X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FLinker%2FLinkModules.cpp;h=001db21555ccddc841f0ad1982afc4838c7120a9;hb=58b1ac76d470eb5faa7e98feae97c4906d4d146e;hp=64c00327f29041ffddd484bbefe605850e7f7993;hpb=849dcd928a58290447a710b856bdd487aac44d24;p=oota-llvm.git diff --git a/lib/Linker/LinkModules.cpp b/lib/Linker/LinkModules.cpp index 64c00327f29..001db21555c 100644 --- a/lib/Linker/LinkModules.cpp +++ b/lib/Linker/LinkModules.cpp @@ -1,4 +1,4 @@ -//===- lib/Linker/LinkModules.cpp - Module Linker Implementation ----------===// + //===- lib/Linker/LinkModules.cpp - Module Linker Implementation ----------===// // // The LLVM Compiler Infrastructure // @@ -26,6 +26,7 @@ #include "llvm/Assembly/Writer.h" #include "llvm/Support/Streams.h" #include "llvm/System/Path.h" +#include "llvm/ADT/DenseMap.h" #include using namespace llvm; @@ -36,14 +37,6 @@ static inline bool Error(std::string *E, const std::string &Message) { return true; } -// ToStr - Simple wrapper function to convert a type to a string. -static std::string ToStr(const Type *Ty, const Module *M) { - std::ostringstream OS; - WriteTypeSymbolic(OS, Ty, M); - return OS.str(); -} - -// // Function: ResolveTypes() // // Description: @@ -75,95 +68,187 @@ static bool ResolveTypes(const Type *DestTy, const Type *SrcTy) { return false; } -static const FunctionType *getFT(const PATypeHolder &TH) { - return cast(TH.get()); -} -static const StructType *getST(const PATypeHolder &TH) { - return cast(TH.get()); +/// 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 TheMapTy; + TheMapTy TheMap; + + LinkerTypeMap(const LinkerTypeMap&); // DO NOT IMPLEMENT + void operator=(const LinkerTypeMap&); // DO NOT IMPLEMENT +public: + LinkerTypeMap() {} + ~LinkerTypeMap() { + for (DenseMap::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 { + cerr << "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 PATypeHolder &DestTy, - const PATypeHolder &SrcTy, - std::vector > &Pointers) { - const Type *SrcTyT = SrcTy.get(); - const Type *DestTyT = DestTy.get(); - if (DestTyT == SrcTyT) return false; // If already equal, noop +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 (isa(DestTyT) || isa(SrcTyT)) - return ResolveTypes(DestTyT, SrcTyT); + if (isa(DstTy) || isa(SrcTy)) + 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 (DestTyT->getTypeID() != SrcTyT->getTypeID()) return true; + 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 (DestTyT->getTypeID()) { + switch (DstTy->getTypeID()) { default: return true; case Type::FunctionTyID: { - if (cast(DestTyT)->isVarArg() != - cast(SrcTyT)->isVarArg() || - cast(DestTyT)->getNumContainedTypes() != - cast(SrcTyT)->getNumContainedTypes()) + const FunctionType *DstFT = cast(DstTy); + const FunctionType *SrcFT = cast(SrcTy); + if (DstFT->isVarArg() != SrcFT->isVarArg() || + DstFT->getNumContainedTypes() != SrcFT->getNumContainedTypes()) return true; - for (unsigned i = 0, e = getFT(DestTy)->getNumContainedTypes(); i != e; ++i) - if (RecursiveResolveTypesI(getFT(DestTy)->getContainedType(i), - getFT(SrcTy)->getContainedType(i), Pointers)) + + // 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: { - if (getST(DestTy)->getNumContainedTypes() != - getST(SrcTy)->getNumContainedTypes()) + const StructType *DstST = cast(DstTy); + const StructType *SrcST = cast(SrcTy); + if (DstST->getNumContainedTypes() != SrcST->getNumContainedTypes()) return true; - for (unsigned i = 0, e = getST(DestTy)->getNumContainedTypes(); i != e; ++i) - if (RecursiveResolveTypesI(getST(DestTy)->getContainedType(i), - getST(SrcTy)->getContainedType(i), Pointers)) + + 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(DestTy.get()); - const ArrayType *SAT = cast(SrcTy.get()); + const ArrayType *DAT = cast(DstTy); + const ArrayType *SAT = cast(SrcTy); if (DAT->getNumElements() != SAT->getNumElements()) return true; return RecursiveResolveTypesI(DAT->getElementType(), SAT->getElementType(), Pointers); } case Type::VectorTyID: { - const VectorType *DVT = cast(DestTy.get()); - const VectorType *SVT = cast(SrcTy.get()); + const VectorType *DVT = cast(DstTy); + const VectorType *SVT = cast(SrcTy); if (DVT->getNumElements() != SVT->getNumElements()) return true; return RecursiveResolveTypesI(DVT->getElementType(), SVT->getElementType(), Pointers); } case Type::PointerTyID: { + const PointerType *DstPT = cast(DstTy); + const PointerType *SrcPT = cast(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... - for (unsigned i = 0, e = Pointers.size(); i != e; ++i) - if (Pointers[i].first == DestTy) - return Pointers[i].second != SrcTy; - + // 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. - Pointers.push_back(std::make_pair(DestTyT, SrcTyT)); - bool Result = - RecursiveResolveTypesI(cast(DestTy.get())->getElementType(), - cast(SrcTy.get())->getElementType(), - Pointers); - return Result; + 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 PATypeHolder &DestTy, - const PATypeHolder &SrcTy) { - std::vector > PointerTypes; +static bool RecursiveResolveTypes(const Type *DestTy, const Type *SrcTy) { + LinkerTypeMap PointerTypes; return RecursiveResolveTypesI(DestTy, SrcTy, PointerTypes); } @@ -225,10 +310,7 @@ static bool LinkTypes(Module *Dest, const Module *Src, std::string *Err) { // two types: { int* } and { opaque* } for (unsigned i = 0, e = DelayedTypesToResolve.size(); i != e; ++i) { const std::string &Name = DelayedTypesToResolve[i]; - PATypeHolder T1(SrcST->lookup(Name)); - PATypeHolder T2(DestST->lookup(Name)); - - if (!RecursiveResolveTypes(T2, T1)) { + if (!RecursiveResolveTypes(SrcST->lookup(Name), DestST->lookup(Name))) { // We are making progress! DelayedTypesToResolve.erase(DelayedTypesToResolve.begin()+i); @@ -250,6 +332,7 @@ static bool LinkTypes(Module *Dest, const Module *Src, std::string *Err) { return false; } +#ifndef NDEBUG static void PrintMap(const std::map &M) { for (std::map::const_iterator I = M.begin(), E =M.end(); I != E; ++I) { @@ -260,6 +343,7 @@ static void PrintMap(const std::map &M) { cerr << "\n"; } } +#endif // RemapOperand - Use ValueMap to convert constants from one module to another. @@ -298,9 +382,8 @@ static Value *RemapOperand(const Value *In, for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) Ops.push_back(cast(RemapOperand(CE->getOperand(i),ValueMap))); Result = CE->getWithOperands(Ops); - } else if (isa(CPV)) { - assert(0 && "Unmapped global?"); } else { + assert(!isa(CPV) && "Unmapped global?"); assert(0 && "Unknown type of derived type constant value!"); } } else if (isa(In)) { @@ -313,12 +396,13 @@ static Value *RemapOperand(const Value *In, return Result; } - +#ifndef NDEBUG cerr << "LinkModules ValueMap: \n"; PrintMap(ValueMap); cerr << "Couldn't remap value: " << (void*)In << " " << *In << "\n"; assert(0 && "Couldn't remap value!"); +#endif return 0; } @@ -331,7 +415,7 @@ static void ForceRenaming(GlobalValue *GV, const std::string &Name) { // If there is a conflict, rename the conflict. if (GlobalValue *ConflictGV = cast_or_null(ST.lookup(Name))) { - assert(ConflictGV->hasInternalLinkage() && + 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 @@ -360,7 +444,7 @@ static void CopyGVAttributes(GlobalValue *DestGV, const GlobalValue *SrcGV) { static bool GetLinkageResult(GlobalValue *Dest, const GlobalValue *Src, GlobalValue::LinkageTypes <, bool &LinkFromSrc, std::string *Err) { - assert((!Dest || !Src->hasInternalLinkage()) && + assert((!Dest || !Src->hasLocalLinkage()) && "If Src has internal linkage, Dest shouldn't be set!"); if (!Dest) { // Linking something to nothing. @@ -393,11 +477,10 @@ static bool GetLinkageResult(GlobalValue *Dest, const GlobalValue *Src, "': can