for (DenseMap<Type*, Type*>::const_iterator
I = MappedTypes.begin(), E = MappedTypes.end(); I != E; ++I) {
dbgs() << "TypeMap: ";
- I->first->dump();
+ I->first->print(dbgs());
dbgs() << " => ";
- I->second->dump();
+ I->second->print(dbgs());
dbgs() << '\n';
}
}
bool run();
private:
+ bool shouldLinkFromSource(const GlobalValue &Dest, const GlobalValue &Src);
+
/// emitError - Helper method for setting a message and returning an error
/// code.
bool emitError(const Twine &Message) {
void computeTypeMapping();
+ void upgradeMismatchedGlobalArray(StringRef Name);
+ void upgradeMismatchedGlobals();
+
bool linkAppendingVarProto(GlobalVariable *DstGV, GlobalVariable *SrcGV);
bool linkGlobalProto(GlobalVariable *SrcGV);
bool linkFunctionProto(Function *SrcF);
SF->getLinkage(), SF->getName(), DstM);
copyGVAttributes(DF, SF);
+ if (Comdat *SC = SF->getComdat()) {
+ Comdat *DC = DstM->getOrInsertComdat(SC->getName());
+ DF->setComdat(DC);
+ }
+
LazilyLinkFunctions.push_back(SF);
return DF;
}
bool ModuleLinker::getComdatResult(const Comdat *SrcC,
Comdat::SelectionKind &Result,
bool &LinkFromSrc) {
+ Comdat::SelectionKind SSK = SrcC->getSelectionKind();
StringRef ComdatName = SrcC->getName();
Module::ComdatSymTabType &ComdatSymTab = DstM->getComdatSymbolTable();
Module::ComdatSymTabType::iterator DstCI = ComdatSymTab.find(ComdatName);
- if (DstCI != ComdatSymTab.end()) {
- const Comdat *DstC = &DstCI->second;
- Comdat::SelectionKind SSK = SrcC->getSelectionKind();
- Comdat::SelectionKind DSK = DstC->getSelectionKind();
- if (computeResultingSelectionKind(ComdatName, SSK, DSK, Result, LinkFromSrc))
+
+ if (DstCI == ComdatSymTab.end()) {
+ // Use the comdat if it is only available in one of the modules.
+ LinkFromSrc = true;
+ Result = SSK;
+ return false;
+ }
+
+ const Comdat *DstC = &DstCI->second;
+ Comdat::SelectionKind DSK = DstC->getSelectionKind();
+ return computeResultingSelectionKind(ComdatName, SSK, DSK, Result,
+ LinkFromSrc);
+}
+
+// FIXME: Duplicated from the gold plugin. This should be refactored somewhere.
+static bool isDeclaration(const GlobalValue &V) {
+ if (V.hasAvailableExternallyLinkage())
+ return true;
+
+ if (V.isMaterializable())
+ return false;
+
+ return V.isDeclaration();
+}
+
+bool ModuleLinker::shouldLinkFromSource(const GlobalValue &Dest,
+ const GlobalValue &Src) {
+ bool SrcIsDeclaration = isDeclaration(Src);
+ bool DestIsDeclaration = isDeclaration(Dest);
+
+ // FIXME: Make datalayout mandatory and just use getDataLayout().
+ DataLayout DL(Dest.getParent());
+
+ if (SrcIsDeclaration) {
+ // If Src is external or if both Src & Dest are external.. Just link the
+ // external globals, we aren't adding anything.
+ if (Src.hasDLLImportStorageClass())
+ // If one of GVs is marked as DLLImport, result should be dllimport'ed.
+ return DestIsDeclaration;
+ // If the Dest is weak, use the source linkage.
+ return Dest.hasExternalWeakLinkage();
+ }
+
+ if (DestIsDeclaration)
+ // If Dest is external but Src is not:
+ return true;
+
+ if (Src.hasCommonLinkage()) {
+ if (Dest.hasLinkOnceLinkage() || Dest.hasWeakLinkage())
return true;
+
+ if (!Dest.hasCommonLinkage())
+ return false;
+
+ uint64_t DestSize = DL.getTypeAllocSize(Dest.getType()->getElementType());
+ uint64_t SrcSize = DL.getTypeAllocSize(Src.getType()->getElementType());
+ return SrcSize > DestSize;
}
- return false;
+
+ if (Src.isWeakForLinker()) {
+ assert(!Dest.hasExternalWeakLinkage());
+ assert(!Dest.hasAvailableExternallyLinkage());
+
+ if (Dest.hasLinkOnceLinkage() && Src.hasWeakLinkage())
+ return true;
+
+ return false;
+ }
+
+ if (Dest.isWeakForLinker()) {
+ assert(Src.hasExternalLinkage());
+ return true;
+ }
+
+ assert(!Src.hasExternalWeakLinkage());
+ assert(!Dest.hasExternalWeakLinkage());
+ assert(Dest.hasExternalLinkage() && Src.hasExternalLinkage() &&
+ "Unexpected linkage type!");
+ return emitError("Linking globals named '" + Src.getName() +
+ "': symbol multiply defined!");
}
-/// getLinkageResult - 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.
