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/Optional.h"
16 #include "llvm/BinaryFormat/Dwarf.h"
17 #include "llvm/IR/Constants.h"
18 #include "llvm/IR/DebugInfo.h"
19 #include "llvm/IR/IRBuilder.h"
20 #include "llvm/IR/Module.h"
21 #include "llvm/Support/CommandLine.h"
22 #include "llvm/Support/Debug.h"
23 
24 using namespace llvm;
25 using namespace llvm::dwarf;
26 
27 static cl::opt<bool>
28     UseDbgAddr("use-dbg-addr",
29                llvm::cl::desc("Use llvm.dbg.addr for all local variables"),
30                cl::init(false), cl::Hidden);
31 
32 DIBuilder::DIBuilder(Module &m, bool AllowUnresolvedNodes, DICompileUnit *CU)
33     : M(m), VMContext(M.getContext()), CUNode(CU), DeclareFn(nullptr),
34       ValueFn(nullptr), LabelFn(nullptr), AddrFn(nullptr),
35       AllowUnresolvedNodes(AllowUnresolvedNodes) {
36   if (CUNode) {
37     if (const auto &ETs = CUNode->getEnumTypes())
38       AllEnumTypes.assign(ETs.begin(), ETs.end());
39     if (const auto &RTs = CUNode->getRetainedTypes())
40       AllRetainTypes.assign(RTs.begin(), RTs.end());
41     if (const auto &GVs = CUNode->getGlobalVariables())
42       AllGVs.assign(GVs.begin(), GVs.end());
43     if (const auto &IMs = CUNode->getImportedEntities())
44       AllImportedModules.assign(IMs.begin(), IMs.end());
45     if (const auto &MNs = CUNode->getMacros())
46       AllMacrosPerParent.insert({nullptr, {MNs.begin(), MNs.end()}});
47   }
48 }
49 
50 void DIBuilder::trackIfUnresolved(MDNode *N) {
51   if (!N)
52     return;
53   if (N->isResolved())
54     return;
55 
56   assert(AllowUnresolvedNodes && "Cannot handle unresolved nodes");
57   UnresolvedNodes.emplace_back(N);
58 }
59 
60 void DIBuilder::finalizeSubprogram(DISubprogram *SP) {
61   MDTuple *Temp = SP->getRetainedNodes().get();
62   if (!Temp || !Temp->isTemporary())
63     return;
64 
65   SmallVector<Metadata *, 16> RetainedNodes;
66 
67   auto PV = PreservedVariables.find(SP);
68   if (PV != PreservedVariables.end())
69     RetainedNodes.append(PV->second.begin(), PV->second.end());
70 
71   auto PL = PreservedLabels.find(SP);
72   if (PL != PreservedLabels.end())
73     RetainedNodes.append(PL->second.begin(), PL->second.end());
74 
75   DINodeArray Node = getOrCreateArray(RetainedNodes);
76 
77   TempMDTuple(Temp)->replaceAllUsesWith(Node.get());
78 }
79 
80 void DIBuilder::finalize() {
81   if (!CUNode) {
82     assert(!AllowUnresolvedNodes &&
83            "creating type nodes without a CU is not supported");
84     return;
85   }
86 
87   if (!AllEnumTypes.empty())
88     CUNode->replaceEnumTypes(MDTuple::get(VMContext, AllEnumTypes));
89 
90   SmallVector<Metadata *, 16> RetainValues;
91   // Declarations and definitions of the same type may be retained. Some
92   // clients RAUW these pairs, leaving duplicates in the retained types
93   // list. Use a set to remove the duplicates while we transform the
94   // TrackingVHs back into Values.
95   SmallPtrSet<Metadata *, 16> RetainSet;
96   for (unsigned I = 0, E = AllRetainTypes.size(); I < E; I++)
97     if (RetainSet.insert(AllRetainTypes[I]).second)
98       RetainValues.push_back(AllRetainTypes[I]);
99 
100   if (!RetainValues.empty())
101     CUNode->replaceRetainedTypes(MDTuple::get(VMContext, RetainValues));
102 
103   DISubprogramArray SPs = MDTuple::get(VMContext, AllSubprograms);
104   for (auto *SP : SPs)
105     finalizeSubprogram(SP);
106   for (auto *N : RetainValues)
107     if (auto *SP = dyn_cast<DISubprogram>(N))
108       finalizeSubprogram(SP);
109 
110   if (!AllGVs.empty())
111     CUNode->replaceGlobalVariables(MDTuple::get(VMContext, AllGVs));
112 
113   if (!AllImportedModules.empty())
114     CUNode->replaceImportedEntities(MDTuple::get(
115         VMContext, SmallVector<Metadata *, 16>(AllImportedModules.begin(),
116                                                AllImportedModules.end())));
117 
118   for (const auto &I : AllMacrosPerParent) {
119     // DIMacroNode's with nullptr parent are DICompileUnit direct children.
120     if (!I.first) {
121       CUNode->replaceMacros(MDTuple::get(VMContext, I.second.getArrayRef()));
122       continue;
123     }
124     // Otherwise, it must be a temporary DIMacroFile that need to be resolved.
125     auto *TMF = cast<DIMacroFile>(I.first);
126     auto *MF = DIMacroFile::get(VMContext, dwarf::DW_MACINFO_start_file,
127                                 TMF->getLine(), TMF->getFile(),
128                                 getOrCreateMacroArray(I.second.getArrayRef()));
129     replaceTemporary(llvm::TempDIMacroNode(TMF), MF);
130   }
131 
132   // Now that all temp nodes have been replaced or deleted, resolve remaining
133   // cycles.
134   for (const auto &N : UnresolvedNodes)
135     if (N && !N->isResolved())
136       N->resolveCycles();
137   UnresolvedNodes.clear();
138 
139   // Can't handle unresolved nodes anymore.
140   AllowUnresolvedNodes = false;
141 }
142 
143 /// If N is compile unit return NULL otherwise return N.
144 static DIScope *getNonCompileUnitScope(DIScope *N) {
145   if (!N || isa<DICompileUnit>(N))
146     return nullptr;
147   return cast<DIScope>(N);
148 }
149 
150 DICompileUnit *DIBuilder::createCompileUnit(
151     unsigned Lang, DIFile *File, StringRef Producer, bool isOptimized,
152     StringRef Flags, unsigned RunTimeVer, StringRef SplitName,
153     DICompileUnit::DebugEmissionKind Kind, uint64_t DWOId,
154     bool SplitDebugInlining, bool DebugInfoForProfiling,
155     DICompileUnit::DebugNameTableKind NameTableKind, bool RangesBaseAddress,
156     StringRef SysRoot, StringRef SDK) {
157 
158   assert(((Lang <= dwarf::DW_LANG_Fortran08 && Lang >= dwarf::DW_LANG_C89) ||
159           (Lang <= dwarf::DW_LANG_hi_user && Lang >= dwarf::DW_LANG_lo_user)) &&
160          "Invalid Language tag");
161 
162   assert(!CUNode && "Can only make one compile unit per DIBuilder instance");
163   CUNode = DICompileUnit::getDistinct(
164       VMContext, Lang, File, Producer, isOptimized, Flags, RunTimeVer,
165       SplitName, Kind, nullptr, nullptr, nullptr, nullptr, nullptr, DWOId,
166       SplitDebugInlining, DebugInfoForProfiling, NameTableKind,
167       RangesBaseAddress, SysRoot, SDK);
168 
169   // Create a named metadata so that it is easier to find cu in a module.
