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methods to try to have the type predicates be more logically positioned. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96349 91177308-0d34-0410-b5e6-96231b3b80d8
1384 lines
55 KiB
C++
1384 lines
55 KiB
C++
//===- lib/Linker/LinkModules.cpp - Module Linker Implementation ----------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements the LLVM module linker.
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//
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// Specifically, this:
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// * Merges global variables between the two modules
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// * Uninit + Uninit = Init, Init + Uninit = Init, Init + Init = Error if !=
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// * Merges functions between two modules
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Linker.h"
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#include "llvm/Constants.h"
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#include "llvm/DerivedTypes.h"
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#include "llvm/LLVMContext.h"
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#include "llvm/Module.h"
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#include "llvm/TypeSymbolTable.h"
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#include "llvm/ValueSymbolTable.h"
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#include "llvm/Instructions.h"
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#include "llvm/Assembly/Writer.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/Support/ErrorHandling.h"
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#include "llvm/Support/raw_ostream.h"
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#include "llvm/System/Path.h"
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#include "llvm/ADT/DenseMap.h"
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using namespace llvm;
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// Error - Simple wrapper function to conditionally assign to E and return true.
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// This just makes error return conditions a little bit simpler...
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static inline bool Error(std::string *E, const Twine &Message) {
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if (E) *E = Message.str();
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return true;
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}
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// Function: ResolveTypes()
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//
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// Description:
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// Attempt to link the two specified types together.
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//
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// Inputs:
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// DestTy - The type to which we wish to resolve.
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// SrcTy - The original type which we want to resolve.
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//
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// Outputs:
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// DestST - The symbol table in which the new type should be placed.
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//
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// Return value:
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// true - There is an error and the types cannot yet be linked.
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// false - No errors.
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//
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static bool ResolveTypes(const Type *DestTy, const Type *SrcTy) {
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if (DestTy == SrcTy) return false; // If already equal, noop
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assert(DestTy && SrcTy && "Can't handle null types");
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if (const OpaqueType *OT = dyn_cast<OpaqueType>(DestTy)) {
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// Type _is_ in module, just opaque...
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const_cast<OpaqueType*>(OT)->refineAbstractTypeTo(SrcTy);
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} else if (const OpaqueType *OT = dyn_cast<OpaqueType>(SrcTy)) {
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const_cast<OpaqueType*>(OT)->refineAbstractTypeTo(DestTy);
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} else {
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return true; // Cannot link types... not-equal and neither is opaque.
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}
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return false;
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}
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/// LinkerTypeMap - This implements a map of types that is stable
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/// even if types are resolved/refined to other types. This is not a general
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/// purpose map, it is specific to the linker's use.
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namespace {
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class LinkerTypeMap : public AbstractTypeUser {
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typedef DenseMap<const Type*, PATypeHolder> TheMapTy;
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TheMapTy TheMap;
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LinkerTypeMap(const LinkerTypeMap&); // DO NOT IMPLEMENT
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void operator=(const LinkerTypeMap&); // DO NOT IMPLEMENT
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public:
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LinkerTypeMap() {}
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~LinkerTypeMap() {
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for (DenseMap<const Type*, PATypeHolder>::iterator I = TheMap.begin(),
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E = TheMap.end(); I != E; ++I)
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I->first->removeAbstractTypeUser(this);
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}
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/// lookup - Return the value for the specified type or null if it doesn't
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/// exist.
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const Type *lookup(const Type *Ty) const {
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TheMapTy::const_iterator I = TheMap.find(Ty);
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if (I != TheMap.end()) return I->second;
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return 0;
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}
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/// erase - Remove the specified type, returning true if it was in the set.
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bool erase(const Type *Ty) {
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if (!TheMap.erase(Ty))
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return false;
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if (Ty->isAbstract())
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Ty->removeAbstractTypeUser(this);
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return true;
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}
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/// insert - This returns true if the pointer was new to the set, false if it
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/// was already in the set.
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bool insert(const Type *Src, const Type *Dst) {
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if (!TheMap.insert(std::make_pair(Src, PATypeHolder(Dst))).second)
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return false; // Already in map.
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if (Src->isAbstract())
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Src->addAbstractTypeUser(this);
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return true;
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}
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protected:
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/// refineAbstractType - The callback method invoked when an abstract type is
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/// resolved to another type. An object must override this method to update
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/// its internal state to reference NewType instead of OldType.
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///
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virtual void refineAbstractType(const DerivedType *OldTy,
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const Type *NewTy) {
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TheMapTy::iterator I = TheMap.find(OldTy);
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const Type *DstTy = I->second;
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TheMap.erase(I);
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if (OldTy->isAbstract())
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OldTy->removeAbstractTypeUser(this);
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// Don't reinsert into the map if the key is concrete now.
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if (NewTy->isAbstract())
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insert(NewTy, DstTy);
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}
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/// The other case which AbstractTypeUsers must be aware of is when a type
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/// makes the transition from being abstract (where it has clients on it's
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/// AbstractTypeUsers list) to concrete (where it does not). This method
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/// notifies ATU's when this occurs for a type.
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virtual void typeBecameConcrete(const DerivedType *AbsTy) {
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TheMap.erase(AbsTy);
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AbsTy->removeAbstractTypeUser(this);
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}
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// for debugging...
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virtual void dump() const {
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dbgs() << "AbstractTypeSet!\n";
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}
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};
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}
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// RecursiveResolveTypes - This is just like ResolveTypes, except that it
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// recurses down into derived types, merging the used types if the parent types
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// are compatible.
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static bool RecursiveResolveTypesI(const Type *DstTy, const Type *SrcTy,
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LinkerTypeMap &Pointers) {
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if (DstTy == SrcTy) return false; // If already equal, noop
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// If we found our opaque type, resolve it now!
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if (DstTy->isOpaqueTy() || SrcTy->isOpaqueTy())
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return ResolveTypes(DstTy, SrcTy);
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// Two types cannot be resolved together if they are of different primitive
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// type. For example, we cannot resolve an int to a float.
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if (DstTy->getTypeID() != SrcTy->getTypeID()) return true;
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// If neither type is abstract, then they really are just different types.
