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/ADT/STLExtras.h"
17 #include "llvm/BinaryFormat/Dwarf.h"
18 #include "llvm/IR/Constants.h"
19 #include "llvm/IR/DebugInfo.h"
20 #include "llvm/IR/IRBuilder.h"
21 #include "llvm/IR/IntrinsicInst.h"
22 #include "llvm/IR/Module.h"
23 #include "llvm/Support/CommandLine.h"
24 #include "llvm/Support/Debug.h"
25 
26 using namespace llvm;
27 using namespace llvm::dwarf;
28 
29 static cl::opt<bool>
30     UseDbgAddr("use-dbg-addr",
31                llvm::cl::desc("Use llvm.dbg.addr for all local variables"),
32                cl::init(false), cl::Hidden);
33 
34 DIBuilder::DIBuilder(Module &m, bool AllowUnresolvedNodes, DICompileUnit *CU)
35   : M(m), VMContext(M.getContext()), CUNode(CU),
36       DeclareFn(nullptr), ValueFn(nullptr), LabelFn(nullptr),
37       AllowUnresolvedNodes(AllowUnresolvedNodes) {}
38 
39 void DIBuilder::trackIfUnresolved(MDNode *N) {
40   if (!N)
41     return;
42   if (N->isResolved())
43     return;
44 
45   assert(AllowUnresolvedNodes && "Cannot handle unresolved nodes");
46   UnresolvedNodes.emplace_back(N);
47 }
48 
49 void DIBuilder::finalizeSubprogram(DISubprogram *SP) {
50   MDTuple *Temp = SP->getRetainedNodes().get();
51   if (!Temp || !Temp->isTemporary())
52     return;
53 
54   SmallVector<Metadata *, 16> RetainedNodes;
55 
56   auto PV = PreservedVariables.find(SP);
57   if (PV != PreservedVariables.end())
58     RetainedNodes.append(PV->second.begin(), PV->second.end());
59 
60   auto PL = PreservedLabels.find(SP);
61   if (PL != PreservedLabels.end())
62     RetainedNodes.append(PL->second.begin(), PL->second.end());
63 
64   DINodeArray Node = getOrCreateArray(RetainedNodes);
65 
66   TempMDTuple(Temp)->replaceAllUsesWith(Node.get());
67 }
68 
69 void DIBuilder::finalize() {
70   if (!CUNode) {
71     assert(!AllowUnresolvedNodes &&
72            "creating type nodes without a CU is not supported");
73     return;
74   }
75 
76   if (!AllEnumTypes.empty())
77     CUNode->replaceEnumTypes(MDTuple::get(VMContext, AllEnumTypes));
78 
79   SmallVector<Metadata *, 16> RetainValues;
80   // Declarations and definitions of the same type may be retained. Some
81   // clients RAUW these pairs, leaving duplicates in the retained types
82   // list. Use a set to remove the duplicates while we transform the
83   // TrackingVHs back into Values.
84   SmallPtrSet<Metadata *, 16> RetainSet;
85   for (unsigned I = 0, E = AllRetainTypes.size(); I < E; I++)
86     if (RetainSet.insert(AllRetainTypes[I]).second)
87       RetainValues.push_back(AllRetainTypes[I]);
88 
89   if (!RetainValues.empty())
90     CUNode->replaceRetainedTypes(MDTuple::get(VMContext, RetainValues));
91 
92   DISubprogramArray SPs = MDTuple::get(VMContext, AllSubprograms);
93   for (auto *SP : SPs)
94     finalizeSubprogram(SP);
95   for (auto *N : RetainValues)
96     if (auto *SP = dyn_cast<DISubprogram>(N))
97       finalizeSubprogram(SP);
98 
99   if (!AllGVs.empty())
100     CUNode->replaceGlobalVariables(MDTuple::get(VMContext, AllGVs));
101 
102   if (!AllImportedModules.empty())
103     CUNode->replaceImportedEntities(MDTuple::get(
104         VMContext, SmallVector<Metadata *, 16>(AllImportedModules.begin(),
105                                                AllImportedModules.end())));
106 
107   for (const auto &I : AllMacrosPerParent) {
108     // DIMacroNode's with nullptr parent are DICompileUnit direct children.
109     if (!I.first) {
110       CUNode->replaceMacros(MDTuple::get(VMContext, I.second.getArrayRef()));
111       continue;
112     }
113     // Otherwise, it must be a temporary DIMacroFile that need to be resolved.
114     auto *TMF = cast<DIMacroFile>(I.first);
115     auto *MF = DIMacroFile::get(VMContext, dwarf::DW_MACINFO_start_file,
116                                 TMF->getLine(), TMF->getFile(),
117                                 getOrCreateMacroArray(I.second.getArrayRef()));
118     replaceTemporary(llvm::TempDIMacroNode(TMF), MF);
119   }
120 
121   // Now that all temp nodes have been replaced or deleted, resolve remaining
122   // cycles.
123   for (const auto &N : UnresolvedNodes)
124     if (N && !N->isResolved())
125       N->resolveCycles();
126   UnresolvedNodes.clear();
127 
128   // Can't handle unresolved nodes anymore.
129   AllowUnresolvedNodes = false;
130 }
131 
132 /// If N is compile unit return NULL otherwise return N.
133 static DIScope *getNonCompileUnitScope(DIScope *N) {
134   if (!N || isa<DICompileUnit>(N))
135     return nullptr;
136   return cast<DIScope>(N);
137 }
138 
139 DICompileUnit *DIBuilder::createCompileUnit(
140     unsigned Lang, DIFile *File, StringRef Producer, bool isOptimized,
141     StringRef Flags, unsigned RunTimeVer, StringRef SplitName,
142     DICompileUnit::DebugEmissionKind Kind, uint64_t DWOId,
143     bool SplitDebugInlining, bool DebugInfoForProfiling,
144     DICompileUnit::DebugNameTableKind NameTableKind, bool RangesBaseAddress,
145     StringRef SysRoot, StringRef SDK) {
146 
147   assert(((Lang <= dwarf::DW_LANG_Fortran08 && Lang >= dwarf::DW_LANG_C89) ||
148           (Lang <= dwarf::DW_LANG_hi_user && Lang >= dwarf::DW_LANG_lo_user)) &&
149          "Invalid Language tag");
150 
151   assert(!CUNode && "Can only make one compile unit per DIBuilder instance");
152   CUNode = DICompileUnit::getDistinct(
153       VMContext, Lang, File, Producer, isOptimized, Flags, RunTimeVer,
154       SplitName, Kind, nullptr, nullptr, nullptr, nullptr, nullptr, DWOId,
155       SplitDebugInlining, DebugInfoForProfiling, NameTableKind,
156       RangesBaseAddress, SysRoot, SDK);
157 
158   // Create a named metadata so that it is easier to find cu in a module.
