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Mikhail Glushenkovc834bbf2009-03-03 10:04:23 +00001//===- lib/Linker/LinkModules.cpp - Module Linker Implementation ----------===//
Misha Brukmanf976c852005-04-21 22:55:34 +00002//
John Criswellb576c942003-10-20 19:43:21 +00003// The LLVM Compiler Infrastructure
4//
Chris Lattner4ee451d2007-12-29 20:36:04 +00005// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
Misha Brukmanf976c852005-04-21 22:55:34 +00007//
John Criswellb576c942003-10-20 19:43:21 +00008//===----------------------------------------------------------------------===//
Chris Lattner52f7e902001-10-13 07:03:50 +00009//
10// This file implements the LLVM module linker.
11//
12// Specifically, this:
Chris Lattner8d2de8a2001-10-15 03:12:52 +000013// * Merges global variables between the two modules
14// * Uninit + Uninit = Init, Init + Uninit = Init, Init + Init = Error if !=
Chris Lattnerc8cc4cb2002-05-07 18:36:35 +000015// * Merges functions between two modules
Chris Lattner52f7e902001-10-13 07:03:50 +000016//
17//===----------------------------------------------------------------------===//
18
Reid Spencer7cc371a2004-11-14 23:27:04 +000019#include "llvm/Linker.h"
Chris Lattneradbc0b52003-11-20 18:23:14 +000020#include "llvm/Constants.h"
21#include "llvm/DerivedTypes.h"
Owen Andersonc9ab7bf2009-07-07 21:07:14 +000022#include "llvm/LLVMContext.h"
Chris Lattner5c377c52001-10-14 23:29:15 +000023#include "llvm/Module.h"
Reid Spencer78d033e2007-01-06 07:24:44 +000024#include "llvm/TypeSymbolTable.h"
Reid Spenceref9b9a72007-02-05 20:47:22 +000025#include "llvm/ValueSymbolTable.h"
Misha Brukman47b14a42004-07-29 17:30:56 +000026#include "llvm/Instructions.h"
Chris Lattneradbc0b52003-11-20 18:23:14 +000027#include "llvm/Assembly/Writer.h"
David Greene0fbf0e32010-01-05 01:27:59 +000028#include "llvm/Support/Debug.h"
Torok Edwinc25e7582009-07-11 20:10:48 +000029#include "llvm/Support/ErrorHandling.h"
Chris Lattner74382b72009-08-23 22:45:37 +000030#include "llvm/Support/raw_ostream.h"
Reid Spencer57a0efa2004-09-11 04:25:17 +000031#include "llvm/System/Path.h"
Chris Lattner62a81a12008-06-16 21:00:18 +000032#include "llvm/ADT/DenseMap.h"
Chris Lattnerf7703df2004-01-09 06:12:26 +000033using namespace llvm;
Brian Gaeked0fde302003-11-11 22:41:34 +000034
Chris Lattner5c377c52001-10-14 23:29:15 +000035// Error - Simple wrapper function to conditionally assign to E and return true.
36// This just makes error return conditions a little bit simpler...
Daniel Dunbar6e0d1cb2009-07-25 04:41:11 +000037static inline bool Error(std::string *E, const Twine &Message) {
38 if (E) *E = Message.str();
Chris Lattner5c377c52001-10-14 23:29:15 +000039 return true;
40}
41
John Criswell700867b2003-11-04 15:22:26 +000042// Function: ResolveTypes()
43//
44// Description:
45// Attempt to link the two specified types together.
46//
47// Inputs:
48// DestTy - The type to which we wish to resolve.
49// SrcTy - The original type which we want to resolve.
John Criswell700867b2003-11-04 15:22:26 +000050//
51// Outputs:
52// DestST - The symbol table in which the new type should be placed.
53//
54// Return value:
55// true - There is an error and the types cannot yet be linked.
56// false - No errors.
Chris Lattner4c00e532003-05-15 16:30:55 +000057//
Chris Lattnerbc1c82a2008-06-16 18:19:05 +000058static bool ResolveTypes(const Type *DestTy, const Type *SrcTy) {
Chris Lattnere76c57a2003-08-22 06:07:12 +000059 if (DestTy == SrcTy) return false; // If already equal, noop
Chris Lattnerbc1c82a2008-06-16 18:19:05 +000060 assert(DestTy && SrcTy && "Can't handle null types");
Chris Lattnere76c57a2003-08-22 06:07:12 +000061
Chris Lattnerbc1c82a2008-06-16 18:19:05 +000062 if (const OpaqueType *OT = dyn_cast<OpaqueType>(DestTy)) {
63 // Type _is_ in module, just opaque...
64 const_cast<OpaqueType*>(OT)->refineAbstractTypeTo(SrcTy);
65 } else if (const OpaqueType *OT = dyn_cast<OpaqueType>(SrcTy)) {
66 const_cast<OpaqueType*>(OT)->refineAbstractTypeTo(DestTy);
67 } else {
68 return true; // Cannot link types... not-equal and neither is opaque.
Chris Lattner4c00e532003-05-15 16:30:55 +000069 }
70 return false;
71}
72
Chris Lattner62a81a12008-06-16 21:00:18 +000073/// LinkerTypeMap - This implements a map of types that is stable
74/// even if types are resolved/refined to other types. This is not a general
75/// purpose map, it is specific to the linker's use.
76namespace {
77class LinkerTypeMap : public AbstractTypeUser {
78 typedef DenseMap<const Type*, PATypeHolder> TheMapTy;
79 TheMapTy TheMap;
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +000080
Chris Lattnerfc196f92008-06-16 23:06:51 +000081 LinkerTypeMap(const LinkerTypeMap&); // DO NOT IMPLEMENT
82 void operator=(const LinkerTypeMap&); // DO NOT IMPLEMENT
83public:
84 LinkerTypeMap() {}
85 ~LinkerTypeMap() {
Chris Lattner62a81a12008-06-16 21:00:18 +000086 for (DenseMap<const Type*, PATypeHolder>::iterator I = TheMap.begin(),
87 E = TheMap.end(); I != E; ++I)
88 I->first->removeAbstractTypeUser(this);
89 }
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +000090
Chris Lattner62a81a12008-06-16 21:00:18 +000091 /// lookup - Return the value for the specified type or null if it doesn't
92 /// exist.
93 const Type *lookup(const Type *Ty) const {
94 TheMapTy::const_iterator I = TheMap.find(Ty);
95 if (I != TheMap.end()) return I->second;
96 return 0;
97 }
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +000098
Chris Lattner62a81a12008-06-16 21:00:18 +000099 /// erase - Remove the specified type, returning true if it was in the set.
100 bool erase(const Type *Ty) {
101 if (!TheMap.erase(Ty))
102 return false;
103 if (Ty->isAbstract())
104 Ty->removeAbstractTypeUser(this);
105 return true;
106 }
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000107
Chris Lattner62a81a12008-06-16 21:00:18 +0000108 /// insert - This returns true if the pointer was new to the set, false if it
109 /// was already in the set.
110 bool insert(const Type *Src, const Type *Dst) {
Dan Gohman6b345ee2008-07-07 17:46:23 +0000111 if (!TheMap.insert(std::make_pair(Src, PATypeHolder(Dst))).second)
Chris Lattner62a81a12008-06-16 21:00:18 +0000112 return false; // Already in map.
113 if (Src->isAbstract())
114 Src->addAbstractTypeUser(this);
115 return true;
116 }
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000117
Chris Lattner62a81a12008-06-16 21:00:18 +0000118protected:
119 /// refineAbstractType - The callback method invoked when an abstract type is
120 /// resolved to another type. An object must override this method to update
121 /// its internal state to reference NewType instead of OldType.
122 ///
123 virtual void refineAbstractType(const DerivedType *OldTy,
124 const Type *NewTy) {
125 TheMapTy::iterator I = TheMap.find(OldTy);
126 const Type *DstTy = I->second;
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000127
Chris Lattner62a81a12008-06-16 21:00:18 +0000128 TheMap.erase(I);
129 if (OldTy->isAbstract())
130 OldTy->removeAbstractTypeUser(this);
131
132 // Don't reinsert into the map if the key is concrete now.
133 if (NewTy->isAbstract())
134 insert(NewTy, DstTy);
135 }
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000136
Chris Lattner62a81a12008-06-16 21:00:18 +0000137 /// The other case which AbstractTypeUsers must be aware of is when a type
138 /// makes the transition from being abstract (where it has clients on it's
139 /// AbstractTypeUsers list) to concrete (where it does not). This method
140 /// notifies ATU's when this occurs for a type.
141 virtual void typeBecameConcrete(const DerivedType *AbsTy) {
142 TheMap.erase(AbsTy);
143 AbsTy->removeAbstractTypeUser(this);
144 }
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000145
Chris Lattner62a81a12008-06-16 21:00:18 +0000146 // for debugging...
147 virtual void dump() const {
David Greene0fbf0e32010-01-05 01:27:59 +0000148 dbgs() << "AbstractTypeSet!\n";
Chris Lattner62a81a12008-06-16 21:00:18 +0000149 }
150};
151}
152
153
Chris Lattnere76c57a2003-08-22 06:07:12 +0000154// RecursiveResolveTypes - This is just like ResolveTypes, except that it
155// recurses down into derived types, merging the used types if the parent types
156// are compatible.
Chris Lattnera4477f92008-06-16 21:17:12 +0000157static bool RecursiveResolveTypesI(const Type *DstTy, const Type *SrcTy,
Chris Lattner62a81a12008-06-16 21:00:18 +0000158 LinkerTypeMap &Pointers) {
Chris Lattnera4477f92008-06-16 21:17:12 +0000159 if (DstTy == SrcTy) return false; // If already equal, noop
Misha Brukmanf976c852005-04-21 22:55:34 +0000160
Chris Lattnere76c57a2003-08-22 06:07:12 +0000161 // If we found our opaque type, resolve it now!
Chris Lattnera4477f92008-06-16 21:17:12 +0000162 if (isa<OpaqueType>(DstTy) || isa<OpaqueType>(SrcTy))
163 return ResolveTypes(DstTy, SrcTy);
Misha Brukmanf976c852005-04-21 22:55:34 +0000164
Chris Lattnere76c57a2003-08-22 06:07:12 +0000165 // Two types cannot be resolved together if they are of different primitive
166 // type. For example, we cannot resolve an int to a float.
Chris Lattnera4477f92008-06-16 21:17:12 +0000167 if (DstTy->getTypeID() != SrcTy->getTypeID()) return true;
Chris Lattnere76c57a2003-08-22 06:07:12 +0000168
Chris Lattner56539652008-06-16 20:03:01 +0000169 // If neither type is abstract, then they really are just different types.
Chris Lattnera4477f92008-06-16 21:17:12 +0000170 if (!DstTy->isAbstract() && !SrcTy->isAbstract())
Chris Lattner56539652008-06-16 20:03:01 +0000171 return true;
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000172
Chris Lattnere76c57a2003-08-22 06:07:12 +0000173 // Otherwise, resolve the used type used by this derived type...
Chris Lattnera4477f92008-06-16 21:17:12 +0000174 switch (DstTy->getTypeID()) {
Chris Lattnerf6f4f7a2008-06-16 18:27:53 +0000175 default:
176 return true;
Chris Lattnere76c57a2003-08-22 06:07:12 +0000177 case Type::FunctionTyID: {
Chris Lattnera4477f92008-06-16 21:17:12 +0000178 const FunctionType *DstFT = cast<FunctionType>(DstTy);
179 const FunctionType *SrcFT = cast<FunctionType>(SrcTy);
Chris Lattner9ddf2c82008-06-16 19:55:40 +0000180 if (DstFT->isVarArg() != SrcFT->isVarArg() ||
181 DstFT->getNumContainedTypes() != SrcFT->getNumContainedTypes())
Chris Lattner43f4ba82003-08-22 19:12:55 +0000182 return true;
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000183
Chris Lattnera4477f92008-06-16 21:17:12 +0000184 // Use TypeHolder's so recursive resolution won't break us.
