-//===- Linker.cpp - Module Linker Implementation --------------------------===//
+//===- lib/Linker/LinkModules.cpp - Module Linker Implementation ----------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
//
// This file implements the LLVM module linker.
//
// Specifically, this:
-// - Merges global variables between the two modules
-// - Uninit + Uninit = Init, Init + Uninit = Init, Init + Init = Error if !=
+// * Merges global variables between the two modules
+// * Uninit + Uninit = Init, Init + Uninit = Init, Init + Init = Error if !=
+// * Merges functions between two modules
//
//===----------------------------------------------------------------------===//
-#include "llvm/Transforms/Linker.h"
+#include "llvm/Linker.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Module.h"
+#include "llvm/SymbolTable.h"
+#include "llvm/Instructions.h"
+#include "llvm/Assembly/Writer.h"
+#include "llvm/System/Path.h"
+#include <iostream>
+#include <sstream>
+using namespace llvm;
+
+// Error - Simple wrapper function to conditionally assign to E and return true.
+// This just makes error return conditions a little bit simpler...
+static inline bool Error(std::string *E, const std::string &Message) {
+ if (E) *E = Message;
+ return true;
+}
+
+// ToStr - Simple wrapper function to convert a type to a string.
+static std::string ToStr(const Type *Ty, const Module *M) {
+ std::ostringstream OS;
+ WriteTypeSymbolic(OS, Ty, M);
+ return OS.str();
+}
+
+//
+// Function: ResolveTypes()
+//
+// Description:
+// 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.
+// Name - The name of the type.
+//
+// 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,
+ SymbolTable *DestST, const std::string &Name) {
+ if (DestTy == SrcTy) return false; // If already equal, noop
+
+ // Does the type already exist in the module?
+ if (DestTy && !isa<OpaqueType>(DestTy)) { // Yup, the type already exists...
+ if (const OpaqueType *OT = dyn_cast<OpaqueType>(SrcTy)) {
+ const_cast<OpaqueType*>(OT)->refineAbstractTypeTo(DestTy);
+ } else {
+ return true; // Cannot link types... neither is opaque and not-equal
+ }
+ } else { // Type not in dest module. Add it now.
+ if (DestTy) // Type _is_ in module, just opaque...
+ const_cast<OpaqueType*>(cast<OpaqueType>(DestTy))
+ ->refineAbstractTypeTo(SrcTy);
+ else if (!Name.empty())
+ DestST->insert(Name, const_cast<Type*>(SrcTy));
+ }
+ return false;
+}
+
+static const FunctionType *getFT(const PATypeHolder &TH) {
+ return cast<FunctionType>(TH.get());
+}
+static const StructType *getST(const PATypeHolder &TH) {
+ return cast<StructType>(TH.get());
+}
+
+// RecursiveResolveTypes - This is just like ResolveTypes, except that it
+// recurses down into derived types, merging the used types if the parent types
+// are compatible.
+static bool RecursiveResolveTypesI(const PATypeHolder &DestTy,
+ const PATypeHolder &SrcTy,
+ SymbolTable *DestST, const std::string &Name,
+ std::vector<std::pair<PATypeHolder, PATypeHolder> > &Pointers) {
+ const Type *SrcTyT = SrcTy.get();
+ const Type *DestTyT = DestTy.get();
+ if (DestTyT == SrcTyT) return false; // If already equal, noop
+
+ // If we found our opaque type, resolve it now!
+ if (isa<OpaqueType>(DestTyT) || isa<OpaqueType>(SrcTyT))
+ return ResolveTypes(DestTyT, SrcTyT, DestST, Name);
+
+ // Two types cannot be resolved together if they are of different primitive
+ // type. For example, we cannot resolve an int to a float.
+ if (DestTyT->getTypeID() != SrcTyT->getTypeID()) return true;
+
+ // Otherwise, resolve the used type used by this derived type...
