1 //===- lib/Linker/IRMover.cpp ---------------------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "llvm/Linker/IRMover.h"
11 #include "LinkDiagnosticInfo.h"
12 #include "llvm/ADT/SetVector.h"
13 #include "llvm/ADT/SmallString.h"
14 #include "llvm/ADT/Triple.h"
15 #include "llvm/IR/Constants.h"
16 #include "llvm/IR/DebugInfo.h"
17 #include "llvm/IR/DiagnosticPrinter.h"
18 #include "llvm/IR/GVMaterializer.h"
19 #include "llvm/IR/Intrinsics.h"
20 #include "llvm/IR/TypeFinder.h"
21 #include "llvm/Support/Error.h"
22 #include "llvm/Transforms/Utils/Cloning.h"
26 //===----------------------------------------------------------------------===//
27 // TypeMap implementation.
28 //===----------------------------------------------------------------------===//
31 class TypeMapTy : public ValueMapTypeRemapper {
32 /// This is a mapping from a source type to a destination type to use.
33 DenseMap<Type *, Type *> MappedTypes;
35 /// When checking to see if two subgraphs are isomorphic, we speculatively
36 /// add types to MappedTypes, but keep track of them here in case we need to
38 SmallVector<Type *, 16> SpeculativeTypes;
40 SmallVector<StructType *, 16> SpeculativeDstOpaqueTypes;
42 /// This is a list of non-opaque structs in the source module that are mapped
43 /// to an opaque struct in the destination module.
44 SmallVector<StructType *, 16> SrcDefinitionsToResolve;
46 /// This is the set of opaque types in the destination modules who are
47 /// getting a body from the source module.
48 SmallPtrSet<StructType *, 16> DstResolvedOpaqueTypes;
51 TypeMapTy(IRMover::IdentifiedStructTypeSet &DstStructTypesSet)
52 : DstStructTypesSet(DstStructTypesSet) {}
54 IRMover::IdentifiedStructTypeSet &DstStructTypesSet;
55 /// Indicate that the specified type in the destination module is conceptually
56 /// equivalent to the specified type in the source module.
57 void addTypeMapping(Type *DstTy, Type *SrcTy);
59 /// Produce a body for an opaque type in the dest module from a type
60 /// definition in the source module.
61 void linkDefinedTypeBodies();
63 /// Return the mapped type to use for the specified input type from the
65 Type *get(Type *SrcTy);
66 Type *get(Type *SrcTy, SmallPtrSet<StructType *, 8> &Visited);
68 void finishType(StructType *DTy, StructType *STy, ArrayRef<Type *> ETypes);
70 FunctionType *get(FunctionType *T) {
71 return cast<FunctionType>(get((Type *)T));
75 Type *remapType(Type *SrcTy) override { return get(SrcTy); }
77 bool areTypesIsomorphic(Type *DstTy, Type *SrcTy);
81 void TypeMapTy::addTypeMapping(Type *DstTy, Type *SrcTy) {
82 assert(SpeculativeTypes.empty());
83 assert(SpeculativeDstOpaqueTypes.empty());
85 // Check to see if these types are recursively isomorphic and establish a
86 // mapping between them if so.
87 if (!areTypesIsomorphic(DstTy, SrcTy)) {
88 // Oops, they aren't isomorphic. Just discard this request by rolling out
89 // any speculative mappings we've established.
90 for (Type *Ty : SpeculativeTypes)
91 MappedTypes.erase(Ty);
93 SrcDefinitionsToResolve.resize(SrcDefinitionsToResolve.size() -
94 SpeculativeDstOpaqueTypes.size());
95 for (StructType *Ty : SpeculativeDstOpaqueTypes)
96 DstResolvedOpaqueTypes.erase(Ty);
98 for (Type *Ty : SpeculativeTypes)
99 if (auto *STy = dyn_cast<StructType>(Ty))
103 SpeculativeTypes.clear();
104 SpeculativeDstOpaqueTypes.clear();
107 /// Recursively walk this pair of types, returning true if they are isomorphic,
108 /// false if they are not.
109 bool TypeMapTy::areTypesIsomorphic(Type *DstTy, Type *SrcTy) {
110 // Two types with differing kinds are clearly not isomorphic.
111 if (DstTy->getTypeID() != SrcTy->getTypeID())
114 // If we have an entry in the MappedTypes table, then we have our answer.
115 Type *&Entry = MappedTypes[SrcTy];
117 return Entry == DstTy;
119 // Two identical types are clearly isomorphic. Remember this
120 // non-speculatively.
121 if (DstTy == SrcTy) {
126 // Okay, we have two types with identical kinds that we haven't seen before.
128 // If this is an opaque struct type, special case it.
129 if (StructType *SSTy = dyn_cast<StructType>(SrcTy)) {
130 // Mapping an opaque type to any struct, just keep the dest struct.
131 if (SSTy->isOpaque()) {
133 SpeculativeTypes.push_back(SrcTy);
137 // Mapping a non-opaque source type to an opaque dest. If this is the first
138 // type that we're mapping onto this destination type then we succeed. Keep
139 // the dest, but fill it in later. If this is the second (different) type
140 // that we're trying to map onto the same opaque type then we fail.
141 if (cast<StructType>(DstTy)->isOpaque()) {
142 // We can only map one source type onto the opaque destination type.
143 if (!DstResolvedOpaqueTypes.insert(cast<StructType>(DstTy)).second)
145 SrcDefinitionsToResolve.push_back(SSTy);
146 SpeculativeTypes.push_back(SrcTy);
147 SpeculativeDstOpaqueTypes.push_back(cast<StructType>(DstTy));
153 // If the number of subtypes disagree between the two types, then we fail.
154 if (SrcTy->getNumContainedTypes() != DstTy->getNumContainedTypes())
157 // Fail if any of the extra properties (e.g. array size) of the type disagree.
158 if (isa<IntegerType>(DstTy))
159 return false; // bitwidth disagrees.
160 if (PointerType *PT = dyn_cast<PointerType>(DstTy)) {
161 if (PT->getAddressSpace() != cast<PointerType>(SrcTy)->getAddressSpace())
164 } else if (FunctionType *FT = dyn_cast<FunctionType>(DstTy)) {
165 if (FT->isVarArg() != cast<FunctionType>(SrcTy)->isVarArg())
167 } else if (StructType *DSTy = dyn_cast<StructType>(DstTy)) {
168 StructType *SSTy = cast<StructType>(SrcTy);
169 if (DSTy->isLiteral() != SSTy->isLiteral() ||
170 DSTy->isPacked() != SSTy->isPacked())
172 } else if (auto *DSeqTy = dyn_cast<SequentialType>(DstTy)) {
173 if (DSeqTy->getNumElements() !=
174 cast<SequentialType>(SrcTy)->getNumElements())
178 // Otherwise, we speculate that these two types will line up and recursively
179 // check the subelements.
181 SpeculativeTypes.push_back(SrcTy);
183 for (unsigned I = 0, E = SrcTy->getNumContainedTypes(); I != E; ++I)
184 if (!areTypesIsomorphic(DstTy->getContainedType(I),
185 SrcTy->getContainedType(I)))
188 // If everything seems to have lined up, then everything is great.
