1 //===- Linker.cpp - Module Linker Implementation --------------------------===//
3 // This file implements the LLVM module linker.
6 // * Merges global variables between the two modules
7 // * Uninit + Uninit = Init, Init + Uninit = Init, Init + Init = Error if !=
8 // * Merges functions between two modules
10 //===----------------------------------------------------------------------===//
12 #include "llvm/Transforms/Utils/Linker.h"
13 #include "llvm/Module.h"
14 #include "llvm/SymbolTable.h"
15 #include "llvm/DerivedTypes.h"
16 #include "llvm/iOther.h"
17 #include "llvm/Constants.h"
19 // Error - Simple wrapper function to conditionally assign to E and return true.
20 // This just makes error return conditions a little bit simpler...
22 static inline bool Error(std::string *E, const std::string &Message) {
27 // ResolveTypes - Attempt to link the two specified types together. Return true
28 // if there is an error and they cannot yet be linked.
30 static bool ResolveTypes(const Type *DestTy, const Type *SrcTy,
31 SymbolTable *DestST, const std::string &Name) {
32 if (DestTy == SrcTy) return false; // If already equal, noop
34 // Does the type already exist in the module?
35 if (DestTy && !isa<OpaqueType>(DestTy)) { // Yup, the type already exists...
36 if (const OpaqueType *OT = dyn_cast<OpaqueType>(SrcTy)) {
37 const_cast<OpaqueType*>(OT)->refineAbstractTypeTo(DestTy);
39 return true; // Cannot link types... neither is opaque and not-equal
41 } else { // Type not in dest module. Add it now.
42 if (DestTy) // Type _is_ in module, just opaque...
43 const_cast<OpaqueType*>(cast<OpaqueType>(DestTy))
44 ->refineAbstractTypeTo(SrcTy);
45 else if (!Name.empty())
46 DestST->insert(Name, const_cast<Type*>(SrcTy));
51 static const FunctionType *getFT(const PATypeHolder &TH) {
52 return cast<FunctionType>(TH.get());
54 static const StructType *getST(const PATypeHolder &TH) {
55 return cast<StructType>(TH.get());
58 // RecursiveResolveTypes - This is just like ResolveTypes, except that it
59 // recurses down into derived types, merging the used types if the parent types
62 static bool RecursiveResolveTypesI(const PATypeHolder &DestTy,
63 const PATypeHolder &SrcTy,
64 SymbolTable *DestST, const std::string &Name,
65 std::vector<std::pair<PATypeHolder, PATypeHolder> > &Pointers) {
66 const Type *SrcTyT = SrcTy.get();
67 const Type *DestTyT = DestTy.get();
68 if (DestTyT == SrcTyT) return false; // If already equal, noop
70 // If we found our opaque type, resolve it now!
71 if (isa<OpaqueType>(DestTyT) || isa<OpaqueType>(SrcTyT))
72 return ResolveTypes(DestTyT, SrcTyT, DestST, Name);
74 // Two types cannot be resolved together if they are of different primitive
75 // type. For example, we cannot resolve an int to a float.
76 if (DestTyT->getPrimitiveID() != SrcTyT->getPrimitiveID()) return true;
78 // Otherwise, resolve the used type used by this derived type...
79 switch (DestTyT->getPrimitiveID()) {
80 case Type::FunctionTyID: {
81 if (cast<FunctionType>(DestTyT)->isVarArg() !=
82 cast<FunctionType>(SrcTyT)->isVarArg() ||
83 cast<FunctionType>(DestTyT)->getNumContainedTypes() !=
84 cast<FunctionType>(SrcTyT)->getNumContainedTypes())
86 for (unsigned i = 0, e = getFT(DestTy)->getNumContainedTypes(); i != e; ++i)
87 if (RecursiveResolveTypesI(getFT(DestTy)->getContainedType(i),
88 getFT(SrcTy)->getContainedType(i), DestST, "",
93 case Type::StructTyID: {
94 if (getST(DestTy)->getNumContainedTypes() !=
95 getST(SrcTy)->getNumContainedTypes()) return 1;
96 for (unsigned i = 0, e = getST(DestTy)->getNumContainedTypes(); i != e; ++i)
97 if (RecursiveResolveTypesI(getST(DestTy)->getContainedType(i),
98 getST(SrcTy)->getContainedType(i), DestST, "",
103 case Type::ArrayTyID: {
104 const ArrayType *DAT = cast<ArrayType>(DestTy.get());
105 const ArrayType *SAT = cast<ArrayType>(SrcTy.get());
106 if (DAT->getNumElements() != SAT->getNumElements()) return true;
107 return RecursiveResolveTypesI(DAT->getElementType(), SAT->getElementType(),
108 DestST, "", Pointers);
110 case Type::PointerTyID: {
111 // If this is a pointer type, check to see if we have already seen it. If
112 // so, we are in a recursive branch. Cut off the search now. We cannot use
113 // an associative container for this search, because the type pointers (keys
114 // in the container) change whenever types get resolved...