+ switch (DestTyT->getTypeID()) {
+ case Type::FunctionTyID: {
+ if (cast<FunctionType>(DestTyT)->isVarArg() !=
+ cast<FunctionType>(SrcTyT)->isVarArg() ||
+ cast<FunctionType>(DestTyT)->getNumContainedTypes() !=
+ cast<FunctionType>(SrcTyT)->getNumContainedTypes())
+ return true;
+ for (unsigned i = 0, e = getFT(DestTy)->getNumContainedTypes(); i != e; ++i)
+ if (RecursiveResolveTypesI(getFT(DestTy)->getContainedType(i),
+ getFT(SrcTy)->getContainedType(i), DestST, "",
+ Pointers))
+ return true;
+ return false;
+ }
+ case Type::StructTyID: {
+ if (getST(DestTy)->getNumContainedTypes() !=
+ getST(SrcTy)->getNumContainedTypes()) return 1;
+ for (unsigned i = 0, e = getST(DestTy)->getNumContainedTypes(); i != e; ++i)
+ if (RecursiveResolveTypesI(getST(DestTy)->getContainedType(i),
+ getST(SrcTy)->getContainedType(i), DestST, "",
+ Pointers))
+ return true;
+ return false;
+ }
+ case Type::ArrayTyID: {
+ const ArrayType *DAT = cast<ArrayType>(DestTy.get());
+ const ArrayType *SAT = cast<ArrayType>(SrcTy.get());
+ if (DAT->getNumElements() != SAT->getNumElements()) return true;
+ return RecursiveResolveTypesI(DAT->getElementType(), SAT->getElementType(),
+ DestST, "", Pointers);
+ }
+ case Type::PointerTyID: {
+ // If this is a pointer type, check to see if we have already seen it. If
+ // so, we are in a recursive branch. Cut off the search now. We cannot use
+ // an associative container for this search, because the type pointers (keys
+ // in the container) change whenever types get resolved...
+ for (unsigned i = 0, e = Pointers.size(); i != e; ++i)
+ if (Pointers[i].first == DestTy)
+ return Pointers[i].second != SrcTy;
+
+ // Otherwise, add the current pointers to the vector to stop recursion on
+ // this pair.
+ Pointers.push_back(std::make_pair(DestTyT, SrcTyT));
+ bool Result =
+ RecursiveResolveTypesI(cast<PointerType>(DestTy.get())->getElementType(),
+ cast<PointerType>(SrcTy.get())->getElementType(),
+ DestST, "", Pointers);
+ Pointers.pop_back();
+ return Result;
+ }
+ default: assert(0 && "Unexpected type!"); return true;
+ }
+}
+
+static bool RecursiveResolveTypes(const PATypeHolder &DestTy,
+ const PATypeHolder &SrcTy,
+ SymbolTable *DestST, const std::string &Name){
+ std::vector<std::pair<PATypeHolder, PATypeHolder> > PointerTypes;
+ return RecursiveResolveTypesI(DestTy, SrcTy, DestST, Name, PointerTypes);
+}
+
+
+// LinkTypes - Go through the symbol table of the Src module and see if any
+// types are named in the src module that are not named in the Dst module.
+// Make sure there are no type name conflicts.
+static bool LinkTypes(Module *Dest, const Module *Src, std::string *Err) {
+ SymbolTable *DestST = &Dest->getSymbolTable();
+ const SymbolTable *SrcST = &Src->getSymbolTable();
+
+ // Look for a type plane for Type's...
+ SymbolTable::type_const_iterator TI = SrcST->type_begin();
+ SymbolTable::type_const_iterator TE = SrcST->type_end();
+ if (TI == TE) return false; // No named types, do nothing.
+
+ // Some types cannot be resolved immediately because they depend on other
+ // types being resolved to each other first. This contains a list of types we
+ // are waiting to recheck.
+ std::vector<std::string> DelayedTypesToResolve;
+
+ for ( ; TI != TE; ++TI ) {
+ const std::string &Name = TI->first;
+ const Type *RHS = TI->second;
+
+ // Check to see if this type name is already in the dest module...
+ Type *Entry = DestST->lookupType(Name);
+
+ if (ResolveTypes(Entry, RHS, DestST, Name)) {
+ // They look different, save the types 'till later to resolve.
+ DelayedTypesToResolve.push_back(Name);
+ }
+ }
+
+ // Iteratively resolve types while we can...
