| //===- 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. |
| // |
| // Specifically, this: |
| // * Merges global variables between the two modules |
| // * Uninit + Uninit = Init, Init + Uninit = Init, Init + Init = Error if != |
| // * Merges functions between two modules |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/Linker.h" |
| #include "llvm/Constants.h" |
| #include "llvm/DerivedTypes.h" |
| #include "llvm/LLVMContext.h" |
| #include "llvm/Module.h" |
| #include "llvm/TypeSymbolTable.h" |
| #include "llvm/ValueSymbolTable.h" |
| #include "llvm/Instructions.h" |
| #include "llvm/Assembly/Writer.h" |
| #include "llvm/Support/Debug.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include "llvm/System/Path.h" |
| #include "llvm/Transforms/Utils/ValueMapper.h" |
| #include "llvm/ADT/DenseMap.h" |
| using namespace llvm; |
| |
| // Error - Simple wrapper function to conditionally assign to E and return true. |
| // This just makes error return conditions a little bit simpler... |
| static inline bool Error(std::string *E, const Twine &Message) { |
| if (E) *E = Message.str(); |
| return true; |
| } |
| |
| // Function: ResolveTypes() |
| // |
| // Description: |
| // Attempt to link the two specified types together. |
| // |
| // Inputs: |
| // DestTy - The type to which we wish to resolve. |
| // SrcTy - The original type which we want to resolve. |
| // |
| // Outputs: |
| // DestST - The symbol table in which the new type should be placed. |
| // |
| // Return value: |
| // true - There is an error and the types cannot yet be linked. |
| // false - No errors. |
| // |
| static bool ResolveTypes(const Type *DestTy, const Type *SrcTy) { |
| if (DestTy == SrcTy) return false; // If already equal, noop |
| assert(DestTy && SrcTy && "Can't handle null types"); |
| |
| if (const OpaqueType *OT = dyn_cast<OpaqueType>(DestTy)) { |
| // Type _is_ in module, just opaque... |
| const_cast<OpaqueType*>(OT)->refineAbstractTypeTo(SrcTy); |
| } else if (const OpaqueType *OT = dyn_cast<OpaqueType>(SrcTy)) { |
| const_cast<OpaqueType*>(OT)->refineAbstractTypeTo(DestTy); |
| } else { |
| return true; // Cannot link types... not-equal and neither is opaque. |
| } |
| return false; |
| } |
| |
| /// LinkerTypeMap - This implements a map of types that is stable |
| /// even if types are resolved/refined to other types. This is not a general |
| /// purpose map, it is specific to the linker's use. |
| namespace { |
| class LinkerTypeMap : public AbstractTypeUser { |
| typedef DenseMap<const Type*, PATypeHolder> TheMapTy; |
| TheMapTy TheMap; |
| |
| LinkerTypeMap(const LinkerTypeMap&); // DO NOT IMPLEMENT |
| void operator=(const LinkerTypeMap&); // DO NOT IMPLEMENT |
| public: |
| LinkerTypeMap() {} |
| ~LinkerTypeMap() { |
| for (DenseMap<const Type*, PATypeHolder>::iterator I = TheMap.begin(), |
| E = TheMap.end(); I != E; ++I) |
| I->first->removeAbstractTypeUser(this); |
| } |
| |
| /// lookup - Return the value for the specified type or null if it doesn't |
| /// exist. |
| const Type *lookup(const Type *Ty) const { |
| TheMapTy::const_iterator I = TheMap.find(Ty); |
| if (I != TheMap.end()) return I->second; |
| return 0; |
| } |
| |
| /// erase - Remove the specified type, returning true if it was in the set. |
| bool erase(const Type *Ty) { |
| if (!TheMap.erase(Ty)) |
| return false; |
| if (Ty->isAbstract()) |
| Ty->removeAbstractTypeUser(this); |
| return true; |
| } |
| |
| /// insert - This returns true if the pointer was new to the set, false if it |
| /// was already in the set. |
| bool insert(const Type *Src, const Type *Dst) { |
| if (!TheMap.insert(std::make_pair(Src, PATypeHolder(Dst))).second) |
| return false; // Already in map. |
| if (Src->isAbstract()) |
| Src->addAbstractTypeUser(this); |
| return true; |
| } |
| |
| protected: |
| /// refineAbstractType - The callback method invoked when an abstract type is |
| /// resolved to another type. An object must override this method to update |
| /// its internal state to reference NewType instead of OldType. |
| /// |
| virtual void refineAbstractType(const DerivedType *OldTy, |
| const Type *NewTy) { |
| TheMapTy::iterator I = TheMap.find(OldTy); |
| const Type *DstTy = I->second; |
| |
| TheMap.erase(I); |
| if (OldTy->isAbstract()) |
| OldTy->removeAbstractTypeUser(this); |
| |
| // Don't reinsert into the map if the key is concrete now. |
| if (NewTy->isAbstract()) |
| insert(NewTy, DstTy); |
| } |
| |
| /// The other case which AbstractTypeUsers must be aware of is when a type |
| /// makes the transition from being abstract (where it has clients on it's |
| /// AbstractTypeUsers list) to concrete (where it does not). This method |
| /// notifies ATU's when this occurs for a type. |
| virtual void typeBecameConcrete(const DerivedType *AbsTy) { |
| TheMap.erase(AbsTy); |
| AbsTy->removeAbstractTypeUser(this); |
| } |
| |
| // for debugging... |
| virtual void dump() const { |
| dbgs() << "AbstractTypeSet!\n"; |
| } |
| }; |
| } |
| |
| |
| // RecursiveResolveTypes - This is just like ResolveTypes, except that it |
| // recurses down into derived types, merging the used types if the parent types |
| // are compatible. |
| static bool RecursiveResolveTypesI(const Type *DstTy, const Type *SrcTy, |
| LinkerTypeMap &Pointers) { |
| if (DstTy == SrcTy) return false; // If already equal, noop |
| |
| // If we found our opaque type, resolve it now! |
| if (DstTy->isOpaqueTy() || SrcTy->isOpaqueTy()) |
| return ResolveTypes(DstTy, SrcTy); |
| |
| // Two types cannot be resolved together if they are of different primitive |
| // type. For example, we cannot resolve an int to a float. |
| if (DstTy->getTypeID() != SrcTy->getTypeID()) return true; |
| |
| // If neither type is abstract, then they really are just different types. |
| if (!DstTy->isAbstract() && !SrcTy->isAbstract()) |
| return true; |
| |
| // Otherwise, resolve the used type used by this derived type... |
| switch (DstTy->getTypeID()) { |
| default: |
| return true; |
| case Type::FunctionTyID: { |
| const FunctionType *DstFT = cast<FunctionType>(DstTy); |
| const FunctionType *SrcFT = cast<FunctionType>(SrcTy); |
| if (DstFT->isVarArg() != SrcFT->isVarArg() || |
