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 DIStringType *DIBuilder::createStringType(StringRef Name,
297                                           DIVariable *StringLength,
298                                           DIExpression *StrLocationExp) {
299   assert(!Name.empty() && "Unable to create type without name");
300   return DIStringType::get(VMContext, dwarf::DW_TAG_string_type, Name,
301                            StringLength, nullptr, StrLocationExp, 0, 0, 0);
302 }
303 
304 DIStringType *DIBuilder::createStringType(StringRef Name,
305                                           DIExpression *StringLengthExp,
306                                           DIExpression *StrLocationExp) {
307   assert(!Name.empty() && "Unable to create type without name");
308   return DIStringType::get(VMContext, dwarf::DW_TAG_string_type, Name, nullptr,
309                            StringLengthExp, StrLocationExp, 0, 0, 0);
310 }
311 
312 DIDerivedType *DIBuilder::createQualifiedType(unsigned Tag, DIType *FromTy) {
313   return DIDerivedType::get(VMContext, Tag, "", nullptr, 0, nullptr, FromTy, 0,
314                             0, 0, None, DINode::FlagZero);
315 }
316 
317 DIDerivedType *
318 DIBuilder::createPointerType(DIType *PointeeTy, uint64_t SizeInBits,
319                              uint32_t AlignInBits,
320                              Optional<unsigned> DWARFAddressSpace,
321                              StringRef Name, DINodeArray Annotations) {
322   // FIXME: Why is there a name here?
323   return DIDerivedType::get(VMContext, dwarf::DW_TAG_pointer_type, Name,
324                             nullptr, 0, nullptr, PointeeTy, SizeInBits,
325                             AlignInBits, 0, DWARFAddressSpace, DINode::FlagZero,
326                             nullptr, Annotations);
327 }
328 
329 DIDerivedType *DIBuilder::createMemberPointerType(DIType *PointeeTy,
330                                                   DIType *Base,
331                                                   uint64_t SizeInBits,
332                                                   uint32_t AlignInBits,
333                                                   DINode::DIFlags Flags) {
334   return DIDerivedType::get(VMContext, dwarf::DW_TAG_ptr_to_member_type, "",
335                             nullptr, 0, nullptr, PointeeTy, SizeInBits,
336                             AlignInBits, 0, None, Flags, Base);
337 }
338 
339 DIDerivedType *
340 DIBuilder::createReferenceType(unsigned Tag, DIType *RTy, uint64_t SizeInBits,
341                                uint32_t AlignInBits,
342                                Optional<unsigned> DWARFAddressSpace) {
343   assert(RTy && "Unable to create reference type");
344   return DIDerivedType::get(VMContext, Tag, "", nullptr, 0, nullptr, RTy,
345                             SizeInBits, AlignInBits, 0, DWARFAddressSpace,
346                             DINode::FlagZero);
347 }
348 
349 DIDerivedType *DIBuilder::createTypedef(DIType *Ty, StringRef Name,
350                                         DIFile *File, unsigned LineNo,
351                                         DIScope *Context, uint32_t AlignInBits,
352                                         DINodeArray Annotations) {
353   return DIDerivedType::get(VMContext, dwarf::DW_TAG_typedef, Name, File,
354                             LineNo, getNonCompileUnitScope(Context), Ty, 0,
355                             AlignInBits, 0, None, DINode::FlagZero, nullptr,
356                             Annotations);
357 }
358 
359 DIDerivedType *DIBuilder::createFriend(DIType *Ty, DIType *FriendTy) {
360   assert(Ty && "Invalid type!");
361   assert(FriendTy && "Invalid friend type!");
362   return DIDerivedType::get(VMContext, dwarf::DW_TAG_friend, "", nullptr, 0, Ty,
363                             FriendTy, 0, 0, 0, None, DINode::FlagZero);
364 }
365 
366 DIDerivedType *DIBuilder::createInheritance(DIType *Ty, DIType *BaseTy,
367                                             uint64_t BaseOffset,
368                                             uint32_t VBPtrOffset,
369                                             DINode::DIFlags Flags) {
370   assert(Ty && "Unable to create inheritance");
371   Metadata *ExtraData = ConstantAsMetadata::get(
372       ConstantInt::get(IntegerType::get(VMContext, 32), VBPtrOffset));
373   return DIDerivedType::get(VMContext, dwarf::DW_TAG_inheritance, "", nullptr,
374                             0, Ty, BaseTy, 0, 0, BaseOffset, None, Flags,
375                             ExtraData);
376 }
377 
378 DIDerivedType *DIBuilder::createMemberType(
379     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
380     uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
381     DINode::DIFlags Flags, DIType *Ty, DINodeArray Annotations) {
382   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
383                             LineNumber, getNonCompileUnitScope(Scope), Ty,
384                             SizeInBits, AlignInBits, OffsetInBits, None, Flags,
385                             nullptr, Annotations);
386 }
387 
388 static ConstantAsMetadata *getConstantOrNull(Constant *C) {
389   if (C)
390     return ConstantAsMetadata::get(C);
391   return nullptr;
392 }
393 
394 DIDerivedType *DIBuilder::createVariantMemberType(
395     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
396     uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
397     Constant *Discriminant, DINode::DIFlags Flags, DIType *Ty) {
398   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
399                             LineNumber, getNonCompileUnitScope(Scope), Ty,
