema &) LLVM_DELETED_FUNCTION;
210   void operator=(const Sema &) LLVM_DELETED_FUNCTION;
211 
212   ///\brief Source of additional semantic information.
213   ExternalSemaSource *ExternalSource;
214 
215   ///\brief Whether Sema has generated a multiplexer and has to delete it.
216   bool isMultiplexExternalSource;
217 
218   static bool mightHaveNonExternalLinkage(const DeclaratorDecl *FD);
219 
220   static bool
shouldLinkPossiblyHiddenDecl(const NamedDecl * Old,const NamedDecl * New)221   shouldLinkPossiblyHiddenDecl(const NamedDecl *Old, const NamedDecl *New) {
222     // We are about to link these. It is now safe to compute the linkage of
223     // the new decl. If the new decl has external linkage, we will
224     // link it with the hidden decl (which also has external linkage) and
225     // it will keep having external linkage. If it has internal linkage, we
226     // will not link it. Since it has no previous decls, it will remain
227     // with internal linkage.
228     return !Old->isHidden() || New->isExternallyVisible();
229   }
230 
231 public:
232   typedef OpaquePtr<DeclGroupRef> DeclGroupPtrTy;
233   typedef OpaquePtr<TemplateName> TemplateTy;
234   typedef OpaquePtr<QualType> TypeTy;
235 
236   OpenCLOptions OpenCLFeatures;
237   FPOptions FPFeatures;
238 
239   const LangOptions &LangOpts;
240   Preprocessor &PP;
241   ASTContext &Context;
242   ASTConsumer &Consumer;
243   DiagnosticsEngine &Diags;
244   SourceManager &SourceMgr;
245 
246   /// \brief Flag indicating whether or not to collect detailed statistics.
247   bool CollectStats;
248 
249   /// \brief Code-completion consumer.
250   CodeCompleteConsumer *CodeCompleter;
251 
252   /// CurContext - This is the current declaration context of parsing.
253   DeclContext *CurContext;
254 
255   /// \brief Generally null except when we temporarily switch decl contexts,
256   /// like in \see ActOnObjCTemporaryExitContainerContext.
257   DeclContext *OriginalLexicalContext;
258 
259   /// VAListTagName - The declaration name corresponding to __va_list_tag.
260   /// This is used as part of a hack to omit that class from ADL results.
261   DeclarationName VAListTagName;
262 
263   /// PackContext - Manages the stack for \#pragma pack. An alignment
264   /// of 0 indicates default alignment.
265   void *PackContext; // Really a "PragmaPackStack*"
266 
267   bool MSStructPragmaOn; // True when \#pragma ms_struct on
268 
269   /// \brief Controls member pointer representation format under the MS ABI.
270   LangOptions::PragmaMSPointersToMembersKind
271       MSPointerToMemberRepresentationMethod;
272 
273   enum PragmaVtorDispKind {
274     PVDK_Push,          ///< #pragma vtordisp(push, mode)
275     PVDK_Set,           ///< #pragma vtordisp(mode)
276     PVDK_Pop,           ///< #pragma vtordisp(pop)
277     PVDK_Reset          ///< #pragma vtordisp()
278   };
279 
280   enum PragmaMsStackAction {
281     PSK_Reset,    // #pragma ()
282     PSK_Set,      // #pragma ("name")
283     PSK_Push,     // #pragma (push[, id])
284     PSK_Push_Set, // #pragma (push[, id], "name")
285     PSK_Pop,      // #pragma (pop[, id])
286     PSK_Pop_Set,  // #pragma (pop[, id], "name")
287   };
288 
289   /// \brief Whether to insert vtordisps prior to virtual bases in the Microsoft
290   /// C++ ABI.  Possible values are 0, 1, and 2, which mean:
291   ///
292   /// 0: Suppress all vtordisps
293   /// 1: Insert vtordisps in the presence of vbase overrides and non-trivial
294   ///    structors
295   /// 2: Always insert vtordisps to support RTTI on partially constructed
296   ///    objects
297   ///
298   /// The stack always has at least one element in it.
299   SmallVector<MSVtorDispAttr::Mode, 2> VtorDispModeStack;
300 
301   /// \brief Source location for newly created implicit MSInheritanceAttrs
302   SourceLocation ImplicitMSInheritanceAttrLoc;
303 
304   template<typename ValueType>
305   struct PragmaStack {
306     struct Slot {
307       llvm::StringRef StackSlotLabel;
308       ValueType Value;
309       SourceLocation PragmaLocation;
SlotPragmaStack::Slot310       Slot(llvm::StringRef StackSlotLabel,
311            ValueType Value,
312            SourceLocation PragmaLocation)
313         : StackSlotLabel(StackSlotLabel), Value(Value),
314           PragmaLocation(PragmaLocation) {}
315     };
316     void Act(SourceLocation PragmaLocation,
317              PragmaMsStackAction Action,
318              llvm::StringRef StackSlotLabel,
319              ValueType Value);
PragmaStackPragmaStack320     explicit PragmaStack(const ValueType &Value)
321       : CurrentValue(Value) {}
322     SmallVector<Slot, 2> Stack;
323     ValueType CurrentValue;
324     SourceLocation CurrentPragmaLocation;
325   };
326   // FIXME: We should serialize / deserialize these if they occur in a PCH (but
327   // we shouldn't do so if they're in a module).
328   PragmaStack<StringLiteral *> DataSegStack;
329   PragmaStack<StringLiteral *> BSSSegStack;
330   PragmaStack<StringLiteral *> ConstSegStack;
331   PragmaStack<StringLiteral *> CodeSegStack;
332 
333   /// Last section used with #pragma init_seg.
334   StringLiteral *CurInitSeg;
335   SourceLocation CurInitSegLoc;
336 
337   /// VisContext - Manages the stack for \#pragma GCC visibility.
338   void *VisContext; // Really a "PragmaVisStack*"
339 
340   /// \brief This represents the last location of a "#pragma clang optimize off"
341   /// directive if such a directive has not been closed by an "on" yet. If
342   /// optimizations are currently "on", this is set to an invalid location.
343   SourceLocation OptimizeOffPragmaLocation;
344 
345   /// \brief Flag indicating if Sema is building a recovery call expression.
346   ///
347   /// This flag is used to avoid building recovery call expressions
348   /// if Sema is already doing so, which would cause infinite recursions.
349   bool IsBuildingRecoveryCallExpr;
350 
351   /// ExprNeedsCleanups - True if the current evaluation context
352   /// requires cleanups to be run at its conclusion.
353   bool ExprNeedsCleanups;
354 
355   /// ExprCleanupObjects - This is the stack of objects requiring
356   /// cleanup that are created by the current full expression.  The
357   /// element type here is ExprWithCleanups::Object.
358   SmallVector<BlockDecl*, 8> ExprCleanupObjects;
359 
360   /// \brief Store a list of either DeclRefExprs or MemberExprs
361   ///  that contain a reference to a variable (constant) that may or may not
362   ///  be odr-used in this Expr, and we won't know until all lvalue-to-rvalue
363   ///  and discarded value conversions have been applied to all subexpressions
364   ///  of the enclosing full expression.  This is cleared at the end of each
365   ///  full expression.
366   llvm::SmallPtrSet<Expr*, 2> MaybeODRUseExprs;
367 
368   /// \brief Stack containing information about each of the nested
369   /// function, block, and method scopes that are currently active.
370   ///
371   /// This array is never empty.  Clients should ignore the first
372   /// element, which is used to cache a single FunctionScopeInfo
373   /// that's used to parse every top-level function.
374   SmallVector<sema::FunctionScopeInfo *, 4> FunctionScopes;
375 
376   typedef LazyVector<TypedefNameDecl *, ExternalSemaSource,
377                      &ExternalSemaSource::ReadExtVectorDecls, 2, 2>
378     ExtVectorDeclsType;
379 
380   /// ExtVectorDecls - This is a list all the extended vector types. This allows
381   /// us to associate a raw vector type with one of the ext_vector type names.
382   /// This is only necessary for issuing pretty diagnostics.
383   ExtVectorDeclsType ExtVectorDecls;
384 
385   /// FieldCollector - Collects CXXFieldDecls during parsing of C++ classes.
386   std::unique_ptr<CXXFieldCollector> FieldCollector;
387 
388   typedef llvm::SmallSetVector<const NamedDecl*, 16> NamedDeclSetType;
389 
390   /// \brief Set containing all declared private fields that are not used.
391   NamedDeclSetType UnusedPrivateFields;
392 
393   /// \brief Set containing all typedefs that are likely unused.
394   llvm::SmallSetVector<const TypedefNameDecl *, 4>
395       UnusedLocalTypedefNameCandidates;
396 
397   typedef llvm::SmallPtrSet<const CXXRecordDecl*, 8> RecordDeclSetTy;
398 
399   /// PureVirtualClassDiagSet - a set of class declarations which we have
400   /// emitted a list of pure virtual functions. Used to prevent emitting the
401   /// same list more than once.
402   std::unique_ptr<RecordDeclSetTy> PureVirtualClassDiagSet;
403 
404   /// ParsingInitForAutoVars - a set of declarations with auto types for which
405   /// we are currently parsing the initializer.
406   llvm::SmallPtrSet<const Decl*, 4> ParsingInitForAutoVars;
407 
408   /// \brief A mapping from external names to the most recent
409   /// locally-scoped extern "C" declaration with that name.
410   ///
411   /// This map contains external declarations introduced in local
412   /// scopes, e.g.,
413   ///
414   /// \code
415   /// extern "C" void f() {
416   ///   void foo(int, int);
417   /// }
418   /// \endcode
419   ///
420   /// Here, the name "foo" will be associated with the declaration of
421   /// "foo" within f. This name is not visible outside of
422   /// "f". However, we still find it in two cases:
423   ///
424   ///   - If we are declaring another global or extern "C" entity with
425   ///     the name "foo", we can find "foo" as a previous declaration,
426   ///     so that the types of this external declaration can be checked
427   ///     for compatibility.
428   ///
429   ///   - If we would implicitly declare "foo" (e.g., due to a call to
430   ///     "foo" in C when no prototype or definition is visible), then
431   ///     we find this declaration of "foo" and complain that it is
432   ///     not visible.
433   llvm::DenseMap<DeclarationName, NamedDecl *> LocallyScopedExternCDecls;
434 
435   /// \brief Look for a locally scoped extern "C" declaration by the given name.
436   NamedDecl *findLocallyScopedExternCDecl(DeclarationName Name);
437 
438   typedef LazyVector<VarDecl *, ExternalSemaSource,
439                      &ExternalSemaSource::ReadTentativeDefinitions, 2, 2>
440     TentativeDefinitionsType;
441 
442   /// \brief All the tentative definitions encountered in the TU.
443   TentativeDefinitionsType TentativeDefinitions;
444 
445   typedef LazyVector<const DeclaratorDecl *, ExternalSemaSource,
446                      &ExternalSemaSource::ReadUnusedFileScopedDecls, 2, 2>
447     UnusedFileScopedDeclsType;
448 
449   /// \brief The set of file scoped decls seen so far that have not been used
450   /// and must warn if not used. Only contains the first declaration.
451   UnusedFileScopedDeclsType UnusedFileScopedDecls;
452 
453   typedef LazyVector<CXXConstructorDecl *, ExternalSemaSource,
454                      &ExternalSemaSource::ReadDelegatingConstructors, 2, 2>
455     DelegatingCtorDeclsType;
456 
457   /// \brief All the delegating constructors seen so far in the file, used for
458   /// cycle detection at the end of the TU.
459   DelegatingCtorDeclsType DelegatingCtorDecls;
460 
461   /// \brief All the overriding functions seen during a class definition
462   /// that had their exception spec checks delayed, plus the overridden
463   /// function.
464   SmallVector<std::pair<const CXXMethodDecl*, const CXXMethodDecl*>, 2>
465     DelayedExceptionSpecChecks;
466 
467   /// \brief All the members seen during a class definition which were both
468   /// explicitly defaulted and had explicitly-specified exception
469   /// specifications, along with the function type containing their
470   /// user-specified exception specification. Those exception specifications
471   /// were overridden with the default specifications, but we still need to
472   /// check whether they are compatible with the default specification, and
473   /// we can't do that until the nesting set of class definitions is complete.
474   SmallVector<std::pair<CXXMethodDecl*, const FunctionProtoType*>, 2>
475     DelayedDefaultedMemberExceptionSpecs;
476 
477   typedef llvm::DenseMap<const FunctionDecl *, LateParsedTemplate *>
478   LateParsedTemplateMapT;
479   LateParsedTemplateMapT LateParsedTemplateMap;
480 
481   /// \brief Callback to the parser to parse templated functions when needed.
482   typedef void LateTemplateParserCB(void *P, LateParsedTemplate &LPT);
483   typedef void LateTemplateParserCleanupCB(void *P);
484   LateTemplateParserCB *LateTemplateParser;
485   LateTemplateParserCleanupCB *LateTemplateParserCleanup;
486   void *OpaqueParser;
487 
SetLateTemplateParser(LateTemplateParserCB * LTP,LateTemplateParserCleanupCB * LTPCleanup,void * P)488   void SetLateTemplateParser(LateTemplateParserCB *LTP,
489                              LateTemplateParserCleanupCB *LTPCleanup,
490                              void *P) {
491     LateTemplateParser = LTP;
492     LateTemplateParserCleanup = LTPCleanup;
493     OpaqueParser = P;
494   }
495 
496   class DelayedDiagnostics;
497 
498   class DelayedDiagnosticsState {
499     sema::DelayedDiagnosticPool *SavedPool;
500     friend class Sema::DelayedDiagnostics;
501   };
502   typedef DelayedDiagnosticsState ParsingDeclState;
503   typedef DelayedDiagnosticsState ProcessingContextState;
504 
505   /// A class which encapsulates the logic for delaying diagnostics
506   /// during parsing and other processing.
507   class DelayedDiagnostics {
508     /// \brief The current pool of diagnostics into which delayed
509     /// diagnostics should go.
510     sema::DelayedDiagnosticPool *CurPool;
511 
512   public:
DelayedDiagnostics()513     DelayedDiagnostics() : CurPool(nullptr) {}
514 
515     /// Adds a delayed diagnostic.
516     void add(const sema::DelayedDiagnostic &diag); // in DelayedDiagnostic.h
517 
518     /// Determines whether diagnostics should be delayed.
shouldDelayDiagnostics()519     bool shouldDelayDiagnostics() { return CurPool != nullptr; }
520 
521     /// Returns the current delayed-diagnostics pool.
getCurrentPool()522     sema::DelayedDiagnosticPool *getCurrentPool() const {
523       return CurPool;
524     }
525 
526     /// Enter a new scope.  Access and deprecation diagnostics will be
527     /// collected in this pool.
push(sema::DelayedDiagnosticPool & pool)528     DelayedDiagnosticsState push(sema::DelayedDiagnosticPool &pool) {
529       DelayedDiagnosticsState state;
530       state.SavedPool = CurPool;
531       CurPool = &pool;
532       return state;
533     }
534 
535     /// Leave a delayed-diagnostic state that was previously pushed.
536     /// Do not emit any of the diagnostics.  This is performed as part
537     /// of the bookkeeping of popping a pool "properly".
popWithoutEmitting(DelayedDiagnosticsState state)538     void popWithoutEmitting(DelayedDiagnosticsState state) {
539       CurPool = state.SavedPool;
540     }
541 
542     /// Enter a new scope where access and deprecation diagnostics are
543     /// not delayed.
pushUndelayed()544     DelayedDiagnosticsState pushUndelayed() {
545       DelayedDiagnosticsState state;
546       state.SavedPool = CurPool;
547       CurPool = nullptr;
548       return state;
549     }
550 
551     /// Undo a previous pushUndelayed().
popUndelayed(DelayedDiagnosticsState state)552     void popUndelayed(DelayedDiagnosticsState state) {
553       assert(CurPool == nullptr);
554       CurPool = state.SavedPool;
555     }
556   } DelayedDiagnostics;
557 
558   /// A RAII object to temporarily push a declaration context.
559   class ContextRAII {
560   private:
561     Sema &S;
562     DeclContext *SavedContext;
563     ProcessingContextState SavedContextState;
564     QualType SavedCXXThisTypeOverride;
565 
566   public:
567     ContextRAII(Sema &S, DeclContext *ContextToPush, bool NewThisContext = true)
S(S)568       : S(S), SavedContext(S.CurContext),
569         SavedContextState(S.DelayedDiagnostics.pushUndelayed()),
570         SavedCXXThisTypeOverride(S.CXXThisTypeOverride)
571     {
572       assert(ContextToPush && "pushing null context");
573       S.CurContext = ContextToPush;
574       if (NewThisContext)
575         S.CXXThisTypeOverride = QualType();
576     }
577 
pop()578     void pop() {
579       if (!SavedContext) return;
580       S.CurContext = SavedContext;
581       S.DelayedDiagnostics.popUndelayed(SavedContextState);
582       S.CXXThisTypeOverride = SavedCXXThisTypeOverride;
583       SavedContext = nullptr;
584     }
585 
~ContextRAII()586     ~ContextRAII() {
587       pop();
588     }
589   };
590 
591   /// \brief RAII object to handle the state changes required to synthesize
592   /// a function body.
593   class SynthesizedFunctionScope {
594     Sema &S;
595     Sema::ContextRAII SavedContext;
596 
597   public:
SynthesizedFunctionScope(Sema & S,DeclContext * DC)598     SynthesizedFunctionScope(Sema &S, DeclContext *DC)
599       : S(S), SavedContext(S, DC)
600     {
601       S.PushFunctionScope();
602       S.PushExpressionEvaluationContext(Sema::PotentiallyEvaluated);
603     }
604 
~SynthesizedFunctionScope()605     ~SynthesizedFunctionScope() {
606       S.PopExpressionEvaluationContext();
607       S.PopFunctionScopeInfo();
608     }
609   };
610 
611   /// WeakUndeclaredIdentifiers - Identifiers contained in
612   /// \#pragma weak before declared. rare. may alias another
613   /// identifier, declared or undeclared
614   llvm::DenseMap<IdentifierInfo*,WeakInfo> WeakUndeclaredIdentifiers;
615 
616   /// ExtnameUndeclaredIdentifiers - Identifiers contained in
617   /// \#pragma redefine_extname before declared.  Used in Solaris system headers
618   /// to define functions that occur in multiple standards to call the version
619   /// in the currently selected standard.
620   llvm::DenseMap<IdentifierInfo*,AsmLabelAttr*> ExtnameUndeclaredIdentifiers;
621 
622 
623   /// \brief Load weak undeclared identifiers from the external source.
624   void LoadExternalWeakUndeclaredIdentifiers();
625 
626   /// WeakTopLevelDecl - Translation-unit scoped declarations generated by
627   /// \#pragma weak during processing of other Decls.
628   /// I couldn't figure out a clean way to generate these in-line, so
629   /// we store them here and handle separately -- which is a hack.
630   /// It would be best to refactor this.
631   SmallVector<Decl*,2> WeakTopLevelDecl;
632 
633   IdentifierResolver IdResolver;
634 
635   /// Translation Unit Scope - useful to Objective-C actions that need
636   /// to lookup file scope declarations in the "ordinary" C decl namespace.
637   /// For example, user-defined classes, built-in "id" type, etc.
638   Scope *TUScope;
639 
640   /// \brief The C++ "std" namespace, where the standard library resides.
641   LazyDeclPtr StdNamespace;
642 
643   /// \brief The C++ "std::bad_alloc" class, which is defined by the C++
644   /// standard library.
645   LazyDeclPtr StdBadAlloc;
646 
647   /// \brief The C++ "std::initializer_list" template, which is defined in
648   /// \<initializer_list>.
649   ClassTemplateDecl *StdInitializerList;
650 
651   /// \brief The C++ "type_info" declaration, which is defined in \<typeinfo>.
652   RecordDecl *CXXTypeInfoDecl;
653 
654   /// \brief The MSVC "_GUID" struct, which is defined in MSVC header files.
655   RecordDecl *MSVCGuidDecl;
656 
657   /// \brief Caches identifiers/selectors for NSFoundation APIs.
658   std::unique_ptr<NSAPI> NSAPIObj;
659 
660   /// \brief The declaration of the Objective-C NSNumber class.
661   ObjCInterfaceDecl *NSNumberDecl;
662 
663   /// \brief Pointer to NSNumber type (NSNumber *).
664   QualType NSNumberPointer;
665 
666   /// \brief The Objective-C NSNumber methods used to create NSNumber literals.
667   ObjCMethodDecl *NSNumberLiteralMethods[NSAPI::NumNSNumberLiteralMethods];
668 
669   /// \brief The declaration of the Objective-C NSString class.
670   ObjCInterfaceDecl *NSStringDecl;
671 
672   /// \brief Pointer to NSString type (NSString *).
673   QualType NSStringPointer;
674 
675   /// \brief The declaration of the stringWithUTF8String: method.
676   ObjCMethodDecl *StringWithUTF8StringMethod;
677 
678   /// \brief The declaration of the Objective-C NSArray class.
679   ObjCInterfaceDecl *NSArrayDecl;
680 
681   /// \brief The declaration of the arrayWithObjects:count: method.
682   ObjCMethodDecl *ArrayWithObjectsMethod;
683 
684   /// \brief The declaration of the Objective-C NSDictionary class.
685   ObjCInterfaceDecl *NSDictionaryDecl;
686 
687   /// \brief The declaration of the dictionaryWithObjects:forKeys:count: method.
688   ObjCMethodDecl *DictionaryWithObjectsMethod;
689 
690   /// \brief id<NSCopying> type.
691   QualType QIDNSCopying;
692 
693   /// \brief will hold 'respondsToSelector:'
694   Selector RespondsToSelectorSel;
695 
696   /// \brief counter for internal MS Asm label names.
697   unsigned MSAsmLabelNameCounter;
698 
699   /// A flag to remember whether the implicit forms of operator new and delete
700   /// have been declared.
701   bool GlobalNewDeleteDeclared;
702 
703   /// A flag to indicate that we're in a context that permits abstract
704   /// references to fields.  This is really a
705   bool AllowAbstractFieldReference;
706 
707   /// \brief Describes how the expressions currently being parsed are
708   /// evaluated at run-time, if at all.
709   enum ExpressionEvaluationContext {
710     /// \brief The current expression and its subexpressions occur within an
711     /// unevaluated operand (C++11 [expr]p7), such as the subexpression of
712     /// \c sizeof, where the type of the expression may be significant but
713     /// no code will be generated to evaluate the value of the expression at
714     /// run time.
715     Unevaluated,
716 
717     /// \brief The current expression occurs within an unevaluated
718     /// operand that unconditionally permits abstract references to
719     /// fields, such as a SIZE operator in MS-style inline assembly.
720     UnevaluatedAbstract,
721 
722     /// \brief The current context is "potentially evaluated" in C++11 terms,
723     /// but the expression is evaluated at compile-time (like the values of
724     /// cases in a switch statement).
725     ConstantEvaluated,
726 
727     /// \brief The current expression is potentially evaluated at run time,
728     /// which means that code may be generated to evaluate the value of the
729     /// expression at run time.
730     PotentiallyEvaluated,
731 
732     /// \brief The current expression is potentially evaluated, but any
733     /// declarations referenced inside that expression are only used if
734     /// in fact the current expression is used.
735     ///
736     /// This value is used when parsing default function arguments, for which
737     /// we would like to provide diagnostics (e.g., passing non-POD arguments
738     /// through varargs) but do not want to mark declarations as "referenced"
739     /// until the default argument is used.
740     PotentiallyEvaluatedIfUsed
741   };
742 
743   /// \brief Data structure used to record current or nested
744   /// expression evaluation contexts.
745   struct ExpressionEvaluationContextRecord {
746     /// \brief The expression evaluation context.
747     ExpressionEvaluationContext Context;
748 
749     /// \brief Whether the enclosing context needed a cleanup.
750     bool ParentNeedsCleanups;
751 
752     /// \brief Whether we are in a decltype expression.
753     bool IsDecltype;
754 
755     /// \brief The number of active cleanup objects when we entered
756     /// this expression evaluation context.
757     unsigned NumCleanupObjects;
758 
759     /// \brief The number of typos encountered during this expression evaluation
760     /// context (i.e. the number of TypoExprs created).
761     unsigned NumTypos;
762 
763     llvm::SmallPtrSet<Expr*, 2> SavedMaybeODRUseExprs;
764 
765     /// \brief The lambdas that are present within this context, if it
766     /// is indeed an unevaluated context.
767     SmallVector<LambdaExpr *, 2> Lambdas;
768 
769     /// \brief The declaration that provides context for lambda expressions
770     /// and block literals if the normal declaration context does not
771     /// suffice, e.g., in a default function argument.
772     Decl *ManglingContextDecl;
773 
774     /// \brief The context information used to mangle lambda expressions
775     /// and block literals within this context.
776     ///
777     /// This mangling information is allocated lazily, since most contexts
778     /// do not have lambda expressions or block literals.
779     IntrusiveRefCntPtr<MangleNumberingContext> MangleNumbering;
780 
781     /// \brief If we are processing a decltype type, a set of call expressions
782     /// for which we have deferred checking the completeness of the return type.
783     SmallVector<CallExpr *, 8> DelayedDecltypeCalls;
784 
785     /// \brief If we are processing a decltype type, a set of temporary binding
786     /// expressions for which we have deferred checking the destructor.
787     SmallVector<CXXBindTemporaryExpr *, 8> DelayedDecltypeBinds;
788 
ExpressionEvaluationContextRecordExpressionEvaluationContextRecord789     ExpressionEvaluationContextRecord(ExpressionEvaluationContext Context,
790                                       unsigned NumCleanupObjects,
791                                       bool ParentNeedsCleanups,
792                                       Decl *ManglingContextDecl,
793                                       bool IsDecltype)
794       : Context(Context), ParentNeedsCleanups(ParentNeedsCleanups),
795         IsDecltype(IsDecltype), NumCleanupObjects(NumCleanupObjects),
796         NumTypos(0),
797         ManglingContextDecl(ManglingContextDecl), MangleNumbering() { }
798 
799     /// \brief Retrieve the mangling numbering context, used to consistently
800     /// number constructs like lambdas for mangling.
801     MangleNumberingContext &getMangleNumberingContext(ASTContext &Ctx);
802 
isUnevaluatedExpressionEvaluationContextRecord803     bool isUnevaluated() const {
804       return Context == Unevaluated || Context == UnevaluatedAbstract;
805     }
806   };
807 
808   /// A stack of expression evaluation contexts.
809   SmallVector<ExpressionEvaluationContextRecord, 8> ExprEvalContexts;
810 
811   /// \brief Compute the mangling number context for a lambda expression or
812   /// block literal.
813   ///
814   /// \param DC - The DeclContext containing the lambda expression or
815   /// block literal.
816   /// \param[out] ManglingContextDecl - Returns the ManglingContextDecl
817   /// associated with the context, if relevant.
818   MangleNumberingContext *getCurrentMangleNumberContext(
819     const DeclContext *DC,
820     Decl *&ManglingContextDecl);
821 
822 
823   /// SpecialMemberOverloadResult - The overloading result for a special member
824   /// function.
825   ///
826   /// This is basically a wrapper around PointerIntPair. The lowest bits of the
827   /// integer are used to determine whether overload resolution succeeded.
828   class SpecialMemberOverloadResult : public llvm::FastFoldingSetNode {
829   public:
830     enum Kind {
831       NoMemberOrDeleted,
832       Ambiguous,
833       Success
834     };
835 
836   private:
837     llvm::PointerIntPair<CXXMethodDecl*, 2> Pair;
838 
839   public:
SpecialMemberOverloadResult(const llvm::FoldingSetNodeID & ID)840     SpecialMemberOverloadResult(const llvm::FoldingSetNodeID &ID)
841       : FastFoldingSetNode(ID)
842     {}
843 
getMethod()844     CXXMethodDecl *getMethod() const { return Pair.getPointer(); }
setMethod(CXXMethodDecl * MD)845     void setMethod(CXXMethodDecl *MD) { Pair.setPointer(MD); }
846 
getKind()847     Kind getKind() const { return static_cast<Kind>(Pair.getInt()); }
setKind(Kind K)848     void setKind(Kind K) { Pair.setInt(K); }
849   };
850 
851   /// \brief A cache of special member function overload resolution results
852   /// for C++ records.
853   llvm::FoldingSet<SpecialMemberOverloadResult> SpecialMemberCache;
854 
855   /// \brief The kind of translation unit we are processing.
856   ///
857   /// When we're processing a complete translation unit, Sema will perform
858   /// end-of-translation-unit semantic tasks (such as creating
859   /// initializers for tentative definitions in C) once parsing has
860   /// completed. Modules and precompiled headers perform different kinds of
861   /// checks.
862   TranslationUnitKind TUKind;
863 
864   llvm::BumpPtrAllocator BumpAlloc;
865 
866   /// \brief The number of SFINAE diagnostics that have been trapped.
867   unsigned NumSFINAEErrors;
868 
869   typedef llvm::DenseMap<ParmVarDecl *, llvm::TinyPtrVector<ParmVarDecl *>>
870     UnparsedDefaultArgInstantiationsMap;
871 
872   /// \brief A mapping from parameters with unparsed default arguments to the
873   /// set of instantiations of each parameter.
874   ///
875   /// This mapping is a temporary data structure used when parsing
876   /// nested class templates or nested classes of class templates,
877   /// where we might end up instantiating an inner class before the
878   /// default arguments of its methods have been parsed.
879   UnparsedDefaultArgInstantiationsMap UnparsedDefaultArgInstantiations;
880 
881   // Contains the locations of the beginning of unparsed default
882   // argument locations.
883   llvm::DenseMap<ParmVarDecl *, SourceLocation> UnparsedDefaultArgLocs;
884 
885   /// UndefinedInternals - all the used, undefined objects which require a
886   /// definition in this translation unit.
887   llvm::DenseMap<NamedDecl *, SourceLocation> UndefinedButUsed;
888 
889   /// Obtain a sorted list of functions that are undefined but ODR-used.
890   void getUndefinedButUsed(
891       SmallVectorImpl<std::pair<NamedDecl *, SourceLocation> > &Undefined);
892 
893   typedef std::pair<ObjCMethodList, ObjCMethodList> GlobalMethods;
894   typedef llvm::DenseMap<Selector, GlobalMethods> GlobalMethodPool;
895 
896   /// Method Pool - allows efficient lookup when typechecking messages to "id".
897   /// We need to maintain a list, since selectors can have differing signatures
898   /// across classes. In Cocoa, this happens to be extremely uncommon (only 1%
899   /// of selectors are "overloaded").
900   /// At the head of the list it is recorded whether there were 0, 1, or >= 2
901   /// methods inside categories with a particular selector.
902   GlobalMethodPool MethodPool;
903 
904   /// Method selectors used in a \@selector expression. Used for implementation
905   /// of -Wselector.
906   llvm::DenseMap<Selector, SourceLocation> ReferencedSelectors;
907 
908   /// Kinds of C++ special members.
909   enum CXXSpecialMember {
910     CXXDefaultConstructor,
911     CXXCopyConstructor,
912     CXXMoveConstructor,
913     CXXCopyAssignment,
914     CXXMoveAssignment,
915     CXXDestructor,
916     CXXInvalid
917   };
918 
919   typedef std::pair<CXXRecordDecl*, CXXSpecialMember> SpecialMemberDecl;
920 
921   /// The C++ special members which we are currently in the process of
922   /// declaring. If this process recursively triggers the declaration of the
923   /// same special member, we should act as if it is not yet declared.
924   llvm::SmallSet<SpecialMemberDecl, 4> SpecialMembersBeingDeclared;
925 
926   void ReadMethodPool(Selector Sel);
927 
928   /// Private Helper predicate to check for 'self'.
929   bool isSelfExpr(Expr *RExpr);
930   bool isSelfExpr(Expr *RExpr, const ObjCMethodDecl *Method);
931 
932   /// \brief Cause the active diagnostic on the DiagosticsEngine to be
933   /// emitted. This is closely coupled to the SemaDiagnosticBuilder class and
934   /// should not be used elsewhere.
935   void EmitCurrentDiagnostic(unsigned DiagID);
936 
937   /// Records and restores the FP_CONTRACT state on entry/exit of compound
938   /// statements.
939   class FPContractStateRAII {
940   public:
FPContractStateRAII(Sema & S)941     FPContractStateRAII(Sema& S)
942       : S(S), OldFPContractState(S.FPFeatures.fp_contract) {}
~FPContractStateRAII()943     ~FPContractStateRAII() {
944       S.FPFeatures.fp_contract = OldFPContractState;
945     }
946   private:
947     Sema& S;
948     bool OldFPContractState : 1;
949   };
950 
951   void addImplicitTypedef(StringRef Name, QualType T);
952 
953 public:
954   Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer,
955        TranslationUnitKind TUKind = TU_Complete,
956        CodeCompleteConsumer *CompletionConsumer = nullptr);
957   ~Sema();
958 
959   /// \brief Perform initialization that occurs after the parser has been
960   /// initialized but before it parses anything.
961   void Initialize();
962 
getLangOpts()963   const LangOptions &getLangOpts() const { return LangOpts; }
getOpenCLOptions()964   OpenCLOptions &getOpenCLOptions() { return OpenCLFeatures; }
getFPOptions()965   FPOptions     &getFPOptions() { return FPFeatures; }
966 
getDiagnostics()967   DiagnosticsEngine &getDiagnostics() const { return Diags; }
getSourceManager()968   SourceManager &getSourceManager() const { return SourceMgr; }
getPreprocessor()969   Preprocessor &getPreprocessor() const { return PP; }
getASTContext()970   ASTContext &getASTContext() const { return Context; }
getASTConsumer()971   ASTConsumer &getASTConsumer() const { return Consumer; }
972   ASTMutationListener *getASTMutationListener() const;
getExternalSource()973   ExternalSemaSource* getExternalSource() const { return ExternalSource; }
974 
975   ///\brief Registers an external source. If an external source already exists,
976   /// creates a multiplex external source and appends to it.
977   ///
978   ///\param[in] E - A non-null external sema source.
979   ///
980   void addExternalSource(ExternalSemaSource *E);
981 
982   void PrintStats() const;
983 
984   /// \brief Helper class that creates diagnostics with optional
985   /// template instantiation stacks.
986   ///
987   /// This class provides a wrapper around the basic DiagnosticBuilder
988   /// class that emits diagnostics. SemaDiagnosticBuilder is
989   /// responsible for emitting the diagnostic (as DiagnosticBuilder
990   /// does) and, if the diagnostic comes from inside a template
991   /// instantiation, printing the template instantiation stack as
992   /// well.
993   class SemaDiagnosticBuilder : public DiagnosticBuilder {
994     Sema &SemaRef;
995     unsigned DiagID;
996 
997   public:
SemaDiagnosticBuilder(DiagnosticBuilder & DB,Sema & SemaRef,unsigned DiagID)998     SemaDiagnosticBuilder(DiagnosticBuilder &DB, Sema &SemaRef, unsigned DiagID)
999       : DiagnosticBuilder(DB), SemaRef(SemaRef), DiagID(DiagID) { }
1000 
~SemaDiagnosticBuilder()1001     ~SemaDiagnosticBuilder() {
1002       // If we aren't active, there is nothing to do.
1003       if (!isActive()) return;
1004 
1005       // Otherwise, we need to emit the diagnostic. First flush the underlying
1006       // DiagnosticBuilder data, and clear the diagnostic builder itself so it
1007       // won't emit the diagnostic in its own destructor.
1008       //
1009       // This seems wasteful, in that as written the DiagnosticBuilder dtor will
1010       // do its own needless checks to see if the diagnostic needs to be
1011       // emitted. However, because we take care to ensure that the builder
1012       // objects never escape, a sufficiently smart compiler will be able to
1013       // eliminate that code.
1014       FlushCounts();
1015       Clear();
1016 
1017       // Dispatch to Sema to emit the diagnostic.
1018       SemaRef.EmitCurrentDiagnostic(DiagID);
1019     }
1020 
1021     /// Teach operator<< to produce an object of the correct type.
1022     template<typename T>
1023     friend const SemaDiagnosticBuilder &operator<<(
1024         const SemaDiagnosticBuilder &Diag, const T &Value) {
1025       const DiagnosticBuilder &BaseDiag = Diag;
1026       BaseDiag << Value;
1027       return Diag;
1028     }
1029   };
1030 
1031   /// \brief Emit a diagnostic.
Diag(SourceLocation Loc,unsigned DiagID)1032   SemaDiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID) {
1033     DiagnosticBuilder DB = Diags.Report(Loc, DiagID);
1034     return SemaDiagnosticBuilder(DB, *this, DiagID);
1035   }
1036 
1037   /// \brief Emit a partial diagnostic.
1038   SemaDiagnosticBuilder Diag(SourceLocation Loc, const PartialDiagnostic& PD);
1039 
1040   /// \brief Build a partial diagnostic.
1041   PartialDiagnostic PDiag(unsigned DiagID = 0); // in SemaInternal.h
1042 
1043   bool findMacroSpelling(SourceLocation &loc, StringRef name);
1044 
1045   /// \brief Get a string to suggest for zero-initialization of a type.
1046   std::string
1047   getFixItZeroInitializerForType(QualType T, SourceLocation Loc) const;
1048   std::string getFixItZeroLiteralForType(QualType T, SourceLocation Loc) const;
1049 
1050   /// \brief Calls \c Lexer::getLocForEndOfToken()
1051   SourceLocation getLocForEndOfToken(SourceLocation Loc, unsigned Offset = 0);
1052 
1053   /// \brief Retrieve the module loader associated with the preprocessor.
1054   ModuleLoader &getModuleLoader() const;
1055 
1056   void emitAndClearUnusedLocalTypedefWarnings();
1057 
1058   void ActOnEndOfTranslationUnit();
1059 
1060   void CheckDelegatingCtorCycles();
1061 
1062   Scope *getScopeForContext(DeclContext *Ctx);
1063 
1064   void PushFunctionScope();
1065   void PushBlockScope(Scope *BlockScope, BlockDecl *Block);
1066   sema::LambdaScopeInfo *PushLambdaScope();
1067 
1068   /// \brief This is used to inform Sema what the current TemplateParameterDepth
1069   /// is during Parsing.  Currently it is used to pass on the depth
1070   /// when parsing generic lambda 'auto' parameters.
1071   void RecordParsingTemplateParameterDepth(unsigned Depth);
1072 
1073   void PushCapturedRegionScope(Scope *RegionScope, CapturedDecl *CD,
1074                                RecordDecl *RD,
1075                                CapturedRegionKind K);
1076   void
1077   PopFunctionScopeInfo(const sema::AnalysisBasedWarnings::Policy *WP = nullptr,
1078                        const Decl *D = nullptr,
1079                        const BlockExpr *blkExpr = nullptr);
1080 
getCurFunction()1081   sema::FunctionScopeInfo *getCurFunction() const {
1082     return FunctionScopes.back();
1083   }
1084 
getEnclosingFunction()1085   sema::FunctionScopeInfo *getEnclosingFunction() const {
1086     if (FunctionScopes.empty())
1087       return nullptr;
1088 
1089     for (int e = FunctionScopes.size()-1; e >= 0; --e) {
1090       if (isa<sema::BlockScopeInfo>(FunctionScopes[e]))
1091         continue;
1092       return FunctionScopes[e];
1093     }
1094     return nullptr;
1095   }
1096 
1097   template <typename ExprT>
1098   void recordUseOfEvaluatedWeak(const ExprT *E, bool IsRead=true) {
1099     if (!isUnevaluatedContext())
1100       getCurFunction()->recordUseOfWeak(E, IsRead);
1101   }
1102 
1103   void PushCompoundScope();
1104   void PopCompoundScope();
1105 
1106   sema::CompoundScopeInfo &getCurCompoundScope() const;
1107 
1108   bool hasAnyUnrecoverableErrorsInThisFunction() const;
1109 
1110   /// \brief Retrieve the current block, if any.
1111   sema::BlockScopeInfo *getCurBlock();
1112 
1113   /// \brief Retrieve the current lambda scope info, if any.
1114   sema::LambdaScopeInfo *getCurLambda();
1115 
1116   /// \brief Retrieve the current generic lambda info, if any.
1117   sema::LambdaScopeInfo *getCurGenericLambda();
1118 
1119   /// \brief Retrieve the current captured region, if any.
1120   sema::CapturedRegionScopeInfo *getCurCapturedRegion();
1121 
1122   /// WeakTopLevelDeclDecls - access to \#pragma weak-generated Decls
WeakTopLevelDecls()1123   SmallVectorImpl<Decl *> &WeakTopLevelDecls() { return WeakTopLevelDecl; }
1124 
1125   void ActOnComment(SourceRange Comment);
1126 
1127   //===--------------------------------------------------------------------===//
1128   // Type Analysis / Processing: SemaType.cpp.
1129   //
1130 
1131   QualType BuildQualifiedType(QualType T, SourceLocation Loc, Qualifiers Qs,
1132                               const DeclSpec *DS = nullptr);
1133   QualType BuildQualifiedType(QualType T, SourceLocation Loc, unsigned CVRA,
1134                               const DeclSpec *DS = nullptr);
1135   QualType BuildPointerType(QualType T,
1136                             SourceLocation Loc, DeclarationName Entity);
1137   QualType BuildReferenceType(QualType T, bool LValueRef,
1138                               SourceLocation Loc, DeclarationName Entity);
1139   QualType BuildArrayType(QualType T, ArrayType::ArraySizeModifier ASM,
1140                           Expr *ArraySize, unsigned Quals,
1141                           SourceRange Brackets, DeclarationName Entity);
1142   QualType BuildExtVectorType(QualType T, Expr *ArraySize,
1143                               SourceLocation AttrLoc);
1144 
1145   bool CheckFunctionReturnType(QualType T, SourceLocation Loc);
1146 
1147   /// \brief Build a function type.
1148   ///
1149   /// This routine checks the function type according to C++ rules and
1150   /// under the assumption that the result type and parameter types have
1151   /// just been instantiated from a template. It therefore duplicates
1152   /// some of the behavior of GetTypeForDeclarator, but in a much
1153   /// simpler form that is only suitable for this narrow use case.
1154   ///
1155   /// \param T The return type of the function.
1156   ///
1157   /// \param ParamTypes The parameter types of the function. This array
1158   /// will be modified to account for adjustments to the types of the
1159   /// function parameters.
1160   ///
1161   /// \param Loc The location of the entity whose type involves this
1162   /// function type or, if there is no such entity, the location of the
1163   /// type that will have function type.
1164   ///
1165   /// \param Entity The name of the entity that involves the function
1166   /// type, if known.
1167   ///
1168   /// \param EPI Extra information about the function type. Usually this will
1169   /// be taken from an existing function with the same prototype.
1170   ///
1171   /// \returns A suitable function type, if there are no errors. The
1172   /// unqualified type will always be a FunctionProtoType.
1173   /// Otherwise, returns a NULL type.
1174   QualType BuildFunctionType(QualType T,
1175                              MutableArrayRef<QualType> ParamTypes,
1176                              SourceLocation Loc, DeclarationName Entity,
1177                              const FunctionProtoType::ExtProtoInfo &EPI);
1178 
1179   QualType BuildMemberPointerType(QualType T, QualType Class,
1180                                   SourceLocation Loc,
1181                                   DeclarationName Entity);
1182   QualType BuildBlockPointerType(QualType T,
1183                                  SourceLocation Loc, DeclarationName Entity);
1184   QualType BuildParenType(QualType T);
1185   QualType BuildAtomicType(QualType T, SourceLocation Loc);
1186 
1187   TypeSourceInfo *GetTypeForDeclarator(Declarator &D, Scope *S);
1188   TypeSourceInfo *GetTypeForDeclaratorCast(Declarator &D, QualType FromTy);
1189   TypeSourceInfo *GetTypeSourceInfoForDeclarator(Declarator &D, QualType T,
1190                                                TypeSourceInfo *ReturnTypeInfo);
1191 
1192   /// \brief Package the given type and TSI into a ParsedType.
1193   ParsedType CreateParsedType(QualType T, TypeSourceInfo *TInfo);
1194   DeclarationNameInfo GetNameForDeclarator(Declarator &D);
1195   DeclarationNameInfo GetNameFromUnqualifiedId(const UnqualifiedId &Name);
1196   static QualType GetTypeFromParser(ParsedType Ty,
1197                                     TypeSourceInfo **TInfo = nullptr);
1198   CanThrowResult canThrow(const Expr *E);
1199   const FunctionProtoType *ResolveExceptionSpec(SourceLocation Loc,
1200                                                 const FunctionProtoType *FPT);
1201   void UpdateExceptionSpec(FunctionDecl *FD,
1202                            const FunctionProtoType::ExceptionSpecInfo &ESI);
1203   bool CheckSpecifiedExceptionType(QualType &T, const SourceRange &Range);
1204   bool CheckDistantExceptionSpec(QualType T);
1205   bool CheckEquivalentExceptionSpec(FunctionDecl *Old, FunctionDecl *New);
1206   bool CheckEquivalentExceptionSpec(
1207       const FunctionProtoType *Old, SourceLocation OldLoc,
1208       const FunctionProtoType *New, SourceLocation NewLoc);
1209   bool CheckEquivalentExceptionSpec(
1210       const PartialDiagnostic &DiagID, const PartialDiagnostic & NoteID,
1211       const FunctionProtoType *Old, SourceLocation OldLoc,
1212       const FunctionProtoType *New, SourceLocation NewLoc,
1213       bool *MissingExceptionSpecification = nullptr,
1214       bool *MissingEmptyExceptionSpecification = nullptr,
1215       bool AllowNoexceptAllMatchWithNoSpec = false,
1216       bool IsOperatorNew = false);
1217   bool CheckExceptionSpecSubset(
1218       const PartialDiagnostic &DiagID, const PartialDiagnostic & NoteID,
1219       const FunctionProtoType *Superset, SourceLocation SuperLoc,
1220       const FunctionProtoType *Subset, SourceLocation SubLoc);
1221   bool CheckParamExceptionSpec(const PartialDiagnostic & NoteID,
1222       const FunctionProtoType *Target, SourceLocation TargetLoc,
1223       const FunctionProtoType *Source, SourceLocation SourceLoc);
1224 
1225   TypeResult ActOnTypeName(Scope *S, Declarator &D);
1226 
1227   /// \brief The parser has parsed the context-sensitive type 'instancetype'
1228   /// in an Objective-C message declaration. Return the appropriate type.
1229   ParsedType ActOnObjCInstanceType(SourceLocation Loc);
1230 
1231   /// \brief Abstract class used to diagnose incomplete types.
1232   struct TypeDiagnoser {
1233     bool Suppressed;
1234 
SuppressedTypeDiagnoser1235     TypeDiagnoser(bool Suppressed = false) : Suppressed(Suppressed) { }
1236 
1237     virtual void diagnose(Sema &S, SourceLocation Loc, QualType T) = 0;
~TypeDiagnoserTypeDiagnoser1238     virtual ~TypeDiagnoser() {}
1239   };
1240 
getPrintable(int I)1241   static int getPrintable(int I) { return I; }
getPrintable(unsigned I)1242   static unsigned getPrintable(unsigned I) { return I; }
getPrintable(bool B)1243   static bool getPrintable(bool B) { return B; }
getPrintable(const char * S)1244   static const char * getPrintable(const char *S) { return S; }
getPrintable(StringRef S)1245   static StringRef getPrintable(StringRef S) { return S; }
getPrintable(const std::string & S)1246   static const std::string &getPrintable(const std::string &S) { return S; }
getPrintable(const IdentifierInfo * II)1247   static const IdentifierInfo *getPrintable(const IdentifierInfo *II) {
1248     return II;
1249   }
getPrintable(DeclarationName N)1250   static DeclarationName getPrintable(DeclarationName N) { return N; }
getPrintable(QualType T)1251   static QualType getPrintable(QualType T) { return T; }
getPrintable(SourceRange R)1252   static SourceRange getPrintable(SourceRange R) { return R; }
getPrintable(SourceLocation L)1253   static SourceRange getPrintable(SourceLocation L) { return L; }
getPrintable(const Expr * E)1254   static SourceRange getPrintable(const Expr *E) { return E->getSourceRange(); }
getPrintable(TypeLoc TL)1255   static SourceRange getPrintable(TypeLoc TL) { return TL.getSourceRange();}
1256 
1257   template<typename T1>
1258   class BoundTypeDiagnoser1 : public TypeDiagnoser {
1259     unsigned DiagID;
1260     const T1 &Arg1;
1261 
1262   public:
BoundTypeDiagnoser1(unsigned DiagID,const T1 & Arg1)1263     BoundTypeDiagnoser1(unsigned DiagID, const T1 &Arg1)
1264       : TypeDiagnoser(DiagID == 0), DiagID(DiagID), Arg1(Arg1) { }
diagnose(Sema & S,SourceLocation Loc,QualType T)1265     void diagnose(Sema &S, SourceLocation Loc, QualType T) override {
1266       if (Suppressed) return;
1267       S.Diag(Loc, DiagID) << getPrintable(Arg1) << T;
1268     }
1269 
~BoundTypeDiagnoser1()1270     virtual ~BoundTypeDiagnoser1() { }
1271   };
1272 
1273   template<typename T1, typename T2>
1274   class BoundTypeDiagnoser2 : public TypeDiagnoser {
1275     unsigned DiagID;
1276     const T1 &Arg1;
1277     const T2 &Arg2;
1278 
1279   public:
BoundTypeDiagnoser2(unsigned DiagID,const T1 & Arg1,const T2 & Arg2)1280     BoundTypeDiagnoser2(unsigned DiagID, const T1 &Arg1,
1281                                   const T2 &Arg2)
1282       : TypeDiagnoser(DiagID == 0), DiagID(DiagID), Arg1(Arg1),
1283         Arg2(Arg2) { }
1284 
diagnose(Sema & S,SourceLocation Loc,QualType T)1285     void diagnose(Sema &S, SourceLocation Loc, QualType T) override {
1286       if (Suppressed) return;
1287       S.Diag(Loc, DiagID) << getPrintable(Arg1) << getPrintable(Arg2) << T;
1288     }
1289 
~BoundTypeDiagnoser2()1290     virtual ~BoundTypeDiagnoser2() { }
1291   };
1292 
1293   template<typename T1, typename T2, typename T3>
1294   class BoundTypeDiagnoser3 : public TypeDiagnoser {
1295     unsigned DiagID;
1296     const T1 &Arg1;
1297     const T2 &Arg2;
1298     const T3 &Arg3;
1299 
1300   public:
BoundTypeDiagnoser3(unsigned DiagID,const T1 & Arg1,const T2 & Arg2,const T3 & Arg3)1301     BoundTypeDiagnoser3(unsigned DiagID, const T1 &Arg1,
1302                                   const T2 &Arg2, const T3 &Arg3)
1303     : TypeDiagnoser(DiagID == 0), DiagID(DiagID), Arg1(Arg1),
1304       Arg2(Arg2), Arg3(Arg3) { }
1305 
diagnose(Sema & S,SourceLocation Loc,QualType T)1306     void diagnose(Sema &S, SourceLocation Loc, QualType T) override {
1307       if (Suppressed) return;
1308       S.Diag(Loc, DiagID)
1309         << getPrintable(Arg1) << getPrintable(Arg2) << getPrintable(Arg3) << T;
1310     }
1311 
~BoundTypeDiagnoser3()1312     virtual ~BoundTypeDiagnoser3() { }
1313   };
1314 
1315 private:
1316   bool RequireCompleteTypeImpl(SourceLocation Loc, QualType T,
1317                            TypeDiagnoser &Diagnoser);
1318 public:
1319   bool RequireCompleteType(SourceLocation Loc, QualType T,
1320                            TypeDiagnoser &Diagnoser);
1321   bool RequireCompleteType(SourceLocation Loc, QualType T,
1322                            unsigned DiagID);
1323 
1324   template<typename T1>
RequireCompleteType(SourceLocation Loc,QualType T,unsigned DiagID,const T1 & Arg1)1325   bool RequireCompleteType(SourceLocation Loc, QualType T,
1326                            unsigned DiagID, const T1 &Arg1) {
1327     BoundTypeDiagnoser1<T1> Diagnoser(DiagID, Arg1);
1328     return RequireCompleteType(Loc, T, Diagnoser);
1329   }
1330 
1331   template<typename T1, typename T2>
RequireCompleteType(SourceLocation Loc,QualType T,unsigned DiagID,const T1 & Arg1,const T2 & Arg2)1332   bool RequireCompleteType(SourceLocation Loc, QualType T,
1333                            unsigned DiagID, const T1 &Arg1, const T2 &Arg2) {
1334     BoundTypeDiagnoser2<T1, T2> Diagnoser(DiagID, Arg1, Arg2);
1335     return RequireCompleteType(Loc, T, Diagnoser);
1336   }
1337 
1338   template<typename T1, typename T2, typename T3>
RequireCompleteType(SourceLocation Loc,QualType T,unsigned DiagID,const T1 & Arg1,const T2 & Arg2,const T3 & Arg3)1339   bool RequireCompleteType(SourceLocation Loc, QualType T,
1340                            unsigned DiagID, const T1 &Arg1, const T2 &Arg2,
1341                            const T3 &Arg3) {
1342     BoundTypeDiagnoser3<T1, T2, T3> Diagnoser(DiagID, Arg1, Arg2,
1343                                                         Arg3);
1344     return RequireCompleteType(Loc, T, Diagnoser);
1345   }
1346 
1347   bool RequireCompleteExprType(Expr *E, TypeDiagnoser &Diagnoser);
1348   bool RequireCompleteExprType(Expr *E, unsigned DiagID);
1349 
1350   template<typename T1>
RequireCompleteExprType(Expr * E,unsigned DiagID,const T1 & Arg1)1351   bool RequireCompleteExprType(Expr *E, unsigned DiagID, const T1 &Arg1) {
1352     BoundTypeDiagnoser1<T1> Diagnoser(DiagID, Arg1);
1353     return RequireCompleteExprType(E, Diagnoser);
1354   }
1355 
1356   template<typename T1, typename T2>
RequireCompleteExprType(Expr * E,unsigned DiagID,const T1 & Arg1,const T2 & Arg2)1357   bool RequireCompleteExprType(Expr *E, unsigned DiagID, const T1 &Arg1,
1358                                const T2 &Arg2) {
1359     BoundTypeDiagnoser2<T1, T2> Diagnoser(DiagID, Arg1, Arg2);
1360     return RequireCompleteExprType(E, Diagnoser);
1361   }
1362 
1363   template<typename T1, typename T2, typename T3>
RequireCompleteExprType(Expr * E,unsigned DiagID,const T1 & Arg1,const T2 & Arg2,const T3 & Arg3)1364   bool RequireCompleteExprType(Expr *E, unsigned DiagID, const T1 &Arg1,
1365                                const T2 &Arg2, const T3 &Arg3) {
1366     BoundTypeDiagnoser3<T1, T2, T3> Diagnoser(DiagID, Arg1, Arg2,
1367                                                         Arg3);
1368     return RequireCompleteExprType(E, Diagnoser);
1369   }
1370 
1371   bool RequireLiteralType(SourceLocation Loc, QualType T,
1372                           TypeDiagnoser &Diagnoser);
1373   bool RequireLiteralType(SourceLocation Loc, QualType T, unsigned DiagID);
1374 
1375   template<typename T1>
RequireLiteralType(SourceLocation Loc,QualType T,unsigned DiagID,const T1 & Arg1)1376   bool RequireLiteralType(SourceLocation Loc, QualType T,
1377                           unsigned DiagID, const T1 &Arg1) {
1378     BoundTypeDiagnoser1<T1> Diagnoser(DiagID, Arg1);
1379     return RequireLiteralType(Loc, T, Diagnoser);
1380   }
1381 
1382   template<typename T1, typename T2>
RequireLiteralType(SourceLocation Loc,QualType T,unsigned DiagID,const T1 & Arg1,const T2 & Arg2)1383   bool RequireLiteralType(SourceLocation Loc, QualType T,
1384                           unsigned DiagID, const T1 &Arg1, const T2 &Arg2) {
1385     BoundTypeDiagnoser2<T1, T2> Diagnoser(DiagID, Arg1, Arg2);
1386     return RequireLiteralType(Loc, T, Diagnoser);
1387   }
1388 
1389   template<typename T1, typename T2, typename T3>
RequireLiteralType(SourceLocation Loc,QualType T,unsigned DiagID,const T1 & Arg1,const T2 & Arg2,const T3 & Arg3)1390   bool RequireLiteralType(SourceLocation Loc, QualType T,
1391                           unsigned DiagID, const T1 &Arg1, const T2 &Arg2,
1392                           const T3 &Arg3) {
1393     BoundTypeDiagnoser3<T1, T2, T3> Diagnoser(DiagID, Arg1, Arg2,
1394                                                         Arg3);
1395     return RequireLiteralType(Loc, T, Diagnoser);
1396   }
1397 
1398   QualType getElaboratedType(ElaboratedTypeKeyword Keyword,
1399                              const CXXScopeSpec &SS, QualType T);
1400 
1401   QualType BuildTypeofExprType(Expr *E, SourceLocation Loc);
1402   /// If AsUnevaluated is false, E is treated as though it were an evaluated
1403   /// context, such as when building a type for decltype(auto).
