--- /dev/null
+//===- IRMover.h ------------------------------------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LINKER_IRMOVER_H
+#define LLVM_LINKER_IRMOVER_H
+
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/DenseSet.h"
+#include "llvm/IR/DiagnosticInfo.h"
+
+namespace llvm {
+class GlobalValue;
+class Module;
+class StructType;
+class Type;
+
+class IRMover {
+ struct StructTypeKeyInfo {
+ struct KeyTy {
+ ArrayRef<Type *> ETypes;
+ bool IsPacked;
+ KeyTy(ArrayRef<Type *> E, bool P);
+ KeyTy(const StructType *ST);
+ bool operator==(const KeyTy &that) const;
+ bool operator!=(const KeyTy &that) const;
+ };
+ static StructType *getEmptyKey();
+ static StructType *getTombstoneKey();
+ static unsigned getHashValue(const KeyTy &Key);
+ static unsigned getHashValue(const StructType *ST);
+ static bool isEqual(const KeyTy &LHS, const StructType *RHS);
+ static bool isEqual(const StructType *LHS, const StructType *RHS);
+ };
+
+public:
+ class IdentifiedStructTypeSet {
+ // The set of opaque types is the composite module.
+ DenseSet<StructType *> OpaqueStructTypes;
+
+ // The set of identified but non opaque structures in the composite module.
+ DenseSet<StructType *, StructTypeKeyInfo> NonOpaqueStructTypes;
+
+ public:
+ void addNonOpaque(StructType *Ty);
+ void switchToNonOpaque(StructType *Ty);
+ void addOpaque(StructType *Ty);
+ StructType *findNonOpaque(ArrayRef<Type *> ETypes, bool IsPacked);
+ bool hasType(StructType *Ty);
+ };
+
+ IRMover(Module &M, DiagnosticHandlerFunction DiagnosticHandler);
+
+ typedef std::function<void(GlobalValue &)> ValueAdder;
+ /// Move in the provide values. The source is destroyed.
+ /// Returns true on error.
+ bool move(Module &Src, ArrayRef<GlobalValue *> ValuesToLink,
+ std::function<void(GlobalValue &GV, ValueAdder Add)> AddLazyFor);
+ Module &getModule() { return Composite; }
+
+ DiagnosticHandlerFunction getDiagnosticHandler() const {
+ return DiagnosticHandler;
+ }
+
+private:
+ Module &Composite;
+ IdentifiedStructTypeSet IdentifiedStructTypes;
+ DiagnosticHandlerFunction DiagnosticHandler;
+};
+
+} // End llvm namespace
+
+#endif
#ifndef LLVM_LINKER_LINKER_H
#define LLVM_LINKER_LINKER_H
-#include "llvm/ADT/ArrayRef.h"
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/DenseSet.h"
#include "llvm/IR/DiagnosticInfo.h"
#include "llvm/IR/FunctionInfo.h"
+#include "llvm/Linker/IRMover.h"
namespace llvm {
class Module;
/// module since it is assumed that the user of this class will want to do
/// something with it after the linking.
class Linker {
-public:
- struct StructTypeKeyInfo {
- struct KeyTy {
- ArrayRef<Type *> ETypes;
- bool IsPacked;
- KeyTy(ArrayRef<Type *> E, bool P);
- KeyTy(const StructType *ST);
- bool operator==(const KeyTy &that) const;
- bool operator!=(const KeyTy &that) const;
- };
- static StructType *getEmptyKey();
- static StructType *getTombstoneKey();
- static unsigned getHashValue(const KeyTy &Key);
- static unsigned getHashValue(const StructType *ST);
- static bool isEqual(const KeyTy &LHS, const StructType *RHS);
- static bool isEqual(const StructType *LHS, const StructType *RHS);
- };
-
- typedef DenseSet<StructType *, StructTypeKeyInfo> NonOpaqueStructTypeSet;
- typedef DenseSet<StructType *> OpaqueStructTypeSet;
-
- struct IdentifiedStructTypeSet {
- // The set of opaque types is the composite module.
- OpaqueStructTypeSet OpaqueStructTypes;
-
- // The set of identified but non opaque structures in the composite module.
- NonOpaqueStructTypeSet NonOpaqueStructTypes;
-
- void addNonOpaque(StructType *Ty);
- void switchToNonOpaque(StructType *Ty);
- void addOpaque(StructType *Ty);
- StructType *findNonOpaque(ArrayRef<Type *> ETypes, bool IsPacked);
- bool hasType(StructType *Ty);
- };
+ IRMover Mover;
+public:
enum Flags {
None = 0,
OverrideFromSrc = (1 << 0),
unsigned Flags = Flags::None);
DiagnosticHandlerFunction getDiagnosticHandler() const {
- return DiagnosticHandler;
+ return Mover.getDiagnosticHandler();
}
-
-private:
- Module &Composite;
-
- IdentifiedStructTypeSet IdentifiedStructTypes;
-
- DiagnosticHandlerFunction DiagnosticHandler;
};
/// Create a new module with exported local functions renamed and promoted
add_llvm_library(LLVMLinker
+ IRMover.cpp
LinkModules.cpp
ADDITIONAL_HEADER_DIRS
--- /dev/null
+//===- lib/Linker/IRMover.cpp ---------------------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Linker/IRMover.h"
+#include "LinkDiagnosticInfo.h"
+#include "llvm/ADT/SetVector.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/DiagnosticPrinter.h"
+#include "llvm/IR/TypeFinder.h"
+#include "llvm/Transforms/Utils/Cloning.h"
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// TypeMap implementation.
