1 //===- DebugInfoMetadata.cpp - Implement debug info metadata --------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the debug info Metadata classes.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/IR/DebugInfoMetadata.h"
15 #include "LLVMContextImpl.h"
16 #include "MetadataImpl.h"
17 #include "llvm/ADT/SmallPtrSet.h"
18 #include "llvm/ADT/StringSwitch.h"
19 #include "llvm/IR/DIBuilder.h"
20 #include "llvm/IR/Function.h"
21 #include "llvm/IR/Instructions.h"
22 
23 using namespace llvm;
24 
25 DILocation::DILocation(LLVMContext &C, StorageType Storage, unsigned Line,
26                        unsigned Column, ArrayRef<Metadata *> MDs)
27     : MDNode(C, DILocationKind, Storage, MDs) {
28   assert((MDs.size() == 1 || MDs.size() == 2) &&
29          "Expected a scope and optional inlined-at");
30 
31   // Set line and column.
32   assert(Column < (1u << 16) && "Expected 16-bit column");
33 
34   SubclassData32 = Line;
35   SubclassData16 = Column;
36 }
37 
38 static void adjustColumn(unsigned &Column) {
39   // Set to unknown on overflow.  We only have 16 bits to play with here.
40   if (Column >= (1u << 16))
41     Column = 0;
42 }
43 
44 DILocation *DILocation::getImpl(LLVMContext &Context, unsigned Line,
45                                 unsigned Column, Metadata *Scope,
46                                 Metadata *InlinedAt, StorageType Storage,
47                                 bool ShouldCreate) {
48   // Fixup column.
49   adjustColumn(Column);
50 
51   if (Storage == Uniqued) {
52     if (auto *N =
53             getUniqued(Context.pImpl->DILocations,
54                        DILocationInfo::KeyTy(Line, Column, Scope, InlinedAt)))
55       return N;
56     if (!ShouldCreate)
57       return nullptr;
58   } else {
59     assert(ShouldCreate && "Expected non-uniqued nodes to always be created");
60   }
61 
62   SmallVector<Metadata *, 2> Ops;
63   Ops.push_back(Scope);
64   if (InlinedAt)
65     Ops.push_back(InlinedAt);
66   return storeImpl(new (Ops.size())
67                        DILocation(Context, Storage, Line, Column, Ops),
68                    Storage, Context.pImpl->DILocations);
69 }
70 
71 const DILocation *
72 DILocation::getMergedLocation(const DILocation *LocA, const DILocation *LocB,
73                               const Instruction *ForInst) {
74   if (!LocA || !LocB)
75     return nullptr;
76 
77   if (LocA == LocB || !LocA->canDiscriminate(*LocB))
78     return LocA;
79 
80   if (!dyn_cast_or_null<CallInst>(ForInst))
81     return nullptr;
82 
83   SmallPtrSet<DILocation *, 5> InlinedLocationsA;
84   for (DILocation *L = LocA->getInlinedAt(); L; L = L->getInlinedAt())
85     InlinedLocationsA.insert(L);
86   const DILocation *Result = LocB;
87   for (DILocation *L = LocB->getInlinedAt(); L; L = L->getInlinedAt()) {
88     Result = L;
89     if (InlinedLocationsA.count(L))
90       break;
91   }
92   return DILocation::get(Result->getContext(), 0, 0, Result->getScope(),
93                          Result->getInlinedAt());
94 }
95 
96 DINode::DIFlags DINode::getFlag(StringRef Flag) {
97   return StringSwitch<DIFlags>(Flag)
98 #define HANDLE_DI_FLAG(ID, NAME) .Case("DIFlag" #NAME, Flag##NAME)
99 #include "llvm/IR/DebugInfoFlags.def"
100       .Default(DINode::FlagZero);
101 }
102 
103 StringRef DINode::getFlagString(DIFlags Flag) {
104   switch (Flag) {
105 #define HANDLE_DI_FLAG(ID, NAME)                                               \
106   case Flag##NAME:                                                             \
107     return "DIFlag" #NAME;
108 #include "llvm/IR/DebugInfoFlags.def"
109   }
110   return "";
111 }
112 
113 DINode::DIFlags DINode::splitFlags(DIFlags Flags,
114                                    SmallVectorImpl<DIFlags> &SplitFlags) {
115   // Flags that are packed together need to be specially handled, so
116   // that, for example, we emit "DIFlagPublic" and not
117   // "DIFlagPrivate | DIFlagProtected".
