1 //===---- CodeCompleteConsumer.h - Code Completion Interface ----*- 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 CodeCompleteConsumer class.
11 //
12 //===----------------------------------------------------------------------===//
13 #ifndef LLVM_CLANG_SEMA_CODECOMPLETECONSUMER_H
14 #define LLVM_CLANG_SEMA_CODECOMPLETECONSUMER_H
15 
16 #include "clang-c/Index.h"
17 #include "clang/AST/CanonicalType.h"
18 #include "clang/AST/Type.h"
19 #include "clang/Sema/CodeCompleteOptions.h"
20 #include "llvm/ADT/SmallVector.h"
21 #include "llvm/ADT/StringRef.h"
22 #include "llvm/Support/Allocator.h"
23 #include <string>
24 
25 namespace clang {
26 
27 class Decl;
28 
29 /// \brief Default priority values for code-completion results based
30 /// on their kind.
31 enum {
32   /// \brief Priority for the next initialization in a constructor initializer
33   /// list.
34   CCP_NextInitializer = 7,
35   /// \brief Priority for an enumeration constant inside a switch whose
36   /// condition is of the enumeration type.
37   CCP_EnumInCase = 7,
38   /// \brief Priority for a send-to-super completion.
39   CCP_SuperCompletion = 20,
40   /// \brief Priority for a declaration that is in the local scope.
41   CCP_LocalDeclaration = 34,
42   /// \brief Priority for a member declaration found from the current
43   /// method or member function.
44   CCP_MemberDeclaration = 35,
45   /// \brief Priority for a language keyword (that isn't any of the other
46   /// categories).
47   CCP_Keyword = 40,
48   /// \brief Priority for a code pattern.
49   CCP_CodePattern = 40,
50   /// \brief Priority for a non-type declaration.
51   CCP_Declaration = 50,
52   /// \brief Priority for a type.
53   CCP_Type = CCP_Declaration,
54   /// \brief Priority for a constant value (e.g., enumerator).
55   CCP_Constant = 65,
56   /// \brief Priority for a preprocessor macro.
57   CCP_Macro = 70,
58   /// \brief Priority for a nested-name-specifier.
59   CCP_NestedNameSpecifier = 75,
60   /// \brief Priority for a result that isn't likely to be what the user wants,
61   /// but is included for completeness.
62   CCP_Unlikely = 80,
63 
64   /// \brief Priority for the Objective-C "_cmd" implicit parameter.
65   CCP_ObjC_cmd = CCP_Unlikely
66 };
67 
68 /// \brief Priority value deltas that are added to code-completion results
69 /// based on the context of the result.
70 enum {
71   /// \brief The result is in a base class.
72   CCD_InBaseClass = 2,
73   /// \brief The result is a C++ non-static member function whose qualifiers
74   /// exactly match the object type on which the member function can be called.
75   CCD_ObjectQualifierMatch = -1,
76   /// \brief The selector of the given message exactly matches the selector
77   /// of the current method, which might imply that some kind of delegation
78   /// is occurring.
79   CCD_SelectorMatch = -3,
80 
81   /// \brief Adjustment to the "bool" type in Objective-C, where the typedef
82   /// "BOOL" is preferred.
83   CCD_bool_in_ObjC = 1,
84 
85   /// \brief Adjustment for KVC code pattern priorities when it doesn't look
86   /// like the
87   CCD_ProbablyNotObjCCollection = 15,
88 
89   /// \brief An Objective-C method being used as a property.
90   CCD_MethodAsProperty = 2
91 };
92 
93 /// \brief Priority value factors by which we will divide or multiply the
94 /// priority of a code-completion result.
95 enum {
96   /// \brief Divide by this factor when a code-completion result's type exactly
97   /// matches the type we expect.
98   CCF_ExactTypeMatch = 4,
99   /// \brief Divide by this factor when a code-completion result's type is
100   /// similar to the type we expect (e.g., both arithmetic types, both
101   /// Objective-C object pointer types).
102   CCF_SimilarTypeMatch = 2
103 };
104 
105 /// \brief A simplified classification of types used when determining
106 /// "similar" types for code completion.
107 enum SimplifiedTypeClass {
108   STC_Arithmetic,
109   STC_Array,
110   STC_Block,
111   STC_Function,
112   STC_ObjectiveC,
113   STC_Other,
114   STC_Pointer,
115   STC_Record,
116   STC_Void
117 };
118 
119 /// \brief Determine the simplified type class of the given canonical type.
120 SimplifiedTypeClass getSimplifiedTypeClass(CanQualType T);
121 
122 /// \brief Determine the type that this declaration will have if it is used
123 /// as a type or in an expression.
124 QualType getDeclUsageType(ASTContext &C, const NamedDecl *ND);
125 
126 /// \brief Determine the priority to be given to a macro code completion result
127 /// with the given name.
128 ///
129 /// \param MacroName The name of the macro.
130 ///
131 /// \param LangOpts Options describing the current language dialect.
