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Reid Spencer361e5132004-11-12 20:37:43 +00001//===- lib/Linker/LinkModules.cpp - Module Linker Implementation ----------===//
Misha Brukman10468d82005-04-21 22:55:34 +00002//
Reid Spencer361e5132004-11-12 20:37:43 +00003// The LLVM Compiler Infrastructure
4//
5// This file was developed by the LLVM research group and is distributed under
6// the University of Illinois Open Source License. See LICENSE.TXT for details.
Misha Brukman10468d82005-04-21 22:55:34 +00007//
Reid Spencer361e5132004-11-12 20:37:43 +00008//===----------------------------------------------------------------------===//
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
Reid Spencer9b0ddbb2004-11-14 23:27:04 +000019#include "llvm/Linker.h"
Reid Spencer361e5132004-11-12 20:37:43 +000020#include "llvm/Constants.h"
21#include "llvm/DerivedTypes.h"
22#include "llvm/Module.h"
Reid Spencer32af9e82007-01-06 07:24:44 +000023#include "llvm/TypeSymbolTable.h"
Reid Spencer3aaaa0b2007-02-05 20:47:22 +000024#include "llvm/ValueSymbolTable.h"
Reid Spencer361e5132004-11-12 20:37:43 +000025#include "llvm/Instructions.h"
26#include "llvm/Assembly/Writer.h"
Bill Wendling7339b8d2006-11-27 10:09:12 +000027#include "llvm/Support/Streams.h"
Reid Spencer361e5132004-11-12 20:37:43 +000028#include "llvm/System/Path.h"
Bill Wendling30c0f332006-12-07 23:41:45 +000029#include <sstream>
Reid Spencer361e5132004-11-12 20:37:43 +000030using 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...
Reid Spencer361e5132004-11-12 20:37:43 +000034static inline bool Error(std::string *E, const std::string &Message) {
35 if (E) *E = Message;
36 return true;
37}
38
Reid Spencer2c4f9a42004-11-25 09:29:44 +000039// ToStr - Simple wrapper function to convert a type to a string.
Reid Spencer361e5132004-11-12 20:37:43 +000040static 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,
Reid Spencer32af9e82007-01-06 07:24:44 +000065 TypeSymbolTable *DestST, const std::string &Name) {
Reid Spencer361e5132004-11-12 20:37:43 +000066 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.
Reid Spencer361e5132004-11-12 20:37:43 +000095static bool RecursiveResolveTypesI(const PATypeHolder &DestTy,
96 const PATypeHolder &SrcTy,
Reid Spencer32af9e82007-01-06 07:24:44 +000097 TypeSymbolTable *DestST,
98 const std::string &Name,
Reid Spencer361e5132004-11-12 20:37:43 +000099 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
Misha Brukman10468d82005-04-21 22:55:34 +0000103
Reid Spencer361e5132004-11-12 20:37:43 +0000104 // If we found our opaque type, resolve it now!
105 if (isa<OpaqueType>(DestTyT) || isa<OpaqueType>(SrcTyT))
106 return ResolveTypes(DestTyT, SrcTyT, DestST, Name);
Misha Brukman10468d82005-04-21 22:55:34 +0000107
Reid Spencer361e5132004-11-12 20:37:43 +0000108 // 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()) {
Reid Spencer7a9c62b2007-01-12 07:05:14 +0000114 case Type::IntegerTyID: {
115 if (cast<IntegerType>(DestTyT)->getBitWidth() !=
116 cast<IntegerType>(SrcTyT)->getBitWidth())
117 return true;
118 return false;
119 }
Reid Spencer361e5132004-11-12 20:37:43 +0000120 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: {
Misha Brukman10468d82005-04-21 22:55:34 +0000134 if (getST(DestTy)->getNumContainedTypes() !=
Reid Spencer361e5132004-11-12 20:37:43 +0000135 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...
Reid Spencer361e5132004-11-12 20:37:43 +0000155 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;
Misha Brukman10468d82005-04-21 22:55:34 +0000170 }
Reid Spencer361e5132004-11-12 20:37:43 +0000171}
172
173static bool RecursiveResolveTypes(const PATypeHolder &DestTy,
174 const PATypeHolder &SrcTy,
Reid Spencer32af9e82007-01-06 07:24:44 +0000175 TypeSymbolTable *DestST,
176 const std::string &Name){
Reid Spencer361e5132004-11-12 20:37:43 +0000177 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.
Reid Spencer361e5132004-11-12 20:37:43 +0000185static bool LinkTypes(Module *Dest, const Module *Src, std::string *Err) {
Reid Spencer32af9e82007-01-06 07:24:44 +0000186 TypeSymbolTable *DestST = &Dest->getTypeSymbolTable();
187 const TypeSymbolTable *SrcST = &Src->getTypeSymbolTable();
Reid Spencer361e5132004-11-12 20:37:43 +0000188
189 // Look for a type plane for Type's...
Reid Spencer32af9e82007-01-06 07:24:44 +0000190 TypeSymbolTable::const_iterator TI = SrcST->begin();
191 TypeSymbolTable::const_iterator TE = SrcST->end();
Reid Spencer361e5132004-11-12 20:37:43 +0000192 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...
Reid Spencer32af9e82007-01-06 07:24:44 +0000204 Type *Entry = DestST->lookup(Name);
Reid Spencer361e5132004-11-12 20:37:43 +0000205
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];
Reid Spencer32af9e82007-01-06 07:24:44 +0000220 Type *T1 = SrcST->lookup(Name);
221 Type *T2 = DestST->lookup(Name);
Reid Spencer361e5132004-11-12 20:37:43 +0000222 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];
Reid Spencer32af9e82007-01-06 07:24:44 +0000235 PATypeHolder T1(SrcST->lookup(Name));
236 PATypeHolder T2(DestST->lookup(Name));
Reid Spencer361e5132004-11-12 20:37:43 +0000237
238 if (!RecursiveResolveTypes(T2, T1, DestST, Name)) {
239 // We are making progress!
240 DelayedTypesToResolve.erase(DelayedTypesToResolve.begin()+i);
Misha Brukman10468d82005-04-21 22:55:34 +0000241
Reid Spencer361e5132004-11-12 20:37:43 +0000242 // 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.
Reid Spencer361e5132004-11-12 20:37:43 +0000249 if (DelayedTypesToResolve.size() == OldSize) {
Reid Spencer361e5132004-11-12 20:37:43 +0000250 // 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) {
Bill Wendlingf3baad32006-12-07 01:30:32 +0000263 cerr << " Fr: " << (void*)I->first << " ";
Reid Spencer361e5132004-11-12 20:37:43 +0000264 I->first->dump();
Bill Wendlingf3baad32006-12-07 01:30:32 +0000265 cerr << " To: " << (void*)I->second << " ";
Reid Spencer361e5132004-11-12 20:37:43 +0000266 I->second->dump();
Bill Wendlingf3baad32006-12-07 01:30:32 +0000267 cerr << "\n";
Reid Spencer361e5132004-11-12 20:37:43 +0000268 }
269}
270
271
Reid Spencerd3ba7d92007-02-04 04:43:17 +0000272// RemapOperand - Use ValueMap to convert constants from one module to another.
