| //===- lib/Linker/LinkModules.cpp - Module Linker Implementation ----------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements the LLVM module linker. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/Linker/Linker.h" |
| #include "llvm-c/Linker.h" |
| #include "llvm/ADT/Hashing.h" |
| #include "llvm/ADT/Optional.h" |
| #include "llvm/ADT/SetVector.h" |
| #include "llvm/ADT/SmallString.h" |
| #include "llvm/ADT/Statistic.h" |
| #include "llvm/IR/Constants.h" |
| #include "llvm/IR/DebugInfo.h" |
| #include "llvm/IR/DiagnosticInfo.h" |
| #include "llvm/IR/DiagnosticPrinter.h" |
| #include "llvm/IR/LLVMContext.h" |
| #include "llvm/IR/Module.h" |
| #include "llvm/IR/TypeFinder.h" |
| #include "llvm/Support/CommandLine.h" |
| #include "llvm/Support/Debug.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include "llvm/Transforms/Utils/Cloning.h" |
| #include <cctype> |
| #include <tuple> |
| using namespace llvm; |
| |
| |
| //===----------------------------------------------------------------------===// |
| // TypeMap implementation. |
| //===----------------------------------------------------------------------===// |
| |
| namespace { |
| class TypeMapTy : public ValueMapTypeRemapper { |
| /// This is a mapping from a source type to a destination type to use. |
| DenseMap<Type*, Type*> MappedTypes; |
| |
| /// When checking to see if two subgraphs are isomorphic, we speculatively |
| /// add types to MappedTypes, but keep track of them here in case we need to |
| /// roll back. |
| SmallVector<Type*, 16> SpeculativeTypes; |
| |
| SmallVector<StructType*, 16> SpeculativeDstOpaqueTypes; |
| |
| /// This is a list of non-opaque structs in the source module that are mapped |
| /// to an opaque struct in the destination module. |
| SmallVector<StructType*, 16> SrcDefinitionsToResolve; |
| |
| /// This is the set of opaque types in the destination modules who are |
| /// getting a body from the source module. |
| SmallPtrSet<StructType*, 16> DstResolvedOpaqueTypes; |
| |
| public: |
| TypeMapTy(Linker::IdentifiedStructTypeSet &DstStructTypesSet) |
| : DstStructTypesSet(DstStructTypesSet) {} |
| |
| Linker::IdentifiedStructTypeSet &DstStructTypesSet; |
| /// Indicate that the specified type in the destination module is conceptually |
| /// equivalent to the specified type in the source module. |
| void addTypeMapping(Type *DstTy, Type *SrcTy); |
| |
| /// Produce a body for an opaque type in the dest module from a type |
| /// definition in the source module. |
| void linkDefinedTypeBodies(); |
| |
| /// Return the mapped type to use for the specified input type from the |
| /// source module. |
| Type *get(Type *SrcTy); |
| Type *get(Type *SrcTy, SmallPtrSet<StructType *, 8> &Visited); |
| |
| void finishType(StructType *DTy, StructType *STy, ArrayRef<Type *> ETypes); |
| |
| FunctionType *get(FunctionType *T) { |
| return cast<FunctionType>(get((Type *)T)); |
| } |
| |
| /// Dump out the type map for debugging purposes. |
| void dump() const { |
| for (auto &Pair : MappedTypes) { |
| dbgs() << "TypeMap: "; |
| Pair.first->print(dbgs()); |
| dbgs() << " => "; |
| Pair.second->print(dbgs()); |
| dbgs() << '\n'; |
| } |
| } |
| |
| private: |
| Type *remapType(Type *SrcTy) override { return get(SrcTy); } |
| |
| bool areTypesIsomorphic(Type *DstTy, Type *SrcTy); |
| }; |
| } |
| |
| void TypeMapTy::addTypeMapping(Type *DstTy, Type *SrcTy) { |
| assert(SpeculativeTypes.empty()); |
| assert(SpeculativeDstOpaqueTypes.empty()); |
| |
| // Check to see if these types are recursively isomorphic and establish a |
| // mapping between them if so. |
| if (!areTypesIsomorphic(DstTy, SrcTy)) { |
| // Oops, they aren't isomorphic. Just discard this request by rolling out |
| // any speculative mappings we've established. |
| for (Type *Ty : SpeculativeTypes) |
| MappedTypes.erase(Ty); |
| |
| SrcDefinitionsToResolve.resize(SrcDefinitionsToResolve.size() - |
| SpeculativeDstOpaqueTypes.size()); |
| for (StructType *Ty : SpeculativeDstOpaqueTypes) |
| DstResolvedOpaqueTypes.erase(Ty); |
| } else { |
| for (Type *Ty : SpeculativeTypes) |
| if (auto *STy = dyn_cast<StructType>(Ty)) |
| if (STy->hasName()) |
| STy->setName(""); |
| } |
| SpeculativeTypes.clear(); |
| SpeculativeDstOpaqueTypes.clear(); |
| } |
| |
| /// Recursively walk this pair of types, returning true if they are isomorphic, |
| /// false if they are not. |
| bool TypeMapTy::areTypesIsomorphic(Type *DstTy, Type *SrcTy) { |
| // Two types with differing kinds are clearly not isomorphic. |
| if (DstTy->getTypeID() != SrcTy->getTypeID()) |
| return false; |
| |
| // If we have an entry in the MappedTypes table, then we have our answer. |
| Type *&Entry = MappedTypes[SrcTy]; |
| if (Entry) |
| return Entry == DstTy; |
| |
| // Two identical types are clearly isomorphic. Remember this |
| // non-speculatively. |
| if (DstTy == SrcTy) { |
| Entry = DstTy; |
| return true; |
| } |
| |
| // Okay, we have two types with identical kinds that we haven't seen before. |
| |
| // If this is an opaque struct type, special case it. |
| if (StructType *SSTy = dyn_cast<StructType>(SrcTy)) { |
| // Mapping an opaque type to any struct, just keep the dest struct. |
| if (SSTy->isOpaque()) { |
| Entry = DstTy; |
| SpeculativeTypes.push_back(SrcTy); |
| return true; |
| } |
| |
| // Mapping a non-opaque source type to an opaque dest. If this is the first |
| // type that we're mapping onto this destination type then we succeed. Keep |
| // the dest, but fill it in later. If this is the second (different) type |
| // that we're trying to map onto the same opaque type then we fail. |
| if (cast<StructType>(DstTy)->isOpaque()) { |
| // We can only map one source type onto the opaque destination type. |
| if (!DstResolvedOpaqueTypes.insert(cast<StructType>(DstTy)).second) |
| return false; |
| SrcDefinitionsToResolve.push_back(SSTy); |
| SpeculativeTypes.push_back(SrcTy); |
| SpeculativeDstOpaqueTypes.push_back(cast<StructType>(DstTy)); |
| Entry = DstTy; |
| return true; |
| } |
| } |
| |
| // If the number of subtypes disagree between the two types, then we fail. |
| if (SrcTy->getNumContainedTypes() != DstTy->getNumContainedTypes()) |
| return false; |
| |
| // Fail if any of the extra properties (e.g. array size) of the type disagree. |
| if (isa<IntegerType>(DstTy)) |
| return false; // bitwidth disagrees. |
| if (PointerType *PT = dyn_cast<PointerType>(DstTy)) { |
| if (PT->getAddressSpace() != cast<PointerType>(SrcTy)->getAddressSpace()) |
| return false; |
| |
| } else if (FunctionType *FT = dyn_cast<FunctionType>(DstTy)) { |
| if (FT->isVarArg() != cast<FunctionType>(SrcTy)->isVarArg()) |
| return false; |
| } else if (StructType *DSTy = dyn_cast<StructType>(DstTy)) { |
| StructType *SSTy = cast<StructType>(SrcTy); |
| if (DSTy->isLiteral() != SSTy->isLiteral() || |
| DSTy->isPacked() != SSTy->isPacked()) |
| return false; |
| } else if (ArrayType *DATy = dyn_cast<ArrayType>(DstTy)) { |
| if (DATy->getNumElements() != cast<ArrayType>(SrcTy)->getNumElements()) |
| return false; |
| } else if (VectorType *DVTy = dyn_cast<VectorType>(DstTy)) { |
| if (DVTy->getNumElements() != cast<VectorType>(SrcTy)->getNumElements()) |
| return false; |
| } |
| |
| // Otherwise, we speculate that these two types will line up and recursively |
| // check the subelements. |
| Entry = DstTy; |
| SpeculativeTypes.push_back(SrcTy); |
| |
| for (unsigned I = 0, E = SrcTy->getNumContainedTypes(); I != E; ++I) |
| if (!areTypesIsomorphic(DstTy->getContainedType(I), |
| SrcTy->getContainedType(I))) |
| return false; |
| |
| // If everything seems to have lined up, then everything is great. |
| return true; |
| } |
| |
| void TypeMapTy::linkDefinedTypeBodies() { |
| SmallVector<Type*, 16> Elements; |
| for (StructType *SrcSTy : SrcDefinitionsToResolve) { |
| StructType *DstSTy = cast<StructType>(MappedTypes[SrcSTy]); |
