bool getComdatResult(const Comdat *SrcC, Comdat::SelectionKind &SK,
bool &LinkFromSrc);
+ /// This analyzes the two global values and determines what the result will
+ /// look like in the destination module.
+ bool getLinkageResult(GlobalValue *Dest, const GlobalValue *Src,
+ GlobalValue::LinkageTypes <,
+ GlobalValue::VisibilityTypes &Vis,
+ bool &LinkFromSrc);
+
/// Given a global in the source module, return the global in the
/// destination module that is being linked to, if any.
GlobalValue *getLinkedToGlobal(const GlobalValue *SrcGV) {
bool linkAppendingVarProto(GlobalVariable *DstGV,
const GlobalVariable *SrcGV);
-
- bool linkGlobalValueProto(GlobalValue *GV);
- GlobalValue *linkGlobalVariableProto(const GlobalVariable *SGVar,
- GlobalValue *DGV, bool LinkFromSrc);
- GlobalValue *linkFunctionProto(const Function *SF, GlobalValue *DGV,
- bool LinkFromSrc);
- GlobalValue *linkGlobalAliasProto(const GlobalAlias *SGA, GlobalValue *DGV,
- bool LinkFromSrc);
-
+ bool linkGlobalProto(const GlobalVariable *SrcGV);
+ bool linkFunctionProto(Function *SrcF);
+ bool linkAliasProto(GlobalAlias *SrcA);
bool linkModuleFlagsMetadata();
void linkAppendingVarInit(const AppendingVarInfo &AVI);
bool ModuleLinker::shouldLinkFromSource(bool &LinkFromSrc,
const GlobalValue &Dest,
const GlobalValue &Src) {
- // We always have to add Src if it has appending linkage.
- if (Src.hasAppendingLinkage()) {
- LinkFromSrc = true;
- return false;
- }
-
bool SrcIsDeclaration = Src.isDeclarationForLinker();
bool DestIsDeclaration = Dest.isDeclarationForLinker();
"': symbol multiply defined!");
}
+/// This analyzes the two global values and determines what the result will look
+/// like in the destination module. In particular, it computes the resultant
+/// linkage type and visibility, computes whether the global in the source
+/// should be copied over to the destination (replacing the existing one), and
+/// computes whether this linkage is an error or not.
+bool ModuleLinker::getLinkageResult(GlobalValue *Dest, const GlobalValue *Src,
+ GlobalValue::LinkageTypes <,
+ GlobalValue::VisibilityTypes &Vis,
+ bool &LinkFromSrc) {
+ assert(Dest && "Must have two globals being queried");
+ assert(!Src->hasLocalLinkage() &&
+ "If Src has internal linkage, Dest shouldn't be set!");
+
+ if (shouldLinkFromSource(LinkFromSrc, *Dest, *Src))
+ return true;
+
+ if (LinkFromSrc)
+ LT = Src->getLinkage();
+ else
+ LT = Dest->getLinkage();
+
+ // Compute the visibility. We follow the rules in the System V Application
+ // Binary Interface.
+ assert(!GlobalValue::isLocalLinkage(LT) &&
+ "Symbols with local linkage should not be merged");
+ Vis = isLessConstraining(Src->getVisibility(), Dest->getVisibility()) ?
+ Dest->getVisibility() : Src->getVisibility();
+ return false;
+}
+
/// Loop over all of the linked values to compute type mappings. For example,
/// if we link "extern Foo *x" and "Foo *x = NULL", then we have two struct
/// types 'Foo' but one got renamed when the module was loaded into the same
return false;
}
-bool ModuleLinker::linkGlobalValueProto(GlobalValue *SGV) {
+/// Loop through the global variables in the src module and merge them into the
+/// dest module.