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if (!DstTy->isAbstract() && !SrcTy->isAbstract())
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return true;
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// Otherwise, resolve the used type used by this derived type...
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switch (DstTy->getTypeID()) {
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default:
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return true;
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case Type::FunctionTyID: {
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const FunctionType *DstFT = cast<FunctionType>(DstTy);
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const FunctionType *SrcFT = cast<FunctionType>(SrcTy);
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if (DstFT->isVarArg() != SrcFT->isVarArg() ||
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DstFT->getNumContainedTypes() != SrcFT->getNumContainedTypes())
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return true;
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// Use TypeHolder's so recursive resolution won't break us.
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PATypeHolder ST(SrcFT), DT(DstFT);
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for (unsigned i = 0, e = DstFT->getNumContainedTypes(); i != e; ++i) {
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const Type *SE = ST->getContainedType(i), *DE = DT->getContainedType(i);
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if (SE != DE && RecursiveResolveTypesI(DE, SE, Pointers))
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return true;
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}
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return false;
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}
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case Type::StructTyID: {
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const StructType *DstST = cast<StructType>(DstTy);
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const StructType *SrcST = cast<StructType>(SrcTy);
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if (DstST->getNumContainedTypes() != SrcST->getNumContainedTypes())
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return true;
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PATypeHolder ST(SrcST), DT(DstST);
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for (unsigned i = 0, e = DstST->getNumContainedTypes(); i != e; ++i) {
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const Type *SE = ST->getContainedType(i), *DE = DT->getContainedType(i);
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if (SE != DE && RecursiveResolveTypesI(DE, SE, Pointers))
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return true;
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}
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return false;
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}
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case Type::ArrayTyID: {
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const ArrayType *DAT = cast<ArrayType>(DstTy);
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const ArrayType *SAT = cast<ArrayType>(SrcTy);
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if (DAT->getNumElements() != SAT->getNumElements()) return true;
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return RecursiveResolveTypesI(DAT->getElementType(), SAT->getElementType(),
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Pointers);
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}
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case Type::VectorTyID: {
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const VectorType *DVT = cast<VectorType>(DstTy);
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const VectorType *SVT = cast<VectorType>(SrcTy);
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if (DVT->getNumElements() != SVT->getNumElements()) return true;
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return RecursiveResolveTypesI(DVT->getElementType(), SVT->getElementType(),
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Pointers);
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}
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case Type::PointerTyID: {
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const PointerType *DstPT = cast<PointerType>(DstTy);
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const PointerType *SrcPT = cast<PointerType>(SrcTy);
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if (DstPT->getAddressSpace() != SrcPT->getAddressSpace())
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return true;
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// If this is a pointer type, check to see if we have already seen it. If
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// so, we are in a recursive branch. Cut off the search now. We cannot use
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// an associative container for this search, because the type pointers (keys
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// in the container) change whenever types get resolved.
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if (SrcPT->isAbstract())
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if (const Type *ExistingDestTy = Pointers.lookup(SrcPT))
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return ExistingDestTy != DstPT;
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if (DstPT->isAbstract())
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if (const Type *ExistingSrcTy = Pointers.lookup(DstPT))
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return ExistingSrcTy != SrcPT;
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// Otherwise, add the current pointers to the vector to stop recursion on
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// this pair.
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if (DstPT->isAbstract())
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Pointers.insert(DstPT, SrcPT);
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if (SrcPT->isAbstract())
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Pointers.insert(SrcPT, DstPT);
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return RecursiveResolveTypesI(DstPT->getElementType(),
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SrcPT->getElementType(), Pointers);
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}
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}
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}
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static bool RecursiveResolveTypes(const Type *DestTy, const Type *SrcTy) {
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LinkerTypeMap PointerTypes;
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return RecursiveResolveTypesI(DestTy, SrcTy, PointerTypes);
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}
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// LinkTypes - Go through the symbol table of the Src module and see if any
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// types are named in the src module that are not named in the Dst module.
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// Make sure there are no type name conflicts.
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static bool LinkTypes(Module *Dest, const Module *Src, std::string *Err) {
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TypeSymbolTable *DestST = &Dest->getTypeSymbolTable();
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const TypeSymbolTable *SrcST = &Src->getTypeSymbolTable();
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// Look for a type plane for Type's...
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TypeSymbolTable::const_iterator TI = SrcST->begin();
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TypeSymbolTable::const_iterator TE = SrcST->end();
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if (TI == TE) return false; // No named types, do nothing.
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// Some types cannot be resolved immediately because they depend on other
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// types being resolved to each other first. This contains a list of types we
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// are waiting to recheck.
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std::vector<std::string> DelayedTypesToResolve;
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for ( ; TI != TE; ++TI ) {
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const std::string &Name = TI->first;
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const Type *RHS = TI->second;
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// Check to see if this type name is already in the dest module.
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Type *Entry = DestST->lookup(Name);
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// If the name is just in the source module, bring it over to the dest.
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if (Entry == 0) {
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if (!Name.empty())
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DestST->insert(Name, const_cast<Type*>(RHS));
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} else if (ResolveTypes(Entry, RHS)) {
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// They look different, save the types 'till later to resolve.
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DelayedTypesToResolve.push_back(Name);
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}
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}
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// Iteratively resolve types while we can...
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while (!DelayedTypesToResolve.empty()) {
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// Loop over all of the types, attempting to resolve them if possible...
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unsigned OldSize = DelayedTypesToResolve.size();
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// Try direct resolution by name...
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for (unsigned i = 0; i != DelayedTypesToResolve.size(); ++i) {
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const std::string &Name = DelayedTypesToResolve[i];
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Type *T1 = SrcST->lookup(Name);
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Type *T2 = DestST->lookup(Name);
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if (!ResolveTypes(T2, T1)) {
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// We are making progress!
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DelayedTypesToResolve.erase(DelayedTypesToResolve.begin()+i);
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--i;
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}
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}
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// Did we not eliminate any types?
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if (DelayedTypesToResolve.size() == OldSize) {
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// Attempt to resolve subelements of types. This allows us to merge these
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// two types: { int* } and { opaque* }
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for (unsigned i = 0, e = DelayedTypesToResolve.size(); i != e; ++i) {
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const std::string &Name = DelayedTypesToResolve[i];
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if (!RecursiveResolveTypes(SrcST->lookup(Name), DestST->lookup(Name))) {
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// We are making progress!