+ while (!DelayedTypesToResolve.empty()) {
+ // Loop over all of the types, attempting to resolve them if possible...
+ unsigned OldSize = DelayedTypesToResolve.size();
+
+ // Try direct resolution by name...
+ for (unsigned i = 0; i != DelayedTypesToResolve.size(); ++i) {
+ const std::string &Name = DelayedTypesToResolve[i];
+ Type *T1 = SrcST->lookupType(Name);
+ Type *T2 = DestST->lookupType(Name);
+ if (!ResolveTypes(T2, T1, DestST, Name)) {
+ // We are making progress!
+ DelayedTypesToResolve.erase(DelayedTypesToResolve.begin()+i);
+ --i;
+ }
+ }
+
+ // Did we not eliminate any types?
+ if (DelayedTypesToResolve.size() == OldSize) {
+ // Attempt to resolve subelements of types. This allows us to merge these
+ // two types: { int* } and { opaque* }
+ for (unsigned i = 0, e = DelayedTypesToResolve.size(); i != e; ++i) {
+ const std::string &Name = DelayedTypesToResolve[i];
+ PATypeHolder T1(SrcST->lookupType(Name));
+ PATypeHolder T2(DestST->lookupType(Name));
+
+ if (!RecursiveResolveTypes(T2, T1, DestST, Name)) {
+ // We are making progress!
+ DelayedTypesToResolve.erase(DelayedTypesToResolve.begin()+i);
+
+ // Go back to the main loop, perhaps we can resolve directly by name
+ // now...
+ break;
+ }
+ }
+
+ // If we STILL cannot resolve the types, then there is something wrong.
+ // Report the warning and delete one of the names.
+ if (DelayedTypesToResolve.size() == OldSize) {
+ const std::string &Name = DelayedTypesToResolve.back();
+
+ const Type *T1 = SrcST->lookupType(Name);
+ const Type *T2 = DestST->lookupType(Name);
+ std::cerr << "WARNING: Type conflict between types named '" << Name
+ << "'.\n Src='";
+ WriteTypeSymbolic(std::cerr, T1, Src);
+ std::cerr << "'.\n Dest='";
+ WriteTypeSymbolic(std::cerr, T2, Dest);
+ std::cerr << "'\n";
+
+ // Remove the symbol name from the destination.
+ DelayedTypesToResolve.pop_back();
+ }
+ }
+ }
+
+
+ return false;
+}
+
+static void PrintMap(const std::map<const Value*, Value*> &M) {
+ for (std::map<const Value*, Value*>::const_iterator I = M.begin(), E =M.end();
+ I != E; ++I) {
+ std::cerr << " Fr: " << (void*)I->first << " ";
+ I->first->dump();
+ std::cerr << " To: " << (void*)I->second << " ";
+ I->second->dump();
+ std::cerr << "\n";
+ }
+}
+
+
+// RemapOperand - Use ValueMap to convert references from one module to another.
+// This is somewhat sophisticated in that it can automatically handle constant
+// references correctly as well...
+static Value *RemapOperand(const Value *In,
+ std::map<const Value*, Value*> &ValueMap) {
+ 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.
+ if (const Constant *CPV = dyn_cast<Constant>(In)) {
+ if ((!isa<DerivedType>(CPV->getType()) && !isa<ConstantExpr>(CPV)) ||
+ isa<ConstantAggregateZero>(CPV))
+ return const_cast<Constant*>(CPV); // Simple constants stay identical.
