| //===- Linker.cpp - Module Linker Implementation --------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file was developed by the LLVM research group and 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/Transforms/Utils/Linker.h" |
| #include "llvm/Module.h" |
| #include "llvm/SymbolTable.h" |
| #include "llvm/DerivedTypes.h" |
| #include "llvm/iOther.h" |
| #include "llvm/Constants.h" |
| |
| // 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 std::string &Message) { |
| if (E) *E = Message; |
| return true; |
| } |
| |
| // ResolveTypes - Attempt to link the two specified types together. Return true |
| // if there is an error and they cannot yet be linked. |
| // |
| static bool ResolveTypes(const Type *DestTy, const Type *SrcTy, |
| SymbolTable *DestST, const std::string &Name) { |
| if (DestTy == SrcTy) return false; // If already equal, noop |
| |
| // Does the type already exist in the module? |
| if (DestTy && !isa<OpaqueType>(DestTy)) { // Yup, the type already exists... |
| if (const OpaqueType *OT = dyn_cast<OpaqueType>(SrcTy)) { |
| const_cast<OpaqueType*>(OT)->refineAbstractTypeTo(DestTy); |
| } else { |
| return true; // Cannot link types... neither is opaque and not-equal |
| } |
| } else { // Type not in dest module. Add it now. |
| if (DestTy) // Type _is_ in module, just opaque... |
| const_cast<OpaqueType*>(cast<OpaqueType>(DestTy)) |
| ->refineAbstractTypeTo(SrcTy); |
| else if (!Name.empty()) |
| DestST->insert(Name, const_cast<Type*>(SrcTy)); |
| } |
| return false; |
| } |
| |
| static const FunctionType *getFT(const PATypeHolder &TH) { |
| return cast<FunctionType>(TH.get()); |
| } |
| static const StructType *getST(const PATypeHolder &TH) { |
| return cast<StructType>(TH.get()); |
| } |
| |
| // 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, |
| SymbolTable *DestST, const std::string &Name, |
| std::vector<std::pair<PATypeHolder, PATypeHolder> > &Pointers) { |
| const Type *SrcTyT = SrcTy.get(); |
| const Type *DestTyT = DestTy.get(); |
| if (DestTyT == SrcTyT) return false; // If already equal, noop |
| |
| // If we found our opaque type, resolve it now! |
| if (isa<OpaqueType>(DestTyT) || isa<OpaqueType>(SrcTyT)) |
| return ResolveTypes(DestTyT, SrcTyT, DestST, Name); |
| |
| // 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->getPrimitiveID() != SrcTyT->getPrimitiveID()) return true; |
| |
| // Otherwise, resolve the used type used by this derived type... |
| switch (DestTyT->getPrimitiveID()) { |
| case Type::FunctionTyID: { |
| if (cast<FunctionType>(DestTyT)->isVarArg() != |
| cast<FunctionType>(SrcTyT)->isVarArg() || |
| cast<FunctionType>(DestTyT)->getNumContainedTypes() != |
| cast<FunctionType>(SrcTyT)->getNumContainedTypes()) |
| return true; |
| for (unsigned i = 0, e = getFT(DestTy)->getNumContainedTypes(); i != e; ++i) |
| if (RecursiveResolveTypesI(getFT(DestTy)->getContainedType(i), |
| getFT(SrcTy)->getContainedType(i), DestST, "", |
| Pointers)) |
| return true; |
| return false; |
| } |
| case Type::StructTyID: { |
| if (getST(DestTy)->getNumContainedTypes() != |
| getST(SrcTy)->getNumContainedTypes()) return 1; |
| for (unsigned i = 0, e = getST(DestTy)->getNumContainedTypes(); i != e; ++i) |
| if (RecursiveResolveTypesI(getST(DestTy)->getContainedType(i), |
| getST(SrcTy)->getContainedType(i), DestST, "", |
| Pointers)) |
| return true; |
| return false; |
| } |
| case Type::ArrayTyID: { |
| const ArrayType *DAT = cast<ArrayType>(DestTy.get()); |
| const ArrayType *SAT = cast<ArrayType>(SrcTy.get()); |
| if (DAT->getNumElements() != SAT->getNumElements()) return true; |
| return RecursiveResolveTypesI(DAT->getElementType(), SAT->getElementType(), |
| DestST, "", Pointers); |
| } |