+bool ModuleLinker::linkGlobalProto(const GlobalVariable *SGV) {
GlobalValue *DGV = getLinkedToGlobal(SGV);
- bool LinkFromSrc = true;
- Comdat *C = nullptr;
- GlobalValue::VisibilityTypes Visibility = SGV->getVisibility();
+ llvm::Optional<GlobalValue::VisibilityTypes> NewVisibility;
bool HasUnnamedAddr = SGV->hasUnnamedAddr();
+ unsigned Alignment = SGV->getAlignment();
+ bool LinkFromSrc = false;
+ Comdat *DC = nullptr;
if (const Comdat *SC = SGV->getComdat()) {
Comdat::SelectionKind SK;
std::tie(SK, LinkFromSrc) = ComdatsChosen[SC];
- C = DstM->getOrInsertComdat(SC->getName());
- C->setSelectionKind(SK);
- } else if (DGV) {
- if (shouldLinkFromSource(LinkFromSrc, *DGV, *SGV))
- return true;
+ DC = DstM->getOrInsertComdat(SC->getName());
+ DC->setSelectionKind(SK);
}
- if (!LinkFromSrc) {
- // Track the source global so that we don't attempt to copy it over when
- // processing global initializers.
- DoNotLinkFromSource.insert(SGV);
+ if (DGV) {
+ if (!DC) {
+ // Concatenation of appending linkage variables is magic and handled later.
+ if (DGV->hasAppendingLinkage() || SGV->hasAppendingLinkage())
+ return linkAppendingVarProto(cast<GlobalVariable>(DGV), SGV);
+
+ // Determine whether linkage of these two globals follows the source
+ // module's definition or the destination module's definition.
+ GlobalValue::LinkageTypes NewLinkage = GlobalValue::InternalLinkage;
+ GlobalValue::VisibilityTypes NV;
+ if (getLinkageResult(DGV, SGV, NewLinkage, NV, LinkFromSrc))
+ return true;
+ NewVisibility = NV;
+ HasUnnamedAddr = HasUnnamedAddr && DGV->hasUnnamedAddr();
+ if (DGV->hasCommonLinkage() && SGV->hasCommonLinkage())
+ Alignment = std::max(Alignment, DGV->getAlignment());
+ else if (!LinkFromSrc)
+ Alignment = DGV->getAlignment();
+
+ // If we're not linking from the source, then keep the definition that we
+ // have.
+ if (!LinkFromSrc) {
+ // Special case for const propagation.
+ if (GlobalVariable *DGVar = dyn_cast<GlobalVariable>(DGV)) {
+ DGVar->setAlignment(Alignment);
+
+ if (DGVar->isDeclaration() && !SGV->isConstant())
+ DGVar->setConstant(false);
+ }
+
+ // Set calculated linkage, visibility and unnamed_addr.
+ DGV->setLinkage(NewLinkage);
+ DGV->setVisibility(*NewVisibility);
+ DGV->setUnnamedAddr(HasUnnamedAddr);
+ }
+ }
- if (DGV)
+ if (!LinkFromSrc) {
// Make sure to remember this mapping.
- ValueMap[SGV] =
- ConstantExpr::getBitCast(DGV, TypeMap.get(SGV->getType()));
- }
+ ValueMap[SGV] = ConstantExpr::getBitCast(DGV,TypeMap.get(SGV->getType()));
- if (DGV) {
- Visibility = isLessConstraining(Visibility, DGV->getVisibility())
- ? DGV->getVisibility()
- : Visibility;
- HasUnnamedAddr = HasUnnamedAddr && DGV->hasUnnamedAddr();
+ // Track the source global so that we don't attempt to copy it over when
+ // processing global initializers.
+ DoNotLinkFromSource.insert(SGV);
+
+ return false;
+ }
}
- if (!LinkFromSrc && !DGV)
+ // If the Comdat this variable was inside of wasn't selected, skip it.
