1 //===--- DIBuilder.cpp - Debug Information Builder ------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements the DIBuilder.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "llvm/IR/DIBuilder.h"
14 #include "LLVMContextImpl.h"
15 #include "llvm/ADT/APInt.h"
16 #include "llvm/ADT/APSInt.h"
17 #include "llvm/BinaryFormat/Dwarf.h"
18 #include "llvm/IR/Constants.h"
19 #include "llvm/IR/DebugInfo.h"
20 #include "llvm/IR/IRBuilder.h"
21 #include "llvm/IR/Module.h"
22 #include "llvm/Support/CommandLine.h"
23 #include <optional>
24 
25 using namespace llvm;
26 using namespace llvm::dwarf;
27 
28 DIBuilder::DIBuilder(Module &m, bool AllowUnresolvedNodes, DICompileUnit *CU)
29     : M(m), VMContext(M.getContext()), CUNode(CU), DeclareFn(nullptr),
30       ValueFn(nullptr), LabelFn(nullptr), AssignFn(nullptr),
31       AllowUnresolvedNodes(AllowUnresolvedNodes) {
32   if (CUNode) {
33     if (const auto &ETs = CUNode->getEnumTypes())
34       AllEnumTypes.assign(ETs.begin(), ETs.end());
35     if (const auto &RTs = CUNode->getRetainedTypes())
36       AllRetainTypes.assign(RTs.begin(), RTs.end());
37     if (const auto &GVs = CUNode->getGlobalVariables())
38       AllGVs.assign(GVs.begin(), GVs.end());
39     if (const auto &IMs = CUNode->getImportedEntities())
40       ImportedModules.assign(IMs.begin(), IMs.end());
41     if (const auto &MNs = CUNode->getMacros())
42       AllMacrosPerParent.insert({nullptr, {MNs.begin(), MNs.end()}});
43   }
44 }
45 
46 void DIBuilder::trackIfUnresolved(MDNode *N) {
47   if (!N)
48     return;
49   if (N->isResolved())
50     return;
51 
52   assert(AllowUnresolvedNodes && "Cannot handle unresolved nodes");
53   UnresolvedNodes.emplace_back(N);
54 }
55 
56 void DIBuilder::finalizeSubprogram(DISubprogram *SP) {
57   auto PN = SubprogramTrackedNodes.find(SP);
58   if (PN != SubprogramTrackedNodes.end())
59     SP->replaceRetainedNodes(
60         MDTuple::get(VMContext, SmallVector<Metadata *, 16>(PN->second.begin(),
61                                                             PN->second.end())));
62 }
63 
64 void DIBuilder::finalize() {
65   if (!CUNode) {
66     assert(!AllowUnresolvedNodes &&
67            "creating type nodes without a CU is not supported");
68     return;
69   }
70 
71   if (!AllEnumTypes.empty())
72     CUNode->replaceEnumTypes(MDTuple::get(
73         VMContext, SmallVector<Metadata *, 16>(AllEnumTypes.begin(),
74                                                AllEnumTypes.end())));
75 
76   SmallVector<Metadata *, 16> RetainValues;
77   // Declarations and definitions of the same type may be retained. Some
78   // clients RAUW these pairs, leaving duplicates in the retained types
79   // list. Use a set to remove the duplicates while we transform the
80   // TrackingVHs back into Values.
81   SmallPtrSet<Metadata *, 16> RetainSet;
82   for (unsigned I = 0, E = AllRetainTypes.size(); I < E; I++)
83     if (RetainSet.insert(AllRetainTypes[I]).second)
84       RetainValues.push_back(AllRetainTypes[I]);
85 
86   if (!RetainValues.empty())
87     CUNode->replaceRetainedTypes(MDTuple::get(VMContext, RetainValues));
88 
89   for (auto *SP : AllSubprograms)
90     finalizeSubprogram(SP);
91   for (auto *N : RetainValues)
92     if (auto *SP = dyn_cast<DISubprogram>(N))
93       finalizeSubprogram(SP);
94 
95   if (!AllGVs.empty())
96     CUNode->replaceGlobalVariables(MDTuple::get(VMContext, AllGVs));
97 
98   if (!ImportedModules.empty())
99     CUNode->replaceImportedEntities(MDTuple::get(
100         VMContext, SmallVector<Metadata *, 16>(ImportedModules.begin(),
101                                                ImportedModules.end())));
102 
103   for (const auto &I : AllMacrosPerParent) {
104     // DIMacroNode's with nullptr parent are DICompileUnit direct children.
105     if (!I.first) {
106       CUNode->replaceMacros(MDTuple::get(VMContext, I.second.getArrayRef()));
107       continue;
108     }
109     // Otherwise, it must be a temporary DIMacroFile that need to be resolved.
110     auto *TMF = cast<DIMacroFile>(I.first);
111     auto *MF = DIMacroFile::get(VMContext, dwarf::DW_MACINFO_start_file,
112                                 TMF->getLine(), TMF->getFile(),
113                                 getOrCreateMacroArray(I.second.getArrayRef()));
114     replaceTemporary(llvm::TempDIMacroNode(TMF), MF);
115   }
116 
117   // Now that all temp nodes have been replaced or deleted, resolve remaining
118   // cycles.
119   for (const auto &N : UnresolvedNodes)
120     if (N && !N->isResolved())
121       N->resolveCycles();
122   UnresolvedNodes.clear();
123 
124   // Can't handle unresolved nodes anymore.
125   AllowUnresolvedNodes = false;
126 }
127 
128 /// If N is compile unit return NULL otherwise return N.
129 static DIScope *getNonCompileUnitScope(DIScope *N) {
130   if (!N || isa<DICompileUnit>(N))
131     return nullptr;
132   return cast<DIScope>(N);
133 }
134 
135 DICompileUnit *DIBuilder::createCompileUnit(
136     unsigned Lang, DIFile *File, StringRef Producer, bool isOptimized,
137     StringRef Flags, unsigned RunTimeVer, StringRef SplitName,
138     DICompileUnit::DebugEmissionKind Kind, uint64_t DWOId,
139     bool SplitDebugInlining, bool DebugInfoForProfiling,
140     DICompileUnit::DebugNameTableKind NameTableKind, bool RangesBaseAddress,
141     StringRef SysRoot, StringRef SDK) {
142 
143   assert(((Lang <= dwarf::DW_LANG_Mojo && Lang >= dwarf::DW_LANG_C89) ||
144           (Lang <= dwarf::DW_LANG_hi_user && Lang >= dwarf::DW_LANG_lo_user)) &&
145          "Invalid Language tag");
146 
147   assert(!CUNode && "Can only make one compile unit per DIBuilder instance");
148   CUNode = DICompileUnit::getDistinct(
149       VMContext, Lang, File, Producer, isOptimized, Flags, RunTimeVer,
150       SplitName, Kind, nullptr, nullptr, nullptr, nullptr, nullptr, DWOId,
151       SplitDebugInlining, DebugInfoForProfiling, NameTableKind,
152       RangesBaseAddress, SysRoot, SDK);
153 
154   // Create a named metadata so that it is easier to find cu in a module.
