//
//===----------------------------------------------------------------------===//
-#include "llvm/Linker.h"
+#include "llvm/Linker/Linker.h"
#include "llvm-c/Linker.h"
+#include "llvm/ADT/Hashing.h"
#include "llvm/ADT/Optional.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/Triple.h"
#include "llvm/IR/Constants.h"
+#include "llvm/IR/DebugInfo.h"
+#include "llvm/IR/DiagnosticInfo.h"
+#include "llvm/IR/DiagnosticPrinter.h"
+#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/TypeFinder.h"
+#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Transforms/Utils/Cloning.h"
+#include <cctype>
+#include <tuple>
using namespace llvm;
+
//===----------------------------------------------------------------------===//
// TypeMap implementation.
//===----------------------------------------------------------------------===//
namespace {
- typedef SmallPtrSet<StructType*, 32> TypeSet;
-
class TypeMapTy : public ValueMapTypeRemapper {
- /// MappedTypes - This is a mapping from a source type to a destination type
- /// to use.
+ /// This is a mapping from a source type to a destination type to use.
DenseMap<Type*, Type*> MappedTypes;
- /// SpeculativeTypes - When checking to see if two subgraphs are isomorphic,
- /// we speculatively add types to MappedTypes, but keep track of them here in
- /// case we need to roll back.
+ /// When checking to see if two subgraphs are isomorphic, we speculatively
+ /// add types to MappedTypes, but keep track of them here in case we need to
+ /// roll back.
SmallVector<Type*, 16> SpeculativeTypes;
-
- /// SrcDefinitionsToResolve - This is a list of non-opaque structs in the
- /// source module that are mapped to an opaque struct in the destination
- /// module.
+
+ SmallVector<StructType*, 16> SpeculativeDstOpaqueTypes;
+
+ /// This is a list of non-opaque structs in the source module that are mapped
+ /// to an opaque struct in the destination module.
SmallVector<StructType*, 16> SrcDefinitionsToResolve;
-
- /// DstResolvedOpaqueTypes - This is the set of opaque types in the
- /// destination modules who are getting a body from the source module.
+
+ /// This is the set of opaque types in the destination modules who are
+ /// getting a body from the source module.
SmallPtrSet<StructType*, 16> DstResolvedOpaqueTypes;
public:
- TypeMapTy(TypeSet &Set) : DstStructTypesSet(Set) {}
+ TypeMapTy(Linker::IdentifiedStructTypeSet &DstStructTypesSet)
+ : DstStructTypesSet(DstStructTypesSet) {}
- TypeSet &DstStructTypesSet;
- /// addTypeMapping - Indicate that the specified type in the destination
- /// module is conceptually equivalent to the specified type in the source
- /// module.
+ Linker::IdentifiedStructTypeSet &DstStructTypesSet;
+ /// Indicate that the specified type in the destination module is conceptually
+ /// equivalent to the specified type in the source module.
void addTypeMapping(Type *DstTy, Type *SrcTy);
- /// linkDefinedTypeBodies - Produce a body for an opaque type in the dest
- /// module from a type definition in the source module.
+ /// Produce a body for an opaque type in the dest module from a type
+ /// definition in the source module.
void linkDefinedTypeBodies();
-
- /// get - Return the mapped type to use for the specified input type from the
+
+ /// Return the mapped type to use for the specified input type from the
/// source module.
Type *get(Type *SrcTy);
+ Type *get(Type *SrcTy, SmallPtrSet<StructType *, 8> &Visited);
- FunctionType *get(FunctionType *T) {return cast<FunctionType>(get((Type*)T));}
+ void finishType(StructType *DTy, StructType *STy, ArrayRef<Type *> ETypes);
+
+ FunctionType *get(FunctionType *T) {
+ return cast<FunctionType>(get((Type *)T));
+ }
- /// dump - Dump out the type map for debugging purposes.
+ /// Dump out the type map for debugging purposes.
void dump() const {
- for (DenseMap<Type*, Type*>::const_iterator
- I = MappedTypes.begin(), E = MappedTypes.end(); I != E; ++I) {
+ for (auto &Pair : MappedTypes) {
dbgs() << "TypeMap: ";
- I->first->dump();
+ Pair.first->print(dbgs());
dbgs() << " => ";
- I->second->dump();
+ Pair.second->print(dbgs());
dbgs() << '\n';
}
}
private:
- Type *getImpl(Type *T);
- /// remapType - Implement the ValueMapTypeRemapper interface.
- Type *remapType(Type *SrcTy) {
- return get(SrcTy);
- }
-
+ Type *remapType(Type *SrcTy) override { return get(SrcTy); }
+
bool areTypesIsomorphic(Type *DstTy, Type *SrcTy);
};
}
void TypeMapTy::addTypeMapping(Type *DstTy, Type *SrcTy) {
- Type *&Entry = MappedTypes[SrcTy];
- if (Entry) return;
-
- if (DstTy == SrcTy) {
- Entry = DstTy;
- return;
- }
-
+ assert(SpeculativeTypes.empty());
+ assert(SpeculativeDstOpaqueTypes.empty());
+
// Check to see if these types are recursively isomorphic and establish a
// mapping between them if so.
if (!areTypesIsomorphic(DstTy, SrcTy)) {
// Oops, they aren't isomorphic. Just discard this request by rolling out
// any speculative mappings we've established.
- for (unsigned i = 0, e = SpeculativeTypes.size(); i != e; ++i)
- MappedTypes.erase(SpeculativeTypes[i]);
+ for (Type *Ty : SpeculativeTypes)
+ MappedTypes.erase(Ty);
+
+ SrcDefinitionsToResolve.resize(SrcDefinitionsToResolve.size() -
+ SpeculativeDstOpaqueTypes.size());
+ for (StructType *Ty : SpeculativeDstOpaqueTypes)
+ DstResolvedOpaqueTypes.erase(Ty);
+ } else {
+ for (Type *Ty : SpeculativeTypes)
+ if (auto *STy = dyn_cast<StructType>(Ty))
+ if (STy->hasName())
+ STy->setName("");
}
SpeculativeTypes.clear();
+ SpeculativeDstOpaqueTypes.clear();
}
-/// areTypesIsomorphic - Recursively walk this pair of types, returning true
-/// if they are isomorphic, false if they are not.
+/// Recursively walk this pair of types, returning true if they are isomorphic,
+/// false if they are not.
bool TypeMapTy::areTypesIsomorphic(Type *DstTy, Type *SrcTy) {
// Two types with differing kinds are clearly not isomorphic.
- if (DstTy->getTypeID() != SrcTy->getTypeID()) return false;
+ if (DstTy->getTypeID() != SrcTy->getTypeID())
+ return false;
// If we have an entry in the MappedTypes table, then we have our answer.
Type *&Entry = MappedTypes[SrcTy];
Entry = DstTy;
return true;
}
-
+
// Okay, we have two types with identical kinds that we haven't seen before.
// If this is an opaque struct type, special case it.
// Mapping a non-opaque source type to an opaque dest. If this is the first
// type that we're mapping onto this destination type then we succeed. Keep
- // the dest, but fill it in later. This doesn't need to be speculative. If
- // this is the second (different) type that we're trying to map onto the
- // same opaque type then we fail.
+ // the dest, but fill it in later. If this is the second (different) type
+ // that we're trying to map onto the same opaque type then we fail.
if (cast<StructType>(DstTy)->isOpaque()) {
// We can only map one source type onto the opaque destination type.
- if (!DstResolvedOpaqueTypes.insert(cast<StructType>(DstTy)))
+ if (!DstResolvedOpaqueTypes.insert(cast<StructType>(DstTy)).second)
return false;
SrcDefinitionsToResolve.push_back(SSTy);
+ SpeculativeTypes.push_back(SrcTy);
+ SpeculativeDstOpaqueTypes.push_back(cast<StructType>(DstTy));
Entry = DstTy;
return true;
}
}
-
+
// If the number of subtypes disagree between the two types, then we fail.
if (SrcTy->getNumContainedTypes() != DstTy->getNumContainedTypes())
return false;
-
+
// Fail if any of the extra properties (e.g. array size) of the type disagree.
if (isa<IntegerType>(DstTy))
return false; // bitwidth disagrees.
if (PointerType *PT = dyn_cast<PointerType>(DstTy)) {
if (PT->getAddressSpace() != cast<PointerType>(SrcTy)->getAddressSpace())
return false;
-
+
} else if (FunctionType *FT = dyn_cast<FunctionType>(DstTy)) {
if (FT->isVarArg() != cast<FunctionType>(SrcTy)->isVarArg())
return false;
Entry = DstTy;
SpeculativeTypes.push_back(SrcTy);
- for (unsigned i = 0, e = SrcTy->getNumContainedTypes(); i != e; ++i)
- if (!areTypesIsomorphic(DstTy->getContainedType(i),
- SrcTy->getContainedType(i)))
+ for (unsigned I = 0, E = SrcTy->getNumContainedTypes(); I != E; ++I)
+ if (!areTypesIsomorphic(DstTy->getContainedType(I),
+ SrcTy->getContainedType(I)))
return false;
-
+
// If everything seems to have lined up, then everything is great.
return true;
}
-/// linkDefinedTypeBodies - Produce a body for an opaque type in the dest
-/// module from a type definition in the source module.
void TypeMapTy::linkDefinedTypeBodies() {
SmallVector<Type*, 16> Elements;
- SmallString<16> TmpName;
-
- // Note that processing entries in this loop (calling 'get') can add new
- // entries to the SrcDefinitionsToResolve vector.
- while (!SrcDefinitionsToResolve.empty()) {
- StructType *SrcSTy = SrcDefinitionsToResolve.pop_back_val();
+ for (StructType *SrcSTy : SrcDefinitionsToResolve) {
StructType *DstSTy = cast<StructType>(MappedTypes[SrcSTy]);
-
- // TypeMap is a many-to-one mapping, if there were multiple types that
- // provide a body for DstSTy then previous iterations of this loop may have
- // already handled it. Just ignore this case.
- if (!DstSTy->isOpaque()) continue;
- assert(!SrcSTy->isOpaque() && "Not resolving a definition?");
-
+ assert(DstSTy->isOpaque());
+
// Map the body of the source type over to a new body for the dest type.
Elements.resize(SrcSTy->getNumElements());
- for (unsigned i = 0, e = Elements.size(); i != e; ++i)
- Elements[i] = getImpl(SrcSTy->getElementType(i));
-
+ for (unsigned I = 0, E = Elements.size(); I != E; ++I)
+ Elements[I] = get(SrcSTy->getElementType(I));
+
DstSTy->setBody(Elements, SrcSTy->isPacked());
-
- // If DstSTy has no name or has a longer name than STy, then viciously steal
- // STy's name.
- if (!SrcSTy->hasName()) continue;
- StringRef SrcName = SrcSTy->getName();
-
- if (!DstSTy->hasName() || DstSTy->getName().size() > SrcName.size()) {
- TmpName.insert(TmpName.end(), SrcName.begin(), SrcName.end());
- SrcSTy->setName("");
- DstSTy->setName(TmpName.str());
- TmpName.clear();
- }
+ DstStructTypesSet.switchToNonOpaque(DstSTy);
}
-
+ SrcDefinitionsToResolve.clear();
DstResolvedOpaqueTypes.clear();
}
-/// get - Return the mapped type to use for the specified input type from the
-/// source module.
+void TypeMapTy::finishType(StructType *DTy, StructType *STy,
+ ArrayRef<Type *> ETypes) {
+ DTy->setBody(ETypes, STy->isPacked());
+
+ // Steal STy's name.
+ if (STy->hasName()) {
+ SmallString<16> TmpName = STy->getName();
+ STy->setName("");
+ DTy->setName(TmpName);
+ }
+
+ DstStructTypesSet.addNonOpaque(DTy);
+}
+
Type *TypeMapTy::get(Type *Ty) {
- Type *Result = getImpl(Ty);
-
- // If this caused a reference to any struct type, resolve it before returning.
- if (!SrcDefinitionsToResolve.empty())
- linkDefinedTypeBodies();
- return Result;
+ SmallPtrSet<StructType *, 8> Visited;
+ return get(Ty, Visited);
}
-/// getImpl - This is the recursive version of get().
-Type *TypeMapTy::getImpl(Type *Ty) {
+Type *TypeMapTy::get(Type *Ty, SmallPtrSet<StructType *, 8> &Visited) {
// If we already have an entry for this type, return it.
Type **Entry = &MappedTypes[Ty];
- if (*Entry) return *Entry;
-
- // If this is not a named struct type, then just map all of the elements and
+ if (*Entry)
+ return *Entry;
+
+ // These are types that LLVM itself will unique.
+ bool IsUniqued = !isa<StructType>(Ty) || cast<StructType>(Ty)->isLiteral();
+
+#ifndef NDEBUG
+ if (!IsUniqued) {
+ for (auto &Pair : MappedTypes) {
+ assert(!(Pair.first != Ty && Pair.second == Ty) &&
+ "mapping to a source type");
+ }
+ }
+#endif
+
+ if (!IsUniqued && !Visited.insert(cast<StructType>(Ty)).second) {
+ StructType *DTy = StructType::create(Ty->getContext());
+ return *Entry = DTy;
+ }
+
+ // If this is not a recursive type, then just map all of the elements and
// then rebuild the type from inside out.
- if (!isa<StructType>(Ty) || cast<StructType>(Ty)->isLiteral()) {
- // If there are no element types to map, then the type is itself. This is
- // true for the anonymous {} struct, things like 'float', integers, etc.
- if (Ty->getNumContainedTypes() == 0)
+ SmallVector<Type *, 4> ElementTypes;
+
+ // If there are no element types to map, then the type is itself. This is
+ // true for the anonymous {} struct, things like 'float', integers, etc.
+ if (Ty->getNumContainedTypes() == 0 && IsUniqued)
+ return *Entry = Ty;
+
+ // Remap all of the elements, keeping track of whether any of them change.