400                             SizeInBits, AlignInBits, OffsetInBits, None, Flags,
401                             getConstantOrNull(Discriminant));
402 }
403 
404 DIDerivedType *DIBuilder::createBitFieldMemberType(
405     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
406     uint64_t SizeInBits, uint64_t OffsetInBits, uint64_t StorageOffsetInBits,
407     DINode::DIFlags Flags, DIType *Ty, DINodeArray Annotations) {
408   Flags |= DINode::FlagBitField;
409   return DIDerivedType::get(
410       VMContext, dwarf::DW_TAG_member, Name, File, LineNumber,
411       getNonCompileUnitScope(Scope), Ty, SizeInBits, /*AlignInBits=*/0,
412       OffsetInBits, None, Flags,
413       ConstantAsMetadata::get(ConstantInt::get(IntegerType::get(VMContext, 64),
414                                                StorageOffsetInBits)),
415       Annotations);
416 }
417 
418 DIDerivedType *
419 DIBuilder::createStaticMemberType(DIScope *Scope, StringRef Name, DIFile *File,
420                                   unsigned LineNumber, DIType *Ty,
421                                   DINode::DIFlags Flags, llvm::Constant *Val,
422                                   uint32_t AlignInBits) {
423   Flags |= DINode::FlagStaticMember;
424   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
425                             LineNumber, getNonCompileUnitScope(Scope), Ty, 0,
426                             AlignInBits, 0, None, Flags,
427                             getConstantOrNull(Val));
428 }
429 
430 DIDerivedType *
431 DIBuilder::createObjCIVar(StringRef Name, DIFile *File, unsigned LineNumber,
432                           uint64_t SizeInBits, uint32_t AlignInBits,
433                           uint64_t OffsetInBits, DINode::DIFlags Flags,
434                           DIType *Ty, MDNode *PropertyNode) {
435   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
436                             LineNumber, getNonCompileUnitScope(File), Ty,
437                             SizeInBits, AlignInBits, OffsetInBits, None, Flags,
438                             PropertyNode);
439 }
440 
441 DIObjCProperty *
442 DIBuilder::createObjCProperty(StringRef Name, DIFile *File, unsigned LineNumber,
443                               StringRef GetterName, StringRef SetterName,
444                               unsigned PropertyAttributes, DIType *Ty) {
445   return DIObjCProperty::get(VMContext, Name, File, LineNumber, GetterName,
446                              SetterName, PropertyAttributes, Ty);
447 }
448 
449 DITemplateTypeParameter *
450 DIBuilder::createTemplateTypeParameter(DIScope *Context, StringRef Name,
451                                        DIType *Ty, bool isDefault) {
452   assert((!Context || isa<DICompileUnit>(Context)) && "Expected compile unit");
453   return DITemplateTypeParameter::get(VMContext, Name, Ty, isDefault);
454 }
455 
456 static DITemplateValueParameter *
457 createTemplateValueParameterHelper(LLVMContext &VMContext, unsigned Tag,
458                                    DIScope *Context, StringRef Name, DIType *Ty,
459                                    bool IsDefault, Metadata *MD) {
460   assert((!Context || isa<DICompileUnit>(Context)) && "Expected compile unit");
461   return DITemplateValueParameter::get(VMContext, Tag, Name, Ty, IsDefault, MD);
462 }
463 
464 DITemplateValueParameter *
465 DIBuilder::createTemplateValueParameter(DIScope *Context, StringRef Name,
466                                         DIType *Ty, bool isDefault,
467                                         Constant *Val) {
468   return createTemplateValueParameterHelper(
469       VMContext, dwarf::DW_TAG_template_value_parameter, Context, Name, Ty,
470       isDefault, getConstantOrNull(Val));
471 }
472 
473 DITemplateValueParameter *
474 DIBuilder::createTemplateTemplateParameter(DIScope *Context, StringRef Name,
475                                            DIType *Ty, StringRef Val) {
476   return createTemplateValueParameterHelper(
477       VMContext, dwarf::DW_TAG_GNU_template_template_param, Context, Name, Ty,
478       false, MDString::get(VMContext, Val));
479 }
480 
481 DITemplateValueParameter *
482 DIBuilder::createTemplateParameterPack(DIScope *Context, StringRef Name,
483                                        DIType *Ty, DINodeArray Val) {
484   return createTemplateValueParameterHelper(
485       VMContext, dwarf::DW_TAG_GNU_template_parameter_pack, Context, Name, Ty,
486       false, Val.get());
487 }
488 
489 DICompositeType *DIBuilder::createClassType(
490     DIScope *Context, StringRef Name, DIFile *File, unsigned LineNumber,
491     uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
492     DINode::DIFlags Flags, DIType *DerivedFrom, DINodeArray Elements,
493     DIType *VTableHolder, MDNode *TemplateParams, StringRef UniqueIdentifier) {
494   assert((!Context || isa<DIScope>(Context)) &&
495          "createClassType should be called with a valid Context");
496 
497   auto *R = DICompositeType::get(
498       VMContext, dwarf::DW_TAG_structure_type, Name, File, LineNumber,
499       getNonCompileUnitScope(Context), DerivedFrom, SizeInBits, AlignInBits,
500       OffsetInBits, Flags, Elements, 0, VTableHolder,
501       cast_or_null<MDTuple>(TemplateParams), UniqueIdentifier);
502   trackIfUnresolved(R);
503   return R;
504 }
505 
506 DICompositeType *DIBuilder::createStructType(
507     DIScope *Context, StringRef Name, DIFile *File, unsigned LineNumber,
508     uint64_t SizeInBits, uint32_t AlignInBits, DINode::DIFlags Flags,
509     DIType *DerivedFrom, DINodeArray Elements, unsigned RunTimeLang,
510     DIType *VTableHolder, StringRef UniqueIdentifier) {
511   auto *R = DICompositeType::get(
