-//===- Linker.cpp - Module Linker Implementation --------------------------===//
+//===- 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.
//
//
//===----------------------------------------------------------------------===//
-#include "llvm/Transforms/Utils/Linker.h"
-#include "llvm/Module.h"
-#include "llvm/SymbolTable.h"
-#include "llvm/DerivedTypes.h"
-#include "llvm/iOther.h"
+#include "llvm/Linker.h"
#include "llvm/Constants.h"
-using std::cerr;
-using std::string;
-using std::map;
+#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/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.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(string *E, string Message) {
- if (E) *E = Message;
+static inline bool Error(std::string *E, const Twine &Message) {
+ if (E) *E = Message.str();
return true;
}
+// Function: ResolveTypes()
+//
+// Description:
+// Attempt to link the two specified types together.
+//
+// Inputs:
+// DestTy - The type to which we wish to resolve.
+// SrcTy - The original type which we want to resolve.
+//
+// Outputs:
+// DestST - The symbol table in which the new type should be placed.
+//
+// Return value:
+// true - There is an error and the types cannot yet be linked.
+// false - No errors.
+//
+static bool ResolveTypes(const Type *DestTy, const Type *SrcTy) {
+ if (DestTy == SrcTy) return false; // If already equal, noop
+ assert(DestTy && SrcTy && "Can't handle null types");
+
+ if (const OpaqueType *OT = dyn_cast<OpaqueType>(DestTy)) {
+ // Type _is_ in module, just opaque...
+ const_cast<OpaqueType*>(OT)->refineAbstractTypeTo(SrcTy);
+ } else if (const OpaqueType *OT = dyn_cast<OpaqueType>(SrcTy)) {
+ const_cast<OpaqueType*>(OT)->refineAbstractTypeTo(DestTy);
+ } else {
+ return true; // Cannot link types... not-equal and neither is opaque.
+ }
+ return false;
+}
+
+/// LinkerTypeMap - This implements a map of types that is stable
+/// even if types are resolved/refined to other types. This is not a general
+/// purpose map, it is specific to the linker's use.
+namespace {
+class LinkerTypeMap : public AbstractTypeUser {
+ typedef DenseMap<const Type*, PATypeHolder> TheMapTy;
+ TheMapTy TheMap;
+
+ LinkerTypeMap(const LinkerTypeMap&); // DO NOT IMPLEMENT
+ void operator=(const LinkerTypeMap&); // DO NOT IMPLEMENT
+public:
+ LinkerTypeMap() {}
+ ~LinkerTypeMap() {
+ for (DenseMap<const Type*, PATypeHolder>::iterator I = TheMap.begin(),
+ E = TheMap.end(); I != E; ++I)
+ I->first->removeAbstractTypeUser(this);
+ }
+
+ /// lookup - Return the value for the specified type or null if it doesn't
+ /// exist.
+ const Type *lookup(const Type *Ty) const {
+ TheMapTy::const_iterator I = TheMap.find(Ty);
+ if (I != TheMap.end()) return I->second;
+ return 0;
+ }
+
+ /// erase - Remove the specified type, returning true if it was in the set.
+ bool erase(const Type *Ty) {
+ if (!TheMap.erase(Ty))
+ return false;
+ if (Ty->isAbstract())
+ Ty->removeAbstractTypeUser(this);
+ return true;
+ }
+
+ /// insert - This returns true if the pointer was new to the set, false if it
+ /// was already in the set.
+ bool insert(const Type *Src, const Type *Dst) {
+ if (!TheMap.insert(std::make_pair(Src, PATypeHolder(Dst))).second)
+ return false; // Already in map.
+ if (Src->isAbstract())
+ Src->addAbstractTypeUser(this);
+ return true;
+ }
+
+protected:
+ /// refineAbstractType - The callback method invoked when an abstract type is
+ /// resolved to another type. An object must override this method to update
+ /// its internal state to reference NewType instead of OldType.