170   NamedMDNode *NMD = M.getOrInsertNamedMetadata("llvm.dbg.cu");
171   NMD->addOperand(CUNode);
172   trackIfUnresolved(CUNode);
173   return CUNode;
174 }
175 
176 static DIImportedEntity *
177 createImportedModule(LLVMContext &C, dwarf::Tag Tag, DIScope *Context,
178                      Metadata *NS, DIFile *File, unsigned Line, StringRef Name,
179                      DINodeArray Elements,
180                      SmallVectorImpl<TrackingMDNodeRef> &AllImportedModules) {
181   if (Line)
182     assert(File && "Source location has line number but no file");
183   unsigned EntitiesCount = C.pImpl->DIImportedEntitys.size();
184   auto *M = DIImportedEntity::get(C, Tag, Context, cast_or_null<DINode>(NS),
185                                   File, Line, Name, Elements);
186   if (EntitiesCount < C.pImpl->DIImportedEntitys.size())
187     // A new Imported Entity was just added to the context.
188     // Add it to the Imported Modules list.
189     AllImportedModules.emplace_back(M);
190   return M;
191 }
192 
193 DIImportedEntity *DIBuilder::createImportedModule(DIScope *Context,
194                                                   DINamespace *NS, DIFile *File,
195                                                   unsigned Line,
196                                                   DINodeArray Elements) {
197   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_module,
198                                 Context, NS, File, Line, StringRef(), Elements,
199                                 AllImportedModules);
200 }
201 
202 DIImportedEntity *DIBuilder::createImportedModule(DIScope *Context,
203                                                   DIImportedEntity *NS,
204                                                   DIFile *File, unsigned Line,
205                                                   DINodeArray Elements) {
206   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_module,
207                                 Context, NS, File, Line, StringRef(), Elements,
208                                 AllImportedModules);
209 }
210 
211 DIImportedEntity *DIBuilder::createImportedModule(DIScope *Context, DIModule *M,
212                                                   DIFile *File, unsigned Line,
213                                                   DINodeArray Elements) {
214   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_module,
215                                 Context, M, File, Line, StringRef(), Elements,
216                                 AllImportedModules);
217 }
218 
219 DIImportedEntity *
220 DIBuilder::createImportedDeclaration(DIScope *Context, DINode *Decl,
221                                      DIFile *File, unsigned Line,
222                                      StringRef Name, DINodeArray Elements) {
223   // Make sure to use the unique identifier based metadata reference for
224   // types that have one.
225   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_declaration,
226                                 Context, Decl, File, Line, Name, Elements,
227                                 AllImportedModules);
228 }
229 
230 DIFile *DIBuilder::createFile(StringRef Filename, StringRef Directory,
231                               Optional<DIFile::ChecksumInfo<StringRef>> CS,
232                               Optional<StringRef> Source) {
233   return DIFile::get(VMContext, Filename, Directory, CS, Source);
234 }
235 
236 DIMacro *DIBuilder::createMacro(DIMacroFile *Parent, unsigned LineNumber,
237                                 unsigned MacroType, StringRef Name,
238                                 StringRef Value) {
239   assert(!Name.empty() && "Unable to create macro without name");
240   assert((MacroType == dwarf::DW_MACINFO_undef ||
241           MacroType == dwarf::DW_MACINFO_define) &&
242          "Unexpected macro type");
243   auto *M = DIMacro::get(VMContext, MacroType, LineNumber, Name, Value);
244   AllMacrosPerParent[Parent].insert(M);
245   return M;
246 }
247 
248 DIMacroFile *DIBuilder::createTempMacroFile(DIMacroFile *Parent,
249                                             unsigned LineNumber, DIFile *File) {
250   auto *MF = DIMacroFile::getTemporary(VMContext, dwarf::DW_MACINFO_start_file,
251                                        LineNumber, File, DIMacroNodeArray())
252                  .release();
253   AllMacrosPerParent[Parent].insert(MF);
254   // Add the new temporary DIMacroFile to the macro per parent map as a parent.
255   // This is needed to assure DIMacroFile with no children to have an entry in
256   // the map. Otherwise, it will not be resolved in DIBuilder::finalize().
257   AllMacrosPerParent.insert({MF, {}});
258   return MF;
259 }
260 
261 DIEnumerator *DIBuilder::createEnumerator(StringRef Name, uint64_t Val,
262                                           bool IsUnsigned) {
263   assert(!Name.empty() && "Unable to create enumerator without name");
264   return DIEnumerator::get(VMContext, APInt(64, Val, !IsUnsigned), IsUnsigned,
265                            Name);
266 }
267 
268 DIEnumerator *DIBuilder::createEnumerator(StringRef Name, const APSInt &Value) {
269   assert(!Name.empty() && "Unable to create enumerator without name");
270   return DIEnumerator::get(VMContext, APInt(Value), Value.isUnsigned(), Name);
271 }
272 
273 DIBasicType *DIBuilder::createUnspecifiedType(StringRef Name) {
274   assert(!Name.empty() && "Unable to create type without name");
275   return DIBasicType::get(VMContext, dwarf::DW_TAG_unspecified_type, Name);
276 }
277 
278 DIBasicType *DIBuilder::createNullPtrType() {
279   return createUnspecifiedType("decltype(nullptr)");
280 }
281 
282 DIBasicType *DIBuilder::createBasicType(StringRef Name, uint64_t SizeInBits,
283                                         unsigned Encoding,
284                                         DINode::DIFlags Flags) {
285   assert(!Name.empty() && "Unable to create type without name");
286   return DIBasicType::get(VMContext, dwarf::DW_TAG_base_type, Name, SizeInBits,
287                           0, Encoding, Flags);
288 }
289 
290 DIStringType *DIBuilder::createStringType(StringRef Name, uint64_t SizeInBits) {
291   assert(!Name.empty() && "Unable to create type without name");
292   return DIStringType::get(VMContext, dwarf::DW_TAG_string_type, Name,
293                            SizeInBits, 0);
294 }
295 
296 DIDerivedType *DIBuilder::createQualifiedType(unsigned Tag, DIType *FromTy) {
297   return DIDerivedType::get(VMContext, Tag, "", nullptr, 0, nullptr, FromTy, 0,
298                             0, 0, None, DINode::FlagZero);
299 }
300 
301 DIDerivedType *
302 DIBuilder::createPointerType(DIType *PointeeTy, uint64_t SizeInBits,
303                              uint32_t AlignInBits,
304                              Optional<unsigned> DWARFAddressSpace,
305                              StringRef Name, DINodeArray Annotations) {
306   // FIXME: Why is there a name here?
