1 //===--- CGDebugInfo.cpp - Emit Debug Information for a Module ------------===//
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 coordinates the debug information generation while generating code.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "CGDebugInfo.h"
15 #include "CGBlocks.h"
16 #include "CGCXXABI.h"
17 #include "CGObjCRuntime.h"
18 #include "CodeGenFunction.h"
19 #include "CodeGenModule.h"
20 #include "clang/AST/ASTContext.h"
21 #include "clang/AST/DeclFriend.h"
22 #include "clang/AST/DeclObjC.h"
23 #include "clang/AST/DeclTemplate.h"
24 #include "clang/AST/Expr.h"
25 #include "clang/AST/RecordLayout.h"
26 #include "clang/Basic/FileManager.h"
27 #include "clang/Basic/SourceManager.h"
28 #include "clang/Basic/Version.h"
29 #include "clang/Frontend/CodeGenOptions.h"
30 #include "llvm/ADT/SmallVector.h"
31 #include "llvm/ADT/StringExtras.h"
32 #include "llvm/IR/Constants.h"
33 #include "llvm/IR/DataLayout.h"
34 #include "llvm/IR/DerivedTypes.h"
35 #include "llvm/IR/Instructions.h"
36 #include "llvm/IR/Intrinsics.h"
37 #include "llvm/IR/Module.h"
38 #include "llvm/Support/Dwarf.h"
39 #include "llvm/Support/FileSystem.h"
40 #include "llvm/Support/Path.h"
41 using namespace clang;
42 using namespace clang::CodeGen;
43 
44 CGDebugInfo::CGDebugInfo(CodeGenModule &CGM)
45     : CGM(CGM), DebugKind(CGM.getCodeGenOpts().getDebugInfo()),
46       DBuilder(CGM.getModule()) {
47   CreateCompileUnit();
48 }
49 
50 CGDebugInfo::~CGDebugInfo() {
51   assert(LexicalBlockStack.empty() &&
52          "Region stack mismatch, stack not empty!");
53 }
54 
55 
56 NoLocation::NoLocation(CodeGenFunction &CGF, CGBuilderTy &B)
57   : DI(CGF.getDebugInfo()), Builder(B) {
58   if (DI) {
59     SavedLoc = DI->getLocation();
60     DI->CurLoc = SourceLocation();
61     Builder.SetCurrentDebugLocation(llvm::DebugLoc());
62   }
63 }
64 
65 NoLocation::~NoLocation() {
66   if (DI) {
67     assert(Builder.getCurrentDebugLocation().isUnknown());
68     DI->CurLoc = SavedLoc;
69   }
70 }
71 
72 ArtificialLocation::ArtificialLocation(CodeGenFunction &CGF, CGBuilderTy &B)
73   : DI(CGF.getDebugInfo()), Builder(B) {
74   if (DI) {
75     SavedLoc = DI->getLocation();
76     DI->CurLoc = SourceLocation();
77     Builder.SetCurrentDebugLocation(llvm::DebugLoc());
78   }
79 }
80 
81 void ArtificialLocation::Emit() {
82   if (DI) {
83     // Sync the Builder.
84     DI->EmitLocation(Builder, SavedLoc);
85     DI->CurLoc = SourceLocation();
86     // Construct a location that has a valid scope, but no line info.
87     assert(!DI->LexicalBlockStack.empty());
88     llvm::DIDescriptor Scope(DI->LexicalBlockStack.back());
89     Builder.SetCurrentDebugLocation(llvm::DebugLoc::get(0, 0, Scope));
90   }
91 }
92 
93 ArtificialLocation::~ArtificialLocation() {
94   if (DI) {
95     assert(Builder.getCurrentDebugLocation().getLine() == 0);
96     DI->CurLoc = SavedLoc;
97   }
98 }
99 
100 void CGDebugInfo::setLocation(SourceLocation Loc) {
101   // If the new location isn't valid return.
102   if (Loc.isInvalid()) return;
103 
104   CurLoc = CGM.getContext().getSourceManager().getExpansionLoc(Loc);
105 
106   // If we've changed files in the middle of a lexical scope go ahead
107   // and create a new lexical scope with file node if it's different
108   // from the one in the scope.
109   if (LexicalBlockStack.empty()) return;
110 
111   SourceManager &SM = CGM.getContext().getSourceManager();
112   PresumedLoc PCLoc = SM.getPresumedLoc(CurLoc);
113   PresumedLoc PPLoc = SM.getPresumedLoc(PrevLoc);
114 
115   if (PCLoc.isInvalid() || PPLoc.isInvalid() ||
116       !strcmp(PPLoc.getFilename(), PCLoc.getFilename()))
117     return;
118 
119   llvm::MDNode *LB = LexicalBlockStack.back();
120   llvm::DIScope Scope = llvm::DIScope(LB);
121   if (Scope.isLexicalBlockFile()) {
122     llvm::DILexicalBlockFile LBF = llvm::DILexicalBlockFile(LB);
123     llvm::DIDescriptor D
124       = DBuilder.createLexicalBlockFile(LBF.getScope(),
125                                         getOrCreateFile(CurLoc));
126     llvm::MDNode *N = D;
127     LexicalBlockStack.pop_back();
128     LexicalBlockStack.push_back(N);
129   } else if (Scope.isLexicalBlock() || Scope.isSubprogram()) {
130     llvm::DIDescriptor D
131       = DBuilder.createLexicalBlockFile(Scope, getOrCreateFile(CurLoc));
132     llvm::MDNode *N = D;
133     LexicalBlockStack.pop_back();
134     LexicalBlockStack.push_back(N);
135   }
136 }
137 
138 /// getContextDescriptor - Get context info for the decl.
139 llvm::DIScope CGDebugInfo::getContextDescriptor(const Decl *Context) {
140   if (!Context)
141     return TheCU;
142 
143   llvm::DenseMap<const Decl *, llvm::WeakVH>::iterator
144     I = RegionMap.find(Context);
145   if (I != RegionMap.end()) {
146     llvm::Value *V = I->second;
147     return llvm::DIScope(dyn_cast_or_null<llvm::MDNode>(V));
148   }
149 
150   // Check namespace.
151   if (const NamespaceDecl *NSDecl = dyn_cast<NamespaceDecl>(Context))
152     return getOrCreateNameSpace(NSDecl);
153 
154   if (const RecordDecl *RDecl = dyn_cast<RecordDecl>(Context))
155     if (!RDecl->isDependentType())
156       return getOrCreateType(CGM.getContext().getTypeDeclType(RDecl),
157                                         getOrCreateMainFile());
158   return TheCU;
159 }
160 
161 /// getFunctionName - Get function name for the given FunctionDecl. If the
162 /// name is constructed on demand (e.g. C++ destructor) then the name
163 /// is stored on the side.
164 StringRef CGDebugInfo::getFunctionName(const FunctionDecl *FD) {
165   assert (FD && "Invalid FunctionDecl!");
166   IdentifierInfo *FII = FD->getIdentifier();
167   FunctionTemplateSpecializationInfo *Info
168     = FD->getTemplateSpecializationInfo();
169   if (!Info && FII)
170     return FII->getName();
171 
172   // Otherwise construct human readable name for debug info.
173   SmallString<128> NS;
174   llvm::raw_svector_ostream OS(NS);
175   FD->printName(OS);
176 
177   // Add any template specialization args.
178   if (Info) {
179     const TemplateArgumentList *TArgs = Info->TemplateArguments;
180     const TemplateArgument *Args = TArgs->data();
181     unsigned NumArgs = TArgs->size();
182     PrintingPolicy Policy(CGM.getLangOpts());
183     TemplateSpecializationType::PrintTemplateArgumentList(OS, Args, NumArgs,
184                                                           Policy);
185   }
186 
187   // Copy this name on the side and use its reference.
188   return internString(OS.str());
189 }
190 
191 StringRef CGDebugInfo::getObjCMethodName(const ObjCMethodDecl *OMD) {
192   SmallString<256> MethodName;
193   llvm::raw_svector_ostream OS(MethodName);
194   OS << (OMD->isInstanceMethod() ? '-' : '+') << '[';
195   const DeclContext *DC = OMD->getDeclContext();
196   if (const ObjCImplementationDecl *OID =
197       dyn_cast<const ObjCImplementationDecl>(DC)) {
198      OS << OID->getName();
199   } else if (const ObjCInterfaceDecl *OID =
200              dyn_cast<const ObjCInterfaceDecl>(DC)) {
201       OS << OID->getName();
202   } else if (const ObjCCategoryImplDecl *OCD =
203              dyn_cast<const ObjCCategoryImplDecl>(DC)){
204       OS << ((const NamedDecl *)OCD)->getIdentifier()->getNameStart() << '(' <<
205           OCD->getIdentifier()->getNameStart() << ')';
206   } else if (isa<ObjCProtocolDecl>(DC)) {
207     // We can extract the type of the class from the self pointer.
208     if (ImplicitParamDecl* SelfDecl = OMD->getSelfDecl()) {
209       QualType ClassTy =
210         cast<ObjCObjectPointerType>(SelfDecl->getType())->getPointeeType();
211       ClassTy.print(OS, PrintingPolicy(LangOptions()));
212     }
213   }
214   OS << ' ' << OMD->getSelector().getAsString() << ']';
215 
216   return internString(OS.str());
217 }
218 
219 /// getSelectorName - Return selector name. This is used for debugging
220 /// info.
221 StringRef CGDebugInfo::getSelectorName(Selector S) {
222   return internString(S.getAsString());
223 }
224 
225 /// getClassName - Get class name including template argument list.
226 StringRef
227 CGDebugInfo::getClassName(const RecordDecl *RD) {
228   const ClassTemplateSpecializationDecl *Spec
229     = dyn_cast<ClassTemplateSpecializationDecl>(RD);
230   if (!Spec)
231     return RD->getName();
232 
233   const TemplateArgument *Args;
234   unsigned NumArgs;
235   if (TypeSourceInfo *TAW = Spec->getTypeAsWritten()) {
236     const TemplateSpecializationType *TST =
237       cast<TemplateSpecializationType>(TAW->getType());
238     Args = TST->getArgs();
239     NumArgs = TST->getNumArgs();
240   } else {
241     const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs();
242     Args = TemplateArgs.data();
243     NumArgs = TemplateArgs.size();
244   }
245   StringRef Name = RD->getIdentifier()->getName();
246   PrintingPolicy Policy(CGM.getLangOpts());
247   SmallString<128> TemplateArgList;
248   {
249     llvm::raw_svector_ostream OS(TemplateArgList);
250     TemplateSpecializationType::PrintTemplateArgumentList(OS, Args, NumArgs,
251                                                           Policy);
252   }
253 
254   // Copy this name on the side and use its reference.
255   return internString(Name, TemplateArgList);
256 }
257 
258 /// getOrCreateFile - Get the file debug info descriptor for the input location.
259 llvm::DIFile CGDebugInfo::getOrCreateFile(SourceLocation Loc) {
260   if (!Loc.isValid())
261     // If Location is not valid then use main input file.
262     return DBuilder.createFile(TheCU.getFilename(), TheCU.getDirectory());
263 
264   SourceManager &SM = CGM.getContext().getSourceManager();
265   PresumedLoc PLoc = SM.getPresumedLoc(Loc);
266 
267   if (PLoc.isInvalid() || StringRef(PLoc.getFilename()).empty())
268     // If the location is not valid then use main input file.
269     return DBuilder.createFile(TheCU.getFilename(), TheCU.getDirectory());
270 
271   // Cache the results.
272   const char *fname = PLoc.getFilename();
273   llvm::DenseMap<const char *, llvm::WeakVH>::iterator it =
274     DIFileCache.find(fname);
275 
276   if (it != DIFileCache.end()) {
277     // Verify that the information still exists.
278     if (llvm::Value *V = it->second)
279       return llvm::DIFile(cast<llvm::MDNode>(V));
280   }
281 
282   llvm::DIFile F = DBuilder.createFile(PLoc.getFilename(), getCurrentDirname());
283 
284   DIFileCache[fname] = F;
285   return F;
286 }
287 
288 /// getOrCreateMainFile - Get the file info for main compile unit.
289 llvm::DIFile CGDebugInfo::getOrCreateMainFile() {
290   return DBuilder.createFile(TheCU.getFilename(), TheCU.getDirectory());
291 }
292 
293 /// getLineNumber - Get line number for the location. If location is invalid
294 /// then use current location.
295 unsigned CGDebugInfo::getLineNumber(SourceLocation Loc) {
296   if (Loc.isInvalid() && CurLoc.isInvalid())
297     return 0;
298   SourceManager &SM = CGM.getContext().getSourceManager();
299   PresumedLoc PLoc = SM.getPresumedLoc(Loc.isValid() ? Loc : CurLoc);
300   return PLoc.isValid()? PLoc.getLine() : 0;
301 }
302 
303 /// getColumnNumber - Get column number for the location.
304 unsigned CGDebugInfo::getColumnNumber(SourceLocation Loc, bool Force) {
305   // We may not want column information at all.
306   if (!Force && !CGM.getCodeGenOpts().DebugColumnInfo)
307     return 0;
308 
309   // If the location is invalid then use the current column.
310   if (Loc.isInvalid() && CurLoc.isInvalid())
311     return 0;
312   SourceManager &SM = CGM.getContext().getSourceManager();
313   PresumedLoc PLoc = SM.getPresumedLoc(Loc.isValid() ? Loc : CurLoc);
314   return PLoc.isValid()? PLoc.getColumn() : 0;
315 }
316 
317 StringRef CGDebugInfo::getCurrentDirname() {
318   if (!CGM.getCodeGenOpts().DebugCompilationDir.empty())
319     return CGM.getCodeGenOpts().DebugCompilationDir;
320 
321   if (!CWDName.empty())
322     return CWDName;
323   SmallString<256> CWD;
324   llvm::sys::fs::current_path(CWD);
325   return CWDName = internString(CWD);
326 }
327 
328 /// CreateCompileUnit - Create new compile unit.
329 void CGDebugInfo::CreateCompileUnit() {
330 
331   // Get absolute path name.
332   SourceManager &SM = CGM.getContext().getSourceManager();
333   std::string MainFileName = CGM.getCodeGenOpts().MainFileName;
334   if (MainFileName.empty())
335     MainFileName = "<unknown>";
336 
337   // The main file name provided via the "-main-file-name" option contains just
338   // the file name itself with no path information. This file name may have had
339   // a relative path, so we look into the actual file entry for the main
340   // file to determine the real absolute path for the file.
341   std::string MainFileDir;
342   if (const FileEntry *MainFile = SM.getFileEntryForID(SM.getMainFileID())) {
343     MainFileDir = MainFile->getDir()->getName();
344     if (MainFileDir != ".") {
345       llvm::SmallString<1024> MainFileDirSS(MainFileDir);
346       llvm::sys::path::append(MainFileDirSS, MainFileName);
347       MainFileName = MainFileDirSS.str();
348     }
349   }
350 
351   // Save filename string.
352   StringRef Filename = internString(MainFileName);
353 
354   // Save split dwarf file string.
355   std::string SplitDwarfFile = CGM.getCodeGenOpts().SplitDwarfFile;
356   StringRef SplitDwarfFilename = internString(SplitDwarfFile);
357 
358   unsigned LangTag;
359   const LangOptions &LO = CGM.getLangOpts();
360   if (LO.CPlusPlus) {
361     if (LO.ObjC1)
362       LangTag = llvm::dwarf::DW_LANG_ObjC_plus_plus;
363     else
364       LangTag = llvm::dwarf::DW_LANG_C_plus_plus;
365   } else if (LO.ObjC1) {
366     LangTag = llvm::dwarf::DW_LANG_ObjC;
367   } else if (LO.C99) {
368     LangTag = llvm::dwarf::DW_LANG_C99;
369   } else {
370     LangTag = llvm::dwarf::DW_LANG_C89;
371   }
372 
373   std::string Producer = getClangFullVersion();
374 
375   // Figure out which version of the ObjC runtime we have.
376   unsigned RuntimeVers = 0;
377   if (LO.ObjC1)
378     RuntimeVers = LO.ObjCRuntime.isNonFragile() ? 2 : 1;
379 
380   // Create new compile unit.
381   // FIXME - Eliminate TheCU.
382   TheCU = DBuilder.createCompileUnit(LangTag, Filename, getCurrentDirname(),
383                                      Producer, LO.Optimize,
384                                      CGM.getCodeGenOpts().DwarfDebugFlags,
385                                      RuntimeVers, SplitDwarfFilename);
386 }
387 
388 /// CreateType - Get the Basic type from the cache or create a new
389 /// one if necessary.
390 llvm::DIType CGDebugInfo::CreateType(const BuiltinType *BT) {
391   unsigned Encoding = 0;
392   StringRef BTName;
393   switch (BT->getKind()) {
394 #define BUILTIN_TYPE(Id, SingletonId)
395 #define PLACEHOLDER_TYPE(Id, SingletonId) \
396   case BuiltinType::Id:
397 #include "clang/AST/BuiltinTypes.def"
398   case BuiltinType::Dependent:
399     llvm_unreachable("Unexpected builtin type");
400   case BuiltinType::NullPtr:
401     return DBuilder.createNullPtrType();
402   case BuiltinType::Void:
403     return llvm::DIType();
404   case BuiltinType::ObjCClass:
405     if (ClassTy)
406       return ClassTy;
407     ClassTy = DBuilder.createForwardDecl(llvm::dwarf::DW_TAG_structure_type,
408                                          "objc_class", TheCU,
409                                          getOrCreateMainFile(), 0);
410     return ClassTy;
411   case BuiltinType::ObjCId: {
412     // typedef struct objc_class *Class;
413     // typedef struct objc_object {
414     //  Class isa;
415     // } *id;
416 
417     if (ObjTy)
418       return ObjTy;
419 
420     if (!ClassTy)
421       ClassTy = DBuilder.createForwardDecl(llvm::dwarf::DW_TAG_structure_type,
422                                            "objc_class", TheCU,
423                                            getOrCreateMainFile(), 0);
424 
425     unsigned Size = CGM.getContext().getTypeSize(CGM.getContext().VoidPtrTy);
426 
427     llvm::DIType ISATy = DBuilder.createPointerType(ClassTy, Size);
428 
429     ObjTy =
430         DBuilder.createStructType(TheCU, "objc_object", getOrCreateMainFile(),
431                                   0, 0, 0, 0, llvm::DIType(), llvm::DIArray());
432 
433     ObjTy.setTypeArray(DBuilder.getOrCreateArray(&*DBuilder.createMemberType(
434         ObjTy, "isa", getOrCreateMainFile(), 0, Size, 0, 0, 0, ISATy)));
435     return ObjTy;
436   }
437   case BuiltinType::ObjCSel: {
438     if (SelTy)
439       return SelTy;
440     SelTy =
441       DBuilder.createForwardDecl(llvm::dwarf::DW_TAG_structure_type,
442                                  "objc_selector", TheCU, getOrCreateMainFile(),
443                                  0);
444     return SelTy;
445   }
446 
447   case BuiltinType::OCLImage1d:
448     return getOrCreateStructPtrType("opencl_image1d_t",
449                                     OCLImage1dDITy);
450   case BuiltinType::OCLImage1dArray:
451     return getOrCreateStructPtrType("opencl_image1d_array_t",
452                                     OCLImage1dArrayDITy);
453   case BuiltinType::OCLImage1dBuffer:
454     return getOrCreateStructPtrType("opencl_image1d_buffer_t",
455                                     OCLImage1dBufferDITy);
456   case BuiltinType::OCLImage2d:
457     return getOrCreateStructPtrType("opencl_image2d_t",
458                                     OCLImage2dDITy);
459   case BuiltinType::OCLImage2dArray:
460     return getOrCreateStructPtrType("opencl_image2d_array_t",
461                                     OCLImage2dArrayDITy);
462   case BuiltinType::OCLImage3d:
463     return getOrCreateStructPtrType("opencl_image3d_t",
464                                     OCLImage3dDITy);
465   case BuiltinType::OCLSampler:
466     return DBuilder.createBasicType("opencl_sampler_t",
467                                     CGM.getContext().getTypeSize(BT),
468                                     CGM.getContext().getTypeAlign(BT),
469                                     llvm::dwarf::DW_ATE_unsigned);
470   case BuiltinType::OCLEvent:
471     return getOrCreateStructPtrType("opencl_event_t",
472                                     OCLEventDITy);
473 
474   case BuiltinType::UChar:
475   case BuiltinType::Char_U: Encoding = llvm::dwarf::DW_ATE_unsigned_char; break;
476   case BuiltinType::Char_S:
477   case BuiltinType::SChar: Encoding = llvm::dwarf::DW_ATE_signed_char; break;
478   case BuiltinType::Char16:
479   case BuiltinType::Char32: Encoding = llvm::dwarf::DW_ATE_UTF; break;
480   case BuiltinType::UShort:
481   case BuiltinType::UInt:
482   case BuiltinType::UInt128:
483   case BuiltinType::ULong:
484   case BuiltinType::WChar_U:
485   case BuiltinType::ULongLong: Encoding = llvm::dwarf::DW_ATE_unsigned; break;
486   case BuiltinType::Short:
487   case BuiltinType::Int:
488   case BuiltinType::Int128:
489   case BuiltinType::Long:
490   case BuiltinType::WChar_S:
491   case BuiltinType::LongLong:  Encoding = llvm::dwarf::DW_ATE_signed; break;
492   case BuiltinType::Bool:      Encoding = llvm::dwarf::DW_ATE_boolean; break;
493   case BuiltinType::Half:
494   case BuiltinType::Float:
495   case BuiltinType::LongDouble:
496   case BuiltinType::Double:    Encoding = llvm::dwarf::DW_ATE_float; break;
497   }
498 
499   switch (BT->getKind()) {
500   case BuiltinType::Long:      BTName = "long int"; break;
501   case BuiltinType::LongLong:  BTName = "long long int"; break;
502   case BuiltinType::ULong:     BTName = "long unsigned int"; break;
503   case BuiltinType::ULongLong: BTName = "long long unsigned int"; break;
504   default:
505     BTName = BT->getName(CGM.getLangOpts());
506     break;
507   }
508   // Bit size, align and offset of the type.