+ ///
+ virtual void refineAbstractType(const DerivedType *OldTy,
+ const Type *NewTy) {
+ TheMapTy::iterator I = TheMap.find(OldTy);
+ const Type *DstTy = I->second;
+
+ TheMap.erase(I);
+ if (OldTy->isAbstract())
+ OldTy->removeAbstractTypeUser(this);
+
+ // Don't reinsert into the map if the key is concrete now.
+ if (NewTy->isAbstract())
+ insert(NewTy, DstTy);
+ }
+
+ /// The other case which AbstractTypeUsers must be aware of is when a type
+ /// makes the transition from being abstract (where it has clients on it's
+ /// AbstractTypeUsers list) to concrete (where it does not). This method
+ /// notifies ATU's when this occurs for a type.
+ virtual void typeBecameConcrete(const DerivedType *AbsTy) {
+ TheMap.erase(AbsTy);
+ AbsTy->removeAbstractTypeUser(this);
+ }
+
+ // for debugging...
+ virtual void dump() const {
+ errs() << "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, string *Err = 0) {
- SymbolTable *DestST = &Dest->getSymbolTable();
- const SymbolTable *SrcST = &Src->getSymbolTable();
+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...
- SymbolTable::const_iterator PI = SrcST->find(Type::TypeTy);
- if (PI == SrcST->end()) return false; // No named types, do nothing.
+ TypeSymbolTable::const_iterator TI = SrcST->begin();
+ TypeSymbolTable::const_iterator TE = SrcST->end();
+ if (TI == TE) return false; // No named types, do nothing.
- const SymbolTable::VarMap &VM = PI->second;
- for (SymbolTable::type_const_iterator I = VM.begin(), E = VM.end();
- I != E; ++I) {
- const string &Name = I->first;
- const Type *RHS = cast<Type>(I->second);
-
- // Check to see if this type name is already in the dest module...
- const Type *Entry = cast_or_null<Type>(DestST->lookup(Type::TypeTy, Name));
- if (Entry) { // Yup, the value already exists...
- if (Entry != RHS) // If it's the same, noop. Otherwise, error.
- return Error(Err, "Type named '" + Name +
- "' of different shape in modules.\n Src='" +
- Entry->getDescription() + "'.\n Dst='" +
- RHS->getDescription() + "'");
- } else { // Type not in dest module. Add it now.
- // TODO: FIXME WHEN TYPES AREN'T CONST
- DestST->insert(Name, const_cast<Type*>(RHS));
+ // 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;
}
-static void PrintMap(const map<const Value*, Value*> &M) {
- for (map<const Value*, Value*>::const_iterator I = M.begin(), E = M.end();
+#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 << " ";
+ errs() << " Fr: " << (void*)I->first << " ";
I->first->dump();
- cerr << " To: " << (void*)I->second << " ";
+ errs() << " To: " << (void*)I->second << " ";
I->second->dump();
- cerr << "\n";
+ errs() << "\n";
}
}
+#endif
-// RemapOperand - Use LocalMap and GlobalMap to convert references from one
-// module to another. This is somewhat sophisticated in that it can
-// automatically handle constant references correctly as well...
-//
-static Value *RemapOperand(const Value *In, map<const Value*, Value*> &LocalMap,
- map<const Value*, Value*> *GlobalMap = 0) {
- map<const Value*,Value*>::const_iterator I = LocalMap.find(In);
- if (I != LocalMap.end()) return I->second;
-
- if (GlobalMap) {
- I = GlobalMap->find(In);
- if (I != GlobalMap->end()) return I->second;
- }
+// 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 interesting in transforming...
+ // 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))
- return const_cast<Constant*>(CPV); // Simple constants stay identical...