Reid Spencer361e5132004-11-12 20:37:43 +0000273static Value *RemapOperand(const Value *In,
Chris Lattner7391dde2004-11-16 17:12:38 +0000274 std::map<const Value*, Value*> &ValueMap) {
275 std::map<const Value*,Value*>::const_iterator I = ValueMap.find(In);
Reid Spencer3aaaa0b2007-02-05 20:47:22 +0000276 if (I != ValueMap.end())
277 return I->second;
Reid Spencer361e5132004-11-12 20:37:43 +0000278
Reid Spencerd3ba7d92007-02-04 04:43:17 +0000279 // Check to see if it's a constant that we are interested in transforming.
Chris Lattnerc7745922006-06-01 19:14:22 +0000280 Value *Result = 0;
Reid Spencer361e5132004-11-12 20:37:43 +0000281 if (const Constant *CPV = dyn_cast<Constant>(In)) {
282 if ((!isa<DerivedType>(CPV->getType()) && !isa<ConstantExpr>(CPV)) ||
Reid Spencer7a9c62b2007-01-12 07:05:14 +0000283 isa<ConstantInt>(CPV) || isa<ConstantAggregateZero>(CPV))
Chris Lattner7391dde2004-11-16 17:12:38 +0000284 return const_cast<Constant*>(CPV); // Simple constants stay identical.
Reid Spencer361e5132004-11-12 20:37:43 +0000285
Reid Spencer361e5132004-11-12 20:37:43 +0000286 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)
Chris Lattner7391dde2004-11-16 17:12:38 +0000289 Operands[i] =cast<Constant>(RemapOperand(CPA->getOperand(i), ValueMap));
Reid Spencer361e5132004-11-12 20:37:43 +0000290 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)
Chris Lattner7391dde2004-11-16 17:12:38 +0000294 Operands[i] =cast<Constant>(RemapOperand(CPS->getOperand(i), ValueMap));
Reid Spencer361e5132004-11-12 20:37:43 +0000295 Result = ConstantStruct::get(cast<StructType>(CPS->getType()), Operands);
296 } else if (isa<ConstantPointerNull>(CPV) || isa<UndefValue>(CPV)) {
297 Result = const_cast<Constant*>(CPV);
Chris Lattner93bde9c2006-01-19 23:15:58 +0000298 } else if (const ConstantPacked *CP = dyn_cast<ConstantPacked>(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 = ConstantPacked::get(Operands);
Reid Spencer361e5132004-11-12 20:37:43 +0000303 } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CPV)) {
Chris Lattner19247f32006-07-14 22:21:31 +0000304 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);
Reid Spencerd3ba7d92007-02-04 04:43:17 +0000308 } else if (isa<GlobalValue>(CPV)) {
309 assert(0 && "Unmapped global?");
Reid Spencer361e5132004-11-12 20:37:43 +0000310 } else {
311 assert(0 && "Unknown type of derived type constant value!");
312 }
Chris Lattnerc7745922006-06-01 19:14:22 +0000313 } else if (isa<InlineAsm>(In)) {
314 Result = const_cast<Value*>(In);
315 }
316
Reid Spencerd3ba7d92007-02-04 04:43:17 +0000317 // Cache the mapping in our local map structure
Chris Lattnerc7745922006-06-01 19:14:22 +0000318 if (Result) {
Chris Lattner7391dde2004-11-16 17:12:38 +0000319 ValueMap.insert(std::make_pair(In, Result));
Reid Spencer361e5132004-11-12 20:37:43 +0000320 return Result;
321 }
Reid Spencer90246aa2007-02-04 04:29:21 +0000322
Reid Spencer361e5132004-11-12 20:37:43 +0000323
Bill Wendlingf3baad32006-12-07 01:30:32 +0000324 cerr << "LinkModules ValueMap: \n";
Chris Lattner7391dde2004-11-16 17:12:38 +0000325 PrintMap(ValueMap);
Reid Spencer361e5132004-11-12 20:37:43 +0000326
Bill Wendlingf3baad32006-12-07 01:30:32 +0000327 cerr << "Couldn't remap value: " << (void*)In << " " << *In << "\n";
Reid Spencer361e5132004-11-12 20:37:43 +0000328 assert(0 && "Couldn't remap value!");
329 return 0;
330}
331
Reid Spencer90246aa2007-02-04 04:29:21 +0000332/// 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.
Reid Spencer361e5132004-11-12 20:37:43 +0000335static void ForceRenaming(GlobalValue *GV, const std::string &Name) {
336 assert(GV->getName() != Name && "Can't force rename to self");
Reid Spencer3aaaa0b2007-02-05 20:47:22 +0000337 ValueSymbolTable &ST = GV->getParent()->getValueSymbolTable();
Reid Spencer361e5132004-11-12 20:37:43 +0000338
339 // If there is a conflict, rename the conflict.
Reid Spencer3aaaa0b2007-02-05 20:47:22 +0000340 GlobalValue *ConflictGV = cast_or_null<GlobalValue>(ST.lookup(Name));
341 if (ConflictGV) {
342 assert(ConflictGV->hasInternalLinkage() &&
343 "Not conflicting with a static global, should link instead!");
344 ConflictGV->setName(""); // Eliminate the conflict
345 }
346 GV->setName(Name); // Force the name back
347 if (ConflictGV) {
348 ConflictGV->setName(Name); // This will cause ConflictGV to get renamed
349 assert(ConflictGV->getName() != Name && "ForceRenaming didn't work");
350 }
351 assert(GV->getName() == Name && "ForceRenaming didn't work");
352}
Reid Spencer90246aa2007-02-04 04:29:21 +0000353
Reid Spencer3aaaa0b2007-02-05 20:47:22 +0000354/// CopyGVAttributes - copy additional attributes (those not needed to construct
355/// a GlobalValue) from the SrcGV to the DestGV.
356static void CopyGVAttributes(GlobalValue *DestGV, const GlobalValue *SrcGV) {
357 // Propagate alignment, visibility and section info.
358 DestGV->setAlignment(std::max(DestGV->getAlignment(), SrcGV->getAlignment()));
359 DestGV->setSection(SrcGV->getSection());
360 DestGV->setVisibility(SrcGV->getVisibility());
361 if (const Function *SrcF = dyn_cast<Function>(SrcGV)) {
362 Function *DestF = cast<Function>(DestGV);
363 DestF->setCallingConv(SrcF->getCallingConv());
364 }
Reid Spencer361e5132004-11-12 20:37:43 +0000365}
366
Chris Lattnerfc61de32004-12-03 22:18:41 +0000367/// 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.