116 for (unsigned i = 0, e = Pointers.size(); i != e; ++i)
117 if (Pointers[i].first == DestTy)
118 return Pointers[i].second != SrcTy;
120 // Otherwise, add the current pointers to the vector to stop recursion on
122 Pointers.push_back(std::make_pair(DestTyT, SrcTyT));
124 RecursiveResolveTypesI(cast<PointerType>(DestTy.get())->getElementType(),
125 cast<PointerType>(SrcTy.get())->getElementType(),
126 DestST, "", Pointers);
130 default: assert(0 && "Unexpected type!"); return true;
134 static bool RecursiveResolveTypes(const PATypeHolder &DestTy,
135 const PATypeHolder &SrcTy,
136 SymbolTable *DestST, const std::string &Name){
137 std::vector<std::pair<PATypeHolder, PATypeHolder> > PointerTypes;
138 return RecursiveResolveTypesI(DestTy, SrcTy, DestST, Name, PointerTypes);
142 // LinkTypes - Go through the symbol table of the Src module and see if any
143 // types are named in the src module that are not named in the Dst module.
144 // Make sure there are no type name conflicts.
146 static bool LinkTypes(Module *Dest, const Module *Src, std::string *Err) {
147 SymbolTable *DestST = &Dest->getSymbolTable();
148 const SymbolTable *SrcST = &Src->getSymbolTable();
150 // Look for a type plane for Type's...
151 SymbolTable::const_iterator PI = SrcST->find(Type::TypeTy);
152 if (PI == SrcST->end()) return false; // No named types, do nothing.
154 // Some types cannot be resolved immediately becuse they depend on other types
155 // being resolved to each other first. This contains a list of types we are
156 // waiting to recheck.
157 std::vector<std::string> DelayedTypesToResolve;
159 const SymbolTable::VarMap &VM = PI->second;
160 for (SymbolTable::type_const_iterator I = VM.begin(), E = VM.end();
162 const std::string &Name = I->first;
163 Type *RHS = cast<Type>(I->second);
165 // Check to see if this type name is already in the dest module...
166 Type *Entry = cast_or_null<Type>(DestST->lookup(Type::TypeTy, Name));
168 if (ResolveTypes(Entry, RHS, DestST, Name)) {
169 // They look different, save the types 'till later to resolve.
170 DelayedTypesToResolve.push_back(Name);
174 // Iteratively resolve types while we can...
175 while (!DelayedTypesToResolve.empty()) {
176 // Loop over all of the types, attempting to resolve them if possible...
177 unsigned OldSize = DelayedTypesToResolve.size();
179 // Try direct resolution by name...
180 for (unsigned i = 0; i != DelayedTypesToResolve.size(); ++i) {
181 const std::string &Name = DelayedTypesToResolve[i];
182 Type *T1 = cast<Type>(VM.find(Name)->second);
183 Type *T2 = cast<Type>(DestST->lookup(Type::TypeTy, Name));
184 if (!ResolveTypes(T2, T1, DestST, Name)) {
185 // We are making progress!
186 DelayedTypesToResolve.erase(DelayedTypesToResolve.begin()+i);
191 // Did we not eliminate any types?
192 if (DelayedTypesToResolve.size() == OldSize) {
193 // Attempt to resolve subelements of types. This allows us to merge these
194 // two types: { int* } and { opaque* }
195 for (unsigned i = 0, e = DelayedTypesToResolve.size(); i != e; ++i) {
196 const std::string &Name = DelayedTypesToResolve[i];
197 PATypeHolder T1(cast<Type>(VM.find(Name)->second));
198 PATypeHolder T2(cast<Type>(DestST->lookup(Type::TypeTy, Name)));
200 if (!RecursiveResolveTypes(T2, T1, DestST, Name)) {
201 // We are making progress!