+ bool AnyChange = false;
+ ElementTypes.resize(Ty->getNumContainedTypes());
+ for (unsigned I = 0, E = Ty->getNumContainedTypes(); I != E; ++I) {
+ ElementTypes[I] = get(Ty->getContainedType(I), Visited);
+ AnyChange |= ElementTypes[I] != Ty->getContainedType(I);
+ }
+
+ // If we found our type while recursively processing stuff, just use it.
+ Entry = &MappedTypes[Ty];
+ if (*Entry) {
+ if (auto *DTy = dyn_cast<StructType>(*Entry)) {
+ if (DTy->isOpaque()) {
+ auto *STy = cast<StructType>(Ty);
+ finishType(DTy, STy, ElementTypes);
+ }
+ }
+ return *Entry;
+ }
+
+ // If all of the element types mapped directly over and the type is not
+ // a nomed struct, then the type is usable as-is.
+ if (!AnyChange && IsUniqued)
+ return *Entry = Ty;
+
+ // Otherwise, rebuild a modified type.
+ switch (Ty->getTypeID()) {
+ default:
+ llvm_unreachable("unknown derived type to remap");
+ case Type::ArrayTyID:
+ return *Entry = ArrayType::get(ElementTypes[0],
+ cast<ArrayType>(Ty)->getNumElements());
+ case Type::VectorTyID:
+ return *Entry = VectorType::get(ElementTypes[0],
+ cast<VectorType>(Ty)->getNumElements());
+ case Type::PointerTyID:
+ return *Entry = PointerType::get(ElementTypes[0],
+ cast<PointerType>(Ty)->getAddressSpace());
+ case Type::FunctionTyID:
+ return *Entry = FunctionType::get(ElementTypes[0],
+ makeArrayRef(ElementTypes).slice(1),
+ cast<FunctionType>(Ty)->isVarArg());
+ case Type::StructTyID: {
+ auto *STy = cast<StructType>(Ty);
+ bool IsPacked = STy->isPacked();
+ if (IsUniqued)
+ return *Entry = StructType::get(Ty->getContext(), ElementTypes, IsPacked);
+
+ // If the type is opaque, we can just use it directly.
+ if (STy->isOpaque()) {
+ DstStructTypesSet.addOpaque(STy);
return *Entry = Ty;
-
- // Remap all of the elements, keeping track of whether any of them change.
- bool AnyChange = false;
- SmallVector<Type*, 4> ElementTypes;
- ElementTypes.resize(Ty->getNumContainedTypes());
- for (unsigned i = 0, e = Ty->getNumContainedTypes(); i != e; ++i) {
- ElementTypes[i] = getImpl(Ty->getContainedType(i));
- AnyChange |= ElementTypes[i] != Ty->getContainedType(i);
}
-
- // If we found our type while recursively processing stuff, just use it.
- Entry = &MappedTypes[Ty];
- if (*Entry) return *Entry;
-
- // If all of the element types mapped directly over, then the type is usable
- // as-is.
- if (!AnyChange)
+
+ if (StructType *OldT =
+ DstStructTypesSet.findNonOpaque(ElementTypes, IsPacked)) {
+ STy->setName("");
+ return *Entry = OldT;
+ }
+
+ if (!AnyChange) {
+ DstStructTypesSet.addNonOpaque(STy);
return *Entry = Ty;
-
- // Otherwise, rebuild a modified type.
- switch (Ty->getTypeID()) {
- default: llvm_unreachable("unknown derived type to remap");
- case Type::ArrayTyID:
- return *Entry = ArrayType::get(ElementTypes[0],
- cast<ArrayType>(Ty)->getNumElements());
- case Type::VectorTyID:
- return *Entry = VectorType::get(ElementTypes[0],
- cast<VectorType>(Ty)->getNumElements());
- case Type::PointerTyID:
- return *Entry = PointerType::get(ElementTypes[0],
- cast<PointerType>(Ty)->getAddressSpace());
- case Type::FunctionTyID:
- return *Entry = FunctionType::get(ElementTypes[0],
- makeArrayRef(ElementTypes).slice(1),
- cast<FunctionType>(Ty)->isVarArg());
- case Type::StructTyID:
- // Note that this is only reached for anonymous structs.
- return *Entry = StructType::get(Ty->getContext(), ElementTypes,
- cast<StructType>(Ty)->isPacked());
}
- }
- // Otherwise, this is an unmapped named struct. If the struct can be directly
- // mapped over, just use it as-is. This happens in a case when the linked-in
- // module has something like:
- // %T = type {%T*, i32}
- // @GV = global %T* null
- // where T does not exist at all in the destination module.
- //
- // The other case we watch for is when the type is not in the destination
- // module, but that it has to be rebuilt because it refers to something that
- // is already mapped. For example, if the destination module has:
- // %A = type { i32 }
- // and the source module has something like
- // %A' = type { i32 }
- // %B = type { %A'* }
- // @GV = global %B* null
- // then we want to create a new type: "%B = type { %A*}" and have it take the
- // pristine "%B" name from the source module.
- //
- // To determine which case this is, we have to recursively walk the type graph
- // speculating that we'll be able to reuse it unmodified. Only if this is
- // safe would we map the entire thing over. Because this is an optimization,
- // and is not required for the prettiness of the linked module, we just skip
- // it and always rebuild a type here.
- StructType *STy = cast<StructType>(Ty);
-
- // If the type is opaque, we can just use it directly.
- if (STy->isOpaque()) {
- // A named structure type from src module is used. Add it to the Set of
- // identified structs in the destination module.
- DstStructTypesSet.insert(STy);
- return *Entry = STy;
- }
-
- // Otherwise we create a new type and resolve its body later. This will be
- // resolved by the top level of get().
- SrcDefinitionsToResolve.push_back(STy);
- StructType *DTy = StructType::create(STy->getContext());
- // A new identified structure type was created. Add it to the set of
- // identified structs in the destination module.
- DstStructTypesSet.insert(DTy);
- DstResolvedOpaqueTypes.insert(DTy);
- return *Entry = DTy;
+ StructType *DTy = StructType::create(Ty->getContext());
+ finishType(DTy, STy, ElementTypes);
+ return *Entry = DTy;
+ }
+ }
}
//===----------------------------------------------------------------------===//
//===----------------------------------------------------------------------===//
namespace {
- class ModuleLinker;
-
- /// ValueMaterializerTy - Creates prototypes for functions that are lazily
- /// linked on the fly. This speeds up linking for modules with many
- /// lazily linked functions of which few get used.
- class ValueMaterializerTy : public ValueMaterializer {
- TypeMapTy &TypeMap;
- Module *DstM;
- std::vector<Function*> &LazilyLinkFunctions;
- public:
- ValueMaterializerTy(TypeMapTy &TypeMap, Module *DstM,
- std::vector<Function*> &LazilyLinkFunctions) :
- ValueMaterializer(), TypeMap(TypeMap), DstM(DstM),
- LazilyLinkFunctions(LazilyLinkFunctions) {
- }
+class ModuleLinker;
- virtual Value *materializeValueFor(Value *V);
- };
+/// Creates prototypes for functions that are lazily linked on the fly. This
+/// speeds up linking for modules with many/ lazily linked functions of which
+/// few get used.
+class ValueMaterializerTy final : public ValueMaterializer {
+ ModuleLinker *ModLinker;
- /// ModuleLinker - This is an implementation class for the LinkModules
- /// function, which is the entrypoint for this file.
- class ModuleLinker {
- Module *DstM, *SrcM;
-
- TypeMapTy TypeMap;
- ValueMaterializerTy ValMaterializer;
-
- /// ValueMap - Mapping of values from what they used to be in Src, to what
- /// they are now in DstM. ValueToValueMapTy is a ValueMap, which involves
- /// some overhead due to the use of Value handles which the Linker doesn't
- /// actually need, but this allows us to reuse the ValueMapper code.
- ValueToValueMapTy ValueMap;
-
- struct AppendingVarInfo {
- GlobalVariable *NewGV; // New aggregate global in dest module.
- Constant *DstInit; // Old initializer from dest module.
- Constant *SrcInit; // Old initializer from src module.
- };
-
- std::vector<AppendingVarInfo> AppendingVars;
-
- unsigned Mode; // Mode to treat source module.
-
- // Set of items not to link in from source.
- SmallPtrSet<const Value*, 16> DoNotLinkFromSource;
-
- // Vector of functions to lazily link in.
- std::vector<Function*> LazilyLinkFunctions;
-
- public:
- std::string ErrorMsg;
-
- ModuleLinker(Module *dstM, TypeSet &Set, Module *srcM, unsigned mode)
- : DstM(dstM), SrcM(srcM), TypeMap(Set),
- ValMaterializer(TypeMap, DstM, LazilyLinkFunctions),
- Mode(mode) { }
-
- bool run();
-
- private:
- /// emitError - Helper method for setting a message and returning an error
- /// code.
- bool emitError(const Twine &Message) {
- ErrorMsg = Message.str();
- return true;
- }
-
- /// getLinkageResult - 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);
-
- /// getLinkedToGlobal - Given a global in the source module, return the
- /// global in the destination module that is being linked to, if any.
- GlobalValue *getLinkedToGlobal(GlobalValue *SrcGV) {
- // If the source has no name it can't link. If it has local linkage,
- // there is no name match-up going on.
- if (!SrcGV->hasName() || SrcGV->hasLocalLinkage())
- return 0;
-
- // Otherwise see if we have a match in the destination module's symtab.
- GlobalValue *DGV = DstM->getNamedValue(SrcGV->getName());
- if (DGV == 0) return 0;
-
- // 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->hasLocalLinkage())
- return 0;
-
- // Otherwise, we do in fact link to the destination global.
- return DGV;
- }
-
- void computeTypeMapping();
-
- bool linkAppendingVarProto(GlobalVariable *DstGV, GlobalVariable *SrcGV);
- bool linkGlobalProto(GlobalVariable *SrcGV);
- bool linkFunctionProto(Function *SrcF);
- bool linkAliasProto(GlobalAlias *SrcA);
- bool linkModuleFlagsMetadata();
-
- void linkAppendingVarInit(const AppendingVarInfo &AVI);
- void linkGlobalInits();
- void linkFunctionBody(Function *Dst, Function *Src);
- void linkAliasBodies();
- void linkNamedMDNodes();
+public:
+ ValueMaterializerTy(ModuleLinker *ModLinker) : ModLinker(ModLinker) {}
+
+ Value *materializeDeclFor(Value *V) override;
+ void materializeInitFor(GlobalValue *New, GlobalValue *Old) override;
+};
+
+class LinkDiagnosticInfo : public DiagnosticInfo {
+ const Twine &Msg;
+
+public:
+ LinkDiagnosticInfo(DiagnosticSeverity Severity, const Twine &Msg);
+ void print(DiagnosticPrinter &DP) const override;
+};
+LinkDiagnosticInfo::LinkDiagnosticInfo(DiagnosticSeverity Severity,
+ const Twine &Msg)
+ : DiagnosticInfo(DK_Linker, Severity), Msg(Msg) {}
+void LinkDiagnosticInfo::print(DiagnosticPrinter &DP) const { DP << Msg; }
+
+/// This is an implementation class for the LinkModules function, which is the
+/// entrypoint for this file.
+class ModuleLinker {
+ Module *DstM, *SrcM;
+
+ TypeMapTy TypeMap;
+ ValueMaterializerTy ValMaterializer;
+
+ /// Mapping of values from what they used to be in Src, to what they are now
+ /// in DstM. ValueToValueMapTy is a ValueMap, which involves some overhead
+ /// due to the use of Value handles which the Linker doesn't actually need,
+ /// but this allows us to reuse the ValueMapper code.
+ ValueToValueMapTy ValueMap;
+
+ struct AppendingVarInfo {
+ GlobalVariable *NewGV; // New aggregate global in dest module.
+ const Constant *DstInit; // Old initializer from dest module.
+ const Constant *SrcInit; // Old initializer from src module.
};
+
+ std::vector<AppendingVarInfo> AppendingVars;
+
+ // Set of items not to link in from source.
+ SmallPtrSet<const GlobalValue *, 16> DoNotLinkFromSource;
+
+ DiagnosticHandlerFunction DiagnosticHandler;
+
+ /// For symbol clashes, prefer those from Src.
+ unsigned Flags;
+
+ /// Function index passed into ModuleLinker for using in function
+ /// importing/exporting handling.
+ const FunctionInfoIndex *ImportIndex;
+
+ /// Function to import from source module, all other functions are
+ /// imported as declarations instead of definitions.
+ Function *ImportFunction;
+
+ /// Set to true if the given FunctionInfoIndex contains any functions
+ /// from this source module, in which case we must conservatively assume
+ /// that any of its functions may be imported into another module
+ /// as part of a different backend compilation process.
+ bool HasExportedFunctions;
+
+ /// Set to true when all global value body linking is complete (including
+ /// lazy linking). Used to prevent metadata linking from creating new
+ /// references.
+ bool DoneLinkingBodies;
+
+ bool HasError = false;
+
+public:
+ ModuleLinker(Module *dstM, Linker::IdentifiedStructTypeSet &Set, Module *srcM,
+ DiagnosticHandlerFunction DiagnosticHandler, unsigned Flags,
+ const FunctionInfoIndex *Index = nullptr,
+ Function *FuncToImport = nullptr)
+ : DstM(dstM), SrcM(srcM), TypeMap(Set), ValMaterializer(this),
+ DiagnosticHandler(DiagnosticHandler), Flags(Flags), ImportIndex(Index),
+ ImportFunction(FuncToImport), HasExportedFunctions(false),
+ DoneLinkingBodies(false) {
+ assert((ImportIndex || !ImportFunction) &&
+ "Expect a FunctionInfoIndex when importing");
+ // If we have a FunctionInfoIndex but no function to import,
+ // then this is the primary module being compiled in a ThinLTO
+ // backend compilation, and we need to see if it has functions that
+ // may be exported to another backend compilation.