only link appending global with another appending global!"); LinkFromSrc = true; // Special cased. LT = Src->getLinkage(); - } else if (Src->hasWeakLinkage() || Src->hasLinkOnceLinkage() || - Src->hasCommonLinkage()) { + } else if (Src->mayBeOverridden()) { // At this point we know that Dest has LinkOnce, External*, Weak, Common, // or DLL* linkage. - if ((Dest->hasLinkOnceLinkage() && + if ((Dest->hasLinkOnceLinkage() && (Src->hasWeakLinkage() || Src->hasCommonLinkage())) || Dest->hasExternalWeakLinkage()) { LinkFromSrc = true; @@ -406,8 +489,7 @@ static bool GetLinkageResult(GlobalValue *Dest, const GlobalValue *Src, LinkFromSrc = false; LT = Dest->getLinkage(); } - } else if (Dest->hasWeakLinkage() || Dest->hasLinkOnceLinkage() || - Dest->hasCommonLinkage()) { + } else if (Dest->mayBeOverridden()) { // At this point we know that Src has External* or DLL* linkage. if (Src->hasExternalWeakLinkage()) { LinkFromSrc = false; @@ -444,30 +526,28 @@ static bool LinkGlobals(Module *Dest, const Module *Src, std::map &ValueMap, std::multimap &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) { + 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 - if (SGV->hasName() && !SGV->hasInternalLinkage()) { - DGV = Dest->getGlobalVariable(SGV->getName()); - if (DGV && DGV->getType() != SGV->getType()) - // If types don't agree due to opaque types, try to resolve them. - RecursiveResolveTypes(SGV->getType(), DGV->getType()); - } - - // Check to see if may have to link the global with the alias - if (!DGV && SGV->hasName() && !SGV->hasInternalLinkage()) { - DGV = Dest->getNamedAlias(SGV->getName()); - if (DGV && DGV->getType() != SGV->getType()) - // If types don't agree due to opaque types, try to resolve them. - RecursiveResolveTypes(SGV->getType(), DGV->getType()); - } - - if (DGV && DGV->hasInternalLinkage()) + // 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(DestSymTab.lookup(SGV->getNameStart(), + SGV->getNameEnd())); + + // 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()) && @@ -478,30 +558,39 @@ static bool LinkGlobals(Module *Dest, const Module *Src, if (GetLinkageResult(DGV, SGV, NewLinkage, LinkFromSrc, Err)) return true; - if (!DGV) { + 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... + // later by LinkGlobalInits. GlobalVariable *NewDGV = new GlobalVariable(SGV->getType()->getElementType(), SGV->isConstant(), SGV->getLinkage(), /*init*/0, - SGV->getName(), Dest); + SGV->getName(), Dest, 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->getName() != SGV->getName() && !NewDGV->hasInternalLinkage()) + if (!NewDGV->hasLocalLinkage() && NewDGV->getName() != SGV->getName()) ForceRenaming(NewDGV, SGV->getName()); - // Make sure to remember this mapping... + // Make sure to remember this mapping. ValueMap[SGV] = NewDGV; + // Keep track that this is an appending variable. if (SGV->hasAppendingLinkage()) - // Keep track that this is an appending variable... AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV)); - } else if (DGV->hasAppendingLinkage()) { + 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 @@ -509,7 +598,8 @@ static bool LinkGlobals(Module *Dest, const Module *Src, GlobalVariable *NewDGV = new GlobalVariable(SGV->getType()->getElementType(), SGV->isConstant(), SGV->getLinkage(), /*init*/0, - "", Dest); + "", Dest, false, + SGV->getType()->getAddressSpace()); // Set alignment allowing CopyGVAttributes merge it with alignment of SGV. NewDGV->setAlignment(DGV->getAlignment()); @@ -521,65 +611,72 @@ static bool LinkGlobals(Module *Dest, const Module *Src, // Keep track that this is an appending variable... AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV)); - } else if (GlobalAlias *DGA = dyn_cast(DGV)) { - // SGV is global, but DGV is alias. The only valid mapping is when SGV is - // external