1404   QualType BuildDecltypeType(Expr *E, SourceLocation Loc,
1405                              bool AsUnevaluated = true);
1406   QualType BuildUnaryTransformType(QualType BaseType,
1407                                    UnaryTransformType::UTTKind UKind,
1408                                    SourceLocation Loc);
1409 
1410   //===--------------------------------------------------------------------===//
1411   // Symbol table / Decl tracking callbacks: SemaDecl.cpp.
1412   //
1413 
1414   /// List of decls defined in a function prototype. This contains EnumConstants
1415   /// that incorrectly end up in translation unit scope because there is no
1416   /// function to pin them on. ActOnFunctionDeclarator reads this list and patches
1417   /// them into the FunctionDecl.
1418   std::vector<NamedDecl*> DeclsInPrototypeScope;
1419 
1420   DeclGroupPtrTy ConvertDeclToDeclGroup(Decl *Ptr, Decl *OwnedType = nullptr);
1421 
1422   void DiagnoseUseOfUnimplementedSelectors();
1423 
1424   bool isSimpleTypeSpecifier(tok::TokenKind Kind) const;
1425 
1426   ParsedType getTypeName(const IdentifierInfo &II, SourceLocation NameLoc,
1427                          Scope *S, CXXScopeSpec *SS = nullptr,
1428                          bool isClassName = false,
1429                          bool HasTrailingDot = false,
1430                          ParsedType ObjectType = ParsedType(),
1431                          bool IsCtorOrDtorName = false,
1432                          bool WantNontrivialTypeSourceInfo = false,
1433                          IdentifierInfo **CorrectedII = nullptr);
1434   TypeSpecifierType isTagName(IdentifierInfo &II, Scope *S);
1435   bool isMicrosoftMissingTypename(const CXXScopeSpec *SS, Scope *S);
1436   void DiagnoseUnknownTypeName(IdentifierInfo *&II,
1437                                SourceLocation IILoc,
1438                                Scope *S,
1439                                CXXScopeSpec *SS,
1440                                ParsedType &SuggestedType,
1441                                bool AllowClassTemplates = false);
1442 
1443   /// \brief For compatibility with MSVC, we delay parsing of some default
1444   /// template type arguments until instantiation time.  Emits a warning and
1445   /// returns a synthesized DependentNameType that isn't really dependent on any
1446   /// other template arguments.
1447   ParsedType ActOnDelayedDefaultTemplateArg(const IdentifierInfo &II,
1448                                             SourceLocation NameLoc);
1449 
1450   /// \brief Describes the result of the name lookup and resolution performed
1451   /// by \c ClassifyName().
1452   enum NameClassificationKind {
1453     NC_Unknown,
1454     NC_Error,
1455     NC_Keyword,
1456     NC_Type,
1457     NC_Expression,
1458     NC_NestedNameSpecifier,
1459     NC_TypeTemplate,
1460     NC_VarTemplate,
1461     NC_FunctionTemplate
1462   };
1463 
1464   class NameClassification {
1465     NameClassificationKind Kind;
1466     ExprResult Expr;
1467     TemplateName Template;
1468     ParsedType Type;
1469     const IdentifierInfo *Keyword;
1470 
NameClassification(NameClassificationKind Kind)1471     explicit NameClassification(NameClassificationKind Kind) : Kind(Kind) {}
1472 
1473   public:
NameClassification(ExprResult Expr)1474     NameClassification(ExprResult Expr) : Kind(NC_Expression), Expr(Expr) {}
1475 
NameClassification(ParsedType Type)1476     NameClassification(ParsedType Type) : Kind(NC_Type), Type(Type) {}
1477 
NameClassification(const IdentifierInfo * Keyword)1478     NameClassification(const IdentifierInfo *Keyword)
1479       : Kind(NC_Keyword), Keyword(Keyword) { }
1480 
Error()1481     static NameClassification Error() {
1482       return NameClassification(NC_Error);
1483     }
1484 
Unknown()1485     static NameClassification Unknown() {
1486       return NameClassification(NC_Unknown);
1487     }
1488 
NestedNameSpecifier()1489     static NameClassification NestedNameSpecifier() {
1490       return NameClassification(NC_NestedNameSpecifier);
1491     }
1492 
TypeTemplate(TemplateName Name)1493     static NameClassification TypeTemplate(TemplateName Name) {
1494       NameClassification Result(NC_TypeTemplate);
1495       Result.Template = Name;
1496       return Result;
1497     }
1498 
VarTemplate(TemplateName Name)1499     static NameClassification VarTemplate(TemplateName Name) {
1500       NameClassification Result(NC_VarTemplate);
1501       Result.Template = Name;
1502       return Result;
1503     }
1504 
FunctionTemplate(TemplateName Name)1505     static NameClassification FunctionTemplate(TemplateName Name) {
1506       NameClassification Result(NC_FunctionTemplate);
1507       Result.Template = Name;
1508       return Result;
1509     }
1510 
getKind()1511     NameClassificationKind getKind() const { return Kind; }
1512 
getType()1513     ParsedType getType() const {
1514       assert(Kind == NC_Type);
1515       return Type;
1516     }
1517 
getExpression()1518     ExprResult getExpression() const {
1519       assert(Kind == NC_Expression);
1520       return Expr;
1521     }
1522 
getTemplateName()1523     TemplateName getTemplateName() const {
1524       assert(Kind == NC_TypeTemplate || Kind == NC_FunctionTemplate ||
1525              Kind == NC_VarTemplate);
1526       return Template;
1527     }
1528 
getTemplateNameKind()1529     TemplateNameKind getTemplateNameKind() const {
1530       switch (Kind) {
1531       case NC_TypeTemplate:
1532         return TNK_Type_template;
1533       case NC_FunctionTemplate:
1534         return TNK_Function_template;
1535       case NC_VarTemplate:
1536         return TNK_Var_template;
1537       default:
1538         llvm_unreachable("unsupported name classification.");
1539       }
1540     }
1541   };
1542 
1543   /// \brief Perform name lookup on the given name, classifying it based on
1544   /// the results of name lookup and the following token.
1545   ///
1546   /// This routine is used by the parser to resolve identifiers and help direct
1547   /// parsing. When the identifier cannot be found, this routine will attempt
1548   /// to correct the typo and classify based on the resulting name.
1549   ///
1550   /// \param S The scope in which we're performing name lookup.
1551   ///
1552   /// \param SS The nested-name-specifier that precedes the name.
1553   ///
1554   /// \param Name The identifier. If typo correction finds an alternative name,
1555   /// this pointer parameter will be updated accordingly.
1556   ///
1557   /// \param NameLoc The location of the identifier.
1558   ///
1559   /// \param NextToken The token following the identifier. Used to help
1560   /// disambiguate the name.
1561   ///
1562   /// \param IsAddressOfOperand True if this name is the operand of a unary
1563   ///        address of ('&') expression, assuming it is classified as an
1564   ///        expression.
1565   ///
1566   /// \param CCC The correction callback, if typo correction is desired.
1567   NameClassification
1568   ClassifyName(Scope *S, CXXScopeSpec &SS, IdentifierInfo *&Name,
1569                SourceLocation NameLoc, const Token &NextToken,
1570                bool IsAddressOfOperand,
1571                std::unique_ptr<CorrectionCandidateCallback> CCC = nullptr);
1572 
1573   Decl *ActOnDeclarator(Scope *S, Declarator &D);
1574 
1575   NamedDecl *HandleDeclarator(Scope *S, Declarator &D,
1576                               MultiTemplateParamsArg TemplateParameterLists);
1577   void RegisterLocallyScopedExternCDecl(NamedDecl *ND, Scope *S);
1578   bool DiagnoseClassNameShadow(DeclContext *DC, DeclarationNameInfo Info);
1579   bool diagnoseQualifiedDeclaration(CXXScopeSpec &SS, DeclContext *DC,
1580                                     DeclarationName Name,
1581                                     SourceLocation Loc);
1582   void
1583   diagnoseIgnoredQualifiers(unsigned DiagID, unsigned Quals,
1584                             SourceLocation FallbackLoc,
1585                             SourceLocation ConstQualLoc = SourceLocation(),
1586                             SourceLocation VolatileQualLoc = SourceLocation(),
1587                             SourceLocation RestrictQualLoc = SourceLocation(),
1588                             SourceLocation AtomicQualLoc = SourceLocation());
1589 
1590   static bool adjustContextForLocalExternDecl(DeclContext *&DC);
1591   void DiagnoseFunctionSpecifiers(const DeclSpec &DS);
1592   void CheckShadow(Scope *S, VarDecl *D, const LookupResult& R);
1593   void CheckShadow(Scope *S, VarDecl *D);
1594   void CheckCastAlign(Expr *Op, QualType T, SourceRange TRange);
1595   void CheckTypedefForVariablyModifiedType(Scope *S, TypedefNameDecl *D);
1596   NamedDecl* ActOnTypedefDeclarator(Scope* S, Declarator& D, DeclContext* DC,
1597                                     TypeSourceInfo *TInfo,
1598                                     LookupResult &Previous);
1599   NamedDecl* ActOnTypedefNameDecl(Scope* S, DeclContext* DC, TypedefNameDecl *D,
1600                                   LookupResult &Previous, bool &Redeclaration);
1601   NamedDecl *ActOnVariableDeclarator(Scope *S, Declarator &D, DeclContext *DC,
1602                                      TypeSourceInfo *TInfo,
1603                                      LookupResult &Previous,
1604                                      MultiTemplateParamsArg TemplateParamLists,
1605                                      bool &AddToScope);
1606   // Returns true if the variable declaration is a redeclaration
1607   bool CheckVariableDeclaration(VarDecl *NewVD, LookupResult &Previous);
1608   void CheckVariableDeclarationType(VarDecl *NewVD);
1609   void CheckCompleteVariableDeclaration(VarDecl *var);
1610   void MaybeSuggestAddingStaticToDecl(const FunctionDecl *D);
1611 
1612   NamedDecl* ActOnFunctionDeclarator(Scope* S, Declarator& D, DeclContext* DC,
1613                                      TypeSourceInfo *TInfo,
1614                                      LookupResult &Previous,
1615                                      MultiTemplateParamsArg TemplateParamLists,
1616                                      bool &AddToScope);
1617   bool AddOverriddenMethods(CXXRecordDecl *DC, CXXMethodDecl *MD);
1618 
1619   bool CheckConstexprFunctionDecl(const FunctionDecl *FD);
1620   bool CheckConstexprFunctionBody(const FunctionDecl *FD, Stmt *Body);
1621 
1622   void DiagnoseHiddenVirtualMethods(CXXMethodDecl *MD);
1623   void FindHiddenVirtualMethods(CXXMethodDecl *MD,
1624                           SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods);
1625   void NoteHiddenVirtualMethods(CXXMethodDecl *MD,
1626                           SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods);
1627   // Returns true if the function declaration is a redeclaration
1628   bool CheckFunctionDeclaration(Scope *S,
1629                                 FunctionDecl *NewFD, LookupResult &Previous,
1630                                 bool IsExplicitSpecialization);
1631   void CheckMain(FunctionDecl *FD, const DeclSpec &D);
1632   void CheckMSVCRTEntryPoint(FunctionDecl *FD);
1633   Decl *ActOnParamDeclarator(Scope *S, Declarator &D);
1634   ParmVarDecl *BuildParmVarDeclForTypedef(DeclContext *DC,
1635                                           SourceLocation Loc,
1636                                           QualType T);
1637   ParmVarDecl *CheckParameter(DeclContext *DC, SourceLocation StartLoc,
1638                               SourceLocation NameLoc, IdentifierInfo *Name,
1639                               QualType T, TypeSourceInfo *TSInfo,
1640                               StorageClass SC);
1641   void ActOnParamDefaultArgument(Decl *param,
1642                                  SourceLocation EqualLoc,
1643                                  Expr *defarg);
1644   void ActOnParamUnparsedDefaultArgument(Decl *param,
1645                                          SourceLocation EqualLoc,
1646                                          SourceLocation ArgLoc);
1647   void ActOnParamDefaultArgumentError(Decl *param, SourceLocation EqualLoc);
1648   bool SetParamDefaultArgument(ParmVarDecl *Param, Expr *DefaultArg,
1649                                SourceLocation EqualLoc);
1650 
1651   void AddInitializerToDecl(Decl *dcl, Expr *init, bool DirectInit,
1652                             bool TypeMayContainAuto);
1653   void ActOnUninitializedDecl(Decl *dcl, bool TypeMayContainAuto);
1654   void ActOnInitializerError(Decl *Dcl);
1655   void ActOnCXXForRangeDecl(Decl *D);
1656   StmtResult ActOnCXXForRangeIdentifier(Scope *S, SourceLocation IdentLoc,
1657                                         IdentifierInfo *Ident,
1658                                         ParsedAttributes &Attrs,
1659                                         SourceLocation AttrEnd);
1660   void SetDeclDeleted(Decl *dcl, SourceLocation DelLoc);
1661   void SetDeclDefaulted(Decl *dcl, SourceLocation DefaultLoc);
1662   void FinalizeDeclaration(Decl *D);
1663   DeclGroupPtrTy FinalizeDeclaratorGroup(Scope *S, const DeclSpec &DS,
1664                                          ArrayRef<Decl *> Group);
1665   DeclGroupPtrTy BuildDeclaratorGroup(MutableArrayRef<Decl *> Group,
1666                                       bool TypeMayContainAuto = true);
1667 
1668   /// Should be called on all declarations that might have attached
1669   /// documentation comments.
1670   void ActOnDocumentableDecl(Decl *D);
1671   void ActOnDocumentableDecls(ArrayRef<Decl *> Group);
1672 
1673   void ActOnFinishKNRParamDeclarations(Scope *S, Declarator &D,
1674                                        SourceLocation LocAfterDecls);
1675   void CheckForFunctionRedefinition(FunctionDecl *FD,
1676                                     const FunctionDecl *EffectiveDefinition =
1677                                         nullptr);
1678   Decl *ActOnStartOfFunctionDef(Scope *S, Declarator &D);
1679   Decl *ActOnStartOfFunctionDef(Scope *S, Decl *D);
1680   void ActOnStartOfObjCMethodDef(Scope *S, Decl *D);
isObjCMethodDecl(Decl * D)1681   bool isObjCMethodDecl(Decl *D) {
1682     return D && isa<ObjCMethodDecl>(D);
1683   }
1684 
1685   /// \brief Determine whether we can delay parsing the body of a function or
1686   /// function template until it is used, assuming we don't care about emitting
1687   /// code for that function.
1688   ///
1689   /// This will be \c false if we may need the body of the function in the
1690   /// middle of parsing an expression (where it's impractical to switch to
1691   /// parsing a different function), for instance, if it's constexpr in C++11
1692   /// or has an 'auto' return type in C++14. These cases are essentially bugs.
1693   bool canDelayFunctionBody(const Declarator &D);
1694 
1695   /// \brief Determine whether we can skip parsing the body of a function
1696   /// definition, assuming we don't care about analyzing its body or emitting
1697   /// code for that function.
1698   ///
1699   /// This will be \c false only if we may need the body of the function in
1700   /// order to parse the rest of the program (for instance, if it is
1701   /// \c constexpr in C++11 or has an 'auto' return type in C++14).
1702   bool canSkipFunctionBody(Decl *D);
1703 
1704   void computeNRVO(Stmt *Body, sema::FunctionScopeInfo *Scope);
1705   Decl *ActOnFinishFunctionBody(Decl *Decl, Stmt *Body);
1706   Decl *ActOnFinishFunctionBody(Decl *Decl, Stmt *Body, bool IsInstantiation);
1707   Decl *ActOnSkippedFunctionBody(Decl *Decl);
1708   void ActOnFinishInlineMethodDef(CXXMethodDecl *D);
1709 
1710   /// ActOnFinishDelayedAttribute - Invoked when we have finished parsing an
1711   /// attribute for which parsing is delayed.
1712   void ActOnFinishDelayedAttribute(Scope *S, Decl *D, ParsedAttributes &Attrs);
1713 
1714   /// \brief Diagnose any unused parameters in the given sequence of
1715   /// ParmVarDecl pointers.
1716   void DiagnoseUnusedParameters(ParmVarDecl * const *Begin,
1717                                 ParmVarDecl * const *End);
1718 
1719   /// \brief Diagnose whether the size of parameters or return value of a
1720   /// function or obj-c method definition is pass-by-value and larger than a
1721   /// specified threshold.
1722   void DiagnoseSizeOfParametersAndReturnValue(ParmVarDecl * const *Begin,
1723                                               ParmVarDecl * const *End,
1724                                               QualType ReturnTy,
1725                                               NamedDecl *D);
1726 
1727   void DiagnoseInvalidJumps(Stmt *Body);
1728   Decl *ActOnFileScopeAsmDecl(Expr *expr,
1729                               SourceLocation AsmLoc,
1730                               SourceLocation RParenLoc);
1731 
1732   /// \brief Handle a C++11 empty-declaration and attribute-declaration.
1733   Decl *ActOnEmptyDeclaration(Scope *S,
1734                               AttributeList *AttrList,
1735                               SourceLocation SemiLoc);
1736 
1737   /// \brief The parser has processed a module import declaration.
1738   ///
1739   /// \param AtLoc The location of the '@' symbol, if any.
1740   ///
1741   /// \param ImportLoc The location of the 'import' keyword.
1742   ///
1743   /// \param Path The module access path.
1744   DeclResult ActOnModuleImport(SourceLocation AtLoc, SourceLocation ImportLoc,
1745                                ModuleIdPath Path);
1746 
1747   /// \brief The parser has processed a module import translated from a
1748   /// #include or similar preprocessing directive.
1749   void ActOnModuleInclude(SourceLocation DirectiveLoc, Module *Mod);
1750 
1751   /// \brief Create an implicit import of the given module at the given
1752   /// source location, for error recovery, if possible.
1753   ///
1754   /// This routine is typically used when an entity found by name lookup
1755   /// is actually hidden within a module that we know about but the user
1756   /// has forgotten to import.
1757   void createImplicitModuleImportForErrorRecovery(SourceLocation Loc,
1758                                                   Module *Mod);
1759 
1760   /// \brief Retrieve a suitable printing policy.
getPrintingPolicy()1761   PrintingPolicy getPrintingPolicy() const {
1762     return getPrintingPolicy(Context, PP);
1763   }
1764 
1765   /// \brief Retrieve a suitable printing policy.
1766   static PrintingPolicy getPrintingPolicy(const ASTContext &Ctx,
1767                                           const Preprocessor &PP);
1768 
1769   /// Scope actions.
1770   void ActOnPopScope(SourceLocation Loc, Scope *S);
1771   void ActOnTranslationUnitScope(Scope *S);
1772 
1773   Decl *ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS,
1774                                    DeclSpec &DS);
1775   Decl *ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS,
1776                                    DeclSpec &DS,
1777                                    MultiTemplateParamsArg TemplateParams,
1778                                    bool IsExplicitInstantiation = false);
1779 
1780   Decl *BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS,
1781                                     AccessSpecifier AS,
1782                                     RecordDecl *Record,
1783                                     const PrintingPolicy &Policy);
1784 
1785   Decl *BuildMicrosoftCAnonymousStruct(Scope *S, DeclSpec &DS,
1786                                        RecordDecl *Record);
1787 
1788   bool isAcceptableTagRedeclaration(const TagDecl *Previous,
1789                                     TagTypeKind NewTag, bool isDefinition,
1790                                     SourceLocation NewTagLoc,
1791                                     const IdentifierInfo &Name);
1792 
1793   enum TagUseKind {
1794     TUK_Reference,   // Reference to a tag:  'struct foo *X;'
1795     TUK_Declaration, // Fwd decl of a tag:   'struct foo;'
1796     TUK_Definition,  // Definition of a tag: 'struct foo { int X; } Y;'
1797     TUK_Friend       // Friend declaration:  'friend struct foo;'
1798   };
1799 
1800   Decl *ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
1801                  SourceLocation KWLoc, CXXScopeSpec &SS,
1802                  IdentifierInfo *Name, SourceLocation NameLoc,
1803                  AttributeList *Attr, AccessSpecifier AS,
1804                  SourceLocation ModulePrivateLoc,
1805                  MultiTemplateParamsArg TemplateParameterLists,
1806                  bool &OwnedDecl, bool &IsDependent,
1807                  SourceLocation ScopedEnumKWLoc,
1808                  bool ScopedEnumUsesClassTag, TypeResult UnderlyingType,
1809                  bool IsTypeSpecifier);
1810 
1811   Decl *ActOnTemplatedFriendTag(Scope *S, SourceLocation FriendLoc,
1812                                 unsigned TagSpec, SourceLocation TagLoc,
1813                                 CXXScopeSpec &SS,
1814                                 IdentifierInfo *Name, SourceLocation NameLoc,
1815                                 AttributeList *Attr,
1816                                 MultiTemplateParamsArg TempParamLists);
1817 
1818   TypeResult ActOnDependentTag(Scope *S,
1819                                unsigned TagSpec,
1820                                TagUseKind TUK,
1821                                const CXXScopeSpec &SS,
1822                                IdentifierInfo *Name,
1823                                SourceLocation TagLoc,
1824                                SourceLocation NameLoc);
1825 
1826   void ActOnDefs(Scope *S, Decl *TagD, SourceLocation DeclStart,
1827                  IdentifierInfo *ClassName,
1828                  SmallVectorImpl<Decl *> &Decls);
1829   Decl *ActOnField(Scope *S, Decl *TagD, SourceLocation DeclStart,
1830                    Declarator &D, Expr *BitfieldWidth);
1831 
1832   FieldDecl *HandleField(Scope *S, RecordDecl *TagD, SourceLocation DeclStart,
1833                          Declarator &D, Expr *BitfieldWidth,
1834                          InClassInitStyle InitStyle,
1835                          AccessSpecifier AS);
1836   MSPropertyDecl *HandleMSProperty(Scope *S, RecordDecl *TagD,
1837                                    SourceLocation DeclStart,
1838                                    Declarator &D, Expr *BitfieldWidth,
1839                                    InClassInitStyle InitStyle,
1840                                    AccessSpecifier AS,
1841                                    AttributeList *MSPropertyAttr);
1842 
1843   FieldDecl *CheckFieldDecl(DeclarationName Name, QualType T,
1844                             TypeSourceInfo *TInfo,
1845                             RecordDecl *Record, SourceLocation Loc,
1846                             bool Mutable, Expr *BitfieldWidth,
1847                             InClassInitStyle InitStyle,
1848                             SourceLocation TSSL,
1849                             AccessSpecifier AS, NamedDecl *PrevDecl,
1850                             Declarator *D = nullptr);
1851 
1852   bool CheckNontrivialField(FieldDecl *FD);
1853   void DiagnoseNontrivial(const CXXRecordDecl *Record, CXXSpecialMember CSM);
1854   bool SpecialMemberIsTrivial(CXXMethodDecl *MD, CXXSpecialMember CSM,
1855                               bool Diagnose = false);
1856   CXXSpecialMember getSpecialMember(const CXXMethodDecl *MD);
1857   void ActOnLastBitfield(SourceLocation DeclStart,
1858                          SmallVectorImpl<Decl *> &AllIvarDecls);
1859   Decl *ActOnIvar(Scope *S, SourceLocation DeclStart,
1860                   Declarator &D, Expr *BitfieldWidth,
1861                   tok::ObjCKeywordKind visibility);
1862 
1863   // This is used for both record definitions and ObjC interface declarations.
1864   void ActOnFields(Scope* S, SourceLocation RecLoc, Decl *TagDecl,
1865                    ArrayRef<Decl *> Fields,
1866                    SourceLocation LBrac, SourceLocation RBrac,
1867                    AttributeList *AttrList);
1868 
1869   /// ActOnTagStartDefinition - Invoked when we have entered the
1870   /// scope of a tag's definition (e.g., for an enumeration, class,
1871   /// struct, or union).
1872   void ActOnTagStartDefinition(Scope *S, Decl *TagDecl);
1873 
1874   Decl *ActOnObjCContainerStartDefinition(Decl *IDecl);
1875 
1876   /// ActOnStartCXXMemberDeclarations - Invoked when we have parsed a
1877   /// C++ record definition's base-specifiers clause and are starting its
1878   /// member declarations.
1879   void ActOnStartCXXMemberDeclarations(Scope *S, Decl *TagDecl,
1880                                        SourceLocation FinalLoc,
1881                                        bool IsFinalSpelledSealed,
1882                                        SourceLocation LBraceLoc);
1883 
1884   /// ActOnTagFinishDefinition - Invoked once we have finished parsing
1885   /// the definition of a tag (enumeration, class, struct, or union).
1886   void ActOnTagFinishDefinition(Scope *S, Decl *TagDecl,
1887                                 SourceLocation RBraceLoc);
1888 
1889   void ActOnObjCContainerFinishDefinition();
1890 
1891   /// \brief Invoked when we must temporarily exit the objective-c container
1892   /// scope for parsing/looking-up C constructs.
1893   ///
1894   /// Must be followed by a call to \see ActOnObjCReenterContainerContext
1895   void ActOnObjCTemporaryExitContainerContext(DeclContext *DC);
1896   void ActOnObjCReenterContainerContext(DeclContext *DC);
1897 
1898   /// ActOnTagDefinitionError - Invoked when there was an unrecoverable
1899   /// error parsing the definition of a tag.
1900   void ActOnTagDefinitionError(Scope *S, Decl *TagDecl);
1901 
1902   EnumConstantDecl *CheckEnumConstant(EnumDecl *Enum,
1903                                       EnumConstantDecl *LastEnumConst,
1904                                       SourceLocation IdLoc,
1905                                       IdentifierInfo *Id,
1906                                       Expr *val);
1907   bool CheckEnumUnderlyingType(TypeSourceInfo *TI);
1908   bool CheckEnumRedeclaration(SourceLocation EnumLoc, bool IsScoped,
1909                               QualType EnumUnderlyingTy, const EnumDecl *Prev);
1910 
1911   Decl *ActOnEnumConstant(Scope *S, Decl *EnumDecl, Decl *LastEnumConstant,
1912                           SourceLocation IdLoc, IdentifierInfo *Id,
1913                           AttributeList *Attrs,
1914                           SourceLocation EqualLoc, Expr *Val);
1915   void ActOnEnumBody(SourceLocation EnumLoc, SourceLocation LBraceLoc,
1916                      SourceLocation RBraceLoc, Decl *EnumDecl,
1917                      ArrayRef<Decl *> Elements,
1918                      Scope *S, AttributeList *Attr);
1919 
1920   DeclContext *getContainingDC(DeclContext *DC);
1921 
1922   /// Set the current declaration context until it gets popped.
1923   void PushDeclContext(Scope *S, DeclContext *DC);
1924   void PopDeclContext();
1925 
1926   /// EnterDeclaratorContext - Used when we must lookup names in the context
1927   /// of a declarator's nested name specifier.
1928   void EnterDeclaratorContext(Scope *S, DeclContext *DC);
1929   void ExitDeclaratorContext(Scope *S);
1930 
1931   /// Push the parameters of D, which must be a function, into scope.
1932   void ActOnReenterFunctionContext(Scope* S, Decl* D);
1933   void ActOnExitFunctionContext();
1934 
1935   DeclContext *getFunctionLevelDeclContext();
1936 
1937   /// getCurFunctionDecl - If inside of a function body, this returns a pointer
1938   /// to the function decl for the function being parsed.  If we're currently
1939   /// in a 'block', this returns the containing context.
1940   FunctionDecl *getCurFunctionDecl();
1941 
1942   /// getCurMethodDecl - If inside of a method body, this returns a pointer to
1943   /// the method decl for the method being parsed.  If we're currently
1944   /// in a 'block', this returns the containing context.
1945   ObjCMethodDecl *getCurMethodDecl();
1946 
1947   /// getCurFunctionOrMethodDecl - Return the Decl for the current ObjC method
1948   /// or C function we're in, otherwise return null.  If we're currently
1949   /// in a 'block', this returns the containing context.
1950   NamedDecl *getCurFunctionOrMethodDecl();
1951 
1952   /// Add this decl to the scope shadowed decl chains.
1953   void PushOnScopeChains(NamedDecl *D, Scope *S, bool AddToContext = true);
1954 
1955   /// \brief Make the given externally-produced declaration visible at the
1956   /// top level scope.
1957   ///
1958   /// \param D The externally-produced declaration to push.
1959   ///
1960   /// \param Name The name of the externally-produced declaration.
1961   void pushExternalDeclIntoScope(NamedDecl *D, DeclarationName Name);
1962 
1963   /// isDeclInScope - If 'Ctx' is a function/method, isDeclInScope returns true
1964   /// if 'D' is in Scope 'S', otherwise 'S' is ignored and isDeclInScope returns
1965   /// true if 'D' belongs to the given declaration context.
1966   ///
1967   /// \param AllowInlineNamespace If \c true, allow the declaration to be in the
1968   ///        enclosing namespace set of the context, rather than contained
1969   ///        directly within it.
1970   bool isDeclInScope(NamedDecl *D, DeclContext *Ctx, Scope *S = nullptr,
1971                      bool AllowInlineNamespace = false);
1972 
1973   /// Finds the scope corresponding to the given decl context, if it
1974   /// happens to be an enclosing scope.  Otherwise return NULL.
1975   static Scope *getScopeForDeclContext(Scope *S, DeclContext *DC);
1976 
1977   /// Subroutines of ActOnDeclarator().
1978   TypedefDecl *ParseTypedefDecl(Scope *S, Declarator &D, QualType T,
1979                                 TypeSourceInfo *TInfo);
1980   bool isIncompatibleTypedef(TypeDecl *Old, TypedefNameDecl *New);
1981 
1982   /// Attribute merging methods. Return true if a new attribute was added.
1983   AvailabilityAttr *mergeAvailabilityAttr(NamedDecl *D, SourceRange Range,
1984                                           IdentifierInfo *Platform,
1985                                           VersionTuple Introduced,
1986                                           VersionTuple Deprecated,
1987                                           VersionTuple Obsoleted,
1988                                           bool IsUnavailable,
1989                                           StringRef Message,
1990                                           bool Override,
1991                                           unsigned AttrSpellingListIndex);
1992   TypeVisibilityAttr *mergeTypeVisibilityAttr(Decl *D, SourceRange Range,
1993                                        TypeVisibilityAttr::VisibilityType Vis,
1994                                               unsigned AttrSpellingListIndex);
1995   VisibilityAttr *mergeVisibilityAttr(Decl *D, SourceRange Range,
1996                                       VisibilityAttr::VisibilityType Vis,
1997                                       unsigned AttrSpellingListIndex);
1998   DLLImportAttr *mergeDLLImportAttr(Decl *D, SourceRange Range,
1999                                     unsigned AttrSpellingListIndex);
2000   DLLExportAttr *mergeDLLExportAttr(Decl *D, SourceRange Range,
2001                                     unsigned AttrSpellingListIndex);
2002   MSInheritanceAttr *
2003   mergeMSInheritanceAttr(Decl *D, SourceRange Range, bool BestCase,
2004                          unsigned AttrSpellingListIndex,
2005                          MSInheritanceAttr::Spelling SemanticSpelling);
2006   FormatAttr *mergeFormatAttr(Decl *D, SourceRange Range,
2007                               IdentifierInfo *Format, int FormatIdx,
2008                               int FirstArg, unsigned AttrSpellingListIndex);
2009   SectionAttr *mergeSectionAttr(Decl *D, SourceRange Range, StringRef Name,
2010                                 unsigned AttrSpellingListIndex);
2011   AlwaysInlineAttr *mergeAlwaysInlineAttr(Decl *D, SourceRange Range,
2012                                           IdentifierInfo *Ident,
2013                                           unsigned AttrSpellingListIndex);
2014   MinSizeAttr *mergeMinSizeAttr(Decl *D, SourceRange Range,
2015                                 unsigned AttrSpellingListIndex);
2016   OptimizeNoneAttr *mergeOptimizeNoneAttr(Decl *D, SourceRange Range,
2017                                           unsigned AttrSpellingListIndex);
2018 
2019   /// \brief Describes the kind of merge to perform for availability
2020   /// attributes (including "deprecated", "unavailable", and "availability").
2021   enum AvailabilityMergeKind {
2022     /// \brief Don't merge availability attributes at all.
2023     AMK_None,
2024     /// \brief Merge availability attributes for a redeclaration, which requires
2025     /// an exact match.
2026     AMK_Redeclaration,
2027     /// \brief Merge availability attributes for an override, which requires
2028     /// an exact match or a weakening of constraints.
2029     AMK_Override
2030   };
2031 
2032   void mergeDeclAttributes(NamedDecl *New, Decl *Old,
2033                            AvailabilityMergeKind AMK = AMK_Redeclaration);
2034   void MergeTypedefNameDecl(TypedefNameDecl *New, LookupResult &OldDecls);
2035   bool MergeFunctionDecl(FunctionDecl *New, NamedDecl *&Old, Scope *S,
2036                          bool MergeTypeWithOld);
2037   bool MergeCompatibleFunctionDecls(FunctionDecl *New, FunctionDecl *Old,
2038                                     Scope *S, bool MergeTypeWithOld);
2039   void mergeObjCMethodDecls(ObjCMethodDecl *New, ObjCMethodDecl *Old);
2040   void MergeVarDecl(VarDecl *New, LookupResult &Previous);
2041   void MergeVarDeclTypes(VarDecl *New, VarDecl *Old, bool MergeTypeWithOld);
2042   void MergeVarDeclExceptionSpecs(VarDecl *New, VarDecl *Old);
2043   bool MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old, Scope *S);
2044 
2045   // AssignmentAction - This is used by all the assignment diagnostic functions
2046   // to represent what is actually causing the operation
2047   enum AssignmentAction {
2048     AA_Assigning,
2049     AA_Passing,
2050     AA_Returning,
2051     AA_Converting,
2052     AA_Initializing,
2053     AA_Sending,
2054     AA_Casting,
2055     AA_Passing_CFAudited
2056   };
2057 
2058   /// C++ Overloading.
2059   enum OverloadKind {
2060     /// This is a legitimate overload: the existing declarations are
2061     /// functions or function templates with different signatures.
2062     Ovl_Overload,
2063 
2064     /// This is not an overload because the signature exactly matches
2065     /// an existing declaration.
2066     Ovl_Match,
2067 
2068     /// This is not an overload because the lookup results contain a
2069     /// non-function.
2070     Ovl_NonFunction
2071   };
2072   OverloadKind CheckOverload(Scope *S,
2073                              FunctionDecl *New,
2074                              const LookupResult &OldDecls,
2075                              NamedDecl *&OldDecl,
2076                              bool IsForUsingDecl);
2077   bool IsOverload(FunctionDecl *New, FunctionDecl *Old, bool IsForUsingDecl);
2078 
2079   /// \brief Checks availability of the function depending on the current
2080   /// function context.Inside an unavailable function,unavailability is ignored.
2081   ///
2082   /// \returns true if \p FD is unavailable and current context is inside
2083   /// an available function, false otherwise.
2084   bool isFunctionConsideredUnavailable(FunctionDecl *FD);
2085 
2086   ImplicitConversionSequence
2087   TryImplicitConversion(Expr *From, QualType ToType,
2088                         bool SuppressUserConversions,
2089                         bool AllowExplicit,
2090                         bool InOverloadResolution,
2091                         bool CStyle,
2092                         bool AllowObjCWritebackConversion);
2093 
2094   bool IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType);
2095   bool IsFloatingPointPromotion(QualType FromType, QualType ToType);
2096   bool IsComplexPromotion(QualType FromType, QualType ToType);
2097   bool IsPointerConversion(Expr *From, QualType FromType, QualType ToType,
2098                            bool InOverloadResolution,
2099                            QualType& ConvertedType, bool &IncompatibleObjC);
2100   bool isObjCPointerConversion(QualType FromType, QualType ToType,
2101                                QualType& ConvertedType, bool &IncompatibleObjC);
2102   bool isObjCWritebackConversion(QualType FromType, QualType ToType,
2103                                  QualType &ConvertedType);
2104   bool IsBlockPointerConversion(QualType FromType, QualType ToType,
2105                                 QualType& ConvertedType);
2106   bool FunctionParamTypesAreEqual(const FunctionProtoType *OldType,
2107                                   const FunctionProtoType *NewType,
2108                                   unsigned *ArgPos = nullptr);
2109   void HandleFunctionTypeMismatch(PartialDiagnostic &PDiag,
2110                                   QualType FromType, QualType ToType);
2111 
2112   CastKind PrepareCastToObjCObjectPointer(ExprResult &E);
2113   bool CheckPointerConversion(Expr *From, QualType ToType,
2114                               CastKind &Kind,
2115                               CXXCastPath& BasePath,
2116                               bool IgnoreBaseAccess);
2117   bool IsMemberPointerConversion(Expr *From, QualType FromType, QualType ToType,
2118                                  bool InOverloadResolution,
2119                                  QualType &ConvertedType);
2120   bool CheckMemberPointerConversion(Expr *From, QualType ToType,
2121                                     CastKind &Kind,
2122                                     CXXCastPath &BasePath,
2123                                     bool IgnoreBaseAccess);
2124   bool IsQualificationConversion(QualType FromType, QualType ToType,
2125                                  bool CStyle, bool &ObjCLifetimeConversion);
2126   bool IsNoReturnConversion(QualType FromType, QualType ToType,
2127                             QualType &ResultTy);
2128   bool DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType);
2129   bool isSameOrCompatibleFunctionType(CanQualType Param, CanQualType Arg);
2130 
2131   ExprResult PerformMoveOrCopyInitialization(const InitializedEntity &Entity,
2132                                              const VarDecl *NRVOCandidate,
2133                                              QualType ResultType,
2134                                              Expr *Value,
2135                                              bool AllowNRVO = true);
2136 
2137   bool CanPerformCopyInitialization(const InitializedEntity &Entity,
2138                                     ExprResult Init);
2139   ExprResult PerformCopyInitialization(const InitializedEntity &Entity,
2140                                        SourceLocation EqualLoc,
2141                                        ExprResult Init,
2142                                        bool TopLevelOfInitList = false,
2143                                        bool AllowExplicit = false);
2144   ExprResult PerformObjectArgumentInitialization(Expr *From,
2145                                                  NestedNameSpecifier *Qualifier,
2146                                                  NamedDecl *FoundDecl,
2147                                                  CXXMethodDecl *Method);
2148 
2149   ExprResult PerformContextuallyConvertToBool(Expr *From);
2150   ExprResult PerformContextuallyConvertToObjCPointer(Expr *From);
2151 
2152   /// Contexts in which a converted constant expression is required.
2153   enum CCEKind {
2154     CCEK_CaseValue,   ///< Expression in a case label.
2155     CCEK_Enumerator,  ///< Enumerator value with fixed underlying type.
2156     CCEK_TemplateArg, ///< Value of a non-type template parameter.
2157     CCEK_NewExpr      ///< Constant expression in a noptr-new-declarator.
2158   };
2159   ExprResult CheckConvertedConstantExpression(Expr *From, QualType T,
2160                                               llvm::APSInt &Value, CCEKind CCE);
2161   ExprResult CheckConvertedConstantExpression(Expr *From, QualType T,
2162                                               APValue &Value, CCEKind CCE);
2163 
2164   /// \brief Abstract base class used to perform a contextual implicit
2165   /// conversion from an expression to any type passing a filter.
2166   class ContextualImplicitConverter {
2167   public:
2168     bool Suppress;
2169     bool SuppressConversion;
2170 
2171     ContextualImplicitConverter(bool Suppress = false,
2172                                 bool SuppressConversion = false)
Suppress(Suppress)2173         : Suppress(Suppress), SuppressConversion(SuppressConversion) {}
2174 
2175     /// \brief Determine whether the specified type is a valid destination type
2176     /// for this conversion.
2177     virtual bool match(QualType T) = 0;
2178 
2179     /// \brief Emits a diagnostic complaining that the expression does not have
2180     /// integral or enumeration type.
2181     virtual SemaDiagnosticBuilder
2182     diagnoseNoMatch(Sema &S, SourceLocation Loc, QualType T) = 0;
2183 
2184     /// \brief Emits a diagnostic when the expression has incomplete class type.
2185     virtual SemaDiagnosticBuilder
2186     diagnoseIncomplete(Sema &S, SourceLocation Loc, QualType T) = 0;
2187 
2188     /// \brief Emits a diagnostic when the only matching conversion function
2189     /// is explicit.
2190     virtual SemaDiagnosticBuilder diagnoseExplicitConv(
2191         Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) = 0;
2192 
2193     /// \brief Emits a note for the explicit conversion function.
2194     virtual SemaDiagnosticBuilder
2195     noteExplicitConv(Sema &S, CXXConversionDecl *Conv, QualType ConvTy) = 0;
2196 
2197     /// \brief Emits a diagnostic when there are multiple possible conversion
2198     /// functions.
2199     virtual SemaDiagnosticBuilder
2200     diagnoseAmbiguous(Sema &S, SourceLocation Loc, QualType T) = 0;
2201 
2202     /// \brief Emits a note for one of the candidate conversions.
2203     virtual SemaDiagnosticBuilder
2204     noteAmbiguous(Sema &S, CXXConversionDecl *Conv, QualType ConvTy) = 0;
2205 
2206     /// \brief Emits a diagnostic when we picked a conversion function
2207     /// (for cases when we are not allowed to pick a conversion function).
2208     virtual SemaDiagnosticBuilder diagnoseConversion(
2209         Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) = 0;
2210 
~ContextualImplicitConverter()2211     virtual ~ContextualImplicitConverter() {}
2212   };
2213 
2214   class ICEConvertDiagnoser : public ContextualImplicitConverter {
2215     bool AllowScopedEnumerations;
2216 
2217   public:
ICEConvertDiagnoser(bool AllowScopedEnumerations,bool Suppress,bool SuppressConversion)2218     ICEConvertDiagnoser(bool AllowScopedEnumerations,
2219                         bool Suppress, bool SuppressConversion)
2220         : ContextualImplicitConverter(Suppress, SuppressConversion),
2221           AllowScopedEnumerations(AllowScopedEnumerations) {}
2222 
2223     /// Match an integral or (possibly scoped) enumeration type.
2224     bool match(QualType T) override;
2225 
2226     SemaDiagnosticBuilder
diagnoseNoMatch(Sema & S,SourceLocation Loc,QualType T)2227     diagnoseNoMatch(Sema &S, SourceLocation Loc, QualType T) override {
2228       return diagnoseNotInt(S, Loc, T);
2229     }
2230 
2231     /// \brief Emits a diagnostic complaining that the expression does not have
2232     /// integral or enumeration type.
2233     virtual SemaDiagnosticBuilder
2234     diagnoseNotInt(Sema &S, SourceLocation Loc, QualType T) = 0;
2235   };
2236 
2237   /// Perform a contextual implicit conversion.
2238   ExprResult PerformContextualImplicitConversion(
2239       SourceLocation Loc, Expr *FromE, ContextualImplicitConverter &Converter);
2240 
2241 
2242   enum ObjCSubscriptKind {
2243     OS_Array,
2244     OS_Dictionary,
2245     OS_Error
2246   };
2247   ObjCSubscriptKind CheckSubscriptingKind(Expr *FromE);
2248 
2249   // Note that LK_String is intentionally after the other literals, as
2250   // this is used for diagnostics logic.
2251   enum ObjCLiteralKind {
2252     LK_Array,
2253     LK_Dictionary,
2254     LK_Numeric,
2255     LK_Boxed,
2256     LK_String,
2257     LK_Block,
2258     LK_None
2259   };
2260   ObjCLiteralKind CheckLiteralKind(Expr *FromE);
2261 
2262   ExprResult PerformObjectMemberConversion(Expr *From,
2263                                            NestedNameSpecifier *Qualifier,
2264                                            NamedDecl *FoundDecl,
2265                                            NamedDecl *Member);
2266 
2267   // Members have to be NamespaceDecl* or TranslationUnitDecl*.
2268   // TODO: make this is a typesafe union.
2269   typedef llvm::SmallPtrSet<DeclContext   *, 16> AssociatedNamespaceSet;
2270   typedef llvm::SmallPtrSet<CXXRecordDecl *, 16> AssociatedClassSet;
2271 
2272   void AddOverloadCandidate(FunctionDecl *Function,
2273                             DeclAccessPair FoundDecl,
2274                             ArrayRef<Expr *> Args,
2275                             OverloadCandidateSet& CandidateSet,
2276                             bool SuppressUserConversions = false,
2277                             bool PartialOverloading = false,
2278                             bool AllowExplicit = false);
2279   void AddFunctionCandidates(const UnresolvedSetImpl &Functions,
2280                       ArrayRef<Expr *> Args,
2281                       OverloadCandidateSet &CandidateSet,
2282                       bool SuppressUserConversions = false,
2283                       TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr);
2284   void AddMethodCandidate(DeclAccessPair FoundDecl,
2285                           QualType ObjectType,
2286                           Expr::Classification ObjectClassification,
2287                           ArrayRef<Expr *> Args,
2288                           OverloadCandidateSet& CandidateSet,
2289                           bool SuppressUserConversion = false);
2290   void AddMethodCandidate(CXXMethodDecl *Method,
2291                           DeclAccessPair FoundDecl,
2292                           CXXRecordDecl *ActingContext, QualType ObjectType,
2293                           Expr::Classification ObjectClassification,
2294                           ArrayRef<Expr *> Args,
2295                           OverloadCandidateSet& CandidateSet,
2296                           bool SuppressUserConversions = false);
2297   void AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl,
2298                                   DeclAccessPair FoundDecl,
2299                                   CXXRecordDecl *ActingContext,
2300                                  TemplateArgumentListInfo *ExplicitTemplateArgs,
2301                                   QualType ObjectType,
2302                                   Expr::Classification ObjectClassification,
2303                                   ArrayRef<Expr *> Args,
2304                                   OverloadCandidateSet& CandidateSet,
2305                                   bool SuppressUserConversions = false);
2306   void AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate,
2307                                     DeclAccessPair FoundDecl,
2308                                  TemplateArgumentListInfo *ExplicitTemplateArgs,
2309                                     ArrayRef<Expr *> Args,
2310                                     OverloadCandidateSet& CandidateSet,
2311                                     bool SuppressUserConversions = false);
2312   void AddConversionCandidate(CXXConversionDecl *Conversion,
2313                               DeclAccessPair FoundDecl,
2314                               CXXRecordDecl *ActingContext,
2315                               Expr *From, QualType ToType,
2316                               OverloadCandidateSet& CandidateSet,
2317                               bool AllowObjCConversionOnExplicit);
2318   void AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate,
2319                                       DeclAccessPair FoundDecl,
2320                                       CXXRecordDecl *ActingContext,
2321                                       Expr *From, QualType ToType,
2322                                       OverloadCandidateSet &CandidateSet,
2323                                       bool AllowObjCConversionOnExplicit);
2324   void AddSurrogateCandidate(CXXConversionDecl *Conversion,
2325                              DeclAccessPair FoundDecl,
2326                              CXXRecordDecl *ActingContext,
2327                              const FunctionProtoType *Proto,
2328                              Expr *Object, ArrayRef<Expr *> Args,
2329                              OverloadCandidateSet& CandidateSet);
2330   void AddMemberOperatorCandidates(OverloadedOperatorKind Op,
2331                                    SourceLocation OpLoc, ArrayRef<Expr *> Args,
2332                                    OverloadCandidateSet& CandidateSet,
2333                                    SourceRange OpRange = SourceRange());
2334   void AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys,
2335                            ArrayRef<Expr *> Args,
2336                            OverloadCandidateSet& CandidateSet,
2337                            bool IsAssignmentOperator = false,
2338                            unsigned NumContextualBoolArguments = 0);
2339   void AddBuiltinOperatorCandidates(OverloadedOperatorKind Op,
2340                                     SourceLocation OpLoc, ArrayRef<Expr *> Args,
2341                                     OverloadCandidateSet& CandidateSet);
2342   void AddArgumentDependentLookupCandidates(DeclarationName Name,
2343                                             SourceLocation Loc,
2344                                             ArrayRef<Expr *> Args,
2345                                 TemplateArgumentListInfo *ExplicitTemplateArgs,
2346                                             OverloadCandidateSet& CandidateSet,
2347                                             bool PartialOverloading = false);
2348 
2349   // Emit as a 'note' the specific overload candidate
2350   void NoteOverloadCandidate(FunctionDecl *Fn, QualType DestType = QualType());
2351 
2352   // Emit as a series of 'note's all template and non-templates
2353   // identified by the expression Expr
2354   void NoteAllOverloadCandidates(Expr* E, QualType DestType = QualType());
2355 
2356   /// Check the enable_if expressions on the given function. Returns the first
2357   /// failing attribute, or NULL if they were all successful.
