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/TypeFinder.h"
20 #include "llvm/Transforms/Utils/Cloning.h"
23 //===----------------------------------------------------------------------===//
24 // TypeMap implementation.
25 //===----------------------------------------------------------------------===//
28 class TypeMapTy : public ValueMapTypeRemapper {
29 /// This is a mapping from a source type to a destination type to use.
30 DenseMap<Type *, Type *> MappedTypes;
32 /// When checking to see if two subgraphs are isomorphic, we speculatively
33 /// add types to MappedTypes, but keep track of them here in case we need to
35 SmallVector<Type *, 16> SpeculativeTypes;
37 SmallVector<StructType *, 16> SpeculativeDstOpaqueTypes;
39 /// This is a list of non-opaque structs in the source module that are mapped
40 /// to an opaque struct in the destination module.
41 SmallVector<StructType *, 16> SrcDefinitionsToResolve;
43 /// This is the set of opaque types in the destination modules who are
44 /// getting a body from the source module.
45 SmallPtrSet<StructType *, 16> DstResolvedOpaqueTypes;
48 TypeMapTy(IRMover::IdentifiedStructTypeSet &DstStructTypesSet)
49 : DstStructTypesSet(DstStructTypesSet) {}
51 IRMover::IdentifiedStructTypeSet &DstStructTypesSet;
52 /// Indicate that the specified type in the destination module is conceptually
53 /// equivalent to the specified type in the source module.
54 void addTypeMapping(Type *DstTy, Type *SrcTy);
56 /// Produce a body for an opaque type in the dest module from a type
57 /// definition in the source module.
58 void linkDefinedTypeBodies();
60 /// Return the mapped type to use for the specified input type from the
62 Type *get(Type *SrcTy);
63 Type *get(Type *SrcTy, SmallPtrSet<StructType *, 8> &Visited);
65 void finishType(StructType *DTy, StructType *STy, ArrayRef<Type *> ETypes);
67 FunctionType *get(FunctionType *T) {
68 return cast<FunctionType>(get((Type *)T));
72 Type *remapType(Type *SrcTy) override { return get(SrcTy); }
74 bool areTypesIsomorphic(Type *DstTy, Type *SrcTy);
78 void TypeMapTy::addTypeMapping(Type *DstTy, Type *SrcTy) {
79 assert(SpeculativeTypes.empty());
80 assert(SpeculativeDstOpaqueTypes.empty());
82 // Check to see if these types are recursively isomorphic and establish a
83 // mapping between them if so.
84 if (!areTypesIsomorphic(DstTy, SrcTy)) {
85 // Oops, they aren't isomorphic. Just discard this request by rolling out
86 // any speculative mappings we've established.
87 for (Type *Ty : SpeculativeTypes)
88 MappedTypes.erase(Ty);
90 SrcDefinitionsToResolve.resize(SrcDefinitionsToResolve.size() -
91 SpeculativeDstOpaqueTypes.size());
92 for (StructType *Ty : SpeculativeDstOpaqueTypes)
93 DstResolvedOpaqueTypes.erase(Ty);
95 for (Type *Ty : SpeculativeTypes)
96 if (auto *STy = dyn_cast<StructType>(Ty))
100 SpeculativeTypes.clear();
101 SpeculativeDstOpaqueTypes.clear();
104 /// Recursively walk this pair of types, returning true if they are isomorphic,
105 /// false if they are not.
106 bool TypeMapTy::areTypesIsomorphic(Type *DstTy, Type *SrcTy) {
107 // Two types with differing kinds are clearly not isomorphic.
108 if (DstTy->getTypeID() != SrcTy->getTypeID())
111 // If we have an entry in the MappedTypes table, then we have our answer.
112 Type *&Entry = MappedTypes[SrcTy];
114 return Entry == DstTy;
116 // Two identical types are clearly isomorphic. Remember this
117 // non-speculatively.
118 if (DstTy == SrcTy) {
123 // Okay, we have two types with identical kinds that we haven't seen before.
125 // If this is an opaque struct type, special case it.
126 if (StructType *SSTy = dyn_cast<StructType>(SrcTy)) {
127 // Mapping an opaque type to any struct, just keep the dest struct.
128 if (SSTy->isOpaque()) {
130 SpeculativeTypes.push_back(SrcTy);
134 // Mapping a non-opaque source type to an opaque dest. If this is the first
135 // type that we're mapping onto this destination type then we succeed. Keep
136 // the dest, but fill it in later. If this is the second (different) type
137 // that we're trying to map onto the same opaque type then we fail.
138 if (cast<StructType>(DstTy)->isOpaque()) {
139 // We can only map one source type onto the opaque destination type.
140 if (!DstResolvedOpaqueTypes.insert(cast<StructType>(DstTy)).second)
142 SrcDefinitionsToResolve.push_back(SSTy);
143 SpeculativeTypes.push_back(SrcTy);
144 SpeculativeDstOpaqueTypes.push_back(cast<StructType>(DstTy));
150 // If the number of subtypes disagree between the two types, then we fail.
151 if (SrcTy->getNumContainedTypes() != DstTy->getNumContainedTypes())
154 // Fail if any of the extra properties (e.g. array size) of the type disagree.
155 if (isa<IntegerType>(DstTy))
156 return false; // bitwidth disagrees.
157 if (PointerType *PT = dyn_cast<PointerType>(DstTy)) {
158 if (PT->getAddressSpace() != cast<PointerType>(SrcTy)->getAddressSpace())
161 } else if (FunctionType *FT = dyn_cast<FunctionType>(DstTy)) {
162 if (FT->isVarArg() != cast<FunctionType>(SrcTy)->isVarArg())
164 } else if (StructType *DSTy = dyn_cast<StructType>(DstTy)) {
165 StructType *SSTy = cast<StructType>(SrcTy);
166 if (DSTy->isLiteral() != SSTy->isLiteral() ||
167 DSTy->isPacked() != SSTy->isPacked())
169 } else if (ArrayType *DATy = dyn_cast<ArrayType>(DstTy)) {
170 if (DATy->getNumElements() != cast<ArrayType>(SrcTy)->getNumElements())
172 } else if (VectorType *DVTy = dyn_cast<VectorType>(DstTy)) {
173 if (DVTy->getNumElements() != cast<VectorType>(SrcTy)->getNumElements())
177 // Otherwise, we speculate that these two types will line up and recursively
178 // check the subelements.
180 SpeculativeTypes.push_back(SrcTy);
182 for (unsigned I = 0, E = SrcTy->getNumContainedTypes(); I != E; ++I)
183 if (!areTypesIsomorphic(DstTy->getContainedType(I),
184 SrcTy->getContainedType(I)))
187 // If everything seems to have lined up, then everything is great.
191 void TypeMapTy::linkDefinedTypeBodies() {
192 SmallVector<Type *, 16> Elements;
193 for (StructType *SrcSTy : SrcDefinitionsToResolve) {
194 StructType *DstSTy = cast<StructType>(MappedTypes[SrcSTy]);
195 assert(DstSTy->isOpaque());
197 // Map the body of the source type over to a new body for the dest type.
198 Elements.resize(SrcSTy->getNumElements());
199 for (unsigned I = 0, E = Elements.size(); I != E; ++I)
200 Elements[I] = get(SrcSTy->getElementType(I));
202 DstSTy->setBody(Elements, SrcSTy->isPacked());
203 DstStructTypesSet.switchToNonOpaque(DstSTy);
205 SrcDefinitionsToResolve.clear();
206 DstResolvedOpaqueTypes.clear();
209 void TypeMapTy::finishType(StructType *DTy, StructType *STy,
210 ArrayRef<Type *> ETypes) {
211 DTy->setBody(ETypes, STy->isPacked());
214 if (STy->hasName()) {
215 SmallString<16> TmpName = STy->getName();
217 DTy->setName(TmpName);
220 DstStructTypesSet.addNonOpaque(DTy);
223 Type *TypeMapTy::get(Type *Ty) {
224 SmallPtrSet<StructType *, 8> Visited;
225 return get(Ty, Visited);
228 Type *TypeMapTy::get(Type *Ty, SmallPtrSet<StructType *, 8> &Visited) {
229 // If we already have an entry for this type, return it.