118   if (DIFlags A = Flags & FlagAccessibility) {
119     if (A == FlagPrivate)
120       SplitFlags.push_back(FlagPrivate);
121     else if (A == FlagProtected)
122       SplitFlags.push_back(FlagProtected);
123     else
124       SplitFlags.push_back(FlagPublic);
125     Flags &= ~A;
126   }
127   if (DIFlags R = Flags & FlagPtrToMemberRep) {
128     if (R == FlagSingleInheritance)
129       SplitFlags.push_back(FlagSingleInheritance);
130     else if (R == FlagMultipleInheritance)
131       SplitFlags.push_back(FlagMultipleInheritance);
132     else
133       SplitFlags.push_back(FlagVirtualInheritance);
134     Flags &= ~R;
135   }
136   if ((Flags & FlagIndirectVirtualBase) == FlagIndirectVirtualBase) {
137     Flags &= ~FlagIndirectVirtualBase;
138     SplitFlags.push_back(FlagIndirectVirtualBase);
139   }
140 
141 #define HANDLE_DI_FLAG(ID, NAME)                                               \
142   if (DIFlags Bit = Flags & Flag##NAME) {                                      \
143     SplitFlags.push_back(Bit);                                                 \
144     Flags &= ~Bit;                                                             \
145   }
146 #include "llvm/IR/DebugInfoFlags.def"
147   return Flags;
148 }
149 
150 DIScopeRef DIScope::getScope() const {
151   if (auto *T = dyn_cast<DIType>(this))
152     return T->getScope();
153 
154   if (auto *SP = dyn_cast<DISubprogram>(this))
155     return SP->getScope();
156 
157   if (auto *LB = dyn_cast<DILexicalBlockBase>(this))
158     return LB->getScope();
159 
160   if (auto *NS = dyn_cast<DINamespace>(this))
161     return NS->getScope();
162 
163   if (auto *M = dyn_cast<DIModule>(this))
164     return M->getScope();
165 
166   assert((isa<DIFile>(this) || isa<DICompileUnit>(this)) &&
167          "Unhandled type of scope.");
168   return nullptr;
169 }
170 
171 StringRef DIScope::getName() const {
172   if (auto *T = dyn_cast<DIType>(this))
173     return T->getName();
174   if (auto *SP = dyn_cast<DISubprogram>(this))
175     return SP->getName();
176   if (auto *NS = dyn_cast<DINamespace>(this))
177     return NS->getName();
178   if (auto *M = dyn_cast<DIModule>(this))
179     return M->getName();
180   assert((isa<DILexicalBlockBase>(this) || isa<DIFile>(this) ||
181           isa<DICompileUnit>(this)) &&
182          "Unhandled type of scope.");
183   return "";
184 }
185 
186 #ifndef NDEBUG
187 static bool isCanonical(const MDString *S) {
188   return !S || !S->getString().empty();
189 }
190 #endif
191 
192 GenericDINode *GenericDINode::getImpl(LLVMContext &Context, unsigned Tag,
193                                       MDString *Header,
194                                       ArrayRef<Metadata *> DwarfOps,
195                                       StorageType Storage, bool ShouldCreate) {
196   unsigned Hash = 0;
197   if (Storage == Uniqued) {
198     GenericDINodeInfo::KeyTy Key(Tag, Header, DwarfOps);
199     if (auto *N = getUniqued(Context.pImpl->GenericDINodes, Key))
200       return N;
201     if (!ShouldCreate)
202       return nullptr;
203     Hash = Key.getHash();
204   } else {
205     assert(ShouldCreate && "Expected non-uniqued nodes to always be created");
206   }
207 
208   // Use a nullptr for empty headers.
209   assert(isCanonical(Header) && "Expected canonical MDString");
210   Metadata *PreOps[] = {Header};
211   return storeImpl(new (DwarfOps.size() + 1) GenericDINode(
212                        Context, Storage, Hash, Tag, PreOps, DwarfOps),
213                    Storage, Context.pImpl->GenericDINodes);
214 }
215 
216 void GenericDINode::recalculateHash() {
217   setHash(GenericDINodeInfo::KeyTy::calculateHash(this));
218 }
219 
220 #define UNWRAP_ARGS_IMPL(...) __VA_ARGS__
221 #define UNWRAP_ARGS(ARGS) UNWRAP_ARGS_IMPL ARGS
222 #define DEFINE_GETIMPL_LOOKUP(CLASS, ARGS)                                     \
223   do {                                                                         \
224     if (Storage == Uniqued) {                                                  \
225       if (auto *N = getUniqued(Context.pImpl->CLASS##s,                        \
226                                CLASS##Info::KeyTy(UNWRAP_ARGS(ARGS))))         \
227         return N;                                                              \
228       if (!ShouldCreate)                                                       \
229         return nullptr;                                                        \
230     } else {                                                                   \
231       assert(ShouldCreate &&                                                   \
232              "Expected non-uniqued nodes to always be created");               \
233     }                                                                          \
234   } while (false)
235 #define DEFINE_GETIMPL_STORE(CLASS, ARGS, OPS)                                 \
236   return storeImpl(new (array_lengthof(OPS))                                   \
237                        CLASS(Context, Storage, UNWRAP_ARGS(ARGS), OPS),        \
238                    Storage, Context.pImpl->CLASS##s)
239 #define DEFINE_GETIMPL_STORE_NO_OPS(CLASS, ARGS)                               \
240   return storeImpl(new (0u) CLASS(Context, Storage, UNWRAP_ARGS(ARGS)),        \
