LinkModules.cpp revision d039156e80bd44d1ba5c4195b3857fa6b8c66312
1//===- lib/Linker/LinkModules.cpp - Module Linker Implementation ----------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements the LLVM module linker. 11// 12// Specifically, this: 13// * Merges global variables between the two modules 14// * Uninit + Uninit = Init, Init + Uninit = Init, Init + Init = Error if != 15// * Merges functions between two modules 16// 17//===----------------------------------------------------------------------===// 18 19#include "llvm/Linker.h" 20#include "llvm/Constants.h" 21#include "llvm/DerivedTypes.h" 22#include "llvm/Module.h" 23#include "llvm/TypeSymbolTable.h" 24#include "llvm/ValueSymbolTable.h" 25#include "llvm/Instructions.h" 26#include "llvm/Assembly/Writer.h" 27#include "llvm/Support/Streams.h" 28#include "llvm/System/Path.h" 29#include <sstream> 30using namespace llvm; 31 32// Error - Simple wrapper function to conditionally assign to E and return true. 33// This just makes error return conditions a little bit simpler... 34static inline bool Error(std::string *E, const std::string &Message) { 35 if (E) *E = Message; 36 return true; 37} 38 39// ToStr - Simple wrapper function to convert a type to a string. 40static std::string ToStr(const Type *Ty, const Module *M) { 41 std::ostringstream OS; 42 WriteTypeSymbolic(OS, Ty, M); 43 return OS.str(); 44} 45 46// 47// Function: ResolveTypes() 48// 49// Description: 50// Attempt to link the two specified types together. 51// 52// Inputs: 53// DestTy - The type to which we wish to resolve. 54// SrcTy - The original type which we want to resolve. 55// Name - The name of the type. 56// 57// Outputs: 58// DestST - The symbol table in which the new type should be placed. 59// 60// Return value: 61// true - There is an error and the types cannot yet be linked. 62// false - No errors. 63// 64static bool ResolveTypes(const Type *DestTy, const Type *SrcTy, 65 TypeSymbolTable *DestST, const std::string &Name) { 66 if (DestTy == SrcTy) return false; // If already equal, noop 67 68 // Does the type already exist in the module? 69 if (DestTy && !isa<OpaqueType>(DestTy)) { // Yup, the type already exists... 70 if (const OpaqueType *OT = dyn_cast<OpaqueType>(SrcTy)) { 71 const_cast<OpaqueType*>(OT)->refineAbstractTypeTo(DestTy); 72 } else { 73 return true; // Cannot link types... neither is opaque and not-equal 74 } 75 } else { // Type not in dest module. Add it now. 76 if (DestTy) // Type _is_ in module, just opaque... 77 const_cast<OpaqueType*>(cast<OpaqueType>(DestTy)) 78 ->refineAbstractTypeTo(SrcTy); 79 else if (!Name.empty()) 80 DestST->insert(Name, const_cast<Type*>(SrcTy)); 81 } 82 return false; 83} 84 85static const FunctionType *getFT(const PATypeHolder &TH) { 86 return cast<FunctionType>(TH.get()); 87} 88static const StructType *getST(const PATypeHolder &TH) { 89 return cast<StructType>(TH.get()); 90} 91 92// RecursiveResolveTypes - This is just like ResolveTypes, except that it 93// recurses down into derived types, merging the used types if the parent types 94// are compatible. 95static bool RecursiveResolveTypesI(const PATypeHolder &DestTy, 96 const PATypeHolder &SrcTy, 97 TypeSymbolTable *DestST, 98 const std::string &Name, 99 std::vector<std::pair<PATypeHolder, PATypeHolder> > &Pointers) { 100 const Type *SrcTyT = SrcTy.get(); 101 const Type *DestTyT = DestTy.get(); 102 if (DestTyT == SrcTyT) return false; // If already equal, noop 103 104 // If we found our opaque type, resolve it now! 105 if (isa<OpaqueType>(DestTyT) || isa<OpaqueType>(SrcTyT)) 106 return ResolveTypes(DestTyT, SrcTyT, DestST, Name); 107 108 // Two types cannot be resolved together if they are of different primitive 109 // type. For example, we cannot resolve an int to a float. 110 if (DestTyT->getTypeID() != SrcTyT->getTypeID()) return true; 111 112 // Otherwise, resolve the used type used by this derived type... 113 switch (DestTyT->getTypeID()) { 114 case Type::IntegerTyID: { 115 if (cast<IntegerType>(DestTyT)->getBitWidth() != 116 cast<IntegerType>(SrcTyT)->getBitWidth()) 117 return true; 118 return false; 119 } 120 case Type::FunctionTyID: { 121 if (cast<FunctionType>(DestTyT)->isVarArg() != 122 cast<FunctionType>(SrcTyT)->isVarArg() || 123 cast<FunctionType>(DestTyT)->getNumContainedTypes() != 124 cast<FunctionType>(SrcTyT)->getNumContainedTypes()) 125 return true; 126 for (unsigned i = 0, e = getFT(DestTy)->getNumContainedTypes(); i != e; ++i) 127 if (RecursiveResolveTypesI(getFT(DestTy)->getContainedType(i), 128 getFT(SrcTy)->getContainedType(i), DestST, "", 129 Pointers)) 130 return true; 131 return false; 132 } 133 case Type::StructTyID: { 134 if (getST(DestTy)->getNumContainedTypes() != 135 getST(SrcTy)->getNumContainedTypes()) return 1; 136 for (unsigned i = 0, e = getST(DestTy)->getNumContainedTypes(); i != e; ++i) 137 if (RecursiveResolveTypesI(getST(DestTy)->getContainedType(i), 138 getST(SrcTy)->getContainedType(i), DestST, "", 139 Pointers)) 140 return true; 141 return false; 142 } 143 case Type::ArrayTyID: { 144 const ArrayType *DAT = cast<ArrayType>(DestTy.get()); 145 const ArrayType *SAT = cast<ArrayType>(SrcTy.get()); 146 if (DAT->getNumElements() != SAT->getNumElements()) return true; 147 return RecursiveResolveTypesI(DAT->getElementType(), SAT->getElementType(), 148 DestST, "", Pointers); 149 } 150 case Type::PointerTyID: { 151 // If this is a pointer type, check to see if we have already seen it. If 152 // so, we are in a recursive branch. Cut off the search now. We cannot use 153 // an associative container for this search, because the type pointers (keys 154 // in the container) change whenever types get resolved... 