-
- Constant *Result = 0;
+ 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)) {
- const std::vector<Use> &Ops = CPA->getValues();
- std::vector<Constant*> Operands(Ops.size());
- for (unsigned i = 0, e = Ops.size(); i != e; ++i)
- Operands[i] =
- cast<Constant>(RemapOperand(Ops[i], LocalMap, GlobalMap));
-
Result = ConstantArray::get(cast<ArrayType>(CPA->getType()), Operands);
+ 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 =
+
ConstantArray::get(cast<ArrayType>(CPA->getType()), Operands);
} else if (const ConstantStruct *CPS = dyn_cast<ConstantStruct>(CPV)) {
- const std::vector<Use> &Ops = CPS->getValues();
- std::vector<Constant*> Operands(Ops.size());
- for (unsigned i = 0; i < Ops.size(); ++i)
- Operands[i] =
- cast<Constant>(RemapOperand(Ops[i], LocalMap, GlobalMap));
- Result = ConstantStruct::get(cast<StructType>(CPS->getType()), Operands);
- } else if (isa<ConstantPointerNull>(CPV)) {
+ 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 =
+ ConstantStruct::get(cast<StructType>(CPS->getType()), Operands);
+ } else if (isa<ConstantPointerNull>(CPV) || isa<UndefValue>(CPV)) {
Result = const_cast<Constant*>(CPV);
- } else if (const ConstantPointerRef *CPR =
- dyn_cast<ConstantPointerRef>(CPV)) {
- Value *V = RemapOperand(CPR->getValue(), LocalMap, GlobalMap);
- Result = ConstantPointerRef::get(cast<GlobalValue>(V));
+ } else if (const 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 = ConstantVector::get(Operands);
} else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CPV)) {
- if (CE->getOpcode() == Instruction::GetElementPtr) {
- Value *Ptr = RemapOperand(CE->getOperand(0), LocalMap, GlobalMap);
- std::vector<Constant*> Indices;
- Indices.reserve(CE->getNumOperands()-1);
- for (unsigned i = 1, e = CE->getNumOperands(); i != e; ++i)
- Indices.push_back(cast<Constant>(RemapOperand(CE->getOperand(i),
- LocalMap, GlobalMap)));
-
- Result = ConstantExpr::getGetElementPtr(cast<Constant>(Ptr), Indices);
- } else if (CE->getNumOperands() == 1) {
- // Cast instruction
- assert(CE->getOpcode() == Instruction::Cast);
- Value *V = RemapOperand(CE->getOperand(0), LocalMap, GlobalMap);
- Result = ConstantExpr::getCast(cast<Constant>(V), CE->getType());
- } else if (CE->getNumOperands() == 2) {
- // Binary operator...
- Value *V1 = RemapOperand(CE->getOperand(0), LocalMap, GlobalMap);
- Value *V2 = RemapOperand(CE->getOperand(1), LocalMap, GlobalMap);
-
- Result = ConstantExpr::get(CE->getOpcode(), cast<Constant>(V1),
- cast<Constant>(V2));
- } else {
- assert(0 && "Unknown constant expr type!");
- }
-
+ 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(0 && "Unknown type of derived type constant value!");
+ assert(!isa<GlobalValue>(CPV) && "Unmapped global?");
+ llvm_unreachable("Unknown type of derived type constant value!");
}
+ } else if (isa<MetadataBase>(In)) {
+ Result = const_cast<Value*>(In);
+ } else if (isa<InlineAsm>(In)) {
+ Result = const_cast<Value*>(In);
+ }
- // Cache the mapping in our local map structure...
- if (GlobalMap)
- GlobalMap->insert(std::make_pair(In, Result));
- else
- LocalMap.insert(std::make_pair(In, Result));
+ // Cache the mapping in our local map structure
+ if (Result) {
+ ValueMap[In] = Result;
return Result;
}
- cerr << "XXX LocalMap: \n";
- PrintMap(LocalMap);
+#ifndef NDEBUG
+ errs() << "LinkModules ValueMap: \n";
+ PrintMap(ValueMap);
+
+ errs() << "Couldn't remap value: " << (void*)In << " " << *In << "\n";
+ llvm_unreachable("Couldn't remap value!");
+#endif
+ return 0;
+}
- if (GlobalMap) {
- cerr << "XXX GlobalMap: \n";
- PrintMap(*GlobalMap);
+/// 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
}
+}
- cerr << "Couldn't remap value: " << (void*)In << " " << *In << "\n";
- assert(0 && "Couldn't remap value!");
- return 0;
+/// CopyGVAttributes - copy additional attributes (those not needed to construct
+/// a GlobalValue) from the SrcGV to the DestGV.