509   uint64_t Size = CGM.getContext().getTypeSize(BT);
510   uint64_t Align = CGM.getContext().getTypeAlign(BT);
511   llvm::DIType DbgTy =
512     DBuilder.createBasicType(BTName, Size, Align, Encoding);
513   return DbgTy;
514 }
515 
516 llvm::DIType CGDebugInfo::CreateType(const ComplexType *Ty) {
517   // Bit size, align and offset of the type.
518   unsigned Encoding = llvm::dwarf::DW_ATE_complex_float;
519   if (Ty->isComplexIntegerType())
520     Encoding = llvm::dwarf::DW_ATE_lo_user;
521 
522   uint64_t Size = CGM.getContext().getTypeSize(Ty);
523   uint64_t Align = CGM.getContext().getTypeAlign(Ty);
524   llvm::DIType DbgTy =
525     DBuilder.createBasicType("complex", Size, Align, Encoding);
526 
527   return DbgTy;
528 }
529 
530 /// CreateCVRType - Get the qualified type from the cache or create
531 /// a new one if necessary.
532 llvm::DIType CGDebugInfo::CreateQualifiedType(QualType Ty, llvm::DIFile Unit) {
533   QualifierCollector Qc;
534   const Type *T = Qc.strip(Ty);
535 
536   // Ignore these qualifiers for now.
537   Qc.removeObjCGCAttr();
538   Qc.removeAddressSpace();
539   Qc.removeObjCLifetime();
540 
541   // We will create one Derived type for one qualifier and recurse to handle any
542   // additional ones.
543   unsigned Tag;
544   if (Qc.hasConst()) {
545     Tag = llvm::dwarf::DW_TAG_const_type;
546     Qc.removeConst();
547   } else if (Qc.hasVolatile()) {
548     Tag = llvm::dwarf::DW_TAG_volatile_type;
549     Qc.removeVolatile();
550   } else if (Qc.hasRestrict()) {
551     Tag = llvm::dwarf::DW_TAG_restrict_type;
552     Qc.removeRestrict();
553   } else {
554     assert(Qc.empty() && "Unknown type qualifier for debug info");
555     return getOrCreateType(QualType(T, 0), Unit);
556   }
557 
558   llvm::DIType FromTy = getOrCreateType(Qc.apply(CGM.getContext(), T), Unit);
559 
560   // No need to fill in the Name, Line, Size, Alignment, Offset in case of
561   // CVR derived types.
562   llvm::DIType DbgTy = DBuilder.createQualifiedType(Tag, FromTy);
563 
564   return DbgTy;
565 }
566 
567 llvm::DIType CGDebugInfo::CreateType(const ObjCObjectPointerType *Ty,
568                                      llvm::DIFile Unit) {
569 
570   // The frontend treats 'id' as a typedef to an ObjCObjectType,
571   // whereas 'id<protocol>' is treated as an ObjCPointerType. For the
572   // debug info, we want to emit 'id' in both cases.
573   if (Ty->isObjCQualifiedIdType())
574       return getOrCreateType(CGM.getContext().getObjCIdType(), Unit);
575 
576   llvm::DIType DbgTy =
577     CreatePointerLikeType(llvm::dwarf::DW_TAG_pointer_type, Ty,
578                           Ty->getPointeeType(), Unit);
579   return DbgTy;
580 }
581 
582 llvm::DIType CGDebugInfo::CreateType(const PointerType *Ty,
583                                      llvm::DIFile Unit) {
584   return CreatePointerLikeType(llvm::dwarf::DW_TAG_pointer_type, Ty,
585                                Ty->getPointeeType(), Unit);
586 }
587 
588 /// In C++ mode, types have linkage, so we can rely on the ODR and
589 /// on their mangled names, if they're external.
590 static SmallString<256>
591 getUniqueTagTypeName(const TagType *Ty, CodeGenModule &CGM,
592                      llvm::DICompileUnit TheCU) {
593   SmallString<256> FullName;
594   // FIXME: ODR should apply to ObjC++ exactly the same wasy it does to C++.
595   // For now, only apply ODR with C++.
596   const TagDecl *TD = Ty->getDecl();
597   if (TheCU.getLanguage() != llvm::dwarf::DW_LANG_C_plus_plus ||
598       !TD->isExternallyVisible())
599     return FullName;
600   // Microsoft Mangler does not have support for mangleCXXRTTIName yet.
601   if (CGM.getTarget().getCXXABI().isMicrosoft())
602     return FullName;
603 
604   // TODO: This is using the RTTI name. Is there a better way to get
605   // a unique string for a type?
606   llvm::raw_svector_ostream Out(FullName);
607   CGM.getCXXABI().getMangleContext().mangleCXXRTTIName(QualType(Ty, 0), Out);
608   Out.flush();
609   return FullName;
610 }
611 
612 // Creates a forward declaration for a RecordDecl in the given context.
613 llvm::DICompositeType
614 CGDebugInfo::getOrCreateRecordFwdDecl(const RecordType *Ty,
615                                       llvm::DIDescriptor Ctx) {
616   const RecordDecl *RD = Ty->getDecl();
617   if (llvm::DIType T = getTypeOrNull(CGM.getContext().getRecordType(RD)))
618     return llvm::DICompositeType(T);
619   llvm::DIFile DefUnit = getOrCreateFile(RD->getLocation());
620   unsigned Line = getLineNumber(RD->getLocation());
621   StringRef RDName = getClassName(RD);
622 
623   unsigned Tag = 0;
624   if (RD->isStruct() || RD->isInterface())
625     Tag = llvm::dwarf::DW_TAG_structure_type;
626   else if (RD->isUnion())
627     Tag = llvm::dwarf::DW_TAG_union_type;
628   else {
629     assert(RD->isClass());
630     Tag = llvm::dwarf::DW_TAG_class_type;
631   }
632 
633   // Create the type.
634   SmallString<256> FullName = getUniqueTagTypeName(Ty, CGM, TheCU);
635   return DBuilder.createForwardDecl(Tag, RDName, Ctx, DefUnit, Line, 0, 0, 0,
636                                     FullName);
637 }
638 
639 llvm::DIType CGDebugInfo::CreatePointerLikeType(unsigned Tag,
640                                                 const Type *Ty,
641                                                 QualType PointeeTy,
642                                                 llvm::DIFile Unit) {
643   if (Tag == llvm::dwarf::DW_TAG_reference_type ||
644       Tag == llvm::dwarf::DW_TAG_rvalue_reference_type)
645     return DBuilder.createReferenceType(Tag, getOrCreateType(PointeeTy, Unit));
646 
647   // Bit size, align and offset of the type.
648   // Size is always the size of a pointer. We can't use getTypeSize here
649   // because that does not return the correct value for references.
650   unsigned AS = CGM.getContext().getTargetAddressSpace(PointeeTy);
651   uint64_t Size = CGM.getTarget().getPointerWidth(AS);
652   uint64_t Align = CGM.getContext().getTypeAlign(Ty);
653 
654   return DBuilder.createPointerType(getOrCreateType(PointeeTy, Unit), Size,
655                                     Align);
656 }
657 
658 llvm::DIType CGDebugInfo::getOrCreateStructPtrType(StringRef Name,
659                                                    llvm::DIType &Cache) {
660   if (Cache)
661     return Cache;
662   Cache = DBuilder.createForwardDecl(llvm::dwarf::DW_TAG_structure_type, Name,
663                                      TheCU, getOrCreateMainFile(), 0);
664   unsigned Size = CGM.getContext().getTypeSize(CGM.getContext().VoidPtrTy);
665   Cache = DBuilder.createPointerType(Cache, Size);
666   return Cache;
667 }
668 
669 llvm::DIType CGDebugInfo::CreateType(const BlockPointerType *Ty,
670                                      llvm::DIFile Unit) {
671   if (BlockLiteralGeneric)
672     return BlockLiteralGeneric;
673 
674   SmallVector<llvm::Value *, 8> EltTys;
675   llvm::DIType FieldTy;
676   QualType FType;
677   uint64_t FieldSize, FieldOffset;
678   unsigned FieldAlign;
679   llvm::DIArray Elements;
680   llvm::DIType EltTy, DescTy;
681 
682   FieldOffset = 0;
683   FType = CGM.getContext().UnsignedLongTy;
684   EltTys.push_back(CreateMemberType(Unit, FType, "reserved", &FieldOffset));
685   EltTys.push_back(CreateMemberType(Unit, FType, "Size", &FieldOffset));
686 
687   Elements = DBuilder.getOrCreateArray(EltTys);
688   EltTys.clear();
689 
690   unsigned Flags = llvm::DIDescriptor::FlagAppleBlock;
691   unsigned LineNo = getLineNumber(CurLoc);
692 
693   EltTy = DBuilder.createStructType(Unit, "__block_descriptor",
694                                     Unit, LineNo, FieldOffset, 0,
695                                     Flags, llvm::DIType(), Elements);
696 
697   // Bit size, align and offset of the type.
698   uint64_t Size = CGM.getContext().getTypeSize(Ty);
699 
700   DescTy = DBuilder.createPointerType(EltTy, Size);
701 
702   FieldOffset = 0;
703   FType = CGM.getContext().getPointerType(CGM.getContext().VoidTy);
704   EltTys.push_back(CreateMemberType(Unit, FType, "__isa", &FieldOffset));
705   FType = CGM.getContext().IntTy;
706   EltTys.push_back(CreateMemberType(Unit, FType, "__flags", &FieldOffset));
707   EltTys.push_back(CreateMemberType(Unit, FType, "__reserved", &FieldOffset));
708   FType = CGM.getContext().getPointerType(CGM.getContext().VoidTy);
709   EltTys.push_back(CreateMemberType(Unit, FType, "__FuncPtr", &FieldOffset));
710 
711   FType = CGM.getContext().getPointerType(CGM.getContext().VoidTy);
712   FieldTy = DescTy;
713   FieldSize = CGM.getContext().getTypeSize(Ty);
714   FieldAlign = CGM.getContext().getTypeAlign(Ty);
715   FieldTy = DBuilder.createMemberType(Unit, "__descriptor", Unit,
716                                       LineNo, FieldSize, FieldAlign,
717                                       FieldOffset, 0, FieldTy);
718   EltTys.push_back(FieldTy);
719 
720   FieldOffset += FieldSize;
721   Elements = DBuilder.getOrCreateArray(EltTys);
722 
723   EltTy = DBuilder.createStructType(Unit, "__block_literal_generic",
724                                     Unit, LineNo, FieldOffset, 0,
725                                     Flags, llvm::DIType(), Elements);
726 
727   BlockLiteralGeneric = DBuilder.createPointerType(EltTy, Size);
728   return BlockLiteralGeneric;
729 }
730 
731 llvm::DIType CGDebugInfo::CreateType(const TypedefType *Ty, llvm::DIFile Unit) {
732   // Typedefs are derived from some other type.  If we have a typedef of a
733   // typedef, make sure to emit the whole chain.
734   llvm::DIType Src = getOrCreateType(Ty->getDecl()->getUnderlyingType(), Unit);
735   if (!Src)
736     return llvm::DIType();
737   // We don't set size information, but do specify where the typedef was
738   // declared.
739   unsigned Line = getLineNumber(Ty->getDecl()->getLocation());
740   const TypedefNameDecl *TyDecl = Ty->getDecl();
741 
742   llvm::DIDescriptor TypedefContext =
743     getContextDescriptor(cast<Decl>(Ty->getDecl()->getDeclContext()));
744 
745   return
746     DBuilder.createTypedef(Src, TyDecl->getName(), Unit, Line, TypedefContext);
747 }
748 
749 llvm::DIType CGDebugInfo::CreateType(const FunctionType *Ty,
750                                      llvm::DIFile Unit) {
751   SmallVector<llvm::Value *, 16> EltTys;
752 
753   // Add the result type at least.
754   EltTys.push_back(getOrCreateType(Ty->getResultType(), Unit));
755 
756   // Set up remainder of arguments if there is a prototype.
757   // FIXME: IF NOT, HOW IS THIS REPRESENTED?  llvm-gcc doesn't represent '...'!
758   if (isa<FunctionNoProtoType>(Ty))
759     EltTys.push_back(DBuilder.createUnspecifiedParameter());
760   else if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(Ty)) {
761     for (unsigned i = 0, e = FPT->getNumArgs(); i != e; ++i)
762       EltTys.push_back(getOrCreateType(FPT->getArgType(i), Unit));
763   }
764 
765   llvm::DIArray EltTypeArray = DBuilder.getOrCreateArray(EltTys);
766   return DBuilder.createSubroutineType(Unit, EltTypeArray);
767 }
768 
769 
770 llvm::DIType CGDebugInfo::createFieldType(StringRef name,
771                                           QualType type,
772                                           uint64_t sizeInBitsOverride,
773                                           SourceLocation loc,
774                                           AccessSpecifier AS,
775                                           uint64_t offsetInBits,
776                                           llvm::DIFile tunit,
777                                           llvm::DIScope scope) {
778   llvm::DIType debugType = getOrCreateType(type, tunit);
779 
780   // Get the location for the field.
781   llvm::DIFile file = getOrCreateFile(loc);
782   unsigned line = getLineNumber(loc);
783 
784   uint64_t sizeInBits = 0;
785   unsigned alignInBits = 0;
786   if (!type->isIncompleteArrayType()) {
787     llvm::tie(sizeInBits, alignInBits) = CGM.getContext().getTypeInfo(type);
788 
789     if (sizeInBitsOverride)
790       sizeInBits = sizeInBitsOverride;
791   }
792 
793   unsigned flags = 0;
794   if (AS == clang::AS_private)
795     flags |= llvm::DIDescriptor::FlagPrivate;
796   else if (AS == clang::AS_protected)
797     flags |= llvm::DIDescriptor::FlagProtected;
798 
799   return DBuilder.createMemberType(scope, name, file, line, sizeInBits,
800                                    alignInBits, offsetInBits, flags, debugType);
801 }
802 
803 /// CollectRecordLambdaFields - Helper for CollectRecordFields.
804 void CGDebugInfo::
805 CollectRecordLambdaFields(const CXXRecordDecl *CXXDecl,
806                           SmallVectorImpl<llvm::Value *> &elements,
807                           llvm::DIType RecordTy) {
808   // For C++11 Lambdas a Field will be the same as a Capture, but the Capture
809   // has the name and the location of the variable so we should iterate over
810   // both concurrently.
811   const ASTRecordLayout &layout = CGM.getContext().getASTRecordLayout(CXXDecl);
812   RecordDecl::field_iterator Field = CXXDecl->field_begin();
813   unsigned fieldno = 0;
814   for (CXXRecordDecl::capture_const_iterator I = CXXDecl->captures_begin(),
815          E = CXXDecl->captures_end(); I != E; ++I, ++Field, ++fieldno) {
816     const LambdaExpr::Capture C = *I;
817     if (C.capturesVariable()) {
818       VarDecl *V = C.getCapturedVar();
819       llvm::DIFile VUnit = getOrCreateFile(C.getLocation());
820       StringRef VName = V->getName();
821       uint64_t SizeInBitsOverride = 0;
822       if (Field->isBitField()) {
823         SizeInBitsOverride = Field->getBitWidthValue(CGM.getContext());
824         assert(SizeInBitsOverride && "found named 0-width bitfield");
825       }
826       llvm::DIType fieldType
827         = createFieldType(VName, Field->getType(), SizeInBitsOverride,
828                           C.getLocation(), Field->getAccess(),
829                           layout.getFieldOffset(fieldno), VUnit, RecordTy);
830       elements.push_back(fieldType);
831     } else {
832       // TODO: Need to handle 'this' in some way by probably renaming the
833       // this of the lambda class and having a field member of 'this' or
834       // by using AT_object_pointer for the function and having that be
835       // used as 'this' for semantic references.
836       assert(C.capturesThis() && "Field that isn't captured and isn't this?");
837       FieldDecl *f = *Field;
838       llvm::DIFile VUnit = getOrCreateFile(f->getLocation());
839       QualType type = f->getType();
840       llvm::DIType fieldType
841         = createFieldType("this", type, 0, f->getLocation(), f->getAccess(),
842                           layout.getFieldOffset(fieldno), VUnit, RecordTy);
843 
844       elements.push_back(fieldType);
845     }
846   }
847 }
848 
849 /// Helper for CollectRecordFields.
850 llvm::DIDerivedType
851 CGDebugInfo::CreateRecordStaticField(const VarDecl *Var,
852                                      llvm::DIType RecordTy) {
853   // Create the descriptor for the static variable, with or without
854   // constant initializers.
855   llvm::DIFile VUnit = getOrCreateFile(Var->getLocation());
856   llvm::DIType VTy = getOrCreateType(Var->getType(), VUnit);
857 
858   unsigned LineNumber = getLineNumber(Var->getLocation());
859   StringRef VName = Var->getName();
860   llvm::Constant *C = NULL;
861   if (Var->getInit()) {
862     const APValue *Value = Var->evaluateValue();
863     if (Value) {
864       if (Value->isInt())
865         C = llvm::ConstantInt::get(CGM.getLLVMContext(), Value->getInt());
866       if (Value->isFloat())
867         C = llvm::ConstantFP::get(CGM.getLLVMContext(), Value->getFloat());
868     }
869   }
870 
871   unsigned Flags = 0;
872   AccessSpecifier Access = Var->getAccess();
873   if (Access == clang::AS_private)
874     Flags |= llvm::DIDescriptor::FlagPrivate;
875   else if (Access == clang::AS_protected)
876     Flags |= llvm::DIDescriptor::FlagProtected;
877 
878   llvm::DIDerivedType GV = DBuilder.createStaticMemberType(
879       RecordTy, VName, VUnit, LineNumber, VTy, Flags, C);
880   StaticDataMemberCache[Var->getCanonicalDecl()] = llvm::WeakVH(GV);
881   return GV;
882 }
883 
884 /// CollectRecordNormalField - Helper for CollectRecordFields.