+//===----------------------------------------------------------------------===//
+
+namespace {
+class TypeMapTy : public ValueMapTypeRemapper {
+ /// This is a mapping from a source type to a destination type to use.
+ DenseMap<Type *, Type *> MappedTypes;
+
+ /// 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;
+
+ 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;
+
+ /// 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(IRMover::IdentifiedStructTypeSet &DstStructTypesSet)
+ : DstStructTypesSet(DstStructTypesSet) {}
+
+ IRMover::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);
+
+ /// Produce a body for an opaque type in the dest module from a type
+ /// definition in the source module.
+ void linkDefinedTypeBodies();
+
+ /// 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);
+
+ void finishType(StructType *DTy, StructType *STy, ArrayRef<Type *> ETypes);
+
+ FunctionType *get(FunctionType *T) {
+ return cast<FunctionType>(get((Type *)T));
+ }
+
+private:
+ Type *remapType(Type *SrcTy) override { return get(SrcTy); }
+
+ bool areTypesIsomorphic(Type *DstTy, Type *SrcTy);
+};
+}
+
+void TypeMapTy::addTypeMapping(Type *DstTy, Type *SrcTy) {
+ 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 (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();
+}
+
+/// 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 we have an entry in the MappedTypes table, then we have our answer.
+ Type *&Entry = MappedTypes[SrcTy];
+ if (Entry)
+ return Entry == DstTy;
+
+ // Two identical types are clearly isomorphic. Remember this
+ // non-speculatively.
+ if (DstTy == 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.
+ if (StructType *SSTy = dyn_cast<StructType>(SrcTy)) {
+ // Mapping an opaque type to any struct, just keep the dest struct.
+ if (SSTy->isOpaque()) {
+ Entry = DstTy;
+ SpeculativeTypes.push_back(SrcTy);
+ return true;
+ }
+
+ // 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. 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)).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;
+ } else if (StructType *DSTy = dyn_cast<StructType>(DstTy)) {
+ StructType *SSTy = cast<StructType>(SrcTy);
+ if (DSTy->isLiteral() != SSTy->isLiteral() ||
+ DSTy->isPacked() != SSTy->isPacked())
+ return false;
+ } else if (ArrayType *DATy = dyn_cast<ArrayType>(DstTy)) {
+ if (DATy->getNumElements() != cast<ArrayType>(SrcTy)->getNumElements())
+ return false;
+ } else if (VectorType *DVTy = dyn_cast<VectorType>(DstTy)) {
+ if (DVTy->getNumElements() != cast<VectorType>(SrcTy)->getNumElements())
+ return false;
+ }
+
+ // Otherwise, we speculate that these two types will line up and recursively
+ // check the subelements.
+ Entry = DstTy;
+ SpeculativeTypes.push_back(SrcTy);
+
+ 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;
+}
+
+void TypeMapTy::linkDefinedTypeBodies() {
+ SmallVector<Type *, 16> Elements;
+ for (StructType *SrcSTy : SrcDefinitionsToResolve) {
+ StructType *DstSTy = cast<StructType>(MappedTypes[SrcSTy]);
+ 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] = get(SrcSTy->getElementType(I));
+
+ DstSTy->setBody(Elements, SrcSTy->isPacked());
+ DstStructTypesSet.switchToNonOpaque(DstSTy);
+ }
+ SrcDefinitionsToResolve.clear();
+ DstResolvedOpaqueTypes.clear();
+}
+
+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) {
+ SmallPtrSet<StructType *, 8> Visited;
+ return get(Ty, Visited);
+}
+
+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;
+
+ // 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.
+ 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;
+ }
+
+ if (StructType *OldT =
+ DstStructTypesSet.findNonOpaque(ElementTypes, IsPacked)) {
+ STy->setName("");
+ return *Entry = OldT;
+ }
+
+ if (!AnyChange) {
+ DstStructTypesSet.addNonOpaque(STy);
+ return *Entry = Ty;
+ }
+
+ StructType *DTy = StructType::create(Ty->getContext());
+ finishType(DTy, STy, ElementTypes);
+ return *Entry = DTy;
+ }
+ }
+}
+
+LinkDiagnosticInfo::LinkDiagnosticInfo(DiagnosticSeverity Severity,
+ const Twine &Msg)
+ : DiagnosticInfo(DK_Linker, Severity), Msg(Msg) {}
+void LinkDiagnosticInfo::print(DiagnosticPrinter &DP) const { DP << Msg; }
+
+//===----------------------------------------------------------------------===//
+// ModuleLinker implementation.