512       VMContext, dwarf::DW_TAG_structure_type, Name, File, LineNumber,
513       getNonCompileUnitScope(Context), DerivedFrom, SizeInBits, AlignInBits, 0,
514       Flags, Elements, RunTimeLang, VTableHolder, nullptr, UniqueIdentifier);
515   trackIfUnresolved(R);
516   return R;
517 }
518 
519 DICompositeType *DIBuilder::createUnionType(
520     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
521     uint64_t SizeInBits, uint32_t AlignInBits, DINode::DIFlags Flags,
522     DINodeArray Elements, unsigned RunTimeLang, StringRef UniqueIdentifier) {
523   auto *R = DICompositeType::get(
524       VMContext, dwarf::DW_TAG_union_type, Name, File, LineNumber,
525       getNonCompileUnitScope(Scope), nullptr, SizeInBits, AlignInBits, 0, Flags,
526       Elements, RunTimeLang, nullptr, nullptr, UniqueIdentifier);
527   trackIfUnresolved(R);
528   return R;
529 }
530 
531 DICompositeType *
532 DIBuilder::createVariantPart(DIScope *Scope, StringRef Name, DIFile *File,
533                              unsigned LineNumber, uint64_t SizeInBits,
534                              uint32_t AlignInBits, DINode::DIFlags Flags,
535                              DIDerivedType *Discriminator, DINodeArray Elements,
536                              StringRef UniqueIdentifier) {
537   auto *R = DICompositeType::get(
538       VMContext, dwarf::DW_TAG_variant_part, Name, File, LineNumber,
539       getNonCompileUnitScope(Scope), nullptr, SizeInBits, AlignInBits, 0, Flags,
540       Elements, 0, nullptr, nullptr, UniqueIdentifier, Discriminator);
541   trackIfUnresolved(R);
542   return R;
543 }
544 
545 DISubroutineType *DIBuilder::createSubroutineType(DITypeRefArray ParameterTypes,
546                                                   DINode::DIFlags Flags,
547                                                   unsigned CC) {
548   return DISubroutineType::get(VMContext, Flags, CC, ParameterTypes);
549 }
550 
551 DICompositeType *DIBuilder::createEnumerationType(
552     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
553     uint64_t SizeInBits, uint32_t AlignInBits, DINodeArray Elements,
554     DIType *UnderlyingType, StringRef UniqueIdentifier, bool IsScoped) {
555   auto *CTy = DICompositeType::get(
556       VMContext, dwarf::DW_TAG_enumeration_type, Name, File, LineNumber,
557       getNonCompileUnitScope(Scope), UnderlyingType, SizeInBits, AlignInBits, 0,
558       IsScoped ? DINode::FlagEnumClass : DINode::FlagZero, Elements, 0, nullptr,
559       nullptr, UniqueIdentifier);
560   AllEnumTypes.push_back(CTy);
561   trackIfUnresolved(CTy);
562   return CTy;
563 }
564 
565 DIDerivedType *DIBuilder::createSetType(DIScope *Scope, StringRef Name,
566                                         DIFile *File, unsigned LineNo,
567                                         uint64_t SizeInBits,
568                                         uint32_t AlignInBits, DIType *Ty) {
569   auto *R =
570       DIDerivedType::get(VMContext, dwarf::DW_TAG_set_type, Name, File, LineNo,
571                          getNonCompileUnitScope(Scope), Ty, SizeInBits,
572                          AlignInBits, 0, None, DINode::FlagZero);
573   trackIfUnresolved(R);
574   return R;
575 }
576 
577 DICompositeType *
578 DIBuilder::createArrayType(uint64_t Size, uint32_t AlignInBits, DIType *Ty,
579                            DINodeArray Subscripts,
580                            PointerUnion<DIExpression *, DIVariable *> DL,
581                            PointerUnion<DIExpression *, DIVariable *> AS,
582                            PointerUnion<DIExpression *, DIVariable *> AL,
583                            PointerUnion<DIExpression *, DIVariable *> RK) {
584   auto *R = DICompositeType::get(
585       VMContext, dwarf::DW_TAG_array_type, "", nullptr, 0, nullptr, Ty, Size,
586       AlignInBits, 0, DINode::FlagZero, Subscripts, 0, nullptr, nullptr, "",
587       nullptr,
588       DL.is<DIExpression *>() ? (Metadata *)DL.get<DIExpression *>()
589                               : (Metadata *)DL.get<DIVariable *>(),
590       AS.is<DIExpression *>() ? (Metadata *)AS.get<DIExpression *>()
591                               : (Metadata *)AS.get<DIVariable *>(),
592       AL.is<DIExpression *>() ? (Metadata *)AL.get<DIExpression *>()
593                               : (Metadata *)AL.get<DIVariable *>(),
594       RK.is<DIExpression *>() ? (Metadata *)RK.get<DIExpression *>()
595                               : (Metadata *)RK.get<DIVariable *>());
596   trackIfUnresolved(R);
597   return R;
598 }
599 
600 DICompositeType *DIBuilder::createVectorType(uint64_t Size,
601                                              uint32_t AlignInBits, DIType *Ty,
602                                              DINodeArray Subscripts) {
603   auto *R = DICompositeType::get(VMContext, dwarf::DW_TAG_array_type, "",
604                                  nullptr, 0, nullptr, Ty, Size, AlignInBits, 0,
605                                  DINode::FlagVector, Subscripts, 0, nullptr);
606   trackIfUnresolved(R);
607   return R;
608 }
609 
610 DISubprogram *DIBuilder::createArtificialSubprogram(DISubprogram *SP) {
611   auto NewSP = SP->cloneWithFlags(SP->getFlags() | DINode::FlagArtificial);
612   return MDNode::replaceWithDistinct(std::move(NewSP));
613 }
614 
615 static DIType *createTypeWithFlags(const DIType *Ty,
616                                    DINode::DIFlags FlagsToSet) {
617   auto NewTy = Ty->cloneWithFlags(Ty->getFlags() | FlagsToSet);
618   return MDNode::replaceWithUniqued(std::move(NewTy));
619 }
620 
621 DIType *DIBuilder::createArtificialType(DIType *Ty) {
622   // FIXME: Restrict this to the nodes where it's valid.