885 void CGDebugInfo::
886 CollectRecordNormalField(const FieldDecl *field, uint64_t OffsetInBits,
887                          llvm::DIFile tunit,
888                          SmallVectorImpl<llvm::Value *> &elements,
889                          llvm::DIType RecordTy) {
890   StringRef name = field->getName();
891   QualType type = field->getType();
892 
893   // Ignore unnamed fields unless they're anonymous structs/unions.
894   if (name.empty() && !type->isRecordType())
895     return;
896 
897   uint64_t SizeInBitsOverride = 0;
898   if (field->isBitField()) {
899     SizeInBitsOverride = field->getBitWidthValue(CGM.getContext());
900     assert(SizeInBitsOverride && "found named 0-width bitfield");
901   }
902 
903   llvm::DIType fieldType
904     = createFieldType(name, type, SizeInBitsOverride,
905                       field->getLocation(), field->getAccess(),
906                       OffsetInBits, tunit, RecordTy);
907 
908   elements.push_back(fieldType);
909 }
910 
911 /// CollectRecordFields - A helper function to collect debug info for
912 /// record fields. This is used while creating debug info entry for a Record.
913 void CGDebugInfo::CollectRecordFields(const RecordDecl *record,
914                                       llvm::DIFile tunit,
915                                       SmallVectorImpl<llvm::Value *> &elements,
916                                       llvm::DICompositeType RecordTy) {
917   const CXXRecordDecl *CXXDecl = dyn_cast<CXXRecordDecl>(record);
918 
919   if (CXXDecl && CXXDecl->isLambda())
920     CollectRecordLambdaFields(CXXDecl, elements, RecordTy);
921   else {
922     const ASTRecordLayout &layout = CGM.getContext().getASTRecordLayout(record);
923 
924     // Field number for non-static fields.
925     unsigned fieldNo = 0;
926 
927     // Static and non-static members should appear in the same order as
928     // the corresponding declarations in the source program.
929     for (RecordDecl::decl_iterator I = record->decls_begin(),
930            E = record->decls_end(); I != E; ++I)
931       if (const VarDecl *V = dyn_cast<VarDecl>(*I)) {
932         // Reuse the existing static member declaration if one exists
933         llvm::DenseMap<const Decl *, llvm::WeakVH>::iterator MI =
934             StaticDataMemberCache.find(V->getCanonicalDecl());
935         if (MI != StaticDataMemberCache.end()) {
936           assert(MI->second &&
937                  "Static data member declaration should still exist");
938           elements.push_back(
939               llvm::DIDerivedType(cast<llvm::MDNode>(MI->second)));
940         } else
941           elements.push_back(CreateRecordStaticField(V, RecordTy));
942       } else if (FieldDecl *field = dyn_cast<FieldDecl>(*I)) {
943         CollectRecordNormalField(field, layout.getFieldOffset(fieldNo),
944                                  tunit, elements, RecordTy);
945 
946         // Bump field number for next field.
947         ++fieldNo;
948       }
949   }
950 }
951 
952 /// getOrCreateMethodType - CXXMethodDecl's type is a FunctionType. This
953 /// function type is not updated to include implicit "this" pointer. Use this
954 /// routine to get a method type which includes "this" pointer.
955 llvm::DICompositeType
956 CGDebugInfo::getOrCreateMethodType(const CXXMethodDecl *Method,
957                                    llvm::DIFile Unit) {
958   const FunctionProtoType *Func = Method->getType()->getAs<FunctionProtoType>();
959   if (Method->isStatic())
960     return llvm::DICompositeType(getOrCreateType(QualType(Func, 0), Unit));
961   return getOrCreateInstanceMethodType(Method->getThisType(CGM.getContext()),
962                                        Func, Unit);
963 }
964 
965 llvm::DICompositeType CGDebugInfo::getOrCreateInstanceMethodType(
966     QualType ThisPtr, const FunctionProtoType *Func, llvm::DIFile Unit) {
967   // Add "this" pointer.
968   llvm::DIArray Args = llvm::DICompositeType(
969       getOrCreateType(QualType(Func, 0), Unit)).getTypeArray();
970   assert (Args.getNumElements() && "Invalid number of arguments!");
971 
972   SmallVector<llvm::Value *, 16> Elts;
973 
974   // First element is always return type. For 'void' functions it is NULL.
975   Elts.push_back(Args.getElement(0));
976 
977   // "this" pointer is always first argument.
978   const CXXRecordDecl *RD = ThisPtr->getPointeeCXXRecordDecl();
979   if (isa<ClassTemplateSpecializationDecl>(RD)) {
980     // Create pointer type directly in this case.
981     const PointerType *ThisPtrTy = cast<PointerType>(ThisPtr);
982     QualType PointeeTy = ThisPtrTy->getPointeeType();
983     unsigned AS = CGM.getContext().getTargetAddressSpace(PointeeTy);
984     uint64_t Size = CGM.getTarget().getPointerWidth(AS);
985     uint64_t Align = CGM.getContext().getTypeAlign(ThisPtrTy);
986     llvm::DIType PointeeType = getOrCreateType(PointeeTy, Unit);
987     llvm::DIType ThisPtrType =
988       DBuilder.createPointerType(PointeeType, Size, Align);
989     TypeCache[ThisPtr.getAsOpaquePtr()] = ThisPtrType;
990     // TODO: This and the artificial type below are misleading, the
991     // types aren't artificial the argument is, but the current
992     // metadata doesn't represent that.
993     ThisPtrType = DBuilder.createObjectPointerType(ThisPtrType);
994     Elts.push_back(ThisPtrType);
995   } else {
996     llvm::DIType ThisPtrType = getOrCreateType(ThisPtr, Unit);
997     TypeCache[ThisPtr.getAsOpaquePtr()] = ThisPtrType;
998     ThisPtrType = DBuilder.createObjectPointerType(ThisPtrType);
999     Elts.push_back(ThisPtrType);
1000   }
1001 
1002   // Copy rest of the arguments.
1003   for (unsigned i = 1, e = Args.getNumElements(); i != e; ++i)
1004     Elts.push_back(Args.getElement(i));
1005 
1006   llvm::DIArray EltTypeArray = DBuilder.getOrCreateArray(Elts);
1007 
1008   return DBuilder.createSubroutineType(Unit, EltTypeArray);
1009 }
1010 
1011 /// isFunctionLocalClass - Return true if CXXRecordDecl is defined
1012 /// inside a function.
1013 static bool isFunctionLocalClass(const CXXRecordDecl *RD) {
1014   if (const CXXRecordDecl *NRD = dyn_cast<CXXRecordDecl>(RD->getDeclContext()))
1015     return isFunctionLocalClass(NRD);
1016   if (isa<FunctionDecl>(RD->getDeclContext()))
1017     return true;
1018   return false;
1019 }
1020 
1021 /// CreateCXXMemberFunction - A helper function to create a DISubprogram for
1022 /// a single member function GlobalDecl.
1023 llvm::DISubprogram
1024 CGDebugInfo::CreateCXXMemberFunction(const CXXMethodDecl *Method,
1025                                      llvm::DIFile Unit,
1026                                      llvm::DIType RecordTy) {
1027   bool IsCtorOrDtor =
1028     isa<CXXConstructorDecl>(Method) || isa<CXXDestructorDecl>(Method);
1029 
1030   StringRef MethodName = getFunctionName(Method);
1031   llvm::DICompositeType MethodTy = getOrCreateMethodType(Method, Unit);
1032 
1033   // Since a single ctor/dtor corresponds to multiple functions, it doesn't
1034   // make sense to give a single ctor/dtor a linkage name.
1035   StringRef MethodLinkageName;
1036   if (!IsCtorOrDtor && !isFunctionLocalClass(Method->getParent()))
1037     MethodLinkageName = CGM.getMangledName(Method);
1038 
1039   // Get the location for the method.
1040   llvm::DIFile MethodDefUnit;
1041   unsigned MethodLine = 0;
1042   if (!Method->isImplicit()) {
1043     MethodDefUnit = getOrCreateFile(Method->getLocation());
1044     MethodLine = getLineNumber(Method->getLocation());
1045   }
1046 
1047   // Collect virtual method info.
1048   llvm::DIType ContainingType;
1049   unsigned Virtuality = 0;
1050   unsigned VIndex = 0;
1051 
1052   if (Method->isVirtual()) {
1053     if (Method->isPure())
1054       Virtuality = llvm::dwarf::DW_VIRTUALITY_pure_virtual;
1055     else
1056       Virtuality = llvm::dwarf::DW_VIRTUALITY_virtual;
1057 
1058     // It doesn't make sense to give a virtual destructor a vtable index,
1059     // since a single destructor has two entries in the vtable.
1060     // FIXME: Add proper support for debug info for virtual calls in
1061     // the Microsoft ABI, where we may use multiple vptrs to make a vftable
1062     // lookup if we have multiple or virtual inheritance.
1063     if (!isa<CXXDestructorDecl>(Method) &&
1064         !CGM.getTarget().getCXXABI().isMicrosoft())
1065       VIndex = CGM.getItaniumVTableContext().getMethodVTableIndex(Method);
1066     ContainingType = RecordTy;
1067   }
1068 
1069   unsigned Flags = 0;
1070   if (Method->isImplicit())
1071     Flags |= llvm::DIDescriptor::FlagArtificial;
1072   AccessSpecifier Access = Method->getAccess();
1073   if (Access == clang::AS_private)
1074     Flags |= llvm::DIDescriptor::FlagPrivate;
1075   else if (Access == clang::AS_protected)
1076     Flags |= llvm::DIDescriptor::FlagProtected;
1077   if (const CXXConstructorDecl *CXXC = dyn_cast<CXXConstructorDecl>(Method)) {
1078     if (CXXC->isExplicit())
1079       Flags |= llvm::DIDescriptor::FlagExplicit;
1080   } else if (const CXXConversionDecl *CXXC =
1081              dyn_cast<CXXConversionDecl>(Method)) {
1082     if (CXXC->isExplicit())
1083       Flags |= llvm::DIDescriptor::FlagExplicit;
1084   }
1085   if (Method->hasPrototype())
1086     Flags |= llvm::DIDescriptor::FlagPrototyped;
1087 
1088   llvm::DIArray TParamsArray = CollectFunctionTemplateParams(Method, Unit);
1089   llvm::DISubprogram SP =
1090     DBuilder.createMethod(RecordTy, MethodName, MethodLinkageName,
1091                           MethodDefUnit, MethodLine,
1092                           MethodTy, /*isLocalToUnit=*/false,
1093                           /* isDefinition=*/ false,
1094                           Virtuality, VIndex, ContainingType,
1095                           Flags, CGM.getLangOpts().Optimize, NULL,
1096                           TParamsArray);
1097 
1098   SPCache[Method->getCanonicalDecl()] = llvm::WeakVH(SP);
1099 
1100   return SP;
1101 }
1102 
1103 /// CollectCXXMemberFunctions - A helper function to collect debug info for
1104 /// C++ member functions. This is used while creating debug info entry for
1105 /// a Record.
1106 void CGDebugInfo::
1107 CollectCXXMemberFunctions(const CXXRecordDecl *RD, llvm::DIFile Unit,
1108                           SmallVectorImpl<llvm::Value *> &EltTys,
1109                           llvm::DIType RecordTy) {
1110 
1111   // Since we want more than just the individual member decls if we
1112   // have templated functions iterate over every declaration to gather
1113   // the functions.
1114   for(DeclContext::decl_iterator I = RD->decls_begin(),
1115         E = RD->decls_end(); I != E; ++I) {
1116     if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*I)) {
1117       // Reuse the existing member function declaration if it exists.
1118       // It may be associated with the declaration of the type & should be
1119       // reused as we're building the definition.
1120       //
1121       // This situation can arise in the vtable-based debug info reduction where
1122       // implicit members are emitted in a non-vtable TU.
1123       llvm::DenseMap<const FunctionDecl *, llvm::WeakVH>::iterator MI =
1124           SPCache.find(Method->getCanonicalDecl());
1125       if (MI == SPCache.end()) {
1126         // If the member is implicit, lazily create it when we see the
1127         // definition, not before. (an ODR-used implicit default ctor that's
1128         // never actually code generated should not produce debug info)
1129         if (!Method->isImplicit())
1130           EltTys.push_back(CreateCXXMemberFunction(Method, Unit, RecordTy));
1131       } else
1132         EltTys.push_back(MI->second);
1133     } else if (const FunctionTemplateDecl *FTD =
1134                    dyn_cast<FunctionTemplateDecl>(*I)) {
1135       // Add any template specializations that have already been seen. Like
1136       // implicit member functions, these may have been added to a declaration
1137       // in the case of vtable-based debug info reduction.
1138       for (FunctionTemplateDecl::spec_iterator SI = FTD->spec_begin(),
1139                                                SE = FTD->spec_end();
1140            SI != SE; ++SI) {
1141         llvm::DenseMap<const FunctionDecl *, llvm::WeakVH>::iterator MI =
1142             SPCache.find(cast<CXXMethodDecl>(*SI)->getCanonicalDecl());
1143         if (MI != SPCache.end())
1144           EltTys.push_back(MI->second);
1145       }
1146     }
1147   }
1148 }
1149 
1150 /// CollectCXXBases - A helper function to collect debug info for
1151 /// C++ base classes. This is used while creating debug info entry for
1152 /// a Record.
1153 void CGDebugInfo::
1154 CollectCXXBases(const CXXRecordDecl *RD, llvm::DIFile Unit,
1155                 SmallVectorImpl<llvm::Value *> &EltTys,
1156                 llvm::DIType RecordTy) {
1157 
1158   const ASTRecordLayout &RL = CGM.getContext().getASTRecordLayout(RD);
1159   for (CXXRecordDecl::base_class_const_iterator BI = RD->bases_begin(),
1160          BE = RD->bases_end(); BI != BE; ++BI) {
1161     unsigned BFlags = 0;
1162     uint64_t BaseOffset;
1163 
1164     const CXXRecordDecl *Base =
1165       cast<CXXRecordDecl>(BI->getType()->getAs<RecordType>()->getDecl());
1166 
1167     if (BI->isVirtual()) {
1168       // virtual base offset offset is -ve. The code generator emits dwarf
1169       // expression where it expects +ve number.
1170       BaseOffset =
1171         0 - CGM.getItaniumVTableContext()
1172                .getVirtualBaseOffsetOffset(RD, Base).getQuantity();
1173       BFlags = llvm::DIDescriptor::FlagVirtual;
1174     } else
1175       BaseOffset = CGM.getContext().toBits(RL.getBaseClassOffset(Base));
1176     // FIXME: Inconsistent units for BaseOffset. It is in bytes when
1177     // BI->isVirtual() and bits when not.
1178 
1179     AccessSpecifier Access = BI->getAccessSpecifier();
1180     if (Access == clang::AS_private)
1181       BFlags |= llvm::DIDescriptor::FlagPrivate;
1182     else if (Access == clang::AS_protected)
1183       BFlags |= llvm::DIDescriptor::FlagProtected;
1184 
1185     llvm::DIType DTy =
1186       DBuilder.createInheritance(RecordTy,
1187                                  getOrCreateType(BI->getType(), Unit),
1188                                  BaseOffset, BFlags);
1189     EltTys.push_back(DTy);
1190   }
1191 }
1192 
1193 /// CollectTemplateParams - A helper function to collect template parameters.
1194 llvm::DIArray CGDebugInfo::
1195 CollectTemplateParams(const TemplateParameterList *TPList,
1196                       ArrayRef<TemplateArgument> TAList,
1197                       llvm::DIFile Unit) {
1198   SmallVector<llvm::Value *, 16> TemplateParams;
1199   for (unsigned i = 0, e = TAList.size(); i != e; ++i) {
1200     const TemplateArgument &TA = TAList[i];
1201     StringRef Name;
1202     if (TPList)
1203       Name = TPList->getParam(i)->getName();
1204     switch (TA.getKind()) {
1205     case TemplateArgument::Type: {
1206       llvm::DIType TTy = getOrCreateType(TA.getAsType(), Unit);
1207       llvm::DITemplateTypeParameter TTP =
1208           DBuilder.createTemplateTypeParameter(TheCU, Name, TTy);
1209       TemplateParams.push_back(TTP);
1210     } break;
1211     case TemplateArgument::Integral: {
1212       llvm::DIType TTy = getOrCreateType(TA.getIntegralType(), Unit);
1213       llvm::DITemplateValueParameter TVP =
1214           DBuilder.createTemplateValueParameter(
1215               TheCU, Name, TTy,
1216               llvm::ConstantInt::get(CGM.getLLVMContext(), TA.getAsIntegral()));
1217       TemplateParams.push_back(TVP);
1218     } break;
1219     case TemplateArgument::Declaration: {
1220       const ValueDecl *D = TA.getAsDecl();
1221       bool InstanceMember = D->isCXXInstanceMember();
1222       QualType T = InstanceMember
1223                        ? CGM.getContext().getMemberPointerType(
1224                              D->getType(), cast<RecordDecl>(D->getDeclContext())
1225                                                ->getTypeForDecl())
1226                        : CGM.getContext().getPointerType(D->getType());
1227       llvm::DIType TTy = getOrCreateType(T, Unit);
1228       llvm::Value *V = 0;
1229       // Variable pointer template parameters have a value that is the address
1230       // of the variable.
1231       if (const VarDecl *VD = dyn_cast<VarDecl>(D))
1232         V = CGM.GetAddrOfGlobalVar(VD);
1233       // Member function pointers have special support for building them, though
1234       // this is currently unsupported in LLVM CodeGen.
1235       if (InstanceMember) {
1236         if (const CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(D))
1237           V = CGM.getCXXABI().EmitMemberPointer(method);
1238       } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
1239         V = CGM.GetAddrOfFunction(FD);
1240       // Member data pointers have special handling too to compute the fixed
1241       // offset within the object.
1242       if (isa<FieldDecl>(D)) {
1243         // These five lines (& possibly the above member function pointer
1244         // handling) might be able to be refactored to use similar code in
1245         // CodeGenModule::getMemberPointerConstant
1246         uint64_t fieldOffset = CGM.getContext().getFieldOffset(D);
1247         CharUnits chars =
1248             CGM.getContext().toCharUnitsFromBits((int64_t) fieldOffset);
1249         V = CGM.getCXXABI().EmitMemberDataPointer(
1250             cast<MemberPointerType>(T.getTypePtr()), chars);
1251       }
1252       llvm::DITemplateValueParameter TVP =
1253           DBuilder.createTemplateValueParameter(TheCU, Name, TTy,
1254                                                 V->stripPointerCasts());
1255       TemplateParams.push_back(TVP);
1256     } break;
1257     case TemplateArgument::NullPtr: {
1258       QualType T = TA.getNullPtrType();
1259       llvm::DIType TTy = getOrCreateType(T, Unit);
1260       llvm::Value *V = 0;
1261       // Special case member data pointer null values since they're actually -1
1262       // instead of zero.
1263       if (const MemberPointerType *MPT =
1264               dyn_cast<MemberPointerType>(T.getTypePtr()))
1265         // But treat member function pointers as simple zero integers because
1266         // it's easier than having a special case in LLVM's CodeGen. If LLVM
1267         // CodeGen grows handling for values of non-null member function
1268         // pointers then perhaps we could remove this special case and rely on
1269         // EmitNullMemberPointer for member function pointers.
