xref: /freebsd/contrib/llvm-project/llvm/lib/IR/Globals.cpp (revision b1879975794772ee51f0b4865753364c7d7626c3)
1 //===-- Globals.cpp - Implement the GlobalValue & GlobalVariable class ----===//
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 GlobalValue & GlobalVariable classes for the IR
10 // library.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "LLVMContextImpl.h"
15 #include "llvm/IR/ConstantRange.h"
16 #include "llvm/IR/Constants.h"
17 #include "llvm/IR/DerivedTypes.h"
18 #include "llvm/IR/GlobalAlias.h"
19 #include "llvm/IR/GlobalValue.h"
20 #include "llvm/IR/GlobalVariable.h"
21 #include "llvm/IR/Module.h"
22 #include "llvm/Support/Error.h"
23 #include "llvm/Support/ErrorHandling.h"
24 #include "llvm/Support/MD5.h"
25 #include "llvm/TargetParser/Triple.h"
26 using namespace llvm;
27 
28 //===----------------------------------------------------------------------===//
29 //                            GlobalValue Class
30 //===----------------------------------------------------------------------===//
31 
32 // GlobalValue should be a Constant, plus a type, a module, some flags, and an
33 // intrinsic ID. Add an assert to prevent people from accidentally growing
34 // GlobalValue while adding flags.
35 static_assert(sizeof(GlobalValue) ==
36                   sizeof(Constant) + 2 * sizeof(void *) + 2 * sizeof(unsigned),
37               "unexpected GlobalValue size growth");
38 
39 // GlobalObject adds a comdat.
40 static_assert(sizeof(GlobalObject) == sizeof(GlobalValue) + sizeof(void *),
41               "unexpected GlobalObject size growth");
42 
43 bool GlobalValue::isMaterializable() const {
44   if (const Function *F = dyn_cast<Function>(this))
45     return F->isMaterializable();
46   return false;
47 }
48 Error GlobalValue::materialize() { return getParent()->materialize(this); }
49 
50 /// Override destroyConstantImpl to make sure it doesn't get called on
51 /// GlobalValue's because they shouldn't be treated like other constants.
52 void GlobalValue::destroyConstantImpl() {
53   llvm_unreachable("You can't GV->destroyConstantImpl()!");
54 }
55 
56 Value *GlobalValue::handleOperandChangeImpl(Value *From, Value *To) {
57   llvm_unreachable("Unsupported class for handleOperandChange()!");
58 }
59 
60 /// copyAttributesFrom - copy all additional attributes (those not needed to
61 /// create a GlobalValue) from the GlobalValue Src to this one.
62 void GlobalValue::copyAttributesFrom(const GlobalValue *Src) {
63   setVisibility(Src->getVisibility());
64   setUnnamedAddr(Src->getUnnamedAddr());
65   setThreadLocalMode(Src->getThreadLocalMode());
66   setDLLStorageClass(Src->getDLLStorageClass());
67   setDSOLocal(Src->isDSOLocal());
68   setPartition(Src->getPartition());
69   if (Src->hasSanitizerMetadata())
70     setSanitizerMetadata(Src->getSanitizerMetadata());
71   else
72     removeSanitizerMetadata();
73 }
74 
75 GlobalValue::GUID GlobalValue::getGUID(StringRef GlobalName) {
76   return MD5Hash(GlobalName);
77 }
78 
79 void GlobalValue::removeFromParent() {
80   switch (getValueID()) {
81 #define HANDLE_GLOBAL_VALUE(NAME)                                              \
82   case Value::NAME##Val:                                                       \
83     return static_cast<NAME *>(this)->removeFromParent();
84 #include "llvm/IR/Value.def"
85   default:
86     break;
87   }
88   llvm_unreachable("not a global");
89 }
90 
91 void GlobalValue::eraseFromParent() {
92   switch (getValueID()) {
93 #define HANDLE_GLOBAL_VALUE(NAME)                                              \
94   case Value::NAME##Val:                                                       \
95     return static_cast<NAME *>(this)->eraseFromParent();
96 #include "llvm/IR/Value.def"
97   default:
98     break;
99   }
100   llvm_unreachable("not a global");
101 }
102 
103 GlobalObject::~GlobalObject() { setComdat(nullptr); }
104 
105 bool GlobalValue::isInterposable() const {
106   if (isInterposableLinkage(getLinkage()))
107     return true;
108   return getParent() && getParent()->getSemanticInterposition() &&
109          !isDSOLocal();
110 }
111 
112 bool GlobalValue::canBenefitFromLocalAlias() const {
113   // See AsmPrinter::getSymbolPreferLocal(). For a deduplicate comdat kind,
114   // references to a discarded local symbol from outside the group are not
115   // allowed, so avoid the local alias.