185 PATypeHolder ST(SrcFT), DT(DstFT);
186 for (unsigned i = 0, e = DstFT->getNumContainedTypes(); i != e; ++i) {
187 const Type *SE = ST->getContainedType(i), *DE = DT->getContainedType(i);
188 if (SE != DE && RecursiveResolveTypesI(DE, SE, Pointers))
Chris Lattnere76c57a2003-08-22 06:07:12 +0000189 return true;
Chris Lattnera4477f92008-06-16 21:17:12 +0000190 }
Chris Lattnere76c57a2003-08-22 06:07:12 +0000191 return false;
192 }
193 case Type::StructTyID: {
Chris Lattnera4477f92008-06-16 21:17:12 +0000194 const StructType *DstST = cast<StructType>(DstTy);
195 const StructType *SrcST = cast<StructType>(SrcTy);
Chris Lattner9ddf2c82008-06-16 19:55:40 +0000196 if (DstST->getNumContainedTypes() != SrcST->getNumContainedTypes())
Chris Lattnerf6f4f7a2008-06-16 18:27:53 +0000197 return true;
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000198
Chris Lattnera4477f92008-06-16 21:17:12 +0000199 PATypeHolder ST(SrcST), DT(DstST);
200 for (unsigned i = 0, e = DstST->getNumContainedTypes(); i != e; ++i) {
201 const Type *SE = ST->getContainedType(i), *DE = DT->getContainedType(i);
202 if (SE != DE && RecursiveResolveTypesI(DE, SE, Pointers))
Chris Lattnere76c57a2003-08-22 06:07:12 +0000203 return true;
Chris Lattnera4477f92008-06-16 21:17:12 +0000204 }
Chris Lattnere76c57a2003-08-22 06:07:12 +0000205 return false;
206 }
207 case Type::ArrayTyID: {
Chris Lattnera4477f92008-06-16 21:17:12 +0000208 const ArrayType *DAT = cast<ArrayType>(DstTy);
209 const ArrayType *SAT = cast<ArrayType>(SrcTy);
Chris Lattnere76c57a2003-08-22 06:07:12 +0000210 if (DAT->getNumElements() != SAT->getNumElements()) return true;
Chris Lattnere3092c92003-08-23 21:25:54 +0000211 return RecursiveResolveTypesI(DAT->getElementType(), SAT->getElementType(),
Chris Lattnerbc1c82a2008-06-16 18:19:05 +0000212 Pointers);
Chris Lattnere76c57a2003-08-22 06:07:12 +0000213 }
Chris Lattnerf6f4f7a2008-06-16 18:27:53 +0000214 case Type::VectorTyID: {
Chris Lattnera4477f92008-06-16 21:17:12 +0000215 const VectorType *DVT = cast<VectorType>(DstTy);
216 const VectorType *SVT = cast<VectorType>(SrcTy);
Chris Lattnerf6f4f7a2008-06-16 18:27:53 +0000217 if (DVT->getNumElements() != SVT->getNumElements()) return true;
218 return RecursiveResolveTypesI(DVT->getElementType(), SVT->getElementType(),
219 Pointers);
220 }
Chris Lattnere3092c92003-08-23 21:25:54 +0000221 case Type::PointerTyID: {
Chris Lattnera4477f92008-06-16 21:17:12 +0000222 const PointerType *DstPT = cast<PointerType>(DstTy);
223 const PointerType *SrcPT = cast<PointerType>(SrcTy);
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000224
Chris Lattner9ddf2c82008-06-16 19:55:40 +0000225 if (DstPT->getAddressSpace() != SrcPT->getAddressSpace())
226 return true;
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000227
Chris Lattnere3092c92003-08-23 21:25:54 +0000228 // If this is a pointer type, check to see if we have already seen it. If
229 // so, we are in a recursive branch. Cut off the search now. We cannot use
230 // an associative container for this search, because the type pointers (keys
Chris Lattner62a81a12008-06-16 21:00:18 +0000231 // in the container) change whenever types get resolved.
232 if (SrcPT->isAbstract())
233 if (const Type *ExistingDestTy = Pointers.lookup(SrcPT))
234 return ExistingDestTy != DstPT;
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000235
Chris Lattner62a81a12008-06-16 21:00:18 +0000236 if (DstPT->isAbstract())
237 if (const Type *ExistingSrcTy = Pointers.lookup(DstPT))
238 return ExistingSrcTy != SrcPT;
Chris Lattnere3092c92003-08-23 21:25:54 +0000239 // Otherwise, add the current pointers to the vector to stop recursion on
240 // this pair.
Chris Lattner62a81a12008-06-16 21:00:18 +0000241 if (DstPT->isAbstract())
242 Pointers.insert(DstPT, SrcPT);
243 if (SrcPT->isAbstract())
244 Pointers.insert(SrcPT, DstPT);
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000245
Chris Lattner9ddf2c82008-06-16 19:55:40 +0000246 return RecursiveResolveTypesI(DstPT->getElementType(),
247 SrcPT->getElementType(), Pointers);
Chris Lattnere3092c92003-08-23 21:25:54 +0000248 }
Misha Brukmanf976c852005-04-21 22:55:34 +0000249 }
Chris Lattnere76c57a2003-08-22 06:07:12 +0000250}
251
Chris Lattnera4477f92008-06-16 21:17:12 +0000252static bool RecursiveResolveTypes(const Type *DestTy, const Type *SrcTy) {
Chris Lattner62a81a12008-06-16 21:00:18 +0000253 LinkerTypeMap PointerTypes;
Chris Lattnerbc1c82a2008-06-16 18:19:05 +0000254 return RecursiveResolveTypesI(DestTy, SrcTy, PointerTypes);
Chris Lattnere3092c92003-08-23 21:25:54 +0000255}
256
Chris Lattnere76c57a2003-08-22 06:07:12 +0000257
Chris Lattner2c236f32001-11-03 05:18:24 +0000258// LinkTypes - Go through the symbol table of the Src module and see if any
259// types are named in the src module that are not named in the Dst module.
260// Make sure there are no type name conflicts.
Chris Lattner5c2d3352003-01-30 19:53:34 +0000261static bool LinkTypes(Module *Dest, const Module *Src, std::string *Err) {
Reid Spencer78d033e2007-01-06 07:24:44 +0000262 TypeSymbolTable *DestST = &Dest->getTypeSymbolTable();
263 const TypeSymbolTable *SrcST = &Src->getTypeSymbolTable();
Chris Lattner2c236f32001-11-03 05:18:24 +0000264
265 // Look for a type plane for Type's...
Reid Spencer78d033e2007-01-06 07:24:44 +0000266 TypeSymbolTable::const_iterator TI = SrcST->begin();
267 TypeSymbolTable::const_iterator TE = SrcST->end();
Reid Spencer567bc2c2004-05-25 08:52:20 +0000268 if (TI == TE) return false; // No named types, do nothing.
Chris Lattner2c236f32001-11-03 05:18:24 +0000269
Misha Brukmancf00c4a2003-10-10 17:57:28 +0000270 // Some types cannot be resolved immediately because they depend on other
271 // types being resolved to each other first. This contains a list of types we
272 // are waiting to recheck.
Chris Lattner4c00e532003-05-15 16:30:55 +0000273 std::vector<std::string> DelayedTypesToResolve;
274
Reid Spencer567bc2c2004-05-25 08:52:20 +0000275 for ( ; TI != TE; ++TI ) {
276 const std::string &Name = TI->first;
Reid Spencerc28a2242004-07-04 11:52:49 +0000277 const Type *RHS = TI->second;
Chris Lattner2c236f32001-11-03 05:18:24 +0000278
Chris Lattnerbc1c82a2008-06-16 18:19:05 +0000279 // Check to see if this type name is already in the dest module.
Reid Spencer78d033e2007-01-06 07:24:44 +0000280 Type *Entry = DestST->lookup(Name);
Chris Lattner2f6bb2b2003-01-30 20:53:43 +0000281
Chris Lattnerbc1c82a2008-06-16 18:19:05 +0000282 // If the name is just in the source module, bring it over to the dest.
283 if (Entry == 0) {
284 if (!Name.empty())
285 DestST->insert(Name, const_cast<Type*>(RHS));
286 } else if (ResolveTypes(Entry, RHS)) {
Chris Lattner4c00e532003-05-15 16:30:55 +0000287 // They look different, save the types 'till later to resolve.
288 DelayedTypesToResolve.push_back(Name);
Chris Lattner2c236f32001-11-03 05:18:24 +0000289 }
290 }
Chris Lattner4c00e532003-05-15 16:30:55 +0000291
292 // Iteratively resolve types while we can...
293 while (!DelayedTypesToResolve.empty()) {
294 // Loop over all of the types, attempting to resolve them if possible...
295 unsigned OldSize = DelayedTypesToResolve.size();
296
Chris Lattnere76c57a2003-08-22 06:07:12 +0000297 // Try direct resolution by name...
Chris Lattner4c00e532003-05-15 16:30:55 +0000298 for (unsigned i = 0; i != DelayedTypesToResolve.size(); ++i) {
299 const std::string &Name = DelayedTypesToResolve[i];
Reid Spencer78d033e2007-01-06 07:24:44 +0000300 Type *T1 = SrcST->lookup(Name);
301 Type *T2 = DestST->lookup(Name);
Chris Lattnerbc1c82a2008-06-16 18:19:05 +0000302 if (!ResolveTypes(T2, T1)) {
Chris Lattner4c00e532003-05-15 16:30:55 +0000303 // We are making progress!
304 DelayedTypesToResolve.erase(DelayedTypesToResolve.begin()+i);
305 --i;
306 }
307 }
308
309 // Did we not eliminate any types?
310 if (DelayedTypesToResolve.size() == OldSize) {
Chris Lattnere76c57a2003-08-22 06:07:12 +0000311 // Attempt to resolve subelements of types. This allows us to merge these
312 // two types: { int* } and { opaque* }
Chris Lattner4c00e532003-05-15 16:30:55 +0000313 for (unsigned i = 0, e = DelayedTypesToResolve.size(); i != e; ++i) {
314 const std::string &Name = DelayedTypesToResolve[i];
Chris Lattnera4477f92008-06-16 21:17:12 +0000315 if (!RecursiveResolveTypes(SrcST->lookup(Name), DestST->lookup(Name))) {
Chris Lattnere76c57a2003-08-22 06:07:12 +0000316 // We are making progress!
317 DelayedTypesToResolve.erase(DelayedTypesToResolve.begin()+i);
Misha Brukmanf976c852005-04-21 22:55:34 +0000318
Chris Lattnere76c57a2003-08-22 06:07:12 +0000319 // Go back to the main loop, perhaps we can resolve directly by name
320 // now...
321 break;
322 }
Chris Lattner4c00e532003-05-15 16:30:55 +0000323 }
Chris Lattnere76c57a2003-08-22 06:07:12 +0000324
325 // If we STILL cannot resolve the types, then there is something wrong.
Chris Lattnere76c57a2003-08-22 06:07:12 +0000326 if (DelayedTypesToResolve.size() == OldSize) {
Chris Lattneraeb18ce2003-10-21 22:46:38 +0000327 // Remove the symbol name from the destination.
328 DelayedTypesToResolve.pop_back();
Chris Lattnere76c57a2003-08-22 06:07:12 +0000329 }
Chris Lattner4c00e532003-05-15 16:30:55 +0000330 }
331 }
332
333
Chris Lattner2c236f32001-11-03 05:18:24 +0000334 return false;
335}
336
Chris Lattner0bb87572008-07-14 05:52:33 +0000337#ifndef NDEBUG
Chris Lattner5c2d3352003-01-30 19:53:34 +0000338static void PrintMap(const std::map<const Value*, Value*> &M) {
339 for (std::map<const Value*, Value*>::const_iterator I = M.begin(), E =M.end();
Chris Lattner2d3e8bb2001-11-03 03:27:29 +0000340 I != E; ++I) {
David Greene0fbf0e32010-01-05 01:27:59 +0000341 dbgs() << " Fr: " << (void*)I->first << " ";
Chris Lattner87182ae2002-04-07 22:31:23 +0000342 I->first->dump();
David Greene0fbf0e32010-01-05 01:27:59 +0000343 dbgs() << " To: " << (void*)I->second << " ";
Chris Lattner87182ae2002-04-07 22:31:23 +0000344 I->second->dump();
David Greene0fbf0e32010-01-05 01:27:59 +0000345 dbgs() << "\n";
Chris Lattner2d3e8bb2001-11-03 03:27:29 +0000346 }
347}
Chris Lattner0bb87572008-07-14 05:52:33 +0000348#endif
Chris Lattner2d3e8bb2001-11-03 03:27:29 +0000349
350
Reid Spencer619f0242007-02-04 04:43:17 +0000351// RemapOperand - Use ValueMap to convert constants from one module to another.
Chris Lattner5c2d3352003-01-30 19:53:34 +0000352static Value *RemapOperand(const Value *In,
Chris Lattner2a749d32009-11-01 02:46:39 +0000353 std::map<const Value*, Value*> &ValueMap) {
Chris Lattner0033baf2004-11-16 17:12:38 +0000354 std::map<const Value*,Value*>::const_iterator I = ValueMap.find(In);
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000355 if (I != ValueMap.end())
Reid Spenceref9b9a72007-02-05 20:47:22 +0000356 return I->second;
Chris Lattner5c377c52001-10-14 23:29:15 +0000357
Reid Spencer619f0242007-02-04 04:43:17 +0000358 // Check to see if it's a constant that we are interested in transforming.
Chris Lattner620fd682006-06-01 19:14:22 +0000359 Value *Result = 0;
Chris Lattner18961502002-06-25 16:12:52 +0000360 if (const Constant *CPV = dyn_cast<Constant>(In)) {
Chris Lattnerde512b52004-02-15 05:55:15 +0000361 if ((!isa<DerivedType>(CPV->getType()) && !isa<ConstantExpr>(CPV)) ||
Reid Spencera54b7cb2007-01-12 07:05:14 +0000362 isa<ConstantInt>(CPV) || isa<ConstantAggregateZero>(CPV))
Chris Lattner0033baf2004-11-16 17:12:38 +0000363 return const_cast<Constant*>(CPV); // Simple constants stay identical.