132 ///
133 /// \param PreferredTypeIsPointer Whether the preferred type for the context
134 /// of this macro is a pointer type.
135 unsigned getMacroUsagePriority(StringRef MacroName,
136                                const LangOptions &LangOpts,
137                                bool PreferredTypeIsPointer = false);
138 
139 /// \brief Determine the libclang cursor kind associated with the given
140 /// declaration.
141 CXCursorKind getCursorKindForDecl(const Decl *D);
142 
143 class FunctionDecl;
144 class FunctionType;
145 class FunctionTemplateDecl;
146 class IdentifierInfo;
147 class NamedDecl;
148 class NestedNameSpecifier;
149 class Sema;
150 
151 /// \brief The context in which code completion occurred, so that the
152 /// code-completion consumer can process the results accordingly.
153 class CodeCompletionContext {
154 public:
155   enum Kind {
156     /// \brief An unspecified code-completion context.
157     CCC_Other,
158     /// \brief An unspecified code-completion context where we should also add
159     /// macro completions.
160     CCC_OtherWithMacros,
161     /// \brief Code completion occurred within a "top-level" completion context,
162     /// e.g., at namespace or global scope.
163     CCC_TopLevel,
164     /// \brief Code completion occurred within an Objective-C interface,
165     /// protocol, or category interface.
166     CCC_ObjCInterface,
167     /// \brief Code completion occurred within an Objective-C implementation
168     /// or category implementation.
169     CCC_ObjCImplementation,
170     /// \brief Code completion occurred within the instance variable list of
171     /// an Objective-C interface, implementation, or category implementation.
172     CCC_ObjCIvarList,
173     /// \brief Code completion occurred within a class, struct, or union.
174     CCC_ClassStructUnion,
175     /// \brief Code completion occurred where a statement (or declaration) is
176     /// expected in a function, method, or block.
177     CCC_Statement,
178     /// \brief Code completion occurred where an expression is expected.
179     CCC_Expression,
180     /// \brief Code completion occurred where an Objective-C message receiver
181     /// is expected.
182     CCC_ObjCMessageReceiver,
183     /// \brief Code completion occurred on the right-hand side of a member
184     /// access expression using the dot operator.
185     ///
186     /// The results of this completion are the members of the type being
187     /// accessed. The type itself is available via
188     /// \c CodeCompletionContext::getType().
189     CCC_DotMemberAccess,
190     /// \brief Code completion occurred on the right-hand side of a member
191     /// access expression using the arrow operator.
192     ///
193     /// The results of this completion are the members of the type being
194     /// accessed. The type itself is available via
195     /// \c CodeCompletionContext::getType().
196     CCC_ArrowMemberAccess,
197     /// \brief Code completion occurred on the right-hand side of an Objective-C
198     /// property access expression.
199     ///
200     /// The results of this completion are the members of the type being
201     /// accessed. The type itself is available via
202     /// \c CodeCompletionContext::getType().
203     CCC_ObjCPropertyAccess,
204     /// \brief Code completion occurred after the "enum" keyword, to indicate
205     /// an enumeration name.
206     CCC_EnumTag,
207     /// \brief Code completion occurred after the "union" keyword, to indicate
208     /// a union name.
209     CCC_UnionTag,
210     /// \brief Code completion occurred after the "struct" or "class" keyword,
211     /// to indicate a struct or class name.
212     CCC_ClassOrStructTag,
213     /// \brief Code completion occurred where a protocol name is expected.
214     CCC_ObjCProtocolName,
215     /// \brief Code completion occurred where a namespace or namespace alias
216     /// is expected.
217     CCC_Namespace,
218     /// \brief Code completion occurred where a type name is expected.
219     CCC_Type,
220     /// \brief Code completion occurred where a new name is expected.
221     CCC_Name,
222     /// \brief Code completion occurred where a new name is expected and a
223     /// qualified name is permissible.
224     CCC_PotentiallyQualifiedName,
225     /// \brief Code completion occurred where an macro is being defined.
226     CCC_MacroName,
227     /// \brief Code completion occurred where a macro name is expected
228     /// (without any arguments, in the case of a function-like macro).
229     CCC_MacroNameUse,
230     /// \brief Code completion occurred within a preprocessor expression.
231     CCC_PreprocessorExpression,
232     /// \brief Code completion occurred where a preprocessor directive is
233     /// expected.
234     CCC_PreprocessorDirective,
235     /// \brief Code completion occurred in a context where natural language is
236     /// expected, e.g., a comment or string literal.
237     ///
238     /// This context usually implies that no completions should be added,
239     /// unless they come from an appropriate natural-language dictionary.
240     CCC_NaturalLanguage,
241     /// \brief Code completion for a selector, as in an \@selector expression.
242     CCC_SelectorName,
243     /// \brief Code completion within a type-qualifier list.
244     CCC_TypeQualifiers,
245     /// \brief Code completion in a parenthesized expression, which means that
246     /// we may also have types here in C and Objective-C (as well as in C++).