+ if (ImportIndex && !ImportFunction)
+ HasExportedFunctions = ImportIndex->hasExportedFunctions(SrcM);
+ }
+
+ bool run();
+ Value *materializeDeclFor(Value *V);
+ void materializeInitFor(GlobalValue *New, GlobalValue *Old);
+
+private:
+ bool shouldOverrideFromSrc() { return Flags & Linker::OverrideFromSrc; }
+ bool shouldLinkOnlyNeeded() { return Flags & Linker::LinkOnlyNeeded; }
+ bool shouldInternalizeLinkedSymbols() {
+ return Flags & Linker::InternalizeLinkedSymbols;
+ }
+
+ /// Handles cloning of a global values from the source module into
+ /// the destination module, including setting the attributes and visibility.
+ GlobalValue *copyGlobalValueProto(TypeMapTy &TypeMap, const GlobalValue *SGV,
+ const GlobalValue *DGV = nullptr);
+
+ /// Check if we should promote the given local value to global scope.
+ bool doPromoteLocalToGlobal(const GlobalValue *SGV);
+
+ /// Check if all global value body linking is complete.
+ bool doneLinkingBodies() { return DoneLinkingBodies; }
+
+ bool shouldLinkFromSource(bool &LinkFromSrc, const GlobalValue &Dest,
+ const GlobalValue &Src);
+
+ /// Helper method for setting a message and returning an error code.
+ bool emitError(const Twine &Message) {
+ DiagnosticHandler(LinkDiagnosticInfo(DS_Error, Message));
+ HasError = true;
+ return true;
+ }
+
+ void emitWarning(const Twine &Message) {
+ DiagnosticHandler(LinkDiagnosticInfo(DS_Warning, Message));
+ }
+
+ bool getComdatLeader(Module *M, StringRef ComdatName,
+ const GlobalVariable *&GVar);
+ bool computeResultingSelectionKind(StringRef ComdatName,
+ Comdat::SelectionKind Src,
+ Comdat::SelectionKind Dst,
+ Comdat::SelectionKind &Result,
+ bool &LinkFromSrc);
+ std::map<const Comdat *, std::pair<Comdat::SelectionKind, bool>>
+ ComdatsChosen;
+ bool getComdatResult(const Comdat *SrcC, Comdat::SelectionKind &SK,
+ bool &LinkFromSrc);
+ // Keep track of the global value members of each comdat in source.
+ DenseMap<const Comdat *, std::vector<GlobalValue *>> ComdatMembers;
+
+ /// 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) {
+ // If the source has no name it can't link. If it has local linkage,
+ // there is no name match-up going on.
+ if (!SrcGV->hasName() || GlobalValue::isLocalLinkage(getLinkage(SrcGV)))
+ return nullptr;
+
+ // Otherwise see if we have a match in the destination module's symtab.
+ GlobalValue *DGV = DstM->getNamedValue(getName(SrcGV));
+ if (!DGV)
+ return nullptr;
+
+ // 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->hasLocalLinkage())
+ return nullptr;
+
+ // Otherwise, we do in fact link to the destination global.
+ return DGV;
+ }
+
+ void computeTypeMapping();
+
+ void upgradeMismatchedGlobalArray(StringRef Name);
+ void upgradeMismatchedGlobals();
+
+ bool linkIfNeeded(GlobalValue &GV);
+ bool linkAppendingVarProto(GlobalVariable *DstGV,
+ const GlobalVariable *SrcGV);
+
+ bool linkGlobalValueProto(GlobalValue *GV);
+ bool linkModuleFlagsMetadata();
+
+ void linkAppendingVarInit(AppendingVarInfo &AVI);
+
+ void linkGlobalInit(GlobalVariable &Dst, GlobalVariable &Src);
+ bool linkFunctionBody(Function &Dst, Function &Src);
+ void linkAliasBody(GlobalAlias &Dst, GlobalAlias &Src);
+ bool linkGlobalValueBody(GlobalValue &Src);
+
+ /// Functions that take care of cloning a specific global value type
+ /// into the destination module.
+ GlobalVariable *copyGlobalVariableProto(TypeMapTy &TypeMap,
+ const GlobalVariable *SGVar);
+ Function *copyFunctionProto(TypeMapTy &TypeMap, const Function *SF);
+ GlobalValue *copyGlobalAliasProto(TypeMapTy &TypeMap, const GlobalAlias *SGA);
+
+ /// Helper methods to check if we are importing from or potentially
+ /// exporting from the current source module.
+ bool isPerformingImport() { return ImportFunction != nullptr; }
+ bool isModuleExporting() { return HasExportedFunctions; }
+
+ /// If we are importing from the source module, checks if we should
+ /// import SGV as a definition, otherwise import as a declaration.
+ bool doImportAsDefinition(const GlobalValue *SGV);
+
+ /// Get the name for SGV that should be used in the linked destination
+ /// module. Specifically, this handles the case where we need to rename
+ /// a local that is being promoted to global scope.
+ std::string getName(const GlobalValue *SGV);
+
+ /// Get the new linkage for SGV that should be used in the linked destination
+ /// module. Specifically, for ThinLTO importing or exporting it may need
+ /// to be adjusted.
+ GlobalValue::LinkageTypes getLinkage(const GlobalValue *SGV);
+
+ /// Copies the necessary global value attributes and name from the source
+ /// to the newly cloned global value.
+ void copyGVAttributes(GlobalValue *NewGV, const GlobalValue *SrcGV);
+
+ /// Updates the visibility for the new global cloned from the source
+ /// and, if applicable, linked with an existing destination global.
+ /// Handles visibility change required for promoted locals.
+ void setVisibility(GlobalValue *NewGV, const GlobalValue *SGV,
+ const GlobalValue *DGV = nullptr);
+
+ void linkNamedMDNodes();
+};
}
-/// forceRenaming - The LLVM SymbolTable class autorenames globals that conflict
-/// in the symbol table. This is good for all clients except for us. Go
-/// through the trouble to force this back.
+/// The LLVM SymbolTable class autorenames globals that conflict in the symbol
+/// table. This is good for all clients except for us. Go through the trouble
+/// to force this back.
static void forceRenaming(GlobalValue *GV, StringRef Name) {
// If the global doesn't force its name or if it already has the right name,
// there is nothing for us to do.
+ // Note that any required local to global promotion should already be done,
+ // so promoted locals will not skip this handling as their linkage is no
+ // longer local.
if (GV->hasLocalLinkage() || GV->getName() == Name)
return;
}
}
-/// copyGVAttributes - copy additional attributes (those not needed to construct
-/// a GlobalValue) from the SrcGV to the DestGV.
-static void copyGVAttributes(GlobalValue *DestGV, const GlobalValue *SrcGV) {
- // Use the maximum alignment, rather than just copying the alignment of SrcGV.
- unsigned Alignment = std::max(DestGV->getAlignment(), SrcGV->getAlignment());
- DestGV->copyAttributesFrom(SrcGV);
- DestGV->setAlignment(Alignment);
-
- forceRenaming(DestGV, SrcGV->getName());
+/// copy additional attributes (those not needed to construct a GlobalValue)
+/// from the SrcGV to the DestGV.
+void ModuleLinker::copyGVAttributes(GlobalValue *NewGV,
+ const GlobalValue *SrcGV) {
+ auto *GA = dyn_cast<GlobalAlias>(SrcGV);
+ // Check for the special case of converting an alias (definition) to a
+ // non-alias (declaration). This can happen when we are importing and
+ // encounter a weak_any alias (weak_any defs may not be imported, see
+ // comments in ModuleLinker::getLinkage) or an alias whose base object is
+ // being imported as a declaration. In that case copy the attributes from the
+ // base object.
+ if (GA && !dyn_cast<GlobalAlias>(NewGV)) {
+ assert(isPerformingImport() && !doImportAsDefinition(GA));
+ NewGV->copyAttributesFrom(GA->getBaseObject());
+ } else
+ NewGV->copyAttributesFrom(SrcGV);
+ forceRenaming(NewGV, getName(SrcGV));
}
-static bool isLessConstraining(GlobalValue::VisibilityTypes a,
- GlobalValue::VisibilityTypes b) {
- if (a == GlobalValue::HiddenVisibility)
+bool ModuleLinker::doImportAsDefinition(const GlobalValue *SGV) {
+ if (!isPerformingImport())
return false;
- if (b == GlobalValue::HiddenVisibility)
+ auto *GA = dyn_cast<GlobalAlias>(SGV);
+ if (GA) {
+ if (GA->hasWeakAnyLinkage())
+ return false;
+ const GlobalObject *GO = GA->getBaseObject();
+ if (!GO->hasLinkOnceODRLinkage())
+ return false;
+ return doImportAsDefinition(GO);
+ }
+ // Always import GlobalVariable definitions, except for the special
+ // case of WeakAny which are imported as ExternalWeak declarations
+ // (see comments in ModuleLinker::getLinkage). The linkage changes
+ // described in ModuleLinker::getLinkage ensure the correct behavior (e.g.
+ // global variables with external linkage are transformed to
+ // available_externally definitions, which are ultimately turned into
+ // declarations after the EliminateAvailableExternally pass).
+ if (isa<GlobalVariable>(SGV) && !SGV->isDeclaration() &&
+ !SGV->hasWeakAnyLinkage())
return true;
- if (a == GlobalValue::ProtectedVisibility)
- return false;
- if (b == GlobalValue::ProtectedVisibility)
+ // Only import the function requested for importing.
+ auto *SF = dyn_cast<Function>(SGV);
+ if (SF && SF == ImportFunction)
return true;
+ // Otherwise no.
+ return false;
+}
+
+bool ModuleLinker::doPromoteLocalToGlobal(const GlobalValue *SGV) {
+ assert(SGV->hasLocalLinkage());
+ // Both the imported references and the original local variable must
+ // be promoted.
+ if (!isPerformingImport() && !isModuleExporting())
+ return false;
+
+ // Local const variables never need to be promoted unless they are address
+ // taken. The imported uses can simply use the clone created in this module.
+ // For now we are conservative in determining which variables are not
+ // address taken by checking the unnamed addr flag. To be more aggressive,
+ // the address taken information must be checked earlier during parsing
+ // of the module and recorded in the function index for use when importing
+ // from that module.
+ auto *GVar = dyn_cast<GlobalVariable>(SGV);
+ if (GVar && GVar->isConstant() && GVar->hasUnnamedAddr())
+ return false;
+
+ // Eventually we only need to promote functions in the exporting module that
+ // are referenced by a potentially exported function (i.e. one that is in the
+ // function index).
+ return true;
+}
+
+std::string ModuleLinker::getName(const GlobalValue *SGV) {
+ // For locals that must be promoted to global scope, ensure that
+ // the promoted name uniquely identifies the copy in the original module,
+ // using the ID assigned during combined index creation. When importing,
+ // we rename all locals (not just those that are promoted) in order to
+ // avoid naming conflicts between locals imported from different modules.
+ if (SGV->hasLocalLinkage() &&
+ (doPromoteLocalToGlobal(SGV) || isPerformingImport()))
+ return FunctionInfoIndex::getGlobalNameForLocal(
+ SGV->getName(),
+ ImportIndex->getModuleId(SGV->getParent()->getModuleIdentifier()));
+ return SGV->getName();
+}
+
+GlobalValue::LinkageTypes ModuleLinker::getLinkage(const GlobalValue *SGV) {
+ // Any local variable that is referenced by an exported function needs
+ // to be promoted to global scope. Since we don't currently know which
+ // functions reference which local variables/functions, we must treat
+ // all as potentially exported if this module is exporting anything.
+ if (isModuleExporting()) {
+ if (SGV->hasLocalLinkage() && doPromoteLocalToGlobal(SGV))
+ return GlobalValue::ExternalLinkage;
+ return SGV->getLinkage();
+ }
+
+ // Otherwise, if we aren't importing, no linkage change is needed.
+ if (!isPerformingImport())
+ return SGV->getLinkage();
+
+ switch (SGV->getLinkage()) {
+ case GlobalValue::ExternalLinkage:
+ // External defnitions are converted to available_externally
+ // definitions upon import, so that they are available for inlining
+ // and/or optimization, but are turned into declarations later
+ // during the EliminateAvailableExternally pass.
+ if (doImportAsDefinition(SGV) && !dyn_cast<GlobalAlias>(SGV))
+ return GlobalValue::AvailableExternallyLinkage;
+ // An imported external declaration stays external.
+ return SGV->getLinkage();
+
+ case GlobalValue::AvailableExternallyLinkage:
+ // An imported available_externally definition converts
+ // to external if imported as a declaration.
+ if (!doImportAsDefinition(SGV))
+ return GlobalValue::ExternalLinkage;
+ // An imported available_externally declaration stays that way.
+ return SGV->getLinkage();
+
+ case GlobalValue::LinkOnceAnyLinkage:
+ case GlobalValue::LinkOnceODRLinkage:
+ // These both stay the same when importing the definition.
+ // The ThinLTO pass will eventually force-import their definitions.
+ return SGV->getLinkage();
+
+ case GlobalValue::WeakAnyLinkage:
+ // Can't import weak_any definitions correctly, or we might change the
+ // program semantics, since the linker will pick the first weak_any
+ // definition and importing would change the order they are seen by the
+ // linker. The module linking caller needs to enforce this.
+ assert(!doImportAsDefinition(SGV));
+ // If imported as a declaration, it becomes external_weak.
+ return GlobalValue::ExternalWeakLinkage;
+
+ case GlobalValue::WeakODRLinkage:
+ // For weak_odr linkage, there is a guarantee that all copies will be
+ // equivalent, so the issue described above for weak_any does not exist,
+ // and the definition can be imported. It can be treated similarly
+ // to an imported externally visible global value.
+ if (doImportAsDefinition(SGV) && !dyn_cast<GlobalAlias>(SGV))
+ return GlobalValue::AvailableExternallyLinkage;
+ else
+ return GlobalValue::ExternalLinkage;
+
+ case GlobalValue::AppendingLinkage:
+ // It would be incorrect to import an appending linkage variable,
+ // since it would cause global constructors/destructors to be
+ // executed multiple times. This should have already been handled
+ // by linkGlobalValueProto.
+ llvm_unreachable("Cannot import appending linkage variable");
+
+ case GlobalValue::InternalLinkage:
+ case GlobalValue::PrivateLinkage:
+ // If we are promoting the local to global scope, it is handled
+ // similarly to a normal externally visible global.