230 Type **Entry = &MappedTypes[Ty];
234 // These are types that LLVM itself will unique.
235 bool IsUniqued = !isa<StructType>(Ty) || cast<StructType>(Ty)->isLiteral();
239 for (auto &Pair : MappedTypes) {
240 assert(!(Pair.first != Ty && Pair.second == Ty) &&
241 "mapping to a source type");
246 if (!IsUniqued && !Visited.insert(cast<StructType>(Ty)).second) {
247 StructType *DTy = StructType::create(Ty->getContext());
251 // If this is not a recursive type, then just map all of the elements and
252 // then rebuild the type from inside out.
253 SmallVector<Type *, 4> ElementTypes;
255 // If there are no element types to map, then the type is itself. This is
256 // true for the anonymous {} struct, things like 'float', integers, etc.
257 if (Ty->getNumContainedTypes() == 0 && IsUniqued)
260 // Remap all of the elements, keeping track of whether any of them change.
261 bool AnyChange = false;
262 ElementTypes.resize(Ty->getNumContainedTypes());
263 for (unsigned I = 0, E = Ty->getNumContainedTypes(); I != E; ++I) {
264 ElementTypes[I] = get(Ty->getContainedType(I), Visited);
265 AnyChange |= ElementTypes[I] != Ty->getContainedType(I);
268 // If we found our type while recursively processing stuff, just use it.
269 Entry = &MappedTypes[Ty];
271 if (auto *DTy = dyn_cast<StructType>(*Entry)) {
272 if (DTy->isOpaque()) {
273 auto *STy = cast<StructType>(Ty);
274 finishType(DTy, STy, ElementTypes);
280 // If all of the element types mapped directly over and the type is not
281 // a nomed struct, then the type is usable as-is.
282 if (!AnyChange && IsUniqued)
285 // Otherwise, rebuild a modified type.
286 switch (Ty->getTypeID()) {
288 llvm_unreachable("unknown derived type to remap");
289 case Type::ArrayTyID:
290 return *Entry = ArrayType::get(ElementTypes[0],
291 cast<ArrayType>(Ty)->getNumElements());
292 case Type::VectorTyID:
293 return *Entry = VectorType::get(ElementTypes[0],
294 cast<VectorType>(Ty)->getNumElements());
295 case Type::PointerTyID:
296 return *Entry = PointerType::get(ElementTypes[0],
297 cast<PointerType>(Ty)->getAddressSpace());
298 case Type::FunctionTyID:
299 return *Entry = FunctionType::get(ElementTypes[0],
300 makeArrayRef(ElementTypes).slice(1),
301 cast<FunctionType>(Ty)->isVarArg());
302 case Type::StructTyID: {
303 auto *STy = cast<StructType>(Ty);
304 bool IsPacked = STy->isPacked();
306 return *Entry = StructType::get(Ty->getContext(), ElementTypes, IsPacked);
308 // If the type is opaque, we can just use it directly.
309 if (STy->isOpaque()) {
310 DstStructTypesSet.addOpaque(STy);
314 if (StructType *OldT =
315 DstStructTypesSet.findNonOpaque(ElementTypes, IsPacked)) {
317 return *Entry = OldT;
321 DstStructTypesSet.addNonOpaque(STy);
325 StructType *DTy = StructType::create(Ty->getContext());
326 finishType(DTy, STy, ElementTypes);
332 LinkDiagnosticInfo::LinkDiagnosticInfo(DiagnosticSeverity Severity,
334 : DiagnosticInfo(DK_Linker, Severity), Msg(Msg) {}
335 void LinkDiagnosticInfo::print(DiagnosticPrinter &DP) const { DP << Msg; }
337 //===----------------------------------------------------------------------===//
338 // IRLinker implementation.
339 //===----------------------------------------------------------------------===//
344 /// Creates prototypes for functions that are lazily linked on the fly. This
345 /// speeds up linking for modules with many/ lazily linked functions of which
347 class GlobalValueMaterializer final : public ValueMaterializer {
348 IRLinker *TheIRLinker;
351 GlobalValueMaterializer(IRLinker *TheIRLinker) : TheIRLinker(TheIRLinker) {}
352 Value *materializeDeclFor(Value *V) override;
353 void materializeInitFor(GlobalValue *New, GlobalValue *Old) override;
354 Metadata *mapTemporaryMetadata(Metadata *MD) override;
355 void replaceTemporaryMetadata(const Metadata *OrigMD,
356 Metadata *NewMD) override;
357 bool isMetadataNeeded(Metadata *MD) override;
360 class LocalValueMaterializer final : public ValueMaterializer {
361 IRLinker *TheIRLinker;
364 LocalValueMaterializer(IRLinker *TheIRLinker) : TheIRLinker(TheIRLinker) {}
365 Value *materializeDeclFor(Value *V) override;
366 void materializeInitFor(GlobalValue *New, GlobalValue *Old) override;
367 Metadata *mapTemporaryMetadata(Metadata *MD) override;
368 void replaceTemporaryMetadata(const Metadata *OrigMD,
369 Metadata *NewMD) override;
370 bool isMetadataNeeded(Metadata *MD) override;
373 /// This is responsible for keeping track of the state used for moving data
374 /// from SrcM to DstM.
379 std::function<void(GlobalValue &, IRMover::ValueAdder)> AddLazyFor;
382 GlobalValueMaterializer GValMaterializer;
383 LocalValueMaterializer LValMaterializer;
385 /// Mapping of values from what they used to be in Src, to what they are now
386 /// in DstM. ValueToValueMapTy is a ValueMap, which involves some overhead
387 /// due to the use of Value handles which the Linker doesn't actually need,
388 /// but this allows us to reuse the ValueMapper code.
389 ValueToValueMapTy ValueMap;
390 ValueToValueMapTy AliasValueMap;
392 DenseSet<GlobalValue *> ValuesToLink;
393 std::vector<GlobalValue *> Worklist;
395 void maybeAdd(GlobalValue *GV) {
396 if (ValuesToLink.insert(GV).second)
397 Worklist.push_back(GV);
400 /// Set to true when all global value body linking is complete (including
401 /// lazy linking). Used to prevent metadata linking from creating new
403 bool DoneLinkingBodies = false;
405 bool HasError = false;
407 /// Flag indicating that we are just linking metadata (after function
409 bool IsMetadataLinkingPostpass;
411 /// Flags to pass to value mapper invocations.
412 RemapFlags ValueMapperFlags = RF_MoveDistinctMDs;
414 /// Association between metadata values created during bitcode parsing and
415 /// the value id. Used to correlate temporary metadata created during
416 /// function importing with the final metadata parsed during the subsequent
417 /// metadata linking postpass.
418 DenseMap<const Metadata *, unsigned> MetadataToIDs;
420 /// Association between metadata value id and temporary metadata that
421 /// remains unmapped after function importing. Saved during function
422 /// importing and consumed during the metadata linking postpass.
423 DenseMap<unsigned, MDNode *> *ValIDToTempMDMap;
425 /// Set of subprogram metadata that does not need to be linked into the
426 /// destination module, because the functions were not imported directly
427 /// or via an inlined body in an imported function.
428 SmallPtrSet<const Metadata *, 16> UnneededSubprograms;
430 /// Handles cloning of a global values from the source module into
431 /// the destination module, including setting the attributes and visibility.
432 GlobalValue *copyGlobalValueProto(const GlobalValue *SGV, bool ForDefinition);
434 /// Helper method for setting a message and returning an error code.
435 bool emitError(const Twine &Message) {
436 SrcM.getContext().diagnose(LinkDiagnosticInfo(DS_Error, Message));
441 void emitWarning(const Twine &Message) {
442 SrcM.getContext().diagnose(LinkDiagnosticInfo(DS_Warning, Message));
445 /// Check whether we should be linking metadata from the source module.