2358   EnableIfAttr *CheckEnableIf(FunctionDecl *Function, ArrayRef<Expr *> Args,
2359                               bool MissingImplicitThis = false);
2360 
2361   // [PossiblyAFunctionType]  -->   [Return]
2362   // NonFunctionType --> NonFunctionType
2363   // R (A) --> R(A)
2364   // R (*)(A) --> R (A)
2365   // R (&)(A) --> R (A)
2366   // R (S::*)(A) --> R (A)
2367   QualType ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType);
2368 
2369   FunctionDecl *
2370   ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr,
2371                                      QualType TargetType,
2372                                      bool Complain,
2373                                      DeclAccessPair &Found,
2374                                      bool *pHadMultipleCandidates = nullptr);
2375 
2376   FunctionDecl *
2377   ResolveSingleFunctionTemplateSpecialization(OverloadExpr *ovl,
2378                                               bool Complain = false,
2379                                               DeclAccessPair *Found = nullptr);
2380 
2381   bool ResolveAndFixSingleFunctionTemplateSpecialization(
2382                       ExprResult &SrcExpr,
2383                       bool DoFunctionPointerConverion = false,
2384                       bool Complain = false,
2385                       const SourceRange& OpRangeForComplaining = SourceRange(),
2386                       QualType DestTypeForComplaining = QualType(),
2387                       unsigned DiagIDForComplaining = 0);
2388 
2389 
2390   Expr *FixOverloadedFunctionReference(Expr *E,
2391                                        DeclAccessPair FoundDecl,
2392                                        FunctionDecl *Fn);
2393   ExprResult FixOverloadedFunctionReference(ExprResult,
2394                                             DeclAccessPair FoundDecl,
2395                                             FunctionDecl *Fn);
2396 
2397   void AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE,
2398                                    ArrayRef<Expr *> Args,
2399                                    OverloadCandidateSet &CandidateSet,
2400                                    bool PartialOverloading = false);
2401 
2402   // An enum used to represent the different possible results of building a
2403   // range-based for loop.
2404   enum ForRangeStatus {
2405     FRS_Success,
2406     FRS_NoViableFunction,
2407     FRS_DiagnosticIssued
2408   };
2409 
2410   // An enum to represent whether something is dealing with a call to begin()
2411   // or a call to end() in a range-based for loop.
2412   enum BeginEndFunction {
2413     BEF_begin,
2414     BEF_end
2415   };
2416 
2417   ForRangeStatus BuildForRangeBeginEndCall(Scope *S, SourceLocation Loc,
2418                                            SourceLocation RangeLoc,
2419                                            VarDecl *Decl,
2420                                            BeginEndFunction BEF,
2421                                            const DeclarationNameInfo &NameInfo,
2422                                            LookupResult &MemberLookup,
2423                                            OverloadCandidateSet *CandidateSet,
2424                                            Expr *Range, ExprResult *CallExpr);
2425 
2426   ExprResult BuildOverloadedCallExpr(Scope *S, Expr *Fn,
2427                                      UnresolvedLookupExpr *ULE,
2428                                      SourceLocation LParenLoc,
2429                                      MultiExprArg Args,
2430                                      SourceLocation RParenLoc,
2431                                      Expr *ExecConfig,
2432                                      bool AllowTypoCorrection=true);
2433 
2434   bool buildOverloadedCallSet(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE,
2435                               MultiExprArg Args, SourceLocation RParenLoc,
2436                               OverloadCandidateSet *CandidateSet,
2437                               ExprResult *Result);
2438 
2439   ExprResult CreateOverloadedUnaryOp(SourceLocation OpLoc,
2440                                      unsigned Opc,
2441                                      const UnresolvedSetImpl &Fns,
2442                                      Expr *input);
2443 
2444   ExprResult CreateOverloadedBinOp(SourceLocation OpLoc,
2445                                    unsigned Opc,
2446                                    const UnresolvedSetImpl &Fns,
2447                                    Expr *LHS, Expr *RHS);
2448 
2449   ExprResult CreateOverloadedArraySubscriptExpr(SourceLocation LLoc,
2450                                                 SourceLocation RLoc,
2451                                                 Expr *Base,Expr *Idx);
2452 
2453   ExprResult
2454   BuildCallToMemberFunction(Scope *S, Expr *MemExpr,
2455                             SourceLocation LParenLoc,
2456                             MultiExprArg Args,
2457                             SourceLocation RParenLoc);
2458   ExprResult
2459   BuildCallToObjectOfClassType(Scope *S, Expr *Object, SourceLocation LParenLoc,
2460                                MultiExprArg Args,
2461                                SourceLocation RParenLoc);
2462 
2463   ExprResult BuildOverloadedArrowExpr(Scope *S, Expr *Base,
2464                                       SourceLocation OpLoc,
2465                                       bool *NoArrowOperatorFound = nullptr);
2466 
2467   /// CheckCallReturnType - Checks that a call expression's return type is
2468   /// complete. Returns true on failure. The location passed in is the location
2469   /// that best represents the call.
2470   bool CheckCallReturnType(QualType ReturnType, SourceLocation Loc,
2471                            CallExpr *CE, FunctionDecl *FD);
2472 
2473   /// Helpers for dealing with blocks and functions.
2474   bool CheckParmsForFunctionDef(ParmVarDecl *const *Param,
2475                                 ParmVarDecl *const *ParamEnd,
2476                                 bool CheckParameterNames);
2477   void CheckCXXDefaultArguments(FunctionDecl *FD);
2478   void CheckExtraCXXDefaultArguments(Declarator &D);
2479   Scope *getNonFieldDeclScope(Scope *S);
2480 
2481   /// \name Name lookup
2482   ///
2483   /// These routines provide name lookup that is used during semantic
2484   /// analysis to resolve the various kinds of names (identifiers,
2485   /// overloaded operator names, constructor names, etc.) into zero or
2486   /// more declarations within a particular scope. The major entry
2487   /// points are LookupName, which performs unqualified name lookup,
2488   /// and LookupQualifiedName, which performs qualified name lookup.
2489   ///
2490   /// All name lookup is performed based on some specific criteria,
2491   /// which specify what names will be visible to name lookup and how
2492   /// far name lookup should work. These criteria are important both
2493   /// for capturing language semantics (certain lookups will ignore
2494   /// certain names, for example) and for performance, since name
2495   /// lookup is often a bottleneck in the compilation of C++. Name
2496   /// lookup criteria is specified via the LookupCriteria enumeration.
2497   ///
2498   /// The results of name lookup can vary based on the kind of name
2499   /// lookup performed, the current language, and the translation
2500   /// unit. In C, for example, name lookup will either return nothing
2501   /// (no entity found) or a single declaration. In C++, name lookup
2502   /// can additionally refer to a set of overloaded functions or
2503   /// result in an ambiguity. All of the possible results of name
2504   /// lookup are captured by the LookupResult class, which provides
2505   /// the ability to distinguish among them.
2506   //@{
2507 
2508   /// @brief Describes the kind of name lookup to perform.
2509   enum LookupNameKind {
2510     /// Ordinary name lookup, which finds ordinary names (functions,
2511     /// variables, typedefs, etc.) in C and most kinds of names
2512     /// (functions, variables, members, types, etc.) in C++.
2513     LookupOrdinaryName = 0,
2514     /// Tag name lookup, which finds the names of enums, classes,
2515     /// structs, and unions.
2516     LookupTagName,
2517     /// Label name lookup.
2518     LookupLabel,
2519     /// Member name lookup, which finds the names of
2520     /// class/struct/union members.
2521     LookupMemberName,
2522     /// Look up of an operator name (e.g., operator+) for use with
2523     /// operator overloading. This lookup is similar to ordinary name
2524     /// lookup, but will ignore any declarations that are class members.
2525     LookupOperatorName,
2526     /// Look up of a name that precedes the '::' scope resolution
2527     /// operator in C++. This lookup completely ignores operator, object,
2528     /// function, and enumerator names (C++ [basic.lookup.qual]p1).
2529     LookupNestedNameSpecifierName,
2530     /// Look up a namespace name within a C++ using directive or
2531     /// namespace alias definition, ignoring non-namespace names (C++
2532     /// [basic.lookup.udir]p1).
2533     LookupNamespaceName,
2534     /// Look up all declarations in a scope with the given name,
2535     /// including resolved using declarations.  This is appropriate
2536     /// for checking redeclarations for a using declaration.
2537     LookupUsingDeclName,
2538     /// Look up an ordinary name that is going to be redeclared as a
2539     /// name with linkage. This lookup ignores any declarations that
2540     /// are outside of the current scope unless they have linkage. See
2541     /// C99 6.2.2p4-5 and C++ [basic.link]p6.
2542     LookupRedeclarationWithLinkage,
2543     /// Look up a friend of a local class. This lookup does not look
2544     /// outside the innermost non-class scope. See C++11 [class.friend]p11.
2545     LookupLocalFriendName,
2546     /// Look up the name of an Objective-C protocol.
2547     LookupObjCProtocolName,
2548     /// Look up implicit 'self' parameter of an objective-c method.
2549     LookupObjCImplicitSelfParam,
2550     /// \brief Look up any declaration with any name.
2551     LookupAnyName
2552   };
2553 
2554   /// \brief Specifies whether (or how) name lookup is being performed for a
2555   /// redeclaration (vs. a reference).
2556   enum RedeclarationKind {
2557     /// \brief The lookup is a reference to this name that is not for the
2558     /// purpose of redeclaring the name.
2559     NotForRedeclaration = 0,
2560     /// \brief The lookup results will be used for redeclaration of a name,
2561     /// if an entity by that name already exists.
2562     ForRedeclaration
2563   };
2564 
2565   /// \brief The possible outcomes of name lookup for a literal operator.
2566   enum LiteralOperatorLookupResult {
2567     /// \brief The lookup resulted in an error.
2568     LOLR_Error,
2569     /// \brief The lookup found a single 'cooked' literal operator, which
2570     /// expects a normal literal to be built and passed to it.
2571     LOLR_Cooked,
2572     /// \brief The lookup found a single 'raw' literal operator, which expects
2573     /// a string literal containing the spelling of the literal token.
2574     LOLR_Raw,
2575     /// \brief The lookup found an overload set of literal operator templates,
2576     /// which expect the characters of the spelling of the literal token to be
2577     /// passed as a non-type template argument pack.
2578     LOLR_Template,
2579     /// \brief The lookup found an overload set of literal operator templates,
2580     /// which expect the character type and characters of the spelling of the
2581     /// string literal token to be passed as template arguments.
2582     LOLR_StringTemplate
2583   };
2584 
2585   SpecialMemberOverloadResult *LookupSpecialMember(CXXRecordDecl *D,
2586                                                    CXXSpecialMember SM,
2587                                                    bool ConstArg,
2588                                                    bool VolatileArg,
2589                                                    bool RValueThis,
2590                                                    bool ConstThis,
2591                                                    bool VolatileThis);
2592 
2593   typedef std::function<void(const TypoCorrection &)> TypoDiagnosticGenerator;
2594   typedef std::function<ExprResult(Sema &, TypoExpr *, TypoCorrection)>
2595       TypoRecoveryCallback;
2596 
2597 private:
2598   bool CppLookupName(LookupResult &R, Scope *S);
2599 
2600   struct TypoExprState {
2601     std::unique_ptr<TypoCorrectionConsumer> Consumer;
2602     TypoDiagnosticGenerator DiagHandler;
2603     TypoRecoveryCallback RecoveryHandler;
2604     TypoExprState();
2605     TypoExprState(TypoExprState&& other) LLVM_NOEXCEPT;
2606     TypoExprState& operator=(TypoExprState&& other) LLVM_NOEXCEPT;
2607   };
2608 
2609   /// \brief The set of unhandled TypoExprs and their associated state.
2610   llvm::MapVector<TypoExpr *, TypoExprState> DelayedTypos;
2611 
2612   /// \brief Creates a new TypoExpr AST node.
2613   TypoExpr *createDelayedTypo(std::unique_ptr<TypoCorrectionConsumer> TCC,
2614                               TypoDiagnosticGenerator TDG,
2615                               TypoRecoveryCallback TRC);
2616 
2617   // \brief The set of known/encountered (unique, canonicalized) NamespaceDecls.
2618   //
2619   // The boolean value will be true to indicate that the namespace was loaded
2620   // from an AST/PCH file, or false otherwise.
2621   llvm::MapVector<NamespaceDecl*, bool> KnownNamespaces;
2622 
2623   /// \brief Whether we have already loaded known namespaces from an extenal
2624   /// source.
2625   bool LoadedExternalKnownNamespaces;
2626 
2627   /// \brief Helper for CorrectTypo and CorrectTypoDelayed used to create and
2628   /// populate a new TypoCorrectionConsumer. Returns nullptr if typo correction
2629   /// should be skipped entirely.
2630   std::unique_ptr<TypoCorrectionConsumer>
2631   makeTypoCorrectionConsumer(const DeclarationNameInfo &Typo,
2632                              Sema::LookupNameKind LookupKind, Scope *S,
2633                              CXXScopeSpec *SS,
2634                              std::unique_ptr<CorrectionCandidateCallback> CCC,
2635                              DeclContext *MemberContext, bool EnteringContext,
2636                              const ObjCObjectPointerType *OPT,
2637                              bool ErrorRecovery);
2638 
2639 public:
2640   const TypoExprState &getTypoExprState(TypoExpr *TE) const;
2641 
2642   /// \brief Clears the state of the given TypoExpr.
2643   void clearDelayedTypo(TypoExpr *TE);
2644 
2645   /// \brief Look up a name, looking for a single declaration.  Return
2646   /// null if the results were absent, ambiguous, or overloaded.
2647   ///
2648   /// It is preferable to use the elaborated form and explicitly handle
2649   /// ambiguity and overloaded.
2650   NamedDecl *LookupSingleName(Scope *S, DeclarationName Name,
2651                               SourceLocation Loc,
2652                               LookupNameKind NameKind,
2653                               RedeclarationKind Redecl
2654                                 = NotForRedeclaration);
2655   bool LookupName(LookupResult &R, Scope *S,
2656                   bool AllowBuiltinCreation = false);
2657   bool LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
2658                            bool InUnqualifiedLookup = false);
2659   bool LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
2660                            CXXScopeSpec &SS);
2661   bool LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS,
2662                         bool AllowBuiltinCreation = false,
2663                         bool EnteringContext = false);
2664   ObjCProtocolDecl *LookupProtocol(IdentifierInfo *II, SourceLocation IdLoc,
2665                                    RedeclarationKind Redecl
2666                                      = NotForRedeclaration);
2667   bool LookupInSuper(LookupResult &R, CXXRecordDecl *Class);
2668 
2669   void LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S,
2670                                     QualType T1, QualType T2,
2671                                     UnresolvedSetImpl &Functions);
2672   void addOverloadedOperatorToUnresolvedSet(UnresolvedSetImpl &Functions,
2673                                             DeclAccessPair Operator,
2674                                             QualType T1, QualType T2);
2675 
2676   LabelDecl *LookupOrCreateLabel(IdentifierInfo *II, SourceLocation IdentLoc,
2677                                  SourceLocation GnuLabelLoc = SourceLocation());
2678 
2679   DeclContextLookupResult LookupConstructors(CXXRecordDecl *Class);
2680   CXXConstructorDecl *LookupDefaultConstructor(CXXRecordDecl *Class);
2681   CXXConstructorDecl *LookupCopyingConstructor(CXXRecordDecl *Class,
2682                                                unsigned Quals);
2683   CXXMethodDecl *LookupCopyingAssignment(CXXRecordDecl *Class, unsigned Quals,
2684                                          bool RValueThis, unsigned ThisQuals);
2685   CXXConstructorDecl *LookupMovingConstructor(CXXRecordDecl *Class,
2686                                               unsigned Quals);
2687   CXXMethodDecl *LookupMovingAssignment(CXXRecordDecl *Class, unsigned Quals,
2688                                         bool RValueThis, unsigned ThisQuals);
2689   CXXDestructorDecl *LookupDestructor(CXXRecordDecl *Class);
2690 
2691   bool checkLiteralOperatorId(const CXXScopeSpec &SS, const UnqualifiedId &Id);
2692   LiteralOperatorLookupResult LookupLiteralOperator(Scope *S, LookupResult &R,
2693                                                     ArrayRef<QualType> ArgTys,
2694                                                     bool AllowRaw,
2695                                                     bool AllowTemplate,
2696                                                     bool AllowStringTemplate);
2697   bool isKnownName(StringRef name);
2698 
2699   void ArgumentDependentLookup(DeclarationName Name, SourceLocation Loc,
2700                                ArrayRef<Expr *> Args, ADLResult &Functions);
2701 
2702   void LookupVisibleDecls(Scope *S, LookupNameKind Kind,
2703                           VisibleDeclConsumer &Consumer,
2704                           bool IncludeGlobalScope = true);
2705   void LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind,
2706                           VisibleDeclConsumer &Consumer,
2707                           bool IncludeGlobalScope = true);
2708 
2709   enum CorrectTypoKind {
2710     CTK_NonError,     // CorrectTypo used in a non error recovery situation.
2711     CTK_ErrorRecovery // CorrectTypo used in normal error recovery.
2712   };
2713 
2714   TypoCorrection CorrectTypo(const DeclarationNameInfo &Typo,
2715                              Sema::LookupNameKind LookupKind,
2716                              Scope *S, CXXScopeSpec *SS,
2717                              std::unique_ptr<CorrectionCandidateCallback> CCC,
2718                              CorrectTypoKind Mode,
2719                              DeclContext *MemberContext = nullptr,
2720                              bool EnteringContext = false,
2721                              const ObjCObjectPointerType *OPT = nullptr,
2722                              bool RecordFailure = true);
2723 
2724   TypoExpr *CorrectTypoDelayed(const DeclarationNameInfo &Typo,
2725                                Sema::LookupNameKind LookupKind, Scope *S,
2726                                CXXScopeSpec *SS,
2727                                std::unique_ptr<CorrectionCandidateCallback> CCC,
2728                                TypoDiagnosticGenerator TDG,
2729                                TypoRecoveryCallback TRC, CorrectTypoKind Mode,
2730                                DeclContext *MemberContext = nullptr,
2731                                bool EnteringContext = false,
2732                                const ObjCObjectPointerType *OPT = nullptr);
2733 
2734   ExprResult
2735   CorrectDelayedTyposInExpr(Expr *E,
2736                             llvm::function_ref<ExprResult(Expr *)> Filter =
2737                                 [](Expr *E) -> ExprResult { return E; });
2738 
2739   ExprResult
2740   CorrectDelayedTyposInExpr(ExprResult ER,
2741                             llvm::function_ref<ExprResult(Expr *)> Filter =
2742                                 [](Expr *E) -> ExprResult { return E; }) {
2743     return ER.isInvalid() ? ER : CorrectDelayedTyposInExpr(ER.get(), Filter);
2744   }
2745 
2746   void diagnoseTypo(const TypoCorrection &Correction,
2747                     const PartialDiagnostic &TypoDiag,
2748                     bool ErrorRecovery = true);
2749 
2750   void diagnoseTypo(const TypoCorrection &Correction,
2751                     const PartialDiagnostic &TypoDiag,
2752                     const PartialDiagnostic &PrevNote,
2753                     bool ErrorRecovery = true);
2754 
2755   void FindAssociatedClassesAndNamespaces(SourceLocation InstantiationLoc,
2756                                           ArrayRef<Expr *> Args,
2757                                    AssociatedNamespaceSet &AssociatedNamespaces,
2758                                    AssociatedClassSet &AssociatedClasses);
2759 
2760   void FilterLookupForScope(LookupResult &R, DeclContext *Ctx, Scope *S,
2761                             bool ConsiderLinkage, bool AllowInlineNamespace);
2762 
2763   void DiagnoseAmbiguousLookup(LookupResult &Result);
2764   //@}
2765 
2766   ObjCInterfaceDecl *getObjCInterfaceDecl(IdentifierInfo *&Id,
2767                                           SourceLocation IdLoc,
2768                                           bool TypoCorrection = false);
2769   NamedDecl *LazilyCreateBuiltin(IdentifierInfo *II, unsigned ID,
2770                                  Scope *S, bool ForRedeclaration,
2771                                  SourceLocation Loc);
2772   NamedDecl *ImplicitlyDefineFunction(SourceLocation Loc, IdentifierInfo &II,
2773                                       Scope *S);
2774   void AddKnownFunctionAttributes(FunctionDecl *FD);
2775 
2776   // More parsing and symbol table subroutines.
2777 
2778   void ProcessPragmaWeak(Scope *S, Decl *D);
2779   // Decl attributes - this routine is the top level dispatcher.
2780   void ProcessDeclAttributes(Scope *S, Decl *D, const Declarator &PD);
2781   void ProcessDeclAttributeList(Scope *S, Decl *D, const AttributeList *AL,
2782                                 bool IncludeCXX11Attributes = true);
2783   bool ProcessAccessDeclAttributeList(AccessSpecDecl *ASDecl,
2784                                       const AttributeList *AttrList);
2785 
2786   void checkUnusedDeclAttributes(Declarator &D);
2787 
2788   /// Determine if type T is a valid subject for a nonnull and similar
2789   /// attributes. By default, we look through references (the behavior used by
2790   /// nonnull), but if the second parameter is true, then we treat a reference
2791   /// type as valid.
2792   bool isValidPointerAttrType(QualType T, bool RefOkay = false);
2793 
2794   bool CheckRegparmAttr(const AttributeList &attr, unsigned &value);
2795   bool CheckCallingConvAttr(const AttributeList &attr, CallingConv &CC,
2796                             const FunctionDecl *FD = nullptr);
2797   bool CheckNoReturnAttr(const AttributeList &attr);
2798   bool checkStringLiteralArgumentAttr(const AttributeList &Attr,
2799                                       unsigned ArgNum, StringRef &Str,
2800                                       SourceLocation *ArgLocation = nullptr);
2801   bool checkMSInheritanceAttrOnDefinition(
2802       CXXRecordDecl *RD, SourceRange Range, bool BestCase,
2803       MSInheritanceAttr::Spelling SemanticSpelling);
2804 
2805   void CheckAlignasUnderalignment(Decl *D);
2806 
2807   /// Adjust the calling convention of a method to be the ABI default if it
2808   /// wasn't specified explicitly.  This handles method types formed from
2809   /// function type typedefs and typename template arguments.
2810   void adjustMemberFunctionCC(QualType &T, bool IsStatic);
2811 
2812   // Check if there is an explicit attribute, but only look through parens.
2813   // The intent is to look for an attribute on the current declarator, but not
2814   // one that came from a typedef.
2815   bool hasExplicitCallingConv(QualType &T);
2816 
2817   /// Get the outermost AttributedType node that sets a calling convention.
2818   /// Valid types should not have multiple attributes with different CCs.
2819   const AttributedType *getCallingConvAttributedType(QualType T) const;
2820 
2821   /// \brief Stmt attributes - this routine is the top level dispatcher.
2822   StmtResult ProcessStmtAttributes(Stmt *Stmt, AttributeList *Attrs,
2823                                    SourceRange Range);
2824 
2825   void WarnConflictingTypedMethods(ObjCMethodDecl *Method,
2826                                    ObjCMethodDecl *MethodDecl,
2827                                    bool IsProtocolMethodDecl);
2828 
2829   void CheckConflictingOverridingMethod(ObjCMethodDecl *Method,
2830                                    ObjCMethodDecl *Overridden,
2831                                    bool IsProtocolMethodDecl);
2832 
2833   /// WarnExactTypedMethods - This routine issues a warning if method
2834   /// implementation declaration matches exactly that of its declaration.
2835   void WarnExactTypedMethods(ObjCMethodDecl *Method,
2836                              ObjCMethodDecl *MethodDecl,
2837                              bool IsProtocolMethodDecl);
2838 
2839   typedef llvm::SmallPtrSet<Selector, 8> SelectorSet;
2840   typedef llvm::DenseMap<Selector, ObjCMethodDecl*> ProtocolsMethodsMap;
2841 
2842   /// CheckImplementationIvars - This routine checks if the instance variables
2843   /// listed in the implelementation match those listed in the interface.
2844   void CheckImplementationIvars(ObjCImplementationDecl *ImpDecl,
2845                                 ObjCIvarDecl **Fields, unsigned nIvars,
2846                                 SourceLocation Loc);
2847 
2848   /// ImplMethodsVsClassMethods - This is main routine to warn if any method
2849   /// remains unimplemented in the class or category \@implementation.
2850   void ImplMethodsVsClassMethods(Scope *S, ObjCImplDecl* IMPDecl,
2851                                  ObjCContainerDecl* IDecl,
2852                                  bool IncompleteImpl = false);
2853 
2854   /// DiagnoseUnimplementedProperties - This routine warns on those properties
2855   /// which must be implemented by this implementation.
2856   void DiagnoseUnimplementedProperties(Scope *S, ObjCImplDecl* IMPDecl,
2857                                        ObjCContainerDecl *CDecl,
2858                                        bool SynthesizeProperties);
2859 
2860   /// DefaultSynthesizeProperties - This routine default synthesizes all
2861   /// properties which must be synthesized in the class's \@implementation.
2862   void DefaultSynthesizeProperties (Scope *S, ObjCImplDecl* IMPDecl,
2863                                     ObjCInterfaceDecl *IDecl);
2864   void DefaultSynthesizeProperties(Scope *S, Decl *D);
2865 
2866   /// IvarBacksCurrentMethodAccessor - This routine returns 'true' if 'IV' is
2867   /// an ivar synthesized for 'Method' and 'Method' is a property accessor
2868   /// declared in class 'IFace'.
2869   bool IvarBacksCurrentMethodAccessor(ObjCInterfaceDecl *IFace,
2870                                       ObjCMethodDecl *Method, ObjCIvarDecl *IV);
2871 
2872   /// DiagnoseUnusedBackingIvarInAccessor - Issue an 'unused' warning if ivar which
2873   /// backs the property is not used in the property's accessor.
2874   void DiagnoseUnusedBackingIvarInAccessor(Scope *S,
2875                                            const ObjCImplementationDecl *ImplD);
2876 
2877   /// GetIvarBackingPropertyAccessor - If method is a property setter/getter and
2878   /// it property has a backing ivar, returns this ivar; otherwise, returns NULL.
2879   /// It also returns ivar's property on success.
2880   ObjCIvarDecl *GetIvarBackingPropertyAccessor(const ObjCMethodDecl *Method,
2881                                                const ObjCPropertyDecl *&PDecl) const;
2882 
2883   /// Called by ActOnProperty to handle \@property declarations in
2884   /// class extensions.
2885   ObjCPropertyDecl *HandlePropertyInClassExtension(Scope *S,
2886                       SourceLocation AtLoc,
2887                       SourceLocation LParenLoc,
2888                       FieldDeclarator &FD,
2889                       Selector GetterSel,
2890                       Selector SetterSel,
2891                       const bool isAssign,
2892                       const bool isReadWrite,
2893                       const unsigned Attributes,
2894                       const unsigned AttributesAsWritten,
2895                       bool *isOverridingProperty,
2896                       TypeSourceInfo *T,
2897                       tok::ObjCKeywordKind MethodImplKind);
2898 
2899   /// Called by ActOnProperty and HandlePropertyInClassExtension to
2900   /// handle creating the ObjcPropertyDecl for a category or \@interface.
2901   ObjCPropertyDecl *CreatePropertyDecl(Scope *S,
2902                                        ObjCContainerDecl *CDecl,
2903                                        SourceLocation AtLoc,
2904                                        SourceLocation LParenLoc,
2905                                        FieldDeclarator &FD,
2906                                        Selector GetterSel,
2907                                        Selector SetterSel,
2908                                        const bool isAssign,
2909                                        const bool isReadWrite,
2910                                        const unsigned Attributes,
2911                                        const unsigned AttributesAsWritten,
2912                                        TypeSourceInfo *T,
2913                                        tok::ObjCKeywordKind MethodImplKind,
2914                                        DeclContext *lexicalDC = nullptr);
2915 
2916   /// AtomicPropertySetterGetterRules - This routine enforces the rule (via
2917   /// warning) when atomic property has one but not the other user-declared
2918   /// setter or getter.
2919   void AtomicPropertySetterGetterRules(ObjCImplDecl* IMPDecl,
2920                                        ObjCContainerDecl* IDecl);
2921 
2922   void DiagnoseOwningPropertyGetterSynthesis(const ObjCImplementationDecl *D);
2923 
2924   void DiagnoseMissingDesignatedInitOverrides(
2925                                           const ObjCImplementationDecl *ImplD,
2926                                           const ObjCInterfaceDecl *IFD);
2927 
2928   void DiagnoseDuplicateIvars(ObjCInterfaceDecl *ID, ObjCInterfaceDecl *SID);
2929 
2930   enum MethodMatchStrategy {
2931     MMS_loose,
2932     MMS_strict
2933   };
2934 
2935   /// MatchTwoMethodDeclarations - Checks if two methods' type match and returns
2936   /// true, or false, accordingly.
2937   bool MatchTwoMethodDeclarations(const ObjCMethodDecl *Method,
2938                                   const ObjCMethodDecl *PrevMethod,
2939                                   MethodMatchStrategy strategy = MMS_strict);
2940 
2941   /// MatchAllMethodDeclarations - Check methods declaraed in interface or
2942   /// or protocol against those declared in their implementations.
2943   void MatchAllMethodDeclarations(const SelectorSet &InsMap,
2944                                   const SelectorSet &ClsMap,
2945                                   SelectorSet &InsMapSeen,
2946                                   SelectorSet &ClsMapSeen,
2947                                   ObjCImplDecl* IMPDecl,
2948                                   ObjCContainerDecl* IDecl,
2949                                   bool &IncompleteImpl,
2950                                   bool ImmediateClass,
2951                                   bool WarnCategoryMethodImpl=false);
2952 
2953   /// CheckCategoryVsClassMethodMatches - Checks that methods implemented in
2954   /// category matches with those implemented in its primary class and
2955   /// warns each time an exact match is found.
2956   void CheckCategoryVsClassMethodMatches(ObjCCategoryImplDecl *CatIMP);
2957 
2958   /// \brief Add the given method to the list of globally-known methods.
2959   void addMethodToGlobalList(ObjCMethodList *List, ObjCMethodDecl *Method);
2960 
2961 private:
2962   /// AddMethodToGlobalPool - Add an instance or factory method to the global
2963   /// pool. See descriptoin of AddInstanceMethodToGlobalPool.
2964   void AddMethodToGlobalPool(ObjCMethodDecl *Method, bool impl, bool instance);
2965 
2966   /// LookupMethodInGlobalPool - Returns the instance or factory method and
2967   /// optionally warns if there are multiple signatures.
2968   ObjCMethodDecl *LookupMethodInGlobalPool(Selector Sel, SourceRange R,
2969                                            bool receiverIdOrClass,
2970                                            bool warn, bool instance);
2971 
2972 public:
2973   /// \brief - Returns instance or factory methods in global method pool for
2974   /// given selector. If no such method or only one method found, function returns
2975   /// false; otherwise, it returns true
2976   bool CollectMultipleMethodsInGlobalPool(Selector Sel,
2977                                           SmallVectorImpl<ObjCMethodDecl*>& Methods,
2978                                           bool instance);
2979 
2980   bool AreMultipleMethodsInGlobalPool(Selector Sel,
2981                                       bool instance);
2982 
2983 private:
2984   /// \brief - Returns a selector which best matches given argument list or
2985   /// nullptr if none could be found
2986   ObjCMethodDecl *SelectBestMethod(Selector Sel, MultiExprArg Args,
2987                                    bool IsInstance);
2988 
2989 
2990   /// \brief Record the typo correction failure and return an empty correction.
2991   TypoCorrection FailedCorrection(IdentifierInfo *Typo, SourceLocation TypoLoc,
2992                                   bool RecordFailure = true) {
2993     if (RecordFailure)
2994       TypoCorrectionFailures[Typo].insert(TypoLoc);
2995     return TypoCorrection();
2996   }
2997 
2998 public:
2999   /// AddInstanceMethodToGlobalPool - All instance methods in a translation
3000   /// unit are added to a global pool. This allows us to efficiently associate
3001   /// a selector with a method declaraation for purposes of typechecking
3002   /// messages sent to "id" (where the class of the object is unknown).
3003   void AddInstanceMethodToGlobalPool(ObjCMethodDecl *Method, bool impl=false) {
3004     AddMethodToGlobalPool(Method, impl, /*instance*/true);
3005   }
3006 
3007   /// AddFactoryMethodToGlobalPool - Same as above, but for factory methods.
3008   void AddFactoryMethodToGlobalPool(ObjCMethodDecl *Method, bool impl=false) {
3009     AddMethodToGlobalPool(Method, impl, /*instance*/false);
3010   }
3011 
3012   /// AddAnyMethodToGlobalPool - Add any method, instance or factory to global
3013   /// pool.
3014   void AddAnyMethodToGlobalPool(Decl *D);
3015 
3016   /// LookupInstanceMethodInGlobalPool - Returns the method and warns if
3017   /// there are multiple signatures.
3018   ObjCMethodDecl *LookupInstanceMethodInGlobalPool(Selector Sel, SourceRange R,
3019                                                    bool receiverIdOrClass=false,
3020                                                    bool warn=true) {
3021     return LookupMethodInGlobalPool(Sel, R, receiverIdOrClass,
3022                                     warn, /*instance*/true);
3023   }
3024 
3025   /// LookupFactoryMethodInGlobalPool - Returns the method and warns if
3026   /// there are multiple signatures.
3027   ObjCMethodDecl *LookupFactoryMethodInGlobalPool(Selector Sel, SourceRange R,
3028                                                   bool receiverIdOrClass=false,
3029                                                   bool warn=true) {
3030     return LookupMethodInGlobalPool(Sel, R, receiverIdOrClass,
3031                                     warn, /*instance*/false);
3032   }
3033 
3034   const ObjCMethodDecl *SelectorsForTypoCorrection(Selector Sel,
3035                               QualType ObjectType=QualType());
3036   /// LookupImplementedMethodInGlobalPool - Returns the method which has an
3037   /// implementation.
3038   ObjCMethodDecl *LookupImplementedMethodInGlobalPool(Selector Sel);
3039 
3040   /// CollectIvarsToConstructOrDestruct - Collect those ivars which require
3041   /// initialization.
3042   void CollectIvarsToConstructOrDestruct(ObjCInterfaceDecl *OI,
3043                                   SmallVectorImpl<ObjCIvarDecl*> &Ivars);
3044 
3045   //===--------------------------------------------------------------------===//
3046   // Statement Parsing Callbacks: SemaStmt.cpp.
3047 public:
3048   class FullExprArg {
3049   public:
FullExprArg(Sema & actions)3050     FullExprArg(Sema &actions) : E(nullptr) { }
3051 
release()3052     ExprResult release() {
3053       return E;
3054     }
3055 
get()3056     Expr *get() const { return E; }
3057 
3058     Expr *operator->() {
3059       return E;
3060     }
3061 
3062   private:
3063     // FIXME: No need to make the entire Sema class a friend when it's just
3064     // Sema::MakeFullExpr that needs access to the constructor below.
3065     friend class Sema;
3066 
FullExprArg(Expr * expr)3067     explicit FullExprArg(Expr *expr) : E(expr) {}
3068 
3069     Expr *E;
3070   };
3071 
MakeFullExpr(Expr * Arg)3072   FullExprArg MakeFullExpr(Expr *Arg) {
3073     return MakeFullExpr(Arg, Arg ? Arg->getExprLoc() : SourceLocation());
3074   }
MakeFullExpr(Expr * Arg,SourceLocation CC)3075   FullExprArg MakeFullExpr(Expr *Arg, SourceLocation CC) {
3076     return FullExprArg(ActOnFinishFullExpr(Arg, CC).get());
3077   }
MakeFullDiscardedValueExpr(Expr * Arg)3078   FullExprArg MakeFullDiscardedValueExpr(Expr *Arg) {
3079     ExprResult FE =
3080       ActOnFinishFullExpr(Arg, Arg ? Arg->getExprLoc() : SourceLocation(),
3081                           /*DiscardedValue*/ true);
3082     return FullExprArg(FE.get());
3083   }
3084 
3085   StmtResult ActOnExprStmt(ExprResult Arg);
3086   StmtResult ActOnExprStmtError();
3087 
3088   StmtResult ActOnNullStmt(SourceLocation SemiLoc,
3089                            bool HasLeadingEmptyMacro = false);
3090 
3091   void ActOnStartOfCompoundStmt();
3092   void ActOnFinishOfCompoundStmt();
3093   StmtResult ActOnCompoundStmt(SourceLocation L, SourceLocation R,
3094                                ArrayRef<Stmt *> Elts, bool isStmtExpr);
3095 
3096   /// \brief A RAII object to enter scope of a compound statement.
3097   class CompoundScopeRAII {
3098   public:
CompoundScopeRAII(Sema & S)3099     CompoundScopeRAII(Sema &S): S(S) {
3100       S.ActOnStartOfCompoundStmt();
3101     }
3102 
~CompoundScopeRAII()3103     ~CompoundScopeRAII() {
3104       S.ActOnFinishOfCompoundStmt();
3105     }
3106 
3107   private:
3108     Sema &S;
3109   };
3110 
3111   /// An RAII helper that pops function a function scope on exit.
3112   struct FunctionScopeRAII {
3113     Sema &S;
3114     bool Active;
FunctionScopeRAIIFunctionScopeRAII3115     FunctionScopeRAII(Sema &S) : S(S), Active(true) {}
~FunctionScopeRAIIFunctionScopeRAII3116     ~FunctionScopeRAII() {
3117       if (Active)
3118         S.PopFunctionScopeInfo();
3119     }
disableFunctionScopeRAII3120     void disable() { Active = false; }
3121   };
3122 
3123   StmtResult ActOnDeclStmt(DeclGroupPtrTy Decl,
3124                                    SourceLocation StartLoc,
3125                                    SourceLocation EndLoc);
3126   void ActOnForEachDeclStmt(DeclGroupPtrTy Decl);
3127   StmtResult ActOnForEachLValueExpr(Expr *E);
3128   StmtResult ActOnCaseStmt(SourceLocation CaseLoc, Expr *LHSVal,
3129                                    SourceLocation DotDotDotLoc, Expr *RHSVal,
3130                                    SourceLocation ColonLoc);
3131   void ActOnCaseStmtBody(Stmt *CaseStmt, Stmt *SubStmt);
3132 
3133   StmtResult ActOnDefaultStmt(SourceLocation DefaultLoc,
3134                                       SourceLocation ColonLoc,
3135                                       Stmt *SubStmt, Scope *CurScope);
3136   StmtResult ActOnLabelStmt(SourceLocation IdentLoc, LabelDecl *TheDecl,
3137                             SourceLocation ColonLoc, Stmt *SubStmt);
3138 
3139   StmtResult ActOnAttributedStmt(SourceLocation AttrLoc,
3140                                  ArrayRef<const Attr*> Attrs,
3141                                  Stmt *SubStmt);
3142 
3143   StmtResult ActOnIfStmt(SourceLocation IfLoc,
3144                          FullExprArg CondVal, Decl *CondVar,
3145                          Stmt *ThenVal,
3146                          SourceLocation ElseLoc, Stmt *ElseVal);
3147   StmtResult ActOnStartOfSwitchStmt(SourceLocation SwitchLoc,
3148                                             Expr *Cond,
3149                                             Decl *CondVar);
3150   StmtResult ActOnFinishSwitchStmt(SourceLocation SwitchLoc,
3151                                            Stmt *Switch, Stmt *Body);
3152   StmtResult ActOnWhileStmt(SourceLocation WhileLoc,
3153                             FullExprArg Cond,
3154                             Decl *CondVar, Stmt *Body);
3155   StmtResult ActOnDoStmt(SourceLocation DoLoc, Stmt *Body,
3156                                  SourceLocation WhileLoc,
3157                                  SourceLocation CondLParen, Expr *Cond,
3158                                  SourceLocation CondRParen);
3159 
3160   StmtResult ActOnForStmt(SourceLocation ForLoc,
3161                           SourceLocation LParenLoc,
3162                           Stmt *First, FullExprArg Second,
3163                           Decl *SecondVar,
3164                           FullExprArg Third,
3165                           SourceLocation RParenLoc,
3166                           Stmt *Body);
3167   ExprResult CheckObjCForCollectionOperand(SourceLocation forLoc,
3168                                            Expr *collection);
3169   StmtResult ActOnObjCForCollectionStmt(SourceLocation ForColLoc,
3170                                         Stmt *First, Expr *collection,
3171                                         SourceLocation RParenLoc);
3172   StmtResult FinishObjCForCollectionStmt(Stmt *ForCollection, Stmt *Body);
3173 
3174   enum BuildForRangeKind {
3175     /// Initial building of a for-range statement.
3176     BFRK_Build,
3177     /// Instantiation or recovery rebuild of a for-range statement. Don't
3178     /// attempt any typo-correction.
3179     BFRK_Rebuild,
3180     /// Determining whether a for-range statement could be built. Avoid any
3181     /// unnecessary or irreversible actions.
3182     BFRK_Check
3183   };
3184 
3185   StmtResult ActOnCXXForRangeStmt(SourceLocation ForLoc, Stmt *LoopVar,
3186                                   SourceLocation ColonLoc, Expr *Collection,
3187                                   SourceLocation RParenLoc,
3188                                   BuildForRangeKind Kind);
3189   StmtResult BuildCXXForRangeStmt(SourceLocation ForLoc,
3190                                   SourceLocation ColonLoc,
3191                                   Stmt *RangeDecl, Stmt *BeginEndDecl,
3192                                   Expr *Cond, Expr *Inc,
3193                                   Stmt *LoopVarDecl,
3194                                   SourceLocation RParenLoc,
3195                                   BuildForRangeKind Kind);
3196   StmtResult FinishCXXForRangeStmt(Stmt *ForRange, Stmt *Body);
3197 
3198   StmtResult ActOnGotoStmt(SourceLocation GotoLoc,
3199                            SourceLocation LabelLoc,
3200                            LabelDecl *TheDecl);
3201   StmtResult ActOnIndirectGotoStmt(SourceLocation GotoLoc,
3202                                    SourceLocation StarLoc,
3203                                    Expr *DestExp);
3204   StmtResult ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope);
3205   StmtResult ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope);
3206 
3207   void ActOnCapturedRegionStart(SourceLocation Loc, Scope *CurScope,
3208                                 CapturedRegionKind Kind, unsigned NumParams);
3209   typedef std::pair<StringRef, QualType> CapturedParamNameType;
3210   void ActOnCapturedRegionStart(SourceLocation Loc, Scope *CurScope,
3211                                 CapturedRegionKind Kind,
3212                                 ArrayRef<CapturedParamNameType> Params);
3213   StmtResult ActOnCapturedRegionEnd(Stmt *S);
3214   void ActOnCapturedRegionError();
3215   RecordDecl *CreateCapturedStmtRecordDecl(CapturedDecl *&CD,
3216                                            SourceLocation Loc,
3217                                            unsigned NumParams);
3218   VarDecl *getCopyElisionCandidate(QualType ReturnType, Expr *E,
3219                                    bool AllowFunctionParameters);
3220   bool isCopyElisionCandidate(QualType ReturnType, const VarDecl *VD,
3221                               bool AllowFunctionParameters);
3222 
3223   StmtResult ActOnReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp,
3224                              Scope *CurScope);
3225   StmtResult BuildReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp);
3226   StmtResult ActOnCapScopeReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp);
3227 
3228   StmtResult ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
3229                              bool IsVolatile, unsigned NumOutputs,
3230                              unsigned NumInputs, IdentifierInfo **Names,
3231                              MultiExprArg Constraints, MultiExprArg Exprs,
3232                              Expr *AsmString, MultiExprArg Clobbers,
3233                              SourceLocation RParenLoc);
3234 
3235   ExprResult LookupInlineAsmIdentifier(CXXScopeSpec &SS,
3236                                        SourceLocation TemplateKWLoc,
3237                                        UnqualifiedId &Id,
3238                                        llvm::InlineAsmIdentifierInfo &Info,
3239                                        bool IsUnevaluatedContext);
3240   bool LookupInlineAsmField(StringRef Base, StringRef Member,
3241                             unsigned &Offset, SourceLocation AsmLoc);
3242   StmtResult ActOnMSAsmStmt(SourceLocation AsmLoc, SourceLocation LBraceLoc,
3243                             ArrayRef<Token> AsmToks,
3244                             StringRef AsmString,
3245                             unsigned NumOutputs, unsigned NumInputs,
3246                             ArrayRef<StringRef> Constraints,
3247                             ArrayRef<StringRef> Clobbers,
3248                             ArrayRef<Expr*> Exprs,
3249                             SourceLocation EndLoc);
3250   LabelDecl *GetOrCreateMSAsmLabel(StringRef ExternalLabelName,
3251                                    SourceLocation Location,
3252                                    bool AlwaysCreate);
3253 
3254   VarDecl *BuildObjCExceptionDecl(TypeSourceInfo *TInfo, QualType ExceptionType,
3255                                   SourceLocation StartLoc,
3256                                   SourceLocation IdLoc, IdentifierInfo *Id,
3257                                   bool Invalid = false);
3258 
3259   Decl *ActOnObjCExceptionDecl(Scope *S, Declarator &D);
3260 
3261   StmtResult ActOnObjCAtCatchStmt(SourceLocation AtLoc, SourceLocation RParen,
3262                                   Decl *Parm, Stmt *Body);
3263 
3264   StmtResult ActOnObjCAtFinallyStmt(SourceLocation AtLoc, Stmt *Body);
3265 
3266   StmtResult ActOnObjCAtTryStmt(SourceLocation AtLoc, Stmt *Try,
3267                                 MultiStmtArg Catch, Stmt *Finally);
3268 
3269   StmtResult BuildObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw);
3270   StmtResult ActOnObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw,
3271                                   Scope *CurScope);
3272   ExprResult ActOnObjCAtSynchronizedOperand(SourceLocation atLoc,
3273                                             Expr *operand);
3274   StmtResult ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc,
3275                                          Expr *SynchExpr,
3276                                          Stmt *SynchBody);
3277 
3278   StmtResult ActOnObjCAutoreleasePoolStmt(SourceLocation AtLoc, Stmt *Body);
3279 
3280   VarDecl *BuildExceptionDeclaration(Scope *S, TypeSourceInfo *TInfo,
3281                                      SourceLocation StartLoc,
3282                                      SourceLocation IdLoc,
3283                                      IdentifierInfo *Id);
3284 
3285   Decl *ActOnExceptionDeclarator(Scope *S, Declarator &D);
3286 
3287   StmtResult ActOnCXXCatchBlock(SourceLocation CatchLoc,
3288                                 Decl *ExDecl, Stmt *HandlerBlock);
3289   StmtResult ActOnCXXTryBlock(SourceLocation TryLoc, Stmt *TryBlock,
3290                               ArrayRef<Stmt *> Handlers);
3291 
3292   StmtResult ActOnSEHTryBlock(bool IsCXXTry, // try (true) or __try (false) ?
3293                               SourceLocation TryLoc, Stmt *TryBlock,
3294                               Stmt *Handler);
3295   StmtResult ActOnSEHExceptBlock(SourceLocation Loc,
3296                                  Expr *FilterExpr,
3297                                  Stmt *Block);
3298   StmtResult ActOnSEHFinallyBlock(SourceLocation Loc, Stmt *Block);
3299   StmtResult ActOnSEHLeaveStmt(SourceLocation Loc, Scope *CurScope);
3300 
3301   void DiagnoseReturnInConstructorExceptionHandler(CXXTryStmt *TryBlock);
3302 
3303   bool ShouldWarnIfUnusedFileScopedDecl(const DeclaratorDecl *D) const;
3304 
3305   /// \brief If it's a file scoped decl that must warn if not used, keep track
3306   /// of it.
3307   void MarkUnusedFileScopedDecl(const DeclaratorDecl *D);
3308 
3309   /// DiagnoseUnusedExprResult - If the statement passed in is an expression
3310   /// whose result is unused, warn.
3311   void DiagnoseUnusedExprResult(const Stmt *S);
3312   void DiagnoseUnusedNestedTypedefs(const RecordDecl *D);
3313   void DiagnoseUnusedDecl(const NamedDecl *ND);
3314 
3315   /// Emit \p DiagID if statement located on \p StmtLoc has a suspicious null
3316   /// statement as a \p Body, and it is located on the same line.
3317   ///
3318   /// This helps prevent bugs due to typos, such as:
3319   ///     if (condition);
3320   ///       do_stuff();
3321   void DiagnoseEmptyStmtBody(SourceLocation StmtLoc,
3322                              const Stmt *Body,
3323                              unsigned DiagID);
3324 
3325   /// Warn if a for/while loop statement \p S, which is followed by
3326   /// \p PossibleBody, has a suspicious null statement as a body.
3327   void DiagnoseEmptyLoopBody(const Stmt *S,
3328                              const Stmt *PossibleBody);
3329 
3330   /// Warn if a value is moved to itself.
3331   void DiagnoseSelfMove(const Expr *LHSExpr, const Expr *RHSExpr,
3332                         SourceLocation OpLoc);
3333 
PushParsingDeclaration(sema::DelayedDiagnosticPool & pool)3334   ParsingDeclState PushParsingDeclaration(sema::DelayedDiagnosticPool &pool) {
3335     return DelayedDiagnostics.push(pool);
3336   }
3337   void PopParsingDeclaration(ParsingDeclState state, Decl *decl);
3338 
3339   typedef ProcessingContextState ParsingClassState;
PushParsingClass()3340   ParsingClassState PushParsingClass() {
3341     return DelayedDiagnostics.pushUndelayed();
3342   }
PopParsingClass(ParsingClassState state)3343   void PopParsingClass(ParsingClassState state) {
3344     DelayedDiagnostics.popUndelayed(state);
3345   }
3346 
3347   void redelayDiagnostics(sema::DelayedDiagnosticPool &pool);
3348 
3349   enum AvailabilityDiagnostic { AD_Deprecation, AD_Unavailable };
3350 
3351   void EmitAvailabilityWarning(AvailabilityDiagnostic AD,
3352                                NamedDecl *D, StringRef Message,
3353                                SourceLocation Loc,
3354                                const ObjCInterfaceDecl *UnknownObjCClass,
3355                                const ObjCPropertyDecl  *ObjCProperty,
3356                                bool ObjCPropertyAccess);
3357 
3358   bool makeUnavailableInSystemHeader(SourceLocation loc,
3359                                      StringRef message);
3360 
3361   //===--------------------------------------------------------------------===//
3362   // Expression Parsing Callbacks: SemaExpr.cpp.
3363 
3364   bool CanUseDecl(NamedDecl *D);
3365   bool DiagnoseUseOfDecl(NamedDecl *D, SourceLocation Loc,
3366                          const ObjCInterfaceDecl *UnknownObjCClass=nullptr,
3367                          bool ObjCPropertyAccess=false);
3368   void NoteDeletedFunction(FunctionDecl *FD);
3369   std::string getDeletedOrUnavailableSuffix(const FunctionDecl *FD);
3370   bool DiagnosePropertyAccessorMismatch(ObjCPropertyDecl *PD,
3371                                         ObjCMethodDecl *Getter,
3372                                         SourceLocation Loc);
3373   void DiagnoseSentinelCalls(NamedDecl *D, SourceLocation Loc,
3374                              ArrayRef<Expr *> Args);
3375 
3376   void PushExpressionEvaluationContext(ExpressionEvaluationContext NewContext,
3377                                        Decl *LambdaContextDecl = nullptr,
3378                                        bool IsDecltype = false);
3379   enum ReuseLambdaContextDecl_t { ReuseLambdaContextDecl };
3380   void PushExpressionEvaluationContext(ExpressionEvaluationContext NewContext,
3381                                        ReuseLambdaContextDecl_t,
3382                                        bool IsDecltype = false);
3383   void PopExpressionEvaluationContext();
3384 
3385   void DiscardCleanupsInEvaluationContext();
3386 
3387   ExprResult TransformToPotentiallyEvaluated(Expr *E);
3388   ExprResult HandleExprEvaluationContextForTypeof(Expr *E);
3389 
3390   ExprResult ActOnConstantExpression(ExprResult Res);
3391 
3392   // Functions for marking a declaration referenced.  These functions also
3393   // contain the relevant logic for marking if a reference to a function or
3394   // variable is an odr-use (in the C++11 sense).  There are separate variants
3395   // for expressions referring to a decl; these exist because odr-use marking
3396   // needs to be delayed for some constant variables when we build one of the
3397   // named expressions.
3398   void MarkAnyDeclReferenced(SourceLocation Loc, Decl *D, bool OdrUse);
3399   void MarkFunctionReferenced(SourceLocation Loc, FunctionDecl *Func,
3400                               bool OdrUse = true);
3401   void MarkVariableReferenced(SourceLocation Loc, VarDecl *Var);
3402   void MarkDeclRefReferenced(DeclRefExpr *E);
3403   void MarkMemberReferenced(MemberExpr *E);
3404 
3405   void UpdateMarkingForLValueToRValue(Expr *E);
3406   void CleanupVarDeclMarking();
3407 
3408   enum TryCaptureKind {
3409     TryCapture_Implicit, TryCapture_ExplicitByVal, TryCapture_ExplicitByRef
3410   };
3411 
3412   /// \brief Try to capture the given variable.