+ if (doPromoteLocalToGlobal(SGV)) {
+ if (doImportAsDefinition(SGV) && !dyn_cast<GlobalAlias>(SGV))
+ return GlobalValue::AvailableExternallyLinkage;
+ else
+ return GlobalValue::ExternalLinkage;
+ }
+ // A non-promoted imported local definition stays local.
+ // The ThinLTO pass will eventually force-import their definitions.
+ return SGV->getLinkage();
+
+ case GlobalValue::ExternalWeakLinkage:
+ // External weak doesn't apply to definitions, must be a declaration.
+ assert(!doImportAsDefinition(SGV));
+ // Linkage stays external_weak.
+ return SGV->getLinkage();
+
+ case GlobalValue::CommonLinkage:
+ // Linkage stays common on definitions.
+ // The ThinLTO pass will eventually force-import their definitions.
+ return SGV->getLinkage();
+ }
+
+ llvm_unreachable("unknown linkage type");
+}
+
+/// Loop through the global variables in the src module and merge them into the
+/// dest module.
+GlobalVariable *
+ModuleLinker::copyGlobalVariableProto(TypeMapTy &TypeMap,
+ const GlobalVariable *SGVar) {
+ // 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(), getLinkage(SGVar), /*init*/ nullptr, getName(SGVar),
+ /*insertbefore*/ nullptr, SGVar->getThreadLocalMode(),
+ SGVar->getType()->getAddressSpace());
+
+ return NewDGV;
+}
+
+/// Link the function in the source module into the destination module if
+/// needed, setting up mapping information.
+Function *ModuleLinker::copyFunctionProto(TypeMapTy &TypeMap,
+ const Function *SF) {
+ // 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()), getLinkage(SF),
+ getName(SF), DstM);
+}
+
+/// Set up prototypes for any aliases that come over from the source module.
+GlobalValue *ModuleLinker::copyGlobalAliasProto(TypeMapTy &TypeMap,
+ const GlobalAlias *SGA) {
+ // If we are importing and encounter a weak_any alias, or an alias to
+ // an object being imported as a declaration, we must import the alias
+ // as a declaration as well, which involves converting it to a non-alias.
+ // See comments in ModuleLinker::getLinkage for why we cannot import
+ // weak_any defintions.
+ if (isPerformingImport() && !doImportAsDefinition(SGA)) {
+ // Need to convert to declaration. All aliases must be definitions.
+ const GlobalValue *GVal = SGA->getBaseObject();
+ GlobalValue *NewGV;
+ if (auto *GVar = dyn_cast<GlobalVariable>(GVal))
+ NewGV = copyGlobalVariableProto(TypeMap, GVar);
+ else {
+ auto *F = dyn_cast<Function>(GVal);
+ assert(F);
+ NewGV = copyFunctionProto(TypeMap, F);
+ }
+ // Set the linkage to External or ExternalWeak (see comments in
+ // ModuleLinker::getLinkage for why WeakAny is converted to ExternalWeak).
+ if (SGA->hasWeakAnyLinkage())
+ NewGV->setLinkage(GlobalValue::ExternalWeakLinkage);
+ else
+ NewGV->setLinkage(GlobalValue::ExternalLinkage);
+ return NewGV;
+ }
+ // If there is no linkage to be performed or we're linking from the source,
+ // bring over SGA.
+ auto *Ty = TypeMap.get(SGA->getValueType());
+ return GlobalAlias::create(Ty, SGA->getType()->getPointerAddressSpace(),
+ getLinkage(SGA), getName(SGA), DstM);
+}
+
+static GlobalValue::VisibilityTypes
+getMinVisibility(GlobalValue::VisibilityTypes A,
+ GlobalValue::VisibilityTypes B) {
+ if (A == GlobalValue::HiddenVisibility || B == GlobalValue::HiddenVisibility)
+ return GlobalValue::HiddenVisibility;
+ if (A == GlobalValue::ProtectedVisibility ||
+ B == GlobalValue::ProtectedVisibility)
+ return GlobalValue::ProtectedVisibility;
+ return GlobalValue::DefaultVisibility;
+}
+
+void ModuleLinker::setVisibility(GlobalValue *NewGV, const GlobalValue *SGV,
+ const GlobalValue *DGV) {
+ GlobalValue::VisibilityTypes Visibility = SGV->getVisibility();
+ if (DGV)
+ Visibility = getMinVisibility(DGV->getVisibility(), Visibility);
+ // For promoted locals, mark them hidden so that they can later be
+ // stripped from the symbol table to reduce bloat.
+ if (SGV->hasLocalLinkage() && doPromoteLocalToGlobal(SGV))
+ Visibility = GlobalValue::HiddenVisibility;
+ NewGV->setVisibility(Visibility);
+}
+
+GlobalValue *ModuleLinker::copyGlobalValueProto(TypeMapTy &TypeMap,
+ const GlobalValue *SGV,
+ const GlobalValue *DGV) {
+ GlobalValue *NewGV;
+ if (auto *SGVar = dyn_cast<GlobalVariable>(SGV))
+ NewGV = copyGlobalVariableProto(TypeMap, SGVar);
+ else if (auto *SF = dyn_cast<Function>(SGV))
+ NewGV = copyFunctionProto(TypeMap, SF);
+ else
+ NewGV = copyGlobalAliasProto(TypeMap, cast<GlobalAlias>(SGV));
+ copyGVAttributes(NewGV, SGV);
+ setVisibility(NewGV, SGV, DGV);
+ return NewGV;
+}
+
+Value *ValueMaterializerTy::materializeDeclFor(Value *V) {
+ return ModLinker->materializeDeclFor(V);
+}
+
+Value *ModuleLinker::materializeDeclFor(Value *V) {
+ auto *SGV = dyn_cast<GlobalValue>(V);
+ if (!SGV)
+ return nullptr;
+
+ // If we are done linking global value bodies (i.e. we are performing
+ // metadata linking), don't link in the global value due to this
+ // reference, simply map it to null.
+ if (doneLinkingBodies())
+ return nullptr;
+
+ linkGlobalValueProto(SGV);
+ if (HasError)
+ return nullptr;
+ Value *Ret = ValueMap[SGV];
+ assert(Ret);
+ return Ret;
+}
+
+void ValueMaterializerTy::materializeInitFor(GlobalValue *New,
+ GlobalValue *Old) {
+ return ModLinker->materializeInitFor(New, Old);
+}
+
+void ModuleLinker::materializeInitFor(GlobalValue *New, GlobalValue *Old) {
+ if (auto *F = dyn_cast<Function>(New)) {
+ if (!F->isDeclaration())
+ return;
+ } else if (auto *V = dyn_cast<GlobalVariable>(New)) {
+ if (V->hasInitializer())
+ return;
+ } else {
+ auto *A = cast<GlobalAlias>(New);
+ if (A->getAliasee())
+ return;
+ }
+
+ if (Old->isDeclaration())
+ return;
+
+ if (isPerformingImport() && !doImportAsDefinition(Old))
+ return;
+
+ if (DoNotLinkFromSource.count(Old))
+ return;
+
+ linkGlobalValueBody(*Old);
+}
+
+bool ModuleLinker::getComdatLeader(Module *M, StringRef ComdatName,
+ const GlobalVariable *&GVar) {
+ const GlobalValue *GVal = M->getNamedValue(ComdatName);
+ if (const auto *GA = dyn_cast_or_null<GlobalAlias>(GVal)) {
+ GVal = GA->getBaseObject();
+ if (!GVal)
+ // We cannot resolve the size of the aliasee yet.
+ return emitError("Linking COMDATs named '" + ComdatName +
+ "': COMDAT key involves incomputable alias size.");
+ }
+
+ GVar = dyn_cast_or_null<GlobalVariable>(GVal);
+ if (!GVar)
+ return emitError(
+ "Linking COMDATs named '" + ComdatName +
+ "': GlobalVariable required for data dependent selection!");
+
return false;
}
-Value *ValueMaterializerTy::materializeValueFor(Value *V) {
- Function *SF = dyn_cast<Function>(V);
- if (!SF)
- return NULL;
-
- Function *DF = Function::Create(TypeMap.get(SF->getFunctionType()),
- SF->getLinkage(), SF->getName(), DstM);
- copyGVAttributes(DF, SF);
-
- LazilyLinkFunctions.push_back(SF);
- return DF;
-}
-
-
-/// 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.
-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!");
-
- bool SrcIsDeclaration = Src->isDeclaration() && !Src->isMaterializable();
- bool DestIsDeclaration = Dest->isDeclaration();
-
+bool ModuleLinker::computeResultingSelectionKind(StringRef ComdatName,
+ Comdat::SelectionKind Src,
+ Comdat::SelectionKind Dst,
+ Comdat::SelectionKind &Result,
+ bool &LinkFromSrc) {
+ // The ability to mix Comdat::SelectionKind::Any with
+ // Comdat::SelectionKind::Largest is a behavior that comes from COFF.
+ bool DstAnyOrLargest = Dst == Comdat::SelectionKind::Any ||
+ Dst == Comdat::SelectionKind::Largest;
+ bool SrcAnyOrLargest = Src == Comdat::SelectionKind::Any ||
+ Src == Comdat::SelectionKind::Largest;
+ if (DstAnyOrLargest && SrcAnyOrLargest) {
+ if (Dst == Comdat::SelectionKind::Largest ||
+ Src == Comdat::SelectionKind::Largest)
+ Result = Comdat::SelectionKind::Largest;
+ else
+ Result = Comdat::SelectionKind::Any;
+ } else if (Src == Dst) {
+ Result = Dst;
+ } else {
+ return emitError("Linking COMDATs named '" + ComdatName +
+ "': invalid selection kinds!");
+ }
+
+ switch (Result) {
+ case Comdat::SelectionKind::Any:
+ // Go with Dst.
+ LinkFromSrc = false;
+ break;
+ case Comdat::SelectionKind::NoDuplicates:
+ return emitError("Linking COMDATs named '" + ComdatName +
+ "': noduplicates has been violated!");
+ case Comdat::SelectionKind::ExactMatch:
+ case Comdat::SelectionKind::Largest:
+ case Comdat::SelectionKind::SameSize: {
+ const GlobalVariable *DstGV;
+ const GlobalVariable *SrcGV;
+ if (getComdatLeader(DstM, ComdatName, DstGV) ||
+ getComdatLeader(SrcM, ComdatName, SrcGV))
+ return true;
+
+ const DataLayout &DstDL = DstM->getDataLayout();
+ const DataLayout &SrcDL = SrcM->getDataLayout();
+ uint64_t DstSize =
+ DstDL.getTypeAllocSize(DstGV->getType()->getPointerElementType());
+ uint64_t SrcSize =
+ SrcDL.getTypeAllocSize(SrcGV->getType()->getPointerElementType());
+ if (Result == Comdat::SelectionKind::ExactMatch) {
+ if (SrcGV->getInitializer() != DstGV->getInitializer())
+ return emitError("Linking COMDATs named '" + ComdatName +
+ "': ExactMatch violated!");
+ LinkFromSrc = false;
+ } else if (Result == Comdat::SelectionKind::Largest) {
+ LinkFromSrc = SrcSize > DstSize;
+ } else if (Result == Comdat::SelectionKind::SameSize) {
+ if (SrcSize != DstSize)
+ return emitError("Linking COMDATs named '" + ComdatName +
+ "': SameSize violated!");
+ LinkFromSrc = false;
+ } else {
+ llvm_unreachable("unknown selection kind");
+ }
+ break;
+ }
+ }
+
+ return false;
+}
+
+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()) {
+ // 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);
+}
+
+bool ModuleLinker::shouldLinkFromSource(bool &LinkFromSrc,
+ const GlobalValue &Dest,
+ const GlobalValue &Src) {
+ // Should we unconditionally use the Src?
+ if (shouldOverrideFromSrc()) {
+ LinkFromSrc = true;
+ return false;
+ }
+
+ // We always have to add Src if it has appending linkage.
+ if (Src.hasAppendingLinkage()) {
+ // Caller should have already determined that we can't link from source
+ // when importing (see comments in linkGlobalValueProto).
+ assert(!isPerformingImport());
+ LinkFromSrc = true;
+ return false;
+ }
+
+ bool SrcIsDeclaration = Src.isDeclarationForLinker();
+ bool DestIsDeclaration = Dest.isDeclarationForLinker();
+
+ if (isPerformingImport()) {
+ if (isa<Function>(&Src)) {
+ // For functions, LinkFromSrc iff this is the function requested
+ // for importing. For variables, decide below normally.
+ LinkFromSrc = (&Src == ImportFunction);
+ return false;
+ }
+
+ // Check if this is an alias with an already existing definition
+ // in Dest, which must have come from a prior importing pass from
+ // the same Src module. Unlike imported function and variable
+ // definitions, which are imported as available_externally and are
+ // not definitions for the linker, that is not a valid linkage for
+ // imported aliases which must be definitions. Simply use the existing
+ // Dest copy.
+ if (isa<GlobalAlias>(&Src) && !DestIsDeclaration) {
+ assert(isa<GlobalAlias>(&Dest));
+ LinkFromSrc = false;
+ return false;
+ }
+ }
+
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->hasDLLImportLinkage()) {
- // If one of GVs has DLLImport linkage, 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();
+ if (Src.hasDLLImportStorageClass()) {
+ // If one of GVs is marked as DLLImport, result should be dllimport'ed.
+ LinkFromSrc = DestIsDeclaration;
+ return false;
}
- } else if (DestIsDeclaration && !Dest->hasDLLImportLinkage()) {
+ // If the Dest is weak, use the source linkage.
+ LinkFromSrc = Dest.hasExternalWeakLinkage();
+ return false;
+ }
+
+ if (DestIsDeclaration) {
// If Dest is external but Src is not:
LinkFromSrc = true;
- 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()))) {
+ return false;
+ }
+
+ if (Src.hasCommonLinkage()) {
+ if (Dest.hasLinkOnceLinkage() || Dest.hasWeakLinkage()) {
LinkFromSrc = true;
- LT = Src->getLinkage();
- } else {
- LinkFromSrc = false;
- LT = Dest->getLinkage();
+ return false;
}
- } else if (Dest->isWeakForLinker()) {
- // At this point we know that Src has External* or DLL* linkage.
