-//===- lib/Linker/LinkModules.cpp - Module Linker Implementation ----------===//
+ //===- lib/Linker/LinkModules.cpp - Module Linker Implementation ----------===//
//
// The LLVM Compiler Infrastructure
//
return true;
}
-// ToStr - Simple wrapper function to convert a type to a string.
-static std::string ToStr(const Type *Ty, const Module *M) {
- std::ostringstream OS;
- WriteTypeSymbolic(OS, Ty, M);
- return OS.str();
-}
-
-//
// Function: ResolveTypes()
//
// Description:
// If there is a conflict, rename the conflict.
if (GlobalValue *ConflictGV = cast_or_null<GlobalValue>(ST.lookup(Name))) {
- assert(ConflictGV->hasInternalLinkage() &&
+ assert(ConflictGV->hasLocalLinkage() &&
"Not conflicting with a static global, should link instead!");
GV->takeName(ConflictGV);
ConflictGV->setName(Name); // This will cause ConflictGV to get renamed
static bool GetLinkageResult(GlobalValue *Dest, const GlobalValue *Src,
GlobalValue::LinkageTypes <, bool &LinkFromSrc,
std::string *Err) {
- assert((!Dest || !Src->hasInternalLinkage()) &&
+ assert((!Dest || !Src->hasLocalLinkage()) &&
"If Src has internal linkage, Dest shouldn't be set!");
if (!Dest) {
// Linking something to nothing.
"': can only link appending global with another appending global!");
LinkFromSrc = true; // Special cased.
LT = Src->getLinkage();
- } else if (Src->isWeakForLinker()) {
+ } else if (Src->mayBeOverridden()) {
// At this point we know that Dest has LinkOnce, External*, Weak, Common,
// or DLL* linkage.
if ((Dest->hasLinkOnceLinkage() &&
LinkFromSrc = false;
LT = Dest->getLinkage();
}
- } else if (Dest->isWeakForLinker()) {
+ } else if (Dest->mayBeOverridden()) {
// At this point we know that Src has External* or DLL* linkage.
if (Src->hasExternalWeakLinkage()) {
LinkFromSrc = false;
// Check to see if may have to link the global with the global, alias or
// function.
- if (SGV->hasName() && !SGV->hasInternalLinkage())
+ if (SGV->hasName() && !SGV->hasLocalLinkage())
DGV = cast_or_null<GlobalValue>(DestSymTab.lookup(SGV->getNameStart(),
SGV->getNameEnd()));
+ // If we found a global with the same name in the dest module, but it has
+ // internal linkage, we are really not doing any linkage here.
+ if (DGV && DGV->hasLocalLinkage())
+ DGV = 0;
+
// If types don't agree due to opaque types, try to resolve them.
if (DGV && DGV->getType() != SGV->getType())
RecursiveResolveTypes(SGV->getType(), DGV->getType());
- if (DGV && DGV->hasInternalLinkage())
- DGV = 0;
-
assert((SGV->hasInitializer() || SGV->hasExternalWeakLinkage() ||
SGV->hasExternalLinkage() || SGV->hasDLLImportLinkage()) &&
"Global must either be external or have an initializer!");
if (GetLinkageResult(DGV, SGV, NewLinkage, LinkFromSrc, Err))
return true;
- if (!DGV) {
+ if (DGV == 0) {
// No linking to be performed, simply create an identical version of the
// symbol over in the dest module... the initializer will be filled in
// later by LinkGlobalInits.
// If the LLVM runtime renamed the global, but it is an externally visible
// symbol, DGV must be an existing global with internal linkage. Rename
// it.
- if (NewDGV->getName() != SGV->getName() && !NewDGV->hasInternalLinkage())
+ if (!NewDGV->hasLocalLinkage() && NewDGV->getName() != SGV->getName())
ForceRenaming(NewDGV, SGV->getName());
- // Make sure to remember this mapping...
+ // Make sure to remember this mapping.
ValueMap[SGV] = NewDGV;
// Keep track that this is an appending variable.
if (SGV->hasAppendingLinkage())
AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV));
- } else if (DGV->hasAppendingLinkage()) {
+ continue;
+ }
+
+ // If the visibilities of the symbols disagree and the destination is a
+ // prototype, take the visibility of its input.
+ if (DGV->isDeclaration())
+ DGV->setVisibility(SGV->getVisibility());
+
+ if (DGV->hasAppendingLinkage()) {
// No linking is performed yet. Just insert a new copy of the global, and
// keep track of the fact that it is an appending variable in the
// AppendingVars map. The name is cleared out so that no linkage is
// Keep track that this is an appending variable...
AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV));
- } else if (GlobalAlias *DGA = dyn_cast<GlobalAlias>(DGV)) {
- // SGV is global, but DGV is alias. The only valid mapping is when SGV is
- // external declaration, which is effectively a no-op. Also make sure
- // linkage calculation was correct.
- if (!SGV->isDeclaration() || LinkFromSrc)
+ continue;
+ }
+
+ if (LinkFromSrc) {
+ if (isa<GlobalAlias>(DGV))
return Error(Err, "Global-Alias Collision on '" + SGV->getName() +
"': symbol multiple defined");
-
- // Make sure to remember this mapping.
- ValueMap[SGV] = DGA;
- } else if (LinkFromSrc) {
+
// If the types don't match, and if we are to link from the source, nuke
// DGV and create a new one of the appropriate type. Note that the thing
// we are replacing may be a function (if a prototype, weak, etc) or a
// global variable.
GlobalVariable *NewDGV =
- new GlobalVariable(SGV->getType()->getElementType(),
- SGV->isConstant(), SGV->getLinkage(),
- /*init*/0, DGV->getName(), Dest, false,
+ new GlobalVariable(SGV->getType()->getElementType(), SGV->isConstant(),
+ NewLinkage, /*init*/0, DGV->getName(), Dest, false,
SGV->getType()->getAddressSpace());
// Propagate alignment, section, and visibility info.
// If the symbol table renamed the global, but it is an externally visible
// symbol, DGV must be an existing global with internal linkage. Rename.
- if (NewDGV->getValueName() != SGV->getValueName() &&
- !NewDGV->hasInternalLinkage())
+ if (NewDGV->getName() != SGV->getName() && !NewDGV->hasLocalLinkage())
ForceRenaming(NewDGV, SGV->getName());
- // Inherit const as appropriate
+ // Inherit const as appropriate.
NewDGV->setConstant(SGV->isConstant());
- // Set calculated linkage
- NewDGV->setLinkage(NewLinkage);
-
- // Make sure to remember this mapping...
- ValueMap[SGV] = ConstantExpr::getBitCast(NewDGV, SGV->getType());
- } else {
- // Not "link from source", keep the one in the DestModule and remap the
- // input onto it.
-
- // Special case for const propagation.
- if (GlobalVariable *DGVar = dyn_cast<GlobalVariable>(DGV))
- if (DGVar->isDeclaration() && SGV->isConstant() && !DGVar->isConstant())
- DGVar->setConstant(true);
-
- // Set calculated linkage
- DGV->setLinkage(NewLinkage);
-
- // Make sure to remember this mapping...
- ValueMap[SGV] = ConstantExpr::getBitCast(DGV, SGV->getType());
+ // Make sure to remember this mapping.
+ ValueMap[SGV] = NewDGV;
+ continue;
}
+
+ // Not "link from source", keep the one in the DestModule and remap the
+ // input onto it.
+
+ // Special case for const propagation.
+ if (GlobalVariable *DGVar = dyn_cast<GlobalVariable>(DGV))
+ if (DGVar->isDeclaration() && SGV->isConstant() && !DGVar->isConstant())
+ DGVar->setConstant(true);
+
+ // SGV is global, but DGV is alias.
+ if (isa<GlobalAlias>(DGV)) {
+ // The only valid mappings are:
+ // - SGV is external declaration, which is effectively a no-op.
+ // - SGV is weak, when we just need to throw SGV out.
+ if (!SGV->isDeclaration() && !SGV->mayBeOverridden())
+ return Error(Err, "Global-Alias Collision on '" + SGV->getName() +
+ "': symbol multiple defined");
+ }
+
+ // Set calculated linkage
+ DGV->setLinkage(NewLinkage);
+
+ // Make sure to remember this mapping...
+ ValueMap[SGV] = ConstantExpr::getBitCast(DGV, SGV->getType());
}
return false;
}
return GlobalValue::ExternalLinkage;
else if (SGV->hasWeakLinkage() || DGV->hasWeakLinkage())
return GlobalValue::WeakLinkage;
- else {
- assert(SGV->hasInternalLinkage() && DGV->hasInternalLinkage() &&
- "Unexpected linkage type");
+ else if (SGV->hasInternalLinkage() && DGV->hasInternalLinkage())
return GlobalValue::InternalLinkage;
+ else {
+ assert (SGV->hasPrivateLinkage() && DGV->hasPrivateLinkage() &&
+ "Unexpected linkage type");
+ return GlobalValue::PrivateLinkage;
}
}
GlobalValue* DGV = NULL;
// Try to find something 'similar' to SGA in destination module.