3413   ///
3414   /// \param Var The variable to capture.
3415   ///
3416   /// \param Loc The location at which the capture occurs.
3417   ///
3418   /// \param Kind The kind of capture, which may be implicit (for either a
3419   /// block or a lambda), or explicit by-value or by-reference (for a lambda).
3420   ///
3421   /// \param EllipsisLoc The location of the ellipsis, if one is provided in
3422   /// an explicit lambda capture.
3423   ///
3424   /// \param BuildAndDiagnose Whether we are actually supposed to add the
3425   /// captures or diagnose errors. If false, this routine merely check whether
3426   /// the capture can occur without performing the capture itself or complaining
3427   /// if the variable cannot be captured.
3428   ///
3429   /// \param CaptureType Will be set to the type of the field used to capture
3430   /// this variable in the innermost block or lambda. Only valid when the
3431   /// variable can be captured.
3432   ///
3433   /// \param DeclRefType Will be set to the type of a reference to the capture
3434   /// from within the current scope. Only valid when the variable can be
3435   /// captured.
3436   ///
3437   /// \param FunctionScopeIndexToStopAt If non-null, it points to the index
3438   /// of the FunctionScopeInfo stack beyond which we do not attempt to capture.
3439   /// This is useful when enclosing lambdas must speculatively capture
3440   /// variables that may or may not be used in certain specializations of
3441   /// a nested generic lambda.
3442   ///
3443   /// \returns true if an error occurred (i.e., the variable cannot be
3444   /// captured) and false if the capture succeeded.
3445   bool tryCaptureVariable(VarDecl *Var, SourceLocation Loc, TryCaptureKind Kind,
3446                           SourceLocation EllipsisLoc, bool BuildAndDiagnose,
3447                           QualType &CaptureType,
3448                           QualType &DeclRefType,
3449                           const unsigned *const FunctionScopeIndexToStopAt);
3450 
3451   /// \brief Try to capture the given variable.
3452   bool tryCaptureVariable(VarDecl *Var, SourceLocation Loc,
3453                           TryCaptureKind Kind = TryCapture_Implicit,
3454                           SourceLocation EllipsisLoc = SourceLocation());
3455 
3456   /// \brief Checks if the variable must be captured.
3457   bool NeedToCaptureVariable(VarDecl *Var, SourceLocation Loc);
3458 
3459   /// \brief Given a variable, determine the type that a reference to that
3460   /// variable will have in the given scope.
3461   QualType getCapturedDeclRefType(VarDecl *Var, SourceLocation Loc);
3462 
3463   void MarkDeclarationsReferencedInType(SourceLocation Loc, QualType T);
3464   void MarkDeclarationsReferencedInExpr(Expr *E,
3465                                         bool SkipLocalVariables = false);
3466 
3467   /// \brief Try to recover by turning the given expression into a
3468   /// call.  Returns true if recovery was attempted or an error was
3469   /// emitted; this may also leave the ExprResult invalid.
3470   bool tryToRecoverWithCall(ExprResult &E, const PartialDiagnostic &PD,
3471                             bool ForceComplain = false,
3472                             bool (*IsPlausibleResult)(QualType) = nullptr);
3473 
3474   /// \brief Figure out if an expression could be turned into a call.
3475   bool tryExprAsCall(Expr &E, QualType &ZeroArgCallReturnTy,
3476                      UnresolvedSetImpl &NonTemplateOverloads);
3477 
3478   /// \brief Conditionally issue a diagnostic based on the current
3479   /// evaluation context.
3480   ///
3481   /// \param Statement If Statement is non-null, delay reporting the
3482   /// diagnostic until the function body is parsed, and then do a basic
3483   /// reachability analysis to determine if the statement is reachable.
3484   /// If it is unreachable, the diagnostic will not be emitted.
3485   bool DiagRuntimeBehavior(SourceLocation Loc, const Stmt *Statement,
3486                            const PartialDiagnostic &PD);
3487 
3488   // Primary Expressions.
3489   SourceRange getExprRange(Expr *E) const;
3490 
3491   ExprResult ActOnIdExpression(
3492       Scope *S, CXXScopeSpec &SS, SourceLocation TemplateKWLoc,
3493       UnqualifiedId &Id, bool HasTrailingLParen, bool IsAddressOfOperand,
3494       std::unique_ptr<CorrectionCandidateCallback> CCC = nullptr,
3495       bool IsInlineAsmIdentifier = false, Token *KeywordReplacement = nullptr);
3496 
3497   void DecomposeUnqualifiedId(const UnqualifiedId &Id,
3498                               TemplateArgumentListInfo &Buffer,
3499                               DeclarationNameInfo &NameInfo,
3500                               const TemplateArgumentListInfo *&TemplateArgs);
3501 
3502   bool
3503   DiagnoseEmptyLookup(Scope *S, CXXScopeSpec &SS, LookupResult &R,
3504                       std::unique_ptr<CorrectionCandidateCallback> CCC,
3505                       TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr,
3506                       ArrayRef<Expr *> Args = None, TypoExpr **Out = nullptr);
3507 
3508   ExprResult LookupInObjCMethod(LookupResult &LookUp, Scope *S,
3509                                 IdentifierInfo *II,
3510                                 bool AllowBuiltinCreation=false);
3511 
3512   ExprResult ActOnDependentIdExpression(const CXXScopeSpec &SS,
3513                                         SourceLocation TemplateKWLoc,
3514                                         const DeclarationNameInfo &NameInfo,
3515                                         bool isAddressOfOperand,
3516                                 const TemplateArgumentListInfo *TemplateArgs);
3517 
3518   ExprResult BuildDeclRefExpr(ValueDecl *D, QualType Ty,
3519                               ExprValueKind VK,
3520                               SourceLocation Loc,
3521                               const CXXScopeSpec *SS = nullptr);
3522   ExprResult
3523   BuildDeclRefExpr(ValueDecl *D, QualType Ty, ExprValueKind VK,
3524                    const DeclarationNameInfo &NameInfo,
3525                    const CXXScopeSpec *SS = nullptr,
3526                    NamedDecl *FoundD = nullptr,
3527                    const TemplateArgumentListInfo *TemplateArgs = nullptr);
3528   ExprResult
3529   BuildAnonymousStructUnionMemberReference(
3530       const CXXScopeSpec &SS,
3531       SourceLocation nameLoc,
3532       IndirectFieldDecl *indirectField,
3533       DeclAccessPair FoundDecl = DeclAccessPair::make(nullptr, AS_none),
3534       Expr *baseObjectExpr = nullptr,
3535       SourceLocation opLoc = SourceLocation());
3536 
3537   ExprResult BuildPossibleImplicitMemberExpr(const CXXScopeSpec &SS,
3538                                              SourceLocation TemplateKWLoc,
3539                                              LookupResult &R,
3540                                 const TemplateArgumentListInfo *TemplateArgs);
3541   ExprResult BuildImplicitMemberExpr(const CXXScopeSpec &SS,
3542                                      SourceLocation TemplateKWLoc,
3543                                      LookupResult &R,
3544                                 const TemplateArgumentListInfo *TemplateArgs,
3545                                      bool IsDefiniteInstance);
3546   bool UseArgumentDependentLookup(const CXXScopeSpec &SS,
3547                                   const LookupResult &R,
3548                                   bool HasTrailingLParen);
3549 
3550   ExprResult BuildQualifiedDeclarationNameExpr(
3551       CXXScopeSpec &SS, const DeclarationNameInfo &NameInfo,
3552       bool IsAddressOfOperand, TypeSourceInfo **RecoveryTSI = nullptr);
3553 
3554   ExprResult BuildDependentDeclRefExpr(const CXXScopeSpec &SS,
3555                                        SourceLocation TemplateKWLoc,
3556                                 const DeclarationNameInfo &NameInfo,
3557                                 const TemplateArgumentListInfo *TemplateArgs);
3558 
3559   ExprResult BuildDeclarationNameExpr(const CXXScopeSpec &SS,
3560                                       LookupResult &R,
3561                                       bool NeedsADL,
3562                                       bool AcceptInvalidDecl = false);
3563   ExprResult BuildDeclarationNameExpr(
3564       const CXXScopeSpec &SS, const DeclarationNameInfo &NameInfo, NamedDecl *D,
3565       NamedDecl *FoundD = nullptr,
3566       const TemplateArgumentListInfo *TemplateArgs = nullptr,
3567       bool AcceptInvalidDecl = false);
3568 
3569   ExprResult BuildLiteralOperatorCall(LookupResult &R,
3570                       DeclarationNameInfo &SuffixInfo,
3571                       ArrayRef<Expr *> Args,
3572                       SourceLocation LitEndLoc,
3573                       TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr);
3574 
3575   ExprResult BuildPredefinedExpr(SourceLocation Loc,
3576                                  PredefinedExpr::IdentType IT);
3577   ExprResult ActOnPredefinedExpr(SourceLocation Loc, tok::TokenKind Kind);
3578   ExprResult ActOnIntegerConstant(SourceLocation Loc, uint64_t Val);
3579 
3580   bool CheckLoopHintExpr(Expr *E, SourceLocation Loc);
3581 
3582   ExprResult ActOnNumericConstant(const Token &Tok, Scope *UDLScope = nullptr);
3583   ExprResult ActOnCharacterConstant(const Token &Tok,
3584                                     Scope *UDLScope = nullptr);
3585   ExprResult ActOnParenExpr(SourceLocation L, SourceLocation R, Expr *E);
3586   ExprResult ActOnParenListExpr(SourceLocation L,
3587                                 SourceLocation R,
3588                                 MultiExprArg Val);
3589 
3590   /// ActOnStringLiteral - The specified tokens were lexed as pasted string
3591   /// fragments (e.g. "foo" "bar" L"baz").
3592   ExprResult ActOnStringLiteral(ArrayRef<Token> StringToks,
3593                                 Scope *UDLScope = nullptr);
3594 
3595   ExprResult ActOnGenericSelectionExpr(SourceLocation KeyLoc,
3596                                        SourceLocation DefaultLoc,
3597                                        SourceLocation RParenLoc,
3598                                        Expr *ControllingExpr,
3599                                        ArrayRef<ParsedType> ArgTypes,
3600                                        ArrayRef<Expr *> ArgExprs);
3601   ExprResult CreateGenericSelectionExpr(SourceLocation KeyLoc,
3602                                         SourceLocation DefaultLoc,
3603                                         SourceLocation RParenLoc,
3604                                         Expr *ControllingExpr,
3605                                         ArrayRef<TypeSourceInfo *> Types,
3606                                         ArrayRef<Expr *> Exprs);
3607 
3608   // Binary/Unary Operators.  'Tok' is the token for the operator.
3609   ExprResult CreateBuiltinUnaryOp(SourceLocation OpLoc, UnaryOperatorKind Opc,
3610                                   Expr *InputExpr);
3611   ExprResult BuildUnaryOp(Scope *S, SourceLocation OpLoc,
3612                           UnaryOperatorKind Opc, Expr *Input);
3613   ExprResult ActOnUnaryOp(Scope *S, SourceLocation OpLoc,
3614                           tok::TokenKind Op, Expr *Input);
3615 
3616   QualType CheckAddressOfOperand(ExprResult &Operand, SourceLocation OpLoc);
3617 
3618   ExprResult CreateUnaryExprOrTypeTraitExpr(TypeSourceInfo *TInfo,
3619                                             SourceLocation OpLoc,
3620                                             UnaryExprOrTypeTrait ExprKind,
3621                                             SourceRange R);
3622   ExprResult CreateUnaryExprOrTypeTraitExpr(Expr *E, SourceLocation OpLoc,
3623                                             UnaryExprOrTypeTrait ExprKind);
3624   ExprResult
3625     ActOnUnaryExprOrTypeTraitExpr(SourceLocation OpLoc,
3626                                   UnaryExprOrTypeTrait ExprKind,
3627                                   bool IsType, void *TyOrEx,
3628                                   const SourceRange &ArgRange);
3629 
3630   ExprResult CheckPlaceholderExpr(Expr *E);
3631   bool CheckVecStepExpr(Expr *E);
3632 
3633   bool CheckUnaryExprOrTypeTraitOperand(Expr *E, UnaryExprOrTypeTrait ExprKind);
3634   bool CheckUnaryExprOrTypeTraitOperand(QualType ExprType, SourceLocation OpLoc,
3635                                         SourceRange ExprRange,
3636                                         UnaryExprOrTypeTrait ExprKind);
3637   ExprResult ActOnSizeofParameterPackExpr(Scope *S,
3638                                           SourceLocation OpLoc,
3639                                           IdentifierInfo &Name,
3640                                           SourceLocation NameLoc,
3641                                           SourceLocation RParenLoc);
3642   ExprResult ActOnPostfixUnaryOp(Scope *S, SourceLocation OpLoc,
3643                                  tok::TokenKind Kind, Expr *Input);
3644 
3645   ExprResult ActOnArraySubscriptExpr(Scope *S, Expr *Base, SourceLocation LLoc,
3646                                      Expr *Idx, SourceLocation RLoc);
3647   ExprResult CreateBuiltinArraySubscriptExpr(Expr *Base, SourceLocation LLoc,
3648                                              Expr *Idx, SourceLocation RLoc);
3649 
3650   // This struct is for use by ActOnMemberAccess to allow
3651   // BuildMemberReferenceExpr to be able to reinvoke ActOnMemberAccess after
3652   // changing the access operator from a '.' to a '->' (to see if that is the
3653   // change needed to fix an error about an unknown member, e.g. when the class
3654   // defines a custom operator->).
3655   struct ActOnMemberAccessExtraArgs {
3656     Scope *S;
3657     UnqualifiedId &Id;
3658     Decl *ObjCImpDecl;
3659     bool HasTrailingLParen;
3660   };
3661 
3662   ExprResult BuildMemberReferenceExpr(
3663       Expr *Base, QualType BaseType, SourceLocation OpLoc, bool IsArrow,
3664       CXXScopeSpec &SS, SourceLocation TemplateKWLoc,
3665       NamedDecl *FirstQualifierInScope, const DeclarationNameInfo &NameInfo,
3666       const TemplateArgumentListInfo *TemplateArgs,
3667       ActOnMemberAccessExtraArgs *ExtraArgs = nullptr);
3668 
3669   ExprResult
3670   BuildMemberReferenceExpr(Expr *Base, QualType BaseType, SourceLocation OpLoc,
3671                            bool IsArrow, const CXXScopeSpec &SS,
3672                            SourceLocation TemplateKWLoc,
3673                            NamedDecl *FirstQualifierInScope, LookupResult &R,
3674                            const TemplateArgumentListInfo *TemplateArgs,
3675                            bool SuppressQualifierCheck = false,
3676                            ActOnMemberAccessExtraArgs *ExtraArgs = nullptr);
3677 
3678   ExprResult PerformMemberExprBaseConversion(Expr *Base, bool IsArrow);
3679 
3680   bool CheckQualifiedMemberReference(Expr *BaseExpr, QualType BaseType,
3681                                      const CXXScopeSpec &SS,
3682                                      const LookupResult &R);
3683 
3684   ExprResult ActOnDependentMemberExpr(Expr *Base, QualType BaseType,
3685                                       bool IsArrow, SourceLocation OpLoc,
3686                                       const CXXScopeSpec &SS,
3687                                       SourceLocation TemplateKWLoc,
3688                                       NamedDecl *FirstQualifierInScope,
3689                                const DeclarationNameInfo &NameInfo,
3690                                const TemplateArgumentListInfo *TemplateArgs);
3691 
3692   ExprResult ActOnMemberAccessExpr(Scope *S, Expr *Base,
3693                                    SourceLocation OpLoc,
3694                                    tok::TokenKind OpKind,
3695                                    CXXScopeSpec &SS,
3696                                    SourceLocation TemplateKWLoc,
3697                                    UnqualifiedId &Member,
3698                                    Decl *ObjCImpDecl,
3699                                    bool HasTrailingLParen);
3700 
3701   void ActOnDefaultCtorInitializers(Decl *CDtorDecl);
3702   bool ConvertArgumentsForCall(CallExpr *Call, Expr *Fn,
3703                                FunctionDecl *FDecl,
3704                                const FunctionProtoType *Proto,
3705                                ArrayRef<Expr *> Args,
3706                                SourceLocation RParenLoc,
3707                                bool ExecConfig = false);
3708   void CheckStaticArrayArgument(SourceLocation CallLoc,
3709                                 ParmVarDecl *Param,
3710                                 const Expr *ArgExpr);
3711 
3712   /// ActOnCallExpr - Handle a call to Fn with the specified array of arguments.
3713   /// This provides the location of the left/right parens and a list of comma
3714   /// locations.
3715   ExprResult ActOnCallExpr(Scope *S, Expr *Fn, SourceLocation LParenLoc,
3716                            MultiExprArg ArgExprs, SourceLocation RParenLoc,
3717                            Expr *ExecConfig = nullptr,
3718                            bool IsExecConfig = false);
3719   ExprResult BuildResolvedCallExpr(Expr *Fn, NamedDecl *NDecl,
3720                                    SourceLocation LParenLoc,
3721                                    ArrayRef<Expr *> Arg,
3722                                    SourceLocation RParenLoc,
3723                                    Expr *Config = nullptr,
3724                                    bool IsExecConfig = false);
3725 
3726   ExprResult ActOnCUDAExecConfigExpr(Scope *S, SourceLocation LLLLoc,
3727                                      MultiExprArg ExecConfig,
3728                                      SourceLocation GGGLoc);
3729 
3730   ExprResult ActOnCastExpr(Scope *S, SourceLocation LParenLoc,
3731                            Declarator &D, ParsedType &Ty,
3732                            SourceLocation RParenLoc, Expr *CastExpr);
3733   ExprResult BuildCStyleCastExpr(SourceLocation LParenLoc,
3734                                  TypeSourceInfo *Ty,
3735                                  SourceLocation RParenLoc,
3736                                  Expr *Op);
3737   CastKind PrepareScalarCast(ExprResult &src, QualType destType);
3738 
3739   /// \brief Build an altivec or OpenCL literal.
3740   ExprResult BuildVectorLiteral(SourceLocation LParenLoc,
3741                                 SourceLocation RParenLoc, Expr *E,
3742                                 TypeSourceInfo *TInfo);
3743 
3744   ExprResult MaybeConvertParenListExprToParenExpr(Scope *S, Expr *ME);
3745 
3746   ExprResult ActOnCompoundLiteral(SourceLocation LParenLoc,
3747                                   ParsedType Ty,
3748                                   SourceLocation RParenLoc,
3749                                   Expr *InitExpr);
3750 
3751   ExprResult BuildCompoundLiteralExpr(SourceLocation LParenLoc,
3752                                       TypeSourceInfo *TInfo,
3753                                       SourceLocation RParenLoc,
3754                                       Expr *LiteralExpr);
3755 
3756   ExprResult ActOnInitList(SourceLocation LBraceLoc,
3757                            MultiExprArg InitArgList,
3758                            SourceLocation RBraceLoc);
3759 
3760   ExprResult ActOnDesignatedInitializer(Designation &Desig,
3761                                         SourceLocation Loc,
3762                                         bool GNUSyntax,
3763                                         ExprResult Init);
3764 
3765 private:
3766   static BinaryOperatorKind ConvertTokenKindToBinaryOpcode(tok::TokenKind Kind);
3767 
3768 public:
3769   ExprResult ActOnBinOp(Scope *S, SourceLocation TokLoc,
3770                         tok::TokenKind Kind, Expr *LHSExpr, Expr *RHSExpr);
3771   ExprResult BuildBinOp(Scope *S, SourceLocation OpLoc,
3772                         BinaryOperatorKind Opc, Expr *LHSExpr, Expr *RHSExpr);
3773   ExprResult CreateBuiltinBinOp(SourceLocation OpLoc, BinaryOperatorKind Opc,
3774                                 Expr *LHSExpr, Expr *RHSExpr);
3775 
3776   /// ActOnConditionalOp - Parse a ?: operation.  Note that 'LHS' may be null
3777   /// in the case of a the GNU conditional expr extension.
3778   ExprResult ActOnConditionalOp(SourceLocation QuestionLoc,
3779                                 SourceLocation ColonLoc,
3780                                 Expr *CondExpr, Expr *LHSExpr, Expr *RHSExpr);
3781 
3782   /// ActOnAddrLabel - Parse the GNU address of label extension: "&&foo".
3783   ExprResult ActOnAddrLabel(SourceLocation OpLoc, SourceLocation LabLoc,
3784                             LabelDecl *TheDecl);
3785 
3786   void ActOnStartStmtExpr();
3787   ExprResult ActOnStmtExpr(SourceLocation LPLoc, Stmt *SubStmt,
3788                            SourceLocation RPLoc); // "({..})"
3789   void ActOnStmtExprError();
3790 
3791   // __builtin_offsetof(type, identifier(.identifier|[expr])*)
3792   struct OffsetOfComponent {
3793     SourceLocation LocStart, LocEnd;
3794     bool isBrackets;  // true if [expr], false if .ident
3795     union {
3796       IdentifierInfo *IdentInfo;
3797       Expr *E;
3798     } U;
3799   };
3800 
3801   /// __builtin_offsetof(type, a.b[123][456].c)
3802   ExprResult BuildBuiltinOffsetOf(SourceLocation BuiltinLoc,
3803                                   TypeSourceInfo *TInfo,
3804                                   OffsetOfComponent *CompPtr,
3805                                   unsigned NumComponents,
3806                                   SourceLocation RParenLoc);
3807   ExprResult ActOnBuiltinOffsetOf(Scope *S,
3808                                   SourceLocation BuiltinLoc,
3809                                   SourceLocation TypeLoc,
3810                                   ParsedType ParsedArgTy,
3811                                   OffsetOfComponent *CompPtr,
3812                                   unsigned NumComponents,
3813                                   SourceLocation RParenLoc);
3814 
3815   // __builtin_choose_expr(constExpr, expr1, expr2)
3816   ExprResult ActOnChooseExpr(SourceLocation BuiltinLoc,
3817                              Expr *CondExpr, Expr *LHSExpr,
3818                              Expr *RHSExpr, SourceLocation RPLoc);
3819 
3820   // __builtin_va_arg(expr, type)
3821   ExprResult ActOnVAArg(SourceLocation BuiltinLoc, Expr *E, ParsedType Ty,
3822                         SourceLocation RPLoc);
3823   ExprResult BuildVAArgExpr(SourceLocation BuiltinLoc, Expr *E,
3824                             TypeSourceInfo *TInfo, SourceLocation RPLoc);
3825 
3826   // __null
3827   ExprResult ActOnGNUNullExpr(SourceLocation TokenLoc);
3828 
3829   bool CheckCaseExpression(Expr *E);
3830 
3831   /// \brief Describes the result of an "if-exists" condition check.
3832   enum IfExistsResult {
3833     /// \brief The symbol exists.
3834     IER_Exists,
3835 
3836     /// \brief The symbol does not exist.
3837     IER_DoesNotExist,
3838 
3839     /// \brief The name is a dependent name, so the results will differ
3840     /// from one instantiation to the next.
3841     IER_Dependent,
3842 
3843     /// \brief An error occurred.
3844     IER_Error
3845   };
3846 
3847   IfExistsResult
3848   CheckMicrosoftIfExistsSymbol(Scope *S, CXXScopeSpec &SS,
3849                                const DeclarationNameInfo &TargetNameInfo);
3850 
3851   IfExistsResult
3852   CheckMicrosoftIfExistsSymbol(Scope *S, SourceLocation KeywordLoc,
3853                                bool IsIfExists, CXXScopeSpec &SS,
3854                                UnqualifiedId &Name);
3855 
3856   StmtResult BuildMSDependentExistsStmt(SourceLocation KeywordLoc,
3857                                         bool IsIfExists,
3858                                         NestedNameSpecifierLoc QualifierLoc,
3859                                         DeclarationNameInfo NameInfo,
3860                                         Stmt *Nested);
3861   StmtResult ActOnMSDependentExistsStmt(SourceLocation KeywordLoc,
3862                                         bool IsIfExists,
3863                                         CXXScopeSpec &SS, UnqualifiedId &Name,
3864                                         Stmt *Nested);
3865 
3866   //===------------------------- "Block" Extension ------------------------===//
3867 
3868   /// ActOnBlockStart - This callback is invoked when a block literal is
3869   /// started.
3870   void ActOnBlockStart(SourceLocation CaretLoc, Scope *CurScope);
3871 
3872   /// ActOnBlockArguments - This callback allows processing of block arguments.
3873   /// If there are no arguments, this is still invoked.
3874   void ActOnBlockArguments(SourceLocation CaretLoc, Declarator &ParamInfo,
3875                            Scope *CurScope);
3876 
3877   /// ActOnBlockError - If there is an error parsing a block, this callback
3878   /// is invoked to pop the information about the block from the action impl.
3879   void ActOnBlockError(SourceLocation CaretLoc, Scope *CurScope);
3880 
3881   /// ActOnBlockStmtExpr - This is called when the body of a block statement
3882   /// literal was successfully completed.  ^(int x){...}
3883   ExprResult ActOnBlockStmtExpr(SourceLocation CaretLoc, Stmt *Body,
3884                                 Scope *CurScope);
3885 
3886   //===---------------------------- Clang Extensions ----------------------===//
3887 
3888   /// __builtin_convertvector(...)
3889   ExprResult ActOnConvertVectorExpr(Expr *E, ParsedType ParsedDestTy,
3890                                     SourceLocation BuiltinLoc,
3891                                     SourceLocation RParenLoc);
3892 
3893   //===---------------------------- OpenCL Features -----------------------===//
3894 
3895   /// __builtin_astype(...)
3896   ExprResult ActOnAsTypeExpr(Expr *E, ParsedType ParsedDestTy,
3897                              SourceLocation BuiltinLoc,
3898                              SourceLocation RParenLoc);
3899 
3900   //===---------------------------- C++ Features --------------------------===//
3901 
3902   // Act on C++ namespaces
3903   Decl *ActOnStartNamespaceDef(Scope *S, SourceLocation InlineLoc,
3904                                SourceLocation NamespaceLoc,
3905                                SourceLocation IdentLoc,
3906                                IdentifierInfo *Ident,
3907                                SourceLocation LBrace,
3908                                AttributeList *AttrList);
3909   void ActOnFinishNamespaceDef(Decl *Dcl, SourceLocation RBrace);
3910 
3911   NamespaceDecl *getStdNamespace() const;
3912   NamespaceDecl *getOrCreateStdNamespace();
3913 
3914   CXXRecordDecl *getStdBadAlloc() const;
3915 
3916   /// \brief Tests whether Ty is an instance of std::initializer_list and, if
3917   /// it is and Element is not NULL, assigns the element type to Element.
3918   bool isStdInitializerList(QualType Ty, QualType *Element);
3919 
3920   /// \brief Looks for the std::initializer_list template and instantiates it
3921   /// with Element, or emits an error if it's not found.
3922   ///
3923   /// \returns The instantiated template, or null on error.
3924   QualType BuildStdInitializerList(QualType Element, SourceLocation Loc);
3925 
3926   /// \brief Determine whether Ctor is an initializer-list constructor, as
3927   /// defined in [dcl.init.list]p2.
3928   bool isInitListConstructor(const CXXConstructorDecl *Ctor);
3929 
3930   Decl *ActOnUsingDirective(Scope *CurScope,
3931                             SourceLocation UsingLoc,
3932                             SourceLocation NamespcLoc,
3933                             CXXScopeSpec &SS,
3934                             SourceLocation IdentLoc,
3935                             IdentifierInfo *NamespcName,
3936                             AttributeList *AttrList);
3937 
3938   void PushUsingDirective(Scope *S, UsingDirectiveDecl *UDir);
3939 
3940   Decl *ActOnNamespaceAliasDef(Scope *CurScope,
3941                                SourceLocation NamespaceLoc,
3942                                SourceLocation AliasLoc,
3943                                IdentifierInfo *Alias,
3944                                CXXScopeSpec &SS,
3945                                SourceLocation IdentLoc,
3946                                IdentifierInfo *Ident);
3947 
3948   void HideUsingShadowDecl(Scope *S, UsingShadowDecl *Shadow);
3949   bool CheckUsingShadowDecl(UsingDecl *UD, NamedDecl *Target,
3950                             const LookupResult &PreviousDecls,
3951                             UsingShadowDecl *&PrevShadow);
3952   UsingShadowDecl *BuildUsingShadowDecl(Scope *S, UsingDecl *UD,
3953                                         NamedDecl *Target,
3954                                         UsingShadowDecl *PrevDecl);
3955 
3956   bool CheckUsingDeclRedeclaration(SourceLocation UsingLoc,
3957                                    bool HasTypenameKeyword,
3958                                    const CXXScopeSpec &SS,
3959                                    SourceLocation NameLoc,
3960                                    const LookupResult &Previous);
3961   bool CheckUsingDeclQualifier(SourceLocation UsingLoc,
3962                                const CXXScopeSpec &SS,
3963                                const DeclarationNameInfo &NameInfo,
3964                                SourceLocation NameLoc);
3965 
3966   NamedDecl *BuildUsingDeclaration(Scope *S, AccessSpecifier AS,
3967                                    SourceLocation UsingLoc,
3968                                    CXXScopeSpec &SS,
3969                                    DeclarationNameInfo NameInfo,
3970                                    AttributeList *AttrList,
3971                                    bool IsInstantiation,
3972                                    bool HasTypenameKeyword,
3973                                    SourceLocation TypenameLoc);
3974 
3975   bool CheckInheritingConstructorUsingDecl(UsingDecl *UD);
3976 
3977   Decl *ActOnUsingDeclaration(Scope *CurScope,
3978                               AccessSpecifier AS,
3979                               bool HasUsingKeyword,
3980                               SourceLocation UsingLoc,
3981                               CXXScopeSpec &SS,
3982                               UnqualifiedId &Name,
3983                               AttributeList *AttrList,
3984                               bool HasTypenameKeyword,
3985                               SourceLocation TypenameLoc);
3986   Decl *ActOnAliasDeclaration(Scope *CurScope,
3987                               AccessSpecifier AS,
3988                               MultiTemplateParamsArg TemplateParams,
3989                               SourceLocation UsingLoc,
3990                               UnqualifiedId &Name,
3991                               AttributeList *AttrList,
3992                               TypeResult Type);
3993 
3994   /// BuildCXXConstructExpr - Creates a complete call to a constructor,
3995   /// including handling of its default argument expressions.
3996   ///
3997   /// \param ConstructKind - a CXXConstructExpr::ConstructionKind
3998   ExprResult
3999   BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
4000                         CXXConstructorDecl *Constructor, MultiExprArg Exprs,
4001                         bool HadMultipleCandidates, bool IsListInitialization,
4002                         bool IsStdInitListInitialization,
4003                         bool RequiresZeroInit, unsigned ConstructKind,
4004                         SourceRange ParenRange);
4005 
4006   // FIXME: Can we remove this and have the above BuildCXXConstructExpr check if
4007   // the constructor can be elidable?
4008   ExprResult
4009   BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
4010                         CXXConstructorDecl *Constructor, bool Elidable,
4011                         MultiExprArg Exprs, bool HadMultipleCandidates,
4012                         bool IsListInitialization,
4013                         bool IsStdInitListInitialization, bool RequiresZeroInit,
4014                         unsigned ConstructKind, SourceRange ParenRange);
4015 
4016   ExprResult BuildCXXDefaultInitExpr(SourceLocation Loc, FieldDecl *Field);
4017 
4018   /// BuildCXXDefaultArgExpr - Creates a CXXDefaultArgExpr, instantiating
4019   /// the default expr if needed.
4020   ExprResult BuildCXXDefaultArgExpr(SourceLocation CallLoc,
4021                                     FunctionDecl *FD,
4022                                     ParmVarDecl *Param);
4023 
4024   /// FinalizeVarWithDestructor - Prepare for calling destructor on the
4025   /// constructed variable.
4026   void FinalizeVarWithDestructor(VarDecl *VD, const RecordType *DeclInitType);
4027 
4028   /// \brief Helper class that collects exception specifications for
4029   /// implicitly-declared special member functions.
4030   class ImplicitExceptionSpecification {
4031     // Pointer to allow copying
4032     Sema *Self;
4033     // We order exception specifications thus:
4034     // noexcept is the most restrictive, but is only used in C++11.
4035     // throw() comes next.
4036     // Then a throw(collected exceptions)
4037     // Finally no specification, which is expressed as noexcept(false).
4038     // throw(...) is used instead if any called function uses it.
4039     ExceptionSpecificationType ComputedEST;
4040     llvm::SmallPtrSet<CanQualType, 4> ExceptionsSeen;
4041     SmallVector<QualType, 4> Exceptions;
4042 
ClearExceptions()4043     void ClearExceptions() {
4044       ExceptionsSeen.clear();
4045       Exceptions.clear();
4046     }
4047 
4048   public:
ImplicitExceptionSpecification(Sema & Self)4049     explicit ImplicitExceptionSpecification(Sema &Self)
4050       : Self(&Self), ComputedEST(EST_BasicNoexcept) {
4051       if (!Self.getLangOpts().CPlusPlus11)
4052         ComputedEST = EST_DynamicNone;
4053     }
4054 
4055     /// \brief Get the computed exception specification type.
getExceptionSpecType()4056     ExceptionSpecificationType getExceptionSpecType() const {
4057       assert(ComputedEST != EST_ComputedNoexcept &&
4058              "noexcept(expr) should not be a possible result");
4059       return ComputedEST;
4060     }
4061 
4062     /// \brief The number of exceptions in the exception specification.
size()4063     unsigned size() const { return Exceptions.size(); }
4064 
4065     /// \brief The set of exceptions in the exception specification.
data()4066     const QualType *data() const { return Exceptions.data(); }
4067 
4068     /// \brief Integrate another called method into the collected data.
4069     void CalledDecl(SourceLocation CallLoc, const CXXMethodDecl *Method);
4070 
4071     /// \brief Integrate an invoked expression into the collected data.
4072     void CalledExpr(Expr *E);
4073 
4074     /// \brief Overwrite an EPI's exception specification with this
4075     /// computed exception specification.
getExceptionSpec()4076     FunctionProtoType::ExceptionSpecInfo getExceptionSpec() const {
4077       FunctionProtoType::ExceptionSpecInfo ESI;
4078       ESI.Type = getExceptionSpecType();
4079       if (ESI.Type == EST_Dynamic) {
4080         ESI.Exceptions = Exceptions;
4081       } else if (ESI.Type == EST_None) {
4082         /// C++11 [except.spec]p14:
4083         ///   The exception-specification is noexcept(false) if the set of
4084         ///   potential exceptions of the special member function contains "any"
4085         ESI.Type = EST_ComputedNoexcept;
4086         ESI.NoexceptExpr = Self->ActOnCXXBoolLiteral(SourceLocation(),
4087                                                      tok::kw_false).get();
4088       }
4089       return ESI;
4090     }
4091   };
4092 
4093   /// \brief Determine what sort of exception specification a defaulted
4094   /// copy constructor of a class will have.
4095   ImplicitExceptionSpecification
4096   ComputeDefaultedDefaultCtorExceptionSpec(SourceLocation Loc,
4097                                            CXXMethodDecl *MD);
4098 
4099   /// \brief Determine what sort of exception specification a defaulted
4100   /// default constructor of a class will have, and whether the parameter
4101   /// will be const.
4102   ImplicitExceptionSpecification
4103   ComputeDefaultedCopyCtorExceptionSpec(CXXMethodDecl *MD);
4104 
4105   /// \brief Determine what sort of exception specification a defautled
4106   /// copy assignment operator of a class will have, and whether the
4107   /// parameter will be const.
4108   ImplicitExceptionSpecification
4109   ComputeDefaultedCopyAssignmentExceptionSpec(CXXMethodDecl *MD);
4110 
4111   /// \brief Determine what sort of exception specification a defaulted move
4112   /// constructor of a class will have.
4113   ImplicitExceptionSpecification
4114   ComputeDefaultedMoveCtorExceptionSpec(CXXMethodDecl *MD);
4115 
4116   /// \brief Determine what sort of exception specification a defaulted move
4117   /// assignment operator of a class will have.
4118   ImplicitExceptionSpecification
4119   ComputeDefaultedMoveAssignmentExceptionSpec(CXXMethodDecl *MD);
4120 
4121   /// \brief Determine what sort of exception specification a defaulted
4122   /// destructor of a class will have.
4123   ImplicitExceptionSpecification
4124   ComputeDefaultedDtorExceptionSpec(CXXMethodDecl *MD);
4125 
4126   /// \brief Determine what sort of exception specification an inheriting
4127   /// constructor of a class will have.
4128   ImplicitExceptionSpecification
4129   ComputeInheritingCtorExceptionSpec(CXXConstructorDecl *CD);
4130 
4131   /// \brief Evaluate the implicit exception specification for a defaulted
4132   /// special member function.
4133   void EvaluateImplicitExceptionSpec(SourceLocation Loc, CXXMethodDecl *MD);
4134 
4135   /// \brief Check the given exception-specification and update the
4136   /// exception specification information with the results.
4137   void checkExceptionSpecification(bool IsTopLevel,
4138                                    ExceptionSpecificationType EST,
4139                                    ArrayRef<ParsedType> DynamicExceptions,
4140                                    ArrayRef<SourceRange> DynamicExceptionRanges,
4141                                    Expr *NoexceptExpr,
4142                                    SmallVectorImpl<QualType> &Exceptions,
4143                                    FunctionProtoType::ExceptionSpecInfo &ESI);
4144 
4145   /// \brief Determine if we're in a case where we need to (incorrectly) eagerly
4146   /// parse an exception specification to work around a libstdc++ bug.
4147   bool isLibstdcxxEagerExceptionSpecHack(const Declarator &D);
4148 
4149   /// \brief Add an exception-specification to the given member function
4150   /// (or member function template). The exception-specification was parsed
4151   /// after the method itself was declared.
4152   void actOnDelayedExceptionSpecification(Decl *Method,
4153          ExceptionSpecificationType EST,
4154          SourceRange SpecificationRange,
4155          ArrayRef<ParsedType> DynamicExceptions,
4156          ArrayRef<SourceRange> DynamicExceptionRanges,
4157          Expr *NoexceptExpr);
4158 
4159   /// \brief Determine if a special member function should have a deleted
4160   /// definition when it is defaulted.
4161   bool ShouldDeleteSpecialMember(CXXMethodDecl *MD, CXXSpecialMember CSM,
4162                                  bool Diagnose = false);
4163 
4164   /// \brief Declare the implicit default constructor for the given class.
4165   ///
4166   /// \param ClassDecl The class declaration into which the implicit
4167   /// default constructor will be added.
4168   ///
4169   /// \returns The implicitly-declared default constructor.
4170   CXXConstructorDecl *DeclareImplicitDefaultConstructor(
4171                                                      CXXRecordDecl *ClassDecl);
4172 
4173   /// DefineImplicitDefaultConstructor - Checks for feasibility of
4174   /// defining this constructor as the default constructor.
4175   void DefineImplicitDefaultConstructor(SourceLocation CurrentLocation,
4176                                         CXXConstructorDecl *Constructor);
4177 
4178   /// \brief Declare the implicit destructor for the given class.
4179   ///
4180   /// \param ClassDecl The class declaration into which the implicit
4181   /// destructor will be added.
4182   ///
4183   /// \returns The implicitly-declared destructor.
4184   CXXDestructorDecl *DeclareImplicitDestructor(CXXRecordDecl *ClassDecl);
4185 
4186   /// DefineImplicitDestructor - Checks for feasibility of
4187   /// defining this destructor as the default destructor.
4188   void DefineImplicitDestructor(SourceLocation CurrentLocation,
4189                                 CXXDestructorDecl *Destructor);
4190 
4191   /// \brief Build an exception spec for destructors that don't have one.
4192   ///
4193   /// C++11 says that user-defined destructors with no exception spec get one
4194   /// that looks as if the destructor was implicitly declared.
4195   void AdjustDestructorExceptionSpec(CXXRecordDecl *ClassDecl,
4196                                      CXXDestructorDecl *Destructor);
4197 
4198   /// \brief Declare all inheriting constructors for the given class.
4199   ///
4200   /// \param ClassDecl The class declaration into which the inheriting
4201   /// constructors will be added.
4202   void DeclareInheritingConstructors(CXXRecordDecl *ClassDecl);
4203 
4204   /// \brief Define the specified inheriting constructor.
4205   void DefineInheritingConstructor(SourceLocation UseLoc,
4206                                    CXXConstructorDecl *Constructor);
4207 
4208   /// \brief Declare the implicit copy constructor for the given class.
4209   ///
4210   /// \param ClassDecl The class declaration into which the implicit
4211   /// copy constructor will be added.
4212   ///
4213   /// \returns The implicitly-declared copy constructor.
4214   CXXConstructorDecl *DeclareImplicitCopyConstructor(CXXRecordDecl *ClassDecl);
4215 
4216   /// DefineImplicitCopyConstructor - Checks for feasibility of
4217   /// defining this constructor as the copy constructor.
4218   void DefineImplicitCopyConstructor(SourceLocation CurrentLocation,
4219                                      CXXConstructorDecl *Constructor);
4220 
4221   /// \brief Declare the implicit move constructor for the given class.
4222   ///
4223   /// \param ClassDecl The Class declaration into which the implicit
4224   /// move constructor will be added.
4225   ///
4226   /// \returns The implicitly-declared move constructor, or NULL if it wasn't
4227   /// declared.
4228   CXXConstructorDecl *DeclareImplicitMoveConstructor(CXXRecordDecl *ClassDecl);
4229 
4230   /// DefineImplicitMoveConstructor - Checks for feasibility of
4231   /// defining this constructor as the move constructor.
4232   void DefineImplicitMoveConstructor(SourceLocation CurrentLocation,
4233                                      CXXConstructorDecl *Constructor);
4234 
4235   /// \brief Declare the implicit copy assignment operator for the given class.
4236   ///
4237   /// \param ClassDecl The class declaration into which the implicit
4238   /// copy assignment operator will be added.
4239   ///
4240   /// \returns The implicitly-declared copy assignment operator.
4241   CXXMethodDecl *DeclareImplicitCopyAssignment(CXXRecordDecl *ClassDecl);
4242 
4243   /// \brief Defines an implicitly-declared copy assignment operator.
4244   void DefineImplicitCopyAssignment(SourceLocation CurrentLocation,
4245                                     CXXMethodDecl *MethodDecl);
4246 
4247   /// \brief Declare the implicit move assignment operator for the given class.
4248   ///
4249   /// \param ClassDecl The Class declaration into which the implicit
4250   /// move assignment operator will be added.
4251   ///
4252   /// \returns The implicitly-declared move assignment operator, or NULL if it
4253   /// wasn't declared.
4254   CXXMethodDecl *DeclareImplicitMoveAssignment(CXXRecordDecl *ClassDecl);
4255 
4256   /// \brief Defines an implicitly-declared move assignment operator.
4257   void DefineImplicitMoveAssignment(SourceLocation CurrentLocation,
4258                                     CXXMethodDecl *MethodDecl);
4259 
4260   /// \brief Force the declaration of any implicitly-declared members of this
4261   /// class.
4262   void ForceDeclarationOfImplicitMembers(CXXRecordDecl *Class);
4263 
4264   /// \brief Determine whether the given function is an implicitly-deleted
4265   /// special member function.
4266   bool isImplicitlyDeleted(FunctionDecl *FD);
4267 
4268   /// \brief Check whether 'this' shows up in the type of a static member
4269   /// function after the (naturally empty) cv-qualifier-seq would be.
4270   ///
4271   /// \returns true if an error occurred.
4272   bool checkThisInStaticMemberFunctionType(CXXMethodDecl *Method);
4273 
4274   /// \brief Whether this' shows up in the exception specification of a static
4275   /// member function.
4276   bool checkThisInStaticMemberFunctionExceptionSpec(CXXMethodDecl *Method);
4277 
4278   /// \brief Check whether 'this' shows up in the attributes of the given
4279   /// static member function.
4280   ///
4281   /// \returns true if an error occurred.
4282   bool checkThisInStaticMemberFunctionAttributes(CXXMethodDecl *Method);
4283 
4284   /// MaybeBindToTemporary - If the passed in expression has a record type with
4285   /// a non-trivial destructor, this will return CXXBindTemporaryExpr. Otherwise
4286   /// it simply returns the passed in expression.
4287   ExprResult MaybeBindToTemporary(Expr *E);
4288 
4289   bool CompleteConstructorCall(CXXConstructorDecl *Constructor,
4290                                MultiExprArg ArgsPtr,
4291                                SourceLocation Loc,
4292                                SmallVectorImpl<Expr*> &ConvertedArgs,
4293                                bool AllowExplicit = false,
4294                                bool IsListInitialization = false);
4295 
4296   ParsedType getInheritingConstructorName(CXXScopeSpec &SS,
4297                                           SourceLocation NameLoc,
4298                                           IdentifierInfo &Name);
4299 
4300   ParsedType getDestructorName(SourceLocation TildeLoc,
4301                                IdentifierInfo &II, SourceLocation NameLoc,
4302                                Scope *S, CXXScopeSpec &SS,
4303                                ParsedType ObjectType,
4304                                bool EnteringContext);
4305 
4306   ParsedType getDestructorType(const DeclSpec& DS, ParsedType ObjectType);
4307 
4308   // Checks that reinterpret casts don't have undefined behavior.
4309   void CheckCompatibleReinterpretCast(QualType SrcType, QualType DestType,
4310                                       bool IsDereference, SourceRange Range);
4311 
4312   /// ActOnCXXNamedCast - Parse {dynamic,static,reinterpret,const}_cast's.
4313   ExprResult ActOnCXXNamedCast(SourceLocation OpLoc,
4314                                tok::TokenKind Kind,
4315                                SourceLocation LAngleBracketLoc,
4316                                Declarator &D,
4317                                SourceLocation RAngleBracketLoc,
4318                                SourceLocation LParenLoc,
4319                                Expr *E,
4320                                SourceLocation RParenLoc);
4321 
4322   ExprResult BuildCXXNamedCast(SourceLocation OpLoc,
4323                                tok::TokenKind Kind,
4324                                TypeSourceInfo *Ty,
4325                                Expr *E,
4326                                SourceRange AngleBrackets,
4327                                SourceRange Parens);
4328 
4329   ExprResult BuildCXXTypeId(QualType TypeInfoType,
4330                             SourceLocation TypeidLoc,
4331                             TypeSourceInfo *Operand,
4332                             SourceLocation RParenLoc);
4333   ExprResult BuildCXXTypeId(QualType TypeInfoType,
4334                             SourceLocation TypeidLoc,
4335                             Expr *Operand,
4336                             SourceLocation RParenLoc);
4337 
4338   /// ActOnCXXTypeid - Parse typeid( something ).
4339   ExprResult ActOnCXXTypeid(SourceLocation OpLoc,
4340                             SourceLocation LParenLoc, bool isType,
4341                             void *TyOrExpr,
4342                             SourceLocation RParenLoc);
4343 
4344   ExprResult BuildCXXUuidof(QualType TypeInfoType,
4345                             SourceLocation TypeidLoc,
4346                             TypeSourceInfo *Operand,
4347                             SourceLocation RParenLoc);
4348   ExprResult BuildCXXUuidof(QualType TypeInfoType,
4349                             SourceLocation TypeidLoc,
4350                             Expr *Operand,
4351                             SourceLocation RParenLoc);
4352 
4353   /// ActOnCXXUuidof - Parse __uuidof( something ).
4354   ExprResult ActOnCXXUuidof(SourceLocation OpLoc,
4355                             SourceLocation LParenLoc, bool isType,
4356                             void *TyOrExpr,
4357                             SourceLocation RParenLoc);
4358 
4359   /// \brief Handle a C++1z fold-expression: ( expr op ... op expr ).
4360   ExprResult ActOnCXXFoldExpr(SourceLocation LParenLoc, Expr *LHS,
4361                               tok::TokenKind Operator,
4362                               SourceLocation EllipsisLoc, Expr *RHS,
4363                               SourceLocation RParenLoc);
4364   ExprResult BuildCXXFoldExpr(SourceLocation LParenLoc, Expr *LHS,
4365                               BinaryOperatorKind Operator,
4366                               SourceLocation EllipsisLoc, Expr *RHS,
4367                               SourceLocation RParenLoc);
4368   ExprResult BuildEmptyCXXFoldExpr(SourceLocation EllipsisLoc,
4369                                    BinaryOperatorKind Operator);
4370 
4371   //// ActOnCXXThis -  Parse 'this' pointer.
4372   ExprResult ActOnCXXThis(SourceLocation loc);
4373 
4374   /// \brief Try to retrieve the type of the 'this' pointer.
4375   ///
4376   /// \returns The type of 'this', if possible. Otherwise, returns a NULL type.
4377   QualType getCurrentThisType();
4378 
4379   /// \brief When non-NULL, the C++ 'this' expression is allowed despite the
4380   /// current context not being a non-static member function. In such cases,
4381   /// this provides the type used for 'this'.
4382   QualType CXXThisTypeOverride;
4383 
4384   /// \brief RAII object used to temporarily allow the C++ 'this' expression
4385   /// to be used, with the given qualifiers on the current class type.
4386   class CXXThisScopeRAII {
4387     Sema &S;
4388     QualType OldCXXThisTypeOverride;
4389     bool Enabled;
4390 
4391   public:
4392     /// \brief Introduce a new scope where 'this' may be allowed (when enabled),
4393     /// using the given declaration (which is either a class template or a
4394     /// class) along with the given qualifiers.
4395     /// along with the qualifiers placed on '*this'.
4396     CXXThisScopeRAII(Sema &S, Decl *ContextDecl, unsigned CXXThisTypeQuals,
4397                      bool Enabled = true);
4398 
4399     ~CXXThisScopeRAII();
4400   };
4401 
4402   /// \brief Make sure the value of 'this' is actually available in the current
4403   /// context, if it is a potentially evaluated context.
4404   ///
4405   /// \param Loc The location at which the capture of 'this' occurs.
4406   ///
4407   /// \param Explicit Whether 'this' is explicitly captured in a lambda
4408   /// capture list.
4409   ///
4410   /// \param FunctionScopeIndexToStopAt If non-null, it points to the index
4411   /// of the FunctionScopeInfo stack beyond which we do not attempt to capture.
4412   /// This is useful when enclosing lambdas must speculatively capture
4413   /// 'this' that may or may not be used in certain specializations of
4414   /// a nested generic lambda (depending on whether the name resolves to
4415   /// a non-static member function or a static function).
4416   /// \return returns 'true' if failed, 'false' if success.
4417   bool CheckCXXThisCapture(SourceLocation Loc, bool Explicit = false,
4418       bool BuildAndDiagnose = true,
4419       const unsigned *const FunctionScopeIndexToStopAt = nullptr);
4420 
4421   /// \brief Determine whether the given type is the type of *this that is used
4422   /// outside of the body of a member function for a type that is currently
4423   /// being defined.
4424   bool isThisOutsideMemberFunctionBody(QualType BaseType);
4425 
4426   /// ActOnCXXBoolLiteral - Parse {true,false} literals.
4427   ExprResult ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind);
4428 
4429 
4430   /// ActOnObjCBoolLiteral - Parse {__objc_yes,__objc_no} literals.
4431   ExprResult ActOnObjCBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind);
4432 
4433   /// ActOnCXXNullPtrLiteral - Parse 'nullptr'.
4434   ExprResult ActOnCXXNullPtrLiteral(SourceLocation Loc);
4435 
4436   //// ActOnCXXThrow -  Parse throw expressions.
4437   ExprResult ActOnCXXThrow(Scope *S, SourceLocation OpLoc, Expr *expr);
4438   ExprResult BuildCXXThrow(SourceLocation OpLoc, Expr *Ex,
4439                            bool IsThrownVarInScope);
4440   ExprResult CheckCXXThrowOperand(SourceLocation ThrowLoc, Expr *E,
4441                                   bool IsThrownVarInScope);
4442 
4443   /// ActOnCXXTypeConstructExpr - Parse construction of a specified type.
4444   /// Can be interpreted either as function-style casting ("int(x)")
4445   /// or class type construction ("ClassType(x,y,z)")
4446   /// or creation of a value-initialized type ("int()").
4447   ExprResult ActOnCXXTypeConstructExpr(ParsedType TypeRep,
4448                                        SourceLocation LParenLoc,
4449                                        MultiExprArg Exprs,
4450                                        SourceLocation RParenLoc);
4451 
4452   ExprResult BuildCXXTypeConstructExpr(TypeSourceInfo *Type,
4453                                        SourceLocation LParenLoc,
4454                                        MultiExprArg Exprs,
4455                                        SourceLocation RParenLoc);
4456 
4457   /// ActOnCXXNew - Parsed a C++ 'new' expression.