| assert(DstSTy->isOpaque()); |
| |
| // Map the body of the source type over to a new body for the dest type. |
| Elements.resize(SrcSTy->getNumElements()); |
| for (unsigned I = 0, E = Elements.size(); I != E; ++I) |
| Elements[I] = get(SrcSTy->getElementType(I)); |
| |
| DstSTy->setBody(Elements, SrcSTy->isPacked()); |
| } |
| SrcDefinitionsToResolve.clear(); |
| DstResolvedOpaqueTypes.clear(); |
| } |
| |
| void TypeMapTy::finishType(StructType *DTy, StructType *STy, |
| ArrayRef<Type *> ETypes) { |
| DTy->setBody(ETypes, STy->isPacked()); |
| |
| // Steal STy's name. |
| if (STy->hasName()) { |
| SmallString<16> TmpName = STy->getName(); |
| STy->setName(""); |
| DTy->setName(TmpName); |
| } |
| |
| DstStructTypesSet.addNonOpaque(DTy); |
| } |
| |
| Type *TypeMapTy::get(Type *Ty) { |
| SmallPtrSet<StructType *, 8> Visited; |
| return get(Ty, Visited); |
| } |
| |
| Type *TypeMapTy::get(Type *Ty, SmallPtrSet<StructType *, 8> &Visited) { |
| // If we already have an entry for this type, return it. |
| Type **Entry = &MappedTypes[Ty]; |
| if (*Entry) |
| return *Entry; |
| |
| // These are types that LLVM itself will unique. |
| bool IsUniqued = !isa<StructType>(Ty) || cast<StructType>(Ty)->isLiteral(); |
| |
| #ifndef NDEBUG |
| if (!IsUniqued) { |
| for (auto &Pair : MappedTypes) { |
| assert(!(Pair.first != Ty && Pair.second == Ty) && |
| "mapping to a source type"); |
| } |
| } |
| #endif |
| |
| if (!IsUniqued && !Visited.insert(cast<StructType>(Ty)).second) { |
| StructType *DTy = StructType::create(Ty->getContext()); |
| return *Entry = DTy; |
| } |
| |
| // If this is not a recursive type, then just map all of the elements and |
| // then rebuild the type from inside out. |
| SmallVector<Type *, 4> ElementTypes; |
| |
| // If there are no element types to map, then the type is itself. This is |
| // true for the anonymous {} struct, things like 'float', integers, etc. |
| if (Ty->getNumContainedTypes() == 0 && IsUniqued) |
| return *Entry = Ty; |
| |
| // Remap all of the elements, keeping track of whether any of them change. |
| bool AnyChange = false; |
| ElementTypes.resize(Ty->getNumContainedTypes()); |
| for (unsigned I = 0, E = Ty->getNumContainedTypes(); I != E; ++I) { |
| ElementTypes[I] = get(Ty->getContainedType(I), Visited); |
| AnyChange |= ElementTypes[I] != Ty->getContainedType(I); |
| } |
| |
| // If we found our type while recursively processing stuff, just use it. |
| Entry = &MappedTypes[Ty]; |
| if (*Entry) { |
| if (auto *DTy = dyn_cast<StructType>(*Entry)) { |
| if (DTy->isOpaque()) { |
| auto *STy = cast<StructType>(Ty); |
| finishType(DTy, STy, ElementTypes); |
| } |
| } |
| return *Entry; |
| } |
| |
| // If all of the element types mapped directly over and the type is not |
| // a nomed struct, then the type is usable as-is. |
| if (!AnyChange && IsUniqued) |
| return *Entry = Ty; |
| |
| // Otherwise, rebuild a modified type. |
| switch (Ty->getTypeID()) { |
| default: |
| llvm_unreachable("unknown derived type to remap"); |
| case Type::ArrayTyID: |
| return *Entry = ArrayType::get(ElementTypes[0], |
| cast<ArrayType>(Ty)->getNumElements()); |
| case Type::VectorTyID: |
| return *Entry = VectorType::get(ElementTypes[0], |
| cast<VectorType>(Ty)->getNumElements()); |
| case Type::PointerTyID: |
| return *Entry = PointerType::get(ElementTypes[0], |
| cast<PointerType>(Ty)->getAddressSpace()); |
| case Type::FunctionTyID: |
| return *Entry = FunctionType::get(ElementTypes[0], |
| makeArrayRef(ElementTypes).slice(1), |
| cast<FunctionType>(Ty)->isVarArg()); |
| case Type::StructTyID: { |
| auto *STy = cast<StructType>(Ty); |
| bool IsPacked = STy->isPacked(); |
| if (IsUniqued) |
| return *Entry = StructType::get(Ty->getContext(), ElementTypes, IsPacked); |
| |
| // If the type is opaque, we can just use it directly. |
| if (STy->isOpaque()) { |
| DstStructTypesSet.addOpaque(STy); |
| return *Entry = Ty; |
| } |
| |
| if (StructType *OldT = |
| DstStructTypesSet.findNonOpaque(ElementTypes, IsPacked)) { |
| STy->setName(""); |
| return *Entry = OldT; |
| } |
| |
| if (!AnyChange) { |
| DstStructTypesSet.addNonOpaque(STy); |
| return *Entry = Ty; |
| } |
| |
| StructType *DTy = StructType::create(Ty->getContext()); |
| finishType(DTy, STy, ElementTypes); |
| return *Entry = DTy; |
| } |
| } |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // ModuleLinker implementation. |
| //===----------------------------------------------------------------------===// |
| |
| namespace { |
| class ModuleLinker; |
| |
| /// Creates prototypes for functions that are lazily linked on the fly. This |
| /// speeds up linking for modules with many/ lazily linked functions of which |
| /// few get used. |
| class ValueMaterializerTy : public ValueMaterializer { |
| TypeMapTy &TypeMap; |
| Module *DstM; |
| std::vector<GlobalValue *> &LazilyLinkGlobalValues; |
| |
| public: |
| ValueMaterializerTy(TypeMapTy &TypeMap, Module *DstM, |
| std::vector<GlobalValue *> &LazilyLinkGlobalValues) |
| : ValueMaterializer(), TypeMap(TypeMap), DstM(DstM), |
| LazilyLinkGlobalValues(LazilyLinkGlobalValues) {} |
| |
| Value *materializeValueFor(Value *V) override; |
| }; |
| |
| class LinkDiagnosticInfo : public DiagnosticInfo { |
| const Twine &Msg; |
| |
| public: |
| LinkDiagnosticInfo(DiagnosticSeverity Severity, const Twine &Msg); |
| void print(DiagnosticPrinter &DP) const override; |
| }; |
| LinkDiagnosticInfo::LinkDiagnosticInfo(DiagnosticSeverity Severity, |
| const Twine &Msg) |
| : DiagnosticInfo(DK_Linker, Severity), Msg(Msg) {} |
| void LinkDiagnosticInfo::print(DiagnosticPrinter &DP) const { DP << Msg; } |
| |
| /// This is an implementation class for the LinkModules function, which is the |
| /// entrypoint for this file. |
| class ModuleLinker { |
| Module *DstM, *SrcM; |
| |
| TypeMapTy TypeMap; |
| ValueMaterializerTy ValMaterializer; |
| |
| /// Mapping of values from what they used to be in Src, to what they are now |
| /// in DstM. ValueToValueMapTy is a ValueMap, which involves some overhead |
| /// due to the use of Value handles which the Linker doesn't actually need, |
| /// but this allows us to reuse the ValueMapper code. |
| ValueToValueMapTy ValueMap; |
| |
| struct AppendingVarInfo { |
| GlobalVariable *NewGV; // New aggregate global in dest module. |
| const Constant *DstInit; // Old initializer from dest module. |
| const Constant *SrcInit; // Old initializer from src module. |
| }; |
| |
| std::vector<AppendingVarInfo> AppendingVars; |
| |
| // Set of items not to link in from source. |
| SmallPtrSet<const Value *, 16> DoNotLinkFromSource; |
| |
| // Vector of GlobalValues to lazily link in. |
| std::vector<GlobalValue *> LazilyLinkGlobalValues; |
| |
| /// Functions that have replaced other functions. |
| SmallPtrSet<const Function *, 16> OverridingFunctions; |
| |
| DiagnosticHandlerFunction DiagnosticHandler; |
| |
| public: |
| ModuleLinker(Module *dstM, Linker::IdentifiedStructTypeSet &Set, Module *srcM, |
| DiagnosticHandlerFunction DiagnosticHandler) |
| : DstM(dstM), SrcM(srcM), TypeMap(Set), |
| ValMaterializer(TypeMap, DstM, LazilyLinkGlobalValues), |
| DiagnosticHandler(DiagnosticHandler) {} |
| |
| bool run(); |
| |
| private: |
| bool shouldLinkFromSource(bool &LinkFromSrc, const GlobalValue &Dest, |
| const GlobalValue &Src); |
| |
| /// Helper method for setting a message and returning an error code. |
| bool emitError(const Twine &Message) { |
| DiagnosticHandler(LinkDiagnosticInfo(DS_Error, Message)); |
| return true; |
| } |
| |
| void emitWarning(const Twine &Message) { |
| DiagnosticHandler(LinkDiagnosticInfo(DS_Warning, Message)); |
| } |
| |
| bool getComdatLeader(Module *M, StringRef ComdatName, |
| const GlobalVariable *&GVar); |
| bool computeResultingSelectionKind(StringRef ComdatName, |
| Comdat::SelectionKind Src, |
| Comdat::SelectionKind Dst, |