+
+ Constant *Result = 0;
+
+ if (const ConstantArray *CPA = dyn_cast<ConstantArray>(CPV)) {
+ std::vector<Constant*> Operands(CPA->getNumOperands());
+ for (unsigned i = 0, e = CPA->getNumOperands(); i != e; ++i)
+ Operands[i] =cast<Constant>(RemapOperand(CPA->getOperand(i), ValueMap));
+ Result = ConstantArray::get(cast<ArrayType>(CPA->getType()), Operands);
+ } else if (const ConstantStruct *CPS = dyn_cast<ConstantStruct>(CPV)) {
+ std::vector<Constant*> Operands(CPS->getNumOperands());
+ for (unsigned i = 0, e = CPS->getNumOperands(); i != e; ++i)
+ Operands[i] =cast<Constant>(RemapOperand(CPS->getOperand(i), ValueMap));
+ Result = ConstantStruct::get(cast<StructType>(CPS->getType()), Operands);
+ } else if (isa<ConstantPointerNull>(CPV) || isa<UndefValue>(CPV)) {
+ Result = const_cast<Constant*>(CPV);
+ } else if (isa<GlobalValue>(CPV)) {
+ Result = cast<Constant>(RemapOperand(CPV, ValueMap));
+ } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CPV)) {
+ if (CE->getOpcode() == Instruction::GetElementPtr) {
+ Value *Ptr = RemapOperand(CE->getOperand(0), ValueMap);
+ 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),
+ ValueMap)));
+
+ 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), ValueMap);
+ Result = ConstantExpr::getCast(cast<Constant>(V), CE->getType());
+ } else if (CE->getNumOperands() == 3) {
+ // Select instruction
+ assert(CE->getOpcode() == Instruction::Select);
+ Value *V1 = RemapOperand(CE->getOperand(0), ValueMap);
+ Value *V2 = RemapOperand(CE->getOperand(1), ValueMap);
+ Value *V3 = RemapOperand(CE->getOperand(2), ValueMap);
+ Result = ConstantExpr::getSelect(cast<Constant>(V1), cast<Constant>(V2),
+ cast<Constant>(V3));
+ } else if (CE->getNumOperands() == 2) {
+ // Binary operator...
+ Value *V1 = RemapOperand(CE->getOperand(0), ValueMap);
+ Value *V2 = RemapOperand(CE->getOperand(1), ValueMap);
+
+ Result = ConstantExpr::get(CE->getOpcode(), cast<Constant>(V1),
+ cast<Constant>(V2));
+ } else {
+ assert(0 && "Unknown constant expr type!");
+ }
+
+ } else {
+ assert(0 && "Unknown type of derived type constant value!");
+ }
+
+ // Cache the mapping in our local map structure...
+ ValueMap.insert(std::make_pair(In, Result));
+ return Result;
+ }
+
+ std::cerr << "LinkModules ValueMap: \n";
+ PrintMap(ValueMap);
+
+ std::cerr << "Couldn't remap value: " << (void*)In << " " << *In << "\n";
+ assert(0 && "Couldn't remap value!");
+ return 0;
+}
+
+/// ForceRenaming - The LLVM SymbolTable class autorenames globals that conflict
+/// in the symbol table. This is good for all clients except for us. Go
+/// through the trouble to force this back.
+static void ForceRenaming(GlobalValue *GV, const std::string &Name) {
+ assert(GV->getName() != Name && "Can't force rename to self");
+ SymbolTable &ST = GV->getParent()->getSymbolTable();
+
+ // If there is a conflict, rename the conflict.
+ Value *ConflictVal = ST.lookup(GV->getType(), Name);
+ assert(ConflictVal&&"Why do we have to force rename if there is no conflic?");
+ GlobalValue *ConflictGV = cast<GlobalValue>(ConflictVal);
+ assert(ConflictGV->hasInternalLinkage() &&
+ "Not conflicting with a static global, should link instead!");
+
+ ConflictGV->setName(""); // Eliminate the conflict
+ GV->setName(Name); // Force the name back
+ ConflictGV->setName(Name); // This will cause ConflictGV to get renamed
+ assert(GV->getName() == Name && ConflictGV->getName() != Name &&
+ "ForceRenaming didn't work");
+}
+
+
+// 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::map<std::string, GlobalValue*> &GlobalsByName,
+ std::string *Err) {
+ // We will need a module level symbol table if the src module has a module
+ // level symbol table...
+ SymbolTable *ST = (SymbolTable*)&Dest->getSymbolTable();
+
+ // Loop over all of the globals in the src module, mapping them over as we go
+ for (Module::const_giterator I = Src->gbegin(), E = Src->gend(); I != E; ++I){
+ const GlobalVariable *SGV = I;
+ GlobalVariable *DGV = 0;
+ // Check to see if may have to link the global.