+static void CopyGVAttributes(GlobalValue *DestGV, const GlobalValue *SrcGV) {
+ // Use the maximum alignment, rather than just copying the alignment of SrcGV.
+ unsigned Alignment = std::max(DestGV->getAlignment(), SrcGV->getAlignment());
+ DestGV->copyAttributesFrom(SrcGV);
+ DestGV->setAlignment(Alignment);
}
+/// GetLinkageResult - This analyzes the two global values and determines what
+/// the result will look like in the destination module. In particular, it
+/// computes the resultant linkage type, computes whether the global in the
+/// source should be copied over to the destination (replacing the existing
+/// one), and computes whether this linkage is an error or not. It also performs
+/// visibility checks: we cannot link together two symbols with different
+/// visibilities.
+static bool GetLinkageResult(GlobalValue *Dest, const GlobalValue *Src,
+ GlobalValue::LinkageTypes <, bool &LinkFromSrc,
+ std::string *Err) {
+ assert((!Dest || !Src->hasLocalLinkage()) &&
+ "If Src has internal linkage, Dest shouldn't be set!");
+ if (!Dest) {
+ // Linking something to nothing.
+ LinkFromSrc = true;
+ LT = Src->getLinkage();
+ } else if (Src->isDeclaration()) {
+ // If Src is external or if both Src & Dest are external.. Just link the
+ // external globals, we aren't adding anything.
+ if (Src->hasDLLImportLinkage()) {
+ // If one of GVs has DLLImport linkage, result should be dllimport'ed.
+ if (Dest->isDeclaration()) {
+ LinkFromSrc = true;
+ LT = Src->getLinkage();
+ }
+ } else if (Dest->hasExternalWeakLinkage()) {
+ // If the Dest is weak, use the source linkage.
+ LinkFromSrc = true;
+ LT = Src->getLinkage();
+ } else {
+ LinkFromSrc = false;
+ LT = Dest->getLinkage();
+ }
+ } else if (Dest->isDeclaration() && !Dest->hasDLLImportLinkage()) {
+ // If Dest is external but Src is not:
+ LinkFromSrc = true;
+ LT = Src->getLinkage();
+ } else if (Src->hasAppendingLinkage() || Dest->hasAppendingLinkage()) {
+ if (Src->getLinkage() != Dest->getLinkage())
+ return Error(Err, "Linking globals named '" + Src->getName() +
+ "': can only link appending global with another appending global!");
+ LinkFromSrc = true; // Special cased.
+ LT = Src->getLinkage();
+ } else if (Src->isWeakForLinker()) {
+ // At this point we know that Dest has LinkOnce, External*, Weak, Common,
+ // or DLL* linkage.
+ if (Dest->hasExternalWeakLinkage() ||
+ Dest->hasAvailableExternallyLinkage() ||
+ (Dest->hasLinkOnceLinkage() &&
+ (Src->hasWeakLinkage() || Src->hasCommonLinkage()))) {
+ LinkFromSrc = true;
+ LT = Src->getLinkage();
+ } else {
+ LinkFromSrc = false;
+ LT = Dest->getLinkage();
+ }
+ } else if (Dest->isWeakForLinker()) {
+ // At this point we know that Src has External* or DLL* linkage.
+ if (Src->hasExternalWeakLinkage()) {
+ LinkFromSrc = false;
+ LT = Dest->getLinkage();
+ } else {
+ LinkFromSrc = true;
+ LT = GlobalValue::ExternalLinkage;
+ }
+ } else {
+ assert((Dest->hasExternalLinkage() ||
+ Dest->hasDLLImportLinkage() ||
+ Dest->hasDLLExportLinkage() ||
+ Dest->hasExternalWeakLinkage()) &&
+ (Src->hasExternalLinkage() ||
+ Src->hasDLLImportLinkage() ||
+ Src->hasDLLExportLinkage() ||
+ Src->hasExternalWeakLinkage()) &&
+ "Unexpected linkage type!");
+ return Error(Err, "Linking globals named '" + Src->getName() +
+ "': symbol multiply defined!");
+ }
+
+ // Check visibility
+ if (Dest && Src->getVisibility() != Dest->getVisibility())
+ if (!Src->isDeclaration() && !Dest->isDeclaration())
+ return Error(Err, "Linking globals named '" + Src->getName() +
+ "': symbols have different visibilities!");
+ return false;
+}
+
+// Insert all of the named mdnoes in Src into the Dest module.