446 bool shouldLinkMetadata() {
447 // ValIDToTempMDMap will be non-null when we are importing or otherwise want
448 // to link metadata lazily, and then when linking the metadata.
449 // We only want to return true for the former case.
450 return ValIDToTempMDMap == nullptr || IsMetadataLinkingPostpass;
453 /// Given a global in the source module, return the global in the
454 /// destination module that is being linked to, if any.
455 GlobalValue *getLinkedToGlobal(const GlobalValue *SrcGV) {
456 // If the source has no name it can't link. If it has local linkage,
457 // there is no name match-up going on.
458 if (!SrcGV->hasName() || SrcGV->hasLocalLinkage())
461 // Otherwise see if we have a match in the destination module's symtab.
462 GlobalValue *DGV = DstM.getNamedValue(SrcGV->getName());
466 // If we found a global with the same name in the dest module, but it has
467 // internal linkage, we are really not doing any linkage here.
468 if (DGV->hasLocalLinkage())
471 // Otherwise, we do in fact link to the destination global.
475 void computeTypeMapping();
477 Constant *linkAppendingVarProto(GlobalVariable *DstGV,
478 const GlobalVariable *SrcGV);
480 bool shouldLink(GlobalValue *DGV, GlobalValue &SGV);
481 Constant *linkGlobalValueProto(GlobalValue *GV, bool ForAlias);
483 bool linkModuleFlagsMetadata();
485 void linkGlobalInit(GlobalVariable &Dst, GlobalVariable &Src);
486 bool linkFunctionBody(Function &Dst, Function &Src);
487 void linkAliasBody(GlobalAlias &Dst, GlobalAlias &Src);
488 bool linkGlobalValueBody(GlobalValue &Dst, GlobalValue &Src);
490 /// Functions that take care of cloning a specific global value type
491 /// into the destination module.
492 GlobalVariable *copyGlobalVariableProto(const GlobalVariable *SGVar);
493 Function *copyFunctionProto(const Function *SF);
494 GlobalValue *copyGlobalAliasProto(const GlobalAlias *SGA);
496 void linkNamedMDNodes();
498 /// Populate the UnneededSubprograms set with the DISubprogram metadata
499 /// from the source module that we don't need to link into the dest module,
500 /// because the functions were not imported directly or via an inlined body
501 /// in an imported function.
502 void findNeededSubprograms(ValueToValueMapTy &ValueMap);
504 /// The value mapper leaves nulls in the list of subprograms for any
505 /// in the UnneededSubprograms map. Strip those out after metadata linking.
506 void stripNullSubprograms();
509 IRLinker(Module &DstM, IRMover::IdentifiedStructTypeSet &Set, Module &SrcM,
510 ArrayRef<GlobalValue *> ValuesToLink,
511 std::function<void(GlobalValue &, IRMover::ValueAdder)> AddLazyFor,
512 DenseMap<unsigned, MDNode *> *ValIDToTempMDMap = nullptr,
513 bool IsMetadataLinkingPostpass = false)
514 : DstM(DstM), SrcM(SrcM), AddLazyFor(AddLazyFor), TypeMap(Set),
515 GValMaterializer(this), LValMaterializer(this),
516 IsMetadataLinkingPostpass(IsMetadataLinkingPostpass),
517 ValIDToTempMDMap(ValIDToTempMDMap) {
518 for (GlobalValue *GV : ValuesToLink)
521 // If appropriate, tell the value mapper that it can expect to see
522 // temporary metadata.
523 if (!shouldLinkMetadata())
524 ValueMapperFlags = ValueMapperFlags | RF_HaveUnmaterializedMetadata;
528 // In the case where we are not linking metadata, we unset the CanReplace
529 // flag on all temporary metadata in the MetadataToIDs map to ensure
530 // none was replaced while being a map key. Now that we are destructing
531 // the map, set the flag back to true, so that it is replaceable during
533 if (!shouldLinkMetadata()) {
534 for (auto MDI : MetadataToIDs) {
535 Metadata *MD = const_cast<Metadata *>(MDI.first);
536 MDNode *Node = dyn_cast<MDNode>(MD);
537 assert((Node && Node->isTemporary()) &&
538 "Found non-temp metadata in map when not linking metadata");
539 Node->setCanReplace(true);
545 Value *materializeDeclFor(Value *V, bool ForAlias);
546 void materializeInitFor(GlobalValue *New, GlobalValue *Old, bool ForAlias);
548 /// Save the mapping between the given temporary metadata and its metadata
549 /// value id. Used to support metadata linking as a postpass for function
551 Metadata *mapTemporaryMetadata(Metadata *MD);
553 /// Replace any temporary metadata saved for the source metadata's id with
554 /// the new non-temporary metadata. Used when metadata linking as a postpass
555 /// for function importing.
556 void replaceTemporaryMetadata(const Metadata *OrigMD, Metadata *NewMD);
558 /// Indicates whether we need to map the given metadata into the destination
559 /// module. Used to prevent linking of metadata only needed by functions not
560 /// linked into the dest module.
561 bool isMetadataNeeded(Metadata *MD);
565 /// The LLVM SymbolTable class autorenames globals that conflict in the symbol
566 /// table. This is good for all clients except for us. Go through the trouble
567 /// to force this back.
568 static void forceRenaming(GlobalValue *GV, StringRef Name) {
569 // If the global doesn't force its name or if it already has the right name,
570 // there is nothing for us to do.
571 if (GV->hasLocalLinkage() || GV->getName() == Name)
574 Module *M = GV->getParent();
576 // If there is a conflict, rename the conflict.
577 if (GlobalValue *ConflictGV = M->getNamedValue(Name)) {
578 GV->takeName(ConflictGV);
579 ConflictGV->setName(Name); // This will cause ConflictGV to get renamed
580 assert(ConflictGV->getName() != Name && "forceRenaming didn't work");
582 GV->setName(Name); // Force the name back
586 Value *GlobalValueMaterializer::materializeDeclFor(Value *V) {
587 return TheIRLinker->materializeDeclFor(V, false);
590 void GlobalValueMaterializer::materializeInitFor(GlobalValue *New,
592 TheIRLinker->materializeInitFor(New, Old, false);
595 Metadata *GlobalValueMaterializer::mapTemporaryMetadata(Metadata *MD) {
596 return TheIRLinker->mapTemporaryMetadata(MD);
599 void GlobalValueMaterializer::replaceTemporaryMetadata(const Metadata *OrigMD,
601 TheIRLinker->replaceTemporaryMetadata(OrigMD, NewMD);
604 bool GlobalValueMaterializer::isMetadataNeeded(Metadata *MD) {
605 return TheIRLinker->isMetadataNeeded(MD);
608 Value *LocalValueMaterializer::materializeDeclFor(Value *V) {
609 return TheIRLinker->materializeDeclFor(V, true);
612 void LocalValueMaterializer::materializeInitFor(GlobalValue *New,
614 TheIRLinker->materializeInitFor(New, Old, true);
617 Metadata *LocalValueMaterializer::mapTemporaryMetadata(Metadata *MD) {
618 return TheIRLinker->mapTemporaryMetadata(MD);
621 void LocalValueMaterializer::replaceTemporaryMetadata(const Metadata *OrigMD,
623 TheIRLinker->replaceTemporaryMetadata(OrigMD, NewMD);
626 bool LocalValueMaterializer::isMetadataNeeded(Metadata *MD) {
627 return TheIRLinker->isMetadataNeeded(MD);
630 Value *IRLinker::materializeDeclFor(Value *V, bool ForAlias) {
631 auto *SGV = dyn_cast<GlobalValue>(V);
635 return linkGlobalValueProto(SGV, ForAlias);
638 void IRLinker::materializeInitFor(GlobalValue *New, GlobalValue *Old,
640 // If we already created the body, just return.