247     CCC_ParenthesizedExpression,
248     /// \brief Code completion where an Objective-C instance message is
249     /// expected.
250     CCC_ObjCInstanceMessage,
251     /// \brief Code completion where an Objective-C class message is expected.
252     CCC_ObjCClassMessage,
253     /// \brief Code completion where the name of an Objective-C class is
254     /// expected.
255     CCC_ObjCInterfaceName,
256     /// \brief Code completion where an Objective-C category name is expected.
257     CCC_ObjCCategoryName,
258     /// \brief An unknown context, in which we are recovering from a parsing
259     /// error and don't know which completions we should give.
260     CCC_Recovery
261   };
262 
263 private:
264   enum Kind Kind;
265 
266   /// \brief The type that would prefer to see at this point (e.g., the type
267   /// of an initializer or function parameter).
268   QualType PreferredType;
269 
270   /// \brief The type of the base object in a member access expression.
271   QualType BaseType;
272 
273   /// \brief The identifiers for Objective-C selector parts.
274   ArrayRef<IdentifierInfo *> SelIdents;
275 
276 public:
277   /// \brief Construct a new code-completion context of the given kind.
CodeCompletionContext(enum Kind Kind)278   CodeCompletionContext(enum Kind Kind) : Kind(Kind), SelIdents(None) { }
279 
280   /// \brief Construct a new code-completion context of the given kind.
281   CodeCompletionContext(enum Kind Kind, QualType T,
282                         ArrayRef<IdentifierInfo *> SelIdents = None)
Kind(Kind)283                         : Kind(Kind),
284                           SelIdents(SelIdents) {
285     if (Kind == CCC_DotMemberAccess || Kind == CCC_ArrowMemberAccess ||
286         Kind == CCC_ObjCPropertyAccess || Kind == CCC_ObjCClassMessage ||
287         Kind == CCC_ObjCInstanceMessage)
288       BaseType = T;
289     else
290       PreferredType = T;
291   }
292 
293   /// \brief Retrieve the kind of code-completion context.
getKind()294   enum Kind getKind() const { return Kind; }
295 
296   /// \brief Retrieve the type that this expression would prefer to have, e.g.,
297   /// if the expression is a variable initializer or a function argument, the
298   /// type of the corresponding variable or function parameter.
getPreferredType()299   QualType getPreferredType() const { return PreferredType; }
300 
301   /// \brief Retrieve the type of the base object in a member-access
302   /// expression.
getBaseType()303   QualType getBaseType() const { return BaseType; }
304 
305   /// \brief Retrieve the Objective-C selector identifiers.
getSelIdents()306   ArrayRef<IdentifierInfo *> getSelIdents() const { return SelIdents; }
307 
308   /// \brief Determines whether we want C++ constructors as results within this
309   /// context.
310   bool wantConstructorResults() const;
311 };
312 
313 
314 /// \brief A "string" used to describe how code completion can
315 /// be performed for an entity.
316 ///
317 /// A code completion string typically shows how a particular entity can be
318 /// used. For example, the code completion string for a function would show
319 /// the syntax to call it, including the parentheses, placeholders for the
320 /// arguments, etc.
321 class CodeCompletionString {
322 public:
323   /// \brief The different kinds of "chunks" that can occur within a code
324   /// completion string.
325   enum ChunkKind {
326     /// \brief The piece of text that the user is expected to type to
327     /// match the code-completion string, typically a keyword or the name of a
328     /// declarator or macro.
329     CK_TypedText,
330     /// \brief A piece of text that should be placed in the buffer, e.g.,
331     /// parentheses or a comma in a function call.
332     CK_Text,
333     /// \brief A code completion string that is entirely optional. For example,
334     /// an optional code completion string that describes the default arguments
335     /// in a function call.
336     CK_Optional,
337     /// \brief A string that acts as a placeholder for, e.g., a function
338     /// call argument.
339     CK_Placeholder,
340     /// \brief A piece of text that describes something about the result but
341     /// should not be inserted into the buffer.
342     CK_Informative,
343     /// \brief A piece of text that describes the type of an entity or, for
344     /// functions and methods, the return type.
345     CK_ResultType,
346     /// \brief A piece of text that describes the parameter that corresponds
347     /// to the code-completion location within a function call, message send,
348     /// macro invocation, etc.
349     CK_CurrentParameter,
350     /// \brief A left parenthesis ('(').
351     CK_LeftParen,
352     /// \brief A right parenthesis (')').
353     CK_RightParen,
354     /// \brief A left bracket ('[').
355     CK_LeftBracket,
356     /// \brief A right bracket (']').
357     CK_RightBracket,
358     /// \brief A left brace ('{').
359     CK_LeftBrace,
360     /// \brief A right brace ('}').
361     CK_RightBrace,
362     /// \brief A left angle bracket ('<').
363     CK_LeftAngle,
364     /// \brief A right angle bracket ('>').