| DstFT->getNumContainedTypes() != SrcFT->getNumContainedTypes()) |
| return true; |
| |
| // Use TypeHolder's so recursive resolution won't break us. |
| PATypeHolder ST(SrcFT), DT(DstFT); |
| for (unsigned i = 0, e = DstFT->getNumContainedTypes(); i != e; ++i) { |
| const Type *SE = ST->getContainedType(i), *DE = DT->getContainedType(i); |
| if (SE != DE && RecursiveResolveTypesI(DE, SE, Pointers)) |
| return true; |
| } |
| return false; |
| } |
| case Type::StructTyID: { |
| const StructType *DstST = cast<StructType>(DstTy); |
| const StructType *SrcST = cast<StructType>(SrcTy); |
| if (DstST->getNumContainedTypes() != SrcST->getNumContainedTypes()) |
| return true; |
| |
| PATypeHolder ST(SrcST), DT(DstST); |
| for (unsigned i = 0, e = DstST->getNumContainedTypes(); i != e; ++i) { |
| const Type *SE = ST->getContainedType(i), *DE = DT->getContainedType(i); |
| if (SE != DE && RecursiveResolveTypesI(DE, SE, Pointers)) |
| return true; |
| } |
| return false; |
| } |
| case Type::ArrayTyID: { |
| const ArrayType *DAT = cast<ArrayType>(DstTy); |
| const ArrayType *SAT = cast<ArrayType>(SrcTy); |
| if (DAT->getNumElements() != SAT->getNumElements()) return true; |
| return RecursiveResolveTypesI(DAT->getElementType(), SAT->getElementType(), |
| Pointers); |
| } |
| case Type::VectorTyID: { |
| const VectorType *DVT = cast<VectorType>(DstTy); |
| const VectorType *SVT = cast<VectorType>(SrcTy); |
| if (DVT->getNumElements() != SVT->getNumElements()) return true; |
| return RecursiveResolveTypesI(DVT->getElementType(), SVT->getElementType(), |
| Pointers); |
| } |
| case Type::PointerTyID: { |
| const PointerType *DstPT = cast<PointerType>(DstTy); |
| const PointerType *SrcPT = cast<PointerType>(SrcTy); |
| |
| if (DstPT->getAddressSpace() != SrcPT->getAddressSpace()) |
| return true; |
| |
| // If this is a pointer type, check to see if we have already seen it. If |
| // so, we are in a recursive branch. Cut off the search now. We cannot use |
| // an associative container for this search, because the type pointers (keys |
| // in the container) change whenever types get resolved. |
| if (SrcPT->isAbstract()) |
| if (const Type *ExistingDestTy = Pointers.lookup(SrcPT)) |
| return ExistingDestTy != DstPT; |
| |
| if (DstPT->isAbstract()) |
| if (const Type *ExistingSrcTy = Pointers.lookup(DstPT)) |
| return ExistingSrcTy != SrcPT; |
| // Otherwise, add the current pointers to the vector to stop recursion on |
| // this pair. |
| if (DstPT->isAbstract()) |
| Pointers.insert(DstPT, SrcPT); |
| if (SrcPT->isAbstract()) |
| Pointers.insert(SrcPT, DstPT); |
| |
| return RecursiveResolveTypesI(DstPT->getElementType(), |
| SrcPT->getElementType(), Pointers); |
| } |
| } |
| } |
| |
| static bool RecursiveResolveTypes(const Type *DestTy, const Type *SrcTy) { |
| LinkerTypeMap PointerTypes; |
| return RecursiveResolveTypesI(DestTy, SrcTy, PointerTypes); |
| } |
| |
| |
| // LinkTypes - Go through the symbol table of the Src module and see if any |
| // types are named in the src module that are not named in the Dst module. |
| // Make sure there are no type name conflicts. |
| static bool LinkTypes(Module *Dest, const Module *Src, std::string *Err) { |
| TypeSymbolTable *DestST = &Dest->getTypeSymbolTable(); |
| const TypeSymbolTable *SrcST = &Src->getTypeSymbolTable(); |
| |
| // Look for a type plane for Type's... |
| TypeSymbolTable::const_iterator TI = SrcST->begin(); |
| TypeSymbolTable::const_iterator TE = SrcST->end(); |
| if (TI == TE) return false; // No named types, do nothing. |
| |
| // Some types cannot be resolved immediately because they depend on other |
| // types being resolved to each other first. This contains a list of types we |
| // are waiting to recheck. |
| std::vector<std::string> DelayedTypesToResolve; |
| |
| for ( ; TI != TE; ++TI ) { |
| const std::string &Name = TI->first; |
| const Type *RHS = TI->second; |
| |
| // Check to see if this type name is already in the dest module. |
| Type *Entry = DestST->lookup(Name); |
| |
| // If the name is just in the source module, bring it over to the dest. |
| if (Entry == 0) { |
| if (!Name.empty()) |
| DestST->insert(Name, const_cast<Type*>(RHS)); |
| } else if (ResolveTypes(Entry, RHS)) { |
| // They look different, save the types 'till later to resolve. |
| DelayedTypesToResolve.push_back(Name); |
| } |
| } |
| |
| // Iteratively resolve types while we can... |
| while (!DelayedTypesToResolve.empty()) { |
| // Loop over all of the types, attempting to resolve them if possible... |
| unsigned OldSize = DelayedTypesToResolve.size(); |
| |
| // Try direct resolution by name... |
| for (unsigned i = 0; i != DelayedTypesToResolve.size(); ++i) { |
| const std::string &Name = DelayedTypesToResolve[i]; |
| Type *T1 = SrcST->lookup(Name); |
| Type *T2 = DestST->lookup(Name); |
| if (!ResolveTypes(T2, T1)) { |
| // We are making progress! |
| DelayedTypesToResolve.erase(DelayedTypesToResolve.begin()+i); |
| --i; |
| } |
| } |
| |
| // Did we not eliminate any types? |
| if (DelayedTypesToResolve.size() == OldSize) { |
| // Attempt to resolve subelements of types. This allows us to merge these |
| // two types: { int* } and { opaque* } |
| for (unsigned i = 0, e = DelayedTypesToResolve.size(); i != e; ++i) { |
| const std::string &Name = DelayedTypesToResolve[i]; |
| if (!RecursiveResolveTypes(SrcST->lookup(Name), DestST->lookup(Name))) { |
| // We are making progress! |
| DelayedTypesToResolve.erase(DelayedTypesToResolve.begin()+i); |
| |
| // Go back to the main loop, perhaps we can resolve directly by name |
| // now... |
| break; |
| } |
| } |
| |
| // If we STILL cannot resolve the types, then there is something wrong. |
| if (DelayedTypesToResolve.size() == OldSize) { |
| // Remove the symbol name from the destination. |
| DelayedTypesToResolve.pop_back(); |
| } |
| } |
| } |
| |
| |
| return false; |
| } |
| |
| /// ForceRenaming - 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, const std::string &Name) { |
| assert(GV->getName() != Name && "Can't force rename to self"); |
| ValueSymbolTable &ST = GV->getParent()->getValueSymbolTable(); |
| |
| // If there is a conflict, rename the conflict. |