declaration, which is effectively a no-op. Also make sure - // linkage calculation was correct. - if (SGV->isDeclaration() && !LinkFromSrc) { - // Make sure to remember this mapping... - ValueMap[SGV] = DGA; - } else + continue; + } + + if (LinkFromSrc) { + if (isa(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(SGV->getType()->getElementType(), SGV->isConstant(), + NewLinkage, /*init*/0, DGV->getName(), Dest, 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(DGV)) + Var->eraseFromParent(); + else + cast(DGV)->eraseFromParent(); + DGV = NewDGV; + + // 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(DGV)) + if (DGVar->isDeclaration() && SGV->isConstant() && !DGVar->isConstant()) + DGVar->setConstant(true); + + // SGV is global, but DGV is alias. + if (isa(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->mayBeOverridden()) return Error(Err, "Global-Alias Collision on '" + SGV->getName() + "': symbol multiple defined"); - } else if (GlobalVariable *DGVar = dyn_cast(DGV)) { - // Otherwise, perform the global-global mapping as instructed by - // GetLinkageResult. - if (LinkFromSrc) { - // Propagate alignment, section, and visibility info. - CopyGVAttributes(DGVar, SGV); - - // 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. - if (SGV->getType() != DGVar->getType()) { - GlobalVariable *NewDGV = - new GlobalVariable(SGV->getType()->getElementType(), - DGVar->isConstant(), DGVar->getLinkage(), - /*init*/0, DGVar->getName(), Dest); - CopyGVAttributes(NewDGV, DGVar); - DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewDGV, - DGVar->getType())); - // DGVar 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. - DGVar->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 it. - if (NewDGV->getName() != SGV->getName() && - !NewDGV->hasInternalLinkage()) - ForceRenaming(NewDGV, SGV->getName()); - - DGVar = NewDGV; - } - - // Inherit const as appropriate - DGVar->setConstant(SGV->isConstant()); - - // Set initializer to zero, so we can link the stuff later - DGVar->setInitializer(0); - } else { - // Special case for const propagation - if (DGVar->isDeclaration() && SGV->isConstant() && !DGVar->isConstant()) - DGVar->setConstant(true); - } - - // Set calculated linkage - DGVar->setLinkage(NewLinkage); - - // Make sure to remember this mapping... - ValueMap[SGV] = ConstantExpr::getBitCast(DGVar, SGV->getType()); } + + // Set calculated linkage + DGV->setLinkage(NewLinkage); + + // Make sure to remember this mapping... + ValueMap[SGV] = ConstantExpr::getBitCast(DGV, SGV->getType()); } return false; } @@ -590,10 +687,12 @@ CalculateAliasLinkage(const GlobalValue *SGV, const GlobalValue *DGV) { return GlobalValue::ExternalLinkage; else if (SGV->hasWeakLinkage() || DGV->hasWeakLinkage()) return GlobalValue::WeakLinkage; - else { - assert(SGV->hasInternalLinkage() && DGV->hasInternalLinkage() && - "Unexpected linkage type"); + else if (SGV->hasInternalLinkage() && DGV->hasInternalLinkage()) return GlobalValue::InternalLinkage; + else { + assert (SGV->hasPrivateLinkage() && DGV->hasPrivateLinkage() && + "Unexpected linkage type"); + return GlobalValue::PrivateLinkage; } } @@ -618,38 +717,32 @@ static bool LinkAlias(Module *Dest, const Module *Src, GlobalValue* DGV = NULL; // Try to find something 'similar' to SGA in destination module. - if (!DGV && !SGA->hasInternalLinkage()) { + 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()) - if (RecursiveResolveTypes(SGA->getType(), DGV->getType())) - return Error(Err, "Alias Collision on '" + SGA->getName()+ - "': aliases have different types"); + RecursiveResolveTypes(SGA->getType(), DGV->getType()); } - if (!DGV && !SGA->hasInternalLinkage()) { + 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()) - if (RecursiveResolveTypes(SGA->getType(), DGV->getType())) - return Error(Err, "Alias Collision