155 for (unsigned i = 0, e = Pointers.size(); i != e; ++i) 156 if (Pointers[i].first == DestTy) 157 return Pointers[i].second != SrcTy; 158 159 // Otherwise, add the current pointers to the vector to stop recursion on 160 // this pair. 161 Pointers.push_back(std::make_pair(DestTyT, SrcTyT)); 162 bool Result = 163 RecursiveResolveTypesI(cast<PointerType>(DestTy.get())->getElementType(), 164 cast<PointerType>(SrcTy.get())->getElementType(), 165 DestST, "", Pointers); 166 Pointers.pop_back(); 167 return Result; 168 } 169 default: assert(0 && "Unexpected type!"); return true; 170 } 171} 172 173static bool RecursiveResolveTypes(const PATypeHolder &DestTy, 174 const PATypeHolder &SrcTy, 175 TypeSymbolTable *DestST, 176 const std::string &Name){ 177 std::vector<std::pair<PATypeHolder, PATypeHolder> > PointerTypes; 178 return RecursiveResolveTypesI(DestTy, SrcTy, DestST, Name, PointerTypes); 179} 180 181 182// LinkTypes - Go through the symbol table of the Src module and see if any 183// types are named in the src module that are not named in the Dst module. 184// Make sure there are no type name conflicts. 185static bool LinkTypes(Module *Dest, const Module *Src, std::string *Err) { 186 TypeSymbolTable *DestST = &Dest->getTypeSymbolTable(); 187 const TypeSymbolTable *SrcST = &Src->getTypeSymbolTable(); 188 189 // Look for a type plane for Type's... 190 TypeSymbolTable::const_iterator TI = SrcST->begin(); 191 TypeSymbolTable::const_iterator TE = SrcST->end(); 192 if (TI == TE) return false; // No named types, do nothing. 193 194 // Some types cannot be resolved immediately because they depend on other 195 // types being resolved to each other first. This contains a list of types we 196 // are waiting to recheck. 197 std::vector<std::string> DelayedTypesToResolve; 198 199 for ( ; TI != TE; ++TI ) { 200 const std::string &Name = TI->first; 201 const Type *RHS = TI->second; 202 203 // Check to see if this type name is already in the dest module... 204 Type *Entry = DestST->lookup(Name); 205 206 if (ResolveTypes(Entry, RHS, DestST, Name)) { 207 // They look different, save the types 'till later to resolve. 208 DelayedTypesToResolve.push_back(Name); 209 } 210 } 211 212 // Iteratively resolve types while we can... 213 while (!DelayedTypesToResolve.empty()) { 214 // Loop over all of the types, attempting to resolve them if possible... 215 unsigned OldSize = DelayedTypesToResolve.size(); 216 217 // Try direct resolution by name... 218 for (unsigned i = 0; i != DelayedTypesToResolve.size(); ++i) { 219 const std::string &Name = DelayedTypesToResolve[i]; 220 Type *T1 = SrcST->lookup(Name); 221 Type *T2 = DestST->lookup(Name); 222 if (!ResolveTypes(T2, T1, DestST, Name)) { 223 // We are making progress! 224 DelayedTypesToResolve.erase(DelayedTypesToResolve.begin()+i); 225 --i; 226 } 227 } 228 229 // Did we not eliminate any types? 230 if (DelayedTypesToResolve.size() == OldSize) { 231 // Attempt to resolve subelements of types. This allows us to merge these 232 // two types: { int* } and { opaque* } 233 for (unsigned i = 0, e = DelayedTypesToResolve.size(); i != e; ++i) { 234 const std::string &Name = DelayedTypesToResolve[i]; 235 PATypeHolder T1(SrcST->lookup(Name)); 236 PATypeHolder T2(DestST->lookup(Name)); 237 238 if (!RecursiveResolveTypes(T2, T1, DestST, Name)) { 239 // We are making progress! 240 DelayedTypesToResolve.erase(DelayedTypesToResolve.begin()+i); 241 242 // Go back to the main loop, perhaps we can resolve directly by name 243 // now... 244 break; 245 } 246 } 247 248 // If we STILL cannot resolve the types, then there is something wrong. 249 if (DelayedTypesToResolve.size() == OldSize) { 250 // Remove the symbol name from the destination. 251 DelayedTypesToResolve.pop_back(); 252 } 253 } 254 } 255 256 257 return false; 258} 259 260static void PrintMap(const std::map<const Value*, Value*> &M) { 261 for (std::map<const Value*, Value*>::const_iterator I = M.begin(), E =M.end(); 262 I != E; ++I) { 263 cerr << " Fr: " << (void*)I->first << " "; 264 I->first->dump(); 265 cerr << " To: " << (void*)I->second << " "; 266 I->second->dump(); 267 cerr << "\n"; 268 } 269} 270 271 272// RemapOperand - Use ValueMap to convert constants from one module to another. 273static Value *RemapOperand(const Value *In, 274 std::map<const Value*, Value*> &ValueMap) { 275 std::map<const Value*,Value*>::const_iterator I = ValueMap.find(In); 276 if (I != ValueMap.end()) 277 return I->second; 278 279 // Check to see if it's a constant that we are interested in transforming. 280 Value *Result = 0; 281 if (const Constant *CPV = dyn_cast<Constant>(In)) { 282 if ((!isa<DerivedType>(CPV->getType()) && !isa<ConstantExpr>(CPV)) || 283 isa<ConstantInt>(CPV) || isa<ConstantAggregateZero>(CPV)) 284 return const_cast<Constant*>(CPV); // Simple constants stay identical. 285 286 if (const ConstantArray *CPA = dyn_cast<ConstantArray>(CPV)) { 287 std::vector<Constant*> Operands(CPA->getNumOperands()); 288 for (unsigned i = 0, e = CPA->getNumOperands(); i != e; ++i) 289 Operands[i] =cast<Constant>(RemapOperand(CPA->getOperand(i), ValueMap)); 290 Result = ConstantArray::get(cast<ArrayType>(CPA->getType()), Operands); 291 } else if (const ConstantStruct *CPS = dyn_cast<ConstantStruct>(CPV)) { 292 std::vector<Constant*> Operands(CPS->getNumOperands()); 293 for (unsigned i = 0, e = CPS->getNumOperands(); i != e; ++i) 294 Operands[i] =cast<Constant>(RemapOperand(CPS->getOperand(i), ValueMap)); 295 Result = ConstantStruct::get(cast<StructType>(CPS->getType()), Operands); 296 } else if (isa<ConstantPointerNull>(CPV) || isa<UndefValue>(CPV)) { 297 Result = const_cast<Constant*>(CPV); 298 } else if (const ConstantVector *CP = dyn_cast<ConstantVector>(CPV)) { 299 std::vector<Constant*> Operands(CP->getNumOperands()); 300 for (unsigned i = 0, e = CP->getNumOperands(); i != e; ++i) 301 Operands[i] = cast<Constant>(RemapOperand(CP->getOperand(i), ValueMap)); 302 Result = ConstantVector::get(Operands); 303 } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CPV)) { 