202 DelayedTypesToResolve.erase(DelayedTypesToResolve.begin()+i);
204 // Go back to the main loop, perhaps we can resolve directly by name
210 // If we STILL cannot resolve the types, then there is something wrong.
212 if (DelayedTypesToResolve.size() == OldSize) {
213 // Build up an error message of all of the mismatched types.
214 std::string ErrorMessage;
215 for (unsigned i = 0, e = DelayedTypesToResolve.size(); i != e; ++i) {
216 const std::string &Name = DelayedTypesToResolve[i];
217 const Type *T1 = cast<Type>(VM.find(Name)->second);
218 const Type *T2 = cast<Type>(DestST->lookup(Type::TypeTy, Name));
219 ErrorMessage += " Type named '" + Name +
220 "' conflicts.\n Src='" + T1->getDescription() +
221 "'.\n Dest='" + T2->getDescription() + "'\n";
223 return Error(Err, "Type conflict between types in modules:\n" +
233 static void PrintMap(const std::map<const Value*, Value*> &M) {
234 for (std::map<const Value*, Value*>::const_iterator I = M.begin(), E =M.end();
236 std::cerr << " Fr: " << (void*)I->first << " ";
238 std::cerr << " To: " << (void*)I->second << " ";
245 // RemapOperand - Use LocalMap and GlobalMap to convert references from one
246 // module to another. This is somewhat sophisticated in that it can
247 // automatically handle constant references correctly as well...
249 static Value *RemapOperand(const Value *In,
250 std::map<const Value*, Value*> &LocalMap,
251 std::map<const Value*, Value*> *GlobalMap) {
252 std::map<const Value*,Value*>::const_iterator I = LocalMap.find(In);
253 if (I != LocalMap.end()) return I->second;
256 I = GlobalMap->find(In);
257 if (I != GlobalMap->end()) return I->second;
260 // Check to see if it's a constant that we are interesting in transforming...
261 if (const Constant *CPV = dyn_cast<Constant>(In)) {
262 if (!isa<DerivedType>(CPV->getType()) && !isa<ConstantExpr>(CPV))
263 return const_cast<Constant*>(CPV); // Simple constants stay identical...
265 Constant *Result = 0;
267 if (const ConstantArray *CPA = dyn_cast<ConstantArray>(CPV)) {
268 const std::vector<Use> &Ops = CPA->getValues();
269 std::vector<Constant*> Operands(Ops.size());
270 for (unsigned i = 0, e = Ops.size(); i != e; ++i)
272 cast<Constant>(RemapOperand(Ops[i], LocalMap, GlobalMap));
273 Result = ConstantArray::get(cast<ArrayType>(CPA->getType()), Operands);
274 } else if (const ConstantStruct *CPS = dyn_cast<ConstantStruct>(CPV)) {
275 const std::vector<Use> &Ops = CPS->getValues();
276 std::vector<Constant*> Operands(Ops.size());
277 for (unsigned i = 0; i < Ops.size(); ++i)
279 cast<Constant>(RemapOperand(Ops[i], LocalMap, GlobalMap));
280 Result = ConstantStruct::get(cast<StructType>(CPS->getType()), Operands);
281 } else if (isa<ConstantPointerNull>(CPV)) {
282 Result = const_cast<Constant*>(CPV);
283 } else if (const ConstantPointerRef *CPR =
284 dyn_cast<ConstantPointerRef>(CPV)) {
285 Value *V = RemapOperand(CPR->getValue(), LocalMap, GlobalMap);
286 Result = ConstantPointerRef::get(cast<GlobalValue>(V));
287 } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CPV)) {
288 if (CE->getOpcode() == Instruction::GetElementPtr) {
289 Value *Ptr = RemapOperand(CE->getOperand(0), LocalMap, GlobalMap);
290 std::vector<Constant*> Indices;
291 Indices.reserve(CE->getNumOperands()-1);
292 for (unsigned i = 1, e = CE->getNumOperands(); i != e; ++i)
293 Indices.push_back(cast<Constant>(RemapOperand(CE->getOperand(i),
294 LocalMap, GlobalMap)));
296 Result = ConstantExpr::getGetElementPtr(cast<Constant>(Ptr), Indices);
297 } else if (CE->getNumOperands() == 1) {
299 assert(CE->getOpcode() == Instruction::Cast);
300 Value *V = RemapOperand(CE->getOperand(0), LocalMap, GlobalMap);
301 Result = ConstantExpr::getCast(cast<Constant>(V), CE->getType());
302 } else if (CE->getNumOperands() == 2) {
303 // Binary operator...