1270         if (MPT->isMemberDataPointer())
1271           V = CGM.getCXXABI().EmitNullMemberPointer(MPT);
1272       if (!V)
1273         V = llvm::ConstantInt::get(CGM.Int8Ty, 0);
1274       llvm::DITemplateValueParameter TVP =
1275           DBuilder.createTemplateValueParameter(TheCU, Name, TTy, V);
1276       TemplateParams.push_back(TVP);
1277     } break;
1278     case TemplateArgument::Template: {
1279       llvm::DITemplateValueParameter TVP =
1280           DBuilder.createTemplateTemplateParameter(
1281               TheCU, Name, llvm::DIType(),
1282               TA.getAsTemplate().getAsTemplateDecl()
1283                   ->getQualifiedNameAsString());
1284       TemplateParams.push_back(TVP);
1285     } break;
1286     case TemplateArgument::Pack: {
1287       llvm::DITemplateValueParameter TVP =
1288           DBuilder.createTemplateParameterPack(
1289               TheCU, Name, llvm::DIType(),
1290               CollectTemplateParams(NULL, TA.getPackAsArray(), Unit));
1291       TemplateParams.push_back(TVP);
1292     } break;
1293     case TemplateArgument::Expression: {
1294       const Expr *E = TA.getAsExpr();
1295       QualType T = E->getType();
1296       llvm::Value *V = CGM.EmitConstantExpr(E, T);
1297       assert(V && "Expression in template argument isn't constant");
1298       llvm::DIType TTy = getOrCreateType(T, Unit);
1299       llvm::DITemplateValueParameter TVP =
1300           DBuilder.createTemplateValueParameter(TheCU, Name, TTy,
1301                                                 V->stripPointerCasts());
1302       TemplateParams.push_back(TVP);
1303     } break;
1304     // And the following should never occur:
1305     case TemplateArgument::TemplateExpansion:
1306     case TemplateArgument::Null:
1307       llvm_unreachable(
1308           "These argument types shouldn't exist in concrete types");
1309     }
1310   }
1311   return DBuilder.getOrCreateArray(TemplateParams);
1312 }
1313 
1314 /// CollectFunctionTemplateParams - A helper function to collect debug
1315 /// info for function template parameters.
1316 llvm::DIArray CGDebugInfo::
1317 CollectFunctionTemplateParams(const FunctionDecl *FD, llvm::DIFile Unit) {
1318   if (FD->getTemplatedKind() ==
1319       FunctionDecl::TK_FunctionTemplateSpecialization) {
1320     const TemplateParameterList *TList =
1321       FD->getTemplateSpecializationInfo()->getTemplate()
1322       ->getTemplateParameters();
1323     return CollectTemplateParams(
1324         TList, FD->getTemplateSpecializationArgs()->asArray(), Unit);
1325   }
1326   return llvm::DIArray();
1327 }
1328 
1329 /// CollectCXXTemplateParams - A helper function to collect debug info for
1330 /// template parameters.
1331 llvm::DIArray CGDebugInfo::
1332 CollectCXXTemplateParams(const ClassTemplateSpecializationDecl *TSpecial,
1333                          llvm::DIFile Unit) {
1334   llvm::PointerUnion<ClassTemplateDecl *,
1335                      ClassTemplatePartialSpecializationDecl *>
1336     PU = TSpecial->getSpecializedTemplateOrPartial();
1337 
1338   TemplateParameterList *TPList = PU.is<ClassTemplateDecl *>() ?
1339     PU.get<ClassTemplateDecl *>()->getTemplateParameters() :
1340     PU.get<ClassTemplatePartialSpecializationDecl *>()->getTemplateParameters();
1341   const TemplateArgumentList &TAList = TSpecial->getTemplateInstantiationArgs();
1342   return CollectTemplateParams(TPList, TAList.asArray(), Unit);
1343 }
1344 
1345 /// getOrCreateVTablePtrType - Return debug info descriptor for vtable.
1346 llvm::DIType CGDebugInfo::getOrCreateVTablePtrType(llvm::DIFile Unit) {
1347   if (VTablePtrType.isValid())
1348     return VTablePtrType;
1349 
1350   ASTContext &Context = CGM.getContext();
1351 
1352   /* Function type */
1353   llvm::Value *STy = getOrCreateType(Context.IntTy, Unit);
1354   llvm::DIArray SElements = DBuilder.getOrCreateArray(STy);
1355   llvm::DIType SubTy = DBuilder.createSubroutineType(Unit, SElements);
1356   unsigned Size = Context.getTypeSize(Context.VoidPtrTy);
1357   llvm::DIType vtbl_ptr_type = DBuilder.createPointerType(SubTy, Size, 0,
1358                                                           "__vtbl_ptr_type");
1359   VTablePtrType = DBuilder.createPointerType(vtbl_ptr_type, Size);
1360   return VTablePtrType;
1361 }
1362 
1363 /// getVTableName - Get vtable name for the given Class.
1364 StringRef CGDebugInfo::getVTableName(const CXXRecordDecl *RD) {
1365   // Copy the gdb compatible name on the side and use its reference.
1366   return internString("_vptr$", RD->getNameAsString());
1367 }
1368 
1369 
1370 /// CollectVTableInfo - If the C++ class has vtable info then insert appropriate
1371 /// debug info entry in EltTys vector.
1372 void CGDebugInfo::
1373 CollectVTableInfo(const CXXRecordDecl *RD, llvm::DIFile Unit,
1374                   SmallVectorImpl<llvm::Value *> &EltTys) {
1375   const ASTRecordLayout &RL = CGM.getContext().getASTRecordLayout(RD);
1376 
1377   // If there is a primary base then it will hold vtable info.
1378   if (RL.getPrimaryBase())
1379     return;
1380 
1381   // If this class is not dynamic then there is not any vtable info to collect.
1382   if (!RD->isDynamicClass())
1383     return;
1384 
1385   unsigned Size = CGM.getContext().getTypeSize(CGM.getContext().VoidPtrTy);
1386   llvm::DIType VPTR
1387     = DBuilder.createMemberType(Unit, getVTableName(RD), Unit,
1388                                 0, Size, 0, 0,
1389                                 llvm::DIDescriptor::FlagArtificial,
1390                                 getOrCreateVTablePtrType(Unit));
1391   EltTys.push_back(VPTR);
1392 }
1393 
1394 /// getOrCreateRecordType - Emit record type's standalone debug info.
1395 llvm::DIType CGDebugInfo::getOrCreateRecordType(QualType RTy,
1396                                                 SourceLocation Loc) {
1397   assert(DebugKind >= CodeGenOptions::LimitedDebugInfo);
1398   llvm::DIType T = getOrCreateType(RTy, getOrCreateFile(Loc));
1399   return T;
1400 }
1401 
1402 /// getOrCreateInterfaceType - Emit an objective c interface type standalone
1403 /// debug info.
1404 llvm::DIType CGDebugInfo::getOrCreateInterfaceType(QualType D,
1405                                                    SourceLocation Loc) {
1406   assert(DebugKind >= CodeGenOptions::LimitedDebugInfo);
1407   llvm::DIType T = getOrCreateType(D, getOrCreateFile(Loc));
1408   RetainedTypes.push_back(D.getAsOpaquePtr());
1409   return T;
1410 }
1411 
1412 void CGDebugInfo::completeType(const RecordDecl *RD) {
1413   if (DebugKind > CodeGenOptions::LimitedDebugInfo ||
1414       !CGM.getLangOpts().CPlusPlus)
1415     completeRequiredType(RD);
1416 }
1417 
1418 void CGDebugInfo::completeRequiredType(const RecordDecl *RD) {
1419   if (const CXXRecordDecl *CXXDecl = dyn_cast<CXXRecordDecl>(RD))
1420     if (CXXDecl->isDynamicClass())
1421       return;
1422 
1423   QualType Ty = CGM.getContext().getRecordType(RD);
1424   llvm::DIType T = getTypeOrNull(Ty);
1425   if (T && T.isForwardDecl())
1426     completeClassData(RD);
1427 }
1428 
1429 void CGDebugInfo::completeClassData(const RecordDecl *RD) {
1430   if (DebugKind <= CodeGenOptions::DebugLineTablesOnly)
1431     return;
1432   QualType Ty = CGM.getContext().getRecordType(RD);
1433   void* TyPtr = Ty.getAsOpaquePtr();
1434   if (CompletedTypeCache.count(TyPtr))
1435     return;
1436   llvm::DIType Res = CreateTypeDefinition(Ty->castAs<RecordType>());
1437   assert(!Res.isForwardDecl());
1438   CompletedTypeCache[TyPtr] = Res;
1439   TypeCache[TyPtr] = Res;
1440 }
1441 
1442 /// CreateType - get structure or union type.
1443 llvm::DIType CGDebugInfo::CreateType(const RecordType *Ty) {
1444   RecordDecl *RD = Ty->getDecl();
1445   const CXXRecordDecl *CXXDecl = dyn_cast<CXXRecordDecl>(RD);
1446   // Always emit declarations for types that aren't required to be complete when
1447   // in limit-debug-info mode. If the type is later found to be required to be
1448   // complete this declaration will be upgraded to a definition by
1449   // `completeRequiredType`.
1450   // If the type is dynamic, only emit the definition in TUs that require class
1451   // data. This is handled by `completeClassData`.
1452   llvm::DICompositeType T(getTypeOrNull(QualType(Ty, 0)));
1453   // If we've already emitted the type, just use that, even if it's only a
1454   // declaration. The completeType, completeRequiredType, and completeClassData
1455   // callbacks will handle promoting the declaration to a definition.
1456   if (T ||
1457       (DebugKind <= CodeGenOptions::LimitedDebugInfo &&
1458        // Under -flimit-debug-info, emit only a declaration unless the type is
1459        // required to be complete.
1460        !RD->isCompleteDefinitionRequired() && CGM.getLangOpts().CPlusPlus) ||
1461       // If the class is dynamic, only emit a declaration. A definition will be
1462       // emitted whenever the vtable is emitted.
1463       (CXXDecl && CXXDecl->hasDefinition() && CXXDecl->isDynamicClass()) || T) {
1464     llvm::DIDescriptor FDContext =
1465       getContextDescriptor(cast<Decl>(RD->getDeclContext()));
1466     if (!T)
1467       T = getOrCreateRecordFwdDecl(Ty, FDContext);
1468     return T;
1469   }
1470 
1471   return CreateTypeDefinition(Ty);
1472 }
1473 
1474 llvm::DIType CGDebugInfo::CreateTypeDefinition(const RecordType *Ty) {
1475   RecordDecl *RD = Ty->getDecl();
1476 
1477   // Get overall information about the record type for the debug info.
1478   llvm::DIFile DefUnit = getOrCreateFile(RD->getLocation());
1479 
1480   // Records and classes and unions can all be recursive.  To handle them, we
1481   // first generate a debug descriptor for the struct as a forward declaration.
1482   // Then (if it is a definition) we go through and get debug info for all of
1483   // its members.  Finally, we create a descriptor for the complete type (which
1484   // may refer to the forward decl if the struct is recursive) and replace all
1485   // uses of the forward declaration with the final definition.
1486 
1487   llvm::DICompositeType FwdDecl(getOrCreateLimitedType(Ty, DefUnit));
1488   assert(FwdDecl.isCompositeType() &&
1489          "The debug type of a RecordType should be a llvm::DICompositeType");
1490 
1491   if (FwdDecl.isForwardDecl())
1492     return FwdDecl;
1493 
1494   if (const CXXRecordDecl *CXXDecl = dyn_cast<CXXRecordDecl>(RD))
1495     CollectContainingType(CXXDecl, FwdDecl);
1496 
1497   // Push the struct on region stack.
1498   LexicalBlockStack.push_back(&*FwdDecl);
1499   RegionMap[Ty->getDecl()] = llvm::WeakVH(FwdDecl);
1500 
1501   // Add this to the completed-type cache while we're completing it recursively.
1502   CompletedTypeCache[QualType(Ty, 0).getAsOpaquePtr()] = FwdDecl;
1503 
1504   // Convert all the elements.
1505   SmallVector<llvm::Value *, 16> EltTys;
1506   // what about nested types?
1507 
1508   // Note: The split of CXXDecl information here is intentional, the
1509   // gdb tests will depend on a certain ordering at printout. The debug
1510   // information offsets are still correct if we merge them all together
1511   // though.
1512   const CXXRecordDecl *CXXDecl = dyn_cast<CXXRecordDecl>(RD);
1513   if (CXXDecl) {
1514     CollectCXXBases(CXXDecl, DefUnit, EltTys, FwdDecl);
1515     CollectVTableInfo(CXXDecl, DefUnit, EltTys);
1516   }
1517 
1518   // Collect data fields (including static variables and any initializers).
1519   CollectRecordFields(RD, DefUnit, EltTys, FwdDecl);
1520   if (CXXDecl)
1521     CollectCXXMemberFunctions(CXXDecl, DefUnit, EltTys, FwdDecl);
1522 
1523   LexicalBlockStack.pop_back();
1524   RegionMap.erase(Ty->getDecl());
1525 
1526   llvm::DIArray Elements = DBuilder.getOrCreateArray(EltTys);
1527   FwdDecl.setTypeArray(Elements);
1528 
1529   RegionMap[Ty->getDecl()] = llvm::WeakVH(FwdDecl);
1530   return FwdDecl;
1531 }
1532 
1533 /// CreateType - get objective-c object type.
1534 llvm::DIType CGDebugInfo::CreateType(const ObjCObjectType *Ty,
1535                                      llvm::DIFile Unit) {
1536   // Ignore protocols.
1537   return getOrCreateType(Ty->getBaseType(), Unit);
1538 }
1539 
1540 
1541 /// \return true if Getter has the default name for the property PD.
1542 static bool hasDefaultGetterName(const ObjCPropertyDecl *PD,
1543                                  const ObjCMethodDecl *Getter) {
1544   assert(PD);
1545   if (!Getter)
1546     return true;
1547 
1548   assert(Getter->getDeclName().isObjCZeroArgSelector());
1549   return PD->getName() ==
1550     Getter->getDeclName().getObjCSelector().getNameForSlot(0);
1551 }
1552 
1553 /// \return true if Setter has the default name for the property PD.
1554 static bool hasDefaultSetterName(const ObjCPropertyDecl *PD,
1555                                  const ObjCMethodDecl *Setter) {
1556   assert(PD);
1557   if (!Setter)
1558     return true;
1559 
1560   assert(Setter->getDeclName().isObjCOneArgSelector());
1561   return SelectorTable::constructSetterName(PD->getName()) ==
1562     Setter->getDeclName().getObjCSelector().getNameForSlot(0);
1563 }
1564 
1565 /// CreateType - get objective-c interface type.
1566 llvm::DIType CGDebugInfo::CreateType(const ObjCInterfaceType *Ty,
1567                                      llvm::DIFile Unit) {
1568   ObjCInterfaceDecl *ID = Ty->getDecl();
1569   if (!ID)
1570     return llvm::DIType();
1571 
1572   // Get overall information about the record type for the debug info.
1573   llvm::DIFile DefUnit = getOrCreateFile(ID->getLocation());
1574   unsigned Line = getLineNumber(ID->getLocation());
1575   unsigned RuntimeLang = TheCU.getLanguage();
1576 
1577   // If this is just a forward declaration return a special forward-declaration
1578   // debug type since we won't be able to lay out the entire type.
1579   ObjCInterfaceDecl *Def = ID->getDefinition();
1580   if (!Def) {
1581     llvm::DIType FwdDecl =
1582       DBuilder.createForwardDecl(llvm::dwarf::DW_TAG_structure_type,
1583                                  ID->getName(), TheCU, DefUnit, Line,
1584                                  RuntimeLang);
1585     return FwdDecl;
1586   }
1587 
1588   ID = Def;
1589 
1590   // Bit size, align and offset of the type.
1591   uint64_t Size = CGM.getContext().getTypeSize(Ty);
1592   uint64_t Align = CGM.getContext().getTypeAlign(Ty);
1593 
1594   unsigned Flags = 0;
1595   if (ID->getImplementation())
1596     Flags |= llvm::DIDescriptor::FlagObjcClassComplete;
1597 
1598   llvm::DICompositeType RealDecl =
1599     DBuilder.createStructType(Unit, ID->getName(), DefUnit,
1600                               Line, Size, Align, Flags,
1601                               llvm::DIType(), llvm::DIArray(), RuntimeLang);
1602 
1603   // Otherwise, insert it into the CompletedTypeCache so that recursive uses
1604   // will find it and we're emitting the complete type.
1605   QualType QualTy = QualType(Ty, 0);
1606   CompletedTypeCache[QualTy.getAsOpaquePtr()] = RealDecl;
1607 
1608   // Push the struct on region stack.
1609   LexicalBlockStack.push_back(static_cast<llvm::MDNode*>(RealDecl));
1610   RegionMap[Ty->getDecl()] = llvm::WeakVH(RealDecl);
1611 
1612   // Convert all the elements.
1613   SmallVector<llvm::Value *, 16> EltTys;
1614 
1615   ObjCInterfaceDecl *SClass = ID->getSuperClass();
1616   if (SClass) {
1617     llvm::DIType SClassTy =
1618       getOrCreateType(CGM.getContext().getObjCInterfaceType(SClass), Unit);
1619     if (!SClassTy.isValid())
1620       return llvm::DIType();
1621 
1622     llvm::DIType InhTag =
1623       DBuilder.createInheritance(RealDecl, SClassTy, 0, 0);
1624     EltTys.push_back(InhTag);
1625   }
1626 
1627   // Create entries for all of the properties.
1628   for (ObjCContainerDecl::prop_iterator I = ID->prop_begin(),
1629          E = ID->prop_end(); I != E; ++I) {
1630     const ObjCPropertyDecl *PD = *I;
1631     SourceLocation Loc = PD->getLocation();
1632     llvm::DIFile PUnit = getOrCreateFile(Loc);
1633     unsigned PLine = getLineNumber(Loc);
1634     ObjCMethodDecl *Getter = PD->getGetterMethodDecl();
1635     ObjCMethodDecl *Setter = PD->getSetterMethodDecl();
1636     llvm::MDNode *PropertyNode =
1637       DBuilder.createObjCProperty(PD->getName(),
1638                                   PUnit, PLine,
1639                                   hasDefaultGetterName(PD, Getter) ? "" :
1640                                   getSelectorName(PD->getGetterName()),
1641                                   hasDefaultSetterName(PD, Setter) ? "" :
1642                                   getSelectorName(PD->getSetterName()),
1643                                   PD->getPropertyAttributes(),
1644                                   getOrCreateType(PD->getType(), PUnit));
1645     EltTys.push_back(PropertyNode);
1646   }
1647 
1648   const ASTRecordLayout &RL = CGM.getContext().getASTObjCInterfaceLayout(ID);
1649   unsigned FieldNo = 0;
1650   for (ObjCIvarDecl *Field = ID->all_declared_ivar_begin(); Field;
1651        Field = Field->getNextIvar(), ++FieldNo) {
1652     llvm::DIType FieldTy = getOrCreateType(Field->getType(), Unit);
1653     if (!FieldTy.isValid())
1654       return llvm::DIType();
1655 
1656     StringRef FieldName = Field->getName();
1657 
1658     // Ignore unnamed fields.
1659     if (FieldName.empty())
1660       continue;
1661 
1662     // Get the location for the field.
1663     llvm::DIFile FieldDefUnit = getOrCreateFile(Field->getLocation());
1664     unsigned FieldLine = getLineNumber(Field->getLocation());
1665     QualType FType = Field->getType();
1666     uint64_t FieldSize = 0;
1667     unsigned FieldAlign = 0;
1668 
1669     if (!FType->isIncompleteArrayType()) {
1670 
1671       // Bit size, align and offset of the type.
1672       FieldSize = Field->isBitField()
1673                       ? Field->getBitWidthValue(CGM.getContext())
1674                       : CGM.getContext().getTypeSize(FType);
1675       FieldAlign = CGM.getContext().getTypeAlign(FType);
1676     }
1677 
1678     uint64_t FieldOffset;
1679     if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
1680       // We don't know the runtime offset of an ivar if we're using the
1681       // non-fragile ABI.  For bitfields, use the bit offset into the first
1682       // byte of storage of the bitfield.  For other fields, use zero.