155   NamedMDNode *NMD = M.getOrInsertNamedMetadata("llvm.dbg.cu");
156   NMD->addOperand(CUNode);
157   trackIfUnresolved(CUNode);
158   return CUNode;
159 }
160 
161 static DIImportedEntity *
162 createImportedModule(LLVMContext &C, dwarf::Tag Tag, DIScope *Context,
163                      Metadata *NS, DIFile *File, unsigned Line, StringRef Name,
164                      DINodeArray Elements,
165                      SmallVectorImpl<TrackingMDNodeRef> &ImportedModules) {
166   if (Line)
167     assert(File && "Source location has line number but no file");
168   unsigned EntitiesCount = C.pImpl->DIImportedEntitys.size();
169   auto *M = DIImportedEntity::get(C, Tag, Context, cast_or_null<DINode>(NS),
170                                   File, Line, Name, Elements);
171   if (EntitiesCount < C.pImpl->DIImportedEntitys.size())
172     // A new Imported Entity was just added to the context.
173     // Add it to the Imported Modules list.
174     ImportedModules.emplace_back(M);
175   return M;
176 }
177 
178 DIImportedEntity *DIBuilder::createImportedModule(DIScope *Context,
179                                                   DINamespace *NS, DIFile *File,
180                                                   unsigned Line,
181                                                   DINodeArray Elements) {
182   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_module,
183                                 Context, NS, File, Line, StringRef(), Elements,
184                                 getImportTrackingVector(Context));
185 }
186 
187 DIImportedEntity *DIBuilder::createImportedModule(DIScope *Context,
188                                                   DIImportedEntity *NS,
189                                                   DIFile *File, unsigned Line,
190                                                   DINodeArray Elements) {
191   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_module,
192                                 Context, NS, File, Line, StringRef(), Elements,
193                                 getImportTrackingVector(Context));
194 }
195 
196 DIImportedEntity *DIBuilder::createImportedModule(DIScope *Context, DIModule *M,
197                                                   DIFile *File, unsigned Line,
198                                                   DINodeArray Elements) {
199   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_module,
200                                 Context, M, File, Line, StringRef(), Elements,
201                                 getImportTrackingVector(Context));
202 }
203 
204 DIImportedEntity *
205 DIBuilder::createImportedDeclaration(DIScope *Context, DINode *Decl,
206                                      DIFile *File, unsigned Line,
207                                      StringRef Name, DINodeArray Elements) {
208   // Make sure to use the unique identifier based metadata reference for
209   // types that have one.
210   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_declaration,
211                                 Context, Decl, File, Line, Name, Elements,
212                                 getImportTrackingVector(Context));
213 }
214 
215 DIFile *DIBuilder::createFile(StringRef Filename, StringRef Directory,
216                               std::optional<DIFile::ChecksumInfo<StringRef>> CS,
217                               std::optional<StringRef> Source) {
218   return DIFile::get(VMContext, Filename, Directory, CS, Source);
219 }
220 
221 DIMacro *DIBuilder::createMacro(DIMacroFile *Parent, unsigned LineNumber,
222                                 unsigned MacroType, StringRef Name,
223                                 StringRef Value) {
224   assert(!Name.empty() && "Unable to create macro without name");
225   assert((MacroType == dwarf::DW_MACINFO_undef ||
226           MacroType == dwarf::DW_MACINFO_define) &&
227          "Unexpected macro type");
228   auto *M = DIMacro::get(VMContext, MacroType, LineNumber, Name, Value);
229   AllMacrosPerParent[Parent].insert(M);
230   return M;
231 }
232 
233 DIMacroFile *DIBuilder::createTempMacroFile(DIMacroFile *Parent,
234                                             unsigned LineNumber, DIFile *File) {
235   auto *MF = DIMacroFile::getTemporary(VMContext, dwarf::DW_MACINFO_start_file,
236                                        LineNumber, File, DIMacroNodeArray())
237                  .release();
238   AllMacrosPerParent[Parent].insert(MF);
239   // Add the new temporary DIMacroFile to the macro per parent map as a parent.
240   // This is needed to assure DIMacroFile with no children to have an entry in
241   // the map. Otherwise, it will not be resolved in DIBuilder::finalize().
242   AllMacrosPerParent.insert({MF, {}});
243   return MF;
244 }
245 
246 DIEnumerator *DIBuilder::createEnumerator(StringRef Name, uint64_t Val,
247                                           bool IsUnsigned) {
248   assert(!Name.empty() && "Unable to create enumerator without name");
249   return DIEnumerator::get(VMContext, APInt(64, Val, !IsUnsigned), IsUnsigned,
250                            Name);
251 }
252 
253 DIEnumerator *DIBuilder::createEnumerator(StringRef Name, const APSInt &Value) {
254   assert(!Name.empty() && "Unable to create enumerator without name");
255   return DIEnumerator::get(VMContext, APInt(Value), Value.isUnsigned(), Name);
256 }
257 
258 DIBasicType *DIBuilder::createUnspecifiedType(StringRef Name) {
259   assert(!Name.empty() && "Unable to create type without name");
260   return DIBasicType::get(VMContext, dwarf::DW_TAG_unspecified_type, Name);
261 }
262 
263 DIBasicType *DIBuilder::createNullPtrType() {
264   return createUnspecifiedType("decltype(nullptr)");
265 }
266 
267 DIBasicType *DIBuilder::createBasicType(StringRef Name, uint64_t SizeInBits,
268                                         unsigned Encoding,
269                                         DINode::DIFlags Flags) {
270   assert(!Name.empty() && "Unable to create type without name");
271   return DIBasicType::get(VMContext, dwarf::DW_TAG_base_type, Name, SizeInBits,
272                           0, Encoding, Flags);
273 }
274 
275 DIStringType *DIBuilder::createStringType(StringRef Name, uint64_t SizeInBits) {
276   assert(!Name.empty() && "Unable to create type without name");
277   return DIStringType::get(VMContext, dwarf::DW_TAG_string_type, Name,
278                            SizeInBits, 0);
279 }
280 
281 DIStringType *DIBuilder::createStringType(StringRef Name,
282                                           DIVariable *StringLength,
283                                           DIExpression *StrLocationExp) {
284   assert(!Name.empty() && "Unable to create type without name");
285   return DIStringType::get(VMContext, dwarf::DW_TAG_string_type, Name,
286                            StringLength, nullptr, StrLocationExp, 0, 0, 0);
287 }
288 
289 DIStringType *DIBuilder::createStringType(StringRef Name,
290                                           DIExpression *StringLengthExp,
291                                           DIExpression *StrLocationExp) {
292   assert(!Name.empty() && "Unable to create type without name");
293   return DIStringType::get(VMContext, dwarf::DW_TAG_string_type, Name, nullptr,
294                            StringLengthExp, StrLocationExp, 0, 0, 0);
295 }
296 
297 DIDerivedType *DIBuilder::createQualifiedType(unsigned Tag, DIType *FromTy) {
298   return DIDerivedType::get(VMContext, Tag, "", nullptr, 0, nullptr, FromTy, 0,
299                             0, 0, std::nullopt, DINode::FlagZero);
300 }
301 
302 DIDerivedType *
303 DIBuilder::createPointerType(DIType *PointeeTy, uint64_t SizeInBits,
304                              uint32_t AlignInBits,
305                              std::optional<unsigned> DWARFAddressSpace,
306                              StringRef Name, DINodeArray Annotations) {
307   // FIXME: Why is there a name here?