623   if (Ty->isArtificial())
624     return Ty;
625   return createTypeWithFlags(Ty, DINode::FlagArtificial);
626 }
627 
628 DIType *DIBuilder::createObjectPointerType(DIType *Ty) {
629   // FIXME: Restrict this to the nodes where it's valid.
630   if (Ty->isObjectPointer())
631     return Ty;
632   DINode::DIFlags Flags = DINode::FlagObjectPointer | DINode::FlagArtificial;
633   return createTypeWithFlags(Ty, Flags);
634 }
635 
636 void DIBuilder::retainType(DIScope *T) {
637   assert(T && "Expected non-null type");
638   assert((isa<DIType>(T) || (isa<DISubprogram>(T) &&
639                              cast<DISubprogram>(T)->isDefinition() == false)) &&
640          "Expected type or subprogram declaration");
641   AllRetainTypes.emplace_back(T);
642 }
643 
644 DIBasicType *DIBuilder::createUnspecifiedParameter() { return nullptr; }
645 
646 DICompositeType *
647 DIBuilder::createForwardDecl(unsigned Tag, StringRef Name, DIScope *Scope,
648                              DIFile *F, unsigned Line, unsigned RuntimeLang,
649                              uint64_t SizeInBits, uint32_t AlignInBits,
650                              StringRef UniqueIdentifier) {
651   // FIXME: Define in terms of createReplaceableForwardDecl() by calling
652   // replaceWithUniqued().
653   auto *RetTy = DICompositeType::get(
654       VMContext, Tag, Name, F, Line, getNonCompileUnitScope(Scope), nullptr,
655       SizeInBits, AlignInBits, 0, DINode::FlagFwdDecl, nullptr, RuntimeLang,
656       nullptr, nullptr, UniqueIdentifier);
657   trackIfUnresolved(RetTy);
658   return RetTy;
659 }
660 
661 DICompositeType *DIBuilder::createReplaceableCompositeType(
662     unsigned Tag, StringRef Name, DIScope *Scope, DIFile *F, unsigned Line,
663     unsigned RuntimeLang, uint64_t SizeInBits, uint32_t AlignInBits,
664     DINode::DIFlags Flags, StringRef UniqueIdentifier,
665     DINodeArray Annotations) {
666   auto *RetTy =
667       DICompositeType::getTemporary(
668           VMContext, Tag, Name, F, Line, getNonCompileUnitScope(Scope), nullptr,
669           SizeInBits, AlignInBits, 0, Flags, nullptr, RuntimeLang, nullptr,
670           nullptr, UniqueIdentifier, nullptr, nullptr, nullptr, nullptr,
671           nullptr, Annotations)
672           .release();
673   trackIfUnresolved(RetTy);
674   return RetTy;
675 }
676 
677 DINodeArray DIBuilder::getOrCreateArray(ArrayRef<Metadata *> Elements) {
678   return MDTuple::get(VMContext, Elements);
679 }
680 
681 DIMacroNodeArray
682 DIBuilder::getOrCreateMacroArray(ArrayRef<Metadata *> Elements) {
683   return MDTuple::get(VMContext, Elements);
684 }
685 
686 DITypeRefArray DIBuilder::getOrCreateTypeArray(ArrayRef<Metadata *> Elements) {
687   SmallVector<llvm::Metadata *, 16> Elts;
688   for (Metadata *E : Elements) {
689     if (isa_and_nonnull<MDNode>(E))
690       Elts.push_back(cast<DIType>(E));
691     else
692       Elts.push_back(E);
693   }
694   return DITypeRefArray(MDNode::get(VMContext, Elts));
695 }
696 
697 DISubrange *DIBuilder::getOrCreateSubrange(int64_t Lo, int64_t Count) {
698   auto *LB = ConstantAsMetadata::get(
699       ConstantInt::getSigned(Type::getInt64Ty(VMContext), Lo));
700   auto *CountNode = ConstantAsMetadata::get(
701       ConstantInt::getSigned(Type::getInt64Ty(VMContext), Count));
702   return DISubrange::get(VMContext, CountNode, LB, nullptr, nullptr);
703 }
704 
705 DISubrange *DIBuilder::getOrCreateSubrange(int64_t Lo, Metadata *CountNode) {
706   auto *LB = ConstantAsMetadata::get(
707       ConstantInt::getSigned(Type::getInt64Ty(VMContext), Lo));
708   return DISubrange::get(VMContext, CountNode, LB, nullptr, nullptr);
709 }
710 
711 DISubrange *DIBuilder::getOrCreateSubrange(Metadata *CountNode, Metadata *LB,
712                                            Metadata *UB, Metadata *Stride) {
713   return DISubrange::get(VMContext, CountNode, LB, UB, Stride);
714 }
715 
716 DIGenericSubrange *DIBuilder::getOrCreateGenericSubrange(
717     DIGenericSubrange::BoundType CountNode, DIGenericSubrange::BoundType LB,
718     DIGenericSubrange::BoundType UB, DIGenericSubrange::BoundType Stride) {
719   auto ConvToMetadata = [&](DIGenericSubrange::BoundType Bound) -> Metadata * {
720     return Bound.is<DIExpression *>() ? (Metadata *)Bound.get<DIExpression *>()
721                                       : (Metadata *)Bound.get<DIVariable *>();
722   };
723   return DIGenericSubrange::get(VMContext, ConvToMetadata(CountNode),
724                                 ConvToMetadata(LB), ConvToMetadata(UB),
725                                 ConvToMetadata(Stride));
726 }
727 
728 static void checkGlobalVariableScope(DIScope *Context) {
729 #ifndef NDEBUG