641 if (auto *F = dyn_cast<Function>(New)) {
642 if (!F->isDeclaration())
644 } else if (auto *V = dyn_cast<GlobalVariable>(New)) {
645 if (V->hasInitializer())
648 auto *A = cast<GlobalAlias>(New);
653 if (ForAlias || shouldLink(New, *Old))
654 linkGlobalValueBody(*New, *Old);
657 Metadata *IRLinker::mapTemporaryMetadata(Metadata *MD) {
658 if (!ValIDToTempMDMap)
660 // If this temporary metadata has a value id recorded during function
661 // parsing, record that in the ValIDToTempMDMap if one was provided.
662 if (MetadataToIDs.count(MD)) {
663 unsigned Idx = MetadataToIDs[MD];
664 // Check if we created a temp MD when importing a different function from
665 // this module. If so, reuse it the same temporary metadata, otherwise
666 // add this temporary metadata to the map.
667 if (!ValIDToTempMDMap->count(Idx)) {
668 MDNode *Node = cast<MDNode>(MD);
669 assert(Node->isTemporary());
670 (*ValIDToTempMDMap)[Idx] = Node;
672 return (*ValIDToTempMDMap)[Idx];
677 void IRLinker::replaceTemporaryMetadata(const Metadata *OrigMD,
679 if (!ValIDToTempMDMap)
682 auto *N = dyn_cast_or_null<MDNode>(NewMD);
683 assert(!N || !N->isTemporary());
685 // If a mapping between metadata value ids and temporary metadata
686 // created during function importing was provided, and the source
687 // metadata has a value id recorded during metadata parsing, replace
688 // the temporary metadata with the final mapped metadata now.
689 if (MetadataToIDs.count(OrigMD)) {
690 unsigned Idx = MetadataToIDs[OrigMD];
691 // Nothing to do if we didn't need to create a temporary metadata during
692 // function importing.
693 if (!ValIDToTempMDMap->count(Idx))
695 MDNode *TempMD = (*ValIDToTempMDMap)[Idx];
696 TempMD->replaceAllUsesWith(NewMD);
697 MDNode::deleteTemporary(TempMD);
698 ValIDToTempMDMap->erase(Idx);
702 bool IRLinker::isMetadataNeeded(Metadata *MD) {
703 // Currently only DISubprogram metadata is marked as being unneeded.
704 if (UnneededSubprograms.empty())
706 MDNode *Node = dyn_cast<MDNode>(MD);
709 DISubprogram *SP = getDISubprogram(Node);
712 return !UnneededSubprograms.count(SP);
715 /// Loop through the global variables in the src module and merge them into the
717 GlobalVariable *IRLinker::copyGlobalVariableProto(const GlobalVariable *SGVar) {
718 // No linking to be performed or linking from the source: simply create an
719 // identical version of the symbol over in the dest module... the
720 // initializer will be filled in later by LinkGlobalInits.
721 GlobalVariable *NewDGV =
722 new GlobalVariable(DstM, TypeMap.get(SGVar->getType()->getElementType()),
723 SGVar->isConstant(), GlobalValue::ExternalLinkage,
724 /*init*/ nullptr, SGVar->getName(),
725 /*insertbefore*/ nullptr, SGVar->getThreadLocalMode(),
726 SGVar->getType()->getAddressSpace());
727 NewDGV->setAlignment(SGVar->getAlignment());
731 /// Link the function in the source module into the destination module if
732 /// needed, setting up mapping information.
733 Function *IRLinker::copyFunctionProto(const Function *SF) {
734 // If there is no linkage to be performed or we are linking from the source,
736 return Function::Create(TypeMap.get(SF->getFunctionType()),
737 GlobalValue::ExternalLinkage, SF->getName(), &DstM);
740 /// Set up prototypes for any aliases that come over from the source module.
741 GlobalValue *IRLinker::copyGlobalAliasProto(const GlobalAlias *SGA) {
742 // If there is no linkage to be performed or we're linking from the source,
744 auto *Ty = TypeMap.get(SGA->getValueType());
745 return GlobalAlias::create(Ty, SGA->getType()->getPointerAddressSpace(),
746 GlobalValue::ExternalLinkage, SGA->getName(),
750 GlobalValue *IRLinker::copyGlobalValueProto(const GlobalValue *SGV,
751 bool ForDefinition) {
753 if (auto *SGVar = dyn_cast<GlobalVariable>(SGV)) {
754 NewGV = copyGlobalVariableProto(SGVar);
755 } else if (auto *SF = dyn_cast<Function>(SGV)) {
756 NewGV = copyFunctionProto(SF);
759 NewGV = copyGlobalAliasProto(cast<GlobalAlias>(SGV));
761 NewGV = new GlobalVariable(
762 DstM, TypeMap.get(SGV->getType()->getElementType()),
763 /*isConstant*/ false, GlobalValue::ExternalLinkage,
764 /*init*/ nullptr, SGV->getName(),
765 /*insertbefore*/ nullptr, SGV->getThreadLocalMode(),
766 SGV->getType()->getAddressSpace());
770 NewGV->setLinkage(SGV->getLinkage());
771 else if (SGV->hasExternalWeakLinkage() || SGV->hasWeakLinkage() ||
772 SGV->hasLinkOnceLinkage())
773 NewGV->setLinkage(GlobalValue::ExternalWeakLinkage);
775 NewGV->copyAttributesFrom(SGV);
779 /// Loop over all of the linked values to compute type mappings. For example,
780 /// if we link "extern Foo *x" and "Foo *x = NULL", then we have two struct
781 /// types 'Foo' but one got renamed when the module was loaded into the same
783 void IRLinker::computeTypeMapping() {
784 for (GlobalValue &SGV : SrcM.globals()) {
785 GlobalValue *DGV = getLinkedToGlobal(&SGV);
789 if (!DGV->hasAppendingLinkage() || !SGV.hasAppendingLinkage()) {
790 TypeMap.addTypeMapping(DGV->getType(), SGV.getType());
794 // Unify the element type of appending arrays.
795 ArrayType *DAT = cast<ArrayType>(DGV->getType()->getElementType());
796 ArrayType *SAT = cast<ArrayType>(SGV.getType()->getElementType());
797 TypeMap.addTypeMapping(DAT->getElementType(), SAT->getElementType());
800 for (GlobalValue &SGV : SrcM)
801 if (GlobalValue *DGV = getLinkedToGlobal(&SGV))
802 TypeMap.addTypeMapping(DGV->getType(), SGV.getType());
804 for (GlobalValue &SGV : SrcM.aliases())
805 if (GlobalValue *DGV = getLinkedToGlobal(&SGV))
806 TypeMap.addTypeMapping(DGV->getType(), SGV.getType());
808 // Incorporate types by name, scanning all the types in the source module.
809 // At this point, the destination module may have a type "%foo = { i32 }" for
810 // example. When the source module got loaded into the same LLVMContext, if
811 // it had the same type, it would have been renamed to "%foo.42 = { i32 }".
812 std::vector<StructType *> Types = SrcM.getIdentifiedStructTypes();
813 for (StructType *ST : Types) {
817 // Check to see if there is a dot in the name followed by a digit.
818 size_t DotPos = ST->getName().rfind('.');
819 if (DotPos == 0 || DotPos == StringRef::npos ||
820 ST->getName().back() == '.' ||
821 !isdigit(static_cast<unsigned char>(ST->getName()[DotPos + 1])))
824 // Check to see if the destination module has a struct with the prefix name.
825 StructType *DST = DstM.getTypeByName(ST->getName().substr(0, DotPos));
829 // Don't use it if this actually came from the source module. They're in
830 // the same LLVMContext after all. Also don't use it unless the type is
831 // actually used in the destination module. This can happen in situations
836 // %Z = type { %A } %B = type { %C.1 }
837 // %A = type { %B.1, [7 x i8] } %C.1 = type { i8* }
838 // %B.1 = type { %C } %A.2 = type { %B.3, [5 x i8] }
839 // %C = type { i8* } %B.3 = type { %C.1 }
841 // When we link Module B with Module A, the '%B' in Module B is
842 // used. However, that would then use '%C.1'. But when we process '%C.1',
843 // we prefer to take the '%C' version. So we are then left with both
844 // '%C.1' and '%C' being used for the same types. This leads to some
845 // variables using one type and some using the other.