116   auto isDeduplicateComdat = [](const Comdat *C) {
117     return C && C->getSelectionKind() != Comdat::NoDeduplicate;
118   };
119   return hasDefaultVisibility() &&
120          GlobalObject::isExternalLinkage(getLinkage()) && !isDeclaration() &&
121          !isa<GlobalIFunc>(this) && !isDeduplicateComdat(getComdat());
122 }
123 
124 const DataLayout &GlobalValue::getDataLayout() const {
125   return getParent()->getDataLayout();
126 }
127 
128 void GlobalObject::setAlignment(MaybeAlign Align) {
129   assert((!Align || *Align <= MaximumAlignment) &&
130          "Alignment is greater than MaximumAlignment!");
131   unsigned AlignmentData = encode(Align);
132   unsigned OldData = getGlobalValueSubClassData();
133   setGlobalValueSubClassData((OldData & ~AlignmentMask) | AlignmentData);
134   assert(getAlign() == Align && "Alignment representation error!");
135 }
136 
137 void GlobalObject::setAlignment(Align Align) {
138   assert(Align <= MaximumAlignment &&
139          "Alignment is greater than MaximumAlignment!");
140   unsigned AlignmentData = encode(Align);
141   unsigned OldData = getGlobalValueSubClassData();
142   setGlobalValueSubClassData((OldData & ~AlignmentMask) | AlignmentData);
143   assert(getAlign() && *getAlign() == Align &&
144          "Alignment representation error!");
145 }
146 
147 void GlobalObject::copyAttributesFrom(const GlobalObject *Src) {
148   GlobalValue::copyAttributesFrom(Src);
149   setAlignment(Src->getAlign());
150   setSection(Src->getSection());
151 }
152 
153 std::string GlobalValue::getGlobalIdentifier(StringRef Name,
154                                              GlobalValue::LinkageTypes Linkage,
155                                              StringRef FileName) {
156   // Value names may be prefixed with a binary '1' to indicate
157   // that the backend should not modify the symbols due to any platform
158   // naming convention. Do not include that '1' in the PGO profile name.
159   Name.consume_front("\1");
160 
161   std::string GlobalName;
162   if (llvm::GlobalValue::isLocalLinkage(Linkage)) {
163     // For local symbols, prepend the main file name to distinguish them.
164     // Do not include the full path in the file name since there's no guarantee
165     // that it will stay the same, e.g., if the files are checked out from
166     // version control in different locations.
167     if (FileName.empty())
168       GlobalName += "<unknown>";
169     else
170       GlobalName += FileName;
171 
172     GlobalName += GlobalIdentifierDelimiter;
173   }
174   GlobalName += Name;
175   return GlobalName;
176 }
177 
178 std::string GlobalValue::getGlobalIdentifier() const {
179   return getGlobalIdentifier(getName(), getLinkage(),
180                              getParent()->getSourceFileName());
181 }
182 
183 StringRef GlobalValue::getSection() const {
184   if (auto *GA = dyn_cast<GlobalAlias>(this)) {
185     // In general we cannot compute this at the IR level, but we try.
186     if (const GlobalObject *GO = GA->getAliaseeObject())
187       return GO->getSection();
188     return "";
189   }
190   return cast<GlobalObject>(this)->getSection();
191 }
192 
193 const Comdat *GlobalValue::getComdat() const {
194   if (auto *GA = dyn_cast<GlobalAlias>(this)) {
195     // In general we cannot compute this at the IR level, but we try.
196     if (const GlobalObject *GO = GA->getAliaseeObject())
197       return const_cast<GlobalObject *>(GO)->getComdat();
198     return nullptr;
199   }
200   // ifunc and its resolver are separate things so don't use resolver comdat.