730   if (auto *CT =
731           dyn_cast_or_null<DICompositeType>(getNonCompileUnitScope(Context)))
732     assert(CT->getIdentifier().empty() &&
733            "Context of a global variable should not be a type with identifier");
734 #endif
735 }
736 
737 DIGlobalVariableExpression *DIBuilder::createGlobalVariableExpression(
738     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
739     unsigned LineNumber, DIType *Ty, bool IsLocalToUnit, bool isDefined,
740     DIExpression *Expr, MDNode *Decl, MDTuple *TemplateParams,
741     uint32_t AlignInBits, DINodeArray Annotations) {
742   checkGlobalVariableScope(Context);
743 
744   auto *GV = DIGlobalVariable::getDistinct(
745       VMContext, cast_or_null<DIScope>(Context), Name, LinkageName, F,
746       LineNumber, Ty, IsLocalToUnit, isDefined,
747       cast_or_null<DIDerivedType>(Decl), TemplateParams, AlignInBits,
748       Annotations);
749   if (!Expr)
750     Expr = createExpression();
751   auto *N = DIGlobalVariableExpression::get(VMContext, GV, Expr);
752   AllGVs.push_back(N);
753   return N;
754 }
755 
756 DIGlobalVariable *DIBuilder::createTempGlobalVariableFwdDecl(
757     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
758     unsigned LineNumber, DIType *Ty, bool IsLocalToUnit, MDNode *Decl,
759     MDTuple *TemplateParams, uint32_t AlignInBits) {
760   checkGlobalVariableScope(Context);
761 
762   return DIGlobalVariable::getTemporary(
763              VMContext, cast_or_null<DIScope>(Context), Name, LinkageName, F,
764              LineNumber, Ty, IsLocalToUnit, false,
765              cast_or_null<DIDerivedType>(Decl), TemplateParams, AlignInBits,
766              nullptr)
767       .release();
768 }
769 
770 static DILocalVariable *createLocalVariable(
771     LLVMContext &VMContext,
772     DenseMap<MDNode *, SmallVector<TrackingMDNodeRef, 1>> &PreservedVariables,
773     DIScope *Scope, StringRef Name, unsigned ArgNo, DIFile *File,
774     unsigned LineNo, DIType *Ty, bool AlwaysPreserve, DINode::DIFlags Flags,
775     uint32_t AlignInBits, DINodeArray Annotations = nullptr) {
776   // FIXME: Why getNonCompileUnitScope()?
777   // FIXME: Why is "!Context" okay here?
778   // FIXME: Why doesn't this check for a subprogram or lexical block (AFAICT
779   // the only valid scopes)?
780   DIScope *Context = getNonCompileUnitScope(Scope);
781 
782   auto *Node = DILocalVariable::get(
783       VMContext, cast_or_null<DILocalScope>(Context), Name, File, LineNo, Ty,
784       ArgNo, Flags, AlignInBits, Annotations);
785   if (AlwaysPreserve) {
786     // The optimizer may remove local variables. If there is an interest
787     // to preserve variable info in such situation then stash it in a
788     // named mdnode.
789     DISubprogram *Fn = getDISubprogram(Scope);
790     assert(Fn && "Missing subprogram for local variable");
791     PreservedVariables[Fn].emplace_back(Node);
792   }
793   return Node;
794 }
795 
796 DILocalVariable *DIBuilder::createAutoVariable(DIScope *Scope, StringRef Name,
797                                                DIFile *File, unsigned LineNo,
798                                                DIType *Ty, bool AlwaysPreserve,
799                                                DINode::DIFlags Flags,
800                                                uint32_t AlignInBits) {
801   return createLocalVariable(VMContext, PreservedVariables, Scope, Name,
802                              /* ArgNo */ 0, File, LineNo, Ty, AlwaysPreserve,
803                              Flags, AlignInBits);
804 }
805 
806 DILocalVariable *DIBuilder::createParameterVariable(
807     DIScope *Scope, StringRef Name, unsigned ArgNo, DIFile *File,
808     unsigned LineNo, DIType *Ty, bool AlwaysPreserve, DINode::DIFlags Flags,
809     DINodeArray Annotations) {
810   assert(ArgNo && "Expected non-zero argument number for parameter");
811   return createLocalVariable(VMContext, PreservedVariables, Scope, Name, ArgNo,
812                              File, LineNo, Ty, AlwaysPreserve, Flags,
813                              /*AlignInBits=*/0, Annotations);
814 }
815 
816 DILabel *DIBuilder::createLabel(DIScope *Scope, StringRef Name, DIFile *File,
817                                 unsigned LineNo, bool AlwaysPreserve) {
818   DIScope *Context = getNonCompileUnitScope(Scope);
819 
820   auto *Node = DILabel::get(VMContext, cast_or_null<DILocalScope>(Context),
821                             Name, File, LineNo);
822 
823   if (AlwaysPreserve) {
824     /// The optimizer may remove labels. If there is an interest
825     /// to preserve label info in such situation then append it to
826     /// the list of retained nodes of the DISubprogram.