1683       if (Field->isBitField()) {
1684         FieldOffset = CGM.getObjCRuntime().ComputeBitfieldBitOffset(
1685             CGM, ID, Field);
1686         FieldOffset %= CGM.getContext().getCharWidth();
1687       } else {
1688         FieldOffset = 0;
1689       }
1690     } else {
1691       FieldOffset = RL.getFieldOffset(FieldNo);
1692     }
1693 
1694     unsigned Flags = 0;
1695     if (Field->getAccessControl() == ObjCIvarDecl::Protected)
1696       Flags = llvm::DIDescriptor::FlagProtected;
1697     else if (Field->getAccessControl() == ObjCIvarDecl::Private)
1698       Flags = llvm::DIDescriptor::FlagPrivate;
1699 
1700     llvm::MDNode *PropertyNode = NULL;
1701     if (ObjCImplementationDecl *ImpD = ID->getImplementation()) {
1702       if (ObjCPropertyImplDecl *PImpD =
1703           ImpD->FindPropertyImplIvarDecl(Field->getIdentifier())) {
1704         if (ObjCPropertyDecl *PD = PImpD->getPropertyDecl()) {
1705           SourceLocation Loc = PD->getLocation();
1706           llvm::DIFile PUnit = getOrCreateFile(Loc);
1707           unsigned PLine = getLineNumber(Loc);
1708           ObjCMethodDecl *Getter = PD->getGetterMethodDecl();
1709           ObjCMethodDecl *Setter = PD->getSetterMethodDecl();
1710           PropertyNode =
1711             DBuilder.createObjCProperty(PD->getName(),
1712                                         PUnit, PLine,
1713                                         hasDefaultGetterName(PD, Getter) ? "" :
1714                                         getSelectorName(PD->getGetterName()),
1715                                         hasDefaultSetterName(PD, Setter) ? "" :
1716                                         getSelectorName(PD->getSetterName()),
1717                                         PD->getPropertyAttributes(),
1718                                         getOrCreateType(PD->getType(), PUnit));
1719         }
1720       }
1721     }
1722     FieldTy = DBuilder.createObjCIVar(FieldName, FieldDefUnit,
1723                                       FieldLine, FieldSize, FieldAlign,
1724                                       FieldOffset, Flags, FieldTy,
1725                                       PropertyNode);
1726     EltTys.push_back(FieldTy);
1727   }
1728 
1729   llvm::DIArray Elements = DBuilder.getOrCreateArray(EltTys);
1730   RealDecl.setTypeArray(Elements);
1731 
1732   // If the implementation is not yet set, we do not want to mark it
1733   // as complete. An implementation may declare additional
1734   // private ivars that we would miss otherwise.
1735   if (ID->getImplementation() == 0)
1736     CompletedTypeCache.erase(QualTy.getAsOpaquePtr());
1737 
1738   LexicalBlockStack.pop_back();
1739   return RealDecl;
1740 }
1741 
1742 llvm::DIType CGDebugInfo::CreateType(const VectorType *Ty, llvm::DIFile Unit) {
1743   llvm::DIType ElementTy = getOrCreateType(Ty->getElementType(), Unit);
1744   int64_t Count = Ty->getNumElements();
1745   if (Count == 0)
1746     // If number of elements are not known then this is an unbounded array.
1747     // Use Count == -1 to express such arrays.
1748     Count = -1;
1749 
1750   llvm::Value *Subscript = DBuilder.getOrCreateSubrange(0, Count);
1751   llvm::DIArray SubscriptArray = DBuilder.getOrCreateArray(Subscript);
1752 
1753   uint64_t Size = CGM.getContext().getTypeSize(Ty);
1754   uint64_t Align = CGM.getContext().getTypeAlign(Ty);
1755 
1756   return DBuilder.createVectorType(Size, Align, ElementTy, SubscriptArray);
1757 }
1758 
1759 llvm::DIType CGDebugInfo::CreateType(const ArrayType *Ty,
1760                                      llvm::DIFile Unit) {
1761   uint64_t Size;
1762   uint64_t Align;
1763 
1764   // FIXME: make getTypeAlign() aware of VLAs and incomplete array types
1765   if (const VariableArrayType *VAT = dyn_cast<VariableArrayType>(Ty)) {
1766     Size = 0;
1767     Align =
1768       CGM.getContext().getTypeAlign(CGM.getContext().getBaseElementType(VAT));
1769   } else if (Ty->isIncompleteArrayType()) {
1770     Size = 0;
1771     if (Ty->getElementType()->isIncompleteType())
1772       Align = 0;
1773     else
1774       Align = CGM.getContext().getTypeAlign(Ty->getElementType());
1775   } else if (Ty->isIncompleteType()) {
1776     Size = 0;
1777     Align = 0;
1778   } else {
1779     // Size and align of the whole array, not the element type.
1780     Size = CGM.getContext().getTypeSize(Ty);
1781     Align = CGM.getContext().getTypeAlign(Ty);
1782   }
1783 
1784   // Add the dimensions of the array.  FIXME: This loses CV qualifiers from
1785   // interior arrays, do we care?  Why aren't nested arrays represented the
1786   // obvious/recursive way?
1787   SmallVector<llvm::Value *, 8> Subscripts;
1788   QualType EltTy(Ty, 0);
1789   while ((Ty = dyn_cast<ArrayType>(EltTy))) {
1790     // If the number of elements is known, then count is that number. Otherwise,
1791     // it's -1. This allows us to represent a subrange with an array of 0
1792     // elements, like this:
1793     //
1794     //   struct foo {
1795     //     int x[0];
1796     //   };
1797     int64_t Count = -1;         // Count == -1 is an unbounded array.
1798     if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(Ty))
1799       Count = CAT->getSize().getZExtValue();
1800 
1801     // FIXME: Verify this is right for VLAs.
1802     Subscripts.push_back(DBuilder.getOrCreateSubrange(0, Count));
1803     EltTy = Ty->getElementType();
1804   }
1805 
1806   llvm::DIArray SubscriptArray = DBuilder.getOrCreateArray(Subscripts);
1807 
1808   llvm::DIType DbgTy =
1809     DBuilder.createArrayType(Size, Align, getOrCreateType(EltTy, Unit),
1810                              SubscriptArray);
1811   return DbgTy;
1812 }
1813 
1814 llvm::DIType CGDebugInfo::CreateType(const LValueReferenceType *Ty,
1815                                      llvm::DIFile Unit) {
1816   return CreatePointerLikeType(llvm::dwarf::DW_TAG_reference_type,
1817                                Ty, Ty->getPointeeType(), Unit);
1818 }
1819 
1820 llvm::DIType CGDebugInfo::CreateType(const RValueReferenceType *Ty,
1821                                      llvm::DIFile Unit) {
1822   return CreatePointerLikeType(llvm::dwarf::DW_TAG_rvalue_reference_type,
1823                                Ty, Ty->getPointeeType(), Unit);
1824 }
1825 
1826 llvm::DIType CGDebugInfo::CreateType(const MemberPointerType *Ty,
1827                                      llvm::DIFile U) {
1828   llvm::DIType ClassType = getOrCreateType(QualType(Ty->getClass(), 0), U);
1829   if (!Ty->getPointeeType()->isFunctionType())
1830     return DBuilder.createMemberPointerType(
1831         getOrCreateType(Ty->getPointeeType(), U), ClassType);
1832   return DBuilder.createMemberPointerType(getOrCreateInstanceMethodType(
1833       CGM.getContext().getPointerType(
1834           QualType(Ty->getClass(), Ty->getPointeeType().getCVRQualifiers())),
1835       Ty->getPointeeType()->getAs<FunctionProtoType>(), U),
1836                                           ClassType);
1837 }
1838 
1839 llvm::DIType CGDebugInfo::CreateType(const AtomicType *Ty,
1840                                      llvm::DIFile U) {
1841   // Ignore the atomic wrapping
1842   // FIXME: What is the correct representation?
1843   return getOrCreateType(Ty->getValueType(), U);
1844 }
1845 
1846 /// CreateEnumType - get enumeration type.
1847 llvm::DIType CGDebugInfo::CreateEnumType(const EnumType *Ty) {
1848   const EnumDecl *ED = Ty->getDecl();
1849   uint64_t Size = 0;
1850   uint64_t Align = 0;
1851   if (!ED->getTypeForDecl()->isIncompleteType()) {
1852     Size = CGM.getContext().getTypeSize(ED->getTypeForDecl());
1853     Align = CGM.getContext().getTypeAlign(ED->getTypeForDecl());
1854   }
1855 
1856   SmallString<256> FullName = getUniqueTagTypeName(Ty, CGM, TheCU);
1857 
1858   // If this is just a forward declaration, construct an appropriately
1859   // marked node and just return it.
1860   if (!ED->getDefinition()) {
1861     llvm::DIDescriptor EDContext;
1862     EDContext = getContextDescriptor(cast<Decl>(ED->getDeclContext()));
1863     llvm::DIFile DefUnit = getOrCreateFile(ED->getLocation());
1864     unsigned Line = getLineNumber(ED->getLocation());
1865     StringRef EDName = ED->getName();
1866     return DBuilder.createForwardDecl(llvm::dwarf::DW_TAG_enumeration_type,
1867                                       EDName, EDContext, DefUnit, Line, 0,
1868                                       Size, Align, FullName);
1869   }
1870 
1871   // Create DIEnumerator elements for each enumerator.
1872   SmallVector<llvm::Value *, 16> Enumerators;
1873   ED = ED->getDefinition();
1874   for (EnumDecl::enumerator_iterator
1875          Enum = ED->enumerator_begin(), EnumEnd = ED->enumerator_end();
1876        Enum != EnumEnd; ++Enum) {
1877     Enumerators.push_back(
1878       DBuilder.createEnumerator(Enum->getName(),
1879                                 Enum->getInitVal().getSExtValue()));
1880   }
1881 
1882   // Return a CompositeType for the enum itself.
1883   llvm::DIArray EltArray = DBuilder.getOrCreateArray(Enumerators);
1884 
1885   llvm::DIFile DefUnit = getOrCreateFile(ED->getLocation());
1886   unsigned Line = getLineNumber(ED->getLocation());
1887   llvm::DIDescriptor EnumContext =
1888     getContextDescriptor(cast<Decl>(ED->getDeclContext()));
1889   llvm::DIType ClassTy = ED->isFixed() ?
1890     getOrCreateType(ED->getIntegerType(), DefUnit) : llvm::DIType();
1891   llvm::DIType DbgTy =
1892     DBuilder.createEnumerationType(EnumContext, ED->getName(), DefUnit, Line,
1893                                    Size, Align, EltArray,
1894                                    ClassTy, FullName);
1895   return DbgTy;
1896 }
1897 
1898 static QualType UnwrapTypeForDebugInfo(QualType T, const ASTContext &C) {
1899   Qualifiers Quals;
1900   do {
1901     Qualifiers InnerQuals = T.getLocalQualifiers();
1902     // Qualifiers::operator+() doesn't like it if you add a Qualifier
1903     // that is already there.
1904     Quals += Qualifiers::removeCommonQualifiers(Quals, InnerQuals);
1905     Quals += InnerQuals;
1906     QualType LastT = T;
1907     switch (T->getTypeClass()) {
1908     default:
1909       return C.getQualifiedType(T.getTypePtr(), Quals);
1910     case Type::TemplateSpecialization:
1911       T = cast<TemplateSpecializationType>(T)->desugar();
1912       break;
1913     case Type::TypeOfExpr:
1914       T = cast<TypeOfExprType>(T)->getUnderlyingExpr()->getType();
1915       break;
1916     case Type::TypeOf:
1917       T = cast<TypeOfType>(T)->getUnderlyingType();
1918       break;
1919     case Type::Decltype:
1920       T = cast<DecltypeType>(T)->getUnderlyingType();
1921       break;
1922     case Type::UnaryTransform:
1923       T = cast<UnaryTransformType>(T)->getUnderlyingType();
1924       break;
1925     case Type::Attributed:
1926       T = cast<AttributedType>(T)->getEquivalentType();
1927       break;
1928     case Type::Elaborated:
1929       T = cast<ElaboratedType>(T)->getNamedType();
1930       break;
1931     case Type::Paren:
1932       T = cast<ParenType>(T)->getInnerType();
1933       break;
1934     case Type::SubstTemplateTypeParm:
1935       T = cast<SubstTemplateTypeParmType>(T)->getReplacementType();
1936       break;
1937     case Type::Auto:
1938       QualType DT = cast<AutoType>(T)->getDeducedType();
1939       if (DT.isNull())
1940         return T;
1941       T = DT;
1942       break;
1943     }
1944 
1945     assert(T != LastT && "Type unwrapping failed to unwrap!");
1946     (void)LastT;
1947   } while (true);
1948 }
1949 
1950 /// getType - Get the type from the cache or return null type if it doesn't
1951 /// exist.
1952 llvm::DIType CGDebugInfo::getTypeOrNull(QualType Ty) {
1953 
1954   // Unwrap the type as needed for debug information.
1955   Ty = UnwrapTypeForDebugInfo(Ty, CGM.getContext());
1956 
1957   // Check for existing entry.
1958   if (Ty->getTypeClass() == Type::ObjCInterface) {
1959     llvm::Value *V = getCachedInterfaceTypeOrNull(Ty);
1960     if (V)
1961       return llvm::DIType(cast<llvm::MDNode>(V));
1962     else return llvm::DIType();
1963   }
1964 
1965   llvm::DenseMap<void *, llvm::WeakVH>::iterator it =
1966     TypeCache.find(Ty.getAsOpaquePtr());
1967   if (it != TypeCache.end()) {
1968     // Verify that the debug info still exists.
1969     if (llvm::Value *V = it->second)
1970       return llvm::DIType(cast<llvm::MDNode>(V));
1971   }
1972 
1973   return llvm::DIType();
1974 }
1975 
1976 /// getCompletedTypeOrNull - Get the type from the cache or return null if it
1977 /// doesn't exist.
1978 llvm::DIType CGDebugInfo::getCompletedTypeOrNull(QualType Ty) {
1979 
1980   // Unwrap the type as needed for debug information.
1981   Ty = UnwrapTypeForDebugInfo(Ty, CGM.getContext());
1982 
1983   // Check for existing entry.
1984   llvm::Value *V = 0;
1985   llvm::DenseMap<void *, llvm::WeakVH>::iterator it =
1986     CompletedTypeCache.find(Ty.getAsOpaquePtr());
1987   if (it != CompletedTypeCache.end())
1988     V = it->second;
1989   else {
1990     V = getCachedInterfaceTypeOrNull(Ty);
1991   }
1992 
1993   // Verify that any cached debug info still exists.
1994   return llvm::DIType(cast_or_null<llvm::MDNode>(V));
1995 }
1996 
1997 /// getCachedInterfaceTypeOrNull - Get the type from the interface
1998 /// cache, unless it needs to regenerated. Otherwise return null.
1999 llvm::Value *CGDebugInfo::getCachedInterfaceTypeOrNull(QualType Ty) {
2000   // Is there a cached interface that hasn't changed?
2001   llvm::DenseMap<void *, std::pair<llvm::WeakVH, unsigned > >
2002     ::iterator it1 = ObjCInterfaceCache.find(Ty.getAsOpaquePtr());
2003 
2004   if (it1 != ObjCInterfaceCache.end())
2005     if (ObjCInterfaceDecl* Decl = getObjCInterfaceDecl(Ty))
2006       if (Checksum(Decl) == it1->second.second)
2007         // Return cached forward declaration.
2008         return it1->second.first;
2009 
2010   return 0;
2011 }
2012 
2013 /// getOrCreateType - Get the type from the cache or create a new
2014 /// one if necessary.
2015 llvm::DIType CGDebugInfo::getOrCreateType(QualType Ty, llvm::DIFile Unit) {
2016   if (Ty.isNull())
2017     return llvm::DIType();
2018 
2019   // Unwrap the type as needed for debug information.
2020   Ty = UnwrapTypeForDebugInfo(Ty, CGM.getContext());
2021 
2022   if (llvm::DIType T = getCompletedTypeOrNull(Ty))
2023     return T;
2024 
2025   // Otherwise create the type.
2026   llvm::DIType Res = CreateTypeNode(Ty, Unit);
2027   void* TyPtr = Ty.getAsOpaquePtr();
2028 
2029   // And update the type cache.
2030   TypeCache[TyPtr] = Res;
2031 
2032   // FIXME: this getTypeOrNull call seems silly when we just inserted the type
2033   // into the cache - but getTypeOrNull has a special case for cached interface
2034   // types. We should probably just pull that out as a special case for the
2035   // "else" block below & skip the otherwise needless lookup.
2036   llvm::DIType TC = getTypeOrNull(Ty);
2037   if (TC && TC.isForwardDecl())
2038     ReplaceMap.push_back(std::make_pair(TyPtr, static_cast<llvm::Value*>(TC)));
2039   else if (ObjCInterfaceDecl* Decl = getObjCInterfaceDecl(Ty)) {
2040     // Interface types may have elements added to them by a
2041     // subsequent implementation or extension, so we keep them in
2042     // the ObjCInterfaceCache together with a checksum. Instead of
2043     // the (possibly) incomplete interface type, we return a forward
2044     // declaration that gets RAUW'd in CGDebugInfo::finalize().
2045     std::pair<llvm::WeakVH, unsigned> &V = ObjCInterfaceCache[TyPtr];
2046     if (V.first)
2047       return llvm::DIType(cast<llvm::MDNode>(V.first));
2048     TC = DBuilder.createForwardDecl(llvm::dwarf::DW_TAG_structure_type,
2049                                     Decl->getName(), TheCU, Unit,
2050                                     getLineNumber(Decl->getLocation()),
2051                                     TheCU.getLanguage());
2052     // Store the forward declaration in the cache.
2053     V.first = TC;
2054     V.second = Checksum(Decl);
2055 
2056     // Register the type for replacement in finalize().
2057     ReplaceMap.push_back(std::make_pair(TyPtr, static_cast<llvm::Value*>(TC)));
2058 
2059     return TC;
2060   }
2061 
2062   if (!Res.isForwardDecl())
2063     CompletedTypeCache[TyPtr] = Res;
2064 
2065   return Res;
2066 }
2067 
2068 /// Currently the checksum of an interface includes the number of
2069 /// ivars and property accessors.
2070 unsigned CGDebugInfo::Checksum(const ObjCInterfaceDecl *ID) {
2071   // The assumption is that the number of ivars can only increase
2072   // monotonically, so it is safe to just use their current number as
2073   // a checksum.
2074   unsigned Sum = 0;
2075   for (const ObjCIvarDecl *Ivar = ID->all_declared_ivar_begin();
2076        Ivar != 0; Ivar = Ivar->getNextIvar())
2077     ++Sum;
2078 
2079   return Sum;
2080 }
2081 
2082 ObjCInterfaceDecl *CGDebugInfo::getObjCInterfaceDecl(QualType Ty) {
2083   switch (Ty->getTypeClass()) {
2084   case Type::ObjCObjectPointer:
2085     return getObjCInterfaceDecl(cast<ObjCObjectPointerType>(Ty)
2086                                     ->getPointeeType());
2087   case Type::ObjCInterface:
2088     return cast<ObjCInterfaceType>(Ty)->getDecl();
2089   default:
2090     return 0;
2091   }
2092 }
2093 
2094 /// CreateTypeNode - Create a new debug type node.
2095 llvm::DIType CGDebugInfo::CreateTypeNode(QualType Ty, llvm::DIFile Unit) {
2096   // Handle qualifiers, which recursively handles what they refer to.
2097   if (Ty.hasLocalQualifiers())
2098     return CreateQualifiedType(Ty, Unit);
2099 
2100   const char *Diag = 0;
2101 
2102   // Work out details of type.