192 void TypeMapTy::linkDefinedTypeBodies() {
193 SmallVector<Type *, 16> Elements;
194 for (StructType *SrcSTy : SrcDefinitionsToResolve) {
195 StructType *DstSTy = cast<StructType>(MappedTypes[SrcSTy]);
196 assert(DstSTy->isOpaque());
198 // Map the body of the source type over to a new body for the dest type.
199 Elements.resize(SrcSTy->getNumElements());
200 for (unsigned I = 0, E = Elements.size(); I != E; ++I)
201 Elements[I] = get(SrcSTy->getElementType(I));
203 DstSTy->setBody(Elements, SrcSTy->isPacked());
204 DstStructTypesSet.switchToNonOpaque(DstSTy);
206 SrcDefinitionsToResolve.clear();
207 DstResolvedOpaqueTypes.clear();
210 void TypeMapTy::finishType(StructType *DTy, StructType *STy,
211 ArrayRef<Type *> ETypes) {
212 DTy->setBody(ETypes, STy->isPacked());
215 if (STy->hasName()) {
216 SmallString<16> TmpName = STy->getName();
218 DTy->setName(TmpName);
221 DstStructTypesSet.addNonOpaque(DTy);
224 Type *TypeMapTy::get(Type *Ty) {
225 SmallPtrSet<StructType *, 8> Visited;
226 return get(Ty, Visited);
229 Type *TypeMapTy::get(Type *Ty, SmallPtrSet<StructType *, 8> &Visited) {
230 // If we already have an entry for this type, return it.
231 Type **Entry = &MappedTypes[Ty];
235 // These are types that LLVM itself will unique.
236 bool IsUniqued = !isa<StructType>(Ty) || cast<StructType>(Ty)->isLiteral();
240 for (auto &Pair : MappedTypes) {
241 assert(!(Pair.first != Ty && Pair.second == Ty) &&
242 "mapping to a source type");
247 if (!IsUniqued && !Visited.insert(cast<StructType>(Ty)).second) {
248 StructType *DTy = StructType::create(Ty->getContext());
252 // If this is not a recursive type, then just map all of the elements and
253 // then rebuild the type from inside out.
254 SmallVector<Type *, 4> ElementTypes;
256 // If there are no element types to map, then the type is itself. This is
257 // true for the anonymous {} struct, things like 'float', integers, etc.
258 if (Ty->getNumContainedTypes() == 0 && IsUniqued)
261 // Remap all of the elements, keeping track of whether any of them change.
262 bool AnyChange = false;
263 ElementTypes.resize(Ty->getNumContainedTypes());
264 for (unsigned I = 0, E = Ty->getNumContainedTypes(); I != E; ++I) {
265 ElementTypes[I] = get(Ty->getContainedType(I), Visited);
266 AnyChange |= ElementTypes[I] != Ty->getContainedType(I);
269 // If we found our type while recursively processing stuff, just use it.
270 Entry = &MappedTypes[Ty];
272 if (auto *DTy = dyn_cast<StructType>(*Entry)) {
273 if (DTy->isOpaque()) {
274 auto *STy = cast<StructType>(Ty);
275 finishType(DTy, STy, ElementTypes);
281 // If all of the element types mapped directly over and the type is not
282 // a named struct, then the type is usable as-is.
283 if (!AnyChange && IsUniqued)
286 // Otherwise, rebuild a modified type.
287 switch (Ty->getTypeID()) {
289 llvm_unreachable("unknown derived type to remap");
290 case Type::ArrayTyID:
291 return *Entry = ArrayType::get(ElementTypes[0],
292 cast<ArrayType>(Ty)->getNumElements());
293 case Type::VectorTyID:
294 return *Entry = VectorType::get(ElementTypes[0],
295 cast<VectorType>(Ty)->getNumElements());
296 case Type::PointerTyID:
297 return *Entry = PointerType::get(ElementTypes[0],
298 cast<PointerType>(Ty)->getAddressSpace());
299 case Type::FunctionTyID:
300 return *Entry = FunctionType::get(ElementTypes[0],
301 makeArrayRef(ElementTypes).slice(1),
302 cast<FunctionType>(Ty)->isVarArg());
303 case Type::StructTyID: {
304 auto *STy = cast<StructType>(Ty);
305 bool IsPacked = STy->isPacked();
307 return *Entry = StructType::get(Ty->getContext(), ElementTypes, IsPacked);
309 // If the type is opaque, we can just use it directly.
310 if (STy->isOpaque()) {
311 DstStructTypesSet.addOpaque(STy);
315 if (StructType *OldT =
316 DstStructTypesSet.findNonOpaque(ElementTypes, IsPacked)) {
318 return *Entry = OldT;
322 DstStructTypesSet.addNonOpaque(STy);
326 StructType *DTy = StructType::create(Ty->getContext());
327 finishType(DTy, STy, ElementTypes);
333 LinkDiagnosticInfo::LinkDiagnosticInfo(DiagnosticSeverity Severity,
335 : DiagnosticInfo(DK_Linker, Severity), Msg(Msg) {}
336 void LinkDiagnosticInfo::print(DiagnosticPrinter &DP) const { DP << Msg; }
338 //===----------------------------------------------------------------------===//
339 // IRLinker implementation.
340 //===----------------------------------------------------------------------===//
345 /// Creates prototypes for functions that are lazily linked on the fly. This
346 /// speeds up linking for modules with many/ lazily linked functions of which
348 class GlobalValueMaterializer final : public ValueMaterializer {
349 IRLinker &TheIRLinker;
352 GlobalValueMaterializer(IRLinker &TheIRLinker) : TheIRLinker(TheIRLinker) {}
353 Value *materialize(Value *V) override;
356 class LocalValueMaterializer final : public ValueMaterializer {
357 IRLinker &TheIRLinker;
360 LocalValueMaterializer(IRLinker &TheIRLinker) : TheIRLinker(TheIRLinker) {}
361 Value *materialize(Value *V) override;
364 /// Type of the Metadata map in \a ValueToValueMapTy.
365 typedef DenseMap<const Metadata *, TrackingMDRef> MDMapT;
367 /// This is responsible for keeping track of the state used for moving data
368 /// from SrcM to DstM.
371 std::unique_ptr<Module> SrcM;
373 /// See IRMover::move().
374 std::function<void(GlobalValue &, IRMover::ValueAdder)> AddLazyFor;
377 GlobalValueMaterializer GValMaterializer;
378 LocalValueMaterializer LValMaterializer;
380 /// A metadata map that's shared between IRLinker instances.
383 /// Mapping of values from what they used to be in Src, to what they are now
384 /// in DstM. ValueToValueMapTy is a ValueMap, which involves some overhead
385 /// due to the use of Value handles which the Linker doesn't actually need,
386 /// but this allows us to reuse the ValueMapper code.
387 ValueToValueMapTy ValueMap;
388 ValueToValueMapTy AliasValueMap;
390 DenseSet<GlobalValue *> ValuesToLink;
391 std::vector<GlobalValue *> Worklist;
393 void maybeAdd(GlobalValue *GV) {
394 if (ValuesToLink.insert(GV).second)
395 Worklist.push_back(GV);
398 /// Whether we are importing globals for ThinLTO, as opposed to linking the
399 /// source module. If this flag is set, it means that we can rely on some
400 /// other object file to define any non-GlobalValue entities defined by the
401 /// source module. This currently causes us to not link retained types in
402 /// debug info metadata and module inline asm.