Chris Lattner8d2de8a2001-10-15 03:12:52 +0000364
Chris Lattner18961502002-06-25 16:12:52 +0000365 if (const ConstantArray *CPA = dyn_cast<ConstantArray>(CPV)) {
Alkis Evlogimenoscc7ba492004-08-04 08:08:13 +0000366 std::vector<Constant*> Operands(CPA->getNumOperands());
367 for (unsigned i = 0, e = CPA->getNumOperands(); i != e; ++i)
Chris Lattner2a749d32009-11-01 02:46:39 +0000368 Operands[i] =cast<Constant>(RemapOperand(CPA->getOperand(i), ValueMap));
369 Result = ConstantArray::get(cast<ArrayType>(CPA->getType()), Operands);
Chris Lattner18961502002-06-25 16:12:52 +0000370 } else if (const ConstantStruct *CPS = dyn_cast<ConstantStruct>(CPV)) {
Alkis Evlogimenoscc7ba492004-08-04 08:08:13 +0000371 std::vector<Constant*> Operands(CPS->getNumOperands());
372 for (unsigned i = 0, e = CPS->getNumOperands(); i != e; ++i)
Chris Lattner2a749d32009-11-01 02:46:39 +0000373 Operands[i] =cast<Constant>(RemapOperand(CPS->getOperand(i), ValueMap));
374 Result = ConstantStruct::get(cast<StructType>(CPS->getType()), Operands);
Chris Lattnerb976e662004-10-16 18:08:06 +0000375 } else if (isa<ConstantPointerNull>(CPV) || isa<UndefValue>(CPV)) {
Chris Lattner18961502002-06-25 16:12:52 +0000376 Result = const_cast<Constant*>(CPV);
Reid Spencer9d6565a2007-02-15 02:26:10 +0000377 } else if (const ConstantVector *CP = dyn_cast<ConstantVector>(CPV)) {
Chris Lattnera88eb922006-01-19 23:15:58 +0000378 std::vector<Constant*> Operands(CP->getNumOperands());
379 for (unsigned i = 0, e = CP->getNumOperands(); i != e; ++i)
Chris Lattner2a749d32009-11-01 02:46:39 +0000380 Operands[i] = cast<Constant>(RemapOperand(CP->getOperand(i), ValueMap));
Owen Andersonaf7ec972009-07-28 21:19:26 +0000381 Result = ConstantVector::get(Operands);
Chris Lattner6cdf1972002-07-18 00:13:08 +0000382 } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CPV)) {
Chris Lattner27d67212006-07-14 22:21:31 +0000383 std::vector<Constant*> Ops;
384 for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i)
Chris Lattner2a749d32009-11-01 02:46:39 +0000385 Ops.push_back(cast<Constant>(RemapOperand(CE->getOperand(i),ValueMap)));
Chris Lattner27d67212006-07-14 22:21:31 +0000386 Result = CE->getWithOperands(Ops);
Chris Lattner2a749d32009-11-01 02:46:39 +0000387 } else if (const BlockAddress *CE = dyn_cast<BlockAddress>(CPV)) {
388 Result = BlockAddress::get(
389 cast<Function>(RemapOperand(CE->getFunction(), ValueMap)),
390 CE->getBasicBlock());
Chris Lattner8d2de8a2001-10-15 03:12:52 +0000391 } else {
Chris Lattner0bb87572008-07-14 05:52:33 +0000392 assert(!isa<GlobalValue>(CPV) && "Unmapped global?");
Torok Edwinc23197a2009-07-14 16:55:14 +0000393 llvm_unreachable("Unknown type of derived type constant value!");
Chris Lattner8d2de8a2001-10-15 03:12:52 +0000394 }
Victor Hernandez2c9ad132010-01-27 00:30:42 +0000395 } else if (const MDNode *MD = dyn_cast<MDNode>(In)) {
396 if (MD->isFunctionLocal()) {
397 SmallVector<Value*, 4> Elts;
398 for (unsigned i = 0, e = MD->getNumOperands(); i != e; ++i) {
399 Value *Op = MD->getOperand(i);
400 // LinkFunctionBody() already handled non-argument values.
401 Elts.push_back(isa<Argument>(Op) ? RemapOperand(Op, ValueMap) : Op);
402 }
403 Result = MDNode::get(In->getContext(), Elts.data(), MD->getNumOperands());
404 } else {
405 Result = const_cast<Value*>(In);
406 }
407 } else if (isa<MDString>(In)) {
Devang Patelfaf8fa52009-09-03 20:35:57 +0000408 Result = const_cast<Value*>(In);
Chris Lattner620fd682006-06-01 19:14:22 +0000409 } else if (isa<InlineAsm>(In)) {
410 Result = const_cast<Value*>(In);
411 }
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000412
Reid Spencer619f0242007-02-04 04:43:17 +0000413 // Cache the mapping in our local map structure
Chris Lattner620fd682006-06-01 19:14:22 +0000414 if (Result) {
Anton Korobeynikov817bf2a2008-03-10 22:36:08 +0000415 ValueMap[In] = Result;
Chris Lattner8d2de8a2001-10-15 03:12:52 +0000416 return Result;
417 }
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000418
Chris Lattner0bb87572008-07-14 05:52:33 +0000419#ifndef NDEBUG
David Greene0fbf0e32010-01-05 01:27:59 +0000420 dbgs() << "LinkModules ValueMap: \n";
Chris Lattner0033baf2004-11-16 17:12:38 +0000421 PrintMap(ValueMap);
Chris Lattner2d3e8bb2001-11-03 03:27:29 +0000422
David Greene0fbf0e32010-01-05 01:27:59 +0000423 dbgs() << "Couldn't remap value: " << (void*)In << " " << *In << "\n";
Torok Edwinc23197a2009-07-14 16:55:14 +0000424 llvm_unreachable("Couldn't remap value!");
Chris Lattner0bb87572008-07-14 05:52:33 +0000425#endif
Chris Lattner8d2de8a2001-10-15 03:12:52 +0000426 return 0;
Chris Lattner5c377c52001-10-14 23:29:15 +0000427}
428
Reid Spencer8bef0372007-02-04 04:29:21 +0000429/// ForceRenaming - The LLVM SymbolTable class autorenames globals that conflict
430/// in the symbol table. This is good for all clients except for us. Go
431/// through the trouble to force this back.
Chris Lattnerc0036282004-08-04 07:05:54 +0000432static void ForceRenaming(GlobalValue *GV, const std::string &Name) {
433 assert(GV->getName() != Name && "Can't force rename to self");
Reid Spenceref9b9a72007-02-05 20:47:22 +0000434 ValueSymbolTable &ST = GV->getParent()->getValueSymbolTable();
Chris Lattnerc0036282004-08-04 07:05:54 +0000435
436 // If there is a conflict, rename the conflict.
Chris Lattner33f29492007-02-11 00:39:38 +0000437 if (GlobalValue *ConflictGV = cast_or_null<GlobalValue>(ST.lookup(Name))) {
Rafael Espindolabb46f522009-01-15 20:18:42 +0000438 assert(ConflictGV->hasLocalLinkage() &&
Reid Spenceref9b9a72007-02-05 20:47:22 +0000439 "Not conflicting with a static global, should link instead!");
Chris Lattner33f29492007-02-11 00:39:38 +0000440 GV->takeName(ConflictGV);
441 ConflictGV->setName(Name); // This will cause ConflictGV to get renamed
Reid Spenceref9b9a72007-02-05 20:47:22 +0000442 assert(ConflictGV->getName() != Name && "ForceRenaming didn't work");
Chris Lattner33f29492007-02-11 00:39:38 +0000443 } else {
444 GV->setName(Name); // Force the name back
Reid Spenceref9b9a72007-02-05 20:47:22 +0000445 }
Reid Spenceref9b9a72007-02-05 20:47:22 +0000446}
Reid Spencer8bef0372007-02-04 04:29:21 +0000447
Reid Spenceref9b9a72007-02-05 20:47:22 +0000448/// CopyGVAttributes - copy additional attributes (those not needed to construct
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000449/// a GlobalValue) from the SrcGV to the DestGV.
Reid Spenceref9b9a72007-02-05 20:47:22 +0000450static void CopyGVAttributes(GlobalValue *DestGV, const GlobalValue *SrcGV) {
Duncan Sands28c3cff2008-05-26 19:58:59 +0000451 // Use the maximum alignment, rather than just copying the alignment of SrcGV.
452 unsigned Alignment = std::max(DestGV->getAlignment(), SrcGV->getAlignment());
453 DestGV->copyAttributesFrom(SrcGV);
454 DestGV->setAlignment(Alignment);
Chris Lattnerc0036282004-08-04 07:05:54 +0000455}
456
Chris Lattneraee38ea2004-12-03 22:18:41 +0000457/// GetLinkageResult - This analyzes the two global values and determines what
458/// the result will look like in the destination module. In particular, it
459/// computes the resultant linkage type, computes whether the global in the
460/// source should be copied over to the destination (replacing the existing
Anton Korobeynikov9cd3ccf2007-04-29 20:56:48 +0000461/// one), and computes whether this linkage is an error or not. It also performs
462/// visibility checks: we cannot link together two symbols with different
463/// visibilities.
Anton Korobeynikov968e39a2008-03-10 22:33:53 +0000464static bool GetLinkageResult(GlobalValue *Dest, const GlobalValue *Src,
Chris Lattneraee38ea2004-12-03 22:18:41 +0000465 GlobalValue::LinkageTypes &LT, bool &LinkFromSrc,
466 std::string *Err) {
Rafael Espindolabb46f522009-01-15 20:18:42 +0000467 assert((!Dest || !Src->hasLocalLinkage()) &&
Chris Lattneraee38ea2004-12-03 22:18:41 +0000468 "If Src has internal linkage, Dest shouldn't be set!");
469 if (!Dest) {
470 // Linking something to nothing.
471 LinkFromSrc = true;
472 LT = Src->getLinkage();
Reid Spencer5cbf9852007-01-30 20:08:39 +0000473 } else if (Src->isDeclaration()) {
Anton Korobeynikov2b48ef02008-03-10 22:33:22 +0000474 // If Src is external or if both Src & Dest are external.. Just link the
Chris Lattneraee38ea2004-12-03 22:18:41 +0000475 // external globals, we aren't adding anything.
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000476 if (Src->hasDLLImportLinkage()) {
Anton Korobeynikov78ee7b72006-12-01 00:25:12 +0000477 // If one of GVs has DLLImport linkage, result should be dllimport'ed.
Reid Spencer5cbf9852007-01-30 20:08:39 +0000478 if (Dest->isDeclaration()) {
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000479 LinkFromSrc = true;
480 LT = Src->getLinkage();
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000481 }
Andrew Lenharth8753c442006-12-15 17:35:32 +0000482 } else if (Dest->hasExternalWeakLinkage()) {
Duncan Sands667d4b82009-03-07 15:45:40 +0000483 // If the Dest is weak, use the source linkage.
Andrew Lenharth8753c442006-12-15 17:35:32 +0000484 LinkFromSrc = true;
485 LT = Src->getLinkage();
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000486 } else {
487 LinkFromSrc = false;
488 LT = Dest->getLinkage();
489 }
Reid Spencer5cbf9852007-01-30 20:08:39 +0000490 } else if (Dest->isDeclaration() && !Dest->hasDLLImportLinkage()) {
Chris Lattneraee38ea2004-12-03 22:18:41 +0000491 // If Dest is external but Src is not:
492 LinkFromSrc = true;
493 LT = Src->getLinkage();
494 } else if (Src->hasAppendingLinkage() || Dest->hasAppendingLinkage()) {
495 if (Src->getLinkage() != Dest->getLinkage())
496 return Error(Err, "Linking globals named '" + Src->getName() +
497 "': can only link appending global with another appending global!");
498 LinkFromSrc = true; // Special cased.
499 LT = Src->getLinkage();
Duncan Sandsa05ef5e2009-03-08 13:35:23 +0000500 } else if (Src->isWeakForLinker()) {
Dale Johannesenaafce772008-05-14 20:12:51 +0000501 // At this point we know that Dest has LinkOnce, External*, Weak, Common,
502 // or DLL* linkage.
Chris Lattner266c7bb2009-04-13 05:44:34 +0000503 if (Dest->hasExternalWeakLinkage() ||
504 Dest->hasAvailableExternallyLinkage() ||
505 (Dest->hasLinkOnceLinkage() &&
506 (Src->hasWeakLinkage() || Src->hasCommonLinkage()))) {
Chris Lattneraee38ea2004-12-03 22:18:41 +0000507 LinkFromSrc = true;
508 LT = Src->getLinkage();
509 } else {
510 LinkFromSrc = false;
511 LT = Dest->getLinkage();
512 }
Duncan Sandsa05ef5e2009-03-08 13:35:23 +0000513 } else if (Dest->isWeakForLinker()) {
Anton Korobeynikov78ee7b72006-12-01 00:25:12 +0000514 // At this point we know that Src has External* or DLL* linkage.