372static bool GetLinkageResult(GlobalValue *Dest, GlobalValue *Src,
373 GlobalValue::LinkageTypes &LT, bool &LinkFromSrc,
374 std::string *Err) {
375 assert((!Dest || !Src->hasInternalLinkage()) &&
376 "If Src has internal linkage, Dest shouldn't be set!");
377 if (!Dest) {
378 // Linking something to nothing.
379 LinkFromSrc = true;
380 LT = Src->getLinkage();
Reid Spencer5301e7c2007-01-30 20:08:39 +0000381 } else if (Src->isDeclaration()) {
Chris Lattnerfc61de32004-12-03 22:18:41 +0000382 // If Src is external or if both Src & Drc are external.. Just link the
383 // external globals, we aren't adding anything.
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000384 if (Src->hasDLLImportLinkage()) {
Anton Korobeynikov12c94942006-12-01 00:25:12 +0000385 // If one of GVs has DLLImport linkage, result should be dllimport'ed.
Reid Spencer5301e7c2007-01-30 20:08:39 +0000386 if (Dest->isDeclaration()) {
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000387 LinkFromSrc = true;
388 LT = Src->getLinkage();
389 }
Andrew Lenharthe06036d2006-12-15 17:35:32 +0000390 } else if (Dest->hasExternalWeakLinkage()) {
391 //If the Dest is weak, use the source linkage
392 LinkFromSrc = true;
393 LT = Src->getLinkage();
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000394 } else {
395 LinkFromSrc = false;
396 LT = Dest->getLinkage();
397 }
Reid Spencer5301e7c2007-01-30 20:08:39 +0000398 } else if (Dest->isDeclaration() && !Dest->hasDLLImportLinkage()) {
Chris Lattnerfc61de32004-12-03 22:18:41 +0000399 // If Dest is external but Src is not:
400 LinkFromSrc = true;
401 LT = Src->getLinkage();
402 } else if (Src->hasAppendingLinkage() || Dest->hasAppendingLinkage()) {
403 if (Src->getLinkage() != Dest->getLinkage())
404 return Error(Err, "Linking globals named '" + Src->getName() +
405 "': can only link appending global with another appending global!");
406 LinkFromSrc = true; // Special cased.
407 LT = Src->getLinkage();
408 } else if (Src->hasWeakLinkage() || Src->hasLinkOnceLinkage()) {
Reid Spencerd3ba7d92007-02-04 04:43:17 +0000409 // At this point we know that Dest has LinkOnce, External*, Weak, or
410 // DLL* linkage.
Anton Korobeynikov12c94942006-12-01 00:25:12 +0000411 if ((Dest->hasLinkOnceLinkage() && Src->hasWeakLinkage()) ||
412 Dest->hasExternalWeakLinkage()) {
Chris Lattnerfc61de32004-12-03 22:18:41 +0000413 LinkFromSrc = true;
414 LT = Src->getLinkage();
415 } else {
416 LinkFromSrc = false;
417 LT = Dest->getLinkage();
418 }
419 } else if (Dest->hasWeakLinkage() || Dest->hasLinkOnceLinkage()) {
Anton Korobeynikov12c94942006-12-01 00:25:12 +0000420 // At this point we know that Src has External* or DLL* linkage.
421 if (Src->hasExternalWeakLinkage()) {
422 LinkFromSrc = false;
423 LT = Dest->getLinkage();
424 } else {
425 LinkFromSrc = true;
426 LT = GlobalValue::ExternalLinkage;
427 }
Chris Lattnerfc61de32004-12-03 22:18:41 +0000428 } else {
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000429 assert((Dest->hasExternalLinkage() ||
430 Dest->hasDLLImportLinkage() ||
Anton Korobeynikov12c94942006-12-01 00:25:12 +0000431 Dest->hasDLLExportLinkage() ||
432 Dest->hasExternalWeakLinkage()) &&
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000433 (Src->hasExternalLinkage() ||
434 Src->hasDLLImportLinkage() ||
Anton Korobeynikov12c94942006-12-01 00:25:12 +0000435 Src->hasDLLExportLinkage() ||
436 Src->hasExternalWeakLinkage()) &&
Chris Lattnerfc61de32004-12-03 22:18:41 +0000437 "Unexpected linkage type!");
Misha Brukman10468d82005-04-21 22:55:34 +0000438 return Error(Err, "Linking globals named '" + Src->getName() +
Chris Lattnerfc61de32004-12-03 22:18:41 +0000439 "': symbol multiply defined!");
440 }
441 return false;
442}
Reid Spencer361e5132004-11-12 20:37:43 +0000443
444// LinkGlobals - Loop through the global variables in the src module and merge
445// them into the dest module.
Chris Lattnerfc61de32004-12-03 22:18:41 +0000446static bool LinkGlobals(Module *Dest, Module *Src,
Reid Spencer361e5132004-11-12 20:37:43 +0000447 std::map<const Value*, Value*> &ValueMap,
448 std::multimap<std::string, GlobalVariable *> &AppendingVars,
Reid Spencer361e5132004-11-12 20:37:43 +0000449 std::string *Err) {
Reid Spencer361e5132004-11-12 20:37:43 +0000450 // Loop over all of the globals in the src module, mapping them over as we go
Chris Lattner44ab8ae2006-06-16 01:24:04 +0000451 for (Module::global_iterator I = Src->global_begin(), E = Src->global_end();
452 I != E; ++I) {
Chris Lattnerfc61de32004-12-03 22:18:41 +0000453 GlobalVariable *SGV = I;
Reid Spencer361e5132004-11-12 20:37:43 +0000454 GlobalVariable *DGV = 0;
455 // Check to see if may have to link the global.
Reid Spencer3aaaa0b2007-02-05 20:47:22 +0000456 if (SGV->hasName() && !SGV->hasInternalLinkage()) {
457 DGV = Dest->getGlobalVariable(SGV->getName());
458 if (DGV && DGV->getType() != SGV->getType())
459 // If types don't agree due to opaque types, try to resolve them.