| if (GlobalValue *ConflictGV = cast_or_null<GlobalValue>(ST.lookup(Name))) { |
| assert(ConflictGV->hasLocalLinkage() && |
| "Not conflicting with a static global, should link instead!"); |
| 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 |
| } |
| } |
| |
| /// CopyGVAttributes - copy additional attributes (those not needed to construct |
| /// a GlobalValue) from the SrcGV to the DestGV. |
| static void CopyGVAttributes(GlobalValue *DestGV, const GlobalValue *SrcGV) { |
| // Use the maximum alignment, rather than just copying the alignment of SrcGV. |
| unsigned Alignment = std::max(DestGV->getAlignment(), SrcGV->getAlignment()); |
| DestGV->copyAttributesFrom(SrcGV); |
| DestGV->setAlignment(Alignment); |
| } |
| |
| /// GetLinkageResult - This analyzes the two global values and determines what |
| /// the result will look like in the destination module. In particular, it |
| /// computes the resultant linkage type, computes whether the global in the |
| /// source should be copied over to the destination (replacing the existing |
| /// one), and computes whether this linkage is an error or not. It also performs |
| /// visibility checks: we cannot link together two symbols with different |
| /// visibilities. |
| static bool GetLinkageResult(GlobalValue *Dest, const GlobalValue *Src, |
| GlobalValue::LinkageTypes <, bool &LinkFromSrc, |
| std::string *Err) { |
| assert((!Dest || !Src->hasLocalLinkage()) && |
| "If Src has internal linkage, Dest shouldn't be set!"); |
| if (!Dest) { |
| // Linking something to nothing. |
| LinkFromSrc = true; |
| LT = Src->getLinkage(); |
| } else if (Src->isDeclaration()) { |
| // If Src is external or if both Src & Dest are external.. Just link the |
| // external globals, we aren't adding anything. |
| if (Src->hasDLLImportLinkage()) { |
| // If one of GVs has DLLImport linkage, result should be dllimport'ed. |
| if (Dest->isDeclaration()) { |
| LinkFromSrc = true; |
| LT = Src->getLinkage(); |
| } |
| } else if (Dest->hasExternalWeakLinkage()) { |
| // If the Dest is weak, use the source linkage. |
| LinkFromSrc = true; |
| LT = Src->getLinkage(); |
| } else { |
| LinkFromSrc = false; |
| LT = Dest->getLinkage(); |
| } |
| } else if (Dest->isDeclaration() && !Dest->hasDLLImportLinkage()) { |
| // If Dest is external but Src is not: |
| LinkFromSrc = true; |
| LT = Src->getLinkage(); |
| } else if (Src->hasAppendingLinkage() || Dest->hasAppendingLinkage()) { |
| if (Src->getLinkage() != Dest->getLinkage()) |
| return Error(Err, "Linking globals named '" + Src->getName() + |
| "': can only link appending global with another appending global!"); |
| LinkFromSrc = true; // Special cased. |
| LT = Src->getLinkage(); |
| } else if (Src->isWeakForLinker()) { |
| // At this point we know that Dest has LinkOnce, External*, Weak, Common, |
| // or DLL* linkage. |
| if (Dest->hasExternalWeakLinkage() || |
| Dest->hasAvailableExternallyLinkage() || |
| (Dest->hasLinkOnceLinkage() && |
| (Src->hasWeakLinkage() || Src->hasCommonLinkage()))) { |
| LinkFromSrc = true; |
| LT = Src->getLinkage(); |
| } else { |
| LinkFromSrc = false; |
| LT = Dest->getLinkage(); |
| } |
| } else if (Dest->isWeakForLinker()) { |
| // At this point we know that Src has External* or DLL* linkage. |
| if (Src->hasExternalWeakLinkage()) { |
| LinkFromSrc = false; |
| LT = Dest->getLinkage(); |
| } else { |
| LinkFromSrc = true; |
| LT = GlobalValue::ExternalLinkage; |
| } |
| } else { |
| assert((Dest->hasExternalLinkage() || |
| Dest->hasDLLImportLinkage() || |
| Dest->hasDLLExportLinkage() || |
| Dest->hasExternalWeakLinkage()) && |
| (Src->hasExternalLinkage() || |
| Src->hasDLLImportLinkage() || |
| Src->hasDLLExportLinkage() || |
| Src->hasExternalWeakLinkage()) && |
| "Unexpected linkage type!"); |
| return Error(Err, "Linking globals named '" + Src->getName() + |
| "': symbol multiply defined!"); |
| } |
| |
| // Check visibility |
| if (Dest && Src->getVisibility() != Dest->getVisibility()) |
| if (!Src->isDeclaration() && !Dest->isDeclaration()) |
| return Error(Err, "Linking globals named '" + Src->getName() + |
| "': symbols have different visibilities!"); |
| return false; |
| } |
| |
| // Insert all of the named mdnoes in Src into the Dest module. |
| static void LinkNamedMDNodes(Module *Dest, Module *Src, |
| ValueToValueMapTy &ValueMap) { |
| for (Module::const_named_metadata_iterator I = Src->named_metadata_begin(), |
| E = Src->named_metadata_end(); I != E; ++I) { |
| const NamedMDNode *SrcNMD = I; |
| NamedMDNode *DestNMD = Dest->getOrInsertNamedMetadata(SrcNMD->getName()); |
| // Add Src elements into Dest node. |
| for (unsigned i = 0, e = SrcNMD->getNumOperands(); i != e; ++i) |
| DestNMD->addOperand(cast<MDNode>(MapValue(SrcNMD->getOperand(i), |
| ValueMap))); |
| } |
| } |
| |
| // LinkGlobals - Loop through the global variables in the src module and merge |
| // them into the dest module. |
| static bool LinkGlobals(Module *Dest, const Module *Src, |
| ValueToValueMapTy &ValueMap, |
| std::multimap<std::string, GlobalVariable *> &AppendingVars, |
| std::string *Err) { |
| ValueSymbolTable &DestSymTab = Dest->getValueSymbolTable(); |
| |
| // Loop over all of the globals in the src module, mapping them over as we go |
| for (Module::const_global_iterator I = Src->global_begin(), |
| E = Src->global_end(); I != E; ++I) { |
| const GlobalVariable *SGV = I; |
| GlobalValue *DGV = 0; |
| |
| // Check to see if may have to link the global with the global, alias or |
| // function. |
| if (SGV->hasName() && !SGV->hasLocalLinkage()) |
| DGV = cast_or_null<GlobalValue>(DestSymTab.lookup(SGV->getName())); |
| |
| // 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 && DGV->hasLocalLinkage()) |
| DGV = 0; |
| |
| // If types don't agree due to opaque types, try to resolve them. |
| if (DGV && DGV->getType() != SGV->getType()) |
| RecursiveResolveTypes(SGV->getType(), DGV->getType()); |
| |
| assert((SGV->hasInitializer() || SGV->hasExternalWeakLinkage() || |
| SGV->hasExternalLinkage() || SGV->hasDLLImportLinkage()) && |
| "Global must either be external or have an initializer!"); |
| |
| GlobalValue::LinkageTypes NewLinkage = GlobalValue::InternalLinkage; |
| bool LinkFromSrc = false; |