307   return DIDerivedType::get(VMContext, dwarf::DW_TAG_pointer_type, Name,
308                             nullptr, 0, nullptr, PointeeTy, SizeInBits,
309                             AlignInBits, 0, DWARFAddressSpace, DINode::FlagZero,
310                             nullptr, Annotations);
311 }
312 
313 DIDerivedType *DIBuilder::createMemberPointerType(DIType *PointeeTy,
314                                                   DIType *Base,
315                                                   uint64_t SizeInBits,
316                                                   uint32_t AlignInBits,
317                                                   DINode::DIFlags Flags) {
318   return DIDerivedType::get(VMContext, dwarf::DW_TAG_ptr_to_member_type, "",
319                             nullptr, 0, nullptr, PointeeTy, SizeInBits,
320                             AlignInBits, 0, None, Flags, Base);
321 }
322 
323 DIDerivedType *
324 DIBuilder::createReferenceType(unsigned Tag, DIType *RTy, uint64_t SizeInBits,
325                                uint32_t AlignInBits,
326                                Optional<unsigned> DWARFAddressSpace) {
327   assert(RTy && "Unable to create reference type");
328   return DIDerivedType::get(VMContext, Tag, "", nullptr, 0, nullptr, RTy,
329                             SizeInBits, AlignInBits, 0, DWARFAddressSpace,
330                             DINode::FlagZero);
331 }
332 
333 DIDerivedType *DIBuilder::createTypedef(DIType *Ty, StringRef Name,
334                                         DIFile *File, unsigned LineNo,
335                                         DIScope *Context, uint32_t AlignInBits,
336                                         DINodeArray Annotations) {
337   return DIDerivedType::get(VMContext, dwarf::DW_TAG_typedef, Name, File,
338                             LineNo, getNonCompileUnitScope(Context), Ty, 0,
339                             AlignInBits, 0, None, DINode::FlagZero, nullptr,
340                             Annotations);
341 }
342 
343 DIDerivedType *DIBuilder::createFriend(DIType *Ty, DIType *FriendTy) {
344   assert(Ty && "Invalid type!");
345   assert(FriendTy && "Invalid friend type!");
346   return DIDerivedType::get(VMContext, dwarf::DW_TAG_friend, "", nullptr, 0, Ty,
347                             FriendTy, 0, 0, 0, None, DINode::FlagZero);
348 }
349 
350 DIDerivedType *DIBuilder::createInheritance(DIType *Ty, DIType *BaseTy,
351                                             uint64_t BaseOffset,
352                                             uint32_t VBPtrOffset,
353                                             DINode::DIFlags Flags) {
354   assert(Ty && "Unable to create inheritance");
355   Metadata *ExtraData = ConstantAsMetadata::get(
356       ConstantInt::get(IntegerType::get(VMContext, 32), VBPtrOffset));
357   return DIDerivedType::get(VMContext, dwarf::DW_TAG_inheritance, "", nullptr,
358                             0, Ty, BaseTy, 0, 0, BaseOffset, None, Flags,
359                             ExtraData);
360 }
361 
362 DIDerivedType *DIBuilder::createMemberType(
363     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
364     uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
365     DINode::DIFlags Flags, DIType *Ty, DINodeArray Annotations) {
366   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
367                             LineNumber, getNonCompileUnitScope(Scope), Ty,
368                             SizeInBits, AlignInBits, OffsetInBits, None, Flags,
369                             nullptr, Annotations);
370 }
371 
372 static ConstantAsMetadata *getConstantOrNull(Constant *C) {
373   if (C)
374     return ConstantAsMetadata::get(C);
375   return nullptr;
376 }
377 
378 DIDerivedType *DIBuilder::createVariantMemberType(
379     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
380     uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
381     Constant *Discriminant, DINode::DIFlags Flags, DIType *Ty) {
382   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
383                             LineNumber, getNonCompileUnitScope(Scope), Ty,
384                             SizeInBits, AlignInBits, OffsetInBits, None, Flags,
385                             getConstantOrNull(Discriminant));
386 }
387 
388 DIDerivedType *DIBuilder::createBitFieldMemberType(
389     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
390     uint64_t SizeInBits, uint64_t OffsetInBits, uint64_t StorageOffsetInBits,
391     DINode::DIFlags Flags, DIType *Ty, DINodeArray Annotations) {
392   Flags |= DINode::FlagBitField;
393   return DIDerivedType::get(
394       VMContext, dwarf::DW_TAG_member, Name, File, LineNumber,
395       getNonCompileUnitScope(Scope), Ty, SizeInBits, /*AlignInBits=*/0,
396       OffsetInBits, None, Flags,
397       ConstantAsMetadata::get(ConstantInt::get(IntegerType::get(VMContext, 64),
398                                                StorageOffsetInBits)),
399       Annotations);
400 }
401 
402 DIDerivedType *
403 DIBuilder::createStaticMemberType(DIScope *Scope, StringRef Name, DIFile *File,
404                                   unsigned LineNumber, DIType *Ty,
405                                   DINode::DIFlags Flags, llvm::Constant *Val,
406                                   uint32_t AlignInBits) {
407   Flags |= DINode::FlagStaticMember;
408   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
409                             LineNumber, getNonCompileUnitScope(Scope), Ty, 0,
410                             AlignInBits, 0, None, Flags,
411                             getConstantOrNull(Val));
412 }
413 
414 DIDerivedType *
415 DIBuilder::createObjCIVar(StringRef Name, DIFile *File, unsigned LineNumber,
416                           uint64_t SizeInBits, uint32_t AlignInBits,
417                           uint64_t OffsetInBits, DINode::DIFlags Flags,
418                           DIType *Ty, MDNode *PropertyNode) {
419   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
420                             LineNumber, getNonCompileUnitScope(File), Ty,
421                             SizeInBits, AlignInBits, OffsetInBits, None, Flags,
422                             PropertyNode);
423 }
424 
425 DIObjCProperty *
426 DIBuilder::createObjCProperty(StringRef Name, DIFile *File, unsigned LineNumber,
427                               StringRef GetterName, StringRef SetterName,
428                               unsigned PropertyAttributes, DIType *Ty) {
429   return DIObjCProperty::get(VMContext, Name, File, LineNumber, GetterName,
430                              SetterName, PropertyAttributes, Ty);
431 }
432 
433 DITemplateTypeParameter *
434 DIBuilder::createTemplateTypeParameter(DIScope *Context, StringRef Name,
435                                        DIType *Ty, bool isDefault) {
436   assert((!Context || isa<DICompileUnit>(Context)) && "Expected compile unit");
437   return DITemplateTypeParameter::get(VMContext, Name, Ty, isDefault);
438 }
439 
440 static DITemplateValueParameter *
441 createTemplateValueParameterHelper(LLVMContext &VMContext, unsigned Tag,
442                                    DIScope *Context, StringRef Name, DIType *Ty,
443                                    bool IsDefault, Metadata *MD) {
444   assert((!Context || isa<DICompileUnit>(Context)) && "Expected compile unit");
445   return DITemplateValueParameter::get(VMContext, Tag, Name, Ty, IsDefault, MD);
446 }
447 
448 DITemplateValueParameter *
449 DIBuilder::createTemplateValueParameter(DIScope *Context, StringRef Name,
450                                         DIType *Ty, bool isDefault,
451                                         Constant *Val) {
452   return createTemplateValueParameterHelper(