827     DISubprogram *Fn = getDISubprogram(Scope);
828     assert(Fn && "Missing subprogram for label");
829     PreservedLabels[Fn].emplace_back(Node);
830   }
831   return Node;
832 }
833 
834 DIExpression *DIBuilder::createExpression(ArrayRef<uint64_t> Addr) {
835   return DIExpression::get(VMContext, Addr);
836 }
837 
838 template <class... Ts>
839 static DISubprogram *getSubprogram(bool IsDistinct, Ts &&...Args) {
840   if (IsDistinct)
841     return DISubprogram::getDistinct(std::forward<Ts>(Args)...);
842   return DISubprogram::get(std::forward<Ts>(Args)...);
843 }
844 
845 DISubprogram *DIBuilder::createFunction(
846     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *File,
847     unsigned LineNo, DISubroutineType *Ty, unsigned ScopeLine,
848     DINode::DIFlags Flags, DISubprogram::DISPFlags SPFlags,
849     DITemplateParameterArray TParams, DISubprogram *Decl,
850     DITypeArray ThrownTypes, DINodeArray Annotations) {
851   bool IsDefinition = SPFlags & DISubprogram::SPFlagDefinition;
852   auto *Node = getSubprogram(
853       /*IsDistinct=*/IsDefinition, VMContext, getNonCompileUnitScope(Context),
854       Name, LinkageName, File, LineNo, Ty, ScopeLine, nullptr, 0, 0, Flags,
855       SPFlags, IsDefinition ? CUNode : nullptr, TParams, Decl,
856       MDTuple::getTemporary(VMContext, None).release(), ThrownTypes,
857       Annotations);
858 
859   if (IsDefinition)
860     AllSubprograms.push_back(Node);
861   trackIfUnresolved(Node);
862   return Node;
863 }
864 
865 DISubprogram *DIBuilder::createTempFunctionFwdDecl(
866     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *File,
867     unsigned LineNo, DISubroutineType *Ty, unsigned ScopeLine,
868     DINode::DIFlags Flags, DISubprogram::DISPFlags SPFlags,
869     DITemplateParameterArray TParams, DISubprogram *Decl,
870     DITypeArray ThrownTypes) {
871   bool IsDefinition = SPFlags & DISubprogram::SPFlagDefinition;
872   return DISubprogram::getTemporary(VMContext, getNonCompileUnitScope(Context),
873                                     Name, LinkageName, File, LineNo, Ty,
874                                     ScopeLine, nullptr, 0, 0, Flags, SPFlags,
875                                     IsDefinition ? CUNode : nullptr, TParams,
876                                     Decl, nullptr, ThrownTypes)
877       .release();
878 }
879 
880 DISubprogram *DIBuilder::createMethod(
881     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
882     unsigned LineNo, DISubroutineType *Ty, unsigned VIndex, int ThisAdjustment,
883     DIType *VTableHolder, DINode::DIFlags Flags,
884     DISubprogram::DISPFlags SPFlags, DITemplateParameterArray TParams,
885     DITypeArray ThrownTypes) {
886   assert(getNonCompileUnitScope(Context) &&
887          "Methods should have both a Context and a context that isn't "
888          "the compile unit.");
889   // FIXME: Do we want to use different scope/lines?
890   bool IsDefinition = SPFlags & DISubprogram::SPFlagDefinition;
891   auto *SP = getSubprogram(
892       /*IsDistinct=*/IsDefinition, VMContext, cast<DIScope>(Context), Name,
893       LinkageName, F, LineNo, Ty, LineNo, VTableHolder, VIndex, ThisAdjustment,
894       Flags, SPFlags, IsDefinition ? CUNode : nullptr, TParams, nullptr,
895       nullptr, ThrownTypes);
896 
897   if (IsDefinition)
898     AllSubprograms.push_back(SP);
899   trackIfUnresolved(SP);
900   return SP;
901 }
902 
903 DICommonBlock *DIBuilder::createCommonBlock(DIScope *Scope,
904                                             DIGlobalVariable *Decl,
905                                             StringRef Name, DIFile *File,
906                                             unsigned LineNo) {
907   return DICommonBlock::get(VMContext, Scope, Decl, Name, File, LineNo);
908 }
909 
910 DINamespace *DIBuilder::createNameSpace(DIScope *Scope, StringRef Name,
911                                         bool ExportSymbols) {
912 
913   // It is okay to *not* make anonymous top-level namespaces distinct, because
914   // all nodes that have an anonymous namespace as their parent scope are
915   // guaranteed to be unique and/or are linked to their containing
916   // DICompileUnit. This decision is an explicit tradeoff of link time versus
917   // memory usage versus code simplicity and may get revisited in the future.
918   return DINamespace::get(VMContext, getNonCompileUnitScope(Scope), Name,
919                           ExportSymbols);
920 }
921 
922 DIModule *DIBuilder::createModule(DIScope *Scope, StringRef Name,
923                                   StringRef ConfigurationMacros,
924                                   StringRef IncludePath, StringRef APINotesFile,
925                                   DIFile *File, unsigned LineNo, bool IsDecl) {
926   return DIModule::get(VMContext, File, getNonCompileUnitScope(Scope), Name,
927                        ConfigurationMacros, IncludePath, APINotesFile, LineNo,
928                        IsDecl);
929 }
930 
931 DILexicalBlockFile *DIBuilder::createLexicalBlockFile(DIScope *Scope,
932                                                       DIFile *File,
933                                                       unsigned Discriminator) {
934   return DILexicalBlockFile::get(VMContext, Scope, File, Discriminator);
935 }
936 
937 DILexicalBlock *DIBuilder::createLexicalBlock(DIScope *Scope, DIFile *File,
938                                               unsigned Line, unsigned Col) {
939   // Make these distinct, to avoid merging two lexical blocks on the same
940   // file/line/column.