403 bool IsPerformingImport;
405 /// Set to true when all global value body linking is complete (including
406 /// lazy linking). Used to prevent metadata linking from creating new
408 bool DoneLinkingBodies = false;
410 /// The Error encountered during materialization. We use an Optional here to
411 /// avoid needing to manage an unconsumed success value.
412 Optional<Error> FoundError;
413 void setError(Error E) {
415 FoundError = std::move(E);
418 /// Most of the errors produced by this module are inconvertible StringErrors.
419 /// This convenience function lets us return one of those more easily.
420 Error stringErr(const Twine &T) {
421 return make_error<StringError>(T, inconvertibleErrorCode());
424 /// Entry point for mapping values and alternate context for mapping aliases.
428 /// Handles cloning of a global values from the source module into
429 /// the destination module, including setting the attributes and visibility.
430 GlobalValue *copyGlobalValueProto(const GlobalValue *SGV, bool ForDefinition);
432 void emitWarning(const Twine &Message) {
433 SrcM->getContext().diagnose(LinkDiagnosticInfo(DS_Warning, Message));
436 /// Given a global in the source module, return the global in the
437 /// destination module that is being linked to, if any.
438 GlobalValue *getLinkedToGlobal(const GlobalValue *SrcGV) {
439 // If the source has no name it can't link. If it has local linkage,
440 // there is no name match-up going on.
441 if (!SrcGV->hasName() || SrcGV->hasLocalLinkage())
444 // Otherwise see if we have a match in the destination module's symtab.
445 GlobalValue *DGV = DstM.getNamedValue(SrcGV->getName());
449 // If we found a global with the same name in the dest module, but it has
450 // internal linkage, we are really not doing any linkage here.
451 if (DGV->hasLocalLinkage())
454 // Otherwise, we do in fact link to the destination global.
458 void computeTypeMapping();
460 Expected<Constant *> linkAppendingVarProto(GlobalVariable *DstGV,
461 const GlobalVariable *SrcGV);
463 /// Given the GlobaValue \p SGV in the source module, and the matching
464 /// GlobalValue \p DGV (if any), return true if the linker will pull \p SGV
465 /// into the destination module.
467 /// Note this code may call the client-provided \p AddLazyFor.
468 bool shouldLink(GlobalValue *DGV, GlobalValue &SGV);
469 Expected<Constant *> linkGlobalValueProto(GlobalValue *GV, bool ForAlias);
471 Error linkModuleFlagsMetadata();
473 void linkGlobalVariable(GlobalVariable &Dst, GlobalVariable &Src);
474 Error linkFunctionBody(Function &Dst, Function &Src);
475 void linkAliasBody(GlobalAlias &Dst, GlobalAlias &Src);
476 Error linkGlobalValueBody(GlobalValue &Dst, GlobalValue &Src);
478 /// Functions that take care of cloning a specific global value type
479 /// into the destination module.
480 GlobalVariable *copyGlobalVariableProto(const GlobalVariable *SGVar);
481 Function *copyFunctionProto(const Function *SF);
482 GlobalValue *copyGlobalAliasProto(const GlobalAlias *SGA);
484 /// When importing for ThinLTO, prevent importing of types listed on
485 /// the DICompileUnit that we don't need a copy of in the importing
487 void prepareCompileUnitsForImport();
488 void linkNamedMDNodes();
491 IRLinker(Module &DstM, MDMapT &SharedMDs,
492 IRMover::IdentifiedStructTypeSet &Set, std::unique_ptr<Module> SrcM,
493 ArrayRef<GlobalValue *> ValuesToLink,
494 std::function<void(GlobalValue &, IRMover::ValueAdder)> AddLazyFor,
495 bool IsPerformingImport)
496 : DstM(DstM), SrcM(std::move(SrcM)), AddLazyFor(std::move(AddLazyFor)),
497 TypeMap(Set), GValMaterializer(*this), LValMaterializer(*this),
498 SharedMDs(SharedMDs), IsPerformingImport(IsPerformingImport),
499 Mapper(ValueMap, RF_MoveDistinctMDs | RF_IgnoreMissingLocals, &TypeMap,
501 AliasMCID(Mapper.registerAlternateMappingContext(AliasValueMap,
502 &LValMaterializer)) {
503 ValueMap.getMDMap() = std::move(SharedMDs);
504 for (GlobalValue *GV : ValuesToLink)
506 if (IsPerformingImport)
507 prepareCompileUnitsForImport();
509 ~IRLinker() { SharedMDs = std::move(*ValueMap.getMDMap()); }
512 Value *materialize(Value *V, bool ForAlias);
516 /// The LLVM SymbolTable class autorenames globals that conflict in the symbol
517 /// table. This is good for all clients except for us. Go through the trouble
518 /// to force this back.
519 static void forceRenaming(GlobalValue *GV, StringRef Name) {
520 // If the global doesn't force its name or if it already has the right name,
521 // there is nothing for us to do.
522 if (GV->hasLocalLinkage() || GV->getName() == Name)
525 Module *M = GV->getParent();
527 // If there is a conflict, rename the conflict.
528 if (GlobalValue *ConflictGV = M->getNamedValue(Name)) {
529 GV->takeName(ConflictGV);
530 ConflictGV->setName(Name); // This will cause ConflictGV to get renamed
531 assert(ConflictGV->getName() != Name && "forceRenaming didn't work");
533 GV->setName(Name); // Force the name back
537 Value *GlobalValueMaterializer::materialize(Value *SGV) {
538 return TheIRLinker.materialize(SGV, false);
541 Value *LocalValueMaterializer::materialize(Value *SGV) {
542 return TheIRLinker.materialize(SGV, true);
545 Value *IRLinker::materialize(Value *V, bool ForAlias) {
546 auto *SGV = dyn_cast<GlobalValue>(V);
550 Expected<Constant *> NewProto = linkGlobalValueProto(SGV, ForAlias);
552 setError(NewProto.takeError());
558 GlobalValue *New = dyn_cast<GlobalValue>(*NewProto);
562 // If we already created the body, just return.
563 if (auto *F = dyn_cast<Function>(New)) {
564 if (!F->isDeclaration())
566 } else if (auto *V = dyn_cast<GlobalVariable>(New)) {
567 if (V->hasInitializer() || V->hasAppendingLinkage())
570 auto *A = cast<GlobalAlias>(New);
575 // When linking a global for an alias, it will always be linked. However we
576 // need to check if it was not already scheduled to satisfy a reference from a
577 // regular global value initializer. We know if it has been schedule if the
578 // "New" GlobalValue that is mapped here for the alias is the same as the one
579 // already mapped. If there is an entry in the ValueMap but the value is
580 // different, it means that the value already had a definition in the
581 // destination module (linkonce for instance), but we need a new definition
582 // for the alias ("New" will be different.
