-}
-
-// LinkAlias - Loop through the alias in the src module and link them into the
-// dest module. We're assuming, that all functions/global variables were already
-// linked in.
-static bool LinkAlias(Module *Dest, const Module *Src,
- ValueToValueMapTy &ValueMap,
- std::string *Err) {
- // Loop over all alias in the src module
- for (Module::const_alias_iterator I = Src->alias_begin(),
- E = Src->alias_end(); I != E; ++I) {
- const GlobalAlias *SGA = I;
- const GlobalValue *SAliasee = SGA->getAliasedGlobal();
- GlobalAlias *NewGA = NULL;
-
- // Globals were already linked, thus we can just query ValueMap for variant
- // of SAliasee in Dest.
- ValueToValueMapTy::const_iterator VMI = ValueMap.find(SAliasee);
- assert(VMI != ValueMap.end() && "Aliasee not linked");
- GlobalValue* DAliasee = cast<GlobalValue>(VMI->second);
- GlobalValue* DGV = NULL;
-
- // Fixup aliases to bitcasts. Note that aliases to GEPs are still broken
- // by this, but aliases to GEPs are broken to a lot of other things, so
- // it's less important.
- Constant *DAliaseeConst = DAliasee;
- if (SGA->getType() != DAliasee->getType())
- DAliaseeConst = ConstantExpr::getBitCast(DAliasee, SGA->getType());
-
- // Try to find something 'similar' to SGA in destination module.
- if (!DGV && !SGA->hasLocalLinkage()) {
- DGV = Dest->getNamedAlias(SGA->getName());
-
- // If types don't agree due to opaque types, try to resolve them.
- if (DGV && DGV->getType() != SGA->getType())
- RecursiveResolveTypes(SGA->getType(), DGV->getType());
- }
-
- if (!DGV && !SGA->hasLocalLinkage()) {
- DGV = Dest->getGlobalVariable(SGA->getName());
-
- // If types don't agree due to opaque types, try to resolve them.
- if (DGV && DGV->getType() != SGA->getType())
- RecursiveResolveTypes(SGA->getType(), DGV->getType());
- }
-
- if (!DGV && !SGA->hasLocalLinkage()) {
- DGV = Dest->getFunction(SGA->getName());
-
- // If types don't agree due to opaque types, try to resolve them.
- if (DGV && DGV->getType() != SGA->getType())
- RecursiveResolveTypes(SGA->getType(), DGV->getType());
- }
-
- // No linking to be performed on internal stuff.
- if (DGV && DGV->hasLocalLinkage())
- DGV = NULL;
-
- if (GlobalAlias *DGA = dyn_cast_or_null<GlobalAlias>(DGV)) {
- // Types are known to be the same, check whether aliasees equal. As
- // globals are already linked we just need query ValueMap to find the
- // mapping.
- if (DAliasee == DGA->getAliasedGlobal()) {
- // This is just two copies of the same alias. Propagate linkage, if
- // necessary.
- DGA->setLinkage(CalculateAliasLinkage(SGA, DGA));
-
- NewGA = DGA;
- // Proceed to 'common' steps
- } else
- return Error(Err, "Alias Collision on '" + SGA->getName()+
- "': aliases have different aliasees");
- } else if (GlobalVariable *DGVar = dyn_cast_or_null<GlobalVariable>(DGV)) {
- // The only allowed way is to link alias with external declaration or weak
- // symbol..
- if (DGVar->isDeclaration() || DGVar->isWeakForLinker()) {
- // But only if aliasee is global too...
- if (!isa<GlobalVariable>(DAliasee))
- return Error(Err, "Global-Alias Collision on '" + SGA->getName() +
- "': aliasee is not global variable");
-
- NewGA = new GlobalAlias(SGA->getType(), SGA->getLinkage(),
- SGA->getName(), DAliaseeConst, Dest);
- CopyGVAttributes(NewGA, SGA);
-
- // Any uses of DGV need to change to NewGA, with cast, if needed.
- if (SGA->getType() != DGVar->getType())
- DGVar->replaceAllUsesWith(ConstantExpr::getBitCast(NewGA,
- DGVar->getType()));
- else
- DGVar->replaceAllUsesWith(NewGA);
-
- // DGVar will conflict with NewGA because they both had the same
- // name. We must erase this now so ForceRenaming doesn't assert
- // because DGV might not have internal linkage.
- DGVar->eraseFromParent();
-
- // Proceed to 'common' steps
- } else
- return Error(Err, "Global-Alias Collision on '" + SGA->getName() +
- "': symbol multiple defined");
- } else if (Function *DF = dyn_cast_or_null<Function>(DGV)) {
- // The only allowed way is to link alias with external declaration or weak
- // symbol...
- if (DF->isDeclaration() || DF->isWeakForLinker()) {
- // But only if aliasee is function too...
- if (!isa<Function>(DAliasee))
- return Error(Err, "Function-Alias Collision on '" + SGA->getName() +
- "': aliasee is not function");
-
- NewGA = new GlobalAlias(SGA->getType(), SGA->getLinkage(),
- SGA->getName(), DAliaseeConst, Dest);
- CopyGVAttributes(NewGA, SGA);
-
- // Any uses of DF need to change to NewGA, with cast, if needed.
- if (SGA->getType() != DF->getType())
- DF->replaceAllUsesWith(ConstantExpr::getBitCast(NewGA,
- DF->getType()));
- else
- DF->replaceAllUsesWith(NewGA);
-
- // DF will conflict with NewGA because they both had the same
- // name. We must erase this now so ForceRenaming doesn't assert
- // because DF might not have internal linkage.
- DF->eraseFromParent();
-
- // Proceed to 'common' steps
- } else
- return Error(Err, "Function-Alias Collision on '" + SGA->getName() +
- "': symbol multiple defined");
- } else {
- // No linking to be performed, simply create an identical version of the
- // alias over in the dest module...
- NewGA = new GlobalAlias(SGA->getType(), SGA->getLinkage(),
- SGA->getName(), DAliaseeConst, Dest);
- CopyGVAttributes(NewGA, SGA);
-
- // Proceed to 'common' steps
- }
-
- assert(NewGA && "No alias was created in destination module!");
-
- // If the symbol table renamed the alias, but it is an externally visible
- // symbol, DGA must be an global value with internal linkage. Rename it.
- if (NewGA->getName() != SGA->getName() &&
- !NewGA->hasLocalLinkage())
- ForceRenaming(NewGA, SGA->getName());
-
- // Remember this mapping so uses in the source module get remapped
- // later by MapValue.
- ValueMap[SGA] = NewGA;
- }
-