453       VMContext, dwarf::DW_TAG_template_value_parameter, Context, Name, Ty,
454       isDefault, getConstantOrNull(Val));
455 }
456 
457 DITemplateValueParameter *
458 DIBuilder::createTemplateTemplateParameter(DIScope *Context, StringRef Name,
459                                            DIType *Ty, StringRef Val) {
460   return createTemplateValueParameterHelper(
461       VMContext, dwarf::DW_TAG_GNU_template_template_param, Context, Name, Ty,
462       false, MDString::get(VMContext, Val));
463 }
464 
465 DITemplateValueParameter *
466 DIBuilder::createTemplateParameterPack(DIScope *Context, StringRef Name,
467                                        DIType *Ty, DINodeArray Val) {
468   return createTemplateValueParameterHelper(
469       VMContext, dwarf::DW_TAG_GNU_template_parameter_pack, Context, Name, Ty,
470       false, Val.get());
471 }
472 
473 DICompositeType *DIBuilder::createClassType(
474     DIScope *Context, StringRef Name, DIFile *File, unsigned LineNumber,
475     uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
476     DINode::DIFlags Flags, DIType *DerivedFrom, DINodeArray Elements,
477     DIType *VTableHolder, MDNode *TemplateParams, StringRef UniqueIdentifier) {
478   assert((!Context || isa<DIScope>(Context)) &&
479          "createClassType should be called with a valid Context");
480 
481   auto *R = DICompositeType::get(
482       VMContext, dwarf::DW_TAG_structure_type, Name, File, LineNumber,
483       getNonCompileUnitScope(Context), DerivedFrom, SizeInBits, AlignInBits,
484       OffsetInBits, Flags, Elements, 0, VTableHolder,
485       cast_or_null<MDTuple>(TemplateParams), UniqueIdentifier);
486   trackIfUnresolved(R);
487   return R;
488 }
489 
490 DICompositeType *DIBuilder::createStructType(
491     DIScope *Context, StringRef Name, DIFile *File, unsigned LineNumber,
492     uint64_t SizeInBits, uint32_t AlignInBits, DINode::DIFlags Flags,
493     DIType *DerivedFrom, DINodeArray Elements, unsigned RunTimeLang,
494     DIType *VTableHolder, StringRef UniqueIdentifier) {
495   auto *R = DICompositeType::get(
496       VMContext, dwarf::DW_TAG_structure_type, Name, File, LineNumber,
497       getNonCompileUnitScope(Context), DerivedFrom, SizeInBits, AlignInBits, 0,
498       Flags, Elements, RunTimeLang, VTableHolder, nullptr, UniqueIdentifier);
499   trackIfUnresolved(R);
500   return R;
501 }
502 
503 DICompositeType *DIBuilder::createUnionType(
504     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
505     uint64_t SizeInBits, uint32_t AlignInBits, DINode::DIFlags Flags,
506     DINodeArray Elements, unsigned RunTimeLang, StringRef UniqueIdentifier) {
507   auto *R = DICompositeType::get(
508       VMContext, dwarf::DW_TAG_union_type, Name, File, LineNumber,
509       getNonCompileUnitScope(Scope), nullptr, SizeInBits, AlignInBits, 0, Flags,
510       Elements, RunTimeLang, nullptr, nullptr, UniqueIdentifier);
511   trackIfUnresolved(R);
512   return R;
513 }
514 
515 DICompositeType *
516 DIBuilder::createVariantPart(DIScope *Scope, StringRef Name, DIFile *File,
517                              unsigned LineNumber, uint64_t SizeInBits,
518                              uint32_t AlignInBits, DINode::DIFlags Flags,
519                              DIDerivedType *Discriminator, DINodeArray Elements,
520                              StringRef UniqueIdentifier) {
521   auto *R = DICompositeType::get(
522       VMContext, dwarf::DW_TAG_variant_part, Name, File, LineNumber,
523       getNonCompileUnitScope(Scope), nullptr, SizeInBits, AlignInBits, 0, Flags,
524       Elements, 0, nullptr, nullptr, UniqueIdentifier, Discriminator);
525   trackIfUnresolved(R);
526   return R;
527 }
528 
529 DISubroutineType *DIBuilder::createSubroutineType(DITypeRefArray ParameterTypes,
530                                                   DINode::DIFlags Flags,
531                                                   unsigned CC) {
532   return DISubroutineType::get(VMContext, Flags, CC, ParameterTypes);
533 }
534 
535 DICompositeType *DIBuilder::createEnumerationType(
536     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
537     uint64_t SizeInBits, uint32_t AlignInBits, DINodeArray Elements,
538     DIType *UnderlyingType, StringRef UniqueIdentifier, bool IsScoped) {
539   auto *CTy = DICompositeType::get(
540       VMContext, dwarf::DW_TAG_enumeration_type, Name, File, LineNumber,
541       getNonCompileUnitScope(Scope), UnderlyingType, SizeInBits, AlignInBits, 0,
542       IsScoped ? DINode::FlagEnumClass : DINode::FlagZero, Elements, 0, nullptr,
543       nullptr, UniqueIdentifier);
544   AllEnumTypes.push_back(CTy);
545   trackIfUnresolved(CTy);
546   return CTy;
547 }
548 
549 DIDerivedType *DIBuilder::createSetType(DIScope *Scope, StringRef Name,
550                                         DIFile *File, unsigned LineNo,
551                                         uint64_t SizeInBits,
552                                         uint32_t AlignInBits, DIType *Ty) {
553   auto *R =
554       DIDerivedType::get(VMContext, dwarf::DW_TAG_set_type, Name, File, LineNo,
555                          getNonCompileUnitScope(Scope), Ty, SizeInBits,
556                          AlignInBits, 0, None, DINode::FlagZero);
557   trackIfUnresolved(R);
558   return R;
559 }
560 
561 DICompositeType *
562 DIBuilder::createArrayType(uint64_t Size, uint32_t AlignInBits, DIType *Ty,
563                            DINodeArray Subscripts,
564                            PointerUnion<DIExpression *, DIVariable *> DL,
565                            PointerUnion<DIExpression *, DIVariable *> AS,
566                            PointerUnion<DIExpression *, DIVariable *> AL,
567                            PointerUnion<DIExpression *, DIVariable *> RK) {
568   auto *R = DICompositeType::get(
569       VMContext, dwarf::DW_TAG_array_type, "", nullptr, 0, nullptr, Ty, Size,
570       AlignInBits, 0, DINode::FlagZero, Subscripts, 0, nullptr, nullptr, "",
571       nullptr,
572       DL.is<DIExpression *>() ? (Metadata *)DL.get<DIExpression *>()
573                               : (Metadata *)DL.get<DIVariable *>(),
574       AS.is<DIExpression *>() ? (Metadata *)AS.get<DIExpression *>()
575                               : (Metadata *)AS.get<DIVariable *>(),
576       AL.is<DIExpression *>() ? (Metadata *)AL.get<DIExpression *>()
577                               : (Metadata *)AL.get<DIVariable *>(),
578       RK.is<DIExpression *>() ? (Metadata *)RK.get<DIExpression *>()
579                               : (Metadata *)RK.get<DIVariable *>());
580   trackIfUnresolved(R);
581   return R;
582 }
583 
584 DICompositeType *DIBuilder::createVectorType(uint64_t Size,
585                                              uint32_t AlignInBits, DIType *Ty,
586                                              DINodeArray Subscripts) {
587   auto *R = DICompositeType::get(VMContext, dwarf::DW_TAG_array_type, "",
588                                  nullptr, 0, nullptr, Ty, Size, AlignInBits, 0,
589                                  DINode::FlagVector, Subscripts, 0, nullptr);
590   trackIfUnresolved(R);
591   return R;
592 }
593 
594 DISubprogram *DIBuilder::createArtificialSubprogram(DISubprogram *SP) {
595   auto NewSP = SP->cloneWithFlags(SP->getFlags() | DINode::FlagArtificial);
596   return MDNode::replaceWithDistinct(std::move(NewSP));
597 }
598 
599 static DIType *createTypeWithFlags(const DIType *Ty,
600                                    DINode::DIFlags FlagsToSet) {
601   auto NewTy = Ty->cloneWithFlags(Ty->getFlags() | FlagsToSet);
602   return MDNode::replaceWithUniqued(std::move(NewTy));
603 }
604 
605 DIType *DIBuilder::createArtificialType(DIType *Ty) {
606   // FIXME: Restrict this to the nodes where it's valid.