159   NamedMDNode *NMD = M.getOrInsertNamedMetadata("llvm.dbg.cu");
160   NMD->addOperand(CUNode);
161   trackIfUnresolved(CUNode);
162   return CUNode;
163 }
164 
165 static DIImportedEntity *
166 createImportedModule(LLVMContext &C, dwarf::Tag Tag, DIScope *Context,
167                      Metadata *NS, DIFile *File, unsigned Line, StringRef Name,
168                      DINodeArray Elements,
169                      SmallVectorImpl<TrackingMDNodeRef> &AllImportedModules) {
170   if (Line)
171     assert(File && "Source location has line number but no file");
172   unsigned EntitiesCount = C.pImpl->DIImportedEntitys.size();
173   auto *M = DIImportedEntity::get(C, Tag, Context, cast_or_null<DINode>(NS),
174                                   File, Line, Name, Elements);
175   if (EntitiesCount < C.pImpl->DIImportedEntitys.size())
176     // A new Imported Entity was just added to the context.
177     // Add it to the Imported Modules list.
178     AllImportedModules.emplace_back(M);
179   return M;
180 }
181 
182 DIImportedEntity *DIBuilder::createImportedModule(DIScope *Context,
183                                                   DINamespace *NS, DIFile *File,
184                                                   unsigned Line,
185                                                   DINodeArray Elements) {
186   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_module,
187                                 Context, NS, File, Line, StringRef(), Elements,
188                                 AllImportedModules);
189 }
190 
191 DIImportedEntity *DIBuilder::createImportedModule(DIScope *Context,
192                                                   DIImportedEntity *NS,
193                                                   DIFile *File, unsigned Line,
194                                                   DINodeArray Elements) {
195   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_module,
196                                 Context, NS, File, Line, StringRef(), Elements,
197                                 AllImportedModules);
198 }
199 
200 DIImportedEntity *DIBuilder::createImportedModule(DIScope *Context, DIModule *M,
201                                                   DIFile *File, unsigned Line,
202                                                   DINodeArray Elements) {
203   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_module,
204                                 Context, M, File, Line, StringRef(), Elements,
205                                 AllImportedModules);
206 }
207 
208 DIImportedEntity *
209 DIBuilder::createImportedDeclaration(DIScope *Context, DINode *Decl,
210                                      DIFile *File, unsigned Line,
211                                      StringRef Name, DINodeArray Elements) {
212   // Make sure to use the unique identifier based metadata reference for
213   // types that have one.
214   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_declaration,
215                                 Context, Decl, File, Line, Name, Elements,
216                                 AllImportedModules);
217 }
218 
219 DIFile *DIBuilder::createFile(StringRef Filename, StringRef Directory,
220                               Optional<DIFile::ChecksumInfo<StringRef>> CS,
221                               Optional<StringRef> Source) {
222   return DIFile::get(VMContext, Filename, Directory, CS, Source);
223 }
224 
225 DIMacro *DIBuilder::createMacro(DIMacroFile *Parent, unsigned LineNumber,
226                                 unsigned MacroType, StringRef Name,
227                                 StringRef Value) {
228   assert(!Name.empty() && "Unable to create macro without name");
229   assert((MacroType == dwarf::DW_MACINFO_undef ||
230           MacroType == dwarf::DW_MACINFO_define) &&
231          "Unexpected macro type");
232   auto *M = DIMacro::get(VMContext, MacroType, LineNumber, Name, Value);
233   AllMacrosPerParent[Parent].insert(M);
234   return M;
235 }
236 
237 DIMacroFile *DIBuilder::createTempMacroFile(DIMacroFile *Parent,
238                                             unsigned LineNumber, DIFile *File) {
239   auto *MF = DIMacroFile::getTemporary(VMContext, dwarf::DW_MACINFO_start_file,
240                                        LineNumber, File, DIMacroNodeArray())
241                  .release();
242   AllMacrosPerParent[Parent].insert(MF);
243   // Add the new temporary DIMacroFile to the macro per parent map as a parent.
244   // This is needed to assure DIMacroFile with no children to have an entry in
245   // the map. Otherwise, it will not be resolved in DIBuilder::finalize().
246   AllMacrosPerParent.insert({MF, {}});
247   return MF;
248 }
249 
250 DIEnumerator *DIBuilder::createEnumerator(StringRef Name, uint64_t Val,
251                                           bool IsUnsigned) {
252   assert(!Name.empty() && "Unable to create enumerator without name");
253   return DIEnumerator::get(VMContext, APInt(64, Val, !IsUnsigned), IsUnsigned,
254                            Name);
255 }
256 
257 DIEnumerator *DIBuilder::createEnumerator(StringRef Name, const APSInt &Value) {
258   assert(!Name.empty() && "Unable to create enumerator without name");
259   return DIEnumerator::get(VMContext, APInt(Value), Value.isUnsigned(), Name);
260 }
261 
262 DIBasicType *DIBuilder::createUnspecifiedType(StringRef Name) {
263   assert(!Name.empty() && "Unable to create type without name");
264   return DIBasicType::get(VMContext, dwarf::DW_TAG_unspecified_type, Name);
265 }
266 
267 DIBasicType *DIBuilder::createNullPtrType() {
268   return createUnspecifiedType("decltype(nullptr)");
269 }
270 
271 DIBasicType *DIBuilder::createBasicType(StringRef Name, uint64_t SizeInBits,
272                                         unsigned Encoding,
273                                         DINode::DIFlags Flags) {
274   assert(!Name.empty() && "Unable to create type without name");
275   return DIBasicType::get(VMContext, dwarf::DW_TAG_base_type, Name, SizeInBits,
276                           0, Encoding, Flags);
277 }
278 
279 DIStringType *DIBuilder::createStringType(StringRef Name, uint64_t SizeInBits) {
280   assert(!Name.empty() && "Unable to create type without name");
281   return DIStringType::get(VMContext, dwarf::DW_TAG_string_type, Name,
282                            SizeInBits, 0);
283 }
284 
285 DIDerivedType *DIBuilder::createQualifiedType(unsigned Tag, DIType *FromTy) {
286   return DIDerivedType::get(VMContext, Tag, "", nullptr, 0, nullptr, FromTy, 0,
287                             0, 0, None, DINode::FlagZero);
288 }
289 
290 DIDerivedType *DIBuilder::createPointerType(
291     DIType *PointeeTy,
292     uint64_t SizeInBits,
293     uint32_t AlignInBits,
294     Optional<unsigned> DWARFAddressSpace,
295     StringRef Name) {
296   // FIXME: Why is there a name here?