515 if (Src->hasExternalWeakLinkage()) {
516 LinkFromSrc = false;
517 LT = Dest->getLinkage();
518 } else {
519 LinkFromSrc = true;
520 LT = GlobalValue::ExternalLinkage;
521 }
Chris Lattneraee38ea2004-12-03 22:18:41 +0000522 } else {
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000523 assert((Dest->hasExternalLinkage() ||
524 Dest->hasDLLImportLinkage() ||
Anton Korobeynikov78ee7b72006-12-01 00:25:12 +0000525 Dest->hasDLLExportLinkage() ||
526 Dest->hasExternalWeakLinkage()) &&
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000527 (Src->hasExternalLinkage() ||
528 Src->hasDLLImportLinkage() ||
Anton Korobeynikov78ee7b72006-12-01 00:25:12 +0000529 Src->hasDLLExportLinkage() ||
530 Src->hasExternalWeakLinkage()) &&
Chris Lattneraee38ea2004-12-03 22:18:41 +0000531 "Unexpected linkage type!");
Misha Brukmanf976c852005-04-21 22:55:34 +0000532 return Error(Err, "Linking globals named '" + Src->getName() +
Chris Lattneraee38ea2004-12-03 22:18:41 +0000533 "': symbol multiply defined!");
534 }
Anton Korobeynikov9cd3ccf2007-04-29 20:56:48 +0000535
536 // Check visibility
537 if (Dest && Src->getVisibility() != Dest->getVisibility())
Chris Lattner97f8b092007-08-19 22:22:54 +0000538 if (!Src->isDeclaration() && !Dest->isDeclaration())
539 return Error(Err, "Linking globals named '" + Src->getName() +
540 "': symbols have different visibilities!");
Chris Lattneraee38ea2004-12-03 22:18:41 +0000541 return false;
542}
Chris Lattner5c377c52001-10-14 23:29:15 +0000543
Devang Patelab67e702009-08-11 18:01:24 +0000544// Insert all of the named mdnoes in Src into the Dest module.
545static void LinkNamedMDNodes(Module *Dest, Module *Src) {
546 for (Module::const_named_metadata_iterator I = Src->named_metadata_begin(),
547 E = Src->named_metadata_end(); I != E; ++I) {
548 const NamedMDNode *SrcNMD = I;
549 NamedMDNode *DestNMD = Dest->getNamedMetadata(SrcNMD->getName());
550 if (!DestNMD)
551 NamedMDNode::Create(SrcNMD, Dest);
552 else {
553 // Add Src elements into Dest node.
Chris Lattner5d0cacd2009-12-31 01:22:29 +0000554 for (unsigned i = 0, e = SrcNMD->getNumOperands(); i != e; ++i)
555 DestNMD->addOperand(SrcNMD->getOperand(i));
Devang Patelab67e702009-08-11 18:01:24 +0000556 }
557 }
558}
559
Chris Lattner5c377c52001-10-14 23:29:15 +0000560// LinkGlobals - Loop through the global variables in the src module and merge
Chris Lattner8166e6e2003-05-13 21:33:43 +0000561// them into the dest module.
Anton Korobeynikov968e39a2008-03-10 22:33:53 +0000562static bool LinkGlobals(Module *Dest, const Module *Src,
Chris Lattner5c2d3352003-01-30 19:53:34 +0000563 std::map<const Value*, Value*> &ValueMap,
Chris Lattner8166e6e2003-05-13 21:33:43 +0000564 std::multimap<std::string, GlobalVariable *> &AppendingVars,
Chris Lattner5c2d3352003-01-30 19:53:34 +0000565 std::string *Err) {
Chris Lattnerd1ec48c2008-07-14 06:49:45 +0000566 ValueSymbolTable &DestSymTab = Dest->getValueSymbolTable();
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000567
Chris Lattner5c377c52001-10-14 23:29:15 +0000568 // Loop over all of the globals in the src module, mapping them over as we go
Chris Lattner0bb87572008-07-14 05:52:33 +0000569 for (Module::const_global_iterator I = Src->global_begin(),
570 E = Src->global_end(); I != E; ++I) {
Anton Korobeynikov968e39a2008-03-10 22:33:53 +0000571 const GlobalVariable *SGV = I;
Anton Korobeynikov01f69392008-03-10 22:34:28 +0000572 GlobalValue *DGV = 0;
573
Chris Lattnerd1ec48c2008-07-14 06:49:45 +0000574 // Check to see if may have to link the global with the global, alias or
575 // function.
Rafael Espindolabb46f522009-01-15 20:18:42 +0000576 if (SGV->hasName() && !SGV->hasLocalLinkage())
Daniel Dunbar03d76512009-07-25 23:55:21 +0000577 DGV = cast_or_null<GlobalValue>(DestSymTab.lookup(SGV->getName()));
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000578
Chris Lattnerae1132d2008-07-14 06:52:19 +0000579 // If we found a global with the same name in the dest module, but it has
580 // internal linkage, we are really not doing any linkage here.
Rafael Espindolabb46f522009-01-15 20:18:42 +0000581 if (DGV && DGV->hasLocalLinkage())
Chris Lattnerae1132d2008-07-14 06:52:19 +0000582 DGV = 0;
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000583
Chris Lattnerd1ec48c2008-07-14 06:49:45 +0000584 // If types don't agree due to opaque types, try to resolve them.
585 if (DGV && DGV->getType() != SGV->getType())
586 RecursiveResolveTypes(SGV->getType(), DGV->getType());
Anton Korobeynikov01f69392008-03-10 22:34:28 +0000587
Dan Gohmanc3183292007-10-08 15:13:30 +0000588 assert((SGV->hasInitializer() || SGV->hasExternalWeakLinkage() ||
589 SGV->hasExternalLinkage() || SGV->hasDLLImportLinkage()) &&
Chris Lattner4ad02e72003-04-16 20:28:45 +0000590 "Global must either be external or have an initializer!");
591
Chris Lattnerb324bd72006-11-09 05:18:12 +0000592 GlobalValue::LinkageTypes NewLinkage = GlobalValue::InternalLinkage;
593 bool LinkFromSrc = false;
Chris Lattneraee38ea2004-12-03 22:18:41 +0000594 if (GetLinkageResult(DGV, SGV, NewLinkage, LinkFromSrc, Err))
595 return true;
Chris Lattner0fec08e2003-04-21 21:07:05 +0000596
Chris Lattner6157e382008-07-14 07:23:24 +0000597 if (DGV == 0) {
Chris Lattner4ad02e72003-04-16 20:28:45 +0000598 // No linking to be performed, simply create an identical version of the
599 // symbol over in the dest module... the initializer will be filled in
Chris Lattnerd1ec48c2008-07-14 06:49:45 +0000600 // later by LinkGlobalInits.
Chris Lattner2719bac2003-04-21 21:15:04 +0000601 GlobalVariable *NewDGV =
Owen Andersone9b11b42009-07-08 19:03:57 +0000602 new GlobalVariable(*Dest, SGV->getType()->getElementType(),
Chris Lattner2719bac2003-04-21 21:15:04 +0000603 SGV->isConstant(), SGV->getLinkage(), /*init*/0,
Owen Andersone9b11b42009-07-08 19:03:57 +0000604 SGV->getName(), 0, false,
Chris Lattnera534b0f2008-06-27 03:10:24 +0000605 SGV->getType()->getAddressSpace());
Reid Spencer471feac2007-02-04 04:30:33 +0000606 // Propagate alignment, visibility and section info.
Reid Spenceref9b9a72007-02-05 20:47:22 +0000607 CopyGVAttributes(NewDGV, SGV);
Andrew Lenharth5dfbaf12007-02-01 17:12:54 +0000608
Chris Lattner2719bac2003-04-21 21:15:04 +0000609 // If the LLVM runtime renamed the global, but it is an externally visible
610 // symbol, DGV must be an existing global with internal linkage. Rename
611 // it.
Rafael Espindolabb46f522009-01-15 20:18:42 +0000612 if (!NewDGV->hasLocalLinkage() && NewDGV->getName() != SGV->getName())
Chris Lattnerc0036282004-08-04 07:05:54 +0000613 ForceRenaming(NewDGV, SGV->getName());
Chris Lattner4ad02e72003-04-16 20:28:45 +0000614
Chris Lattner6157e382008-07-14 07:23:24 +0000615 // Make sure to remember this mapping.
Anton Korobeynikov817bf2a2008-03-10 22:36:08 +0000616 ValueMap[SGV] = NewDGV;
617
Chris Lattnerd1ec48c2008-07-14 06:49:45 +0000618 // Keep track that this is an appending variable.
Chris Lattner8166e6e2003-05-13 21:33:43 +0000619 if (SGV->hasAppendingLinkage())
Chris Lattner8166e6e2003-05-13 21:33:43 +0000620 AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV));
Chris Lattner6157e382008-07-14 07:23:24 +0000621 continue;
622 }
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000623
Chris Lattner6157e382008-07-14 07:23:24 +0000624 // If the visibilities of the symbols disagree and the destination is a
625 // prototype, take the visibility of its input.
626 if (DGV->isDeclaration())
627 DGV->setVisibility(SGV->getVisibility());
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000628
Chris Lattner6157e382008-07-14 07:23:24 +0000629 if (DGV->hasAppendingLinkage()) {
Chris Lattner8166e6e2003-05-13 21:33:43 +0000630 // No linking is performed yet. Just insert a new copy of the global, and
631 // keep track of the fact that it is an appending variable in the
632 // AppendingVars map. The name is cleared out so that no linkage is
633 // performed.
634 GlobalVariable *NewDGV =
Owen Andersone9b11b42009-07-08 19:03:57 +0000635 new GlobalVariable(*Dest, SGV->getType()->getElementType(),
Chris Lattner8166e6e2003-05-13 21:33:43 +0000636 SGV->isConstant(), SGV->getLinkage(), /*init*/0,
Owen Andersone9b11b42009-07-08 19:03:57 +0000637 "", 0, false,
Chris Lattnera534b0f2008-06-27 03:10:24 +0000638 SGV->getType()->getAddressSpace());
Chris Lattner8166e6e2003-05-13 21:33:43 +0000639
Anton Korobeynikov75c79152008-03-07 18:34:50 +0000640 // Set alignment allowing CopyGVAttributes merge it with alignment of SGV.
Reid Spenceref9b9a72007-02-05 20:47:22 +0000641 NewDGV->setAlignment(DGV->getAlignment());
Anton Korobeynikov75c79152008-03-07 18:34:50 +0000642 // Propagate alignment, section and visibility info.
Reid Spenceref9b9a72007-02-05 20:47:22 +0000643 CopyGVAttributes(NewDGV, SGV);
Andrew Lenharth5dfbaf12007-02-01 17:12:54 +0000644
Chris Lattner8166e6e2003-05-13 21:33:43 +0000645 // Make sure to remember this mapping...
Anton Korobeynikov817bf2a2008-03-10 22:36:08 +0000646 ValueMap[SGV] = NewDGV;
Chris Lattner8166e6e2003-05-13 21:33:43 +0000647
648 // Keep track that this is an appending variable...
649 AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV));
Chris Lattner6157e382008-07-14 07:23:24 +0000650 continue;
651 }
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000652
Chris Lattner6157e382008-07-14 07:23:24 +0000653 if (LinkFromSrc) {
654 if (isa<GlobalAlias>(DGV))
Anton Korobeynikov1438b9d2008-03-10 22:34:46 +0000655 return Error(Err, "Global-Alias Collision on '" + SGV->getName() +
656 "': symbol multiple defined");
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000657
Chris Lattnerd1ec48c2008-07-14 06:49:45 +0000658 // If the types don't match, and if we are to link from the source, nuke
659 // DGV and create a new one of the appropriate type. Note that the thing
660 // we are replacing may be a function (if a prototype, weak, etc) or a
661 // global variable.
662 GlobalVariable *NewDGV =
Owen Andersone9b11b42009-07-08 19:03:57 +0000663 new GlobalVariable(*Dest, SGV->getType()->getElementType(),
Owen Anderson3d29df32009-07-08 01:26:06 +0000664 SGV->isConstant(), NewLinkage, /*init*/0,
Owen Andersone9b11b42009-07-08 19:03:57 +0000665 DGV->getName(), 0, false,
Chris Lattnerd1ec48c2008-07-14 06:49:45 +0000666 SGV->getType()->getAddressSpace());
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000667
Chris Lattnerd1ec48c2008-07-14 06:49:45 +0000668 // Propagate alignment, section, and visibility info.
669 CopyGVAttributes(NewDGV, SGV);
Owen Andersonbaf3c402009-07-29 18:55:55 +0000670 DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewDGV,
Owen Andersonc9ab7bf2009-07-07 21:07:14 +0000671 DGV->getType()));
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000672
Chris Lattnerd1ec48c2008-07-14 06:49:45 +0000673 // DGV will conflict with NewDGV because they both had the same
674 // name. We must erase this now so ForceRenaming doesn't assert
675 // because DGV might not have internal linkage.
676 if (GlobalVariable *Var = dyn_cast<GlobalVariable>(DGV))
677 Var->eraseFromParent();
678 else
679 cast<Function>(DGV)->eraseFromParent();
Anton Korobeynikov968e39a2008-03-10 22:33:53 +0000680
Chris Lattnerd1ec48c2008-07-14 06:49:45 +0000681 // If the symbol table renamed the global, but it is an externally visible
682 // symbol, DGV must be an existing global with internal linkage. Rename.
Rafael Espindolabb46f522009-01-15 20:18:42 +0000683 if (NewDGV->getName() != SGV->getName() && !NewDGV->hasLocalLinkage())
Chris Lattnerd1ec48c2008-07-14 06:49:45 +0000684 ForceRenaming(NewDGV, SGV->getName());
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000685
Chris Lattner6157e382008-07-14 07:23:24 +0000686 // Inherit const as appropriate.
Chris Lattnerd1ec48c2008-07-14 06:49:45 +0000687 NewDGV->setConstant(SGV->isConstant());
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000688
Chris Lattner6157e382008-07-14 07:23:24 +0000689 // Make sure to remember this mapping.