304 std::vector<Constant*> Ops; 305 for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) 306 Ops.push_back(cast<Constant>(RemapOperand(CE->getOperand(i),ValueMap))); 307 Result = CE->getWithOperands(Ops); 308 } else if (isa<GlobalValue>(CPV)) { 309 assert(0 && "Unmapped global?"); 310 } else { 311 assert(0 && "Unknown type of derived type constant value!"); 312 } 313 } else if (isa<InlineAsm>(In)) { 314 Result = const_cast<Value*>(In); 315 } 316 317 // Cache the mapping in our local map structure 318 if (Result) { 319 ValueMap.insert(std::make_pair(In, Result)); 320 return Result; 321 } 322 323 324 cerr << "LinkModules ValueMap: \n"; 325 PrintMap(ValueMap); 326 327 cerr << "Couldn't remap value: " << (void*)In << " " << *In << "\n"; 328 assert(0 && "Couldn't remap value!"); 329 return 0; 330} 331 332/// ForceRenaming - The LLVM SymbolTable class autorenames globals that conflict 333/// in the symbol table. This is good for all clients except for us. Go 334/// through the trouble to force this back. 335static void ForceRenaming(GlobalValue *GV, const std::string &Name) { 336 assert(GV->getName() != Name && "Can't force rename to self"); 337 ValueSymbolTable &ST = GV->getParent()->getValueSymbolTable(); 338 339 // If there is a conflict, rename the conflict. 340 if (GlobalValue *ConflictGV = cast_or_null<GlobalValue>(ST.lookup(Name))) { 341 assert(ConflictGV->hasInternalLinkage() && 342 "Not conflicting with a static global, should link instead!"); 343 GV->takeName(ConflictGV); 344 ConflictGV->setName(Name); // This will cause ConflictGV to get renamed 345 assert(ConflictGV->getName() != Name && "ForceRenaming didn't work"); 346 } else { 347 GV->setName(Name); // Force the name back 348 } 349} 350 351/// CopyGVAttributes - copy additional attributes (those not needed to construct 352/// a GlobalValue) from the SrcGV to the DestGV. 353static void CopyGVAttributes(GlobalValue *DestGV, const GlobalValue *SrcGV) { 354 // Propagate alignment, visibility and section info. 355 DestGV->setAlignment(std::max(DestGV->getAlignment(), SrcGV->getAlignment())); 356 DestGV->setSection(SrcGV->getSection()); 357 DestGV->setVisibility(SrcGV->getVisibility()); 358 if (const Function *SrcF = dyn_cast<Function>(SrcGV)) { 359 Function *DestF = cast<Function>(DestGV); 360 DestF->setCallingConv(SrcF->getCallingConv()); 361 DestF->setParamAttrs(SrcF->getParamAttrs()); 362 if (SrcF->hasCollector()) 363 DestF->setCollector(SrcF->getCollector()); 364 } 365} 366 367/// GetLinkageResult - This analyzes the two global values and determines what 368/// the result will look like in the destination module. In particular, it 369/// computes the resultant linkage type, computes whether the global in the 370/// source should be copied over to the destination (replacing the existing 371/// one), and computes whether this linkage is an error or not. It also performs 372/// visibility checks: we cannot link together two symbols with different 373/// visibilities. 374static bool GetLinkageResult(GlobalValue *Dest, GlobalValue *Src, 375 GlobalValue::LinkageTypes <, bool &LinkFromSrc, 376 std::string *Err) { 377 assert((!Dest || !Src->hasInternalLinkage()) && 378 "If Src has internal linkage, Dest shouldn't be set!"); 379 if (!Dest) { 380 // Linking something to nothing. 381 LinkFromSrc = true; 382 LT = Src->getLinkage(); 383 } else if (Src->isDeclaration()) { 384 // If Src is external or if both Src & Drc are external.. Just link the 385 // external globals, we aren't adding anything. 386 if (Src->hasDLLImportLinkage()) { 387 // If one of GVs has DLLImport linkage, result should be dllimport'ed. 388 if (Dest->isDeclaration()) { 389 LinkFromSrc = true; 390 LT = Src->getLinkage(); 391 } 392 } else if (Dest->hasExternalWeakLinkage()) { 393 //If the Dest is weak, use the source linkage 394 LinkFromSrc = true; 395 LT = Src->getLinkage(); 396 } else { 397 LinkFromSrc = false; 398 LT = Dest->getLinkage(); 399 } 400 } else if (Dest->isDeclaration() && !Dest->hasDLLImportLinkage()) { 401 // If Dest is external but Src is not: 402 LinkFromSrc = true; 403 LT = Src->getLinkage(); 404 } else if (Src->hasAppendingLinkage() || Dest->hasAppendingLinkage()) { 405 if (Src->getLinkage() != Dest->getLinkage()) 406 return Error(Err, "Linking globals named '" + Src->getName() + 407 "': can only link appending global with another appending global!"); 408 LinkFromSrc = true; // Special cased. 409 LT = Src->getLinkage(); 410 } else if (Src->hasWeakLinkage() || Src->hasLinkOnceLinkage()) { 411 // At this point we know that Dest has LinkOnce, External*, Weak, or 412 // DLL* linkage. 413 if ((Dest->hasLinkOnceLinkage() && Src->hasWeakLinkage()) || 414 Dest->hasExternalWeakLinkage()) { 415 LinkFromSrc = true; 416 LT = Src->getLinkage(); 417 } else { 418 LinkFromSrc = false; 419 LT = Dest->getLinkage(); 420 } 421 } else if (Dest->hasWeakLinkage() || Dest->hasLinkOnceLinkage()) { 422 // At this point we know that Src has External* or DLL* linkage. 423 if (Src->hasExternalWeakLinkage()) { 424 LinkFromSrc = false; 425 LT = Dest->getLinkage(); 426 } else { 427 LinkFromSrc = true; 428 LT = GlobalValue::ExternalLinkage; 429 } 430 } else { 431 assert((Dest->hasExternalLinkage() || 432 Dest->hasDLLImportLinkage() || 433 Dest->hasDLLExportLinkage() || 434 Dest->hasExternalWeakLinkage()) && 435 (Src->hasExternalLinkage() || 436 Src->hasDLLImportLinkage() || 437 Src->hasDLLExportLinkage() || 438 Src->hasExternalWeakLinkage()) && 439 "Unexpected linkage type!"); 440 return Error(Err, "Linking globals named '" + Src->getName() + 441 "': symbol multiply defined!"); 442 } 443 444 // Check visibility 445 if (Dest && Src->getVisibility() != Dest->getVisibility()) 446 if (!Src->isDeclaration() && !Dest->isDeclaration()) 447 return Error(Err, "Linking globals named '" + Src->getName() + 448 "': symbols have different visibilities!"); 449 return false; 450} 451 452// LinkGlobals - Loop through the global variables in the src module and merge 453// them into the dest module. 