+//===----------------------------------------------------------------------===//
+
+namespace {
+class IRLinker;
+
+/// 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 GlobalValueMaterializer final : public ValueMaterializer {
+ IRLinker *ModLinker;
+
+public:
+ GlobalValueMaterializer(IRLinker *ModLinker) : ModLinker(ModLinker) {}
+ Value *materializeDeclFor(Value *V) override;
+ void materializeInitFor(GlobalValue *New, GlobalValue *Old) override;
+};
+
+class LocalValueMaterializer final : public ValueMaterializer {
+ IRLinker *ModLinker;
+
+public:
+ LocalValueMaterializer(IRLinker *ModLinker) : ModLinker(ModLinker) {}
+ Value *materializeDeclFor(Value *V) override;
+ void materializeInitFor(GlobalValue *New, GlobalValue *Old) override;
+};
+
+/// This is responsible for keeping track of the state used for moving data
+/// from SrcM to DstM.
+class IRLinker {
+ Module &DstM;
+ Module &SrcM;
+
+ std::function<void(GlobalValue &, IRMover::ValueAdder)> AddLazyFor;
+
+ TypeMapTy TypeMap;
+ GlobalValueMaterializer GValMaterializer;
+ LocalValueMaterializer LValMaterializer;
+
+ /// 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;
+ ValueToValueMapTy AliasValueMap;
+
+ DenseSet<GlobalValue *> ValuesToLink;
+ std::vector<GlobalValue *> Worklist;
+
+ void maybeAdd(GlobalValue *GV) {
+ if (ValuesToLink.insert(GV).second)
+ Worklist.push_back(GV);
+ }
+
+ DiagnosticHandlerFunction DiagnosticHandler;
+
+ /// 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 = false;
+
+ bool HasError = false;
+
+ /// Handles cloning of a global values from the source module into
+ /// the destination module, including setting the attributes and visibility.
+ GlobalValue *copyGlobalValueProto(const GlobalValue *SGV, bool ForDefinition);
+
+ /// 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));
+ }
+
+ /// 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() || SrcGV->hasLocalLinkage())
+ return nullptr;
+
+ // Otherwise see if we have a match in the destination module's symtab.
+ GlobalValue *DGV = DstM.getNamedValue(SrcGV->getName());
+ 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();
+
+ Constant *linkAppendingVarProto(GlobalVariable *DstGV,
+ const GlobalVariable *SrcGV);
+
+ bool shouldLink(GlobalValue *DGV, GlobalValue &SGV);
+ Constant *linkGlobalValueProto(GlobalValue *GV, bool ForAlias);
+
+ bool linkModuleFlagsMetadata();
+
+ void linkGlobalInit(GlobalVariable &Dst, GlobalVariable &Src);
+ bool linkFunctionBody(Function &Dst, Function &Src);
+ void linkAliasBody(GlobalAlias &Dst, GlobalAlias &Src);
+ bool linkGlobalValueBody(GlobalValue &Dst, GlobalValue &Src);
+
+ /// Functions that take care of cloning a specific global value type
+ /// into the destination module.
+ GlobalVariable *copyGlobalVariableProto(const GlobalVariable *SGVar);
+ Function *copyFunctionProto(const Function *SF);
+ GlobalValue *copyGlobalAliasProto(const GlobalAlias *SGA);
+
+ void linkNamedMDNodes();
+
+public:
+ IRLinker(Module &DstM, IRMover::IdentifiedStructTypeSet &Set, Module &SrcM,
+ DiagnosticHandlerFunction DiagnosticHandler,
+ ArrayRef<GlobalValue *> ValuesToLink,
+ std::function<void(GlobalValue &, IRMover::ValueAdder)> AddLazyFor)
+ : DstM(DstM), SrcM(SrcM), AddLazyFor(AddLazyFor), TypeMap(Set),
+ GValMaterializer(this), LValMaterializer(this),
+ DiagnosticHandler(DiagnosticHandler) {
+ for (GlobalValue *GV : ValuesToLink)
+ maybeAdd(GV);
+ }
+
+ bool run();
+ Value *materializeDeclFor(Value *V, bool ForAlias);
+ void materializeInitFor(GlobalValue *New, GlobalValue *Old, bool ForAlias);
+};
+}
+
+/// 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.
+ if (GV->hasLocalLinkage() || GV->getName() == Name)
+ return;
+
+ Module *M = GV->getParent();
+
+ // If there is a conflict, rename the conflict.
+ if (GlobalValue *ConflictGV = M->getNamedValue(Name)) {
+ GV->takeName(ConflictGV);
+ ConflictGV->setName(Name); // This will cause ConflictGV to get renamed
+ assert(ConflictGV->getName() != Name && "forceRenaming didn't work");
+ } else {
+ GV->setName(Name); // Force the name back
+ }
+}
+
+Value *GlobalValueMaterializer::materializeDeclFor(Value *V) {
+ return ModLinker->materializeDeclFor(V, false);
+}
+
+void GlobalValueMaterializer::materializeInitFor(GlobalValue *New,
+ GlobalValue *Old) {
+ ModLinker->materializeInitFor(New, Old, false);
+}
+
+Value *LocalValueMaterializer::materializeDeclFor(Value *V) {
+ return ModLinker->materializeDeclFor(V, true);
+}
+
+void LocalValueMaterializer::materializeInitFor(GlobalValue *New,
+ GlobalValue *Old) {
+ ModLinker->materializeInitFor(New, Old, true);
+}
+
+Value *IRLinker::materializeDeclFor(Value *V, bool ForAlias) {
+ auto *SGV = dyn_cast<GlobalValue>(V);
+ if (!SGV)
+ return nullptr;
+
+ return linkGlobalValueProto(SGV, ForAlias);
+}
+
+void IRLinker::materializeInitFor(GlobalValue *New, GlobalValue *Old,
+ bool ForAlias) {
+ // If we already created the body, just return.