308   return DIDerivedType::get(VMContext, dwarf::DW_TAG_pointer_type, Name,
309                             nullptr, 0, nullptr, PointeeTy, SizeInBits,
310                             AlignInBits, 0, DWARFAddressSpace, DINode::FlagZero,
311                             nullptr, Annotations);
312 }
313 
314 DIDerivedType *DIBuilder::createMemberPointerType(DIType *PointeeTy,
315                                                   DIType *Base,
316                                                   uint64_t SizeInBits,
317                                                   uint32_t AlignInBits,
318                                                   DINode::DIFlags Flags) {
319   return DIDerivedType::get(VMContext, dwarf::DW_TAG_ptr_to_member_type, "",
320                             nullptr, 0, nullptr, PointeeTy, SizeInBits,
321                             AlignInBits, 0, std::nullopt, Flags, Base);
322 }
323 
324 DIDerivedType *
325 DIBuilder::createReferenceType(unsigned Tag, DIType *RTy, uint64_t SizeInBits,
326                                uint32_t AlignInBits,
327                                std::optional<unsigned> DWARFAddressSpace) {
328   assert(RTy && "Unable to create reference type");
329   return DIDerivedType::get(VMContext, Tag, "", nullptr, 0, nullptr, RTy,
330                             SizeInBits, AlignInBits, 0, DWARFAddressSpace,
331                             DINode::FlagZero);
332 }
333 
334 DIDerivedType *DIBuilder::createTypedef(DIType *Ty, StringRef Name,
335                                         DIFile *File, unsigned LineNo,
336                                         DIScope *Context, uint32_t AlignInBits,
337                                         DINode::DIFlags Flags,
338                                         DINodeArray Annotations) {
339   return DIDerivedType::get(VMContext, dwarf::DW_TAG_typedef, Name, File,
340                             LineNo, getNonCompileUnitScope(Context), Ty, 0,
341                             AlignInBits, 0, std::nullopt, Flags, nullptr,
342                             Annotations);
343 }
344 
345 DIDerivedType *DIBuilder::createFriend(DIType *Ty, DIType *FriendTy) {
346   assert(Ty && "Invalid type!");
347   assert(FriendTy && "Invalid friend type!");
348   return DIDerivedType::get(VMContext, dwarf::DW_TAG_friend, "", nullptr, 0, Ty,
349                             FriendTy, 0, 0, 0, std::nullopt, DINode::FlagZero);
350 }
351 
352 DIDerivedType *DIBuilder::createInheritance(DIType *Ty, DIType *BaseTy,
353                                             uint64_t BaseOffset,
354                                             uint32_t VBPtrOffset,
355                                             DINode::DIFlags Flags) {
356   assert(Ty && "Unable to create inheritance");
357   Metadata *ExtraData = ConstantAsMetadata::get(
358       ConstantInt::get(IntegerType::get(VMContext, 32), VBPtrOffset));
359   return DIDerivedType::get(VMContext, dwarf::DW_TAG_inheritance, "", nullptr,
360                             0, Ty, BaseTy, 0, 0, BaseOffset, std::nullopt,
361                             Flags, ExtraData);
362 }
363 
364 DIDerivedType *DIBuilder::createMemberType(
365     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
366     uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
367     DINode::DIFlags Flags, DIType *Ty, DINodeArray Annotations) {
368   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
369                             LineNumber, getNonCompileUnitScope(Scope), Ty,
370                             SizeInBits, AlignInBits, OffsetInBits, std::nullopt,
371                             Flags, nullptr, Annotations);
372 }
373 
374 static ConstantAsMetadata *getConstantOrNull(Constant *C) {
375   if (C)
376     return ConstantAsMetadata::get(C);
377   return nullptr;
378 }
379 
380 DIDerivedType *DIBuilder::createVariantMemberType(
381     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
382     uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
383     Constant *Discriminant, DINode::DIFlags Flags, DIType *Ty) {
384   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
385                             LineNumber, getNonCompileUnitScope(Scope), Ty,
386                             SizeInBits, AlignInBits, OffsetInBits, std::nullopt,
387                             Flags, getConstantOrNull(Discriminant));
388 }
389 
390 DIDerivedType *DIBuilder::createBitFieldMemberType(
391     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
392     uint64_t SizeInBits, uint64_t OffsetInBits, uint64_t StorageOffsetInBits,
393     DINode::DIFlags Flags, DIType *Ty, DINodeArray Annotations) {
394   Flags |= DINode::FlagBitField;
395   return DIDerivedType::get(
396       VMContext, dwarf::DW_TAG_member, Name, File, LineNumber,
397       getNonCompileUnitScope(Scope), Ty, SizeInBits, /*AlignInBits=*/0,
398       OffsetInBits, std::nullopt, Flags,
399       ConstantAsMetadata::get(ConstantInt::get(IntegerType::get(VMContext, 64),
400                                                StorageOffsetInBits)),
401       Annotations);
402 }
403 
404 DIDerivedType *
405 DIBuilder::createStaticMemberType(DIScope *Scope, StringRef Name, DIFile *File,
406                                   unsigned LineNumber, DIType *Ty,
407                                   DINode::DIFlags Flags, llvm::Constant *Val,
408                                   uint32_t AlignInBits) {
409   Flags |= DINode::FlagStaticMember;
410   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
411                             LineNumber, getNonCompileUnitScope(Scope), Ty, 0,
412                             AlignInBits, 0, std::nullopt, Flags,
413                             getConstantOrNull(Val));
414 }
415 
416 DIDerivedType *
417 DIBuilder::createObjCIVar(StringRef Name, DIFile *File, unsigned LineNumber,
418                           uint64_t SizeInBits, uint32_t AlignInBits,
419                           uint64_t OffsetInBits, DINode::DIFlags Flags,
420                           DIType *Ty, MDNode *PropertyNode) {
421   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
422                             LineNumber, getNonCompileUnitScope(File), Ty,
423                             SizeInBits, AlignInBits, OffsetInBits, std::nullopt,
424                             Flags, PropertyNode);
425 }
426 
427 DIObjCProperty *
428 DIBuilder::createObjCProperty(StringRef Name, DIFile *File, unsigned LineNumber,
429                               StringRef GetterName, StringRef SetterName,
430                               unsigned PropertyAttributes, DIType *Ty) {
431   return DIObjCProperty::get(VMContext, Name, File, LineNumber, GetterName,
432                              SetterName, PropertyAttributes, Ty);
433 }
434 
435 DITemplateTypeParameter *
436 DIBuilder::createTemplateTypeParameter(DIScope *Context, StringRef Name,
437                                        DIType *Ty, bool isDefault) {
438   assert((!Context || isa<DICompileUnit>(Context)) && "Expected compile unit");
439   return DITemplateTypeParameter::get(VMContext, Name, Ty, isDefault);
440 }
441 
442 static DITemplateValueParameter *
443 createTemplateValueParameterHelper(LLVMContext &VMContext, unsigned Tag,
444                                    DIScope *Context, StringRef Name, DIType *Ty,
445                                    bool IsDefault, Metadata *MD) {
446   assert((!Context || isa<DICompileUnit>(Context)) && "Expected compile unit");
447   return DITemplateValueParameter::get(VMContext, Tag, Name, Ty, IsDefault, MD);
448 }
449 
450 DITemplateValueParameter *
451 DIBuilder::createTemplateValueParameter(DIScope *Context, StringRef Name,
452                                         DIType *Ty, bool isDefault,
453                                         Constant *Val) {
454   return createTemplateValueParameterHelper(