454static bool LinkGlobals(Module *Dest, Module *Src, 455 std::map<const Value*, Value*> &ValueMap, 456 std::multimap<std::string, GlobalVariable *> &AppendingVars, 457 std::string *Err) { 458 // Loop over all of the globals in the src module, mapping them over as we go 459 for (Module::global_iterator I = Src->global_begin(), E = Src->global_end(); 460 I != E; ++I) { 461 GlobalVariable *SGV = I; 462 GlobalVariable *DGV = 0; 463 // Check to see if may have to link the global. 464 if (SGV->hasName() && !SGV->hasInternalLinkage()) { 465 DGV = Dest->getGlobalVariable(SGV->getName()); 466 if (DGV && DGV->getType() != SGV->getType()) 467 // If types don't agree due to opaque types, try to resolve them. 468 RecursiveResolveTypes(SGV->getType(), DGV->getType(), 469 &Dest->getTypeSymbolTable(), ""); 470 } 471 472 if (DGV && DGV->hasInternalLinkage()) 473 DGV = 0; 474 475 assert((SGV->hasInitializer() || SGV->hasExternalWeakLinkage() || 476 SGV->hasExternalLinkage() || SGV->hasDLLImportLinkage()) && 477 "Global must either be external or have an initializer!"); 478 479 GlobalValue::LinkageTypes NewLinkage = GlobalValue::InternalLinkage; 480 bool LinkFromSrc = false; 481 if (GetLinkageResult(DGV, SGV, NewLinkage, LinkFromSrc, Err)) 482 return true; 483 484 if (!DGV) { 485 // No linking to be performed, simply create an identical version of the 486 // symbol over in the dest module... the initializer will be filled in 487 // later by LinkGlobalInits... 488 GlobalVariable *NewDGV = 489 new GlobalVariable(SGV->getType()->getElementType(), 490 SGV->isConstant(), SGV->getLinkage(), /*init*/0, 491 SGV->getName(), Dest, SGV->isThreadLocal()); 492 // Propagate alignment, visibility and section info. 493 CopyGVAttributes(NewDGV, SGV); 494 495 // If the LLVM runtime renamed the global, but it is an externally visible 496 // symbol, DGV must be an existing global with internal linkage. Rename 497 // it. 498 if (NewDGV->getName() != SGV->getName() && !NewDGV->hasInternalLinkage()) 499 ForceRenaming(NewDGV, SGV->getName()); 500 501 // Make sure to remember this mapping... 502 ValueMap.insert(std::make_pair(SGV, NewDGV)); 503 if (SGV->hasAppendingLinkage()) 504 // Keep track that this is an appending variable... 505 AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV)); 506 } else if (DGV->hasAppendingLinkage()) { 507 // No linking is performed yet. Just insert a new copy of the global, and 508 // keep track of the fact that it is an appending variable in the 509 // AppendingVars map. The name is cleared out so that no linkage is 510 // performed. 511 GlobalVariable *NewDGV = 512 new GlobalVariable(SGV->getType()->getElementType(), 513 SGV->isConstant(), SGV->getLinkage(), /*init*/0, 514 "", Dest, SGV->isThreadLocal()); 515 516 // Propagate alignment, section and visibility info. 517 NewDGV->setAlignment(DGV->getAlignment()); 518 CopyGVAttributes(NewDGV, SGV); 519 520 // Make sure to remember this mapping... 521 ValueMap.insert(std::make_pair(SGV, NewDGV)); 522 523 // Keep track that this is an appending variable... 524 AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV)); 525 } else { 526 // Propagate alignment, section, and visibility info. 527 CopyGVAttributes(DGV, SGV); 528 529 // Otherwise, perform the mapping as instructed by GetLinkageResult. If 530 // the types don't match, and if we are to link from the source, nuke DGV 531 // and create a new one of the appropriate type. 532 if (SGV->getType() != DGV->getType() && LinkFromSrc) { 533 GlobalVariable *NewDGV = 534 new GlobalVariable(SGV->getType()->getElementType(), 535 DGV->isConstant(), DGV->getLinkage()); 536 NewDGV->setThreadLocal(DGV->isThreadLocal()); 537 CopyGVAttributes(NewDGV, DGV); 538 Dest->getGlobalList().insert(DGV, NewDGV); 539 DGV->replaceAllUsesWith( 540 ConstantExpr::getBitCast(NewDGV, DGV->getType())); 541 DGV->eraseFromParent(); 542 NewDGV->setName(SGV->getName()); 543 DGV = NewDGV; 544 } 545 546 DGV->setLinkage(NewLinkage); 547 548 if (LinkFromSrc) { 549 // Inherit const as appropriate 550 DGV->setConstant(SGV->isConstant()); 551 DGV->setInitializer(0); 552 } else { 553 if (SGV->isConstant() && !DGV->isConstant()) { 554 if (DGV->isDeclaration()) 555 DGV->setConstant(true); 556 } 557 SGV->setLinkage(GlobalValue::ExternalLinkage); 558 SGV->setInitializer(0); 559 } 560 561 ValueMap.insert( 562 std::make_pair(SGV, ConstantExpr::getBitCast(DGV, SGV->getType()))); 563 } 564 } 565 return false; 566} 567 568static GlobalValue::LinkageTypes 569CalculateAliasLinkage(const GlobalValue *SGV, const GlobalValue *DGV) { 570 if (SGV->hasExternalLinkage() || DGV->hasExternalLinkage()) 571 return GlobalValue::ExternalLinkage; 572 else if (SGV->hasWeakLinkage() || DGV->hasWeakLinkage()) 573 return GlobalValue::WeakLinkage; 574 else { 575 assert(SGV->hasInternalLinkage() && DGV->hasInternalLinkage() && 576 "Unexpected linkage type"); 577 return GlobalValue::InternalLinkage; 578 } 579} 580 581// LinkAlias - Loop through the alias in the src module and link them into the 582// dest module. We're assuming, that all functions/global variables were already 583// linked in. 584static bool LinkAlias(Module *Dest, const Module *Src, 585 std::map<const Value*, Value*> &ValueMap, 586 std::string *Err) { 587 // Loop over all alias in the src module 588 for (Module::const_alias_iterator I = Src->alias_begin(), 589 E = Src->alias_end(); I != E; ++I) { 590 const GlobalAlias *SGA = I; 591 const GlobalValue *SAliasee = SGA->getAliasedGlobal(); 592 GlobalAlias *NewGA = NULL; 593 594 // Globals were already linked, thus we can just query ValueMap for variant 595 // of SAliasee in Dest 596 std::map<const Value*,Value*>::const_iterator I = ValueMap.find(SAliasee); 597 assert(I != ValueMap.end() && "Aliasee not linked"); 598 GlobalValue* DAliasee = cast<GlobalValue>(I->second); 599 600 // Try to find something 'similar' to SGA in destination module. 