// 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/Transforms/Utils/Linker.h"
+#include "llvm/Module.h"
+#include "llvm/SymbolTable.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/iOther.h"
+#include "llvm/Constants.h"
+using std::cerr;
+using std::string;
+using std::map;
+
+// 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;
+ return true;
+}
+
+// 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) {
+ // No symbol table? Can't have named types.
+ if (!Src->hasSymbolTable()) return false;
+
+ SymbolTable *DestST = Dest->getSymbolTableSure();
+ const SymbolTable *SrcST = Src->getSymbolTable();
+
+ // Look for a type plane for Type's...
+ SymbolTable::const_iterator PI = SrcST->find(Type::TypeTy);
+ if (PI == SrcST->end()) return false; // No named types, do nothing.
+
+ 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));
+ }
+ }
+ return false;
+}
+
+static void PrintMap(const map<const Value*, Value*> &M) {
+ for (map<const Value*, Value*>::const_iterator I = M.begin(), E = M.end();
+ I != E; ++I) {
+ cerr << " Fr: " << (void*)I->first << " ";
+ I->first->dump();
+ cerr << " To: " << (void*)I->second << " ";
+ I->second->dump();
+ cerr << "\n";
+ }
+}
+
+
+// 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,
+ const 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;
+ }
+
+ // Check to see if it's a constant that we are interesting in transforming...
+ if (const Constant *CPV = dyn_cast<Constant>(In)) {
+ if (!isa<DerivedType>(CPV->getType()) && !isa<ConstantExpr>(CPV))
+ return const_cast<Constant*>(CPV); // Simple constants stay identical...
+
+ Constant *Result = 0;
+
+ if (const ConstantArray *CPA = dyn_cast<ConstantArray>(CPV)) {
+ const std::vector<Use> &Ops = CPA->getValues();
+ std::vector<Constant*> Operands(Ops.size());
+ for (unsigned i = 0, e = Ops.size(); i != e; ++i)
+ Operands[i] =
+ cast<Constant>(RemapOperand(Ops[i], LocalMap, GlobalMap));
+ Result = ConstantArray::get(cast<ArrayType>(CPA->getType()), Operands);
+ } else if (const ConstantStruct *CPS = dyn_cast<ConstantStruct>(CPV)) {
+ const std::vector<Use> &Ops = CPS->getValues();
+ std::vector<Constant*> Operands(Ops.size());
+ for (unsigned i = 0; i < Ops.size(); ++i)
+ Operands[i] =
+ cast<Constant>(RemapOperand(Ops[i], LocalMap, GlobalMap));
+ Result = ConstantStruct::get(cast<StructType>(CPS->getType()), Operands);
+ } else if (isa<ConstantPointerNull>(CPV)) {
+ Result = const_cast<Constant*>(CPV);
+ } else if (const ConstantPointerRef *CPR =
+ dyn_cast<ConstantPointerRef>(CPV)) {
+ Value *V = RemapOperand(CPR->getValue(), LocalMap, GlobalMap);
+ Result = ConstantPointerRef::get(cast<GlobalValue>(V));
+ } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CPV)) {
+ if (CE->getOpcode() == Instruction::GetElementPtr) {
+ Value *Ptr = RemapOperand(CE->getOperand(0), LocalMap, GlobalMap);
+ std::vector<Constant*> Indices;
+ Indices.reserve(CE->getNumOperands()-1);
+ for (unsigned i = 1, e = CE->getNumOperands(); i != e; ++i)
+ Indices.push_back(cast<Constant>(RemapOperand(CE->getOperand(i),
+ LocalMap, GlobalMap)));
+
+ Result = ConstantExpr::getGetElementPtr(cast<Constant>(Ptr), Indices);
+ } else if (CE->getNumOperands() == 1) {
+ // Cast instruction
+ assert(CE->getOpcode() == Instruction::Cast);
+ Value *V = RemapOperand(CE->getOperand(0), LocalMap, GlobalMap);
+ Result = ConstantExpr::getCast(cast<Constant>(V), CE->getType());
+ } else if (CE->getNumOperands() == 2) {
+ // Binary operator...
+ Value *V1 = RemapOperand(CE->getOperand(0), LocalMap, GlobalMap);
+ Value *V2 = RemapOperand(CE->getOperand(1), LocalMap, GlobalMap);
+
+ Result = ConstantExpr::get(CE->getOpcode(), cast<Constant>(V1),
+ cast<Constant>(V2));
+ } else {
+ assert(0 && "Unknown constant expr type!");
+ }
+
+ } else {
+ assert(0 && "Unknown type of derived type constant value!");
+ }
+
+ // Cache the mapping in our local map structure...
+ LocalMap.insert(std::make_pair(In, Result));
+ return Result;
+ }
+
+ cerr << "XXX LocalMap: \n";
+ PrintMap(LocalMap);
+
+ if (GlobalMap) {
+ cerr << "XXX GlobalMap: \n";
+ PrintMap(*GlobalMap);
+ }
+
+ cerr << "Couldn't remap value: " << (void*)In << " " << *In << "\n";
+ assert(0 && "Couldn't remap value!");
+ return 0;
+}
+
+
+// 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,
+ 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 = Src->getSymbolTable() ? Dest->getSymbolTableSure() : 0;
+
+ // 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;
+ 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 {
+ // 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());
+
+ // Add the new global to the dest module
+ Dest->getGlobalList().push_back(DGV);
+
+ // Make sure to remember this mapping...