297   return DIDerivedType::get(VMContext, dwarf::DW_TAG_pointer_type, Name,
298                             nullptr, 0, nullptr, PointeeTy, SizeInBits,
299                             AlignInBits, 0, DWARFAddressSpace,
300                             DINode::FlagZero);
301 }
302 
303 DIDerivedType *DIBuilder::createMemberPointerType(DIType *PointeeTy,
304                                                   DIType *Base,
305                                                   uint64_t SizeInBits,
306                                                   uint32_t AlignInBits,
307                                                   DINode::DIFlags Flags) {
308   return DIDerivedType::get(VMContext, dwarf::DW_TAG_ptr_to_member_type, "",
309                             nullptr, 0, nullptr, PointeeTy, SizeInBits,
310                             AlignInBits, 0, None, Flags, Base);
311 }
312 
313 DIDerivedType *DIBuilder::createReferenceType(
314     unsigned Tag, DIType *RTy,
315     uint64_t SizeInBits,
316     uint32_t AlignInBits,
317     Optional<unsigned> DWARFAddressSpace) {
318   assert(RTy && "Unable to create reference type");
319   return DIDerivedType::get(VMContext, Tag, "", nullptr, 0, nullptr, RTy,
320                             SizeInBits, AlignInBits, 0, DWARFAddressSpace,
321                             DINode::FlagZero);
322 }
323 
324 DIDerivedType *DIBuilder::createTypedef(DIType *Ty, StringRef Name,
325                                         DIFile *File, unsigned LineNo,
326                                         DIScope *Context,
327                                         uint32_t AlignInBits) {
328   return DIDerivedType::get(VMContext, dwarf::DW_TAG_typedef, Name, File,
329                             LineNo, getNonCompileUnitScope(Context), Ty, 0,
330                             AlignInBits, 0, None, DINode::FlagZero);
331 }
332 
333 DIDerivedType *DIBuilder::createFriend(DIType *Ty, DIType *FriendTy) {
334   assert(Ty && "Invalid type!");
335   assert(FriendTy && "Invalid friend type!");
336   return DIDerivedType::get(VMContext, dwarf::DW_TAG_friend, "", nullptr, 0, Ty,
337                             FriendTy, 0, 0, 0, None, DINode::FlagZero);
338 }
339 
340 DIDerivedType *DIBuilder::createInheritance(DIType *Ty, DIType *BaseTy,
341                                             uint64_t BaseOffset,
342                                             uint32_t VBPtrOffset,
343                                             DINode::DIFlags Flags) {
344   assert(Ty && "Unable to create inheritance");
345   Metadata *ExtraData = ConstantAsMetadata::get(
346       ConstantInt::get(IntegerType::get(VMContext, 32), VBPtrOffset));
347   return DIDerivedType::get(VMContext, dwarf::DW_TAG_inheritance, "", nullptr,
348                             0, Ty, BaseTy, 0, 0, BaseOffset, None,
349                             Flags, ExtraData);
350 }
351 
352 DIDerivedType *DIBuilder::createMemberType(
353     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
354     uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
355     DINode::DIFlags Flags, DIType *Ty, DINodeArray Annotations) {
356   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
357                             LineNumber, getNonCompileUnitScope(Scope), Ty,
358                             SizeInBits, AlignInBits, OffsetInBits, None, Flags,
359                             nullptr, Annotations);
360 }
361 
362 static ConstantAsMetadata *getConstantOrNull(Constant *C) {
363   if (C)
364     return ConstantAsMetadata::get(C);
365   return nullptr;
366 }
367 
368 DIDerivedType *DIBuilder::createVariantMemberType(
369     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
370     uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
371     Constant *Discriminant, DINode::DIFlags Flags, DIType *Ty) {
372   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
373                             LineNumber, getNonCompileUnitScope(Scope), Ty,
374                             SizeInBits, AlignInBits, OffsetInBits, None, Flags,
375                             getConstantOrNull(Discriminant));
376 }
377 
378 DIDerivedType *DIBuilder::createBitFieldMemberType(
379     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
380     uint64_t SizeInBits, uint64_t OffsetInBits, uint64_t StorageOffsetInBits,
381     DINode::DIFlags Flags, DIType *Ty, DINodeArray Annotations) {
382   Flags |= DINode::FlagBitField;
383   return DIDerivedType::get(
384       VMContext, dwarf::DW_TAG_member, Name, File, LineNumber,
385       getNonCompileUnitScope(Scope), Ty, SizeInBits, /* AlignInBits */ 0,
386       OffsetInBits, None, Flags,
387       ConstantAsMetadata::get(ConstantInt::get(IntegerType::get(VMContext, 64),
388                                                StorageOffsetInBits)),
389       Annotations);
390 }
391 
392 DIDerivedType *
393 DIBuilder::createStaticMemberType(DIScope *Scope, StringRef Name, DIFile *File,
394                                   unsigned LineNumber, DIType *Ty,
395                                   DINode::DIFlags Flags, llvm::Constant *Val,
396                                   uint32_t AlignInBits) {
397   Flags |= DINode::FlagStaticMember;
398   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
399                             LineNumber, getNonCompileUnitScope(Scope), Ty, 0,
400                             AlignInBits, 0, None, Flags,
401                             getConstantOrNull(Val));
402 }
403 
404 DIDerivedType *
405 DIBuilder::createObjCIVar(StringRef Name, DIFile *File, unsigned LineNumber,
406                           uint64_t SizeInBits, uint32_t AlignInBits,
407                           uint64_t OffsetInBits, DINode::DIFlags Flags,
408                           DIType *Ty, MDNode *PropertyNode) {
409   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
410                             LineNumber, getNonCompileUnitScope(File), Ty,
411                             SizeInBits, AlignInBits, OffsetInBits, None, Flags,
412                             PropertyNode);
413 }
414 
415 DIObjCProperty *
416 DIBuilder::createObjCProperty(StringRef Name, DIFile *File, unsigned LineNumber,
417                               StringRef GetterName, StringRef SetterName,