201   if (isa<GlobalIFunc>(this))
202     return nullptr;
203   return cast<GlobalObject>(this)->getComdat();
204 }
205 
206 void GlobalObject::setComdat(Comdat *C) {
207   if (ObjComdat)
208     ObjComdat->removeUser(this);
209   ObjComdat = C;
210   if (C)
211     C->addUser(this);
212 }
213 
214 StringRef GlobalValue::getPartition() const {
215   if (!hasPartition())
216     return "";
217   return getContext().pImpl->GlobalValuePartitions[this];
218 }
219 
220 void GlobalValue::setPartition(StringRef S) {
221   // Do nothing if we're clearing the partition and it is already empty.
222   if (!hasPartition() && S.empty())
223     return;
224 
225   // Get or create a stable partition name string and put it in the table in the
226   // context.
227   if (!S.empty())
228     S = getContext().pImpl->Saver.save(S);
229   getContext().pImpl->GlobalValuePartitions[this] = S;
230 
231   // Update the HasPartition field. Setting the partition to the empty string
232   // means this global no longer has a partition.
233   HasPartition = !S.empty();
234 }
235 
236 using SanitizerMetadata = GlobalValue::SanitizerMetadata;
237 const SanitizerMetadata &GlobalValue::getSanitizerMetadata() const {
238   assert(hasSanitizerMetadata());
239   assert(getContext().pImpl->GlobalValueSanitizerMetadata.count(this));
240   return getContext().pImpl->GlobalValueSanitizerMetadata[this];
241 }
242 
243 void GlobalValue::setSanitizerMetadata(SanitizerMetadata Meta) {
244   getContext().pImpl->GlobalValueSanitizerMetadata[this] = Meta;
245   HasSanitizerMetadata = true;
246 }
247 
248 void GlobalValue::removeSanitizerMetadata() {
249   DenseMap<const GlobalValue *, SanitizerMetadata> &MetadataMap =
250       getContext().pImpl->GlobalValueSanitizerMetadata;
251   MetadataMap.erase(this);
252   HasSanitizerMetadata = false;
253 }
254 
255 void GlobalValue::setNoSanitizeMetadata() {
256   SanitizerMetadata Meta;
257   Meta.NoAddress = true;
258   Meta.NoHWAddress = true;
259   setSanitizerMetadata(Meta);
260 }
261 
262 StringRef GlobalObject::getSectionImpl() const {
263   assert(hasSection());
264   return getContext().pImpl->GlobalObjectSections[this];
265 }
266 
267 void GlobalObject::setSection(StringRef S) {
268   // Do nothing if we're clearing the section and it is already empty.
269   if (!hasSection() && S.empty())
270     return;
271 
272   // Get or create a stable section name string and put it in the table in the
273   // context.
274   if (!S.empty())
275     S = getContext().pImpl->Saver.save(S);
276   getContext().pImpl->GlobalObjectSections[this] = S;
277 
278   // Update the HasSectionHashEntryBit. Setting the section to the empty string
279   // means this global no longer has a section.
280   setGlobalObjectFlag(HasSectionHashEntryBit, !S.empty());
281 }
282 
283 bool GlobalValue::isNobuiltinFnDef() const {
284   const Function *F = dyn_cast<Function>(this);
285   if (!F || F->empty())
286     return false;
287   return F->hasFnAttribute(Attribute::NoBuiltin);
288 }
289 
290 bool GlobalValue::isDeclaration() const {
291   // Globals are definitions if they have an initializer.
292   if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(this))
293     return GV->getNumOperands() == 0;
294 
295   // Functions are definitions if they have a body.
296   if (const Function *F = dyn_cast<Function>(this))
297     return F->empty() && !F->isMaterializable();
298 
299   // Aliases and ifuncs are always definitions.
300   assert(isa<GlobalAlias>(this) || isa<GlobalIFunc>(this));
301   return false;
302 }
303 
304 bool GlobalObject::canIncreaseAlignment() const {
305   // Firstly, can only increase the alignment of a global if it
306   // is a strong definition.
307   if (!isStrongDefinitionForLinker())
308     return false;
309 
310   // It also has to either not have a section defined, or, not have
311   // alignment specified. (If it is assigned a section, the global
312   // could be densely packed with other objects in the section, and
313   // increasing the alignment could cause padding issues.)
