mirror of
https://github.com/c64scene-ar/llvm-6502.git
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1015 91177308-0d34-0410-b5e6-96231b3b80d8
354 lines
14 KiB
C++
354 lines
14 KiB
C++
//===- Linker.cpp - Module Linker Implementation --------------------------===//
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//
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// This file implements the LLVM module linker.
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//
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// Specifically, this:
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// * Merges global variables between the two modules
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// * Uninit + Uninit = Init, Init + Uninit = Init, Init + Init = Error if !=
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// * Merges methods between two modules
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Transforms/Linker.h"
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#include "llvm/Module.h"
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#include "llvm/Method.h"
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#include "llvm/GlobalVariable.h"
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#include "llvm/SymbolTable.h"
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#include "llvm/DerivedTypes.h"
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#include "llvm/iOther.h"
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// Error - Simple wrapper function to conditionally assign to E and return true.
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// This just makes error return conditions a little bit simpler...
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//
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static inline bool Error(string *E, string Message) {
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if (E) *E = Message;
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return true;
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}
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#include "llvm/Assembly/Writer.h" // TODO: REMOVE
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// RemapOperand - Use LocalMap and GlobalMap to convert references from one
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// module to another. This is somewhat sophisticated in that it can
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// automatically handle constant references correctly as well...
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//
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static Value *RemapOperand(const Value *In, map<const Value*, Value*> &LocalMap,
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const map<const Value*, Value*> *GlobalMap = 0) {
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map<const Value*,Value*>::const_iterator I = LocalMap.find(In);
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if (I != LocalMap.end()) return I->second;
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if (GlobalMap) {
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I = GlobalMap->find(In);
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if (I != GlobalMap->end()) return I->second;
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}
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// Check to see if it's a constant that we are interesting in transforming...
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if (ConstPoolVal *CPV = dyn_cast<ConstPoolVal>(In)) {
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if (!isa<DerivedType>(CPV->getType()))
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return CPV; // Simple constants stay identical...
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ConstPoolVal *Result = 0;
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if (ConstPoolArray *CPA = dyn_cast<ConstPoolArray>(CPV)) {
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const vector<Use> &Ops = CPA->getValues();
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vector<ConstPoolVal*> Operands(Ops.size());
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for (unsigned i = 0; i < Ops.size(); ++i)
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Operands[i] =
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cast<ConstPoolVal>(RemapOperand(Ops[i], LocalMap, GlobalMap));
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Result = ConstPoolArray::get(cast<ArrayType>(CPA->getType()), Operands);
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} else if (ConstPoolStruct *CPS = dyn_cast<ConstPoolStruct>(CPV)) {
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const vector<Use> &Ops = CPS->getValues();
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vector<ConstPoolVal*> Operands(Ops.size());
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for (unsigned i = 0; i < Ops.size(); ++i)
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Operands[i] =
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cast<ConstPoolVal>(RemapOperand(Ops[i], LocalMap, GlobalMap));
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Result = ConstPoolStruct::get(cast<StructType>(CPS->getType()), Operands);
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} else if (isa<ConstPoolPointerNull>(CPV)) {
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Result = CPV;
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} else if (ConstPoolPointerRef *CPR = dyn_cast<ConstPoolPointerRef>(CPV)) {
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Value *V = RemapOperand(CPR->getValue(), LocalMap, GlobalMap);
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Result = ConstPoolPointerRef::get(cast<GlobalValue>(V));
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} else {
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assert(0 && "Unknown type of derived type constant value!");
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}
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// Cache the mapping in our local map structure...
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LocalMap.insert(make_pair(In, CPV));
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return Result;
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}
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cerr << "Couldn't remap value: " << In << endl;
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assert(0 && "Couldn't remap value!");
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return 0;
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}
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// LinkGlobals - Loop through the global variables in the src module and merge
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// them into the dest module...
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//
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static bool LinkGlobals(Module *Dest, const Module *Src,
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map<const Value*, Value*> &ValueMap, string *Err = 0) {
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// We will need a module level symbol table if the src module has a module
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// level symbol table...
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SymbolTable *ST = Src->getSymbolTable() ? Dest->getSymbolTableSure() : 0;
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// Loop over all of the globals in the src module, mapping them over as we go
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//
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for (Module::const_giterator I = Src->gbegin(), E = Src->gend(); I != E; ++I){
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const GlobalVariable *SGV = *I;
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Value *V;
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// If the global variable has a name, and that name is already in use in the
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// Dest module, make sure that the name is a compatible global variable...