304 Value *V1 = RemapOperand(CE->getOperand(0), LocalMap, GlobalMap);
305 Value *V2 = RemapOperand(CE->getOperand(1), LocalMap, GlobalMap);
307 Result = ConstantExpr::get(CE->getOpcode(), cast<Constant>(V1),
310 assert(0 && "Unknown constant expr type!");
314 assert(0 && "Unknown type of derived type constant value!");
317 // Cache the mapping in our local map structure...
319 GlobalMap->insert(std::make_pair(In, Result));
321 LocalMap.insert(std::make_pair(In, Result));
325 std::cerr << "XXX LocalMap: \n";
329 std::cerr << "XXX GlobalMap: \n";
330 PrintMap(*GlobalMap);
333 std::cerr << "Couldn't remap value: " << (void*)In << " " << *In << "\n";
334 assert(0 && "Couldn't remap value!");
338 /// FindGlobalNamed - Look in the specified symbol table for a global with the
339 /// specified name and type. If an exactly matching global does not exist, see
340 /// if there is a global which is "type compatible" with the specified
341 /// name/type. This allows us to resolve things like '%x = global int*' with
342 /// '%x = global opaque*'.
344 static GlobalValue *FindGlobalNamed(const std::string &Name, const Type *Ty,
346 // See if an exact match exists in the symbol table...
347 if (Value *V = ST->lookup(Ty, Name)) return cast<GlobalValue>(V);
349 // It doesn't exist exactly, scan through all of the type planes in the symbol
350 // table, checking each of them for a type-compatible version.
352 for (SymbolTable::iterator I = ST->begin(), E = ST->end(); I != E; ++I)
353 if (I->first != Type::TypeTy) {
354 SymbolTable::VarMap &VM = I->second;
355 // Does this type plane contain an entry with the specified name?
356 SymbolTable::type_iterator TI = VM.find(Name);
357 if (TI != VM.end()) {
358 // Determine whether we can fold the two types together, resolving them.
359 // If so, we can use this value.
360 if (!RecursiveResolveTypes(Ty, I->first, ST, ""))
361 return cast<GlobalValue>(TI->second);
364 return 0; // Otherwise, nothing could be found.
368 // LinkGlobals - Loop through the global variables in the src module and merge
369 // them into the dest module.
371 static bool LinkGlobals(Module *Dest, const Module *Src,
372 std::map<const Value*, Value*> &ValueMap,
373 std::multimap<std::string, GlobalVariable *> &AppendingVars,
375 // We will need a module level symbol table if the src module has a module
376 // level symbol table...
377 SymbolTable *ST = (SymbolTable*)&Dest->getSymbolTable();
379 // Loop over all of the globals in the src module, mapping them over as we go
381 for (Module::const_giterator I = Src->gbegin(), E = Src->gend(); I != E; ++I){
382 const GlobalVariable *SGV = I;
383 GlobalVariable *DGV = 0;
384 if (SGV->hasName()) {
385 // A same named thing is a global variable, because the only two things
386 // that may be in a module level symbol table are Global Vars and
387 // Functions, and they both have distinct, nonoverlapping, possible types.
389 DGV = cast_or_null<GlobalVariable>(FindGlobalNamed(SGV->getName(),
390 SGV->getType(), ST));
393 assert(SGV->hasInitializer() || SGV->hasExternalLinkage() &&
394 "Global must either be external or have an initializer!");
396 bool SGExtern = SGV->isExternal();
397 bool DGExtern = DGV ? DGV->isExternal() : false;
399 if (!DGV || DGV->hasInternalLinkage() || SGV->hasInternalLinkage()) {
400 // No linking to be performed, simply create an identical version of the
401 // symbol over in the dest module... the initializer will be filled in
402 // later by LinkGlobalInits...