+ if (DC && !DGV && !LinkFromSrc) {
+ DoNotLinkFromSource.insert(SGV);
return false;
-
- GlobalValue *NewGV;
- if (auto *SGVar = dyn_cast<GlobalVariable>(SGV)) {
- NewGV = linkGlobalVariableProto(SGVar, DGV, LinkFromSrc);
- if (!NewGV)
- return true;
- } else if (auto *SF = dyn_cast<Function>(SGV)) {
- NewGV = linkFunctionProto(SF, DGV, LinkFromSrc);
- } else {
- NewGV = linkGlobalAliasProto(cast<GlobalAlias>(SGV), DGV, LinkFromSrc);
}
- if (NewGV) {
- if (NewGV != DGV)
- copyGVAttributes(NewGV, SGV);
-
- NewGV->setUnnamedAddr(HasUnnamedAddr);
- NewGV->setVisibility(Visibility);
+ // No linking to be performed or linking from the source: simply create an
+ // identical version of the symbol over in the dest module... the
+ // initializer will be filled in later by LinkGlobalInits.
+ GlobalVariable *NewDGV =
+ new GlobalVariable(*DstM, TypeMap.get(SGV->getType()->getElementType()),
+ SGV->isConstant(), SGV->getLinkage(), /*init*/nullptr,
+ SGV->getName(), /*insertbefore*/nullptr,
+ SGV->getThreadLocalMode(),
+ SGV->getType()->getAddressSpace());
+ // Propagate alignment, visibility and section info.
+ copyGVAttributes(NewDGV, SGV);
+ NewDGV->setAlignment(Alignment);
+ if (NewVisibility)
+ NewDGV->setVisibility(*NewVisibility);
+ NewDGV->setUnnamedAddr(HasUnnamedAddr);
- if (auto *NewGO = dyn_cast<GlobalObject>(NewGV)) {
- if (C)
- NewGO->setComdat(C);
- }
+ if (DC)
+ NewDGV->setComdat(DC);
- // Make sure to remember this mapping.
- if (NewGV != DGV) {
- if (DGV) {
- DGV->replaceAllUsesWith(
- ConstantExpr::getBitCast(NewGV, DGV->getType()));
- DGV->eraseFromParent();
- }
- ValueMap[SGV] = NewGV;
- }
+ if (DGV) {
+ DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewDGV, DGV->getType()));
+ DGV->eraseFromParent();
}
+ // Make sure to remember this mapping.
+ ValueMap[SGV] = NewDGV;
return false;
}
-/// Loop through the global variables in the src module and merge them into the
-/// dest module.
-GlobalValue *ModuleLinker::linkGlobalVariableProto(const GlobalVariable *SGVar,
- GlobalValue *DGV,
- bool LinkFromSrc) {
- unsigned Alignment = 0;
- bool ClearConstant = false;
+/// Link the function in the source module into the destination module if
+/// needed, setting up mapping information.
+bool ModuleLinker::linkFunctionProto(Function *SF) {
+ GlobalValue *DGV = getLinkedToGlobal(SF);
+ llvm::Optional<GlobalValue::VisibilityTypes> NewVisibility;
+ bool HasUnnamedAddr = SF->hasUnnamedAddr();
+
+ bool LinkFromSrc = false;
+ Comdat *DC = nullptr;
+ if (const Comdat *SC = SF->getComdat()) {
+ Comdat::SelectionKind SK;
+ std::tie(SK, LinkFromSrc) = ComdatsChosen[SC];
+ DC = DstM->getOrInsertComdat(SC->getName());
+ DC->setSelectionKind(SK);
+ }
if (DGV) {
- // Concatenation of appending linkage variables is magic and handled later.
- if (DGV->hasAppendingLinkage()) {
- if (linkAppendingVarProto(cast<GlobalVariable>(DGV), SGVar))
- return nullptr;
- return DGV;
+ if (!DC) {
+ GlobalValue::LinkageTypes NewLinkage = GlobalValue::InternalLinkage;
+ GlobalValue::VisibilityTypes NV;
+ if (getLinkageResult(DGV, SF, NewLinkage, NV, LinkFromSrc))
+ return true;
+ NewVisibility = NV;
+ HasUnnamedAddr = HasUnnamedAddr && DGV->hasUnnamedAddr();
+
+ if (!LinkFromSrc) {
+ // Set calculated linkage
+ DGV->setLinkage(NewLinkage);
+ DGV->setVisibility(*NewVisibility);
+ DGV->setUnnamedAddr(HasUnnamedAddr);
+ }
}
- if (DGV->hasCommonLinkage() && SGVar->hasCommonLinkage())
- Alignment = std::max(SGVar->getAlignment(), DGV->getAlignment());
+ if (!LinkFromSrc) {
+ // Make sure to remember this mapping.