- if (Src->hasExternalWeakLinkage()) {
+
+ if (!Dest.hasCommonLinkage()) {
LinkFromSrc = false;
- LT = Dest->getLinkage();
- } else {
+ return false;
+ }
+
+ const DataLayout &DL = Dest.getParent()->getDataLayout();
+ uint64_t DestSize = DL.getTypeAllocSize(Dest.getType()->getElementType());
+ uint64_t SrcSize = DL.getTypeAllocSize(Src.getType()->getElementType());
+ LinkFromSrc = SrcSize > DestSize;
+ return false;
+ }
+
+ if (Src.isWeakForLinker()) {
+ assert(!Dest.hasExternalWeakLinkage());
+ assert(!Dest.hasAvailableExternallyLinkage());
+
+ if (Dest.hasLinkOnceLinkage() && Src.hasWeakLinkage()) {
LinkFromSrc = true;
- LT = GlobalValue::ExternalLinkage;
+ return false;
}
- } else {
- assert((Dest->hasExternalLinkage() || Dest->hasDLLImportLinkage() ||
- Dest->hasDLLExportLinkage() || Dest->hasExternalWeakLinkage()) &&
- (Src->hasExternalLinkage() || Src->hasDLLImportLinkage() ||
- Src->hasDLLExportLinkage() || Src->hasExternalWeakLinkage()) &&
- "Unexpected linkage type!");
- return emitError("Linking globals named '" + Src->getName() +
- "': symbol multiply defined!");
- }
-
- // Compute the visibility. We follow the rules in the System V Application
- // Binary Interface.
- Vis = isLessConstraining(Src->getVisibility(), Dest->getVisibility()) ?
- Dest->getVisibility() : Src->getVisibility();
- return false;
+
+ LinkFromSrc = false;
+ return false;
+ }
+
+ if (Dest.isWeakForLinker()) {
+ assert(Src.hasExternalLinkage());
+ LinkFromSrc = true;
+ return false;
+ }
+
+ assert(!Src.hasExternalWeakLinkage());
+ assert(!Dest.hasExternalWeakLinkage());
+ assert(Dest.hasExternalLinkage() && Src.hasExternalLinkage() &&
+ "Unexpected linkage type!");
+ return emitError("Linking globals named '" + Src.getName() +
+ "': symbol multiply defined!");
}
-/// computeTypeMapping - 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 LLVMContext.
+/// 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
+/// LLVMContext.
void ModuleLinker::computeTypeMapping() {
- // Incorporate globals.
- for (Module::global_iterator I = SrcM->global_begin(),
- E = SrcM->global_end(); I != E; ++I) {
- GlobalValue *DGV = getLinkedToGlobal(I);
- if (DGV == 0) continue;
-
- if (!DGV->hasAppendingLinkage() || !I->hasAppendingLinkage()) {
- TypeMap.addTypeMapping(DGV->getType(), I->getType());
- continue;
+ for (GlobalValue &SGV : SrcM->globals()) {
+ GlobalValue *DGV = getLinkedToGlobal(&SGV);
+ if (!DGV)
+ continue;
+
+ if (!DGV->hasAppendingLinkage() || !SGV.hasAppendingLinkage()) {
+ TypeMap.addTypeMapping(DGV->getType(), SGV.getType());
+ continue;
}
-
+
// Unify the element type of appending arrays.
ArrayType *DAT = cast<ArrayType>(DGV->getType()->getElementType());
- ArrayType *SAT = cast<ArrayType>(I->getType()->getElementType());
+ ArrayType *SAT = cast<ArrayType>(SGV.getType()->getElementType());
TypeMap.addTypeMapping(DAT->getElementType(), SAT->getElementType());
}
-
- // Incorporate functions.
- for (Module::iterator I = SrcM->begin(), E = SrcM->end(); I != E; ++I) {
- if (GlobalValue *DGV = getLinkedToGlobal(I))
- TypeMap.addTypeMapping(DGV->getType(), I->getType());
+
+ for (GlobalValue &SGV : *SrcM) {
+ if (GlobalValue *DGV = getLinkedToGlobal(&SGV))
+ TypeMap.addTypeMapping(DGV->getType(), SGV.getType());
+ }
+
+ for (GlobalValue &SGV : SrcM->aliases()) {
+ if (GlobalValue *DGV = getLinkedToGlobal(&SGV))
+ TypeMap.addTypeMapping(DGV->getType(), SGV.getType());
}
// Incorporate types by name, scanning all the types in the source module.
// At this point, the destination module may have a type "%foo = { i32 }" for
// example. When the source module got loaded into the same LLVMContext, if
// it had the same type, it would have been renamed to "%foo.42 = { i32 }".
- TypeFinder SrcStructTypes;
- SrcStructTypes.run(*SrcM, true);
- SmallPtrSet<StructType*, 32> SrcStructTypesSet(SrcStructTypes.begin(),
- SrcStructTypes.end());
-
- for (unsigned i = 0, e = SrcStructTypes.size(); i != e; ++i) {
- StructType *ST = SrcStructTypes[i];
- if (!ST->hasName()) continue;
-
+ std::vector<StructType *> Types = SrcM->getIdentifiedStructTypes();
+ for (StructType *ST : Types) {
+ if (!ST->hasName())
+ continue;
+
// Check to see if there is a dot in the name followed by a digit.
size_t DotPos = ST->getName().rfind('.');
if (DotPos == 0 || DotPos == StringRef::npos ||
ST->getName().back() == '.' ||
- !isdigit(static_cast<unsigned char>(ST->getName()[DotPos+1])))
+ !isdigit(static_cast<unsigned char>(ST->getName()[DotPos + 1])))
continue;
-
+
// Check to see if the destination module has a struct with the prefix name.
- if (StructType *DST = DstM->getTypeByName(ST->getName().substr(0, DotPos)))
- // Don't use it if this actually came from the source module. They're in
- // the same LLVMContext after all. Also don't use it unless the type is
- // actually used in the destination module. This can happen in situations
- // like this:
- //
- // Module A Module B
- // -------- --------
- // %Z = type { %A } %B = type { %C.1 }
- // %A = type { %B.1, [7 x i8] } %C.1 = type { i8* }
- // %B.1 = type { %C } %A.2 = type { %B.3, [5 x i8] }
- // %C = type { i8* } %B.3 = type { %C.1 }
- //
- // When we link Module B with Module A, the '%B' in Module B is
- // used. However, that would then use '%C.1'. But when we process '%C.1',
- // we prefer to take the '%C' version. So we are then left with both
- // '%C.1' and '%C' being used for the same types. This leads to some
- // variables using one type and some using the other.
- if (!SrcStructTypesSet.count(DST) && TypeMap.DstStructTypesSet.count(DST))
- TypeMap.addTypeMapping(DST, ST);
- }
-
- // Don't bother incorporating aliases, they aren't generally typed well.
-
+ StructType *DST = DstM->getTypeByName(ST->getName().substr(0, DotPos));
+ if (!DST)
+ continue;
+
+ // Don't use it if this actually came from the source module. They're in
+ // the same LLVMContext after all. Also don't use it unless the type is
+ // actually used in the destination module. This can happen in situations
+ // like this:
+ //
+ // Module A Module B
+ // -------- --------
+ // %Z = type { %A } %B = type { %C.1 }
+ // %A = type { %B.1, [7 x i8] } %C.1 = type { i8* }
+ // %B.1 = type { %C } %A.2 = type { %B.3, [5 x i8] }
+ // %C = type { i8* } %B.3 = type { %C.1 }
+ //
+ // When we link Module B with Module A, the '%B' in Module B is
+ // used. However, that would then use '%C.1'. But when we process '%C.1',
+ // we prefer to take the '%C' version. So we are then left with both
+ // '%C.1' and '%C' being used for the same types. This leads to some
+ // variables using one type and some using the other.
+ if (TypeMap.DstStructTypesSet.hasType(DST))
+ TypeMap.addTypeMapping(DST, ST);
+ }
+
// Now that we have discovered all of the type equivalences, get a body for
- // any 'opaque' types in the dest module that are now resolved.
+ // any 'opaque' types in the dest module that are now resolved.
TypeMap.linkDefinedTypeBodies();
}
-/// linkAppendingVarProto - If there were any appending global variables, link
-/// them together now. Return true on error.
+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");
+}
+
+/// If there were any appending global variables, link them together now.
+/// Return true on error.
bool ModuleLinker::linkAppendingVarProto(GlobalVariable *DstGV,
- GlobalVariable *SrcGV) {
-
- if (!SrcGV->hasAppendingLinkage() || !DstGV->hasAppendingLinkage())
- return emitError("Linking globals named '" + SrcGV->getName() +
- "': can only link appending global with another appending global!");
-
- ArrayType *DstTy = cast<ArrayType>(DstGV->getType()->getElementType());
+ const GlobalVariable *SrcGV) {
ArrayType *SrcTy =
- cast<ArrayType>(TypeMap.get(SrcGV->getType()->getElementType()));
- Type *EltTy = DstTy->getElementType();
-
- // Check to see that they two arrays agree on type.
- if (EltTy != SrcTy->getElementType())
- return emitError("Appending variables with different element types!");
- if (DstGV->isConstant() != SrcGV->isConstant())
- return emitError("Appending variables linked with different const'ness!");
-
- if (DstGV->getAlignment() != SrcGV->getAlignment())
- return emitError(
- "Appending variables with different alignment need to be linked!");
-
- if (DstGV->getVisibility() != SrcGV->getVisibility())
- return emitError(
- "Appending variables with different visibility need to be linked!");
-
- if (DstGV->getSection() != SrcGV->getSection())
- return emitError(
+ cast<ArrayType>(TypeMap.get(SrcGV->getType()->getElementType()));
+ Type *EltTy = SrcTy->getElementType();
+
+ uint64_t NewSize = SrcTy->getNumElements();
+ if (DstGV) {
+ ArrayType *DstTy = cast<ArrayType>(DstGV->getType()->getElementType());
+ NewSize += DstTy->getNumElements();
+
+ if (!SrcGV->hasAppendingLinkage() || !DstGV->hasAppendingLinkage())
+ return emitError(
+ "Linking globals named '" + SrcGV->getName() +
+ "': can only link appending global with another appending global!");
+
+ // Check to see that they two arrays agree on type.
+ if (EltTy != DstTy->getElementType())
+ return emitError("Appending variables with different element types!");
+ if (DstGV->isConstant() != SrcGV->isConstant())
+ return emitError("Appending variables linked with different const'ness!");
+
+ if (DstGV->getAlignment() != SrcGV->getAlignment())
+ return emitError(
+ "Appending variables with different alignment need to be linked!");
+
+ if (DstGV->getVisibility() != SrcGV->getVisibility())
+ return emitError(
+ "Appending variables with different visibility need to be linked!");
+
+ if (DstGV->hasUnnamedAddr() != SrcGV->hasUnnamedAddr())
+ return emitError(
+ "Appending variables with different unnamed_addr need to be linked!");
+
+ if (StringRef(DstGV->getSection()) != SrcGV->getSection())
+ return emitError(
"Appending variables with different section name need to be linked!");
-
- uint64_t NewSize = DstTy->getNumElements() + SrcTy->getNumElements();
+ }
+
ArrayType *NewType = ArrayType::get(EltTy, NewSize);
-
+
// Create the new global variable.
- GlobalVariable *NG =
- new GlobalVariable(*DstGV->getParent(), NewType, SrcGV->isConstant(),
- DstGV->getLinkage(), /*init*/0, /*name*/"", DstGV,
- DstGV->getThreadLocalMode(),
- DstGV->getType()->getAddressSpace());
-
+ GlobalVariable *NG = new GlobalVariable(
+ *DstM, NewType, SrcGV->isConstant(), SrcGV->getLinkage(),
+ /*init*/ nullptr, /*name*/ "", DstGV, SrcGV->getThreadLocalMode(),
+ SrcGV->getType()->getAddressSpace());
+
// Propagate alignment, visibility and section info.
- copyGVAttributes(NG, DstGV);
-
+ copyGVAttributes(NG, SrcGV);
+
AppendingVarInfo AVI;
AVI.NewGV = NG;
- AVI.DstInit = DstGV->getInitializer();
+ AVI.DstInit = DstGV ? DstGV->getInitializer() : nullptr;
AVI.SrcInit = SrcGV->getInitializer();
AppendingVars.push_back(AVI);
// global.
ValueMap[SrcGV] = ConstantExpr::getBitCast(NG, TypeMap.get(SrcGV->getType()));
- DstGV->replaceAllUsesWith(ConstantExpr::getBitCast(NG, DstGV->getType()));
- DstGV->eraseFromParent();
-
+ if (DstGV) {
+ DstGV->replaceAllUsesWith(ConstantExpr::getBitCast(NG, DstGV->getType()));
+ DstGV->eraseFromParent();
+ }
+
// Track the source variable so we don't try to link it.
DoNotLinkFromSource.insert(SrcGV);
-
+
return false;
}
-/// linkGlobalProto - Loop through the global variables in the src module and
-/// merge them into the dest module.
-bool ModuleLinker::linkGlobalProto(GlobalVariable *SGV) {
+bool ModuleLinker::linkGlobalValueProto(GlobalValue *SGV) {
GlobalValue *DGV = getLinkedToGlobal(SGV);
- llvm::Optional<GlobalValue::VisibilityTypes> NewVisibility;
+
+ // Handle the ultra special appending linkage case first.
+ assert(!DGV || SGV->hasAppendingLinkage() == DGV->hasAppendingLinkage());
+ if (SGV->hasAppendingLinkage() && isPerformingImport()) {
+ // Don't want to append to global_ctors list, for example, when we
+ // are importing for ThinLTO, otherwise the global ctors and dtors
+ // get executed multiple times for local variables (the latter causing
+ // double frees).