4458   ExprResult ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal,
4459                          SourceLocation PlacementLParen,
4460                          MultiExprArg PlacementArgs,
4461                          SourceLocation PlacementRParen,
4462                          SourceRange TypeIdParens, Declarator &D,
4463                          Expr *Initializer);
4464   ExprResult BuildCXXNew(SourceRange Range, bool UseGlobal,
4465                          SourceLocation PlacementLParen,
4466                          MultiExprArg PlacementArgs,
4467                          SourceLocation PlacementRParen,
4468                          SourceRange TypeIdParens,
4469                          QualType AllocType,
4470                          TypeSourceInfo *AllocTypeInfo,
4471                          Expr *ArraySize,
4472                          SourceRange DirectInitRange,
4473                          Expr *Initializer,
4474                          bool TypeMayContainAuto = true);
4475 
4476   bool CheckAllocatedType(QualType AllocType, SourceLocation Loc,
4477                           SourceRange R);
4478   bool FindAllocationFunctions(SourceLocation StartLoc, SourceRange Range,
4479                                bool UseGlobal, QualType AllocType, bool IsArray,
4480                                MultiExprArg PlaceArgs,
4481                                FunctionDecl *&OperatorNew,
4482                                FunctionDecl *&OperatorDelete);
4483   bool FindAllocationOverload(SourceLocation StartLoc, SourceRange Range,
4484                               DeclarationName Name, MultiExprArg Args,
4485                               DeclContext *Ctx,
4486                               bool AllowMissing, FunctionDecl *&Operator,
4487                               bool Diagnose = true);
4488   void DeclareGlobalNewDelete();
4489   void DeclareGlobalAllocationFunction(DeclarationName Name, QualType Return,
4490                                        QualType Param1,
4491                                        QualType Param2 = QualType(),
4492                                        bool addMallocAttr = false);
4493 
4494   bool FindDeallocationFunction(SourceLocation StartLoc, CXXRecordDecl *RD,
4495                                 DeclarationName Name, FunctionDecl* &Operator,
4496                                 bool Diagnose = true);
4497   FunctionDecl *FindUsualDeallocationFunction(SourceLocation StartLoc,
4498                                               bool CanProvideSize,
4499                                               DeclarationName Name);
4500 
4501   /// ActOnCXXDelete - Parsed a C++ 'delete' expression
4502   ExprResult ActOnCXXDelete(SourceLocation StartLoc,
4503                             bool UseGlobal, bool ArrayForm,
4504                             Expr *Operand);
4505 
4506   DeclResult ActOnCXXConditionDeclaration(Scope *S, Declarator &D);
4507   ExprResult CheckConditionVariable(VarDecl *ConditionVar,
4508                                     SourceLocation StmtLoc,
4509                                     bool ConvertToBoolean);
4510 
4511   ExprResult ActOnNoexceptExpr(SourceLocation KeyLoc, SourceLocation LParen,
4512                                Expr *Operand, SourceLocation RParen);
4513   ExprResult BuildCXXNoexceptExpr(SourceLocation KeyLoc, Expr *Operand,
4514                                   SourceLocation RParen);
4515 
4516   /// \brief Parsed one of the type trait support pseudo-functions.
4517   ExprResult ActOnTypeTrait(TypeTrait Kind, SourceLocation KWLoc,
4518                             ArrayRef<ParsedType> Args,
4519                             SourceLocation RParenLoc);
4520   ExprResult BuildTypeTrait(TypeTrait Kind, SourceLocation KWLoc,
4521                             ArrayRef<TypeSourceInfo *> Args,
4522                             SourceLocation RParenLoc);
4523 
4524   /// ActOnArrayTypeTrait - Parsed one of the bianry type trait support
4525   /// pseudo-functions.
4526   ExprResult ActOnArrayTypeTrait(ArrayTypeTrait ATT,
4527                                  SourceLocation KWLoc,
4528                                  ParsedType LhsTy,
4529                                  Expr *DimExpr,
4530                                  SourceLocation RParen);
4531 
4532   ExprResult BuildArrayTypeTrait(ArrayTypeTrait ATT,
4533                                  SourceLocation KWLoc,
4534                                  TypeSourceInfo *TSInfo,
4535                                  Expr *DimExpr,
4536                                  SourceLocation RParen);
4537 
4538   /// ActOnExpressionTrait - Parsed one of the unary type trait support
4539   /// pseudo-functions.
4540   ExprResult ActOnExpressionTrait(ExpressionTrait OET,
4541                                   SourceLocation KWLoc,
4542                                   Expr *Queried,
4543                                   SourceLocation RParen);
4544 
4545   ExprResult BuildExpressionTrait(ExpressionTrait OET,
4546                                   SourceLocation KWLoc,
4547                                   Expr *Queried,
4548                                   SourceLocation RParen);
4549 
4550   ExprResult ActOnStartCXXMemberReference(Scope *S,
4551                                           Expr *Base,
4552                                           SourceLocation OpLoc,
4553                                           tok::TokenKind OpKind,
4554                                           ParsedType &ObjectType,
4555                                           bool &MayBePseudoDestructor);
4556 
4557   ExprResult DiagnoseDtorReference(SourceLocation NameLoc, Expr *MemExpr);
4558 
4559   ExprResult BuildPseudoDestructorExpr(Expr *Base,
4560                                        SourceLocation OpLoc,
4561                                        tok::TokenKind OpKind,
4562                                        const CXXScopeSpec &SS,
4563                                        TypeSourceInfo *ScopeType,
4564                                        SourceLocation CCLoc,
4565                                        SourceLocation TildeLoc,
4566                                      PseudoDestructorTypeStorage DestroyedType,
4567                                        bool HasTrailingLParen);
4568 
4569   ExprResult ActOnPseudoDestructorExpr(Scope *S, Expr *Base,
4570                                        SourceLocation OpLoc,
4571                                        tok::TokenKind OpKind,
4572                                        CXXScopeSpec &SS,
4573                                        UnqualifiedId &FirstTypeName,
4574                                        SourceLocation CCLoc,
4575                                        SourceLocation TildeLoc,
4576                                        UnqualifiedId &SecondTypeName,
4577                                        bool HasTrailingLParen);
4578 
4579   ExprResult ActOnPseudoDestructorExpr(Scope *S, Expr *Base,
4580                                        SourceLocation OpLoc,
4581                                        tok::TokenKind OpKind,
4582                                        SourceLocation TildeLoc,
4583                                        const DeclSpec& DS,
4584                                        bool HasTrailingLParen);
4585 
4586   /// MaybeCreateExprWithCleanups - If the current full-expression
4587   /// requires any cleanups, surround it with a ExprWithCleanups node.
4588   /// Otherwise, just returns the passed-in expression.
4589   Expr *MaybeCreateExprWithCleanups(Expr *SubExpr);
4590   Stmt *MaybeCreateStmtWithCleanups(Stmt *SubStmt);
4591   ExprResult MaybeCreateExprWithCleanups(ExprResult SubExpr);
4592 
ActOnFinishFullExpr(Expr * Expr)4593   ExprResult ActOnFinishFullExpr(Expr *Expr) {
4594     return ActOnFinishFullExpr(Expr, Expr ? Expr->getExprLoc()
4595                                           : SourceLocation());
4596   }
4597   ExprResult ActOnFinishFullExpr(Expr *Expr, SourceLocation CC,
4598                                  bool DiscardedValue = false,
4599                                  bool IsConstexpr = false,
4600                                  bool IsLambdaInitCaptureInitializer = false);
4601   StmtResult ActOnFinishFullStmt(Stmt *Stmt);
4602 
4603   // Marks SS invalid if it represents an incomplete type.
4604   bool RequireCompleteDeclContext(CXXScopeSpec &SS, DeclContext *DC);
4605 
4606   DeclContext *computeDeclContext(QualType T);
4607   DeclContext *computeDeclContext(const CXXScopeSpec &SS,
4608                                   bool EnteringContext = false);
4609   bool isDependentScopeSpecifier(const CXXScopeSpec &SS);
4610   CXXRecordDecl *getCurrentInstantiationOf(NestedNameSpecifier *NNS);
4611 
4612   /// \brief The parser has parsed a global nested-name-specifier '::'.
4613   ///
4614   /// \param CCLoc The location of the '::'.
4615   ///
4616   /// \param SS The nested-name-specifier, which will be updated in-place
4617   /// to reflect the parsed nested-name-specifier.
4618   ///
4619   /// \returns true if an error occurred, false otherwise.
4620   bool ActOnCXXGlobalScopeSpecifier(SourceLocation CCLoc, CXXScopeSpec &SS);
4621 
4622   /// \brief The parser has parsed a '__super' nested-name-specifier.
4623   ///
4624   /// \param SuperLoc The location of the '__super' keyword.
4625   ///
4626   /// \param ColonColonLoc The location of the '::'.
4627   ///
4628   /// \param SS The nested-name-specifier, which will be updated in-place
4629   /// to reflect the parsed nested-name-specifier.
4630   ///
4631   /// \returns true if an error occurred, false otherwise.
4632   bool ActOnSuperScopeSpecifier(SourceLocation SuperLoc,
4633                                 SourceLocation ColonColonLoc, CXXScopeSpec &SS);
4634 
4635   bool isAcceptableNestedNameSpecifier(const NamedDecl *SD);
4636   NamedDecl *FindFirstQualifierInScope(Scope *S, NestedNameSpecifier *NNS);
4637 
4638   bool isNonTypeNestedNameSpecifier(Scope *S, CXXScopeSpec &SS,
4639                                     SourceLocation IdLoc,
4640                                     IdentifierInfo &II,
4641                                     ParsedType ObjectType);
4642 
4643   bool BuildCXXNestedNameSpecifier(Scope *S,
4644                                    IdentifierInfo &Identifier,
4645                                    SourceLocation IdentifierLoc,
4646                                    SourceLocation CCLoc,
4647                                    QualType ObjectType,
4648                                    bool EnteringContext,
4649                                    CXXScopeSpec &SS,
4650                                    NamedDecl *ScopeLookupResult,
4651                                    bool ErrorRecoveryLookup,
4652                                    bool *IsCorrectedToColon = nullptr);
4653 
4654   /// \brief The parser has parsed a nested-name-specifier 'identifier::'.
4655   ///
4656   /// \param S The scope in which this nested-name-specifier occurs.
4657   ///
4658   /// \param Identifier The identifier preceding the '::'.
4659   ///
4660   /// \param IdentifierLoc The location of the identifier.
4661   ///
4662   /// \param CCLoc The location of the '::'.
4663   ///
4664   /// \param ObjectType The type of the object, if we're parsing
4665   /// nested-name-specifier in a member access expression.
4666   ///
4667   /// \param EnteringContext Whether we're entering the context nominated by
4668   /// this nested-name-specifier.
4669   ///
4670   /// \param SS The nested-name-specifier, which is both an input
4671   /// parameter (the nested-name-specifier before this type) and an
4672   /// output parameter (containing the full nested-name-specifier,
4673   /// including this new type).
4674   ///
4675   /// \param ErrorRecoveryLookup If true, then this method is called to improve
4676   /// error recovery. In this case do not emit error message.
4677   ///
4678   /// \param IsCorrectedToColon If not null, suggestions to replace '::' -> ':'
4679   /// are allowed.  The bool value pointed by this parameter is set to 'true'
4680   /// if the identifier is treated as if it was followed by ':', not '::'.
4681   ///
4682   /// \returns true if an error occurred, false otherwise.
4683   bool ActOnCXXNestedNameSpecifier(Scope *S,
4684                                    IdentifierInfo &Identifier,
4685                                    SourceLocation IdentifierLoc,
4686                                    SourceLocation CCLoc,
4687                                    ParsedType ObjectType,
4688                                    bool EnteringContext,
4689                                    CXXScopeSpec &SS,
4690                                    bool ErrorRecoveryLookup = false,
4691                                    bool *IsCorrectedToColon = nullptr);
4692 
4693   ExprResult ActOnDecltypeExpression(Expr *E);
4694 
4695   bool ActOnCXXNestedNameSpecifierDecltype(CXXScopeSpec &SS,
4696                                            const DeclSpec &DS,
4697                                            SourceLocation ColonColonLoc);
4698 
4699   bool IsInvalidUnlessNestedName(Scope *S, CXXScopeSpec &SS,
4700                                  IdentifierInfo &Identifier,
4701                                  SourceLocation IdentifierLoc,
4702                                  SourceLocation ColonLoc,
4703                                  ParsedType ObjectType,
4704                                  bool EnteringContext);
4705 
4706   /// \brief The parser has parsed a nested-name-specifier
4707   /// 'template[opt] template-name < template-args >::'.
4708   ///
4709   /// \param S The scope in which this nested-name-specifier occurs.
4710   ///
4711   /// \param SS The nested-name-specifier, which is both an input
4712   /// parameter (the nested-name-specifier before this type) and an
4713   /// output parameter (containing the full nested-name-specifier,
4714   /// including this new type).
4715   ///
4716   /// \param TemplateKWLoc the location of the 'template' keyword, if any.
4717   /// \param TemplateName the template name.
4718   /// \param TemplateNameLoc The location of the template name.
4719   /// \param LAngleLoc The location of the opening angle bracket  ('<').
4720   /// \param TemplateArgs The template arguments.
4721   /// \param RAngleLoc The location of the closing angle bracket  ('>').
4722   /// \param CCLoc The location of the '::'.
4723   ///
4724   /// \param EnteringContext Whether we're entering the context of the
4725   /// nested-name-specifier.
4726   ///
4727   ///
4728   /// \returns true if an error occurred, false otherwise.
4729   bool ActOnCXXNestedNameSpecifier(Scope *S,
4730                                    CXXScopeSpec &SS,
4731                                    SourceLocation TemplateKWLoc,
4732                                    TemplateTy TemplateName,
4733                                    SourceLocation TemplateNameLoc,
4734                                    SourceLocation LAngleLoc,
4735                                    ASTTemplateArgsPtr TemplateArgs,
4736                                    SourceLocation RAngleLoc,
4737                                    SourceLocation CCLoc,
4738                                    bool EnteringContext);
4739 
4740   /// \brief Given a C++ nested-name-specifier, produce an annotation value
4741   /// that the parser can use later to reconstruct the given
4742   /// nested-name-specifier.
4743   ///
4744   /// \param SS A nested-name-specifier.
4745   ///
4746   /// \returns A pointer containing all of the information in the
4747   /// nested-name-specifier \p SS.
4748   void *SaveNestedNameSpecifierAnnotation(CXXScopeSpec &SS);
4749 
4750   /// \brief Given an annotation pointer for a nested-name-specifier, restore
4751   /// the nested-name-specifier structure.
4752   ///
4753   /// \param Annotation The annotation pointer, produced by
4754   /// \c SaveNestedNameSpecifierAnnotation().
4755   ///
4756   /// \param AnnotationRange The source range corresponding to the annotation.
4757   ///
4758   /// \param SS The nested-name-specifier that will be updated with the contents
4759   /// of the annotation pointer.
4760   void RestoreNestedNameSpecifierAnnotation(void *Annotation,
4761                                             SourceRange AnnotationRange,
4762                                             CXXScopeSpec &SS);
4763 
4764   bool ShouldEnterDeclaratorScope(Scope *S, const CXXScopeSpec &SS);
4765 
4766   /// ActOnCXXEnterDeclaratorScope - Called when a C++ scope specifier (global
4767   /// scope or nested-name-specifier) is parsed, part of a declarator-id.
4768   /// After this method is called, according to [C++ 3.4.3p3], names should be
4769   /// looked up in the declarator-id's scope, until the declarator is parsed and
4770   /// ActOnCXXExitDeclaratorScope is called.
4771   /// The 'SS' should be a non-empty valid CXXScopeSpec.
4772   bool ActOnCXXEnterDeclaratorScope(Scope *S, CXXScopeSpec &SS);
4773 
4774   /// ActOnCXXExitDeclaratorScope - Called when a declarator that previously
4775   /// invoked ActOnCXXEnterDeclaratorScope(), is finished. 'SS' is the same
4776   /// CXXScopeSpec that was passed to ActOnCXXEnterDeclaratorScope as well.
4777   /// Used to indicate that names should revert to being looked up in the
4778   /// defining scope.
4779   void ActOnCXXExitDeclaratorScope(Scope *S, const CXXScopeSpec &SS);
4780 
4781   /// ActOnCXXEnterDeclInitializer - Invoked when we are about to parse an
4782   /// initializer for the declaration 'Dcl'.
4783   /// After this method is called, according to [C++ 3.4.1p13], if 'Dcl' is a
4784   /// static data member of class X, names should be looked up in the scope of
4785   /// class X.
4786   void ActOnCXXEnterDeclInitializer(Scope *S, Decl *Dcl);
4787 
4788   /// ActOnCXXExitDeclInitializer - Invoked after we are finished parsing an
4789   /// initializer for the declaration 'Dcl'.
4790   void ActOnCXXExitDeclInitializer(Scope *S, Decl *Dcl);
4791 
4792   /// \brief Create a new lambda closure type.
4793   CXXRecordDecl *createLambdaClosureType(SourceRange IntroducerRange,
4794                                          TypeSourceInfo *Info,
4795                                          bool KnownDependent,
4796                                          LambdaCaptureDefault CaptureDefault);
4797 
4798   /// \brief Start the definition of a lambda expression.
4799   CXXMethodDecl *startLambdaDefinition(CXXRecordDecl *Class,
4800                                        SourceRange IntroducerRange,
4801                                        TypeSourceInfo *MethodType,
4802                                        SourceLocation EndLoc,
4803                                        ArrayRef<ParmVarDecl *> Params);
4804 
4805   /// \brief Endow the lambda scope info with the relevant properties.
4806   void buildLambdaScope(sema::LambdaScopeInfo *LSI,
4807                         CXXMethodDecl *CallOperator,
4808                         SourceRange IntroducerRange,
4809                         LambdaCaptureDefault CaptureDefault,
4810                         SourceLocation CaptureDefaultLoc,
4811                         bool ExplicitParams,
4812                         bool ExplicitResultType,
4813                         bool Mutable);
4814 
4815   /// \brief Perform initialization analysis of the init-capture and perform
4816   /// any implicit conversions such as an lvalue-to-rvalue conversion if
4817   /// not being used to initialize a reference.
4818   QualType performLambdaInitCaptureInitialization(SourceLocation Loc,
4819       bool ByRef, IdentifierInfo *Id, Expr *&Init);
4820   /// \brief Create a dummy variable within the declcontext of the lambda's
4821   ///  call operator, for name lookup purposes for a lambda init capture.
4822   ///
4823   ///  CodeGen handles emission of lambda captures, ignoring these dummy
4824   ///  variables appropriately.
4825   VarDecl *createLambdaInitCaptureVarDecl(SourceLocation Loc,
4826     QualType InitCaptureType, IdentifierInfo *Id, Expr *Init);
4827 
4828   /// \brief Build the implicit field for an init-capture.
4829   FieldDecl *buildInitCaptureField(sema::LambdaScopeInfo *LSI, VarDecl *Var);
4830 
4831   /// \brief Note that we have finished the explicit captures for the
4832   /// given lambda.
4833   void finishLambdaExplicitCaptures(sema::LambdaScopeInfo *LSI);
4834 
4835   /// \brief Introduce the lambda parameters into scope.
4836   void addLambdaParameters(CXXMethodDecl *CallOperator, Scope *CurScope);
4837 
4838   /// \brief Deduce a block or lambda's return type based on the return
4839   /// statements present in the body.
4840   void deduceClosureReturnType(sema::CapturingScopeInfo &CSI);
4841 
4842   /// ActOnStartOfLambdaDefinition - This is called just before we start
4843   /// parsing the body of a lambda; it analyzes the explicit captures and
4844   /// arguments, and sets up various data-structures for the body of the
4845   /// lambda.
4846   void ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro,
4847                                     Declarator &ParamInfo, Scope *CurScope);
4848 
4849   /// ActOnLambdaError - If there is an error parsing a lambda, this callback
4850   /// is invoked to pop the information about the lambda.
4851   void ActOnLambdaError(SourceLocation StartLoc, Scope *CurScope,
4852                         bool IsInstantiation = false);
4853 
4854   /// ActOnLambdaExpr - This is called when the body of a lambda expression
4855   /// was successfully completed.
4856   ExprResult ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body,
4857                              Scope *CurScope,
4858                              bool IsInstantiation = false);
4859 
4860   /// \brief Define the "body" of the conversion from a lambda object to a
4861   /// function pointer.
4862   ///
4863   /// This routine doesn't actually define a sensible body; rather, it fills
4864   /// in the initialization expression needed to copy the lambda object into
4865   /// the block, and IR generation actually generates the real body of the
4866   /// block pointer conversion.
4867   void DefineImplicitLambdaToFunctionPointerConversion(
4868          SourceLocation CurrentLoc, CXXConversionDecl *Conv);
4869 
4870   /// \brief Define the "body" of the conversion from a lambda object to a
4871   /// block pointer.
4872   ///
4873   /// This routine doesn't actually define a sensible body; rather, it fills
4874   /// in the initialization expression needed to copy the lambda object into
4875   /// the block, and IR generation actually generates the real body of the
4876   /// block pointer conversion.
4877   void DefineImplicitLambdaToBlockPointerConversion(SourceLocation CurrentLoc,
4878                                                     CXXConversionDecl *Conv);
4879 
4880   ExprResult BuildBlockForLambdaConversion(SourceLocation CurrentLocation,
4881                                            SourceLocation ConvLocation,
4882                                            CXXConversionDecl *Conv,
4883                                            Expr *Src);
4884 
4885   // ParseObjCStringLiteral - Parse Objective-C string literals.
4886   ExprResult ParseObjCStringLiteral(SourceLocation *AtLocs,
4887                                     Expr **Strings,
4888                                     unsigned NumStrings);
4889 
4890   ExprResult BuildObjCStringLiteral(SourceLocation AtLoc, StringLiteral *S);
4891 
4892   /// BuildObjCNumericLiteral - builds an ObjCBoxedExpr AST node for the
4893   /// numeric literal expression. Type of the expression will be "NSNumber *"
4894   /// or "id" if NSNumber is unavailable.
4895   ExprResult BuildObjCNumericLiteral(SourceLocation AtLoc, Expr *Number);
4896   ExprResult ActOnObjCBoolLiteral(SourceLocation AtLoc, SourceLocation ValueLoc,
4897                                   bool Value);
4898   ExprResult BuildObjCArrayLiteral(SourceRange SR, MultiExprArg Elements);
4899 
4900   /// BuildObjCBoxedExpr - builds an ObjCBoxedExpr AST node for the
4901   /// '@' prefixed parenthesized expression. The type of the expression will
4902   /// either be "NSNumber *" or "NSString *" depending on the type of
4903   /// ValueType, which is allowed to be a built-in numeric type or
4904   /// "char *" or "const char *".
4905   ExprResult BuildObjCBoxedExpr(SourceRange SR, Expr *ValueExpr);
4906 
4907   ExprResult BuildObjCSubscriptExpression(SourceLocation RB, Expr *BaseExpr,
4908                                           Expr *IndexExpr,
4909                                           ObjCMethodDecl *getterMethod,
4910                                           ObjCMethodDecl *setterMethod);
4911 
4912   ExprResult BuildObjCDictionaryLiteral(SourceRange SR,
4913                                         ObjCDictionaryElement *Elements,
4914                                         unsigned NumElements);
4915 
4916   ExprResult BuildObjCEncodeExpression(SourceLocation AtLoc,
4917                                   TypeSourceInfo *EncodedTypeInfo,
4918                                   SourceLocation RParenLoc);
4919   ExprResult BuildCXXMemberCallExpr(Expr *Exp, NamedDecl *FoundDecl,
4920                                     CXXConversionDecl *Method,
4921                                     bool HadMultipleCandidates);
4922 
4923   ExprResult ParseObjCEncodeExpression(SourceLocation AtLoc,
4924                                        SourceLocation EncodeLoc,
4925                                        SourceLocation LParenLoc,
4926                                        ParsedType Ty,
4927                                        SourceLocation RParenLoc);
4928 
4929   /// ParseObjCSelectorExpression - Build selector expression for \@selector
4930   ExprResult ParseObjCSelectorExpression(Selector Sel,
4931                                          SourceLocation AtLoc,
4932                                          SourceLocation SelLoc,
4933                                          SourceLocation LParenLoc,
4934                                          SourceLocation RParenLoc,
4935                                          bool WarnMultipleSelectors);
4936 
4937   /// ParseObjCProtocolExpression - Build protocol expression for \@protocol
4938   ExprResult ParseObjCProtocolExpression(IdentifierInfo * ProtocolName,
4939                                          SourceLocation AtLoc,
4940                                          SourceLocation ProtoLoc,
4941                                          SourceLocation LParenLoc,
4942                                          SourceLocation ProtoIdLoc,
4943                                          SourceLocation RParenLoc);
4944 
4945   //===--------------------------------------------------------------------===//
4946   // C++ Declarations
4947   //
4948   Decl *ActOnStartLinkageSpecification(Scope *S,
4949                                        SourceLocation ExternLoc,
4950                                        Expr *LangStr,
4951                                        SourceLocation LBraceLoc);
4952   Decl *ActOnFinishLinkageSpecification(Scope *S,
4953                                         Decl *LinkageSpec,
4954                                         SourceLocation RBraceLoc);
4955 
4956 
4957   //===--------------------------------------------------------------------===//
4958   // C++ Classes
4959   //
4960   bool isCurrentClassName(const IdentifierInfo &II, Scope *S,
4961                           const CXXScopeSpec *SS = nullptr);
4962   bool isCurrentClassNameTypo(IdentifierInfo *&II, const CXXScopeSpec *SS);
4963 
4964   bool ActOnAccessSpecifier(AccessSpecifier Access,
4965                             SourceLocation ASLoc,
4966                             SourceLocation ColonLoc,
4967                             AttributeList *Attrs = nullptr);
4968 
4969   NamedDecl *ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS,
4970                                  Declarator &D,
4971                                  MultiTemplateParamsArg TemplateParameterLists,
4972                                  Expr *BitfieldWidth, const VirtSpecifiers &VS,
4973                                  InClassInitStyle InitStyle);
4974 
4975   void ActOnStartCXXInClassMemberInitializer();
4976   void ActOnFinishCXXInClassMemberInitializer(Decl *VarDecl,
4977                                               SourceLocation EqualLoc,
4978                                               Expr *Init);
4979 
4980   MemInitResult ActOnMemInitializer(Decl *ConstructorD,
4981                                     Scope *S,
4982                                     CXXScopeSpec &SS,
4983                                     IdentifierInfo *MemberOrBase,
4984                                     ParsedType TemplateTypeTy,
4985                                     const DeclSpec &DS,
4986                                     SourceLocation IdLoc,
4987                                     SourceLocation LParenLoc,
4988                                     ArrayRef<Expr *> Args,
4989                                     SourceLocation RParenLoc,
4990                                     SourceLocation EllipsisLoc);
4991 
4992   MemInitResult ActOnMemInitializer(Decl *ConstructorD,
4993                                     Scope *S,
4994                                     CXXScopeSpec &SS,
4995                                     IdentifierInfo *MemberOrBase,
4996                                     ParsedType TemplateTypeTy,
4997                                     const DeclSpec &DS,
4998                                     SourceLocation IdLoc,
4999                                     Expr *InitList,
5000                                     SourceLocation EllipsisLoc);
5001 
5002   MemInitResult BuildMemInitializer(Decl *ConstructorD,
5003                                     Scope *S,
5004                                     CXXScopeSpec &SS,
5005                                     IdentifierInfo *MemberOrBase,
5006                                     ParsedType TemplateTypeTy,
5007                                     const DeclSpec &DS,
5008                                     SourceLocation IdLoc,
5009                                     Expr *Init,
5010                                     SourceLocation EllipsisLoc);
5011 
5012   MemInitResult BuildMemberInitializer(ValueDecl *Member,
5013                                        Expr *Init,
5014                                        SourceLocation IdLoc);
5015 
5016   MemInitResult BuildBaseInitializer(QualType BaseType,
5017                                      TypeSourceInfo *BaseTInfo,
5018                                      Expr *Init,
5019                                      CXXRecordDecl *ClassDecl,
5020                                      SourceLocation EllipsisLoc);
5021 
5022   MemInitResult BuildDelegatingInitializer(TypeSourceInfo *TInfo,
5023                                            Expr *Init,
5024                                            CXXRecordDecl *ClassDecl);
5025 
5026   bool SetDelegatingInitializer(CXXConstructorDecl *Constructor,
5027                                 CXXCtorInitializer *Initializer);
5028 
5029   bool SetCtorInitializers(CXXConstructorDecl *Constructor, bool AnyErrors,
5030                            ArrayRef<CXXCtorInitializer *> Initializers = None);
5031 
5032   void SetIvarInitializers(ObjCImplementationDecl *ObjCImplementation);
5033 
5034 
5035   /// MarkBaseAndMemberDestructorsReferenced - Given a record decl,
5036   /// mark all the non-trivial destructors of its members and bases as
5037   /// referenced.
5038   void MarkBaseAndMemberDestructorsReferenced(SourceLocation Loc,
5039                                               CXXRecordDecl *Record);
5040 
5041   /// \brief The list of classes whose vtables have been used within
5042   /// this translation unit, and the source locations at which the
5043   /// first use occurred.
5044   typedef std::pair<CXXRecordDecl*, SourceLocation> VTableUse;
5045 
5046   /// \brief The list of vtables that are required but have not yet been
5047   /// materialized.
5048   SmallVector<VTableUse, 16> VTableUses;
5049 
5050   /// \brief The set of classes whose vtables have been used within
5051   /// this translation unit, and a bit that will be true if the vtable is
5052   /// required to be emitted (otherwise, it should be emitted only if needed
5053   /// by code generation).
5054   llvm::DenseMap<CXXRecordDecl *, bool> VTablesUsed;
5055 
5056   /// \brief Load any externally-stored vtable uses.
5057   void LoadExternalVTableUses();
5058 
5059   typedef LazyVector<CXXRecordDecl *, ExternalSemaSource,
5060                      &ExternalSemaSource::ReadDynamicClasses, 2, 2>
5061     DynamicClassesType;
5062 
5063   /// \brief A list of all of the dynamic classes in this translation
5064   /// unit.
5065   DynamicClassesType DynamicClasses;
5066 
5067   /// \brief Note that the vtable for the given class was used at the
5068   /// given location.
5069   void MarkVTableUsed(SourceLocation Loc, CXXRecordDecl *Class,
5070                       bool DefinitionRequired = false);
5071 
5072   /// \brief Mark the exception specifications of all virtual member functions
5073   /// in the given class as needed.
5074   void MarkVirtualMemberExceptionSpecsNeeded(SourceLocation Loc,
5075                                              const CXXRecordDecl *RD);
5076 
5077   /// MarkVirtualMembersReferenced - Will mark all members of the given
5078   /// CXXRecordDecl referenced.
5079   void MarkVirtualMembersReferenced(SourceLocation Loc,
5080                                     const CXXRecordDecl *RD);
5081 
5082   /// \brief Define all of the vtables that have been used in this
5083   /// translation unit and reference any virtual members used by those
5084   /// vtables.
5085   ///
5086   /// \returns true if any work was done, false otherwise.
5087   bool DefineUsedVTables();
5088 
5089   void AddImplicitlyDeclaredMembersToClass(CXXRecordDecl *ClassDecl);
5090 
5091   void ActOnMemInitializers(Decl *ConstructorDecl,
5092                             SourceLocation ColonLoc,
5093                             ArrayRef<CXXCtorInitializer*> MemInits,
5094                             bool AnyErrors);
5095 
5096   void CheckCompletedCXXClass(CXXRecordDecl *Record);
5097   void ActOnFinishCXXMemberSpecification(Scope* S, SourceLocation RLoc,
5098                                          Decl *TagDecl,
5099                                          SourceLocation LBrac,
5100                                          SourceLocation RBrac,
5101                                          AttributeList *AttrList);
5102   void ActOnFinishCXXMemberDecls();
5103 
5104   void ActOnReenterCXXMethodParameter(Scope *S, ParmVarDecl *Param);
5105   unsigned ActOnReenterTemplateScope(Scope *S, Decl *Template);
5106   void ActOnStartDelayedMemberDeclarations(Scope *S, Decl *Record);
5107   void ActOnStartDelayedCXXMethodDeclaration(Scope *S, Decl *Method);
5108   void ActOnDelayedCXXMethodParameter(Scope *S, Decl *Param);
5109   void ActOnFinishDelayedMemberDeclarations(Scope *S, Decl *Record);
5110   void ActOnFinishDelayedCXXMethodDeclaration(Scope *S, Decl *Method);
5111   void ActOnFinishDelayedMemberInitializers(Decl *Record);
5112   void MarkAsLateParsedTemplate(FunctionDecl *FD, Decl *FnD,
5113                                 CachedTokens &Toks);
5114   void UnmarkAsLateParsedTemplate(FunctionDecl *FD);
5115   bool IsInsideALocalClassWithinATemplateFunction();
5116 
5117   Decl *ActOnStaticAssertDeclaration(SourceLocation StaticAssertLoc,
5118                                      Expr *AssertExpr,
5119                                      Expr *AssertMessageExpr,
5120                                      SourceLocation RParenLoc);
5121   Decl *BuildStaticAssertDeclaration(SourceLocation StaticAssertLoc,
5122                                      Expr *AssertExpr,
5123                                      StringLiteral *AssertMessageExpr,
5124                                      SourceLocation RParenLoc,
5125                                      bool Failed);
5126 
5127   FriendDecl *CheckFriendTypeDecl(SourceLocation LocStart,
5128                                   SourceLocation FriendLoc,
5129                                   TypeSourceInfo *TSInfo);
5130   Decl *ActOnFriendTypeDecl(Scope *S, const DeclSpec &DS,
5131                             MultiTemplateParamsArg TemplateParams);
5132   NamedDecl *ActOnFriendFunctionDecl(Scope *S, Declarator &D,
5133                                      MultiTemplateParamsArg TemplateParams);
5134 
5135   QualType CheckConstructorDeclarator(Declarator &D, QualType R,
5136                                       StorageClass& SC);
5137   void CheckConstructor(CXXConstructorDecl *Constructor);
5138   QualType CheckDestructorDeclarator(Declarator &D, QualType R,
5139                                      StorageClass& SC);
5140   bool CheckDestructor(CXXDestructorDecl *Destructor);
5141   void CheckConversionDeclarator(Declarator &D, QualType &R,
5142                                  StorageClass& SC);
5143   Decl *ActOnConversionDeclarator(CXXConversionDecl *Conversion);
5144 
5145   void CheckExplicitlyDefaultedSpecialMember(CXXMethodDecl *MD);
5146   void CheckExplicitlyDefaultedMemberExceptionSpec(CXXMethodDecl *MD,
5147                                                    const FunctionProtoType *T);
5148   void CheckDelayedMemberExceptionSpecs();
5149 
5150   //===--------------------------------------------------------------------===//
5151   // C++ Derived Classes
5152   //
5153 
5154   /// ActOnBaseSpecifier - Parsed a base specifier
5155   CXXBaseSpecifier *CheckBaseSpecifier(CXXRecordDecl *Class,
5156                                        SourceRange SpecifierRange,
5157                                        bool Virtual, AccessSpecifier Access,
5158                                        TypeSourceInfo *TInfo,
5159                                        SourceLocation EllipsisLoc);
5160 
5161   BaseResult ActOnBaseSpecifier(Decl *classdecl,
5162                                 SourceRange SpecifierRange,
5163                                 ParsedAttributes &Attrs,
5164                                 bool Virtual, AccessSpecifier Access,
5165                                 ParsedType basetype,
5166                                 SourceLocation BaseLoc,
5167                                 SourceLocation EllipsisLoc);
5168 
5169   bool AttachBaseSpecifiers(CXXRecordDecl *Class, CXXBaseSpecifier **Bases,
5170                             unsigned NumBases);
5171   void ActOnBaseSpecifiers(Decl *ClassDecl, CXXBaseSpecifier **Bases,
5172                            unsigned NumBases);
5173 
5174   bool IsDerivedFrom(QualType Derived, QualType Base);
5175   bool IsDerivedFrom(QualType Derived, QualType Base, CXXBasePaths &Paths);
5176 
5177   // FIXME: I don't like this name.
5178   void BuildBasePathArray(const CXXBasePaths &Paths, CXXCastPath &BasePath);
5179 
5180   bool BasePathInvolvesVirtualBase(const CXXCastPath &BasePath);
5181 
5182   bool CheckDerivedToBaseConversion(QualType Derived, QualType Base,
5183                                     SourceLocation Loc, SourceRange Range,
5184                                     CXXCastPath *BasePath = nullptr,
5185                                     bool IgnoreAccess = false);
5186   bool CheckDerivedToBaseConversion(QualType Derived, QualType Base,
5187                                     unsigned InaccessibleBaseID,
5188                                     unsigned AmbigiousBaseConvID,
5189                                     SourceLocation Loc, SourceRange Range,
5190                                     DeclarationName Name,
5191                                     CXXCastPath *BasePath);
5192 
5193   std::string getAmbiguousPathsDisplayString(CXXBasePaths &Paths);
5194 
5195   bool CheckOverridingFunctionAttributes(const CXXMethodDecl *New,
5196                                          const CXXMethodDecl *Old);
5197 
5198   /// CheckOverridingFunctionReturnType - Checks whether the return types are
5199   /// covariant, according to C++ [class.virtual]p5.
5200   bool CheckOverridingFunctionReturnType(const CXXMethodDecl *New,
5201                                          const CXXMethodDecl *Old);
5202 
5203   /// CheckOverridingFunctionExceptionSpec - Checks whether the exception
5204   /// spec is a subset of base spec.
5205   bool CheckOverridingFunctionExceptionSpec(const CXXMethodDecl *New,
5206                                             const CXXMethodDecl *Old);
5207 
5208   bool CheckPureMethod(CXXMethodDecl *Method, SourceRange InitRange);
5209 
5210   /// CheckOverrideControl - Check C++11 override control semantics.
5211   void CheckOverrideControl(NamedDecl *D);
5212 
5213   /// DiagnoseAbsenceOfOverrideControl - Diagnose if 'override' keyword was
5214   /// not used in the declaration of an overriding method.
5215   void DiagnoseAbsenceOfOverrideControl(NamedDecl *D);
5216 
5217   /// CheckForFunctionMarkedFinal - Checks whether a virtual member function
5218   /// overrides a virtual member function marked 'final', according to
5219   /// C++11 [class.virtual]p4.
5220   bool CheckIfOverriddenFunctionIsMarkedFinal(const CXXMethodDecl *New,
5221                                               const CXXMethodDecl *Old);
5222 
5223 
5224   //===--------------------------------------------------------------------===//
5225   // C++ Access Control
5226   //
5227 
5228   enum AccessResult {
5229     AR_accessible,
5230     AR_inaccessible,
5231     AR_dependent,
5232     AR_delayed
5233   };
5234 
5235   bool SetMemberAccessSpecifier(NamedDecl *MemberDecl,
5236                                 NamedDecl *PrevMemberDecl,
5237                                 AccessSpecifier LexicalAS);
5238 
5239   AccessResult CheckUnresolvedMemberAccess(UnresolvedMemberExpr *E,
5240                                            DeclAccessPair FoundDecl);
5241   AccessResult CheckUnresolvedLookupAccess(UnresolvedLookupExpr *E,
5242                                            DeclAccessPair FoundDecl);
5243   AccessResult CheckAllocationAccess(SourceLocation OperatorLoc,
5244                                      SourceRange PlacementRange,
5245                                      CXXRecordDecl *NamingClass,
5246                                      DeclAccessPair FoundDecl,
5247                                      bool Diagnose = true);
5248   AccessResult CheckConstructorAccess(SourceLocation Loc,
5249                                       CXXConstructorDecl *D,
5250                                       const InitializedEntity &Entity,
5251                                       AccessSpecifier Access,
5252                                       bool IsCopyBindingRefToTemp = false);
5253   AccessResult CheckConstructorAccess(SourceLocation Loc,
5254                                       CXXConstructorDecl *D,
5255                                       const InitializedEntity &Entity,
5256                                       AccessSpecifier Access,
5257                                       const PartialDiagnostic &PDiag);
5258   AccessResult CheckDestructorAccess(SourceLocation Loc,
5259                                      CXXDestructorDecl *Dtor,
5260                                      const PartialDiagnostic &PDiag,
5261                                      QualType objectType = QualType());
5262   AccessResult CheckFriendAccess(NamedDecl *D);
5263   AccessResult CheckMemberAccess(SourceLocation UseLoc,
5264                                  CXXRecordDecl *NamingClass,
5265                                  DeclAccessPair Found);
5266   AccessResult CheckMemberOperatorAccess(SourceLocation Loc,
5267                                          Expr *ObjectExpr,
5268                                          Expr *ArgExpr,
5269                                          DeclAccessPair FoundDecl);
5270   AccessResult CheckAddressOfMemberAccess(Expr *OvlExpr,
5271                                           DeclAccessPair FoundDecl);
5272   AccessResult CheckBaseClassAccess(SourceLocation AccessLoc,
5273                                     QualType Base, QualType Derived,
5274                                     const CXXBasePath &Path,
5275                                     unsigned DiagID,
5276                                     bool ForceCheck = false,
5277                                     bool ForceUnprivileged = false);
5278   void CheckLookupAccess(const LookupResult &R);
5279   bool IsSimplyAccessible(NamedDecl *decl, DeclContext *Ctx);
5280   bool isSpecialMemberAccessibleForDeletion(CXXMethodDecl *decl,
5281                                             AccessSpecifier access,
5282                                             QualType objectType);
5283 
5284   void HandleDependentAccessCheck(const DependentDiagnostic &DD,
5285                          const MultiLevelTemplateArgumentList &TemplateArgs);
5286   void PerformDependentDiagnostics(const DeclContext *Pattern,
5287                         const MultiLevelTemplateArgumentList &TemplateArgs);
5288 
5289   void HandleDelayedAccessCheck(sema::DelayedDiagnostic &DD, Decl *Ctx);
5290 
5291   /// \brief When true, access checking violations are treated as SFINAE
5292   /// failures rather than hard errors.
5293   bool AccessCheckingSFINAE;
5294 
5295   enum AbstractDiagSelID {
5296     AbstractNone = -1,
5297     AbstractReturnType,
5298     AbstractParamType,
5299     AbstractVariableType,
5300     AbstractFieldType,
5301     AbstractIvarType,
5302     AbstractSynthesizedIvarType,
5303     AbstractArrayType
5304   };
5305 
5306   bool RequireNonAbstractType(SourceLocation Loc, QualType T,
5307                               TypeDiagnoser &Diagnoser);
5308   template<typename T1>
RequireNonAbstractType(SourceLocation Loc,QualType T,unsigned DiagID,const T1 & Arg1)5309   bool RequireNonAbstractType(SourceLocation Loc, QualType T,
5310                               unsigned DiagID,
5311                               const T1 &Arg1) {
5312     BoundTypeDiagnoser1<T1> Diagnoser(DiagID, Arg1);
5313     return RequireNonAbstractType(Loc, T, Diagnoser);
5314   }
5315 
5316   template<typename T1, typename T2>
RequireNonAbstractType(SourceLocation Loc,QualType T,unsigned DiagID,const T1 & Arg1,const T2 & Arg2)5317   bool RequireNonAbstractType(SourceLocation Loc, QualType T,
5318                               unsigned DiagID,
5319                               const T1 &Arg1, const T2 &Arg2) {
5320     BoundTypeDiagnoser2<T1, T2> Diagnoser(DiagID, Arg1, Arg2);
5321     return RequireNonAbstractType(Loc, T, Diagnoser);
5322   }
5323 
5324   template<typename T1, typename T2, typename T3>
RequireNonAbstractType(SourceLocation Loc,QualType T,unsigned DiagID,const T1 & Arg1,const T2 & Arg2,const T3 & Arg3)5325   bool RequireNonAbstractType(SourceLocation Loc, QualType T,
5326                               unsigned DiagID,
5327                               const T1 &Arg1, const T2 &Arg2, const T3 &Arg3) {
5328     BoundTypeDiagnoser3<T1, T2, T3> Diagnoser(DiagID, Arg1, Arg2, Arg3);
5329     return RequireNonAbstractType(Loc, T, Diagnoser);
5330   }
5331 
5332   void DiagnoseAbstractType(const CXXRecordDecl *RD);
5333 
5334   bool RequireNonAbstractType(SourceLocation Loc, QualType T, unsigned DiagID,
5335                               AbstractDiagSelID SelID = AbstractNone);
5336 
5337   //===--------------------------------------------------------------------===//
5338   // C++ Overloaded Operators [C++ 13.5]
5339   //
5340 
5341   bool CheckOverloadedOperatorDeclaration(FunctionDecl *FnDecl);
5342 
5343   bool CheckLiteralOperatorDeclaration(FunctionDecl *FnDecl);
5344 
5345   //===--------------------------------------------------------------------===//
5346   // C++ Templates [C++ 14]
5347   //
5348   void FilterAcceptableTemplateNames(LookupResult &R,
5349                                      bool AllowFunctionTemplates = true);
5350   bool hasAnyAcceptableTemplateNames(LookupResult &R,
5351                                      bool AllowFunctionTemplates = true);
5352 
5353   void LookupTemplateName(LookupResult &R, Scope *S, CXXScopeSpec &SS,
5354                           QualType ObjectType, bool EnteringContext,
5355                           bool &MemberOfUnknownSpecialization);
5356 
5357   TemplateNameKind isTemplateName(Scope *S,
5358                                   CXXScopeSpec &SS,
5359                                   bool hasTemplateKeyword,
5360                                   UnqualifiedId &Name,
5361                                   ParsedType ObjectType,
5362                                   bool EnteringContext,
5363                                   TemplateTy &Template,
5364                                   bool &MemberOfUnknownSpecialization);
5365 
5366   bool DiagnoseUnknownTemplateName(const IdentifierInfo &II,
5367                                    SourceLocation IILoc,
5368                                    Scope *S,
5369                                    const CXXScopeSpec *SS,
5370                                    TemplateTy &SuggestedTemplate,
5371                                    TemplateNameKind &SuggestedKind);
5372 
5373   void DiagnoseTemplateParameterShadow(SourceLocation Loc, Decl *PrevDecl);
5374   TemplateDecl *AdjustDeclIfTemplate(Decl *&Decl);
5375 
5376   Decl *ActOnTypeParameter(Scope *S, bool Typename,
5377                            SourceLocation EllipsisLoc,
5378                            SourceLocation KeyLoc,
5379                            IdentifierInfo *ParamName,
5380                            SourceLocation ParamNameLoc,
5381                            unsigned Depth, unsigned Position,
5382                            SourceLocation EqualLoc,
5383                            ParsedType DefaultArg);
5384 
5385   QualType CheckNonTypeTemplateParameterType(QualType T, SourceLocation Loc);
5386   Decl *ActOnNonTypeTemplateParameter(Scope *S, Declarator &D,
5387                                       unsigned Depth,
5388                                       unsigned Position,
5389                                       SourceLocation EqualLoc,
5390                                       Expr *DefaultArg);
5391   Decl *ActOnTemplateTemplateParameter(Scope *S,
5392                                        SourceLocation TmpLoc,
5393                                        TemplateParameterList *Params,
5394                                        SourceLocation EllipsisLoc,
5395                                        IdentifierInfo *ParamName,
5396                                        SourceLocation ParamNameLoc,
5397                                        unsigned Depth,
5398                                        unsigned Position,
5399                                        SourceLocation EqualLoc,
5400                                        ParsedTemplateArgument DefaultArg);
5401 
5402   TemplateParameterList *
5403   ActOnTemplateParameterList(unsigned Depth,
5404                              SourceLocation ExportLoc,
5405                              SourceLocation TemplateLoc,
5406                              SourceLocation LAngleLoc,
5407                              Decl **Params, unsigned NumParams,
5408                              SourceLocation RAngleLoc);
5409 
5410   /// \brief The context in which we are checking a template parameter list.
5411   enum TemplateParamListContext {
5412     TPC_ClassTemplate,
5413     TPC_VarTemplate,
5414     TPC_FunctionTemplate,
5415     TPC_ClassTemplateMember,
5416     TPC_FriendClassTemplate,
5417     TPC_FriendFunctionTemplate,
5418     TPC_FriendFunctionTemplateDefinition,
5419     TPC_TypeAliasTemplate
5420   };
5421 
5422   bool CheckTemplateParameterList(TemplateParameterList *NewParams,
5423                                   TemplateParameterList *OldParams,
5424                                   TemplateParamListContext TPC);
5425   TemplateParameterList *MatchTemplateParametersToScopeSpecifier(
5426       SourceLocation DeclStartLoc, SourceLocation DeclLoc,
5427       const CXXScopeSpec &SS, TemplateIdAnnotation *TemplateId,
5428       ArrayRef<TemplateParameterList *> ParamLists,
5429       bool IsFriend, bool &IsExplicitSpecialization, bool &Invalid);
5430 
5431   DeclResult CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK,
5432                                 SourceLocation KWLoc, CXXScopeSpec &SS,
5433                                 IdentifierInfo *Name, SourceLocation NameLoc,
5434                                 AttributeList *Attr,
5435                                 TemplateParameterList *TemplateParams,
5436                                 AccessSpecifier AS,
5437                                 SourceLocation ModulePrivateLoc,
5438                                 SourceLocation FriendLoc,
5439                                 unsigned NumOuterTemplateParamLists,
5440                             TemplateParameterList **OuterTemplateParamLists);
5441 
5442   void translateTemplateArguments(const ASTTemplateArgsPtr &In,
5443                                   TemplateArgumentListInfo &Out);
5444 
5445   void NoteAllFoundTemplates(TemplateName Name);
5446 
5447   QualType CheckTemplateIdType(TemplateName Template,
5448                                SourceLocation TemplateLoc,
5449                               TemplateArgumentListInfo &TemplateArgs);
5450 
5451   TypeResult
5452   ActOnTemplateIdType(CXXScopeSpec &SS, SourceLocation TemplateKWLoc,
5453                       TemplateTy Template, SourceLocation TemplateLoc,
5454                       SourceLocation LAngleLoc,
5455                       ASTTemplateArgsPtr TemplateArgs,
5456                       SourceLocation RAngleLoc,
5457                       bool IsCtorOrDtorName = false);
5458 
5459   /// \brief Parsed an elaborated-type-specifier that refers to a template-id,
5460   /// such as \c class T::template apply<U>.