418                               unsigned PropertyAttributes, DIType *Ty) {
419   return DIObjCProperty::get(VMContext, Name, File, LineNumber, GetterName,
420                              SetterName, PropertyAttributes, Ty);
421 }
422 
423 DITemplateTypeParameter *
424 DIBuilder::createTemplateTypeParameter(DIScope *Context, StringRef Name,
425                                        DIType *Ty, bool isDefault) {
426   assert((!Context || isa<DICompileUnit>(Context)) && "Expected compile unit");
427   return DITemplateTypeParameter::get(VMContext, Name, Ty, isDefault);
428 }
429 
430 static DITemplateValueParameter *
431 createTemplateValueParameterHelper(LLVMContext &VMContext, unsigned Tag,
432                                    DIScope *Context, StringRef Name, DIType *Ty,
433                                    bool IsDefault, Metadata *MD) {
434   assert((!Context || isa<DICompileUnit>(Context)) && "Expected compile unit");
435   return DITemplateValueParameter::get(VMContext, Tag, Name, Ty, IsDefault, MD);
436 }
437 
438 DITemplateValueParameter *
439 DIBuilder::createTemplateValueParameter(DIScope *Context, StringRef Name,
440                                         DIType *Ty, bool isDefault,
441                                         Constant *Val) {
442   return createTemplateValueParameterHelper(
443       VMContext, dwarf::DW_TAG_template_value_parameter, Context, Name, Ty,
444       isDefault, getConstantOrNull(Val));
445 }
446 
447 DITemplateValueParameter *
448 DIBuilder::createTemplateTemplateParameter(DIScope *Context, StringRef Name,
449                                            DIType *Ty, StringRef Val) {
450   return createTemplateValueParameterHelper(
451       VMContext, dwarf::DW_TAG_GNU_template_template_param, Context, Name, Ty,
452       false, MDString::get(VMContext, Val));
453 }
454 
455 DITemplateValueParameter *
456 DIBuilder::createTemplateParameterPack(DIScope *Context, StringRef Name,
457                                        DIType *Ty, DINodeArray Val) {
458   return createTemplateValueParameterHelper(
459       VMContext, dwarf::DW_TAG_GNU_template_parameter_pack, Context, Name, Ty,
460       false, Val.get());
461 }
462 
463 DICompositeType *DIBuilder::createClassType(
464     DIScope *Context, StringRef Name, DIFile *File, unsigned LineNumber,
465     uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
466     DINode::DIFlags Flags, DIType *DerivedFrom, DINodeArray Elements,
467     DIType *VTableHolder, MDNode *TemplateParams, StringRef UniqueIdentifier) {
468   assert((!Context || isa<DIScope>(Context)) &&
469          "createClassType should be called with a valid Context");
470 
471   auto *R = DICompositeType::get(
472       VMContext, dwarf::DW_TAG_structure_type, Name, File, LineNumber,
473       getNonCompileUnitScope(Context), DerivedFrom, SizeInBits, AlignInBits,
474       OffsetInBits, Flags, Elements, 0, VTableHolder,
475       cast_or_null<MDTuple>(TemplateParams), UniqueIdentifier);
476   trackIfUnresolved(R);
477   return R;
478 }
479 
480 DICompositeType *DIBuilder::createStructType(
481     DIScope *Context, StringRef Name, DIFile *File, unsigned LineNumber,
482     uint64_t SizeInBits, uint32_t AlignInBits, DINode::DIFlags Flags,
483     DIType *DerivedFrom, DINodeArray Elements, unsigned RunTimeLang,
484     DIType *VTableHolder, StringRef UniqueIdentifier) {
485   auto *R = DICompositeType::get(
486       VMContext, dwarf::DW_TAG_structure_type, Name, File, LineNumber,
487       getNonCompileUnitScope(Context), DerivedFrom, SizeInBits, AlignInBits, 0,
488       Flags, Elements, RunTimeLang, VTableHolder, nullptr, UniqueIdentifier);
489   trackIfUnresolved(R);
490   return R;
491 }
492 
493 DICompositeType *DIBuilder::createUnionType(
494     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
495     uint64_t SizeInBits, uint32_t AlignInBits, DINode::DIFlags Flags,
496     DINodeArray Elements, unsigned RunTimeLang, StringRef UniqueIdentifier) {
497   auto *R = DICompositeType::get(
498       VMContext, dwarf::DW_TAG_union_type, Name, File, LineNumber,
499       getNonCompileUnitScope(Scope), nullptr, SizeInBits, AlignInBits, 0, Flags,
500       Elements, RunTimeLang, nullptr, nullptr, UniqueIdentifier);
501   trackIfUnresolved(R);
502   return R;
503 }
504 
505 DICompositeType *DIBuilder::createVariantPart(
506     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
507     uint64_t SizeInBits, uint32_t AlignInBits, DINode::DIFlags Flags,
508     DIDerivedType *Discriminator, DINodeArray Elements, StringRef UniqueIdentifier) {
509   auto *R = DICompositeType::get(
510       VMContext, dwarf::DW_TAG_variant_part, Name, File, LineNumber,
511       getNonCompileUnitScope(Scope), nullptr, SizeInBits, AlignInBits, 0, Flags,
512       Elements, 0, nullptr, nullptr, UniqueIdentifier, Discriminator);
513   trackIfUnresolved(R);
514   return R;
515 }
516 
517 DISubroutineType *DIBuilder::createSubroutineType(DITypeRefArray ParameterTypes,
518                                                   DINode::DIFlags Flags,
519                                                   unsigned CC) {
520   return DISubroutineType::get(VMContext, Flags, CC, ParameterTypes);
521 }
522 
523 DICompositeType *DIBuilder::createEnumerationType(
524     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
525     uint64_t SizeInBits, uint32_t AlignInBits, DINodeArray Elements,
526     DIType *UnderlyingType, StringRef UniqueIdentifier, bool IsScoped) {
527   auto *CTy = DICompositeType::get(
528       VMContext, dwarf::DW_TAG_enumeration_type, Name, File, LineNumber,
529       getNonCompileUnitScope(Scope), UnderlyingType, SizeInBits, AlignInBits, 0,
530       IsScoped ? DINode::FlagEnumClass : DINode::FlagZero, Elements, 0, nullptr,
531       nullptr, UniqueIdentifier);
532   AllEnumTypes.push_back(CTy);
533   trackIfUnresolved(CTy);
534   return CTy;
535 }
536 
537 DIDerivedType *DIBuilder::createSetType(DIScope *Scope, StringRef Name,
538                                         DIFile *File, unsigned LineNo,
539                                         uint64_t SizeInBits,
540                                         uint32_t AlignInBits, DIType *Ty) {
541   auto *R =
542       DIDerivedType::get(VMContext, dwarf::DW_TAG_set_type, Name, File, LineNo,