846 if (TypeMap.DstStructTypesSet.hasType(DST))
847 TypeMap.addTypeMapping(DST, ST);
850 // Now that we have discovered all of the type equivalences, get a body for
851 // any 'opaque' types in the dest module that are now resolved.
852 TypeMap.linkDefinedTypeBodies();
855 static void getArrayElements(const Constant *C,
856 SmallVectorImpl<Constant *> &Dest) {
857 unsigned NumElements = cast<ArrayType>(C->getType())->getNumElements();
859 for (unsigned i = 0; i != NumElements; ++i)
860 Dest.push_back(C->getAggregateElement(i));
863 /// If there were any appending global variables, link them together now.
864 /// Return true on error.
865 Constant *IRLinker::linkAppendingVarProto(GlobalVariable *DstGV,
866 const GlobalVariable *SrcGV) {
867 Type *EltTy = cast<ArrayType>(TypeMap.get(SrcGV->getType()->getElementType()))
870 StringRef Name = SrcGV->getName();
871 bool IsNewStructor = false;
872 bool IsOldStructor = false;
873 if (Name == "llvm.global_ctors" || Name == "llvm.global_dtors") {
874 if (cast<StructType>(EltTy)->getNumElements() == 3)
875 IsNewStructor = true;
877 IsOldStructor = true;
880 PointerType *VoidPtrTy = Type::getInt8Ty(SrcGV->getContext())->getPointerTo();
882 auto &ST = *cast<StructType>(EltTy);
883 Type *Tys[3] = {ST.getElementType(0), ST.getElementType(1), VoidPtrTy};
884 EltTy = StructType::get(SrcGV->getContext(), Tys, false);
888 ArrayType *DstTy = cast<ArrayType>(DstGV->getType()->getElementType());
890 if (!SrcGV->hasAppendingLinkage() || !DstGV->hasAppendingLinkage()) {
892 "Linking globals named '" + SrcGV->getName() +
893 "': can only link appending global with another appending global!");
897 // Check to see that they two arrays agree on type.
898 if (EltTy != DstTy->getElementType()) {
899 emitError("Appending variables with different element types!");
902 if (DstGV->isConstant() != SrcGV->isConstant()) {
903 emitError("Appending variables linked with different const'ness!");
907 if (DstGV->getAlignment() != SrcGV->getAlignment()) {
909 "Appending variables with different alignment need to be linked!");
913 if (DstGV->getVisibility() != SrcGV->getVisibility()) {
915 "Appending variables with different visibility need to be linked!");
919 if (DstGV->hasUnnamedAddr() != SrcGV->hasUnnamedAddr()) {
921 "Appending variables with different unnamed_addr need to be linked!");
925 if (StringRef(DstGV->getSection()) != SrcGV->getSection()) {
927 "Appending variables with different section name need to be linked!");
932 SmallVector<Constant *, 16> DstElements;
934 getArrayElements(DstGV->getInitializer(), DstElements);
936 SmallVector<Constant *, 16> SrcElements;
937 getArrayElements(SrcGV->getInitializer(), SrcElements);
941 std::remove_if(SrcElements.begin(), SrcElements.end(),
942 [this](Constant *E) {
943 auto *Key = dyn_cast<GlobalValue>(
944 E->getAggregateElement(2)->stripPointerCasts());
947 GlobalValue *DGV = getLinkedToGlobal(Key);
948 return !shouldLink(DGV, *Key);
951 uint64_t NewSize = DstElements.size() + SrcElements.size();
952 ArrayType *NewType = ArrayType::get(EltTy, NewSize);
954 // Create the new global variable.
955 GlobalVariable *NG = new GlobalVariable(
956 DstM, NewType, SrcGV->isConstant(), SrcGV->getLinkage(),
957 /*init*/ nullptr, /*name*/ "", DstGV, SrcGV->getThreadLocalMode(),
958 SrcGV->getType()->getAddressSpace());
960 NG->copyAttributesFrom(SrcGV);
961 forceRenaming(NG, SrcGV->getName());
963 Constant *Ret = ConstantExpr::getBitCast(NG, TypeMap.get(SrcGV->getType()));
966 ValueMap[SrcGV] = Ret;
968 for (auto *V : SrcElements) {
971 auto *S = cast<ConstantStruct>(V);
972 auto *E1 = MapValue(S->getOperand(0), ValueMap, ValueMapperFlags,
973 &TypeMap, &GValMaterializer);
974 auto *E2 = MapValue(S->getOperand(1), ValueMap, ValueMapperFlags,
975 &TypeMap, &GValMaterializer);
976 Value *Null = Constant::getNullValue(VoidPtrTy);
978 ConstantStruct::get(cast<StructType>(EltTy), E1, E2, Null, nullptr);
981 MapValue(V, ValueMap, ValueMapperFlags, &TypeMap, &GValMaterializer);
983 DstElements.push_back(NewV);
986 NG->setInitializer(ConstantArray::get(NewType, DstElements));
988 // Replace any uses of the two global variables with uses of the new
991 DstGV->replaceAllUsesWith(ConstantExpr::getBitCast(NG, DstGV->getType()));
992 DstGV->eraseFromParent();
998 static bool useExistingDest(GlobalValue &SGV, GlobalValue *DGV,
1003 if (SGV.isDeclaration())
1006 if (DGV->isDeclarationForLinker() && !SGV.isDeclarationForLinker())
1015 bool IRLinker::shouldLink(GlobalValue *DGV, GlobalValue &SGV) {
1016 // Already imported all the values. Just map to the Dest value
1017 // in case it is referenced in the metadata.
1018 if (IsMetadataLinkingPostpass) {
1019 assert(!ValuesToLink.count(&SGV) &&
1020 "Source value unexpectedly requested for link during metadata link");
1024 if (ValuesToLink.count(&SGV))
1027 if (SGV.hasLocalLinkage())
1030 if (DGV && !DGV->isDeclaration())
1033 if (SGV.hasAvailableExternallyLinkage())
1036 if (DoneLinkingBodies)
1039 AddLazyFor(SGV, [this](GlobalValue &GV) { maybeAdd(&GV); });
1040 return ValuesToLink.count(&SGV);
1043 Constant *IRLinker::linkGlobalValueProto(GlobalValue *SGV, bool ForAlias) {
1044 GlobalValue *DGV = getLinkedToGlobal(SGV);
1046 bool ShouldLink = shouldLink(DGV, *SGV);
1048 // just missing from map
1050 auto I = ValueMap.find(SGV);
1051 if (I != ValueMap.end())
1052 return cast<Constant>(I->second);
1054 I = AliasValueMap.find(SGV);
1055 if (I != AliasValueMap.end())
1056 return cast<Constant>(I->second);
1060 if (ShouldLink || !ForAlias)
1061 DGV = getLinkedToGlobal(SGV);
1063 // Handle the ultra special appending linkage case first.
1064 assert(!DGV || SGV->hasAppendingLinkage() == DGV->hasAppendingLinkage());
1065 if (SGV->hasAppendingLinkage())
1066 return linkAppendingVarProto(cast_or_null<GlobalVariable>(DGV),
1067 cast<GlobalVariable>(SGV));
1070 if (useExistingDest(*SGV, DGV, ShouldLink)) {
1073 // If we are done linking global value bodies (i.e. we are performing
1074 // metadata linking), don't link in the global value due to this
1075 // reference, simply map it to null.