455       VMContext, dwarf::DW_TAG_template_value_parameter, Context, Name, Ty,
456       isDefault, getConstantOrNull(Val));
457 }
458 
459 DITemplateValueParameter *
460 DIBuilder::createTemplateTemplateParameter(DIScope *Context, StringRef Name,
461                                            DIType *Ty, StringRef Val,
462                                            bool IsDefault) {
463   return createTemplateValueParameterHelper(
464       VMContext, dwarf::DW_TAG_GNU_template_template_param, Context, Name, Ty,
465       IsDefault, MDString::get(VMContext, Val));
466 }
467 
468 DITemplateValueParameter *
469 DIBuilder::createTemplateParameterPack(DIScope *Context, StringRef Name,
470                                        DIType *Ty, DINodeArray Val) {
471   return createTemplateValueParameterHelper(
472       VMContext, dwarf::DW_TAG_GNU_template_parameter_pack, Context, Name, Ty,
473       false, Val.get());
474 }
475 
476 DICompositeType *DIBuilder::createClassType(
477     DIScope *Context, StringRef Name, DIFile *File, unsigned LineNumber,
478     uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
479     DINode::DIFlags Flags, DIType *DerivedFrom, DINodeArray Elements,
480     DIType *VTableHolder, MDNode *TemplateParams, StringRef UniqueIdentifier) {
481   assert((!Context || isa<DIScope>(Context)) &&
482          "createClassType should be called with a valid Context");
483 
484   auto *R = DICompositeType::get(
485       VMContext, dwarf::DW_TAG_structure_type, Name, File, LineNumber,
486       getNonCompileUnitScope(Context), DerivedFrom, SizeInBits, AlignInBits,
487       OffsetInBits, Flags, Elements, 0, VTableHolder,
488       cast_or_null<MDTuple>(TemplateParams), UniqueIdentifier);
489   trackIfUnresolved(R);
490   return R;
491 }
492 
493 DICompositeType *DIBuilder::createStructType(
494     DIScope *Context, StringRef Name, DIFile *File, unsigned LineNumber,
495     uint64_t SizeInBits, uint32_t AlignInBits, DINode::DIFlags Flags,
496     DIType *DerivedFrom, DINodeArray Elements, unsigned RunTimeLang,
497     DIType *VTableHolder, StringRef UniqueIdentifier) {
498   auto *R = DICompositeType::get(
499       VMContext, dwarf::DW_TAG_structure_type, Name, File, LineNumber,
500       getNonCompileUnitScope(Context), DerivedFrom, SizeInBits, AlignInBits, 0,
501       Flags, Elements, RunTimeLang, VTableHolder, nullptr, UniqueIdentifier);
502   trackIfUnresolved(R);
503   return R;
504 }
505 
506 DICompositeType *DIBuilder::createUnionType(
507     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
508     uint64_t SizeInBits, uint32_t AlignInBits, DINode::DIFlags Flags,
509     DINodeArray Elements, unsigned RunTimeLang, StringRef UniqueIdentifier) {
510   auto *R = DICompositeType::get(
511       VMContext, dwarf::DW_TAG_union_type, Name, File, LineNumber,
512       getNonCompileUnitScope(Scope), nullptr, SizeInBits, AlignInBits, 0, Flags,
513       Elements, RunTimeLang, nullptr, nullptr, UniqueIdentifier);
514   trackIfUnresolved(R);
515   return R;
516 }
517 
518 DICompositeType *
519 DIBuilder::createVariantPart(DIScope *Scope, StringRef Name, DIFile *File,
520                              unsigned LineNumber, uint64_t SizeInBits,
521                              uint32_t AlignInBits, DINode::DIFlags Flags,
522                              DIDerivedType *Discriminator, DINodeArray Elements,
523                              StringRef UniqueIdentifier) {
524   auto *R = DICompositeType::get(
525       VMContext, dwarf::DW_TAG_variant_part, Name, File, LineNumber,
526       getNonCompileUnitScope(Scope), nullptr, SizeInBits, AlignInBits, 0, Flags,
527       Elements, 0, nullptr, nullptr, UniqueIdentifier, Discriminator);
528   trackIfUnresolved(R);
529   return R;
530 }
531 
532 DISubroutineType *DIBuilder::createSubroutineType(DITypeRefArray ParameterTypes,
533                                                   DINode::DIFlags Flags,
534                                                   unsigned CC) {
535   return DISubroutineType::get(VMContext, Flags, CC, ParameterTypes);
536 }
537 
538 DICompositeType *DIBuilder::createEnumerationType(
539     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
540     uint64_t SizeInBits, uint32_t AlignInBits, DINodeArray Elements,
541     DIType *UnderlyingType, StringRef UniqueIdentifier, bool IsScoped) {
542   auto *CTy = DICompositeType::get(
543       VMContext, dwarf::DW_TAG_enumeration_type, Name, File, LineNumber,
544       getNonCompileUnitScope(Scope), UnderlyingType, SizeInBits, AlignInBits, 0,
545       IsScoped ? DINode::FlagEnumClass : DINode::FlagZero, Elements, 0, nullptr,
546       nullptr, UniqueIdentifier);
547   AllEnumTypes.emplace_back(CTy);
548   trackIfUnresolved(CTy);
549   return CTy;
550 }
551 
552 DIDerivedType *DIBuilder::createSetType(DIScope *Scope, StringRef Name,
553                                         DIFile *File, unsigned LineNo,
554                                         uint64_t SizeInBits,
555                                         uint32_t AlignInBits, DIType *Ty) {
556   auto *R =
557       DIDerivedType::get(VMContext, dwarf::DW_TAG_set_type, Name, File, LineNo,
558                          getNonCompileUnitScope(Scope), Ty, SizeInBits,
559                          AlignInBits, 0, std::nullopt, DINode::FlagZero);
560   trackIfUnresolved(R);
561   return R;
562 }
563 
564 DICompositeType *
565 DIBuilder::createArrayType(uint64_t Size, uint32_t AlignInBits, DIType *Ty,
566                            DINodeArray Subscripts,
567                            PointerUnion<DIExpression *, DIVariable *> DL,
568                            PointerUnion<DIExpression *, DIVariable *> AS,
569                            PointerUnion<DIExpression *, DIVariable *> AL,
570                            PointerUnion<DIExpression *, DIVariable *> RK) {
571   auto *R = DICompositeType::get(
572       VMContext, dwarf::DW_TAG_array_type, "", nullptr, 0, nullptr, Ty, Size,
573       AlignInBits, 0, DINode::FlagZero, Subscripts, 0, nullptr, nullptr, "",
574       nullptr,
575       isa<DIExpression *>(DL) ? (Metadata *)cast<DIExpression *>(DL)
576                               : (Metadata *)cast<DIVariable *>(DL),
577       isa<DIExpression *>(AS) ? (Metadata *)cast<DIExpression *>(AS)
578                               : (Metadata *)cast<DIVariable *>(AS),
579       isa<DIExpression *>(AL) ? (Metadata *)cast<DIExpression *>(AL)
580                               : (Metadata *)cast<DIVariable *>(AL),
581       isa<DIExpression *>(RK) ? (Metadata *)cast<DIExpression *>(RK)
582                               : (Metadata *)cast<DIVariable *>(RK));
583   trackIfUnresolved(R);
584   return R;
585 }
586 
587 DICompositeType *DIBuilder::createVectorType(uint64_t Size,
588                                              uint32_t AlignInBits, DIType *Ty,
589                                              DINodeArray Subscripts) {
590   auto *R = DICompositeType::get(VMContext, dwarf::DW_TAG_array_type, "",
591                                  nullptr, 0, nullptr, Ty, Size, AlignInBits, 0,
592                                  DINode::FlagVector, Subscripts, 0, nullptr);
593   trackIfUnresolved(R);
594   return R;
595 }
596 
597 DISubprogram *DIBuilder::createArtificialSubprogram(DISubprogram *SP) {
598   auto NewSP = SP->cloneWithFlags(SP->getFlags() | DINode::FlagArtificial);
599   return MDNode::replaceWithDistinct(std::move(NewSP));
600 }
601 
602 static DIType *createTypeWithFlags(const DIType *Ty,
603                                    DINode::DIFlags FlagsToSet) {
604   auto NewTy = Ty->cloneWithFlags(Ty->getFlags() | FlagsToSet);
605   return MDNode::replaceWithUniqued(std::move(NewTy));
606 }
607 
608 DIType *DIBuilder::createArtificialType(DIType *Ty) {
609   // FIXME: Restrict this to the nodes where it's valid.