601 if (GlobalAlias *DGA = Dest->getNamedAlias(SGA->getName())) { 602 // If types don't agree due to opaque types, try to resolve them. 603 if (RecursiveResolveTypes(SGA->getType(), DGA->getType(), 604 &Dest->getTypeSymbolTable(), "")) 605 return Error(Err, "Alias Collision on '" + 606 ToStr(SGA->getType(), Src) +"':%"+SGA->getName()+ 607 " - aliases have different types"); 608 609 // Now types are known to be the same, check whether aliasees equal. As 610 // globals are already linked we just need query ValueMap to find the 611 // mapping. 612 if (DAliasee == DGA->getAliasedGlobal()) { 613 // This is just two copies of the same alias. Propagate linkage, if 614 // necessary. 615 DGA->setLinkage(CalculateAliasLinkage(SGA, DGA)); 616 617 NewGA = DGA; 618 // Proceed to 'common' steps 619 } else 620 return Error(Err, "Alias Collision on '" + 621 ToStr(SGA->getType(), Src) +"':%"+SGA->getName()+ 622 " - aliases have different aliasees"); 623 } else if (GlobalVariable *DGV = Dest->getGlobalVariable(SGA->getName())) { 624 RecursiveResolveTypes(SGA->getType(), DGV->getType(), 625 &Dest->getTypeSymbolTable(), ""); 626 // The only allowed way is to link alias with external declaration. 627 if (DGV->isDeclaration()) { 628 NewGA = new GlobalAlias(SGA->getType(), SGA->getLinkage(), 629 SGA->getName(), DAliasee, Dest); 630 CopyGVAttributes(NewGA, SGA); 631 632 // Any uses of DGV need to change to NewGA, with cast, if needed. 633 if (SGA->getType() != DGV->getType()) 634 DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewGA, 635 DGV->getType())); 636 else 637 DGV->replaceAllUsesWith(NewGA); 638 639 // DGV will conflict with NewGA because they both had the same 640 // name. We must erase this now so ForceRenaming doesn't assert 641 // because DGV might not have internal linkage. 642 DGV->eraseFromParent(); 643 644 // Proceed to 'common' steps 645 } else 646 return Error(Err, "Alias Collision on '" + 647 ToStr(SGA->getType(), Src) +"':%"+SGA->getName()+ 648 " - symbol multiple defined"); 649 } else if (Function *DF = Dest->getFunction(SGA->getName())) { 650 RecursiveResolveTypes(SGA->getType(), DF->getType(), 651 &Dest->getTypeSymbolTable(), ""); 652 assert(0 && "FIXME"); 653 } else { 654 // Nothing similar found, just copy alias into destination module. 655 656 NewGA = new GlobalAlias(SGA->getType(), SGA->getLinkage(), 657 SGA->getName(), DAliasee, Dest); 658 CopyGVAttributes(NewGA, SGA); 659 660 // Proceed to 'common' steps 661 } 662 663 assert(NewGA && "No alias was created in destination module!"); 664 665 // If the symbol table renamed the function, but it is an externally 666 // visible symbol, DGV must be an existing function with internal 667 // linkage. Rename it. 668 if (NewGA->getName() != SGA->getName() && 669 !NewGA->hasInternalLinkage()) 670 ForceRenaming(NewGA, SGA->getName()); 671 672 // Remember this mapping so uses in the source module get remapped 673 // later by RemapOperand. 674 ValueMap.insert(std::make_pair(SGA, NewGA)); 675 } 676 677 return false; 678} 679 680 681// LinkGlobalInits - Update the initializers in the Dest module now that all 682// globals that may be referenced are in Dest. 683static bool LinkGlobalInits(Module *Dest, const Module *Src, 684 std::map<const Value*, Value*> &ValueMap, 685 std::string *Err) { 686 687 // Loop over all of the globals in the src module, mapping them over as we go 688 for (Module::const_global_iterator I = Src->global_begin(), 689 E = Src->global_end(); I != E; ++I) { 690 const GlobalVariable *SGV = I; 691 692 if (SGV->hasInitializer()) { // Only process initialized GV's 693 // Figure out what the initializer looks like in the dest module... 694 Constant *SInit = 695 cast<Constant>(RemapOperand(SGV->getInitializer(), ValueMap)); 696 697 GlobalVariable *DGV = cast<GlobalVariable>(ValueMap[SGV]); 698 if (DGV->hasInitializer()) { 699 if (SGV->hasExternalLinkage()) { 700 if (DGV->getInitializer() != SInit) 701 return Error(Err, "Global Variable Collision on '" + 702 ToStr(SGV->getType(), Src) +"':%"+SGV->getName()+ 703 " - Global variables have different initializers"); 704 } else if (DGV->hasLinkOnceLinkage() || DGV->hasWeakLinkage()) { 705 // Nothing is required, mapped values will take the new global 706 // automatically. 707 } else if (SGV->hasLinkOnceLinkage() || SGV->hasWeakLinkage()) { 708 // Nothing is required, mapped values will take the new global 709 // automatically. 710 } else if (DGV->hasAppendingLinkage()) { 711 assert(0 && "Appending linkage unimplemented!"); 712 } else { 713 assert(0 && "Unknown linkage!"); 714 } 715 } else { 716 // Copy the initializer over now... 717 DGV->setInitializer(SInit); 718 } 719 } 720 } 721 return false; 722} 723 724// LinkFunctionProtos - Link the functions together between the two modules, 725// without doing function bodies... this just adds external function prototypes 726// to the Dest function... 727// 728static bool LinkFunctionProtos(Module *Dest, const Module *Src, 729 std::map<const Value*, Value*> &ValueMap, 730 std::string *Err) { 731 // Loop over all of the functions in the src module, mapping them over 732 for (Module::const_iterator I = Src->begin(), E = Src->end(); I != E; ++I) { 733 const Function *SF = I; // SrcFunction 734 Function *DF = 0; 735 if (SF->hasName() && !SF->hasInternalLinkage()) { 736 // Check to see if may have to link the function. 737 DF = Dest->getFunction(SF->getName()); 738 if (DF && SF->getType() != DF->getType()) 739 // If types don't agree because of opaque, try to resolve them 740 RecursiveResolveTypes(SF->getType(), DF->getType(), 741 &Dest->getTypeSymbolTable(), ""); 742 } 743 744 // Check visibility 745 if (DF && !DF->hasInternalLinkage() && 746 SF->getVisibility() != DF->getVisibility()) { 747 // If one is a prototype, ignore its visibility. Prototypes are always 748 // overridden by the definition. 