460 RecursiveResolveTypes(SGV->getType(), DGV->getType(),
461 &Dest->getTypeSymbolTable(), "");
462 }
Reid Spencer361e5132004-11-12 20:37:43 +0000463
Chris Lattnerfc61de32004-12-03 22:18:41 +0000464 if (DGV && DGV->hasInternalLinkage())
465 DGV = 0;
466
Andrew Lenharthe06036d2006-12-15 17:35:32 +0000467 assert(SGV->hasInitializer() || SGV->hasExternalWeakLinkage() ||
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000468 SGV->hasExternalLinkage() || SGV->hasDLLImportLinkage() &&
Reid Spencer361e5132004-11-12 20:37:43 +0000469 "Global must either be external or have an initializer!");
470
Chris Lattner1b9633d2006-11-09 05:18:12 +0000471 GlobalValue::LinkageTypes NewLinkage = GlobalValue::InternalLinkage;
472 bool LinkFromSrc = false;
Chris Lattnerfc61de32004-12-03 22:18:41 +0000473 if (GetLinkageResult(DGV, SGV, NewLinkage, LinkFromSrc, Err))
474 return true;
Reid Spencer361e5132004-11-12 20:37:43 +0000475
Chris Lattnerfc61de32004-12-03 22:18:41 +0000476 if (!DGV) {
Reid Spencer361e5132004-11-12 20:37:43 +0000477 // No linking to be performed, simply create an identical version of the
478 // symbol over in the dest module... the initializer will be filled in
479 // later by LinkGlobalInits...
Reid Spencer361e5132004-11-12 20:37:43 +0000480 GlobalVariable *NewDGV =
481 new GlobalVariable(SGV->getType()->getElementType(),
482 SGV->isConstant(), SGV->getLinkage(), /*init*/0,
483 SGV->getName(), Dest);
Reid Spencer2dc36532007-02-04 04:30:33 +0000484 // Propagate alignment, visibility and section info.
Reid Spencer3aaaa0b2007-02-05 20:47:22 +0000485 CopyGVAttributes(NewDGV, SGV);
Andrew Lenharthdd924e42007-02-01 17:12:54 +0000486
Reid Spencer361e5132004-11-12 20:37:43 +0000487 // If the LLVM runtime renamed the global, but it is an externally visible
488 // symbol, DGV must be an existing global with internal linkage. Rename
489 // it.
490 if (NewDGV->getName() != SGV->getName() && !NewDGV->hasInternalLinkage())
491 ForceRenaming(NewDGV, SGV->getName());
492
493 // Make sure to remember this mapping...
494 ValueMap.insert(std::make_pair(SGV, NewDGV));
495 if (SGV->hasAppendingLinkage())
496 // Keep track that this is an appending variable...
497 AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV));
Chris Lattnerfc61de32004-12-03 22:18:41 +0000498 } else if (DGV->hasAppendingLinkage()) {
Reid Spencer361e5132004-11-12 20:37:43 +0000499 // No linking is performed yet. Just insert a new copy of the global, and
500 // keep track of the fact that it is an appending variable in the
501 // AppendingVars map. The name is cleared out so that no linkage is
502 // performed.
503 GlobalVariable *NewDGV =
504 new GlobalVariable(SGV->getType()->getElementType(),
505 SGV->isConstant(), SGV->getLinkage(), /*init*/0,
506 "", Dest);
507
Reid Spencer2dc36532007-02-04 04:30:33 +0000508 // Propagate alignment, section and visibility info.
Reid Spencer3aaaa0b2007-02-05 20:47:22 +0000509 NewDGV->setAlignment(DGV->getAlignment());
510 CopyGVAttributes(NewDGV, SGV);
Andrew Lenharthdd924e42007-02-01 17:12:54 +0000511
Reid Spencer361e5132004-11-12 20:37:43 +0000512 // Make sure to remember this mapping...
513 ValueMap.insert(std::make_pair(SGV, NewDGV));
514
515 // Keep track that this is an appending variable...
516 AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV));
517 } else {
Reid Spencer2dc36532007-02-04 04:30:33 +0000518 // Propagate alignment, section, and visibility info.
Reid Spencer3aaaa0b2007-02-05 20:47:22 +0000519 CopyGVAttributes(DGV, SGV);
Andrew Lenharthdd924e42007-02-01 17:12:54 +0000520
Chris Lattnerfc61de32004-12-03 22:18:41 +0000521 // Otherwise, perform the mapping as instructed by GetLinkageResult. If
522 // the types don't match, and if we are to link from the source, nuke DGV
523 // and create a new one of the appropriate type.
524 if (SGV->getType() != DGV->getType() && LinkFromSrc) {
525 GlobalVariable *NewDGV =
526 new GlobalVariable(SGV->getType()->getElementType(),
527 DGV->isConstant(), DGV->getLinkage());
Reid Spencer3aaaa0b2007-02-05 20:47:22 +0000528 CopyGVAttributes(NewDGV, DGV);
Chris Lattnerfc61de32004-12-03 22:18:41 +0000529 Dest->getGlobalList().insert(DGV, NewDGV);
Reid Spencerb341b082006-12-12 05:05:00 +0000530 DGV->replaceAllUsesWith(
531 ConstantExpr::getBitCast(NewDGV, DGV->getType()));
Chris Lattnerfc61de32004-12-03 22:18:41 +0000532 DGV->eraseFromParent();
533 NewDGV->setName(SGV->getName());
534 DGV = NewDGV;
535 }
536
537 DGV->setLinkage(NewLinkage);
538
539 if (LinkFromSrc) {
Chris Lattnerfc61de32004-12-03 22:18:41 +0000540 // Inherit const as appropriate
Chris Lattner16277c12005-02-12 19:20:28 +0000541 DGV->setConstant(SGV->isConstant());
Chris Lattnerfc61de32004-12-03 22:18:41 +0000542 DGV->setInitializer(0);
543 } else {
544 if (SGV->isConstant() && !DGV->isConstant()) {
Reid Spencer5301e7c2007-01-30 20:08:39 +0000545 if (DGV->isDeclaration())
Chris Lattnerfc61de32004-12-03 22:18:41 +0000546 DGV->setConstant(true);
547 }
Chris Lattnera57c1052004-12-04 18:54:48 +0000548 SGV->setLinkage(GlobalValue::ExternalLinkage);
549 SGV->setInitializer(0);
Chris Lattnerfc61de32004-12-03 22:18:41 +0000550 }
551
Reid Spencerb341b082006-12-12 05:05:00 +0000552 ValueMap.insert(
553 std::make_pair(SGV, ConstantExpr::getBitCast(DGV, SGV->getType())));
Reid Spencer361e5132004-11-12 20:37:43 +0000554 }
555 }
556 return false;
557}
558
559
560// LinkGlobalInits - Update the initializers in the Dest module now that all
561// globals that may be referenced are in Dest.
Reid Spencer361e5132004-11-12 20:37:43 +0000562static bool LinkGlobalInits(Module *Dest, const Module *Src,
563 std::map<const Value*, Value*> &ValueMap,
564 std::string *Err) {
565
566 // Loop over all of the globals in the src module, mapping them over as we go
Chris Lattner44ab8ae2006-06-16 01:24:04 +0000567 for (Module::const_global_iterator I = Src->global_begin(),
568 E = Src->global_end(); I != E; ++I) {
Reid Spencer361e5132004-11-12 20:37:43 +0000569 const GlobalVariable *SGV = I;
570
571 if (SGV->hasInitializer()) { // Only process initialized GV's
572 // Figure out what the initializer looks like in the dest module...