| Comdat::SelectionKind &Result, |
| bool &LinkFromSrc); |
| std::map<const Comdat *, std::pair<Comdat::SelectionKind, bool>> |
| ComdatsChosen; |
| bool getComdatResult(const Comdat *SrcC, Comdat::SelectionKind &SK, |
| bool &LinkFromSrc); |
| |
| /// Given a global in the source module, return the global in the |
| /// destination module that is being linked to, if any. |
| GlobalValue *getLinkedToGlobal(const GlobalValue *SrcGV) { |
| // If the source has no name it can't link. If it has local linkage, |
| // there is no name match-up going on. |
| if (!SrcGV->hasName() || SrcGV->hasLocalLinkage()) |
| return nullptr; |
| |
| // Otherwise see if we have a match in the destination module's symtab. |
| GlobalValue *DGV = DstM->getNamedValue(SrcGV->getName()); |
| if (!DGV) |
| return nullptr; |
| |
| // If we found a global with the same name in the dest module, but it has |
| // internal linkage, we are really not doing any linkage here. |
| if (DGV->hasLocalLinkage()) |
| return nullptr; |
| |
| // Otherwise, we do in fact link to the destination global. |
| return DGV; |
| } |
| |
| void computeTypeMapping(); |
| |
| void upgradeMismatchedGlobalArray(StringRef Name); |
| void upgradeMismatchedGlobals(); |
| |
| bool linkAppendingVarProto(GlobalVariable *DstGV, |
| const GlobalVariable *SrcGV); |
| |
| bool linkGlobalValueProto(GlobalValue *GV); |
| bool linkModuleFlagsMetadata(); |
| |
| void linkAppendingVarInit(const AppendingVarInfo &AVI); |
| |
| void linkGlobalInit(GlobalVariable &Dst, GlobalVariable &Src); |
| bool linkFunctionBody(Function &Dst, Function &Src); |
| void linkAliasBody(GlobalAlias &Dst, GlobalAlias &Src); |
| bool linkGlobalValueBody(GlobalValue &Src); |
| |
| void linkNamedMDNodes(); |
| void stripReplacedSubprograms(); |
| }; |
| } |
| |
| /// The LLVM SymbolTable class autorenames globals that conflict in the symbol |
| /// table. This is good for all clients except for us. Go through the trouble |
| /// to force this back. |
| static void forceRenaming(GlobalValue *GV, StringRef Name) { |
| // If the global doesn't force its name or if it already has the right name, |
| // there is nothing for us to do. |
| if (GV->hasLocalLinkage() || GV->getName() == Name) |
| return; |
| |
| Module *M = GV->getParent(); |
| |
| // If there is a conflict, rename the conflict. |
| if (GlobalValue *ConflictGV = M->getNamedValue(Name)) { |
| GV->takeName(ConflictGV); |
| ConflictGV->setName(Name); // This will cause ConflictGV to get renamed |
| assert(ConflictGV->getName() != Name && "forceRenaming didn't work"); |
| } else { |
| GV->setName(Name); // Force the name back |
| } |
| } |
| |
| /// copy additional attributes (those not needed to construct a GlobalValue) |
| /// from the SrcGV to the DestGV. |
| static void copyGVAttributes(GlobalValue *DestGV, const GlobalValue *SrcGV) { |
| DestGV->copyAttributesFrom(SrcGV); |
| forceRenaming(DestGV, SrcGV->getName()); |
| } |
| |
| static bool isLessConstraining(GlobalValue::VisibilityTypes a, |
| GlobalValue::VisibilityTypes b) { |
| if (a == GlobalValue::HiddenVisibility) |
| return false; |
| if (b == GlobalValue::HiddenVisibility) |
| return true; |
| if (a == GlobalValue::ProtectedVisibility) |
| return false; |
| if (b == GlobalValue::ProtectedVisibility) |
| return true; |
| return false; |
| } |
| |
| /// Loop through the global variables in the src module and merge them into the |
| /// dest module. |
| static GlobalVariable *copyGlobalVariableProto(TypeMapTy &TypeMap, Module &DstM, |
| const GlobalVariable *SGVar) { |
| // No linking to be performed or linking from the source: simply create an |
| // identical version of the symbol over in the dest module... the |
| // initializer will be filled in later by LinkGlobalInits. |
| GlobalVariable *NewDGV = new GlobalVariable( |
| DstM, TypeMap.get(SGVar->getType()->getElementType()), |
| SGVar->isConstant(), SGVar->getLinkage(), /*init*/ nullptr, |
| SGVar->getName(), /*insertbefore*/ nullptr, SGVar->getThreadLocalMode(), |
| SGVar->getType()->getAddressSpace()); |
| |
| return NewDGV; |
| } |
| |
| /// Link the function in the source module into the destination module if |
| /// needed, setting up mapping information. |
| static Function *copyFunctionProto(TypeMapTy &TypeMap, Module &DstM, |
| const Function *SF) { |
| // If there is no linkage to be performed or we are linking from the source, |
| // bring SF over. |
| return Function::Create(TypeMap.get(SF->getFunctionType()), SF->getLinkage(), |
| SF->getName(), &DstM); |
| } |
| |
| /// Set up prototypes for any aliases that come over from the source module. |
| static GlobalAlias *copyGlobalAliasProto(TypeMapTy &TypeMap, Module &DstM, |
| const GlobalAlias *SGA) { |
| // If there is no linkage to be performed or we're linking from the source, |
| // bring over SGA. |
| auto *PTy = cast<PointerType>(TypeMap.get(SGA->getType())); |
| return GlobalAlias::create(PTy->getElementType(), PTy->getAddressSpace(), |
| SGA->getLinkage(), SGA->getName(), &DstM); |
| } |
| |
| static GlobalValue *copyGlobalValueProto(TypeMapTy &TypeMap, Module &DstM, |
| const GlobalValue *SGV) { |
| GlobalValue *NewGV; |
| if (auto *SGVar = dyn_cast<GlobalVariable>(SGV)) |
| NewGV = copyGlobalVariableProto(TypeMap, DstM, SGVar); |
| else if (auto *SF = dyn_cast<Function>(SGV)) |
| NewGV = copyFunctionProto(TypeMap, DstM, SF); |
| else |
| NewGV = copyGlobalAliasProto(TypeMap, DstM, cast<GlobalAlias>(SGV)); |
| copyGVAttributes(NewGV, SGV); |
| return NewGV; |
| } |
| |
| Value *ValueMaterializerTy::materializeValueFor(Value *V) { |
| auto *SGV = dyn_cast<GlobalValue>(V); |
| if (!SGV) |
| return nullptr; |
| |
| GlobalValue *DGV = copyGlobalValueProto(TypeMap, *DstM, SGV); |
| |
| if (Comdat *SC = SGV->getComdat()) { |
| if (auto *DGO = dyn_cast<GlobalObject>(DGV)) { |
| Comdat *DC = DstM->getOrInsertComdat(SC->getName()); |
| DGO->setComdat(DC); |
| } |
| } |
| |
| LazilyLinkGlobalValues.push_back(SGV); |
| return DGV; |
| } |
| |
| bool ModuleLinker::getComdatLeader(Module *M, StringRef ComdatName, |
| const GlobalVariable *&GVar) { |
| const GlobalValue *GVal = M->getNamedValue(ComdatName); |
| if (const auto *GA = dyn_cast_or_null<GlobalAlias>(GVal)) { |
| GVal = GA->getBaseObject(); |
| if (!GVal) |
| // We cannot resolve the size of the aliasee yet. |
| return emitError("Linking COMDATs named '" + ComdatName + |
| "': COMDAT key involves incomputable alias size."); |
| } |
| |
| GVar = dyn_cast_or_null<GlobalVariable>(GVal); |
| if (!GVar) |
| return emitError( |
| "Linking COMDATs named '" + ComdatName + |
| "': GlobalVariable required for data dependent selection!"); |
| |
| return false; |
| } |
| |
| bool ModuleLinker::computeResultingSelectionKind(StringRef ComdatName, |
| Comdat::SelectionKind Src, |
| Comdat::SelectionKind Dst, |
| Comdat::SelectionKind &Result, |
| bool &LinkFromSrc) { |
| // The ability to mix Comdat::SelectionKind::Any with |
| // Comdat::SelectionKind::Largest is a behavior that comes from COFF. |
| bool DstAnyOrLargest = Dst == Comdat::SelectionKind::Any || |
| Dst == Comdat::SelectionKind::Largest; |
| bool SrcAnyOrLargest = Src == Comdat::SelectionKind::Any || |
| Src == Comdat::SelectionKind::Largest; |
| if (DstAnyOrLargest && SrcAnyOrLargest) { |
| if (Dst == Comdat::SelectionKind::Largest || |
| Src == Comdat::SelectionKind::Largest) |
| Result = Comdat::SelectionKind::Largest; |
| else |
| Result = Comdat::SelectionKind::Any; |
| } else if (Src == Dst) { |
| Result = Dst; |
| } else { |
| return emitError("Linking COMDATs named '" + ComdatName + |
| "': invalid selection kinds!"); |
| } |
| |
| switch (Result) { |
| case Comdat::SelectionKind::Any: |
| // Go with Dst. |
| LinkFromSrc = false; |
| break; |
| case Comdat::SelectionKind::NoDuplicates: |
| return emitError("Linking COMDATs named '" + ComdatName + |
| "': noduplicates has been violated!"); |