+ 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 (ForAlias || shouldLink(New, *Old))
+ linkGlobalValueBody(*New, *Old);
+}
+
+/// Loop through the global variables in the src module and merge them into the
+/// dest module.
+GlobalVariable *IRLinker::copyGlobalVariableProto(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(), GlobalValue::ExternalLinkage,
+ /*init*/ nullptr, SGVar->getName(),
+ /*insertbefore*/ nullptr, SGVar->getThreadLocalMode(),
+ SGVar->getType()->getAddressSpace());
+ NewDGV->setAlignment(SGVar->getAlignment());
+ return NewDGV;
+}
+
+/// Link the function in the source module into the destination module if
+/// needed, setting up mapping information.
+Function *IRLinker::copyFunctionProto(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()),
+ GlobalValue::ExternalLinkage, SF->getName(), &DstM);
+}
+
+/// Set up prototypes for any aliases that come over from the source module.
+GlobalValue *IRLinker::copyGlobalAliasProto(const GlobalAlias *SGA) {
+ // 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(),
+ GlobalValue::ExternalLinkage, SGA->getName(),
+ &DstM);
+}
+
+GlobalValue *IRLinker::copyGlobalValueProto(const GlobalValue *SGV,
+ bool ForDefinition) {
+ GlobalValue *NewGV;
+ if (auto *SGVar = dyn_cast<GlobalVariable>(SGV)) {
+ NewGV = copyGlobalVariableProto(SGVar);
+ } else if (auto *SF = dyn_cast<Function>(SGV)) {
+ NewGV = copyFunctionProto(SF);
+ } else {
+ if (ForDefinition)
+ NewGV = copyGlobalAliasProto(cast<GlobalAlias>(SGV));
+ else
+ NewGV = new GlobalVariable(
+ DstM, TypeMap.get(SGV->getType()->getElementType()),
+ /*isConstant*/ false, GlobalValue::ExternalLinkage,
+ /*init*/ nullptr, SGV->getName(),
+ /*insertbefore*/ nullptr, SGV->getThreadLocalMode(),
+ SGV->getType()->getAddressSpace());
+ }
+
+ if (ForDefinition)
+ NewGV->setLinkage(SGV->getLinkage());
+ else if (SGV->hasExternalWeakLinkage() || SGV->hasWeakLinkage() ||
+ SGV->hasLinkOnceLinkage())
+ NewGV->setLinkage(GlobalValue::ExternalWeakLinkage);
+
+ NewGV->copyAttributesFrom(SGV);
+ return NewGV;
+}
+
+/// 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 IRLinker::computeTypeMapping() {
+ 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>(SGV.getType()->getElementType());
+ TypeMap.addTypeMapping(DAT->getElementType(), SAT->getElementType());
+ }
+
+ 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 }".
+ 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])))
+ continue;
+
+ // Check to see if the destination module has a struct with the prefix name.
+ 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.
+ TypeMap.linkDefinedTypeBodies();
+}
+
+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));
+}
+
+/// If there were any appending global variables, link them together now.
+/// Return true on error.
+Constant *IRLinker::linkAppendingVarProto(GlobalVariable *DstGV,
+ const GlobalVariable *SrcGV) {
+ Type *EltTy = cast<ArrayType>(TypeMap.get(SrcGV->getType()->getElementType()))
+ ->getElementType();
+
+ StringRef Name = SrcGV->getName();
+ bool IsNewStructor = false;
+ bool IsOldStructor = false;
+ if (Name == "llvm.global_ctors" || Name == "llvm.global_dtors") {
+ if (cast<StructType>(EltTy)->getNumElements() == 3)
+ IsNewStructor = true;
+ else
+ IsOldStructor = true;
+ }
+
+ PointerType *VoidPtrTy = Type::getInt8Ty(SrcGV->getContext())->getPointerTo();
+ if (IsOldStructor) {
+ auto &ST = *cast<StructType>(EltTy);
+ Type *Tys[3] = {ST.getElementType(0), ST.getElementType(1), VoidPtrTy};
+ EltTy = StructType::get(SrcGV->getContext(), Tys, false);
+ }
+
+ if (DstGV) {
+ ArrayType *DstTy = cast<ArrayType>(DstGV->getType()->getElementType());
+
+ if (!SrcGV->hasAppendingLinkage() || !DstGV->hasAppendingLinkage()) {
+ emitError(
+ "Linking globals named '" + SrcGV->getName() +
+ "': can only link appending global with another appending global!");
+ return nullptr;
+ }
+
+ // Check to see that they two arrays agree on type.