607   if (Ty->isArtificial())
608     return Ty;
609   return createTypeWithFlags(Ty, DINode::FlagArtificial);
610 }
611 
612 DIType *DIBuilder::createObjectPointerType(DIType *Ty) {
613   // FIXME: Restrict this to the nodes where it's valid.
614   if (Ty->isObjectPointer())
615     return Ty;
616   DINode::DIFlags Flags = DINode::FlagObjectPointer | DINode::FlagArtificial;
617   return createTypeWithFlags(Ty, Flags);
618 }
619 
620 void DIBuilder::retainType(DIScope *T) {
621   assert(T && "Expected non-null type");
622   assert((isa<DIType>(T) || (isa<DISubprogram>(T) &&
623                              cast<DISubprogram>(T)->isDefinition() == false)) &&
624          "Expected type or subprogram declaration");
625   AllRetainTypes.emplace_back(T);
626 }
627 
628 DIBasicType *DIBuilder::createUnspecifiedParameter() { return nullptr; }
629 
630 DICompositeType *
631 DIBuilder::createForwardDecl(unsigned Tag, StringRef Name, DIScope *Scope,
632                              DIFile *F, unsigned Line, unsigned RuntimeLang,
633                              uint64_t SizeInBits, uint32_t AlignInBits,
634                              StringRef UniqueIdentifier) {
635   // FIXME: Define in terms of createReplaceableForwardDecl() by calling
636   // replaceWithUniqued().
637   auto *RetTy = DICompositeType::get(
638       VMContext, Tag, Name, F, Line, getNonCompileUnitScope(Scope), nullptr,
639       SizeInBits, AlignInBits, 0, DINode::FlagFwdDecl, nullptr, RuntimeLang,
640       nullptr, nullptr, UniqueIdentifier);
641   trackIfUnresolved(RetTy);
642   return RetTy;
643 }
644 
645 DICompositeType *DIBuilder::createReplaceableCompositeType(
646     unsigned Tag, StringRef Name, DIScope *Scope, DIFile *F, unsigned Line,
647     unsigned RuntimeLang, uint64_t SizeInBits, uint32_t AlignInBits,
648     DINode::DIFlags Flags, StringRef UniqueIdentifier,
649     DINodeArray Annotations) {
650   auto *RetTy =
651       DICompositeType::getTemporary(
652           VMContext, Tag, Name, F, Line, getNonCompileUnitScope(Scope), nullptr,
653           SizeInBits, AlignInBits, 0, Flags, nullptr, RuntimeLang, nullptr,
654           nullptr, UniqueIdentifier, nullptr, nullptr, nullptr, nullptr,
655           nullptr, Annotations)
656           .release();
657   trackIfUnresolved(RetTy);
658   return RetTy;
659 }
660 
661 DINodeArray DIBuilder::getOrCreateArray(ArrayRef<Metadata *> Elements) {
662   return MDTuple::get(VMContext, Elements);
663 }
664 
665 DIMacroNodeArray
666 DIBuilder::getOrCreateMacroArray(ArrayRef<Metadata *> Elements) {
667   return MDTuple::get(VMContext, Elements);
668 }
669 
670 DITypeRefArray DIBuilder::getOrCreateTypeArray(ArrayRef<Metadata *> Elements) {
671   SmallVector<llvm::Metadata *, 16> Elts;
672   for (Metadata *E : Elements) {
673     if (isa_and_nonnull<MDNode>(E))
674       Elts.push_back(cast<DIType>(E));
675     else
676       Elts.push_back(E);
677   }
678   return DITypeRefArray(MDNode::get(VMContext, Elts));
679 }
680 
681 DISubrange *DIBuilder::getOrCreateSubrange(int64_t Lo, int64_t Count) {
682   auto *LB = ConstantAsMetadata::get(
683       ConstantInt::getSigned(Type::getInt64Ty(VMContext), Lo));
684   auto *CountNode = ConstantAsMetadata::get(
685       ConstantInt::getSigned(Type::getInt64Ty(VMContext), Count));
686   return DISubrange::get(VMContext, CountNode, LB, nullptr, nullptr);
687 }
688 
689 DISubrange *DIBuilder::getOrCreateSubrange(int64_t Lo, Metadata *CountNode) {
690   auto *LB = ConstantAsMetadata::get(
691       ConstantInt::getSigned(Type::getInt64Ty(VMContext), Lo));
692   return DISubrange::get(VMContext, CountNode, LB, nullptr, nullptr);
693 }
694 
695 DISubrange *DIBuilder::getOrCreateSubrange(Metadata *CountNode, Metadata *LB,
696                                            Metadata *UB, Metadata *Stride) {
697   return DISubrange::get(VMContext, CountNode, LB, UB, Stride);
698 }
699 
700 DIGenericSubrange *DIBuilder::getOrCreateGenericSubrange(
701     DIGenericSubrange::BoundType CountNode, DIGenericSubrange::BoundType LB,
702     DIGenericSubrange::BoundType UB, DIGenericSubrange::BoundType Stride) {
703   auto ConvToMetadata = [&](DIGenericSubrange::BoundType Bound) -> Metadata * {
704     return Bound.is<DIExpression *>() ? (Metadata *)Bound.get<DIExpression *>()
705                                       : (Metadata *)Bound.get<DIVariable *>();
706   };
707   return DIGenericSubrange::get(VMContext, ConvToMetadata(CountNode),
708                                 ConvToMetadata(LB), ConvToMetadata(UB),
709                                 ConvToMetadata(Stride));
710 }
711 
712 static void checkGlobalVariableScope(DIScope *Context) {
713 #ifndef NDEBUG
714   if (auto *CT =
715           dyn_cast_or_null<DICompositeType>(getNonCompileUnitScope(Context)))
716     assert(CT->getIdentifier().empty() &&
717            "Context of a global variable should not be a type with identifier");
718 #endif
719 }
720 
721 DIGlobalVariableExpression *DIBuilder::createGlobalVariableExpression(
722     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
723     unsigned LineNumber, DIType *Ty, bool IsLocalToUnit, bool isDefined,
724     DIExpression *Expr, MDNode *Decl, MDTuple *TemplateParams,
725     uint32_t AlignInBits, DINodeArray Annotations) {
726   checkGlobalVariableScope(Context);
727 
728   auto *GV = DIGlobalVariable::getDistinct(
729       VMContext, cast_or_null<DIScope>(Context), Name, LinkageName, F,
730       LineNumber, Ty, IsLocalToUnit, isDefined,
731       cast_or_null<DIDerivedType>(Decl), TemplateParams, AlignInBits,
732       Annotations);
733   if (!Expr)
734     Expr = createExpression();
735   auto *N = DIGlobalVariableExpression::get(VMContext, GV, Expr);
736   AllGVs.push_back(N);
737   return N;
738 }
739 
740 DIGlobalVariable *DIBuilder::createTempGlobalVariableFwdDecl(
741     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
742     unsigned LineNumber, DIType *Ty, bool IsLocalToUnit, MDNode *Decl,
743     MDTuple *TemplateParams, uint32_t AlignInBits) {
744   checkGlobalVariableScope(Context);
745 
746   return DIGlobalVariable::getTemporary(