+ ValueMap[SF] = ConstantExpr::getBitCast(DGV, TypeMap.get(SF->getType()));
- auto *DGVar = dyn_cast<GlobalVariable>(DGV);
- if (!SGVar->isConstant() || (DGVar && !DGVar->isConstant()))
- ClearConstant = true;
- }
+ // Track the function from the source module so we don't attempt to remap
+ // it.
+ DoNotLinkFromSource.insert(SF);
- if (!LinkFromSrc) {
- if (auto *NewGVar = dyn_cast<GlobalVariable>(DGV)) {
- if (Alignment)
- NewGVar->setAlignment(Alignment);
- if (NewGVar->isDeclaration() && ClearConstant)
- NewGVar->setConstant(false);
+ return false;
}
- return DGV;
}
- // No linking to be performed or linking from the source: simply create an
- // identical version of the symbol over in the dest module... the
- // initializer will be filled in later by LinkGlobalInits.
- GlobalVariable *NewDGV = new GlobalVariable(
- *DstM, TypeMap.get(SGVar->getType()->getElementType()),
- SGVar->isConstant(), SGVar->getLinkage(), /*init*/ nullptr,
- SGVar->getName(), /*insertbefore*/ nullptr, SGVar->getThreadLocalMode(),
- SGVar->getType()->getAddressSpace());
-
- if (Alignment)
- NewDGV->setAlignment(Alignment);
-
- return NewDGV;
-}
-
-/// Link the function in the source module into the destination module if
-/// needed, setting up mapping information.
-GlobalValue *ModuleLinker::linkFunctionProto(const Function *SF,
- GlobalValue *DGV,
- bool LinkFromSrc) {
- if (!LinkFromSrc)
- return DGV;
-
// If the function is to be lazily linked, don't create it just yet.
// The ValueMaterializerTy will deal with creating it if it's used.
if (!DGV && (SF->hasLocalLinkage() || SF->hasLinkOnceLinkage() ||
SF->hasAvailableExternallyLinkage())) {
DoNotLinkFromSource.insert(SF);
- return nullptr;
+ return false;
+ }
+
+ // If the Comdat this function was inside of wasn't selected, skip it.
+ if (DC && !DGV && !LinkFromSrc) {
+ DoNotLinkFromSource.insert(SF);
+ return false;
}
// If there is no linkage to be performed or we are linking from the source,
// bring SF over.
- return Function::Create(TypeMap.get(SF->getFunctionType()), SF->getLinkage(),
- SF->getName(), DstM);
+ Function *NewDF = Function::Create(TypeMap.get(SF->getFunctionType()),
+ SF->getLinkage(), SF->getName(), DstM);
+ copyGVAttributes(NewDF, SF);
+ if (NewVisibility)
+ NewDF->setVisibility(*NewVisibility);
+ NewDF->setUnnamedAddr(HasUnnamedAddr);
+
+ if (DC)
+ NewDF->setComdat(DC);
+
+ if (DGV) {
+ // Any uses of DF need to change to NewDF, with cast.
+ DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewDF, DGV->getType()));
+ DGV->eraseFromParent();
+ }
+
+ ValueMap[SF] = NewDF;
+ return false;
}
/// Set up prototypes for any aliases that come over from the source module.