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DelayedTypesToResolve.erase(DelayedTypesToResolve.begin()+i);
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// Go back to the main loop, perhaps we can resolve directly by name
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// now...
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break;
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}
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}
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// If we STILL cannot resolve the types, then there is something wrong.
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if (DelayedTypesToResolve.size() == OldSize) {
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// Remove the symbol name from the destination.
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DelayedTypesToResolve.pop_back();
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}
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}
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}
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return false;
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}
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#ifndef NDEBUG
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static void PrintMap(const std::map<const Value*, Value*> &M) {
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for (std::map<const Value*, Value*>::const_iterator I = M.begin(), E =M.end();
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I != E; ++I) {
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dbgs() << " Fr: " << (void*)I->first << " ";
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I->first->dump();
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dbgs() << " To: " << (void*)I->second << " ";
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I->second->dump();
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dbgs() << "\n";
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}
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}
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#endif
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// RemapOperand - Use ValueMap to convert constants from one module to another.
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static Value *RemapOperand(const Value *In,
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std::map<const Value*, Value*> &ValueMap) {
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std::map<const Value*,Value*>::const_iterator I = ValueMap.find(In);
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if (I != ValueMap.end())
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return I->second;
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// Check to see if it's a constant that we are interested in transforming.
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Value *Result = 0;
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if (const Constant *CPV = dyn_cast<Constant>(In)) {
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if ((!isa<DerivedType>(CPV->getType()) && !isa<ConstantExpr>(CPV)) ||
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isa<ConstantInt>(CPV) || isa<ConstantAggregateZero>(CPV))
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return const_cast<Constant*>(CPV); // Simple constants stay identical.
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if (const ConstantArray *CPA = dyn_cast<ConstantArray>(CPV)) {
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std::vector<Constant*> Operands(CPA->getNumOperands());
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for (unsigned i = 0, e = CPA->getNumOperands(); i != e; ++i)
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Operands[i] =cast<Constant>(RemapOperand(CPA->getOperand(i), ValueMap));
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Result = ConstantArray::get(cast<ArrayType>(CPA->getType()), Operands);
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} else if (const ConstantStruct *CPS = dyn_cast<ConstantStruct>(CPV)) {
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std::vector<Constant*> Operands(CPS->getNumOperands());
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for (unsigned i = 0, e = CPS->getNumOperands(); i != e; ++i)
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Operands[i] =cast<Constant>(RemapOperand(CPS->getOperand(i), ValueMap));
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Result = ConstantStruct::get(cast<StructType>(CPS->getType()), Operands);
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} else if (isa<ConstantPointerNull>(CPV) || isa<UndefValue>(CPV)) {
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Result = const_cast<Constant*>(CPV);
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} else if (const ConstantVector *CP = dyn_cast<ConstantVector>(CPV)) {
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std::vector<Constant*> Operands(CP->getNumOperands());
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for (unsigned i = 0, e = CP->getNumOperands(); i != e; ++i)
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Operands[i] = cast<Constant>(RemapOperand(CP->getOperand(i), ValueMap));
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Result = ConstantVector::get(Operands);
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} else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CPV)) {
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std::vector<Constant*> Ops;
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for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i)
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Ops.push_back(cast<Constant>(RemapOperand(CE->getOperand(i),ValueMap)));
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Result = CE->getWithOperands(Ops);
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} else if (const BlockAddress *CE = dyn_cast<BlockAddress>(CPV)) {
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Result = BlockAddress::get(
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cast<Function>(RemapOperand(CE->getFunction(), ValueMap)),
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CE->getBasicBlock());
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} else {
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assert(!isa<GlobalValue>(CPV) && "Unmapped global?");
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llvm_unreachable("Unknown type of derived type constant value!");
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}
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} else if (const MDNode *MD = dyn_cast<MDNode>(In)) {
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if (MD->isFunctionLocal()) {
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SmallVector<Value*, 4> Elts;
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for (unsigned i = 0, e = MD->getNumOperands(); i != e; ++i) {
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if (MD->getOperand(i))
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Elts.push_back(RemapOperand(MD->getOperand(i), ValueMap));
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else
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Elts.push_back(NULL);
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}
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Result = MDNode::get(In->getContext(), Elts.data(), MD->getNumOperands());
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} else {
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Result = const_cast<Value*>(In);
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}
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} else if (isa<MDString>(In) || isa<InlineAsm>(In) || isa<Instruction>(In)) {
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Result = const_cast<Value*>(In);
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}
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// Cache the mapping in our local map structure
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if (Result) {
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ValueMap[In] = Result;
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return Result;
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}
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#ifndef NDEBUG
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dbgs() << "LinkModules ValueMap: \n";
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PrintMap(ValueMap);
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dbgs() << "Couldn't remap value: " << (void*)In << " " << *In << "\n";
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llvm_unreachable("Couldn't remap value!");
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#endif
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return 0;
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}
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/// ForceRenaming - The LLVM SymbolTable class autorenames globals that conflict
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/// in the symbol table. This is good for all clients except for us. Go
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/// through the trouble to force this back.
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static void ForceRenaming(GlobalValue *GV, const std::string &Name) {
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assert(GV->getName() != Name && "Can't force rename to self");
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ValueSymbolTable &ST = GV->getParent()->getValueSymbolTable();
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// If there is a conflict, rename the conflict.
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if (GlobalValue *ConflictGV = cast_or_null<GlobalValue>(ST.lookup(Name))) {
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assert(ConflictGV->hasLocalLinkage() &&
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"Not conflicting with a static global, should link instead!");
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GV->takeName(ConflictGV);
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ConflictGV->setName(Name); // This will cause ConflictGV to get renamed
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assert(ConflictGV->getName() != Name && "ForceRenaming didn't work");
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} else {
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GV->setName(Name); // Force the name back
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}
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}
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/// CopyGVAttributes - copy additional attributes (those not needed to construct
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/// a GlobalValue) from the SrcGV to the DestGV.