| case Comdat::SelectionKind::ExactMatch: |
| case Comdat::SelectionKind::Largest: |
| case Comdat::SelectionKind::SameSize: { |
| const GlobalVariable *DstGV; |
| const GlobalVariable *SrcGV; |
| if (getComdatLeader(DstM, ComdatName, DstGV) || |
| getComdatLeader(SrcM, ComdatName, SrcGV)) |
| return true; |
| |
| const DataLayout *DstDL = DstM->getDataLayout(); |
| const DataLayout *SrcDL = SrcM->getDataLayout(); |
| if (!DstDL || !SrcDL) { |
| return emitError( |
| "Linking COMDATs named '" + ComdatName + |
| "': can't do size dependent selection without DataLayout!"); |
| } |
| uint64_t DstSize = |
| DstDL->getTypeAllocSize(DstGV->getType()->getPointerElementType()); |
| uint64_t SrcSize = |
| SrcDL->getTypeAllocSize(SrcGV->getType()->getPointerElementType()); |
| if (Result == Comdat::SelectionKind::ExactMatch) { |
| if (SrcGV->getInitializer() != DstGV->getInitializer()) |
| return emitError("Linking COMDATs named '" + ComdatName + |
| "': ExactMatch violated!"); |
| LinkFromSrc = false; |
| } else if (Result == Comdat::SelectionKind::Largest) { |
| LinkFromSrc = SrcSize > DstSize; |
| } else if (Result == Comdat::SelectionKind::SameSize) { |
| if (SrcSize != DstSize) |
| return emitError("Linking COMDATs named '" + ComdatName + |
| "': SameSize violated!"); |
| LinkFromSrc = false; |
| } else { |
| llvm_unreachable("unknown selection kind"); |
| } |
| break; |
| } |
| } |
| |
| return false; |
| } |
| |
| bool ModuleLinker::getComdatResult(const Comdat *SrcC, |
| Comdat::SelectionKind &Result, |
| bool &LinkFromSrc) { |
| Comdat::SelectionKind SSK = SrcC->getSelectionKind(); |
| StringRef ComdatName = SrcC->getName(); |
| Module::ComdatSymTabType &ComdatSymTab = DstM->getComdatSymbolTable(); |
| Module::ComdatSymTabType::iterator DstCI = ComdatSymTab.find(ComdatName); |
| |
| if (DstCI == ComdatSymTab.end()) { |
| // Use the comdat if it is only available in one of the modules. |
| LinkFromSrc = true; |
| Result = SSK; |
| return false; |
| } |
| |
| const Comdat *DstC = &DstCI->second; |
| Comdat::SelectionKind DSK = DstC->getSelectionKind(); |
| return computeResultingSelectionKind(ComdatName, SSK, DSK, Result, |
| LinkFromSrc); |
| } |
| |
| bool ModuleLinker::shouldLinkFromSource(bool &LinkFromSrc, |
| const GlobalValue &Dest, |
| const GlobalValue &Src) { |
| // We always have to add Src if it has appending linkage. |
| if (Src.hasAppendingLinkage()) { |
| LinkFromSrc = true; |
| return false; |
| } |
| |
| bool SrcIsDeclaration = Src.isDeclarationForLinker(); |
| bool DestIsDeclaration = Dest.isDeclarationForLinker(); |
| |
| if (SrcIsDeclaration) { |
| // If Src is external or if both Src & Dest are external.. Just link the |
| // external globals, we aren't adding anything. |
| if (Src.hasDLLImportStorageClass()) { |
| // If one of GVs is marked as DLLImport, result should be dllimport'ed. |
| LinkFromSrc = DestIsDeclaration; |
| return false; |
| } |
| // If the Dest is weak, use the source linkage. |
| LinkFromSrc = Dest.hasExternalWeakLinkage(); |
| return false; |
| } |
| |
| if (DestIsDeclaration) { |
| // If Dest is external but Src is not: |
| LinkFromSrc = true; |
| return false; |
| } |
| |
| if (Src.hasCommonLinkage()) { |
| if (Dest.hasLinkOnceLinkage() || Dest.hasWeakLinkage()) { |
| LinkFromSrc = true; |
| return false; |
| } |
| |
| if (!Dest.hasCommonLinkage()) { |
| LinkFromSrc = false; |
| return false; |
| } |
| |
| // FIXME: Make datalayout mandatory and just use getDataLayout(). |
| DataLayout DL(Dest.getParent()); |
| |
| uint64_t DestSize = DL.getTypeAllocSize(Dest.getType()->getElementType()); |
| uint64_t SrcSize = DL.getTypeAllocSize(Src.getType()->getElementType()); |
| LinkFromSrc = SrcSize > DestSize; |
| return false; |
| } |
| |
| if (Src.isWeakForLinker()) { |
| assert(!Dest.hasExternalWeakLinkage()); |
| assert(!Dest.hasAvailableExternallyLinkage()); |
| |
| if (Dest.hasLinkOnceLinkage() && Src.hasWeakLinkage()) { |
| LinkFromSrc = true; |
| return false; |
| } |
| |
| LinkFromSrc = false; |
| return false; |
| } |
| |
| if (Dest.isWeakForLinker()) { |
| assert(Src.hasExternalLinkage()); |
| LinkFromSrc = true; |
| return false; |
| } |
| |
| assert(!Src.hasExternalWeakLinkage()); |
| assert(!Dest.hasExternalWeakLinkage()); |
| assert(Dest.hasExternalLinkage() && Src.hasExternalLinkage() && |
| "Unexpected linkage type!"); |
| return emitError("Linking globals named '" + Src.getName() + |
| "': symbol multiply defined!"); |
| } |
| |
| /// Loop over all of the linked values to compute type mappings. For example, |
| /// if we link "extern Foo *x" and "Foo *x = NULL", then we have two struct |
| /// types 'Foo' but one got renamed when the module was loaded into the same |
| /// LLVMContext. |
| void ModuleLinker::computeTypeMapping() { |
| for (GlobalValue &SGV : SrcM->globals()) { |
| GlobalValue *DGV = getLinkedToGlobal(&SGV); |
| if (!DGV) |
| continue; |
| |
| if (!DGV->hasAppendingLinkage() || !SGV.hasAppendingLinkage()) { |
| TypeMap.addTypeMapping(DGV->getType(), SGV.getType()); |
| continue; |
| } |
| |
| // Unify the element type of appending arrays. |
| ArrayType *DAT = cast<ArrayType>(DGV->getType()->getElementType()); |
| ArrayType *SAT = cast<ArrayType>(SGV.getType()->getElementType()); |
| TypeMap.addTypeMapping(DAT->getElementType(), SAT->getElementType()); |
| } |
| |
| for (GlobalValue &SGV : *SrcM) { |
| if (GlobalValue *DGV = getLinkedToGlobal(&SGV)) |
| TypeMap.addTypeMapping(DGV->getType(), SGV.getType()); |
| } |
| |
| for (GlobalValue &SGV : SrcM->aliases()) { |
| if (GlobalValue *DGV = getLinkedToGlobal(&SGV)) |
| TypeMap.addTypeMapping(DGV->getType(), SGV.getType()); |
| } |
| |
| // Incorporate types by name, scanning all the types in the source module. |
| // At this point, the destination module may have a type "%foo = { i32 }" for |
| // example. When the source module got loaded into the same LLVMContext, if |
| // it had the same type, it would have been renamed to "%foo.42 = { i32 }". |
| std::vector<StructType *> Types = SrcM->getIdentifiedStructTypes(); |
| for (StructType *ST : Types) { |
| if (!ST->hasName()) |
| continue; |
| |
| // Check to see if there is a dot in the name followed by a digit. |
| size_t DotPos = ST->getName().rfind('.'); |
| if (DotPos == 0 || DotPos == StringRef::npos || |
| ST->getName().back() == '.' || |
| !isdigit(static_cast<unsigned char>(ST->getName()[DotPos + 1]))) |
| continue; |
| |
| // Check to see if the destination module has a struct with the prefix name. |
| StructType *DST = DstM->getTypeByName(ST->getName().substr(0, DotPos)); |
| if (!DST) |
| continue; |
| |
| // Don't use it if this actually came from the source module. They're in |
| // the same LLVMContext after all. Also don't use it unless the type is |
| // actually used in the destination module. This can happen in situations |
| // like this: |
| // |
| // Module A Module B |
| // -------- -------- |
| // %Z = type { %A } %B = type { %C.1 } |
| // %A = type { %B.1, [7 x i8] } %C.1 = type { i8* } |
| // %B.1 = type { %C } %A.2 = type { %B.3, [5 x i8] } |
| // %C = type { i8* } %B.3 = type { %C.1 } |
| // |
| // When we link Module B with Module A, the '%B' in Module B is |
| // used. However, that would then use '%C.1'. But when we process '%C.1', |
| // we prefer to take the '%C' version. So we are then left with both |
| // '%C.1' and '%C' being used for the same types. This leads to some |
| // variables using one type and some using the other. |
| if (TypeMap.DstStructTypesSet.hasType(DST)) |
| TypeMap.addTypeMapping(DST, ST); |
| } |
| |
| // Now that we have discovered all of the type equivalences, get a body for |
| // any 'opaque' types in the dest module that are now resolved. |
| TypeMap.linkDefinedTypeBodies(); |
| } |
| |
| static void upgradeGlobalArray(GlobalVariable *GV) { |
| ArrayType *ATy = cast<ArrayType>(GV->getType()->getElementType()); |