573 Constant *SInit =
Chris Lattner7391dde2004-11-16 17:12:38 +0000574 cast<Constant>(RemapOperand(SGV->getInitializer(), ValueMap));
Reid Spencer361e5132004-11-12 20:37:43 +0000575
Misha Brukman10468d82005-04-21 22:55:34 +0000576 GlobalVariable *DGV = cast<GlobalVariable>(ValueMap[SGV]);
Reid Spencer361e5132004-11-12 20:37:43 +0000577 if (DGV->hasInitializer()) {
578 if (SGV->hasExternalLinkage()) {
579 if (DGV->getInitializer() != SInit)
Misha Brukman10468d82005-04-21 22:55:34 +0000580 return Error(Err, "Global Variable Collision on '" +
Reid Spencer361e5132004-11-12 20:37:43 +0000581 ToStr(SGV->getType(), Src) +"':%"+SGV->getName()+
582 " - Global variables have different initializers");
583 } else if (DGV->hasLinkOnceLinkage() || DGV->hasWeakLinkage()) {
584 // Nothing is required, mapped values will take the new global
585 // automatically.
586 } else if (SGV->hasLinkOnceLinkage() || SGV->hasWeakLinkage()) {
587 // Nothing is required, mapped values will take the new global
588 // automatically.
589 } else if (DGV->hasAppendingLinkage()) {
590 assert(0 && "Appending linkage unimplemented!");
591 } else {
592 assert(0 && "Unknown linkage!");
593 }
594 } else {
595 // Copy the initializer over now...
596 DGV->setInitializer(SInit);
597 }
598 }
599 }
600 return false;
601}
602
603// LinkFunctionProtos - Link the functions together between the two modules,
604// without doing function bodies... this just adds external function prototypes
605// to the Dest function...
606//
607static bool LinkFunctionProtos(Module *Dest, const Module *Src,
608 std::map<const Value*, Value*> &ValueMap,
Reid Spencer361e5132004-11-12 20:37:43 +0000609 std::string *Err) {
Reid Spencerd3ba7d92007-02-04 04:43:17 +0000610 // Loop over all of the functions in the src module, mapping them over
Reid Spencer361e5132004-11-12 20:37:43 +0000611 for (Module::const_iterator I = Src->begin(), E = Src->end(); I != E; ++I) {
612 const Function *SF = I; // SrcFunction
613 Function *DF = 0;
Reid Spencer90246aa2007-02-04 04:29:21 +0000614 if (SF->hasName() && !SF->hasInternalLinkage()) {
615 // Check to see if may have to link the function.
Reid Spencer3aaaa0b2007-02-05 20:47:22 +0000616 DF = Dest->getFunction(SF->getName());
617 if (DF && SF->getType() != DF->getType())
618 // If types don't agree because of opaque, try to resolve them
619 RecursiveResolveTypes(SF->getType(), DF->getType(),
620 &Dest->getTypeSymbolTable(), "");
Reid Spencer90246aa2007-02-04 04:29:21 +0000621 }
Reid Spencer3aaaa0b2007-02-05 20:47:22 +0000622
623 if (DF && DF->getType() != SF->getType()) {
624 if (DF->isDeclaration() && !SF->isDeclaration()) {
625 // We have a definition of the same name but different type in the
626 // source module. Copy the prototype to the destination and replace
627 // uses of the destination's prototype with the new prototype.
628 Function *NewDF = new Function(SF->getFunctionType(), SF->getLinkage(),
629 SF->getName(), Dest);
630 CopyGVAttributes(NewDF, SF);
Reid Spencer361e5132004-11-12 20:37:43 +0000631
Reid Spencer3aaaa0b2007-02-05 20:47:22 +0000632 // Any uses of DF need to change to NewDF, with cast
633 DF->replaceAllUsesWith(ConstantExpr::getBitCast(NewDF, DF->getType()));
634
635 // DF will conflict with NewDF because they both had the same. We must
636 // erase this now so ForceRenaming doesn't assert because DF might
637 // not have internal linkage.
638 DF->eraseFromParent();
639
640 // If the symbol table renamed the function, but it is an externally
641 // visible symbol, DF must be an existing function with internal
642 // linkage. Rename it.
643 if (NewDF->getName() != SF->getName() && !NewDF->hasInternalLinkage())
644 ForceRenaming(NewDF, SF->getName());
645
646 // Remember this mapping so uses in the source module get remapped
647 // later by RemapOperand.
648 ValueMap[SF] = NewDF;
649 } else if (SF->isDeclaration()) {
650 // We have two functions of the same name but different type and the
651 // source is a declaration while the destination is not. Any use of
652 // the source must be mapped to the destination, with a cast.
653 ValueMap[SF] = ConstantExpr::getBitCast(DF, SF->getType());
654 } else {
655 // We have two functions of the same name but different types and they
656 // are both definitions. This is an error.
657 return Error(Err, "Function '" + DF->getName() + "' defined as both '" +
658 ToStr(SF->getFunctionType(), Src) + "' and '" +
659 ToStr(DF->getFunctionType(), Dest) + "'");
660 }
661 } else if (!DF || SF->hasInternalLinkage() || DF->hasInternalLinkage()) {
Reid Spencer361e5132004-11-12 20:37:43 +0000662 // Function does not already exist, simply insert an function signature
663 // identical to SF into the dest module...
664 Function *NewDF = new Function(SF->getFunctionType(), SF->getLinkage(),
665 SF->getName(), Dest);
Reid Spencer3aaaa0b2007-02-05 20:47:22 +0000666 CopyGVAttributes(NewDF, SF);
Reid Spencer361e5132004-11-12 20:37:43 +0000667
668 // If the LLVM runtime renamed the function, but it is an externally
669 // visible symbol, DF must be an existing function with internal linkage.
670 // Rename it.
671 if (NewDF->getName() != SF->getName() && !NewDF->hasInternalLinkage())
672 ForceRenaming(NewDF, SF->getName());
673
674 // ... and remember this mapping...
675 ValueMap.insert(std::make_pair(SF, NewDF));
Reid Spencer5301e7c2007-01-30 20:08:39 +0000676 } else if (SF->isDeclaration()) {
Reid Spencer3aaaa0b2007-02-05 20:47:22 +0000677 // If SF is a declaration or if both SF & DF are declarations, just link
678 // the declarations, we aren't adding anything.