+ DoNotLinkFromSource.insert(SGV);
+ return false;
+ }
+ if (SGV->hasAppendingLinkage())
+ return linkAppendingVarProto(cast_or_null<GlobalVariable>(DGV),
+ cast<GlobalVariable>(SGV));
+
+ bool LinkFromSrc = true;
+ Comdat *C = nullptr;
bool HasUnnamedAddr = SGV->hasUnnamedAddr();
- if (DGV) {
- // 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;
- HasUnnamedAddr = HasUnnamedAddr && DGV->hasUnnamedAddr();
- GlobalValue::VisibilityTypes NV;
- bool LinkFromSrc = false;
- if (getLinkageResult(DGV, SGV, NewLinkage, NV, LinkFromSrc))
+ 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;
- NewVisibility = NV;
-
- // 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 (DGVar->isDeclaration() && SGV->isConstant() && !DGVar->isConstant())
- DGVar->setConstant(true);
+ }
- // Set calculated linkage, visibility and unnamed_addr.
- DGV->setLinkage(NewLinkage);
- DGV->setVisibility(*NewVisibility);
- DGV->setUnnamedAddr(HasUnnamedAddr);
+ 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)
// Make sure to remember this mapping.
- ValueMap[SGV] = ConstantExpr::getBitCast(DGV,TypeMap.get(SGV->getType()));
-
- // Track the source global so that we don't attempt to copy it over when
- // processing global initializers.
- DoNotLinkFromSource.insert(SGV);
-
- return false;
- }
+ ValueMap[SGV] =
+ ConstantExpr::getBitCast(DGV, TypeMap.get(SGV->getType()));
}
-
- // 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*/0,
- SGV->getName(), /*insertbefore*/0,
- SGV->getThreadLocalMode(),
- SGV->getType()->getAddressSpace());
- // Propagate alignment, visibility and section info.
- copyGVAttributes(NewDGV, SGV);
- if (NewVisibility)
- NewDGV->setVisibility(*NewVisibility);
- NewDGV->setUnnamedAddr(HasUnnamedAddr);
-
- if (DGV) {
- DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewDGV, DGV->getType()));
- DGV->eraseFromParent();
- }
-
- // Make sure to remember this mapping.
- ValueMap[SGV] = NewDGV;
- return false;
-}
-/// linkFunctionProto - 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;
-
- if (DGV) {
- GlobalValue::LinkageTypes NewLinkage = GlobalValue::InternalLinkage;
- bool LinkFromSrc = false;
- GlobalValue::VisibilityTypes NV;
- if (getLinkageResult(DGV, SF, NewLinkage, NV, LinkFromSrc))
- return true;
- NewVisibility = NV;
+ if (DGV)
+ HasUnnamedAddr = HasUnnamedAddr && DGV->hasUnnamedAddr();
- if (!LinkFromSrc) {
- // Set calculated linkage
- DGV->setLinkage(NewLinkage);
- DGV->setVisibility(*NewVisibility);
+ GlobalValue *NewGV;
+ if (!LinkFromSrc && DGV) {
+ NewGV = DGV;
+ // When linking from source we setVisibility from copyGlobalValueProto.
+ setVisibility(NewGV, SGV, DGV);
+ } else {
+ NewGV = copyGlobalValueProto(TypeMap, SGV, DGV);
- // Make sure to remember this mapping.
- ValueMap[SF] = ConstantExpr::getBitCast(DGV, TypeMap.get(SF->getType()));
-
- // Track the function from the source module so we don't attempt to remap
- // it.
- DoNotLinkFromSource.insert(SF);
-
- return false;
- }
- }
-
- // 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 false;
+ if (isPerformingImport() && !doImportAsDefinition(SGV))
+ DoNotLinkFromSource.insert(SGV);
}
- // If there is no linkage to be performed or we are linking from the source,
- // bring SF over.
- Function *NewDF = Function::Create(TypeMap.get(SF->getFunctionType()),
- SF->getLinkage(), SF->getName(), DstM);
- copyGVAttributes(NewDF, SF);
- if (NewVisibility)
- NewDF->setVisibility(*NewVisibility);
-
- 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;
-}
+ NewGV->setUnnamedAddr(HasUnnamedAddr);
-/// LinkAliasProto - Set up prototypes for any aliases that come over from the
-/// source module.
-bool ModuleLinker::linkAliasProto(GlobalAlias *SGA) {
- GlobalValue *DGV = getLinkedToGlobal(SGA);
- llvm::Optional<GlobalValue::VisibilityTypes> NewVisibility;
+ if (auto *NewGO = dyn_cast<GlobalObject>(NewGV)) {
+ if (C && LinkFromSrc)
+ NewGO->setComdat(C);
- if (DGV) {
- GlobalValue::LinkageTypes NewLinkage = GlobalValue::InternalLinkage;
- GlobalValue::VisibilityTypes NV;
- bool LinkFromSrc = false;
- if (getLinkageResult(DGV, SGA, NewLinkage, NV, LinkFromSrc))
- return true;
- NewVisibility = NV;
+ if (DGV && DGV->hasCommonLinkage() && SGV->hasCommonLinkage())
+ NewGO->setAlignment(std::max(DGV->getAlignment(), SGV->getAlignment()));
+ }
- if (!LinkFromSrc) {
- // Set calculated linkage.
- DGV->setLinkage(NewLinkage);
- DGV->setVisibility(*NewVisibility);
+ if (auto *NewGVar = dyn_cast<GlobalVariable>(NewGV)) {
+ auto *DGVar = dyn_cast_or_null<GlobalVariable>(DGV);
+ auto *SGVar = dyn_cast<GlobalVariable>(SGV);
+ if (DGVar && SGVar && DGVar->isDeclaration() && SGVar->isDeclaration() &&
+ (!DGVar->isConstant() || !SGVar->isConstant()))
+ NewGVar->setConstant(false);
+ }
- // 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;
+ // Make sure to remember this mapping.
+ if (NewGV != DGV) {
+ if (DGV) {
+ DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewGV, DGV->getType()));
+ DGV->eraseFromParent();
}
+ ValueMap[SGV] = NewGV;
}
-
- // If there is no linkage to be performed or we're linking from the source,
- // bring over SGA.
- GlobalAlias *NewDA = new GlobalAlias(TypeMap.get(SGA->getType()),
- SGA->getLinkage(), SGA->getName(),
- /*aliasee*/0, DstM);
- copyGVAttributes(NewDA, SGA);
- if (NewVisibility)
- NewDA->setVisibility(*NewVisibility);
-
- 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(Constant *C, SmallVectorImpl<Constant*> &Dest) {
+static void getArrayElements(const Constant *C,
+ SmallVectorImpl<Constant *> &Dest) {
unsigned NumElements = cast<ArrayType>(C->getType())->getNumElements();
for (unsigned i = 0; i != NumElements; ++i)
Dest.push_back(C->getAggregateElement(i));
}
-
-void ModuleLinker::linkAppendingVarInit(const AppendingVarInfo &AVI) {
+
+void ModuleLinker::linkAppendingVarInit(AppendingVarInfo &AVI) {
// Merge the initializer.
- SmallVector<Constant*, 16> Elements;
- getArrayElements(AVI.DstInit, Elements);
-
- Constant *SrcInit = MapValue(AVI.SrcInit, ValueMap, RF_None, &TypeMap, &ValMaterializer);
- getArrayElements(SrcInit, Elements);
-
+ SmallVector<Constant *, 16> DstElements;
+ if (AVI.DstInit)
+ getArrayElements(AVI.DstInit, DstElements);
+
+ SmallVector<Constant *, 16> SrcElements;
+ getArrayElements(AVI.SrcInit, SrcElements);
+
ArrayType *NewType = cast<ArrayType>(AVI.NewGV->getType()->getElementType());
- AVI.NewGV->setInitializer(ConstantArray::get(NewType, Elements));
-}
-/// linkGlobalInits - Update the initializers in the Dest module now that all
-/// globals that may be referenced are in Dest.
-void ModuleLinker::linkGlobalInits() {
- // Loop over all of the globals in the src module, mapping them over as we go
- for (Module::const_global_iterator I = SrcM->global_begin(),
- E = SrcM->global_end(); I != E; ++I) {
-
- // Only process initialized GV's or ones not already in dest.
- if (!I->hasInitializer() || DoNotLinkFromSource.count(I)) continue;
-
- // Grab destination global variable.
- GlobalVariable *DGV = cast<GlobalVariable>(ValueMap[I]);
- // Figure out what the initializer looks like in the dest module.
- DGV->setInitializer(MapValue(I->getInitializer(), ValueMap,
- RF_None, &TypeMap, &ValMaterializer));
+ 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) {
+ auto *Key =
+ dyn_cast<GlobalValue>(V->getAggregateElement(2)->stripPointerCasts());
+ if (DoNotLinkFromSource.count(Key))
+ continue;
+ }
+ DstElements.push_back(
+ MapValue(V, ValueMap, RF_MoveDistinctMDs, &TypeMap, &ValMaterializer));
}
+ if (DstElements.size() != NewType->getNumElements()) {
+ NewType = ArrayType::get(NewType->getElementType(), DstElements.size());
+ GlobalVariable *Old = AVI.NewGV;
+ GlobalVariable *NG = new GlobalVariable(
+ *DstM, NewType, Old->isConstant(), Old->getLinkage(), /*init*/ nullptr,
+ /*name*/ "", Old, Old->getThreadLocalMode(),
+ Old->getType()->getAddressSpace());
+ copyGVAttributes(NG, Old);
+ AVI.NewGV->replaceAllUsesWith(
+ ConstantExpr::getBitCast(NG, AVI.NewGV->getType()));
+ AVI.NewGV->eraseFromParent();
+ AVI.NewGV = NG;
+ }
+
+ AVI.NewGV->setInitializer(ConstantArray::get(NewType, DstElements));
+}
+
+/// Update the initializers in the Dest module now that all globals that may be
+/// referenced are in Dest.
+void ModuleLinker::linkGlobalInit(GlobalVariable &Dst, GlobalVariable &Src) {
+ // Figure out what the initializer looks like in the dest module.
+ Dst.setInitializer(MapValue(Src.getInitializer(), ValueMap,
+ RF_MoveDistinctMDs, &TypeMap, &ValMaterializer));
}
-/// linkFunctionBody - Copy the source function over into the dest function and
-/// fix up references to values. At this point we know that Dest is an external
-/// function, and that Src is not.
-void ModuleLinker::linkFunctionBody(Function *Dst, Function *Src) {
- assert(Src && Dst && Dst->isDeclaration() && !Src->isDeclaration());
+/// Copy the source function over into the dest function and fix up references
+/// to values. At this point we know that Dest is an external function, and
+/// that Src is not.
+bool ModuleLinker::linkFunctionBody(Function &Dst, Function &Src) {
+ assert(Dst.isDeclaration() && !Src.isDeclaration());
+
+ // Materialize if needed.
+ if (std::error_code EC = Src.materialize())
+ return emitError(EC.message());
+
+ // Link in the prefix data.
+ if (Src.hasPrefixData())
+ Dst.setPrefixData(MapValue(Src.getPrefixData(), ValueMap,
+ RF_MoveDistinctMDs, &TypeMap, &ValMaterializer));
+
+ // Link in the prologue data.
+ if (Src.hasPrologueData())
+ Dst.setPrologueData(MapValue(Src.getPrologueData(), ValueMap,
+ RF_MoveDistinctMDs, &TypeMap,
+ &ValMaterializer));
+
+ // Link in the personality function.
+ if (Src.hasPersonalityFn())
+ Dst.setPersonalityFn(MapValue(Src.getPersonalityFn(), ValueMap,
+ RF_MoveDistinctMDs, &TypeMap,
+ &ValMaterializer));
// Go through and convert function arguments over, remembering the mapping.
- Function::arg_iterator DI = Dst->arg_begin();
- for (Function::arg_iterator I = Src->arg_begin(), E = Src->arg_end();
- I != E; ++I, ++DI) {
- DI->setName(I->getName()); // Copy the name over.
+ Function::arg_iterator DI = Dst.arg_begin();
+ for (Argument &Arg : Src.args()) {
+ DI->setName(Arg.getName()); // Copy the name over.
// Add a mapping to our mapping.
- ValueMap[I] = DI;
- }
-
- if (Mode == Linker::DestroySource) {
- // Splice the body of the source function into the dest function.
- Dst->getBasicBlockList().splice(Dst->end(), Src->getBasicBlockList());
-
- // At this point, all of the instructions and values of the function are now
- // copied over. The only problem is that they are still referencing values in
- // the Source function as operands. Loop through all of the operands of the
- // functions and patch them up to point to the local versions.
- for (Function::iterator BB = Dst->begin(), BE = Dst->end(); BB != BE; ++BB)
- for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
- RemapInstruction(I, ValueMap, RF_IgnoreMissingEntries,
- &TypeMap, &ValMaterializer);
-
- } else {
- // Clone the body of the function into the dest function.
- SmallVector<ReturnInst*, 8> Returns; // Ignore returns.
- CloneFunctionInto(Dst, Src, ValueMap, false, Returns, "", NULL,
- &TypeMap, &ValMaterializer);
+ ValueMap[&Arg] = &*DI;
+ ++DI;
}
-
+
+ // Copy over the metadata attachments.
+ SmallVector<std::pair<unsigned, MDNode *>, 8> MDs;
+ Src.getAllMetadata(MDs);
+ for (const auto &I : MDs)
+ Dst.setMetadata(I.first, MapMetadata(I.second, ValueMap, RF_MoveDistinctMDs,
+ &TypeMap, &ValMaterializer));
+
+ // Splice the body of the source function into the dest function.
+ Dst.getBasicBlockList().splice(Dst.end(), Src.getBasicBlockList());
+
+ // At this point, all of the instructions and values of the function are now
+ // copied over. The only problem is that they are still referencing values in
+ // the Source function as operands. Loop through all of the operands of the
+ // functions and patch them up to point to the local versions.
+ for (BasicBlock &BB : Dst)
+ for (Instruction &I : BB)
+ RemapInstruction(&I, ValueMap,
+ RF_IgnoreMissingEntries | RF_MoveDistinctMDs, &TypeMap,
+ &ValMaterializer);
+
// There is no need to map the arguments anymore.