583 if (ForAlias && ValueMap.lookup(SGV) == New)
586 if (ForAlias || shouldLink(New, *SGV))
587 setError(linkGlobalValueBody(*New, *SGV));
592 /// Loop through the global variables in the src module and merge them into the
594 GlobalVariable *IRLinker::copyGlobalVariableProto(const GlobalVariable *SGVar) {
595 // No linking to be performed or linking from the source: simply create an
596 // identical version of the symbol over in the dest module... the
597 // initializer will be filled in later by LinkGlobalInits.
598 GlobalVariable *NewDGV =
599 new GlobalVariable(DstM, TypeMap.get(SGVar->getValueType()),
600 SGVar->isConstant(), GlobalValue::ExternalLinkage,
601 /*init*/ nullptr, SGVar->getName(),
602 /*insertbefore*/ nullptr, SGVar->getThreadLocalMode(),
603 SGVar->getType()->getAddressSpace());
604 NewDGV->setAlignment(SGVar->getAlignment());
605 NewDGV->copyAttributesFrom(SGVar);
609 /// Link the function in the source module into the destination module if
610 /// needed, setting up mapping information.
611 Function *IRLinker::copyFunctionProto(const Function *SF) {
612 // If there is no linkage to be performed or we are linking from the source,
615 Function::Create(TypeMap.get(SF->getFunctionType()),
616 GlobalValue::ExternalLinkage, SF->getName(), &DstM);
617 F->copyAttributesFrom(SF);
621 /// Set up prototypes for any aliases that come over from the source module.
622 GlobalValue *IRLinker::copyGlobalAliasProto(const GlobalAlias *SGA) {
623 // If there is no linkage to be performed or we're linking from the source,
625 auto *Ty = TypeMap.get(SGA->getValueType());
627 GlobalAlias::create(Ty, SGA->getType()->getPointerAddressSpace(),
628 GlobalValue::ExternalLinkage, SGA->getName(), &DstM);
629 GA->copyAttributesFrom(SGA);
633 GlobalValue *IRLinker::copyGlobalValueProto(const GlobalValue *SGV,
634 bool ForDefinition) {
636 if (auto *SGVar = dyn_cast<GlobalVariable>(SGV)) {
637 NewGV = copyGlobalVariableProto(SGVar);
638 } else if (auto *SF = dyn_cast<Function>(SGV)) {
639 NewGV = copyFunctionProto(SF);
642 NewGV = copyGlobalAliasProto(cast<GlobalAlias>(SGV));
644 NewGV = new GlobalVariable(
645 DstM, TypeMap.get(SGV->getValueType()),
646 /*isConstant*/ false, GlobalValue::ExternalLinkage,
647 /*init*/ nullptr, SGV->getName(),
648 /*insertbefore*/ nullptr, SGV->getThreadLocalMode(),
649 SGV->getType()->getAddressSpace());
653 NewGV->setLinkage(SGV->getLinkage());
654 else if (SGV->hasExternalWeakLinkage())
655 NewGV->setLinkage(GlobalValue::ExternalWeakLinkage);
657 if (auto *NewGO = dyn_cast<GlobalObject>(NewGV)) {
658 // Metadata for global variables and function declarations is copied eagerly.
659 if (isa<GlobalVariable>(SGV) || SGV->isDeclaration())
660 NewGO->copyMetadata(cast<GlobalObject>(SGV), 0);
663 // Remove these copied constants in case this stays a declaration, since
664 // they point to the source module. If the def is linked the values will
665 // be mapped in during linkFunctionBody.
666 if (auto *NewF = dyn_cast<Function>(NewGV)) {
667 NewF->setPersonalityFn(nullptr);
668 NewF->setPrefixData(nullptr);
669 NewF->setPrologueData(nullptr);
675 /// Loop over all of the linked values to compute type mappings. For example,
676 /// if we link "extern Foo *x" and "Foo *x = NULL", then we have two struct
677 /// types 'Foo' but one got renamed when the module was loaded into the same
679 void IRLinker::computeTypeMapping() {
680 for (GlobalValue &SGV : SrcM->globals()) {
681 GlobalValue *DGV = getLinkedToGlobal(&SGV);
685 if (!DGV->hasAppendingLinkage() || !SGV.hasAppendingLinkage()) {
686 TypeMap.addTypeMapping(DGV->getType(), SGV.getType());
690 // Unify the element type of appending arrays.
691 ArrayType *DAT = cast<ArrayType>(DGV->getValueType());
692 ArrayType *SAT = cast<ArrayType>(SGV.getValueType());
693 TypeMap.addTypeMapping(DAT->getElementType(), SAT->getElementType());
696 for (GlobalValue &SGV : *SrcM)
697 if (GlobalValue *DGV = getLinkedToGlobal(&SGV))
698 TypeMap.addTypeMapping(DGV->getType(), SGV.getType());
700 for (GlobalValue &SGV : SrcM->aliases())
701 if (GlobalValue *DGV = getLinkedToGlobal(&SGV))
702 TypeMap.addTypeMapping(DGV->getType(), SGV.getType());
704 // Incorporate types by name, scanning all the types in the source module.
705 // At this point, the destination module may have a type "%foo = { i32 }" for
706 // example. When the source module got loaded into the same LLVMContext, if
707 // it had the same type, it would have been renamed to "%foo.42 = { i32 }".
708 std::vector<StructType *> Types = SrcM->getIdentifiedStructTypes();
709 for (StructType *ST : Types) {
713 if (TypeMap.DstStructTypesSet.hasType(ST)) {
714 // This is actually a type from the destination module.
715 // getIdentifiedStructTypes() can have found it by walking debug info
716 // metadata nodes, some of which get linked by name when ODR Type Uniquing
717 // is enabled on the Context, from the source to the destination module.
721 // Check to see if there is a dot in the name followed by a digit.
722 size_t DotPos = ST->getName().rfind('.');
723 if (DotPos == 0 || DotPos == StringRef::npos ||
724 ST->getName().back() == '.' ||
725 !isdigit(static_cast<unsigned char>(ST->getName()[DotPos + 1])))
728 // Check to see if the destination module has a struct with the prefix name.
729 StructType *DST = DstM.getTypeByName(ST->getName().substr(0, DotPos));
733 // Don't use it if this actually came from the source module. They're in
734 // the same LLVMContext after all. Also don't use it unless the type is
735 // actually used in the destination module. This can happen in situations
740 // %Z = type { %A } %B = type { %C.1 }
741 // %A = type { %B.1, [7 x i8] } %C.1 = type { i8* }
742 // %B.1 = type { %C } %A.2 = type { %B.3, [5 x i8] }
743 // %C = type { i8* } %B.3 = type { %C.1 }
745 // When we link Module B with Module A, the '%B' in Module B is
746 // used. However, that would then use '%C.1'. But when we process '%C.1',
747 // we prefer to take the '%C' version. So we are then left with both
748 // '%C.1' and '%C' being used for the same types. This leads to some
749 // variables using one type and some using the other.
750 if (TypeMap.DstStructTypesSet.hasType(DST))
751 TypeMap.addTypeMapping(DST, ST);
754 // Now that we have discovered all of the type equivalences, get a body for
755 // any 'opaque' types in the dest module that are now resolved.