241                    Storage, Context.pImpl->CLASS##s)
242 #define DEFINE_GETIMPL_STORE_NO_CONSTRUCTOR_ARGS(CLASS, OPS)                   \
243   return storeImpl(new (array_lengthof(OPS)) CLASS(Context, Storage, OPS),     \
244                    Storage, Context.pImpl->CLASS##s)
245 #define DEFINE_GETIMPL_STORE_N(CLASS, ARGS, OPS, NUM_OPS)                      \
246   return storeImpl(new (NUM_OPS)                                               \
247                        CLASS(Context, Storage, UNWRAP_ARGS(ARGS), OPS),        \
248                    Storage, Context.pImpl->CLASS##s)
249 
250 DISubrange *DISubrange::getImpl(LLVMContext &Context, int64_t Count, int64_t Lo,
251                                 StorageType Storage, bool ShouldCreate) {
252   DEFINE_GETIMPL_LOOKUP(DISubrange, (Count, Lo));
253   DEFINE_GETIMPL_STORE_NO_OPS(DISubrange, (Count, Lo));
254 }
255 
256 DIEnumerator *DIEnumerator::getImpl(LLVMContext &Context, int64_t Value,
257                                     MDString *Name, StorageType Storage,
258                                     bool ShouldCreate) {
259   assert(isCanonical(Name) && "Expected canonical MDString");
260   DEFINE_GETIMPL_LOOKUP(DIEnumerator, (Value, Name));
261   Metadata *Ops[] = {Name};
262   DEFINE_GETIMPL_STORE(DIEnumerator, (Value), Ops);
263 }
264 
265 DIBasicType *DIBasicType::getImpl(LLVMContext &Context, unsigned Tag,
266                                   MDString *Name, uint64_t SizeInBits,
267                                   uint32_t AlignInBits, unsigned Encoding,
268                                   StorageType Storage, bool ShouldCreate) {
269   assert(isCanonical(Name) && "Expected canonical MDString");
270   DEFINE_GETIMPL_LOOKUP(DIBasicType,
271                         (Tag, Name, SizeInBits, AlignInBits, Encoding));
272   Metadata *Ops[] = {nullptr, nullptr, Name};
273   DEFINE_GETIMPL_STORE(DIBasicType, (Tag, SizeInBits, AlignInBits, Encoding),
274                        Ops);
275 }
276 
277 DIDerivedType *DIDerivedType::getImpl(
278     LLVMContext &Context, unsigned Tag, MDString *Name, Metadata *File,
279     unsigned Line, Metadata *Scope, Metadata *BaseType, uint64_t SizeInBits,
280     uint32_t AlignInBits, uint64_t OffsetInBits,
281     Optional<unsigned> DWARFAddressSpace, DIFlags Flags, Metadata *ExtraData,
282     StorageType Storage, bool ShouldCreate) {
283   assert(isCanonical(Name) && "Expected canonical MDString");
284   DEFINE_GETIMPL_LOOKUP(DIDerivedType,
285                         (Tag, Name, File, Line, Scope, BaseType, SizeInBits,
286                          AlignInBits, OffsetInBits, DWARFAddressSpace, Flags,
287                          ExtraData));
288   Metadata *Ops[] = {File, Scope, Name, BaseType, ExtraData};
289   DEFINE_GETIMPL_STORE(
290       DIDerivedType, (Tag, Line, SizeInBits, AlignInBits, OffsetInBits,
291                       DWARFAddressSpace, Flags), Ops);
292 }
293 
294 DICompositeType *DICompositeType::getImpl(
295     LLVMContext &Context, unsigned Tag, MDString *Name, Metadata *File,
296     unsigned Line, Metadata *Scope, Metadata *BaseType, uint64_t SizeInBits,
297     uint32_t AlignInBits, uint64_t OffsetInBits, DIFlags Flags,
298     Metadata *Elements, unsigned RuntimeLang, Metadata *VTableHolder,
299     Metadata *TemplateParams, MDString *Identifier, StorageType Storage,
300     bool ShouldCreate) {
301   assert(isCanonical(Name) && "Expected canonical MDString");
302 
303   // Keep this in sync with buildODRType.
304   DEFINE_GETIMPL_LOOKUP(
305       DICompositeType, (Tag, Name, File, Line, Scope, BaseType, SizeInBits,
306                         AlignInBits, OffsetInBits, Flags, Elements, RuntimeLang,
307                         VTableHolder, TemplateParams, Identifier));
308   Metadata *Ops[] = {File,     Scope,        Name,           BaseType,
309                      Elements, VTableHolder, TemplateParams, Identifier};
310   DEFINE_GETIMPL_STORE(DICompositeType, (Tag, Line, RuntimeLang, SizeInBits,
311                                          AlignInBits, OffsetInBits, Flags),
312                        Ops);
313 }
314 
315 DICompositeType *DICompositeType::buildODRType(
316     LLVMContext &Context, MDString &Identifier, unsigned Tag, MDString *Name,
317     Metadata *File, unsigned Line, Metadata *Scope, Metadata *BaseType,
318     uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
319     DIFlags Flags, Metadata *Elements, unsigned RuntimeLang,
320     Metadata *VTableHolder, Metadata *TemplateParams) {
321   assert(!Identifier.getString().empty() && "Expected valid identifier");
322   if (!Context.isODRUniquingDebugTypes())
323     return nullptr;
324   auto *&CT = (*Context.pImpl->DITypeMap)[&Identifier];
325   if (!CT)
326     return CT = DICompositeType::getDistinct(
327                Context, Tag, Name, File, Line, Scope, BaseType, SizeInBits,
328                AlignInBits, OffsetInBits, Flags, Elements, RuntimeLang,
329                VTableHolder, TemplateParams, &Identifier);
330 
331   // Only mutate CT if it's a forward declaration and the new operands aren't.
332   assert(CT->getRawIdentifier() == &Identifier && "Wrong ODR identifier?");
333   if (!CT->isForwardDecl() || (Flags & DINode::FlagFwdDecl))
334     return CT;
335 
336   // Mutate CT in place.  Keep this in sync with getImpl.