| case Type::PointerTyID: { |
| // 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; |
| |
| // 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<PointerType>(DestTy.get())->getElementType(), |
| cast<PointerType>(SrcTy.get())->getElementType(), |
| DestST, "", Pointers); |
| Pointers.pop_back(); |
| return Result; |
| } |
| default: assert(0 && "Unexpected type!"); return true; |
| } |
| } |
| |
| static bool RecursiveResolveTypes(const PATypeHolder &DestTy, |
| const PATypeHolder &SrcTy, |
| SymbolTable *DestST, const std::string &Name){ |
| std::vector<std::pair<PATypeHolder, PATypeHolder> > PointerTypes; |
| return RecursiveResolveTypesI(DestTy, SrcTy, DestST, Name, 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) { |
| SymbolTable *DestST = &Dest->getSymbolTable(); |
| const SymbolTable *SrcST = &Src->getSymbolTable(); |
| |
| // Look for a type plane for Type's... |
| SymbolTable::const_iterator PI = SrcST->find(Type::TypeTy); |
| if (PI == SrcST->end()) 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; |
| |
| const SymbolTable::VarMap &VM = PI->second; |
| for (SymbolTable::type_const_iterator I = VM.begin(), E = VM.end(); |
| I != E; ++I) { |
| const std::string &Name = I->first; |
| Type *RHS = cast<Type>(I->second); |
| |
| // Check to see if this type name is already in the dest module... |
| Type *Entry = cast_or_null<Type>(DestST->lookup(Type::TypeTy, Name)); |
| |
| if (ResolveTypes(Entry, RHS, DestST, Name)) { |
| // 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 = cast<Type>(VM.find(Name)->second); |
| Type *T2 = cast<Type>(DestST->lookup(Type::TypeTy, Name)); |
| if (!ResolveTypes(T2, T1, DestST, Name)) { |
| // 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]; |
| PATypeHolder T1(cast<Type>(VM.find(Name)->second)); |
| PATypeHolder T2(cast<Type>(DestST->lookup(Type::TypeTy, Name))); |
| |
| if (!RecursiveResolveTypes(T2, T1, DestST, 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. |
| // Report the warning and delete one of the names. |
| if (DelayedTypesToResolve.size() == OldSize) { |
| const std::string &Name = DelayedTypesToResolve.back(); |
| |
| const Type *T1 = cast<Type>(VM.find(Name)->second); |
| const Type *T2 = cast<Type>(DestST->lookup(Type::TypeTy, Name)); |
| std::cerr << "WARNING: Type conflict between types named '" << Name |
| << "'.\n Src='" << *T1 << "'.\n Dest='" << *T2 << "'\n"; |
| |
| // Remove the symbol name from the destination. |
| DelayedTypesToResolve.pop_back(); |
| } |
| } |
| } |
| |
| |
| return false; |
| } |
| |
| static void PrintMap(const std::map<const Value*, Value*> &M) { |
| for (std::map<const Value*, Value*>::const_iterator I = M.begin(), E =M.end(); |
| I != E; ++I) { |
| std::cerr << " Fr: " << (void*)I->first << " "; |
| I->first->dump(); |
| std::cerr << " To: " << (void*)I->second << " "; |
| I->second->dump(); |
| std::cerr << "\n"; |
| } |
| } |
| |
| |
| // RemapOperand - Use LocalMap and GlobalMap to convert references from one |
| // module to another. This is somewhat sophisticated in that it can |
| // automatically handle constant references correctly as well... |
| // |
| static Value *RemapOperand(const Value *In, |
| std::map<const Value*, Value*> &LocalMap, |
| std::map<const Value*, Value*> *GlobalMap) { |
| std::map<const Value*,Value*>::const_iterator I = LocalMap.find(In); |
| if (I != LocalMap.end()) return I->second; |
| |
| if (GlobalMap) { |
| I = GlobalMap->find(In); |
| if (I != GlobalMap->end()) return I->second; |
| } |
| |
| // Check to see if it's a constant that we are interesting in transforming... |
| if (const Constant *CPV = dyn_cast<Constant>(In)) { |
| if (!isa<DerivedType>(CPV->getType()) && !isa<ConstantExpr>(CPV)) |