| StructType *OldTy = cast<StructType>(ATy->getElementType()); |
| assert(OldTy->getNumElements() == 2 && "Expected to upgrade from 2 elements"); |
| |
| // Get the upgraded 3 element type. |
| PointerType *VoidPtrTy = Type::getInt8Ty(GV->getContext())->getPointerTo(); |
| Type *Tys[3] = {OldTy->getElementType(0), OldTy->getElementType(1), |
| VoidPtrTy}; |
| StructType *NewTy = StructType::get(GV->getContext(), Tys, false); |
| |
| // Build new constants with a null third field filled in. |
| Constant *OldInitC = GV->getInitializer(); |
| ConstantArray *OldInit = dyn_cast<ConstantArray>(OldInitC); |
| if (!OldInit && !isa<ConstantAggregateZero>(OldInitC)) |
| // Invalid initializer; give up. |
| return; |
| std::vector<Constant *> Initializers; |
| if (OldInit && OldInit->getNumOperands()) { |
| Value *Null = Constant::getNullValue(VoidPtrTy); |
| for (Use &U : OldInit->operands()) { |
| ConstantStruct *Init = cast<ConstantStruct>(U.get()); |
| Initializers.push_back(ConstantStruct::get( |
| NewTy, Init->getOperand(0), Init->getOperand(1), Null, nullptr)); |
| } |
| } |
| assert(Initializers.size() == ATy->getNumElements() && |
| "Failed to copy all array elements"); |
| |
| // Replace the old GV with a new one. |
| ATy = ArrayType::get(NewTy, Initializers.size()); |
| Constant *NewInit = ConstantArray::get(ATy, Initializers); |
| GlobalVariable *NewGV = new GlobalVariable( |
| *GV->getParent(), ATy, GV->isConstant(), GV->getLinkage(), NewInit, "", |
| GV, GV->getThreadLocalMode(), GV->getType()->getAddressSpace(), |
| GV->isExternallyInitialized()); |
| NewGV->copyAttributesFrom(GV); |
| NewGV->takeName(GV); |
| assert(GV->use_empty() && "program cannot use initializer list"); |
| GV->eraseFromParent(); |
| } |
| |
| void ModuleLinker::upgradeMismatchedGlobalArray(StringRef Name) { |
| // Look for the global arrays. |
| auto *DstGV = dyn_cast_or_null<GlobalVariable>(DstM->getNamedValue(Name)); |
| if (!DstGV) |
| return; |
| auto *SrcGV = dyn_cast_or_null<GlobalVariable>(SrcM->getNamedValue(Name)); |
| if (!SrcGV) |
| return; |
| |
| // Check if the types already match. |
| auto *DstTy = cast<ArrayType>(DstGV->getType()->getElementType()); |
| auto *SrcTy = |
| cast<ArrayType>(TypeMap.get(SrcGV->getType()->getElementType())); |
| if (DstTy == SrcTy) |
| return; |
| |
| // Grab the element types. We can only upgrade an array of a two-field |
| // struct. Only bother if the other one has three-fields. |
| auto *DstEltTy = cast<StructType>(DstTy->getElementType()); |
| auto *SrcEltTy = cast<StructType>(SrcTy->getElementType()); |
| if (DstEltTy->getNumElements() == 2 && SrcEltTy->getNumElements() == 3) { |
| upgradeGlobalArray(DstGV); |
| return; |
| } |
| if (DstEltTy->getNumElements() == 3 && SrcEltTy->getNumElements() == 2) |
| upgradeGlobalArray(SrcGV); |
| |
| // We can't upgrade any other differences. |
| } |
| |
| void ModuleLinker::upgradeMismatchedGlobals() { |
| upgradeMismatchedGlobalArray("llvm.global_ctors"); |
| upgradeMismatchedGlobalArray("llvm.global_dtors"); |
| } |
| |
| /// If there were any appending global variables, link them together now. |
| /// Return true on error. |
| bool ModuleLinker::linkAppendingVarProto(GlobalVariable *DstGV, |
| const GlobalVariable *SrcGV) { |
| |
| if (!SrcGV->hasAppendingLinkage() || !DstGV->hasAppendingLinkage()) |
| return emitError("Linking globals named '" + SrcGV->getName() + |
| "': can only link appending global with another appending global!"); |
| |
| ArrayType *DstTy = cast<ArrayType>(DstGV->getType()->getElementType()); |
| ArrayType *SrcTy = |
| cast<ArrayType>(TypeMap.get(SrcGV->getType()->getElementType())); |
| Type *EltTy = DstTy->getElementType(); |
| |
| // Check to see that they two arrays agree on type. |
| if (EltTy != SrcTy->getElementType()) |
| return emitError("Appending variables with different element types!"); |
| if (DstGV->isConstant() != SrcGV->isConstant()) |
| return emitError("Appending variables linked with different const'ness!"); |
| |
| if (DstGV->getAlignment() != SrcGV->getAlignment()) |
| return emitError( |
| "Appending variables with different alignment need to be linked!"); |
| |
| if (DstGV->getVisibility() != SrcGV->getVisibility()) |
| return emitError( |
| "Appending variables with different visibility need to be linked!"); |
| |
| if (DstGV->hasUnnamedAddr() != SrcGV->hasUnnamedAddr()) |
| return emitError( |
| "Appending variables with different unnamed_addr need to be linked!"); |
| |
| if (StringRef(DstGV->getSection()) != SrcGV->getSection()) |
| return emitError( |
| "Appending variables with different section name need to be linked!"); |
| |
| uint64_t NewSize = DstTy->getNumElements() + SrcTy->getNumElements(); |
| ArrayType *NewType = ArrayType::get(EltTy, NewSize); |
| |
| // Create the new global variable. |
| GlobalVariable *NG = |
| new GlobalVariable(*DstGV->getParent(), NewType, SrcGV->isConstant(), |
| DstGV->getLinkage(), /*init*/nullptr, /*name*/"", DstGV, |
| DstGV->getThreadLocalMode(), |
| DstGV->getType()->getAddressSpace()); |
| |
| // Propagate alignment, visibility and section info. |
| copyGVAttributes(NG, DstGV); |
| |
| AppendingVarInfo AVI; |
| AVI.NewGV = NG; |
| AVI.DstInit = DstGV->getInitializer(); |
| AVI.SrcInit = SrcGV->getInitializer(); |
| AppendingVars.push_back(AVI); |
| |
| // Replace any uses of the two global variables with uses of the new |
| // global. |
| ValueMap[SrcGV] = ConstantExpr::getBitCast(NG, TypeMap.get(SrcGV->getType())); |
| |
| DstGV->replaceAllUsesWith(ConstantExpr::getBitCast(NG, DstGV->getType())); |
| DstGV->eraseFromParent(); |
| |
| // Track the source variable so we don't try to link it. |
| DoNotLinkFromSource.insert(SrcGV); |
| |
| return false; |
| } |
| |
| bool ModuleLinker::linkGlobalValueProto(GlobalValue *SGV) { |
| GlobalValue *DGV = getLinkedToGlobal(SGV); |
| |
| // Handle the ultra special appending linkage case first. |
| if (DGV && DGV->hasAppendingLinkage()) |
| return linkAppendingVarProto(cast<GlobalVariable>(DGV), |
| cast<GlobalVariable>(SGV)); |
| |
| bool LinkFromSrc = true; |
| Comdat *C = nullptr; |
| GlobalValue::VisibilityTypes Visibility = SGV->getVisibility(); |
| bool HasUnnamedAddr = SGV->hasUnnamedAddr(); |
| |
| if (const Comdat *SC = SGV->getComdat()) { |
| Comdat::SelectionKind SK; |
| std::tie(SK, LinkFromSrc) = ComdatsChosen[SC]; |
| C = DstM->getOrInsertComdat(SC->getName()); |
| C->setSelectionKind(SK); |
| } else if (DGV) { |
| if (shouldLinkFromSource(LinkFromSrc, *DGV, *SGV)) |
| return true; |
| } |
| |
| if (!LinkFromSrc) { |
| // Track the source global so that we don't attempt to copy it over when |
| // processing global initializers. |
| DoNotLinkFromSource.insert(SGV); |
| |
| if (DGV) |
| // Make sure to remember this mapping. |
| ValueMap[SGV] = |
| ConstantExpr::getBitCast(DGV, TypeMap.get(SGV->getType())); |
| } |
| |
| if (DGV) { |
| Visibility = isLessConstraining(Visibility, DGV->getVisibility()) |
| ? DGV->getVisibility() |
| : Visibility; |
| HasUnnamedAddr = HasUnnamedAddr && DGV->hasUnnamedAddr(); |
| } |
| |
| if (!LinkFromSrc && !DGV) |
| return false; |
| |
| GlobalValue *NewGV; |
| if (!LinkFromSrc) { |
| NewGV = DGV; |
| } else { |
| // If the GV is to be lazily linked, don't create it just yet. |
| // The ValueMaterializerTy will deal with creating it if it's used. |
| if (!DGV && (SGV->hasLocalLinkage() || SGV->hasLinkOnceLinkage() || |
| SGV->hasAvailableExternallyLinkage())) { |
| DoNotLinkFromSource.insert(SGV); |
| return false; |
| } |
| |
| NewGV = copyGlobalValueProto(TypeMap, *DstM, SGV); |
| |
| if (DGV && isa<Function>(DGV)) |
| if (auto *NewF = dyn_cast<Function>(NewGV)) |
| OverridingFunctions.insert(NewF); |
| } |
| |
| NewGV->setUnnamedAddr(HasUnnamedAddr); |
| NewGV->setVisibility(Visibility); |
| |
| if (auto *NewGO = dyn_cast<GlobalObject>(NewGV)) { |