+/// 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,
assert(!Src->hasLocalLinkage() &&
"If Src has internal linkage, Dest shouldn't be set!");
- bool SrcIsDeclaration = Src->isDeclaration() && !Src->isMaterializable();
- bool DestIsDeclaration = Dest->isDeclaration();
+ assert(ErrorMsg.empty());
+ LinkFromSrc = shouldLinkFromSource(*Dest, *Src);
+ if (!ErrorMsg.empty())
+ return true;
- if (SrcIsDeclaration) {
- // If Src is external or if both Src & Dest are external.. Just link the
- // external globals, we aren't adding anything.
- if (Src->hasDLLImportStorageClass()) {
- // If one of GVs is marked as DLLImport, result should be dllimport'ed.
- if (DestIsDeclaration) {
- LinkFromSrc = true;
- LT = Src->getLinkage();
- }
- } else if (Dest->hasExternalWeakLinkage()) {
- // If the Dest is weak, use the source linkage.
- LinkFromSrc = true;
- LT = Src->getLinkage();
- } else {
- LinkFromSrc = false;
- LT = Dest->getLinkage();
- }
- } else if (DestIsDeclaration && !Dest->hasDLLImportStorageClass()) {
- // If Dest is external but Src is not:
- LinkFromSrc = true;
+ if (LinkFromSrc)
LT = Src->getLinkage();
- } else if (Src->isWeakForLinker()) {
- // At this point we know that Dest has LinkOnce, External*, Weak, Common,
- // or DLL* linkage.
- if (Dest->hasExternalWeakLinkage() ||
- Dest->hasAvailableExternallyLinkage() ||
- (Dest->hasLinkOnceLinkage() &&
- (Src->hasWeakLinkage() || Src->hasCommonLinkage()))) {
- LinkFromSrc = true;
- LT = Src->getLinkage();
- } else {
- LinkFromSrc = false;
- LT = Dest->getLinkage();
- }
- } else if (Dest->isWeakForLinker()) {
- // At this point we know that Src has External* or DLL* linkage.
- if (Src->hasExternalWeakLinkage()) {
- LinkFromSrc = false;
- LT = Dest->getLinkage();
- } else {
- LinkFromSrc = true;
- LT = GlobalValue::ExternalLinkage;
- }
- } else {
- assert((Dest->hasExternalLinkage() || Dest->hasExternalWeakLinkage()) &&
- (Src->hasExternalLinkage() || Src->hasExternalWeakLinkage()) &&
- "Unexpected linkage type!");
- return emitError("Linking globals named '" + Src->getName() +
- "': symbol multiply defined!");
- }
+ else
+ LT = Dest->getLinkage();
// Compute the visibility. We follow the rules in the System V Application
// Binary Interface.
TypeMap.linkDefinedTypeBodies();
}
+static void upgradeGlobalArray(GlobalVariable *GV) {
+ ArrayType *ATy = cast<ArrayType>(GV->getType()->getElementType());
+ StructType *OldTy = cast<StructType>(ATy->getElementType());
+ assert(OldTy->getNumElements() == 2 && "Expected to upgrade from 2 elements");
+
+ // Get the upgraded 3 element type.
+ PointerType *VoidPtrTy = Type::getInt8Ty(GV->getContext())->getPointerTo();
+ Type *Tys[3] = {OldTy->getElementType(0), OldTy->getElementType(1),
+ VoidPtrTy};
+ StructType *NewTy = StructType::get(GV->getContext(), Tys, false);
+
+ // Build new constants with a null third field filled in.
+ Constant *OldInitC = GV->getInitializer();
+ ConstantArray *OldInit = dyn_cast<ConstantArray>(OldInitC);
+ if (!OldInit && !isa<ConstantAggregateZero>(OldInitC))
+ // Invalid initializer; give up.
+ return;
+ std::vector<Constant *> Initializers;
+ if (OldInit && OldInit->getNumOperands()) {
+ Value *Null = Constant::getNullValue(VoidPtrTy);
+ for (Use &U : OldInit->operands()) {
+ ConstantStruct *Init = cast<ConstantStruct>(U.get());
+ Initializers.push_back(ConstantStruct::get(
+ NewTy, Init->getOperand(0), Init->getOperand(1), Null, nullptr));
+ }
+ }
+ assert(Initializers.size() == ATy->getNumElements() &&
+ "Failed to copy all array elements");
+
+ // Replace the old GV with a new one.
+ ATy = ArrayType::get(NewTy, Initializers.size());
+ Constant *NewInit = ConstantArray::get(ATy, Initializers);
+ GlobalVariable *NewGV = new GlobalVariable(
+ *GV->getParent(), ATy, GV->isConstant(), GV->getLinkage(), NewInit, "",
+ GV, GV->getThreadLocalMode(), GV->getType()->getAddressSpace(),
+ GV->isExternallyInitialized());
+ NewGV->copyAttributesFrom(GV);
+ NewGV->takeName(GV);
+ assert(GV->use_empty() && "program cannot use initializer list");
+ GV->eraseFromParent();
+}
+
+void ModuleLinker::upgradeMismatchedGlobalArray(StringRef Name) {
+ // Look for the global arrays.