+ if (SGV->hasName() && !SGV->hasInternalLinkage())
+ if (!(DGV = Dest->getGlobalVariable(SGV->getName(),
+ SGV->getType()->getElementType()))) {
+ std::map<std::string, GlobalValue*>::iterator EGV =
+ GlobalsByName.find(SGV->getName());
+ if (EGV != GlobalsByName.end())
+ DGV = dyn_cast<GlobalVariable>(EGV->second);
+ if (DGV && RecursiveResolveTypes(SGV->getType(), DGV->getType(),ST, ""))
+ DGV = 0; // FIXME: gross.
+ }
+
+ assert(SGV->hasInitializer() || SGV->hasExternalLinkage() &&
+ "Global must either be external or have an initializer!");
+
+ bool SGExtern = SGV->isExternal();
+ bool DGExtern = DGV ? DGV->isExternal() : false;
+
+ if (!DGV || DGV->hasInternalLinkage() || SGV->hasInternalLinkage()) {
+ // No linking to be performed, simply create an identical version of the
+ // symbol over in the dest module... the initializer will be filled in
+ // later by LinkGlobalInits...
+ GlobalVariable *NewDGV =
+ new GlobalVariable(SGV->getType()->getElementType(),
+ SGV->isConstant(), SGV->getLinkage(), /*init*/0,
+ SGV->getName(), Dest);
+
+ // If the LLVM runtime renamed the global, but it is an externally visible
+ // symbol, DGV must be an existing global with internal linkage. Rename
+ // it.
+ if (NewDGV->getName() != SGV->getName() && !NewDGV->hasInternalLinkage())
+ ForceRenaming(NewDGV, SGV->getName());
+
+ // Make sure to remember this mapping...
+ ValueMap.insert(std::make_pair(SGV, NewDGV));
+ if (SGV->hasAppendingLinkage())
+ // Keep track that this is an appending variable...
+ AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV));
+
+ } else if (SGV->isExternal()) {
+ // If SGV is external or if both SGV & DGV are external.. Just link the
+ // external globals, we aren't adding anything.
+ ValueMap.insert(std::make_pair(SGV, DGV));
+
+ // Inherit 'const' information.
+ if (SGV->isConstant()) DGV->setConstant(true);
+
+ } else if (DGV->isExternal()) { // If DGV is external but SGV is not...
+ ValueMap.insert(std::make_pair(SGV, DGV));
+ DGV->setLinkage(SGV->getLinkage()); // Inherit linkage!
+
+ if (DGV->isConstant() && !SGV->isConstant())
+ return Error(Err, "Linking globals named '" + SGV->getName() +
+ "': declaration is const but definition is not!");
+
+ // Inherit 'const' information.
+ if (SGV->isConstant()) DGV->setConstant(true);
+
+ } else if (SGV->hasWeakLinkage() || SGV->hasLinkOnceLinkage()) {
+ // At this point we know that DGV has LinkOnce, Appending, Weak, or
+ // External linkage. If DGV is Appending, this is an error.
+ if (DGV->hasAppendingLinkage())
+ return Error(Err, "Linking globals named '" + SGV->getName() +
+ "' with 'weak' and 'appending' linkage is not allowed!");
+
+ if (SGV->isConstant() != DGV->isConstant())
+ return Error(Err, "Global Variable Collision on '" +
+ ToStr(SGV->getType(), Src) + " %" + SGV->getName() +
+ "' - Global variables differ in const'ness");
+
+ // Otherwise, just perform the link.
+ ValueMap.insert(std::make_pair(SGV, DGV));
+
+ // Linkonce+Weak = Weak
+ if (DGV->hasLinkOnceLinkage() && SGV->hasWeakLinkage())
+ DGV->setLinkage(SGV->getLinkage());
+
+ } else if (DGV->hasWeakLinkage() || DGV->hasLinkOnceLinkage()) {
+ // At this point we know that SGV has LinkOnce, Appending, or External
+ // linkage. If SGV is Appending, this is an error.