365     CK_RightAngle,
366     /// \brief A comma separator (',').
367     CK_Comma,
368     /// \brief A colon (':').
369     CK_Colon,
370     /// \brief A semicolon (';').
371     CK_SemiColon,
372     /// \brief An '=' sign.
373     CK_Equal,
374     /// \brief Horizontal whitespace (' ').
375     CK_HorizontalSpace,
376     /// \brief Vertical whitespace ('\\n' or '\\r\\n', depending on the
377     /// platform).
378     CK_VerticalSpace
379   };
380 
381   /// \brief One piece of the code completion string.
382   struct Chunk {
383     /// \brief The kind of data stored in this piece of the code completion
384     /// string.
385     ChunkKind Kind;
386 
387     union {
388       /// \brief The text string associated with a CK_Text, CK_Placeholder,
389       /// CK_Informative, or CK_Comma chunk.
390       /// The string is owned by the chunk and will be deallocated
391       /// (with delete[]) when the chunk is destroyed.
392       const char *Text;
393 
394       /// \brief The code completion string associated with a CK_Optional chunk.
395       /// The optional code completion string is owned by the chunk, and will
396       /// be deallocated (with delete) when the chunk is destroyed.
397       CodeCompletionString *Optional;
398     };
399 
ChunkChunk400     Chunk() : Kind(CK_Text), Text(nullptr) { }
401 
402     explicit Chunk(ChunkKind Kind, const char *Text = "");
403 
404     /// \brief Create a new text chunk.
405     static Chunk CreateText(const char *Text);
406 
407     /// \brief Create a new optional chunk.
408     static Chunk CreateOptional(CodeCompletionString *Optional);
409 
410     /// \brief Create a new placeholder chunk.
411     static Chunk CreatePlaceholder(const char *Placeholder);
412 
413     /// \brief Create a new informative chunk.
414     static Chunk CreateInformative(const char *Informative);
415 
416     /// \brief Create a new result type chunk.
417     static Chunk CreateResultType(const char *ResultType);
418 
419     /// \brief Create a new current-parameter chunk.
420     static Chunk CreateCurrentParameter(const char *CurrentParameter);
421   };
422 
423 private:
424   /// \brief The number of chunks stored in this string.
425   unsigned NumChunks : 16;
426 
427   /// \brief The number of annotations for this code-completion result.
428   unsigned NumAnnotations : 16;
429 
430   /// \brief The priority of this code-completion string.
431   unsigned Priority : 16;
432 
433   /// \brief The availability of this code-completion result.
434   unsigned Availability : 2;
435 
436   /// \brief The name of the parent context.
437   StringRef ParentName;
438 
439   /// \brief A brief documentation comment attached to the declaration of
440   /// entity being completed by this result.
441   const char *BriefComment;
442 
443   CodeCompletionString(const CodeCompletionString &) LLVM_DELETED_FUNCTION;
444   void operator=(const CodeCompletionString &) LLVM_DELETED_FUNCTION;
445 
446   CodeCompletionString(const Chunk *Chunks, unsigned NumChunks,
447                        unsigned Priority, CXAvailabilityKind Availability,
448                        const char **Annotations, unsigned NumAnnotations,
449                        StringRef ParentName,
450                        const char *BriefComment);
~CodeCompletionString()451   ~CodeCompletionString() { }
452 
453   friend class CodeCompletionBuilder;
454   friend class CodeCompletionResult;
455 
456 public:
457   typedef const Chunk *iterator;
begin()458   iterator begin() const { return reinterpret_cast<const Chunk *>(this + 1); }
end()459   iterator end() const { return begin() + NumChunks; }
empty()460   bool empty() const { return NumChunks == 0; }
size()461   unsigned size() const { return NumChunks; }
462 
463   const Chunk &operator[](unsigned I) const {
464     assert(I < size() && "Chunk index out-of-range");
465     return begin()[I];
466   }
467 
468   /// \brief Returns the text in the TypedText chunk.
469   const char *getTypedText() const;
470 
471   /// \brief Retrieve the priority of this code completion result.
getPriority()472   unsigned getPriority() const { return Priority; }
473 
474   /// \brief Retrieve the availability of this code completion result.
getAvailability()475   unsigned getAvailability() const { return Availability; }
476 
477   /// \brief Retrieve the number of annotations for this code completion result.
478   unsigned getAnnotationCount() const;
479 
480   /// \brief Retrieve the annotation string specified by \c AnnotationNr.
481   const char *getAnnotation(unsigned AnnotationNr) const;
482 
483   /// \brief Retrieve the name of the parent context.
getParentContextName()484   StringRef getParentContextName() const {
485     return ParentName;
486   }
487 
getBriefComment()488   const char *getBriefComment() const {
489     return BriefComment;
490   }
491 
492   /// \brief Retrieve a string representation of the code completion string,
493   /// which is mainly useful for debugging.
494   std::string getAsString() const;
495 };
496 
497 /// \brief An allocator used specifically for the purpose of code completion.