314   if (hasSection() && getAlign())
315     return false;
316 
317   // On ELF platforms, we're further restricted in that we can't
318   // increase the alignment of any variable which might be emitted
319   // into a shared library, and which is exported. If the main
320   // executable accesses a variable found in a shared-lib, the main
321   // exe actually allocates memory for and exports the symbol ITSELF,
322   // overriding the symbol found in the library. That is, at link
323   // time, the observed alignment of the variable is copied into the
324   // executable binary. (A COPY relocation is also generated, to copy
325   // the initial data from the shadowed variable in the shared-lib
326   // into the location in the main binary, before running code.)
327   //
328   // And thus, even though you might think you are defining the
329   // global, and allocating the memory for the global in your object
330   // file, and thus should be able to set the alignment arbitrarily,
331   // that's not actually true. Doing so can cause an ABI breakage; an
332   // executable might have already been built with the previous
333   // alignment of the variable, and then assuming an increased
334   // alignment will be incorrect.
335 
336   // Conservatively assume ELF if there's no parent pointer.
337   bool isELF =
338       (!Parent || Triple(Parent->getTargetTriple()).isOSBinFormatELF());
339   if (isELF && !isDSOLocal())
340     return false;
341 
342   // GV with toc-data attribute is defined in a TOC entry. To mitigate TOC
343   // overflow, the alignment of such symbol should not be increased. Otherwise,
344   // padding is needed thus more TOC entries are wasted.
345   bool isXCOFF =
346       (!Parent || Triple(Parent->getTargetTriple()).isOSBinFormatXCOFF());
347   if (isXCOFF)
348     if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(this))
349       if (GV->hasAttribute("toc-data"))
350         return false;
351 
352   return true;
353 }
354 
355 template <typename Operation>
356 static const GlobalObject *
357 findBaseObject(const Constant *C, DenseSet<const GlobalAlias *> &Aliases,
358                const Operation &Op) {
359   if (auto *GO = dyn_cast<GlobalObject>(C)) {
360     Op(*GO);
361     return GO;
362   }
363   if (auto *GA = dyn_cast<GlobalAlias>(C)) {
364     Op(*GA);
365     if (Aliases.insert(GA).second)
366       return findBaseObject(GA->getOperand(0), Aliases, Op);
367   }
368   if (auto *CE = dyn_cast<ConstantExpr>(C)) {
369     switch (CE->getOpcode()) {
370     case Instruction::Add: {
371       auto *LHS = findBaseObject(CE->getOperand(0), Aliases, Op);
372       auto *RHS = findBaseObject(CE->getOperand(1), Aliases, Op);
373       if (LHS && RHS)
374         return nullptr;
375       return LHS ? LHS : RHS;
376     }
377     case Instruction::Sub: {
378       if (findBaseObject(CE->getOperand(1), Aliases, Op))
379         return nullptr;
380       return findBaseObject(CE->getOperand(0), Aliases, Op);
381     }
382     case Instruction::IntToPtr:
383     case Instruction::PtrToInt:
384     case Instruction::BitCast:
385     case Instruction::GetElementPtr:
386       return findBaseObject(CE->getOperand(0), Aliases, Op);
387     default:
388       break;
389     }
390   }
391   return nullptr;
392 }
393 
394 const GlobalObject *GlobalValue::getAliaseeObject() const {
395   DenseSet<const GlobalAlias *> Aliases;
396   return findBaseObject(this, Aliases, [](const GlobalValue &) {});
397 }
398 
399 bool GlobalValue::isAbsoluteSymbolRef() const {
400   auto *GO = dyn_cast<GlobalObject>(this);
401   if (!GO)
402     return false;
403 
404   return GO->getMetadata(LLVMContext::MD_absolute_symbol);
405 }
406 
407 std::optional<ConstantRange> GlobalValue::getAbsoluteSymbolRange() const {
408   auto *GO = dyn_cast<GlobalObject>(this);
409   if (!GO)
410     return std::nullopt;
411 
412   MDNode *MD = GO->getMetadata(LLVMContext::MD_absolute_symbol);
413   if (!MD)
414     return std::nullopt;
415 
416   return getConstantRangeFromMetadata(*MD);
417 }
418 
419 bool GlobalValue::canBeOmittedFromSymbolTable() const {
420   if (!hasLinkOnceODRLinkage())
421     return false;
422 
423   // We assume that anyone who sets global unnamed_addr on a non-constant
424   // knows what they're doing.
425   if (hasGlobalUnnamedAddr())
426     return true;
427 
428   // If it is a non constant variable, it needs to be uniqued across shared
429   // objects.