+ if (SGV->hasAppendingLinkage())
+ return Error(Err, "Linking globals named '" + SGV->getName() +
+ " ' with 'weak' and 'appending' linkage is not allowed!");
+
+ if (SGV->isConstant() != DGV->isConstant())
+ return Error(Err, "Global Variable Collision on '" +
+ ToStr(SGV->getType(), Src) + " %" + SGV->getName() +
+ "' - Global variables differ in const'ness");
+
+ if (!SGV->hasLinkOnceLinkage())
+ DGV->setLinkage(SGV->getLinkage()); // Inherit linkage!
+ ValueMap.insert(std::make_pair(SGV, DGV));
+
+ } else if (SGV->getLinkage() != DGV->getLinkage()) {
+ return Error(Err, "Global variables named '" + SGV->getName() +
+ "' have different linkage specifiers!");
+ // Inherit 'const' information.
+ if (SGV->isConstant()) DGV->setConstant(true);
+
+ } else if (SGV->hasExternalLinkage()) {
+ // Allow linking two exactly identical external global variables...
+ if (SGV->isConstant() != DGV->isConstant())
+ return Error(Err, "Global Variable Collision on '" +
+ ToStr(SGV->getType(), Src) + " %" + SGV->getName() +
+ "' - Global variables differ in const'ness");
+
+ if (SGV->getInitializer() != DGV->getInitializer())
+ return Error(Err, "Global Variable Collision on '" +
+ ToStr(SGV->getType(), Src) + " %" + SGV->getName() +
+ "' - External linkage globals have different initializers");
+
+ ValueMap.insert(std::make_pair(SGV, DGV));
+ } else if (SGV->hasAppendingLinkage()) {
+ // No linking is performed yet. Just insert a new copy of the global, and
+ // keep track of the fact that it is an appending variable in the
+ // AppendingVars map. The name is cleared out so that no linkage is
+ // performed.
+ GlobalVariable *NewDGV =
+ new GlobalVariable(SGV->getType()->getElementType(),
+ SGV->isConstant(), SGV->getLinkage(), /*init*/0,
+ "", Dest);
+
+ // Make sure to remember this mapping...
+ ValueMap.insert(std::make_pair(SGV, NewDGV));
+
+ // Keep track that this is an appending variable...
+ AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV));
+ } else {
+ assert(0 && "Unknown linkage!");
+ }
+ }
+ return false;
+}
+
+
+// LinkGlobalInits - Update the initializers in the Dest module now that all
+// globals that may be referenced are in Dest.
+static bool LinkGlobalInits(Module *Dest, const Module *Src,
+ std::map<const Value*, Value*> &ValueMap,
+ std::string *Err) {
+
+ // Loop over all of the globals in the src module, mapping them over as we go
+ for (Module::const_giterator I = Src->gbegin(), E = Src->gend(); I != E; ++I){
+ const GlobalVariable *SGV = I;
+
+ if (SGV->hasInitializer()) { // Only process initialized GV's
+ // Figure out what the initializer looks like in the dest module...
+ Constant *SInit =
+ cast<Constant>(RemapOperand(SGV->getInitializer(), ValueMap));
+
+ GlobalVariable *DGV = cast<GlobalVariable>(ValueMap[SGV]);
+ if (DGV->hasInitializer()) {
+ if (SGV->hasExternalLinkage()) {
+ if (DGV->getInitializer() != SInit)
+ return Error(Err, "Global Variable Collision on '" +
+ ToStr(SGV->getType(), Src) +"':%"+SGV->getName()+
+ " - Global variables have different initializers");
+ } else if (DGV->hasLinkOnceLinkage() || DGV->hasWeakLinkage()) {
+ // Nothing is required, mapped values will take the new global
+ // automatically.
+ } else if (SGV->hasLinkOnceLinkage() || SGV->hasWeakLinkage()) {
+ // Nothing is required, mapped values will take the new global
+ // automatically.
+ } else if (DGV->hasAppendingLinkage()) {
+ assert(0 && "Appending linkage unimplemented!");
+ } else {
+ assert(0 && "Unknown linkage!");
+ }
+ } else {
+ // Copy the initializer over now...