| return const_cast<Constant*>(CPV); // Simple constants stay identical... |
| |
| Constant *Result = 0; |
| |
| if (const ConstantArray *CPA = dyn_cast<ConstantArray>(CPV)) { |
| const std::vector<Use> &Ops = CPA->getValues(); |
| std::vector<Constant*> Operands(Ops.size()); |
| for (unsigned i = 0, e = Ops.size(); i != e; ++i) |
| Operands[i] = |
| cast<Constant>(RemapOperand(Ops[i], LocalMap, GlobalMap)); |
| Result = ConstantArray::get(cast<ArrayType>(CPA->getType()), Operands); |
| } else if (const ConstantStruct *CPS = dyn_cast<ConstantStruct>(CPV)) { |
| const std::vector<Use> &Ops = CPS->getValues(); |
| std::vector<Constant*> Operands(Ops.size()); |
| for (unsigned i = 0; i < Ops.size(); ++i) |
| Operands[i] = |
| cast<Constant>(RemapOperand(Ops[i], LocalMap, GlobalMap)); |
| Result = ConstantStruct::get(cast<StructType>(CPS->getType()), Operands); |
| } else if (isa<ConstantPointerNull>(CPV)) { |
| Result = const_cast<Constant*>(CPV); |
| } else if (const ConstantPointerRef *CPR = |
| dyn_cast<ConstantPointerRef>(CPV)) { |
| Value *V = RemapOperand(CPR->getValue(), LocalMap, GlobalMap); |
| Result = ConstantPointerRef::get(cast<GlobalValue>(V)); |
| } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CPV)) { |
| if (CE->getOpcode() == Instruction::GetElementPtr) { |
| Value *Ptr = RemapOperand(CE->getOperand(0), LocalMap, GlobalMap); |
| std::vector<Constant*> Indices; |
| Indices.reserve(CE->getNumOperands()-1); |
| for (unsigned i = 1, e = CE->getNumOperands(); i != e; ++i) |
| Indices.push_back(cast<Constant>(RemapOperand(CE->getOperand(i), |
| LocalMap, GlobalMap))); |
| |
| Result = ConstantExpr::getGetElementPtr(cast<Constant>(Ptr), Indices); |
| } else if (CE->getNumOperands() == 1) { |
| // Cast instruction |
| assert(CE->getOpcode() == Instruction::Cast); |
| Value *V = RemapOperand(CE->getOperand(0), LocalMap, GlobalMap); |
| Result = ConstantExpr::getCast(cast<Constant>(V), CE->getType()); |
| } else if (CE->getNumOperands() == 2) { |
| // Binary operator... |
| Value *V1 = RemapOperand(CE->getOperand(0), LocalMap, GlobalMap); |
| Value *V2 = RemapOperand(CE->getOperand(1), LocalMap, GlobalMap); |
| |
| Result = ConstantExpr::get(CE->getOpcode(), cast<Constant>(V1), |
| cast<Constant>(V2)); |
| } else { |
| assert(0 && "Unknown constant expr type!"); |
| } |
| |
| } else { |
| assert(0 && "Unknown type of derived type constant value!"); |
| } |
| |
| // Cache the mapping in our local map structure... |
| if (GlobalMap) |
| GlobalMap->insert(std::make_pair(In, Result)); |
| else |
| LocalMap.insert(std::make_pair(In, Result)); |
| return Result; |
| } |
| |
| std::cerr << "XXX LocalMap: \n"; |
| PrintMap(LocalMap); |
| |
| if (GlobalMap) { |
| std::cerr << "XXX GlobalMap: \n"; |
| PrintMap(*GlobalMap); |
| } |
| |
| std::cerr << "Couldn't remap value: " << (void*)In << " " << *In << "\n"; |
| assert(0 && "Couldn't remap value!"); |
| return 0; |
| } |
| |
| /// FindGlobalNamed - Look in the specified symbol table for a global with the |
| /// specified name and type. If an exactly matching global does not exist, see |
| /// if there is a global which is "type compatible" with the specified |
| /// name/type. This allows us to resolve things like '%x = global int*' with |
| /// '%x = global opaque*'. |
| /// |
| static GlobalValue *FindGlobalNamed(const std::string &Name, const Type *Ty, |
| SymbolTable *ST) { |
| // See if an exact match exists in the symbol table... |
| if (Value *V = ST->lookup(Ty, Name)) return cast<GlobalValue>(V); |
| |
| // It doesn't exist exactly, scan through all of the type planes in the symbol |
| // table, checking each of them for a type-compatible version. |
| // |
| for (SymbolTable::iterator I = ST->begin(), E = ST->end(); I != E; ++I) |