337   CT->mutate(Tag, Line, RuntimeLang, SizeInBits, AlignInBits, OffsetInBits,
338              Flags);
339   Metadata *Ops[] = {File,     Scope,        Name,           BaseType,
340                      Elements, VTableHolder, TemplateParams, &Identifier};
341   assert((std::end(Ops) - std::begin(Ops)) == (int)CT->getNumOperands() &&
342          "Mismatched number of operands");
343   for (unsigned I = 0, E = CT->getNumOperands(); I != E; ++I)
344     if (Ops[I] != CT->getOperand(I))
345       CT->setOperand(I, Ops[I]);
346   return CT;
347 }
348 
349 DICompositeType *DICompositeType::getODRType(
350     LLVMContext &Context, MDString &Identifier, unsigned Tag, MDString *Name,
351     Metadata *File, unsigned Line, Metadata *Scope, Metadata *BaseType,
352     uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
353     DIFlags Flags, Metadata *Elements, unsigned RuntimeLang,
354     Metadata *VTableHolder, Metadata *TemplateParams) {
355   assert(!Identifier.getString().empty() && "Expected valid identifier");
356   if (!Context.isODRUniquingDebugTypes())
357     return nullptr;
358   auto *&CT = (*Context.pImpl->DITypeMap)[&Identifier];
359   if (!CT)
360     CT = DICompositeType::getDistinct(
361         Context, Tag, Name, File, Line, Scope, BaseType, SizeInBits,
362         AlignInBits, OffsetInBits, Flags, Elements, RuntimeLang, VTableHolder,
363         TemplateParams, &Identifier);
364   return CT;
365 }
366 
367 DICompositeType *DICompositeType::getODRTypeIfExists(LLVMContext &Context,
368                                                      MDString &Identifier) {
369   assert(!Identifier.getString().empty() && "Expected valid identifier");
370   if (!Context.isODRUniquingDebugTypes())
371     return nullptr;
372   return Context.pImpl->DITypeMap->lookup(&Identifier);
373 }
374 
375 DISubroutineType *DISubroutineType::getImpl(LLVMContext &Context, DIFlags Flags,
376                                             uint8_t CC, Metadata *TypeArray,
377                                             StorageType Storage,
378                                             bool ShouldCreate) {
379   DEFINE_GETIMPL_LOOKUP(DISubroutineType, (Flags, CC, TypeArray));
380   Metadata *Ops[] = {nullptr, nullptr, nullptr, TypeArray};
381   DEFINE_GETIMPL_STORE(DISubroutineType, (Flags, CC), Ops);
382 }
383 
384 // FIXME: Implement this string-enum correspondence with a .def file and macros,
385 // so that the association is explicit rather than implied.
386 static const char *ChecksumKindName[DIFile::CSK_Last + 1] = {
387   "CSK_None",
388   "CSK_MD5",
389   "CSK_SHA1"
390 };
391 
392 DIFile::ChecksumKind DIFile::getChecksumKind(StringRef CSKindStr) {
393   return StringSwitch<DIFile::ChecksumKind>(CSKindStr)
394       .Case("CSK_MD5", DIFile::CSK_MD5)
395       .Case("CSK_SHA1", DIFile::CSK_SHA1)
396       .Default(DIFile::CSK_None);
397 }
398 
399 StringRef DIFile::getChecksumKindAsString() const {
400   assert(CSKind <= DIFile::CSK_Last && "Invalid checksum kind");
401   return ChecksumKindName[CSKind];
402 }
403 
404 DIFile *DIFile::getImpl(LLVMContext &Context, MDString *Filename,
405                         MDString *Directory, DIFile::ChecksumKind CSKind,
406                         MDString *Checksum, StorageType Storage,
407                         bool ShouldCreate) {
408   assert(isCanonical(Filename) && "Expected canonical MDString");
409   assert(isCanonical(Directory) && "Expected canonical MDString");
410   assert(isCanonical(Checksum) && "Expected canonical MDString");
411   DEFINE_GETIMPL_LOOKUP(DIFile, (Filename, Directory, CSKind, Checksum));
412   Metadata *Ops[] = {Filename, Directory, Checksum};
413   DEFINE_GETIMPL_STORE(DIFile, (CSKind), Ops);
414 }
415 
416 DICompileUnit *DICompileUnit::getImpl(
417     LLVMContext &Context, unsigned SourceLanguage, Metadata *File,
418     MDString *Producer, bool IsOptimized, MDString *Flags,
419     unsigned RuntimeVersion, MDString *SplitDebugFilename,
420     unsigned EmissionKind, Metadata *EnumTypes, Metadata *RetainedTypes,
421     Metadata *GlobalVariables, Metadata *ImportedEntities, Metadata *Macros,
422     uint64_t DWOId, bool SplitDebugInlining, bool DebugInfoForProfiling,
423     bool GnuPubnames, StorageType Storage, bool ShouldCreate) {
424   assert(Storage != Uniqued && "Cannot unique DICompileUnit");
425   assert(isCanonical(Producer) && "Expected canonical MDString");
426   assert(isCanonical(Flags) && "Expected canonical MDString");
427   assert(isCanonical(SplitDebugFilename) && "Expected canonical MDString");
428 
429   Metadata *Ops[] = {
430       File,      Producer,      Flags,           SplitDebugFilename,
431       EnumTypes, RetainedTypes, GlobalVariables, ImportedEntities,
432       Macros};
433   return storeImpl(new (array_lengthof(Ops)) DICompileUnit(
434                        Context, Storage, SourceLanguage, IsOptimized,
435                        RuntimeVersion, EmissionKind, DWOId, SplitDebugInlining,