543                          getNonCompileUnitScope(Scope), Ty, SizeInBits,
544                          AlignInBits, 0, None, DINode::FlagZero);
545   trackIfUnresolved(R);
546   return R;
547 }
548 
549 DICompositeType *DIBuilder::createArrayType(
550     uint64_t Size, uint32_t AlignInBits, DIType *Ty, DINodeArray Subscripts,
551     PointerUnion<DIExpression *, DIVariable *> DL,
552     PointerUnion<DIExpression *, DIVariable *> AS,
553     PointerUnion<DIExpression *, DIVariable *> AL,
554     PointerUnion<DIExpression *, DIVariable *> RK) {
555   auto *R = DICompositeType::get(
556       VMContext, dwarf::DW_TAG_array_type, "", nullptr, 0,
557       nullptr, Ty, Size, AlignInBits, 0, DINode::FlagZero,
558       Subscripts, 0, nullptr, nullptr, "", nullptr,
559       DL.is<DIExpression *>() ? (Metadata *)DL.get<DIExpression *>()
560                               : (Metadata *)DL.get<DIVariable *>(),
561       AS.is<DIExpression *>() ? (Metadata *)AS.get<DIExpression *>()
562                               : (Metadata *)AS.get<DIVariable *>(),
563       AL.is<DIExpression *>() ? (Metadata *)AL.get<DIExpression *>()
564                               : (Metadata *)AL.get<DIVariable *>(),
565       RK.is<DIExpression *>() ? (Metadata *)RK.get<DIExpression *>()
566                               : (Metadata *)RK.get<DIVariable *>());
567   trackIfUnresolved(R);
568   return R;
569 }
570 
571 DICompositeType *DIBuilder::createVectorType(uint64_t Size,
572                                              uint32_t AlignInBits, DIType *Ty,
573                                              DINodeArray Subscripts) {
574   auto *R = DICompositeType::get(VMContext, dwarf::DW_TAG_array_type, "",
575                                  nullptr, 0, nullptr, Ty, Size, AlignInBits, 0,
576                                  DINode::FlagVector, Subscripts, 0, nullptr);
577   trackIfUnresolved(R);
578   return R;
579 }
580 
581 DISubprogram *DIBuilder::createArtificialSubprogram(DISubprogram *SP) {
582   auto NewSP = SP->cloneWithFlags(SP->getFlags() | DINode::FlagArtificial);
583   return MDNode::replaceWithDistinct(std::move(NewSP));
584 }
585 
586 static DIType *createTypeWithFlags(const DIType *Ty,
587                                    DINode::DIFlags FlagsToSet) {
588   auto NewTy = Ty->cloneWithFlags(Ty->getFlags() | FlagsToSet);
589   return MDNode::replaceWithUniqued(std::move(NewTy));
590 }
591 
592 DIType *DIBuilder::createArtificialType(DIType *Ty) {
593   // FIXME: Restrict this to the nodes where it's valid.
594   if (Ty->isArtificial())
595     return Ty;
596   return createTypeWithFlags(Ty, DINode::FlagArtificial);
597 }
598 
599 DIType *DIBuilder::createObjectPointerType(DIType *Ty) {
600   // FIXME: Restrict this to the nodes where it's valid.
601   if (Ty->isObjectPointer())
602     return Ty;
603   DINode::DIFlags Flags = DINode::FlagObjectPointer | DINode::FlagArtificial;
604   return createTypeWithFlags(Ty, Flags);
605 }
606 
607 void DIBuilder::retainType(DIScope *T) {
608   assert(T && "Expected non-null type");
609   assert((isa<DIType>(T) || (isa<DISubprogram>(T) &&
610                              cast<DISubprogram>(T)->isDefinition() == false)) &&
611          "Expected type or subprogram declaration");
612   AllRetainTypes.emplace_back(T);
613 }
614 
615 DIBasicType *DIBuilder::createUnspecifiedParameter() { return nullptr; }
616 
617 DICompositeType *
618 DIBuilder::createForwardDecl(unsigned Tag, StringRef Name, DIScope *Scope,
619                              DIFile *F, unsigned Line, unsigned RuntimeLang,
620                              uint64_t SizeInBits, uint32_t AlignInBits,
621                              StringRef UniqueIdentifier) {
622   // FIXME: Define in terms of createReplaceableForwardDecl() by calling
623   // replaceWithUniqued().
624   auto *RetTy = DICompositeType::get(
625       VMContext, Tag, Name, F, Line, getNonCompileUnitScope(Scope), nullptr,
626       SizeInBits, AlignInBits, 0, DINode::FlagFwdDecl, nullptr, RuntimeLang,
627       nullptr, nullptr, UniqueIdentifier);
628   trackIfUnresolved(RetTy);
629   return RetTy;
630 }
631 
632 DICompositeType *DIBuilder::createReplaceableCompositeType(
633     unsigned Tag, StringRef Name, DIScope *Scope, DIFile *F, unsigned Line,
634     unsigned RuntimeLang, uint64_t SizeInBits, uint32_t AlignInBits,
635     DINode::DIFlags Flags, StringRef UniqueIdentifier,
636     DINodeArray Annotations) {
637   auto *RetTy =
638       DICompositeType::getTemporary(
639           VMContext, Tag, Name, F, Line, getNonCompileUnitScope(Scope), nullptr,
640           SizeInBits, AlignInBits, 0, Flags, nullptr, RuntimeLang, nullptr,
641           nullptr, UniqueIdentifier, nullptr, nullptr, nullptr, nullptr, nullptr,
642           Annotations)
643           .release();
644   trackIfUnresolved(RetTy);
645   return RetTy;
646 }
647 
648 DINodeArray DIBuilder::getOrCreateArray(ArrayRef<Metadata *> Elements) {
649   return MDTuple::get(VMContext, Elements);
650 }
651 
652 DIMacroNodeArray
653 DIBuilder::getOrCreateMacroArray(ArrayRef<Metadata *> Elements) {
654   return MDTuple::get(VMContext, Elements);
655 }
656 
657 DITypeRefArray DIBuilder::getOrCreateTypeArray(ArrayRef<Metadata *> Elements) {
658   SmallVector<llvm::Metadata *, 16> Elts;
659   for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
660     if (Elements[i] && isa<MDNode>(Elements[i]))
661       Elts.push_back(cast<DIType>(Elements[i]));
662     else
663       Elts.push_back(Elements[i]);
664   }
665   return DITypeRefArray(MDNode::get(VMContext, Elts));
666 }
667 
668 DISubrange *DIBuilder::getOrCreateSubrange(int64_t Lo, int64_t Count) {
669   auto *LB = ConstantAsMetadata::get(
670       ConstantInt::getSigned(Type::getInt64Ty(VMContext), Lo));
671   auto *CountNode = ConstantAsMetadata::get(
672       ConstantInt::getSigned(Type::getInt64Ty(VMContext), Count));
673   return DISubrange::get(VMContext, CountNode, LB, nullptr, nullptr);
674 }
675 
676 DISubrange *DIBuilder::getOrCreateSubrange(int64_t Lo, Metadata *CountNode) {
677   auto *LB = ConstantAsMetadata::get(
678       ConstantInt::getSigned(Type::getInt64Ty(VMContext), Lo));
679   return DISubrange::get(VMContext, CountNode, LB, nullptr, nullptr);
