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- //===- 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/Streams.h"
- #include "llvm/Support/ErrorHandling.h"
- #include "llvm/System/Path.h"
- #include "llvm/ADT/DenseMap.h"
- #include <sstream>
- 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 std::string &Message) {
- if (E) *E = Message;
- 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 {
- 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 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<OpaqueType>(DstTy) || isa<OpaqueType>(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 (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;
- }
- #ifndef NDEBUG
- 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) {
- cerr << " Fr: " << (void*)I->first << " ";
- I->first->dump();
- cerr << " To: " << (void*)I->second << " ";
- I->second->dump();
- cerr << "\n";
- }
- }
- #endif
- // RemapOperand - Use ValueMap to convert constants from one module to another.
- static Value *RemapOperand(const Value *In,
- std::map<const Value*, Value*> &ValueMap,
- LLVMContext &Context) {
- std::map<const Value*,Value*>::const_iterator I = ValueMap.find(In);
- if (I != ValueMap.end())
- return I->second;
- // Check to see if it's a constant that we are interested in transforming.
- Value *Result = 0;
- if (const Constant *CPV = dyn_cast<Constant>(In)) {
- if ((!isa<DerivedType>(CPV->getType()) && !isa<ConstantExpr>(CPV)) ||
- isa<ConstantInt>(CPV) || isa<ConstantAggregateZero>(CPV))
- return const_cast<Constant*>(CPV); // Simple constants stay identical.
- if (const ConstantArray *CPA = dyn_cast<ConstantArray>(CPV)) {
- std::vector<Constant*> Operands(CPA->getNumOperands());
- for (unsigned i = 0, e = CPA->getNumOperands(); i != e; ++i)
- Operands[i] =cast<Constant>(RemapOperand(CPA->getOperand(i), ValueMap,
- Context));
- Result =
- Context.getConstantArray(cast<ArrayType>(CPA->getType()), Operands);
- } else if (const ConstantStruct *CPS = dyn_cast<ConstantStruct>(CPV)) {
- std::vector<Constant*> Operands(CPS->getNumOperands());
- for (unsigned i = 0, e = CPS->getNumOperands(); i != e; ++i)
- Operands[i] =cast<Constant>(RemapOperand(CPS->getOperand(i), ValueMap,
- Context));
- Result =
- Context.getConstantStruct(cast<StructType>(CPS->getType()), Operands);
- } else if (isa<ConstantPointerNull>(CPV) || isa<UndefValue>(CPV)) {
- Result = const_cast<Constant*>(CPV);
- } else if (const ConstantVector *CP = dyn_cast<ConstantVector>(CPV)) {
- std::vector<Constant*> Operands(CP->getNumOperands());
- for (unsigned i = 0, e = CP->getNumOperands(); i != e; ++i)
- Operands[i] = cast<Constant>(RemapOperand(CP->getOperand(i), ValueMap,
- Context));
- Result = Context.getConstantVector(Operands);
- } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CPV)) {
- std::vector<Constant*> Ops;
- for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i)
- Ops.push_back(cast<Constant>(RemapOperand(CE->getOperand(i),ValueMap,
- Context)));
- Result = CE->getWithOperands(Ops);
- } else {
- assert(!isa<GlobalValue>(CPV) && "Unmapped global?");
- LLVM_UNREACHABLE("Unknown type of derived type constant value!");
- }
- } else if (isa<InlineAsm>(In)) {
- Result = const_cast<Value*>(In);
- }
- // Cache the mapping in our local map structure
- if (Result) {
- ValueMap[In] = Result;
- return Result;
- }
- #ifndef NDEBUG
- cerr << "LinkModules ValueMap: \n";
- PrintMap(ValueMap);
- cerr << "Couldn't remap value: " << (void*)In << " " << *In << "\n";
- LLVM_UNREACHABLE("Couldn't remap value!");
- #endif
- return 0;
- }
- /// 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;
- }
- // 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) {
- ValueSymbolTable &DestSymTab = Dest->getValueSymbolTable();
- LLVMContext &Context = Dest->getContext();
- // 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->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()) &&
- "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(Context.getConstantExprBitCast(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();
- 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<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] = Context.getConstantExprBitCast(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 {
- 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,
- std::map<const Value*, Value*> &ValueMap,
- std::string *Err) {
- LLVMContext &Context = Dest->getContext();
- // 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.
- std::map<const Value*,Value*>::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(Context.getConstantExprBitCast(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(Context.getConstantExprBitCast(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...
- NewGA = new GlobalAlias(SGA->getType(), SGA->getLinkage(),
- SGA->getName(), DAliasee, 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 RemapOperand.
- 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,
- 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_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>(RemapOperand(SGV->getInitializer(), ValueMap,
- Dest->getContext()));
- // 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,
- std::map<const Value*, Value*> &ValueMap,
- std::string *Err) {
- ValueSymbolTable &DestSymTab = Dest->getValueSymbolTable();
- LLVMContext &Context = Dest->getContext();
- // 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->getNameStart(),
- SF->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() != 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(Context.getConstantExprBitCast(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 RemapOperand.
- 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] = Context.getConstantExprBitCast(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,
- std::map<const Value*, Value*> &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 = RemapOperand(*OI, ValueMap, *Dest->getContext());
- // 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,
- 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::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.
- LLVMContext &Context = M->getContext();
- // 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 = Context.getArrayType(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 = Context.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 = Context.getNullValue(T2->getElementType());
- for (unsigned i = 0, e = T2->getNumElements(); i != e; ++i)
- Inits.push_back(CV);
- }
- NG->setInitializer(Context.getConstantArray(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(Context.getConstantExprBitCast(NG,
- G1->getType()));
- G2->replaceAllUsesWith(Context.getConstantExprBitCast(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)
- if (const GlobalValue *GV = I->resolveAliasedGlobal())
- if (GV != I && !GV->isDeclaration())
- I->replaceAllUsesWith(const_cast<GlobalValue*>(GV));
- 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())
- cerr << "WARNING: Linking two modules of different data layouts!\n";
- if (!Src->getTargetTriple().empty() &&
- Dest->getTargetTriple() != Src->getTargetTriple())
- cerr << "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.
- 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;
- 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;
- // 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
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