| if (GetLinkageResult(DGV, SGV, NewLinkage, LinkFromSrc, Err)) |
| return true; |
| |
| if (DGV == 0) { |
| // No linking to be performed, 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(*Dest, SGV->getType()->getElementType(), |
| SGV->isConstant(), SGV->getLinkage(), /*init*/0, |
| SGV->getName(), 0, false, |
| SGV->getType()->getAddressSpace()); |
| // Propagate alignment, visibility and section info. |
| CopyGVAttributes(NewDGV, SGV); |
| |
| // If the LLVM runtime renamed the global, but it is an externally visible |
| // symbol, DGV must be an existing global with internal linkage. Rename |
| // it. |
| if (!NewDGV->hasLocalLinkage() && NewDGV->getName() != SGV->getName()) |
| ForceRenaming(NewDGV, SGV->getName()); |
| |
| // Make sure to remember this mapping. |
| ValueMap[SGV] = NewDGV; |
| |
| // Keep track that this is an appending variable. |
| if (SGV->hasAppendingLinkage()) |
| AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV)); |
| continue; |
| } |
| |
| // If the visibilities of the symbols disagree and the destination is a |
| // prototype, take the visibility of its input. |
| if (DGV->isDeclaration()) |
| DGV->setVisibility(SGV->getVisibility()); |
| |
| if (DGV->hasAppendingLinkage()) { |
| // No linking is performed yet. Just insert a new copy of the global, and |
| // keep track of the fact that it is an appending variable in the |
| // AppendingVars map. The name is cleared out so that no linkage is |
| // performed. |
| GlobalVariable *NewDGV = |
| new GlobalVariable(*Dest, SGV->getType()->getElementType(), |
| SGV->isConstant(), SGV->getLinkage(), /*init*/0, |
| "", 0, false, |
| SGV->getType()->getAddressSpace()); |
| |
| // Set alignment allowing CopyGVAttributes merge it with alignment of SGV. |
| NewDGV->setAlignment(DGV->getAlignment()); |
| // Propagate alignment, section and visibility info. |
| CopyGVAttributes(NewDGV, SGV); |
| |
| // Make sure to remember this mapping... |
| ValueMap[SGV] = NewDGV; |
| |
| // Keep track that this is an appending variable... |
| AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV)); |
| continue; |
| } |
| |
| if (LinkFromSrc) { |
| if (isa<GlobalAlias>(DGV)) |
| return Error(Err, "Global-Alias Collision on '" + SGV->getName() + |
| "': symbol multiple defined"); |
| |
| // If the types don't match, and if we are to link from the source, nuke |
| // DGV and create a new one of the appropriate type. Note that the thing |
| // we are replacing may be a function (if a prototype, weak, etc) or a |
| // global variable. |
| GlobalVariable *NewDGV = |
| new GlobalVariable(*Dest, SGV->getType()->getElementType(), |
| SGV->isConstant(), NewLinkage, /*init*/0, |
| DGV->getName(), 0, false, |
| SGV->getType()->getAddressSpace()); |
| |
| // Propagate alignment, section, and visibility info. |
| CopyGVAttributes(NewDGV, SGV); |
| DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewDGV, |
| DGV->getType())); |
| |
| // DGV will conflict with NewDGV because they both had the same |
| // name. We must erase this now so ForceRenaming doesn't assert |
| // because DGV might not have internal linkage. |
| if (GlobalVariable *Var = dyn_cast<GlobalVariable>(DGV)) |
| Var->eraseFromParent(); |
| else |
| cast<Function>(DGV)->eraseFromParent(); |
| |
| // If the symbol table renamed the global, but it is an externally visible |
| // symbol, DGV must be an existing global with internal linkage. Rename. |
| if (NewDGV->getName() != SGV->getName() && !NewDGV->hasLocalLinkage()) |
| ForceRenaming(NewDGV, SGV->getName()); |
| |
| // Inherit const as appropriate. |
| NewDGV->setConstant(SGV->isConstant()); |
| |
| // Make sure to remember this mapping. |
| ValueMap[SGV] = NewDGV; |
| continue; |
| } |
| |
| // Not "link from source", keep the one in the DestModule and remap the |
| // input onto it. |
| |
| // Special case for const propagation. |
| if (GlobalVariable *DGVar = dyn_cast<GlobalVariable>(DGV)) |
| if (DGVar->isDeclaration() && SGV->isConstant() && !DGVar->isConstant()) |
| DGVar->setConstant(true); |
| |
| // SGV is global, but DGV is alias. |
| if (isa<GlobalAlias>(DGV)) { |
| // The only valid mappings are: |
| // - SGV is external declaration, which is effectively a no-op. |
| // - SGV is weak, when we just need to throw SGV out. |
| if (!SGV->isDeclaration() && !SGV->isWeakForLinker()) |
| return Error(Err, "Global-Alias Collision on '" + SGV->getName() + |
| "': symbol multiple defined"); |
| } |
| |
| // Set calculated linkage |
| DGV->setLinkage(NewLinkage); |
| |
| // Make sure to remember this mapping... |
| ValueMap[SGV] = ConstantExpr::getBitCast(DGV, SGV->getType()); |
| } |
| return false; |
| } |
| |
| static GlobalValue::LinkageTypes |
| CalculateAliasLinkage(const GlobalValue *SGV, const GlobalValue *DGV) { |
| GlobalValue::LinkageTypes SL = SGV->getLinkage(); |
| GlobalValue::LinkageTypes DL = DGV->getLinkage(); |
| if (SL == GlobalValue::ExternalLinkage || DL == GlobalValue::ExternalLinkage) |
| return GlobalValue::ExternalLinkage; |
| else if (SL == GlobalValue::WeakAnyLinkage || |
| DL == GlobalValue::WeakAnyLinkage) |
| return GlobalValue::WeakAnyLinkage; |
| else if (SL == GlobalValue::WeakODRLinkage || |
| DL == GlobalValue::WeakODRLinkage) |
| return GlobalValue::WeakODRLinkage; |
| else if (SL == GlobalValue::InternalLinkage && |
| DL == GlobalValue::InternalLinkage) |
| return GlobalValue::InternalLinkage; |
| else if (SL == GlobalValue::LinkerPrivateLinkage && |
| DL == GlobalValue::LinkerPrivateLinkage) |
| return GlobalValue::LinkerPrivateLinkage; |
| else if (SL == GlobalValue::LinkerPrivateWeakLinkage && |
| DL == GlobalValue::LinkerPrivateWeakLinkage) |
| return GlobalValue::LinkerPrivateWeakLinkage; |
| else if (SL == GlobalValue::LinkerPrivateWeakDefAutoLinkage && |
| DL == GlobalValue::LinkerPrivateWeakDefAutoLinkage) |
| return GlobalValue::LinkerPrivateWeakDefAutoLinkage; |
| else { |
| assert (SL == GlobalValue::PrivateLinkage && |
| DL == GlobalValue::PrivateLinkage && "Unexpected linkage type"); |
| return GlobalValue::PrivateLinkage; |
| } |
| } |
| |
| // LinkAlias - Loop through the alias in the src module and link them into the |
| // dest module. We're assuming, that all functions/global variables were already |