1076 if (DoneLinkingBodies)
1079 NewGV = copyGlobalValueProto(SGV, ShouldLink);
1081 forceRenaming(NewGV, SGV->getName());
1083 if (ShouldLink || ForAlias) {
1084 if (const Comdat *SC = SGV->getComdat()) {
1085 if (auto *GO = dyn_cast<GlobalObject>(NewGV)) {
1086 Comdat *DC = DstM.getOrInsertComdat(SC->getName());
1087 DC->setSelectionKind(SC->getSelectionKind());
1093 if (!ShouldLink && ForAlias)
1094 NewGV->setLinkage(GlobalValue::InternalLinkage);
1096 Constant *C = NewGV;
1098 C = ConstantExpr::getBitCast(NewGV, TypeMap.get(SGV->getType()));
1100 if (DGV && NewGV != DGV) {
1101 DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewGV, DGV->getType()));
1102 DGV->eraseFromParent();
1108 /// Update the initializers in the Dest module now that all globals that may be
1109 /// referenced are in Dest.
1110 void IRLinker::linkGlobalInit(GlobalVariable &Dst, GlobalVariable &Src) {
1111 // Figure out what the initializer looks like in the dest module.
1112 Dst.setInitializer(MapValue(Src.getInitializer(), ValueMap, ValueMapperFlags,
1113 &TypeMap, &GValMaterializer));
1116 /// Copy the source function over into the dest function and fix up references
1117 /// to values. At this point we know that Dest is an external function, and
1118 /// that Src is not.
1119 bool IRLinker::linkFunctionBody(Function &Dst, Function &Src) {
1120 assert(Dst.isDeclaration() && !Src.isDeclaration());
1122 // Materialize if needed.
1123 if (std::error_code EC = Src.materialize())
1124 return emitError(EC.message());
1126 if (!shouldLinkMetadata())
1127 // This is only supported for lazy links. Do after materialization of
1128 // a function and before remapping metadata on instructions below
1129 // in RemapInstruction, as the saved mapping is used to handle
1130 // the temporary metadata hanging off instructions.
1131 SrcM.getMaterializer()->saveMetadataList(MetadataToIDs, true);
1133 // Link in the prefix data.
1134 if (Src.hasPrefixData())
1135 Dst.setPrefixData(MapValue(Src.getPrefixData(), ValueMap, ValueMapperFlags,
1136 &TypeMap, &GValMaterializer));
1138 // Link in the prologue data.
1139 if (Src.hasPrologueData())
1140 Dst.setPrologueData(MapValue(Src.getPrologueData(), ValueMap,
1141 ValueMapperFlags, &TypeMap,
1142 &GValMaterializer));
1144 // Link in the personality function.
1145 if (Src.hasPersonalityFn())
1146 Dst.setPersonalityFn(MapValue(Src.getPersonalityFn(), ValueMap,
1147 ValueMapperFlags, &TypeMap,
1148 &GValMaterializer));
1150 // Go through and convert function arguments over, remembering the mapping.
1151 Function::arg_iterator DI = Dst.arg_begin();
1152 for (Argument &Arg : Src.args()) {
1153 DI->setName(Arg.getName()); // Copy the name over.
1155 // Add a mapping to our mapping.
1156 ValueMap[&Arg] = &*DI;
1160 // Copy over the metadata attachments.
1161 SmallVector<std::pair<unsigned, MDNode *>, 8> MDs;
1162 Src.getAllMetadata(MDs);
1163 for (const auto &I : MDs)
1164 Dst.setMetadata(I.first, MapMetadata(I.second, ValueMap, ValueMapperFlags,
1165 &TypeMap, &GValMaterializer));
1167 // Splice the body of the source function into the dest function.
1168 Dst.getBasicBlockList().splice(Dst.end(), Src.getBasicBlockList());
1170 // At this point, all of the instructions and values of the function are now
1171 // copied over. The only problem is that they are still referencing values in
1172 // the Source function as operands. Loop through all of the operands of the
1173 // functions and patch them up to point to the local versions.
1174 for (BasicBlock &BB : Dst)
1175 for (Instruction &I : BB)
1176 RemapInstruction(&I, ValueMap, RF_IgnoreMissingEntries | ValueMapperFlags,
1177 &TypeMap, &GValMaterializer);
1179 // There is no need to map the arguments anymore.
1180 for (Argument &Arg : Src.args())
1181 ValueMap.erase(&Arg);
1186 void IRLinker::linkAliasBody(GlobalAlias &Dst, GlobalAlias &Src) {
1187 Constant *Aliasee = Src.getAliasee();
1188 Constant *Val = MapValue(Aliasee, AliasValueMap, ValueMapperFlags, &TypeMap,
1190 Dst.setAliasee(Val);
1193 bool IRLinker::linkGlobalValueBody(GlobalValue &Dst, GlobalValue &Src) {
1194 if (auto *F = dyn_cast<Function>(&Src))
1195 return linkFunctionBody(cast<Function>(Dst), *F);
1196 if (auto *GVar = dyn_cast<GlobalVariable>(&Src)) {
1197 linkGlobalInit(cast<GlobalVariable>(Dst), *GVar);
1200 linkAliasBody(cast<GlobalAlias>(Dst), cast<GlobalAlias>(Src));
1204 void IRLinker::findNeededSubprograms(ValueToValueMapTy &ValueMap) {
1205 // Track unneeded nodes to make it simpler to handle the case
1206 // where we are checking if an already-mapped SP is needed.
1207 NamedMDNode *CompileUnits = SrcM.getNamedMetadata("llvm.dbg.cu");
1210 for (unsigned I = 0, E = CompileUnits->getNumOperands(); I != E; ++I) {
1211 auto *CU = cast<DICompileUnit>(CompileUnits->getOperand(I));
1212 assert(CU && "Expected valid compile unit");
1213 for (auto *Op : CU->getSubprograms()) {
1214 // Unless we were doing function importing and deferred metadata linking,
1215 // any needed SPs should have been mapped as they would be reached
1216 // from the function linked in (either on the function itself for linked
1217 // function bodies, or from DILocation on inlined instructions).
1218 assert(!(ValueMap.MD()[Op] && IsMetadataLinkingPostpass) &&
1219 "DISubprogram shouldn't be mapped yet");
1220 if (!ValueMap.MD()[Op])
1221 UnneededSubprograms.insert(Op);
1224 if (!IsMetadataLinkingPostpass)
1226 // In the case of metadata linking as a postpass (e.g. for function
1227 // importing), see which DISubprogram MD from the source has an associated
1228 // temporary metadata node, which means the SP was needed by an imported
1230 for (auto MDI : MetadataToIDs) {
1231 const MDNode *Node = dyn_cast<MDNode>(MDI.first);
1234 DISubprogram *SP = getDISubprogram(Node);
1235 if (!SP || !ValIDToTempMDMap->count(MDI.second))
1237 UnneededSubprograms.erase(SP);
1241 // Squash null subprograms from compile unit subprogram lists.
1242 void IRLinker::stripNullSubprograms() {
1243 NamedMDNode *CompileUnits = DstM.getNamedMetadata("llvm.dbg.cu");
1246 for (unsigned I = 0, E = CompileUnits->getNumOperands(); I != E; ++I) {
1247 auto *CU = cast<DICompileUnit>(CompileUnits->getOperand(I));
1248 assert(CU && "Expected valid compile unit");
1250 SmallVector<Metadata *, 16> NewSPs;
1251 NewSPs.reserve(CU->getSubprograms().size());
1252 bool FoundNull = false;
1253 for (DISubprogram *SP : CU->getSubprograms()) {
1258 NewSPs.push_back(SP);
1261 CU->replaceSubprograms(MDTuple::get(CU->getContext(), NewSPs));
1265 /// Insert all of the named MDNodes in Src into the Dest module.
1266 void IRLinker::linkNamedMDNodes() {
1267 findNeededSubprograms(ValueMap);
1268 const NamedMDNode *SrcModFlags = SrcM.getModuleFlagsMetadata();
1269 for (const NamedMDNode &NMD : SrcM.named_metadata()) {
1270 // Don't link module flags here. Do them separately.
1271 if (&NMD == SrcModFlags)
1273 NamedMDNode *DestNMD = DstM.getOrInsertNamedMetadata(NMD.getName());
1274 // Add Src elements into Dest node.