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000679 if (SF->hasDLLImportLinkage()) {
Reid Spencer5301e7c2007-01-30 20:08:39 +0000680 if (DF->isDeclaration()) {
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000681 ValueMap.insert(std::make_pair(SF, DF));
682 DF->setLinkage(SF->getLinkage());
683 }
684 } else {
685 ValueMap.insert(std::make_pair(SF, DF));
Reid Spencer90246aa2007-02-04 04:29:21 +0000686 }
Reid Spencer5301e7c2007-01-30 20:08:39 +0000687 } else if (DF->isDeclaration() && !DF->hasDLLImportLinkage()) {
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000688 // If DF is external but SF is not...
Reid Spencer361e5132004-11-12 20:37:43 +0000689 // Link the external functions, update linkage qualifiers
690 ValueMap.insert(std::make_pair(SF, DF));
691 DF->setLinkage(SF->getLinkage());
Reid Spencer361e5132004-11-12 20:37:43 +0000692 } else if (SF->hasWeakLinkage() || SF->hasLinkOnceLinkage()) {
Anton Korobeynikov12c94942006-12-01 00:25:12 +0000693 // At this point we know that DF has LinkOnce, Weak, or External* linkage.
Reid Spencer361e5132004-11-12 20:37:43 +0000694 ValueMap.insert(std::make_pair(SF, DF));
695
696 // Linkonce+Weak = Weak
Anton Korobeynikov12c94942006-12-01 00:25:12 +0000697 // *+External Weak = *
698 if ((DF->hasLinkOnceLinkage() && SF->hasWeakLinkage()) ||
699 DF->hasExternalWeakLinkage())
Reid Spencer361e5132004-11-12 20:37:43 +0000700 DF->setLinkage(SF->getLinkage());
Reid Spencer361e5132004-11-12 20:37:43 +0000701 } else if (DF->hasWeakLinkage() || DF->hasLinkOnceLinkage()) {
Anton Korobeynikov12c94942006-12-01 00:25:12 +0000702 // At this point we know that SF has LinkOnce or External* linkage.
Reid Spencer361e5132004-11-12 20:37:43 +0000703 ValueMap.insert(std::make_pair(SF, DF));
Anton Korobeynikov12c94942006-12-01 00:25:12 +0000704 if (!SF->hasLinkOnceLinkage() && !SF->hasExternalWeakLinkage())
705 // Don't inherit linkonce & external weak linkage
Reid Spencer361e5132004-11-12 20:37:43 +0000706 DF->setLinkage(SF->getLinkage());
Reid Spencer361e5132004-11-12 20:37:43 +0000707 } else if (SF->getLinkage() != DF->getLinkage()) {
Reid Spencer3aaaa0b2007-02-05 20:47:22 +0000708 return Error(Err, "Functions named '" + SF->getName() +
709 "' have different linkage specifiers!");
Reid Spencer361e5132004-11-12 20:37:43 +0000710 } else if (SF->hasExternalLinkage()) {
Reid Spencer3aaaa0b2007-02-05 20:47:22 +0000711 // The function is defined identically in both modules!!
Misha Brukman10468d82005-04-21 22:55:34 +0000712 return Error(Err, "Function '" +
713 ToStr(SF->getFunctionType(), Src) + "':\"" +
Reid Spencer361e5132004-11-12 20:37:43 +0000714 SF->getName() + "\" - Function is already defined!");
715 } else {
716 assert(0 && "Unknown linkage configuration found!");
717 }
718 }
719 return false;
720}
721
722// LinkFunctionBody - Copy the source function over into the dest function and
723// fix up references to values. At this point we know that Dest is an external
724// function, and that Src is not.
Chris Lattner2f0557d2004-11-16 07:31:51 +0000725static bool LinkFunctionBody(Function *Dest, Function *Src,
Reid Spencer3aaaa0b2007-02-05 20:47:22 +0000726 std::map<const Value*, Value*> &ValueMap,
Reid Spencer361e5132004-11-12 20:37:43 +0000727 std::string *Err) {
Reid Spencer5301e7c2007-01-30 20:08:39 +0000728 assert(Src && Dest && Dest->isDeclaration() && !Src->isDeclaration());
Reid Spencer361e5132004-11-12 20:37:43 +0000729
Chris Lattner7391dde2004-11-16 17:12:38 +0000730 // Go through and convert function arguments over, remembering the mapping.
Chris Lattner531f9e92005-03-15 04:54:21 +0000731 Function::arg_iterator DI = Dest->arg_begin();
732 for (Function::arg_iterator I = Src->arg_begin(), E = Src->arg_end();
Reid Spencer361e5132004-11-12 20:37:43 +0000733 I != E; ++I, ++DI) {
734 DI->setName(I->getName()); // Copy the name information over...
735
736 // Add a mapping to our local map
Reid Spencer3aaaa0b2007-02-05 20:47:22 +0000737 ValueMap.insert(std::make_pair(I, DI));
Reid Spencer361e5132004-11-12 20:37:43 +0000738 }
739
Chris Lattner2f0557d2004-11-16 07:31:51 +0000740 // Splice the body of the source function into the dest function.
741 Dest->getBasicBlockList().splice(Dest->end(), Src->getBasicBlockList());
Reid Spencer361e5132004-11-12 20:37:43 +0000742
743 // At this point, all of the instructions and values of the function are now
744 // copied over. The only problem is that they are still referencing values in
745 // the Source function as operands. Loop through all of the operands of the
746 // functions and patch them up to point to the local versions...
747 //
748 for (Function::iterator BB = Dest->begin(), BE = Dest->end(); BB != BE; ++BB)
749 for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
750 for (Instruction::op_iterator OI = I->op_begin(), OE = I->op_end();
751 OI != OE; ++OI)
Chris Lattner2f0557d2004-11-16 07:31:51 +0000752 if (!isa<Instruction>(*OI) && !isa<BasicBlock>(*OI))
Reid Spencer3aaaa0b2007-02-05 20:47:22 +0000753 *OI = RemapOperand(*OI, ValueMap);
Chris Lattner7391dde2004-11-16 17:12:38 +0000754
755 // There is no need to map the arguments anymore.
Chris Lattner44ab8ae2006-06-16 01:24:04 +0000756 for (Function::arg_iterator I = Src->arg_begin(), E = Src->arg_end();
757 I != E; ++I)
Reid Spencer3aaaa0b2007-02-05 20:47:22 +0000758 ValueMap.erase(I);
Reid Spencer361e5132004-11-12 20:37:43 +0000759
760 return false;
761}
762
763
764// LinkFunctionBodies - Link in the function bodies that are defined in the
765// source module into the DestModule. This consists basically of copying the
766// function over and fixing up references to values.