5461   TypeResult ActOnTagTemplateIdType(TagUseKind TUK,
5462                                     TypeSpecifierType TagSpec,
5463                                     SourceLocation TagLoc,
5464                                     CXXScopeSpec &SS,
5465                                     SourceLocation TemplateKWLoc,
5466                                     TemplateTy TemplateD,
5467                                     SourceLocation TemplateLoc,
5468                                     SourceLocation LAngleLoc,
5469                                     ASTTemplateArgsPtr TemplateArgsIn,
5470                                     SourceLocation RAngleLoc);
5471 
5472   DeclResult ActOnVarTemplateSpecialization(
5473       Scope *S, Declarator &D, TypeSourceInfo *DI,
5474       SourceLocation TemplateKWLoc, TemplateParameterList *TemplateParams,
5475       StorageClass SC, bool IsPartialSpecialization);
5476 
5477   DeclResult CheckVarTemplateId(VarTemplateDecl *Template,
5478                                 SourceLocation TemplateLoc,
5479                                 SourceLocation TemplateNameLoc,
5480                                 const TemplateArgumentListInfo &TemplateArgs);
5481 
5482   ExprResult CheckVarTemplateId(const CXXScopeSpec &SS,
5483                                 const DeclarationNameInfo &NameInfo,
5484                                 VarTemplateDecl *Template,
5485                                 SourceLocation TemplateLoc,
5486                                 const TemplateArgumentListInfo *TemplateArgs);
5487 
5488   ExprResult BuildTemplateIdExpr(const CXXScopeSpec &SS,
5489                                  SourceLocation TemplateKWLoc,
5490                                  LookupResult &R,
5491                                  bool RequiresADL,
5492                                const TemplateArgumentListInfo *TemplateArgs);
5493 
5494   ExprResult BuildQualifiedTemplateIdExpr(CXXScopeSpec &SS,
5495                                           SourceLocation TemplateKWLoc,
5496                                const DeclarationNameInfo &NameInfo,
5497                                const TemplateArgumentListInfo *TemplateArgs);
5498 
5499   TemplateNameKind ActOnDependentTemplateName(Scope *S,
5500                                               CXXScopeSpec &SS,
5501                                               SourceLocation TemplateKWLoc,
5502                                               UnqualifiedId &Name,
5503                                               ParsedType ObjectType,
5504                                               bool EnteringContext,
5505                                               TemplateTy &Template);
5506 
5507   DeclResult
5508   ActOnClassTemplateSpecialization(Scope *S, unsigned TagSpec, TagUseKind TUK,
5509                                    SourceLocation KWLoc,
5510                                    SourceLocation ModulePrivateLoc,
5511                                    TemplateIdAnnotation &TemplateId,
5512                                    AttributeList *Attr,
5513                                  MultiTemplateParamsArg TemplateParameterLists);
5514 
5515   Decl *ActOnTemplateDeclarator(Scope *S,
5516                                 MultiTemplateParamsArg TemplateParameterLists,
5517                                 Declarator &D);
5518 
5519   Decl *ActOnStartOfFunctionTemplateDef(Scope *FnBodyScope,
5520                                   MultiTemplateParamsArg TemplateParameterLists,
5521                                         Declarator &D);
5522 
5523   bool
5524   CheckSpecializationInstantiationRedecl(SourceLocation NewLoc,
5525                                          TemplateSpecializationKind NewTSK,
5526                                          NamedDecl *PrevDecl,
5527                                          TemplateSpecializationKind PrevTSK,
5528                                          SourceLocation PrevPtOfInstantiation,
5529                                          bool &SuppressNew);
5530 
5531   bool CheckDependentFunctionTemplateSpecialization(FunctionDecl *FD,
5532                     const TemplateArgumentListInfo &ExplicitTemplateArgs,
5533                                                     LookupResult &Previous);
5534 
5535   bool CheckFunctionTemplateSpecialization(FunctionDecl *FD,
5536                          TemplateArgumentListInfo *ExplicitTemplateArgs,
5537                                            LookupResult &Previous);
5538   bool CheckMemberSpecialization(NamedDecl *Member, LookupResult &Previous);
5539 
5540   DeclResult
5541   ActOnExplicitInstantiation(Scope *S,
5542                              SourceLocation ExternLoc,
5543                              SourceLocation TemplateLoc,
5544                              unsigned TagSpec,
5545                              SourceLocation KWLoc,
5546                              const CXXScopeSpec &SS,
5547                              TemplateTy Template,
5548                              SourceLocation TemplateNameLoc,
5549                              SourceLocation LAngleLoc,
5550                              ASTTemplateArgsPtr TemplateArgs,
5551                              SourceLocation RAngleLoc,
5552                              AttributeList *Attr);
5553 
5554   DeclResult
5555   ActOnExplicitInstantiation(Scope *S,
5556                              SourceLocation ExternLoc,
5557                              SourceLocation TemplateLoc,
5558                              unsigned TagSpec,
5559                              SourceLocation KWLoc,
5560                              CXXScopeSpec &SS,
5561                              IdentifierInfo *Name,
5562                              SourceLocation NameLoc,
5563                              AttributeList *Attr);
5564 
5565   DeclResult ActOnExplicitInstantiation(Scope *S,
5566                                         SourceLocation ExternLoc,
5567                                         SourceLocation TemplateLoc,
5568                                         Declarator &D);
5569 
5570   TemplateArgumentLoc
5571   SubstDefaultTemplateArgumentIfAvailable(TemplateDecl *Template,
5572                                           SourceLocation TemplateLoc,
5573                                           SourceLocation RAngleLoc,
5574                                           Decl *Param,
5575                                           SmallVectorImpl<TemplateArgument>
5576                                             &Converted,
5577                                           bool &HasDefaultArg);
5578 
5579   /// \brief Specifies the context in which a particular template
5580   /// argument is being checked.
5581   enum CheckTemplateArgumentKind {
5582     /// \brief The template argument was specified in the code or was
5583     /// instantiated with some deduced template arguments.
5584     CTAK_Specified,
5585 
5586     /// \brief The template argument was deduced via template argument
5587     /// deduction.
5588     CTAK_Deduced,
5589 
5590     /// \brief The template argument was deduced from an array bound
5591     /// via template argument deduction.
5592     CTAK_DeducedFromArrayBound
5593   };
5594 
5595   bool CheckTemplateArgument(NamedDecl *Param,
5596                              TemplateArgumentLoc &Arg,
5597                              NamedDecl *Template,
5598                              SourceLocation TemplateLoc,
5599                              SourceLocation RAngleLoc,
5600                              unsigned ArgumentPackIndex,
5601                            SmallVectorImpl<TemplateArgument> &Converted,
5602                              CheckTemplateArgumentKind CTAK = CTAK_Specified);
5603 
5604   /// \brief Check that the given template arguments can be be provided to
5605   /// the given template, converting the arguments along the way.
5606   ///
5607   /// \param Template The template to which the template arguments are being
5608   /// provided.
5609   ///
5610   /// \param TemplateLoc The location of the template name in the source.
5611   ///
5612   /// \param TemplateArgs The list of template arguments. If the template is
5613   /// a template template parameter, this function may extend the set of
5614   /// template arguments to also include substituted, defaulted template
5615   /// arguments.
5616   ///
5617   /// \param PartialTemplateArgs True if the list of template arguments is
5618   /// intentionally partial, e.g., because we're checking just the initial
5619   /// set of template arguments.
5620   ///
5621   /// \param Converted Will receive the converted, canonicalized template
5622   /// arguments.
5623   ///
5624   /// \returns true if an error occurred, false otherwise.
5625   bool CheckTemplateArgumentList(TemplateDecl *Template,
5626                                  SourceLocation TemplateLoc,
5627                                  TemplateArgumentListInfo &TemplateArgs,
5628                                  bool PartialTemplateArgs,
5629                            SmallVectorImpl<TemplateArgument> &Converted);
5630 
5631   bool CheckTemplateTypeArgument(TemplateTypeParmDecl *Param,
5632                                  TemplateArgumentLoc &Arg,
5633                            SmallVectorImpl<TemplateArgument> &Converted);
5634 
5635   bool CheckTemplateArgument(TemplateTypeParmDecl *Param,
5636                              TypeSourceInfo *Arg);
5637   ExprResult CheckTemplateArgument(NonTypeTemplateParmDecl *Param,
5638                                    QualType InstantiatedParamType, Expr *Arg,
5639                                    TemplateArgument &Converted,
5640                                CheckTemplateArgumentKind CTAK = CTAK_Specified);
5641   bool CheckTemplateArgument(TemplateTemplateParmDecl *Param,
5642                              TemplateArgumentLoc &Arg,
5643                              unsigned ArgumentPackIndex);
5644 
5645   ExprResult
5646   BuildExpressionFromDeclTemplateArgument(const TemplateArgument &Arg,
5647                                           QualType ParamType,
5648                                           SourceLocation Loc);
5649   ExprResult
5650   BuildExpressionFromIntegralTemplateArgument(const TemplateArgument &Arg,
5651                                               SourceLocation Loc);
5652 
5653   /// \brief Enumeration describing how template parameter lists are compared
5654   /// for equality.
5655   enum TemplateParameterListEqualKind {
5656     /// \brief We are matching the template parameter lists of two templates
5657     /// that might be redeclarations.
5658     ///
5659     /// \code
5660     /// template<typename T> struct X;
5661     /// template<typename T> struct X;
5662     /// \endcode
5663     TPL_TemplateMatch,
5664 
5665     /// \brief We are matching the template parameter lists of two template
5666     /// template parameters as part of matching the template parameter lists
5667     /// of two templates that might be redeclarations.
5668     ///
5669     /// \code
5670     /// template<template<int I> class TT> struct X;
5671     /// template<template<int Value> class Other> struct X;
5672     /// \endcode
5673     TPL_TemplateTemplateParmMatch,
5674 
5675     /// \brief We are matching the template parameter lists of a template
5676     /// template argument against the template parameter lists of a template
5677     /// template parameter.
5678     ///
5679     /// \code
5680     /// template<template<int Value> class Metafun> struct X;
5681     /// template<int Value> struct integer_c;
5682     /// X<integer_c> xic;
5683     /// \endcode
5684     TPL_TemplateTemplateArgumentMatch
5685   };
5686 
5687   bool TemplateParameterListsAreEqual(TemplateParameterList *New,
5688                                       TemplateParameterList *Old,
5689                                       bool Complain,
5690                                       TemplateParameterListEqualKind Kind,
5691                                       SourceLocation TemplateArgLoc
5692                                         = SourceLocation());
5693 
5694   bool CheckTemplateDeclScope(Scope *S, TemplateParameterList *TemplateParams);
5695 
5696   /// \brief Called when the parser has parsed a C++ typename
5697   /// specifier, e.g., "typename T::type".
5698   ///
5699   /// \param S The scope in which this typename type occurs.
5700   /// \param TypenameLoc the location of the 'typename' keyword
5701   /// \param SS the nested-name-specifier following the typename (e.g., 'T::').
5702   /// \param II the identifier we're retrieving (e.g., 'type' in the example).
5703   /// \param IdLoc the location of the identifier.
5704   TypeResult
5705   ActOnTypenameType(Scope *S, SourceLocation TypenameLoc,
5706                     const CXXScopeSpec &SS, const IdentifierInfo &II,
5707                     SourceLocation IdLoc);
5708 
5709   /// \brief Called when the parser has parsed a C++ typename
5710   /// specifier that ends in a template-id, e.g.,
5711   /// "typename MetaFun::template apply<T1, T2>".
5712   ///
5713   /// \param S The scope in which this typename type occurs.
5714   /// \param TypenameLoc the location of the 'typename' keyword
5715   /// \param SS the nested-name-specifier following the typename (e.g., 'T::').
5716   /// \param TemplateLoc the location of the 'template' keyword, if any.
5717   /// \param TemplateName The template name.
5718   /// \param TemplateNameLoc The location of the template name.
5719   /// \param LAngleLoc The location of the opening angle bracket  ('<').
5720   /// \param TemplateArgs The template arguments.
5721   /// \param RAngleLoc The location of the closing angle bracket  ('>').
5722   TypeResult
5723   ActOnTypenameType(Scope *S, SourceLocation TypenameLoc,
5724                     const CXXScopeSpec &SS,
5725                     SourceLocation TemplateLoc,
5726                     TemplateTy TemplateName,
5727                     SourceLocation TemplateNameLoc,
5728                     SourceLocation LAngleLoc,
5729                     ASTTemplateArgsPtr TemplateArgs,
5730                     SourceLocation RAngleLoc);
5731 
5732   QualType CheckTypenameType(ElaboratedTypeKeyword Keyword,
5733                              SourceLocation KeywordLoc,
5734                              NestedNameSpecifierLoc QualifierLoc,
5735                              const IdentifierInfo &II,
5736                              SourceLocation IILoc);
5737 
5738   TypeSourceInfo *RebuildTypeInCurrentInstantiation(TypeSourceInfo *T,
5739                                                     SourceLocation Loc,
5740                                                     DeclarationName Name);
5741   bool RebuildNestedNameSpecifierInCurrentInstantiation(CXXScopeSpec &SS);
5742 
5743   ExprResult RebuildExprInCurrentInstantiation(Expr *E);
5744   bool RebuildTemplateParamsInCurrentInstantiation(
5745                                                 TemplateParameterList *Params);
5746 
5747   std::string
5748   getTemplateArgumentBindingsText(const TemplateParameterList *Params,
5749                                   const TemplateArgumentList &Args);
5750 
5751   std::string
5752   getTemplateArgumentBindingsText(const TemplateParameterList *Params,
5753                                   const TemplateArgument *Args,
5754                                   unsigned NumArgs);
5755 
5756   //===--------------------------------------------------------------------===//
5757   // C++ Variadic Templates (C++0x [temp.variadic])
5758   //===--------------------------------------------------------------------===//
5759 
5760   /// Determine whether an unexpanded parameter pack might be permitted in this
5761   /// location. Useful for error recovery.
5762   bool isUnexpandedParameterPackPermitted();
5763 
5764   /// \brief The context in which an unexpanded parameter pack is
5765   /// being diagnosed.
5766   ///
5767   /// Note that the values of this enumeration line up with the first
5768   /// argument to the \c err_unexpanded_parameter_pack diagnostic.
5769   enum UnexpandedParameterPackContext {
5770     /// \brief An arbitrary expression.
5771     UPPC_Expression = 0,
5772 
5773     /// \brief The base type of a class type.
5774     UPPC_BaseType,
5775 
5776     /// \brief The type of an arbitrary declaration.
5777     UPPC_DeclarationType,
5778 
5779     /// \brief The type of a data member.
5780     UPPC_DataMemberType,
5781 
5782     /// \brief The size of a bit-field.
5783     UPPC_BitFieldWidth,
5784 
5785     /// \brief The expression in a static assertion.
5786     UPPC_StaticAssertExpression,
5787 
5788     /// \brief The fixed underlying type of an enumeration.
5789     UPPC_FixedUnderlyingType,
5790 
5791     /// \brief The enumerator value.
5792     UPPC_EnumeratorValue,
5793 
5794     /// \brief A using declaration.
5795     UPPC_UsingDeclaration,
5796 
5797     /// \brief A friend declaration.
5798     UPPC_FriendDeclaration,
5799 
5800     /// \brief A declaration qualifier.
5801     UPPC_DeclarationQualifier,
5802 
5803     /// \brief An initializer.
5804     UPPC_Initializer,
5805 
5806     /// \brief A default argument.
5807     UPPC_DefaultArgument,
5808 
5809     /// \brief The type of a non-type template parameter.
5810     UPPC_NonTypeTemplateParameterType,
5811 
5812     /// \brief The type of an exception.
5813     UPPC_ExceptionType,
5814 
5815     /// \brief Partial specialization.
5816     UPPC_PartialSpecialization,
5817 
5818     /// \brief Microsoft __if_exists.
5819     UPPC_IfExists,
5820 
5821     /// \brief Microsoft __if_not_exists.
5822     UPPC_IfNotExists,
5823 
5824     /// \brief Lambda expression.
5825     UPPC_Lambda,
5826 
5827     /// \brief Block expression,
5828     UPPC_Block
5829   };
5830 
5831   /// \brief Diagnose unexpanded parameter packs.
5832   ///
5833   /// \param Loc The location at which we should emit the diagnostic.
5834   ///
5835   /// \param UPPC The context in which we are diagnosing unexpanded
5836   /// parameter packs.
5837   ///
5838   /// \param Unexpanded the set of unexpanded parameter packs.
5839   ///
5840   /// \returns true if an error occurred, false otherwise.
5841   bool DiagnoseUnexpandedParameterPacks(SourceLocation Loc,
5842                                         UnexpandedParameterPackContext UPPC,
5843                                   ArrayRef<UnexpandedParameterPack> Unexpanded);
5844 
5845   /// \brief If the given type contains an unexpanded parameter pack,
5846   /// diagnose the error.
5847   ///
5848   /// \param Loc The source location where a diagnostc should be emitted.
5849   ///
5850   /// \param T The type that is being checked for unexpanded parameter
5851   /// packs.
5852   ///
5853   /// \returns true if an error occurred, false otherwise.
5854   bool DiagnoseUnexpandedParameterPack(SourceLocation Loc, TypeSourceInfo *T,
5855                                        UnexpandedParameterPackContext UPPC);
5856 
5857   /// \brief If the given expression contains an unexpanded parameter
5858   /// pack, diagnose the error.
5859   ///
5860   /// \param E The expression that is being checked for unexpanded
5861   /// parameter packs.
5862   ///
5863   /// \returns true if an error occurred, false otherwise.
5864   bool DiagnoseUnexpandedParameterPack(Expr *E,
5865                        UnexpandedParameterPackContext UPPC = UPPC_Expression);
5866 
5867   /// \brief If the given nested-name-specifier contains an unexpanded
5868   /// parameter pack, diagnose the error.
5869   ///
5870   /// \param SS The nested-name-specifier that is being checked for
5871   /// unexpanded parameter packs.
5872   ///
5873   /// \returns true if an error occurred, false otherwise.
5874   bool DiagnoseUnexpandedParameterPack(const CXXScopeSpec &SS,
5875                                        UnexpandedParameterPackContext UPPC);
5876 
5877   /// \brief If the given name contains an unexpanded parameter pack,
5878   /// diagnose the error.
5879   ///
5880   /// \param NameInfo The name (with source location information) that
5881   /// is being checked for unexpanded parameter packs.
5882   ///
5883   /// \returns true if an error occurred, false otherwise.
5884   bool DiagnoseUnexpandedParameterPack(const DeclarationNameInfo &NameInfo,
5885                                        UnexpandedParameterPackContext UPPC);
5886 
5887   /// \brief If the given template name contains an unexpanded parameter pack,
5888   /// diagnose the error.
5889   ///
5890   /// \param Loc The location of the template name.
5891   ///
5892   /// \param Template The template name that is being checked for unexpanded
5893   /// parameter packs.
5894   ///
5895   /// \returns true if an error occurred, false otherwise.
5896   bool DiagnoseUnexpandedParameterPack(SourceLocation Loc,
5897                                        TemplateName Template,
5898                                        UnexpandedParameterPackContext UPPC);
5899 
5900   /// \brief If the given template argument contains an unexpanded parameter
5901   /// pack, diagnose the error.
5902   ///
5903   /// \param Arg The template argument that is being checked for unexpanded
5904   /// parameter packs.
5905   ///
5906   /// \returns true if an error occurred, false otherwise.
5907   bool DiagnoseUnexpandedParameterPack(TemplateArgumentLoc Arg,
5908                                        UnexpandedParameterPackContext UPPC);
5909 
5910   /// \brief Collect the set of unexpanded parameter packs within the given
5911   /// template argument.
5912   ///
5913   /// \param Arg The template argument that will be traversed to find
5914   /// unexpanded parameter packs.
5915   void collectUnexpandedParameterPacks(TemplateArgument Arg,
5916                    SmallVectorImpl<UnexpandedParameterPack> &Unexpanded);
5917 
5918   /// \brief Collect the set of unexpanded parameter packs within the given
5919   /// template argument.
5920   ///
5921   /// \param Arg The template argument that will be traversed to find
5922   /// unexpanded parameter packs.
5923   void collectUnexpandedParameterPacks(TemplateArgumentLoc Arg,
5924                     SmallVectorImpl<UnexpandedParameterPack> &Unexpanded);
5925 
5926   /// \brief Collect the set of unexpanded parameter packs within the given
5927   /// type.
5928   ///
5929   /// \param T The type that will be traversed to find
5930   /// unexpanded parameter packs.
5931   void collectUnexpandedParameterPacks(QualType T,
5932                    SmallVectorImpl<UnexpandedParameterPack> &Unexpanded);
5933 
5934   /// \brief Collect the set of unexpanded parameter packs within the given
5935   /// type.
5936   ///
5937   /// \param TL The type that will be traversed to find
5938   /// unexpanded parameter packs.
5939   void collectUnexpandedParameterPacks(TypeLoc TL,
5940                    SmallVectorImpl<UnexpandedParameterPack> &Unexpanded);
5941 
5942   /// \brief Collect the set of unexpanded parameter packs within the given
5943   /// nested-name-specifier.
5944   ///
5945   /// \param SS The nested-name-specifier that will be traversed to find
5946   /// unexpanded parameter packs.
5947   void collectUnexpandedParameterPacks(CXXScopeSpec &SS,
5948                          SmallVectorImpl<UnexpandedParameterPack> &Unexpanded);
5949 
5950   /// \brief Collect the set of unexpanded parameter packs within the given
5951   /// name.
5952   ///
5953   /// \param NameInfo The name that will be traversed to find
5954   /// unexpanded parameter packs.
5955   void collectUnexpandedParameterPacks(const DeclarationNameInfo &NameInfo,
5956                          SmallVectorImpl<UnexpandedParameterPack> &Unexpanded);
5957 
5958   /// \brief Invoked when parsing a template argument followed by an
5959   /// ellipsis, which creates a pack expansion.
5960   ///
5961   /// \param Arg The template argument preceding the ellipsis, which
5962   /// may already be invalid.
5963   ///
5964   /// \param EllipsisLoc The location of the ellipsis.
5965   ParsedTemplateArgument ActOnPackExpansion(const ParsedTemplateArgument &Arg,
5966                                             SourceLocation EllipsisLoc);
5967 
5968   /// \brief Invoked when parsing a type followed by an ellipsis, which
5969   /// creates a pack expansion.
5970   ///
5971   /// \param Type The type preceding the ellipsis, which will become
5972   /// the pattern of the pack expansion.
5973   ///
5974   /// \param EllipsisLoc The location of the ellipsis.
5975   TypeResult ActOnPackExpansion(ParsedType Type, SourceLocation EllipsisLoc);
5976 
5977   /// \brief Construct a pack expansion type from the pattern of the pack
5978   /// expansion.
5979   TypeSourceInfo *CheckPackExpansion(TypeSourceInfo *Pattern,
5980                                      SourceLocation EllipsisLoc,
5981                                      Optional<unsigned> NumExpansions);
5982 
5983   /// \brief Construct a pack expansion type from the pattern of the pack
5984   /// expansion.
5985   QualType CheckPackExpansion(QualType Pattern,
5986                               SourceRange PatternRange,
5987                               SourceLocation EllipsisLoc,
5988                               Optional<unsigned> NumExpansions);
5989 
5990   /// \brief Invoked when parsing an expression followed by an ellipsis, which
5991   /// creates a pack expansion.
5992   ///
5993   /// \param Pattern The expression preceding the ellipsis, which will become
5994   /// the pattern of the pack expansion.
5995   ///
5996   /// \param EllipsisLoc The location of the ellipsis.
5997   ExprResult ActOnPackExpansion(Expr *Pattern, SourceLocation EllipsisLoc);
5998 
5999   /// \brief Invoked when parsing an expression followed by an ellipsis, which
6000   /// creates a pack expansion.
6001   ///
6002   /// \param Pattern The expression preceding the ellipsis, which will become
6003   /// the pattern of the pack expansion.
6004   ///
6005   /// \param EllipsisLoc The location of the ellipsis.
6006   ExprResult CheckPackExpansion(Expr *Pattern, SourceLocation EllipsisLoc,
6007                                 Optional<unsigned> NumExpansions);
6008 
6009   /// \brief Determine whether we could expand a pack expansion with the
6010   /// given set of parameter packs into separate arguments by repeatedly
6011   /// transforming the pattern.
6012   ///
6013   /// \param EllipsisLoc The location of the ellipsis that identifies the
6014   /// pack expansion.
6015   ///
6016   /// \param PatternRange The source range that covers the entire pattern of
6017   /// the pack expansion.
6018   ///
6019   /// \param Unexpanded The set of unexpanded parameter packs within the
6020   /// pattern.
6021   ///
6022   /// \param ShouldExpand Will be set to \c true if the transformer should
6023   /// expand the corresponding pack expansions into separate arguments. When
6024   /// set, \c NumExpansions must also be set.
6025   ///
6026   /// \param RetainExpansion Whether the caller should add an unexpanded
6027   /// pack expansion after all of the expanded arguments. This is used
6028   /// when extending explicitly-specified template argument packs per
6029   /// C++0x [temp.arg.explicit]p9.
6030   ///
6031   /// \param NumExpansions The number of separate arguments that will be in
6032   /// the expanded form of the corresponding pack expansion. This is both an
6033   /// input and an output parameter, which can be set by the caller if the
6034   /// number of expansions is known a priori (e.g., due to a prior substitution)
6035   /// and will be set by the callee when the number of expansions is known.
6036   /// The callee must set this value when \c ShouldExpand is \c true; it may
6037   /// set this value in other cases.
6038   ///
6039   /// \returns true if an error occurred (e.g., because the parameter packs
6040   /// are to be instantiated with arguments of different lengths), false
6041   /// otherwise. If false, \c ShouldExpand (and possibly \c NumExpansions)
6042   /// must be set.
6043   bool CheckParameterPacksForExpansion(SourceLocation EllipsisLoc,
6044                                        SourceRange PatternRange,
6045                              ArrayRef<UnexpandedParameterPack> Unexpanded,
6046                              const MultiLevelTemplateArgumentList &TemplateArgs,
6047                                        bool &ShouldExpand,
6048                                        bool &RetainExpansion,
6049                                        Optional<unsigned> &NumExpansions);
6050 
6051   /// \brief Determine the number of arguments in the given pack expansion
6052   /// type.
6053   ///
6054   /// This routine assumes that the number of arguments in the expansion is
6055   /// consistent across all of the unexpanded parameter packs in its pattern.
6056   ///
6057   /// Returns an empty Optional if the type can't be expanded.
6058   Optional<unsigned> getNumArgumentsInExpansion(QualType T,
6059       const MultiLevelTemplateArgumentList &TemplateArgs);
6060 
6061   /// \brief Determine whether the given declarator contains any unexpanded
6062   /// parameter packs.
6063   ///
6064   /// This routine is used by the parser to disambiguate function declarators
6065   /// with an ellipsis prior to the ')', e.g.,
6066   ///
6067   /// \code
6068   ///   void f(T...);
6069   /// \endcode
6070   ///
6071   /// To determine whether we have an (unnamed) function parameter pack or
6072   /// a variadic function.
6073   ///
6074   /// \returns true if the declarator contains any unexpanded parameter packs,
6075   /// false otherwise.
6076   bool containsUnexpandedParameterPacks(Declarator &D);
6077 
6078   /// \brief Returns the pattern of the pack expansion for a template argument.
6079   ///
6080   /// \param OrigLoc The template argument to expand.
6081   ///
6082   /// \param Ellipsis Will be set to the location of the ellipsis.
6083   ///
6084   /// \param NumExpansions Will be set to the number of expansions that will
6085   /// be generated from this pack expansion, if known a priori.
6086   TemplateArgumentLoc getTemplateArgumentPackExpansionPattern(
6087       TemplateArgumentLoc OrigLoc,
6088       SourceLocation &Ellipsis,
6089       Optional<unsigned> &NumExpansions) const;
6090 
6091   //===--------------------------------------------------------------------===//
6092   // C++ Template Argument Deduction (C++ [temp.deduct])
6093   //===--------------------------------------------------------------------===//
6094 
6095   QualType adjustCCAndNoReturn(QualType ArgFunctionType, QualType FunctionType);
6096 
6097   /// \brief Describes the result of template argument deduction.
6098   ///
6099   /// The TemplateDeductionResult enumeration describes the result of
6100   /// template argument deduction, as returned from
6101   /// DeduceTemplateArguments(). The separate TemplateDeductionInfo
6102   /// structure provides additional information about the results of
6103   /// template argument deduction, e.g., the deduced template argument
6104   /// list (if successful) or the specific template parameters or
6105   /// deduced arguments that were involved in the failure.
6106   enum TemplateDeductionResult {
6107     /// \brief Template argument deduction was successful.
6108     TDK_Success = 0,
6109     /// \brief The declaration was invalid; do nothing.
6110     TDK_Invalid,
6111     /// \brief Template argument deduction exceeded the maximum template
6112     /// instantiation depth (which has already been diagnosed).
6113     TDK_InstantiationDepth,
6114     /// \brief Template argument deduction did not deduce a value
6115     /// for every template parameter.
6116     TDK_Incomplete,
6117     /// \brief Template argument deduction produced inconsistent
6118     /// deduced values for the given template parameter.
6119     TDK_Inconsistent,
6120     /// \brief Template argument deduction failed due to inconsistent
6121     /// cv-qualifiers on a template parameter type that would
6122     /// otherwise be deduced, e.g., we tried to deduce T in "const T"
6123     /// but were given a non-const "X".
6124     TDK_Underqualified,
6125     /// \brief Substitution of the deduced template argument values
6126     /// resulted in an error.
6127     TDK_SubstitutionFailure,
6128     /// \brief A non-depnedent component of the parameter did not match the
6129     /// corresponding component of the argument.
6130     TDK_NonDeducedMismatch,
6131     /// \brief When performing template argument deduction for a function
6132     /// template, there were too many call arguments.
6133     TDK_TooManyArguments,
6134     /// \brief When performing template argument deduction for a function
6135     /// template, there were too few call arguments.
6136     TDK_TooFewArguments,
6137     /// \brief The explicitly-specified template arguments were not valid
6138     /// template arguments for the given template.
6139     TDK_InvalidExplicitArguments,
6140     /// \brief The arguments included an overloaded function name that could
6141     /// not be resolved to a suitable function.
6142     TDK_FailedOverloadResolution,
6143     /// \brief Deduction failed; that's all we know.
6144     TDK_MiscellaneousDeductionFailure
6145   };
6146 
6147   TemplateDeductionResult
6148   DeduceTemplateArguments(ClassTemplatePartialSpecializationDecl *Partial,
6149                           const TemplateArgumentList &TemplateArgs,
6150                           sema::TemplateDeductionInfo &Info);
6151 
6152   TemplateDeductionResult
6153   DeduceTemplateArguments(VarTemplatePartialSpecializationDecl *Partial,
6154                           const TemplateArgumentList &TemplateArgs,
6155                           sema::TemplateDeductionInfo &Info);
6156 
6157   TemplateDeductionResult SubstituteExplicitTemplateArguments(
6158       FunctionTemplateDecl *FunctionTemplate,
6159       TemplateArgumentListInfo &ExplicitTemplateArgs,
6160       SmallVectorImpl<DeducedTemplateArgument> &Deduced,
6161       SmallVectorImpl<QualType> &ParamTypes, QualType *FunctionType,
6162       sema::TemplateDeductionInfo &Info);
6163 
6164   /// brief A function argument from which we performed template argument
6165   // deduction for a call.
6166   struct OriginalCallArg {
OriginalCallArgOriginalCallArg6167     OriginalCallArg(QualType OriginalParamType,
6168                     unsigned ArgIdx,
6169                     QualType OriginalArgType)
6170       : OriginalParamType(OriginalParamType), ArgIdx(ArgIdx),
6171         OriginalArgType(OriginalArgType) { }
6172 
6173     QualType OriginalParamType;
6174     unsigned ArgIdx;
6175     QualType OriginalArgType;
6176   };
6177 
6178   TemplateDeductionResult
6179   FinishTemplateArgumentDeduction(FunctionTemplateDecl *FunctionTemplate,
6180                       SmallVectorImpl<DeducedTemplateArgument> &Deduced,
6181                                   unsigned NumExplicitlySpecified,
6182                                   FunctionDecl *&Specialization,
6183                                   sema::TemplateDeductionInfo &Info,
6184            SmallVectorImpl<OriginalCallArg> const *OriginalCallArgs = nullptr);
6185 
6186   TemplateDeductionResult
6187   DeduceTemplateArguments(FunctionTemplateDecl *FunctionTemplate,
6188                           TemplateArgumentListInfo *ExplicitTemplateArgs,
6189                           ArrayRef<Expr *> Args,
6190                           FunctionDecl *&Specialization,
6191                           sema::TemplateDeductionInfo &Info);
6192 
6193   TemplateDeductionResult
6194   DeduceTemplateArguments(FunctionTemplateDecl *FunctionTemplate,
6195                           TemplateArgumentListInfo *ExplicitTemplateArgs,
6196                           QualType ArgFunctionType,
6197                           FunctionDecl *&Specialization,
6198                           sema::TemplateDeductionInfo &Info,
6199                           bool InOverloadResolution = false);
6200 
6201   TemplateDeductionResult
6202   DeduceTemplateArguments(FunctionTemplateDecl *FunctionTemplate,
6203                           QualType ToType,
6204                           CXXConversionDecl *&Specialization,
6205                           sema::TemplateDeductionInfo &Info);
6206 
6207   TemplateDeductionResult
6208   DeduceTemplateArguments(FunctionTemplateDecl *FunctionTemplate,
6209                           TemplateArgumentListInfo *ExplicitTemplateArgs,
6210                           FunctionDecl *&Specialization,
6211                           sema::TemplateDeductionInfo &Info,
6212                           bool InOverloadResolution = false);
6213 
6214   /// \brief Substitute Replacement for \p auto in \p TypeWithAuto
6215   QualType SubstAutoType(QualType TypeWithAuto, QualType Replacement);
6216   /// \brief Substitute Replacement for auto in TypeWithAuto
6217   TypeSourceInfo* SubstAutoTypeSourceInfo(TypeSourceInfo *TypeWithAuto,
6218                                           QualType Replacement);
6219 
6220   /// \brief Result type of DeduceAutoType.
6221   enum DeduceAutoResult {
6222     DAR_Succeeded,
6223     DAR_Failed,
6224     DAR_FailedAlreadyDiagnosed
6225   };
6226 
6227   DeduceAutoResult DeduceAutoType(TypeSourceInfo *AutoType, Expr *&Initializer,
6228                                   QualType &Result);
6229   DeduceAutoResult DeduceAutoType(TypeLoc AutoTypeLoc, Expr *&Initializer,
6230                                   QualType &Result);
6231   void DiagnoseAutoDeductionFailure(VarDecl *VDecl, Expr *Init);
6232   bool DeduceReturnType(FunctionDecl *FD, SourceLocation Loc,
6233                         bool Diagnose = true);
6234 
6235   TypeLoc getReturnTypeLoc(FunctionDecl *FD) const;
6236 
6237   bool DeduceFunctionTypeFromReturnExpr(FunctionDecl *FD,
6238                                         SourceLocation ReturnLoc,
6239                                         Expr *&RetExpr, AutoType *AT);
6240 
6241   FunctionTemplateDecl *getMoreSpecializedTemplate(FunctionTemplateDecl *FT1,
6242                                                    FunctionTemplateDecl *FT2,
6243                                                    SourceLocation Loc,
6244                                            TemplatePartialOrderingContext TPOC,
6245                                                    unsigned NumCallArguments1,
6246                                                    unsigned NumCallArguments2);
6247   UnresolvedSetIterator
6248   getMostSpecialized(UnresolvedSetIterator SBegin, UnresolvedSetIterator SEnd,
6249                      TemplateSpecCandidateSet &FailedCandidates,
6250                      SourceLocation Loc,
6251                      const PartialDiagnostic &NoneDiag,
6252                      const PartialDiagnostic &AmbigDiag,
6253                      const PartialDiagnostic &CandidateDiag,
6254                      bool Complain = true, QualType TargetType = QualType());
6255 
6256   ClassTemplatePartialSpecializationDecl *
6257   getMoreSpecializedPartialSpecialization(
6258                                   ClassTemplatePartialSpecializationDecl *PS1,
6259                                   ClassTemplatePartialSpecializationDecl *PS2,
6260                                   SourceLocation Loc);
6261 
6262   VarTemplatePartialSpecializationDecl *getMoreSpecializedPartialSpecialization(
6263       VarTemplatePartialSpecializationDecl *PS1,
6264       VarTemplatePartialSpecializationDecl *PS2, SourceLocation Loc);
6265 
6266   void MarkUsedTemplateParameters(const TemplateArgumentList &TemplateArgs,
6267                                   bool OnlyDeduced,
6268                                   unsigned Depth,
6269                                   llvm::SmallBitVector &Used);
MarkDeducedTemplateParameters(const FunctionTemplateDecl * FunctionTemplate,llvm::SmallBitVector & Deduced)6270   void MarkDeducedTemplateParameters(
6271                                   const FunctionTemplateDecl *FunctionTemplate,
6272                                   llvm::SmallBitVector &Deduced) {
6273     return MarkDeducedTemplateParameters(Context, FunctionTemplate, Deduced);
6274   }
6275   static void MarkDeducedTemplateParameters(ASTContext &Ctx,
6276                                   const FunctionTemplateDecl *FunctionTemplate,
6277                                   llvm::SmallBitVector &Deduced);
6278 
6279   //===--------------------------------------------------------------------===//
6280   // C++ Template Instantiation
6281   //
6282 
6283   MultiLevelTemplateArgumentList
6284   getTemplateInstantiationArgs(NamedDecl *D,
6285                                const TemplateArgumentList *Innermost = nullptr,
6286                                bool RelativeToPrimary = false,
6287                                const FunctionDecl *Pattern = nullptr);
6288 
6289   /// \brief A template instantiation that is currently in progress.
6290   struct ActiveTemplateInstantiation {
6291     /// \brief The kind of template instantiation we are performing
6292     enum InstantiationKind {
6293       /// We are instantiating a template declaration. The entity is
6294       /// the declaration we're instantiating (e.g., a CXXRecordDecl).
6295       TemplateInstantiation,
6296 
6297       /// We are instantiating a default argument for a template
6298       /// parameter. The Entity is the template, and
6299       /// TemplateArgs/NumTemplateArguments provides the template
6300       /// arguments as specified.
6301       /// FIXME: Use a TemplateArgumentList
6302       DefaultTemplateArgumentInstantiation,
6303 
6304       /// We are instantiating a default argument for a function.
6305       /// The Entity is the ParmVarDecl, and TemplateArgs/NumTemplateArgs
6306       /// provides the template arguments as specified.
6307       DefaultFunctionArgumentInstantiation,
6308 
6309       /// We are substituting explicit template arguments provided for
6310       /// a function template. The entity is a FunctionTemplateDecl.
6311       ExplicitTemplateArgumentSubstitution,
6312 
6313       /// We are substituting template argument determined as part of
6314       /// template argument deduction for either a class template
6315       /// partial specialization or a function template. The
6316       /// Entity is either a ClassTemplatePartialSpecializationDecl or
6317       /// a FunctionTemplateDecl.
6318       DeducedTemplateArgumentSubstitution,
6319 
6320       /// We are substituting prior template arguments into a new
6321       /// template parameter. The template parameter itself is either a
6322       /// NonTypeTemplateParmDecl or a TemplateTemplateParmDecl.
6323       PriorTemplateArgumentSubstitution,
6324 
6325       /// We are checking the validity of a default template argument that
6326       /// has been used when naming a template-id.
6327       DefaultTemplateArgumentChecking,
6328 
6329       /// We are instantiating the exception specification for a function
6330       /// template which was deferred until it was needed.
6331       ExceptionSpecInstantiation
6332     } Kind;
6333 
6334     /// \brief The point of instantiation within the source code.
6335     SourceLocation PointOfInstantiation;
6336 
6337     /// \brief The template (or partial specialization) in which we are
6338     /// performing the instantiation, for substitutions of prior template
6339     /// arguments.
6340     NamedDecl *Template;
6341 
6342     /// \brief The entity that is being instantiated.
6343     Decl *Entity;
6344 
6345     /// \brief The list of template arguments we are substituting, if they
6346     /// are not part of the entity.
6347     const TemplateArgument *TemplateArgs;
6348 
6349     /// \brief The number of template arguments in TemplateArgs.
6350     unsigned NumTemplateArgs;
6351 
6352     /// \brief The template deduction info object associated with the
6353     /// substitution or checking of explicit or deduced template arguments.
6354     sema::TemplateDeductionInfo *DeductionInfo;
6355 
6356     /// \brief The source range that covers the construct that cause
6357     /// the instantiation, e.g., the template-id that causes a class
6358     /// template instantiation.
6359     SourceRange InstantiationRange;
6360 
ActiveTemplateInstantiationActiveTemplateInstantiation6361     ActiveTemplateInstantiation()
6362       : Kind(TemplateInstantiation), Template(nullptr), Entity(nullptr),
6363         TemplateArgs(nullptr), NumTemplateArgs(0), DeductionInfo(nullptr) {}
6364 
6365     /// \brief Determines whether this template is an actual instantiation
6366     /// that should be counted toward the maximum instantiation depth.
6367     bool isInstantiationRecord() const;
6368 
6369     friend bool operator==(const ActiveTemplateInstantiation &X,
6370                            const ActiveTemplateInstantiation &Y) {
6371       if (X.Kind != Y.Kind)
6372         return false;
6373 
6374       if (X.Entity != Y.Entity)
6375         return false;
6376 
6377       switch (X.Kind) {
6378       case TemplateInstantiation:
6379       case ExceptionSpecInstantiation:
6380         return true;
6381 
6382       case PriorTemplateArgumentSubstitution:
6383       case DefaultTemplateArgumentChecking:
6384         return X.Template == Y.Template && X.TemplateArgs == Y.TemplateArgs;
6385 
6386       case DefaultTemplateArgumentInstantiation:
6387       case ExplicitTemplateArgumentSubstitution:
6388       case DeducedTemplateArgumentSubstitution:
6389       case DefaultFunctionArgumentInstantiation:
6390         return X.TemplateArgs == Y.TemplateArgs;
6391 
6392       }
6393 
6394       llvm_unreachable("Invalid InstantiationKind!");
6395     }
6396 
6397     friend bool operator!=(const ActiveTemplateInstantiation &X,
6398                            const ActiveTemplateInstantiation &Y) {
6399       return !(X == Y);
6400     }
6401   };
6402 
6403   /// \brief List of active template instantiations.
6404   ///
6405   /// This vector is treated as a stack. As one template instantiation
6406   /// requires another template instantiation, additional
6407   /// instantiations are pushed onto the stack up to a
6408   /// user-configurable limit LangOptions::InstantiationDepth.
6409   SmallVector<ActiveTemplateInstantiation, 16>
6410     ActiveTemplateInstantiations;
6411 
6412   /// \brief Extra modules inspected when performing a lookup during a template
6413   /// instantiation. Computed lazily.
6414   SmallVector<Module*, 16> ActiveTemplateInstantiationLookupModules;
6415 
6416   /// \brief Cache of additional modules that should be used for name lookup
6417   /// within the current template instantiation. Computed lazily; use
6418   /// getLookupModules() to get a complete set.
6419   llvm::DenseSet<Module*> LookupModulesCache;
6420 
6421   /// \brief Get the set of additional modules that should be checked during
6422   /// name lookup. A module and its imports become visible when instanting a
6423   /// template defined within it.
6424   llvm::DenseSet<Module*> &getLookupModules();
6425 
6426   /// \brief Whether we are in a SFINAE context that is not associated with
6427   /// template instantiation.
6428   ///
6429   /// This is used when setting up a SFINAE trap (\c see SFINAETrap) outside
6430   /// of a template instantiation or template argument deduction.
6431   bool InNonInstantiationSFINAEContext;
6432 
6433   /// \brief The number of ActiveTemplateInstantiation entries in
6434   /// \c ActiveTemplateInstantiations that are not actual instantiations and,
6435   /// therefore, should not be counted as part of the instantiation depth.
6436   unsigned NonInstantiationEntries;
6437 
6438   /// \brief The last template from which a template instantiation
6439   /// error or warning was produced.
6440   ///
6441   /// This value is used to suppress printing of redundant template
6442   /// instantiation backtraces when there are multiple errors in the
6443   /// same instantiation. FIXME: Does this belong in Sema? It's tough
6444   /// to implement it anywhere else.
6445   ActiveTemplateInstantiation LastTemplateInstantiationErrorContext;
6446 
6447   /// \brief The current index into pack expansion arguments that will be
6448   /// used for substitution of parameter packs.
6449   ///
6450   /// The pack expansion index will be -1 to indicate that parameter packs
6451   /// should be instantiated as themselves. Otherwise, the index specifies
6452   /// which argument within the parameter pack will be used for substitution.
6453   int ArgumentPackSubstitutionIndex;
6454 
6455   /// \brief RAII object used to change the argument pack substitution index
6456   /// within a \c Sema object.
6457   ///
6458   /// See \c ArgumentPackSubstitutionIndex for more information.
6459   class ArgumentPackSubstitutionIndexRAII {
6460     Sema &Self;
6461     int OldSubstitutionIndex;
6462 
6463   public:
ArgumentPackSubstitutionIndexRAII(Sema & Self,int NewSubstitutionIndex)6464     ArgumentPackSubstitutionIndexRAII(Sema &Self, int NewSubstitutionIndex)
6465       : Self(Self), OldSubstitutionIndex(Self.ArgumentPackSubstitutionIndex) {
6466       Self.ArgumentPackSubstitutionIndex = NewSubstitutionIndex;
6467     }
6468 
~ArgumentPackSubstitutionIndexRAII()6469     ~ArgumentPackSubstitutionIndexRAII() {
6470       Self.ArgumentPackSubstitutionIndex = OldSubstitutionIndex;
6471     }
6472   };
6473 
6474   friend class ArgumentPackSubstitutionRAII;
6475 
6476   /// \brief The stack of calls expression undergoing template instantiation.
6477   ///
6478   /// The top of this stack is used by a fixit instantiating unresolved
6479   /// function calls to fix the AST to match the textual change it prints.
6480   SmallVector<CallExpr *, 8> CallsUndergoingInstantiation;
6481 
6482   /// \brief For each declaration that involved template argument deduction, the
6483   /// set of diagnostics that were suppressed during that template argument
6484   /// deduction.
6485   ///
6486   /// FIXME: Serialize this structure to the AST file.
6487   typedef llvm::DenseMap<Decl *, SmallVector<PartialDiagnosticAt, 1> >
6488     SuppressedDiagnosticsMap;
6489   SuppressedDiagnosticsMap SuppressedDiagnostics;
6490 
6491   /// \brief A stack object to be created when performing template
6492   /// instantiation.
6493   ///
6494   /// Construction of an object of type \c InstantiatingTemplate
6495   /// pushes the current instantiation onto the stack of active
6496   /// instantiations. If the size of this stack exceeds the maximum
6497   /// number of recursive template instantiations, construction
6498   /// produces an error and evaluates true.
6499   ///
6500   /// Destruction of this object will pop the named instantiation off
6501   /// the stack.
6502   struct InstantiatingTemplate {
6503     /// \brief Note that we are instantiating a class template,
6504     /// function template, or a member thereof.
6505     InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
6506                           Decl *Entity,
6507                           SourceRange InstantiationRange = SourceRange());
6508 
6509     struct ExceptionSpecification {};
6510     /// \brief Note that we are instantiating an exception specification
6511     /// of a function template.
6512     InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
6513                           FunctionDecl *Entity, ExceptionSpecification,
6514                           SourceRange InstantiationRange = SourceRange());
6515 
6516     /// \brief Note that we are instantiating a default argument in a
6517     /// template-id.
6518     InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
6519                           TemplateDecl *Template,
6520                           ArrayRef<TemplateArgument> TemplateArgs,
6521                           SourceRange InstantiationRange = SourceRange());
6522 
6523     /// \brief Note that we are instantiating a default argument in a
6524     /// template-id.
6525     InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
6526                           FunctionTemplateDecl *FunctionTemplate,
6527                           ArrayRef<TemplateArgument> TemplateArgs,
6528                           ActiveTemplateInstantiation::InstantiationKind Kind,
6529                           sema::TemplateDeductionInfo &DeductionInfo,
6530                           SourceRange InstantiationRange = SourceRange());
6531 
6532     /// \brief Note that we are instantiating as part of template
6533     /// argument deduction for a class template partial
6534     /// specialization.
6535     InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
6536                           ClassTemplatePartialSpecializationDecl *PartialSpec,
6537                           ArrayRef<TemplateArgument> TemplateArgs,
6538                           sema::TemplateDeductionInfo &DeductionInfo,
6539                           SourceRange InstantiationRange = SourceRange());
6540 
6541     /// \brief Note that we are instantiating as part of template
6542     /// argument deduction for a variable template partial
6543     /// specialization.
6544     InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
6545                           VarTemplatePartialSpecializationDecl *PartialSpec,
6546                           ArrayRef<TemplateArgument> TemplateArgs,
6547                           sema::TemplateDeductionInfo &DeductionInfo,
6548                           SourceRange InstantiationRange = SourceRange());
6549 
6550     InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
6551                           ParmVarDecl *Param,
6552                           ArrayRef<TemplateArgument> TemplateArgs,
6553                           SourceRange InstantiationRange = SourceRange());
6554 
6555     /// \brief Note that we are substituting prior template arguments into a
6556     /// non-type parameter.
6557     InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
6558                           NamedDecl *Template,
6559                           NonTypeTemplateParmDecl *Param,
6560                           ArrayRef<TemplateArgument> TemplateArgs,
6561                           SourceRange InstantiationRange);
6562 
6563     /// \brief Note that we are substituting prior template arguments into a
6564     /// template template parameter.
6565     InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
6566                           NamedDecl *Template,
6567                           TemplateTemplateParmDecl *Param,
6568                           ArrayRef<TemplateArgument> TemplateArgs,
6569                           SourceRange InstantiationRange);
6570 
6571     /// \brief Note that we are checking the default template argument
6572     /// against the template parameter for a given template-id.
6573     InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
6574                           TemplateDecl *Template,
6575                           NamedDecl *Param,
6576                           ArrayRef<TemplateArgument> TemplateArgs,
6577                           SourceRange InstantiationRange);
6578 
6579 
6580     /// \brief Note that we have finished instantiating this template.
6581     void Clear();
6582 
~InstantiatingTemplateInstantiatingTemplate6583     ~InstantiatingTemplate() { Clear(); }
6584 
6585     /// \brief Determines whether we have exceeded the maximum
6586     /// recursive template instantiations.
isInvalidInstantiatingTemplate6587     bool isInvalid() const { return Invalid; }
6588 
6589   private:
6590     Sema &SemaRef;
6591     bool Invalid;
6592     bool SavedInNonInstantiationSFINAEContext;
6593     bool CheckInstantiationDepth(SourceLocation PointOfInstantiation,
6594                                  SourceRange InstantiationRange);
6595 
6596     // FIXME: Replace this with a constructor once we can use delegating
6597     // constructors in llvm.
6598     void Initialize(
6599         ActiveTemplateInstantiation::InstantiationKind Kind,
6600         SourceLocation PointOfInstantiation, SourceRange InstantiationRange,
6601         Decl *Entity, NamedDecl *Template = nullptr,
6602         ArrayRef<TemplateArgument> TemplateArgs = ArrayRef<TemplateArgument>(),
6603         sema::TemplateDeductionInfo *DeductionInfo = nullptr);
6604 
6605     InstantiatingTemplate(const InstantiatingTemplate&) LLVM_DELETED_FUNCTION;
6606 
6607     InstantiatingTemplate&
6608     operator=(const InstantiatingTemplate&) LLVM_DELETED_FUNCTION;
6609   };
6610 
6611   void PrintInstantiationStack();
6612 
6613   /// \brief Determines whether we are currently in a context where
6614   /// template argument substitution failures are not considered
6615   /// errors.
6616   ///
6617   /// \returns An empty \c Optional if we're not in a SFINAE context.
6618   /// Otherwise, contains a pointer that, if non-NULL, contains the nearest
6619   /// template-deduction context object, which can be used to capture
6620   /// diagnostics that will be suppressed.
6621   Optional<sema::TemplateDeductionInfo *> isSFINAEContext() const;
6622 
6623   /// \brief Determines whether we are currently in a context that
6624   /// is not evaluated as per C++ [expr] p5.
isUnevaluatedContext()6625   bool isUnevaluatedContext() const {
6626     assert(!ExprEvalContexts.empty() &&
6627            "Must be in an expression evaluation context");
6628     return ExprEvalContexts.back().isUnevaluated();
6629   }
6630 
6631   /// \brief RAII class used to determine whether SFINAE has
6632   /// trapped any errors that occur during template argument
6633   /// deduction.
6634   class SFINAETrap {
6635     Sema &SemaRef;
6636     unsigned PrevSFINAEErrors;
6637     bool PrevInNonInstantiationSFINAEContext;
6638     bool PrevAccessCheckingSFINAE;
6639 
6640   public:
6641     explicit SFINAETrap(Sema &SemaRef, bool AccessCheckingSFINAE = false)
SemaRef(SemaRef)6642       : SemaRef(SemaRef), PrevSFINAEErrors(SemaRef.NumSFINAEErrors),
6643         PrevInNonInstantiationSFINAEContext(
6644                                       SemaRef.InNonInstantiationSFINAEContext),
6645         PrevAccessCheckingSFINAE(SemaRef.AccessCheckingSFINAE)
6646     {
6647       if (!SemaRef.isSFINAEContext())
6648         SemaRef.InNonInstantiationSFINAEContext = true;
6649       SemaRef.AccessCheckingSFINAE = AccessCheckingSFINAE;
6650     }
6651 
~SFINAETrap()6652     ~SFINAETrap() {
6653       SemaRef.NumSFINAEErrors = PrevSFINAEErrors;
6654       SemaRef.InNonInstantiationSFINAEContext
6655         = PrevInNonInstantiationSFINAEContext;
6656       SemaRef.AccessCheckingSFINAE = PrevAccessCheckingSFINAE;
6657     }
6658 
6659     /// \brief Determine whether any SFINAE errors have been trapped.
hasErrorOccurred()6660     bool hasErrorOccurred() const {
6661       return SemaRef.NumSFINAEErrors > PrevSFINAEErrors;
6662     }
6663   };
6664 
6665   /// \brief RAII class used to indicate that we are performing provisional
6666   /// semantic analysis to determine the validity of a construct, so
6667   /// typo-correction and diagnostics in the immediate context (not within
6668   /// implicitly-instantiated templates) should be suppressed.
6669   class TentativeAnalysisScope {
6670     Sema &SemaRef;
6671     // FIXME: Using a SFINAETrap for this is a hack.
6672     SFINAETrap Trap;
6673     bool PrevDisableTypoCorrection;
6674   public:
TentativeAnalysisScope(Sema & SemaRef)6675     explicit TentativeAnalysisScope(Sema &SemaRef)
6676         : SemaRef(SemaRef), Trap(SemaRef, true),
6677           PrevDisableTypoCorrection(SemaRef.DisableTypoCorrection) {
6678       SemaRef.DisableTypoCorrection = true;
6679     }
~TentativeAnalysisScope()6680     ~TentativeAnalysisScope() {
6681       SemaRef.DisableTypoCorrection = PrevDisableTypoCorrection;
6682     }
6683   };
6684 
6685   /// \brief The current instantiation scope used to store local
6686   /// variables.