| if (C) |
| NewGO->setComdat(C); |
| |
| if (DGV && DGV->hasCommonLinkage() && SGV->hasCommonLinkage()) |
| NewGO->setAlignment(std::max(DGV->getAlignment(), SGV->getAlignment())); |
| } |
| |
| if (auto *NewGVar = dyn_cast<GlobalVariable>(NewGV)) { |
| auto *DGVar = dyn_cast_or_null<GlobalVariable>(DGV); |
| auto *SGVar = dyn_cast<GlobalVariable>(SGV); |
| if (DGVar && SGVar && DGVar->isDeclaration() && SGVar->isDeclaration() && |
| (!DGVar->isConstant() || !SGVar->isConstant())) |
| NewGVar->setConstant(false); |
| } |
| |
| // Make sure to remember this mapping. |
| if (NewGV != DGV) { |
| if (DGV) { |
| DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewGV, DGV->getType())); |
| DGV->eraseFromParent(); |
| } |
| ValueMap[SGV] = NewGV; |
| } |
| |
| return false; |
| } |
| |
| static void getArrayElements(const Constant *C, |
| SmallVectorImpl<Constant *> &Dest) { |
| unsigned NumElements = cast<ArrayType>(C->getType())->getNumElements(); |
| |
| for (unsigned i = 0; i != NumElements; ++i) |
| Dest.push_back(C->getAggregateElement(i)); |
| } |
| |
| void ModuleLinker::linkAppendingVarInit(const AppendingVarInfo &AVI) { |
| // Merge the initializer. |
| SmallVector<Constant *, 16> DstElements; |
| getArrayElements(AVI.DstInit, DstElements); |
| |
| SmallVector<Constant *, 16> SrcElements; |
| getArrayElements(AVI.SrcInit, SrcElements); |
| |
| ArrayType *NewType = cast<ArrayType>(AVI.NewGV->getType()->getElementType()); |
| |
| StringRef Name = AVI.NewGV->getName(); |
| bool IsNewStructor = |
| (Name == "llvm.global_ctors" || Name == "llvm.global_dtors") && |
| cast<StructType>(NewType->getElementType())->getNumElements() == 3; |
| |
| for (auto *V : SrcElements) { |
| if (IsNewStructor) { |
| Constant *Key = V->getAggregateElement(2); |
| if (DoNotLinkFromSource.count(Key)) |
| continue; |
| } |
| DstElements.push_back( |
| MapValue(V, ValueMap, RF_None, &TypeMap, &ValMaterializer)); |
| } |
| if (IsNewStructor) { |
| NewType = ArrayType::get(NewType->getElementType(), DstElements.size()); |
| AVI.NewGV->mutateType(PointerType::get(NewType, 0)); |
| } |
| |
| AVI.NewGV->setInitializer(ConstantArray::get(NewType, DstElements)); |
| } |
| |
| /// Update the initializers in the Dest module now that all globals that may be |
| /// referenced are in Dest. |
| void ModuleLinker::linkGlobalInit(GlobalVariable &Dst, GlobalVariable &Src) { |
| // Figure out what the initializer looks like in the dest module. |
| Dst.setInitializer(MapValue(Src.getInitializer(), ValueMap, RF_None, &TypeMap, |
| &ValMaterializer)); |
| } |
| |
| /// Copy the source function over into the dest function and fix up references |
| /// to values. At this point we know that Dest is an external function, and |
| /// that Src is not. |
| bool ModuleLinker::linkFunctionBody(Function &Dst, Function &Src) { |
| assert(Dst.isDeclaration() && !Src.isDeclaration()); |
| |
| // Materialize if needed. |
| if (std::error_code EC = Src.materialize()) |
| return emitError(EC.message()); |
| |
| // Link in the prefix data. |
| if (Src.hasPrefixData()) |
| Dst.setPrefixData(MapValue(Src.getPrefixData(), ValueMap, RF_None, &TypeMap, |
| &ValMaterializer)); |
| |
| // Link in the prologue data. |
| if (Src.hasPrologueData()) |
| Dst.setPrologueData(MapValue(Src.getPrologueData(), ValueMap, RF_None, |
| &TypeMap, &ValMaterializer)); |
| |
| // Go through and convert function arguments over, remembering the mapping. |
| Function::arg_iterator DI = Dst.arg_begin(); |
| for (Argument &Arg : Src.args()) { |
| DI->setName(Arg.getName()); // Copy the name over. |
| |
| // Add a mapping to our mapping. |
| ValueMap[&Arg] = DI; |
| ++DI; |
| } |
| |
| // Splice the body of the source function into the dest function. |
| Dst.getBasicBlockList().splice(Dst.end(), Src.getBasicBlockList()); |
| |
| // At this point, all of the instructions and values of the function are now |
| // copied over. The only problem is that they are still referencing values in |
| // the Source function as operands. Loop through all of the operands of the |
| // functions and patch them up to point to the local versions. |
| for (BasicBlock &BB : Dst) |
| for (Instruction &I : BB) |
| RemapInstruction(&I, ValueMap, RF_IgnoreMissingEntries, &TypeMap, |
| &ValMaterializer); |
| |
| // There is no need to map the arguments anymore. |
| for (Argument &Arg : Src.args()) |
| ValueMap.erase(&Arg); |
| |
| Src.Dematerialize(); |
| return false; |
| } |
| |
| void ModuleLinker::linkAliasBody(GlobalAlias &Dst, GlobalAlias &Src) { |
| Constant *Aliasee = Src.getAliasee(); |
| Constant *Val = |
| MapValue(Aliasee, ValueMap, RF_None, &TypeMap, &ValMaterializer); |
| Dst.setAliasee(Val); |
| } |
| |
| bool ModuleLinker::linkGlobalValueBody(GlobalValue &Src) { |
| Value *Dst = ValueMap[&Src]; |
| assert(Dst); |
| if (auto *F = dyn_cast<Function>(&Src)) |
| return linkFunctionBody(cast<Function>(*Dst), *F); |
| if (auto *GVar = dyn_cast<GlobalVariable>(&Src)) { |
| linkGlobalInit(cast<GlobalVariable>(*Dst), *GVar); |
| return false; |
| } |
| linkAliasBody(cast<GlobalAlias>(*Dst), cast<GlobalAlias>(Src)); |
| return false; |
| } |
| |
| /// Insert all of the named MDNodes in Src into the Dest module. |
| void ModuleLinker::linkNamedMDNodes() { |
| const NamedMDNode *SrcModFlags = SrcM->getModuleFlagsMetadata(); |
| for (Module::const_named_metadata_iterator I = SrcM->named_metadata_begin(), |
| E = SrcM->named_metadata_end(); I != E; ++I) { |
| // Don't link module flags here. Do them separately. |
| if (&*I == SrcModFlags) continue; |
| NamedMDNode *DestNMD = DstM->getOrInsertNamedMetadata(I->getName()); |
| // Add Src elements into Dest node. |
| for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) |
| DestNMD->addOperand(MapMetadata(I->getOperand(i), ValueMap, RF_None, |
| &TypeMap, &ValMaterializer)); |
| } |
| } |
| |
| /// Drop DISubprograms that have been superseded. |
| /// |
| /// FIXME: this creates an asymmetric result: we strip losing subprograms from |
| /// DstM, but leave losing subprograms in SrcM. Instead we should also strip |
| /// losers from SrcM, but this requires extra plumbing in MapMetadata. |
| void ModuleLinker::stripReplacedSubprograms() { |
| // Avoid quadratic runtime by returning early when there's nothing to do. |
| if (OverridingFunctions.empty()) |
| return; |
| |
| // Move the functions now, so the set gets cleared even on early returns. |
| auto Functions = std::move(OverridingFunctions); |
| OverridingFunctions.clear(); |
| |
| // Drop subprograms whose functions have been overridden by the new compile |
| // unit. |
| NamedMDNode *CompileUnits = DstM->getNamedMetadata("llvm.dbg.cu"); |
| if (!CompileUnits) |
| return; |
| for (unsigned I = 0, E = CompileUnits->getNumOperands(); I != E; ++I) { |
| DICompileUnit CU(CompileUnits->getOperand(I)); |
| assert(CU && "Expected valid compile unit"); |
| |
| DITypedArray<DISubprogram> SPs(CU.getSubprograms()); |
| assert(SPs && "Expected valid subprogram array"); |
| |
| SmallVector<Metadata *, 16> NewSPs; |
| NewSPs.reserve(SPs.getNumElements()); |
| for (unsigned S = 0, SE = SPs.getNumElements(); S != SE; ++S) { |
| DISubprogram SP = SPs.getElement(S); |
| if (SP && SP.getFunction() && Functions.count(SP.getFunction())) |
| continue; |
| |
| NewSPs.push_back(SP); |
| } |
| |
| // Redirect operand to the overriding subprogram. |
| if (NewSPs.size() != SPs.getNumElements()) |
| CU.replaceSubprograms(DIArray(MDNode::get(DstM->getContext(), NewSPs))); |
| } |
| } |
| |
| /// Merge the linker flags in Src into the Dest module. |
| bool ModuleLinker::linkModuleFlagsMetadata() { |
| // If the source module has no module flags, we are done. |
| const NamedMDNode *SrcModFlags = SrcM->getModuleFlagsMetadata(); |
| if (!SrcModFlags) return false; |
| |
| // If the destination module doesn't have module flags yet, then just copy |