- if (!DGV && !SGA->hasInternalLinkage()) {
+ if (!DGV && !SGA->hasLocalLinkage()) {
DGV = Dest->getNamedAlias(SGA->getName());
// If types don't agree due to opaque types, try to resolve them.
RecursiveResolveTypes(SGA->getType(), DGV->getType());
}
- if (!DGV && !SGA->hasInternalLinkage()) {
+ if (!DGV && !SGA->hasLocalLinkage()) {
DGV = Dest->getGlobalVariable(SGA->getName());
// If types don't agree due to opaque types, try to resolve them.
RecursiveResolveTypes(SGA->getType(), DGV->getType());
}
- if (!DGV && !SGA->hasInternalLinkage()) {
+ if (!DGV && !SGA->hasLocalLinkage()) {
DGV = Dest->getFunction(SGA->getName());
// If types don't agree due to opaque types, try to resolve them.
}
// No linking to be performed on internal stuff.
- if (DGV && DGV->hasInternalLinkage())
+ if (DGV && DGV->hasLocalLinkage())
DGV = NULL;
if (GlobalAlias *DGA = dyn_cast_or_null<GlobalAlias>(DGV)) {
} 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()) {
+ if (DGVar->isDeclaration() || DGVar->mayBeOverridden()) {
// But only if aliasee is global too...
if (!isa<GlobalVariable>(DAliasee))
return Error(Err, "Global-Alias Collision on '" + SGA->getName() +
} 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()) {
+ if (DF->isDeclaration() || DF->mayBeOverridden()) {
// But only if aliasee is function too...
if (!isa<Function>(DAliasee))
return Error(Err, "Function-Alias Collision on '" + SGA->getName() +
// 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->hasInternalLinkage())
+ !NewGA->hasLocalLinkage())
ForceRenaming(NewGA, SGA->getName());
// Remember this mapping so uses in the source module get remapped
// Figure out what the initializer looks like in the dest module...
Constant *SInit =
cast<Constant>(RemapOperand(SGV->getInitializer(), ValueMap));
-
- GlobalVariable *DGV =
- cast<GlobalVariable>(ValueMap[SGV]->stripPointerCasts());
- if (DGV->hasInitializer()) {
- if (SGV->hasExternalLinkage()) {
- if (DGV->getInitializer() != SInit)
- return Error(Err, "Global Variable Collision on '" + SGV->getName() +
- "': global variables have different initializers");
- } else if (DGV->isWeakForLinker()) {
- // Nothing is required, mapped values will take the new global
- // automatically.
- } else if (SGV->isWeakForLinker()) {
- // Nothing is required, mapped values will take the new global
- // automatically.
- } else if (DGV->hasAppendingLinkage()) {
- assert(0 && "Appending linkage unimplemented!");
+ // Grab destination global variable or alias.
+ GlobalValue *DGV = cast<GlobalValue>(ValueMap[SGV]->stripPointerCasts());
+
+ // If dest if global variable, check that initializers match.
+ if (GlobalVariable *DGVar = dyn_cast<GlobalVariable>(DGV)) {
+ if (DGVar->hasInitializer()) {
+ if (SGV->hasExternalLinkage()) {
+ if (DGVar->getInitializer() != SInit)
+ return Error(Err, "Global Variable Collision on '" +
+ SGV->getName() +
+ "': global variables have different initializers");
+ } else if (DGVar->mayBeOverridden()) {
+ // Nothing is required, mapped values will take the new global
+ // automatically.
+ } else if (SGV->mayBeOverridden()) {
+ // Nothing is required, mapped values will take the new global
+ // automatically.
+ } else if (DGVar->hasAppendingLinkage()) {
+ assert(0 && "Appending linkage unimplemented!");
+ } else {
+ assert(0 && "Unknown linkage!");
+ }
} else {
- assert(0 && "Unknown linkage!");
+ // Copy the initializer over now...
+ DGVar->setInitializer(SInit);
}
} else {
- // Copy the initializer over now...
- DGV->setInitializer(SInit);
+ // Destination is alias, the only valid situation is when source is
+ // weak. Also, note, that we already checked linkage in LinkGlobals(),
+ // thus we assert here.
+ // FIXME: Should we weaken this assumption, 'dereference' alias and
+ // check for initializer of aliasee?
+ assert(SGV->mayBeOverridden());
}
}
}
for (Module::const_iterator I = Src->begin(), E = Src->end(); I != E; ++I) {
const Function *SF = I; // SrcFunction
GlobalValue *DGV = 0;
- Value *MappedDF;
// Check to see if may have to link the function with the global, alias or
// function.