+ if (EltTy != DstTy->getElementType()) {
+ emitError("Appending variables with different element types!");
+ return nullptr;
+ }
+ if (DstGV->isConstant() != SrcGV->isConstant()) {
+ emitError("Appending variables linked with different const'ness!");
+ return nullptr;
+ }
+
+ if (DstGV->getAlignment() != SrcGV->getAlignment()) {
+ emitError(
+ "Appending variables with different alignment need to be linked!");
+ return nullptr;
+ }
+
+ if (DstGV->getVisibility() != SrcGV->getVisibility()) {
+ emitError(
+ "Appending variables with different visibility need to be linked!");
+ return nullptr;
+ }
+
+ if (DstGV->hasUnnamedAddr() != SrcGV->hasUnnamedAddr()) {
+ emitError(
+ "Appending variables with different unnamed_addr need to be linked!");
+ return nullptr;
+ }
+
+ if (StringRef(DstGV->getSection()) != SrcGV->getSection()) {
+ emitError(
+ "Appending variables with different section name need to be linked!");
+ return nullptr;
+ }
+ }
+
+ SmallVector<Constant *, 16> DstElements;
+ if (DstGV)
+ getArrayElements(DstGV->getInitializer(), DstElements);
+
+ SmallVector<Constant *, 16> SrcElements;
+ getArrayElements(SrcGV->getInitializer(), SrcElements);
+
+ if (IsNewStructor)
+ SrcElements.erase(
+ std::remove_if(SrcElements.begin(), SrcElements.end(),
+ [this](Constant *E) {
+ auto *Key = dyn_cast<GlobalValue>(
+ E->getAggregateElement(2)->stripPointerCasts());
+ if (!Key)
+ return false;
+ GlobalValue *DGV = getLinkedToGlobal(Key);
+ return !shouldLink(DGV, *Key);
+ }),
+ SrcElements.end());
+ uint64_t NewSize = DstElements.size() + SrcElements.size();
+ ArrayType *NewType = ArrayType::get(EltTy, NewSize);
+
+ // Create the new global variable.
+ GlobalVariable *NG = new GlobalVariable(
+ DstM, NewType, SrcGV->isConstant(), SrcGV->getLinkage(),
+ /*init*/ nullptr, /*name*/ "", DstGV, SrcGV->getThreadLocalMode(),
+ SrcGV->getType()->getAddressSpace());
+
+ NG->copyAttributesFrom(SrcGV);
+ forceRenaming(NG, SrcGV->getName());
+
+ Constant *Ret = ConstantExpr::getBitCast(NG, TypeMap.get(SrcGV->getType()));
+
+ // Stop recursion.
+ ValueMap[SrcGV] = Ret;
+
+ for (auto *V : SrcElements) {
+ Constant *NewV;
+ if (IsOldStructor) {
+ auto *S = cast<ConstantStruct>(V);
+ auto *E1 = MapValue(S->getOperand(0), ValueMap, RF_MoveDistinctMDs,
+ &TypeMap, &GValMaterializer);
+ auto *E2 = MapValue(S->getOperand(1), ValueMap, RF_MoveDistinctMDs,
+ &TypeMap, &GValMaterializer);
+ Value *Null = Constant::getNullValue(VoidPtrTy);
+ NewV =
+ ConstantStruct::get(cast<StructType>(EltTy), E1, E2, Null, nullptr);
+ } else {
+ NewV = MapValue(V, ValueMap, RF_MoveDistinctMDs, &TypeMap,
+ &GValMaterializer);
+ }
+ DstElements.push_back(NewV);
+ }
+
+ NG->setInitializer(ConstantArray::get(NewType, DstElements));
+
+ // Replace any uses of the two global variables with uses of the new
+ // global.
+ if (DstGV) {
+ DstGV->replaceAllUsesWith(ConstantExpr::getBitCast(NG, DstGV->getType()));
+ DstGV->eraseFromParent();
+ }
+
+ return Ret;
+}
+
+static bool useExistingDest(GlobalValue &SGV, GlobalValue *DGV,
+ bool ShouldLink) {
+ if (!DGV)
+ return false;
+
+ if (SGV.isDeclaration())
+ return true;
+
+ if (DGV->isDeclarationForLinker())
+ return false;
+
+ if (ShouldLink)
+ return false;
+
+ return true;
+}
+
+bool IRLinker::shouldLink(GlobalValue *DGV, GlobalValue &SGV) {
+ if (ValuesToLink.count(&SGV))
+ return true;
+
+ if (SGV.hasLocalLinkage())
+ return true;
+
+ if (DGV && !DGV->isDeclaration())
+ return false;
+
+ if (SGV.hasAvailableExternallyLinkage())
+ return true;
+
+ if (DoneLinkingBodies)
+ return false;
+
+ AddLazyFor(SGV, [this](GlobalValue &GV) { maybeAdd(&GV); });
+ return ValuesToLink.count(&SGV);
+}
+
+Constant *IRLinker::linkGlobalValueProto(GlobalValue *SGV, bool ForAlias) {
+ GlobalValue *DGV = getLinkedToGlobal(SGV);
+
+ bool ShouldLink = shouldLink(DGV, *SGV);
+
+ // just missing from map
+ if (ShouldLink) {
+ auto I = ValueMap.find(SGV);
+ if (I != ValueMap.end())
+ return cast<Constant>(I->second);
+
+ I = AliasValueMap.find(SGV);
+ if (I != AliasValueMap.end())
+ return cast<Constant>(I->second);
+ }
+
+ DGV = nullptr;
+ if (ShouldLink || !ForAlias)
+ DGV = getLinkedToGlobal(SGV);
+
+ // Handle the ultra special appending linkage case first.