+ DGV->setInitializer(SInit);
+ }
+ }
+ }
+ return false;
+}
+
+// LinkFunctionProtos - Link the functions together between the two modules,
+// without doing function bodies... this just adds external function prototypes
+// to the Dest function...
+//
+static bool LinkFunctionProtos(Module *Dest, const Module *Src,
+ std::map<const Value*, Value*> &ValueMap,
+ std::map<std::string, GlobalValue*> &GlobalsByName,
+ std::string *Err) {
+ SymbolTable *ST = (SymbolTable*)&Dest->getSymbolTable();
+
+ // Loop over all of the functions in the src module, mapping them over as we
+ // go
+ for (Module::const_iterator I = Src->begin(), E = Src->end(); I != E; ++I) {
+ const Function *SF = I; // SrcFunction
+ Function *DF = 0;
+ if (SF->hasName() && !SF->hasInternalLinkage()) {
+ // Check to see if may have to link the function.
+ if (!(DF = Dest->getFunction(SF->getName(), SF->getFunctionType()))) {
+ std::map<std::string, GlobalValue*>::iterator EF =
+ GlobalsByName.find(SF->getName());
+ if (EF != GlobalsByName.end())
+ DF = dyn_cast<Function>(EF->second);
+ if (DF && RecursiveResolveTypes(SF->getType(), DF->getType(), ST, ""))
+ DF = 0; // FIXME: gross.
+ }
+ }
+
+ if (!DF || SF->hasInternalLinkage() || DF->hasInternalLinkage()) {
+ // Function does not already exist, simply insert an function signature
+ // identical to SF into the dest module...
+ Function *NewDF = new Function(SF->getFunctionType(), SF->getLinkage(),
+ SF->getName(), Dest);
+
+ // If the LLVM runtime renamed the function, but it is an externally
+ // visible symbol, DF must be an existing function with internal linkage.
+ // Rename it.
+ if (NewDF->getName() != SF->getName() && !NewDF->hasInternalLinkage())
+ ForceRenaming(NewDF, SF->getName());
+
+ // ... and remember this mapping...
+ ValueMap.insert(std::make_pair(SF, NewDF));
+ } else if (SF->isExternal()) {
+ // If SF is external or if both SF & DF are external.. Just link the
+ // external functions, we aren't adding anything.
+ ValueMap.insert(std::make_pair(SF, DF));
+ } else if (DF->isExternal()) { // If DF is external but SF is not...
+ // Link the external functions, update linkage qualifiers
+ ValueMap.insert(std::make_pair(SF, DF));
+ DF->setLinkage(SF->getLinkage());
+
+ } else if (SF->hasWeakLinkage() || SF->hasLinkOnceLinkage()) {
+ // At this point we know that DF has LinkOnce, Weak, or External linkage.
+ ValueMap.insert(std::make_pair(SF, DF));
+
+ // Linkonce+Weak = Weak
+ if (DF->hasLinkOnceLinkage() && SF->hasWeakLinkage())
+ DF->setLinkage(SF->getLinkage());
+
+ } else if (DF->hasWeakLinkage() || DF->hasLinkOnceLinkage()) {
+ // At this point we know that SF has LinkOnce or External linkage.
+ ValueMap.insert(std::make_pair(SF, DF));
+ if (!SF->hasLinkOnceLinkage()) // Don't inherit linkonce linkage
+ DF->setLinkage(SF->getLinkage());
+
+ } else if (SF->getLinkage() != DF->getLinkage()) {
+ return Error(Err, "Functions named '" + SF->getName() +
+ "' have different linkage specifiers!");
+ } else if (SF->hasExternalLinkage()) {
+ // The function is defined in both modules!!
+ return Error(Err, "Function '" +
+ ToStr(SF->getFunctionType(), Src) + "':\"" +
+ SF->getName() + "\" - Function is already defined!");
+ } else {
+ assert(0 && "Unknown linkage configuration found!");
+ }
+ }
+ return false;
+}
+
+// LinkFunctionBody - Copy the source function over into the dest function and
+// fix up references to values. At this point we know that Dest is an external
+// function, and that Src is not.