| // linked in. |
| static bool LinkAlias(Module *Dest, const Module *Src, |
| ValueToValueMapTy &ValueMap, |
| std::string *Err) { |
| // Loop over all alias in the src module |
| for (Module::const_alias_iterator I = Src->alias_begin(), |
| E = Src->alias_end(); I != E; ++I) { |
| const GlobalAlias *SGA = I; |
| const GlobalValue *SAliasee = SGA->getAliasedGlobal(); |
| GlobalAlias *NewGA = NULL; |
| |
| // Globals were already linked, thus we can just query ValueMap for variant |
| // of SAliasee in Dest. |
| ValueToValueMapTy::const_iterator VMI = ValueMap.find(SAliasee); |
| assert(VMI != ValueMap.end() && "Aliasee not linked"); |
| GlobalValue* DAliasee = cast<GlobalValue>(VMI->second); |
| GlobalValue* DGV = NULL; |
| |
| // Try to find something 'similar' to SGA in destination module. |
| if (!DGV && !SGA->hasLocalLinkage()) { |
| DGV = Dest->getNamedAlias(SGA->getName()); |
| |
| // If types don't agree due to opaque types, try to resolve them. |
| if (DGV && DGV->getType() != SGA->getType()) |
| RecursiveResolveTypes(SGA->getType(), DGV->getType()); |
| } |
| |
| if (!DGV && !SGA->hasLocalLinkage()) { |
| DGV = Dest->getGlobalVariable(SGA->getName()); |
| |
| // If types don't agree due to opaque types, try to resolve them. |
| if (DGV && DGV->getType() != SGA->getType()) |
| RecursiveResolveTypes(SGA->getType(), DGV->getType()); |
| } |
| |
| if (!DGV && !SGA->hasLocalLinkage()) { |
| DGV = Dest->getFunction(SGA->getName()); |
| |
| // If types don't agree due to opaque types, try to resolve them. |
| if (DGV && DGV->getType() != SGA->getType()) |
| RecursiveResolveTypes(SGA->getType(), DGV->getType()); |
| } |
| |
| // No linking to be performed on internal stuff. |
| if (DGV && DGV->hasLocalLinkage()) |
| DGV = NULL; |
| |
| if (GlobalAlias *DGA = dyn_cast_or_null<GlobalAlias>(DGV)) { |
| // Types are known to be the same, check whether aliasees equal. As |
| // globals are already linked we just need query ValueMap to find the |
| // mapping. |
| if (DAliasee == DGA->getAliasedGlobal()) { |
| // This is just two copies of the same alias. Propagate linkage, if |
| // necessary. |
| DGA->setLinkage(CalculateAliasLinkage(SGA, DGA)); |
| |
| NewGA = DGA; |
| // Proceed to 'common' steps |
| } else |
| return Error(Err, "Alias Collision on '" + SGA->getName()+ |
| "': aliases have different aliasees"); |
| } else if (GlobalVariable *DGVar = dyn_cast_or_null<GlobalVariable>(DGV)) { |
| // The only allowed way is to link alias with external declaration or weak |
| // symbol.. |
| if (DGVar->isDeclaration() || DGVar->isWeakForLinker()) { |
| // But only if aliasee is global too... |
| if (!isa<GlobalVariable>(DAliasee)) |
| return Error(Err, "Global-Alias Collision on '" + SGA->getName() + |
| "': aliasee is not global variable"); |
| |
| NewGA = new GlobalAlias(SGA->getType(), SGA->getLinkage(), |
| SGA->getName(), DAliasee, Dest); |
| CopyGVAttributes(NewGA, SGA); |
| |
| // Any uses of DGV need to change to NewGA, with cast, if needed. |
| if (SGA->getType() != DGVar->getType()) |
| DGVar->replaceAllUsesWith(ConstantExpr::getBitCast(NewGA, |
| DGVar->getType())); |
| else |
| DGVar->replaceAllUsesWith(NewGA); |
| |
| // DGVar will conflict with NewGA because they both had the same |
| // name. We must erase this now so ForceRenaming doesn't assert |
| // because DGV might not have internal linkage. |
| DGVar->eraseFromParent(); |
| |
| // Proceed to 'common' steps |
| } else |
| return Error(Err, "Global-Alias Collision on '" + SGA->getName() + |
| "': symbol multiple defined"); |
| } else if (Function *DF = dyn_cast_or_null<Function>(DGV)) { |
| // The only allowed way is to link alias with external declaration or weak |
| // symbol... |
| if (DF->isDeclaration() || DF->isWeakForLinker()) { |
| // But only if aliasee is function too... |
| if (!isa<Function>(DAliasee)) |
| return Error(Err, "Function-Alias Collision on '" + SGA->getName() + |
| "': aliasee is not function"); |
| |
| NewGA = new GlobalAlias(SGA->getType(), SGA->getLinkage(), |
| SGA->getName(), DAliasee, Dest); |
| CopyGVAttributes(NewGA, SGA); |
| |
| // Any uses of DF need to change to NewGA, with cast, if needed. |
| if (SGA->getType() != DF->getType()) |
| DF->replaceAllUsesWith(ConstantExpr::getBitCast(NewGA, |
| DF->getType())); |
| else |
| DF->replaceAllUsesWith(NewGA); |
| |
| // DF will conflict with NewGA because they both had the same |
| // name. We must erase this now so ForceRenaming doesn't assert |
| // because DF might not have internal linkage. |
| DF->eraseFromParent(); |
| |
| // Proceed to 'common' steps |
| } else |
| return Error(Err, "Function-Alias Collision on '" + SGA->getName() + |
| "': symbol multiple defined"); |
| } else { |
| // No linking to be performed, simply create an identical version of the |
| // alias over in the dest module... |
| Constant *Aliasee = DAliasee; |
| // Fixup aliases to bitcasts. Note that aliases to GEPs are still broken |
| // by this, but aliases to GEPs are broken to a lot of other things, so |
| // it's less important. |
| if (SGA->getType() != DAliasee->getType()) |
| Aliasee = ConstantExpr::getBitCast(DAliasee, SGA->getType()); |
| NewGA = new GlobalAlias(SGA->getType(), SGA->getLinkage(), |
| SGA->getName(), Aliasee, Dest); |
| CopyGVAttributes(NewGA, SGA); |
| |
| // Proceed to 'common' steps |
| } |
| |
| assert(NewGA && "No alias was created in destination module!"); |
| |
| // If the symbol table renamed the alias, but it is an externally visible |
| // symbol, DGA must be an global value with internal linkage. Rename it. |
| if (NewGA->getName() != SGA->getName() && |
| !NewGA->hasLocalLinkage()) |
| ForceRenaming(NewGA, SGA->getName()); |
| |
| // Remember this mapping so uses in the source module get remapped |
| // later by MapValue. |
| ValueMap[SGA] = NewGA; |
| } |
| |
| return false; |
| } |
| |
| |
| // LinkGlobalInits - Update the initializers in the Dest module now that all |
| // globals that may be referenced are in Dest. |
| static bool LinkGlobalInits(Module *Dest, const Module *Src, |
| ValueToValueMapTy &ValueMap, |
| std::string *Err) { |
| // Loop over all of the globals in the src module, mapping them over as we go |