498 class CodeCompletionAllocator : public llvm::BumpPtrAllocator {
499 public:
500   /// \brief Copy the given string into this allocator.
501   const char *CopyString(StringRef String);
502 
503   /// \brief Copy the given string into this allocator.
504   const char *CopyString(Twine String);
505 
506   // \brief Copy the given string into this allocator.
CopyString(const char * String)507   const char *CopyString(const char *String) {
508     return CopyString(StringRef(String));
509   }
510 
511   /// \brief Copy the given string into this allocator.
CopyString(const std::string & String)512   const char *CopyString(const std::string &String) {
513     return CopyString(StringRef(String));
514   }
515 };
516 
517 /// \brief Allocator for a cached set of global code completions.
518 class GlobalCodeCompletionAllocator
519   : public CodeCompletionAllocator,
520     public RefCountedBase<GlobalCodeCompletionAllocator>
521 {
522 
523 };
524 
525 class CodeCompletionTUInfo {
526   llvm::DenseMap<const DeclContext *, StringRef> ParentNames;
527   IntrusiveRefCntPtr<GlobalCodeCompletionAllocator> AllocatorRef;
528 
529 public:
CodeCompletionTUInfo(IntrusiveRefCntPtr<GlobalCodeCompletionAllocator> Allocator)530   explicit CodeCompletionTUInfo(
531                     IntrusiveRefCntPtr<GlobalCodeCompletionAllocator> Allocator)
532     : AllocatorRef(Allocator) { }
533 
getAllocatorRef()534   IntrusiveRefCntPtr<GlobalCodeCompletionAllocator> getAllocatorRef() const {
535     return AllocatorRef;
536   }
getAllocator()537   CodeCompletionAllocator &getAllocator() const {
538     assert(AllocatorRef);
539     return *AllocatorRef;
540   }
541 
542   StringRef getParentName(const DeclContext *DC);
543 };
544 
545 } // end namespace clang
546 
547 namespace llvm {
548   template <> struct isPodLike<clang::CodeCompletionString::Chunk> {
549     static const bool value = true;
550   };
551 }
552 
553 namespace clang {
554 
555 /// \brief A builder class used to construct new code-completion strings.
556 class CodeCompletionBuilder {
557 public:
558   typedef CodeCompletionString::Chunk Chunk;
559 
560 private:
561   CodeCompletionAllocator &Allocator;
562   CodeCompletionTUInfo &CCTUInfo;
563   unsigned Priority;
564   CXAvailabilityKind Availability;
565   StringRef ParentName;
566   const char *BriefComment;
567 
568   /// \brief The chunks stored in this string.
569   SmallVector<Chunk, 4> Chunks;
570 
571   SmallVector<const char *, 2> Annotations;
572 
573 public:
574   CodeCompletionBuilder(CodeCompletionAllocator &Allocator,
575                         CodeCompletionTUInfo &CCTUInfo)
576     : Allocator(Allocator), CCTUInfo(CCTUInfo),
577       Priority(0), Availability(CXAvailability_Available),
578       BriefComment(nullptr) { }
579 
580   CodeCompletionBuilder(CodeCompletionAllocator &Allocator,
581                         CodeCompletionTUInfo &CCTUInfo,
582                         unsigned Priority, CXAvailabilityKind Availability)
583     : Allocator(Allocator), CCTUInfo(CCTUInfo),
584       Priority(Priority), Availability(Availability),
585       BriefComment(nullptr) { }
586 
587   /// \brief Retrieve the allocator into which the code completion
588   /// strings should be allocated.
589   CodeCompletionAllocator &getAllocator() const { return Allocator; }
590 
591   CodeCompletionTUInfo &getCodeCompletionTUInfo() const { return CCTUInfo; }
592 
593   /// \brief Take the resulting completion string.
594   ///
595   /// This operation can only be performed once.
596   CodeCompletionString *TakeString();
597 
598   /// \brief Add a new typed-text chunk.
599   void AddTypedTextChunk(const char *Text);
600 
601   /// \brief Add a new text chunk.
602   void AddTextChunk(const char *Text);
603 
604   /// \brief Add a new optional chunk.
605   void AddOptionalChunk(CodeCompletionString *Optional);
606 
607   /// \brief Add a new placeholder chunk.
608   void AddPlaceholderChunk(const char *Placeholder);
609 
610   /// \brief Add a new informative chunk.
611   void AddInformativeChunk(const char *Text);
612 
613   /// \brief Add a new result-type chunk.
614   void AddResultTypeChunk(const char *ResultType);
615 
616   /// \brief Add a new current-parameter chunk.
617   void AddCurrentParameterChunk(const char *CurrentParameter);
618 
619   /// \brief Add a new chunk.
620   void AddChunk(CodeCompletionString::ChunkKind CK, const char *Text = "");
621 
622   void AddAnnotation(const char *A) { Annotations.push_back(A); }
623 
624   /// \brief Add the parent context information to this code completion.