610   if (Ty->isArtificial())
611     return Ty;
612   return createTypeWithFlags(Ty, DINode::FlagArtificial);
613 }
614 
615 DIType *DIBuilder::createObjectPointerType(DIType *Ty) {
616   // FIXME: Restrict this to the nodes where it's valid.
617   if (Ty->isObjectPointer())
618     return Ty;
619   DINode::DIFlags Flags = DINode::FlagObjectPointer | DINode::FlagArtificial;
620   return createTypeWithFlags(Ty, Flags);
621 }
622 
623 void DIBuilder::retainType(DIScope *T) {
624   assert(T && "Expected non-null type");
625   assert((isa<DIType>(T) || (isa<DISubprogram>(T) &&
626                              cast<DISubprogram>(T)->isDefinition() == false)) &&
627          "Expected type or subprogram declaration");
628   AllRetainTypes.emplace_back(T);
629 }
630 
631 DIBasicType *DIBuilder::createUnspecifiedParameter() { return nullptr; }
632 
633 DICompositeType *
634 DIBuilder::createForwardDecl(unsigned Tag, StringRef Name, DIScope *Scope,
635                              DIFile *F, unsigned Line, unsigned RuntimeLang,
636                              uint64_t SizeInBits, uint32_t AlignInBits,
637                              StringRef UniqueIdentifier) {
638   // FIXME: Define in terms of createReplaceableForwardDecl() by calling
639   // replaceWithUniqued().
640   auto *RetTy = DICompositeType::get(
641       VMContext, Tag, Name, F, Line, getNonCompileUnitScope(Scope), nullptr,
642       SizeInBits, AlignInBits, 0, DINode::FlagFwdDecl, nullptr, RuntimeLang,
643       nullptr, nullptr, UniqueIdentifier);
644   trackIfUnresolved(RetTy);
645   return RetTy;
646 }
647 
648 DICompositeType *DIBuilder::createReplaceableCompositeType(
649     unsigned Tag, StringRef Name, DIScope *Scope, DIFile *F, unsigned Line,
650     unsigned RuntimeLang, uint64_t SizeInBits, uint32_t AlignInBits,
651     DINode::DIFlags Flags, StringRef UniqueIdentifier,
652     DINodeArray Annotations) {
653   auto *RetTy =
654       DICompositeType::getTemporary(
655           VMContext, Tag, Name, F, Line, getNonCompileUnitScope(Scope), nullptr,
656           SizeInBits, AlignInBits, 0, Flags, nullptr, RuntimeLang, nullptr,
657           nullptr, UniqueIdentifier, nullptr, nullptr, nullptr, nullptr,
658           nullptr, Annotations)
659           .release();
660   trackIfUnresolved(RetTy);
661   return RetTy;
662 }
663 
664 DINodeArray DIBuilder::getOrCreateArray(ArrayRef<Metadata *> Elements) {
665   return MDTuple::get(VMContext, Elements);
666 }
667 
668 DIMacroNodeArray
669 DIBuilder::getOrCreateMacroArray(ArrayRef<Metadata *> Elements) {
670   return MDTuple::get(VMContext, Elements);
671 }
672 
673 DITypeRefArray DIBuilder::getOrCreateTypeArray(ArrayRef<Metadata *> Elements) {
674   SmallVector<llvm::Metadata *, 16> Elts;
675   for (Metadata *E : Elements) {
676     if (isa_and_nonnull<MDNode>(E))
677       Elts.push_back(cast<DIType>(E));
678     else
679       Elts.push_back(E);
680   }
681   return DITypeRefArray(MDNode::get(VMContext, Elts));
682 }
683 
684 DISubrange *DIBuilder::getOrCreateSubrange(int64_t Lo, int64_t Count) {
685   auto *LB = ConstantAsMetadata::get(
686       ConstantInt::getSigned(Type::getInt64Ty(VMContext), Lo));
687   auto *CountNode = ConstantAsMetadata::get(
688       ConstantInt::getSigned(Type::getInt64Ty(VMContext), Count));
689   return DISubrange::get(VMContext, CountNode, LB, nullptr, nullptr);
690 }
691 
692 DISubrange *DIBuilder::getOrCreateSubrange(int64_t Lo, Metadata *CountNode) {
693   auto *LB = ConstantAsMetadata::get(
694       ConstantInt::getSigned(Type::getInt64Ty(VMContext), Lo));
695   return DISubrange::get(VMContext, CountNode, LB, nullptr, nullptr);
696 }
697 
698 DISubrange *DIBuilder::getOrCreateSubrange(Metadata *CountNode, Metadata *LB,
699                                            Metadata *UB, Metadata *Stride) {
700   return DISubrange::get(VMContext, CountNode, LB, UB, Stride);
701 }
702 
703 DIGenericSubrange *DIBuilder::getOrCreateGenericSubrange(
704     DIGenericSubrange::BoundType CountNode, DIGenericSubrange::BoundType LB,
705     DIGenericSubrange::BoundType UB, DIGenericSubrange::BoundType Stride) {
706   auto ConvToMetadata = [&](DIGenericSubrange::BoundType Bound) -> Metadata * {
707     return isa<DIExpression *>(Bound) ? (Metadata *)cast<DIExpression *>(Bound)
708                                       : (Metadata *)cast<DIVariable *>(Bound);
709   };
710   return DIGenericSubrange::get(VMContext, ConvToMetadata(CountNode),
711                                 ConvToMetadata(LB), ConvToMetadata(UB),
712                                 ConvToMetadata(Stride));
713 }
714 
715 static void checkGlobalVariableScope(DIScope *Context) {
716 #ifndef NDEBUG
717   if (auto *CT =
718           dyn_cast_or_null<DICompositeType>(getNonCompileUnitScope(Context)))
719     assert(CT->getIdentifier().empty() &&
720            "Context of a global variable should not be a type with identifier");
721 #endif
722 }
723 
724 DIGlobalVariableExpression *DIBuilder::createGlobalVariableExpression(
725     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
726     unsigned LineNumber, DIType *Ty, bool IsLocalToUnit, bool isDefined,
727     DIExpression *Expr, MDNode *Decl, MDTuple *TemplateParams,
728     uint32_t AlignInBits, DINodeArray Annotations) {
729   checkGlobalVariableScope(Context);
730 
731   auto *GV = DIGlobalVariable::getDistinct(
732       VMContext, cast_or_null<DIScope>(Context), Name, LinkageName, F,
733       LineNumber, Ty, IsLocalToUnit, isDefined,
734       cast_or_null<DIDerivedType>(Decl), TemplateParams, AlignInBits,
735       Annotations);
736   if (!Expr)
737     Expr = createExpression();
738   auto *N = DIGlobalVariableExpression::get(VMContext, GV, Expr);
739   AllGVs.push_back(N);
740   return N;
741 }
742 
743 DIGlobalVariable *DIBuilder::createTempGlobalVariableFwdDecl(
744     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
745     unsigned LineNumber, DIType *Ty, bool IsLocalToUnit, MDNode *Decl,
746     MDTuple *TemplateParams, uint32_t AlignInBits) {