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static void CopyGVAttributes(GlobalValue *DestGV, const GlobalValue *SrcGV) {
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// Use the maximum alignment, rather than just copying the alignment of SrcGV.
|
|
unsigned Alignment = std::max(DestGV->getAlignment(), SrcGV->getAlignment());
|
|
DestGV->copyAttributesFrom(SrcGV);
|
|
DestGV->setAlignment(Alignment);
|
|
}
|
|
|
|
/// GetLinkageResult - This analyzes the two global values and determines what
|
|
/// the result will look like in the destination module. In particular, it
|
|
/// computes the resultant linkage type, computes whether the global in the
|
|
/// source should be copied over to the destination (replacing the existing
|
|
/// one), and computes whether this linkage is an error or not. It also performs
|
|
/// visibility checks: we cannot link together two symbols with different
|
|
/// visibilities.
|
|
static bool GetLinkageResult(GlobalValue *Dest, const GlobalValue *Src,
|
|
GlobalValue::LinkageTypes <, bool &LinkFromSrc,
|
|
std::string *Err) {
|
|
assert((!Dest || !Src->hasLocalLinkage()) &&
|
|
"If Src has internal linkage, Dest shouldn't be set!");
|
|
if (!Dest) {
|
|
// Linking something to nothing.
|
|
LinkFromSrc = true;
|
|
LT = Src->getLinkage();
|
|
} else if (Src->isDeclaration()) {
|
|
// If Src is external or if both Src & Dest are external.. Just link the
|
|
// external globals, we aren't adding anything.
|
|
if (Src->hasDLLImportLinkage()) {
|
|
// If one of GVs has DLLImport linkage, result should be dllimport'ed.
|
|
if (Dest->isDeclaration()) {
|
|
LinkFromSrc = true;
|
|
LT = Src->getLinkage();
|
|
}
|
|
} else if (Dest->hasExternalWeakLinkage()) {
|
|
// If the Dest is weak, use the source linkage.
|
|
LinkFromSrc = true;
|
|
LT = Src->getLinkage();
|
|
} else {
|
|
LinkFromSrc = false;
|
|
LT = Dest->getLinkage();
|
|
}
|
|
} else if (Dest->isDeclaration() && !Dest->hasDLLImportLinkage()) {
|
|
// If Dest is external but Src is not:
|
|
LinkFromSrc = true;
|
|
LT = Src->getLinkage();
|
|
} else if (Src->hasAppendingLinkage() || Dest->hasAppendingLinkage()) {
|
|
if (Src->getLinkage() != Dest->getLinkage())
|
|
return Error(Err, "Linking globals named '" + Src->getName() +
|
|
"': can only link appending global with another appending global!");
|
|
LinkFromSrc = true; // Special cased.
|
|
LT = Src->getLinkage();
|
|
} else if (Src->isWeakForLinker()) {
|
|
// At this point we know that Dest has LinkOnce, External*, Weak, Common,
|
|
// or DLL* linkage.
|
|
if (Dest->hasExternalWeakLinkage() ||
|
|
Dest->hasAvailableExternallyLinkage() ||
|
|
(Dest->hasLinkOnceLinkage() &&
|
|
(Src->hasWeakLinkage() || Src->hasCommonLinkage()))) {
|
|
LinkFromSrc = true;
|
|
LT = Src->getLinkage();
|
|
} else {
|
|
LinkFromSrc = false;
|
|
LT = Dest->getLinkage();
|
|
}
|
|
} else if (Dest->isWeakForLinker()) {
|
|
// At this point we know that Src has External* or DLL* linkage.
|
|
if (Src->hasExternalWeakLinkage()) {
|
|
LinkFromSrc = false;
|
|
LT = Dest->getLinkage();
|
|
} else {
|
|
LinkFromSrc = true;
|
|
LT = GlobalValue::ExternalLinkage;
|
|
}
|
|
} else {
|
|
assert((Dest->hasExternalLinkage() ||
|
|
Dest->hasDLLImportLinkage() ||
|
|
Dest->hasDLLExportLinkage() ||
|
|
Dest->hasExternalWeakLinkage()) &&
|
|
(Src->hasExternalLinkage() ||
|
|
Src->hasDLLImportLinkage() ||
|
|
Src->hasDLLExportLinkage() ||
|
|
Src->hasExternalWeakLinkage()) &&
|
|
"Unexpected linkage type!");
|
|
return Error(Err, "Linking globals named '" + Src->getName() +
|
|
"': symbol multiply defined!");
|
|
}
|
|
|
|
// Check visibility
|
|
if (Dest && Src->getVisibility() != Dest->getVisibility())
|
|
if (!Src->isDeclaration() && !Dest->isDeclaration())
|
|
return Error(Err, "Linking globals named '" + Src->getName() +
|
|
"': symbols have different visibilities!");
|
|
return false;
|
|
}
|
|
|
|
// Insert all of the named mdnoes in Src into the Dest module.
|
|
static void LinkNamedMDNodes(Module *Dest, Module *Src) {
|
|
for (Module::const_named_metadata_iterator I = Src->named_metadata_begin(),
|
|
E = Src->named_metadata_end(); I != E; ++I) {
|
|
const NamedMDNode *SrcNMD = I;
|
|
NamedMDNode *DestNMD = Dest->getNamedMetadata(SrcNMD->getName());
|
|
if (!DestNMD)
|
|
NamedMDNode::Create(SrcNMD, Dest);
|
|
else {
|
|
// Add Src elements into Dest node.
|
|
for (unsigned i = 0, e = SrcNMD->getNumOperands(); i != e; ++i)
|
|
DestNMD->addOperand(SrcNMD->getOperand(i));
|
|
}
|
|
}
|
|
}
|
|
|
|
// 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();
|
|
|
|
// Loop over all of the globals in the src module, mapping them over as we go
|
|
for (Module::const_global_iterator I = Src->global_begin(),
|
|
E = Src->global_end(); I != E; ++I) {
|
|
const GlobalVariable *SGV = I;
|
|
GlobalValue *DGV = 0;
|
|
|
|
// Check to see if may have to link the global with the global, alias or
|
|
// function.
|
|
if (SGV->hasName() && !SGV->hasLocalLinkage())
|
|
DGV = cast_or_null<GlobalValue>(DestSymTab.lookup(SGV->getName()));
|
|
|
|
// If we found a global with the same name in the dest module, but it has
|
|
// internal linkage, we are really not doing any linkage here.