| for (Module::const_global_iterator I = Src->global_begin(), |
| E = Src->global_end(); I != E; ++I) { |
| const GlobalVariable *SGV = I; |
| |
| if (SGV->hasInitializer()) { // Only process initialized GV's |
| // Figure out what the initializer looks like in the dest module... |
| Constant *SInit = |
| cast<Constant>(MapValue(SGV->getInitializer(), ValueMap)); |
| // Grab destination global variable or alias. |
| GlobalValue *DGV = cast<GlobalValue>(ValueMap[SGV]->stripPointerCasts()); |
| |
| // If dest if global variable, check that initializers match. |
| if (GlobalVariable *DGVar = dyn_cast<GlobalVariable>(DGV)) { |
| if (DGVar->hasInitializer()) { |
| if (SGV->hasExternalLinkage()) { |
| if (DGVar->getInitializer() != SInit) |
| return Error(Err, "Global Variable Collision on '" + |
| SGV->getName() + |
| "': global variables have different initializers"); |
| } else if (DGVar->isWeakForLinker()) { |
| // Nothing is required, mapped values will take the new global |
| // automatically. |
| } else if (SGV->isWeakForLinker()) { |
| // Nothing is required, mapped values will take the new global |
| // automatically. |
| } else if (DGVar->hasAppendingLinkage()) { |
| llvm_unreachable("Appending linkage unimplemented!"); |
| } else { |
| llvm_unreachable("Unknown linkage!"); |
| } |
| } else { |
| // Copy the initializer over now... |
| DGVar->setInitializer(SInit); |
| } |
| } else { |
| // Destination is alias, the only valid situation is when source is |
| // weak. Also, note, that we already checked linkage in LinkGlobals(), |
| // thus we assert here. |
| // FIXME: Should we weaken this assumption, 'dereference' alias and |
| // check for initializer of aliasee? |
| assert(SGV->isWeakForLinker()); |
| } |
| } |
| } |
| return false; |
| } |
| |
| // LinkFunctionProtos - Link the functions together between the two modules, |
| // without doing function bodies... this just adds external function prototypes |
| // to the Dest function... |
| // |
| static bool LinkFunctionProtos(Module *Dest, const Module *Src, |
| ValueToValueMapTy &ValueMap, |
| std::string *Err) { |
| ValueSymbolTable &DestSymTab = Dest->getValueSymbolTable(); |
| |
| // Loop over all of the functions in the src module, mapping them over |
| for (Module::const_iterator I = Src->begin(), E = Src->end(); I != E; ++I) { |
| const Function *SF = I; // SrcFunction |
| GlobalValue *DGV = 0; |
| |
| // Check to see if may have to link the function with the global, alias or |
| // function. |
| if (SF->hasName() && !SF->hasLocalLinkage()) |
| DGV = cast_or_null<GlobalValue>(DestSymTab.lookup(SF->getName())); |
| |
| // 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 && DGV->hasLocalLinkage()) |
| DGV = 0; |
| |
| // If types don't agree due to opaque types, try to resolve them. |
| if (DGV && DGV->getType() != SF->getType()) |
| RecursiveResolveTypes(SF->getType(), DGV->getType()); |
| |
| GlobalValue::LinkageTypes NewLinkage = GlobalValue::InternalLinkage; |
| bool LinkFromSrc = false; |
| if (GetLinkageResult(DGV, SF, NewLinkage, LinkFromSrc, Err)) |
| return true; |
| |
| // If there is no linkage to be performed, just bring over SF without |
| // modifying it. |
| if (DGV == 0) { |
| // Function does not already exist, simply insert an function signature |
| // identical to SF into the dest module. |
| Function *NewDF = Function::Create(SF->getFunctionType(), |
| SF->getLinkage(), |
| SF->getName(), Dest); |
| CopyGVAttributes(NewDF, SF); |
| |
| // If the LLVM runtime renamed the function, but it is an externally |
| // visible symbol, DF must be an existing function with internal linkage. |
| // Rename it. |
| if (!NewDF->hasLocalLinkage() && NewDF->getName() != SF->getName()) |
| ForceRenaming(NewDF, SF->getName()); |
| |
| // ... and remember this mapping... |
| ValueMap[SF] = NewDF; |
| continue; |
| } |
| |
| // If the visibilities of the symbols disagree and the destination is a |
| // prototype, take the visibility of its input. |
| if (DGV->isDeclaration()) |
| DGV->setVisibility(SF->getVisibility()); |
| |
| if (LinkFromSrc) { |
| if (isa<GlobalAlias>(DGV)) |
| return Error(Err, "Function-Alias Collision on '" + SF->getName() + |
| "': symbol multiple defined"); |
| |
| // We have a definition of the same name but different type in the |
| // source module. Copy the prototype to the destination and replace |
| // uses of the destination's prototype with the new prototype. |
| Function *NewDF = Function::Create(SF->getFunctionType(), NewLinkage, |
| SF->getName(), Dest); |
| CopyGVAttributes(NewDF, SF); |
| |
| // Any uses of DF need to change to NewDF, with cast |
| DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewDF, |
| DGV->getType())); |
| |
| // DF will conflict with NewDF because they both had the same. We must |
| // erase this now so ForceRenaming doesn't assert because DF might |
| // not have internal linkage. |
| if (GlobalVariable *Var = dyn_cast<GlobalVariable>(DGV)) |
| Var->eraseFromParent(); |
| else |
| cast<Function>(DGV)->eraseFromParent(); |
| |
| // If the symbol table renamed the function, but it is an externally |
| // visible symbol, DF must be an existing function with internal |
| // linkage. Rename it. |
| if (NewDF->getName() != SF->getName() && !NewDF->hasLocalLinkage()) |
| ForceRenaming(NewDF, SF->getName()); |
| |
| // Remember this mapping so uses in the source module get remapped |
| // later by MapValue. |
| ValueMap[SF] = NewDF; |
| continue; |
| } |
| |
| // Not "link from source", keep the one in the DestModule and remap the |
| // input onto it. |
| |
| if (isa<GlobalAlias>(DGV)) { |
| // The only valid mappings are: |
| // - SF is external declaration, which is effectively a no-op. |
| // - SF is weak, when we just need to throw SF out. |
| if (!SF->isDeclaration() && !SF->isWeakForLinker()) |
| return Error(Err, "Function-Alias Collision on '" + SF->getName() + |
| "': symbol multiple defined"); |
| } |
| |
| // Set calculated linkage |
| DGV->setLinkage(NewLinkage); |
| |
| // Make sure to remember this mapping. |
| ValueMap[SF] = ConstantExpr::getBitCast(DGV, SF->getType()); |
| } |
| return false; |
| } |
| |