747   checkGlobalVariableScope(Context);
748 
749   return DIGlobalVariable::getTemporary(
750              VMContext, cast_or_null<DIScope>(Context), Name, LinkageName, F,
751              LineNumber, Ty, IsLocalToUnit, false,
752              cast_or_null<DIDerivedType>(Decl), TemplateParams, AlignInBits,
753              nullptr)
754       .release();
755 }
756 
757 static DILocalVariable *createLocalVariable(
758     LLVMContext &VMContext,
759     SmallVectorImpl<TrackingMDNodeRef> &PreservedNodes,
760     DIScope *Context, StringRef Name, unsigned ArgNo, DIFile *File,
761     unsigned LineNo, DIType *Ty, bool AlwaysPreserve, DINode::DIFlags Flags,
762     uint32_t AlignInBits, DINodeArray Annotations = nullptr) {
763   // FIXME: Why doesn't this check for a subprogram or lexical block (AFAICT
764   // the only valid scopes)?
765   auto *Scope = cast<DILocalScope>(Context);
766   auto *Node = DILocalVariable::get(VMContext, Scope, Name, File, LineNo, Ty,
767                                     ArgNo, Flags, AlignInBits, Annotations);
768   if (AlwaysPreserve) {
769     // The optimizer may remove local variables. If there is an interest
770     // to preserve variable info in such situation then stash it in a
771     // named mdnode.
772     PreservedNodes.emplace_back(Node);
773   }
774   return Node;
775 }
776 
777 DILocalVariable *DIBuilder::createAutoVariable(DIScope *Scope, StringRef Name,
778                                                DIFile *File, unsigned LineNo,
779                                                DIType *Ty, bool AlwaysPreserve,
780                                                DINode::DIFlags Flags,
781                                                uint32_t AlignInBits) {
782   assert(Scope && isa<DILocalScope>(Scope) &&
783          "Unexpected scope for a local variable.");
784   return createLocalVariable(
785       VMContext, getSubprogramNodesTrackingVector(Scope), Scope, Name,
786       /* ArgNo */ 0, File, LineNo, Ty, AlwaysPreserve, Flags, AlignInBits);
787 }
788 
789 DILocalVariable *DIBuilder::createParameterVariable(
790     DIScope *Scope, StringRef Name, unsigned ArgNo, DIFile *File,
791     unsigned LineNo, DIType *Ty, bool AlwaysPreserve, DINode::DIFlags Flags,
792     DINodeArray Annotations) {
793   assert(ArgNo && "Expected non-zero argument number for parameter");
794   assert(Scope && isa<DILocalScope>(Scope) &&
795          "Unexpected scope for a local variable.");
796   return createLocalVariable(
797       VMContext, getSubprogramNodesTrackingVector(Scope), Scope, Name, ArgNo,
798       File, LineNo, Ty, AlwaysPreserve, Flags, /*AlignInBits=*/0, Annotations);
799 }
800 
801 DILabel *DIBuilder::createLabel(DIScope *Context, StringRef Name, DIFile *File,
802                                  unsigned LineNo, bool AlwaysPreserve) {
803   auto *Scope = cast<DILocalScope>(Context);
804   auto *Node = DILabel::get(VMContext, Scope, Name, File, LineNo);
805 
806   if (AlwaysPreserve) {
807     /// The optimizer may remove labels. If there is an interest
808     /// to preserve label info in such situation then append it to
809     /// the list of retained nodes of the DISubprogram.
810     getSubprogramNodesTrackingVector(Scope).emplace_back(Node);
811   }
812   return Node;
813 }
814 
815 DIExpression *DIBuilder::createExpression(ArrayRef<uint64_t> Addr) {
816   return DIExpression::get(VMContext, Addr);
817 }
818 
819 template <class... Ts>
820 static DISubprogram *getSubprogram(bool IsDistinct, Ts &&...Args) {
821   if (IsDistinct)
822     return DISubprogram::getDistinct(std::forward<Ts>(Args)...);
823   return DISubprogram::get(std::forward<Ts>(Args)...);
824 }
825 
826 DISubprogram *DIBuilder::createFunction(
827     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *File,
828     unsigned LineNo, DISubroutineType *Ty, unsigned ScopeLine,
829     DINode::DIFlags Flags, DISubprogram::DISPFlags SPFlags,
830     DITemplateParameterArray TParams, DISubprogram *Decl,
831     DITypeArray ThrownTypes, DINodeArray Annotations,
832     StringRef TargetFuncName) {
833   bool IsDefinition = SPFlags & DISubprogram::SPFlagDefinition;
834   auto *Node = getSubprogram(
835       /*IsDistinct=*/IsDefinition, VMContext, getNonCompileUnitScope(Context),
836       Name, LinkageName, File, LineNo, Ty, ScopeLine, nullptr, 0, 0, Flags,
837       SPFlags, IsDefinition ? CUNode : nullptr, TParams, Decl, nullptr,
838       ThrownTypes, Annotations, TargetFuncName);
839 
840   if (IsDefinition)
841     AllSubprograms.push_back(Node);
842   trackIfUnresolved(Node);
843   return Node;
844 }
845 
846 DISubprogram *DIBuilder::createTempFunctionFwdDecl(
847     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *File,
848     unsigned LineNo, DISubroutineType *Ty, unsigned ScopeLine,
849     DINode::DIFlags Flags, DISubprogram::DISPFlags SPFlags,
850     DITemplateParameterArray TParams, DISubprogram *Decl,
851     DITypeArray ThrownTypes) {
852   bool IsDefinition = SPFlags & DISubprogram::SPFlagDefinition;
853   return DISubprogram::getTemporary(VMContext, getNonCompileUnitScope(Context),
854                                     Name, LinkageName, File, LineNo, Ty,
855                                     ScopeLine, nullptr, 0, 0, Flags, SPFlags,
856                                     IsDefinition ? CUNode : nullptr, TParams,
857                                     Decl, nullptr, ThrownTypes)
858       .release();
859 }
860 
861 DISubprogram *DIBuilder::createMethod(
862     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
863     unsigned LineNo, DISubroutineType *Ty, unsigned VIndex, int ThisAdjustment,
864     DIType *VTableHolder, DINode::DIFlags Flags,
865     DISubprogram::DISPFlags SPFlags, DITemplateParameterArray TParams,
866     DITypeArray ThrownTypes) {
867   assert(getNonCompileUnitScope(Context) &&
868          "Methods should have both a Context and a context that isn't "
869          "the compile unit.");
870   // FIXME: Do we want to use different scope/lines?