on '" + SGA->getName()+ - "': aliases have different types"); + RecursiveResolveTypes(SGA->getType(), DGV->getType()); } - if (!DGV && !SGA->hasInternalLinkage()) { + 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()) - if (RecursiveResolveTypes(SGA->getType(), DGV->getType())) - return Error(Err, "Alias Collision on '" + SGA->getName()+ - "': aliases have different types"); + RecursiveResolveTypes(SGA->getType(), DGV->getType()); } // No linking to be performed on internal stuff. - if (DGV && DGV->hasInternalLinkage()) + if (DGV && DGV->hasLocalLinkage()) DGV = NULL; if (GlobalAlias *DGA = dyn_cast_or_null(DGV)) { @@ -667,8 +760,9 @@ static bool LinkAlias(Module *Dest, const Module *Src, return Error(Err, "Alias Collision on '" + SGA->getName()+ "': aliases have different aliasees"); } else if (GlobalVariable *DGVar = dyn_cast_or_null(DGV)) { - // The only allowed way is to link alias with external declaration. - if (DGVar->isDeclaration()) { + // The only allowed way is to link alias with external declaration or weak + // symbol.. + if (DGVar->isDeclaration() || DGVar->mayBeOverridden()) { // But only if aliasee is global too... if (!isa(DAliasee)) return Error(Err, "Global-Alias Collision on '" + SGA->getName() + @@ -695,8 +789,9 @@ static bool LinkAlias(Module *Dest, const Module *Src, return Error(Err, "Global-Alias Collision on '" + SGA->getName() + "': symbol multiple defined"); } else if (Function *DF = dyn_cast_or_null(DGV)) { - // The only allowed way is to link alias with external declaration. - if (DF->isDeclaration()) { + // The only allowed way is to link alias with external declaration or weak + // symbol... + if (DF->isDeclaration() || DF->mayBeOverridden()) { // But only if aliasee is function too... if (!isa(DAliasee)) return Error(Err, "Function-Alias Collision on '" + SGA->getName() + @@ -738,7 +833,7 @@ static bool LinkAlias(Module *Dest, const Module *Src, // 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->hasInternalLinkage()) + !NewGA->hasLocalLinkage()) ForceRenaming(NewGA, SGA->getName()); // Remember this mapping so uses in the source module get remapped @@ -755,7 +850,6 @@ static bool LinkAlias(Module *Dest, const Module *Src, static bool LinkGlobalInits(Module *Dest, const Module *Src, std::map &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) { @@ -765,30 +859,39 @@ static bool LinkGlobalInits(Module *Dest, const Module *Src, // Figure out what the initializer looks like in the dest module... Constant *SInit = cast(RemapOperand(SGV->getInitializer(), ValueMap)); - - GlobalVariable *DGV = - cast(ValueMap[SGV]->stripPointerCasts()); - if (DGV->hasInitializer()) { - if (SGV->hasExternalLinkage()) { - if (DGV->getInitializer() != SInit) - return Error(Err, "Global Variable Collision on '" + SGV->getName() + - "': global variables have different initializers"); - } else if (DGV->hasLinkOnceLinkage() || DGV->hasWeakLinkage() || - DGV->hasCommonLinkage()) { - // Nothing is required, mapped values will take the new global - // automatically. - } else if (SGV->hasLinkOnceLinkage() || SGV->hasWeakLinkage() || - SGV->hasCommonLinkage()) { - // Nothing is required, mapped values will take the new global - // automatically. - } else if (DGV->hasAppendingLinkage()) { - assert(0 && "Appending linkage unimplemented!"); + // Grab destination global variable or alias. + GlobalValue *DGV = cast(ValueMap[SGV]->stripPointerCasts()); + + // If dest if global variable, check that initializers match. + if (GlobalVariable *DGVar = dyn_cast(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->mayBeOverridden()) { + // Nothing is required, mapped values will take the new global + // automatically. + } else if (SGV->mayBeOverridden()) { + // Nothing is required, mapped values will take the new global + // automatically. + } else