| // LinkFunctionBody - 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. |
| static bool LinkFunctionBody(Function *Dest, Function *Src, |
| ValueToValueMapTy &ValueMap, |
| std::string *Err) { |
| assert(Src && Dest && Dest->isDeclaration() && !Src->isDeclaration()); |
| |
| // Go through and convert function arguments over, remembering the mapping. |
| Function::arg_iterator DI = Dest->arg_begin(); |
| for (Function::arg_iterator I = Src->arg_begin(), E = Src->arg_end(); |
| I != E; ++I, ++DI) { |
| DI->setName(I->getName()); // Copy the name information over... |
| |
| // Add a mapping to our local map |
| ValueMap[I] = DI; |
| } |
| |
| // Splice the body of the source function into the dest function. |
| Dest->getBasicBlockList().splice(Dest->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 (Function::iterator BB = Dest->begin(), BE = Dest->end(); BB != BE; ++BB) |
| for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) |
| for (Instruction::op_iterator OI = I->op_begin(), OE = I->op_end(); |
| OI != OE; ++OI) |
| if (!isa<Instruction>(*OI) && !isa<BasicBlock>(*OI)) |
| *OI = MapValue(*OI, ValueMap); |
| |
| // There is no need to map the arguments anymore. |
| for (Function::arg_iterator I = Src->arg_begin(), E = Src->arg_end(); |
| I != E; ++I) |
| ValueMap.erase(I); |
| |
| return false; |
| } |
| |
| |
| // LinkFunctionBodies - Link in the function bodies that are defined in the |
| // source module into the DestModule. This consists basically of copying the |
| // function over and fixing up references to values. |
| static bool LinkFunctionBodies(Module *Dest, Module *Src, |
| ValueToValueMapTy &ValueMap, |
| std::string *Err) { |
| |
| // Loop over all of the functions in the src module, mapping them over as we |
| // go |
| for (Module::iterator SF = Src->begin(), E = Src->end(); SF != E; ++SF) { |
| if (!SF->isDeclaration()) { // No body if function is external |
| Function *DF = dyn_cast<Function>(ValueMap[SF]); // Destination function |
| |
| // DF not external SF external? |
| if (DF && DF->isDeclaration()) |
| // Only provide the function body if there isn't one already. |
| if (LinkFunctionBody(DF, SF, ValueMap, Err)) |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| // LinkAppendingVars - If there were any appending global variables, link them |
| // together now. Return true on error. |
| static bool LinkAppendingVars(Module *M, |
| std::multimap<std::string, GlobalVariable *> &AppendingVars, |
| std::string *ErrorMsg) { |
| if (AppendingVars.empty()) return false; // Nothing to do. |
| |
| // Loop over the multimap of appending vars, processing any variables with the |
| // same name, forming a new appending global variable with both of the |
| // initializers merged together, then rewrite references to the old variables |
| // and delete them. |
| std::vector<Constant*> Inits; |
| while (AppendingVars.size() > 1) { |
| // Get the first two elements in the map... |
| std::multimap<std::string, |
| GlobalVariable*>::iterator Second = AppendingVars.begin(), First=Second++; |
| |
| // If the first two elements are for different names, there is no pair... |
| // Otherwise there is a pair, so link them together... |
| if (First->first == Second->first) { |
| GlobalVariable *G1 = First->second, *G2 = Second->second; |
| const ArrayType *T1 = cast<ArrayType>(G1->getType()->getElementType()); |
| const ArrayType *T2 = cast<ArrayType>(G2->getType()->getElementType()); |
| |
| // Check to see that they two arrays agree on type... |
| if (T1->getElementType() != T2->getElementType()) |
| return Error(ErrorMsg, |
| "Appending variables with different element types need to be linked!"); |
| if (G1->isConstant() != G2->isConstant()) |
| return Error(ErrorMsg, |
| "Appending variables linked with different const'ness!"); |
| |
| if (G1->getAlignment() != G2->getAlignment()) |
| return Error(ErrorMsg, |
| "Appending variables with different alignment need to be linked!"); |
| |
| if (G1->getVisibility() != G2->getVisibility()) |
| return Error(ErrorMsg, |
| "Appending variables with different visibility need to be linked!"); |
| |
| if (G1->getSection() != G2->getSection()) |
| return Error(ErrorMsg, |
| "Appending variables with different section name need to be linked!"); |
| |
| unsigned NewSize = T1->getNumElements() + T2->getNumElements(); |
| ArrayType *NewType = ArrayType::get(T1->getElementType(), |
| NewSize); |
| |
| G1->setName(""); // Clear G1's name in case of a conflict! |
| |
| // Create the new global variable... |
| GlobalVariable *NG = |
| new GlobalVariable(*M, NewType, G1->isConstant(), G1->getLinkage(), |
| /*init*/0, First->first, 0, G1->isThreadLocal(), |
| G1->getType()->getAddressSpace()); |
| |
| // Propagate alignment, visibility and section info. |
| CopyGVAttributes(NG, G1); |
| |
| // Merge the initializer... |
| Inits.reserve(NewSize); |
| if (ConstantArray *I = dyn_cast<ConstantArray>(G1->getInitializer())) { |
| for (unsigned i = 0, e = T1->getNumElements(); i != e; ++i) |
| Inits.push_back(I->getOperand(i)); |
| } else { |
| assert(isa<ConstantAggregateZero>(G1->getInitializer())); |
| Constant *CV = Constant::getNullValue(T1->getElementType()); |
| for (unsigned i = 0, e = T1->getNumElements(); i != e; ++i) |
| Inits.push_back(CV); |
| } |
| if (ConstantArray *I = dyn_cast<ConstantArray>(G2->getInitializer())) { |
| for (unsigned i = 0, e = T2->getNumElements(); i != e; ++i) |
| Inits.push_back(I->getOperand(i)); |
| } else { |
| assert(isa<ConstantAggregateZero>(G2->getInitializer())); |
| Constant *CV = Constant::getNullValue(T2->getElementType()); |
| for (unsigned i = 0, e = T2->getNumElements(); i != e; ++i) |
| Inits.push_back(CV); |
| } |
| NG->setInitializer(ConstantArray::get(NewType, Inits)); |
| Inits.clear(); |
| |
| // Replace any uses of the two global variables with uses of the new |
| // global... |
| |
| // FIXME: This should rewrite simple/straight-forward uses such as |
| // getelementptr instructions to not use the Cast! |
| G1->replaceAllUsesWith(ConstantExpr::getBitCast(NG, |
| G1->getType())); |
| G2->replaceAllUsesWith(ConstantExpr::getBitCast(NG, |
| G2->getType())); |
| |
| // Remove the two globals from the module now... |