941   return DILexicalBlock::getDistinct(VMContext, getNonCompileUnitScope(Scope),
942                                      File, Line, Col);
943 }
944 
945 Instruction *DIBuilder::insertDeclare(Value *Storage, DILocalVariable *VarInfo,
946                                       DIExpression *Expr, const DILocation *DL,
947                                       Instruction *InsertBefore) {
948   return insertDeclare(Storage, VarInfo, Expr, DL, InsertBefore->getParent(),
949                        InsertBefore);
950 }
951 
952 Instruction *DIBuilder::insertDeclare(Value *Storage, DILocalVariable *VarInfo,
953                                       DIExpression *Expr, const DILocation *DL,
954                                       BasicBlock *InsertAtEnd) {
955   // If this block already has a terminator then insert this intrinsic before
956   // the terminator. Otherwise, put it at the end of the block.
957   Instruction *InsertBefore = InsertAtEnd->getTerminator();
958   return insertDeclare(Storage, VarInfo, Expr, DL, InsertAtEnd, InsertBefore);
959 }
960 
961 Instruction *DIBuilder::insertLabel(DILabel *LabelInfo, const DILocation *DL,
962                                     Instruction *InsertBefore) {
963   return insertLabel(LabelInfo, DL,
964                      InsertBefore ? InsertBefore->getParent() : nullptr,
965                      InsertBefore);
966 }
967 
968 Instruction *DIBuilder::insertLabel(DILabel *LabelInfo, const DILocation *DL,
969                                     BasicBlock *InsertAtEnd) {
970   return insertLabel(LabelInfo, DL, InsertAtEnd, nullptr);
971 }
972 
973 Instruction *DIBuilder::insertDbgValueIntrinsic(Value *V,
974                                                 DILocalVariable *VarInfo,
975                                                 DIExpression *Expr,
976                                                 const DILocation *DL,
977                                                 Instruction *InsertBefore) {
978   return insertDbgValueIntrinsic(
979       V, VarInfo, Expr, DL, InsertBefore ? InsertBefore->getParent() : nullptr,
980       InsertBefore);
981 }
982 
983 Instruction *DIBuilder::insertDbgValueIntrinsic(Value *V,
984                                                 DILocalVariable *VarInfo,
985                                                 DIExpression *Expr,
986                                                 const DILocation *DL,
987                                                 BasicBlock *InsertAtEnd) {
988   return insertDbgValueIntrinsic(V, VarInfo, Expr, DL, InsertAtEnd, nullptr);
989 }
990 
991 Instruction *DIBuilder::insertDbgAddrIntrinsic(Value *V,
992                                                DILocalVariable *VarInfo,
993                                                DIExpression *Expr,
994                                                const DILocation *DL,
995                                                Instruction *InsertBefore) {
996   return insertDbgAddrIntrinsic(
997       V, VarInfo, Expr, DL, InsertBefore ? InsertBefore->getParent() : nullptr,
998       InsertBefore);
999 }
1000 
1001 Instruction *DIBuilder::insertDbgAddrIntrinsic(Value *V,
1002                                                DILocalVariable *VarInfo,
1003                                                DIExpression *Expr,
1004                                                const DILocation *DL,
1005                                                BasicBlock *InsertAtEnd) {
1006   return insertDbgAddrIntrinsic(V, VarInfo, Expr, DL, InsertAtEnd, nullptr);
1007 }
1008 
1009 /// Initialize IRBuilder for inserting dbg.declare and dbg.value intrinsics.
1010 /// This abstracts over the various ways to specify an insert position.