430   if (auto *Var = dyn_cast<GlobalVariable>(this))
431     if (!Var->isConstant())
432       return false;
433 
434   return hasAtLeastLocalUnnamedAddr();
435 }
436 
437 //===----------------------------------------------------------------------===//
438 // GlobalVariable Implementation
439 //===----------------------------------------------------------------------===//
440 
441 GlobalVariable::GlobalVariable(Type *Ty, bool constant, LinkageTypes Link,
442                                Constant *InitVal, const Twine &Name,
443                                ThreadLocalMode TLMode, unsigned AddressSpace,
444                                bool isExternallyInitialized)
445     : GlobalObject(Ty, Value::GlobalVariableVal,
446                    OperandTraits<GlobalVariable>::op_begin(this),
447                    InitVal != nullptr, Link, Name, AddressSpace),
448       isConstantGlobal(constant),
449       isExternallyInitializedConstant(isExternallyInitialized) {
450   assert(!Ty->isFunctionTy() && PointerType::isValidElementType(Ty) &&
451          "invalid type for global variable");
452   setThreadLocalMode(TLMode);
453   if (InitVal) {
454     assert(InitVal->getType() == Ty &&
455            "Initializer should be the same type as the GlobalVariable!");
456     Op<0>() = InitVal;
457   }
458 }
459 
460 GlobalVariable::GlobalVariable(Module &M, Type *Ty, bool constant,
461                                LinkageTypes Link, Constant *InitVal,
462                                const Twine &Name, GlobalVariable *Before,
463                                ThreadLocalMode TLMode,
464                                std::optional<unsigned> AddressSpace,
465                                bool isExternallyInitialized)
466     : GlobalVariable(Ty, constant, Link, InitVal, Name, TLMode,
467                      AddressSpace
468                          ? *AddressSpace
469                          : M.getDataLayout().getDefaultGlobalsAddressSpace(),
470                      isExternallyInitialized) {
471   if (Before)
472     Before->getParent()->insertGlobalVariable(Before->getIterator(), this);
473   else
474     M.insertGlobalVariable(this);
475 }
476 
477 void GlobalVariable::removeFromParent() {
478   getParent()->removeGlobalVariable(this);
479 }
480 
481 void GlobalVariable::eraseFromParent() {
482   getParent()->eraseGlobalVariable(this);
483 }
484 
485 void GlobalVariable::setInitializer(Constant *InitVal) {
486   if (!InitVal) {
487     if (hasInitializer()) {
488       // Note, the num operands is used to compute the offset of the operand, so
489       // the order here matters.  Clearing the operand then clearing the num
490       // operands ensures we have the correct offset to the operand.
491       Op<0>().set(nullptr);
492       setGlobalVariableNumOperands(0);
493     }
494   } else {
495     assert(InitVal->getType() == getValueType() &&
496            "Initializer type must match GlobalVariable type");
497     // Note, the num operands is used to compute the offset of the operand, so
498     // the order here matters.  We need to set num operands to 1 first so that
499     // we get the correct offset to the first operand when we set it.
500     if (!hasInitializer())
501       setGlobalVariableNumOperands(1);
502     Op<0>().set(InitVal);
503   }
504 }
505 
506 /// Copy all additional attributes (those not needed to create a GlobalVariable)
507 /// from the GlobalVariable Src to this one.