| // over the source module's flags. |
| NamedMDNode *DstModFlags = DstM->getOrInsertModuleFlagsMetadata(); |
| if (DstModFlags->getNumOperands() == 0) { |
| for (unsigned I = 0, E = SrcModFlags->getNumOperands(); I != E; ++I) |
| DstModFlags->addOperand(SrcModFlags->getOperand(I)); |
| |
| return false; |
| } |
| |
| // First build a map of the existing module flags and requirements. |
| DenseMap<MDString *, std::pair<MDNode *, unsigned>> Flags; |
| SmallSetVector<MDNode*, 16> Requirements; |
| for (unsigned I = 0, E = DstModFlags->getNumOperands(); I != E; ++I) { |
| MDNode *Op = DstModFlags->getOperand(I); |
| ConstantInt *Behavior = mdconst::extract<ConstantInt>(Op->getOperand(0)); |
| MDString *ID = cast<MDString>(Op->getOperand(1)); |
| |
| if (Behavior->getZExtValue() == Module::Require) { |
| Requirements.insert(cast<MDNode>(Op->getOperand(2))); |
| } else { |
| Flags[ID] = std::make_pair(Op, I); |
| } |
| } |
| |
| // Merge in the flags from the source module, and also collect its set of |
| // requirements. |
| bool HasErr = false; |
| for (unsigned I = 0, E = SrcModFlags->getNumOperands(); I != E; ++I) { |
| MDNode *SrcOp = SrcModFlags->getOperand(I); |
| ConstantInt *SrcBehavior = |
| mdconst::extract<ConstantInt>(SrcOp->getOperand(0)); |
| MDString *ID = cast<MDString>(SrcOp->getOperand(1)); |
| MDNode *DstOp; |
| unsigned DstIndex; |
| std::tie(DstOp, DstIndex) = Flags.lookup(ID); |
| unsigned SrcBehaviorValue = SrcBehavior->getZExtValue(); |
| |
| // If this is a requirement, add it and continue. |
| if (SrcBehaviorValue == Module::Require) { |
| // If the destination module does not already have this requirement, add |
| // it. |
| if (Requirements.insert(cast<MDNode>(SrcOp->getOperand(2)))) { |
| DstModFlags->addOperand(SrcOp); |
| } |
| continue; |
| } |
| |
| // If there is no existing flag with this ID, just add it. |
| if (!DstOp) { |
| Flags[ID] = std::make_pair(SrcOp, DstModFlags->getNumOperands()); |
| DstModFlags->addOperand(SrcOp); |
| continue; |
| } |
| |
| // Otherwise, perform a merge. |
| ConstantInt *DstBehavior = |
| mdconst::extract<ConstantInt>(DstOp->getOperand(0)); |
| unsigned DstBehaviorValue = DstBehavior->getZExtValue(); |
| |
| // If either flag has override behavior, handle it first. |
| if (DstBehaviorValue == Module::Override) { |
| // Diagnose inconsistent flags which both have override behavior. |
| if (SrcBehaviorValue == Module::Override && |
| SrcOp->getOperand(2) != DstOp->getOperand(2)) { |
| HasErr |= emitError("linking module flags '" + ID->getString() + |
| "': IDs have conflicting override values"); |
| } |
| continue; |
| } else if (SrcBehaviorValue == Module::Override) { |
| // Update the destination flag to that of the source. |
| DstModFlags->setOperand(DstIndex, SrcOp); |
| Flags[ID].first = SrcOp; |
| continue; |
| } |
| |
| // Diagnose inconsistent merge behavior types. |
| if (SrcBehaviorValue != DstBehaviorValue) { |
| HasErr |= emitError("linking module flags '" + ID->getString() + |
| "': IDs have conflicting behaviors"); |
| continue; |
| } |
| |
| auto replaceDstValue = [&](MDNode *New) { |
| Metadata *FlagOps[] = {DstOp->getOperand(0), ID, New}; |
| MDNode *Flag = MDNode::get(DstM->getContext(), FlagOps); |
| DstModFlags->setOperand(DstIndex, Flag); |
| Flags[ID].first = Flag; |
| }; |
| |
| // Perform the merge for standard behavior types. |
| switch (SrcBehaviorValue) { |
| case Module::Require: |
| case Module::Override: llvm_unreachable("not possible"); |
| case Module::Error: { |
| // Emit an error if the values differ. |
| if (SrcOp->getOperand(2) != DstOp->getOperand(2)) { |
| HasErr |= emitError("linking module flags '" + ID->getString() + |
| "': IDs have conflicting values"); |
| } |
| continue; |
| } |
| case Module::Warning: { |
| // Emit a warning if the values differ. |
| if (SrcOp->getOperand(2) != DstOp->getOperand(2)) { |
| emitWarning("linking module flags '" + ID->getString() + |
| "': IDs have conflicting values"); |
| } |
| continue; |
| } |
| case Module::Append: { |
| MDNode *DstValue = cast<MDNode>(DstOp->getOperand(2)); |
| MDNode *SrcValue = cast<MDNode>(SrcOp->getOperand(2)); |
| SmallVector<Metadata *, 8> MDs; |
| MDs.reserve(DstValue->getNumOperands() + SrcValue->getNumOperands()); |
| for (unsigned i = 0, e = DstValue->getNumOperands(); i != e; ++i) |
| MDs.push_back(DstValue->getOperand(i)); |
| for (unsigned i = 0, e = SrcValue->getNumOperands(); i != e; ++i) |
| MDs.push_back(SrcValue->getOperand(i)); |
| |
| replaceDstValue(MDNode::get(DstM->getContext(), MDs)); |
| break; |
| } |
| case Module::AppendUnique: { |
| SmallSetVector<Metadata *, 16> Elts; |
| MDNode *DstValue = cast<MDNode>(DstOp->getOperand(2)); |
| MDNode *SrcValue = cast<MDNode>(SrcOp->getOperand(2)); |
| for (unsigned i = 0, e = DstValue->getNumOperands(); i != e; ++i) |
| Elts.insert(DstValue->getOperand(i)); |
| for (unsigned i = 0, e = SrcValue->getNumOperands(); i != e; ++i) |
| Elts.insert(SrcValue->getOperand(i)); |
| |
| replaceDstValue(MDNode::get(DstM->getContext(), |
| makeArrayRef(Elts.begin(), Elts.end()))); |
| break; |
| } |
| } |
| } |
| |
| // Check all of the requirements. |
| for (unsigned I = 0, E = Requirements.size(); I != E; ++I) { |
| MDNode *Requirement = Requirements[I]; |
| MDString *Flag = cast<MDString>(Requirement->getOperand(0)); |
| Metadata *ReqValue = Requirement->getOperand(1); |
| |
| MDNode *Op = Flags[Flag].first; |
| if (!Op || Op->getOperand(2) != ReqValue) { |
| HasErr |= emitError("linking module flags '" + Flag->getString() + |
| "': does not have the required value"); |
| continue; |
| } |
| } |
| |
| return HasErr; |
| } |
| |
| bool ModuleLinker::run() { |
| assert(DstM && "Null destination module"); |
| assert(SrcM && "Null source module"); |
| |
| // Inherit the target data from the source module if the destination module |
| // doesn't have one already. |
| if (!DstM->getDataLayout() && SrcM->getDataLayout()) |
| DstM->setDataLayout(SrcM->getDataLayout()); |
| |
| // Copy the target triple from the source to dest if the dest's is empty. |
| if (DstM->getTargetTriple().empty() && !SrcM->getTargetTriple().empty()) |
| DstM->setTargetTriple(SrcM->getTargetTriple()); |
| |
| if (SrcM->getDataLayout() && DstM->getDataLayout() && |
| *SrcM->getDataLayout() != *DstM->getDataLayout()) { |
| emitWarning("Linking two modules of different data layouts: '" + |
| SrcM->getModuleIdentifier() + "' is '" + |
| SrcM->getDataLayoutStr() + "' whereas '" + |
| DstM->getModuleIdentifier() + "' is '" + |
| DstM->getDataLayoutStr() + "'\n"); |
| } |
| if (!SrcM->getTargetTriple().empty() && |
| DstM->getTargetTriple() != SrcM->getTargetTriple()) { |
| emitWarning("Linking two modules of different target triples: " + |
| SrcM->getModuleIdentifier() + "' is '" + |
| SrcM->getTargetTriple() + "' whereas '" + |
| DstM->getModuleIdentifier() + "' is '" + |
| DstM->getTargetTriple() + "'\n"); |
| } |
| |
| // Append the module inline asm string. |
| if (!SrcM->getModuleInlineAsm().empty()) { |
| if (DstM->getModuleInlineAsm().empty()) |
| DstM->setModuleInlineAsm(SrcM->getModuleInlineAsm()); |
| else |
| DstM->setModuleInlineAsm(DstM->getModuleInlineAsm()+"\n"+ |
| SrcM->getModuleInlineAsm()); |
| } |
| |
| // Loop over all of the linked values to compute type mappings. |
| computeTypeMapping(); |
| |
| ComdatsChosen.clear(); |
| for (const auto &SMEC : SrcM->getComdatSymbolTable()) { |
| const Comdat &C = SMEC.getValue(); |
| if (ComdatsChosen.count(&C)) |
| continue; |
| Comdat::SelectionKind SK; |
| bool LinkFromSrc; |
| if (getComdatResult(&C, SK, LinkFromSrc)) |
| return true; |
| ComdatsChosen[&C] = std::make_pair(SK, LinkFromSrc); |
| } |
| |
| // Upgrade mismatched global arrays. |
| upgradeMismatchedGlobals(); |
| |
| // Insert all of the globals in src into the DstM module... without linking |