747              VMContext, cast_or_null<DIScope>(Context), Name, LinkageName, F,
748              LineNumber, Ty, IsLocalToUnit, false,
749              cast_or_null<DIDerivedType>(Decl), TemplateParams, AlignInBits,
750              nullptr)
751       .release();
752 }
753 
754 static DILocalVariable *createLocalVariable(
755     LLVMContext &VMContext,
756     DenseMap<MDNode *, SmallVector<TrackingMDNodeRef, 1>> &PreservedVariables,
757     DIScope *Scope, StringRef Name, unsigned ArgNo, DIFile *File,
758     unsigned LineNo, DIType *Ty, bool AlwaysPreserve, DINode::DIFlags Flags,
759     uint32_t AlignInBits, DINodeArray Annotations = nullptr) {
760   // FIXME: Why getNonCompileUnitScope()?
761   // FIXME: Why is "!Context" okay here?
762   // FIXME: Why doesn't this check for a subprogram or lexical block (AFAICT
763   // the only valid scopes)?
764   DIScope *Context = getNonCompileUnitScope(Scope);
765 
766   auto *Node = DILocalVariable::get(
767       VMContext, cast_or_null<DILocalScope>(Context), Name, File, LineNo, Ty,
768       ArgNo, Flags, AlignInBits, Annotations);
769   if (AlwaysPreserve) {
770     // The optimizer may remove local variables. If there is an interest
771     // to preserve variable info in such situation then stash it in a
772     // named mdnode.
773     DISubprogram *Fn = getDISubprogram(Scope);
774     assert(Fn && "Missing subprogram for local variable");
775     PreservedVariables[Fn].emplace_back(Node);
776   }
777   return Node;
778 }
779 
780 DILocalVariable *DIBuilder::createAutoVariable(DIScope *Scope, StringRef Name,
781                                                DIFile *File, unsigned LineNo,
782                                                DIType *Ty, bool AlwaysPreserve,
783                                                DINode::DIFlags Flags,
784                                                uint32_t AlignInBits) {
785   return createLocalVariable(VMContext, PreservedVariables, Scope, Name,
786                              /* ArgNo */ 0, File, LineNo, Ty, AlwaysPreserve,
787                              Flags, AlignInBits);
788 }
789 
790 DILocalVariable *DIBuilder::createParameterVariable(
791     DIScope *Scope, StringRef Name, unsigned ArgNo, DIFile *File,
792     unsigned LineNo, DIType *Ty, bool AlwaysPreserve, DINode::DIFlags Flags,
793     DINodeArray Annotations) {
794   assert(ArgNo && "Expected non-zero argument number for parameter");
795   return createLocalVariable(VMContext, PreservedVariables, Scope, Name, ArgNo,
796                              File, LineNo, Ty, AlwaysPreserve, Flags,
797                              /*AlignInBits=*/0, Annotations);
798 }
799 
800 DILabel *DIBuilder::createLabel(DIScope *Scope, StringRef Name, DIFile *File,
801                                 unsigned LineNo, bool AlwaysPreserve) {
802   DIScope *Context = getNonCompileUnitScope(Scope);
803 
804   auto *Node = DILabel::get(VMContext, cast_or_null<DILocalScope>(Context),
805                             Name, File, LineNo);
806 
807   if (AlwaysPreserve) {
808     /// The optimizer may remove labels. If there is an interest
809     /// to preserve label info in such situation then append it to
810     /// the list of retained nodes of the DISubprogram.
811     DISubprogram *Fn = getDISubprogram(Scope);
812     assert(Fn && "Missing subprogram for label");
813     PreservedLabels[Fn].emplace_back(Node);
814   }
815   return Node;
816 }
817 
818 DIExpression *DIBuilder::createExpression(ArrayRef<uint64_t> Addr) {
819   return DIExpression::get(VMContext, Addr);
820 }
821 
822 template <class... Ts>
823 static DISubprogram *getSubprogram(bool IsDistinct, Ts &&...Args) {
824   if (IsDistinct)
825     return DISubprogram::getDistinct(std::forward<Ts>(Args)...);
826   return DISubprogram::get(std::forward<Ts>(Args)...);
827 }
828 
829 DISubprogram *DIBuilder::createFunction(
830     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *File,
831     unsigned LineNo, DISubroutineType *Ty, unsigned ScopeLine,
832     DINode::DIFlags Flags, DISubprogram::DISPFlags SPFlags,
833     DITemplateParameterArray TParams, DISubprogram *Decl,
834     DITypeArray ThrownTypes, DINodeArray Annotations) {
835   bool IsDefinition = SPFlags & DISubprogram::SPFlagDefinition;
836   auto *Node = getSubprogram(
837       /*IsDistinct=*/IsDefinition, VMContext, getNonCompileUnitScope(Context),
838       Name, LinkageName, File, LineNo, Ty, ScopeLine, nullptr, 0, 0, Flags,
839       SPFlags, IsDefinition ? CUNode : nullptr, TParams, Decl,
840       MDTuple::getTemporary(VMContext, None).release(), ThrownTypes,
841       Annotations);
842 
843   if (IsDefinition)
844     AllSubprograms.push_back(Node);
845   trackIfUnresolved(Node);
846   return Node;
847 }
848 
849 DISubprogram *DIBuilder::createTempFunctionFwdDecl(
850     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *File,
851     unsigned LineNo, DISubroutineType *Ty, unsigned ScopeLine,
852     DINode::DIFlags Flags, DISubprogram::DISPFlags SPFlags,
853     DITemplateParameterArray TParams, DISubprogram *Decl,
854     DITypeArray ThrownTypes) {
855   bool IsDefinition = SPFlags & DISubprogram::SPFlagDefinition;
856   return DISubprogram::getTemporary(VMContext, getNonCompileUnitScope(Context),
857                                     Name, LinkageName, File, LineNo, Ty,
858                                     ScopeLine, nullptr, 0, 0, Flags, SPFlags,
859                                     IsDefinition ? CUNode : nullptr, TParams,
860                                     Decl, nullptr, ThrownTypes)
861       .release();
862 }
863 
864 DISubprogram *DIBuilder::createMethod(
865     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
866     unsigned LineNo, DISubroutineType *Ty, unsigned VIndex, int ThisAdjustment,
867     DIType *VTableHolder, DINode::DIFlags Flags,
868     DISubprogram::DISPFlags SPFlags, DITemplateParameterArray TParams,
869     DITypeArray ThrownTypes) {
870   assert(getNonCompileUnitScope(Context) &&
871          "Methods should have both a Context and a context that isn't "
872          "the compile unit.");
873   // FIXME: Do we want to use different scope/lines?