- if (SF->hasName() && !SF->hasInternalLinkage())
+ if (SF->hasName() && !SF->hasLocalLinkage())
DGV = cast_or_null<GlobalValue>(DestSymTab.lookup(SF->getNameStart(),
SF->getNameEnd()));
+ // If we found a global with the same name in the dest module, but it has
+ // internal linkage, we are really not doing any linkage here.
+ if (DGV && DGV->hasLocalLinkage())
+ DGV = 0;
+
// If types don't agree due to opaque types, try to resolve them.
if (DGV && DGV->getType() != SF->getType())
RecursiveResolveTypes(SF->getType(), DGV->getType());
- if (DGV && DGV->hasInternalLinkage())
- DGV = 0;
-
+ GlobalValue::LinkageTypes NewLinkage = GlobalValue::InternalLinkage;
+ bool LinkFromSrc = false;
+ if (GetLinkageResult(DGV, SF, NewLinkage, LinkFromSrc, Err))
+ return true;
+
// If there is no linkage to be performed, just bring over SF without
// modifying it.
if (DGV == 0) {
// If the LLVM runtime renamed the function, but it is an externally
// visible symbol, DF must be an existing function with internal linkage.
// Rename it.
- if (!NewDF->hasInternalLinkage() && NewDF->getName() != SF->getName())
+ if (!NewDF->hasLocalLinkage() && NewDF->getName() != SF->getName())
ForceRenaming(NewDF, SF->getName());
// ... and remember this mapping...
ValueMap[SF] = NewDF;
continue;
- } else if (GlobalAlias *DGA = dyn_cast<GlobalAlias>(DGV)) {
- // SF is function, but DF is alias.
- // The only valid mappings are:
- // - SF is external declaration, which is effectively a no-op.
- // - SF is weak, when we just need to throw SF out.
- if (!SF->isDeclaration() && !SF->isWeakForLinker())
- return Error(Err, "Function-Alias Collision on '" + SF->getName() +
- "': symbol multiple defined");
-
- // Make sure to remember this mapping...
- ValueMap[SF] = ConstantExpr::getBitCast(DGA, SF->getType());
- continue;
- }
-
- Function* DF = cast<Function>(DGV);
- // If types don't agree because of opaque, try to resolve them.
- if (SF->getType() != DF->getType())
- RecursiveResolveTypes(SF->getType(), DF->getType());
-
- // Check visibility, merging if a definition overrides a prototype.
- if (SF->getVisibility() != DF->getVisibility()) {
- // If one is a prototype, ignore its visibility. Prototypes are always
- // overridden by the definition.
- if (!SF->isDeclaration() && !DF->isDeclaration())
- return Error(Err, "Linking functions named '" + SF->getName() +
- "': symbols have different visibilities!");
-
- // Otherwise, replace the visibility of DF if DF is a prototype.
- if (DF->isDeclaration())
- DF->setVisibility(SF->getVisibility());
- }
-
- if (DF->getType() != SF->getType()) {
- if (DF->isDeclaration() && !SF->isDeclaration()) {
- // We have a definition of the same name but different type in the
- // source module. Copy the prototype to the destination and replace
- // uses of the destination's prototype with the new prototype.
- Function *NewDF = Function::Create(SF->getFunctionType(),
- SF->getLinkage(),
- SF->getName(), Dest);
- CopyGVAttributes(NewDF, SF);
-
- // Any uses of DF need to change to NewDF, with cast
- DF->replaceAllUsesWith(ConstantExpr::getBitCast(NewDF, DF->getType()));
-
- // DF will conflict with NewDF because they both had the same. We must
- // erase this now so ForceRenaming doesn't assert because DF might
- // not have internal linkage.
- DF->eraseFromParent();
-
- // If the symbol table renamed the function, but it is an externally
- // visible symbol, DF must be an existing function with internal
- // linkage. Rename it.
- if (NewDF->getName() != SF->getName() && !NewDF->hasInternalLinkage())
- ForceRenaming(NewDF, SF->getName());
-
- // Remember this mapping so uses in the source module get remapped
- // later by RemapOperand.
- ValueMap[SF] = NewDF;
- continue;
- } else {
- // We have two functions of the same name but different type. Any use
- // of the source must be mapped to the destination, with a cast.
- MappedDF = ConstantExpr::getBitCast(DF, SF->getType());
- }
- } else {
- MappedDF = DF;
}
- if (SF->isDeclaration()) {
- // If SF is a declaration or if both SF & DF are declarations, just link
- // the declarations, we aren't adding anything.