| if (I->first != Type::TypeTy) { |
| SymbolTable::VarMap &VM = I->second; |
| // Does this type plane contain an entry with the specified name? |
| SymbolTable::type_iterator TI = VM.find(Name); |
| if (TI != VM.end()) { |
| // Determine whether we can fold the two types together, resolving them. |
| // If so, we can use this value. |
| if (!RecursiveResolveTypes(Ty, I->first, ST, "")) |
| return cast<GlobalValue>(TI->second); |
| } |
| } |
| return 0; // Otherwise, nothing could be found. |
| } |
| |
| |
| // 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, |
| std::map<const Value*, Value*> &ValueMap, |
| std::multimap<std::string, GlobalVariable *> &AppendingVars, |
| std::string *Err) { |
| // We will need a module level symbol table if the src module has a module |
| // level symbol table... |
| SymbolTable *ST = (SymbolTable*)&Dest->getSymbolTable(); |
| |
| // Loop over all of the globals in the src module, mapping them over as we go |
| // |
| for (Module::const_giterator I = Src->gbegin(), E = Src->gend(); I != E; ++I){ |
| const GlobalVariable *SGV = I; |
| GlobalVariable *DGV = 0; |
| if (SGV->hasName()) { |
| // A same named thing is a global variable, because the only two things |
| // that may be in a module level symbol table are Global Vars and |
| // Functions, and they both have distinct, nonoverlapping, possible types. |
| // |
| DGV = cast_or_null<GlobalVariable>(FindGlobalNamed(SGV->getName(), |
| SGV->getType(), ST)); |
| } |
| |
| assert(SGV->hasInitializer() || SGV->hasExternalLinkage() && |
| "Global must either be external or have an initializer!"); |
| |
| bool SGExtern = SGV->isExternal(); |
| bool DGExtern = DGV ? DGV->isExternal() : false; |
| |
| if (!DGV || DGV->hasInternalLinkage() || SGV->hasInternalLinkage()) { |
| // 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(SGV->getType()->getElementType(), |
| SGV->isConstant(), SGV->getLinkage(), /*init*/0, |
| SGV->getName(), Dest); |
| |
| // 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()){ |
| assert(DGV && DGV->getName() == SGV->getName() && |
| DGV->hasInternalLinkage()); |
| DGV->setName(""); |
| NewDGV->setName(SGV->getName()); // Force the name back |
| DGV->setName(SGV->getName()); // This will cause a renaming |
| assert(NewDGV->getName() == SGV->getName() && |
| DGV->getName() != SGV->getName()); |
| } |
| |
| // Make sure to remember this mapping... |
| ValueMap.insert(std::make_pair(SGV, NewDGV)); |
| if (SGV->hasAppendingLinkage()) |
| // Keep track that this is an appending variable... |
| AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV)); |
| |
| } else if (SGV->isExternal()) { |
| // If SGV is external or if both SGV & DGV are external.. Just link the |
| // external globals, we aren't adding anything. |
| ValueMap.insert(std::make_pair(SGV, DGV)); |
| |
| } else if (DGV->isExternal()) { // If DGV is external but SGV is not... |
| ValueMap.insert(std::make_pair(SGV, DGV)); |
| DGV->setLinkage(SGV->getLinkage()); // Inherit linkage! |
| } else if (SGV->hasWeakLinkage()) { |
| // At this point we know that DGV has LinkOnce, Appending, Weak, or |
| // External linkage. If DGV is Appending, this is an error. |
| if (DGV->hasAppendingLinkage()) |
| return Error(Err, "Linking globals named '" + SGV->getName() + |
| " ' with 'weak' and 'appending' linkage is not allowed!"); |
| // Otherwise, just perform the link. |
| ValueMap.insert(std::make_pair(SGV, DGV)); |
| } else if (DGV->hasWeakLinkage()) { |
| // At this point we know that SGV has LinkOnce, Appending, or External |
| // linkage. If SGV is Appending, this is an error. |
| if (SGV->hasAppendingLinkage()) |
| return Error(Err, "Linking globals named '" + SGV->getName() + |