6687   LocalInstantiationScope *CurrentInstantiationScope;
6688 
6689   /// \brief Tracks whether we are in a context where typo correction is
6690   /// disabled.
6691   bool DisableTypoCorrection;
6692 
6693   /// \brief The number of typos corrected by CorrectTypo.
6694   unsigned TyposCorrected;
6695 
6696   typedef llvm::SmallSet<SourceLocation, 2> SrcLocSet;
6697   typedef llvm::DenseMap<IdentifierInfo *, SrcLocSet> IdentifierSourceLocations;
6698 
6699   /// \brief A cache containing identifiers for which typo correction failed and
6700   /// their locations, so that repeated attempts to correct an identifier in a
6701   /// given location are ignored if typo correction already failed for it.
6702   IdentifierSourceLocations TypoCorrectionFailures;
6703 
6704   /// \brief Worker object for performing CFG-based warnings.
6705   sema::AnalysisBasedWarnings AnalysisWarnings;
6706 
6707   /// \brief An entity for which implicit template instantiation is required.
6708   ///
6709   /// The source location associated with the declaration is the first place in
6710   /// the source code where the declaration was "used". It is not necessarily
6711   /// the point of instantiation (which will be either before or after the
6712   /// namespace-scope declaration that triggered this implicit instantiation),
6713   /// However, it is the location that diagnostics should generally refer to,
6714   /// because users will need to know what code triggered the instantiation.
6715   typedef std::pair<ValueDecl *, SourceLocation> PendingImplicitInstantiation;
6716 
6717   /// \brief The queue of implicit template instantiations that are required
6718   /// but have not yet been performed.
6719   std::deque<PendingImplicitInstantiation> PendingInstantiations;
6720 
6721   class SavePendingInstantiationsAndVTableUsesRAII {
6722   public:
SavePendingInstantiationsAndVTableUsesRAII(Sema & S)6723     SavePendingInstantiationsAndVTableUsesRAII(Sema &S): S(S) {
6724       SavedPendingInstantiations.swap(S.PendingInstantiations);
6725       SavedVTableUses.swap(S.VTableUses);
6726     }
6727 
~SavePendingInstantiationsAndVTableUsesRAII()6728     ~SavePendingInstantiationsAndVTableUsesRAII() {
6729       // Restore the set of pending vtables.
6730       assert(S.VTableUses.empty() &&
6731              "VTableUses should be empty before it is discarded.");
6732       S.VTableUses.swap(SavedVTableUses);
6733 
6734       // Restore the set of pending implicit instantiations.
6735       assert(S.PendingInstantiations.empty() &&
6736              "PendingInstantiations should be empty before it is discarded.");
6737       S.PendingInstantiations.swap(SavedPendingInstantiations);
6738     }
6739 
6740   private:
6741     Sema &S;
6742     SmallVector<VTableUse, 16> SavedVTableUses;
6743     std::deque<PendingImplicitInstantiation> SavedPendingInstantiations;
6744   };
6745 
6746   /// \brief The queue of implicit template instantiations that are required
6747   /// and must be performed within the current local scope.
6748   ///
6749   /// This queue is only used for member functions of local classes in
6750   /// templates, which must be instantiated in the same scope as their
6751   /// enclosing function, so that they can reference function-local
6752   /// types, static variables, enumerators, etc.
6753   std::deque<PendingImplicitInstantiation> PendingLocalImplicitInstantiations;
6754 
6755   class SavePendingLocalImplicitInstantiationsRAII {
6756   public:
SavePendingLocalImplicitInstantiationsRAII(Sema & S)6757     SavePendingLocalImplicitInstantiationsRAII(Sema &S): S(S) {
6758       SavedPendingLocalImplicitInstantiations.swap(
6759           S.PendingLocalImplicitInstantiations);
6760     }
6761 
~SavePendingLocalImplicitInstantiationsRAII()6762     ~SavePendingLocalImplicitInstantiationsRAII() {
6763       assert(S.PendingLocalImplicitInstantiations.empty() &&
6764              "there shouldn't be any pending local implicit instantiations");
6765       SavedPendingLocalImplicitInstantiations.swap(
6766           S.PendingLocalImplicitInstantiations);
6767     }
6768 
6769   private:
6770     Sema &S;
6771     std::deque<PendingImplicitInstantiation>
6772     SavedPendingLocalImplicitInstantiations;
6773   };
6774 
6775   void PerformPendingInstantiations(bool LocalOnly = false);
6776 
6777   TypeSourceInfo *SubstType(TypeSourceInfo *T,
6778                             const MultiLevelTemplateArgumentList &TemplateArgs,
6779                             SourceLocation Loc, DeclarationName Entity);
6780 
6781   QualType SubstType(QualType T,
6782                      const MultiLevelTemplateArgumentList &TemplateArgs,
6783                      SourceLocation Loc, DeclarationName Entity);
6784 
6785   TypeSourceInfo *SubstType(TypeLoc TL,
6786                             const MultiLevelTemplateArgumentList &TemplateArgs,
6787                             SourceLocation Loc, DeclarationName Entity);
6788 
6789   TypeSourceInfo *SubstFunctionDeclType(TypeSourceInfo *T,
6790                             const MultiLevelTemplateArgumentList &TemplateArgs,
6791                                         SourceLocation Loc,
6792                                         DeclarationName Entity,
6793                                         CXXRecordDecl *ThisContext,
6794                                         unsigned ThisTypeQuals);
6795   void SubstExceptionSpec(FunctionDecl *New, const FunctionProtoType *Proto,
6796                           const MultiLevelTemplateArgumentList &Args);
6797   ParmVarDecl *SubstParmVarDecl(ParmVarDecl *D,
6798                             const MultiLevelTemplateArgumentList &TemplateArgs,
6799                                 int indexAdjustment,
6800                                 Optional<unsigned> NumExpansions,
6801                                 bool ExpectParameterPack);
6802   bool SubstParmTypes(SourceLocation Loc,
6803                       ParmVarDecl **Params, unsigned NumParams,
6804                       const MultiLevelTemplateArgumentList &TemplateArgs,
6805                       SmallVectorImpl<QualType> &ParamTypes,
6806                       SmallVectorImpl<ParmVarDecl *> *OutParams = nullptr);
6807   ExprResult SubstExpr(Expr *E,
6808                        const MultiLevelTemplateArgumentList &TemplateArgs);
6809 
6810   /// \brief Substitute the given template arguments into a list of
6811   /// expressions, expanding pack expansions if required.
6812   ///
6813   /// \param Exprs The list of expressions to substitute into.
6814   ///
6815   /// \param NumExprs The number of expressions in \p Exprs.
6816   ///
6817   /// \param IsCall Whether this is some form of call, in which case
6818   /// default arguments will be dropped.
6819   ///
6820   /// \param TemplateArgs The set of template arguments to substitute.
6821   ///
6822   /// \param Outputs Will receive all of the substituted arguments.
6823   ///
6824   /// \returns true if an error occurred, false otherwise.
6825   bool SubstExprs(Expr **Exprs, unsigned NumExprs, bool IsCall,
6826                   const MultiLevelTemplateArgumentList &TemplateArgs,
6827                   SmallVectorImpl<Expr *> &Outputs);
6828 
6829   StmtResult SubstStmt(Stmt *S,
6830                        const MultiLevelTemplateArgumentList &TemplateArgs);
6831 
6832   Decl *SubstDecl(Decl *D, DeclContext *Owner,
6833                   const MultiLevelTemplateArgumentList &TemplateArgs);
6834 
6835   ExprResult SubstInitializer(Expr *E,
6836                        const MultiLevelTemplateArgumentList &TemplateArgs,
6837                        bool CXXDirectInit);
6838 
6839   bool
6840   SubstBaseSpecifiers(CXXRecordDecl *Instantiation,
6841                       CXXRecordDecl *Pattern,
6842                       const MultiLevelTemplateArgumentList &TemplateArgs);
6843 
6844   bool
6845   InstantiateClass(SourceLocation PointOfInstantiation,
6846                    CXXRecordDecl *Instantiation, CXXRecordDecl *Pattern,
6847                    const MultiLevelTemplateArgumentList &TemplateArgs,
6848                    TemplateSpecializationKind TSK,
6849                    bool Complain = true);
6850 
6851   bool InstantiateEnum(SourceLocation PointOfInstantiation,
6852                        EnumDecl *Instantiation, EnumDecl *Pattern,
6853                        const MultiLevelTemplateArgumentList &TemplateArgs,
6854                        TemplateSpecializationKind TSK);
6855 
6856   bool InstantiateInClassInitializer(
6857       SourceLocation PointOfInstantiation, FieldDecl *Instantiation,
6858       FieldDecl *Pattern, const MultiLevelTemplateArgumentList &TemplateArgs);
6859 
6860   struct LateInstantiatedAttribute {
6861     const Attr *TmplAttr;
6862     LocalInstantiationScope *Scope;
6863     Decl *NewDecl;
6864 
LateInstantiatedAttributeLateInstantiatedAttribute6865     LateInstantiatedAttribute(const Attr *A, LocalInstantiationScope *S,
6866                               Decl *D)
6867       : TmplAttr(A), Scope(S), NewDecl(D)
6868     { }
6869   };
6870   typedef SmallVector<LateInstantiatedAttribute, 16> LateInstantiatedAttrVec;
6871 
6872   void InstantiateAttrs(const MultiLevelTemplateArgumentList &TemplateArgs,
6873                         const Decl *Pattern, Decl *Inst,
6874                         LateInstantiatedAttrVec *LateAttrs = nullptr,
6875                         LocalInstantiationScope *OuterMostScope = nullptr);
6876 
6877   bool
6878   InstantiateClassTemplateSpecialization(SourceLocation PointOfInstantiation,
6879                            ClassTemplateSpecializationDecl *ClassTemplateSpec,
6880                            TemplateSpecializationKind TSK,
6881                            bool Complain = true);
6882 
6883   void InstantiateClassMembers(SourceLocation PointOfInstantiation,
6884                                CXXRecordDecl *Instantiation,
6885                             const MultiLevelTemplateArgumentList &TemplateArgs,
6886                                TemplateSpecializationKind TSK);
6887 
6888   void InstantiateClassTemplateSpecializationMembers(
6889                                           SourceLocation PointOfInstantiation,
6890                            ClassTemplateSpecializationDecl *ClassTemplateSpec,
6891                                                 TemplateSpecializationKind TSK);
6892 
6893   NestedNameSpecifierLoc
6894   SubstNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS,
6895                            const MultiLevelTemplateArgumentList &TemplateArgs);
6896 
6897   DeclarationNameInfo
6898   SubstDeclarationNameInfo(const DeclarationNameInfo &NameInfo,
6899                            const MultiLevelTemplateArgumentList &TemplateArgs);
6900   TemplateName
6901   SubstTemplateName(NestedNameSpecifierLoc QualifierLoc, TemplateName Name,
6902                     SourceLocation Loc,
6903                     const MultiLevelTemplateArgumentList &TemplateArgs);
6904   bool Subst(const TemplateArgumentLoc *Args, unsigned NumArgs,
6905              TemplateArgumentListInfo &Result,
6906              const MultiLevelTemplateArgumentList &TemplateArgs);
6907 
6908   void InstantiateExceptionSpec(SourceLocation PointOfInstantiation,
6909                                 FunctionDecl *Function);
6910   void InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
6911                                      FunctionDecl *Function,
6912                                      bool Recursive = false,
6913                                      bool DefinitionRequired = false);
6914   VarTemplateSpecializationDecl *BuildVarTemplateInstantiation(
6915       VarTemplateDecl *VarTemplate, VarDecl *FromVar,
6916       const TemplateArgumentList &TemplateArgList,
6917       const TemplateArgumentListInfo &TemplateArgsInfo,
6918       SmallVectorImpl<TemplateArgument> &Converted,
6919       SourceLocation PointOfInstantiation, void *InsertPos,
6920       LateInstantiatedAttrVec *LateAttrs = nullptr,
6921       LocalInstantiationScope *StartingScope = nullptr);
6922   VarTemplateSpecializationDecl *CompleteVarTemplateSpecializationDecl(
6923       VarTemplateSpecializationDecl *VarSpec, VarDecl *PatternDecl,
6924       const MultiLevelTemplateArgumentList &TemplateArgs);
6925   void
6926   BuildVariableInstantiation(VarDecl *NewVar, VarDecl *OldVar,
6927                              const MultiLevelTemplateArgumentList &TemplateArgs,
6928                              LateInstantiatedAttrVec *LateAttrs,
6929                              DeclContext *Owner,
6930                              LocalInstantiationScope *StartingScope,
6931                              bool InstantiatingVarTemplate = false);
6932   void InstantiateVariableInitializer(
6933       VarDecl *Var, VarDecl *OldVar,
6934       const MultiLevelTemplateArgumentList &TemplateArgs);
6935   void InstantiateVariableDefinition(SourceLocation PointOfInstantiation,
6936                                      VarDecl *Var, bool Recursive = false,
6937                                      bool DefinitionRequired = false);
6938   void InstantiateStaticDataMemberDefinition(
6939                                      SourceLocation PointOfInstantiation,
6940                                      VarDecl *Var,
6941                                      bool Recursive = false,
6942                                      bool DefinitionRequired = false);
6943 
6944   void InstantiateMemInitializers(CXXConstructorDecl *New,
6945                                   const CXXConstructorDecl *Tmpl,
6946                             const MultiLevelTemplateArgumentList &TemplateArgs);
6947 
6948   NamedDecl *FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
6949                           const MultiLevelTemplateArgumentList &TemplateArgs);
6950   DeclContext *FindInstantiatedContext(SourceLocation Loc, DeclContext *DC,
6951                           const MultiLevelTemplateArgumentList &TemplateArgs);
6952 
6953   // Objective-C declarations.
6954   enum ObjCContainerKind {
6955     OCK_None = -1,
6956     OCK_Interface = 0,
6957     OCK_Protocol,
6958     OCK_Category,
6959     OCK_ClassExtension,
6960     OCK_Implementation,
6961     OCK_CategoryImplementation
6962   };
6963   ObjCContainerKind getObjCContainerKind() const;
6964 
6965   Decl *ActOnStartClassInterface(SourceLocation AtInterfaceLoc,
6966                                  IdentifierInfo *ClassName,
6967                                  SourceLocation ClassLoc,
6968                                  IdentifierInfo *SuperName,
6969                                  SourceLocation SuperLoc,
6970                                  Decl * const *ProtoRefs,
6971                                  unsigned NumProtoRefs,
6972                                  const SourceLocation *ProtoLocs,
6973                                  SourceLocation EndProtoLoc,
6974                                  AttributeList *AttrList);
6975 
6976   void ActOnTypedefedProtocols(SmallVectorImpl<Decl *> &ProtocolRefs,
6977                                IdentifierInfo *SuperName,
6978                                SourceLocation SuperLoc);
6979 
6980   Decl *ActOnCompatibilityAlias(
6981                     SourceLocation AtCompatibilityAliasLoc,
6982                     IdentifierInfo *AliasName,  SourceLocation AliasLocation,
6983                     IdentifierInfo *ClassName, SourceLocation ClassLocation);
6984 
6985   bool CheckForwardProtocolDeclarationForCircularDependency(
6986     IdentifierInfo *PName,
6987     SourceLocation &PLoc, SourceLocation PrevLoc,
6988     const ObjCList<ObjCProtocolDecl> &PList);
6989 
6990   Decl *ActOnStartProtocolInterface(
6991                     SourceLocation AtProtoInterfaceLoc,
6992                     IdentifierInfo *ProtocolName, SourceLocation ProtocolLoc,
6993                     Decl * const *ProtoRefNames, unsigned NumProtoRefs,
6994                     const SourceLocation *ProtoLocs,
6995                     SourceLocation EndProtoLoc,
6996                     AttributeList *AttrList);
6997 
6998   Decl *ActOnStartCategoryInterface(SourceLocation AtInterfaceLoc,
6999                                     IdentifierInfo *ClassName,
7000                                     SourceLocation ClassLoc,
7001                                     IdentifierInfo *CategoryName,
7002                                     SourceLocation CategoryLoc,
7003                                     Decl * const *ProtoRefs,
7004                                     unsigned NumProtoRefs,
7005                                     const SourceLocation *ProtoLocs,
7006                                     SourceLocation EndProtoLoc);
7007 
7008   Decl *ActOnStartClassImplementation(
7009                     SourceLocation AtClassImplLoc,
7010                     IdentifierInfo *ClassName, SourceLocation ClassLoc,
7011                     IdentifierInfo *SuperClassname,
7012                     SourceLocation SuperClassLoc);
7013 
7014   Decl *ActOnStartCategoryImplementation(SourceLocation AtCatImplLoc,
7015                                          IdentifierInfo *ClassName,
7016                                          SourceLocation ClassLoc,
7017                                          IdentifierInfo *CatName,
7018                                          SourceLocation CatLoc);
7019 
7020   DeclGroupPtrTy ActOnFinishObjCImplementation(Decl *ObjCImpDecl,
7021                                                ArrayRef<Decl *> Decls);
7022 
7023   DeclGroupPtrTy ActOnForwardClassDeclaration(SourceLocation Loc,
7024                                      IdentifierInfo **IdentList,
7025                                      SourceLocation *IdentLocs,
7026                                      unsigned NumElts);
7027 
7028   DeclGroupPtrTy ActOnForwardProtocolDeclaration(SourceLocation AtProtoclLoc,
7029                                         const IdentifierLocPair *IdentList,
7030                                         unsigned NumElts,
7031                                         AttributeList *attrList);
7032 
7033   void FindProtocolDeclaration(bool WarnOnDeclarations,
7034                                const IdentifierLocPair *ProtocolId,
7035                                unsigned NumProtocols,
7036                                SmallVectorImpl<Decl *> &Protocols);
7037 
7038   /// Ensure attributes are consistent with type.
7039   /// \param [in, out] Attributes The attributes to check; they will
7040   /// be modified to be consistent with \p PropertyTy.
7041   void CheckObjCPropertyAttributes(Decl *PropertyPtrTy,
7042                                    SourceLocation Loc,
7043                                    unsigned &Attributes,
7044                                    bool propertyInPrimaryClass);
7045 
7046   /// Process the specified property declaration and create decls for the
7047   /// setters and getters as needed.
7048   /// \param property The property declaration being processed
7049   /// \param CD The semantic container for the property
7050   /// \param redeclaredProperty Declaration for property if redeclared
7051   ///        in class extension.
7052   /// \param lexicalDC Container for redeclaredProperty.
7053   void ProcessPropertyDecl(ObjCPropertyDecl *property,
7054                            ObjCContainerDecl *CD,
7055                            ObjCPropertyDecl *redeclaredProperty = nullptr,
7056                            ObjCContainerDecl *lexicalDC = nullptr);
7057 
7058 
7059   void DiagnosePropertyMismatch(ObjCPropertyDecl *Property,
7060                                 ObjCPropertyDecl *SuperProperty,
7061                                 const IdentifierInfo *Name,
7062                                 bool OverridingProtocolProperty);
7063 
7064   void DiagnoseClassExtensionDupMethods(ObjCCategoryDecl *CAT,
7065                                         ObjCInterfaceDecl *ID);
7066 
7067   Decl *ActOnAtEnd(Scope *S, SourceRange AtEnd,
7068                    ArrayRef<Decl *> allMethods = None,
7069                    ArrayRef<DeclGroupPtrTy> allTUVars = None);
7070 
7071   Decl *ActOnProperty(Scope *S, SourceLocation AtLoc,
7072                       SourceLocation LParenLoc,
7073                       FieldDeclarator &FD, ObjCDeclSpec &ODS,
7074                       Selector GetterSel, Selector SetterSel,
7075                       bool *OverridingProperty,
7076                       tok::ObjCKeywordKind MethodImplKind,
7077                       DeclContext *lexicalDC = nullptr);
7078 
7079   Decl *ActOnPropertyImplDecl(Scope *S,
7080                               SourceLocation AtLoc,
7081                               SourceLocation PropertyLoc,
7082                               bool ImplKind,
7083                               IdentifierInfo *PropertyId,
7084                               IdentifierInfo *PropertyIvar,
7085                               SourceLocation PropertyIvarLoc);
7086 
7087   enum ObjCSpecialMethodKind {
7088     OSMK_None,
7089     OSMK_Alloc,
7090     OSMK_New,
7091     OSMK_Copy,
7092     OSMK_RetainingInit,
7093     OSMK_NonRetainingInit
7094   };
7095 
7096   struct ObjCArgInfo {
7097     IdentifierInfo *Name;
7098     SourceLocation NameLoc;
7099     // The Type is null if no type was specified, and the DeclSpec is invalid
7100     // in this case.
7101     ParsedType Type;
7102     ObjCDeclSpec DeclSpec;
7103 
7104     /// ArgAttrs - Attribute list for this argument.
7105     AttributeList *ArgAttrs;
7106   };
7107 
7108   Decl *ActOnMethodDeclaration(
7109     Scope *S,
7110     SourceLocation BeginLoc, // location of the + or -.
7111     SourceLocation EndLoc,   // location of the ; or {.
7112     tok::TokenKind MethodType,
7113     ObjCDeclSpec &ReturnQT, ParsedType ReturnType,
7114     ArrayRef<SourceLocation> SelectorLocs, Selector Sel,
7115     // optional arguments. The number of types/arguments is obtained
7116     // from the Sel.getNumArgs().
7117     ObjCArgInfo *ArgInfo,
7118     DeclaratorChunk::ParamInfo *CParamInfo, unsigned CNumArgs, // c-style args
7119     AttributeList *AttrList, tok::ObjCKeywordKind MethodImplKind,
7120     bool isVariadic, bool MethodDefinition);
7121 
7122   ObjCMethodDecl *LookupMethodInQualifiedType(Selector Sel,
7123                                               const ObjCObjectPointerType *OPT,
7124                                               bool IsInstance);
7125   ObjCMethodDecl *LookupMethodInObjectType(Selector Sel, QualType Ty,
7126                                            bool IsInstance);
7127 
7128   bool CheckARCMethodDecl(ObjCMethodDecl *method);
7129   bool inferObjCARCLifetime(ValueDecl *decl);
7130 
7131   ExprResult
7132   HandleExprPropertyRefExpr(const ObjCObjectPointerType *OPT,
7133                             Expr *BaseExpr,
7134                             SourceLocation OpLoc,
7135                             DeclarationName MemberName,
7136                             SourceLocation MemberLoc,
7137                             SourceLocation SuperLoc, QualType SuperType,
7138                             bool Super);
7139 
7140   ExprResult
7141   ActOnClassPropertyRefExpr(IdentifierInfo &receiverName,
7142                             IdentifierInfo &propertyName,
7143                             SourceLocation receiverNameLoc,
7144                             SourceLocation propertyNameLoc);
7145 
7146   ObjCMethodDecl *tryCaptureObjCSelf(SourceLocation Loc);
7147 
7148   /// \brief Describes the kind of message expression indicated by a message
7149   /// send that starts with an identifier.
7150   enum ObjCMessageKind {
7151     /// \brief The message is sent to 'super'.
7152     ObjCSuperMessage,
7153     /// \brief The message is an instance message.
7154     ObjCInstanceMessage,
7155     /// \brief The message is a class message, and the identifier is a type
7156     /// name.
7157     ObjCClassMessage
7158   };
7159 
7160   ObjCMessageKind getObjCMessageKind(Scope *S,
7161                                      IdentifierInfo *Name,
7162                                      SourceLocation NameLoc,
7163                                      bool IsSuper,
7164                                      bool HasTrailingDot,
7165                                      ParsedType &ReceiverType);
7166 
7167   ExprResult ActOnSuperMessage(Scope *S, SourceLocation SuperLoc,
7168                                Selector Sel,
7169                                SourceLocation LBracLoc,
7170                                ArrayRef<SourceLocation> SelectorLocs,
7171                                SourceLocation RBracLoc,
7172                                MultiExprArg Args);
7173 
7174   ExprResult BuildClassMessage(TypeSourceInfo *ReceiverTypeInfo,
7175                                QualType ReceiverType,
7176                                SourceLocation SuperLoc,
7177                                Selector Sel,
7178                                ObjCMethodDecl *Method,
7179                                SourceLocation LBracLoc,
7180                                ArrayRef<SourceLocation> SelectorLocs,
7181                                SourceLocation RBracLoc,
7182                                MultiExprArg Args,
7183                                bool isImplicit = false);
7184 
7185   ExprResult BuildClassMessageImplicit(QualType ReceiverType,
7186                                        bool isSuperReceiver,
7187                                        SourceLocation Loc,
7188                                        Selector Sel,
7189                                        ObjCMethodDecl *Method,
7190                                        MultiExprArg Args);
7191 
7192   ExprResult ActOnClassMessage(Scope *S,
7193                                ParsedType Receiver,
7194                                Selector Sel,
7195                                SourceLocation LBracLoc,
7196                                ArrayRef<SourceLocation> SelectorLocs,
7197                                SourceLocation RBracLoc,
7198                                MultiExprArg Args);
7199 
7200   ExprResult BuildInstanceMessage(Expr *Receiver,
7201                                   QualType ReceiverType,
7202                                   SourceLocation SuperLoc,
7203                                   Selector Sel,
7204                                   ObjCMethodDecl *Method,
7205                                   SourceLocation LBracLoc,
7206                                   ArrayRef<SourceLocation> SelectorLocs,
7207                                   SourceLocation RBracLoc,
7208                                   MultiExprArg Args,
7209                                   bool isImplicit = false);
7210 
7211   ExprResult BuildInstanceMessageImplicit(Expr *Receiver,
7212                                           QualType ReceiverType,
7213                                           SourceLocation Loc,
7214                                           Selector Sel,
7215                                           ObjCMethodDecl *Method,
7216                                           MultiExprArg Args);
7217 
7218   ExprResult ActOnInstanceMessage(Scope *S,
7219                                   Expr *Receiver,
7220                                   Selector Sel,
7221                                   SourceLocation LBracLoc,
7222                                   ArrayRef<SourceLocation> SelectorLocs,
7223                                   SourceLocation RBracLoc,
7224                                   MultiExprArg Args);
7225 
7226   ExprResult BuildObjCBridgedCast(SourceLocation LParenLoc,
7227                                   ObjCBridgeCastKind Kind,
7228                                   SourceLocation BridgeKeywordLoc,
7229                                   TypeSourceInfo *TSInfo,
7230                                   Expr *SubExpr);
7231 
7232   ExprResult ActOnObjCBridgedCast(Scope *S,
7233                                   SourceLocation LParenLoc,
7234                                   ObjCBridgeCastKind Kind,
7235                                   SourceLocation BridgeKeywordLoc,
7236                                   ParsedType Type,
7237                                   SourceLocation RParenLoc,
7238                                   Expr *SubExpr);
7239 
7240   void CheckTollFreeBridgeCast(QualType castType, Expr *castExpr);
7241 
7242   void CheckObjCBridgeRelatedCast(QualType castType, Expr *castExpr);
7243 
7244   bool CheckTollFreeBridgeStaticCast(QualType castType, Expr *castExpr,
7245                                      CastKind &Kind);
7246 
7247   bool checkObjCBridgeRelatedComponents(SourceLocation Loc,
7248                                         QualType DestType, QualType SrcType,
7249                                         ObjCInterfaceDecl *&RelatedClass,
7250                                         ObjCMethodDecl *&ClassMethod,
7251                                         ObjCMethodDecl *&InstanceMethod,
7252                                         TypedefNameDecl *&TDNDecl,
7253                                         bool CfToNs);
7254 
7255   bool CheckObjCBridgeRelatedConversions(SourceLocation Loc,
7256                                          QualType DestType, QualType SrcType,
7257                                          Expr *&SrcExpr);
7258 
7259   bool ConversionToObjCStringLiteralCheck(QualType DstType, Expr *&SrcExpr);
7260 
7261   bool checkInitMethod(ObjCMethodDecl *method, QualType receiverTypeIfCall);
7262 
7263   /// \brief Check whether the given new method is a valid override of the
7264   /// given overridden method, and set any properties that should be inherited.
7265   void CheckObjCMethodOverride(ObjCMethodDecl *NewMethod,
7266                                const ObjCMethodDecl *Overridden);
7267 
7268   /// \brief Describes the compatibility of a result type with its method.
7269   enum ResultTypeCompatibilityKind {
7270     RTC_Compatible,
7271     RTC_Incompatible,
7272     RTC_Unknown
7273   };
7274 
7275   void CheckObjCMethodOverrides(ObjCMethodDecl *ObjCMethod,
7276                                 ObjCInterfaceDecl *CurrentClass,
7277                                 ResultTypeCompatibilityKind RTC);
7278 
7279   enum PragmaOptionsAlignKind {
7280     POAK_Native,  // #pragma options align=native
7281     POAK_Natural, // #pragma options align=natural
7282     POAK_Packed,  // #pragma options align=packed
7283     POAK_Power,   // #pragma options align=power
7284     POAK_Mac68k,  // #pragma options align=mac68k
7285     POAK_Reset    // #pragma options align=reset
7286   };
7287 
7288   /// ActOnPragmaOptionsAlign - Called on well formed \#pragma options align.
7289   void ActOnPragmaOptionsAlign(PragmaOptionsAlignKind Kind,
7290                                SourceLocation PragmaLoc);
7291 
7292   enum PragmaPackKind {
7293     PPK_Default, // #pragma pack([n])
7294     PPK_Show,    // #pragma pack(show), only supported by MSVC.
7295     PPK_Push,    // #pragma pack(push, [identifier], [n])
7296     PPK_Pop      // #pragma pack(pop, [identifier], [n])
7297   };
7298 
7299   enum PragmaMSStructKind {
7300     PMSST_OFF,  // #pragms ms_struct off
7301     PMSST_ON    // #pragms ms_struct on
7302   };
7303 
7304   enum PragmaMSCommentKind {
7305     PCK_Unknown,
7306     PCK_Linker,   // #pragma comment(linker, ...)
7307     PCK_Lib,      // #pragma comment(lib, ...)
7308     PCK_Compiler, // #pragma comment(compiler, ...)
7309     PCK_ExeStr,   // #pragma comment(exestr, ...)
7310     PCK_User      // #pragma comment(user, ...)
7311   };
7312 
7313   /// ActOnPragmaPack - Called on well formed \#pragma pack(...).
7314   void ActOnPragmaPack(PragmaPackKind Kind,
7315                        IdentifierInfo *Name,
7316                        Expr *Alignment,
7317                        SourceLocation PragmaLoc,
7318                        SourceLocation LParenLoc,
7319                        SourceLocation RParenLoc);
7320 
7321   /// ActOnPragmaMSStruct - Called on well formed \#pragma ms_struct [on|off].
7322   void ActOnPragmaMSStruct(PragmaMSStructKind Kind);
7323 
7324   /// ActOnPragmaMSComment - Called on well formed
7325   /// \#pragma comment(kind, "arg").
7326   void ActOnPragmaMSComment(PragmaMSCommentKind Kind, StringRef Arg);
7327 
7328   /// ActOnPragmaMSPointersToMembers - called on well formed \#pragma
7329   /// pointers_to_members(representation method[, general purpose
7330   /// representation]).
7331   void ActOnPragmaMSPointersToMembers(
7332       LangOptions::PragmaMSPointersToMembersKind Kind,
7333       SourceLocation PragmaLoc);
7334 
7335   /// \brief Called on well formed \#pragma vtordisp().
7336   void ActOnPragmaMSVtorDisp(PragmaVtorDispKind Kind, SourceLocation PragmaLoc,
7337                              MSVtorDispAttr::Mode Value);
7338 
7339   enum PragmaSectionKind {
7340     PSK_DataSeg,
7341     PSK_BSSSeg,
7342     PSK_ConstSeg,
7343     PSK_CodeSeg,
7344   };
7345 
7346   bool UnifySection(StringRef SectionName,
7347                     int SectionFlags,
7348                     DeclaratorDecl *TheDecl);
7349   bool UnifySection(StringRef SectionName,
7350                     int SectionFlags,
7351                     SourceLocation PragmaSectionLocation);
7352 
7353   /// \brief Called on well formed \#pragma bss_seg/data_seg/const_seg/code_seg.
7354   void ActOnPragmaMSSeg(SourceLocation PragmaLocation,
7355                         PragmaMsStackAction Action,
7356                         llvm::StringRef StackSlotLabel,
7357                         StringLiteral *SegmentName,
7358                         llvm::StringRef PragmaName);
7359 
7360   /// \brief Called on well formed \#pragma section().
7361   void ActOnPragmaMSSection(SourceLocation PragmaLocation,
7362                             int SectionFlags, StringLiteral *SegmentName);
7363 
7364   /// \brief Called on well-formed \#pragma init_seg().
7365   void ActOnPragmaMSInitSeg(SourceLocation PragmaLocation,
7366                             StringLiteral *SegmentName);
7367 
7368   /// ActOnPragmaDetectMismatch - Call on well-formed \#pragma detect_mismatch
7369   void ActOnPragmaDetectMismatch(StringRef Name, StringRef Value);
7370 
7371   /// ActOnPragmaUnused - Called on well-formed '\#pragma unused'.
7372   void ActOnPragmaUnused(const Token &Identifier,
7373                          Scope *curScope,
7374                          SourceLocation PragmaLoc);
7375 
7376   /// ActOnPragmaVisibility - Called on well formed \#pragma GCC visibility... .
7377   void ActOnPragmaVisibility(const IdentifierInfo* VisType,
7378                              SourceLocation PragmaLoc);
7379 
7380   NamedDecl *DeclClonePragmaWeak(NamedDecl *ND, IdentifierInfo *II,
7381                                  SourceLocation Loc);
7382   void DeclApplyPragmaWeak(Scope *S, NamedDecl *ND, WeakInfo &W);
7383 
7384   /// ActOnPragmaWeakID - Called on well formed \#pragma weak ident.
7385   void ActOnPragmaWeakID(IdentifierInfo* WeakName,
7386                          SourceLocation PragmaLoc,
7387                          SourceLocation WeakNameLoc);
7388 
7389   /// ActOnPragmaRedefineExtname - Called on well formed
7390   /// \#pragma redefine_extname oldname newname.
7391   void ActOnPragmaRedefineExtname(IdentifierInfo* WeakName,
7392                                   IdentifierInfo* AliasName,
7393                                   SourceLocation PragmaLoc,
7394                                   SourceLocation WeakNameLoc,
7395                                   SourceLocation AliasNameLoc);
7396 
7397   /// ActOnPragmaWeakAlias - Called on well formed \#pragma weak ident = ident.
7398   void ActOnPragmaWeakAlias(IdentifierInfo* WeakName,
7399                             IdentifierInfo* AliasName,
7400                             SourceLocation PragmaLoc,
7401                             SourceLocation WeakNameLoc,
7402                             SourceLocation AliasNameLoc);
7403 
7404   /// ActOnPragmaFPContract - Called on well formed
7405   /// \#pragma {STDC,OPENCL} FP_CONTRACT
7406   void ActOnPragmaFPContract(tok::OnOffSwitch OOS);
7407 
7408   /// AddAlignmentAttributesForRecord - Adds any needed alignment attributes to
7409   /// a the record decl, to handle '\#pragma pack' and '\#pragma options align'.
7410   void AddAlignmentAttributesForRecord(RecordDecl *RD);
7411 
7412   /// AddMsStructLayoutForRecord - Adds ms_struct layout attribute to record.
7413   void AddMsStructLayoutForRecord(RecordDecl *RD);
7414 
7415   /// FreePackedContext - Deallocate and null out PackContext.
7416   void FreePackedContext();
7417 
7418   /// PushNamespaceVisibilityAttr - Note that we've entered a
7419   /// namespace with a visibility attribute.
7420   void PushNamespaceVisibilityAttr(const VisibilityAttr *Attr,
7421                                    SourceLocation Loc);
7422 
7423   /// AddPushedVisibilityAttribute - If '\#pragma GCC visibility' was used,
7424   /// add an appropriate visibility attribute.
7425   void AddPushedVisibilityAttribute(Decl *RD);
7426 
7427   /// PopPragmaVisibility - Pop the top element of the visibility stack; used
7428   /// for '\#pragma GCC visibility' and visibility attributes on namespaces.
7429   void PopPragmaVisibility(bool IsNamespaceEnd, SourceLocation EndLoc);
7430 
7431   /// FreeVisContext - Deallocate and null out VisContext.
7432   void FreeVisContext();
7433 
7434   /// AddCFAuditedAttribute - Check whether we're currently within
7435   /// '\#pragma clang arc_cf_code_audited' and, if so, consider adding
7436   /// the appropriate attribute.
7437   void AddCFAuditedAttribute(Decl *D);
7438 
7439   /// \brief Called on well formed \#pragma clang optimize.
7440   void ActOnPragmaOptimize(bool On, SourceLocation PragmaLoc);
7441 
7442   /// \brief Get the location for the currently active "\#pragma clang optimize
7443   /// off". If this location is invalid, then the state of the pragma is "on".
getOptimizeOffPragmaLocation()7444   SourceLocation getOptimizeOffPragmaLocation() const {
7445     return OptimizeOffPragmaLocation;
7446   }
7447 
7448   /// \brief Only called on function definitions; if there is a pragma in scope
7449   /// with the effect of a range-based optnone, consider marking the function
7450   /// with attribute optnone.
7451   void AddRangeBasedOptnone(FunctionDecl *FD);
7452 
7453   /// \brief Adds the 'optnone' attribute to the function declaration if there
7454   /// are no conflicts; Loc represents the location causing the 'optnone'
7455   /// attribute to be added (usually because of a pragma).
7456   void AddOptnoneAttributeIfNoConflicts(FunctionDecl *FD, SourceLocation Loc);
7457 
7458   /// AddAlignedAttr - Adds an aligned attribute to a particular declaration.
7459   void AddAlignedAttr(SourceRange AttrRange, Decl *D, Expr *E,
7460                       unsigned SpellingListIndex, bool IsPackExpansion);
7461   void AddAlignedAttr(SourceRange AttrRange, Decl *D, TypeSourceInfo *T,
7462                       unsigned SpellingListIndex, bool IsPackExpansion);
7463 
7464   /// AddAssumeAlignedAttr - Adds an assume_aligned attribute to a particular
7465   /// declaration.
7466   void AddAssumeAlignedAttr(SourceRange AttrRange, Decl *D, Expr *E, Expr *OE,
7467                             unsigned SpellingListIndex);
7468 
7469   /// AddAlignValueAttr - Adds an align_value attribute to a particular
7470   /// declaration.
7471   void AddAlignValueAttr(SourceRange AttrRange, Decl *D, Expr *E,
7472                          unsigned SpellingListIndex);
7473 
7474   // OpenMP directives and clauses.
7475 private:
7476   void *VarDataSharingAttributesStack;
7477   /// \brief Initialization of data-sharing attributes stack.
7478   void InitDataSharingAttributesStack();
7479   void DestroyDataSharingAttributesStack();
7480   ExprResult VerifyPositiveIntegerConstantInClause(Expr *Op,
7481                                                    OpenMPClauseKind CKind);
7482   /// \brief Checks if the specified variable is used in one of the private
7483   /// clauses in OpenMP constructs.
7484   bool IsOpenMPCapturedVar(VarDecl *VD);
7485 
7486 public:
7487   ExprResult PerformOpenMPImplicitIntegerConversion(SourceLocation OpLoc,
7488                                                     Expr *Op);
7489   /// \brief Called on start of new data sharing attribute block.
7490   void StartOpenMPDSABlock(OpenMPDirectiveKind K,
7491                            const DeclarationNameInfo &DirName, Scope *CurScope,
7492                            SourceLocation Loc);
7493   /// \brief Called on end of data sharing attribute block.
7494   void EndOpenMPDSABlock(Stmt *CurDirective);
7495 
7496   // OpenMP directives and clauses.
7497   /// \brief Called on correct id-expression from the '#pragma omp
7498   /// threadprivate'.
7499   ExprResult ActOnOpenMPIdExpression(Scope *CurScope,
7500                                      CXXScopeSpec &ScopeSpec,
7501                                      const DeclarationNameInfo &Id);
7502   /// \brief Called on well-formed '#pragma omp threadprivate'.
7503   DeclGroupPtrTy ActOnOpenMPThreadprivateDirective(
7504                                      SourceLocation Loc,
7505                                      ArrayRef<Expr *> VarList);
7506   /// \brief Builds a new OpenMPThreadPrivateDecl and checks its correctness.
7507   OMPThreadPrivateDecl *CheckOMPThreadPrivateDecl(
7508                                      SourceLocation Loc,
7509                                      ArrayRef<Expr *> VarList);
7510 
7511   /// \brief Initialization of captured region for OpenMP region.
7512   void ActOnOpenMPRegionStart(OpenMPDirectiveKind DKind, Scope *CurScope);
7513   StmtResult ActOnOpenMPExecutableDirective(OpenMPDirectiveKind Kind,
7514                                             const DeclarationNameInfo &DirName,
7515                                             ArrayRef<OMPClause *> Clauses,
7516                                             Stmt *AStmt,
7517                                             SourceLocation StartLoc,
7518                                             SourceLocation EndLoc);
7519   /// \brief Called on well-formed '\#pragma omp parallel' after parsing
7520   /// of the  associated statement.
7521   StmtResult ActOnOpenMPParallelDirective(ArrayRef<OMPClause *> Clauses,
7522                                           Stmt *AStmt,
7523                                           SourceLocation StartLoc,
7524                                           SourceLocation EndLoc);
7525   /// \brief Called on well-formed '\#pragma omp simd' after parsing
7526   /// of the associated statement.
7527   StmtResult ActOnOpenMPSimdDirective(
7528       ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
7529       SourceLocation EndLoc,
7530       llvm::DenseMap<VarDecl *, Expr *> &VarsWithImplicitDSA);
7531   /// \brief Called on well-formed '\#pragma omp for' after parsing
7532   /// of the associated statement.
7533   StmtResult ActOnOpenMPForDirective(
7534       ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
7535       SourceLocation EndLoc,
7536       llvm::DenseMap<VarDecl *, Expr *> &VarsWithImplicitDSA);
7537   /// \brief Called on well-formed '\#pragma omp for simd' after parsing
7538   /// of the associated statement.
7539   StmtResult ActOnOpenMPForSimdDirective(
7540       ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
7541       SourceLocation EndLoc,
7542       llvm::DenseMap<VarDecl *, Expr *> &VarsWithImplicitDSA);
7543   /// \brief Called on well-formed '\#pragma omp sections' after parsing
7544   /// of the associated statement.
7545   StmtResult ActOnOpenMPSectionsDirective(ArrayRef<OMPClause *> Clauses,
7546                                           Stmt *AStmt, SourceLocation StartLoc,
7547                                           SourceLocation EndLoc);
7548   /// \brief Called on well-formed '\#pragma omp section' after parsing of the
7549   /// associated statement.
7550   StmtResult ActOnOpenMPSectionDirective(Stmt *AStmt, SourceLocation StartLoc,
7551                                          SourceLocation EndLoc);
7552   /// \brief Called on well-formed '\#pragma omp single' after parsing of the
7553   /// associated statement.
7554   StmtResult ActOnOpenMPSingleDirective(ArrayRef<OMPClause *> Clauses,
7555                                         Stmt *AStmt, SourceLocation StartLoc,
7556                                         SourceLocation EndLoc);
7557   /// \brief Called on well-formed '\#pragma omp master' after parsing of the
7558   /// associated statement.
7559   StmtResult ActOnOpenMPMasterDirective(Stmt *AStmt, SourceLocation StartLoc,
7560                                         SourceLocation EndLoc);
7561   /// \brief Called on well-formed '\#pragma omp critical' after parsing of the
7562   /// associated statement.
7563   StmtResult ActOnOpenMPCriticalDirective(const DeclarationNameInfo &DirName,
7564                                           Stmt *AStmt, SourceLocation StartLoc,
7565                                           SourceLocation EndLoc);
7566   /// \brief Called on well-formed '\#pragma omp parallel for' after parsing
7567   /// of the  associated statement.
7568   StmtResult ActOnOpenMPParallelForDirective(
7569       ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
7570       SourceLocation EndLoc,
7571       llvm::DenseMap<VarDecl *, Expr *> &VarsWithImplicitDSA);
7572   /// \brief Called on well-formed '\#pragma omp parallel for simd' after
7573   /// parsing of the  associated statement.
7574   StmtResult ActOnOpenMPParallelForSimdDirective(
7575       ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
7576       SourceLocation EndLoc,
7577       llvm::DenseMap<VarDecl *, Expr *> &VarsWithImplicitDSA);
7578   /// \brief Called on well-formed '\#pragma omp parallel sections' after
7579   /// parsing of the  associated statement.
7580   StmtResult ActOnOpenMPParallelSectionsDirective(ArrayRef<OMPClause *> Clauses,
7581                                                   Stmt *AStmt,
7582                                                   SourceLocation StartLoc,
7583                                                   SourceLocation EndLoc);
7584   /// \brief Called on well-formed '\#pragma omp task' after parsing of the
7585   /// associated statement.
7586   StmtResult ActOnOpenMPTaskDirective(ArrayRef<OMPClause *> Clauses,
7587                                       Stmt *AStmt, SourceLocation StartLoc,
7588                                       SourceLocation EndLoc);
7589   /// \brief Called on well-formed '\#pragma omp taskyield'.
7590   StmtResult ActOnOpenMPTaskyieldDirective(SourceLocation StartLoc,
7591                                            SourceLocation EndLoc);
7592   /// \brief Called on well-formed '\#pragma omp barrier'.
7593   StmtResult ActOnOpenMPBarrierDirective(SourceLocation StartLoc,
7594                                          SourceLocation EndLoc);
7595   /// \brief Called on well-formed '\#pragma omp taskwait'.
7596   StmtResult ActOnOpenMPTaskwaitDirective(SourceLocation StartLoc,
7597                                           SourceLocation EndLoc);
7598   /// \brief Called on well-formed '\#pragma omp flush'.
7599   StmtResult ActOnOpenMPFlushDirective(ArrayRef<OMPClause *> Clauses,
7600                                        SourceLocation StartLoc,
7601                                        SourceLocation EndLoc);
7602   /// \brief Called on well-formed '\#pragma omp ordered' after parsing of the
7603   /// associated statement.
7604   StmtResult ActOnOpenMPOrderedDirective(Stmt *AStmt, SourceLocation StartLoc,
7605                                          SourceLocation EndLoc);
7606   /// \brief Called on well-formed '\#pragma omp atomic' after parsing of the
7607   /// associated statement.
7608   StmtResult ActOnOpenMPAtomicDirective(ArrayRef<OMPClause *> Clauses,
7609                                         Stmt *AStmt, SourceLocation StartLoc,
7610                                         SourceLocation EndLoc);
7611   /// \brief Called on well-formed '\#pragma omp target' after parsing of the
7612   /// associated statement.
7613   StmtResult ActOnOpenMPTargetDirective(ArrayRef<OMPClause *> Clauses,
7614                                         Stmt *AStmt, SourceLocation StartLoc,
7615                                         SourceLocation EndLoc);
7616   /// \brief Called on well-formed '\#pragma omp teams' after parsing of the
7617   /// associated statement.
7618   StmtResult ActOnOpenMPTeamsDirective(ArrayRef<OMPClause *> Clauses,
7619                                        Stmt *AStmt, SourceLocation StartLoc,
7620                                        SourceLocation EndLoc);
7621 
7622   OMPClause *ActOnOpenMPSingleExprClause(OpenMPClauseKind Kind,
7623                                          Expr *Expr,
7624                                          SourceLocation StartLoc,
7625                                          SourceLocation LParenLoc,
7626                                          SourceLocation EndLoc);
7627   /// \brief Called on well-formed 'if' clause.
7628   OMPClause *ActOnOpenMPIfClause(Expr *Condition, SourceLocation StartLoc,
7629                                  SourceLocation LParenLoc,
7630                                  SourceLocation EndLoc);
7631   /// \brief Called on well-formed 'final' clause.
7632   OMPClause *ActOnOpenMPFinalClause(Expr *Condition, SourceLocation StartLoc,
7633                                     SourceLocation LParenLoc,
7634                                     SourceLocation EndLoc);
7635   /// \brief Called on well-formed 'num_threads' clause.
7636   OMPClause *ActOnOpenMPNumThreadsClause(Expr *NumThreads,
7637                                          SourceLocation StartLoc,
7638                                          SourceLocation LParenLoc,
7639                                          SourceLocation EndLoc);
7640   /// \brief Called on well-formed 'safelen' clause.
7641   OMPClause *ActOnOpenMPSafelenClause(Expr *Length,
7642                                       SourceLocation StartLoc,
7643                                       SourceLocation LParenLoc,
7644                                       SourceLocation EndLoc);
7645   /// \brief Called on well-formed 'collapse' clause.
7646   OMPClause *ActOnOpenMPCollapseClause(Expr *NumForLoops,
7647                                        SourceLocation StartLoc,
7648                                        SourceLocation LParenLoc,
7649                                        SourceLocation EndLoc);
7650 
7651   OMPClause *ActOnOpenMPSimpleClause(OpenMPClauseKind Kind,
7652                                      unsigned Argument,
7653                                      SourceLocation ArgumentLoc,
7654                                      SourceLocation StartLoc,
7655                                      SourceLocation LParenLoc,
7656                                      SourceLocation EndLoc);
7657   /// \brief Called on well-formed 'default' clause.
7658   OMPClause *ActOnOpenMPDefaultClause(OpenMPDefaultClauseKind Kind,
7659                                       SourceLocation KindLoc,
7660                                       SourceLocation StartLoc,
7661                                       SourceLocation LParenLoc,
7662                                       SourceLocation EndLoc);
7663   /// \brief Called on well-formed 'proc_bind' clause.
7664   OMPClause *ActOnOpenMPProcBindClause(OpenMPProcBindClauseKind Kind,
7665                                        SourceLocation KindLoc,
7666                                        SourceLocation StartLoc,
7667                                        SourceLocation LParenLoc,
7668                                        SourceLocation EndLoc);
7669 
7670   OMPClause *ActOnOpenMPSingleExprWithArgClause(OpenMPClauseKind Kind,
7671                                                 unsigned Argument, Expr *Expr,
7672                                                 SourceLocation StartLoc,
7673                                                 SourceLocation LParenLoc,
7674                                                 SourceLocation ArgumentLoc,
7675                                                 SourceLocation CommaLoc,
7676                                                 SourceLocation EndLoc);
7677   /// \brief Called on well-formed 'schedule' clause.
7678   OMPClause *ActOnOpenMPScheduleClause(OpenMPScheduleClauseKind Kind,
7679                                        Expr *ChunkSize, SourceLocation StartLoc,
7680                                        SourceLocation LParenLoc,
7681                                        SourceLocation KindLoc,
7682                                        SourceLocation CommaLoc,
7683                                        SourceLocation EndLoc);
7684 
7685   OMPClause *ActOnOpenMPClause(OpenMPClauseKind Kind, SourceLocation StartLoc,
7686                                SourceLocation EndLoc);
7687   /// \brief Called on well-formed 'ordered' clause.
7688   OMPClause *ActOnOpenMPOrderedClause(SourceLocation StartLoc,
7689                                       SourceLocation EndLoc);
7690   /// \brief Called on well-formed 'nowait' clause.
7691   OMPClause *ActOnOpenMPNowaitClause(SourceLocation StartLoc,
7692                                      SourceLocation EndLoc);
7693   /// \brief Called on well-formed 'untied' clause.
7694   OMPClause *ActOnOpenMPUntiedClause(SourceLocation StartLoc,
7695                                      SourceLocation EndLoc);
7696   /// \brief Called on well-formed 'mergeable' clause.
7697   OMPClause *ActOnOpenMPMergeableClause(SourceLocation StartLoc,
7698                                         SourceLocation EndLoc);
7699   /// \brief Called on well-formed 'read' clause.
7700   OMPClause *ActOnOpenMPReadClause(SourceLocation StartLoc,
7701                                    SourceLocation EndLoc);
7702   /// \brief Called on well-formed 'write' clause.
7703   OMPClause *ActOnOpenMPWriteClause(SourceLocation StartLoc,
7704                                     SourceLocation EndLoc);
7705   /// \brief Called on well-formed 'update' clause.
7706   OMPClause *ActOnOpenMPUpdateClause(SourceLocation StartLoc,
7707                                      SourceLocation EndLoc);
7708   /// \brief Called on well-formed 'capture' clause.
7709   OMPClause *ActOnOpenMPCaptureClause(SourceLocation StartLoc,
7710                                       SourceLocation EndLoc);
7711   /// \brief Called on well-formed 'seq_cst' clause.