436                        DebugInfoForProfiling, GnuPubnames, Ops),
437                    Storage);
438 }
439 
440 Optional<DICompileUnit::DebugEmissionKind>
441 DICompileUnit::getEmissionKind(StringRef Str) {
442   return StringSwitch<Optional<DebugEmissionKind>>(Str)
443       .Case("NoDebug", NoDebug)
444       .Case("FullDebug", FullDebug)
445       .Case("LineTablesOnly", LineTablesOnly)
446       .Default(None);
447 }
448 
449 const char *DICompileUnit::EmissionKindString(DebugEmissionKind EK) {
450   switch (EK) {
451   case NoDebug:        return "NoDebug";
452   case FullDebug:      return "FullDebug";
453   case LineTablesOnly: return "LineTablesOnly";
454   }
455   return nullptr;
456 }
457 
458 DISubprogram *DILocalScope::getSubprogram() const {
459   if (auto *Block = dyn_cast<DILexicalBlockBase>(this))
460     return Block->getScope()->getSubprogram();
461   return const_cast<DISubprogram *>(cast<DISubprogram>(this));
462 }
463 
464 DILocalScope *DILocalScope::getNonLexicalBlockFileScope() const {
465   if (auto *File = dyn_cast<DILexicalBlockFile>(this))
466     return File->getScope()->getNonLexicalBlockFileScope();
467   return const_cast<DILocalScope *>(this);
468 }
469 
470 DISubprogram *DISubprogram::getImpl(
471     LLVMContext &Context, Metadata *Scope, MDString *Name,
472     MDString *LinkageName, Metadata *File, unsigned Line, Metadata *Type,
473     bool IsLocalToUnit, bool IsDefinition, unsigned ScopeLine,
474     Metadata *ContainingType, unsigned Virtuality, unsigned VirtualIndex,
475     int ThisAdjustment, DIFlags Flags, bool IsOptimized, Metadata *Unit,
476     Metadata *TemplateParams, Metadata *Declaration, Metadata *Variables,
477     Metadata *ThrownTypes, StorageType Storage, bool ShouldCreate) {
478   assert(isCanonical(Name) && "Expected canonical MDString");
479   assert(isCanonical(LinkageName) && "Expected canonical MDString");
480   DEFINE_GETIMPL_LOOKUP(
481       DISubprogram, (Scope, Name, LinkageName, File, Line, Type, IsLocalToUnit,
482                      IsDefinition, ScopeLine, ContainingType, Virtuality,
483                      VirtualIndex, ThisAdjustment, Flags, IsOptimized, Unit,
484                      TemplateParams, Declaration, Variables, ThrownTypes));
485   SmallVector<Metadata *, 11> Ops = {
486       File,        Scope,     Name,           LinkageName,    Type,       Unit,
487       Declaration, Variables, ContainingType, TemplateParams, ThrownTypes};
488   if (!ThrownTypes) {
489     Ops.pop_back();
490     if (!TemplateParams) {
491       Ops.pop_back();
492       if (!ContainingType)
493         Ops.pop_back();
494     }
495   }
496   DEFINE_GETIMPL_STORE_N(DISubprogram,
497                          (Line, ScopeLine, Virtuality, VirtualIndex,
498                           ThisAdjustment, Flags, IsLocalToUnit, IsDefinition,
499                           IsOptimized),
500                          Ops, Ops.size());
501 }
502 
503 bool DISubprogram::describes(const Function *F) const {
504   assert(F && "Invalid function");
505   if (F->getSubprogram() == this)
506     return true;
507   StringRef Name = getLinkageName();
508   if (Name.empty())
509     Name = getName();
510   return F->getName() == Name;
511 }
512 
513 DILexicalBlock *DILexicalBlock::getImpl(LLVMContext &Context, Metadata *Scope,
514                                         Metadata *File, unsigned Line,
515                                         unsigned Column, StorageType Storage,
516                                         bool ShouldCreate) {
517   // Fixup column.
518   adjustColumn(Column);
519 
520   assert(Scope && "Expected scope");
521   DEFINE_GETIMPL_LOOKUP(DILexicalBlock, (Scope, File, Line, Column));
522   Metadata *Ops[] = {File, Scope};
523   DEFINE_GETIMPL_STORE(DILexicalBlock, (Line, Column), Ops);
524 }
525 
526 DILexicalBlockFile *DILexicalBlockFile::getImpl(LLVMContext &Context,
527                                                 Metadata *Scope, Metadata *File,
528                                                 unsigned Discriminator,
529                                                 StorageType Storage,
530                                                 bool ShouldCreate) {
531   assert(Scope && "Expected scope");
532   DEFINE_GETIMPL_LOOKUP(DILexicalBlockFile, (Scope, File, Discriminator));
533   Metadata *Ops[] = {File, Scope};
534   DEFINE_GETIMPL_STORE(DILexicalBlockFile, (Discriminator), Ops);
535 }
536 
537 DINamespace *DINamespace::getImpl(LLVMContext &Context, Metadata *Scope,
538                                   MDString *Name, bool ExportSymbols,
539                                   StorageType Storage, bool ShouldCreate) {
540   assert(isCanonical(Name) && "Expected canonical MDString");
541   DEFINE_GETIMPL_LOOKUP(DINamespace, (Scope, Name, ExportSymbols));
542   // The nullptr is for DIScope's File operand. This should be refactored.