508 void GlobalVariable::copyAttributesFrom(const GlobalVariable *Src) {
509   GlobalObject::copyAttributesFrom(Src);
510   setExternallyInitialized(Src->isExternallyInitialized());
511   setAttributes(Src->getAttributes());
512   if (auto CM = Src->getCodeModel())
513     setCodeModel(*CM);
514 }
515 
516 void GlobalVariable::dropAllReferences() {
517   User::dropAllReferences();
518   clearMetadata();
519 }
520 
521 void GlobalVariable::setCodeModel(CodeModel::Model CM) {
522   unsigned CodeModelData = static_cast<unsigned>(CM) + 1;
523   unsigned OldData = getGlobalValueSubClassData();
524   unsigned NewData = (OldData & ~(CodeModelMask << CodeModelShift)) |
525                      (CodeModelData << CodeModelShift);
526   setGlobalValueSubClassData(NewData);
527   assert(getCodeModel() == CM && "Code model representation error!");
528 }
529 
530 //===----------------------------------------------------------------------===//
531 // GlobalAlias Implementation
532 //===----------------------------------------------------------------------===//
533 
534 GlobalAlias::GlobalAlias(Type *Ty, unsigned AddressSpace, LinkageTypes Link,
535                          const Twine &Name, Constant *Aliasee,
536                          Module *ParentModule)
537     : GlobalValue(Ty, Value::GlobalAliasVal, &Op<0>(), 1, Link, Name,
538                   AddressSpace) {
539   setAliasee(Aliasee);
540   if (ParentModule)
541     ParentModule->insertAlias(this);
542 }
543 
544 GlobalAlias *GlobalAlias::create(Type *Ty, unsigned AddressSpace,
545                                  LinkageTypes Link, const Twine &Name,
546                                  Constant *Aliasee, Module *ParentModule) {
547   return new GlobalAlias(Ty, AddressSpace, Link, Name, Aliasee, ParentModule);
548 }
549 
550 GlobalAlias *GlobalAlias::create(Type *Ty, unsigned AddressSpace,
551                                  LinkageTypes Linkage, const Twine &Name,
552                                  Module *Parent) {
553   return create(Ty, AddressSpace, Linkage, Name, nullptr, Parent);
554 }
555 
556 GlobalAlias *GlobalAlias::create(Type *Ty, unsigned AddressSpace,
557                                  LinkageTypes Linkage, const Twine &Name,
558                                  GlobalValue *Aliasee) {
559   return create(Ty, AddressSpace, Linkage, Name, Aliasee, Aliasee->getParent());
560 }
561 
562 GlobalAlias *GlobalAlias::create(LinkageTypes Link, const Twine &Name,
563                                  GlobalValue *Aliasee) {
564   return create(Aliasee->getValueType(), Aliasee->getAddressSpace(), Link, Name,
565                 Aliasee);
566 }
567 
568 GlobalAlias *GlobalAlias::create(const Twine &Name, GlobalValue *Aliasee) {
569   return create(Aliasee->getLinkage(), Name, Aliasee);
570 }
571 
572 void GlobalAlias::removeFromParent() { getParent()->removeAlias(this); }
573 
574 void GlobalAlias::eraseFromParent() { getParent()->eraseAlias(this); }
575 
576 void GlobalAlias::setAliasee(Constant *Aliasee) {
577   assert((!Aliasee || Aliasee->getType() == getType()) &&
578          "Alias and aliasee types should match!");
579   Op<0>().set(Aliasee);
580 }
581 
582 const GlobalObject *GlobalAlias::getAliaseeObject() const {
583   DenseSet<const GlobalAlias *> Aliases;
584   return findBaseObject(getOperand(0), Aliases, [](const GlobalValue &) {});
585 }
586 
587 //===----------------------------------------------------------------------===//
588 // GlobalIFunc Implementation
589 //===----------------------------------------------------------------------===//
590 
591 GlobalIFunc::GlobalIFunc(Type *Ty, unsigned AddressSpace, LinkageTypes Link,
592                          const Twine &Name, Constant *Resolver,
593                          Module *ParentModule)
594     : GlobalObject(Ty, Value::GlobalIFuncVal, &Op<0>(), 1, Link, Name,
595                    AddressSpace) {
596   setResolver(Resolver);
597   if (ParentModule)
598     ParentModule->insertIFunc(this);
599 }
600 
601 GlobalIFunc *GlobalIFunc::create(Type *Ty, unsigned AddressSpace,
602                                  LinkageTypes Link, const Twine &Name,
603                                  Constant *Resolver, Module *ParentModule) {
604   return new GlobalIFunc(Ty, AddressSpace, Link, Name, Resolver, ParentModule);
605 }
606 
607 void GlobalIFunc::removeFromParent() { getParent()->removeIFunc(this); }
608 
609 void GlobalIFunc::eraseFromParent() { getParent()->eraseIFunc(this); }
610 
611 const Function *GlobalIFunc::getResolverFunction() const {
612   return dyn_cast<Function>(getResolver()->stripPointerCastsAndAliases());
613 }
614 
615 void GlobalIFunc::applyAlongResolverPath(
616     function_ref<void(const GlobalValue &)> Op) const {
617   DenseSet<const GlobalAlias *> Aliases;
618   findBaseObject(getResolver(), Aliases, Op);
619 }
620