749 if (!SF->isDeclaration() && !DF->isDeclaration()) 750 return Error(Err, "Linking functions named '" + SF->getName() + 751 "': symbols have different visibilities!"); 752 } 753 754 if (DF && DF->hasInternalLinkage()) 755 DF = NULL; 756 757 if (DF && DF->getType() != SF->getType()) { 758 if (DF->isDeclaration() && !SF->isDeclaration()) { 759 // We have a definition of the same name but different type in the 760 // source module. Copy the prototype to the destination and replace 761 // uses of the destination's prototype with the new prototype. 762 Function *NewDF = new Function(SF->getFunctionType(), SF->getLinkage(), 763 SF->getName(), Dest); 764 CopyGVAttributes(NewDF, SF); 765 766 // Any uses of DF need to change to NewDF, with cast 767 DF->replaceAllUsesWith(ConstantExpr::getBitCast(NewDF, DF->getType())); 768 769 // DF will conflict with NewDF because they both had the same. We must 770 // erase this now so ForceRenaming doesn't assert because DF might 771 // not have internal linkage. 772 DF->eraseFromParent(); 773 774 // If the symbol table renamed the function, but it is an externally 775 // visible symbol, DF must be an existing function with internal 776 // linkage. Rename it. 777 if (NewDF->getName() != SF->getName() && !NewDF->hasInternalLinkage()) 778 ForceRenaming(NewDF, SF->getName()); 779 780 // Remember this mapping so uses in the source module get remapped 781 // later by RemapOperand. 782 ValueMap[SF] = NewDF; 783 } else if (SF->isDeclaration()) { 784 // We have two functions of the same name but different type and the 785 // source is a declaration while the destination is not. Any use of 786 // the source must be mapped to the destination, with a cast. 787 ValueMap[SF] = ConstantExpr::getBitCast(DF, SF->getType()); 788 } else { 789 // We have two functions of the same name but different types and they 790 // are both definitions. This is an error. 791 return Error(Err, "Function '" + DF->getName() + "' defined as both '" + 792 ToStr(SF->getFunctionType(), Src) + "' and '" + 793 ToStr(DF->getFunctionType(), Dest) + "'"); 794 } 795 } else if (!DF || SF->hasInternalLinkage() || DF->hasInternalLinkage()) { 796 // Function does not already exist, simply insert an function signature 797 // identical to SF into the dest module. 798 Function *NewDF = new Function(SF->getFunctionType(), SF->getLinkage(), 799 SF->getName(), Dest); 800 CopyGVAttributes(NewDF, SF); 801 802 // If the LLVM runtime renamed the function, but it is an externally 803 // visible symbol, DF must be an existing function with internal linkage. 804 // Rename it. 805 if (NewDF->getName() != SF->getName() && !NewDF->hasInternalLinkage()) 806 ForceRenaming(NewDF, SF->getName()); 807 808 // ... and remember this mapping... 809 ValueMap.insert(std::make_pair(SF, NewDF)); 810 } else if (SF->isDeclaration()) { 811 // If SF is a declaration or if both SF & DF are declarations, just link 812 // the declarations, we aren't adding anything. 813 if (SF->hasDLLImportLinkage()) { 814 if (DF->isDeclaration()) { 815 ValueMap.insert(std::make_pair(SF, DF)); 816 DF->setLinkage(SF->getLinkage()); 817 } 818 } else { 819 ValueMap.insert(std::make_pair(SF, DF)); 820 } 821 } else if (DF->isDeclaration() && !DF->hasDLLImportLinkage()) { 822 // If DF is external but SF is not... 823 // Link the external functions, update linkage qualifiers 824 ValueMap.insert(std::make_pair(SF, DF)); 825 DF->setLinkage(SF->getLinkage()); 826 // Visibility of prototype is overridden by vis of definition. 827 DF->setVisibility(SF->getVisibility()); 828 } else if (SF->hasWeakLinkage() || SF->hasLinkOnceLinkage()) { 829 // At this point we know that DF has LinkOnce, Weak, or External* linkage. 830 ValueMap.insert(std::make_pair(SF, DF)); 831 832 // Linkonce+Weak = Weak 833 // *+External Weak = * 834 if ((DF->hasLinkOnceLinkage() && SF->hasWeakLinkage()) || 835 DF->hasExternalWeakLinkage()) 836 DF->setLinkage(SF->getLinkage()); 837 } else if (DF->hasWeakLinkage() || DF->hasLinkOnceLinkage()) { 838 // At this point we know that SF has LinkOnce or External* linkage. 839 ValueMap.insert(std::make_pair(SF, DF)); 840 if (!SF->hasLinkOnceLinkage() && !SF->hasExternalWeakLinkage()) 841 // Don't inherit linkonce & external weak linkage 842 DF->setLinkage(SF->getLinkage()); 843 } else if (SF->getLinkage() != DF->getLinkage()) { 844 return Error(Err, "Functions named '" + SF->getName() + 845 "' have different linkage specifiers!"); 846 } else if (SF->hasExternalLinkage()) { 847 // The function is defined identically in both modules!! 848 return Error(Err, "Function '" + 849 ToStr(SF->getFunctionType(), Src) + "':\"" + 850 SF->getName() + "\" - Function is already defined!"); 851 } else { 852 assert(0 && "Unknown linkage configuration found!"); 853 } 854 } 855 return false; 856} 857 858// LinkFunctionBody - Copy the source function over into the dest function and 859// fix up references to values. At this point we know that Dest is an external 860// function, and that Src is not. 861static bool LinkFunctionBody(Function *Dest, Function *Src, 862 std::map<const Value*, Value*> &ValueMap, 863 std::string *Err) { 864 assert(Src && Dest && Dest->isDeclaration() && !Src->isDeclaration()); 865 866 // Go through and convert function arguments over, remembering the mapping. 867 Function::arg_iterator DI = Dest->arg_begin(); 868 for (Function::arg_iterator I = Src->arg_begin(), E = Src->arg_end(); 869 I != E; ++I, ++DI) { 870 DI->setName(I->getName()); // Copy the name information over... 871 872 // Add a mapping to our local map 873 ValueMap.insert(std::make_pair(I, DI)); 874 } 875 876 // Splice the body of the source function into the dest function. 