- for (Function::arg_iterator I = Src->arg_begin(), E = Src->arg_end();
- I != E; ++I)
- ValueMap.erase(I);
-
+ for (Argument &Arg : Src.args())
+ ValueMap.erase(&Arg);
+
+ Src.dematerialize();
+ return false;
}
-/// linkAliasBodies - Insert all of the aliases in Src into the Dest module.
-void ModuleLinker::linkAliasBodies() {
- for (Module::alias_iterator I = SrcM->alias_begin(), E = SrcM->alias_end();
- I != E; ++I) {
- if (DoNotLinkFromSource.count(I))
- continue;
- if (Constant *Aliasee = I->getAliasee()) {
- GlobalAlias *DA = cast<GlobalAlias>(ValueMap[I]);
- DA->setAliasee(MapValue(Aliasee, ValueMap, RF_None,
- &TypeMap, &ValMaterializer));
+void ModuleLinker::linkAliasBody(GlobalAlias &Dst, GlobalAlias &Src) {
+ Constant *Aliasee = Src.getAliasee();
+ Constant *Val = MapValue(Aliasee, ValueMap, RF_MoveDistinctMDs, &TypeMap,
+ &ValMaterializer);
+ Dst.setAliasee(Val);
+}
+
+bool ModuleLinker::linkGlobalValueBody(GlobalValue &Src) {
+ Value *Dst = ValueMap[&Src];
+ assert(Dst);
+ if (const Comdat *SC = Src.getComdat()) {
+ // To ensure that we don't generate an incomplete comdat group,
+ // we must materialize and map in any other members that are not
+ // yet materialized in Dst, which also ensures their definitions
+ // are linked in. Otherwise, linkonce and other lazy linked GVs will
+ // not be materialized if they aren't referenced.
+ for (auto *SGV : ComdatMembers[SC]) {
+ auto *DGV = cast_or_null<GlobalValue>(ValueMap[SGV]);
+ if (DGV && !DGV->isDeclaration())
+ continue;
+ MapValue(SGV, ValueMap, RF_MoveDistinctMDs, &TypeMap, &ValMaterializer);
}
}
+ if (shouldInternalizeLinkedSymbols())
+ if (auto *DGV = dyn_cast<GlobalValue>(Dst))
+ DGV->setLinkage(GlobalValue::InternalLinkage);
+ if (auto *F = dyn_cast<Function>(&Src))
+ return linkFunctionBody(cast<Function>(*Dst), *F);
+ if (auto *GVar = dyn_cast<GlobalVariable>(&Src)) {
+ linkGlobalInit(cast<GlobalVariable>(*Dst), *GVar);
+ return false;
+ }
+ linkAliasBody(cast<GlobalAlias>(*Dst), cast<GlobalAlias>(Src));
+ return false;
}
-/// linkNamedMDNodes - Insert all of the named MDNodes in Src into the Dest
-/// module.
+/// Insert all of the named MDNodes in Src into the Dest module.
void ModuleLinker::linkNamedMDNodes() {
const NamedMDNode *SrcModFlags = SrcM->getModuleFlagsMetadata();
- for (Module::const_named_metadata_iterator I = SrcM->named_metadata_begin(),
- E = SrcM->named_metadata_end(); I != E; ++I) {
+ for (const NamedMDNode &NMD : SrcM->named_metadata()) {
// Don't link module flags here. Do them separately.
- if (&*I == SrcModFlags) continue;
- NamedMDNode *DestNMD = DstM->getOrInsertNamedMetadata(I->getName());
+ if (&NMD == SrcModFlags)
+ continue;
+ NamedMDNode *DestNMD = DstM->getOrInsertNamedMetadata(NMD.getName());
// Add Src elements into Dest node.
- for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i)
- DestNMD->addOperand(MapValue(I->getOperand(i), ValueMap,
- RF_None, &TypeMap, &ValMaterializer));
+ for (const MDNode *op : NMD.operands())
+ DestNMD->addOperand(MapMetadata(
+ op, ValueMap, RF_MoveDistinctMDs | RF_NullMapMissingGlobalValues,
+ &TypeMap, &ValMaterializer));
}
}
-/// linkModuleFlagsMetadata - Merge the linker flags in Src into the Dest
-/// module.
+/// Merge the linker flags in Src into the Dest module.
bool ModuleLinker::linkModuleFlagsMetadata() {
// If the source module has no module flags, we are done.
const NamedMDNode *SrcModFlags = SrcM->getModuleFlagsMetadata();
}
// First build a map of the existing module flags and requirements.
- DenseMap<MDString*, MDNode*> Flags;
+ DenseMap<MDString *, std::pair<MDNode *, unsigned>> Flags;
SmallSetVector<MDNode*, 16> Requirements;
for (unsigned I = 0, E = DstModFlags->getNumOperands(); I != E; ++I) {
MDNode *Op = DstModFlags->getOperand(I);
- ConstantInt *Behavior = cast<ConstantInt>(Op->getOperand(0));
+ ConstantInt *Behavior = mdconst::extract<ConstantInt>(Op->getOperand(0));
MDString *ID = cast<MDString>(Op->getOperand(1));
if (Behavior->getZExtValue() == Module::Require) {
Requirements.insert(cast<MDNode>(Op->getOperand(2)));
} else {
- Flags[ID] = Op;
+ Flags[ID] = std::make_pair(Op, I);
}
}
bool HasErr = false;
for (unsigned I = 0, E = SrcModFlags->getNumOperands(); I != E; ++I) {
MDNode *SrcOp = SrcModFlags->getOperand(I);
- ConstantInt *SrcBehavior = cast<ConstantInt>(SrcOp->getOperand(0));
+ ConstantInt *SrcBehavior =
+ mdconst::extract<ConstantInt>(SrcOp->getOperand(0));
MDString *ID = cast<MDString>(SrcOp->getOperand(1));
- MDNode *DstOp = Flags.lookup(ID);
+ MDNode *DstOp;
+ unsigned DstIndex;
+ std::tie(DstOp, DstIndex) = Flags.lookup(ID);
unsigned SrcBehaviorValue = SrcBehavior->getZExtValue();
// If this is a requirement, add it and continue.
// If there is no existing flag with this ID, just add it.
if (!DstOp) {
- Flags[ID] = SrcOp;
+ Flags[ID] = std::make_pair(SrcOp, DstModFlags->getNumOperands());
DstModFlags->addOperand(SrcOp);
continue;
}
// Otherwise, perform a merge.
- ConstantInt *DstBehavior = cast<ConstantInt>(DstOp->getOperand(0));
+ ConstantInt *DstBehavior =
+ mdconst::extract<ConstantInt>(DstOp->getOperand(0));
unsigned DstBehaviorValue = DstBehavior->getZExtValue();
// If either flag has override behavior, handle it first.
continue;
} else if (SrcBehaviorValue == Module::Override) {
// Update the destination flag to that of the source.
- DstOp->replaceOperandWith(0, SrcBehavior);
- DstOp->replaceOperandWith(2, SrcOp->getOperand(2));
+ DstModFlags->setOperand(DstIndex, SrcOp);
+ Flags[ID].first = SrcOp;
continue;
}
continue;
}
+ auto replaceDstValue = [&](MDNode *New) {
+ Metadata *FlagOps[] = {DstOp->getOperand(0), ID, New};
+ MDNode *Flag = MDNode::get(DstM->getContext(), FlagOps);
+ DstModFlags->setOperand(DstIndex, Flag);
+ Flags[ID].first = Flag;
+ };
+
// Perform the merge for standard behavior types.
switch (SrcBehaviorValue) {
case Module::Require:
- case Module::Override: assert(0 && "not possible"); break;
+ case Module::Override: llvm_unreachable("not possible");
case Module::Error: {
// Emit an error if the values differ.
if (SrcOp->getOperand(2) != DstOp->getOperand(2)) {
case Module::Warning: {
// Emit a warning if the values differ.
if (SrcOp->getOperand(2) != DstOp->getOperand(2)) {
- errs() << "WARNING: linking module flags '" << ID->getString()
- << "': IDs have conflicting values";
+ emitWarning("linking module flags '" + ID->getString() +
+ "': IDs have conflicting values");
}
continue;
}
case Module::Append: {
MDNode *DstValue = cast<MDNode>(DstOp->getOperand(2));
MDNode *SrcValue = cast<MDNode>(SrcOp->getOperand(2));
- unsigned NumOps = DstValue->getNumOperands() + SrcValue->getNumOperands();
- Value **VP, **Values = VP = new Value*[NumOps];
- for (unsigned i = 0, e = DstValue->getNumOperands(); i != e; ++i, ++VP)
- *VP = DstValue->getOperand(i);
- for (unsigned i = 0, e = SrcValue->getNumOperands(); i != e; ++i, ++VP)
- *VP = SrcValue->getOperand(i);
- DstOp->replaceOperandWith(2, MDNode::get(DstM->getContext(),
- ArrayRef<Value*>(Values,
- NumOps)));
- delete[] Values;
+ SmallVector<Metadata *, 8> MDs;
+ MDs.reserve(DstValue->getNumOperands() + SrcValue->getNumOperands());
+ MDs.append(DstValue->op_begin(), DstValue->op_end());
+ MDs.append(SrcValue->op_begin(), SrcValue->op_end());
+
+ replaceDstValue(MDNode::get(DstM->getContext(), MDs));
break;
}
case Module::AppendUnique: {
- SmallSetVector<Value*, 16> Elts;
+ SmallSetVector<Metadata *, 16> Elts;
MDNode *DstValue = cast<MDNode>(DstOp->getOperand(2));
MDNode *SrcValue = cast<MDNode>(SrcOp->getOperand(2));
- for (unsigned i = 0, e = DstValue->getNumOperands(); i != e; ++i)
- Elts.insert(DstValue->getOperand(i));
- for (unsigned i = 0, e = SrcValue->getNumOperands(); i != e; ++i)
- Elts.insert(SrcValue->getOperand(i));
- DstOp->replaceOperandWith(2, MDNode::get(DstM->getContext(),
- ArrayRef<Value*>(Elts.begin(),
- Elts.end())));
+ Elts.insert(DstValue->op_begin(), DstValue->op_end());
+ Elts.insert(SrcValue->op_begin(), SrcValue->op_end());
+
+ replaceDstValue(MDNode::get(DstM->getContext(),
+ makeArrayRef(Elts.begin(), Elts.end())));
break;
}
}
for (unsigned I = 0, E = Requirements.size(); I != E; ++I) {
MDNode *Requirement = Requirements[I];
MDString *Flag = cast<MDString>(Requirement->getOperand(0));
- Value *ReqValue = Requirement->getOperand(1);
+ Metadata *ReqValue = Requirement->getOperand(1);
- MDNode *Op = Flags[Flag];
+ MDNode *Op = Flags[Flag].first;
if (!Op || Op->getOperand(2) != ReqValue) {
HasErr |= emitError("linking module flags '" + Flag->getString() +
"': does not have the required value");
return HasErr;
}
-
+
+// This function returns true if the triples match.
+static bool triplesMatch(const Triple &T0, const Triple &T1) {
+ // If vendor is apple, ignore the version number.
+ if (T0.getVendor() == Triple::Apple)
+ return T0.getArch() == T1.getArch() &&
+ T0.getSubArch() == T1.getSubArch() &&
+ T0.getVendor() == T1.getVendor() &&
+ T0.getOS() == T1.getOS();
+
+ return T0 == T1;
+}
+
+// This function returns the merged triple.
+static std::string mergeTriples(const Triple &SrcTriple, const Triple &DstTriple) {
+ // If vendor is apple, pick the triple with the larger version number.
+ if (SrcTriple.getVendor() == Triple::Apple)
+ if (DstTriple.isOSVersionLT(SrcTriple))
+ return SrcTriple.str();
+
+ return DstTriple.str();
+}
+
+bool ModuleLinker::linkIfNeeded(GlobalValue &GV) {
+ GlobalValue *DGV = getLinkedToGlobal(&GV);
+
+ if (shouldLinkOnlyNeeded() && !(DGV && DGV->isDeclaration()))
+ return false;
+
+ if (DGV && !GV.hasLocalLinkage()) {
+ GlobalValue::VisibilityTypes Visibility =
+ getMinVisibility(DGV->getVisibility(), GV.getVisibility());
+ DGV->setVisibility(Visibility);
+ GV.setVisibility(Visibility);
+ }
+
+ if (const Comdat *SC = GV.getComdat()) {
+ bool LinkFromSrc;
+ Comdat::SelectionKind SK;
+ std::tie(SK, LinkFromSrc) = ComdatsChosen[SC];
+ if (!LinkFromSrc) {
+ DoNotLinkFromSource.insert(&GV);
+ return false;
+ }
+ }
+
+ if (!DGV && !shouldOverrideFromSrc() &&
+ (GV.hasLocalLinkage() || GV.hasLinkOnceLinkage() ||
+ GV.hasAvailableExternallyLinkage())) {
+ return false;
+ }
+ MapValue(&GV, ValueMap, RF_MoveDistinctMDs, &TypeMap, &ValMaterializer);
+ return HasError;
+}
+
bool ModuleLinker::run() {
assert(DstM && "Null destination module");
assert(SrcM && "Null source module");
// Inherit the target data from the source module if the destination module
// doesn't have one already.