543   Metadata *Ops[] = {nullptr, Scope, Name};
544   DEFINE_GETIMPL_STORE(DINamespace, (ExportSymbols), Ops);
545 }
546 
547 DIModule *DIModule::getImpl(LLVMContext &Context, Metadata *Scope,
548                             MDString *Name, MDString *ConfigurationMacros,
549                             MDString *IncludePath, MDString *ISysRoot,
550                             StorageType Storage, bool ShouldCreate) {
551   assert(isCanonical(Name) && "Expected canonical MDString");
552   DEFINE_GETIMPL_LOOKUP(
553       DIModule, (Scope, Name, ConfigurationMacros, IncludePath, ISysRoot));
554   Metadata *Ops[] = {Scope, Name, ConfigurationMacros, IncludePath, ISysRoot};
555   DEFINE_GETIMPL_STORE_NO_CONSTRUCTOR_ARGS(DIModule, Ops);
556 }
557 
558 DITemplateTypeParameter *DITemplateTypeParameter::getImpl(LLVMContext &Context,
559                                                           MDString *Name,
560                                                           Metadata *Type,
561                                                           StorageType Storage,
562                                                           bool ShouldCreate) {
563   assert(isCanonical(Name) && "Expected canonical MDString");
564   DEFINE_GETIMPL_LOOKUP(DITemplateTypeParameter, (Name, Type));
565   Metadata *Ops[] = {Name, Type};
566   DEFINE_GETIMPL_STORE_NO_CONSTRUCTOR_ARGS(DITemplateTypeParameter, Ops);
567 }
568 
569 DITemplateValueParameter *DITemplateValueParameter::getImpl(
570     LLVMContext &Context, unsigned Tag, MDString *Name, Metadata *Type,
571     Metadata *Value, StorageType Storage, bool ShouldCreate) {
572   assert(isCanonical(Name) && "Expected canonical MDString");
573   DEFINE_GETIMPL_LOOKUP(DITemplateValueParameter, (Tag, Name, Type, Value));
574   Metadata *Ops[] = {Name, Type, Value};
575   DEFINE_GETIMPL_STORE(DITemplateValueParameter, (Tag), Ops);
576 }
577 
578 DIGlobalVariable *
579 DIGlobalVariable::getImpl(LLVMContext &Context, Metadata *Scope, MDString *Name,
580                           MDString *LinkageName, Metadata *File, unsigned Line,
581                           Metadata *Type, bool IsLocalToUnit, bool IsDefinition,
582                           Metadata *StaticDataMemberDeclaration,
583                           uint32_t AlignInBits, StorageType Storage,
584                           bool ShouldCreate) {
585   assert(isCanonical(Name) && "Expected canonical MDString");
586   assert(isCanonical(LinkageName) && "Expected canonical MDString");
587   DEFINE_GETIMPL_LOOKUP(DIGlobalVariable,
588                         (Scope, Name, LinkageName, File, Line, Type,
589                          IsLocalToUnit, IsDefinition,
590                          StaticDataMemberDeclaration, AlignInBits));
591   Metadata *Ops[] = {
592       Scope, Name, File, Type, Name, LinkageName, StaticDataMemberDeclaration};
593   DEFINE_GETIMPL_STORE(DIGlobalVariable,
594                        (Line, IsLocalToUnit, IsDefinition, AlignInBits),
595                        Ops);
596 }
597 
598 DILocalVariable *DILocalVariable::getImpl(LLVMContext &Context, Metadata *Scope,
599                                           MDString *Name, Metadata *File,
600                                           unsigned Line, Metadata *Type,
601                                           unsigned Arg, DIFlags Flags,
602                                           uint32_t AlignInBits,
603                                           StorageType Storage,
604                                           bool ShouldCreate) {
605   // 64K ought to be enough for any frontend.
606   assert(Arg <= UINT16_MAX && "Expected argument number to fit in 16-bits");
607 
608   assert(Scope && "Expected scope");
609   assert(isCanonical(Name) && "Expected canonical MDString");
610   DEFINE_GETIMPL_LOOKUP(DILocalVariable,
611                         (Scope, Name, File, Line, Type, Arg, Flags,
612                          AlignInBits));
613   Metadata *Ops[] = {Scope, Name, File, Type};
614   DEFINE_GETIMPL_STORE(DILocalVariable, (Line, Arg, Flags, AlignInBits), Ops);
615 }
616 
617 Optional<uint64_t> DIVariable::getSizeInBits() const {
618   // This is used by the Verifier so be mindful of broken types.
619   const Metadata *RawType = getRawType();
620   while (RawType) {
621     // Try to get the size directly.
622     if (auto *T = dyn_cast<DIType>(RawType))
623       if (uint64_t Size = T->getSizeInBits())
624         return Size;
625 
626     if (auto *DT = dyn_cast<DIDerivedType>(RawType)) {
627       // Look at the base type.
628       RawType = DT->getRawBaseType();
629       continue;
630     }
631 
632     // Missing type or size.
633     break;
634   }
635 
636   // Fail gracefully.