| " ' with 'weak' and 'appending' linkage is not allowed!"); |
| if (!SGV->hasLinkOnceLinkage()) |
| DGV->setLinkage(SGV->getLinkage()); // Inherit linkage! |
| ValueMap.insert(std::make_pair(SGV, DGV)); |
| |
| } else if (SGV->getLinkage() != DGV->getLinkage()) { |
| return Error(Err, "Global variables named '" + SGV->getName() + |
| "' have different linkage specifiers!"); |
| } else if (SGV->hasExternalLinkage()) { |
| // Allow linking two exactly identical external global variables... |
| if (SGV->isConstant() != DGV->isConstant()) |
| return Error(Err, "Global Variable Collision on '" + |
| SGV->getType()->getDescription() + " %" + SGV->getName() + |
| "' - Global variables differ in const'ness"); |
| |
| if (SGV->getInitializer() != DGV->getInitializer()) |
| return Error(Err, "Global Variable Collision on '" + |
| SGV->getType()->getDescription() + " %" + SGV->getName() + |
| "' - External linkage globals have different initializers"); |
| |
| ValueMap.insert(std::make_pair(SGV, DGV)); |
| } else if (SGV->hasLinkOnceLinkage()) { |
| // If the global variable has a name, and that name is already in use in |
| // the Dest module, make sure that the name is a compatible global |
| // variable... |
| // |
| // Check to see if the two GV's have the same Const'ness... |
| if (SGV->isConstant() != DGV->isConstant()) |
| return Error(Err, "Global Variable Collision on '" + |
| SGV->getType()->getDescription() + " %" + SGV->getName() + |
| "' - Global variables differ in const'ness"); |
| |
| // Okay, everything is cool, remember the mapping... |
| ValueMap.insert(std::make_pair(SGV, DGV)); |
| } else if (SGV->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(SGV->getType()->getElementType(), |
| SGV->isConstant(), SGV->getLinkage(), /*init*/0, |
| "", Dest); |
| |
| // Make sure to remember this mapping... |
| ValueMap.insert(std::make_pair(SGV, NewDGV)); |
| |
| // Keep track that this is an appending variable... |
| AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV)); |
| } else { |
| assert(0 && "Unknown linkage!"); |
| } |
| } |
| 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, |
| std::map<const Value*, Value*> &ValueMap, |
| std::string *Err) { |
| |
| // Loop over all of the globals in the src module, mapping them over as we go |
| // |
| for (Module::const_giterator I = Src->gbegin(), E = Src->gend(); 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>(RemapOperand(SGV->getInitializer(), ValueMap, 0)); |
| |
| GlobalVariable *DGV = cast<GlobalVariable>(ValueMap[SGV]); |
| if (DGV->hasInitializer()) { |
| assert(SGV->getLinkage() == DGV->getLinkage()); |
| if (SGV->hasExternalLinkage()) { |
| if (DGV->getInitializer() != SInit) |
| return Error(Err, "Global Variable Collision on '" + |
| SGV->getType()->getDescription() +"':%"+SGV->getName()+ |
| " - Global variables have different initializers"); |
| } else if (DGV->hasLinkOnceLinkage() || DGV->hasWeakLinkage()) { |
| // Nothing is required, mapped values will take the new global |
| // automatically. |
| } else if (DGV->hasAppendingLinkage()) { |
| assert(0 && "Appending linkage unimplemented!"); |
| } else { |
| assert(0 && "Unknown linkage!"); |
| } |
| } else { |
| // Copy the initializer over now... |
| DGV->setInitializer(SInit); |
| } |
| } |
| } |
| 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, |
| std::map<const Value*, Value*> &ValueMap, |
| std::string *Err) { |
| SymbolTable *ST = (SymbolTable*)&Dest->getSymbolTable(); |
| |
| // Loop over all of the functions in the src module, mapping them over as we |
| // go |
| // |
| for (Module::const_iterator I = Src->begin(), E = Src->end(); I != E; ++I) { |
| const Function *SF = I; // SrcFunction |
| Function *DF = 0; |
| if (SF->hasName()) |