+ ValueMap.insert(std::make_pair(SGV, DGV));
+ }
+ }
+ 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) {
+
+ // 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 *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");
+ } else {
+ // Copy the initializer over now...
+ DGV->setInitializer(DInit);
+ }
+ }
+ }
+ 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,
+ 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 = Src->getSymbolTable() ? Dest->getSymbolTableSure() : 0;
+
+ // 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
+ 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());
+
+ // Add the function signature to the dest module...
+ Dest->getFunctionList().push_back(DF);
+
+ // ... and remember this mapping...
+ ValueMap.insert(std::make_pair(SF, DF));
+ }
+ }
+ 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,
+ const 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...
+ for (Function::const_aiterator I = Src->abegin(), E = Src->aend();
+ I != E; ++I) {
+ // Create the new function argument and add to the dest function...
+ Argument *DFA = new Argument(I->getType(), I->getName());
+ Dest->getArgumentList().push_back(DFA);
+
+ // Add a mapping to our local map
+ LocalMap.insert(std::make_pair(I, DFA));
+ }
+
+ // Loop over all of the basic blocks, copying the instructions over...
+ //
+ for (Function::const_iterator I = Src->begin(), E = Src->end(); I != E; ++I) {
+ // Create new basic block and add to mapping and the Dest function...
+ BasicBlock *DBB = new BasicBlock(I->getName(), Dest);
+ LocalMap.insert(std::make_pair(I, DBB));
+
+ // Loop over all of the instructions in the src basic block, copying them
+ // over. Note that this is broken in a strict sense because the cloned
+ // instructions will still be referencing values in the Src module, not
+ // the remapped values. In our case, however, we will not get caught and
+ // so we can delay patching the values up until later...
+ //
+ for (BasicBlock::const_iterator II = I->begin(), IE = I->end();
+ II != IE; ++II) {
+ Instruction *DI = II->clone();
+ DI->setName(II->getName());
+ DBB->getInstList().push_back(DI);
+ LocalMap.insert(std::make_pair(II, DI));
+ }
+ }
+
+ // At this point, all of the instructions and values of the function are now
+ // copied over. The only problem is that they are still referencing values in
+ // the Source function as operands. Loop through all of the operands of the
+ // functions and patch them up to point to the local versions...
+ //
+ for (Function::iterator BB = Dest->begin(), BE = Dest->end(); BB != BE; ++BB)
+ for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
+ for (Instruction::op_iterator OI = I->op_begin(), OE = I->op_end();
+ OI != OE; ++OI)
+ *OI = RemapOperand(*OI, LocalMap, &GlobalMap);
+
+ return false;
+}
+
+
+// LinkFunctionBodies - Link in the function bodies that are defined in the
+// source module into the DestModule. This consists basically of copying the
+// function over and fixing up references to values.
+//
+static bool LinkFunctionBodies(Module *Dest, const Module *Src,
+ map<const Value*, Value*> &ValueMap,
+ string *Err = 0) {
+
+ // Loop over all of the functions in the src module, mapping them over as we
+ // go
+ //
+ for (Module::const_iterator SF = Src->begin(), E = Src->end(); SF != E; ++SF){
+ if (!SF->isExternal()) { // No body if function is external
+ Function *DF = cast<Function>(ValueMap[SF]); // Destination function
+
+ // DF not external SF external?
+ if (!DF->isExternal()) {
+ if (Err)
+ *Err = "Function '" + (SF->hasName() ? SF->getName() : string("")) +
+ "' body multiply defined!";
+ return true;
+ }
+
+ if (LinkFunctionBody(DF, SF, ValueMap, Err)) return true;
+ }
+ }
+ 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.
+// 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 = 0) {
+bool LinkModules(Module *Dest, const Module *Src, string *ErrorMsg) {
+
+ // 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.
+ //
+ map<const Value*, Value*> ValueMap;
+
+ // Insert all of the globals in src into the Dest module... without
+ // initializers
+ if (LinkGlobals(Dest, Src, ValueMap, ErrorMsg)) return true;
+
+ // Link the functions together between the two modules, without doing function
+ // bodies... this just adds external function prototypes to the Dest
+ // function... We do this so that when we begin processing function bodies,
+ // all of the global values that may be referenced are available in our
+ // ValueMap.
+ //
+ if (LinkFunctionProtos(Dest, Src, ValueMap, ErrorMsg)) return true;
+
+ // Update the initializers in the Dest module now that all globals that may
+ // be referenced are in Dest.
+ //
+ if (LinkGlobalInits(Dest, Src, ValueMap, ErrorMsg)) return true;
+
+ // Link in the function bodies that are defined in the source module into the
+ // DestModule. This consists basically of copying the function over and
+ // fixing up references to values.
+ //
+ if (LinkFunctionBodies(Dest, Src, ValueMap, ErrorMsg)) return true;
return false;
}
+
projects / oota-llvm.git / blobdiff