680 }
681 
682 DISubrange *DIBuilder::getOrCreateSubrange(Metadata *CountNode, Metadata *LB,
683                                            Metadata *UB, Metadata *Stride) {
684   return DISubrange::get(VMContext, CountNode, LB, UB, Stride);
685 }
686 
687 DIGenericSubrange *DIBuilder::getOrCreateGenericSubrange(
688     DIGenericSubrange::BoundType CountNode, DIGenericSubrange::BoundType LB,
689     DIGenericSubrange::BoundType UB, DIGenericSubrange::BoundType Stride) {
690   auto ConvToMetadata = [&](DIGenericSubrange::BoundType Bound) -> Metadata * {
691     return Bound.is<DIExpression *>() ? (Metadata *)Bound.get<DIExpression *>()
692                                       : (Metadata *)Bound.get<DIVariable *>();
693   };
694   return DIGenericSubrange::get(VMContext, ConvToMetadata(CountNode),
695                                 ConvToMetadata(LB), ConvToMetadata(UB),
696                                 ConvToMetadata(Stride));
697 }
698 
699 static void checkGlobalVariableScope(DIScope *Context) {
700 #ifndef NDEBUG
701   if (auto *CT =
702           dyn_cast_or_null<DICompositeType>(getNonCompileUnitScope(Context)))
703     assert(CT->getIdentifier().empty() &&
704            "Context of a global variable should not be a type with identifier");
705 #endif
706 }
707 
708 DIGlobalVariableExpression *DIBuilder::createGlobalVariableExpression(
709     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
710     unsigned LineNumber, DIType *Ty, bool IsLocalToUnit,
711     bool isDefined, DIExpression *Expr,
712     MDNode *Decl, MDTuple *TemplateParams, uint32_t AlignInBits,
713     DINodeArray Annotations) {
714   checkGlobalVariableScope(Context);
715 
716   auto *GV = DIGlobalVariable::getDistinct(
717       VMContext, cast_or_null<DIScope>(Context), Name, LinkageName, F,
718       LineNumber, Ty, IsLocalToUnit, isDefined, cast_or_null<DIDerivedType>(Decl),
719       TemplateParams, AlignInBits, Annotations);
720   if (!Expr)
721     Expr = createExpression();
722   auto *N = DIGlobalVariableExpression::get(VMContext, GV, Expr);
723   AllGVs.push_back(N);
724   return N;
725 }
726 
727 DIGlobalVariable *DIBuilder::createTempGlobalVariableFwdDecl(
728     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
729     unsigned LineNumber, DIType *Ty, bool IsLocalToUnit, MDNode *Decl,
730     MDTuple *TemplateParams, uint32_t AlignInBits) {
731   checkGlobalVariableScope(Context);
732 
733   return DIGlobalVariable::getTemporary(
734              VMContext, cast_or_null<DIScope>(Context), Name, LinkageName, F,
735              LineNumber, Ty, IsLocalToUnit, false,
736              cast_or_null<DIDerivedType>(Decl), TemplateParams, AlignInBits,
737              nullptr)
738       .release();
739 }
740 
741 static DILocalVariable *createLocalVariable(
742     LLVMContext &VMContext,
743     DenseMap<MDNode *, SmallVector<TrackingMDNodeRef, 1>> &PreservedVariables,
744     DIScope *Scope, StringRef Name, unsigned ArgNo, DIFile *File,
745     unsigned LineNo, DIType *Ty, bool AlwaysPreserve, DINode::DIFlags Flags,
746     uint32_t AlignInBits, DINodeArray Annotations = nullptr) {
747   // FIXME: Why getNonCompileUnitScope()?
748   // FIXME: Why is "!Context" okay here?
749   // FIXME: Why doesn't this check for a subprogram or lexical block (AFAICT
750   // the only valid scopes)?
751   DIScope *Context = getNonCompileUnitScope(Scope);
752 
753   auto *Node =
754       DILocalVariable::get(VMContext, cast_or_null<DILocalScope>(Context), Name,
755                            File, LineNo, Ty, ArgNo, Flags, AlignInBits,
756                            Annotations);
757   if (AlwaysPreserve) {
758     // The optimizer may remove local variables. If there is an interest
759     // to preserve variable info in such situation then stash it in a
760     // named mdnode.
761     DISubprogram *Fn = getDISubprogram(Scope);
762     assert(Fn && "Missing subprogram for local variable");
763     PreservedVariables[Fn].emplace_back(Node);
764   }
765   return Node;
766 }
767 
768 DILocalVariable *DIBuilder::createAutoVariable(DIScope *Scope, StringRef Name,
769                                                DIFile *File, unsigned LineNo,
770                                                DIType *Ty, bool AlwaysPreserve,
771                                                DINode::DIFlags Flags,
772                                                uint32_t AlignInBits) {
773   return createLocalVariable(VMContext, PreservedVariables, Scope, Name,
774                              /* ArgNo */ 0, File, LineNo, Ty, AlwaysPreserve,
775                              Flags, AlignInBits);
776 }
777 
778 DILocalVariable *DIBuilder::createParameterVariable(
779     DIScope *Scope, StringRef Name, unsigned ArgNo, DIFile *File,
780     unsigned LineNo, DIType *Ty, bool AlwaysPreserve, DINode::DIFlags Flags,
781     DINodeArray Annotations) {
782   assert(ArgNo && "Expected non-zero argument number for parameter");
783   return createLocalVariable(VMContext, PreservedVariables, Scope, Name, ArgNo,
784                              File, LineNo, Ty, AlwaysPreserve, Flags,
785                              /* AlignInBits */0, Annotations);
786 }
787 
788 DILabel *DIBuilder::createLabel(
789     DIScope *Scope, StringRef Name, DIFile *File,
790     unsigned LineNo, bool AlwaysPreserve) {
791   DIScope *Context = getNonCompileUnitScope(Scope);
792 
793   auto *Node =
794       DILabel::get(VMContext, cast_or_null<DILocalScope>(Context), Name,
795                    File, LineNo);
796 
797   if (AlwaysPreserve) {
798     /// The optimizer may remove labels. If there is an interest
799     /// to preserve label info in such situation then append it to
800     /// the list of retained nodes of the DISubprogram.
801     DISubprogram *Fn = getDISubprogram(Scope);
802     assert(Fn && "Missing subprogram for label");
803     PreservedLabels[Fn].emplace_back(Node);
804   }
805   return Node;
806 }
807 
808 DIExpression *DIBuilder::createExpression(ArrayRef<uint64_t> Addr) {
809   return DIExpression::get(VMContext, Addr);
810 }
811 
812 DIExpression *DIBuilder::createExpression(ArrayRef<int64_t> Signed) {
813   // TODO: Remove the callers of this signed version and delete.