| // The same named thing is a Function, because the only two things |
| // that may be in a module level symbol table are Global Vars and |
| // Functions, and they both have distinct, nonoverlapping, possible types. |
| // |
| DF = cast_or_null<Function>(FindGlobalNamed(SF->getName(), SF->getType(), |
| ST)); |
| |
| if (!DF || SF->hasInternalLinkage() || DF->hasInternalLinkage()) { |
| // Function does not already exist, simply insert an function signature |
| // identical to SF into the dest module... |
| Function *NewDF = new Function(SF->getFunctionType(), SF->getLinkage(), |
| SF->getName(), Dest); |
| |
| // 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->getName() != SF->getName() && !NewDF->hasInternalLinkage()) { |
| assert(DF && DF->getName() == SF->getName() &&DF->hasInternalLinkage()); |
| DF->setName(""); |
| NewDF->setName(SF->getName()); // Force the name back |
| DF->setName(SF->getName()); // This will cause a renaming |
| assert(NewDF->getName() == SF->getName() && |
| DF->getName() != SF->getName()); |
| } |
| |
| // ... and remember this mapping... |
| ValueMap.insert(std::make_pair(SF, NewDF)); |
| } else if (SF->isExternal()) { |
| // If SF is external or if both SF & DF are external.. Just link the |
| // external functions, we aren't adding anything. |
| ValueMap.insert(std::make_pair(SF, DF)); |
| } else if (DF->isExternal()) { // If DF is external but SF is not... |
| // Link the external functions, update linkage qualifiers |
| ValueMap.insert(std::make_pair(SF, DF)); |
| DF->setLinkage(SF->getLinkage()); |
| |
| } else if (SF->hasWeakLinkage()) { |
| // At this point we know that DF has LinkOnce, Weak, or External linkage. |
| ValueMap.insert(std::make_pair(SF, DF)); |
| |
| } else if (DF->hasWeakLinkage()) { |
| // At this point we know that SF has LinkOnce or External linkage. |
| ValueMap.insert(std::make_pair(SF, DF)); |
| if (!SF->hasLinkOnceLinkage()) // Don't inherit linkonce linkage |
| DF->setLinkage(SF->getLinkage()); |
| |
| } else if (SF->getLinkage() != DF->getLinkage()) { |
| return Error(Err, "Functions named '" + SF->getName() + |
| "' have different linkage specifiers!"); |
| } else if (SF->hasExternalLinkage()) { |
| // The function is defined in both modules!! |
| return Error(Err, "Function '" + |
| SF->getFunctionType()->getDescription() + "':\"" + |
| SF->getName() + "\" - Function is already defined!"); |
| } else if (SF->hasLinkOnceLinkage()) { |
| // Completely ignore the source function. |
| ValueMap.insert(std::make_pair(SF, DF)); |
| } else { |
| assert(0 && "Unknown linkage configuration found!"); |
| } |
| } |
| 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, const Function *Src, |
| std::map<const Value*, Value*> &GlobalMap, |
| std::string *Err) { |
| assert(Src && Dest && Dest->isExternal() && !Src->isExternal()); |
| std::map<const Value*, Value*> LocalMap; // Map for function local values |
| |
| // Go through and convert function arguments over... |
| Function::aiterator DI = Dest->abegin(); |
| for (Function::const_aiterator I = Src->abegin(), E = Src->aend(); |
| I != E; ++I, ++DI) { |
| DI->setName(I->getName()); // Copy the name information over... |
| |
| // Add a mapping to our local map |
| LocalMap.insert(std::make_pair(I, DI)); |
| } |
| |
| // Loop over all of the basic blocks, copying the instructions over... |
| // |
| for (Function::const_iterator I = Src->begin(), E = Src->end(); I != E; ++I) { |
| // Create new basic block and add to mapping and the Dest function... |
| BasicBlock *DBB = new BasicBlock(I->getName(), Dest); |
| LocalMap.insert(std::make_pair(I, DBB)); |
| |
| // Loop over all of the instructions in the src basic block, copying them |