756 TypeMap.linkDefinedTypeBodies();
759 static void getArrayElements(const Constant *C,
760 SmallVectorImpl<Constant *> &Dest) {
761 unsigned NumElements = cast<ArrayType>(C->getType())->getNumElements();
763 for (unsigned i = 0; i != NumElements; ++i)
764 Dest.push_back(C->getAggregateElement(i));
767 /// If there were any appending global variables, link them together now.
769 IRLinker::linkAppendingVarProto(GlobalVariable *DstGV,
770 const GlobalVariable *SrcGV) {
771 Type *EltTy = cast<ArrayType>(TypeMap.get(SrcGV->getValueType()))
774 // FIXME: This upgrade is done during linking to support the C API. Once the
775 // old form is deprecated, we should move this upgrade to
776 // llvm::UpgradeGlobalVariable() and simplify the logic here and in
777 // Mapper::mapAppendingVariable() in ValueMapper.cpp.
778 StringRef Name = SrcGV->getName();
779 bool IsNewStructor = false;
780 bool IsOldStructor = false;
781 if (Name == "llvm.global_ctors" || Name == "llvm.global_dtors") {
782 if (cast<StructType>(EltTy)->getNumElements() == 3)
783 IsNewStructor = true;
785 IsOldStructor = true;
788 PointerType *VoidPtrTy = Type::getInt8Ty(SrcGV->getContext())->getPointerTo();
790 auto &ST = *cast<StructType>(EltTy);
791 Type *Tys[3] = {ST.getElementType(0), ST.getElementType(1), VoidPtrTy};
792 EltTy = StructType::get(SrcGV->getContext(), Tys, false);
795 uint64_t DstNumElements = 0;
797 ArrayType *DstTy = cast<ArrayType>(DstGV->getValueType());
798 DstNumElements = DstTy->getNumElements();
800 if (!SrcGV->hasAppendingLinkage() || !DstGV->hasAppendingLinkage())
802 "Linking globals named '" + SrcGV->getName() +
803 "': can only link appending global with another appending "
806 // Check to see that they two arrays agree on type.
807 if (EltTy != DstTy->getElementType())
808 return stringErr("Appending variables with different element types!");
809 if (DstGV->isConstant() != SrcGV->isConstant())
810 return stringErr("Appending variables linked with different const'ness!");
812 if (DstGV->getAlignment() != SrcGV->getAlignment())
814 "Appending variables with different alignment need to be linked!");
816 if (DstGV->getVisibility() != SrcGV->getVisibility())
818 "Appending variables with different visibility need to be linked!");
820 if (DstGV->hasGlobalUnnamedAddr() != SrcGV->hasGlobalUnnamedAddr())
822 "Appending variables with different unnamed_addr need to be linked!");
824 if (DstGV->getSection() != SrcGV->getSection())
826 "Appending variables with different section name need to be linked!");
829 SmallVector<Constant *, 16> SrcElements;
830 getArrayElements(SrcGV->getInitializer(), SrcElements);
833 auto It = remove_if(SrcElements, [this](Constant *E) {
835 dyn_cast<GlobalValue>(E->getAggregateElement(2)->stripPointerCasts());
838 GlobalValue *DGV = getLinkedToGlobal(Key);
839 return !shouldLink(DGV, *Key);
841 SrcElements.erase(It, SrcElements.end());
843 uint64_t NewSize = DstNumElements + SrcElements.size();
844 ArrayType *NewType = ArrayType::get(EltTy, NewSize);
846 // Create the new global variable.
847 GlobalVariable *NG = new GlobalVariable(
848 DstM, NewType, SrcGV->isConstant(), SrcGV->getLinkage(),
849 /*init*/ nullptr, /*name*/ "", DstGV, SrcGV->getThreadLocalMode(),
850 SrcGV->getType()->getAddressSpace());
852 NG->copyAttributesFrom(SrcGV);
853 forceRenaming(NG, SrcGV->getName());
855 Constant *Ret = ConstantExpr::getBitCast(NG, TypeMap.get(SrcGV->getType()));
857 Mapper.scheduleMapAppendingVariable(*NG,
858 DstGV ? DstGV->getInitializer() : nullptr,
859 IsOldStructor, SrcElements);
861 // Replace any uses of the two global variables with uses of the new
864 DstGV->replaceAllUsesWith(ConstantExpr::getBitCast(NG, DstGV->getType()));
865 DstGV->eraseFromParent();
871 bool IRLinker::shouldLink(GlobalValue *DGV, GlobalValue &SGV) {
872 if (ValuesToLink.count(&SGV) || SGV.hasLocalLinkage())
875 if (DGV && !DGV->isDeclarationForLinker())
878 if (SGV.isDeclaration() || DoneLinkingBodies)
881 // Callback to the client to give a chance to lazily add the Global to the
882 // list of value to link.
883 bool LazilyAdded = false;
884 AddLazyFor(SGV, [this, &LazilyAdded](GlobalValue &GV) {
891 Expected<Constant *> IRLinker::linkGlobalValueProto(GlobalValue *SGV,
893 GlobalValue *DGV = getLinkedToGlobal(SGV);
895 bool ShouldLink = shouldLink(DGV, *SGV);
897 // just missing from map
899 auto I = ValueMap.find(SGV);
900 if (I != ValueMap.end())
901 return cast<Constant>(I->second);
903 I = AliasValueMap.find(SGV);
904 if (I != AliasValueMap.end())
905 return cast<Constant>(I->second);
908 if (!ShouldLink && ForAlias)
911 // Handle the ultra special appending linkage case first.
912 assert(!DGV || SGV->hasAppendingLinkage() == DGV->hasAppendingLinkage());
913 if (SGV->hasAppendingLinkage())
914 return linkAppendingVarProto(cast_or_null<GlobalVariable>(DGV),
915 cast<GlobalVariable>(SGV));
918 if (DGV && !ShouldLink) {
921 // If we are done linking global value bodies (i.e. we are performing
922 // metadata linking), don't link in the global value due to this
923 // reference, simply map it to null.
924 if (DoneLinkingBodies)
927 NewGV = copyGlobalValueProto(SGV, ShouldLink);
928 if (ShouldLink || !ForAlias)
929 forceRenaming(NewGV, SGV->getName());
932 // Overloaded intrinsics have overloaded types names as part of their
933 // names. If we renamed overloaded types we should rename the intrinsic
935 if (Function *F = dyn_cast<Function>(NewGV))
936 if (auto Remangled = Intrinsic::remangleIntrinsicFunction(F))
937 NewGV = Remangled.getValue();
939 if (ShouldLink || ForAlias) {
940 if (const Comdat *SC = SGV->getComdat()) {
941 if (auto *GO = dyn_cast<GlobalObject>(NewGV)) {
942 Comdat *DC = DstM.getOrInsertComdat(SC->getName());
943 DC->setSelectionKind(SC->getSelectionKind());
949 if (!ShouldLink && ForAlias)
950 NewGV->setLinkage(GlobalValue::InternalLinkage);
954 C = ConstantExpr::getBitCast(NewGV, TypeMap.get(SGV->getType()));
956 if (DGV && NewGV != DGV) {
957 DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewGV, DGV->getType()));
958 DGV->eraseFromParent();
964 /// Update the initializers in the Dest module now that all globals that may be
965 /// referenced are in Dest.