if (DGVar->hasAppendingLinkage()) { + assert(0 && "Appending linkage unimplemented!"); + } else { + assert(0 && "Unknown linkage!"); + } } else { - assert(0 && "Unknown linkage!"); + // Copy the initializer over now... + DGVar->setInitializer(SInit); } } else { - // Copy the initializer over now... - DGV->setInitializer(SInit); + // 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->mayBeOverridden()); } } } @@ -802,24 +905,36 @@ static bool LinkGlobalInits(Module *Dest, const Module *Src, static bool LinkFunctionProtos(Module *Dest, const Module *Src, std::map &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; - Function *DF = 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(DestSymTab.lookup(SF->getNameStart(), + SF->getNameEnd())); - // If this function is internal or has no name, it doesn't participate in - // linkage. - if (SF->hasName() && !SF->hasInternalLinkage()) { - // Check to see if may have to link the function. - DF = Dest->getFunction(SF->getName()); - if (DF && DF->hasInternalLinkage()) - DF = 0; - } + // 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 (DF == 0) { + 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(), @@ -830,7 +945,7 @@ static bool LinkFunctionProtos(Module *Dest, const Module *Src, // 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->hasInternalLinkage() && NewDF->getName() != SF->getName()) + if (!NewDF->hasLocalLinkage() && NewDF->getName() != SF->getName()) ForceRenaming(NewDF, SF->getName()); // ... and remember this mapping... @@ -838,127 +953,63 @@ static bool LinkFunctionProtos(Module *Dest, const Module *Src, 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 types don't agree because of opaque, try to resolve them. - if (SF->getType() != DF->getType()) - RecursiveResolveTypes(SF->getType(), DF->getType()); - - // Check visibility, merging if a definition overrides a prototype. - if (SF->getVisibility() != DF->getVisibility()) { - // If one is a prototype, ignore its visibility. Prototypes are always - // overridden by the definition. - if (!SF->isDeclaration() && !DF->isDeclaration()) - return Error(Err, "Linking functions named '" + SF->getName() + - "': symbols have different visibilities!"); + if (LinkFromSrc) { + if (isa(DGV)) + return Error(Err, "Function-Alias Collision on '" + SF->getName() + + "': symbol multiple defined"); - // Otherwise, replace the visibility of DF if DF is a prototype. - if (DF->isDeclaration()) - DF->setVisibility(SF->getVisibility()); - } - - if (DF->getType() != SF->getType()) { - if (DF->isDeclaration() && !SF->isDeclaration()) { - // 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(), - SF->getLinkage(), - SF->getName(), Dest); - CopyGVAttributes(NewDF, SF); - - // Any uses of DF need to change to NewDF, with cast - DF->replaceAllUsesWith(ConstantExpr::getBitCast(NewDF, DF->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. - DF->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->hasInternalLinkage()) - ForceRenaming(NewDF, SF->getName()); - - // Remember this mapping so uses in the source module get remapped - // later by RemapOperand. - ValueMap[SF] = NewDF; - } else if (SF->isDeclaration()) { - // We have two functions of the same name but different type and the - // source is a declaration while the destination is not. Any use of - // the source must be mapped to the destination, with a cast. - ValueMap[SF] = ConstantExpr::getBitCast(DF, SF->getType()); - } else { - // We have two functions of the same name but different types and they - // are both definitions. This is an error. - return Error(Err, "Function '" + DF->getName() + "' defined as both '" + - ToStr(SF->getFunctionType(), Src) + "' and '" + - ToStr(DF->getFunctionType(), Dest) + "'"); - } - continue; - } - - if (SF->isDeclaration()) { - // If SF is a declaration