+static void LinkNamedMDNodes(Module *Dest, Module *Src) {
+ 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->getNumElements(); i != e; ++i)
+ DestNMD->addElement(SrcNMD->getElement(i));
+ }
+ }
+}
// LinkGlobals - Loop through the global variables in the src module and merge
-// them into the dest module...
-//
+// them into the dest module.
static bool LinkGlobals(Module *Dest, const Module *Src,
- map<const Value*, Value*> &ValueMap, string *Err = 0) {
- // We will need a module level symbol table if the src module has a module
- // level symbol table...
- SymbolTable *ST = (SymbolTable*)&Dest->getSymbolTable();
-
+ 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_giterator I = Src->gbegin(), E = Src->gend(); I != E; ++I){
+ for (Module::const_global_iterator I = Src->global_begin(),
+ E = Src->global_end(); I != E; ++I) {
const GlobalVariable *SGV = I;
- Value *V;
-
- // If the global variable has a name, and that name is already in use in the
- // Dest module, make sure that the name is a compatible global variable...
- //
- if (SGV->hasExternalLinkage() && SGV->hasName() &&
- (V = ST->lookup(SGV->getType(), SGV->getName())) &&
- cast<GlobalVariable>(V)->hasExternalLinkage()) {
- // The same named thing is a global variable, because the only two things
- // that may be in a module level symbol table are Global Vars and
- // Functions, and they both have distinct, nonoverlapping, possible types.
- //
- GlobalVariable *DGV = cast<GlobalVariable>(V);
-
- // Check to see if the two GV's have the same Const'ness...
- if (SGV->isConstant() != DGV->isConstant())
- return Error(Err, "Global Variable Collision on '" +
- SGV->getType()->getDescription() + "':%" + SGV->getName() +
- " - Global variables differ in const'ness");
-
- // Okay, everything is cool, remember the mapping...
- ValueMap.insert(std::make_pair(SGV, DGV));
- } else {
+ 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 *DGV =
- new GlobalVariable(SGV->getType()->getElementType(), SGV->isConstant(),
- SGV->hasInternalLinkage(), 0, SGV->getName());
+ // 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());
- // Add the new global to the dest module
- Dest->getGlobalList().push_back(DGV);
+ 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.insert(std::make_pair(SGV, DGV));
+ 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();
+ 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] = 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...
+
+ 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,
- map<const Value*, Value*> &ValueMap,
- string *Err = 0) {
-
+ std::map<const Value*, Value*> &ValueMap,
+ std::string *Err) {
// Loop over all of the globals in the src module, mapping them over as we go
- //
- for (Module::const_giterator I = Src->gbegin(), E = Src->gend(); I != E; ++I){
+ 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 *DInit =
- cast<Constant>(RemapOperand(SGV->getInitializer(), ValueMap));
-
- GlobalVariable *DGV = cast<GlobalVariable>(ValueMap[SGV]);
- if (DGV->hasInitializer() && SGV->hasExternalLinkage() &&
- DGV->hasExternalLinkage()) {
- if (DGV->getInitializer() != DInit)
- return Error(Err, "Global Variable Collision on '" +
- SGV->getType()->getDescription() + "':%" +SGV->getName()+
- " - Global variables have different initializers");
+ 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 {
- // Copy the initializer over now...
- DGV->setInitializer(DInit);
+ // 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());
}
}
}
// to the Dest function...
//
static bool LinkFunctionProtos(Module *Dest, const Module *Src,
- map<const Value*, Value*> &ValueMap,
- string *Err = 0) {
- // We will need a module level symbol table if the src module has a module
- // level symbol table...