625   void addParentContext(const DeclContext *DC);
626 
627   const char *getBriefComment() const { return BriefComment; }
628   void addBriefComment(StringRef Comment);
629 
630   StringRef getParentName() const { return ParentName; }
631 };
632 
633 /// \brief Captures a result of code completion.
634 class CodeCompletionResult {
635 public:
636   /// \brief Describes the kind of result generated.
637   enum ResultKind {
638     RK_Declaration = 0, ///< Refers to a declaration
639     RK_Keyword,         ///< Refers to a keyword or symbol.
640     RK_Macro,           ///< Refers to a macro
641     RK_Pattern          ///< Refers to a precomputed pattern.
642   };
643 
644   /// \brief When Kind == RK_Declaration or RK_Pattern, the declaration we are
645   /// referring to. In the latter case, the declaration might be NULL.
646   const NamedDecl *Declaration;
647 
648   union {
649     /// \brief When Kind == RK_Keyword, the string representing the keyword
650     /// or symbol's spelling.
651     const char *Keyword;
652 
653     /// \brief When Kind == RK_Pattern, the code-completion string that
654     /// describes the completion text to insert.
655     CodeCompletionString *Pattern;
656 
657     /// \brief When Kind == RK_Macro, the identifier that refers to a macro.
658     const IdentifierInfo *Macro;
659   };
660 
661   /// \brief The priority of this particular code-completion result.
662   unsigned Priority;
663 
664   /// \brief Specifies which parameter (of a function, Objective-C method,
665   /// macro, etc.) we should start with when formatting the result.
666   unsigned StartParameter;
667 
668   /// \brief The kind of result stored here.
669   ResultKind Kind;
670 
671   /// \brief The cursor kind that describes this result.
672   CXCursorKind CursorKind;
673 
674   /// \brief The availability of this result.
675   CXAvailabilityKind Availability;
676 
677   /// \brief Whether this result is hidden by another name.
678   bool Hidden : 1;
679 
680   /// \brief Whether this result was found via lookup into a base class.
681   bool QualifierIsInformative : 1;
682 
683   /// \brief Whether this declaration is the beginning of a
684   /// nested-name-specifier and, therefore, should be followed by '::'.
685   bool StartsNestedNameSpecifier : 1;
686 
687   /// \brief Whether all parameters (of a function, Objective-C
688   /// method, etc.) should be considered "informative".
689   bool AllParametersAreInformative : 1;
690 
691   /// \brief Whether we're completing a declaration of the given entity,
692   /// rather than a use of that entity.
693   bool DeclaringEntity : 1;
694 
695   /// \brief If the result should have a nested-name-specifier, this is it.
696   /// When \c QualifierIsInformative, the nested-name-specifier is
697   /// informative rather than required.
698   NestedNameSpecifier *Qualifier;
699 
700   /// \brief Build a result that refers to a declaration.
701   CodeCompletionResult(const NamedDecl *Declaration,
702                        unsigned Priority,
703                        NestedNameSpecifier *Qualifier = nullptr,
704                        bool QualifierIsInformative = false,
705                        bool Accessible = true)
706     : Declaration(Declaration), Priority(Priority),
707       StartParameter(0), Kind(RK_Declaration),
708       Availability(CXAvailability_Available), Hidden(false),
709       QualifierIsInformative(QualifierIsInformative),
710       StartsNestedNameSpecifier(false), AllParametersAreInformative(false),
711       DeclaringEntity(false), Qualifier(Qualifier) {
712     computeCursorKindAndAvailability(Accessible);
713   }
714 
715   /// \brief Build a result that refers to a keyword or symbol.
716   CodeCompletionResult(const char *Keyword, unsigned Priority = CCP_Keyword)
717     : Declaration(nullptr), Keyword(Keyword), Priority(Priority),
718       StartParameter(0), Kind(RK_Keyword), CursorKind(CXCursor_NotImplemented),
719       Availability(CXAvailability_Available), Hidden(false),
720       QualifierIsInformative(0), StartsNestedNameSpecifier(false),
721       AllParametersAreInformative(false), DeclaringEntity(false),
722       Qualifier(nullptr) {}
723 
724   /// \brief Build a result that refers to a macro.
725   CodeCompletionResult(const IdentifierInfo *Macro,
726                        unsigned Priority = CCP_Macro)
727     : Declaration(nullptr), Macro(Macro), Priority(Priority), StartParameter(0),
728       Kind(RK_Macro), CursorKind(CXCursor_MacroDefinition),
729       Availability(CXAvailability_Available), Hidden(false),
730       QualifierIsInformative(0), StartsNestedNameSpecifier(false),
731       AllParametersAreInformative(false), DeclaringEntity(false),
732       Qualifier(nullptr) {}
733 
734   /// \brief Build a result that refers to a pattern.