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//
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if (SGV->hasName() && (V = ST->lookup(SGV->getType(), SGV->getName()))) {
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// The same named thing is a global variable, because the only two things
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// that may be in a module level symbol table are Global Vars and Methods,
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// and they both have distinct, nonoverlapping, possible types.
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//
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GlobalVariable *DGV = cast<GlobalVariable>(V);
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// Check to see if the two GV's have the same Const'ness...
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if (SGV->isConstant() != DGV->isConstant())
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return Error(Err, "Global Variable Collision on '" +
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SGV->getType()->getDescription() + "':%" + SGV->getName() +
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" - Global variables differ in const'ness");
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// Okay, everything is cool, remember the mapping...
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ValueMap.insert(make_pair(SGV, DGV));
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} else {
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// No linking to be performed, simply create an identical version of the
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// symbol over in the dest module... the initializer will be filled in
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// later by LinkGlobalInits...
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//
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GlobalVariable *DGV =
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new GlobalVariable(SGV->getType()->getValueType(), SGV->isConstant(),
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0, SGV->getName());
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// Add the new global to the dest module
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Dest->getGlobalList().push_back(DGV);
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// Make sure to remember this mapping...
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ValueMap.insert(make_pair(SGV, DGV));
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}
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}
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return false;
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}
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// LinkGlobalInits - Update the initializers in the Dest module now that all
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// globals that may be referenced are in Dest.
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//
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static bool LinkGlobalInits(Module *Dest, const Module *Src,
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map<const Value*, Value*> &ValueMap,
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string *Err = 0) {
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// Loop over all of the globals in the src module, mapping them over as we go
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//
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for (Module::const_giterator I = Src->gbegin(), E = Src->gend(); I != E; ++I){
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const GlobalVariable *SGV = *I;
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if (SGV->hasInitializer()) { // Only process initialized GV's
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// Figure out what the initializer looks like in the dest module...
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ConstPoolVal *DInit =
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cast<ConstPoolVal>(RemapOperand(SGV->getInitializer(), ValueMap));
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GlobalVariable *DGV = cast<GlobalVariable>(ValueMap[SGV]);
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if (DGV->hasInitializer()) {
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if (DGV->getInitializer() != DInit)
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return Error(Err, "Global Variable Collision on '" +
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SGV->getType()->getDescription() + "':%" +SGV->getName()+
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" - Global variables have different initializers");
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} else {
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// Copy the initializer over now...
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DGV->setInitializer(DInit);
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}
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}
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}
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return false;
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}
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// LinkMethodProtos - Link the methods together between the two modules, without
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// doing method bodies... this just adds external method prototypes to the Dest
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// method...
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//
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static bool LinkMethodProtos(Module *Dest, const Module *Src,
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map<const Value*, Value*> &ValueMap,
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string *Err = 0) {
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// We will need a module level symbol table if the src module has a module
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// level symbol table...
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SymbolTable *ST = Src->getSymbolTable() ? Dest->getSymbolTableSure() : 0;
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// Loop over all of the methods in the src module, mapping them over as we go
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//
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for (Module::const_iterator I = Src->begin(), E = Src->end(); I != E; ++I) {
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const Method *SM = *I; // SrcMethod
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Value *V;
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// If the method has a name, and that name is already in use in the
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// Dest module, make sure that the name is a compatible method...
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//
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if (SM->hasName() && (V = ST->lookup(SM->getType(), SM->getName()))) {
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// The same named thing is a Method, because the only two things
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// that may be in a module level symbol table are Global Vars and Methods,
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// and they both have distinct, nonoverlapping, possible types.
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//
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Method *DM = cast<Method>(V); // DestMethod
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// Check to make sure the method is not defined in both modules...
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if (!SM->isExternal() && !DM->isExternal())
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return Error(Err, "Method '" +
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SM->getMethodType()->getDescription() + "':\"" +
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SM->getName() + "\" - Method is already defined!");
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// Otherwise, just remember this mapping...
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ValueMap.insert(make_pair(SM, DM));
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} else {
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// Method does not already exist, simply insert an external method
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// signature identical to SM into the dest module...
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Method *DM = new Method(SM->getMethodType(), SM->getName());
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// Add the method signature to the dest module...
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Dest->getMethodList().push_back(DM);
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// ... and remember this mapping...
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ValueMap.insert(make_pair(SM, DM));
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}
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}
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return false;
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}
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// LinkMethodBody - Copy the source method over into the dest method and fix up
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// references to values. At this point we know that Dest is an external method,
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// and that Src is not.
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//
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static bool LinkMethodBody(Method *Dest, const Method *Src,
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const map<const Value*, Value*> &GlobalMap,
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string *Err = 0) {
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assert(Src && Dest && Dest->isExternal() && !Src->isExternal());
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map<const Value*, Value*> LocalMap; // Map for method local values
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// Go through and convert method arguments over...