966 void IRLinker::linkGlobalVariable(GlobalVariable &Dst, GlobalVariable &Src) {
967 // Figure out what the initializer looks like in the dest module.
968 Mapper.scheduleMapGlobalInitializer(Dst, *Src.getInitializer());
971 /// Copy the source function over into the dest function and fix up references
972 /// to values. At this point we know that Dest is an external function, and
974 Error IRLinker::linkFunctionBody(Function &Dst, Function &Src) {
975 assert(Dst.isDeclaration() && !Src.isDeclaration());
977 // Materialize if needed.
978 if (Error Err = Src.materialize())
981 // Link in the operands without remapping.
982 if (Src.hasPrefixData())
983 Dst.setPrefixData(Src.getPrefixData());
984 if (Src.hasPrologueData())
985 Dst.setPrologueData(Src.getPrologueData());
986 if (Src.hasPersonalityFn())
987 Dst.setPersonalityFn(Src.getPersonalityFn());
989 // Copy over the metadata attachments without remapping.
990 Dst.copyMetadata(&Src, 0);
992 // Steal arguments and splice the body of Src into Dst.
993 Dst.stealArgumentListFrom(Src);
994 Dst.getBasicBlockList().splice(Dst.end(), Src.getBasicBlockList());
996 // Everything has been moved over. Remap it.
997 Mapper.scheduleRemapFunction(Dst);
998 return Error::success();
1001 void IRLinker::linkAliasBody(GlobalAlias &Dst, GlobalAlias &Src) {
1002 Mapper.scheduleMapGlobalAliasee(Dst, *Src.getAliasee(), AliasMCID);
1005 Error IRLinker::linkGlobalValueBody(GlobalValue &Dst, GlobalValue &Src) {
1006 if (auto *F = dyn_cast<Function>(&Src))
1007 return linkFunctionBody(cast<Function>(Dst), *F);
1008 if (auto *GVar = dyn_cast<GlobalVariable>(&Src)) {
1009 linkGlobalVariable(cast<GlobalVariable>(Dst), *GVar);
1010 return Error::success();
1012 linkAliasBody(cast<GlobalAlias>(Dst), cast<GlobalAlias>(Src));
1013 return Error::success();
1016 void IRLinker::prepareCompileUnitsForImport() {
1017 NamedMDNode *SrcCompileUnits = SrcM->getNamedMetadata("llvm.dbg.cu");
1018 if (!SrcCompileUnits)
1020 // When importing for ThinLTO, prevent importing of types listed on
1021 // the DICompileUnit that we don't need a copy of in the importing
1022 // module. They will be emitted by the originating module.
1023 for (unsigned I = 0, E = SrcCompileUnits->getNumOperands(); I != E; ++I) {
1024 auto *CU = cast<DICompileUnit>(SrcCompileUnits->getOperand(I));
1025 assert(CU && "Expected valid compile unit");
1026 // Enums, macros, and retained types don't need to be listed on the
1027 // imported DICompileUnit. This means they will only be imported
1028 // if reached from the mapped IR. Do this by setting their value map
1029 // entries to nullptr, which will automatically prevent their importing
1030 // when reached from the DICompileUnit during metadata mapping.
1031 ValueMap.MD()[CU->getRawEnumTypes()].reset(nullptr);
1032 ValueMap.MD()[CU->getRawMacros()].reset(nullptr);
1033 ValueMap.MD()[CU->getRawRetainedTypes()].reset(nullptr);
1034 // If we ever start importing global variable defs, we'll need to
1035 // add their DIGlobalVariable to the globals list on the imported
1036 // DICompileUnit. Confirm none are imported, and then we can
1037 // map the list of global variables to nullptr.
1040 [](const GlobalValue *GV) { return isa<GlobalVariable>(GV); }) &&
1041 "Unexpected importing of a GlobalVariable definition");
1042 ValueMap.MD()[CU->getRawGlobalVariables()].reset(nullptr);
1044 // Imported entities only need to be mapped in if they have local
1045 // scope, as those might correspond to an imported entity inside a
1046 // function being imported (any locally scoped imported entities that
1047 // don't end up referenced by an imported function will not be emitted
1048 // into the object). Imported entities not in a local scope
1049 // (e.g. on the namespace) only need to be emitted by the originating
1050 // module. Create a list of the locally scoped imported entities, and
1051 // replace the source CUs imported entity list with the new list, so
1052 // only those are mapped in.
1053 // FIXME: Locally-scoped imported entities could be moved to the
1054 // functions they are local to instead of listing them on the CU, and
1055 // we would naturally only link in those needed by function importing.
1056 SmallVector<TrackingMDNodeRef, 4> AllImportedModules;
1057 bool ReplaceImportedEntities = false;
1058 for (auto *IE : CU->getImportedEntities()) {
1059 DIScope *Scope = IE->getScope();
1060 assert(Scope && "Invalid Scope encoding!");
1061 if (isa<DILocalScope>(Scope))
1062 AllImportedModules.emplace_back(IE);
1064 ReplaceImportedEntities = true;
1066 if (ReplaceImportedEntities) {
1067 if (!AllImportedModules.empty())
1068 CU->replaceImportedEntities(MDTuple::get(
1070 SmallVector<Metadata *, 16>(AllImportedModules.begin(),
1071 AllImportedModules.end())));
1073 // If there were no local scope imported entities, we can map
1074 // the whole list to nullptr.
1075 ValueMap.MD()[CU->getRawImportedEntities()].reset(nullptr);
1080 /// Insert all of the named MDNodes in Src into the Dest module.
1081 void IRLinker::linkNamedMDNodes() {
1082 const NamedMDNode *SrcModFlags = SrcM->getModuleFlagsMetadata();
1083 for (const NamedMDNode &NMD : SrcM->named_metadata()) {
1084 // Don't link module flags here. Do them separately.
1085 if (&NMD == SrcModFlags)
1087 NamedMDNode *DestNMD = DstM.getOrInsertNamedMetadata(NMD.getName());
1088 // Add Src elements into Dest node.
1089 for (const MDNode *Op : NMD.operands())
1090 DestNMD->addOperand(Mapper.mapMDNode(*Op));
1094 /// Merge the linker flags in Src into the Dest module.
1095 Error IRLinker::linkModuleFlagsMetadata() {
1096 // If the source module has no module flags, we are done.
1097 const NamedMDNode *SrcModFlags = SrcM->getModuleFlagsMetadata();
1099 return Error::success();
1101 // If the destination module doesn't have module flags yet, then just copy
1102 // over the source module's flags.
1103 NamedMDNode *DstModFlags = DstM.getOrInsertModuleFlagsMetadata();
1104 if (DstModFlags->getNumOperands() == 0) {
1105 for (unsigned I = 0, E = SrcModFlags->getNumOperands(); I != E; ++I)
1106 DstModFlags->addOperand(SrcModFlags->getOperand(I));
1108 return Error::success();
1111 // First build a map of the existing module flags and requirements.