877 Dest->getBasicBlockList().splice(Dest->end(), Src->getBasicBlockList()); 878 879 // At this point, all of the instructions and values of the function are now 880 // copied over. The only problem is that they are still referencing values in 881 // the Source function as operands. Loop through all of the operands of the 882 // functions and patch them up to point to the local versions... 883 // 884 for (Function::iterator BB = Dest->begin(), BE = Dest->end(); BB != BE; ++BB) 885 for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) 886 for (Instruction::op_iterator OI = I->op_begin(), OE = I->op_end(); 887 OI != OE; ++OI) 888 if (!isa<Instruction>(*OI) && !isa<BasicBlock>(*OI)) 889 *OI = RemapOperand(*OI, ValueMap); 890 891 // There is no need to map the arguments anymore. 892 for (Function::arg_iterator I = Src->arg_begin(), E = Src->arg_end(); 893 I != E; ++I) 894 ValueMap.erase(I); 895 896 return false; 897} 898 899 900// LinkFunctionBodies - Link in the function bodies that are defined in the 901// source module into the DestModule. This consists basically of copying the 902// function over and fixing up references to values. 903static bool LinkFunctionBodies(Module *Dest, Module *Src, 904 std::map<const Value*, Value*> &ValueMap, 905 std::string *Err) { 906 907 // Loop over all of the functions in the src module, mapping them over as we 908 // go 909 for (Module::iterator SF = Src->begin(), E = Src->end(); SF != E; ++SF) { 910 if (!SF->isDeclaration()) { // No body if function is external 911 Function *DF = cast<Function>(ValueMap[SF]); // Destination function 912 913 // DF not external SF external? 914 if (DF->isDeclaration()) 915 // Only provide the function body if there isn't one already. 916 if (LinkFunctionBody(DF, SF, ValueMap, Err)) 917 return true; 918 } 919 } 920 return false; 921} 922 923// LinkAppendingVars - If there were any appending global variables, link them 924// together now. Return true on error. 925static bool LinkAppendingVars(Module *M, 926 std::multimap<std::string, GlobalVariable *> &AppendingVars, 927 std::string *ErrorMsg) { 928 if (AppendingVars.empty()) return false; // Nothing to do. 929 930 // Loop over the multimap of appending vars, processing any variables with the 931 // same name, forming a new appending global variable with both of the 932 // initializers merged together, then rewrite references to the old variables 933 // and delete them. 934 std::vector<Constant*> Inits; 935 while (AppendingVars.size() > 1) { 936 // Get the first two elements in the map... 937 std::multimap<std::string, 938 GlobalVariable*>::iterator Second = AppendingVars.begin(), First=Second++; 939 940 // If the first two elements are for different names, there is no pair... 941 // Otherwise there is a pair, so link them together... 942 if (First->first == Second->first) { 943 GlobalVariable *G1 = First->second, *G2 = Second->second; 944 const ArrayType *T1 = cast<ArrayType>(G1->getType()->getElementType()); 945 const ArrayType *T2 = cast<ArrayType>(G2->getType()->getElementType()); 946 947 // Check to see that they two arrays agree on type... 948 if (T1->getElementType() != T2->getElementType()) 949 return Error(ErrorMsg, 950 "Appending variables with different element types need to be linked!"); 951 if (G1->isConstant() != G2->isConstant()) 952 return Error(ErrorMsg, 953 "Appending variables linked with different const'ness!"); 954 955 if (G1->getAlignment() != G2->getAlignment()) 956 return Error(ErrorMsg, 957 "Appending variables with different alignment need to be linked!"); 958 959 if (G1->getVisibility() != G2->getVisibility()) 960 return Error(ErrorMsg, 961 "Appending variables with different visibility need to be linked!"); 962 963 if (G1->getSection() != G2->getSection()) 964 return Error(ErrorMsg, 965 "Appending variables with different section name need to be linked!"); 966 967 unsigned NewSize = T1->getNumElements() + T2->getNumElements(); 968 ArrayType *NewType = ArrayType::get(T1->getElementType(), NewSize); 969 970 G1->setName(""); // Clear G1's name in case of a conflict! 971 972 // Create the new global variable... 973 GlobalVariable *NG = 974 new GlobalVariable(NewType, G1->isConstant(), G1->getLinkage(), 975 /*init*/0, First->first, M, G1->isThreadLocal()); 976 977 // Propagate alignment, visibility and section info. 978 CopyGVAttributes(NG, G1); 979 980 // Merge the initializer... 981 Inits.reserve(NewSize); 982 if (ConstantArray *I = dyn_cast<ConstantArray>(G1->getInitializer())) { 983 for (unsigned i = 0, e = T1->getNumElements(); i != e; ++i) 984 Inits.push_back(I->getOperand(i)); 985 } else { 986 assert(isa<ConstantAggregateZero>(G1->getInitializer())); 987 Constant *CV = Constant::getNullValue(T1->getElementType()); 988 for (unsigned i = 0, e = T1->getNumElements(); i != e; ++i) 989 Inits.push_back(CV); 990 } 991 if (ConstantArray *I = dyn_cast<ConstantArray>(G2->getInitializer())) { 992 for (unsigned i = 0, e = T2->getNumElements(); i != e; ++i) 993 Inits.push_back(I->getOperand(i)); 994 } else { 995 assert(isa<ConstantAggregateZero>(G2->getInitializer())); 996 Constant *CV = Constant::getNullValue(T2->getElementType()); 997 for (unsigned i = 0, e = T2->getNumElements(); i != e; ++i) 998 Inits.push_back(CV); 999 } 1000 NG->setInitializer(ConstantArray::get(NewType, Inits)); 1001 Inits.clear(); 1002 1003 // Replace any uses of the two global variables with uses of the new 1004 // global... 