or if both SF & DF are declarations, just link - // the declarations, we aren't adding anything. - if (SF->hasDLLImportLinkage()) { - if (DF->isDeclaration()) { - ValueMap[SF] = DF; - DF->setLinkage(SF->getLinkage()); - } - } else { - ValueMap[SF] = DF; - } - continue; - } - - // If DF is external but SF is not, link the external functions, update - // linkage qualifiers. - if (DF->isDeclaration() && !DF->hasDLLImportLinkage()) { - ValueMap.insert(std::make_pair(SF, DF)); - DF->setLinkage(SF->getLinkage()); + // 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(DGV)) + Var->eraseFromParent(); + else + cast(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 RemapOperand. + ValueMap[SF] = NewDF; continue; } - // At this point we know that DF has LinkOnce, Weak, or External* linkage. - if (SF->hasWeakLinkage() || SF->hasLinkOnceLinkage() || - SF->hasCommonLinkage()) { - ValueMap[SF] = DF; - - // Linkonce+Weak = Weak - // *+External Weak = * - if ((DF->hasLinkOnceLinkage() && - (SF->hasWeakLinkage() || SF->hasCommonLinkage())) || - DF->hasExternalWeakLinkage()) - DF->setLinkage(SF->getLinkage()); - continue; - } + // Not "link from source", keep the one in the DestModule and remap the + // input onto it. - if (DF->hasWeakLinkage() || DF->hasLinkOnceLinkage() || - DF->hasCommonLinkage()) { - // At this point we know that SF has LinkOnce or External* linkage. - ValueMap[SF] = DF; - - // If the source function has stronger linkage than the destination, - // its body and linkage should override ours. - if (!SF->hasLinkOnceLinkage() && !SF->hasExternalWeakLinkage()) { - // Don't inherit linkonce & external weak linkage. - DF->setLinkage(SF->getLinkage()); - DF->deleteBody(); - } - continue; + if (isa(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->mayBeOverridden()) + return Error(Err, "Function-Alias Collision on '" + SF->getName() + + "': symbol multiple defined"); } - - if (SF->getLinkage() != DF->getLinkage()) - return Error(Err, "Functions named '" + SF->getName() + - "' have different linkage specifiers!"); - - // The function is defined identically in both modules! - if (SF->hasExternalLinkage()) - return Error(Err, "Function '" + - ToStr(SF->getFunctionType(), Src) + "':\"" + - SF->getName() + "\" - Function is already defined!"); - assert(0 && "Unknown linkage configuration found!"); + + // Set calculated linkage + DGV->setLinkage(NewLinkage); + + // Make sure to remember this mapping. + ValueMap[SF] = ConstantExpr::getBitCast(DGV, SF->getType()); } return false; } @@ -1016,10 +1067,10 @@ static bool LinkFunctionBodies(Module *Dest, Module *Src, // go for (Module::iterator SF = Src->begin(), E = Src->end(); SF != E; ++SF) { if (!SF->isDeclaration()) { // No body if function is external - Function *DF = cast(ValueMap[SF]); // Destination function + Function *DF = dyn_cast(ValueMap[SF]); // Destination function // DF not external SF external? - if (DF->isDeclaration()) + if (DF && DF->isDeclaration()) // Only provide the function body if there isn't one already. if (LinkFunctionBody(DF, SF, ValueMap, Err)) return true; @@ -1080,7 +1131,8 @@ static bool LinkAppendingVars(Module *M, // Create the new global variable... GlobalVariable *NG = new GlobalVariable(NewType, G1->isConstant(), G1->getLinkage(), - /*init*/0, First->first, M, G1->isThreadLocal()); + /*init*/0, First->first, M, G1->isThreadLocal(), + G1->getType()->getAddressSpace()); // Propagate alignment, visibility and section info. CopyGVAttributes(NG, G1); @@ -1134,7 +1186,7 @@ static bool ResolveAliases(Module *Dest) { for (Module::alias_iterator I = Dest->alias_begin(), E = Dest->alias_end(); I != E; ++I) if (const GlobalValue *GV = I->resolveAliasedGlobal()) - if (!GV->isDeclaration()) + if (GV != I && !GV->isDeclaration()) I->replaceAllUsesWith(const_cast(GV)); return false;