690 ValueMap[SGV] = NewDGV;
691 continue;
Chris Lattner5c377c52001-10-14 23:29:15 +0000692 }
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000693
Chris Lattner6157e382008-07-14 07:23:24 +0000694 // Not "link from source", keep the one in the DestModule and remap the
695 // input onto it.
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000696
Chris Lattner6157e382008-07-14 07:23:24 +0000697 // Special case for const propagation.
698 if (GlobalVariable *DGVar = dyn_cast<GlobalVariable>(DGV))
699 if (DGVar->isDeclaration() && SGV->isConstant() && !DGVar->isConstant())
700 DGVar->setConstant(true);
701
Anton Korobeynikovd13726f2008-10-15 20:10:50 +0000702 // SGV is global, but DGV is alias.
703 if (isa<GlobalAlias>(DGV)) {
704 // The only valid mappings are:
705 // - SGV is external declaration, which is effectively a no-op.
706 // - SGV is weak, when we just need to throw SGV out.
Duncan Sandsa05ef5e2009-03-08 13:35:23 +0000707 if (!SGV->isDeclaration() && !SGV->isWeakForLinker())
Anton Korobeynikovd13726f2008-10-15 20:10:50 +0000708 return Error(Err, "Global-Alias Collision on '" + SGV->getName() +
709 "': symbol multiple defined");
710 }
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000711
Chris Lattner6157e382008-07-14 07:23:24 +0000712 // Set calculated linkage
713 DGV->setLinkage(NewLinkage);
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000714
Chris Lattner6157e382008-07-14 07:23:24 +0000715 // Make sure to remember this mapping...
Owen Andersonbaf3c402009-07-29 18:55:55 +0000716 ValueMap[SGV] = ConstantExpr::getBitCast(DGV, SGV->getType());
Chris Lattner5c377c52001-10-14 23:29:15 +0000717 }
718 return false;
719}
720
Anton Korobeynikov58887bc2008-03-05 22:22:46 +0000721static GlobalValue::LinkageTypes
722CalculateAliasLinkage(const GlobalValue *SGV, const GlobalValue *DGV) {
Duncan Sands667d4b82009-03-07 15:45:40 +0000723 GlobalValue::LinkageTypes SL = SGV->getLinkage();
724 GlobalValue::LinkageTypes DL = DGV->getLinkage();
725 if (SL == GlobalValue::ExternalLinkage || DL == GlobalValue::ExternalLinkage)
Anton Korobeynikov58887bc2008-03-05 22:22:46 +0000726 return GlobalValue::ExternalLinkage;
Duncan Sands667d4b82009-03-07 15:45:40 +0000727 else if (SL == GlobalValue::WeakAnyLinkage ||
728 DL == GlobalValue::WeakAnyLinkage)
729 return GlobalValue::WeakAnyLinkage;
730 else if (SL == GlobalValue::WeakODRLinkage ||
731 DL == GlobalValue::WeakODRLinkage)
732 return GlobalValue::WeakODRLinkage;
733 else if (SL == GlobalValue::InternalLinkage &&
734 DL == GlobalValue::InternalLinkage)
Anton Korobeynikov58887bc2008-03-05 22:22:46 +0000735 return GlobalValue::InternalLinkage;
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000736 else if (SL == GlobalValue::LinkerPrivateLinkage &&
737 DL == GlobalValue::LinkerPrivateLinkage)
738 return GlobalValue::LinkerPrivateLinkage;
Rafael Espindolabb46f522009-01-15 20:18:42 +0000739 else {
Duncan Sands667d4b82009-03-07 15:45:40 +0000740 assert (SL == GlobalValue::PrivateLinkage &&
741 DL == GlobalValue::PrivateLinkage && "Unexpected linkage type");
Rafael Espindolabb46f522009-01-15 20:18:42 +0000742 return GlobalValue::PrivateLinkage;
Anton Korobeynikov58887bc2008-03-05 22:22:46 +0000743 }
744}
745
Lauro Ramos Venancio31ed0fb2007-06-28 19:02:54 +0000746// LinkAlias - Loop through the alias in the src module and link them into the
Anton Korobeynikov58887bc2008-03-05 22:22:46 +0000747// dest module. We're assuming, that all functions/global variables were already
748// linked in.
Anton Korobeynikov4fb28732008-03-05 15:27:21 +0000749static bool LinkAlias(Module *Dest, const Module *Src,
750 std::map<const Value*, Value*> &ValueMap,
751 std::string *Err) {
Lauro Ramos Venancio31ed0fb2007-06-28 19:02:54 +0000752 // Loop over all alias in the src module
753 for (Module::const_alias_iterator I = Src->alias_begin(),
754 E = Src->alias_end(); I != E; ++I) {
Anton Korobeynikov58887bc2008-03-05 22:22:46 +0000755 const GlobalAlias *SGA = I;
756 const GlobalValue *SAliasee = SGA->getAliasedGlobal();
757 GlobalAlias *NewGA = NULL;
Lauro Ramos Venancio31ed0fb2007-06-28 19:02:54 +0000758
Anton Korobeynikov58887bc2008-03-05 22:22:46 +0000759 // Globals were already linked, thus we can just query ValueMap for variant
Anton Korobeynikovcaa8ae82008-05-10 14:41:43 +0000760 // of SAliasee in Dest.
Ted Kremenek58d5e052008-03-09 18:32:50 +0000761 std::map<const Value*,Value*>::const_iterator VMI = ValueMap.find(SAliasee);
762 assert(VMI != ValueMap.end() && "Aliasee not linked");
763 GlobalValue* DAliasee = cast<GlobalValue>(VMI->second);
Anton Korobeynikovcaa8ae82008-05-10 14:41:43 +0000764 GlobalValue* DGV = NULL;
Lauro Ramos Venancio31ed0fb2007-06-28 19:02:54 +0000765
Anton Korobeynikov58887bc2008-03-05 22:22:46 +0000766 // Try to find something 'similar' to SGA in destination module.
Rafael Espindolabb46f522009-01-15 20:18:42 +0000767 if (!DGV && !SGA->hasLocalLinkage()) {
Anton Korobeynikovcaa8ae82008-05-10 14:41:43 +0000768 DGV = Dest->getNamedAlias(SGA->getName());
Anton Korobeynikov4fb28732008-03-05 15:27:21 +0000769
Anton Korobeynikovcaa8ae82008-05-10 14:41:43 +0000770 // If types don't agree due to opaque types, try to resolve them.
771 if (DGV && DGV->getType() != SGA->getType())
Chris Lattner5ed2ba22008-07-10 01:09:33 +0000772 RecursiveResolveTypes(SGA->getType(), DGV->getType());
Anton Korobeynikovcaa8ae82008-05-10 14:41:43 +0000773 }
774
Rafael Espindolabb46f522009-01-15 20:18:42 +0000775 if (!DGV && !SGA->hasLocalLinkage()) {
Anton Korobeynikovcaa8ae82008-05-10 14:41:43 +0000776 DGV = Dest->getGlobalVariable(SGA->getName());
777
778 // If types don't agree due to opaque types, try to resolve them.
779 if (DGV && DGV->getType() != SGA->getType())
Chris Lattner5ed2ba22008-07-10 01:09:33 +0000780 RecursiveResolveTypes(SGA->getType(), DGV->getType());
Anton Korobeynikovcaa8ae82008-05-10 14:41:43 +0000781 }
782
Rafael Espindolabb46f522009-01-15 20:18:42 +0000783 if (!DGV && !SGA->hasLocalLinkage()) {
Anton Korobeynikovcaa8ae82008-05-10 14:41:43 +0000784 DGV = Dest->getFunction(SGA->getName());
785
786 // If types don't agree due to opaque types, try to resolve them.
787 if (DGV && DGV->getType() != SGA->getType())
Chris Lattner5ed2ba22008-07-10 01:09:33 +0000788 RecursiveResolveTypes(SGA->getType(), DGV->getType());
Anton Korobeynikovcaa8ae82008-05-10 14:41:43 +0000789 }
790
791 // No linking to be performed on internal stuff.
Rafael Espindolabb46f522009-01-15 20:18:42 +0000792 if (DGV && DGV->hasLocalLinkage())
Anton Korobeynikovcaa8ae82008-05-10 14:41:43 +0000793 DGV = NULL;
794
795 if (GlobalAlias *DGA = dyn_cast_or_null<GlobalAlias>(DGV)) {
796 // Types are known to be the same, check whether aliasees equal. As
Anton Korobeynikov58887bc2008-03-05 22:22:46 +0000797 // globals are already linked we just need query ValueMap to find the
798 // mapping.
799 if (DAliasee == DGA->getAliasedGlobal()) {
800 // This is just two copies of the same alias. Propagate linkage, if
801 // necessary.
802 DGA->setLinkage(CalculateAliasLinkage(SGA, DGA));
803
804 NewGA = DGA;
805 // Proceed to 'common' steps
806 } else
Anton Korobeynikov1438b9d2008-03-10 22:34:46 +0000807 return Error(Err, "Alias Collision on '" + SGA->getName()+
808 "': aliases have different aliasees");
Anton Korobeynikovcaa8ae82008-05-10 14:41:43 +0000809 } else if (GlobalVariable *DGVar = dyn_cast_or_null<GlobalVariable>(DGV)) {
Anton Korobeynikovf88bc652008-07-05 23:33:22 +0000810 // The only allowed way is to link alias with external declaration or weak
811 // symbol..
Duncan Sandsa05ef5e2009-03-08 13:35:23 +0000812 if (DGVar->isDeclaration() || DGVar->isWeakForLinker()) {
Anton Korobeynikoved61c0b2008-03-10 22:36:53 +0000813 // But only if aliasee is global too...
814 if (!isa<GlobalVariable>(DAliasee))
Anton Korobeynikovcaa8ae82008-05-10 14:41:43 +0000815 return Error(Err, "Global-Alias Collision on '" + SGA->getName() +
816 "': aliasee is not global variable");
Anton Korobeynikoved61c0b2008-03-10 22:36:53 +0000817
Anton Korobeynikov58887bc2008-03-05 22:22:46 +0000818 NewGA = new GlobalAlias(SGA->getType(), SGA->getLinkage(),
819 SGA->getName(), DAliasee, Dest);
820 CopyGVAttributes(NewGA, SGA);
821
822 // Any uses of DGV need to change to NewGA, with cast, if needed.
Anton Korobeynikovcaa8ae82008-05-10 14:41:43 +0000823 if (SGA->getType() != DGVar->getType())
Owen Andersonbaf3c402009-07-29 18:55:55 +0000824 DGVar->replaceAllUsesWith(ConstantExpr::getBitCast(NewGA,
Anton Korobeynikovcaa8ae82008-05-10 14:41:43 +0000825 DGVar->getType()));
Anton Korobeynikov58887bc2008-03-05 22:22:46 +0000826 else
Anton Korobeynikovcaa8ae82008-05-10 14:41:43 +0000827 DGVar->replaceAllUsesWith(NewGA);
Anton Korobeynikov58887bc2008-03-05 22:22:46 +0000828
Anton Korobeynikovcaa8ae82008-05-10 14:41:43 +0000829 // DGVar will conflict with NewGA because they both had the same
Anton Korobeynikov58887bc2008-03-05 22:22:46 +0000830 // name. We must erase this now so ForceRenaming doesn't assert
831 // because DGV might not have internal linkage.
Anton Korobeynikovcaa8ae82008-05-10 14:41:43 +0000832 DGVar->eraseFromParent();
Anton Korobeynikov58887bc2008-03-05 22:22:46 +0000833
834 // Proceed to 'common' steps
835 } else
Anton Korobeynikov1438b9d2008-03-10 22:34:46 +0000836 return Error(Err, "Global-Alias Collision on '" + SGA->getName() +
837 "': symbol multiple defined");
Anton Korobeynikovcaa8ae82008-05-10 14:41:43 +0000838 } else if (Function *DF = dyn_cast_or_null<Function>(DGV)) {
Anton Korobeynikovf88bc652008-07-05 23:33:22 +0000839 // The only allowed way is to link alias with external declaration or weak
840 // symbol...
Duncan Sandsa05ef5e2009-03-08 13:35:23 +0000841 if (DF->isDeclaration() || DF->isWeakForLinker()) {
Anton Korobeynikoved61c0b2008-03-10 22:36:53 +0000842 // But only if aliasee is function too...
843 if (!isa<Function>(DAliasee))
Anton Korobeynikovcaa8ae82008-05-10 14:41:43 +0000844 return Error(Err, "Function-Alias Collision on '" + SGA->getName() +
845 "': aliasee is not function");
Anton Korobeynikoved61c0b2008-03-10 22:36:53 +0000846
Anton Korobeynikovb5a4bd82008-03-05 23:08:16 +0000847 NewGA = new GlobalAlias(SGA->getType(), SGA->getLinkage(),
848 SGA->getName(), DAliasee, Dest);
849 CopyGVAttributes(NewGA, SGA);
850
851 // Any uses of DF need to change to NewGA, with cast, if needed.