7712   OMPClause *ActOnOpenMPSeqCstClause(SourceLocation StartLoc,
7713                                      SourceLocation EndLoc);
7714 
7715   OMPClause *
7716   ActOnOpenMPVarListClause(OpenMPClauseKind Kind, ArrayRef<Expr *> Vars,
7717                            Expr *TailExpr, SourceLocation StartLoc,
7718                            SourceLocation LParenLoc, SourceLocation ColonLoc,
7719                            SourceLocation EndLoc,
7720                            CXXScopeSpec &ReductionIdScopeSpec,
7721                            const DeclarationNameInfo &ReductionId);
7722   /// \brief Called on well-formed 'private' clause.
7723   OMPClause *ActOnOpenMPPrivateClause(ArrayRef<Expr *> VarList,
7724                                       SourceLocation StartLoc,
7725                                       SourceLocation LParenLoc,
7726                                       SourceLocation EndLoc);
7727   /// \brief Called on well-formed 'firstprivate' clause.
7728   OMPClause *ActOnOpenMPFirstprivateClause(ArrayRef<Expr *> VarList,
7729                                            SourceLocation StartLoc,
7730                                            SourceLocation LParenLoc,
7731                                            SourceLocation EndLoc);
7732   /// \brief Called on well-formed 'lastprivate' clause.
7733   OMPClause *ActOnOpenMPLastprivateClause(ArrayRef<Expr *> VarList,
7734                                           SourceLocation StartLoc,
7735                                           SourceLocation LParenLoc,
7736                                           SourceLocation EndLoc);
7737   /// \brief Called on well-formed 'shared' clause.
7738   OMPClause *ActOnOpenMPSharedClause(ArrayRef<Expr *> VarList,
7739                                      SourceLocation StartLoc,
7740                                      SourceLocation LParenLoc,
7741                                      SourceLocation EndLoc);
7742   /// \brief Called on well-formed 'reduction' clause.
7743   OMPClause *
7744   ActOnOpenMPReductionClause(ArrayRef<Expr *> VarList, SourceLocation StartLoc,
7745                              SourceLocation LParenLoc, SourceLocation ColonLoc,
7746                              SourceLocation EndLoc,
7747                              CXXScopeSpec &ReductionIdScopeSpec,
7748                              const DeclarationNameInfo &ReductionId);
7749   /// \brief Called on well-formed 'linear' clause.
7750   OMPClause *ActOnOpenMPLinearClause(ArrayRef<Expr *> VarList,
7751                                      Expr *Step,
7752                                      SourceLocation StartLoc,
7753                                      SourceLocation LParenLoc,
7754                                      SourceLocation ColonLoc,
7755                                      SourceLocation EndLoc);
7756   /// \brief Called on well-formed 'aligned' clause.
7757   OMPClause *ActOnOpenMPAlignedClause(ArrayRef<Expr *> VarList,
7758                                       Expr *Alignment,
7759                                       SourceLocation StartLoc,
7760                                       SourceLocation LParenLoc,
7761                                       SourceLocation ColonLoc,
7762                                       SourceLocation EndLoc);
7763   /// \brief Called on well-formed 'copyin' clause.
7764   OMPClause *ActOnOpenMPCopyinClause(ArrayRef<Expr *> VarList,
7765                                      SourceLocation StartLoc,
7766                                      SourceLocation LParenLoc,
7767                                      SourceLocation EndLoc);
7768   /// \brief Called on well-formed 'copyprivate' clause.
7769   OMPClause *ActOnOpenMPCopyprivateClause(ArrayRef<Expr *> VarList,
7770                                           SourceLocation StartLoc,
7771                                           SourceLocation LParenLoc,
7772                                           SourceLocation EndLoc);
7773   /// \brief Called on well-formed 'flush' pseudo clause.
7774   OMPClause *ActOnOpenMPFlushClause(ArrayRef<Expr *> VarList,
7775                                     SourceLocation StartLoc,
7776                                     SourceLocation LParenLoc,
7777                                     SourceLocation EndLoc);
7778 
7779   /// \brief The kind of conversion being performed.
7780   enum CheckedConversionKind {
7781     /// \brief An implicit conversion.
7782     CCK_ImplicitConversion,
7783     /// \brief A C-style cast.
7784     CCK_CStyleCast,
7785     /// \brief A functional-style cast.
7786     CCK_FunctionalCast,
7787     /// \brief A cast other than a C-style cast.
7788     CCK_OtherCast
7789   };
7790 
7791   /// ImpCastExprToType - If Expr is not of type 'Type', insert an implicit
7792   /// cast.  If there is already an implicit cast, merge into the existing one.
7793   /// If isLvalue, the result of the cast is an lvalue.
7794   ExprResult ImpCastExprToType(Expr *E, QualType Type, CastKind CK,
7795                                ExprValueKind VK = VK_RValue,
7796                                const CXXCastPath *BasePath = nullptr,
7797                                CheckedConversionKind CCK
7798                                   = CCK_ImplicitConversion);
7799 
7800   /// ScalarTypeToBooleanCastKind - Returns the cast kind corresponding
7801   /// to the conversion from scalar type ScalarTy to the Boolean type.
7802   static CastKind ScalarTypeToBooleanCastKind(QualType ScalarTy);
7803 
7804   /// IgnoredValueConversions - Given that an expression's result is
7805   /// syntactically ignored, perform any conversions that are
7806   /// required.
7807   ExprResult IgnoredValueConversions(Expr *E);
7808 
7809   // UsualUnaryConversions - promotes integers (C99 6.3.1.1p2) and converts
7810   // functions and arrays to their respective pointers (C99 6.3.2.1).
7811   ExprResult UsualUnaryConversions(Expr *E);
7812 
7813   /// CallExprUnaryConversions - a special case of an unary conversion
7814   /// performed on a function designator of a call expression.
7815   ExprResult CallExprUnaryConversions(Expr *E);
7816 
7817   // DefaultFunctionArrayConversion - converts functions and arrays
7818   // to their respective pointers (C99 6.3.2.1).
7819   ExprResult DefaultFunctionArrayConversion(Expr *E);
7820 
7821   // DefaultFunctionArrayLvalueConversion - converts functions and
7822   // arrays to their respective pointers and performs the
7823   // lvalue-to-rvalue conversion.
7824   ExprResult DefaultFunctionArrayLvalueConversion(Expr *E);
7825 
7826   // DefaultLvalueConversion - performs lvalue-to-rvalue conversion on
7827   // the operand.  This is DefaultFunctionArrayLvalueConversion,
7828   // except that it assumes the operand isn't of function or array
7829   // type.
7830   ExprResult DefaultLvalueConversion(Expr *E);
7831 
7832   // DefaultArgumentPromotion (C99 6.5.2.2p6). Used for function calls that
7833   // do not have a prototype. Integer promotions are performed on each
7834   // argument, and arguments that have type float are promoted to double.
7835   ExprResult DefaultArgumentPromotion(Expr *E);
7836 
7837   // Used for emitting the right warning by DefaultVariadicArgumentPromotion
7838   enum VariadicCallType {
7839     VariadicFunction,
7840     VariadicBlock,
7841     VariadicMethod,
7842     VariadicConstructor,
7843     VariadicDoesNotApply
7844   };
7845 
7846   VariadicCallType getVariadicCallType(FunctionDecl *FDecl,
7847                                        const FunctionProtoType *Proto,
7848                                        Expr *Fn);
7849 
7850   // Used for determining in which context a type is allowed to be passed to a
7851   // vararg function.
7852   enum VarArgKind {
7853     VAK_Valid,
7854     VAK_ValidInCXX11,
7855     VAK_Undefined,
7856     VAK_MSVCUndefined,
7857     VAK_Invalid
7858   };
7859 
7860   // Determines which VarArgKind fits an expression.
7861   VarArgKind isValidVarArgType(const QualType &Ty);
7862 
7863   /// Check to see if the given expression is a valid argument to a variadic
7864   /// function, issuing a diagnostic if not.
7865   void checkVariadicArgument(const Expr *E, VariadicCallType CT);
7866 
7867   /// Check to see if a given expression could have '.c_str()' called on it.
7868   bool hasCStrMethod(const Expr *E);
7869 
7870   /// GatherArgumentsForCall - Collector argument expressions for various
7871   /// form of call prototypes.
7872   bool GatherArgumentsForCall(SourceLocation CallLoc, FunctionDecl *FDecl,
7873                               const FunctionProtoType *Proto,
7874                               unsigned FirstParam, ArrayRef<Expr *> Args,
7875                               SmallVectorImpl<Expr *> &AllArgs,
7876                               VariadicCallType CallType = VariadicDoesNotApply,
7877                               bool AllowExplicit = false,
7878                               bool IsListInitialization = false);
7879 
7880   // DefaultVariadicArgumentPromotion - Like DefaultArgumentPromotion, but
7881   // will create a runtime trap if the resulting type is not a POD type.
7882   ExprResult DefaultVariadicArgumentPromotion(Expr *E, VariadicCallType CT,
7883                                               FunctionDecl *FDecl);
7884 
7885   // UsualArithmeticConversions - performs the UsualUnaryConversions on it's
7886   // operands and then handles various conversions that are common to binary
7887   // operators (C99 6.3.1.8). If both operands aren't arithmetic, this
7888   // routine returns the first non-arithmetic type found. The client is
7889   // responsible for emitting appropriate error diagnostics.
7890   QualType UsualArithmeticConversions(ExprResult &LHS, ExprResult &RHS,
7891                                       bool IsCompAssign = false);
7892 
7893   /// AssignConvertType - All of the 'assignment' semantic checks return this
7894   /// enum to indicate whether the assignment was allowed.  These checks are
7895   /// done for simple assignments, as well as initialization, return from
7896   /// function, argument passing, etc.  The query is phrased in terms of a
7897   /// source and destination type.
7898   enum AssignConvertType {
7899     /// Compatible - the types are compatible according to the standard.
7900     Compatible,
7901 
7902     /// PointerToInt - The assignment converts a pointer to an int, which we
7903     /// accept as an extension.
7904     PointerToInt,
7905 
7906     /// IntToPointer - The assignment converts an int to a pointer, which we
7907     /// accept as an extension.
7908     IntToPointer,
7909 
7910     /// FunctionVoidPointer - The assignment is between a function pointer and
7911     /// void*, which the standard doesn't allow, but we accept as an extension.
7912     FunctionVoidPointer,
7913 
7914     /// IncompatiblePointer - The assignment is between two pointers types that
7915     /// are not compatible, but we accept them as an extension.
7916     IncompatiblePointer,
7917 
7918     /// IncompatiblePointer - The assignment is between two pointers types which
7919     /// point to integers which have a different sign, but are otherwise
7920     /// identical. This is a subset of the above, but broken out because it's by
7921     /// far the most common case of incompatible pointers.
7922     IncompatiblePointerSign,
7923 
7924     /// CompatiblePointerDiscardsQualifiers - The assignment discards
7925     /// c/v/r qualifiers, which we accept as an extension.
7926     CompatiblePointerDiscardsQualifiers,
7927 
7928     /// IncompatiblePointerDiscardsQualifiers - The assignment
7929     /// discards qualifiers that we don't permit to be discarded,
7930     /// like address spaces.
7931     IncompatiblePointerDiscardsQualifiers,
7932 
7933     /// IncompatibleNestedPointerQualifiers - The assignment is between two
7934     /// nested pointer types, and the qualifiers other than the first two
7935     /// levels differ e.g. char ** -> const char **, but we accept them as an
7936     /// extension.
7937     IncompatibleNestedPointerQualifiers,
7938 
7939     /// IncompatibleVectors - The assignment is between two vector types that
7940     /// have the same size, which we accept as an extension.
7941     IncompatibleVectors,
7942 
7943     /// IntToBlockPointer - The assignment converts an int to a block
7944     /// pointer. We disallow this.
7945     IntToBlockPointer,
7946 
7947     /// IncompatibleBlockPointer - The assignment is between two block
7948     /// pointers types that are not compatible.
7949     IncompatibleBlockPointer,
7950 
7951     /// IncompatibleObjCQualifiedId - The assignment is between a qualified
7952     /// id type and something else (that is incompatible with it). For example,
7953     /// "id <XXX>" = "Foo *", where "Foo *" doesn't implement the XXX protocol.
7954     IncompatibleObjCQualifiedId,
7955 
7956     /// IncompatibleObjCWeakRef - Assigning a weak-unavailable object to an
7957     /// object with __weak qualifier.
7958     IncompatibleObjCWeakRef,
7959 
7960     /// Incompatible - We reject this conversion outright, it is invalid to
7961     /// represent it in the AST.
7962     Incompatible
7963   };
7964 
7965   /// DiagnoseAssignmentResult - Emit a diagnostic, if required, for the
7966   /// assignment conversion type specified by ConvTy.  This returns true if the
7967   /// conversion was invalid or false if the conversion was accepted.
7968   bool DiagnoseAssignmentResult(AssignConvertType ConvTy,
7969                                 SourceLocation Loc,
7970                                 QualType DstType, QualType SrcType,
7971                                 Expr *SrcExpr, AssignmentAction Action,
7972                                 bool *Complained = nullptr);
7973 
7974   /// DiagnoseAssignmentEnum - Warn if assignment to enum is a constant
7975   /// integer not in the range of enum values.
7976   void DiagnoseAssignmentEnum(QualType DstType, QualType SrcType,
7977                               Expr *SrcExpr);
7978 
7979   /// CheckAssignmentConstraints - Perform type checking for assignment,
7980   /// argument passing, variable initialization, and function return values.
7981   /// C99 6.5.16.
7982   AssignConvertType CheckAssignmentConstraints(SourceLocation Loc,
7983                                                QualType LHSType,
7984                                                QualType RHSType);
7985 
7986   /// Check assignment constraints and prepare for a conversion of the
7987   /// RHS to the LHS type.
7988   AssignConvertType CheckAssignmentConstraints(QualType LHSType,
7989                                                ExprResult &RHS,
7990                                                CastKind &Kind);
7991 
7992   // CheckSingleAssignmentConstraints - Currently used by
7993   // CheckAssignmentOperands, and ActOnReturnStmt. Prior to type checking,
7994   // this routine performs the default function/array converions.
7995   AssignConvertType CheckSingleAssignmentConstraints(QualType LHSType,
7996                                                      ExprResult &RHS,
7997                                                      bool Diagnose = true,
7998                                                      bool DiagnoseCFAudited = false);
7999 
8000   // \brief If the lhs type is a transparent union, check whether we
8001   // can initialize the transparent union with the given expression.
8002   AssignConvertType CheckTransparentUnionArgumentConstraints(QualType ArgType,
8003                                                              ExprResult &RHS);
8004 
8005   bool IsStringLiteralToNonConstPointerConversion(Expr *From, QualType ToType);
8006 
8007   bool CheckExceptionSpecCompatibility(Expr *From, QualType ToType);
8008 
8009   ExprResult PerformImplicitConversion(Expr *From, QualType ToType,
8010                                        AssignmentAction Action,
8011                                        bool AllowExplicit = false);
8012   ExprResult PerformImplicitConversion(Expr *From, QualType ToType,
8013                                        AssignmentAction Action,
8014                                        bool AllowExplicit,
8015                                        ImplicitConversionSequence& ICS);
8016   ExprResult PerformImplicitConversion(Expr *From, QualType ToType,
8017                                        const ImplicitConversionSequence& ICS,
8018                                        AssignmentAction Action,
8019                                        CheckedConversionKind CCK
8020                                           = CCK_ImplicitConversion);
8021   ExprResult PerformImplicitConversion(Expr *From, QualType ToType,
8022                                        const StandardConversionSequence& SCS,
8023                                        AssignmentAction Action,
8024                                        CheckedConversionKind CCK);
8025 
8026   /// the following "Check" methods will return a valid/converted QualType
8027   /// or a null QualType (indicating an error diagnostic was issued).
8028 
8029   /// type checking binary operators (subroutines of CreateBuiltinBinOp).
8030   QualType InvalidOperands(SourceLocation Loc, ExprResult &LHS,
8031                            ExprResult &RHS);
8032   QualType CheckPointerToMemberOperands( // C++ 5.5
8033     ExprResult &LHS, ExprResult &RHS, ExprValueKind &VK,
8034     SourceLocation OpLoc, bool isIndirect);
8035   QualType CheckMultiplyDivideOperands( // C99 6.5.5
8036     ExprResult &LHS, ExprResult &RHS, SourceLocation Loc, bool IsCompAssign,
8037     bool IsDivide);
8038   QualType CheckRemainderOperands( // C99 6.5.5
8039     ExprResult &LHS, ExprResult &RHS, SourceLocation Loc,
8040     bool IsCompAssign = false);
8041   QualType CheckAdditionOperands( // C99 6.5.6
8042     ExprResult &LHS, ExprResult &RHS, SourceLocation Loc, unsigned Opc,
8043     QualType* CompLHSTy = nullptr);
8044   QualType CheckSubtractionOperands( // C99 6.5.6
8045     ExprResult &LHS, ExprResult &RHS, SourceLocation Loc,
8046     QualType* CompLHSTy = nullptr);
8047   QualType CheckShiftOperands( // C99 6.5.7
8048     ExprResult &LHS, ExprResult &RHS, SourceLocation Loc, unsigned Opc,
8049     bool IsCompAssign = false);
8050   QualType CheckCompareOperands( // C99 6.5.8/9
8051     ExprResult &LHS, ExprResult &RHS, SourceLocation Loc, unsigned OpaqueOpc,
8052                                 bool isRelational);
8053   QualType CheckBitwiseOperands( // C99 6.5.[10...12]
8054     ExprResult &LHS, ExprResult &RHS, SourceLocation Loc,
8055     bool IsCompAssign = false);
8056   QualType CheckLogicalOperands( // C99 6.5.[13,14]
8057     ExprResult &LHS, ExprResult &RHS, SourceLocation Loc, unsigned Opc);
8058   // CheckAssignmentOperands is used for both simple and compound assignment.
8059   // For simple assignment, pass both expressions and a null converted type.
8060   // For compound assignment, pass both expressions and the converted type.
8061   QualType CheckAssignmentOperands( // C99 6.5.16.[1,2]
8062     Expr *LHSExpr, ExprResult &RHS, SourceLocation Loc, QualType CompoundType);
8063 
8064   ExprResult checkPseudoObjectIncDec(Scope *S, SourceLocation OpLoc,
8065                                      UnaryOperatorKind Opcode, Expr *Op);
8066   ExprResult checkPseudoObjectAssignment(Scope *S, SourceLocation OpLoc,
8067                                          BinaryOperatorKind Opcode,
8068                                          Expr *LHS, Expr *RHS);
8069   ExprResult checkPseudoObjectRValue(Expr *E);
8070   Expr *recreateSyntacticForm(PseudoObjectExpr *E);
8071 
8072   QualType CheckConditionalOperands( // C99 6.5.15
8073     ExprResult &Cond, ExprResult &LHS, ExprResult &RHS,
8074     ExprValueKind &VK, ExprObjectKind &OK, SourceLocation QuestionLoc);
8075   QualType CXXCheckConditionalOperands( // C++ 5.16
8076     ExprResult &cond, ExprResult &lhs, ExprResult &rhs,
8077     ExprValueKind &VK, ExprObjectKind &OK, SourceLocation questionLoc);
8078   QualType FindCompositePointerType(SourceLocation Loc, Expr *&E1, Expr *&E2,
8079                                     bool *NonStandardCompositeType = nullptr);
8080   QualType FindCompositePointerType(SourceLocation Loc,
8081                                     ExprResult &E1, ExprResult &E2,
8082                                     bool *NonStandardCompositeType = nullptr) {
8083     Expr *E1Tmp = E1.get(), *E2Tmp = E2.get();
8084     QualType Composite = FindCompositePointerType(Loc, E1Tmp, E2Tmp,
8085                                                   NonStandardCompositeType);
8086     E1 = E1Tmp;
8087     E2 = E2Tmp;
8088     return Composite;
8089   }
8090 
8091   QualType FindCompositeObjCPointerType(ExprResult &LHS, ExprResult &RHS,
8092                                         SourceLocation QuestionLoc);
8093 
8094   bool DiagnoseConditionalForNull(Expr *LHSExpr, Expr *RHSExpr,
8095                                   SourceLocation QuestionLoc);
8096 
8097   void DiagnoseAlwaysNonNullPointer(Expr *E,
8098                                     Expr::NullPointerConstantKind NullType,
8099                                     bool IsEqual, SourceRange Range);
8100 
8101   /// type checking for vector binary operators.
8102   QualType CheckVectorOperands(ExprResult &LHS, ExprResult &RHS,
8103                                SourceLocation Loc, bool IsCompAssign);
8104   QualType GetSignedVectorType(QualType V);
8105   QualType CheckVectorCompareOperands(ExprResult &LHS, ExprResult &RHS,
8106                                       SourceLocation Loc, bool isRelational);
8107   QualType CheckVectorLogicalOperands(ExprResult &LHS, ExprResult &RHS,
8108                                       SourceLocation Loc);
8109 
8110   bool isLaxVectorConversion(QualType srcType, QualType destType);
8111 
8112   /// type checking declaration initializers (C99 6.7.8)
8113   bool CheckForConstantInitializer(Expr *e, QualType t);
8114 
8115   // type checking C++ declaration initializers (C++ [dcl.init]).
8116 
8117   /// ReferenceCompareResult - Expresses the result of comparing two
8118   /// types (cv1 T1 and cv2 T2) to determine their compatibility for the
8119   /// purposes of initialization by reference (C++ [dcl.init.ref]p4).
8120   enum ReferenceCompareResult {
8121     /// Ref_Incompatible - The two types are incompatible, so direct
8122     /// reference binding is not possible.
8123     Ref_Incompatible = 0,
8124     /// Ref_Related - The two types are reference-related, which means
8125     /// that their unqualified forms (T1 and T2) are either the same
8126     /// or T1 is a base class of T2.
8127     Ref_Related,
8128     /// Ref_Compatible_With_Added_Qualification - The two types are
8129     /// reference-compatible with added qualification, meaning that
8130     /// they are reference-compatible and the qualifiers on T1 (cv1)
8131     /// are greater than the qualifiers on T2 (cv2).
8132     Ref_Compatible_With_Added_Qualification,
8133     /// Ref_Compatible - The two types are reference-compatible and
8134     /// have equivalent qualifiers (cv1 == cv2).
8135     Ref_Compatible
8136   };
8137 
8138   ReferenceCompareResult CompareReferenceRelationship(SourceLocation Loc,
8139                                                       QualType T1, QualType T2,
8140                                                       bool &DerivedToBase,
8141                                                       bool &ObjCConversion,
8142                                                 bool &ObjCLifetimeConversion);
8143 
8144   ExprResult checkUnknownAnyCast(SourceRange TypeRange, QualType CastType,
8145                                  Expr *CastExpr, CastKind &CastKind,
8146                                  ExprValueKind &VK, CXXCastPath &Path);
8147 
8148   /// \brief Force an expression with unknown-type to an expression of the
8149   /// given type.
8150   ExprResult forceUnknownAnyToType(Expr *E, QualType ToType);
8151 
8152   /// \brief Type-check an expression that's being passed to an
8153   /// __unknown_anytype parameter.
8154   ExprResult checkUnknownAnyArg(SourceLocation callLoc,
8155                                 Expr *result, QualType &paramType);
8156 
8157   // CheckVectorCast - check type constraints for vectors.
8158   // Since vectors are an extension, there are no C standard reference for this.
8159   // We allow casting between vectors and integer datatypes of the same size.
8160   // returns true if the cast is invalid
8161   bool CheckVectorCast(SourceRange R, QualType VectorTy, QualType Ty,
8162                        CastKind &Kind);
8163 
8164   // CheckExtVectorCast - check type constraints for extended vectors.
8165   // Since vectors are an extension, there are no C standard reference for this.
8166   // We allow casting between vectors and integer datatypes of the same size,
8167   // or vectors and the element type of that vector.
8168   // returns the cast expr
8169   ExprResult CheckExtVectorCast(SourceRange R, QualType DestTy, Expr *CastExpr,
8170                                 CastKind &Kind);
8171 
8172   ExprResult BuildCXXFunctionalCastExpr(TypeSourceInfo *TInfo,
8173                                         SourceLocation LParenLoc,
8174                                         Expr *CastExpr,
8175                                         SourceLocation RParenLoc);
8176 
8177   enum ARCConversionResult { ACR_okay, ACR_unbridged };
8178 
8179   /// \brief Checks for invalid conversions and casts between
8180   /// retainable pointers and other pointer kinds.
8181   ARCConversionResult CheckObjCARCConversion(SourceRange castRange,
8182                                              QualType castType, Expr *&op,
8183                                              CheckedConversionKind CCK,
8184                                              bool DiagnoseCFAudited = false,
8185                                              BinaryOperatorKind Opc = BO_PtrMemD
8186                                              );
8187 
8188   Expr *stripARCUnbridgedCast(Expr *e);
8189   void diagnoseARCUnbridgedCast(Expr *e);
8190 
8191   bool CheckObjCARCUnavailableWeakConversion(QualType castType,
8192                                              QualType ExprType);
8193 
8194   /// checkRetainCycles - Check whether an Objective-C message send
8195   /// might create an obvious retain cycle.
8196   void checkRetainCycles(ObjCMessageExpr *msg);
8197   void checkRetainCycles(Expr *receiver, Expr *argument);
8198   void checkRetainCycles(VarDecl *Var, Expr *Init);
8199 
8200   /// checkUnsafeAssigns - Check whether +1 expr is being assigned
8201   /// to weak/__unsafe_unretained type.
8202   bool checkUnsafeAssigns(SourceLocation Loc, QualType LHS, Expr *RHS);
8203 
8204   /// checkUnsafeExprAssigns - Check whether +1 expr is being assigned
8205   /// to weak/__unsafe_unretained expression.
8206   void checkUnsafeExprAssigns(SourceLocation Loc, Expr *LHS, Expr *RHS);
8207 
8208   /// CheckMessageArgumentTypes - Check types in an Obj-C message send.
8209   /// \param Method - May be null.
8210   /// \param [out] ReturnType - The return type of the send.
8211   /// \return true iff there were any incompatible types.
8212   bool CheckMessageArgumentTypes(QualType ReceiverType,
8213                                  MultiExprArg Args, Selector Sel,
8214                                  ArrayRef<SourceLocation> SelectorLocs,
8215                                  ObjCMethodDecl *Method, bool isClassMessage,
8216                                  bool isSuperMessage,
8217                                  SourceLocation lbrac, SourceLocation rbrac,
8218                                  SourceRange RecRange,
8219                                  QualType &ReturnType, ExprValueKind &VK);
8220 
8221   /// \brief Determine the result of a message send expression based on
8222   /// the type of the receiver, the method expected to receive the message,
8223   /// and the form of the message send.
8224   QualType getMessageSendResultType(QualType ReceiverType,
8225                                     ObjCMethodDecl *Method,
8226                                     bool isClassMessage, bool isSuperMessage);
8227 
8228   /// \brief If the given expression involves a message send to a method
8229   /// with a related result type, emit a note describing what happened.
8230   void EmitRelatedResultTypeNote(const Expr *E);
8231 
8232   /// \brief Given that we had incompatible pointer types in a return
8233   /// statement, check whether we're in a method with a related result
8234   /// type, and if so, emit a note describing what happened.
8235   void EmitRelatedResultTypeNoteForReturn(QualType destType);
8236 
8237   /// CheckBooleanCondition - Diagnose problems involving the use of
8238   /// the given expression as a boolean condition (e.g. in an if
8239   /// statement).  Also performs the standard function and array
8240   /// decays, possibly changing the input variable.
8241   ///
8242   /// \param Loc - A location associated with the condition, e.g. the
8243   /// 'if' keyword.
8244   /// \return true iff there were any errors
8245   ExprResult CheckBooleanCondition(Expr *E, SourceLocation Loc);
8246 
8247   ExprResult ActOnBooleanCondition(Scope *S, SourceLocation Loc,
8248                                    Expr *SubExpr);
8249 
8250   /// DiagnoseAssignmentAsCondition - Given that an expression is
8251   /// being used as a boolean condition, warn if it's an assignment.
8252   void DiagnoseAssignmentAsCondition(Expr *E);
8253 
8254   /// \brief Redundant parentheses over an equality comparison can indicate
8255   /// that the user intended an assignment used as condition.
8256   void DiagnoseEqualityWithExtraParens(ParenExpr *ParenE);
8257 
8258   /// CheckCXXBooleanCondition - Returns true if conversion to bool is invalid.
8259   ExprResult CheckCXXBooleanCondition(Expr *CondExpr);
8260 
8261   /// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have
8262   /// the specified width and sign.  If an overflow occurs, detect it and emit
8263   /// the specified diagnostic.
8264   void ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &OldVal,
8265                                           unsigned NewWidth, bool NewSign,
8266                                           SourceLocation Loc, unsigned DiagID);
8267 
8268   /// Checks that the Objective-C declaration is declared in the global scope.
8269   /// Emits an error and marks the declaration as invalid if it's not declared
8270   /// in the global scope.
8271   bool CheckObjCDeclScope(Decl *D);
8272 
8273   /// \brief Abstract base class used for diagnosing integer constant
8274   /// expression violations.
8275   class VerifyICEDiagnoser {
8276   public:
8277     bool Suppress;
8278 
Suppress(Suppress)8279     VerifyICEDiagnoser(bool Suppress = false) : Suppress(Suppress) { }
8280 
8281     virtual void diagnoseNotICE(Sema &S, SourceLocation Loc, SourceRange SR) =0;
8282     virtual void diagnoseFold(Sema &S, SourceLocation Loc, SourceRange SR);
~VerifyICEDiagnoser()8283     virtual ~VerifyICEDiagnoser() { }
8284   };
8285 
8286   /// VerifyIntegerConstantExpression - Verifies that an expression is an ICE,
8287   /// and reports the appropriate diagnostics. Returns false on success.
8288   /// Can optionally return the value of the expression.
8289   ExprResult VerifyIntegerConstantExpression(Expr *E, llvm::APSInt *Result,
8290                                              VerifyICEDiagnoser &Diagnoser,
8291                                              bool AllowFold = true);
8292   ExprResult VerifyIntegerConstantExpression(Expr *E, llvm::APSInt *Result,
8293                                              unsigned DiagID,
8294                                              bool AllowFold = true);
8295   ExprResult VerifyIntegerConstantExpression(Expr *E,
8296                                              llvm::APSInt *Result = nullptr);
8297 
8298   /// VerifyBitField - verifies that a bit field expression is an ICE and has
8299   /// the correct width, and that the field type is valid.
8300   /// Returns false on success.
8301   /// Can optionally return whether the bit-field is of width 0
8302   ExprResult VerifyBitField(SourceLocation FieldLoc, IdentifierInfo *FieldName,
8303                             QualType FieldTy, bool IsMsStruct,
8304                             Expr *BitWidth, bool *ZeroWidth = nullptr);
8305 
8306   enum CUDAFunctionTarget {
8307     CFT_Device,
8308     CFT_Global,
8309     CFT_Host,
8310     CFT_HostDevice,
8311     CFT_InvalidTarget
8312   };
8313 
8314   CUDAFunctionTarget IdentifyCUDATarget(const FunctionDecl *D);
8315 
8316   bool CheckCUDATarget(const FunctionDecl *Caller, const FunctionDecl *Callee);
8317 
8318   /// Given a implicit special member, infer its CUDA target from the
8319   /// calls it needs to make to underlying base/field special members.
8320   /// \param ClassDecl the class for which the member is being created.
8321   /// \param CSM the kind of special member.
8322   /// \param MemberDecl the special member itself.
8323   /// \param ConstRHS true if this is a copy operation with a const object on
8324   ///        its RHS.
8325   /// \param Diagnose true if this call should emit diagnostics.
8326   /// \return true if there was an error inferring.
8327   /// The result of this call is implicit CUDA target attribute(s) attached to
8328   /// the member declaration.
8329   bool inferCUDATargetForImplicitSpecialMember(CXXRecordDecl *ClassDecl,
8330                                                CXXSpecialMember CSM,
8331                                                CXXMethodDecl *MemberDecl,
8332                                                bool ConstRHS,
8333                                                bool Diagnose);
8334 
8335   /// \name Code completion
8336   //@{
8337   /// \brief Describes the context in which code completion occurs.
8338   enum ParserCompletionContext {
8339     /// \brief Code completion occurs at top-level or namespace context.
8340     PCC_Namespace,
8341     /// \brief Code completion occurs within a class, struct, or union.
8342     PCC_Class,
8343     /// \brief Code completion occurs within an Objective-C interface, protocol,
8344     /// or category.
8345     PCC_ObjCInterface,
8346     /// \brief Code completion occurs within an Objective-C implementation or
8347     /// category implementation
8348     PCC_ObjCImplementation,
8349     /// \brief Code completion occurs within the list of instance variables
8350     /// in an Objective-C interface, protocol, category, or implementation.
8351     PCC_ObjCInstanceVariableList,
8352     /// \brief Code completion occurs following one or more template
8353     /// headers.
8354     PCC_Template,
8355     /// \brief Code completion occurs following one or more template
8356     /// headers within a class.
8357     PCC_MemberTemplate,
8358     /// \brief Code completion occurs within an expression.
8359     PCC_Expression,
8360     /// \brief Code completion occurs within a statement, which may
8361     /// also be an expression or a declaration.
8362     PCC_Statement,
8363     /// \brief Code completion occurs at the beginning of the
8364     /// initialization statement (or expression) in a for loop.
8365     PCC_ForInit,
8366     /// \brief Code completion occurs within the condition of an if,
8367     /// while, switch, or for statement.
8368     PCC_Condition,
8369     /// \brief Code completion occurs within the body of a function on a
8370     /// recovery path, where we do not have a specific handle on our position
8371     /// in the grammar.
8372     PCC_RecoveryInFunction,
8373     /// \brief Code completion occurs where only a type is permitted.
8374     PCC_Type,
8375     /// \brief Code completion occurs in a parenthesized expression, which
8376     /// might also be a type cast.
8377     PCC_ParenthesizedExpression,
8378     /// \brief Code completion occurs within a sequence of declaration
8379     /// specifiers within a function, method, or block.
8380     PCC_LocalDeclarationSpecifiers
8381   };
8382 
8383   void CodeCompleteModuleImport(SourceLocation ImportLoc, ModuleIdPath Path);
8384   void CodeCompleteOrdinaryName(Scope *S,
8385                                 ParserCompletionContext CompletionContext);
8386   void CodeCompleteDeclSpec(Scope *S, DeclSpec &DS,
8387                             bool AllowNonIdentifiers,
8388                             bool AllowNestedNameSpecifiers);
8389 
8390   struct CodeCompleteExpressionData;
8391   void CodeCompleteExpression(Scope *S,
8392                               const CodeCompleteExpressionData &Data);
8393   void CodeCompleteMemberReferenceExpr(Scope *S, Expr *Base,
8394                                        SourceLocation OpLoc,
8395                                        bool IsArrow);
8396   void CodeCompletePostfixExpression(Scope *S, ExprResult LHS);
8397   void CodeCompleteTag(Scope *S, unsigned TagSpec);
8398   void CodeCompleteTypeQualifiers(DeclSpec &DS);
8399   void CodeCompleteCase(Scope *S);
8400   void CodeCompleteCall(Scope *S, Expr *Fn, ArrayRef<Expr *> Args);
8401   void CodeCompleteInitializer(Scope *S, Decl *D);
8402   void CodeCompleteReturn(Scope *S);
8403   void CodeCompleteAfterIf(Scope *S);
8404   void CodeCompleteAssignmentRHS(Scope *S, Expr *LHS);
8405 
8406   void CodeCompleteQualifiedId(Scope *S, CXXScopeSpec &SS,
8407                                bool EnteringContext);
8408   void CodeCompleteUsing(Scope *S);
8409   void CodeCompleteUsingDirective(Scope *S);
8410   void CodeCompleteNamespaceDecl(Scope *S);
8411   void CodeCompleteNamespaceAliasDecl(Scope *S);
8412   void CodeCompleteOperatorName(Scope *S);
8413   void CodeCompleteConstructorInitializer(
8414                                 Decl *Constructor,
8415                                 ArrayRef<CXXCtorInitializer *> Initializers);
8416 
8417   void CodeCompleteLambdaIntroducer(Scope *S, LambdaIntroducer &Intro,
8418                                     bool AfterAmpersand);
8419 
8420   void CodeCompleteObjCAtDirective(Scope *S);
8421   void CodeCompleteObjCAtVisibility(Scope *S);
8422   void CodeCompleteObjCAtStatement(Scope *S);
8423   void CodeCompleteObjCAtExpression(Scope *S);
8424   void CodeCompleteObjCPropertyFlags(Scope *S, ObjCDeclSpec &ODS);
8425   void CodeCompleteObjCPropertyGetter(Scope *S);
8426   void CodeCompleteObjCPropertySetter(Scope *S);
8427   void CodeCompleteObjCPassingType(Scope *S, ObjCDeclSpec &DS,
8428                                    bool IsParameter);
8429   void CodeCompleteObjCMessageReceiver(Scope *S);
8430   void CodeCompleteObjCSuperMessage(Scope *S, SourceLocation SuperLoc,
8431                                     ArrayRef<IdentifierInfo *> SelIdents,
8432                                     bool AtArgumentExpression);
8433   void CodeCompleteObjCClassMessage(Scope *S, ParsedType Receiver,
8434                                     ArrayRef<IdentifierInfo *> SelIdents,
8435                                     bool AtArgumentExpression,
8436                                     bool IsSuper = false);
8437   void CodeCompleteObjCInstanceMessage(Scope *S, Expr *Receiver,
8438                                        ArrayRef<IdentifierInfo *> SelIdents,
8439                                        bool AtArgumentExpression,
8440                                        ObjCInterfaceDecl *Super = nullptr);
8441   void CodeCompleteObjCForCollection(Scope *S,
8442                                      DeclGroupPtrTy IterationVar);
8443   void CodeCompleteObjCSelector(Scope *S,
8444                                 ArrayRef<IdentifierInfo *> SelIdents);
8445   void CodeCompleteObjCProtocolReferences(IdentifierLocPair *Protocols,
8446                                           unsigned NumProtocols);
8447   void CodeCompleteObjCProtocolDecl(Scope *S);
8448   void CodeCompleteObjCInterfaceDecl(Scope *S);
8449   void CodeCompleteObjCSuperclass(Scope *S,
8450                                   IdentifierInfo *ClassName,
8451                                   SourceLocation ClassNameLoc);
8452   void CodeCompleteObjCImplementationDecl(Scope *S);
8453   void CodeCompleteObjCInterfaceCategory(Scope *S,
8454                                          IdentifierInfo *ClassName,
8455                                          SourceLocation ClassNameLoc);
8456   void CodeCompleteObjCImplementationCategory(Scope *S,
8457                                               IdentifierInfo *ClassName,
8458                                               SourceLocation ClassNameLoc);
8459   void CodeCompleteObjCPropertyDefinition(Scope *S);
8460   void CodeCompleteObjCPropertySynthesizeIvar(Scope *S,
8461                                               IdentifierInfo *PropertyName);
8462   void CodeCompleteObjCMethodDecl(Scope *S,
8463                                   bool IsInstanceMethod,
8464                                   ParsedType ReturnType);
8465   void CodeCompleteObjCMethodDeclSelector(Scope *S,
8466                                           bool IsInstanceMethod,
8467                                           bool AtParameterName,
8468                                           ParsedType ReturnType,
8469                                           ArrayRef<IdentifierInfo *> SelIdents);
8470   void CodeCompletePreprocessorDirective(bool InConditional);
8471   void CodeCompleteInPreprocessorConditionalExclusion(Scope *S);
8472   void CodeCompletePreprocessorMacroName(bool IsDefinition);
8473   void CodeCompletePreprocessorExpression();
8474   void CodeCompletePreprocessorMacroArgument(Scope *S,
8475                                              IdentifierInfo *Macro,
8476                                              MacroInfo *MacroInfo,
8477                                              unsigned Argument);
8478   void CodeCompleteNaturalLanguage();
8479   void GatherGlobalCodeCompletions(CodeCompletionAllocator &Allocator,
8480                                    CodeCompletionTUInfo &CCTUInfo,
8481                   SmallVectorImpl<CodeCompletionResult> &Results);
8482   //@}
8483 
8484   //===--------------------------------------------------------------------===//
8485   // Extra semantic analysis beyond the C type system
8486 
8487 public:
8488   SourceLocation getLocationOfStringLiteralByte(const StringLiteral *SL,
8489                                                 unsigned ByteNo) const;
8490 
8491 private:
8492   void CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr,
8493                         const ArraySubscriptExpr *ASE=nullptr,
8494                         bool AllowOnePastEnd=true, bool IndexNegated=false);
8495   void CheckArrayAccess(const Expr *E);
8496   // Used to grab the relevant information from a FormatAttr and a
8497   // FunctionDeclaration.
8498   struct FormatStringInfo {
8499     unsigned FormatIdx;
8500     unsigned FirstDataArg;
8501     bool HasVAListArg;
8502   };
8503 
8504   bool getFormatStringInfo(const FormatAttr *Format, bool IsCXXMember,
8505                            FormatStringInfo *FSI);
8506   bool CheckFunctionCall(FunctionDecl *FDecl, CallExpr *TheCall,
8507                          const FunctionProtoType *Proto);
8508   bool CheckObjCMethodCall(ObjCMethodDecl *Method, SourceLocation loc,
8509                            ArrayRef<const Expr *> Args);
8510   bool CheckPointerCall(NamedDecl *NDecl, CallExpr *TheCall,
8511                         const FunctionProtoType *Proto);
8512   bool CheckOtherCall(CallExpr *TheCall, const FunctionProtoType *Proto);
8513   void CheckConstructorCall(FunctionDecl *FDecl,
8514                             ArrayRef<const Expr *> Args,
8515                             const FunctionProtoType *Proto,
8516                             SourceLocation Loc);
8517 
8518   void checkCall(NamedDecl *FDecl, ArrayRef<const Expr *> Args,
8519                  unsigned NumParams, bool IsMemberFunction, SourceLocation Loc,
8520                  SourceRange Range, VariadicCallType CallType);
8521 
8522   bool CheckObjCString(Expr *Arg);
8523 
8524   ExprResult CheckBuiltinFunctionCall(FunctionDecl *FDecl,
8525 		                      unsigned BuiltinID, CallExpr *TheCall);
8526 
8527   bool CheckARMBuiltinExclusiveCall(unsigned BuiltinID, CallExpr *TheCall,
8528                                     unsigned MaxWidth);
8529   bool CheckNeonBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
8530   bool CheckARMBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
8531 
8532   bool CheckAArch64BuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
8533   bool CheckMipsBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
8534   bool CheckX86BuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
8535 
8536   bool SemaBuiltinVAStart(CallExpr *TheCall);
8537   bool SemaBuiltinVAStartARM(CallExpr *Call);
8538   bool SemaBuiltinUnorderedCompare(CallExpr *TheCall);
8539   bool SemaBuiltinFPClassification(CallExpr *TheCall, unsigned NumArgs);
8540 
8541 public:
8542   // Used by C++ template instantiation.
8543   ExprResult SemaBuiltinShuffleVector(CallExpr *TheCall);
8544   ExprResult SemaConvertVectorExpr(Expr *E, TypeSourceInfo *TInfo,
8545                                    SourceLocation BuiltinLoc,
8546                                    SourceLocation RParenLoc);
8547 
8548 private:
8549   bool SemaBuiltinPrefetch(CallExpr *TheCall);
8550   bool SemaBuiltinAssume(CallExpr *TheCall);
8551   bool SemaBuiltinAssumeAligned(CallExpr *TheCall);
8552   bool SemaBuiltinLongjmp(CallExpr *TheCall);
8553   bool SemaBuiltinSetjmp(CallExpr *TheCall);
8554   ExprResult SemaBuiltinAtomicOverloaded(ExprResult TheCallResult);
8555   ExprResult SemaAtomicOpsOverloaded(ExprResult TheCallResult,
8556                                      AtomicExpr::AtomicOp Op);
8557   bool SemaBuiltinConstantArg(CallExpr *TheCall, int ArgNum,
8558                               llvm::APSInt &Result);
8559   bool SemaBuiltinConstantArgRange(CallExpr *TheCall, int ArgNum,
8560                                    int Low, int High);
8561 
8562 public:
8563   enum FormatStringType {
8564     FST_Scanf,
8565     FST_Printf,
8566     FST_NSString,
8567     FST_Strftime,
8568     FST_Strfmon,
8569     FST_Kprintf,
8570     FST_Unknown
8571   };
8572   static FormatStringType GetFormatStringType(const FormatAttr *Format);
8573 
8574   void CheckFormatString(const StringLiteral *FExpr, const Expr *OrigFormatExpr,
8575                          ArrayRef<const Expr *> Args, bool HasVAListArg,
8576                          unsigned format_idx, unsigned firstDataArg,
8577                          FormatStringType Type, bool inFunctionCall,
8578                          VariadicCallType CallType,
8579                          llvm::SmallBitVector &CheckedVarArgs);
8580 
8581   bool FormatStringHasSArg(const StringLiteral *FExpr);
8582 
8583   bool GetFormatNSStringIdx(const FormatAttr *Format, unsigned &Idx);
8584 
8585 private:
8586   bool CheckFormatArguments(const FormatAttr *Format,
8587                             ArrayRef<const Expr *> Args,
8588                             bool IsCXXMember,
8589                             VariadicCallType CallType,
8590                             SourceLocation Loc, SourceRange Range,
8591                             llvm::SmallBitVector &CheckedVarArgs);
8592   bool CheckFormatArguments(ArrayRef<const Expr *> Args,
8593                             bool HasVAListArg, unsigned format_idx,
8594                             unsigned firstDataArg, FormatStringType Type,
8595                             VariadicCallType CallType,
8596                             SourceLocation Loc, SourceRange range,
8597                             llvm::SmallBitVector &CheckedVarArgs);
8598 
8599   void CheckAbsoluteValueFunction(const CallExpr *Call,
8600                                   const FunctionDecl *FDecl,
8601                                   IdentifierInfo *FnInfo);
8602 
8603   void CheckMemaccessArguments(const CallExpr *Call,
8604                                unsigned BId,
8605                                IdentifierInfo *FnName);
8606 
8607   void CheckStrlcpycatArguments(const CallExpr *Call,
8608                                 IdentifierInfo *FnName);
8609 
8610   void CheckStrncatArguments(const CallExpr *Call,
8611                              IdentifierInfo *FnName);
8612 
8613   void CheckReturnValExpr(Expr *RetValExp, QualType lhsType,
8614                           SourceLocation ReturnLoc,
8615                           bool isObjCMethod = false,
8616                           const AttrVec *Attrs = nullptr,
8617                           const FunctionDecl *FD = nullptr);
8618 
8619   void CheckFloatComparison(SourceLocation Loc, Expr* LHS, Expr* RHS);
8620   void CheckImplicitConversions(Expr *E, SourceLocation CC = SourceLocation());
8621   void CheckBoolLikeConversion(Expr *E, SourceLocation CC);
8622   void CheckForIntOverflow(Expr *E);
8623   void CheckUnsequencedOperations(Expr *E);
8624 
8625   /// \brief Perform semantic checks on a completed expression. This will either
8626   /// be a full-expression or a default argument expression.
8627   void CheckCompletedExpr(Expr *E, SourceLocation CheckLoc = SourceLocation(),
8628                           bool IsConstexpr = false);
8629 
8630   void CheckBitFieldInitialization(SourceLocation InitLoc, FieldDecl *Field,
8631                                    Expr *Init);
8632 
8633   /// \brief Check if the given expression contains 'break' or 'continue'
8634   /// statement that produces control flow different from GCC.
8635   void CheckBreakContinueBinding(Expr *E);
8636 
8637 public:
8638   /// \brief Register a magic integral constant to be used as a type tag.
8639   void RegisterTypeTagForDatatype(const IdentifierInfo *ArgumentKind,
8640                                   uint64_t MagicValue, QualType Type,
8641                                   bool LayoutCompatible, bool MustBeNull);
8642 
8643   struct TypeTagData {
TypeTagDataTypeTagData8644     TypeTagData() {}
8645 
TypeTagDataTypeTagData8646     TypeTagData(QualType Type, bool LayoutCompatible, bool MustBeNull) :
8647         Type(Type), LayoutCompatible(LayoutCompatible),
8648         MustBeNull(MustBeNull)
8649     {}
8650 
8651     QualType Type;
8652 
8653     /// If true, \c Type should be compared with other expression's types for
8654     /// layout-compatibility.
8655     unsigned LayoutCompatible : 1;
8656     unsigned MustBeNull : 1;
8657   };
8658 
8659   /// A pair of ArgumentKind identifier and magic value.  This uniquely
8660   /// identifies the magic value.
8661   typedef std::pair<const IdentifierInfo *, uint64_t> TypeTagMagicValue;
8662 
8663 private:
8664   /// \brief A map from magic value to type information.
8665   std::unique_ptr<llvm::DenseMap<TypeTagMagicValue, TypeTagData>>
8666       TypeTagForDatatypeMagicValues;
8667 
8668   /// \brief Peform checks on a call of a function with argument_with_type_tag
8669   /// or pointer_with_type_tag attributes.
8670   void CheckArgumentWithTypeTag(const ArgumentWithTypeTagAttr *Attr,
8671                                 const Expr * const *ExprArgs);
8672 
8673   /// \brief The parser's current scope.
8674   ///
8675   /// The parser maintains this state here.
8676   Scope *CurScope;
8677 
8678   mutable IdentifierInfo *Ident_super;
8679   mutable IdentifierInfo *Ident___float128;
8680 
8681 protected:
8682   friend class Parser;
8683   friend class InitializationSequence;
8684   friend class ASTReader;
8685   friend class ASTWriter;
8686 
8687 public:
8688   /// \brief Retrieve the parser's current scope.
8689   ///
8690   /// This routine must only be used when it is certain that semantic analysis
8691   /// and the parser are in precisely the same context, which is not the case
8692   /// when, e.g., we are performing any kind of template instantiation.
8693   /// Therefore, the only safe places to use this scope are in the parser
8694   /// itself and in routines directly invoked from the parser and *never* from
8695   /// template substitution or instantiation.
getCurScope()8696   Scope *getCurScope() const { return CurScope; }
8697 
incrementMSLocalManglingNumber()8698   void incrementMSLocalManglingNumber() const {
8699     return CurScope->incrementMSLocalManglingNumber();
8700   }
8701 
8702   IdentifierInfo *getSuperIdentifier() const;
8703   IdentifierInfo *getFloat128Identifier() const;
8704 
8705   Decl *getObjCDeclContext() const;
8706 
getCurLexicalContext()8707   DeclContext *getCurLexicalContext() const {
8708     return OriginalLexicalContext ? OriginalLexicalContext : CurContext;
8709   }
8710 
8711   AvailabilityResult getCurContextAvailability() const;
8712 
getCurObjCLexicalContext()8713   const DeclContext *getCurObjCLexicalContext() const {
8714     const DeclContext *DC = getCurLexicalContext();
8715     // A category implicitly has the attribute of the interface.
8716     if (const ObjCCategoryDecl *CatD = dyn_cast<ObjCCategoryDecl>(DC))
8717       DC = CatD->getClassInterface();
8718     return DC;
8719   }
8720 };
8721 
8722 /// \brief RAII object that enters a new expression evaluation context.
8723 class EnterExpressionEvaluationContext {
8724   Sema &Actions;
8725 
8726 public:
8727   EnterExpressionEvaluationContext(Sema &Actions,
8728                                    Sema::ExpressionEvaluationContext NewContext,
8729                                    Decl *LambdaContextDecl = nullptr,
8730                                    bool IsDecltype = false)
Actions(Actions)8731     : Actions(Actions) {
8732     Actions.PushExpressionEvaluationContext(NewContext, LambdaContextDecl,
8733                                             IsDecltype);
8734   }
8735   EnterExpressionEvaluationContext(Sema &Actions,
8736                                    Sema::ExpressionEvaluationContext NewContext,
8737                                    Sema::ReuseLambdaContextDecl_t,
8738                                    bool IsDecltype = false)
Actions(Actions)8739     : Actions(Actions) {
8740     Actions.PushExpressionEvaluationContext(NewContext,
8741                                             Sema::ReuseLambdaContextDecl,
8742                                             IsDecltype);
8743   }
8744 
~EnterExpressionEvaluationContext()8745   ~EnterExpressionEvaluationContext() {
8746     Actions.PopExpressionEvaluationContext();
8747   }
8748 };
8749 
8750 DeductionFailureInfo
8751 MakeDeductionFailureInfo(ASTContext &Context, Sema::TemplateDeductionResult TDK,
8752                          sema::TemplateDeductionInfo &Info);
8753 
8754 /// \brief Contains a late templated function.
8755 /// Will be parsed at the end of the translation unit, used by Sema & Parser.
8756 struct LateParsedTemplate {
8757   CachedTokens Toks;
8758   /// \brief The template function declaration to be late parsed.
8759   Decl *D;
8760 };
8761 
8762 } // end namespace clang
8763 
8764 #endif
8765