814   SmallVector<uint64_t, 8> Addr(Signed.begin(), Signed.end());
815   return createExpression(Addr);
816 }
817 
818 template <class... Ts>
819 static DISubprogram *getSubprogram(bool IsDistinct, Ts &&... Args) {
820   if (IsDistinct)
821     return DISubprogram::getDistinct(std::forward<Ts>(Args)...);
822   return DISubprogram::get(std::forward<Ts>(Args)...);
823 }
824 
825 DISubprogram *DIBuilder::createFunction(
826     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *File,
827     unsigned LineNo, DISubroutineType *Ty, unsigned ScopeLine,
828     DINode::DIFlags Flags, DISubprogram::DISPFlags SPFlags,
829     DITemplateParameterArray TParams, DISubprogram *Decl,
830     DITypeArray ThrownTypes, DINodeArray Annotations) {
831   bool IsDefinition = SPFlags & DISubprogram::SPFlagDefinition;
832   auto *Node = getSubprogram(
833       /*IsDistinct=*/IsDefinition, VMContext, getNonCompileUnitScope(Context),
834       Name, LinkageName, File, LineNo, Ty, ScopeLine, nullptr, 0, 0, Flags,
835       SPFlags, IsDefinition ? CUNode : nullptr, TParams, Decl,
836       MDTuple::getTemporary(VMContext, None).release(), ThrownTypes,
837       Annotations);
838 
839   if (IsDefinition)
840     AllSubprograms.push_back(Node);
841   trackIfUnresolved(Node);
842   return Node;
843 }
844 
845 DISubprogram *DIBuilder::createTempFunctionFwdDecl(
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) {
851   bool IsDefinition = SPFlags & DISubprogram::SPFlagDefinition;
852   return DISubprogram::getTemporary(VMContext, getNonCompileUnitScope(Context),
853                                     Name, LinkageName, File, LineNo, Ty,
854                                     ScopeLine, nullptr, 0, 0, Flags, SPFlags,
855                                     IsDefinition ? CUNode : nullptr, TParams,
856                                     Decl, nullptr, ThrownTypes)
857       .release();
858 }
859 
860 DISubprogram *DIBuilder::createMethod(
861     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
862     unsigned LineNo, DISubroutineType *Ty, unsigned VIndex, int ThisAdjustment,
863     DIType *VTableHolder, DINode::DIFlags Flags,
864     DISubprogram::DISPFlags SPFlags, DITemplateParameterArray TParams,
865     DITypeArray ThrownTypes) {
866   assert(getNonCompileUnitScope(Context) &&
867          "Methods should have both a Context and a context that isn't "
868          "the compile unit.");
869   // FIXME: Do we want to use different scope/lines?
870   bool IsDefinition = SPFlags & DISubprogram::SPFlagDefinition;
871   auto *SP = getSubprogram(
872       /*IsDistinct=*/IsDefinition, VMContext, cast<DIScope>(Context), Name,
873       LinkageName, F, LineNo, Ty, LineNo, VTableHolder, VIndex, ThisAdjustment,
874       Flags, SPFlags, IsDefinition ? CUNode : nullptr, TParams, nullptr,
875       nullptr, ThrownTypes);
876 
877   if (IsDefinition)
878     AllSubprograms.push_back(SP);
879   trackIfUnresolved(SP);
880   return SP;
881 }
882 
883 DICommonBlock *DIBuilder::createCommonBlock(
884     DIScope *Scope, DIGlobalVariable *Decl, StringRef Name, DIFile *File,
885     unsigned LineNo) {
886   return DICommonBlock::get(
887       VMContext, Scope, Decl, Name, File, LineNo);
888 }
889 
890 DINamespace *DIBuilder::createNameSpace(DIScope *Scope, StringRef Name,
891                                         bool ExportSymbols) {
892 
893   // It is okay to *not* make anonymous top-level namespaces distinct, because
894   // all nodes that have an anonymous namespace as their parent scope are
895   // guaranteed to be unique and/or are linked to their containing
896   // DICompileUnit. This decision is an explicit tradeoff of link time versus
897   // memory usage versus code simplicity and may get revisited in the future.
898   return DINamespace::get(VMContext, getNonCompileUnitScope(Scope), Name,
899                           ExportSymbols);
900 }
901 
902 DIModule *DIBuilder::createModule(DIScope *Scope, StringRef Name,
903                                   StringRef ConfigurationMacros,
904                                   StringRef IncludePath, StringRef APINotesFile,
905                                   DIFile *File, unsigned LineNo, bool IsDecl) {
906   return DIModule::get(VMContext, File, getNonCompileUnitScope(Scope), Name,
907                        ConfigurationMacros, IncludePath, APINotesFile, LineNo,
908                        IsDecl);
909 }
910 
911 DILexicalBlockFile *DIBuilder::createLexicalBlockFile(DIScope *Scope,
912                                                       DIFile *File,
913                                                       unsigned Discriminator) {
914   return DILexicalBlockFile::get(VMContext, Scope, File, Discriminator);
915 }
916 
917 DILexicalBlock *DIBuilder::createLexicalBlock(DIScope *Scope, DIFile *File,
918                                               unsigned Line, unsigned Col) {
919   // Make these distinct, to avoid merging two lexical blocks on the same
920   // file/line/column.
921   return DILexicalBlock::getDistinct(VMContext, getNonCompileUnitScope(Scope),
922                                      File, Line, Col);
923 }
924 
925 Instruction *DIBuilder::insertDeclare(Value *Storage, DILocalVariable *VarInfo,
926                                       DIExpression *Expr, const DILocation *DL,
927                                       Instruction *InsertBefore) {
928   return insertDeclare(Storage, VarInfo, Expr, DL, InsertBefore->getParent(),
929                        InsertBefore);
930 }
931 
932 Instruction *DIBuilder::insertDeclare(Value *Storage, DILocalVariable *VarInfo,
933                                       DIExpression *Expr, const DILocation *DL,
934                                       BasicBlock *InsertAtEnd) {
935   // If this block already has a terminator then insert this intrinsic before
936   // the terminator. Otherwise, put it at the end of the block.
937   Instruction *InsertBefore = InsertAtEnd->getTerminator();
938   return insertDeclare(Storage, VarInfo, Expr, DL, InsertAtEnd, InsertBefore);
939 }
940 
941 Instruction *DIBuilder::insertLabel(DILabel *LabelInfo, const DILocation *DL,
942                                     Instruction *InsertBefore) {
943   return insertLabel(
944       LabelInfo, DL, InsertBefore ? InsertBefore->getParent() : nullptr,
945       InsertBefore);
946 }
947 
948 Instruction *DIBuilder::insertLabel(DILabel *LabelInfo, const DILocation *DL,
949                                     BasicBlock *InsertAtEnd) {
950   return insertLabel(LabelInfo, DL, InsertAtEnd, nullptr);
951 }
952 
953 Instruction *DIBuilder::insertDbgValueIntrinsic(Value *V,
954                                                 DILocalVariable *VarInfo,
955                                                 DIExpression *Expr,
956                                                 const DILocation *DL,
957                                                 Instruction *InsertBefore) {
958   return insertDbgValueIntrinsic(
959       V, VarInfo, Expr, DL, InsertBefore ? InsertBefore->getParent() : nullptr,
960       InsertBefore);
961 }
962 
963 Instruction *DIBuilder::insertDbgValueIntrinsic(Value *V,
964                                                 DILocalVariable *VarInfo,
965                                                 DIExpression *Expr,
966                                                 const DILocation *DL,
967                                                 BasicBlock *InsertAtEnd) {
968   return insertDbgValueIntrinsic(V, VarInfo, Expr, DL, InsertAtEnd, nullptr);
969 }
970 
971 /// Initialize IRBuilder for inserting dbg.declare and dbg.value intrinsics.