852 if (SGA->getType() != DF->getType())
Owen Andersonbaf3c402009-07-29 18:55:55 +0000853 DF->replaceAllUsesWith(ConstantExpr::getBitCast(NewGA,
Anton Korobeynikovb5a4bd82008-03-05 23:08:16 +0000854 DF->getType()));
855 else
856 DF->replaceAllUsesWith(NewGA);
857
858 // DF will conflict with NewGA because they both had the same
859 // name. We must erase this now so ForceRenaming doesn't assert
860 // because DF might not have internal linkage.
861 DF->eraseFromParent();
862
863 // Proceed to 'common' steps
864 } else
Anton Korobeynikov1438b9d2008-03-10 22:34:46 +0000865 return Error(Err, "Function-Alias Collision on '" + SGA->getName() +
866 "': symbol multiple defined");
Anton Korobeynikov58887bc2008-03-05 22:22:46 +0000867 } else {
Anton Korobeynikovcaa8ae82008-05-10 14:41:43 +0000868 // No linking to be performed, simply create an identical version of the
869 // alias over in the dest module...
David Chisnall34722462010-01-09 16:27:31 +0000870 Constant *Aliasee = DAliasee;
871 // Fixup aliases to bitcasts. Note that aliases to GEPs are still broken
872 // by this, but aliases to GEPs are broken to a lot of other things, so
873 // it's less important.
874 if (SGA->getType() != DAliasee->getType())
875 Aliasee = ConstantExpr::getBitCast(DAliasee, SGA->getType());
Anton Korobeynikov58887bc2008-03-05 22:22:46 +0000876 NewGA = new GlobalAlias(SGA->getType(), SGA->getLinkage(),
David Chisnall34722462010-01-09 16:27:31 +0000877 SGA->getName(), Aliasee, Dest);
Anton Korobeynikov58887bc2008-03-05 22:22:46 +0000878 CopyGVAttributes(NewGA, SGA);
879
880 // Proceed to 'common' steps
881 }
882
883 assert(NewGA && "No alias was created in destination module!");
884
Anton Korobeynikovb8cdaf72008-03-10 22:36:35 +0000885 // If the symbol table renamed the alias, but it is an externally visible
Anton Korobeynikovcaa8ae82008-05-10 14:41:43 +0000886 // symbol, DGA must be an global value with internal linkage. Rename it.
Anton Korobeynikov58887bc2008-03-05 22:22:46 +0000887 if (NewGA->getName() != SGA->getName() &&
Rafael Espindolabb46f522009-01-15 20:18:42 +0000888 !NewGA->hasLocalLinkage())
Anton Korobeynikov58887bc2008-03-05 22:22:46 +0000889 ForceRenaming(NewGA, SGA->getName());
890
891 // Remember this mapping so uses in the source module get remapped
892 // later by RemapOperand.
Anton Korobeynikov817bf2a2008-03-10 22:36:08 +0000893 ValueMap[SGA] = NewGA;
Lauro Ramos Venancio31ed0fb2007-06-28 19:02:54 +0000894 }
Anton Korobeynikov58887bc2008-03-05 22:22:46 +0000895
Lauro Ramos Venancio31ed0fb2007-06-28 19:02:54 +0000896 return false;
897}
898
Chris Lattner5c377c52001-10-14 23:29:15 +0000899
Chris Lattner8d2de8a2001-10-15 03:12:52 +0000900// LinkGlobalInits - Update the initializers in the Dest module now that all
901// globals that may be referenced are in Dest.
Chris Lattner8d2de8a2001-10-15 03:12:52 +0000902static bool LinkGlobalInits(Module *Dest, const Module *Src,
Chris Lattner5c2d3352003-01-30 19:53:34 +0000903 std::map<const Value*, Value*> &ValueMap,
904 std::string *Err) {
Chris Lattner8d2de8a2001-10-15 03:12:52 +0000905 // Loop over all of the globals in the src module, mapping them over as we go
Chris Lattner11273152006-06-16 01:24:04 +0000906 for (Module::const_global_iterator I = Src->global_begin(),
907 E = Src->global_end(); I != E; ++I) {
Chris Lattner18961502002-06-25 16:12:52 +0000908 const GlobalVariable *SGV = I;
Chris Lattner8d2de8a2001-10-15 03:12:52 +0000909
910 if (SGV->hasInitializer()) { // Only process initialized GV's
911 // Figure out what the initializer looks like in the dest module...
Chris Lattner4ad02e72003-04-16 20:28:45 +0000912 Constant *SInit =
Chris Lattner2a749d32009-11-01 02:46:39 +0000913 cast<Constant>(RemapOperand(SGV->getInitializer(), ValueMap));
Anton Korobeynikovd13726f2008-10-15 20:10:50 +0000914 // Grab destination global variable or alias.
915 GlobalValue *DGV = cast<GlobalValue>(ValueMap[SGV]->stripPointerCasts());
Chris Lattner8d2de8a2001-10-15 03:12:52 +0000916
Anton Korobeynikovd13726f2008-10-15 20:10:50 +0000917 // If dest if global variable, check that initializers match.
918 if (GlobalVariable *DGVar = dyn_cast<GlobalVariable>(DGV)) {
919 if (DGVar->hasInitializer()) {
920 if (SGV->hasExternalLinkage()) {
921 if (DGVar->getInitializer() != SInit)
922 return Error(Err, "Global Variable Collision on '" +
923 SGV->getName() +
924 "': global variables have different initializers");
Duncan Sandsa05ef5e2009-03-08 13:35:23 +0000925 } else if (DGVar->isWeakForLinker()) {
Anton Korobeynikovd13726f2008-10-15 20:10:50 +0000926 // Nothing is required, mapped values will take the new global
927 // automatically.
Duncan Sandsa05ef5e2009-03-08 13:35:23 +0000928 } else if (SGV->isWeakForLinker()) {
Anton Korobeynikovd13726f2008-10-15 20:10:50 +0000929 // Nothing is required, mapped values will take the new global
930 // automatically.
931 } else if (DGVar->hasAppendingLinkage()) {
Torok Edwinc23197a2009-07-14 16:55:14 +0000932 llvm_unreachable("Appending linkage unimplemented!");
Anton Korobeynikovd13726f2008-10-15 20:10:50 +0000933 } else {
Torok Edwinc23197a2009-07-14 16:55:14 +0000934 llvm_unreachable("Unknown linkage!");
Anton Korobeynikovd13726f2008-10-15 20:10:50 +0000935 }
Chris Lattner4ad02e72003-04-16 20:28:45 +0000936 } else {
Anton Korobeynikovd13726f2008-10-15 20:10:50 +0000937 // Copy the initializer over now...
938 DGVar->setInitializer(SInit);
Chris Lattner4ad02e72003-04-16 20:28:45 +0000939 }
Chris Lattner8d2de8a2001-10-15 03:12:52 +0000940 } else {
Anton Korobeynikovd13726f2008-10-15 20:10:50 +0000941 // Destination is alias, the only valid situation is when source is
942 // weak. Also, note, that we already checked linkage in LinkGlobals(),
943 // thus we assert here.
944 // FIXME: Should we weaken this assumption, 'dereference' alias and
945 // check for initializer of aliasee?
Duncan Sandsa05ef5e2009-03-08 13:35:23 +0000946 assert(SGV->isWeakForLinker());
Chris Lattner8d2de8a2001-10-15 03:12:52 +0000947 }
948 }
949 }
950 return false;
951}
Chris Lattner5c377c52001-10-14 23:29:15 +0000952
Chris Lattner79df7c02002-03-26 18:01:55 +0000953// LinkFunctionProtos - Link the functions together between the two modules,
Chris Lattnerc8cc4cb2002-05-07 18:36:35 +0000954// without doing function bodies... this just adds external function prototypes
955// to the Dest function...
Chris Lattner5c377c52001-10-14 23:29:15 +0000956//
Chris Lattner79df7c02002-03-26 18:01:55 +0000957static bool LinkFunctionProtos(Module *Dest, const Module *Src,
Chris Lattner5c2d3352003-01-30 19:53:34 +0000958 std::map<const Value*, Value*> &ValueMap,
959 std::string *Err) {
Chris Lattnerd1ec48c2008-07-14 06:49:45 +0000960 ValueSymbolTable &DestSymTab = Dest->getValueSymbolTable();
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000961
Reid Spencer619f0242007-02-04 04:43:17 +0000962 // Loop over all of the functions in the src module, mapping them over
Chris Lattner5c377c52001-10-14 23:29:15 +0000963 for (Module::const_iterator I = Src->begin(), E = Src->end(); I != E; ++I) {
Chris Lattner18961502002-06-25 16:12:52 +0000964 const Function *SF = I; // SrcFunction
Anton Korobeynikov194c2ce2008-07-05 23:03:21 +0000965 GlobalValue *DGV = 0;
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000966
Chris Lattnerd1ec48c2008-07-14 06:49:45 +0000967 // Check to see if may have to link the function with the global, alias or
968 // function.
Rafael Espindolabb46f522009-01-15 20:18:42 +0000969 if (SF->hasName() && !SF->hasLocalLinkage())
Daniel Dunbar03d76512009-07-25 23:55:21 +0000970 DGV = cast_or_null<GlobalValue>(DestSymTab.lookup(SF->getName()));
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000971
Chris Lattnerae1132d2008-07-14 06:52:19 +0000972 // If we found a global with the same name in the dest module, but it has
973 // internal linkage, we are really not doing any linkage here.
Rafael Espindolabb46f522009-01-15 20:18:42 +0000974 if (DGV && DGV->hasLocalLinkage())
Chris Lattnerae1132d2008-07-14 06:52:19 +0000975 DGV = 0;
976
Chris Lattnerd1ec48c2008-07-14 06:49:45 +0000977 // If types don't agree due to opaque types, try to resolve them.
978 if (DGV && DGV->getType() != SF->getType())
979 RecursiveResolveTypes(SF->getType(), DGV->getType());
Anton Korobeynikov194c2ce2008-07-05 23:03:21 +0000980
Chris Lattner6157e382008-07-14 07:23:24 +0000981 GlobalValue::LinkageTypes NewLinkage = GlobalValue::InternalLinkage;
982 bool LinkFromSrc = false;
983 if (GetLinkageResult(DGV, SF, NewLinkage, LinkFromSrc, Err))
984 return true;
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000985
Chris Lattner82468492008-06-09 07:36:11 +0000986 // If there is no linkage to be performed, just bring over SF without
987 // modifying it.
Anton Korobeynikov194c2ce2008-07-05 23:03:21 +0000988 if (DGV == 0) {
Chris Lattner82468492008-06-09 07:36:11 +0000989 // Function does not already exist, simply insert an function signature
990 // identical to SF into the dest module.
991 Function *NewDF = Function::Create(SF->getFunctionType(),
992 SF->getLinkage(),
993 SF->getName(), Dest);
994 CopyGVAttributes(NewDF, SF);
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +0000995
Chris Lattner82468492008-06-09 07:36:11 +0000996 // If the LLVM runtime renamed the function, but it is an externally
997 // visible symbol, DF must be an existing function with internal linkage.
998 // Rename it.
Rafael Espindolabb46f522009-01-15 20:18:42 +0000999 if (!NewDF->hasLocalLinkage() && NewDF->getName() != SF->getName())
Chris Lattner82468492008-06-09 07:36:11 +00001000 ForceRenaming(NewDF, SF->getName());
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +00001001
Chris Lattner82468492008-06-09 07:36:11 +00001002 // ... and remember this mapping...
1003 ValueMap[SF] = NewDF;
1004 continue;
Chris Lattner6157e382008-07-14 07:23:24 +00001005 }
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +00001006
Chris Lattner6157e382008-07-14 07:23:24 +00001007 // If the visibilities of the symbols disagree and the destination is a
1008 // prototype, take the visibility of its input.
1009 if (DGV->isDeclaration())
1010 DGV->setVisibility(SF->getVisibility());
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +00001011
Chris Lattner6157e382008-07-14 07:23:24 +00001012 if (LinkFromSrc) {
1013 if (isa<GlobalAlias>(DGV))
1014 return Error(Err, "Function-Alias Collision on '" + SF->getName() +
1015 "': symbol multiple defined");
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +00001016
Chris Lattner6157e382008-07-14 07:23:24 +00001017 // We have a definition of the same name but different type in the
1018 // source module. Copy the prototype to the destination and replace
1019 // uses of the destination's prototype with the new prototype.
1020 Function *NewDF = Function::Create(SF->getFunctionType(), NewLinkage,
1021 SF->getName(), Dest);
1022 CopyGVAttributes(NewDF, SF);
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +00001023
Chris Lattner6157e382008-07-14 07:23:24 +00001024 // Any uses of DF need to change to NewDF, with cast
Owen Andersonbaf3c402009-07-29 18:55:55 +00001025 DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewDF,
Owen Andersonc9ab7bf2009-07-07 21:07:14 +00001026 DGV->getType()));
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +00001027
Chris Lattner6157e382008-07-14 07:23:24 +00001028 // DF will conflict with NewDF because they both had the same. We must
1029 // erase this now so ForceRenaming doesn't assert because DF might
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +00001030 // not have internal linkage.
Chris Lattner6157e382008-07-14 07:23:24 +00001031 if (GlobalVariable *Var = dyn_cast<GlobalVariable>(DGV))
1032 Var->eraseFromParent();
1033 else
1034 cast<Function>(DGV)->eraseFromParent();
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +00001035
Chris Lattner6157e382008-07-14 07:23:24 +00001036 // If the symbol table renamed the function, but it is an externally
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +00001037 // visible symbol, DF must be an existing function with internal
Chris Lattner6157e382008-07-14 07:23:24 +00001038 // linkage. Rename it.