735   CodeCompletionResult(CodeCompletionString *Pattern,
736                        unsigned Priority = CCP_CodePattern,
737                        CXCursorKind CursorKind = CXCursor_NotImplemented,
738                    CXAvailabilityKind Availability = CXAvailability_Available,
739                        const NamedDecl *D = nullptr)
740     : Declaration(D), Pattern(Pattern), Priority(Priority), StartParameter(0),
741       Kind(RK_Pattern), CursorKind(CursorKind), Availability(Availability),
742       Hidden(false), QualifierIsInformative(0),
743       StartsNestedNameSpecifier(false), AllParametersAreInformative(false),
744       DeclaringEntity(false), Qualifier(nullptr)
745   {
746   }
747 
748   /// \brief Build a result that refers to a pattern with an associated
749   /// declaration.
750   CodeCompletionResult(CodeCompletionString *Pattern, NamedDecl *D,
751                        unsigned Priority)
752     : Declaration(D), Pattern(Pattern), Priority(Priority), StartParameter(0),
753       Kind(RK_Pattern), Availability(CXAvailability_Available), Hidden(false),
754       QualifierIsInformative(false), StartsNestedNameSpecifier(false),
755       AllParametersAreInformative(false), DeclaringEntity(false),
756       Qualifier(nullptr) {
757     computeCursorKindAndAvailability();
758   }
759 
760   /// \brief Retrieve the declaration stored in this result.
761   const NamedDecl *getDeclaration() const {
762     assert(Kind == RK_Declaration && "Not a declaration result");
763     return Declaration;
764   }
765 
766   /// \brief Retrieve the keyword stored in this result.
767   const char *getKeyword() const {
768     assert(Kind == RK_Keyword && "Not a keyword result");
769     return Keyword;
770   }
771 
772   /// \brief Create a new code-completion string that describes how to insert
773   /// this result into a program.
774   ///
775   /// \param S The semantic analysis that created the result.
776   ///
777   /// \param Allocator The allocator that will be used to allocate the
778   /// string itself.
779   CodeCompletionString *CreateCodeCompletionString(Sema &S,
780                                            CodeCompletionAllocator &Allocator,
781                                            CodeCompletionTUInfo &CCTUInfo,
782                                            bool IncludeBriefComments);
783   CodeCompletionString *CreateCodeCompletionString(ASTContext &Ctx,
784                                                    Preprocessor &PP,
785                                            CodeCompletionAllocator &Allocator,
786                                            CodeCompletionTUInfo &CCTUInfo,
787                                            bool IncludeBriefComments);
788 
789 private:
790   void computeCursorKindAndAvailability(bool Accessible = true);
791 };
792 
793 bool operator<(const CodeCompletionResult &X, const CodeCompletionResult &Y);
794 
795 inline bool operator>(const CodeCompletionResult &X,
796                       const CodeCompletionResult &Y) {
797   return Y < X;
798 }
799 
800 inline bool operator<=(const CodeCompletionResult &X,
801                       const CodeCompletionResult &Y) {
802   return !(Y < X);
803 }
804 
805 inline bool operator>=(const CodeCompletionResult &X,
806                        const CodeCompletionResult &Y) {
807   return !(X < Y);
808 }
809 
810 
811 raw_ostream &operator<<(raw_ostream &OS,
812                               const CodeCompletionString &CCS);
813 
814 /// \brief Abstract interface for a consumer of code-completion
815 /// information.
816 class CodeCompleteConsumer {
817 protected:
818   const CodeCompleteOptions CodeCompleteOpts;
819 
820   /// \brief Whether the output format for the code-completion consumer is
821   /// binary.
822   bool OutputIsBinary;
823 
824 public:
825   class OverloadCandidate {
826   public:
827     /// \brief Describes the type of overload candidate.
828     enum CandidateKind {
829       /// \brief The candidate is a function declaration.
830       CK_Function,
831       /// \brief The candidate is a function template.
832       CK_FunctionTemplate,
833       /// \brief The "candidate" is actually a variable, expression, or block
834       /// for which we only have a function prototype.
835       CK_FunctionType
836     };
837 
838   private:
839     /// \brief The kind of overload candidate.
840     CandidateKind Kind;
841 
842     union {
843       /// \brief The function overload candidate, available when
844       /// Kind == CK_Function.
845       FunctionDecl *Function;
846 
847       /// \brief The function template overload candidate, available when
848       /// Kind == CK_FunctionTemplate.
849       FunctionTemplateDecl *FunctionTemplate;
850 
851       /// \brief The function type that describes the entity being called,
852       /// when Kind == CK_FunctionType.
853       const FunctionType *Type;
854     };
855 
856   public:
857     OverloadCandidate(FunctionDecl *Function)
858       : Kind(CK_Function), Function(Function) { }
859 
860     OverloadCandidate(FunctionTemplateDecl *FunctionTemplateDecl)
861       : Kind(CK_FunctionTemplate), FunctionTemplate(FunctionTemplateDecl) { }
862 
863     OverloadCandidate(const FunctionType *Type)
864       : Kind(CK_FunctionType), Type(Type) { }
865 
866     /// \brief Determine the kind of overload candidate.
