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