637   return None;
638 }
639 
640 DIExpression *DIExpression::getImpl(LLVMContext &Context,
641                                     ArrayRef<uint64_t> Elements,
642                                     StorageType Storage, bool ShouldCreate) {
643   DEFINE_GETIMPL_LOOKUP(DIExpression, (Elements));
644   DEFINE_GETIMPL_STORE_NO_OPS(DIExpression, (Elements));
645 }
646 
647 unsigned DIExpression::ExprOperand::getSize() const {
648   switch (getOp()) {
649   case dwarf::DW_OP_LLVM_fragment:
650     return 3;
651   case dwarf::DW_OP_constu:
652   case dwarf::DW_OP_plus_uconst:
653     return 2;
654   default:
655     return 1;
656   }
657 }
658 
659 bool DIExpression::isValid() const {
660   for (auto I = expr_op_begin(), E = expr_op_end(); I != E; ++I) {
661     // Check that there's space for the operand.
662     if (I->get() + I->getSize() > E->get())
663       return false;
664 
665     // Check that the operand is valid.
666     switch (I->getOp()) {
667     default:
668       return false;
669     case dwarf::DW_OP_LLVM_fragment:
670       // A fragment operator must appear at the end.
671       return I->get() + I->getSize() == E->get();
672     case dwarf::DW_OP_stack_value: {
673       // Must be the last one or followed by a DW_OP_LLVM_fragment.
674       if (I->get() + I->getSize() == E->get())
675         break;
676       auto J = I;
677       if ((++J)->getOp() != dwarf::DW_OP_LLVM_fragment)
678         return false;
679       break;
680     }
681     case dwarf::DW_OP_swap: {
682       // Must be more than one implicit element on the stack.
683 
684       // FIXME: A better way to implement this would be to add a local variable
685       // that keeps track of the stack depth and introduce something like a
686       // DW_LLVM_OP_implicit_location as a placeholder for the location this
687       // DIExpression is attached to, or else pass the number of implicit stack
688       // elements into isValid.
689       if (getNumElements() == 1)
690         return false;
691       break;
692     }
693     case dwarf::DW_OP_constu:
694     case dwarf::DW_OP_plus_uconst:
695     case dwarf::DW_OP_plus:
696     case dwarf::DW_OP_minus:
697     case dwarf::DW_OP_mul:
698     case dwarf::DW_OP_deref:
699     case dwarf::DW_OP_xderef:
700       break;
701     }
702   }
703   return true;
704 }
705 
706 Optional<DIExpression::FragmentInfo>
707 DIExpression::getFragmentInfo(expr_op_iterator Start, expr_op_iterator End) {
708   for (auto I = Start; I != End; ++I)
709     if (I->getOp() == dwarf::DW_OP_LLVM_fragment) {
710       DIExpression::FragmentInfo Info = {I->getArg(1), I->getArg(0)};
711       return Info;
712     }
713   return None;
714 }
715 
716 void DIExpression::appendOffset(SmallVectorImpl<uint64_t> &Ops,
717                                 int64_t Offset) {
718   if (Offset > 0) {
719     Ops.push_back(dwarf::DW_OP_plus_uconst);
720     Ops.push_back(Offset);
721   } else if (Offset < 0) {
722     Ops.push_back(dwarf::DW_OP_constu);
723     Ops.push_back(-Offset);
724     Ops.push_back(dwarf::DW_OP_minus);
725   }
726 }
727 
728 bool DIExpression::extractIfOffset(int64_t &Offset) const {
729   if (getNumElements() == 0) {
730     Offset = 0;
731     return true;
732   }
733 
734   if (getNumElements() == 2 && Elements[0] == dwarf::DW_OP_plus_uconst) {
735     Offset = Elements[1];
736     return true;
737   }
738 
739   if (getNumElements() == 3 && Elements[0] == dwarf::DW_OP_constu) {
740     if (Elements[2] == dwarf::DW_OP_plus) {
741       Offset = Elements[1];
742       return true;
743     }
744     if (Elements[2] == dwarf::DW_OP_minus) {
745       Offset = -Elements[1];
746       return true;
747     }
748   }
749 
750   return false;
751 }
752 
753 DIExpression *DIExpression::prepend(const DIExpression *Expr, bool DerefBefore,
754                                     int64_t Offset, bool DerefAfter,
755                                     bool StackValue) {
756   SmallVector<uint64_t, 8> Ops;
757   if (DerefBefore)
758     Ops.push_back(dwarf::DW_OP_deref);
759 
760   appendOffset(Ops, Offset);
761   if (DerefAfter)
762     Ops.push_back(dwarf::DW_OP_deref);
763 
764   if (Expr)
765     for (auto Op : Expr->expr_ops()) {
766       // A DW_OP_stack_value comes at the end, but before a DW_OP_LLVM_fragment.
767       if (StackValue) {
768         if (Op.getOp() == dwarf::DW_OP_stack_value)
769           StackValue = false;
770         else if (Op.getOp() == dwarf::DW_OP_LLVM_fragment) {
771           Ops.push_back(dwarf::DW_OP_stack_value);
772           StackValue = false;
773         }
774       }
775       Ops.push_back(Op.getOp());
776       for (unsigned I = 0; I < Op.getNumArgs(); ++I)
777         Ops.push_back(Op.getArg(I));
778     }
779   if (StackValue)
780     Ops.push_back(dwarf::DW_OP_stack_value);
781   return DIExpression::get(Expr->getContext(), Ops);
782 }
783 
784 Optional<DIExpression *> DIExpression::createFragmentExpression(
785     const DIExpression *Expr, unsigned OffsetInBits, unsigned SizeInBits) {
786   SmallVector<uint64_t, 8> Ops;
787   // Copy over the expression, but leave off any trailing DW_OP_LLVM_fragment.