Chris Lattner2f0557d2004-11-16 07:31:51 +0000767static bool LinkFunctionBodies(Module *Dest, Module *Src,
Reid Spencer361e5132004-11-12 20:37:43 +0000768 std::map<const Value*, Value*> &ValueMap,
769 std::string *Err) {
770
Reid Spencer90246aa2007-02-04 04:29:21 +0000771 // Loop over all of the functions in the src module, mapping them over as we
772 // go
Chris Lattner2f0557d2004-11-16 07:31:51 +0000773 for (Module::iterator SF = Src->begin(), E = Src->end(); SF != E; ++SF) {
Reid Spencerd3ba7d92007-02-04 04:43:17 +0000774 if (!SF->isDeclaration()) { // No body if function is external
Reid Spencer361e5132004-11-12 20:37:43 +0000775 Function *DF = cast<Function>(ValueMap[SF]); // Destination function
776
777 // DF not external SF external?
Reid Spencer3aaaa0b2007-02-05 20:47:22 +0000778 if (DF->isDeclaration())
Reid Spencer361e5132004-11-12 20:37:43 +0000779 // Only provide the function body if there isn't one already.
780 if (LinkFunctionBody(DF, SF, ValueMap, Err))
781 return true;
Reid Spencer361e5132004-11-12 20:37:43 +0000782 }
783 }
784 return false;
785}
786
787// LinkAppendingVars - If there were any appending global variables, link them
788// together now. Return true on error.
Reid Spencer361e5132004-11-12 20:37:43 +0000789static bool LinkAppendingVars(Module *M,
790 std::multimap<std::string, GlobalVariable *> &AppendingVars,
791 std::string *ErrorMsg) {
792 if (AppendingVars.empty()) return false; // Nothing to do.
Misha Brukman10468d82005-04-21 22:55:34 +0000793
Reid Spencer361e5132004-11-12 20:37:43 +0000794 // Loop over the multimap of appending vars, processing any variables with the
795 // same name, forming a new appending global variable with both of the
796 // initializers merged together, then rewrite references to the old variables
797 // and delete them.
Reid Spencer361e5132004-11-12 20:37:43 +0000798 std::vector<Constant*> Inits;
799 while (AppendingVars.size() > 1) {
800 // Get the first two elements in the map...
801 std::multimap<std::string,
802 GlobalVariable*>::iterator Second = AppendingVars.begin(), First=Second++;
803
804 // If the first two elements are for different names, there is no pair...
805 // Otherwise there is a pair, so link them together...
806 if (First->first == Second->first) {
807 GlobalVariable *G1 = First->second, *G2 = Second->second;
808 const ArrayType *T1 = cast<ArrayType>(G1->getType()->getElementType());
809 const ArrayType *T2 = cast<ArrayType>(G2->getType()->getElementType());
Misha Brukman10468d82005-04-21 22:55:34 +0000810
Reid Spencer361e5132004-11-12 20:37:43 +0000811 // Check to see that they two arrays agree on type...
812 if (T1->getElementType() != T2->getElementType())
813 return Error(ErrorMsg,
814 "Appending variables with different element types need to be linked!");
815 if (G1->isConstant() != G2->isConstant())
816 return Error(ErrorMsg,
817 "Appending variables linked with different const'ness!");
818
819 unsigned NewSize = T1->getNumElements() + T2->getNumElements();
820 ArrayType *NewType = ArrayType::get(T1->getElementType(), NewSize);
821
Chris Lattnerd490d4f2005-12-06 17:30:58 +0000822 G1->setName(""); // Clear G1's name in case of a conflict!
823
Reid Spencer361e5132004-11-12 20:37:43 +0000824 // Create the new global variable...
825 GlobalVariable *NG =
826 new GlobalVariable(NewType, G1->isConstant(), G1->getLinkage(),
827 /*init*/0, First->first, M);
828
829 // Merge the initializer...
830 Inits.reserve(NewSize);
831 if (ConstantArray *I = dyn_cast<ConstantArray>(G1->getInitializer())) {
832 for (unsigned i = 0, e = T1->getNumElements(); i != e; ++i)
833 Inits.push_back(I->getOperand(i));
834 } else {
835 assert(isa<ConstantAggregateZero>(G1->getInitializer()));
836 Constant *CV = Constant::getNullValue(T1->getElementType());
837 for (unsigned i = 0, e = T1->getNumElements(); i != e; ++i)
838 Inits.push_back(CV);
839 }
840 if (ConstantArray *I = dyn_cast<ConstantArray>(G2->getInitializer())) {
841 for (unsigned i = 0, e = T2->getNumElements(); i != e; ++i)
842 Inits.push_back(I->getOperand(i));
843 } else {
844 assert(isa<ConstantAggregateZero>(G2->getInitializer()));
845 Constant *CV = Constant::getNullValue(T2->getElementType());
846 for (unsigned i = 0, e = T2->getNumElements(); i != e; ++i)
847 Inits.push_back(CV);
848 }
849 NG->setInitializer(ConstantArray::get(NewType, Inits));
850 Inits.clear();
851
852 // Replace any uses of the two global variables with uses of the new
853 // global...
854
855 // FIXME: This should rewrite simple/straight-forward uses such as
856 // getelementptr instructions to not use the Cast!
Reid Spencerb341b082006-12-12 05:05:00 +0000857 G1->replaceAllUsesWith(ConstantExpr::getBitCast(NG, G1->getType()));
858 G2->replaceAllUsesWith(ConstantExpr::getBitCast(NG, G2->getType()));
Reid Spencer361e5132004-11-12 20:37:43 +0000859
860 // Remove the two globals from the module now...
861 M->getGlobalList().erase(G1);
862 M->getGlobalList().erase(G2);
863
864 // Put the new global into the AppendingVars map so that we can handle
865 // linking of more than two vars...
866 Second->second = NG;
867 }
868 AppendingVars.erase(First);
869 }
870
871 return false;
872}
873
874
875// LinkModules - This function links two modules together, with the resulting
876// left module modified to be the composite of the two input modules. If an
877// error occurs, true is returned and ErrorMsg (if not null) is set to indicate
878// the problem. Upon failure, the Dest module could be in a modified state, and
879// shouldn't be relied on to be consistent.