871   bool IsDefinition = SPFlags & DISubprogram::SPFlagDefinition;
872   auto *SP = getSubprogram(
873       /*IsDistinct=*/IsDefinition, VMContext, cast<DIScope>(Context), Name,
874       LinkageName, F, LineNo, Ty, LineNo, VTableHolder, VIndex, ThisAdjustment,
875       Flags, SPFlags, IsDefinition ? CUNode : nullptr, TParams, nullptr,
876       nullptr, ThrownTypes);
877 
878   if (IsDefinition)
879     AllSubprograms.push_back(SP);
880   trackIfUnresolved(SP);
881   return SP;
882 }
883 
884 DICommonBlock *DIBuilder::createCommonBlock(DIScope *Scope,
885                                             DIGlobalVariable *Decl,
886                                             StringRef Name, DIFile *File,
887                                             unsigned LineNo) {
888   return DICommonBlock::get(VMContext, Scope, Decl, Name, File, LineNo);
889 }
890 
891 DINamespace *DIBuilder::createNameSpace(DIScope *Scope, StringRef Name,
892                                         bool ExportSymbols) {
893 
894   // It is okay to *not* make anonymous top-level namespaces distinct, because
895   // all nodes that have an anonymous namespace as their parent scope are
896   // guaranteed to be unique and/or are linked to their containing
897   // DICompileUnit. This decision is an explicit tradeoff of link time versus
898   // memory usage versus code simplicity and may get revisited in the future.
899   return DINamespace::get(VMContext, getNonCompileUnitScope(Scope), Name,
900                           ExportSymbols);
901 }
902 
903 DIModule *DIBuilder::createModule(DIScope *Scope, StringRef Name,
904                                   StringRef ConfigurationMacros,
905                                   StringRef IncludePath, StringRef APINotesFile,
906                                   DIFile *File, unsigned LineNo, bool IsDecl) {
907   return DIModule::get(VMContext, File, getNonCompileUnitScope(Scope), Name,
908                        ConfigurationMacros, IncludePath, APINotesFile, LineNo,
909                        IsDecl);
910 }
911 
912 DILexicalBlockFile *DIBuilder::createLexicalBlockFile(DIScope *Scope,
913                                                       DIFile *File,
914                                                       unsigned Discriminator) {
915   return DILexicalBlockFile::get(VMContext, Scope, File, Discriminator);
916 }
917 
918 DILexicalBlock *DIBuilder::createLexicalBlock(DIScope *Scope, DIFile *File,
919                                               unsigned Line, unsigned Col) {
920   // Make these distinct, to avoid merging two lexical blocks on the same
921   // file/line/column.
922   return DILexicalBlock::getDistinct(VMContext, getNonCompileUnitScope(Scope),
923                                      File, Line, Col);
924 }
925 
926 Instruction *DIBuilder::insertDeclare(Value *Storage, DILocalVariable *VarInfo,
927                                       DIExpression *Expr, const DILocation *DL,
928                                       Instruction *InsertBefore) {
929   return insertDeclare(Storage, VarInfo, Expr, DL, InsertBefore->getParent(),
930                        InsertBefore);
931 }
932 
933 Instruction *DIBuilder::insertDeclare(Value *Storage, DILocalVariable *VarInfo,
934                                       DIExpression *Expr, const DILocation *DL,
935                                       BasicBlock *InsertAtEnd) {
936   // If this block already has a terminator then insert this intrinsic before
937   // the terminator. Otherwise, put it at the end of the block.
938   Instruction *InsertBefore = InsertAtEnd->getTerminator();
939   return insertDeclare(Storage, VarInfo, Expr, DL, InsertAtEnd, InsertBefore);
940 }
941 
942 DbgAssignIntrinsic *
943 DIBuilder::insertDbgAssign(Instruction *LinkedInstr, Value *Val,
944                            DILocalVariable *SrcVar, DIExpression *ValExpr,
945                            Value *Addr, DIExpression *AddrExpr,
946                            const DILocation *DL) {
947   LLVMContext &Ctx = LinkedInstr->getContext();
948   Module *M = LinkedInstr->getModule();
949   if (!AssignFn)
950     AssignFn = Intrinsic::getDeclaration(M, Intrinsic::dbg_assign);
951 
952   auto *Link = LinkedInstr->getMetadata(LLVMContext::MD_DIAssignID);
953   assert(Link && "Linked instruction must have DIAssign metadata attached");
954 
955   std::array<Value *, 6> Args = {
956       MetadataAsValue::get(Ctx, ValueAsMetadata::get(Val)),
957       MetadataAsValue::get(Ctx, SrcVar),
958       MetadataAsValue::get(Ctx, ValExpr),
959       MetadataAsValue::get(Ctx, Link),
960       MetadataAsValue::get(Ctx, ValueAsMetadata::get(Addr)),
961       MetadataAsValue::get(Ctx, AddrExpr),
962   };
963 
964   IRBuilder<> B(Ctx);
965   B.SetCurrentDebugLocation(DL);
966 
967   auto *DVI = cast<DbgAssignIntrinsic>(B.CreateCall(AssignFn, Args));
968   DVI->insertAfter(LinkedInstr);
969   return DVI;
970 }
971 
972 Instruction *DIBuilder::insertLabel(DILabel *LabelInfo, const DILocation *DL,
973                                     Instruction *InsertBefore) {
974   return insertLabel(LabelInfo, DL,
975                      InsertBefore ? InsertBefore->getParent() : nullptr,
976                      InsertBefore);
977 }
978 
979 Instruction *DIBuilder::insertLabel(DILabel *LabelInfo, const DILocation *DL,
980                                     BasicBlock *InsertAtEnd) {
981   return insertLabel(LabelInfo, DL, InsertAtEnd, nullptr);
982 }
983 
984 Instruction *DIBuilder::insertDbgValueIntrinsic(Value *V,
985                                                 DILocalVariable *VarInfo,
986                                                 DIExpression *Expr,
987                                                 const DILocation *DL,
988                                                 Instruction *InsertBefore) {
989   return insertDbgValueIntrinsic(
990       V, VarInfo, Expr, DL, InsertBefore ? InsertBefore->getParent() : nullptr,
991       InsertBefore);
992 }
993 
994 Instruction *DIBuilder::insertDbgValueIntrinsic(Value *V,
995                                                 DILocalVariable *VarInfo,
996                                                 DIExpression *Expr,
997                                                 const DILocation *DL,
998                                                 BasicBlock *InsertAtEnd) {
999   return insertDbgValueIntrinsic(V, VarInfo, Expr, DL, InsertAtEnd, nullptr);
1000 }
1001 
1002 /// Initialize IRBuilder for inserting dbg.declare and dbg.value intrinsics.