+ auto *DstGV = dyn_cast_or_null<GlobalVariable>(DstM->getNamedValue(Name));
+ if (!DstGV)
+ return;
+ auto *SrcGV = dyn_cast_or_null<GlobalVariable>(SrcM->getNamedValue(Name));
+ if (!SrcGV)
+ return;
+
+ // Check if the types already match.
+ auto *DstTy = cast<ArrayType>(DstGV->getType()->getElementType());
+ auto *SrcTy =
+ cast<ArrayType>(TypeMap.get(SrcGV->getType()->getElementType()));
+ if (DstTy == SrcTy)
+ return;
+
+ // Grab the element types. We can only upgrade an array of a two-field
+ // struct. Only bother if the other one has three-fields.
+ auto *DstEltTy = cast<StructType>(DstTy->getElementType());
+ auto *SrcEltTy = cast<StructType>(SrcTy->getElementType());
+ if (DstEltTy->getNumElements() == 2 && SrcEltTy->getNumElements() == 3) {
+ upgradeGlobalArray(DstGV);
+ return;
+ }
+ if (DstEltTy->getNumElements() == 3 && SrcEltTy->getNumElements() == 2)
+ upgradeGlobalArray(SrcGV);
+
+ // We can't upgrade any other differences.
+}
+
+void ModuleLinker::upgradeMismatchedGlobals() {
+ upgradeMismatchedGlobalArray("llvm.global_ctors");
+ upgradeMismatchedGlobalArray("llvm.global_dtors");
+}
+
/// linkAppendingVarProto - If there were any appending global variables, link
/// them together now. Return true on error.
bool ModuleLinker::linkAppendingVarProto(GlobalVariable *DstGV,
GlobalValue *DGV = getLinkedToGlobal(SGV);
llvm::Optional<GlobalValue::VisibilityTypes> NewVisibility;
bool HasUnnamedAddr = SGV->hasUnnamedAddr();
+ unsigned Alignment = SGV->getAlignment();
bool LinkFromSrc = false;
Comdat *DC = nullptr;
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))
+ if (GlobalVariable *DGVar = dyn_cast<GlobalVariable>(DGV)) {
+ DGVar->setAlignment(Alignment);
+
if (DGVar->isDeclaration() && SGV->isConstant() &&
!DGVar->isConstant())
DGVar->setConstant(true);
+ }
// Set calculated linkage, visibility and unnamed_addr.
DGV->setLinkage(NewLinkage);
SGV->getType()->getAddressSpace());
// Propagate alignment, visibility and section info.
copyGVAttributes(NewDGV, SGV);
+ NewDGV->setAlignment(Alignment);
if (NewVisibility)
NewDGV->setVisibility(*NewVisibility);
NewDGV->setUnnamedAddr(HasUnnamedAddr);
void ModuleLinker::linkAppendingVarInit(const AppendingVarInfo &AVI) {
// Merge the initializer.
- SmallVector<Constant*, 16> Elements;
- getArrayElements(AVI.DstInit, Elements);
+ SmallVector<Constant *, 16> DstElements;
+ getArrayElements(AVI.DstInit, DstElements);
- Constant *SrcInit = MapValue(AVI.SrcInit, ValueMap, RF_None, &TypeMap, &ValMaterializer);
- getArrayElements(SrcInit, Elements);
+ SmallVector<Constant *, 16> SrcElements;
+ getArrayElements(AVI.SrcInit, SrcElements);
ArrayType *NewType = cast<ArrayType>(AVI.NewGV->getType()->getElementType());
- AVI.NewGV->setInitializer(ConstantArray::get(NewType, Elements));
+
+ StringRef Name = AVI.NewGV->getName();
+ bool IsNewStructor =
+ (Name == "llvm.global_ctors" || Name == "llvm.global_dtors") &&
+ cast<StructType>(NewType->getElementType())->getNumElements() == 3;
+
+ for (auto *V : SrcElements) {
+ if (IsNewStructor) {
+ Constant *Key = V->getAggregateElement(2);
+ if (DoNotLinkFromSource.count(Key))
+ continue;
+ }
+ DstElements.push_back(
+ MapValue(V, ValueMap, RF_None, &TypeMap, &ValMaterializer));
+ }
+ if (IsNewStructor) {
+ NewType = ArrayType::get(NewType->getElementType(), DstElements.size());
+ AVI.NewGV->mutateType(PointerType::get(NewType, 0));
+ }
+
+ AVI.NewGV->setInitializer(ConstantArray::get(NewType, DstElements));
}
/// linkGlobalInits - Update the initializers in the Dest module now that all
ComdatsChosen[&C] = std::make_pair(SK, LinkFromSrc);
}
+ // Upgrade mismatched global arrays.
+ upgradeMismatchedGlobals();
+
// Insert all of the globals in src into the DstM module... without linking
// initializers (which could refer to functions not yet mapped over).
for (Module::global_iterator I = SrcM->global_begin(),