+ assert(!DGV || SGV->hasAppendingLinkage() == DGV->hasAppendingLinkage());
+ if (SGV->hasAppendingLinkage())
+ return linkAppendingVarProto(cast_or_null<GlobalVariable>(DGV),
+ cast<GlobalVariable>(SGV));
+
+ GlobalValue *NewGV;
+ if (useExistingDest(*SGV, DGV, ShouldLink)) {
+ NewGV = DGV;
+ } else {
+ // 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;
+
+ NewGV = copyGlobalValueProto(SGV, ShouldLink);
+ if (!ForAlias)
+ forceRenaming(NewGV, SGV->getName());
+ }
+ if (ShouldLink || ForAlias) {
+ if (const Comdat *SC = SGV->getComdat()) {
+ if (auto *GO = dyn_cast<GlobalObject>(NewGV)) {
+ Comdat *DC = DstM.getOrInsertComdat(SC->getName());
+ DC->setSelectionKind(SC->getSelectionKind());
+ GO->setComdat(DC);
+ }
+ }
+ }
+
+ if (!ShouldLink && ForAlias)
+ NewGV->setLinkage(GlobalValue::InternalLinkage);
+
+ Constant *C = NewGV;
+ if (DGV)
+ C = ConstantExpr::getBitCast(NewGV, TypeMap.get(SGV->getType()));
+
+ if (DGV && NewGV != DGV) {
+ DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewGV, DGV->getType()));
+ DGV->eraseFromParent();
+ }
+
+ return C;
+}
+
+/// Update the initializers in the Dest module now that all globals that may be
+/// referenced are in Dest.
+void IRLinker::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, &GValMaterializer));
+}
+
+/// 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 IRLinker::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,
+ &GValMaterializer));
+
+ // Link in the prologue data.
+ if (Src.hasPrologueData())
+ Dst.setPrologueData(MapValue(Src.getPrologueData(), ValueMap,
+ RF_MoveDistinctMDs, &TypeMap,
+ &GValMaterializer));
+
+ // Link in the personality function.
+ if (Src.hasPersonalityFn())
+ Dst.setPersonalityFn(MapValue(Src.getPersonalityFn(), ValueMap,
+ RF_MoveDistinctMDs, &TypeMap,
+ &GValMaterializer));
+
+ // Go through and convert function arguments over, remembering the mapping.
+ 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[&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, &GValMaterializer));
+
+ // 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,
+ &GValMaterializer);
+
+ // There is no need to map the arguments anymore.
+ for (Argument &Arg : Src.args())
+ ValueMap.erase(&Arg);
+
+ Src.dematerialize();
+ return false;
+}
+
+void IRLinker::linkAliasBody(GlobalAlias &Dst, GlobalAlias &Src) {
+ Constant *Aliasee = Src.getAliasee();
+ Constant *Val = MapValue(Aliasee, AliasValueMap, RF_MoveDistinctMDs, &TypeMap,
+ &LValMaterializer);
+ Dst.setAliasee(Val);
+}
+
+bool IRLinker::linkGlobalValueBody(GlobalValue &Dst, GlobalValue &Src) {
+ 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;
+}
+
+/// Insert all of the named MDNodes in Src into the Dest module.
+void IRLinker::linkNamedMDNodes() {
+ const NamedMDNode *SrcModFlags = SrcM.getModuleFlagsMetadata();
+ for (const NamedMDNode &NMD : SrcM.named_metadata()) {
+ // Don't link module flags here. Do them separately.
+ if (&NMD == SrcModFlags)
+ continue;
+ NamedMDNode *DestNMD = DstM.getOrInsertNamedMetadata(NMD.getName());
+ // Add Src elements into Dest node.
+ for (const MDNode *op : NMD.operands())
+ DestNMD->addOperand(MapMetadata(
+ op, ValueMap, RF_MoveDistinctMDs | RF_NullMapMissingGlobalValues,
+ &TypeMap, &GValMaterializer));
+ }
+}
+
+/// Merge the linker flags in Src into the Dest module.
+bool IRLinker::linkModuleFlagsMetadata() {
+ // If the source module has no module flags, we are done.
+ const NamedMDNode *SrcModFlags = SrcM.getModuleFlagsMetadata();
+ if (!SrcModFlags)
+ return false;
+
+ // If the destination module doesn't have module flags yet, then just copy
+ // over the source module's flags.
+ NamedMDNode *DstModFlags = DstM.getOrInsertModuleFlagsMetadata();
+ if (DstModFlags->getNumOperands() == 0) {
+ for (unsigned I = 0, E = SrcModFlags->getNumOperands(); I != E; ++I)
+ DstModFlags->addOperand(SrcModFlags->getOperand(I));
+
+ return false;
+ }
+
+ // First build a map of the existing module flags and requirements.
+ 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 = 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] = std::make_pair(Op, I);
+ }
+ }
+
+ // Merge in the flags from the source module, and also collect its set of
+ // requirements.
+ for (unsigned I = 0, E = SrcModFlags->getNumOperands(); I != E; ++I) {
+ MDNode *SrcOp = SrcModFlags->getOperand(I);
+ ConstantInt *SrcBehavior =
+ mdconst::extract<ConstantInt>(SrcOp->getOperand(0));
+ MDString *ID = cast<MDString>(SrcOp->getOperand(1));
+ 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 (SrcBehaviorValue == Module::Require) {
+ // If the destination module does not already have this requirement, add
+ // it.