874   bool IsDefinition = SPFlags & DISubprogram::SPFlagDefinition;
875   auto *SP = getSubprogram(
876       /*IsDistinct=*/IsDefinition, VMContext, cast<DIScope>(Context), Name,
877       LinkageName, F, LineNo, Ty, LineNo, VTableHolder, VIndex, ThisAdjustment,
878       Flags, SPFlags, IsDefinition ? CUNode : nullptr, TParams, nullptr,
879       nullptr, ThrownTypes);
880 
881   if (IsDefinition)
882     AllSubprograms.push_back(SP);
883   trackIfUnresolved(SP);
884   return SP;
885 }
886 
887 DICommonBlock *DIBuilder::createCommonBlock(DIScope *Scope,
888                                             DIGlobalVariable *Decl,
889                                             StringRef Name, DIFile *File,
890                                             unsigned LineNo) {
891   return DICommonBlock::get(VMContext, Scope, Decl, Name, File, LineNo);
892 }
893 
894 DINamespace *DIBuilder::createNameSpace(DIScope *Scope, StringRef Name,
895                                         bool ExportSymbols) {
896 
897   // It is okay to *not* make anonymous top-level namespaces distinct, because
898   // all nodes that have an anonymous namespace as their parent scope are
899   // guaranteed to be unique and/or are linked to their containing
900   // DICompileUnit. This decision is an explicit tradeoff of link time versus
901   // memory usage versus code simplicity and may get revisited in the future.
902   return DINamespace::get(VMContext, getNonCompileUnitScope(Scope), Name,
903                           ExportSymbols);
904 }
905 
906 DIModule *DIBuilder::createModule(DIScope *Scope, StringRef Name,
907                                   StringRef ConfigurationMacros,
908                                   StringRef IncludePath, StringRef APINotesFile,
909                                   DIFile *File, unsigned LineNo, bool IsDecl) {
910   return DIModule::get(VMContext, File, getNonCompileUnitScope(Scope), Name,
911                        ConfigurationMacros, IncludePath, APINotesFile, LineNo,
912                        IsDecl);
913 }
914 
915 DILexicalBlockFile *DIBuilder::createLexicalBlockFile(DIScope *Scope,
916                                                       DIFile *File,
917                                                       unsigned Discriminator) {
918   return DILexicalBlockFile::get(VMContext, Scope, File, Discriminator);
919 }
920 
921 DILexicalBlock *DIBuilder::createLexicalBlock(DIScope *Scope, DIFile *File,
922                                               unsigned Line, unsigned Col) {
923   // Make these distinct, to avoid merging two lexical blocks on the same
924   // file/line/column.
925   return DILexicalBlock::getDistinct(VMContext, getNonCompileUnitScope(Scope),
926                                      File, Line, Col);
927 }
928 
929 Instruction *DIBuilder::insertDeclare(Value *Storage, DILocalVariable *VarInfo,
930                                       DIExpression *Expr, const DILocation *DL,
931                                       Instruction *InsertBefore) {
932   return insertDeclare(Storage, VarInfo, Expr, DL, InsertBefore->getParent(),
933                        InsertBefore);
934 }
935 
936 Instruction *DIBuilder::insertDeclare(Value *Storage, DILocalVariable *VarInfo,
937                                       DIExpression *Expr, const DILocation *DL,
938                                       BasicBlock *InsertAtEnd) {
939   // If this block already has a terminator then insert this intrinsic before
940   // the terminator. Otherwise, put it at the end of the block.
941   Instruction *InsertBefore = InsertAtEnd->getTerminator();
942   return insertDeclare(Storage, VarInfo, Expr, DL, InsertAtEnd, InsertBefore);
943 }
944 
945 Instruction *DIBuilder::insertLabel(DILabel *LabelInfo, const DILocation *DL,
946                                     Instruction *InsertBefore) {
947   return insertLabel(LabelInfo, DL,
948                      InsertBefore ? InsertBefore->getParent() : nullptr,
949                      InsertBefore);
950 }
951 
952 Instruction *DIBuilder::insertLabel(DILabel *LabelInfo, const DILocation *DL,
953                                     BasicBlock *InsertAtEnd) {
954   return insertLabel(LabelInfo, DL, InsertAtEnd, nullptr);
955 }
956 
957 Instruction *DIBuilder::insertDbgValueIntrinsic(Value *V,
958                                                 DILocalVariable *VarInfo,
959                                                 DIExpression *Expr,
960                                                 const DILocation *DL,
961                                                 Instruction *InsertBefore) {
962   return insertDbgValueIntrinsic(
963       V, VarInfo, Expr, DL, InsertBefore ? InsertBefore->getParent() : nullptr,
964       InsertBefore);
965 }
966 
967 Instruction *DIBuilder::insertDbgValueIntrinsic(Value *V,
968                                                 DILocalVariable *VarInfo,
969                                                 DIExpression *Expr,
970                                                 const DILocation *DL,
971                                                 BasicBlock *InsertAtEnd) {
972   return insertDbgValueIntrinsic(V, VarInfo, Expr, DL, InsertAtEnd, nullptr);
973 }
974 
975 Instruction *DIBuilder::insertDbgAddrIntrinsic(Value *V,
976                                                DILocalVariable *VarInfo,
977                                                DIExpression *Expr,
978                                                const DILocation *DL,
979                                                Instruction *InsertBefore) {
980   return insertDbgAddrIntrinsic(
981       V, VarInfo, Expr, DL, InsertBefore ? InsertBefore->getParent() : nullptr,
982       InsertBefore);
983 }
984 
985 Instruction *DIBuilder::insertDbgAddrIntrinsic(Value *V,
986                                                DILocalVariable *VarInfo,
987                                                DIExpression *Expr,
988                                                const DILocation *DL,
989                                                BasicBlock *InsertAtEnd) {
990   return insertDbgAddrIntrinsic(V, VarInfo, Expr, DL, InsertAtEnd, nullptr);
991 }
992 
993 /// Initialize IRBuilder for inserting dbg.declare and dbg.value intrinsics.