|
|
if (DGV && DGV->hasLocalLinkage())
|
|
DGV = 0;
|
|
|
|
// If types don't agree due to opaque types, try to resolve them.
|
|
if (DGV && DGV->getType() != SGV->getType())
|
|
RecursiveResolveTypes(SGV->getType(), DGV->getType());
|
|
|
|
assert((SGV->hasInitializer() || SGV->hasExternalWeakLinkage() ||
|
|
SGV->hasExternalLinkage() || SGV->hasDLLImportLinkage()) &&
|
|
"Global must either be external or have an initializer!");
|
|
|
|
GlobalValue::LinkageTypes NewLinkage = GlobalValue::InternalLinkage;
|
|
bool LinkFromSrc = false;
|
|
if (GetLinkageResult(DGV, SGV, NewLinkage, LinkFromSrc, Err))
|
|
return true;
|
|
|
|
if (DGV == 0) {
|
|
// No linking to be performed, simply create an identical version of the
|
|
// symbol over in the dest module... the initializer will be filled in
|
|
// later by LinkGlobalInits.
|
|
GlobalVariable *NewDGV =
|
|
new GlobalVariable(*Dest, SGV->getType()->getElementType(),
|
|
SGV->isConstant(), SGV->getLinkage(), /*init*/0,
|
|
SGV->getName(), 0, false,
|
|
SGV->getType()->getAddressSpace());
|
|
// Propagate alignment, visibility and section info.
|
|
CopyGVAttributes(NewDGV, SGV);
|
|
|
|
// If the LLVM runtime renamed the global, but it is an externally visible
|
|
// symbol, DGV must be an existing global with internal linkage. Rename
|
|
// it.
|
|
if (!NewDGV->hasLocalLinkage() && NewDGV->getName() != SGV->getName())
|
|
ForceRenaming(NewDGV, SGV->getName());
|
|
|
|
// Make sure to remember this mapping.
|
|
ValueMap[SGV] = NewDGV;
|
|
|
|
// Keep track that this is an appending variable.
|
|
if (SGV->hasAppendingLinkage())
|
|
AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV));
|
|
continue;
|
|
}
|
|
|
|
// If the visibilities of the symbols disagree and the destination is a
|
|
// prototype, take the visibility of its input.
|
|
if (DGV->isDeclaration())
|
|
DGV->setVisibility(SGV->getVisibility());
|
|
|
|
if (DGV->hasAppendingLinkage()) {
|
|
// No linking is performed yet. Just insert a new copy of the global, and
|
|
// keep track of the fact that it is an appending variable in the
|
|
// AppendingVars map. The name is cleared out so that no linkage is
|
|
// performed.
|
|
GlobalVariable *NewDGV =
|
|
new GlobalVariable(*Dest, SGV->getType()->getElementType(),
|
|
SGV->isConstant(), SGV->getLinkage(), /*init*/0,
|
|
"", 0, false,
|
|
SGV->getType()->getAddressSpace());
|
|
|
|
// Set alignment allowing CopyGVAttributes merge it with alignment of SGV.
|
|
NewDGV->setAlignment(DGV->getAlignment());
|
|
// Propagate alignment, section and visibility info.
|
|
CopyGVAttributes(NewDGV, SGV);
|
|
|
|
// Make sure to remember this mapping...
|
|
ValueMap[SGV] = NewDGV;
|
|
|
|
// Keep track that this is an appending variable...
|
|
AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV));
|
|
continue;
|
|
}
|
|
|
|
if (LinkFromSrc) {
|
|
if (isa<GlobalAlias>(DGV))
|
|
return Error(Err, "Global-Alias Collision on '" + SGV->getName() +
|
|
"': symbol multiple defined");
|
|
|
|
// If the types don't match, and if we are to link from the source, nuke
|
|
// DGV and create a new one of the appropriate type. Note that the thing
|
|
// we are replacing may be a function (if a prototype, weak, etc) or a
|
|
// global variable.
|
|
GlobalVariable *NewDGV =
|
|
new GlobalVariable(*Dest, SGV->getType()->getElementType(),
|
|
SGV->isConstant(), NewLinkage, /*init*/0,
|
|
DGV->getName(), 0, false,
|
|
SGV->getType()->getAddressSpace());
|
|
|
|
// Propagate alignment, section, and visibility info.
|
|
CopyGVAttributes(NewDGV, SGV);
|
|
DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewDGV,
|
|
DGV->getType()));
|
|
|
|
// DGV will conflict with NewDGV because they both had the same
|
|
// name. We must erase this now so ForceRenaming doesn't assert
|
|
// because DGV might not have internal linkage.
|
|
if (GlobalVariable *Var = dyn_cast<GlobalVariable>(DGV))
|
|
Var->eraseFromParent();
|
|
else
|
|
cast<Function>(DGV)->eraseFromParent();
|
|
|
|
// If the symbol table renamed the global, but it is an externally visible
|
|
// symbol, DGV must be an existing global with internal linkage. Rename.
|
|
if (NewDGV->getName() != SGV->getName() && !NewDGV->hasLocalLinkage())
|
|
ForceRenaming(NewDGV, SGV->getName());
|
|
|
|
// Inherit const as appropriate.
|
|
NewDGV->setConstant(SGV->isConstant());
|
|
|
|
// Make sure to remember this mapping.
|
|
ValueMap[SGV] = NewDGV;
|
|
continue;
|
|
}
|
|
|
|
// Not "link from source", keep the one in the DestModule and remap the
|
|
// input onto it.
|
|
|
|
// Special case for const propagation.
|
|
if (GlobalVariable *DGVar = dyn_cast<GlobalVariable>(DGV))
|
|
if (DGVar->isDeclaration() && SGV->isConstant() && !DGVar->isConstant())
|
|
DGVar->setConstant(true);
|
|
|
|
// SGV is global, but DGV is alias.
|
|
if (isa<GlobalAlias>(DGV)) {
|
|
// The only valid mappings are:
|
|
// - SGV is external declaration, which is effectively a no-op.
|
|
// - SGV is weak, when we just need to throw SGV out.