+ if (Requirements.insert(cast<MDNode>(SrcOp->getOperand(2)))) {
+ DstModFlags->addOperand(SrcOp);
+ }
+ continue;
+ }
+
+ // If there is no existing flag with this ID, just add it.
+ if (!DstOp) {
+ Flags[ID] = std::make_pair(SrcOp, DstModFlags->getNumOperands());
+ DstModFlags->addOperand(SrcOp);
+ continue;
+ }
+
+ // Otherwise, perform a merge.
+ ConstantInt *DstBehavior =
+ mdconst::extract<ConstantInt>(DstOp->getOperand(0));
+ unsigned DstBehaviorValue = DstBehavior->getZExtValue();
+
+ // If either flag has override behavior, handle it first.
+ if (DstBehaviorValue == Module::Override) {
+ // Diagnose inconsistent flags which both have override behavior.
+ if (SrcBehaviorValue == Module::Override &&
+ SrcOp->getOperand(2) != DstOp->getOperand(2)) {
+ emitError("linking module flags '" + ID->getString() +
+ "': IDs have conflicting override values");
+ }
+ continue;
+ } else if (SrcBehaviorValue == Module::Override) {
+ // Update the destination flag to that of the source.
+ DstModFlags->setOperand(DstIndex, SrcOp);
+ Flags[ID].first = SrcOp;
+ continue;
+ }
+
+ // Diagnose inconsistent merge behavior types.
+ if (SrcBehaviorValue != DstBehaviorValue) {
+ emitError("linking module flags '" + ID->getString() +
+ "': IDs have conflicting behaviors");
+ 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:
+ llvm_unreachable("not possible");
+ case Module::Error: {
+ // Emit an error if the values differ.
+ if (SrcOp->getOperand(2) != DstOp->getOperand(2)) {
+ emitError("linking module flags '" + ID->getString() +
+ "': IDs have conflicting values");
+ }
+ continue;
+ }
+ case Module::Warning: {
+ // Emit a warning if the values differ.
+ if (SrcOp->getOperand(2) != DstOp->getOperand(2)) {
+ 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));
+ 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<Metadata *, 16> Elts;
+ MDNode *DstValue = cast<MDNode>(DstOp->getOperand(2));
+ MDNode *SrcValue = cast<MDNode>(SrcOp->getOperand(2));
+ 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;
+ }
+ }
+ }
+
+ // Check all of the requirements.
+ for (unsigned I = 0, E = Requirements.size(); I != E; ++I) {
+ MDNode *Requirement = Requirements[I];
+ MDString *Flag = cast<MDString>(Requirement->getOperand(0));
+ Metadata *ReqValue = Requirement->getOperand(1);
+
+ MDNode *Op = Flags[Flag].first;
+ if (!Op || Op->getOperand(2) != ReqValue) {
+ emitError("linking module flags '" + Flag->getString() +
+ "': does not have the required value");
+ continue;
+ }
+ }
+
+ return HasError;
+}
+
+// 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 IRLinker::run() {
+ // Inherit the target data from the source module if the destination module
+ // doesn't have one already.
+ 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());
+
+ 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()) {
+ if (DstM.getModuleInlineAsm().empty())
+ DstM.setModuleInlineAsm(SrcM.getModuleInlineAsm());
+ else
+ DstM.setModuleInlineAsm(DstM.getModuleInlineAsm() + "\n" +
+ SrcM.getModuleInlineAsm());
+ }
+
+ // Loop over all of the linked values to compute type mappings.
+ computeTypeMapping();
+
+ std::reverse(Worklist.begin(), Worklist.end());
+ while (!Worklist.empty()) {
+ GlobalValue *GV = Worklist.back();
+ Worklist.pop_back();
+
+ // Already mapped.
+ if (ValueMap.find(GV) != ValueMap.end() ||
+ AliasValueMap.find(GV) != AliasValueMap.end())
+ continue;
+
+ assert(!GV->isDeclaration());
+ MapValue(GV, ValueMap, RF_MoveDistinctMDs, &TypeMap, &GValMaterializer);
+ if (HasError)
+ return true;
+ }
+
+ // 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
+ // are properly remapped.
+ linkNamedMDNodes();
+
+ // Merge the module flags into the DstM module.