404 GlobalVariable *NewDGV =
405 new GlobalVariable(SGV->getType()->getElementType(),
406 SGV->isConstant(), SGV->getLinkage(), /*init*/0,
407 SGV->getName(), Dest);
409 // If the LLVM runtime renamed the global, but it is an externally visible
410 // symbol, DGV must be an existing global with internal linkage. Rename
412 if (NewDGV->getName() != SGV->getName() && !NewDGV->hasInternalLinkage()){
413 assert(DGV && DGV->getName() == SGV->getName() &&
414 DGV->hasInternalLinkage());
416 NewDGV->setName(SGV->getName()); // Force the name back
417 DGV->setName(SGV->getName()); // This will cause a renaming
418 assert(NewDGV->getName() == SGV->getName() &&
419 DGV->getName() != SGV->getName());
422 // Make sure to remember this mapping...
423 ValueMap.insert(std::make_pair(SGV, NewDGV));
424 if (SGV->hasAppendingLinkage())
425 // Keep track that this is an appending variable...
426 AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV));
428 } else if (SGV->isExternal()) {
429 // If SGV is external or if both SGV & DGV are external.. Just link the
430 // external globals, we aren't adding anything.
431 ValueMap.insert(std::make_pair(SGV, DGV));
433 } else if (DGV->isExternal()) { // If DGV is external but SGV is not...
434 ValueMap.insert(std::make_pair(SGV, DGV));
435 DGV->setLinkage(SGV->getLinkage()); // Inherit linkage!
436 } else if (SGV->getLinkage() != DGV->getLinkage()) {
437 return Error(Err, "Global variables named '" + SGV->getName() +
438 "' have different linkage specifiers!");
439 } else if (SGV->hasExternalLinkage()) {
440 // Allow linking two exactly identical external global variables...
441 if (SGV->isConstant() != DGV->isConstant() ||
442 SGV->getInitializer() != DGV->getInitializer())
443 return Error(Err, "Global Variable Collision on '" +
444 SGV->getType()->getDescription() + " %" + SGV->getName() +
445 "' - Global variables differ in const'ness");
446 ValueMap.insert(std::make_pair(SGV, DGV));
447 } else if (SGV->hasLinkOnceLinkage()) {
448 // If the global variable has a name, and that name is already in use in
449 // the Dest module, make sure that the name is a compatible global
452 // Check to see if the two GV's have the same Const'ness...
453 if (SGV->isConstant() != DGV->isConstant())
454 return Error(Err, "Global Variable Collision on '" +
455 SGV->getType()->getDescription() + " %" + SGV->getName() +
456 "' - Global variables differ in const'ness");
458 // Okay, everything is cool, remember the mapping...
459 ValueMap.insert(std::make_pair(SGV, DGV));
460 } else if (SGV->hasAppendingLinkage()) {
461 // No linking is performed yet. Just insert a new copy of the global, and
462 // keep track of the fact that it is an appending variable in the
463 // AppendingVars map. The name is cleared out so that no linkage is
465 GlobalVariable *NewDGV =
466 new GlobalVariable(SGV->getType()->getElementType(),
467 SGV->isConstant(), SGV->getLinkage(), /*init*/0,
470 // Make sure to remember this mapping...
471 ValueMap.insert(std::make_pair(SGV, NewDGV));
473 // Keep track that this is an appending variable...
474 AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV));
476 assert(0 && "Unknown linkage!");
483 // LinkGlobalInits - Update the initializers in the Dest module now that all
484 // globals that may be referenced are in Dest.
486 static bool LinkGlobalInits(Module *Dest, const Module *Src,
487 std::map<const Value*, Value*> &ValueMap,
490 // Loop over all of the globals in the src module, mapping them over as we go
492 for (Module::const_giterator I = Src->gbegin(), E = Src->gend(); I != E; ++I){
493 const GlobalVariable *SGV = I;
495 if (SGV->hasInitializer()) { // Only process initialized GV's
496 // Figure out what the initializer looks like in the dest module...