1011 static void initIRBuilder(IRBuilder<> &Builder, const DILocation *DL,
1012                           BasicBlock *InsertBB, Instruction *InsertBefore) {
1013   if (InsertBefore)
1014     Builder.SetInsertPoint(InsertBefore);
1015   else if (InsertBB)
1016     Builder.SetInsertPoint(InsertBB);
1017   Builder.SetCurrentDebugLocation(DL);
1018 }
1019 
1020 static Value *getDbgIntrinsicValueImpl(LLVMContext &VMContext, Value *V) {
1021   assert(V && "no value passed to dbg intrinsic");
1022   return MetadataAsValue::get(VMContext, ValueAsMetadata::get(V));
1023 }
1024 
1025 static Function *getDeclareIntrin(Module &M) {
1026   return Intrinsic::getDeclaration(&M, UseDbgAddr ? Intrinsic::dbg_addr
1027                                                   : Intrinsic::dbg_declare);
1028 }
1029 
1030 Instruction *DIBuilder::insertDbgValueIntrinsic(
1031     llvm::Value *Val, DILocalVariable *VarInfo, DIExpression *Expr,
1032     const DILocation *DL, BasicBlock *InsertBB, Instruction *InsertBefore) {
1033   if (!ValueFn)
1034     ValueFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_value);
1035   return insertDbgIntrinsic(ValueFn, Val, VarInfo, Expr, DL, InsertBB,
1036                             InsertBefore);
1037 }
1038 
1039 Instruction *DIBuilder::insertDbgAddrIntrinsic(
1040     llvm::Value *Val, DILocalVariable *VarInfo, DIExpression *Expr,
1041     const DILocation *DL, BasicBlock *InsertBB, Instruction *InsertBefore) {
1042   if (!AddrFn)
1043     AddrFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_addr);
1044   return insertDbgIntrinsic(AddrFn, Val, VarInfo, Expr, DL, InsertBB,
1045                             InsertBefore);
1046 }
1047 
1048 Instruction *DIBuilder::insertDeclare(Value *Storage, DILocalVariable *VarInfo,
1049                                       DIExpression *Expr, const DILocation *DL,
1050                                       BasicBlock *InsertBB,
1051                                       Instruction *InsertBefore) {
1052   assert(VarInfo && "empty or invalid DILocalVariable* passed to dbg.declare");
1053   assert(DL && "Expected debug loc");
1054   assert(DL->getScope()->getSubprogram() ==
1055              VarInfo->getScope()->getSubprogram() &&
1056          "Expected matching subprograms");
1057   if (!DeclareFn)
1058     DeclareFn = getDeclareIntrin(M);
1059 
1060   trackIfUnresolved(VarInfo);
1061   trackIfUnresolved(Expr);
1062   Value *Args[] = {getDbgIntrinsicValueImpl(VMContext, Storage),
1063                    MetadataAsValue::get(VMContext, VarInfo),
1064                    MetadataAsValue::get(VMContext, Expr)};
1065 
1066   IRBuilder<> B(DL->getContext());
1067   initIRBuilder(B, DL, InsertBB, InsertBefore);
1068   return B.CreateCall(DeclareFn, Args);
1069 }
1070 
1071 Instruction *DIBuilder::insertDbgIntrinsic(llvm::Function *IntrinsicFn,
1072                                            Value *V, DILocalVariable *VarInfo,
1073                                            DIExpression *Expr,
1074                                            const DILocation *DL,
1075                                            BasicBlock *InsertBB,
1076                                            Instruction *InsertBefore) {
1077   assert(IntrinsicFn && "must pass a non-null intrinsic function");
1078   assert(V && "must pass a value to a dbg intrinsic");
1079   assert(VarInfo &&
1080          "empty or invalid DILocalVariable* passed to debug intrinsic");
1081   assert(DL && "Expected debug loc");
1082   assert(DL->getScope()->getSubprogram() ==
1083              VarInfo->getScope()->getSubprogram() &&
1084          "Expected matching subprograms");
1085 
1086   trackIfUnresolved(VarInfo);
1087   trackIfUnresolved(Expr);
1088   Value *Args[] = {getDbgIntrinsicValueImpl(VMContext, V),
1089                    MetadataAsValue::get(VMContext, VarInfo),
1090                    MetadataAsValue::get(VMContext, Expr)};
1091 
1092   IRBuilder<> B(DL->getContext());
1093   initIRBuilder(B, DL, InsertBB, InsertBefore);
1094   return B.CreateCall(IntrinsicFn, Args);
1095 }
1096 
1097 Instruction *DIBuilder::insertLabel(DILabel *LabelInfo, const DILocation *DL,
1098                                     BasicBlock *InsertBB,
1099                                     Instruction *InsertBefore) {
1100   assert(LabelInfo && "empty or invalid DILabel* passed to dbg.label");
1101   assert(DL && "Expected debug loc");
1102   assert(DL->getScope()->getSubprogram() ==
1103              LabelInfo->getScope()->getSubprogram() &&
1104          "Expected matching subprograms");
1105   if (!LabelFn)
1106     LabelFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_label);
1107 
1108   trackIfUnresolved(LabelInfo);
1109   Value *Args[] = {MetadataAsValue::get(VMContext, LabelInfo)};
1110 
1111   IRBuilder<> B(DL->getContext());
1112   initIRBuilder(B, DL, InsertBB, InsertBefore);
1113   return B.CreateCall(LabelFn, Args);
1114 }
1115 
1116 void DIBuilder::replaceVTableHolder(DICompositeType *&T, DIType *VTableHolder) {
1117   {
1118     TypedTrackingMDRef<DICompositeType> N(T);
1119     N->replaceVTableHolder(VTableHolder);
1120     T = N.get();
1121   }
1122 
1123   // If this didn't create a self-reference, just return.
1124   if (T != VTableHolder)
1125     return;
1126 
1127   // Look for unresolved operands.  T will drop RAUW support, orphaning any
1128   // cycles underneath it.
1129   if (T->isResolved())
1130     for (const MDOperand &O : T->operands())
1131       if (auto *N = dyn_cast_or_null<MDNode>(O))
1132         trackIfUnresolved(N);
1133 }
1134 
1135 void DIBuilder::replaceArrays(DICompositeType *&T, DINodeArray Elements,
1136                               DINodeArray TParams) {
1137   {
1138     TypedTrackingMDRef<DICompositeType> N(T);
1139     if (Elements)
1140       N->replaceElements(Elements);
1141     if (TParams)
1142       N->replaceTemplateParams(DITemplateParameterArray(TParams));
1143     T = N.get();
1144   }
1145 
1146   // If T isn't resolved, there's no problem.
1147   if (!T->isResolved())
1148     return;
1149 
1150   // If T is resolved, it may be due to a self-reference cycle.  Track the
1151   // arrays explicitly if they're unresolved, or else the cycles will be
1152   // orphaned.
1153   if (Elements)
1154     trackIfUnresolved(Elements.get());
1155   if (TParams)
1156     trackIfUnresolved(TParams.get());
1157 }
1158