994 /// This abstracts over the various ways to specify an insert position.
995 static void initIRBuilder(IRBuilder<> &Builder, const DILocation *DL,
996                           BasicBlock *InsertBB, Instruction *InsertBefore) {
997   if (InsertBefore)
998     Builder.SetInsertPoint(InsertBefore);
999   else if (InsertBB)
1000     Builder.SetInsertPoint(InsertBB);
1001   Builder.SetCurrentDebugLocation(DL);
1002 }
1003 
1004 static Value *getDbgIntrinsicValueImpl(LLVMContext &VMContext, Value *V) {
1005   assert(V && "no value passed to dbg intrinsic");
1006   return MetadataAsValue::get(VMContext, ValueAsMetadata::get(V));
1007 }
1008 
1009 static Function *getDeclareIntrin(Module &M) {
1010   return Intrinsic::getDeclaration(&M, UseDbgAddr ? Intrinsic::dbg_addr
1011                                                   : Intrinsic::dbg_declare);
1012 }
1013 
1014 Instruction *DIBuilder::insertDbgValueIntrinsic(
1015     llvm::Value *Val, DILocalVariable *VarInfo, DIExpression *Expr,
1016     const DILocation *DL, BasicBlock *InsertBB, Instruction *InsertBefore) {
1017   if (!ValueFn)
1018     ValueFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_value);
1019   return insertDbgIntrinsic(ValueFn, Val, VarInfo, Expr, DL, InsertBB,
1020                             InsertBefore);
1021 }
1022 
1023 Instruction *DIBuilder::insertDbgAddrIntrinsic(
1024     llvm::Value *Val, DILocalVariable *VarInfo, DIExpression *Expr,
1025     const DILocation *DL, BasicBlock *InsertBB, Instruction *InsertBefore) {
1026   if (!AddrFn)
1027     AddrFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_addr);
1028   return insertDbgIntrinsic(AddrFn, Val, VarInfo, Expr, DL, InsertBB,
1029                             InsertBefore);
1030 }
1031 
1032 Instruction *DIBuilder::insertDeclare(Value *Storage, DILocalVariable *VarInfo,
1033                                       DIExpression *Expr, const DILocation *DL,
1034                                       BasicBlock *InsertBB,
1035                                       Instruction *InsertBefore) {
1036   assert(VarInfo && "empty or invalid DILocalVariable* passed to dbg.declare");
1037   assert(DL && "Expected debug loc");
1038   assert(DL->getScope()->getSubprogram() ==
1039              VarInfo->getScope()->getSubprogram() &&
1040          "Expected matching subprograms");
1041   if (!DeclareFn)
1042     DeclareFn = getDeclareIntrin(M);
1043 
1044   trackIfUnresolved(VarInfo);
1045   trackIfUnresolved(Expr);
1046   Value *Args[] = {getDbgIntrinsicValueImpl(VMContext, Storage),
1047                    MetadataAsValue::get(VMContext, VarInfo),
1048                    MetadataAsValue::get(VMContext, Expr)};
1049 
1050   IRBuilder<> B(DL->getContext());
1051   initIRBuilder(B, DL, InsertBB, InsertBefore);
1052   return B.CreateCall(DeclareFn, Args);
1053 }
1054 
1055 Instruction *DIBuilder::insertDbgIntrinsic(llvm::Function *IntrinsicFn,
1056                                            Value *V, DILocalVariable *VarInfo,
1057                                            DIExpression *Expr,
1058                                            const DILocation *DL,
1059                                            BasicBlock *InsertBB,
1060                                            Instruction *InsertBefore) {
1061   assert(IntrinsicFn && "must pass a non-null intrinsic function");
1062   assert(V && "must pass a value to a dbg intrinsic");
1063   assert(VarInfo &&
1064          "empty or invalid DILocalVariable* passed to debug intrinsic");
1065   assert(DL && "Expected debug loc");
1066   assert(DL->getScope()->getSubprogram() ==
1067              VarInfo->getScope()->getSubprogram() &&
1068          "Expected matching subprograms");
1069 
1070   trackIfUnresolved(VarInfo);
1071   trackIfUnresolved(Expr);
1072   Value *Args[] = {getDbgIntrinsicValueImpl(VMContext, V),
1073                    MetadataAsValue::get(VMContext, VarInfo),
1074                    MetadataAsValue::get(VMContext, Expr)};
1075 
1076   IRBuilder<> B(DL->getContext());
1077   initIRBuilder(B, DL, InsertBB, InsertBefore);
1078   return B.CreateCall(IntrinsicFn, Args);
1079 }
1080 
1081 Instruction *DIBuilder::insertLabel(DILabel *LabelInfo, const DILocation *DL,
1082                                     BasicBlock *InsertBB,
1083                                     Instruction *InsertBefore) {
1084   assert(LabelInfo && "empty or invalid DILabel* passed to dbg.label");
1085   assert(DL && "Expected debug loc");
1086   assert(DL->getScope()->getSubprogram() ==
1087              LabelInfo->getScope()->getSubprogram() &&
1088          "Expected matching subprograms");
1089   if (!LabelFn)
1090     LabelFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_label);
1091 
1092   trackIfUnresolved(LabelInfo);
1093   Value *Args[] = {MetadataAsValue::get(VMContext, LabelInfo)};
1094 
1095   IRBuilder<> B(DL->getContext());
1096   initIRBuilder(B, DL, InsertBB, InsertBefore);
1097   return B.CreateCall(LabelFn, Args);
1098 }
1099 
1100 void DIBuilder::replaceVTableHolder(DICompositeType *&T, DIType *VTableHolder) {
1101   {
1102     TypedTrackingMDRef<DICompositeType> N(T);
1103     N->replaceVTableHolder(VTableHolder);
1104     T = N.get();
1105   }
1106 
1107   // If this didn't create a self-reference, just return.
1108   if (T != VTableHolder)
1109     return;
1110 
1111   // Look for unresolved operands.  T will drop RAUW support, orphaning any
1112   // cycles underneath it.
1113   if (T->isResolved())
1114     for (const MDOperand &O : T->operands())
1115       if (auto *N = dyn_cast_or_null<MDNode>(O))
1116         trackIfUnresolved(N);
1117 }
1118 
1119 void DIBuilder::replaceArrays(DICompositeType *&T, DINodeArray Elements,
1120                               DINodeArray TParams) {
1121   {
1122     TypedTrackingMDRef<DICompositeType> N(T);
1123     if (Elements)
1124       N->replaceElements(Elements);
1125     if (TParams)
1126       N->replaceTemplateParams(DITemplateParameterArray(TParams));
1127     T = N.get();
1128   }
1129 
1130   // If T isn't resolved, there's no problem.
1131   if (!T->isResolved())
1132     return;
1133 
1134   // If T is resolved, it may be due to a self-reference cycle.  Track the
1135   // arrays explicitly if they're unresolved, or else the cycles will be
1136   // orphaned.
1137   if (Elements)
1138     trackIfUnresolved(Elements.get());
1139   if (TParams)
1140     trackIfUnresolved(TParams.get());
1141 }
1142