| // initializers (which could refer to functions not yet mapped over). |
| for (Module::global_iterator I = SrcM->global_begin(), |
| E = SrcM->global_end(); I != E; ++I) |
| if (linkGlobalValueProto(I)) |
| return true; |
| |
| // Link the functions together between the two modules, without doing function |
| // bodies... this just adds external function prototypes to the DstM |
| // function... We do this so that when we begin processing function bodies, |
| // all of the global values that may be referenced are available in our |
| // ValueMap. |
| for (Module::iterator I = SrcM->begin(), E = SrcM->end(); I != E; ++I) |
| if (linkGlobalValueProto(I)) |
| return true; |
| |
| // If there were any aliases, link them now. |
| for (Module::alias_iterator I = SrcM->alias_begin(), |
| E = SrcM->alias_end(); I != E; ++I) |
| if (linkGlobalValueProto(I)) |
| return true; |
| |
| for (unsigned i = 0, e = AppendingVars.size(); i != e; ++i) |
| linkAppendingVarInit(AppendingVars[i]); |
| |
| for (const auto &Entry : DstM->getComdatSymbolTable()) { |
| const Comdat &C = Entry.getValue(); |
| if (C.getSelectionKind() == Comdat::Any) |
| continue; |
| const GlobalValue *GV = SrcM->getNamedValue(C.getName()); |
| assert(GV); |
| MapValue(GV, ValueMap, RF_None, &TypeMap, &ValMaterializer); |
| } |
| |
| // Link in the function bodies that are defined in the source module into |
| // DstM. |
| for (Function &SF : *SrcM) { |
| // Skip if no body (function is external). |
| if (SF.isDeclaration()) |
| continue; |
| |
| // Skip if not linking from source. |
| if (DoNotLinkFromSource.count(&SF)) |
| continue; |
| |
| if (linkGlobalValueBody(SF)) |
| return true; |
| } |
| |
| // Resolve all uses of aliases with aliasees. |
| for (GlobalAlias &Src : SrcM->aliases()) { |
| if (DoNotLinkFromSource.count(&Src)) |
| continue; |
| linkGlobalValueBody(Src); |
| } |
| |
| // Strip replaced subprograms before linking together compile units. |
| stripReplacedSubprograms(); |
| |
| // Remap all of the named MDNodes in Src into the DstM module. We do this |
| // after linking GlobalValues so that MDNodes that reference GlobalValues |
| // are properly remapped. |
| linkNamedMDNodes(); |
| |
| // Merge the module flags into the DstM module. |
| if (linkModuleFlagsMetadata()) |
| return true; |
| |
| // Update the initializers in the DstM module now that all globals that may |
| // be referenced are in DstM. |
| for (GlobalVariable &Src : SrcM->globals()) { |
| // Only process initialized GV's or ones not already in dest. |
| if (!Src.hasInitializer() || DoNotLinkFromSource.count(&Src)) |
| continue; |
| linkGlobalValueBody(Src); |
| } |
| |
| // Process vector of lazily linked in functions. |
| while (!LazilyLinkGlobalValues.empty()) { |
| GlobalValue *SGV = LazilyLinkGlobalValues.back(); |
| LazilyLinkGlobalValues.pop_back(); |
| |
| assert(!SGV->isDeclaration() && "users should not pass down decls"); |
| if (linkGlobalValueBody(*SGV)) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| Linker::StructTypeKeyInfo::KeyTy::KeyTy(ArrayRef<Type *> E, bool P) |
| : ETypes(E), IsPacked(P) {} |
| |
| Linker::StructTypeKeyInfo::KeyTy::KeyTy(const StructType *ST) |
| : ETypes(ST->elements()), IsPacked(ST->isPacked()) {} |
| |
| bool Linker::StructTypeKeyInfo::KeyTy::operator==(const KeyTy &That) const { |
| if (IsPacked != That.IsPacked) |
| return false; |
| if (ETypes != That.ETypes) |
| return false; |
| return true; |
| } |
| |
| bool Linker::StructTypeKeyInfo::KeyTy::operator!=(const KeyTy &That) const { |
| return !this->operator==(That); |
| } |
| |
| StructType *Linker::StructTypeKeyInfo::getEmptyKey() { |
| return DenseMapInfo<StructType *>::getEmptyKey(); |
| } |
| |
| StructType *Linker::StructTypeKeyInfo::getTombstoneKey() { |
| return DenseMapInfo<StructType *>::getTombstoneKey(); |
| } |
| |
| unsigned Linker::StructTypeKeyInfo::getHashValue(const KeyTy &Key) { |
| return hash_combine(hash_combine_range(Key.ETypes.begin(), Key.ETypes.end()), |
| Key.IsPacked); |
| } |
| |
| unsigned Linker::StructTypeKeyInfo::getHashValue(const StructType *ST) { |
| return getHashValue(KeyTy(ST)); |
| } |
| |
| bool Linker::StructTypeKeyInfo::isEqual(const KeyTy &LHS, |
| const StructType *RHS) { |
| if (RHS == getEmptyKey() || RHS == getTombstoneKey()) |
| return false; |
| return LHS == KeyTy(RHS); |
| } |
| |
| bool Linker::StructTypeKeyInfo::isEqual(const StructType *LHS, |
| const StructType *RHS) { |
| if (RHS == getEmptyKey()) |
| return LHS == getEmptyKey(); |
| |
| if (RHS == getTombstoneKey()) |
| return LHS == getTombstoneKey(); |
| |
| return KeyTy(LHS) == KeyTy(RHS); |
| } |
| |
| void Linker::IdentifiedStructTypeSet::addNonOpaque(StructType *Ty) { |
| assert(!Ty->isOpaque()); |
| NonOpaqueStructTypes.insert(Ty); |
| } |
| |
| void Linker::IdentifiedStructTypeSet::addOpaque(StructType *Ty) { |
| assert(Ty->isOpaque()); |
| OpaqueStructTypes.insert(Ty); |
| } |
| |
| StructType * |
| Linker::IdentifiedStructTypeSet::findNonOpaque(ArrayRef<Type *> ETypes, |
| bool IsPacked) { |
| Linker::StructTypeKeyInfo::KeyTy Key(ETypes, IsPacked); |
| auto I = NonOpaqueStructTypes.find_as(Key); |
| if (I == NonOpaqueStructTypes.end()) |
| return nullptr; |
| return *I; |
| } |
| |
| bool Linker::IdentifiedStructTypeSet::hasType(StructType *Ty) { |
| if (Ty->isOpaque()) |
| return OpaqueStructTypes.count(Ty); |
| auto I = NonOpaqueStructTypes.find(Ty); |
| if (I == NonOpaqueStructTypes.end()) |
| return false; |
| return *I == Ty; |
| } |
| |
| void Linker::init(Module *M, DiagnosticHandlerFunction DiagnosticHandler) { |
| this->Composite = M; |
| this->DiagnosticHandler = DiagnosticHandler; |
| |
| TypeFinder StructTypes; |
| StructTypes.run(*M, true); |
| for (StructType *Ty : StructTypes) { |
| if (Ty->isOpaque()) |
| IdentifiedStructTypes.addOpaque(Ty); |
| else |
| IdentifiedStructTypes.addNonOpaque(Ty); |
| } |
| } |
| |
| Linker::Linker(Module *M, DiagnosticHandlerFunction DiagnosticHandler) { |
| init(M, DiagnosticHandler); |
| } |
| |
| Linker::Linker(Module *M) { |
| init(M, [this](const DiagnosticInfo &DI) { |
| Composite->getContext().diagnose(DI); |
| }); |
| } |
| |
| Linker::~Linker() { |
| } |
| |
| void Linker::deleteModule() { |
| delete Composite; |
| Composite = nullptr; |
| } |
| |
| bool Linker::linkInModule(Module *Src) { |
| ModuleLinker TheLinker(Composite, IdentifiedStructTypes, Src, |
| DiagnosticHandler); |
| return TheLinker.run(); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // LinkModules entrypoint. |
| //===----------------------------------------------------------------------===// |
| |
| /// This function links two modules together, with the resulting Dest module |
| /// modified to be the composite of the two input modules. If an error occurs, |
| /// true is returned and ErrorMsg (if not null) is set to indicate the problem. |
| /// Upon failure, the Dest module could be in a modified state, and shouldn't be |
| /// relied on to be consistent. |
| bool Linker::LinkModules(Module *Dest, Module *Src, |
| DiagnosticHandlerFunction DiagnosticHandler) { |
| Linker L(Dest, DiagnosticHandler); |
| return L.linkInModule(Src); |
| } |
| |
| bool Linker::LinkModules(Module *Dest, Module *Src) { |
| Linker L(Dest); |
| return L.linkInModule(Src); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // C API. |
| //===----------------------------------------------------------------------===// |
| |
| LLVMBool LLVMLinkModules(LLVMModuleRef Dest, LLVMModuleRef Src, |
| LLVMLinkerMode Mode, char **OutMessages) { |
| Module *D = unwrap(Dest); |
| std::string Message; |
| raw_string_ostream Stream(Message); |
| DiagnosticPrinterRawOStream DP(Stream); |
| |
| LLVMBool Result = Linker::LinkModules( |
| D, unwrap(Src), [&](const DiagnosticInfo &DI) { DI.print(DP); }); |
| |
| if (OutMessages && Result) |
| *OutMessages = strdup(Message.c_str()); |
| return Result; |
| } |