867     CandidateKind getKind() const { return Kind; }
868 
869     /// \brief Retrieve the function overload candidate or the templated
870     /// function declaration for a function template.
871     FunctionDecl *getFunction() const;
872 
873     /// \brief Retrieve the function template overload candidate.
874     FunctionTemplateDecl *getFunctionTemplate() const {
875       assert(getKind() == CK_FunctionTemplate && "Not a function template");
876       return FunctionTemplate;
877     }
878 
879     /// \brief Retrieve the function type of the entity, regardless of how the
880     /// function is stored.
881     const FunctionType *getFunctionType() const;
882 
883     /// \brief Create a new code-completion string that describes the function
884     /// signature of this overload candidate.
885     CodeCompletionString *CreateSignatureString(unsigned CurrentArg,
886                                                 Sema &S,
887                                       CodeCompletionAllocator &Allocator,
888                                       CodeCompletionTUInfo &CCTUInfo) const;
889   };
890 
891   CodeCompleteConsumer(const CodeCompleteOptions &CodeCompleteOpts,
892                        bool OutputIsBinary)
893     : CodeCompleteOpts(CodeCompleteOpts), OutputIsBinary(OutputIsBinary)
894   { }
895 
896   /// \brief Whether the code-completion consumer wants to see macros.
897   bool includeMacros() const {
898     return CodeCompleteOpts.IncludeMacros;
899   }
900 
901   /// \brief Whether the code-completion consumer wants to see code patterns.
902   bool includeCodePatterns() const {
903     return CodeCompleteOpts.IncludeCodePatterns;
904   }
905 
906   /// \brief Whether to include global (top-level) declaration results.
907   bool includeGlobals() const {
908     return CodeCompleteOpts.IncludeGlobals;
909   }
910 
911   /// \brief Whether to include brief documentation comments within the set of
912   /// code completions returned.
913   bool includeBriefComments() const {
914     return CodeCompleteOpts.IncludeBriefComments;
915   }
916 
917   /// \brief Determine whether the output of this consumer is binary.
918   bool isOutputBinary() const { return OutputIsBinary; }
919 
920   /// \brief Deregisters and destroys this code-completion consumer.
921   virtual ~CodeCompleteConsumer();
922 
923   /// \name Code-completion callbacks
924   //@{
925   /// \brief Process the finalized code-completion results.
926   virtual void ProcessCodeCompleteResults(Sema &S,
927                                           CodeCompletionContext Context,
928                                           CodeCompletionResult *Results,
929                                           unsigned NumResults) { }
930 
931   /// \param S the semantic-analyzer object for which code-completion is being
932   /// done.
933   ///
934   /// \param CurrentArg the index of the current argument.
935   ///
936   /// \param Candidates an array of overload candidates.
937   ///
938   /// \param NumCandidates the number of overload candidates
939   virtual void ProcessOverloadCandidates(Sema &S, unsigned CurrentArg,
940                                          OverloadCandidate *Candidates,
941                                          unsigned NumCandidates) { }
942   //@}
943 
944   /// \brief Retrieve the allocator that will be used to allocate
945   /// code completion strings.
946   virtual CodeCompletionAllocator &getAllocator() = 0;
947 
948   virtual CodeCompletionTUInfo &getCodeCompletionTUInfo() = 0;
949 };
950 
951 /// \brief A simple code-completion consumer that prints the results it
952 /// receives in a simple format.
953 class PrintingCodeCompleteConsumer : public CodeCompleteConsumer {
954   /// \brief The raw output stream.
955   raw_ostream &OS;
956 
957   CodeCompletionTUInfo CCTUInfo;
958 
959 public:
960   /// \brief Create a new printing code-completion consumer that prints its
961   /// results to the given raw output stream.
962   PrintingCodeCompleteConsumer(const CodeCompleteOptions &CodeCompleteOpts,
963                                raw_ostream &OS)
964     : CodeCompleteConsumer(CodeCompleteOpts, false), OS(OS),
965       CCTUInfo(new GlobalCodeCompletionAllocator) {}
966 
967   /// \brief Prints the finalized code-completion results.
968   void ProcessCodeCompleteResults(Sema &S, CodeCompletionContext Context,
969                                   CodeCompletionResult *Results,
970                                   unsigned NumResults) override;
971 
972   void ProcessOverloadCandidates(Sema &S, unsigned CurrentArg,
973                                  OverloadCandidate *Candidates,
974                                  unsigned NumCandidates) override;
975 
976   CodeCompletionAllocator &getAllocator() override {
977     return CCTUInfo.getAllocator();
978   }
979 
980   CodeCompletionTUInfo &getCodeCompletionTUInfo() override { return CCTUInfo; }
981 };
982 
983 } // end namespace clang
984 
985 #endif // LLVM_CLANG_SEMA_CODECOMPLETECONSUMER_H
986