1112 DenseMap<MDString *, std::pair<MDNode *, unsigned>> Flags;
1113 SmallSetVector<MDNode *, 16> Requirements;
1114 for (unsigned I = 0, E = DstModFlags->getNumOperands(); I != E; ++I) {
1115 MDNode *Op = DstModFlags->getOperand(I);
1116 ConstantInt *Behavior = mdconst::extract<ConstantInt>(Op->getOperand(0));
1117 MDString *ID = cast<MDString>(Op->getOperand(1));
1119 if (Behavior->getZExtValue() == Module::Require) {
1120 Requirements.insert(cast<MDNode>(Op->getOperand(2)));
1122 Flags[ID] = std::make_pair(Op, I);
1126 // Merge in the flags from the source module, and also collect its set of
1128 for (unsigned I = 0, E = SrcModFlags->getNumOperands(); I != E; ++I) {
1129 MDNode *SrcOp = SrcModFlags->getOperand(I);
1130 ConstantInt *SrcBehavior =
1131 mdconst::extract<ConstantInt>(SrcOp->getOperand(0));
1132 MDString *ID = cast<MDString>(SrcOp->getOperand(1));
1135 std::tie(DstOp, DstIndex) = Flags.lookup(ID);
1136 unsigned SrcBehaviorValue = SrcBehavior->getZExtValue();
1138 // If this is a requirement, add it and continue.
1139 if (SrcBehaviorValue == Module::Require) {
1140 // If the destination module does not already have this requirement, add
1142 if (Requirements.insert(cast<MDNode>(SrcOp->getOperand(2)))) {
1143 DstModFlags->addOperand(SrcOp);
1148 // If there is no existing flag with this ID, just add it.
1150 Flags[ID] = std::make_pair(SrcOp, DstModFlags->getNumOperands());
1151 DstModFlags->addOperand(SrcOp);
1155 // Otherwise, perform a merge.
1156 ConstantInt *DstBehavior =
1157 mdconst::extract<ConstantInt>(DstOp->getOperand(0));
1158 unsigned DstBehaviorValue = DstBehavior->getZExtValue();
1160 auto overrideDstValue = [&]() {
1161 DstModFlags->setOperand(DstIndex, SrcOp);
1162 Flags[ID].first = SrcOp;
1165 // If either flag has override behavior, handle it first.
1166 if (DstBehaviorValue == Module::Override) {
1167 // Diagnose inconsistent flags which both have override behavior.
1168 if (SrcBehaviorValue == Module::Override &&
1169 SrcOp->getOperand(2) != DstOp->getOperand(2))
1170 return stringErr("linking module flags '" + ID->getString() +
1171 "': IDs have conflicting override values");
1173 } else if (SrcBehaviorValue == Module::Override) {
1174 // Update the destination flag to that of the source.
1179 // Diagnose inconsistent merge behavior types.
1180 if (SrcBehaviorValue != DstBehaviorValue)
1181 return stringErr("linking module flags '" + ID->getString() +
1182 "': IDs have conflicting behaviors");
1184 auto replaceDstValue = [&](MDNode *New) {
1185 Metadata *FlagOps[] = {DstOp->getOperand(0), ID, New};
1186 MDNode *Flag = MDNode::get(DstM.getContext(), FlagOps);
1187 DstModFlags->setOperand(DstIndex, Flag);
1188 Flags[ID].first = Flag;
1191 // Perform the merge for standard behavior types.
1192 switch (SrcBehaviorValue) {
1193 case Module::Require:
1194 case Module::Override:
1195 llvm_unreachable("not possible");
1196 case Module::Error: {
1197 // Emit an error if the values differ.
1198 if (SrcOp->getOperand(2) != DstOp->getOperand(2))
1199 return stringErr("linking module flags '" + ID->getString() +
1200 "': IDs have conflicting values");
1203 case Module::Warning: {
1204 // Emit a warning if the values differ.
1205 if (SrcOp->getOperand(2) != DstOp->getOperand(2)) {
1206 emitWarning("linking module flags '" + ID->getString() +
1207 "': IDs have conflicting values");
1212 ConstantInt *DstValue =
1213 mdconst::extract<ConstantInt>(DstOp->getOperand(2));
1214 ConstantInt *SrcValue =
1215 mdconst::extract<ConstantInt>(SrcOp->getOperand(2));
1216 if (SrcValue->getZExtValue() > DstValue->getZExtValue())
1220 case Module::Append: {
1221 MDNode *DstValue = cast<MDNode>(DstOp->getOperand(2));
1222 MDNode *SrcValue = cast<MDNode>(SrcOp->getOperand(2));
1223 SmallVector<Metadata *, 8> MDs;
1224 MDs.reserve(DstValue->getNumOperands() + SrcValue->getNumOperands());
1225 MDs.append(DstValue->op_begin(), DstValue->op_end());
1226 MDs.append(SrcValue->op_begin(), SrcValue->op_end());
1228 replaceDstValue(MDNode::get(DstM.getContext(), MDs));
1231 case Module::AppendUnique: {
1232 SmallSetVector<Metadata *, 16> Elts;
1233 MDNode *DstValue = cast<MDNode>(DstOp->getOperand(2));
1234 MDNode *SrcValue = cast<MDNode>(SrcOp->getOperand(2));
1235 Elts.insert(DstValue->op_begin(), DstValue->op_end());
1236 Elts.insert(SrcValue->op_begin(), SrcValue->op_end());
1238 replaceDstValue(MDNode::get(DstM.getContext(),
1239 makeArrayRef(Elts.begin(), Elts.end())));
1245 // Check all of the requirements.
1246 for (unsigned I = 0, E = Requirements.size(); I != E; ++I) {
1247 MDNode *Requirement = Requirements[I];
1248 MDString *Flag = cast<MDString>(Requirement->getOperand(0));
1249 Metadata *ReqValue = Requirement->getOperand(1);
1251 MDNode *Op = Flags[Flag].first;
1252 if (!Op || Op->getOperand(2) != ReqValue)
1253 return stringErr("linking module flags '" + Flag->getString() +
1254 "': does not have the required value");
1256 return Error::success();
1259 /// Return InlineAsm adjusted with target-specific directives if required.
1260 /// For ARM and Thumb, we have to add directives to select the appropriate ISA
1261 /// to support mixing module-level inline assembly from ARM and Thumb modules.
1262 static std::string adjustInlineAsm(const std::string &InlineAsm,
1263 const Triple &Triple) {
1264 if (Triple.getArch() == Triple::thumb || Triple.getArch() == Triple::thumbeb)
1265 return ".text\n.balign 2\n.thumb\n" + InlineAsm;
1266 if (Triple.getArch() == Triple::arm || Triple.getArch() == Triple::armeb)
1267 return ".text\n.balign 4\n.arm\n" + InlineAsm;
1271 Error IRLinker::run() {
1272 // Ensure metadata materialized before value mapping.
1273 if (SrcM->getMaterializer())
1274 if (Error Err = SrcM->getMaterializer()->materializeMetadata())
1277 // Inherit the target data from the source module if the destination module
1278 // doesn't have one already.