1275 for (const MDNode *op : NMD.operands())
1276 DestNMD->addOperand(MapMetadata(
1277 op, ValueMap, ValueMapperFlags | RF_NullMapMissingGlobalValues,
1278 &TypeMap, &GValMaterializer));
1280 stripNullSubprograms();
1283 /// Merge the linker flags in Src into the Dest module.
1284 bool IRLinker::linkModuleFlagsMetadata() {
1285 // If the source module has no module flags, we are done.
1286 const NamedMDNode *SrcModFlags = SrcM.getModuleFlagsMetadata();
1290 // If the destination module doesn't have module flags yet, then just copy
1291 // over the source module's flags.
1292 NamedMDNode *DstModFlags = DstM.getOrInsertModuleFlagsMetadata();
1293 if (DstModFlags->getNumOperands() == 0) {
1294 for (unsigned I = 0, E = SrcModFlags->getNumOperands(); I != E; ++I)
1295 DstModFlags->addOperand(SrcModFlags->getOperand(I));
1300 // First build a map of the existing module flags and requirements.
1301 DenseMap<MDString *, std::pair<MDNode *, unsigned>> Flags;
1302 SmallSetVector<MDNode *, 16> Requirements;
1303 for (unsigned I = 0, E = DstModFlags->getNumOperands(); I != E; ++I) {
1304 MDNode *Op = DstModFlags->getOperand(I);
1305 ConstantInt *Behavior = mdconst::extract<ConstantInt>(Op->getOperand(0));
1306 MDString *ID = cast<MDString>(Op->getOperand(1));
1308 if (Behavior->getZExtValue() == Module::Require) {
1309 Requirements.insert(cast<MDNode>(Op->getOperand(2)));
1311 Flags[ID] = std::make_pair(Op, I);
1315 // Merge in the flags from the source module, and also collect its set of
1317 for (unsigned I = 0, E = SrcModFlags->getNumOperands(); I != E; ++I) {
1318 MDNode *SrcOp = SrcModFlags->getOperand(I);
1319 ConstantInt *SrcBehavior =
1320 mdconst::extract<ConstantInt>(SrcOp->getOperand(0));
1321 MDString *ID = cast<MDString>(SrcOp->getOperand(1));
1324 std::tie(DstOp, DstIndex) = Flags.lookup(ID);
1325 unsigned SrcBehaviorValue = SrcBehavior->getZExtValue();
1327 // If this is a requirement, add it and continue.
1328 if (SrcBehaviorValue == Module::Require) {
1329 // If the destination module does not already have this requirement, add
1331 if (Requirements.insert(cast<MDNode>(SrcOp->getOperand(2)))) {
1332 DstModFlags->addOperand(SrcOp);
1337 // If there is no existing flag with this ID, just add it.
1339 Flags[ID] = std::make_pair(SrcOp, DstModFlags->getNumOperands());
1340 DstModFlags->addOperand(SrcOp);
1344 // Otherwise, perform a merge.
1345 ConstantInt *DstBehavior =
1346 mdconst::extract<ConstantInt>(DstOp->getOperand(0));
1347 unsigned DstBehaviorValue = DstBehavior->getZExtValue();
1349 // If either flag has override behavior, handle it first.
1350 if (DstBehaviorValue == Module::Override) {
1351 // Diagnose inconsistent flags which both have override behavior.
1352 if (SrcBehaviorValue == Module::Override &&
1353 SrcOp->getOperand(2) != DstOp->getOperand(2)) {
1354 emitError("linking module flags '" + ID->getString() +
1355 "': IDs have conflicting override values");
1358 } else if (SrcBehaviorValue == Module::Override) {
1359 // Update the destination flag to that of the source.
1360 DstModFlags->setOperand(DstIndex, SrcOp);
1361 Flags[ID].first = SrcOp;
1365 // Diagnose inconsistent merge behavior types.
1366 if (SrcBehaviorValue != DstBehaviorValue) {
1367 emitError("linking module flags '" + ID->getString() +
1368 "': IDs have conflicting behaviors");
1372 auto replaceDstValue = [&](MDNode *New) {
1373 Metadata *FlagOps[] = {DstOp->getOperand(0), ID, New};
1374 MDNode *Flag = MDNode::get(DstM.getContext(), FlagOps);
1375 DstModFlags->setOperand(DstIndex, Flag);
1376 Flags[ID].first = Flag;
1379 // Perform the merge for standard behavior types.
1380 switch (SrcBehaviorValue) {
1381 case Module::Require:
1382 case Module::Override:
1383 llvm_unreachable("not possible");
1384 case Module::Error: {
1385 // Emit an error if the values differ.
1386 if (SrcOp->getOperand(2) != DstOp->getOperand(2)) {
1387 emitError("linking module flags '" + ID->getString() +
1388 "': IDs have conflicting values");
1392 case Module::Warning: {
1393 // Emit a warning if the values differ.
1394 if (SrcOp->getOperand(2) != DstOp->getOperand(2)) {
1395 emitWarning("linking module flags '" + ID->getString() +
1396 "': IDs have conflicting values");
1400 case Module::Append: {
1401 MDNode *DstValue = cast<MDNode>(DstOp->getOperand(2));
1402 MDNode *SrcValue = cast<MDNode>(SrcOp->getOperand(2));
1403 SmallVector<Metadata *, 8> MDs;
1404 MDs.reserve(DstValue->getNumOperands() + SrcValue->getNumOperands());
1405 MDs.append(DstValue->op_begin(), DstValue->op_end());
1406 MDs.append(SrcValue->op_begin(), SrcValue->op_end());
1408 replaceDstValue(MDNode::get(DstM.getContext(), MDs));
1411 case Module::AppendUnique: {
1412 SmallSetVector<Metadata *, 16> Elts;
1413 MDNode *DstValue = cast<MDNode>(DstOp->getOperand(2));
1414 MDNode *SrcValue = cast<MDNode>(SrcOp->getOperand(2));
1415 Elts.insert(DstValue->op_begin(), DstValue->op_end());
1416 Elts.insert(SrcValue->op_begin(), SrcValue->op_end());
1418 replaceDstValue(MDNode::get(DstM.getContext(),
1419 makeArrayRef(Elts.begin(), Elts.end())));
1425 // Check all of the requirements.
1426 for (unsigned I = 0, E = Requirements.size(); I != E; ++I) {
1427 MDNode *Requirement = Requirements[I];
1428 MDString *Flag = cast<MDString>(Requirement->getOperand(0));
1429 Metadata *ReqValue = Requirement->getOperand(1);
1431 MDNode *Op = Flags[Flag].first;
1432 if (!Op || Op->getOperand(2) != ReqValue) {
1433 emitError("linking module flags '" + Flag->getString() +
1434 "': does not have the required value");
1442 // This function returns true if the triples match.
1443 static bool triplesMatch(const Triple &T0, const Triple &T1) {
1444 // If vendor is apple, ignore the version number.
1445 if (T0.getVendor() == Triple::Apple)
1446 return T0.getArch() == T1.getArch() && T0.getSubArch() == T1.getSubArch() &&
1447 T0.getVendor() == T1.getVendor() && T0.getOS() == T1.getOS();
1452 // This function returns the merged triple.
1453 static std::string mergeTriples(const Triple &SrcTriple,
1454 const Triple &DstTriple) {
1455 // If vendor is apple, pick the triple with the larger version number.
1456 if (SrcTriple.getVendor() == Triple::Apple)
1457 if (DstTriple.isOSVersionLT(SrcTriple))
1458 return SrcTriple.str();
1460 return DstTriple.str();
1463 bool IRLinker::run() {
1464 // Inherit the target data from the source module if the destination module
1465 // doesn't have one already.