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for (Method::ArgumentListType::const_iterator
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I = Src->getArgumentList().begin(),
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E = Src->getArgumentList().end(); I != E; ++I) {
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const MethodArgument *SMA = *I;
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// Create the new method argument and add to the dest method...
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MethodArgument *DMA = new MethodArgument(SMA->getType(), SMA->getName());
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Dest->getArgumentList().push_back(DMA);
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// Add a mapping to our local map
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LocalMap.insert(make_pair(SMA, DMA));
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}
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// Loop over all of the basic blocks, copying the instructions over...
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//
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for (Method::const_iterator I = Src->begin(), E = Src->end(); I != E; ++I) {
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const BasicBlock *SBB = *I;
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// Create new basic block and add to mapping and the Dest method...
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BasicBlock *DBB = new BasicBlock(SBB->getName(), Dest);
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LocalMap.insert(make_pair(SBB, DBB));
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// Loop over all of the instructions in the src basic block, copying them
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// over. Note that this is broken in a strict sense because the cloned
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// instructions will still be referencing values in the Src module, not
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// the remapped values. In our case, however, we will not get caught and
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// so we can delay patching the values up until later...
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//
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for (BasicBlock::const_iterator II = SBB->begin(), IE = SBB->end();
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II != IE; ++II) {
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const Instruction *SI = *II;
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Instruction *DI = SI->clone();
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DBB->getInstList().push_back(DI);
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LocalMap.insert(make_pair(SI, DI));
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}
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}
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// At this point, all of the instructions and values of the method are now
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// copied over. The only problem is that they are still referencing values
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// in the Source method as operands. Loop through all of the operands of the
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// methods and patch them up to point to the local versions...
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//
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for (Method::inst_iterator I = Dest->inst_begin(), E = Dest->inst_end();
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I != E; ++I) {
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Instruction *Inst = *I;
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for (Instruction::op_iterator OI = Inst->op_begin(), OE = Inst->op_end();
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OI != OE; ++OI)
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*OI = RemapOperand(*OI, LocalMap, &GlobalMap);
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}
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return false;
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}
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// LinkMethodBodies - Link in the method bodies that are defined in the source
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// module into the DestModule. This consists basically of copying the method
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// over and fixing up references to values.
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//
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static bool LinkMethodBodies(Module *Dest, const Module *Src,
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map<const Value*, Value*> &ValueMap,
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string *Err = 0) {
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// Loop over all of the methods in the src module, mapping them over as we go
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//
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for (Module::const_iterator I = Src->begin(), E = Src->end(); I != E; ++I) {
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const Method *SM = *I; // Source Method
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if (!SM->isExternal()) { // No body if method is external
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Method *DM = cast<Method>(ValueMap[SM]); // Destination method
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// DM not external SM external?
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if (!DM->isExternal()) {
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if (Err)
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*Err = "Method '" + (SM->hasName() ? SM->getName() : string("")) +
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"' body multiply defined!";
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return true;
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}
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if (LinkMethodBody(DM, SM, ValueMap, Err)) return true;
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}
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}
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return false;
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}
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// LinkModules - This function links two modules together, with the resulting
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// left module modified to be the composite of the two input modules. If an
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// error occurs, true is returned and ErrorMsg (if not null) is set to indicate
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// the problem. Upon failure, the Dest module could be in a modified state, and
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// shouldn't be relied on to be consistent.
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//
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bool LinkModules(Module *Dest, const Module *Src, string *ErrorMsg = 0) {
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// ValueMap - Mapping of values from what they used to be in Src, to what they
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// are now in Dest.
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//
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map<const Value*, Value*> ValueMap;
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// Insert all of the globals in src into the Dest module... without
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// initializers
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if (LinkGlobals(Dest, Src, ValueMap, ErrorMsg)) return true;
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// Update the initializers in the Dest module now that all globals that may
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// be referenced are in Dest.
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//
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if (LinkGlobalInits(Dest, Src, ValueMap, ErrorMsg)) return true;
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// Link the methods together between the two modules, without doing method
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// bodies... this just adds external method prototypes to the Dest method...
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// We do this so that when we begin processing method bodies, all of the
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// global values that may be referenced are available in our ValueMap.
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//
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if (LinkMethodProtos(Dest, Src, ValueMap, ErrorMsg)) return true;
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// Link in the method bodies that are defined in the source module into the
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// DestModule. This consists basically of copying the method over and fixing
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// up references to values.
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//
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if (LinkMethodBodies(Dest, Src, ValueMap, ErrorMsg)) return true;
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return false;
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}
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