Rafael Espindolabb46f522009-01-15 20:18:42 +00001039 if (NewDF->getName() != SF->getName() && !NewDF->hasLocalLinkage())
Chris Lattner6157e382008-07-14 07:23:24 +00001040 ForceRenaming(NewDF, SF->getName());
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +00001041
Chris Lattner6157e382008-07-14 07:23:24 +00001042 // Remember this mapping so uses in the source module get remapped
1043 // later by RemapOperand.
1044 ValueMap[SF] = NewDF;
1045 continue;
1046 }
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +00001047
Chris Lattner6157e382008-07-14 07:23:24 +00001048 // Not "link from source", keep the one in the DestModule and remap the
1049 // input onto it.
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +00001050
Chris Lattner6157e382008-07-14 07:23:24 +00001051 if (isa<GlobalAlias>(DGV)) {
Anton Korobeynikovf88bc652008-07-05 23:33:22 +00001052 // The only valid mappings are:
1053 // - SF is external declaration, which is effectively a no-op.
1054 // - SF is weak, when we just need to throw SF out.
Duncan Sandsa05ef5e2009-03-08 13:35:23 +00001055 if (!SF->isDeclaration() && !SF->isWeakForLinker())
Anton Korobeynikov194c2ce2008-07-05 23:03:21 +00001056 return Error(Err, "Function-Alias Collision on '" + SF->getName() +
1057 "': symbol multiple defined");
Chris Lattner82468492008-06-09 07:36:11 +00001058 }
Anton Korobeynikov194c2ce2008-07-05 23:03:21 +00001059
Chris Lattner6157e382008-07-14 07:23:24 +00001060 // Set calculated linkage
1061 DGV->setLinkage(NewLinkage);
Chris Lattner5c377c52001-10-14 23:29:15 +00001062
Chris Lattner6157e382008-07-14 07:23:24 +00001063 // Make sure to remember this mapping.
Owen Andersonbaf3c402009-07-29 18:55:55 +00001064 ValueMap[SF] = ConstantExpr::getBitCast(DGV, SF->getType());
Chris Lattner5c377c52001-10-14 23:29:15 +00001065 }
1066 return false;
1067}
1068
Chris Lattnerc8cc4cb2002-05-07 18:36:35 +00001069// LinkFunctionBody - Copy the source function over into the dest function and
1070// fix up references to values. At this point we know that Dest is an external
1071// function, and that Src is not.
Chris Lattner4bbfbff2004-11-16 07:31:51 +00001072static bool LinkFunctionBody(Function *Dest, Function *Src,
Reid Spenceref9b9a72007-02-05 20:47:22 +00001073 std::map<const Value*, Value*> &ValueMap,
Chris Lattner5c2d3352003-01-30 19:53:34 +00001074 std::string *Err) {
Reid Spencer5cbf9852007-01-30 20:08:39 +00001075 assert(Src && Dest && Dest->isDeclaration() && !Src->isDeclaration());
Chris Lattner5c377c52001-10-14 23:29:15 +00001076
Chris Lattner0033baf2004-11-16 17:12:38 +00001077 // Go through and convert function arguments over, remembering the mapping.
Chris Lattnere4d5c442005-03-15 04:54:21 +00001078 Function::arg_iterator DI = Dest->arg_begin();
1079 for (Function::arg_iterator I = Src->arg_begin(), E = Src->arg_end();
Chris Lattner69da5cf2002-10-13 20:57:00 +00001080 I != E; ++I, ++DI) {
Owen Anderson6bc41e82008-04-14 17:38:21 +00001081 DI->setName(I->getName()); // Copy the name information over...
Chris Lattner5c377c52001-10-14 23:29:15 +00001082
1083 // Add a mapping to our local map
Anton Korobeynikov817bf2a2008-03-10 22:36:08 +00001084 ValueMap[I] = DI;
Chris Lattner5c377c52001-10-14 23:29:15 +00001085 }
1086
Chris Lattner4bbfbff2004-11-16 07:31:51 +00001087 // Splice the body of the source function into the dest function.
1088 Dest->getBasicBlockList().splice(Dest->end(), Src->getBasicBlockList());
Chris Lattner5c377c52001-10-14 23:29:15 +00001089
Chris Lattnerc8cc4cb2002-05-07 18:36:35 +00001090 // At this point, all of the instructions and values of the function are now
1091 // copied over. The only problem is that they are still referencing values in
1092 // the Source function as operands. Loop through all of the operands of the
1093 // functions and patch them up to point to the local versions...
Chris Lattner5c377c52001-10-14 23:29:15 +00001094 //
Chris Lattner18961502002-06-25 16:12:52 +00001095 for (Function::iterator BB = Dest->begin(), BE = Dest->end(); BB != BE; ++BB)
1096 for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
1097 for (Instruction::op_iterator OI = I->op_begin(), OE = I->op_end();
Chris Lattner221d6882002-02-12 21:07:25 +00001098 OI != OE; ++OI)
Chris Lattner4bbfbff2004-11-16 07:31:51 +00001099 if (!isa<Instruction>(*OI) && !isa<BasicBlock>(*OI))
Chris Lattner2a749d32009-11-01 02:46:39 +00001100 *OI = RemapOperand(*OI, ValueMap);
Chris Lattner0033baf2004-11-16 17:12:38 +00001101
1102 // There is no need to map the arguments anymore.
Chris Lattner11273152006-06-16 01:24:04 +00001103 for (Function::arg_iterator I = Src->arg_begin(), E = Src->arg_end();
1104 I != E; ++I)
Reid Spenceref9b9a72007-02-05 20:47:22 +00001105 ValueMap.erase(I);
Chris Lattner5c377c52001-10-14 23:29:15 +00001106
1107 return false;
1108}
1109
1110
Chris Lattnerc8cc4cb2002-05-07 18:36:35 +00001111// LinkFunctionBodies - Link in the function bodies that are defined in the
1112// source module into the DestModule. This consists basically of copying the
1113// function over and fixing up references to values.
Chris Lattner4bbfbff2004-11-16 07:31:51 +00001114static bool LinkFunctionBodies(Module *Dest, Module *Src,
Chris Lattner5c2d3352003-01-30 19:53:34 +00001115 std::map<const Value*, Value*> &ValueMap,
1116 std::string *Err) {
Chris Lattner5c377c52001-10-14 23:29:15 +00001117
Reid Spencer8bef0372007-02-04 04:29:21 +00001118 // Loop over all of the functions in the src module, mapping them over as we
1119 // go
Chris Lattner4bbfbff2004-11-16 07:31:51 +00001120 for (Module::iterator SF = Src->begin(), E = Src->end(); SF != E; ++SF) {
Reid Spencer619f0242007-02-04 04:43:17 +00001121 if (!SF->isDeclaration()) { // No body if function is external
Chris Lattnerec91ccb2008-06-20 05:29:39 +00001122 Function *DF = dyn_cast<Function>(ValueMap[SF]); // Destination function
Chris Lattner5c377c52001-10-14 23:29:15 +00001123
Chris Lattner18961502002-06-25 16:12:52 +00001124 // DF not external SF external?
Chris Lattnerec91ccb2008-06-20 05:29:39 +00001125 if (DF && DF->isDeclaration())
Chris Lattner35956552003-10-27 16:39:39 +00001126 // Only provide the function body if there isn't one already.
1127 if (LinkFunctionBody(DF, SF, ValueMap, Err))
1128 return true;
Chris Lattnerc2d774b2001-10-23 20:43:42 +00001129 }
Chris Lattner5c377c52001-10-14 23:29:15 +00001130 }
1131 return false;
1132}
1133
Chris Lattner8166e6e2003-05-13 21:33:43 +00001134// LinkAppendingVars - If there were any appending global variables, link them
1135// together now. Return true on error.
Chris Lattner8166e6e2003-05-13 21:33:43 +00001136static bool LinkAppendingVars(Module *M,
1137 std::multimap<std::string, GlobalVariable *> &AppendingVars,
1138 std::string *ErrorMsg) {
1139 if (AppendingVars.empty()) return false; // Nothing to do.
Misha Brukmanf976c852005-04-21 22:55:34 +00001140
Chris Lattner8166e6e2003-05-13 21:33:43 +00001141 // Loop over the multimap of appending vars, processing any variables with the
1142 // same name, forming a new appending global variable with both of the
1143 // initializers merged together, then rewrite references to the old variables
1144 // and delete them.
Chris Lattner8166e6e2003-05-13 21:33:43 +00001145 std::vector<Constant*> Inits;
1146 while (AppendingVars.size() > 1) {
1147 // Get the first two elements in the map...
1148 std::multimap<std::string,
1149 GlobalVariable*>::iterator Second = AppendingVars.begin(), First=Second++;
1150
1151 // If the first two elements are for different names, there is no pair...
1152 // Otherwise there is a pair, so link them together...
1153 if (First->first == Second->first) {
1154 GlobalVariable *G1 = First->second, *G2 = Second->second;
1155 const ArrayType *T1 = cast<ArrayType>(G1->getType()->getElementType());
1156 const ArrayType *T2 = cast<ArrayType>(G2->getType()->getElementType());
Misha Brukmanf976c852005-04-21 22:55:34 +00001157
Chris Lattner8166e6e2003-05-13 21:33:43 +00001158 // Check to see that they two arrays agree on type...
1159 if (T1->getElementType() != T2->getElementType())
1160 return Error(ErrorMsg,
1161 "Appending variables with different element types need to be linked!");
1162 if (G1->isConstant() != G2->isConstant())
1163 return Error(ErrorMsg,
1164 "Appending variables linked with different const'ness!");
1165
Lauro Ramos Venancio9613e872007-06-06 22:01:12 +00001166 if (G1->getAlignment() != G2->getAlignment())
1167 return Error(ErrorMsg,
1168 "Appending variables with different alignment need to be linked!");
1169
1170 if (G1->getVisibility() != G2->getVisibility())
1171 return Error(ErrorMsg,
1172 "Appending variables with different visibility need to be linked!");
1173
1174 if (G1->getSection() != G2->getSection())
1175 return Error(ErrorMsg,
1176 "Appending variables with different section name need to be linked!");
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +00001177
Chris Lattner8166e6e2003-05-13 21:33:43 +00001178 unsigned NewSize = T1->getNumElements() + T2->getNumElements();
Owen Andersondebcb012009-07-29 22:17:13 +00001179 ArrayType *NewType = ArrayType::get(T1->getElementType(),
Owen Andersonc9ab7bf2009-07-07 21:07:14 +00001180 NewSize);
Chris Lattner8166e6e2003-05-13 21:33:43 +00001181
Chris Lattnered74a4e2005-12-06 17:30:58 +00001182 G1->setName(""); // Clear G1's name in case of a conflict!
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +00001183
Chris Lattner8166e6e2003-05-13 21:33:43 +00001184 // Create the new global variable...
1185 GlobalVariable *NG =
Owen Andersone9b11b42009-07-08 19:03:57 +00001186 new GlobalVariable(*M, NewType, G1->isConstant(), G1->getLinkage(),
1187 /*init*/0, First->first, 0, G1->isThreadLocal(),
Chris Lattnera534b0f2008-06-27 03:10:24 +00001188 G1->getType()->getAddressSpace());
Chris Lattner8166e6e2003-05-13 21:33:43 +00001189
Lauro Ramos Venancio9613e872007-06-06 22:01:12 +00001190 // Propagate alignment, visibility and section info.
1191 CopyGVAttributes(NG, G1);
1192
Chris Lattner8166e6e2003-05-13 21:33:43 +00001193 // Merge the initializer...
1194 Inits.reserve(NewSize);
Chris Lattnerde512b52004-02-15 05:55:15 +00001195 if (ConstantArray *I = dyn_cast<ConstantArray>(G1->getInitializer())) {
1196 for (unsigned i = 0, e = T1->getNumElements(); i != e; ++i)
Alkis Evlogimenoscc7ba492004-08-04 08:08:13 +00001197 Inits.push_back(I->getOperand(i));
Chris Lattnerde512b52004-02-15 05:55:15 +00001198 } else {
1199 assert(isa<ConstantAggregateZero>(G1->getInitializer()));
Owen Andersona7235ea2009-07-31 20:28:14 +00001200 Constant *CV = Constant::getNullValue(T1->getElementType());
Chris Lattnerde512b52004-02-15 05:55:15 +00001201 for (unsigned i = 0, e = T1->getNumElements(); i != e; ++i)
1202 Inits.push_back(CV);
1203 }
1204 if (ConstantArray *I = dyn_cast<ConstantArray>(G2->getInitializer())) {
1205 for (unsigned i = 0, e = T2->getNumElements(); i != e; ++i)
Alkis Evlogimenoscc7ba492004-08-04 08:08:13 +00001206 Inits.push_back(I->getOperand(i));
Chris Lattnerde512b52004-02-15 05:55:15 +00001207 } else {
1208 assert(isa<ConstantAggregateZero>(G2->getInitializer()));
Owen Andersona7235ea2009-07-31 20:28:14 +00001209 Constant *CV = Constant::getNullValue(T2->getElementType());
Chris Lattnerde512b52004-02-15 05:55:15 +00001210 for (unsigned i = 0, e = T2->getNumElements(); i != e; ++i)
1211 Inits.push_back(CV);
1212 }
Owen Anderson1fd70962009-07-28 18:32:17 +00001213 NG->setInitializer(ConstantArray::get(NewType, Inits));
Chris Lattner8166e6e2003-05-13 21:33:43 +00001214 Inits.clear();
1215
1216 // Replace any uses of the two global variables with uses of the new
1217 // global...