+static bool LinkFunctionBody(Function *Dest, Function *Src,
+ std::map<const Value*, Value*> &GlobalMap,
+ std::string *Err) {
+ assert(Src && Dest && Dest->isExternal() && !Src->isExternal());
+
+ // Go through and convert function arguments over, remembering the mapping.
+ Function::aiterator DI = Dest->abegin();
+ for (Function::aiterator I = Src->abegin(), E = Src->aend();
+ I != E; ++I, ++DI) {
+ DI->setName(I->getName()); // Copy the name information over...
+
+ // Add a mapping to our local map
+ GlobalMap.insert(std::make_pair(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, GlobalMap);
+
+ // There is no need to map the arguments anymore.
+ for (Function::aiterator I = Src->abegin(), E = Src->aend(); I != E; ++I)
+ GlobalMap.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->isExternal()) { // No body if function is external
+ Function *DF = cast<Function>(ValueMap[SF]); // Destination function
+
+ // DF not external SF external?
+ if (DF->isExternal()) {
+ // 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!");
+
+ unsigned NewSize = T1->getNumElements() + T2->getNumElements();
+ ArrayType *NewType = ArrayType::get(T1->getElementType(), NewSize);
+
+ // Create the new global variable...
+ GlobalVariable *NG =
+ new GlobalVariable(NewType, G1->isConstant(), G1->getLinkage(),
+ /*init*/0, First->first, M);
+
+ // Merge the initializer...
+ Inits.reserve(NewSize);
+ 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::getCast(NG, G1->getType()));
+ G2->replaceAllUsesWith(ConstantExpr::getCast(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;
+}
// 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.
-//
-bool LinkModules(Module *Dest, const Module *Src, string *ErrorMsg = 0) {
+// the problem. Upon failure, the Dest module could be in a modified state, and
+// shouldn't be relied on to be consistent.
+bool llvm::LinkModules(Module *Dest, Module *Src, std::string *ErrorMsg) {
+ assert(Dest != 0 && "Invalid Destination module");
+ assert(Src != 0 && "Invalid Source Module");
+
+ if (Dest->getEndianness() == Module::AnyEndianness)
+ Dest->setEndianness(Src->getEndianness());
+ if (Dest->getPointerSize() == Module::AnyPointerSize)
+ Dest->setPointerSize(Src->getPointerSize());
+
+ if (Src->getEndianness() != Module::AnyEndianness &&
+ Dest->getEndianness() != Src->getEndianness())
+ std::cerr << "WARNING: Linking two modules of different endianness!\n";
+ if (Src->getPointerSize() != Module::AnyPointerSize &&
+ Dest->getPointerSize() != Src->getPointerSize())
+ std::cerr << "WARNING: Linking two modules of different pointer size!\n";
+
+ // 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.
+ Module::lib_iterator SI = Src->lib_begin();
+ Module::lib_iterator SE = Src->lib_end();
+ while ( SI != SE ) {
+ Dest->addLibrary(*SI);
+ ++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;
+
+ // GlobalsByName - The LLVM SymbolTable class fights our best efforts at
+ // linking by separating globals by type. Until PR411 is fixed, we replicate
+ // it's functionality here.
+ std::map<std::string, GlobalValue*> GlobalsByName;
+
+ for (Module::giterator I = Dest->gbegin(), E = Dest->gend(); 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));
+
+ // Keep track of all globals by name.
+ if (!I->hasInternalLinkage() && I->hasName())
+ GlobalsByName[I->getName()] = I;
+ }
+
+ // Keep track of all globals by name.
+ for (Module::iterator I = Dest->begin(), E = Dest->end(); I != E; ++I)
+ if (!I->hasInternalLinkage() && I->hasName())
+ GlobalsByName[I->getName()] = I;
+
+ // Insert all of the globals in src into the Dest module... without linking
+ // initializers (which could refer to functions not yet mapped over).
+ if (LinkGlobals(Dest, Src, ValueMap, AppendingVars, GlobalsByName, 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, GlobalsByName, 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;
+
+ // 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.setFile(Src->getModuleIdentifier());
+ if (!modId.isEmpty())
+ Dest->removeLibrary(modId.getBasename());
return false;
}
+
+// vim: sw=2