2103   switch (Ty->getTypeClass()) {
2104 #define TYPE(Class, Base)
2105 #define ABSTRACT_TYPE(Class, Base)
2106 #define NON_CANONICAL_TYPE(Class, Base)
2107 #define DEPENDENT_TYPE(Class, Base) case Type::Class:
2108 #include "clang/AST/TypeNodes.def"
2109     llvm_unreachable("Dependent types cannot show up in debug information");
2110 
2111   case Type::ExtVector:
2112   case Type::Vector:
2113     return CreateType(cast<VectorType>(Ty), Unit);
2114   case Type::ObjCObjectPointer:
2115     return CreateType(cast<ObjCObjectPointerType>(Ty), Unit);
2116   case Type::ObjCObject:
2117     return CreateType(cast<ObjCObjectType>(Ty), Unit);
2118   case Type::ObjCInterface:
2119     return CreateType(cast<ObjCInterfaceType>(Ty), Unit);
2120   case Type::Builtin:
2121     return CreateType(cast<BuiltinType>(Ty));
2122   case Type::Complex:
2123     return CreateType(cast<ComplexType>(Ty));
2124   case Type::Pointer:
2125     return CreateType(cast<PointerType>(Ty), Unit);
2126   case Type::Decayed:
2127     // Decayed types are just pointers in LLVM and DWARF.
2128     return CreateType(
2129         cast<PointerType>(cast<DecayedType>(Ty)->getDecayedType()), Unit);
2130   case Type::BlockPointer:
2131     return CreateType(cast<BlockPointerType>(Ty), Unit);
2132   case Type::Typedef:
2133     return CreateType(cast<TypedefType>(Ty), Unit);
2134   case Type::Record:
2135     return CreateType(cast<RecordType>(Ty));
2136   case Type::Enum:
2137     return CreateEnumType(cast<EnumType>(Ty));
2138   case Type::FunctionProto:
2139   case Type::FunctionNoProto:
2140     return CreateType(cast<FunctionType>(Ty), Unit);
2141   case Type::ConstantArray:
2142   case Type::VariableArray:
2143   case Type::IncompleteArray:
2144     return CreateType(cast<ArrayType>(Ty), Unit);
2145 
2146   case Type::LValueReference:
2147     return CreateType(cast<LValueReferenceType>(Ty), Unit);
2148   case Type::RValueReference:
2149     return CreateType(cast<RValueReferenceType>(Ty), Unit);
2150 
2151   case Type::MemberPointer:
2152     return CreateType(cast<MemberPointerType>(Ty), Unit);
2153 
2154   case Type::Atomic:
2155     return CreateType(cast<AtomicType>(Ty), Unit);
2156 
2157   case Type::Attributed:
2158   case Type::TemplateSpecialization:
2159   case Type::Elaborated:
2160   case Type::Paren:
2161   case Type::SubstTemplateTypeParm:
2162   case Type::TypeOfExpr:
2163   case Type::TypeOf:
2164   case Type::Decltype:
2165   case Type::UnaryTransform:
2166   case Type::PackExpansion:
2167     llvm_unreachable("type should have been unwrapped!");
2168   case Type::Auto:
2169     Diag = "auto";
2170     break;
2171   }
2172 
2173   assert(Diag && "Fall through without a diagnostic?");
2174   unsigned DiagID = CGM.getDiags().getCustomDiagID(DiagnosticsEngine::Error,
2175                                "debug information for %0 is not yet supported");
2176   CGM.getDiags().Report(DiagID)
2177     << Diag;
2178   return llvm::DIType();
2179 }
2180 
2181 /// getOrCreateLimitedType - Get the type from the cache or create a new
2182 /// limited type if necessary.
2183 llvm::DIType CGDebugInfo::getOrCreateLimitedType(const RecordType *Ty,
2184                                                  llvm::DIFile Unit) {
2185   QualType QTy(Ty, 0);
2186 
2187   llvm::DICompositeType T(getTypeOrNull(QTy));
2188 
2189   // We may have cached a forward decl when we could have created
2190   // a non-forward decl. Go ahead and create a non-forward decl
2191   // now.
2192   if (T && !T.isForwardDecl()) return T;
2193 
2194   // Otherwise create the type.
2195   llvm::DICompositeType Res = CreateLimitedType(Ty);
2196 
2197   // Propagate members from the declaration to the definition
2198   // CreateType(const RecordType*) will overwrite this with the members in the
2199   // correct order if the full type is needed.
2200   Res.setTypeArray(T.getTypeArray());
2201 
2202   if (T && T.isForwardDecl())
2203     ReplaceMap.push_back(
2204         std::make_pair(QTy.getAsOpaquePtr(), static_cast<llvm::Value *>(T)));
2205 
2206   // And update the type cache.
2207   TypeCache[QTy.getAsOpaquePtr()] = Res;
2208   return Res;
2209 }
2210 
2211 // TODO: Currently used for context chains when limiting debug info.
2212 llvm::DICompositeType CGDebugInfo::CreateLimitedType(const RecordType *Ty) {
2213   RecordDecl *RD = Ty->getDecl();
2214 
2215   // Get overall information about the record type for the debug info.
2216   llvm::DIFile DefUnit = getOrCreateFile(RD->getLocation());
2217   unsigned Line = getLineNumber(RD->getLocation());
2218   StringRef RDName = getClassName(RD);
2219 
2220   llvm::DIDescriptor RDContext =
2221       getContextDescriptor(cast<Decl>(RD->getDeclContext()));
2222 
2223   // If we ended up creating the type during the context chain construction,
2224   // just return that.
2225   // FIXME: this could be dealt with better if the type was recorded as
2226   // completed before we started this (see the CompletedTypeCache usage in
2227   // CGDebugInfo::CreateTypeDefinition(const RecordType*) - that would need to
2228   // be pushed to before context creation, but after it was known to be
2229   // destined for completion (might still have an issue if this caller only
2230   // required a declaration but the context construction ended up creating a
2231   // definition)
2232   llvm::DICompositeType T(getTypeOrNull(CGM.getContext().getRecordType(RD)));
2233   if (T && (!T.isForwardDecl() || !RD->getDefinition()))
2234       return T;
2235 
2236   // If this is just a forward declaration, construct an appropriately
2237   // marked node and just return it.
2238   if (!RD->getDefinition())
2239     return getOrCreateRecordFwdDecl(Ty, RDContext);
2240 
2241   uint64_t Size = CGM.getContext().getTypeSize(Ty);
2242   uint64_t Align = CGM.getContext().getTypeAlign(Ty);
2243   llvm::DICompositeType RealDecl;
2244 
2245   SmallString<256> FullName = getUniqueTagTypeName(Ty, CGM, TheCU);
2246 
2247   if (RD->isUnion())
2248     RealDecl = DBuilder.createUnionType(RDContext, RDName, DefUnit, Line,
2249                                         Size, Align, 0, llvm::DIArray(), 0,
2250                                         FullName);
2251   else if (RD->isClass()) {
2252     // FIXME: This could be a struct type giving a default visibility different
2253     // than C++ class type, but needs llvm metadata changes first.
2254     RealDecl = DBuilder.createClassType(RDContext, RDName, DefUnit, Line,
2255                                         Size, Align, 0, 0, llvm::DIType(),
2256                                         llvm::DIArray(), llvm::DIType(),
2257                                         llvm::DIArray(), FullName);
2258   } else
2259     RealDecl = DBuilder.createStructType(RDContext, RDName, DefUnit, Line,
2260                                          Size, Align, 0, llvm::DIType(),
2261                                          llvm::DIArray(), 0, llvm::DIType(),
2262                                          FullName);
2263 
2264   RegionMap[Ty->getDecl()] = llvm::WeakVH(RealDecl);
2265   TypeCache[QualType(Ty, 0).getAsOpaquePtr()] = RealDecl;
2266 
2267   if (const ClassTemplateSpecializationDecl *TSpecial =
2268           dyn_cast<ClassTemplateSpecializationDecl>(RD))
2269     RealDecl.setTypeArray(llvm::DIArray(),
2270                           CollectCXXTemplateParams(TSpecial, DefUnit));
2271   return RealDecl;
2272 }
2273 
2274 void CGDebugInfo::CollectContainingType(const CXXRecordDecl *RD,
2275                                         llvm::DICompositeType RealDecl) {
2276   // A class's primary base or the class itself contains the vtable.
2277   llvm::DICompositeType ContainingType;
2278   const ASTRecordLayout &RL = CGM.getContext().getASTRecordLayout(RD);
2279   if (const CXXRecordDecl *PBase = RL.getPrimaryBase()) {
2280     // Seek non virtual primary base root.
2281     while (1) {
2282       const ASTRecordLayout &BRL = CGM.getContext().getASTRecordLayout(PBase);
2283       const CXXRecordDecl *PBT = BRL.getPrimaryBase();
2284       if (PBT && !BRL.isPrimaryBaseVirtual())
2285         PBase = PBT;
2286       else
2287         break;
2288     }
2289     ContainingType = llvm::DICompositeType(
2290         getOrCreateType(QualType(PBase->getTypeForDecl(), 0),
2291                         getOrCreateFile(RD->getLocation())));
2292   } else if (RD->isDynamicClass())
2293     ContainingType = RealDecl;
2294 
2295   RealDecl.setContainingType(ContainingType);
2296 }
2297 
2298 /// CreateMemberType - Create new member and increase Offset by FType's size.
2299 llvm::DIType CGDebugInfo::CreateMemberType(llvm::DIFile Unit, QualType FType,
2300                                            StringRef Name,
2301                                            uint64_t *Offset) {
2302   llvm::DIType FieldTy = CGDebugInfo::getOrCreateType(FType, Unit);
2303   uint64_t FieldSize = CGM.getContext().getTypeSize(FType);
2304   unsigned FieldAlign = CGM.getContext().getTypeAlign(FType);
2305   llvm::DIType Ty = DBuilder.createMemberType(Unit, Name, Unit, 0,
2306                                               FieldSize, FieldAlign,
2307                                               *Offset, 0, FieldTy);
2308   *Offset += FieldSize;
2309   return Ty;
2310 }
2311 
2312 llvm::DIDescriptor CGDebugInfo::getDeclarationOrDefinition(const Decl *D) {
2313   // We only need a declaration (not a definition) of the type - so use whatever
2314   // we would otherwise do to get a type for a pointee. (forward declarations in
2315   // limited debug info, full definitions (if the type definition is available)
2316   // in unlimited debug info)
2317   if (const TypeDecl *TD = dyn_cast<TypeDecl>(D))
2318     return getOrCreateType(CGM.getContext().getTypeDeclType(TD),
2319                            getOrCreateFile(TD->getLocation()));
2320   // Otherwise fall back to a fairly rudimentary cache of existing declarations.
2321   // This doesn't handle providing declarations (for functions or variables) for
2322   // entities without definitions in this TU, nor when the definition proceeds
2323   // the call to this function.
2324   // FIXME: This should be split out into more specific maps with support for
2325   // emitting forward declarations and merging definitions with declarations,
2326   // the same way as we do for types.
2327   llvm::DenseMap<const Decl *, llvm::WeakVH>::iterator I =
2328       DeclCache.find(D->getCanonicalDecl());
2329   if (I == DeclCache.end())
2330     return llvm::DIDescriptor();
2331   llvm::Value *V = I->second;
2332   return llvm::DIDescriptor(dyn_cast_or_null<llvm::MDNode>(V));
2333 }
2334 
2335 /// getFunctionDeclaration - Return debug info descriptor to describe method
2336 /// declaration for the given method definition.
2337 llvm::DISubprogram CGDebugInfo::getFunctionDeclaration(const Decl *D) {
2338   if (!D || DebugKind == CodeGenOptions::DebugLineTablesOnly)
2339     return llvm::DISubprogram();
2340 
2341   const FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
2342   if (!FD) return llvm::DISubprogram();
2343 
2344   // Setup context.
2345   llvm::DIScope S = getContextDescriptor(cast<Decl>(D->getDeclContext()));
2346 
2347   llvm::DenseMap<const FunctionDecl *, llvm::WeakVH>::iterator
2348     MI = SPCache.find(FD->getCanonicalDecl());
2349   if (MI == SPCache.end()) {
2350     if (const CXXMethodDecl *MD =
2351             dyn_cast<CXXMethodDecl>(FD->getCanonicalDecl())) {
2352       llvm::DICompositeType T(S);
2353       llvm::DISubprogram SP =
2354           CreateCXXMemberFunction(MD, getOrCreateFile(MD->getLocation()), T);
2355       T.addMember(SP);
2356       return SP;
2357     }
2358   }
2359   if (MI != SPCache.end()) {
2360     llvm::Value *V = MI->second;
2361     llvm::DISubprogram SP(dyn_cast_or_null<llvm::MDNode>(V));
2362     if (SP.isSubprogram() && !SP.isDefinition())
2363       return SP;
2364   }
2365 
2366   for (FunctionDecl::redecl_iterator I = FD->redecls_begin(),
2367          E = FD->redecls_end(); I != E; ++I) {
2368     const FunctionDecl *NextFD = *I;
2369     llvm::DenseMap<const FunctionDecl *, llvm::WeakVH>::iterator
2370       MI = SPCache.find(NextFD->getCanonicalDecl());
2371     if (MI != SPCache.end()) {
2372       llvm::Value *V = MI->second;
2373       llvm::DISubprogram SP(dyn_cast_or_null<llvm::MDNode>(V));
2374       if (SP.isSubprogram() && !SP.isDefinition())
2375         return SP;
2376     }
2377   }
2378   return llvm::DISubprogram();
2379 }
2380 
2381 // getOrCreateFunctionType - Construct DIType. If it is a c++ method, include
2382 // implicit parameter "this".
2383 llvm::DICompositeType CGDebugInfo::getOrCreateFunctionType(const Decl *D,
2384                                                            QualType FnType,
2385                                                            llvm::DIFile F) {
2386   if (!D || DebugKind == CodeGenOptions::DebugLineTablesOnly)
2387     // Create fake but valid subroutine type. Otherwise
2388     // llvm::DISubprogram::Verify() would return false, and
2389     // subprogram DIE will miss DW_AT_decl_file and
2390     // DW_AT_decl_line fields.
2391     return DBuilder.createSubroutineType(F, DBuilder.getOrCreateArray(None));
2392 
2393   if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D))
2394     return getOrCreateMethodType(Method, F);
2395   if (const ObjCMethodDecl *OMethod = dyn_cast<ObjCMethodDecl>(D)) {
2396     // Add "self" and "_cmd"
2397     SmallVector<llvm::Value *, 16> Elts;
2398 
2399     // First element is always return type. For 'void' functions it is NULL.
2400     QualType ResultTy = OMethod->getResultType();
2401 
2402     // Replace the instancetype keyword with the actual type.
2403     if (ResultTy == CGM.getContext().getObjCInstanceType())
2404       ResultTy = CGM.getContext().getPointerType(
2405         QualType(OMethod->getClassInterface()->getTypeForDecl(), 0));
2406 
2407     Elts.push_back(getOrCreateType(ResultTy, F));
2408     // "self" pointer is always first argument.
2409     QualType SelfDeclTy = OMethod->getSelfDecl()->getType();
2410     llvm::DIType SelfTy = getOrCreateType(SelfDeclTy, F);
2411     Elts.push_back(CreateSelfType(SelfDeclTy, SelfTy));
2412     // "_cmd" pointer is always second argument.
2413     llvm::DIType CmdTy = getOrCreateType(OMethod->getCmdDecl()->getType(), F);
2414     Elts.push_back(DBuilder.createArtificialType(CmdTy));
2415     // Get rest of the arguments.
2416     for (ObjCMethodDecl::param_const_iterator PI = OMethod->param_begin(),
2417            PE = OMethod->param_end(); PI != PE; ++PI)
2418       Elts.push_back(getOrCreateType((*PI)->getType(), F));
2419 
2420     llvm::DIArray EltTypeArray = DBuilder.getOrCreateArray(Elts);
2421     return DBuilder.createSubroutineType(F, EltTypeArray);
2422   }
2423   return llvm::DICompositeType(getOrCreateType(FnType, F));
2424 }
2425 
2426 /// EmitFunctionStart - Constructs the debug code for entering a function.
2427 void CGDebugInfo::EmitFunctionStart(GlobalDecl GD, QualType FnType,
2428                                     llvm::Function *Fn,
2429                                     CGBuilderTy &Builder) {
2430 
2431   StringRef Name;
2432   StringRef LinkageName;
2433 
2434   FnBeginRegionCount.push_back(LexicalBlockStack.size());
2435 
2436   const Decl *D = GD.getDecl();
2437   // Function may lack declaration in source code if it is created by Clang
2438   // CodeGen (examples: _GLOBAL__I_a, __cxx_global_array_dtor, thunk).
2439   bool HasDecl = (D != 0);
2440   // Use the location of the declaration.
2441   SourceLocation Loc;
2442   if (HasDecl)
2443     Loc = D->getLocation();
2444 
2445   unsigned Flags = 0;
2446   llvm::DIFile Unit = getOrCreateFile(Loc);
2447   llvm::DIDescriptor FDContext(Unit);
2448   llvm::DIArray TParamsArray;
2449   if (!HasDecl) {
2450     // Use llvm function name.
2451     LinkageName = Fn->getName();
2452   } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
2453     // If there is a DISubprogram for this function available then use it.
2454     llvm::DenseMap<const FunctionDecl *, llvm::WeakVH>::iterator
2455       FI = SPCache.find(FD->getCanonicalDecl());
2456     if (FI != SPCache.end()) {
2457       llvm::Value *V = FI->second;
2458       llvm::DIDescriptor SP(dyn_cast_or_null<llvm::MDNode>(V));
2459       if (SP.isSubprogram() && llvm::DISubprogram(SP).isDefinition()) {
2460         llvm::MDNode *SPN = SP;
2461         LexicalBlockStack.push_back(SPN);
2462         RegionMap[D] = llvm::WeakVH(SP);
2463         return;
2464       }
2465     }
2466     Name = getFunctionName(FD);
2467     // Use mangled name as linkage name for C/C++ functions.
2468     if (FD->hasPrototype()) {
2469       LinkageName = CGM.getMangledName(GD);
2470       Flags |= llvm::DIDescriptor::FlagPrototyped;
2471     }
2472     // No need to replicate the linkage name if it isn't different from the
2473     // subprogram name, no need to have it at all unless coverage is enabled or
2474     // debug is set to more than just line tables.
2475     if (LinkageName == Name ||
2476         (!CGM.getCodeGenOpts().EmitGcovArcs &&
2477          !CGM.getCodeGenOpts().EmitGcovNotes &&
2478          DebugKind <= CodeGenOptions::DebugLineTablesOnly))
2479       LinkageName = StringRef();
2480 
2481     if (DebugKind >= CodeGenOptions::LimitedDebugInfo) {
2482       if (const NamespaceDecl *NSDecl =
2483               dyn_cast_or_null<NamespaceDecl>(FD->getDeclContext()))
2484         FDContext = getOrCreateNameSpace(NSDecl);
2485       else if (const RecordDecl *RDecl =
2486                    dyn_cast_or_null<RecordDecl>(FD->getDeclContext()))
2487         FDContext = getContextDescriptor(cast<Decl>(RDecl));
2488 
2489       // Collect template parameters.
2490       TParamsArray = CollectFunctionTemplateParams(FD, Unit);
2491     }
2492   } else if (const ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(D)) {
2493     Name = getObjCMethodName(OMD);
2494     Flags |= llvm::DIDescriptor::FlagPrototyped;
2495   } else {
2496     // Use llvm function name.
2497     Name = Fn->getName();
2498     Flags |= llvm::DIDescriptor::FlagPrototyped;
2499   }
2500   if (!Name.empty() && Name[0] == '\01')
2501     Name = Name.substr(1);
2502 
2503   unsigned LineNo = getLineNumber(Loc);
2504   if (!HasDecl || D->isImplicit())
2505     Flags |= llvm::DIDescriptor::FlagArtificial;
2506 
2507   llvm::DISubprogram SP =
2508       DBuilder.createFunction(FDContext, Name, LinkageName, Unit, LineNo,
2509                               getOrCreateFunctionType(D, FnType, Unit),
2510                               Fn->hasInternalLinkage(), true /*definition*/,
2511                               getLineNumber(CurLoc), Flags,
2512                               CGM.getLangOpts().Optimize, Fn, TParamsArray,
2513                               getFunctionDeclaration(D));
2514   if (HasDecl)
2515     DeclCache.insert(std::make_pair(D->getCanonicalDecl(), llvm::WeakVH(SP)));
2516 
2517   // Push function on region stack.