1003 /// This abstracts over the various ways to specify an insert position.
1004 static void initIRBuilder(IRBuilder<> &Builder, const DILocation *DL,
1005                           BasicBlock *InsertBB, Instruction *InsertBefore) {
1006   if (InsertBefore)
1007     Builder.SetInsertPoint(InsertBefore);
1008   else if (InsertBB)
1009     Builder.SetInsertPoint(InsertBB);
1010   Builder.SetCurrentDebugLocation(DL);
1011 }
1012 
1013 static Value *getDbgIntrinsicValueImpl(LLVMContext &VMContext, Value *V) {
1014   assert(V && "no value passed to dbg intrinsic");
1015   return MetadataAsValue::get(VMContext, ValueAsMetadata::get(V));
1016 }
1017 
1018 static Function *getDeclareIntrin(Module &M) {
1019   return Intrinsic::getDeclaration(&M, Intrinsic::dbg_declare);
1020 }
1021 
1022 Instruction *DIBuilder::insertDbgValueIntrinsic(
1023     llvm::Value *Val, DILocalVariable *VarInfo, DIExpression *Expr,
1024     const DILocation *DL, BasicBlock *InsertBB, Instruction *InsertBefore) {
1025   if (!ValueFn)
1026     ValueFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_value);
1027   return insertDbgIntrinsic(ValueFn, Val, VarInfo, Expr, DL, InsertBB,
1028                             InsertBefore);
1029 }
1030 
1031 Instruction *DIBuilder::insertDeclare(Value *Storage, DILocalVariable *VarInfo,
1032                                       DIExpression *Expr, const DILocation *DL,
1033                                       BasicBlock *InsertBB,
1034                                       Instruction *InsertBefore) {
1035   assert(VarInfo && "empty or invalid DILocalVariable* passed to dbg.declare");
1036   assert(DL && "Expected debug loc");
1037   assert(DL->getScope()->getSubprogram() ==
1038              VarInfo->getScope()->getSubprogram() &&
1039          "Expected matching subprograms");
1040   if (!DeclareFn)
1041     DeclareFn = getDeclareIntrin(M);
1042 
1043   trackIfUnresolved(VarInfo);
1044   trackIfUnresolved(Expr);
1045   Value *Args[] = {getDbgIntrinsicValueImpl(VMContext, Storage),
1046                    MetadataAsValue::get(VMContext, VarInfo),
1047                    MetadataAsValue::get(VMContext, Expr)};
1048 
1049   IRBuilder<> B(DL->getContext());
1050   initIRBuilder(B, DL, InsertBB, InsertBefore);
1051   return B.CreateCall(DeclareFn, Args);
1052 }
1053 
1054 Instruction *DIBuilder::insertDbgIntrinsic(llvm::Function *IntrinsicFn,
1055                                            Value *V, DILocalVariable *VarInfo,
1056                                            DIExpression *Expr,
1057                                            const DILocation *DL,
1058                                            BasicBlock *InsertBB,
1059                                            Instruction *InsertBefore) {
1060   assert(IntrinsicFn && "must pass a non-null intrinsic function");
1061   assert(V && "must pass a value to a dbg intrinsic");
1062   assert(VarInfo &&
1063          "empty or invalid DILocalVariable* passed to debug intrinsic");
1064   assert(DL && "Expected debug loc");
1065   assert(DL->getScope()->getSubprogram() ==
1066              VarInfo->getScope()->getSubprogram() &&
1067          "Expected matching subprograms");
1068 
1069   trackIfUnresolved(VarInfo);
1070   trackIfUnresolved(Expr);
1071   Value *Args[] = {getDbgIntrinsicValueImpl(VMContext, V),
1072                    MetadataAsValue::get(VMContext, VarInfo),
1073                    MetadataAsValue::get(VMContext, Expr)};
1074 
1075   IRBuilder<> B(DL->getContext());
1076   initIRBuilder(B, DL, InsertBB, InsertBefore);
1077   return B.CreateCall(IntrinsicFn, Args);
1078 }
1079 
1080 Instruction *DIBuilder::insertLabel(DILabel *LabelInfo, const DILocation *DL,
1081                                     BasicBlock *InsertBB,
1082                                     Instruction *InsertBefore) {
1083   assert(LabelInfo && "empty or invalid DILabel* passed to dbg.label");
1084   assert(DL && "Expected debug loc");
1085   assert(DL->getScope()->getSubprogram() ==
1086              LabelInfo->getScope()->getSubprogram() &&
1087          "Expected matching subprograms");
1088   if (!LabelFn)
1089     LabelFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_label);
1090 
1091   trackIfUnresolved(LabelInfo);
1092   Value *Args[] = {MetadataAsValue::get(VMContext, LabelInfo)};
1093 
1094   IRBuilder<> B(DL->getContext());
1095   initIRBuilder(B, DL, InsertBB, InsertBefore);
1096   return B.CreateCall(LabelFn, Args);
1097 }
1098 
1099 void DIBuilder::replaceVTableHolder(DICompositeType *&T, DIType *VTableHolder) {
1100   {
1101     TypedTrackingMDRef<DICompositeType> N(T);
1102     N->replaceVTableHolder(VTableHolder);
1103     T = N.get();
1104   }
1105 
1106   // If this didn't create a self-reference, just return.
1107   if (T != VTableHolder)
1108     return;
1109 
1110   // Look for unresolved operands.  T will drop RAUW support, orphaning any
1111   // cycles underneath it.
1112   if (T->isResolved())
1113     for (const MDOperand &O : T->operands())
1114       if (auto *N = dyn_cast_or_null<MDNode>(O))
1115         trackIfUnresolved(N);
1116 }
1117 
1118 void DIBuilder::replaceArrays(DICompositeType *&T, DINodeArray Elements,
1119                               DINodeArray TParams) {
1120   {
1121     TypedTrackingMDRef<DICompositeType> N(T);
1122     if (Elements)
1123       N->replaceElements(Elements);
1124     if (TParams)
1125       N->replaceTemplateParams(DITemplateParameterArray(TParams));
1126     T = N.get();
1127   }
1128 
1129   // If T isn't resolved, there's no problem.
1130   if (!T->isResolved())
1131     return;
1132 
1133   // If T is resolved, it may be due to a self-reference cycle.  Track the
1134   // arrays explicitly if they're unresolved, or else the cycles will be
1135   // orphaned.
1136   if (Elements)
1137     trackIfUnresolved(Elements.get());
1138   if (TParams)
1139     trackIfUnresolved(TParams.get());
1140 }
1141