1466 if (DstM.getDataLayout().isDefault())
1467 DstM.setDataLayout(SrcM.getDataLayout());
1469 if (SrcM.getDataLayout() != DstM.getDataLayout()) {
1470 emitWarning("Linking two modules of different data layouts: '" +
1471 SrcM.getModuleIdentifier() + "' is '" +
1472 SrcM.getDataLayoutStr() + "' whereas '" +
1473 DstM.getModuleIdentifier() + "' is '" +
1474 DstM.getDataLayoutStr() + "'\n");
1477 // Copy the target triple from the source to dest if the dest's is empty.
1478 if (DstM.getTargetTriple().empty() && !SrcM.getTargetTriple().empty())
1479 DstM.setTargetTriple(SrcM.getTargetTriple());
1481 Triple SrcTriple(SrcM.getTargetTriple()), DstTriple(DstM.getTargetTriple());
1483 if (!SrcM.getTargetTriple().empty() && !triplesMatch(SrcTriple, DstTriple))
1484 emitWarning("Linking two modules of different target triples: " +
1485 SrcM.getModuleIdentifier() + "' is '" + SrcM.getTargetTriple() +
1486 "' whereas '" + DstM.getModuleIdentifier() + "' is '" +
1487 DstM.getTargetTriple() + "'\n");
1489 DstM.setTargetTriple(mergeTriples(SrcTriple, DstTriple));
1491 // Append the module inline asm string.
1492 if (!SrcM.getModuleInlineAsm().empty()) {
1493 if (DstM.getModuleInlineAsm().empty())
1494 DstM.setModuleInlineAsm(SrcM.getModuleInlineAsm());
1496 DstM.setModuleInlineAsm(DstM.getModuleInlineAsm() + "\n" +
1497 SrcM.getModuleInlineAsm());
1500 // Loop over all of the linked values to compute type mappings.
1501 computeTypeMapping();
1503 std::reverse(Worklist.begin(), Worklist.end());
1504 while (!Worklist.empty()) {
1505 GlobalValue *GV = Worklist.back();
1506 Worklist.pop_back();
1509 if (ValueMap.find(GV) != ValueMap.end() ||
1510 AliasValueMap.find(GV) != AliasValueMap.end())
1513 assert(!GV->isDeclaration());
1514 MapValue(GV, ValueMap, ValueMapperFlags, &TypeMap, &GValMaterializer);
1519 // Note that we are done linking global value bodies. This prevents
1520 // metadata linking from creating new references.
1521 DoneLinkingBodies = true;
1523 // Remap all of the named MDNodes in Src into the DstM module. We do this
1524 // after linking GlobalValues so that MDNodes that reference GlobalValues
1525 // are properly remapped.
1526 if (shouldLinkMetadata()) {
1527 // Even if just linking metadata we should link decls above in case
1528 // any are referenced by metadata. IRLinker::shouldLink ensures that
1529 // we don't actually link anything from source.
1530 if (IsMetadataLinkingPostpass) {
1531 // Ensure metadata materialized
1532 if (SrcM.getMaterializer()->materializeMetadata())
1534 SrcM.getMaterializer()->saveMetadataList(MetadataToIDs, false);
1539 if (IsMetadataLinkingPostpass) {
1540 // Handle anything left in the ValIDToTempMDMap, such as metadata nodes
1541 // not reached by the dbg.cu NamedMD (i.e. only reached from
1543 // Walk the MetadataToIDs once to find the set of new (imported) MD
1544 // that still has corresponding temporary metadata, and invoke metadata
1545 // mapping on each one.
1546 for (auto MDI : MetadataToIDs) {
1547 if (!ValIDToTempMDMap->count(MDI.second))
1549 MapMetadata(MDI.first, ValueMap, ValueMapperFlags, &TypeMap,
1552 assert(ValIDToTempMDMap->empty());
1555 // Merge the module flags into the DstM module.
1556 if (linkModuleFlagsMetadata())
1563 IRMover::StructTypeKeyInfo::KeyTy::KeyTy(ArrayRef<Type *> E, bool P)
1564 : ETypes(E), IsPacked(P) {}
1566 IRMover::StructTypeKeyInfo::KeyTy::KeyTy(const StructType *ST)
1567 : ETypes(ST->elements()), IsPacked(ST->isPacked()) {}
1569 bool IRMover::StructTypeKeyInfo::KeyTy::operator==(const KeyTy &That) const {
1570 if (IsPacked != That.IsPacked)
1572 if (ETypes != That.ETypes)
1577 bool IRMover::StructTypeKeyInfo::KeyTy::operator!=(const KeyTy &That) const {
1578 return !this->operator==(That);
1581 StructType *IRMover::StructTypeKeyInfo::getEmptyKey() {
1582 return DenseMapInfo<StructType *>::getEmptyKey();
1585 StructType *IRMover::StructTypeKeyInfo::getTombstoneKey() {
1586 return DenseMapInfo<StructType *>::getTombstoneKey();
1589 unsigned IRMover::StructTypeKeyInfo::getHashValue(const KeyTy &Key) {
1590 return hash_combine(hash_combine_range(Key.ETypes.begin(), Key.ETypes.end()),
1594 unsigned IRMover::StructTypeKeyInfo::getHashValue(const StructType *ST) {
1595 return getHashValue(KeyTy(ST));
1598 bool IRMover::StructTypeKeyInfo::isEqual(const KeyTy &LHS,
1599 const StructType *RHS) {
1600 if (RHS == getEmptyKey() || RHS == getTombstoneKey())
1602 return LHS == KeyTy(RHS);
1605 bool IRMover::StructTypeKeyInfo::isEqual(const StructType *LHS,
1606 const StructType *RHS) {
1607 if (RHS == getEmptyKey())
1608 return LHS == getEmptyKey();
1610 if (RHS == getTombstoneKey())
1611 return LHS == getTombstoneKey();
1613 return KeyTy(LHS) == KeyTy(RHS);
1616 void IRMover::IdentifiedStructTypeSet::addNonOpaque(StructType *Ty) {
1617 assert(!Ty->isOpaque());
1618 NonOpaqueStructTypes.insert(Ty);
1621 void IRMover::IdentifiedStructTypeSet::switchToNonOpaque(StructType *Ty) {
1622 assert(!Ty->isOpaque());
1623 NonOpaqueStructTypes.insert(Ty);
1624 bool Removed = OpaqueStructTypes.erase(Ty);
1629 void IRMover::IdentifiedStructTypeSet::addOpaque(StructType *Ty) {
1630 assert(Ty->isOpaque());
1631 OpaqueStructTypes.insert(Ty);
1635 IRMover::IdentifiedStructTypeSet::findNonOpaque(ArrayRef<Type *> ETypes,
1637 IRMover::StructTypeKeyInfo::KeyTy Key(ETypes, IsPacked);
1638 auto I = NonOpaqueStructTypes.find_as(Key);
1639 if (I == NonOpaqueStructTypes.end())
1644 bool IRMover::IdentifiedStructTypeSet::hasType(StructType *Ty) {
1646 return OpaqueStructTypes.count(Ty);
1647 auto I = NonOpaqueStructTypes.find(Ty);
1648 if (I == NonOpaqueStructTypes.end())
1653 IRMover::IRMover(Module &M) : Composite(M) {
1654 TypeFinder StructTypes;
1655 StructTypes.run(M, true);
1656 for (StructType *Ty : StructTypes) {
1658 IdentifiedStructTypes.addOpaque(Ty);
1660 IdentifiedStructTypes.addNonOpaque(Ty);
1665 Module &Src, ArrayRef<GlobalValue *> ValuesToLink,
1666 std::function<void(GlobalValue &, ValueAdder Add)> AddLazyFor,
1667 DenseMap<unsigned, MDNode *> *ValIDToTempMDMap,
1668 bool IsMetadataLinkingPostpass) {
1669 IRLinker TheIRLinker(Composite, IdentifiedStructTypes, Src, ValuesToLink,
1670 AddLazyFor, ValIDToTempMDMap, IsMetadataLinkingPostpass);
1671 bool RetCode = TheIRLinker.run();
1672 Composite.dropTriviallyDeadConstantArrays();