2518   llvm::MDNode *SPN = SP;
2519   LexicalBlockStack.push_back(SPN);
2520   if (HasDecl)
2521     RegionMap[D] = llvm::WeakVH(SP);
2522 }
2523 
2524 /// EmitLocation - Emit metadata to indicate a change in line/column
2525 /// information in the source file. If the location is invalid, the
2526 /// previous location will be reused.
2527 void CGDebugInfo::EmitLocation(CGBuilderTy &Builder, SourceLocation Loc,
2528                                bool ForceColumnInfo) {
2529   // Update our current location
2530   setLocation(Loc);
2531 
2532   if (CurLoc.isInvalid() || CurLoc.isMacroID()) return;
2533 
2534   // Don't bother if things are the same as last time.
2535   SourceManager &SM = CGM.getContext().getSourceManager();
2536   if (CurLoc == PrevLoc ||
2537       SM.getExpansionLoc(CurLoc) == SM.getExpansionLoc(PrevLoc))
2538     // New Builder may not be in sync with CGDebugInfo.
2539     if (!Builder.getCurrentDebugLocation().isUnknown() &&
2540         Builder.getCurrentDebugLocation().getScope(CGM.getLLVMContext()) ==
2541           LexicalBlockStack.back())
2542       return;
2543 
2544   // Update last state.
2545   PrevLoc = CurLoc;
2546 
2547   llvm::MDNode *Scope = LexicalBlockStack.back();
2548   Builder.SetCurrentDebugLocation(llvm::DebugLoc::get
2549                                   (getLineNumber(CurLoc),
2550                                    getColumnNumber(CurLoc, ForceColumnInfo),
2551                                    Scope));
2552 }
2553 
2554 /// CreateLexicalBlock - Creates a new lexical block node and pushes it on
2555 /// the stack.
2556 void CGDebugInfo::CreateLexicalBlock(SourceLocation Loc) {
2557   llvm::DIDescriptor D =
2558     DBuilder.createLexicalBlock(LexicalBlockStack.empty() ?
2559                                 llvm::DIDescriptor() :
2560                                 llvm::DIDescriptor(LexicalBlockStack.back()),
2561                                 getOrCreateFile(CurLoc),
2562                                 getLineNumber(CurLoc),
2563                                 getColumnNumber(CurLoc));
2564   llvm::MDNode *DN = D;
2565   LexicalBlockStack.push_back(DN);
2566 }
2567 
2568 /// EmitLexicalBlockStart - Constructs the debug code for entering a declarative
2569 /// region - beginning of a DW_TAG_lexical_block.
2570 void CGDebugInfo::EmitLexicalBlockStart(CGBuilderTy &Builder,
2571                                         SourceLocation Loc) {
2572   // Set our current location.
2573   setLocation(Loc);
2574 
2575   // Create a new lexical block and push it on the stack.
2576   CreateLexicalBlock(Loc);
2577 
2578   // Emit a line table change for the current location inside the new scope.
2579   Builder.SetCurrentDebugLocation(llvm::DebugLoc::get(getLineNumber(Loc),
2580                                   getColumnNumber(Loc),
2581                                   LexicalBlockStack.back()));
2582 }
2583 
2584 /// EmitLexicalBlockEnd - Constructs the debug code for exiting a declarative
2585 /// region - end of a DW_TAG_lexical_block.
2586 void CGDebugInfo::EmitLexicalBlockEnd(CGBuilderTy &Builder,
2587                                       SourceLocation Loc) {
2588   assert(!LexicalBlockStack.empty() && "Region stack mismatch, stack empty!");
2589 
2590   // Provide an entry in the line table for the end of the block.
2591   EmitLocation(Builder, Loc);
2592 
2593   LexicalBlockStack.pop_back();
2594 }
2595 
2596 /// EmitFunctionEnd - Constructs the debug code for exiting a function.
2597 void CGDebugInfo::EmitFunctionEnd(CGBuilderTy &Builder) {
2598   assert(!LexicalBlockStack.empty() && "Region stack mismatch, stack empty!");
2599   unsigned RCount = FnBeginRegionCount.back();
2600   assert(RCount <= LexicalBlockStack.size() && "Region stack mismatch");
2601 
2602   // Pop all regions for this function.
2603   while (LexicalBlockStack.size() != RCount)
2604     EmitLexicalBlockEnd(Builder, CurLoc);
2605   FnBeginRegionCount.pop_back();
2606 }
2607 
2608 // EmitTypeForVarWithBlocksAttr - Build up structure info for the byref.
2609 // See BuildByRefType.
2610 llvm::DIType CGDebugInfo::EmitTypeForVarWithBlocksAttr(const VarDecl *VD,
2611                                                        uint64_t *XOffset) {
2612 
2613   SmallVector<llvm::Value *, 5> EltTys;
2614   QualType FType;
2615   uint64_t FieldSize, FieldOffset;
2616   unsigned FieldAlign;
2617 
2618   llvm::DIFile Unit = getOrCreateFile(VD->getLocation());
2619   QualType Type = VD->getType();
2620 
2621   FieldOffset = 0;
2622   FType = CGM.getContext().getPointerType(CGM.getContext().VoidTy);
2623   EltTys.push_back(CreateMemberType(Unit, FType, "__isa", &FieldOffset));
2624   EltTys.push_back(CreateMemberType(Unit, FType, "__forwarding", &FieldOffset));
2625   FType = CGM.getContext().IntTy;
2626   EltTys.push_back(CreateMemberType(Unit, FType, "__flags", &FieldOffset));
2627   EltTys.push_back(CreateMemberType(Unit, FType, "__size", &FieldOffset));
2628 
2629   bool HasCopyAndDispose = CGM.getContext().BlockRequiresCopying(Type, VD);
2630   if (HasCopyAndDispose) {
2631     FType = CGM.getContext().getPointerType(CGM.getContext().VoidTy);
2632     EltTys.push_back(CreateMemberType(Unit, FType, "__copy_helper",
2633                                       &FieldOffset));
2634     EltTys.push_back(CreateMemberType(Unit, FType, "__destroy_helper",
2635                                       &FieldOffset));
2636   }
2637   bool HasByrefExtendedLayout;
2638   Qualifiers::ObjCLifetime Lifetime;
2639   if (CGM.getContext().getByrefLifetime(Type,
2640                                         Lifetime, HasByrefExtendedLayout)
2641       && HasByrefExtendedLayout) {
2642     FType = CGM.getContext().getPointerType(CGM.getContext().VoidTy);
2643     EltTys.push_back(CreateMemberType(Unit, FType,
2644                                       "__byref_variable_layout",
2645                                       &FieldOffset));
2646   }
2647 
2648   CharUnits Align = CGM.getContext().getDeclAlign(VD);
2649   if (Align > CGM.getContext().toCharUnitsFromBits(
2650         CGM.getTarget().getPointerAlign(0))) {
2651     CharUnits FieldOffsetInBytes
2652       = CGM.getContext().toCharUnitsFromBits(FieldOffset);
2653     CharUnits AlignedOffsetInBytes
2654       = FieldOffsetInBytes.RoundUpToAlignment(Align);
2655     CharUnits NumPaddingBytes
2656       = AlignedOffsetInBytes - FieldOffsetInBytes;
2657 
2658     if (NumPaddingBytes.isPositive()) {
2659       llvm::APInt pad(32, NumPaddingBytes.getQuantity());
2660       FType = CGM.getContext().getConstantArrayType(CGM.getContext().CharTy,
2661                                                     pad, ArrayType::Normal, 0);
2662       EltTys.push_back(CreateMemberType(Unit, FType, "", &FieldOffset));
2663     }
2664   }
2665 
2666   FType = Type;
2667   llvm::DIType FieldTy = CGDebugInfo::getOrCreateType(FType, Unit);
2668   FieldSize = CGM.getContext().getTypeSize(FType);
2669   FieldAlign = CGM.getContext().toBits(Align);
2670 
2671   *XOffset = FieldOffset;
2672   FieldTy = DBuilder.createMemberType(Unit, VD->getName(), Unit,
2673                                       0, FieldSize, FieldAlign,
2674                                       FieldOffset, 0, FieldTy);
2675   EltTys.push_back(FieldTy);
2676   FieldOffset += FieldSize;
2677 
2678   llvm::DIArray Elements = DBuilder.getOrCreateArray(EltTys);
2679 
2680   unsigned Flags = llvm::DIDescriptor::FlagBlockByrefStruct;
2681 
2682   return DBuilder.createStructType(Unit, "", Unit, 0, FieldOffset, 0, Flags,
2683                                    llvm::DIType(), Elements);
2684 }
2685 
2686 /// EmitDeclare - Emit local variable declaration debug info.
2687 void CGDebugInfo::EmitDeclare(const VarDecl *VD, unsigned Tag,
2688                               llvm::Value *Storage,
2689                               unsigned ArgNo, CGBuilderTy &Builder) {
2690   assert(DebugKind >= CodeGenOptions::LimitedDebugInfo);
2691   assert(!LexicalBlockStack.empty() && "Region stack mismatch, stack empty!");
2692 
2693   bool Unwritten =
2694       VD->isImplicit() || (isa<Decl>(VD->getDeclContext()) &&
2695                            cast<Decl>(VD->getDeclContext())->isImplicit());
2696   llvm::DIFile Unit;
2697   if (!Unwritten)
2698     Unit = getOrCreateFile(VD->getLocation());
2699   llvm::DIType Ty;
2700   uint64_t XOffset = 0;
2701   if (VD->hasAttr<BlocksAttr>())
2702     Ty = EmitTypeForVarWithBlocksAttr(VD, &XOffset);
2703   else
2704     Ty = getOrCreateType(VD->getType(), Unit);
2705 
2706   // If there is no debug info for this type then do not emit debug info
2707   // for this variable.
2708   if (!Ty)
2709     return;
2710 
2711   // Get location information.
2712   unsigned Line = 0;
2713   unsigned Column = 0;
2714   if (!Unwritten) {
2715     Line = getLineNumber(VD->getLocation());
2716     Column = getColumnNumber(VD->getLocation());
2717   }
2718   unsigned Flags = 0;
2719   if (VD->isImplicit())
2720     Flags |= llvm::DIDescriptor::FlagArtificial;
2721   // If this is the first argument and it is implicit then
2722   // give it an object pointer flag.
2723   // FIXME: There has to be a better way to do this, but for static
2724   // functions there won't be an implicit param at arg1 and
2725   // otherwise it is 'self' or 'this'.
2726   if (isa<ImplicitParamDecl>(VD) && ArgNo == 1)
2727     Flags |= llvm::DIDescriptor::FlagObjectPointer;
2728   if (llvm::Argument *Arg = dyn_cast<llvm::Argument>(Storage))
2729     if (Arg->getType()->isPointerTy() && !Arg->hasByValAttr() &&
2730         !VD->getType()->isPointerType())
2731       Flags |= llvm::DIDescriptor::FlagIndirectVariable;
2732 
2733   llvm::MDNode *Scope = LexicalBlockStack.back();
2734 
2735   StringRef Name = VD->getName();
2736   if (!Name.empty()) {
2737     if (VD->hasAttr<BlocksAttr>()) {
2738       CharUnits offset = CharUnits::fromQuantity(32);
2739       SmallVector<llvm::Value *, 9> addr;
2740       llvm::Type *Int64Ty = CGM.Int64Ty;
2741       addr.push_back(llvm::ConstantInt::get(Int64Ty, llvm::DIBuilder::OpPlus));
2742       // offset of __forwarding field
2743       offset = CGM.getContext().toCharUnitsFromBits(
2744         CGM.getTarget().getPointerWidth(0));
2745       addr.push_back(llvm::ConstantInt::get(Int64Ty, offset.getQuantity()));
2746       addr.push_back(llvm::ConstantInt::get(Int64Ty, llvm::DIBuilder::OpDeref));
2747       addr.push_back(llvm::ConstantInt::get(Int64Ty, llvm::DIBuilder::OpPlus));
2748       // offset of x field
2749       offset = CGM.getContext().toCharUnitsFromBits(XOffset);
2750       addr.push_back(llvm::ConstantInt::get(Int64Ty, offset.getQuantity()));
2751 
2752       // Create the descriptor for the variable.
2753       llvm::DIVariable D =
2754         DBuilder.createComplexVariable(Tag,
2755                                        llvm::DIDescriptor(Scope),
2756                                        VD->getName(), Unit, Line, Ty,
2757                                        addr, ArgNo);
2758 
2759       // Insert an llvm.dbg.declare into the current block.
2760       llvm::Instruction *Call =
2761         DBuilder.insertDeclare(Storage, D, Builder.GetInsertBlock());
2762       Call->setDebugLoc(llvm::DebugLoc::get(Line, Column, Scope));
2763       return;
2764     } else if (isa<VariableArrayType>(VD->getType()))
2765       Flags |= llvm::DIDescriptor::FlagIndirectVariable;
2766   } else if (const RecordType *RT = dyn_cast<RecordType>(VD->getType())) {
2767     // If VD is an anonymous union then Storage represents value for
2768     // all union fields.
2769     const RecordDecl *RD = cast<RecordDecl>(RT->getDecl());
2770     if (RD->isUnion() && RD->isAnonymousStructOrUnion()) {
2771       for (RecordDecl::field_iterator I = RD->field_begin(),
2772              E = RD->field_end();
2773            I != E; ++I) {
2774         FieldDecl *Field = *I;
2775         llvm::DIType FieldTy = getOrCreateType(Field->getType(), Unit);
2776         StringRef FieldName = Field->getName();
2777 
2778         // Ignore unnamed fields. Do not ignore unnamed records.
2779         if (FieldName.empty() && !isa<RecordType>(Field->getType()))
2780           continue;
2781 
2782         // Use VarDecl's Tag, Scope and Line number.
2783         llvm::DIVariable D =
2784           DBuilder.createLocalVariable(Tag, llvm::DIDescriptor(Scope),
2785                                        FieldName, Unit, Line, FieldTy,
2786                                        CGM.getLangOpts().Optimize, Flags,
2787                                        ArgNo);
2788 
2789         // Insert an llvm.dbg.declare into the current block.
2790         llvm::Instruction *Call =
2791           DBuilder.insertDeclare(Storage, D, Builder.GetInsertBlock());
2792         Call->setDebugLoc(llvm::DebugLoc::get(Line, Column, Scope));
2793       }
2794       return;
2795     }
2796   }
2797 
2798   // Create the descriptor for the variable.
2799   llvm::DIVariable D =
2800     DBuilder.createLocalVariable(Tag, llvm::DIDescriptor(Scope),
2801                                  Name, Unit, Line, Ty,
2802                                  CGM.getLangOpts().Optimize, Flags, ArgNo);
2803 
2804   // Insert an llvm.dbg.declare into the current block.
2805   llvm::Instruction *Call =
2806     DBuilder.insertDeclare(Storage, D, Builder.GetInsertBlock());
2807   Call->setDebugLoc(llvm::DebugLoc::get(Line, Column, Scope));
2808 }
2809 
2810 void CGDebugInfo::EmitDeclareOfAutoVariable(const VarDecl *VD,
2811                                             llvm::Value *Storage,
2812                                             CGBuilderTy &Builder) {
2813   assert(DebugKind >= CodeGenOptions::LimitedDebugInfo);
2814   EmitDeclare(VD, llvm::dwarf::DW_TAG_auto_variable, Storage, 0, Builder);
2815 }
2816 
2817 /// Look up the completed type for a self pointer in the TypeCache and
2818 /// create a copy of it with the ObjectPointer and Artificial flags
2819 /// set. If the type is not cached, a new one is created. This should
2820 /// never happen though, since creating a type for the implicit self
2821 /// argument implies that we already parsed the interface definition
2822 /// and the ivar declarations in the implementation.
2823 llvm::DIType CGDebugInfo::CreateSelfType(const QualType &QualTy,
2824                                          llvm::DIType Ty) {
2825   llvm::DIType CachedTy = getTypeOrNull(QualTy);
2826   if (CachedTy) Ty = CachedTy;
2827   else DEBUG(llvm::dbgs() << "No cached type for self.");
2828   return DBuilder.createObjectPointerType(Ty);
2829 }
2830 
2831 void CGDebugInfo::EmitDeclareOfBlockDeclRefVariable(const VarDecl *VD,
2832                                                     llvm::Value *Storage,
2833                                                     CGBuilderTy &Builder,
2834                                                  const CGBlockInfo &blockInfo) {
2835   assert(DebugKind >= CodeGenOptions::LimitedDebugInfo);
2836   assert(!LexicalBlockStack.empty() && "Region stack mismatch, stack empty!");
2837 
2838   if (Builder.GetInsertBlock() == 0)
2839     return;
2840 
2841   bool isByRef = VD->hasAttr<BlocksAttr>();
2842 
2843   uint64_t XOffset = 0;
2844   llvm::DIFile Unit = getOrCreateFile(VD->getLocation());
2845   llvm::DIType Ty;
2846   if (isByRef)
2847     Ty = EmitTypeForVarWithBlocksAttr(VD, &XOffset);
2848   else
2849     Ty = getOrCreateType(VD->getType(), Unit);
2850 
2851   // Self is passed along as an implicit non-arg variable in a
2852   // block. Mark it as the object pointer.
2853   if (isa<ImplicitParamDecl>(VD) && VD->getName() == "self")
2854     Ty = CreateSelfType(VD->getType(), Ty);
2855 
2856   // Get location information.
2857   unsigned Line = getLineNumber(VD->getLocation());
2858   unsigned Column = getColumnNumber(VD->getLocation());
2859 
2860   const llvm::DataLayout &target = CGM.getDataLayout();
2861 
2862   CharUnits offset = CharUnits::fromQuantity(
2863     target.getStructLayout(blockInfo.StructureType)
2864           ->getElementOffset(blockInfo.getCapture(VD).getIndex()));
2865 
2866   SmallVector<llvm::Value *, 9> addr;
2867   llvm::Type *Int64Ty = CGM.Int64Ty;
2868   if (isa<llvm::AllocaInst>(Storage))
2869     addr.push_back(llvm::ConstantInt::get(Int64Ty, llvm::DIBuilder::OpDeref));
2870   addr.push_back(llvm::ConstantInt::get(Int64Ty, llvm::DIBuilder::OpPlus));
2871   addr.push_back(llvm::ConstantInt::get(Int64Ty, offset.getQuantity()));
2872   if (isByRef) {
2873     addr.push_back(llvm::ConstantInt::get(Int64Ty, llvm::DIBuilder::OpDeref));
2874     addr.push_back(llvm::ConstantInt::get(Int64Ty, llvm::DIBuilder::OpPlus));
2875     // offset of __forwarding field
2876     offset = CGM.getContext()
2877                 .toCharUnitsFromBits(target.getPointerSizeInBits(0));
2878     addr.push_back(llvm::ConstantInt::get(Int64Ty, offset.getQuantity()));
2879     addr.push_back(llvm::ConstantInt::get(Int64Ty, llvm::DIBuilder::OpDeref));
2880     addr.push_back(llvm::ConstantInt::get(Int64Ty, llvm::DIBuilder::OpPlus));
2881     // offset of x field
2882     offset = CGM.getContext().toCharUnitsFromBits(XOffset);
2883     addr.push_back(llvm::ConstantInt::get(Int64Ty, offset.getQuantity()));
2884   }
2885 
2886   // Create the descriptor for the variable.
2887   llvm::DIVariable D =
2888     DBuilder.createComplexVariable(llvm::dwarf::DW_TAG_auto_variable,
2889                                    llvm::DIDescriptor(LexicalBlockStack.back()),
2890                                    VD->getName(), Unit, Line, Ty, addr);
2891 
2892   // Insert an llvm.dbg.declare into the current block.