498 cast<Constant>(RemapOperand(SGV->getInitializer(), ValueMap, 0));
500 GlobalVariable *DGV = cast<GlobalVariable>(ValueMap[SGV]);
501 if (DGV->hasInitializer()) {
502 assert(SGV->getLinkage() == DGV->getLinkage());
503 if (SGV->hasExternalLinkage()) {
504 if (DGV->getInitializer() != SInit)
505 return Error(Err, "Global Variable Collision on '" +
506 SGV->getType()->getDescription() +"':%"+SGV->getName()+
507 " - Global variables have different initializers");
508 } else if (DGV->hasLinkOnceLinkage()) {
509 // Nothing is required, mapped values will take the new global
511 } else if (DGV->hasAppendingLinkage()) {
512 assert(0 && "Appending linkage unimplemented!");
514 assert(0 && "Unknown linkage!");
517 // Copy the initializer over now...
518 DGV->setInitializer(SInit);
525 // LinkFunctionProtos - Link the functions together between the two modules,
526 // without doing function bodies... this just adds external function prototypes
527 // to the Dest function...
529 static bool LinkFunctionProtos(Module *Dest, const Module *Src,
530 std::map<const Value*, Value*> &ValueMap,
532 SymbolTable *ST = (SymbolTable*)&Dest->getSymbolTable();
534 // Loop over all of the functions in the src module, mapping them over as we
537 for (Module::const_iterator I = Src->begin(), E = Src->end(); I != E; ++I) {
538 const Function *SF = I; // SrcFunction
541 // The same named thing is a Function, because the only two things
542 // that may be in a module level symbol table are Global Vars and
543 // Functions, and they both have distinct, nonoverlapping, possible types.
545 DF = cast_or_null<Function>(FindGlobalNamed(SF->getName(), SF->getType(),
548 if (!DF || SF->hasInternalLinkage() || DF->hasInternalLinkage()) {
549 // Function does not already exist, simply insert an function signature
550 // identical to SF into the dest module...
551 Function *NewDF = new Function(SF->getFunctionType(), SF->getLinkage(),
552 SF->getName(), Dest);
554 // If the LLVM runtime renamed the function, but it is an externally
555 // visible symbol, DF must be an existing function with internal linkage.
557 if (NewDF->getName() != SF->getName() && !NewDF->hasInternalLinkage()) {
558 assert(DF && DF->getName() == SF->getName() &&DF->hasInternalLinkage());
560 NewDF->setName(SF->getName()); // Force the name back
561 DF->setName(SF->getName()); // This will cause a renaming
562 assert(NewDF->getName() == SF->getName() &&
563 DF->getName() != SF->getName());
566 // ... and remember this mapping...
567 ValueMap.insert(std::make_pair(SF, NewDF));
568 } else if (SF->isExternal()) {
569 // If SF is external or if both SF & DF are external.. Just link the
570 // external functions, we aren't adding anything.
571 ValueMap.insert(std::make_pair(SF, DF));
572 } else if (DF->isExternal()) { // If DF is external but SF is not...
573 // Link the external functions, update linkage qualifiers
574 ValueMap.insert(std::make_pair(SF, DF));
575 DF->setLinkage(SF->getLinkage());
577 } else if (SF->getLinkage() != DF->getLinkage()) {
578 return Error(Err, "Functions named '" + SF->getName() +
579 "' have different linkage specifiers!");
580 } else if (SF->hasExternalLinkage()) {
581 // The function is defined in both modules!!
582 return Error(Err, "Function '" +
583 SF->getFunctionType()->getDescription() + "':\"" +
584 SF->getName() + "\" - Function is already defined!");
585 } else if (SF->hasLinkOnceLinkage()) {
586 // Completely ignore the source function.
587 ValueMap.insert(std::make_pair(SF, DF));
589 assert(0 && "Unknown linkage configuration found!");
595 // LinkFunctionBody - Copy the source function over into the dest function and
596 // fix up references to values. At this point we know that Dest is an external
597 // function, and that Src is not.
599 static bool LinkFunctionBody(Function *Dest, const Function *Src,
600 std::map<const Value*, Value*> &GlobalMap,
602 assert(Src && Dest && Dest->isExternal() && !Src->isExternal());
603 std::map<const Value*, Value*> LocalMap; // Map for function local values
605 // Go through and convert function arguments over...
606 Function::aiterator DI = Dest->abegin();
607 for (Function::const_aiterator I = Src->abegin(), E = Src->aend();
609 DI->setName(I->getName()); // Copy the name information over...
611 // Add a mapping to our local map
612 LocalMap.insert(std::make_pair(I, DI));
615 // Loop over all of the basic blocks, copying the instructions over...