- if (DstM->getDataLayout().empty() && !SrcM->getDataLayout().empty())
+ if (DstM->getDataLayout().isDefault())
DstM->setDataLayout(SrcM->getDataLayout());
+ if (SrcM->getDataLayout() != DstM->getDataLayout()) {
+ emitWarning("Linking two modules of different data layouts: '" +
+ SrcM->getModuleIdentifier() + "' is '" +
+ SrcM->getDataLayoutStr() + "' whereas '" +
+ DstM->getModuleIdentifier() + "' is '" +
+ DstM->getDataLayoutStr() + "'\n");
+ }
+
// Copy the target triple from the source to dest if the dest's is empty.
if (DstM->getTargetTriple().empty() && !SrcM->getTargetTriple().empty())
DstM->setTargetTriple(SrcM->getTargetTriple());
- if (!SrcM->getDataLayout().empty() && !DstM->getDataLayout().empty() &&
- SrcM->getDataLayout() != DstM->getDataLayout())
- errs() << "WARNING: Linking two modules of different data layouts!\n";
- if (!SrcM->getTargetTriple().empty() &&
- DstM->getTargetTriple() != SrcM->getTargetTriple()) {
- errs() << "WARNING: Linking two modules of different target triples: ";
- if (!SrcM->getModuleIdentifier().empty())
- errs() << SrcM->getModuleIdentifier() << ": ";
- errs() << "'" << SrcM->getTargetTriple() << "' and '"
- << DstM->getTargetTriple() << "'\n";
- }
+ Triple SrcTriple(SrcM->getTargetTriple()), DstTriple(DstM->getTargetTriple());
+
+ if (!SrcM->getTargetTriple().empty() && !triplesMatch(SrcTriple, DstTriple))
+ emitWarning("Linking two modules of different target triples: " +
+ SrcM->getModuleIdentifier() + "' is '" +
+ SrcM->getTargetTriple() + "' whereas '" +
+ DstM->getModuleIdentifier() + "' is '" +
+ DstM->getTargetTriple() + "'\n");
+
+ DstM->setTargetTriple(mergeTriples(SrcTriple, DstTriple));
// Append the module inline asm string.
if (!SrcM->getModuleInlineAsm().empty()) {
// Loop over all of the linked values to compute type mappings.
computeTypeMapping();
+ ComdatsChosen.clear();
+ for (const auto &SMEC : SrcM->getComdatSymbolTable()) {
+ const Comdat &C = SMEC.getValue();
+ if (ComdatsChosen.count(&C))
+ continue;
+ Comdat::SelectionKind SK;
+ bool LinkFromSrc;
+ if (getComdatResult(&C, SK, LinkFromSrc))
+ return true;
+ ComdatsChosen[&C] = std::make_pair(SK, LinkFromSrc);
+ }
+
+ // Upgrade mismatched global arrays.
+ upgradeMismatchedGlobals();
+
+ for (GlobalVariable &GV : SrcM->globals())
+ if (const Comdat *SC = GV.getComdat())
+ ComdatMembers[SC].push_back(&GV);
+
+ for (Function &SF : *SrcM)
+ if (const Comdat *SC = SF.getComdat())
+ ComdatMembers[SC].push_back(&SF);
+
+ for (GlobalAlias &GA : SrcM->aliases())
+ if (const Comdat *SC = GA.getComdat())
+ ComdatMembers[SC].push_back(&GA);
+
// 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(),
- E = SrcM->global_end(); I != E; ++I)
- if (linkGlobalProto(I))
+ for (GlobalVariable &GV : SrcM->globals())
+ if (linkIfNeeded(GV))
return true;
- // Link the functions together between the two modules, without doing function
- // bodies... this just adds external function prototypes to the DstM
- // function... We do this so that when we begin processing function bodies,
- // 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 (linkFunctionProto(I))
+ for (Function &SF : *SrcM)
+ if (linkIfNeeded(SF))
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 (linkAliasProto(I))
+ for (GlobalAlias &GA : SrcM->aliases())
+ if (linkIfNeeded(GA))
return true;
- for (unsigned i = 0, e = AppendingVars.size(); i != e; ++i)
- linkAppendingVarInit(AppendingVars[i]);
-
- // Update the initializers in the DstM module now that all globals that may
- // be referenced are in DstM.
- linkGlobalInits();
-
- // Link in the function bodies that are defined in the source module into
- // DstM.
- for (Module::iterator SF = SrcM->begin(), E = SrcM->end(); SF != E; ++SF) {
- // Skip if not linking from source.
- if (DoNotLinkFromSource.count(SF)) continue;
-
- // Skip if no body (function is external) or materialize.
- if (SF->isDeclaration()) {
- if (!SF->isMaterializable())
- continue;
- if (SF->Materialize(&ErrorMsg))
- return true;
- }
-
- linkFunctionBody(cast<Function>(ValueMap[SF]), SF);
- SF->Dematerialize();
+ for (AppendingVarInfo &AppendingVar : AppendingVars)
+ linkAppendingVarInit(AppendingVar);
+
+ for (const auto &Entry : DstM->getComdatSymbolTable()) {
+ const Comdat &C = Entry.getValue();
+ if (C.getSelectionKind() == Comdat::Any)
+ continue;
+ const GlobalValue *GV = SrcM->getNamedValue(C.getName());
+ if (GV)
+ MapValue(GV, ValueMap, RF_MoveDistinctMDs, &TypeMap, &ValMaterializer);
}
- // Resolve all uses of aliases with aliasees.
- linkAliasBodies();
+ // Note that we are done linking global value bodies. This prevents
+ // metadata linking from creating new references.
+ DoneLinkingBodies = true;
// Remap all of the named MDNodes in Src into the DstM module. We do this
// after linking GlobalValues so that MDNodes that reference GlobalValues
if (linkModuleFlagsMetadata())
return true;
- // Process vector of lazily linked in functions.
- bool LinkedInAnyFunctions;
- do {
- LinkedInAnyFunctions = false;
-
- for(std::vector<Function*>::iterator I = LazilyLinkFunctions.begin(),
- E = LazilyLinkFunctions.end(); I != E; ++I) {
- Function *SF = *I;
- if (!SF)
- continue;
+ return false;
+}
- Function *DF = cast<Function>(ValueMap[SF]);
+Linker::StructTypeKeyInfo::KeyTy::KeyTy(ArrayRef<Type *> E, bool P)
+ : ETypes(E), IsPacked(P) {}
- // Materialize if necessary.
- if (SF->isDeclaration()) {
- if (!SF->isMaterializable())
- continue;
- if (SF->Materialize(&ErrorMsg))
- return true;
- }
-
- // Erase from vector *before* the function body is linked - linkFunctionBody could
- // invalidate I.
- LazilyLinkFunctions.erase(I);
-
- // Link in function body.
- linkFunctionBody(DF, SF);
- SF->Dematerialize();
-
- // Set flag to indicate we may have more functions to lazily link in
- // since we linked in a function.
- LinkedInAnyFunctions = true;
- break;
- }
- } while (LinkedInAnyFunctions);
-
- // Now that all of the types from the source are used, resolve any structs
- // copied over to the dest that didn't exist there.
- TypeMap.linkDefinedTypeBodies();
-
- return false;
+Linker::StructTypeKeyInfo::KeyTy::KeyTy(const StructType *ST)
+ : ETypes(ST->elements()), IsPacked(ST->isPacked()) {}
+
+bool Linker::StructTypeKeyInfo::KeyTy::operator==(const KeyTy &That) const {
+ if (IsPacked != That.IsPacked)
+ return false;
+ if (ETypes != That.ETypes)
+ return false;
+ return true;
}
-Linker::Linker(Module *M) : Composite(M) {
+bool Linker::StructTypeKeyInfo::KeyTy::operator!=(const KeyTy &That) const {
+ return !this->operator==(That);
+}
+
+StructType *Linker::StructTypeKeyInfo::getEmptyKey() {
+ return DenseMapInfo<StructType *>::getEmptyKey();
+}
+
+StructType *Linker::StructTypeKeyInfo::getTombstoneKey() {
+ return DenseMapInfo<StructType *>::getTombstoneKey();
+}
+
+unsigned Linker::StructTypeKeyInfo::getHashValue(const KeyTy &Key) {
+ return hash_combine(hash_combine_range(Key.ETypes.begin(), Key.ETypes.end()),
+ Key.IsPacked);
+}
+
+unsigned Linker::StructTypeKeyInfo::getHashValue(const StructType *ST) {
+ return getHashValue(KeyTy(ST));
+}
+
+bool Linker::StructTypeKeyInfo::isEqual(const KeyTy &LHS,
+ const StructType *RHS) {
+ if (RHS == getEmptyKey() || RHS == getTombstoneKey())
+ return false;
+ return LHS == KeyTy(RHS);
+}
+
+bool Linker::StructTypeKeyInfo::isEqual(const StructType *LHS,
+ const StructType *RHS) {
+ if (RHS == getEmptyKey())
+ return LHS == getEmptyKey();
+
+ if (RHS == getTombstoneKey())
+ return LHS == getTombstoneKey();
+
+ return KeyTy(LHS) == KeyTy(RHS);
+}
+
+void Linker::IdentifiedStructTypeSet::addNonOpaque(StructType *Ty) {
+ assert(!Ty->isOpaque());
+ NonOpaqueStructTypes.insert(Ty);
+}
+
+void Linker::IdentifiedStructTypeSet::switchToNonOpaque(StructType *Ty) {
+ assert(!Ty->isOpaque());
+ NonOpaqueStructTypes.insert(Ty);
+ bool Removed = OpaqueStructTypes.erase(Ty);
+ (void)Removed;
+ assert(Removed);
+}
+
+void Linker::IdentifiedStructTypeSet::addOpaque(StructType *Ty) {
+ assert(Ty->isOpaque());
+ OpaqueStructTypes.insert(Ty);
+}
+
+StructType *
+Linker::IdentifiedStructTypeSet::findNonOpaque(ArrayRef<Type *> ETypes,
+ bool IsPacked) {
+ Linker::StructTypeKeyInfo::KeyTy Key(ETypes, IsPacked);
+ auto I = NonOpaqueStructTypes.find_as(Key);
+ if (I == NonOpaqueStructTypes.end())
+ return nullptr;
+ return *I;
+}
+
+bool Linker::IdentifiedStructTypeSet::hasType(StructType *Ty) {
+ if (Ty->isOpaque())
+ return OpaqueStructTypes.count(Ty);
+ auto I = NonOpaqueStructTypes.find(Ty);
+ if (I == NonOpaqueStructTypes.end())
+ return false;
+ return *I == Ty;
+}
+
+void Linker::init(Module *M, DiagnosticHandlerFunction DiagnosticHandler) {
+ this->Composite = M;
+ this->DiagnosticHandler = DiagnosticHandler;
+
TypeFinder StructTypes;
StructTypes.run(*M, true);
- IdentifiedStructTypes.insert(StructTypes.begin(), StructTypes.end());
+ for (StructType *Ty : StructTypes) {
+ if (Ty->isOpaque())
+ IdentifiedStructTypes.addOpaque(Ty);
+ else
+ IdentifiedStructTypes.addNonOpaque(Ty);
+ }
}
-Linker::~Linker() {
+Linker::Linker(Module *M, DiagnosticHandlerFunction DiagnosticHandler) {
+ init(M, DiagnosticHandler);
}
-bool Linker::linkInModule(Module *Src, unsigned Mode, std::string *ErrorMsg) {
- ModuleLinker TheLinker(Composite, IdentifiedStructTypes, Src, Mode);
- if (TheLinker.run()) {
- if (ErrorMsg)
- *ErrorMsg = TheLinker.ErrorMsg;
- return true;
- }
- return false;
+Linker::Linker(Module *M) {
+ init(M, [this](const DiagnosticInfo &DI) {
+ Composite->getContext().diagnose(DI);
+ });
+}
+
+void Linker::deleteModule() {
+ delete Composite;
+ Composite = nullptr;
+}
+
+bool Linker::linkInModule(Module *Src, unsigned Flags,
+ const FunctionInfoIndex *Index,
+ Function *FuncToImport) {
+ ModuleLinker TheLinker(Composite, IdentifiedStructTypes, Src,
+ DiagnosticHandler, Flags, Index, FuncToImport);
+ bool RetCode = TheLinker.run();
+ Composite->dropTriviallyDeadConstantArrays();
+ return RetCode;
+}
+
+void Linker::setModule(Module *Dst) {
+ init(Dst, DiagnosticHandler);
}
//===----------------------------------------------------------------------===//
// LinkModules entrypoint.
//===----------------------------------------------------------------------===//
-/// LinkModules - This function links two modules together, with the resulting
-/// Dest module modified to be the composite of the two input modules. If an
-/// error occurs, true is returned and ErrorMsg (if not null) is set to indicate
-/// the problem. Upon failure, the Dest module could be in a modified state,
-/// and shouldn't be relied on to be consistent.
-bool Linker::LinkModules(Module *Dest, Module *Src, unsigned Mode,
- std::string *ErrorMsg) {
+/// This function links two modules together, with the resulting Dest module
+/// modified to be the composite of the two input modules. If an error occurs,
+/// true is returned and ErrorMsg (if not null) is set to indicate the problem.
+/// Upon failure, the Dest module could be in a modified state, and shouldn't be
+/// relied on to be consistent.
+bool Linker::LinkModules(Module *Dest, Module *Src,
+ DiagnosticHandlerFunction DiagnosticHandler,
+ unsigned Flags) {
+ Linker L(Dest, DiagnosticHandler);
+ return L.linkInModule(Src, Flags);
+}
+
+bool Linker::LinkModules(Module *Dest, Module *Src, unsigned Flags) {
Linker L(Dest);
- return L.linkInModule(Src, Mode, ErrorMsg);
+ return L.linkInModule(Src, Flags);
}
//===----------------------------------------------------------------------===//
//===----------------------------------------------------------------------===//
LLVMBool LLVMLinkModules(LLVMModuleRef Dest, LLVMModuleRef Src,
- LLVMLinkerMode Mode, char **OutMessages) {
- std::string Messages;
- LLVMBool Result = Linker::LinkModules(unwrap(Dest), unwrap(Src),
- Mode, OutMessages? &Messages : 0);
- if (OutMessages)
- *OutMessages = strdup(Messages.c_str());
+ LLVMLinkerMode Unused, char **OutMessages) {
+ Module *D = unwrap(Dest);
+ std::string Message;
+ raw_string_ostream Stream(Message);
+ DiagnosticPrinterRawOStream DP(Stream);
+
+ LLVMBool Result = Linker::LinkModules(
+ D, unwrap(Src), [&](const DiagnosticInfo &DI) { DI.print(DP); });
+
+ if (OutMessages && Result) {
+ Stream.flush();
+ *OutMessages = strdup(Message.c_str());
+ }
return Result;
}
projects / oota-llvm.git / blobdiff