|
|
if (!SGV->isDeclaration() && !SGV->isWeakForLinker())
|
|
return Error(Err, "Global-Alias Collision on '" + SGV->getName() +
|
|
"': symbol multiple defined");
|
|
}
|
|
|
|
// Set calculated linkage
|
|
DGV->setLinkage(NewLinkage);
|
|
|
|
// Make sure to remember this mapping...
|
|
ValueMap[SGV] = ConstantExpr::getBitCast(DGV, SGV->getType());
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static GlobalValue::LinkageTypes
|
|
CalculateAliasLinkage(const GlobalValue *SGV, const GlobalValue *DGV) {
|
|
GlobalValue::LinkageTypes SL = SGV->getLinkage();
|
|
GlobalValue::LinkageTypes DL = DGV->getLinkage();
|
|
if (SL == GlobalValue::ExternalLinkage || DL == GlobalValue::ExternalLinkage)
|
|
return GlobalValue::ExternalLinkage;
|
|
else if (SL == GlobalValue::WeakAnyLinkage ||
|
|
DL == GlobalValue::WeakAnyLinkage)
|
|
return GlobalValue::WeakAnyLinkage;
|
|
else if (SL == GlobalValue::WeakODRLinkage ||
|
|
DL == GlobalValue::WeakODRLinkage)
|
|
return GlobalValue::WeakODRLinkage;
|
|
else if (SL == GlobalValue::InternalLinkage &&
|
|
DL == GlobalValue::InternalLinkage)
|
|
return GlobalValue::InternalLinkage;
|
|
else if (SL == GlobalValue::LinkerPrivateLinkage &&
|
|
DL == GlobalValue::LinkerPrivateLinkage)
|
|
return GlobalValue::LinkerPrivateLinkage;
|
|
else {
|
|
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) {
|
|
// 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(ConstantExpr::getBitCast(NewGA,
|
|
DGVar->getType()));
|
|
else
|
|
DGVar->replaceAllUsesWith(NewGA);
|
|
|
|
// DGVar will conflict with NewGA because they both had the same
|
|
// name. We must erase this now so ForceRenaming doesn't assert
|
|
// because DGV might not have internal linkage.
|
|
DGVar->eraseFromParent();
|
|
|
|
// Proceed to 'common' steps
|
|
} else
|
|
return Error(Err, "Global-Alias Collision on '" + SGA->getName() +
|
|
"': symbol multiple defined");
|
|
} else if (Function *DF = dyn_cast_or_null<Function>(DGV)) {
|
|
// The only allowed way is to link alias with external declaration or weak
|
|
// symbol...
|
|
if (DF->isDeclaration() || DF->isWeakForLinker()) {
|
|
// But only if aliasee is function too...
|
|
if (!isa<Function>(DAliasee))
|
|
return Error(Err, "Function-Alias Collision on '" + SGA->getName() +
|
|
"': aliasee is not function");
|
|
|
|
NewGA = new GlobalAlias(SGA->getType(), SGA->getLinkage(),
|
|
SGA->getName(), DAliasee, Dest);
|
|
CopyGVAttributes(NewGA, SGA);
|
|
|
|
// Any uses of DF need to change to NewGA, with cast, if needed.
|
|
if (SGA->getType() != DF->getType())
|
|
DF->replaceAllUsesWith(ConstantExpr::getBitCast(NewGA,
|
|
DF->getType()));
|
|
else
|
|
DF->replaceAllUsesWith(NewGA);
|
|
|
|
// DF will conflict with NewGA because they both had the same
|
|
// name. We must erase this now so ForceRenaming doesn't assert
|
|
// because DF might not have internal linkage.
|
|
DF->eraseFromParent();
|
|
|
|
// Proceed to 'common' steps
|
|
} else
|
|
return Error(Err, "Function-Alias Collision on '" + SGA->getName() +
|
|
"': symbol multiple defined");
|
|
} else {
|
|
// No linking to be performed, simply create an identical version of the
|
|
// alias over in the dest module...
|
|
Constant *Aliasee = DAliasee;
|
|
// Fixup aliases to bitcasts. Note that aliases to GEPs are still broken
|
|
// by this, but aliases to GEPs are broken to a lot of other things, so
|
|
// it's less important.
|
|
if (SGA->getType() != DAliasee->getType())
|
|
Aliasee = ConstantExpr::getBitCast(DAliasee, SGA->getType());
|
|
NewGA = new GlobalAlias(SGA->getType(), SGA->getLinkage(),
|
|
SGA->getName(), Aliasee, Dest);
|
|
CopyGVAttributes(NewGA, SGA);
|
|
|
|
// Proceed to 'common' steps
|
|
}
|
|
|
|
assert(NewGA && "No alias was created in destination module!");
|
|
|
|
// If the symbol table renamed the alias, but it is an externally visible
|
|
// symbol, DGA must be an global value with internal linkage. Rename it.
|
|
if (NewGA->getName() != SGA->getName() &&
|
|
!NewGA->hasLocalLinkage())
|
|
ForceRenaming(NewGA, SGA->getName());
|
|
|
|
// Remember this mapping so uses in the source module get remapped
|
|
// later by 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));
|
|
// 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();
|
|
|
|
// Loop over all of the functions in the src module, mapping them over
|
|
for (Module::const_iterator I = Src->begin(), E = Src->end(); I != E; ++I) {
|
|
const Function *SF = I; // SrcFunction
|
|
GlobalValue *DGV = 0;
|
|
|
|
// Check to see if may have to link the function with the global, alias or
|
|
// function.
|
|
if (SF->hasName() && !SF->hasLocalLinkage())
|
|
DGV = cast_or_null<GlobalValue>(DestSymTab.lookup(SF->getName()));
|
|
|
|
// If we found a global with the same name in the dest module, but it has
|
|
// internal linkage, we are really not doing any linkage here.
|
|
if (DGV && DGV->hasLocalLinkage())
|
|
DGV = 0;
|
|
|
|
// If types don't agree due to opaque types, try to resolve them.