Misha Brukman10468d82005-04-21 22:55:34 +0000880bool
Reid Spencerc4e31532004-12-13 03:00:16 +0000881Linker::LinkModules(Module *Dest, Module *Src, std::string *ErrorMsg) {
Reid Spencer361e5132004-11-12 20:37:43 +0000882 assert(Dest != 0 && "Invalid Destination module");
883 assert(Src != 0 && "Invalid Source Module");
884
Chris Lattner7f3bd822007-01-29 00:21:34 +0000885 if (Dest->getDataLayout().empty()) {
886 if (!Src->getDataLayout().empty()) {
Chris Lattner78bddc32007-01-29 02:18:13 +0000887 Dest->setDataLayout(Src->getDataLayout());
Chris Lattner7f3bd822007-01-29 00:21:34 +0000888 } else {
889 std::string DataLayout;
Reid Spencer3ac38e92007-01-26 08:11:39 +0000890
Chris Lattner7f3bd822007-01-29 00:21:34 +0000891 if (Dest->getEndianness() == Module::AnyEndianness)
892 if (Src->getEndianness() == Module::BigEndian)
893 DataLayout.append("E");
894 else if (Src->getEndianness() == Module::LittleEndian)
895 DataLayout.append("e");
896 if (Dest->getPointerSize() == Module::AnyPointerSize)
897 if (Src->getPointerSize() == Module::Pointer64)
898 DataLayout.append(DataLayout.length() == 0 ? "p:64:64" : "-p:64:64");
899 else if (Src->getPointerSize() == Module::Pointer32)
900 DataLayout.append(DataLayout.length() == 0 ? "p:32:32" : "-p:32:32");
901 Dest->setDataLayout(DataLayout);
902 }
903 }
904
Reid Spencerd3ba7d92007-02-04 04:43:17 +0000905 // COpy the target triple from the source to dest if the dest's is empty
Chris Lattner7f3bd822007-01-29 00:21:34 +0000906 if (Dest->getTargetTriple().empty() && !Src->getTargetTriple().empty())
Chris Lattnerb7f59162004-12-10 20:26:15 +0000907 Dest->setTargetTriple(Src->getTargetTriple());
Chris Lattner7f3bd822007-01-29 00:21:34 +0000908
909 if (!Src->getDataLayout().empty() && !Dest->getDataLayout().empty() &&
910 Src->getDataLayout() != Dest->getDataLayout())
Reid Spencer3ac38e92007-01-26 08:11:39 +0000911 cerr << "WARNING: Linking two modules of different data layouts!\n";
Chris Lattnerb7f59162004-12-10 20:26:15 +0000912 if (!Src->getTargetTriple().empty() &&
913 Dest->getTargetTriple() != Src->getTargetTriple())
Bill Wendlingf3baad32006-12-07 01:30:32 +0000914 cerr << "WARNING: Linking two modules of different target triples!\n";
Misha Brukman10468d82005-04-21 22:55:34 +0000915
Reid Spencerd3ba7d92007-02-04 04:43:17 +0000916 // Append the module inline asm string
Chris Lattner8ebd2162006-01-24 04:14:29 +0000917 if (!Src->getModuleInlineAsm().empty()) {
918 if (Dest->getModuleInlineAsm().empty())
919 Dest->setModuleInlineAsm(Src->getModuleInlineAsm());
Chris Lattnerdd2d3fa2006-01-23 23:08:37 +0000920 else
Chris Lattner8ebd2162006-01-24 04:14:29 +0000921 Dest->setModuleInlineAsm(Dest->getModuleInlineAsm()+"\n"+
922 Src->getModuleInlineAsm());
Chris Lattnerdd2d3fa2006-01-23 23:08:37 +0000923 }
924
Reid Spencer2c4f9a42004-11-25 09:29:44 +0000925 // Update the destination module's dependent libraries list with the libraries
Reid Spencer361e5132004-11-12 20:37:43 +0000926 // from the source module. There's no opportunity for duplicates here as the
927 // Module ensures that duplicate insertions are discarded.
928 Module::lib_iterator SI = Src->lib_begin();
929 Module::lib_iterator SE = Src->lib_end();
930 while ( SI != SE ) {
931 Dest->addLibrary(*SI);
932 ++SI;
933 }
934
935 // LinkTypes - Go through the symbol table of the Src module and see if any
936 // types are named in the src module that are not named in the Dst module.
937 // Make sure there are no type name conflicts.
Reid Spencerd3ba7d92007-02-04 04:43:17 +0000938 if (LinkTypes(Dest, Src, ErrorMsg))
939 return true;
Reid Spencer361e5132004-11-12 20:37:43 +0000940
941 // ValueMap - Mapping of values from what they used to be in Src, to what they
942 // are now in Dest.
Reid Spencer361e5132004-11-12 20:37:43 +0000943 std::map<const Value*, Value*> ValueMap;
944
945 // AppendingVars - Keep track of global variables in the destination module
946 // with appending linkage. After the module is linked together, they are
947 // appended and the module is rewritten.
Reid Spencer361e5132004-11-12 20:37:43 +0000948 std::multimap<std::string, GlobalVariable *> AppendingVars;
Chris Lattner44ab8ae2006-06-16 01:24:04 +0000949 for (Module::global_iterator I = Dest->global_begin(), E = Dest->global_end();
950 I != E; ++I) {
Reid Spencer361e5132004-11-12 20:37:43 +0000951 // Add all of the appending globals already in the Dest module to
952 // AppendingVars.
953 if (I->hasAppendingLinkage())
954 AppendingVars.insert(std::make_pair(I->getName(), I));
Reid Spencer361e5132004-11-12 20:37:43 +0000955 }
956
Reid Spencer361e5132004-11-12 20:37:43 +0000957 // Insert all of the globals in src into the Dest module... without linking
958 // initializers (which could refer to functions not yet mapped over).
Reid Spencer3aaaa0b2007-02-05 20:47:22 +0000959 if (LinkGlobals(Dest, Src, ValueMap, AppendingVars, ErrorMsg))
Reid Spencer361e5132004-11-12 20:37:43 +0000960 return true;
961
962 // Link the functions together between the two modules, without doing function
963 // bodies... this just adds external function prototypes to the Dest
964 // function... We do this so that when we begin processing function bodies,
965 // all of the global values that may be referenced are available in our
966 // ValueMap.
Reid Spencer3aaaa0b2007-02-05 20:47:22 +0000967 if (LinkFunctionProtos(Dest, Src, ValueMap, ErrorMsg))
Reid Spencer361e5132004-11-12 20:37:43 +0000968 return true;
969
970 // Update the initializers in the Dest module now that all globals that may
971 // be referenced are in Dest.
Reid Spencer361e5132004-11-12 20:37:43 +0000972 if (LinkGlobalInits(Dest, Src, ValueMap, ErrorMsg)) return true;
973
974 // Link in the function bodies that are defined in the source module into the
975 // DestModule. This consists basically of copying the function over and
976 // fixing up references to values.
Reid Spencer361e5132004-11-12 20:37:43 +0000977 if (LinkFunctionBodies(Dest, Src, ValueMap, ErrorMsg)) return true;
978
979 // If there were any appending global variables, link them together now.
Reid Spencer361e5132004-11-12 20:37:43 +0000980 if (LinkAppendingVars(Dest, AppendingVars, ErrorMsg)) return true;
981
982 // If the source library's module id is in the dependent library list of the
983 // destination library, remove it since that module is now linked in.
984 sys::Path modId;
Reid Spencerc9c04732005-07-07 23:21:43 +0000985 modId.set(Src->getModuleIdentifier());
Reid Spencer361e5132004-11-12 20:37:43 +0000986 if (!modId.isEmpty())
987 Dest->removeLibrary(modId.getBasename());
988
989 return false;
990}
991
992// vim: sw=2