| M->getGlobalList().erase(G1); |
| M->getGlobalList().erase(G2); |
| |
| // Put the new global into the AppendingVars map so that we can handle |
| // linking of more than two vars... |
| Second->second = NG; |
| } |
| AppendingVars.erase(First); |
| } |
| |
| return false; |
| } |
| |
| static bool ResolveAliases(Module *Dest) { |
| for (Module::alias_iterator I = Dest->alias_begin(), E = Dest->alias_end(); |
| I != E; ++I) |
| // We can't sue resolveGlobalAlias here because we need to preserve |
| // bitcasts and GEPs. |
| if (const Constant *C = I->getAliasee()) { |
| while (dyn_cast<GlobalAlias>(C)) |
| C = cast<GlobalAlias>(C)->getAliasee(); |
| const GlobalValue *GV = dyn_cast<GlobalValue>(C); |
| if (C != I && !(GV && GV->isDeclaration())) |
| I->replaceAllUsesWith(const_cast<Constant*>(C)); |
| } |
| |
| return false; |
| } |
| |
| // LinkModules - This function links two modules together, with the resulting |
| // left 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, std::string *ErrorMsg) { |
| assert(Dest != 0 && "Invalid Destination module"); |
| assert(Src != 0 && "Invalid Source Module"); |
| |
| if (Dest->getDataLayout().empty()) { |
| if (!Src->getDataLayout().empty()) { |
| Dest->setDataLayout(Src->getDataLayout()); |
| } else { |
| std::string DataLayout; |
| |
| if (Dest->getEndianness() == Module::AnyEndianness) { |
| if (Src->getEndianness() == Module::BigEndian) |
| DataLayout.append("E"); |
| else if (Src->getEndianness() == Module::LittleEndian) |
| DataLayout.append("e"); |
| } |
| |
| if (Dest->getPointerSize() == Module::AnyPointerSize) { |
| if (Src->getPointerSize() == Module::Pointer64) |
| DataLayout.append(DataLayout.length() == 0 ? "p:64:64" : "-p:64:64"); |
| else if (Src->getPointerSize() == Module::Pointer32) |
| DataLayout.append(DataLayout.length() == 0 ? "p:32:32" : "-p:32:32"); |
| } |
| Dest->setDataLayout(DataLayout); |
| } |
| } |
| |
| // Copy the target triple from the source to dest if the dest's is empty. |
| if (Dest->getTargetTriple().empty() && !Src->getTargetTriple().empty()) |
| Dest->setTargetTriple(Src->getTargetTriple()); |
| |
| if (!Src->getDataLayout().empty() && !Dest->getDataLayout().empty() && |
| Src->getDataLayout() != Dest->getDataLayout()) |
| errs() << "WARNING: Linking two modules of different data layouts!\n"; |
| if (!Src->getTargetTriple().empty() && |
| Dest->getTargetTriple() != Src->getTargetTriple()) |
| errs() << "WARNING: Linking two modules of different target triples!\n"; |
| |
| // Append the module inline asm string. |
| if (!Src->getModuleInlineAsm().empty()) { |
| if (Dest->getModuleInlineAsm().empty()) |
| Dest->setModuleInlineAsm(Src->getModuleInlineAsm()); |
| else |
| Dest->setModuleInlineAsm(Dest->getModuleInlineAsm()+"\n"+ |
| Src->getModuleInlineAsm()); |
| } |
| |
| // Update the destination module's dependent libraries list with the libraries |
| // from the source module. There's no opportunity for duplicates here as the |
| // Module ensures that duplicate insertions are discarded. |
| for (Module::lib_iterator SI = Src->lib_begin(), SE = Src->lib_end(); |
| SI != SE; ++SI) |
| Dest->addLibrary(*SI); |
| |
| // LinkTypes - Go through the symbol table of the Src module and see if any |
| // types are named in the src module that are not named in the Dst module. |
| // Make sure there are no type name conflicts. |
| if (LinkTypes(Dest, Src, ErrorMsg)) |
| return true; |
| |
| // ValueMap - Mapping of values from what they used to be in Src, to what they |
| // are now in Dest. 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; |
| |
| // AppendingVars - Keep track of global variables in the destination module |
| // with appending linkage. After the module is linked together, they are |
| // appended and the module is rewritten. |
| std::multimap<std::string, GlobalVariable *> AppendingVars; |
| for (Module::global_iterator I = Dest->global_begin(), E = Dest->global_end(); |
| I != E; ++I) { |
| // Add all of the appending globals already in the Dest module to |
| // AppendingVars. |
| if (I->hasAppendingLinkage()) |
| AppendingVars.insert(std::make_pair(I->getName(), I)); |
| } |
| |
| // Insert all of the globals in src into the Dest module... without linking |
| // initializers (which could refer to functions not yet mapped over). |
| if (LinkGlobals(Dest, Src, ValueMap, AppendingVars, ErrorMsg)) |
| return true; |
| |
| // Link the functions together between the two modules, without doing function |
| // bodies... this just adds external function prototypes to the Dest |
| // 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. |
| if (LinkFunctionProtos(Dest, Src, ValueMap, ErrorMsg)) |
| return true; |
| |
| // If there were any alias, link them now. We really need to do this now, |
| // because all of the aliases that may be referenced need to be available in |
| // ValueMap |
| if (LinkAlias(Dest, Src, ValueMap, ErrorMsg)) return true; |
| |
| // Update the initializers in the Dest module now that all globals that may |
| // be referenced are in Dest. |
| if (LinkGlobalInits(Dest, Src, ValueMap, ErrorMsg)) return true; |
| |
| // Link in the function bodies that are defined in the source module into the |
| // DestModule. This consists basically of copying the function over and |
| // fixing up references to values. |
| if (LinkFunctionBodies(Dest, Src, ValueMap, ErrorMsg)) return true; |
| |
| // If there were any appending global variables, link them together now. |
| if (LinkAppendingVars(Dest, AppendingVars, ErrorMsg)) return true; |
| |
| // Resolve all uses of aliases with aliasees |
| if (ResolveAliases(Dest)) return true; |
| |
| // Remap all of the named mdnoes in Src into the Dest module. We do this |
| // after linking GlobalValues so that MDNodes that reference GlobalValues |
| // are properly remapped. |
| LinkNamedMDNodes(Dest, Src, ValueMap); |
| |
| // If the source library's module id is in the dependent library list of the |
| // destination library, remove it since that module is now linked in. |
| sys::Path modId; |
| modId.set(Src->getModuleIdentifier()); |
| if (!modId.isEmpty()) |
| Dest->removeLibrary(modId.getBasename()); |
| |
| return false; |
| } |
| |
| // vim: sw=2 |