| // over. Note that this is broken in a strict sense because the cloned |
| // instructions will still be referencing values in the Src module, not |
| // the remapped values. In our case, however, we will not get caught and |
| // so we can delay patching the values up until later... |
| // |
| for (BasicBlock::const_iterator II = I->begin(), IE = I->end(); |
| II != IE; ++II) { |
| Instruction *DI = II->clone(); |
| DI->setName(II->getName()); |
| DBB->getInstList().push_back(DI); |
| LocalMap.insert(std::make_pair(II, DI)); |
| } |
| } |
| |
| // 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) |
| *OI = RemapOperand(*OI, LocalMap, &GlobalMap); |
| |
| 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, const Module *Src, |
| std::map<const Value*, Value*> &ValueMap, |
| std::string *Err) { |
| |
| // Loop over all of the functions in the src module, mapping them over as we |
| // go |
| // |
| for (Module::const_iterator SF = Src->begin(), E = Src->end(); SF != E; ++SF){ |
| if (!SF->isExternal()) { // No body if function is external |
| Function *DF = cast<Function>(ValueMap[SF]); // Destination function |
| |
| // DF not external SF external? |
| if (!DF->isExternal()) { |
| if (DF->hasLinkOnceLinkage()) continue; // No relinkage for link-once! |
| if (SF->hasWeakLinkage()) continue; |
| return Error(Err, "Function '" + SF->getName() + |
| "' body multiply defined!"); |
| } |
| |
| 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!"); |
| |
| unsigned NewSize = T1->getNumElements() + T2->getNumElements(); |
| ArrayType *NewType = ArrayType::get(T1->getElementType(), NewSize); |
| |
| // Create the new global variable... |
| GlobalVariable *NG = |
| new GlobalVariable(NewType, G1->isConstant(), G1->getLinkage(), |
| /*init*/0, First->first, M); |
| |
| // Merge the initializer... |
| Inits.reserve(NewSize); |
| ConstantArray *I = cast<ConstantArray>(G1->getInitializer()); |
| for (unsigned i = 0, e = T1->getNumElements(); i != e; ++i) |
| Inits.push_back(cast<Constant>(I->getValues()[i])); |
| I = cast<ConstantArray>(G2->getInitializer()); |
| for (unsigned i = 0, e = T2->getNumElements(); i != e; ++i) |
| Inits.push_back(cast<Constant>(I->getValues()[i])); |
| 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! |
| ConstantPointerRef *NGCP = ConstantPointerRef::get(NG); |
| G1->replaceAllUsesWith(ConstantExpr::getCast(NGCP, G1->getType())); |
| G2->replaceAllUsesWith(ConstantExpr::getCast(NGCP, 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; |
| } |
| |
| |
| // 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 LinkModules(Module *Dest, const Module *Src, std::string *ErrorMsg) { |
| if (Dest->getEndianness() == Module::AnyEndianness) |
| Dest->setEndianness(Src->getEndianness()); |
| if (Dest->getPointerSize() == Module::AnyPointerSize) |
| Dest->setPointerSize(Src->getPointerSize()); |
| |
| if (Src->getEndianness() != Module::AnyEndianness && |
| Dest->getEndianness() != Src->getEndianness()) |
| std::cerr << "WARNING: Linking two modules of different endianness!\n"; |
| if (Src->getPointerSize() != Module::AnyPointerSize && |
| Dest->getPointerSize() != Src->getPointerSize()) |
| std::cerr << "WARNING: Linking two modules of different pointer size!\n"; |
| |
| // 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. |
| // |
| std::map<const Value*, Value*> 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; |
| |
| // Add all of the appending globals already in the Dest module to |
| // AppendingVars. |
| for (Module::giterator I = Dest->gbegin(), E = Dest->gend(); I != E; ++I) |
| 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; |
| |
| // 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; |
| |
| return false; |
| } |
| |