- if (SF->hasDLLImportLinkage()) {
- if (DF->isDeclaration()) {
- ValueMap[SF] = MappedDF;
- DF->setLinkage(SF->getLinkage());
- }
- } else {
- ValueMap[SF] = MappedDF;
- }
- continue;
- }
+ // If the visibilities of the symbols disagree and the destination is a
+ // prototype, take the visibility of its input.
+ if (DGV->isDeclaration())
+ DGV->setVisibility(SF->getVisibility());
- // If DF is external but SF is not, link the external functions, update
- // linkage qualifiers.
- if (DF->isDeclaration() && !DF->hasDLLImportLinkage()) {
- ValueMap.insert(std::make_pair(SF, MappedDF));
- DF->setLinkage(SF->getLinkage());
+ if (LinkFromSrc) {
+ if (isa<GlobalAlias>(DGV))
+ return Error(Err, "Function-Alias Collision on '" + SF->getName() +
+ "': symbol multiple defined");
+
+ // We have a definition of the same name but different type in the
+ // source module. Copy the prototype to the destination and replace
+ // uses of the destination's prototype with the new prototype.
+ Function *NewDF = Function::Create(SF->getFunctionType(), NewLinkage,
+ SF->getName(), Dest);
+ CopyGVAttributes(NewDF, SF);
+
+ // Any uses of DF need to change to NewDF, with cast
+ DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewDF, DGV->getType()));
+
+ // DF will conflict with NewDF because they both had the same. We must
+ // erase this now so ForceRenaming doesn't assert because DF might
+ // not have internal linkage.
+ if (GlobalVariable *Var = dyn_cast<GlobalVariable>(DGV))
+ Var->eraseFromParent();
+ else
+ cast<Function>(DGV)->eraseFromParent();
+
+ // If the symbol table renamed the function, but it is an externally
+ // visible symbol, DF must be an existing function with internal
+ // linkage. Rename it.
+ if (NewDF->getName() != SF->getName() && !NewDF->hasLocalLinkage())
+ ForceRenaming(NewDF, SF->getName());
+
+ // Remember this mapping so uses in the source module get remapped
+ // later by RemapOperand.
+ ValueMap[SF] = NewDF;
continue;
}
- // At this point we know that DF has LinkOnce, Weak, or External* linkage.
- if (SF->isWeakForLinker()) {
- ValueMap[SF] = MappedDF;
-
- // Linkonce+Weak = Weak
- // *+External Weak = *
- if ((DF->hasLinkOnceLinkage() &&
- (SF->hasWeakLinkage() || SF->hasCommonLinkage())) ||
- DF->hasExternalWeakLinkage())
- DF->setLinkage(SF->getLinkage());
- continue;
- }
+ // Not "link from source", keep the one in the DestModule and remap the
+ // input onto it.
- if (DF->isWeakForLinker()) {
- // At this point we know that SF has LinkOnce or External* linkage.
- ValueMap[SF] = MappedDF;
-
- // If the source function has stronger linkage than the destination,
- // its body and linkage should override ours.
- if (!SF->hasLinkOnceLinkage() && !SF->hasExternalWeakLinkage()) {
- // Don't inherit linkonce & external weak linkage.
- DF->setLinkage(SF->getLinkage());
- DF->deleteBody();
- }
- continue;
+ if (isa<GlobalAlias>(DGV)) {
+ // The only valid mappings are:
+ // - SF is external declaration, which is effectively a no-op.
+ // - SF is weak, when we just need to throw SF out.
+ if (!SF->isDeclaration() && !SF->mayBeOverridden())
+ return Error(Err, "Function-Alias Collision on '" + SF->getName() +
+ "': symbol multiple defined");
}
-
- if (SF->getLinkage() != DF->getLinkage())
- return Error(Err, "Functions named '" + SF->getName() +
- "' have different linkage specifiers!");
-
- // The function is defined identically in both modules!
- if (SF->hasExternalLinkage())
- return Error(Err, "Function '" +
- ToStr(SF->getFunctionType(), Src) + "':\"" +
- SF->getName() + "\" - Function is already defined!");
- assert(0 && "Unknown linkage configuration found!");
+
+ // Set calculated linkage
+ DGV->setLinkage(NewLinkage);
+
+ // Make sure to remember this mapping.
+ ValueMap[SF] = ConstantExpr::getBitCast(DGV, SF->getType());
}
return false;
}
for (Module::alias_iterator I = Dest->alias_begin(), E = Dest->alias_end();
I != E; ++I)
if (const GlobalValue *GV = I->resolveAliasedGlobal())
- if (!GV->isDeclaration())
+ if (GV != I && !GV->isDeclaration())
I->replaceAllUsesWith(const_cast<GlobalValue*>(GV));
return false;
projects / oota-llvm.git / blobdiff