1279 if (DstM.getDataLayout().isDefault())
1280 DstM.setDataLayout(SrcM->getDataLayout());
1282 if (SrcM->getDataLayout() != DstM.getDataLayout()) {
1283 emitWarning("Linking two modules of different data layouts: '" +
1284 SrcM->getModuleIdentifier() + "' is '" +
1285 SrcM->getDataLayoutStr() + "' whereas '" +
1286 DstM.getModuleIdentifier() + "' is '" +
1287 DstM.getDataLayoutStr() + "'\n");
1290 // Copy the target triple from the source to dest if the dest's is empty.
1291 if (DstM.getTargetTriple().empty() && !SrcM->getTargetTriple().empty())
1292 DstM.setTargetTriple(SrcM->getTargetTriple());
1294 Triple SrcTriple(SrcM->getTargetTriple()), DstTriple(DstM.getTargetTriple());
1296 if (!SrcM->getTargetTriple().empty()&&
1297 !SrcTriple.isCompatibleWith(DstTriple))
1298 emitWarning("Linking two modules of different target triples: " +
1299 SrcM->getModuleIdentifier() + "' is '" +
1300 SrcM->getTargetTriple() + "' whereas '" +
1301 DstM.getModuleIdentifier() + "' is '" + DstM.getTargetTriple() +
1304 DstM.setTargetTriple(SrcTriple.merge(DstTriple));
1306 // Append the module inline asm string.
1307 if (!IsPerformingImport && !SrcM->getModuleInlineAsm().empty()) {
1308 std::string SrcModuleInlineAsm = adjustInlineAsm(SrcM->getModuleInlineAsm(),
1310 if (DstM.getModuleInlineAsm().empty())
1311 DstM.setModuleInlineAsm(SrcModuleInlineAsm);
1313 DstM.setModuleInlineAsm(DstM.getModuleInlineAsm() + "\n" +
1314 SrcModuleInlineAsm);
1317 // Loop over all of the linked values to compute type mappings.
1318 computeTypeMapping();
1320 std::reverse(Worklist.begin(), Worklist.end());
1321 while (!Worklist.empty()) {
1322 GlobalValue *GV = Worklist.back();
1323 Worklist.pop_back();
1326 if (ValueMap.find(GV) != ValueMap.end() ||
1327 AliasValueMap.find(GV) != AliasValueMap.end())
1330 assert(!GV->isDeclaration());
1331 Mapper.mapValue(*GV);
1333 return std::move(*FoundError);
1336 // Note that we are done linking global value bodies. This prevents
1337 // metadata linking from creating new references.
1338 DoneLinkingBodies = true;
1339 Mapper.addFlags(RF_NullMapMissingGlobalValues);
1341 // Remap all of the named MDNodes in Src into the DstM module. We do this
1342 // after linking GlobalValues so that MDNodes that reference GlobalValues
1343 // are properly remapped.
1346 // Merge the module flags into the DstM module.
1347 return linkModuleFlagsMetadata();
1350 IRMover::StructTypeKeyInfo::KeyTy::KeyTy(ArrayRef<Type *> E, bool P)
1351 : ETypes(E), IsPacked(P) {}
1353 IRMover::StructTypeKeyInfo::KeyTy::KeyTy(const StructType *ST)
1354 : ETypes(ST->elements()), IsPacked(ST->isPacked()) {}
1356 bool IRMover::StructTypeKeyInfo::KeyTy::operator==(const KeyTy &That) const {
1357 return IsPacked == That.IsPacked && ETypes == That.ETypes;
1360 bool IRMover::StructTypeKeyInfo::KeyTy::operator!=(const KeyTy &That) const {
1361 return !this->operator==(That);
1364 StructType *IRMover::StructTypeKeyInfo::getEmptyKey() {
1365 return DenseMapInfo<StructType *>::getEmptyKey();
1368 StructType *IRMover::StructTypeKeyInfo::getTombstoneKey() {
1369 return DenseMapInfo<StructType *>::getTombstoneKey();
1372 unsigned IRMover::StructTypeKeyInfo::getHashValue(const KeyTy &Key) {
1373 return hash_combine(hash_combine_range(Key.ETypes.begin(), Key.ETypes.end()),
1377 unsigned IRMover::StructTypeKeyInfo::getHashValue(const StructType *ST) {
1378 return getHashValue(KeyTy(ST));
1381 bool IRMover::StructTypeKeyInfo::isEqual(const KeyTy &LHS,
1382 const StructType *RHS) {
1383 if (RHS == getEmptyKey() || RHS == getTombstoneKey())
1385 return LHS == KeyTy(RHS);
1388 bool IRMover::StructTypeKeyInfo::isEqual(const StructType *LHS,
1389 const StructType *RHS) {
1390 if (RHS == getEmptyKey() || RHS == getTombstoneKey())
1392 return KeyTy(LHS) == KeyTy(RHS);
1395 void IRMover::IdentifiedStructTypeSet::addNonOpaque(StructType *Ty) {
1396 assert(!Ty->isOpaque());
1397 NonOpaqueStructTypes.insert(Ty);
1400 void IRMover::IdentifiedStructTypeSet::switchToNonOpaque(StructType *Ty) {
1401 assert(!Ty->isOpaque());
1402 NonOpaqueStructTypes.insert(Ty);
1403 bool Removed = OpaqueStructTypes.erase(Ty);
1408 void IRMover::IdentifiedStructTypeSet::addOpaque(StructType *Ty) {
1409 assert(Ty->isOpaque());
1410 OpaqueStructTypes.insert(Ty);
1414 IRMover::IdentifiedStructTypeSet::findNonOpaque(ArrayRef<Type *> ETypes,
1416 IRMover::StructTypeKeyInfo::KeyTy Key(ETypes, IsPacked);
1417 auto I = NonOpaqueStructTypes.find_as(Key);
1418 return I == NonOpaqueStructTypes.end() ? nullptr : *I;
1421 bool IRMover::IdentifiedStructTypeSet::hasType(StructType *Ty) {
1423 return OpaqueStructTypes.count(Ty);
1424 auto I = NonOpaqueStructTypes.find(Ty);
1425 return I == NonOpaqueStructTypes.end() ? false : *I == Ty;
1428 IRMover::IRMover(Module &M) : Composite(M) {
1429 TypeFinder StructTypes;
1430 StructTypes.run(M, /* OnlyNamed */ false);
1431 for (StructType *Ty : StructTypes) {
1433 IdentifiedStructTypes.addOpaque(Ty);
1435 IdentifiedStructTypes.addNonOpaque(Ty);
1437 // Self-map metadatas in the destination module. This is needed when
1438 // DebugTypeODRUniquing is enabled on the LLVMContext, since metadata in the
1439 // destination module may be reached from the source module.
1440 for (auto *MD : StructTypes.getVisitedMetadata()) {
1441 SharedMDs[MD].reset(const_cast<MDNode *>(MD));
1445 Error IRMover::move(
1446 std::unique_ptr<Module> Src, ArrayRef<GlobalValue *> ValuesToLink,
1447 std::function<void(GlobalValue &, ValueAdder Add)> AddLazyFor,
1448 bool IsPerformingImport) {
1449 IRLinker TheIRLinker(Composite, SharedMDs, IdentifiedStructTypes,
1450 std::move(Src), ValuesToLink, std::move(AddLazyFor),
1451 IsPerformingImport);
1452 Error E = TheIRLinker.run();
1453 Composite.dropTriviallyDeadConstantArrays();