617 for (Function::const_iterator I = Src->begin(), E = Src->end(); I != E; ++I) {
618 // Create new basic block and add to mapping and the Dest function...
619 BasicBlock *DBB = new BasicBlock(I->getName(), Dest);
620 LocalMap.insert(std::make_pair(I, DBB));
622 // Loop over all of the instructions in the src basic block, copying them
623 // over. Note that this is broken in a strict sense because the cloned
624 // instructions will still be referencing values in the Src module, not
625 // the remapped values. In our case, however, we will not get caught and
626 // so we can delay patching the values up until later...
628 for (BasicBlock::const_iterator II = I->begin(), IE = I->end();
630 Instruction *DI = II->clone();
631 DI->setName(II->getName());
632 DBB->getInstList().push_back(DI);
633 LocalMap.insert(std::make_pair(II, DI));
637 // At this point, all of the instructions and values of the function are now
638 // copied over. The only problem is that they are still referencing values in
639 // the Source function as operands. Loop through all of the operands of the
640 // functions and patch them up to point to the local versions...
642 for (Function::iterator BB = Dest->begin(), BE = Dest->end(); BB != BE; ++BB)
643 for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
644 for (Instruction::op_iterator OI = I->op_begin(), OE = I->op_end();
646 *OI = RemapOperand(*OI, LocalMap, &GlobalMap);
652 // LinkFunctionBodies - Link in the function bodies that are defined in the
653 // source module into the DestModule. This consists basically of copying the
654 // function over and fixing up references to values.
656 static bool LinkFunctionBodies(Module *Dest, const Module *Src,
657 std::map<const Value*, Value*> &ValueMap,
660 // Loop over all of the functions in the src module, mapping them over as we
663 for (Module::const_iterator SF = Src->begin(), E = Src->end(); SF != E; ++SF){
664 if (!SF->isExternal()) { // No body if function is external
665 Function *DF = cast<Function>(ValueMap[SF]); // Destination function
667 // DF not external SF external?
668 if (!DF->isExternal()) {
669 if (DF->hasLinkOnceLinkage()) continue; // No relinkage for link-once!
671 *Err = "Function '" + (SF->hasName() ? SF->getName() :std::string(""))
672 + "' body multiply defined!";
676 if (LinkFunctionBody(DF, SF, ValueMap, Err)) return true;
682 // LinkAppendingVars - If there were any appending global variables, link them
683 // together now. Return true on error.
685 static bool LinkAppendingVars(Module *M,
686 std::multimap<std::string, GlobalVariable *> &AppendingVars,
687 std::string *ErrorMsg) {
688 if (AppendingVars.empty()) return false; // Nothing to do.
690 // Loop over the multimap of appending vars, processing any variables with the
691 // same name, forming a new appending global variable with both of the
692 // initializers merged together, then rewrite references to the old variables
695 std::vector<Constant*> Inits;
696 while (AppendingVars.size() > 1) {
697 // Get the first two elements in the map...
698 std::multimap<std::string,
699 GlobalVariable*>::iterator Second = AppendingVars.begin(), First=Second++;
701 // If the first two elements are for different names, there is no pair...
702 // Otherwise there is a pair, so link them together...
703 if (First->first == Second->first) {
704 GlobalVariable *G1 = First->second, *G2 = Second->second;
705 const ArrayType *T1 = cast<ArrayType>(G1->getType()->getElementType());
706 const ArrayType *T2 = cast<ArrayType>(G2->getType()->getElementType());
708 // Check to see that they two arrays agree on type...
709 if (T1->getElementType() != T2->getElementType())
710 return Error(ErrorMsg,
711 "Appending variables with different element types need to be linked!");
712 if (G1->isConstant() != G2->isConstant())
713 return Error(ErrorMsg,
714 "Appending variables linked with different const'ness!");
716 unsigned NewSize = T1->getNumElements() + T2->getNumElements();
717 ArrayType *NewType = ArrayType::get(T1->getElementType(), NewSize);
719 // Create the new global variable...
721 new GlobalVariable(NewType, G1->isConstant(), G1->getLinkage(),
722 /*init*/0, First->first, M);
724 // Merge the initializer...