- SymbolTable *ST = (SymbolTable*)&Dest->getSymbolTable();
-
- // Loop over all of the functions in the src module, mapping them over as we
- // go
- //
+ 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
- Value *V;
-
- // If the function has a name, and that name is already in use in the Dest
- // module, make sure that the name is a compatible function...
- //
- if (SF->hasExternalLinkage() && SF->hasName() &&
- (V = ST->lookup(SF->getType(), SF->getName())) &&
- cast<Function>(V)->hasExternalLinkage()) {
- // The same named thing is a Function, because the only two things
- // that may be in a module level symbol table are Global Vars and
- // Functions, and they both have distinct, nonoverlapping, possible types.
- //
- Function *DF = cast<Function>(V); // DestFunction
-
- // Check to make sure the function is not defined in both modules...
- if (!SF->isExternal() && !DF->isExternal())
- return Error(Err, "Function '" +
- SF->getFunctionType()->getDescription() + "':\"" +
- SF->getName() + "\" - Function is already defined!");
-
- // Otherwise, just remember this mapping...
- ValueMap.insert(std::make_pair(SF, DF));
- } else {
- // Function does not already exist, simply insert an external function
- // signature identical to SF into the dest module...
- Function *DF = new Function(SF->getFunctionType(),
- SF->hasInternalLinkage(),
- SF->getName());
+ 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);
- // Add the function signature to the dest module...
- Dest->getFunctionList().push_back(DF);
+ // 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.insert(std::make_pair(SF, DF));
+ 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, const Function *Src,
- map<const Value*, Value*> &GlobalMap,
- string *Err = 0) {
- assert(Src && Dest && Dest->isExternal() && !Src->isExternal());
- map<const Value*, Value*> LocalMap; // Map for function local values
-
- // Go through and convert function arguments over...
- Function::aiterator DI = Dest->abegin();
- for (Function::const_aiterator I = Src->abegin(), E = Src->aend();
+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
- LocalMap.insert(std::make_pair(I, DI));
+ ValueMap[I] = DI;
}
- // Loop over all of the basic blocks, copying the instructions over...
- //
- for (Function::const_iterator I = Src->begin(), E = Src->end(); I != E; ++I) {
- // Create new basic block and add to mapping and the Dest function...
- BasicBlock *DBB = new BasicBlock(I->getName(), Dest);
- LocalMap.insert(std::make_pair(I, DBB));
-
- // Loop over all of the instructions in the src basic block, copying them
- // over. Note that this is broken in a strict sense because the cloned
- // instructions will still be referencing values in the Src module, not
- // the remapped values. In our case, however, we will not get caught and
- // so we can delay patching the values up until later...
- //
- for (BasicBlock::const_iterator II = I->begin(), IE = I->end();
- II != IE; ++II) {
- Instruction *DI = II->clone();
- DI->setName(II->getName());
- DBB->getInstList().push_back(DI);
- LocalMap.insert(std::make_pair(II, DI));
- }
- }
+ // 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
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
for (Instruction::op_iterator OI = I->op_begin(), OE = I->op_end();
OI != OE; ++OI)
- *OI = RemapOperand(*OI, LocalMap, &GlobalMap);
+ 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, const Module *Src,
- map<const Value*, Value*> &ValueMap,
- string *Err = 0) {
+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::const_iterator SF = Src->begin(), E = Src->end(); SF != E; ++SF){
- if (!SF->isExternal()) { // No body if function is external
- Function *DF = cast<Function>(ValueMap[SF]); // Destination function
+ 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->isExternal()) {
- if (Err)
- *Err = "Function '" + (SF->hasName() ? SF->getName() : string("")) +
- "' body multiply defined!";
- return true;
+ 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...
- if (LinkFunctionBody(DF, SF, ValueMap, Err)) return true;
+ // 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)
+ 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 LinkModules(Module *Dest, const Module *Src, string *ErrorMsg) {
+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;
+ 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.
- //
- map<const Value*, Value*> ValueMap;
+ 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
- // initializers
- if (LinkGlobals(Dest, Src, ValueMap, ErrorMsg)) return true;
+ // 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 (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
projects / oota-llvm.git / blobdiff