972 /// This abstracts over the various ways to specify an insert position.
973 static void initIRBuilder(IRBuilder<> &Builder, const DILocation *DL,
974                           BasicBlock *InsertBB, Instruction *InsertBefore) {
975   if (InsertBefore)
976     Builder.SetInsertPoint(InsertBefore);
977   else if (InsertBB)
978     Builder.SetInsertPoint(InsertBB);
979   Builder.SetCurrentDebugLocation(DL);
980 }
981 
982 static Value *getDbgIntrinsicValueImpl(LLVMContext &VMContext, Value *V) {
983   assert(V && "no value passed to dbg intrinsic");
984   return MetadataAsValue::get(VMContext, ValueAsMetadata::get(V));
985 }
986 
987 static Function *getDeclareIntrin(Module &M) {
988   return Intrinsic::getDeclaration(&M, UseDbgAddr ? Intrinsic::dbg_addr
989                                                   : Intrinsic::dbg_declare);
990 }
991 
992 Instruction *DIBuilder::insertDeclare(Value *Storage, DILocalVariable *VarInfo,
993                                       DIExpression *Expr, const DILocation *DL,
994                                       BasicBlock *InsertBB, Instruction *InsertBefore) {
995   assert(VarInfo && "empty or invalid DILocalVariable* passed to dbg.declare");
996   assert(DL && "Expected debug loc");
997   assert(DL->getScope()->getSubprogram() ==
998              VarInfo->getScope()->getSubprogram() &&
999          "Expected matching subprograms");
1000   if (!DeclareFn)
1001     DeclareFn = getDeclareIntrin(M);
1002 
1003   trackIfUnresolved(VarInfo);
1004   trackIfUnresolved(Expr);
1005   Value *Args[] = {getDbgIntrinsicValueImpl(VMContext, Storage),
1006                    MetadataAsValue::get(VMContext, VarInfo),
1007                    MetadataAsValue::get(VMContext, Expr)};
1008 
1009   IRBuilder<> B(DL->getContext());
1010   initIRBuilder(B, DL, InsertBB, InsertBefore);
1011   return B.CreateCall(DeclareFn, Args);
1012 }
1013 
1014 Instruction *DIBuilder::insertDbgValueIntrinsic(
1015     Value *V, DILocalVariable *VarInfo, DIExpression *Expr,
1016     const DILocation *DL, BasicBlock *InsertBB, Instruction *InsertBefore) {
1017   assert(V && "no value passed to dbg.value");
1018   assert(VarInfo && "empty or invalid DILocalVariable* passed to dbg.value");
1019   assert(DL && "Expected debug loc");
1020   assert(DL->getScope()->getSubprogram() ==
1021              VarInfo->getScope()->getSubprogram() &&
1022          "Expected matching subprograms");
1023   if (!ValueFn)
1024     ValueFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_value);
1025 
1026   trackIfUnresolved(VarInfo);
1027   trackIfUnresolved(Expr);
1028   Value *Args[] = {getDbgIntrinsicValueImpl(VMContext, V),
1029                    MetadataAsValue::get(VMContext, VarInfo),
1030                    MetadataAsValue::get(VMContext, Expr)};
1031 
1032   IRBuilder<> B(DL->getContext());
1033   initIRBuilder(B, DL, InsertBB, InsertBefore);
1034   return B.CreateCall(ValueFn, Args);
1035 }
1036 
1037 Instruction *DIBuilder::insertLabel(
1038     DILabel *LabelInfo, const DILocation *DL,
1039     BasicBlock *InsertBB, Instruction *InsertBefore) {
1040   assert(LabelInfo && "empty or invalid DILabel* passed to dbg.label");
1041   assert(DL && "Expected debug loc");
1042   assert(DL->getScope()->getSubprogram() ==
1043              LabelInfo->getScope()->getSubprogram() &&
1044          "Expected matching subprograms");
1045   if (!LabelFn)
1046     LabelFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_label);
1047 
1048   trackIfUnresolved(LabelInfo);
1049   Value *Args[] = {MetadataAsValue::get(VMContext, LabelInfo)};
1050 
1051   IRBuilder<> B(DL->getContext());
1052   initIRBuilder(B, DL, InsertBB, InsertBefore);
1053   return B.CreateCall(LabelFn, Args);
1054 }
1055 
1056 void DIBuilder::replaceVTableHolder(DICompositeType *&T,
1057                                     DIType *VTableHolder) {
1058   {
1059     TypedTrackingMDRef<DICompositeType> N(T);
1060     N->replaceVTableHolder(VTableHolder);
1061     T = N.get();
1062   }
1063 
1064   // If this didn't create a self-reference, just return.
1065   if (T != VTableHolder)
1066     return;
1067 
1068   // Look for unresolved operands.  T will drop RAUW support, orphaning any
1069   // cycles underneath it.
1070   if (T->isResolved())
1071     for (const MDOperand &O : T->operands())
1072       if (auto *N = dyn_cast_or_null<MDNode>(O))
1073         trackIfUnresolved(N);
1074 }
1075 
1076 void DIBuilder::replaceArrays(DICompositeType *&T, DINodeArray Elements,
1077                               DINodeArray TParams) {
1078   {
1079     TypedTrackingMDRef<DICompositeType> N(T);
1080     if (Elements)
1081       N->replaceElements(Elements);
1082     if (TParams)
1083       N->replaceTemplateParams(DITemplateParameterArray(TParams));
1084     T = N.get();
1085   }
1086 
1087   // If T isn't resolved, there's no problem.
1088   if (!T->isResolved())
1089     return;
1090 
1091   // If T is resolved, it may be due to a self-reference cycle.  Track the
1092   // arrays explicitly if they're unresolved, or else the cycles will be
1093   // orphaned.
1094   if (Elements)
1095     trackIfUnresolved(Elements.get());
1096   if (TParams)
1097     trackIfUnresolved(TParams.get());
1098 }
1099