788   if (Expr) {
789     for (auto Op : Expr->expr_ops()) {
790       switch (Op.getOp()) {
791       default: break;
792       case dwarf::DW_OP_plus:
793       case dwarf::DW_OP_minus:
794         // We can't safely split arithmetic into multiple fragments because we
795         // can't express carry-over between fragments.
796         //
797         // FIXME: We *could* preserve the lowest fragment of a constant offset
798         // operation if the offset fits into SizeInBits.
799         return None;
800       case dwarf::DW_OP_LLVM_fragment: {
801         // Make the new offset point into the existing fragment.
802         uint64_t FragmentOffsetInBits = Op.getArg(0);
803         // Op.getArg(0) is FragmentOffsetInBits.
804         // Op.getArg(1) is FragmentSizeInBits.
805         assert((OffsetInBits + SizeInBits <= Op.getArg(0) + Op.getArg(1)) &&
806                "new fragment outside of original fragment");
807         OffsetInBits += FragmentOffsetInBits;
808         continue;
809       }
810       }
811       Ops.push_back(Op.getOp());
812       for (unsigned I = 0; I < Op.getNumArgs(); ++I)
813         Ops.push_back(Op.getArg(I));
814     }
815   }
816   Ops.push_back(dwarf::DW_OP_LLVM_fragment);
817   Ops.push_back(OffsetInBits);
818   Ops.push_back(SizeInBits);
819   return DIExpression::get(Expr->getContext(), Ops);
820 }
821 
822 bool DIExpression::isConstant() const {
823   // Recognize DW_OP_constu C DW_OP_stack_value (DW_OP_LLVM_fragment Len Ofs)?.
824   if (getNumElements() != 3 && getNumElements() != 6)
825     return false;
826   if (getElement(0) != dwarf::DW_OP_constu ||
827       getElement(2) != dwarf::DW_OP_stack_value)
828     return false;
829   if (getNumElements() == 6 && getElement(3) != dwarf::DW_OP_LLVM_fragment)
830     return false;
831   return true;
832 }
833 
834 DIGlobalVariableExpression *
835 DIGlobalVariableExpression::getImpl(LLVMContext &Context, Metadata *Variable,
836                                     Metadata *Expression, StorageType Storage,
837                                     bool ShouldCreate) {
838   DEFINE_GETIMPL_LOOKUP(DIGlobalVariableExpression, (Variable, Expression));
839   Metadata *Ops[] = {Variable, Expression};
840   DEFINE_GETIMPL_STORE_NO_CONSTRUCTOR_ARGS(DIGlobalVariableExpression, Ops);
841 }
842 
843 DIObjCProperty *DIObjCProperty::getImpl(
844     LLVMContext &Context, MDString *Name, Metadata *File, unsigned Line,
845     MDString *GetterName, MDString *SetterName, unsigned Attributes,
846     Metadata *Type, StorageType Storage, bool ShouldCreate) {
847   assert(isCanonical(Name) && "Expected canonical MDString");
848   assert(isCanonical(GetterName) && "Expected canonical MDString");
849   assert(isCanonical(SetterName) && "Expected canonical MDString");
850   DEFINE_GETIMPL_LOOKUP(DIObjCProperty, (Name, File, Line, GetterName,
851                                          SetterName, Attributes, Type));
852   Metadata *Ops[] = {Name, File, GetterName, SetterName, Type};
853   DEFINE_GETIMPL_STORE(DIObjCProperty, (Line, Attributes), Ops);
854 }
855 
856 DIImportedEntity *DIImportedEntity::getImpl(LLVMContext &Context, unsigned Tag,
857                                             Metadata *Scope, Metadata *Entity,
858                                             Metadata *File, unsigned Line,
859                                             MDString *Name, StorageType Storage,
860                                             bool ShouldCreate) {
861   assert(isCanonical(Name) && "Expected canonical MDString");
862   DEFINE_GETIMPL_LOOKUP(DIImportedEntity,
863                         (Tag, Scope, Entity, File, Line, Name));
864   Metadata *Ops[] = {Scope, Entity, Name, File};
865   DEFINE_GETIMPL_STORE(DIImportedEntity, (Tag, Line), Ops);
866 }
867 
868 DIMacro *DIMacro::getImpl(LLVMContext &Context, unsigned MIType,
869                           unsigned Line, MDString *Name, MDString *Value,
870                           StorageType Storage, bool ShouldCreate) {
871   assert(isCanonical(Name) && "Expected canonical MDString");
872   DEFINE_GETIMPL_LOOKUP(DIMacro, (MIType, Line, Name, Value));
873   Metadata *Ops[] = { Name, Value };
874   DEFINE_GETIMPL_STORE(DIMacro, (MIType, Line), Ops);
875 }
876 
877 DIMacroFile *DIMacroFile::getImpl(LLVMContext &Context, unsigned MIType,
878                                   unsigned Line, Metadata *File,
879                                   Metadata *Elements, StorageType Storage,
880                                   bool ShouldCreate) {
881   DEFINE_GETIMPL_LOOKUP(DIMacroFile,
882                         (MIType, Line, File, Elements));
883   Metadata *Ops[] = { File, Elements };
884   DEFINE_GETIMPL_STORE(DIMacroFile, (MIType, Line), Ops);
885 }
886 
887