1005 1006 // FIXME: This should rewrite simple/straight-forward uses such as 1007 // getelementptr instructions to not use the Cast! 1008 G1->replaceAllUsesWith(ConstantExpr::getBitCast(NG, G1->getType())); 1009 G2->replaceAllUsesWith(ConstantExpr::getBitCast(NG, G2->getType())); 1010 1011 // Remove the two globals from the module now... 1012 M->getGlobalList().erase(G1); 1013 M->getGlobalList().erase(G2); 1014 1015 // Put the new global into the AppendingVars map so that we can handle 1016 // linking of more than two vars... 1017 Second->second = NG; 1018 } 1019 AppendingVars.erase(First); 1020 } 1021 1022 return false; 1023} 1024 1025 1026// LinkModules - This function links two modules together, with the resulting 1027// left module modified to be the composite of the two input modules. If an 1028// error occurs, true is returned and ErrorMsg (if not null) is set to indicate 1029// the problem. Upon failure, the Dest module could be in a modified state, and 1030// shouldn't be relied on to be consistent. 1031bool 1032Linker::LinkModules(Module *Dest, Module *Src, std::string *ErrorMsg) { 1033 assert(Dest != 0 && "Invalid Destination module"); 1034 assert(Src != 0 && "Invalid Source Module"); 1035 1036 if (Dest->getDataLayout().empty()) { 1037 if (!Src->getDataLayout().empty()) { 1038 Dest->setDataLayout(Src->getDataLayout()); 1039 } else { 1040 std::string DataLayout; 1041 1042 if (Dest->getEndianness() == Module::AnyEndianness) { 1043 if (Src->getEndianness() == Module::BigEndian) 1044 DataLayout.append("E"); 1045 else if (Src->getEndianness() == Module::LittleEndian) 1046 DataLayout.append("e"); 1047 } 1048 1049 if (Dest->getPointerSize() == Module::AnyPointerSize) { 1050 if (Src->getPointerSize() == Module::Pointer64) 1051 DataLayout.append(DataLayout.length() == 0 ? "p:64:64" : "-p:64:64"); 1052 else if (Src->getPointerSize() == Module::Pointer32) 1053 DataLayout.append(DataLayout.length() == 0 ? "p:32:32" : "-p:32:32"); 1054 } 1055 Dest->setDataLayout(DataLayout); 1056 } 1057 } 1058 1059 // Copy the target triple from the source to dest if the dest's is empty. 1060 if (Dest->getTargetTriple().empty() && !Src->getTargetTriple().empty()) 1061 Dest->setTargetTriple(Src->getTargetTriple()); 1062 1063 if (!Src->getDataLayout().empty() && !Dest->getDataLayout().empty() && 1064 Src->getDataLayout() != Dest->getDataLayout()) 1065 cerr << "WARNING: Linking two modules of different data layouts!\n"; 1066 if (!Src->getTargetTriple().empty() && 1067 Dest->getTargetTriple() != Src->getTargetTriple()) 1068 cerr << "WARNING: Linking two modules of different target triples!\n"; 1069 1070 // Append the module inline asm string. 1071 if (!Src->getModuleInlineAsm().empty()) { 1072 if (Dest->getModuleInlineAsm().empty()) 1073 Dest->setModuleInlineAsm(Src->getModuleInlineAsm()); 1074 else 1075 Dest->setModuleInlineAsm(Dest->getModuleInlineAsm()+"\n"+ 1076 Src->getModuleInlineAsm()); 1077 } 1078 1079 // Update the destination module's dependent libraries list with the libraries 1080 // from the source module. There's no opportunity for duplicates here as the 1081 // Module ensures that duplicate insertions are discarded. 1082 for (Module::lib_iterator SI = Src->lib_begin(), SE = Src->lib_end(); 1083 SI != SE; ++SI) 1084 Dest->addLibrary(*SI); 1085 1086 // LinkTypes - Go through the symbol table of the Src module and see if any 1087 // types are named in the src module that are not named in the Dst module. 1088 // Make sure there are no type name conflicts. 1089 if (LinkTypes(Dest, Src, ErrorMsg)) 1090 return true; 1091 1092 // ValueMap - Mapping of values from what they used to be in Src, to what they 1093 // are now in Dest. 1094 std::map<const Value*, Value*> ValueMap; 1095 1096 // AppendingVars - Keep track of global variables in the destination module 1097 // with appending linkage. After the module is linked together, they are 1098 // appended and the module is rewritten. 1099 std::multimap<std::string, GlobalVariable *> AppendingVars; 1100 for (Module::global_iterator I = Dest->global_begin(), E = Dest->global_end(); 1101 I != E; ++I) { 1102 // Add all of the appending globals already in the Dest module to 1103 // AppendingVars. 1104 if (I->hasAppendingLinkage()) 1105 AppendingVars.insert(std::make_pair(I->getName(), I)); 1106 } 1107 1108 // Insert all of the globals in src into the Dest module... without linking 1109 // initializers (which could refer to functions not yet mapped over). 1110 if (LinkGlobals(Dest, Src, ValueMap, AppendingVars, ErrorMsg)) 1111 return true; 1112 1113 // Link the functions together between the two modules, without doing function 1114 // bodies... this just adds external function prototypes to the Dest 1115 // function... We do this so that when we begin processing function bodies, 1116 // all of the global values that may be referenced are available in our 1117 // ValueMap. 1118 if (LinkFunctionProtos(Dest, Src, ValueMap, ErrorMsg)) 1119 return true; 1120 1121 // If there were any alias, link them now. We really need to do this now, 1122 // because all of the aliases that may be referenced need to be available in 1123 // ValueMap 1124 if (LinkAlias(Dest, Src, ValueMap, ErrorMsg)) return true; 1125 1126 // Update the initializers in the Dest module now that all globals that may 1127 // be referenced are in Dest. 1128 if (LinkGlobalInits(Dest, Src, ValueMap, ErrorMsg)) return true; 1129 1130 // Link in the function bodies that are defined in the source module into the 1131 // DestModule. This consists basically of copying the function over and 1132 // fixing up references to values. 1133 if (LinkFunctionBodies(Dest, Src, ValueMap, ErrorMsg)) return true; 1134 1135 // If there were any appending global variables, link them together now. 1136 if (LinkAppendingVars(Dest, AppendingVars, ErrorMsg)) return true; 1137 1138 // If the source library's module id is in the dependent library list of the 1139 // destination library, remove it since that module is now linked in. 1140 sys::Path modId; 1141 modId.set(Src->getModuleIdentifier()); 1142 if (!modId.isEmpty()) 1143 Dest->removeLibrary(modId.getBasename()); 1144 1145 return false; 1146} 1147 1148// vim: sw=2 1149