|
|
if (DGV && DGV->getType() != SF->getType())
|
|
RecursiveResolveTypes(SF->getType(), DGV->getType());
|
|
|
|
GlobalValue::LinkageTypes NewLinkage = GlobalValue::InternalLinkage;
|
|
bool LinkFromSrc = false;
|
|
if (GetLinkageResult(DGV, SF, NewLinkage, LinkFromSrc, Err))
|
|
return true;
|
|
|
|
// If there is no linkage to be performed, just bring over SF without
|
|
// modifying it.
|
|
if (DGV == 0) {
|
|
// Function does not already exist, simply insert an function signature
|
|
// identical to SF into the dest module.
|
|
Function *NewDF = Function::Create(SF->getFunctionType(),
|
|
SF->getLinkage(),
|
|
SF->getName(), Dest);
|
|
CopyGVAttributes(NewDF, SF);
|
|
|
|
// If the LLVM runtime renamed the function, but it is an externally
|
|
// visible symbol, DF must be an existing function with internal linkage.
|
|
// Rename it.
|
|
if (!NewDF->hasLocalLinkage() && NewDF->getName() != SF->getName())
|
|
ForceRenaming(NewDF, SF->getName());
|
|
|
|
// ... and remember this mapping...
|
|
ValueMap[SF] = NewDF;
|
|
continue;
|
|
}
|
|
|
|
// If the visibilities of the symbols disagree and the destination is a
|
|
// prototype, take the visibility of its input.
|
|
if (DGV->isDeclaration())
|
|
DGV->setVisibility(SF->getVisibility());
|
|
|
|
if (LinkFromSrc) {
|
|
if (isa<GlobalAlias>(DGV))
|
|
return Error(Err, "Function-Alias Collision on '" + SF->getName() +
|
|
"': symbol multiple defined");
|
|
|
|
// We have a definition of the same name but different type in the
|
|
// source module. Copy the prototype to the destination and replace
|
|
// uses of the destination's prototype with the new prototype.
|
|
Function *NewDF = Function::Create(SF->getFunctionType(), NewLinkage,
|
|
SF->getName(), Dest);
|
|
CopyGVAttributes(NewDF, SF);
|
|
|
|
// Any uses of DF need to change to NewDF, with cast
|
|
DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewDF,
|
|
DGV->getType()));
|
|
|
|
// DF will conflict with NewDF because they both had the same. We must
|
|
// erase this now so ForceRenaming doesn't assert because DF might
|
|
// not have internal linkage.
|
|
if (GlobalVariable *Var = dyn_cast<GlobalVariable>(DGV))
|
|
Var->eraseFromParent();
|
|
else
|
|
cast<Function>(DGV)->eraseFromParent();
|
|
|
|
// If the symbol table renamed the function, but it is an externally
|
|
// visible symbol, DF must be an existing function with internal
|
|
// linkage. Rename it.
|
|
if (NewDF->getName() != SF->getName() && !NewDF->hasLocalLinkage())
|
|
ForceRenaming(NewDF, SF->getName());
|
|
|
|
// Remember this mapping so uses in the source module get remapped
|
|
// later by 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] = ConstantExpr::getBitCast(DGV, SF->getType());
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// LinkFunctionBody - Copy the source function over into the dest function and
|
|
// fix up references to values. At this point we know that Dest is an external
|
|
// function, and that Src is not.
|
|
static bool LinkFunctionBody(Function *Dest, Function *Src,
|
|
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);
|
|
|
|
// 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.
|
|
|
|
// Loop over the multimap of appending vars, processing any variables with the
|
|
// same name, forming a new appending global variable with both of the
|
|
// initializers merged together, then rewrite references to the old variables
|
|
// and delete them.
|
|
std::vector<Constant*> Inits;
|
|
while (AppendingVars.size() > 1) {
|
|
// Get the first two elements in the map...
|
|
std::multimap<std::string,
|
|
GlobalVariable*>::iterator Second = AppendingVars.begin(), First=Second++;
|
|
|
|
// If the first two elements are for different names, there is no pair...
|
|
// Otherwise there is a pair, so link them together...
|
|
if (First->first == Second->first) {
|
|
GlobalVariable *G1 = First->second, *G2 = Second->second;
|
|
const ArrayType *T1 = cast<ArrayType>(G1->getType()->getElementType());
|
|
const ArrayType *T2 = cast<ArrayType>(G2->getType()->getElementType());
|
|
|
|
// Check to see that they two arrays agree on type...
|
|
if (T1->getElementType() != T2->getElementType())
|
|
return Error(ErrorMsg,
|
|
"Appending variables with different element types need to be linked!");
|
|
if (G1->isConstant() != G2->isConstant())
|
|
return Error(ErrorMsg,
|
|
"Appending variables linked with different const'ness!");
|
|
|
|
if (G1->getAlignment() != G2->getAlignment())
|
|
return Error(ErrorMsg,
|
|
"Appending variables with different alignment need to be linked!");
|
|
|
|
if (G1->getVisibility() != G2->getVisibility())
|
|
return Error(ErrorMsg,
|
|
"Appending variables with different visibility need to be linked!");
|
|
|
|
if (G1->getSection() != G2->getSection())
|
|
return Error(ErrorMsg,
|
|
"Appending variables with different section name need to be linked!");
|
|
|
|
unsigned NewSize = T1->getNumElements() + T2->getNumElements();
|
|
ArrayType *NewType = ArrayType::get(T1->getElementType(),
|
|
NewSize);
|
|
|
|
G1->setName(""); // Clear G1's name in case of a conflict!
|
|
|
|
// Create the new global variable...
|
|
GlobalVariable *NG =
|
|
new GlobalVariable(*M, NewType, G1->isConstant(), G1->getLinkage(),
|
|
/*init*/0, First->first, 0, G1->isThreadLocal(),
|
|
G1->getType()->getAddressSpace());
|
|
|
|
// Propagate alignment, visibility and section info.
|
|
CopyGVAttributes(NG, G1);
|
|
|
|
// Merge the initializer...