-GlobalValue *ModuleLinker::linkGlobalAliasProto(const GlobalAlias *SGA,
- GlobalValue *DGV,
- bool LinkFromSrc) {
- if (!LinkFromSrc)
- return DGV;
+bool ModuleLinker::linkAliasProto(GlobalAlias *SGA) {
+ GlobalValue *DGV = getLinkedToGlobal(SGA);
+ llvm::Optional<GlobalValue::VisibilityTypes> NewVisibility;
+ bool HasUnnamedAddr = SGA->hasUnnamedAddr();
+
+ bool LinkFromSrc = false;
+ Comdat *DC = nullptr;
+ if (const Comdat *SC = SGA->getComdat()) {
+ Comdat::SelectionKind SK;
+ std::tie(SK, LinkFromSrc) = ComdatsChosen[SC];
+ DC = DstM->getOrInsertComdat(SC->getName());
+ DC->setSelectionKind(SK);
+ }
+
+ if (DGV) {
+ if (!DC) {
+ GlobalValue::LinkageTypes NewLinkage = GlobalValue::InternalLinkage;
+ GlobalValue::VisibilityTypes NV;
+ if (getLinkageResult(DGV, SGA, NewLinkage, NV, LinkFromSrc))
+ return true;
+ NewVisibility = NV;
+ HasUnnamedAddr = HasUnnamedAddr && DGV->hasUnnamedAddr();
+
+ if (!LinkFromSrc) {
+ // Set calculated linkage.
+ DGV->setLinkage(NewLinkage);
+ DGV->setVisibility(*NewVisibility);
+ DGV->setUnnamedAddr(HasUnnamedAddr);
+ }
+ }
+
+ if (!LinkFromSrc) {
+ // Make sure to remember this mapping.
+ ValueMap[SGA] = ConstantExpr::getBitCast(DGV,TypeMap.get(SGA->getType()));
+
+ // Track the alias from the source module so we don't attempt to remap it.
+ DoNotLinkFromSource.insert(SGA);
+
+ return false;
+ }
+ }
+
+ // If the Comdat this alias was inside of wasn't selected, skip it.
+ if (DC && !DGV && !LinkFromSrc) {
+ DoNotLinkFromSource.insert(SGA);
+ return false;
+ }
// If there is no linkage to be performed or we're linking from the source,
// bring over SGA.
auto *PTy = cast<PointerType>(TypeMap.get(SGA->getType()));
- return GlobalAlias::create(PTy->getElementType(), PTy->getAddressSpace(),
- SGA->getLinkage(), SGA->getName(), DstM);
+ auto *NewDA =
+ GlobalAlias::create(PTy->getElementType(), PTy->getAddressSpace(),
+ SGA->getLinkage(), SGA->getName(), DstM);
+ copyGVAttributes(NewDA, SGA);
+ if (NewVisibility)
+ NewDA->setVisibility(*NewVisibility);
+ NewDA->setUnnamedAddr(HasUnnamedAddr);
+
+ if (DGV) {
+ // Any uses of DGV need to change to NewDA, with cast.
+ DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewDA, DGV->getType()));
+ DGV->eraseFromParent();
+ }
+
+ ValueMap[SGA] = NewDA;
+ return false;
}
static void getArrayElements(const Constant *C,
// initializers (which could refer to functions not yet mapped over).
for (Module::global_iterator I = SrcM->global_begin(),
E = SrcM->global_end(); I != E; ++I)
- if (linkGlobalValueProto(I))
+ if (linkGlobalProto(I))
return true;
// Link the functions together between the two modules, without doing function
// all of the global values that may be referenced are available in our
// ValueMap.
for (Module::iterator I = SrcM->begin(), E = SrcM->end(); I != E; ++I)
- if (linkGlobalValueProto(I))
+ if (linkFunctionProto(I))
return true;
// If there were any aliases, link them now.
for (Module::alias_iterator I = SrcM->alias_begin(),
E = SrcM->alias_end(); I != E; ++I)
- if (linkGlobalValueProto(I))
+ if (linkAliasProto(I))
return true;
for (unsigned i = 0, e = AppendingVars.size(); i != e; ++i)
projects / oota-llvm.git / blobdiff