2893   llvm::Instruction *Call =
2894     DBuilder.insertDeclare(Storage, D, Builder.GetInsertPoint());
2895   Call->setDebugLoc(llvm::DebugLoc::get(Line, Column,
2896                                         LexicalBlockStack.back()));
2897 }
2898 
2899 /// EmitDeclareOfArgVariable - Emit call to llvm.dbg.declare for an argument
2900 /// variable declaration.
2901 void CGDebugInfo::EmitDeclareOfArgVariable(const VarDecl *VD, llvm::Value *AI,
2902                                            unsigned ArgNo,
2903                                            CGBuilderTy &Builder) {
2904   assert(DebugKind >= CodeGenOptions::LimitedDebugInfo);
2905   EmitDeclare(VD, llvm::dwarf::DW_TAG_arg_variable, AI, ArgNo, Builder);
2906 }
2907 
2908 namespace {
2909   struct BlockLayoutChunk {
2910     uint64_t OffsetInBits;
2911     const BlockDecl::Capture *Capture;
2912   };
2913   bool operator<(const BlockLayoutChunk &l, const BlockLayoutChunk &r) {
2914     return l.OffsetInBits < r.OffsetInBits;
2915   }
2916 }
2917 
2918 void CGDebugInfo::EmitDeclareOfBlockLiteralArgVariable(const CGBlockInfo &block,
2919                                                        llvm::Value *Arg,
2920                                                        llvm::Value *LocalAddr,
2921                                                        CGBuilderTy &Builder) {
2922   assert(DebugKind >= CodeGenOptions::LimitedDebugInfo);
2923   ASTContext &C = CGM.getContext();
2924   const BlockDecl *blockDecl = block.getBlockDecl();
2925 
2926   // Collect some general information about the block's location.
2927   SourceLocation loc = blockDecl->getCaretLocation();
2928   llvm::DIFile tunit = getOrCreateFile(loc);
2929   unsigned line = getLineNumber(loc);
2930   unsigned column = getColumnNumber(loc);
2931 
2932   // Build the debug-info type for the block literal.
2933   getContextDescriptor(cast<Decl>(blockDecl->getDeclContext()));
2934 
2935   const llvm::StructLayout *blockLayout =
2936     CGM.getDataLayout().getStructLayout(block.StructureType);
2937 
2938   SmallVector<llvm::Value*, 16> fields;
2939   fields.push_back(createFieldType("__isa", C.VoidPtrTy, 0, loc, AS_public,
2940                                    blockLayout->getElementOffsetInBits(0),
2941                                    tunit, tunit));
2942   fields.push_back(createFieldType("__flags", C.IntTy, 0, loc, AS_public,
2943                                    blockLayout->getElementOffsetInBits(1),
2944                                    tunit, tunit));
2945   fields.push_back(createFieldType("__reserved", C.IntTy, 0, loc, AS_public,
2946                                    blockLayout->getElementOffsetInBits(2),
2947                                    tunit, tunit));
2948   fields.push_back(createFieldType("__FuncPtr", C.VoidPtrTy, 0, loc, AS_public,
2949                                    blockLayout->getElementOffsetInBits(3),
2950                                    tunit, tunit));
2951   fields.push_back(createFieldType("__descriptor",
2952                                    C.getPointerType(block.NeedsCopyDispose ?
2953                                         C.getBlockDescriptorExtendedType() :
2954                                         C.getBlockDescriptorType()),
2955                                    0, loc, AS_public,
2956                                    blockLayout->getElementOffsetInBits(4),
2957                                    tunit, tunit));
2958 
2959   // We want to sort the captures by offset, not because DWARF
2960   // requires this, but because we're paranoid about debuggers.
2961   SmallVector<BlockLayoutChunk, 8> chunks;
2962 
2963   // 'this' capture.
2964   if (blockDecl->capturesCXXThis()) {
2965     BlockLayoutChunk chunk;
2966     chunk.OffsetInBits =
2967       blockLayout->getElementOffsetInBits(block.CXXThisIndex);
2968     chunk.Capture = 0;
2969     chunks.push_back(chunk);
2970   }
2971 
2972   // Variable captures.
2973   for (BlockDecl::capture_const_iterator
2974          i = blockDecl->capture_begin(), e = blockDecl->capture_end();
2975        i != e; ++i) {
2976     const BlockDecl::Capture &capture = *i;
2977     const VarDecl *variable = capture.getVariable();
2978     const CGBlockInfo::Capture &captureInfo = block.getCapture(variable);
2979 
2980     // Ignore constant captures.
2981     if (captureInfo.isConstant())
2982       continue;
2983 
2984     BlockLayoutChunk chunk;
2985     chunk.OffsetInBits =
2986       blockLayout->getElementOffsetInBits(captureInfo.getIndex());
2987     chunk.Capture = &capture;
2988     chunks.push_back(chunk);
2989   }
2990 
2991   // Sort by offset.
2992   llvm::array_pod_sort(chunks.begin(), chunks.end());
2993 
2994   for (SmallVectorImpl<BlockLayoutChunk>::iterator
2995          i = chunks.begin(), e = chunks.end(); i != e; ++i) {
2996     uint64_t offsetInBits = i->OffsetInBits;
2997     const BlockDecl::Capture *capture = i->Capture;
2998 
2999     // If we have a null capture, this must be the C++ 'this' capture.
3000     if (!capture) {
3001       const CXXMethodDecl *method =
3002         cast<CXXMethodDecl>(blockDecl->getNonClosureContext());
3003       QualType type = method->getThisType(C);
3004 
3005       fields.push_back(createFieldType("this", type, 0, loc, AS_public,
3006                                        offsetInBits, tunit, tunit));
3007       continue;
3008     }
3009 
3010     const VarDecl *variable = capture->getVariable();
3011     StringRef name = variable->getName();
3012 
3013     llvm::DIType fieldType;
3014     if (capture->isByRef()) {
3015       std::pair<uint64_t,unsigned> ptrInfo = C.getTypeInfo(C.VoidPtrTy);
3016 
3017       // FIXME: this creates a second copy of this type!
3018       uint64_t xoffset;
3019       fieldType = EmitTypeForVarWithBlocksAttr(variable, &xoffset);
3020       fieldType = DBuilder.createPointerType(fieldType, ptrInfo.first);
3021       fieldType = DBuilder.createMemberType(tunit, name, tunit, line,
3022                                             ptrInfo.first, ptrInfo.second,
3023                                             offsetInBits, 0, fieldType);
3024     } else {
3025       fieldType = createFieldType(name, variable->getType(), 0,
3026                                   loc, AS_public, offsetInBits, tunit, tunit);
3027     }
3028     fields.push_back(fieldType);
3029   }
3030 
3031   SmallString<36> typeName;
3032   llvm::raw_svector_ostream(typeName)
3033     << "__block_literal_" << CGM.getUniqueBlockCount();
3034 
3035   llvm::DIArray fieldsArray = DBuilder.getOrCreateArray(fields);
3036 
3037   llvm::DIType type =
3038     DBuilder.createStructType(tunit, typeName.str(), tunit, line,
3039                               CGM.getContext().toBits(block.BlockSize),
3040                               CGM.getContext().toBits(block.BlockAlign),
3041                               0, llvm::DIType(), fieldsArray);
3042   type = DBuilder.createPointerType(type, CGM.PointerWidthInBits);
3043 
3044   // Get overall information about the block.
3045   unsigned flags = llvm::DIDescriptor::FlagArtificial;
3046   llvm::MDNode *scope = LexicalBlockStack.back();
3047 
3048   // Create the descriptor for the parameter.
3049   llvm::DIVariable debugVar =
3050     DBuilder.createLocalVariable(llvm::dwarf::DW_TAG_arg_variable,
3051                                  llvm::DIDescriptor(scope),
3052                                  Arg->getName(), tunit, line, type,
3053                                  CGM.getLangOpts().Optimize, flags,
3054                                  cast<llvm::Argument>(Arg)->getArgNo() + 1);
3055 
3056   if (LocalAddr) {
3057     // Insert an llvm.dbg.value into the current block.
3058     llvm::Instruction *DbgVal =
3059       DBuilder.insertDbgValueIntrinsic(LocalAddr, 0, debugVar,
3060                                        Builder.GetInsertBlock());
3061     DbgVal->setDebugLoc(llvm::DebugLoc::get(line, column, scope));
3062   }
3063 
3064   // Insert an llvm.dbg.declare into the current block.
3065   llvm::Instruction *DbgDecl =
3066     DBuilder.insertDeclare(Arg, debugVar, Builder.GetInsertBlock());
3067   DbgDecl->setDebugLoc(llvm::DebugLoc::get(line, column, scope));
3068 }
3069 
3070 /// If D is an out-of-class definition of a static data member of a class, find
3071 /// its corresponding in-class declaration.
3072 llvm::DIDerivedType
3073 CGDebugInfo::getOrCreateStaticDataMemberDeclarationOrNull(const VarDecl *D) {
3074   if (!D->isStaticDataMember())
3075     return llvm::DIDerivedType();
3076   llvm::DenseMap<const Decl *, llvm::WeakVH>::iterator MI =
3077       StaticDataMemberCache.find(D->getCanonicalDecl());
3078   if (MI != StaticDataMemberCache.end()) {
3079     assert(MI->second && "Static data member declaration should still exist");
3080     return llvm::DIDerivedType(cast<llvm::MDNode>(MI->second));
3081   }
3082 
3083   // If the member wasn't found in the cache, lazily construct and add it to the
3084   // type (used when a limited form of the type is emitted).
3085   llvm::DICompositeType Ctxt(
3086       getContextDescriptor(cast<Decl>(D->getDeclContext())));
3087   llvm::DIDerivedType T = CreateRecordStaticField(D, Ctxt);
3088   Ctxt.addMember(T);
3089   return T;
3090 }
3091 
3092 /// EmitGlobalVariable - Emit information about a global variable.
3093 void CGDebugInfo::EmitGlobalVariable(llvm::GlobalVariable *Var,
3094                                      const VarDecl *D) {
3095   assert(DebugKind >= CodeGenOptions::LimitedDebugInfo);
3096   // Create global variable debug descriptor.
3097   llvm::DIFile Unit = getOrCreateFile(D->getLocation());
3098   unsigned LineNo = getLineNumber(D->getLocation());
3099 
3100   setLocation(D->getLocation());
3101 
3102   QualType T = D->getType();
3103   if (T->isIncompleteArrayType()) {
3104 
3105     // CodeGen turns int[] into int[1] so we'll do the same here.
3106     llvm::APInt ConstVal(32, 1);
3107     QualType ET = CGM.getContext().getAsArrayType(T)->getElementType();
3108 
3109     T = CGM.getContext().getConstantArrayType(ET, ConstVal,
3110                                               ArrayType::Normal, 0);
3111   }
3112   StringRef DeclName = D->getName();
3113   StringRef LinkageName;
3114   if (D->getDeclContext() && !isa<FunctionDecl>(D->getDeclContext())
3115       && !isa<ObjCMethodDecl>(D->getDeclContext()))
3116     LinkageName = Var->getName();
3117   if (LinkageName == DeclName)
3118     LinkageName = StringRef();
3119   llvm::DIDescriptor DContext =
3120     getContextDescriptor(dyn_cast<Decl>(D->getDeclContext()));
3121   llvm::DIGlobalVariable GV = DBuilder.createStaticVariable(
3122       DContext, DeclName, LinkageName, Unit, LineNo, getOrCreateType(T, Unit),
3123       Var->hasInternalLinkage(), Var,
3124       getOrCreateStaticDataMemberDeclarationOrNull(D));
3125   DeclCache.insert(std::make_pair(D->getCanonicalDecl(), llvm::WeakVH(GV)));
3126 }
3127 
3128 /// EmitGlobalVariable - Emit information about an objective-c interface.
3129 void CGDebugInfo::EmitGlobalVariable(llvm::GlobalVariable *Var,
3130                                      ObjCInterfaceDecl *ID) {
3131   assert(DebugKind >= CodeGenOptions::LimitedDebugInfo);
3132   // Create global variable debug descriptor.
3133   llvm::DIFile Unit = getOrCreateFile(ID->getLocation());
3134   unsigned LineNo = getLineNumber(ID->getLocation());
3135 
3136   StringRef Name = ID->getName();
3137 
3138   QualType T = CGM.getContext().getObjCInterfaceType(ID);
3139   if (T->isIncompleteArrayType()) {
3140 
3141     // CodeGen turns int[] into int[1] so we'll do the same here.
3142     llvm::APInt ConstVal(32, 1);
3143     QualType ET = CGM.getContext().getAsArrayType(T)->getElementType();
3144 
3145     T = CGM.getContext().getConstantArrayType(ET, ConstVal,
3146                                            ArrayType::Normal, 0);
3147   }
3148 
3149   DBuilder.createGlobalVariable(Name, Unit, LineNo,
3150                                 getOrCreateType(T, Unit),
3151                                 Var->hasInternalLinkage(), Var);
3152 }
3153 
3154 /// EmitGlobalVariable - Emit global variable's debug info.
3155 void CGDebugInfo::EmitGlobalVariable(const ValueDecl *VD,
3156                                      llvm::Constant *Init) {
3157   assert(DebugKind >= CodeGenOptions::LimitedDebugInfo);
3158   // Create the descriptor for the variable.
3159   llvm::DIFile Unit = getOrCreateFile(VD->getLocation());
3160   StringRef Name = VD->getName();
3161   llvm::DIType Ty = getOrCreateType(VD->getType(), Unit);
3162   if (const EnumConstantDecl *ECD = dyn_cast<EnumConstantDecl>(VD)) {
3163     const EnumDecl *ED = cast<EnumDecl>(ECD->getDeclContext());
3164     assert(isa<EnumType>(ED->getTypeForDecl()) && "Enum without EnumType?");
3165     Ty = getOrCreateType(QualType(ED->getTypeForDecl(), 0), Unit);
3166   }
3167   // Do not use DIGlobalVariable for enums.
3168   if (Ty.getTag() == llvm::dwarf::DW_TAG_enumeration_type)
3169     return;
3170   llvm::DIGlobalVariable GV = DBuilder.createStaticVariable(
3171       Unit, Name, Name, Unit, getLineNumber(VD->getLocation()), Ty, true, Init,
3172       getOrCreateStaticDataMemberDeclarationOrNull(cast<VarDecl>(VD)));
3173   DeclCache.insert(std::make_pair(VD->getCanonicalDecl(), llvm::WeakVH(GV)));
3174 }
3175 
3176 llvm::DIScope CGDebugInfo::getCurrentContextDescriptor(const Decl *D) {
3177   if (!LexicalBlockStack.empty())
3178     return llvm::DIScope(LexicalBlockStack.back());
3179   return getContextDescriptor(D);
3180 }
3181 
3182 void CGDebugInfo::EmitUsingDirective(const UsingDirectiveDecl &UD) {
3183   if (CGM.getCodeGenOpts().getDebugInfo() < CodeGenOptions::LimitedDebugInfo)
3184     return;
3185   DBuilder.createImportedModule(
3186       getCurrentContextDescriptor(cast<Decl>(UD.getDeclContext())),
3187       getOrCreateNameSpace(UD.getNominatedNamespace()),
3188       getLineNumber(UD.getLocation()));
3189 }
3190 
3191 void CGDebugInfo::EmitUsingDecl(const UsingDecl &UD) {
3192   if (CGM.getCodeGenOpts().getDebugInfo() < CodeGenOptions::LimitedDebugInfo)
3193     return;
3194   assert(UD.shadow_size() &&
3195          "We shouldn't be codegening an invalid UsingDecl containing no decls");
3196   // Emitting one decl is sufficient - debuggers can detect that this is an
3197   // overloaded name & provide lookup for all the overloads.
3198   const UsingShadowDecl &USD = **UD.shadow_begin();
3199   if (llvm::DIDescriptor Target =
3200           getDeclarationOrDefinition(USD.getUnderlyingDecl()))
3201     DBuilder.createImportedDeclaration(
3202         getCurrentContextDescriptor(cast<Decl>(USD.getDeclContext())), Target,
3203         getLineNumber(USD.getLocation()));
3204 }
3205 
3206 llvm::DIImportedEntity
3207 CGDebugInfo::EmitNamespaceAlias(const NamespaceAliasDecl &NA) {
3208   if (CGM.getCodeGenOpts().getDebugInfo() < CodeGenOptions::LimitedDebugInfo)
3209     return llvm::DIImportedEntity(0);
3210   llvm::WeakVH &VH = NamespaceAliasCache[&NA];
3211   if (VH)
3212     return llvm::DIImportedEntity(cast<llvm::MDNode>(VH));
3213   llvm::DIImportedEntity R(0);
3214   if (const NamespaceAliasDecl *Underlying =
3215           dyn_cast<NamespaceAliasDecl>(NA.getAliasedNamespace()))
3216     // This could cache & dedup here rather than relying on metadata deduping.
3217     R = DBuilder.createImportedModule(
3218         getCurrentContextDescriptor(cast<Decl>(NA.getDeclContext())),
3219         EmitNamespaceAlias(*Underlying), getLineNumber(NA.getLocation()),
3220         NA.getName());
3221   else
3222     R = DBuilder.createImportedModule(
3223         getCurrentContextDescriptor(cast<Decl>(NA.getDeclContext())),
3224         getOrCreateNameSpace(cast<NamespaceDecl>(NA.getAliasedNamespace())),
3225         getLineNumber(NA.getLocation()), NA.getName());
3226   VH = R;
3227   return R;
3228 }
3229 
3230 /// getOrCreateNamesSpace - Return namespace descriptor for the given
3231 /// namespace decl.
3232 llvm::DINameSpace
3233 CGDebugInfo::getOrCreateNameSpace(const NamespaceDecl *NSDecl) {
3234   NSDecl = NSDecl->getCanonicalDecl();
3235   llvm::DenseMap<const NamespaceDecl *, llvm::WeakVH>::iterator I =
3236     NameSpaceCache.find(NSDecl);
3237   if (I != NameSpaceCache.end())
3238     return llvm::DINameSpace(cast<llvm::MDNode>(I->second));
3239 
3240   unsigned LineNo = getLineNumber(NSDecl->getLocation());
3241   llvm::DIFile FileD = getOrCreateFile(NSDecl->getLocation());
3242   llvm::DIDescriptor Context =
3243     getContextDescriptor(dyn_cast<Decl>(NSDecl->getDeclContext()));
3244   llvm::DINameSpace NS =
3245     DBuilder.createNameSpace(Context, NSDecl->getName(), FileD, LineNo);
3246   NameSpaceCache[NSDecl] = llvm::WeakVH(NS);
3247   return NS;
3248 }
3249 
3250 void CGDebugInfo::finalize() {
3251   for (std::vector<std::pair<void *, llvm::WeakVH> >::const_iterator VI
3252          = ReplaceMap.begin(), VE = ReplaceMap.end(); VI != VE; ++VI) {
3253     llvm::DIType Ty, RepTy;
3254     // Verify that the debug info still exists.
3255     if (llvm::Value *V = VI->second)
3256       Ty = llvm::DIType(cast<llvm::MDNode>(V));
3257 
3258     llvm::DenseMap<void *, llvm::WeakVH>::iterator it =
3259       TypeCache.find(VI->first);
3260     if (it != TypeCache.end()) {
3261       // Verify that the debug info still exists.
3262       if (llvm::Value *V = it->second)
3263         RepTy = llvm::DIType(cast<llvm::MDNode>(V));
3264     }
3265 
3266     if (Ty && Ty.isForwardDecl() && RepTy)
3267       Ty.replaceAllUsesWith(RepTy);
3268   }
3269 
3270   // We keep our own list of retained types, because we need to look
3271   // up the final type in the type cache.
3272   for (std::vector<void *>::const_iterator RI = RetainedTypes.begin(),
3273          RE = RetainedTypes.end(); RI != RE; ++RI)
3274     DBuilder.retainType(llvm::DIType(cast<llvm::MDNode>(TypeCache[*RI])));
3275 
3276   DBuilder.finalize();
3277 }
3278