725 Inits.reserve(NewSize);
726 ConstantArray *I = cast<ConstantArray>(G1->getInitializer());
727 for (unsigned i = 0, e = T1->getNumElements(); i != e; ++i)
728 Inits.push_back(cast<Constant>(I->getValues()[i]));
729 I = cast<ConstantArray>(G2->getInitializer());
730 for (unsigned i = 0, e = T2->getNumElements(); i != e; ++i)
731 Inits.push_back(cast<Constant>(I->getValues()[i]));
732 NG->setInitializer(ConstantArray::get(NewType, Inits));
735 // Replace any uses of the two global variables with uses of the new
738 // FIXME: This should rewrite simple/straight-forward uses such as
739 // getelementptr instructions to not use the Cast!
740 ConstantPointerRef *NGCP = ConstantPointerRef::get(NG);
741 G1->replaceAllUsesWith(ConstantExpr::getCast(NGCP, G1->getType()));
742 G2->replaceAllUsesWith(ConstantExpr::getCast(NGCP, G2->getType()));
744 // Remove the two globals from the module now...
745 M->getGlobalList().erase(G1);
746 M->getGlobalList().erase(G2);
748 // Put the new global into the AppendingVars map so that we can handle
749 // linking of more than two vars...
752 AppendingVars.erase(First);
759 // LinkModules - This function links two modules together, with the resulting
760 // left module modified to be the composite of the two input modules. If an
761 // error occurs, true is returned and ErrorMsg (if not null) is set to indicate
762 // the problem. Upon failure, the Dest module could be in a modified state, and
763 // shouldn't be relied on to be consistent.
765 bool LinkModules(Module *Dest, const Module *Src, std::string *ErrorMsg) {
766 if (Dest->getEndianness() == Module::AnyEndianness)
767 Dest->setEndianness(Src->getEndianness());
768 if (Dest->getPointerSize() == Module::AnyPointerSize)
769 Dest->setPointerSize(Src->getPointerSize());
771 if (Src->getEndianness() != Module::AnyEndianness &&
772 Dest->getEndianness() != Src->getEndianness())
773 std::cerr << "WARNING: Linking two modules of different endianness!\n";
774 if (Src->getPointerSize() != Module::AnyPointerSize &&
775 Dest->getPointerSize() != Src->getPointerSize())
776 std::cerr << "WARNING: Linking two modules of different pointer size!\n";
778 // LinkTypes - Go through the symbol table of the Src module and see if any
779 // types are named in the src module that are not named in the Dst module.
780 // Make sure there are no type name conflicts.
782 if (LinkTypes(Dest, Src, ErrorMsg)) return true;
784 // ValueMap - Mapping of values from what they used to be in Src, to what they
787 std::map<const Value*, Value*> ValueMap;
789 // AppendingVars - Keep track of global variables in the destination module
790 // with appending linkage. After the module is linked together, they are
791 // appended and the module is rewritten.
793 std::multimap<std::string, GlobalVariable *> AppendingVars;
795 // Add all of the appending globals already in the Dest module to
797 for (Module::giterator I = Dest->gbegin(), E = Dest->gend(); I != E; ++I)
798 if (I->hasAppendingLinkage())
799 AppendingVars.insert(std::make_pair(I->getName(), I));
801 // Insert all of the globals in src into the Dest module... without linking
802 // initializers (which could refer to functions not yet mapped over).
804 if (LinkGlobals(Dest, Src, ValueMap, AppendingVars, ErrorMsg)) return true;
806 // Link the functions together between the two modules, without doing function
807 // bodies... this just adds external function prototypes to the Dest
808 // function... We do this so that when we begin processing function bodies,
809 // all of the global values that may be referenced are available in our
812 if (LinkFunctionProtos(Dest, Src, ValueMap, ErrorMsg)) return true;
814 // Update the initializers in the Dest module now that all globals that may
815 // be referenced are in Dest.
817 if (LinkGlobalInits(Dest, Src, ValueMap, ErrorMsg)) return true;
819 // Link in the function bodies that are defined in the source module into the
820 // DestModule. This consists basically of copying the function over and
821 // fixing up references to values.
823 if (LinkFunctionBodies(Dest, Src, ValueMap, ErrorMsg)) return true;
825 // If there were any appending global variables, link them together now.
827 if (LinkAppendingVars(Dest, AppendingVars, ErrorMsg)) return true;