1218
1219 // FIXME: This should rewrite simple/straight-forward uses such as
1220 // getelementptr instructions to not use the Cast!
Owen Andersonbaf3c402009-07-29 18:55:55 +00001221 G1->replaceAllUsesWith(ConstantExpr::getBitCast(NG,
Owen Andersonc9ab7bf2009-07-07 21:07:14 +00001222 G1->getType()));
Owen Andersonbaf3c402009-07-29 18:55:55 +00001223 G2->replaceAllUsesWith(ConstantExpr::getBitCast(NG,
Owen Andersonc9ab7bf2009-07-07 21:07:14 +00001224 G2->getType()));
Chris Lattner8166e6e2003-05-13 21:33:43 +00001225
1226 // Remove the two globals from the module now...
1227 M->getGlobalList().erase(G1);
1228 M->getGlobalList().erase(G2);
1229
1230 // Put the new global into the AppendingVars map so that we can handle
1231 // linking of more than two vars...
1232 Second->second = NG;
1233 }
1234 AppendingVars.erase(First);
1235 }
1236
1237 return false;
1238}
Chris Lattner52f7e902001-10-13 07:03:50 +00001239
Anton Korobeynikov9f2ee702008-03-05 23:21:39 +00001240static bool ResolveAliases(Module *Dest) {
1241 for (Module::alias_iterator I = Dest->alias_begin(), E = Dest->alias_end();
Anton Korobeynikov52419572008-03-11 22:51:09 +00001242 I != E; ++I)
David Chisnall34722462010-01-09 16:27:31 +00001243 // We can't sue resolveGlobalAlias here because we need to preserve
1244 // bitcasts and GEPs.
1245 if (const Constant *C = I->getAliasee()) {
1246 while (dyn_cast<GlobalAlias>(C))
1247 C = cast<GlobalAlias>(C)->getAliasee();
1248 const GlobalValue *GV = dyn_cast<GlobalValue>(C);
1249 if (C != I && !(GV && GV->isDeclaration()))
1250 I->replaceAllUsesWith(const_cast<Constant*>(C));
1251 }
Anton Korobeynikov9f2ee702008-03-05 23:21:39 +00001252
1253 return false;
1254}
Chris Lattner52f7e902001-10-13 07:03:50 +00001255
1256// LinkModules - This function links two modules together, with the resulting
1257// left module modified to be the composite of the two input modules. If an
1258// error occurs, true is returned and ErrorMsg (if not null) is set to indicate
Chris Lattner5c377c52001-10-14 23:29:15 +00001259// the problem. Upon failure, the Dest module could be in a modified state, and
1260// shouldn't be relied on to be consistent.
Misha Brukmanf976c852005-04-21 22:55:34 +00001261bool
Reid Spencer0ba9e212004-12-13 03:00:16 +00001262Linker::LinkModules(Module *Dest, Module *Src, std::string *ErrorMsg) {
Reid Spencer57a0efa2004-09-11 04:25:17 +00001263 assert(Dest != 0 && "Invalid Destination module");
1264 assert(Src != 0 && "Invalid Source Module");
1265
Chris Lattnerc36357c2007-01-29 00:21:34 +00001266 if (Dest->getDataLayout().empty()) {
1267 if (!Src->getDataLayout().empty()) {
Chris Lattnerec9bfdc2007-01-29 02:18:13 +00001268 Dest->setDataLayout(Src->getDataLayout());
Chris Lattnerc36357c2007-01-29 00:21:34 +00001269 } else {
1270 std::string DataLayout;
Reid Spencer26f23852007-01-26 08:11:39 +00001271
Anton Korobeynikova27694d2008-02-20 11:27:04 +00001272 if (Dest->getEndianness() == Module::AnyEndianness) {
Chris Lattnerc36357c2007-01-29 00:21:34 +00001273 if (Src->getEndianness() == Module::BigEndian)
1274 DataLayout.append("E");
1275 else if (Src->getEndianness() == Module::LittleEndian)
1276 DataLayout.append("e");
Anton Korobeynikova27694d2008-02-20 11:27:04 +00001277 }
1278
1279 if (Dest->getPointerSize() == Module::AnyPointerSize) {
Chris Lattnerc36357c2007-01-29 00:21:34 +00001280 if (Src->getPointerSize() == Module::Pointer64)
1281 DataLayout.append(DataLayout.length() == 0 ? "p:64:64" : "-p:64:64");
1282 else if (Src->getPointerSize() == Module::Pointer32)
1283 DataLayout.append(DataLayout.length() == 0 ? "p:32:32" : "-p:32:32");
Anton Korobeynikova27694d2008-02-20 11:27:04 +00001284 }
Chris Lattnerc36357c2007-01-29 00:21:34 +00001285 Dest->setDataLayout(DataLayout);
1286 }
1287 }
1288
Chris Lattnerf27dfcb2008-02-19 18:49:08 +00001289 // Copy the target triple from the source to dest if the dest's is empty.
Chris Lattnerc36357c2007-01-29 00:21:34 +00001290 if (Dest->getTargetTriple().empty() && !Src->getTargetTriple().empty())
Chris Lattner152f19a2004-12-10 20:26:15 +00001291 Dest->setTargetTriple(Src->getTargetTriple());
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +00001292
Chris Lattnerc36357c2007-01-29 00:21:34 +00001293 if (!Src->getDataLayout().empty() && !Dest->getDataLayout().empty() &&
1294 Src->getDataLayout() != Dest->getDataLayout())
Chris Lattnerbdff5482009-08-23 04:37:46 +00001295 errs() << "WARNING: Linking two modules of different data layouts!\n";
Chris Lattner152f19a2004-12-10 20:26:15 +00001296 if (!Src->getTargetTriple().empty() &&
1297 Dest->getTargetTriple() != Src->getTargetTriple())
Chris Lattnerbdff5482009-08-23 04:37:46 +00001298 errs() << "WARNING: Linking two modules of different target triples!\n";
Misha Brukmanf976c852005-04-21 22:55:34 +00001299
Chris Lattnerf27dfcb2008-02-19 18:49:08 +00001300 // Append the module inline asm string.
Chris Lattner66316012006-01-24 04:14:29 +00001301 if (!Src->getModuleInlineAsm().empty()) {
1302 if (Dest->getModuleInlineAsm().empty())
1303 Dest->setModuleInlineAsm(Src->getModuleInlineAsm());
Chris Lattnere1b2e142006-01-23 23:08:37 +00001304 else
Chris Lattner66316012006-01-24 04:14:29 +00001305 Dest->setModuleInlineAsm(Dest->getModuleInlineAsm()+"\n"+
1306 Src->getModuleInlineAsm());
Chris Lattnere1b2e142006-01-23 23:08:37 +00001307 }
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +00001308
Reid Spencer719012d2004-11-25 09:29:44 +00001309 // Update the destination module's dependent libraries list with the libraries
Reid Spencer57a0efa2004-09-11 04:25:17 +00001310 // from the source module. There's no opportunity for duplicates here as the
1311 // Module ensures that duplicate insertions are discarded.
Chris Lattnerf27dfcb2008-02-19 18:49:08 +00001312 for (Module::lib_iterator SI = Src->lib_begin(), SE = Src->lib_end();
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +00001313 SI != SE; ++SI)
Reid Spencer57a0efa2004-09-11 04:25:17 +00001314 Dest->addLibrary(*SI);
Reid Spencer57a0efa2004-09-11 04:25:17 +00001315
Chris Lattner2c236f32001-11-03 05:18:24 +00001316 // LinkTypes - Go through the symbol table of the Src module and see if any
1317 // types are named in the src module that are not named in the Dst module.
1318 // Make sure there are no type name conflicts.
Mikhail Glushenkoveba2cb02009-03-03 07:22:23 +00001319 if (LinkTypes(Dest, Src, ErrorMsg))
Reid Spencer619f0242007-02-04 04:43:17 +00001320 return true;
Chris Lattner2c236f32001-11-03 05:18:24 +00001321
Chris Lattner5c377c52001-10-14 23:29:15 +00001322 // ValueMap - Mapping of values from what they used to be in Src, to what they
1323 // are now in Dest.
Chris Lattner5c2d3352003-01-30 19:53:34 +00001324 std::map<const Value*, Value*> ValueMap;
Chris Lattner5c377c52001-10-14 23:29:15 +00001325
Chris Lattner8166e6e2003-05-13 21:33:43 +00001326 // AppendingVars - Keep track of global variables in the destination module
1327 // with appending linkage. After the module is linked together, they are
1328 // appended and the module is rewritten.
Chris Lattner8166e6e2003-05-13 21:33:43 +00001329 std::multimap<std::string, GlobalVariable *> AppendingVars;
Chris Lattner11273152006-06-16 01:24:04 +00001330 for (Module::global_iterator I = Dest->global_begin(), E = Dest->global_end();
1331 I != E; ++I) {
Chris Lattner5a837de2004-08-04 07:44:58 +00001332 // Add all of the appending globals already in the Dest module to
1333 // AppendingVars.
Chris Lattnerf4146462003-05-14 12:11:51 +00001334 if (I->hasAppendingLinkage())
1335 AppendingVars.insert(std::make_pair(I->getName(), I));
Chris Lattner5a837de2004-08-04 07:44:58 +00001336 }
1337
Devang Patelab67e702009-08-11 18:01:24 +00001338 // Insert all of the named mdnoes in Src into the Dest module.
1339 LinkNamedMDNodes(Dest, Src);
1340
Chris Lattner8166e6e2003-05-13 21:33:43 +00001341 // Insert all of the globals in src into the Dest module... without linking
1342 // initializers (which could refer to functions not yet mapped over).
Reid Spenceref9b9a72007-02-05 20:47:22 +00001343 if (LinkGlobals(Dest, Src, ValueMap, AppendingVars, ErrorMsg))
Chris Lattner5a837de2004-08-04 07:44:58 +00001344 return true;
Chris Lattner5c377c52001-10-14 23:29:15 +00001345
Chris Lattnerc8cc4cb2002-05-07 18:36:35 +00001346 // Link the functions together between the two modules, without doing function
1347 // bodies... this just adds external function prototypes to the Dest
1348 // function... We do this so that when we begin processing function bodies,
1349 // all of the global values that may be referenced are available in our
1350 // ValueMap.
Reid Spenceref9b9a72007-02-05 20:47:22 +00001351 if (LinkFunctionProtos(Dest, Src, ValueMap, ErrorMsg))
Chris Lattner5a837de2004-08-04 07:44:58 +00001352 return true;
Chris Lattner5c377c52001-10-14 23:29:15 +00001353
Anton Korobeynikov4fb28732008-03-05 15:27:21 +00001354 // If there were any alias, link them now. We really need to do this now,
1355 // because all of the aliases that may be referenced need to be available in
1356 // ValueMap
1357 if (LinkAlias(Dest, Src, ValueMap, ErrorMsg)) return true;
1358
Chris Lattner6cdf1972002-07-18 00:13:08 +00001359 // Update the initializers in the Dest module now that all globals that may
1360 // be referenced are in Dest.
Chris Lattner6cdf1972002-07-18 00:13:08 +00001361 if (LinkGlobalInits(Dest, Src, ValueMap, ErrorMsg)) return true;
1362
Chris Lattnerc8cc4cb2002-05-07 18:36:35 +00001363 // Link in the function bodies that are defined in the source module into the
1364 // DestModule. This consists basically of copying the function over and
1365 // fixing up references to values.
Chris Lattner79df7c02002-03-26 18:01:55 +00001366 if (LinkFunctionBodies(Dest, Src, ValueMap, ErrorMsg)) return true;
Chris Lattner52f7e902001-10-13 07:03:50 +00001367
Chris Lattner8166e6e2003-05-13 21:33:43 +00001368 // If there were any appending global variables, link them together now.
Chris Lattner8166e6e2003-05-13 21:33:43 +00001369 if (LinkAppendingVars(Dest, AppendingVars, ErrorMsg)) return true;
1370
Anton Korobeynikov3db91912008-03-05 23:08:47 +00001371 // Resolve all uses of aliases with aliasees
1372 if (ResolveAliases(Dest)) return true;
1373
Reid Spencer57a0efa2004-09-11 04:25:17 +00001374 // If the source library's module id is in the dependent library list of the
1375 // destination library, remove it since that module is now linked in.
1376 sys::Path modId;
Reid Spencerdd04df02005-07-07 23:21:43 +00001377 modId.set(Src->getModuleIdentifier());
Reid Spencer07adb282004-11-05 22:15:36 +00001378 if (!modId.isEmpty())
1379 Dest->removeLibrary(modId.getBasename());
Reid Spencer57a0efa2004-09-11 04:25:17 +00001380
Chris Lattner52f7e902001-10-13 07:03:50 +00001381 return false;
1382}
Vikram S. Adve9466f512001-10-28 21:38:02 +00001383
Reid Spencer567bc2c2004-05-25 08:52:20 +00001384// vim: sw=2