|
|
Inits.reserve(NewSize);
|
|
if (ConstantArray *I = dyn_cast<ConstantArray>(G1->getInitializer())) {
|
|
for (unsigned i = 0, e = T1->getNumElements(); i != e; ++i)
|
|
Inits.push_back(I->getOperand(i));
|
|
} else {
|
|
assert(isa<ConstantAggregateZero>(G1->getInitializer()));
|
|
Constant *CV = Constant::getNullValue(T1->getElementType());
|
|
for (unsigned i = 0, e = T1->getNumElements(); i != e; ++i)
|
|
Inits.push_back(CV);
|
|
}
|
|
if (ConstantArray *I = dyn_cast<ConstantArray>(G2->getInitializer())) {
|
|
for (unsigned i = 0, e = T2->getNumElements(); i != e; ++i)
|
|
Inits.push_back(I->getOperand(i));
|
|
} else {
|
|
assert(isa<ConstantAggregateZero>(G2->getInitializer()));
|
|
Constant *CV = Constant::getNullValue(T2->getElementType());
|
|
for (unsigned i = 0, e = T2->getNumElements(); i != e; ++i)
|
|
Inits.push_back(CV);
|
|
}
|
|
NG->setInitializer(ConstantArray::get(NewType, Inits));
|
|
Inits.clear();
|
|
|
|
// Replace any uses of the two global variables with uses of the new
|
|
// global...
|
|
|
|
// FIXME: This should rewrite simple/straight-forward uses such as
|
|
// getelementptr instructions to not use the Cast!
|
|
G1->replaceAllUsesWith(ConstantExpr::getBitCast(NG,
|
|
G1->getType()));
|
|
G2->replaceAllUsesWith(ConstantExpr::getBitCast(NG,
|
|
G2->getType()));
|
|
|
|
// Remove the two globals from the module now...
|
|
M->getGlobalList().erase(G1);
|
|
M->getGlobalList().erase(G2);
|
|
|
|
// Put the new global into the AppendingVars map so that we can handle
|
|
// linking of more than two vars...
|
|
Second->second = NG;
|
|
}
|
|
AppendingVars.erase(First);
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static bool ResolveAliases(Module *Dest) {
|
|
for (Module::alias_iterator I = Dest->alias_begin(), E = Dest->alias_end();
|
|
I != E; ++I)
|
|
// We can't sue resolveGlobalAlias here because we need to preserve
|
|
// bitcasts and GEPs.
|
|
if (const Constant *C = I->getAliasee()) {
|
|
while (dyn_cast<GlobalAlias>(C))
|
|
C = cast<GlobalAlias>(C)->getAliasee();
|
|
const GlobalValue *GV = dyn_cast<GlobalValue>(C);
|
|
if (C != I && !(GV && GV->isDeclaration()))
|
|
I->replaceAllUsesWith(const_cast<Constant*>(C));
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
// LinkModules - This function links two modules together, with the resulting
|
|
// left module modified to be the composite of the two input modules. If an
|
|
// error occurs, true is returned and ErrorMsg (if not null) is set to indicate
|
|
// the problem. Upon failure, the Dest module could be in a modified state, and
|
|
// shouldn't be relied on to be consistent.
|
|
bool
|
|
Linker::LinkModules(Module *Dest, Module *Src, std::string *ErrorMsg) {
|
|
assert(Dest != 0 && "Invalid Destination module");
|
|
assert(Src != 0 && "Invalid Source Module");
|
|
|
|
if (Dest->getDataLayout().empty()) {
|
|
if (!Src->getDataLayout().empty()) {
|
|
Dest->setDataLayout(Src->getDataLayout());
|
|
} else {
|
|
std::string DataLayout;
|
|
|
|
if (Dest->getEndianness() == Module::AnyEndianness) {
|
|
if (Src->getEndianness() == Module::BigEndian)
|
|
DataLayout.append("E");
|
|
else if (Src->getEndianness() == Module::LittleEndian)
|
|
DataLayout.append("e");
|
|
}
|
|
|
|
if (Dest->getPointerSize() == Module::AnyPointerSize) {
|
|
if (Src->getPointerSize() == Module::Pointer64)
|
|
DataLayout.append(DataLayout.length() == 0 ? "p:64:64" : "-p:64:64");
|
|
else if (Src->getPointerSize() == Module::Pointer32)
|
|
DataLayout.append(DataLayout.length() == 0 ? "p:32:32" : "-p:32:32");
|
|
}
|
|
Dest->setDataLayout(DataLayout);
|
|
}
|
|
}
|
|
|
|
// Copy the target triple from the source to dest if the dest's is empty.
|
|
if (Dest->getTargetTriple().empty() && !Src->getTargetTriple().empty())
|
|
Dest->setTargetTriple(Src->getTargetTriple());
|
|
|
|
if (!Src->getDataLayout().empty() && !Dest->getDataLayout().empty() &&
|
|
Src->getDataLayout() != Dest->getDataLayout())
|
|
errs() << "WARNING: Linking two modules of different data layouts!\n";
|
|
if (!Src->getTargetTriple().empty() &&
|
|
Dest->getTargetTriple() != Src->getTargetTriple())
|
|
errs() << "WARNING: Linking two modules of different target triples!\n";
|
|
|
|
// Append the module inline asm string.
|
|
if (!Src->getModuleInlineAsm().empty()) {
|
|
if (Dest->getModuleInlineAsm().empty())
|
|
Dest->setModuleInlineAsm(Src->getModuleInlineAsm());
|
|
else
|
|
Dest->setModuleInlineAsm(Dest->getModuleInlineAsm()+"\n"+
|
|
Src->getModuleInlineAsm());
|
|
}
|
|
|
|
// Update the destination module's dependent libraries list with the libraries
|
|
// from the source module. There's no opportunity for duplicates here as the
|
|
// Module ensures that duplicate insertions are discarded.
|
|
for (Module::lib_iterator SI = Src->lib_begin(), SE = Src->lib_end();
|
|
SI != SE; ++SI)
|
|
Dest->addLibrary(*SI);
|
|
|
|
// LinkTypes - Go through the symbol table of the Src module and see if any
|
|
// types are named in the src module that are not named in the Dst module.
|
|
// Make sure there are no type name conflicts.
|
|
if (LinkTypes(Dest, Src, ErrorMsg))
|
|
return true;
|
|
|
|
// ValueMap - Mapping of values from what they used to be in Src, to what they
|
|
// are now in Dest.
|
|
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 named mdnoes in Src into the Dest module.
|
|
LinkNamedMDNodes(Dest, Src);
|
|
|
|
// 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
|