+ if (linkModuleFlagsMetadata())
+ return true;
+
+ return false;
+}
+
+IRMover::StructTypeKeyInfo::KeyTy::KeyTy(ArrayRef<Type *> E, bool P)
+ : ETypes(E), IsPacked(P) {}
+
+IRMover::StructTypeKeyInfo::KeyTy::KeyTy(const StructType *ST)
+ : ETypes(ST->elements()), IsPacked(ST->isPacked()) {}
+
+bool IRMover::StructTypeKeyInfo::KeyTy::operator==(const KeyTy &That) const {
+ if (IsPacked != That.IsPacked)
+ return false;
+ if (ETypes != That.ETypes)
+ return false;
+ return true;
+}
+
+bool IRMover::StructTypeKeyInfo::KeyTy::operator!=(const KeyTy &That) const {
+ return !this->operator==(That);
+}
+
+StructType *IRMover::StructTypeKeyInfo::getEmptyKey() {
+ return DenseMapInfo<StructType *>::getEmptyKey();
+}
+
+StructType *IRMover::StructTypeKeyInfo::getTombstoneKey() {
+ return DenseMapInfo<StructType *>::getTombstoneKey();
+}
+
+unsigned IRMover::StructTypeKeyInfo::getHashValue(const KeyTy &Key) {
+ return hash_combine(hash_combine_range(Key.ETypes.begin(), Key.ETypes.end()),
+ Key.IsPacked);
+}
+
+unsigned IRMover::StructTypeKeyInfo::getHashValue(const StructType *ST) {
+ return getHashValue(KeyTy(ST));
+}
+
+bool IRMover::StructTypeKeyInfo::isEqual(const KeyTy &LHS,
+ const StructType *RHS) {
+ if (RHS == getEmptyKey() || RHS == getTombstoneKey())
+ return false;
+ return LHS == KeyTy(RHS);
+}
+
+bool IRMover::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 IRMover::IdentifiedStructTypeSet::addNonOpaque(StructType *Ty) {
+ assert(!Ty->isOpaque());
+ NonOpaqueStructTypes.insert(Ty);
+}
+
+void IRMover::IdentifiedStructTypeSet::switchToNonOpaque(StructType *Ty) {
+ assert(!Ty->isOpaque());
+ NonOpaqueStructTypes.insert(Ty);
+ bool Removed = OpaqueStructTypes.erase(Ty);
+ (void)Removed;
+ assert(Removed);
+}
+
+void IRMover::IdentifiedStructTypeSet::addOpaque(StructType *Ty) {
+ assert(Ty->isOpaque());
+ OpaqueStructTypes.insert(Ty);
+}
+
+StructType *
+IRMover::IdentifiedStructTypeSet::findNonOpaque(ArrayRef<Type *> ETypes,
+ bool IsPacked) {
+ IRMover::StructTypeKeyInfo::KeyTy Key(ETypes, IsPacked);
+ auto I = NonOpaqueStructTypes.find_as(Key);
+ if (I == NonOpaqueStructTypes.end())
+ return nullptr;
+ return *I;
+}
+
+bool IRMover::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;
+}
+
+IRMover::IRMover(Module &M, DiagnosticHandlerFunction DiagnosticHandler)
+ : Composite(M), DiagnosticHandler(DiagnosticHandler) {
+ TypeFinder StructTypes;
+ StructTypes.run(M, true);
+ for (StructType *Ty : StructTypes) {
+ if (Ty->isOpaque())
+ IdentifiedStructTypes.addOpaque(Ty);
+ else
+ IdentifiedStructTypes.addNonOpaque(Ty);
+ }
+}
+
+bool IRMover::move(
+ Module &Src, ArrayRef<GlobalValue *> ValuesToLink,
+ std::function<void(GlobalValue &, ValueAdder Add)> AddLazyFor) {
+ IRLinker TheLinker(Composite, IdentifiedStructTypes, Src, DiagnosticHandler,
+ ValuesToLink, AddLazyFor);
+ bool RetCode = TheLinker.run();
+ Composite.dropTriviallyDeadConstantArrays();
+ return RetCode;
+}
--- /dev/null
+//===- LinkDiagnosticInfo.h -------------------------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_LINKER_LINK_DIAGNOSTIC_INFO_H
+#define LLVM_LIB_LINKER_LINK_DIAGNOSTIC_INFO_H
+
+#include "llvm/IR/DiagnosticInfo.h"
+
+namespace llvm {
+class LinkDiagnosticInfo : public DiagnosticInfo {
+ const Twine &Msg;
+
+public:
+ LinkDiagnosticInfo(DiagnosticSeverity Severity, const Twine &Msg);
+ void print(DiagnosticPrinter &DP) const override;
+};
+}
+
+#endif
//===----------------------------------------------------------------------===//
#include "llvm/Linker/Linker.h"
+#include "LinkDiagnosticInfo.h"
#include "llvm-c/Linker.h"
#include "llvm/ADT/SetVector.h"
-#include "llvm/ADT/SmallString.h"
-#include "llvm/ADT/Triple.h"
-#include "llvm/IR/Constants.h"
-#include "llvm/IR/DiagnosticInfo.h"
+#include "llvm/ADT/StringSet.h"
#include "llvm/IR/DiagnosticPrinter.h"
-#include "llvm/IR/LLVMContext.h"
-#include "llvm/IR/Module.h"
-#include "llvm/IR/TypeFinder.h"
-#include "llvm/Transforms/Utils/Cloning.h"
using namespace llvm;
-//===----------------------------------------------------------------------===//
-// TypeMap implementation.
-//===----------------------------------------------------------------------===//
-
namespace {
-class TypeMapTy : public ValueMapTypeRemapper {
- /// This is a mapping from a source type to a destination type to use.
- DenseMap<Type *, Type *> MappedTypes;
-
- /// 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;
-
- 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;
-
- /// 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(Linker::IdentifiedStructTypeSet &DstStructTypesSet)
- : DstStructTypesSet(DstStructTypesSet) {}
-
- 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);
-
- /// Produce a body for an opaque type in the dest module from a type
- /// definition in the source module.
- void linkDefinedTypeBodies();
-
- /// 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);
-
- void finishType(StructType *DTy, StructType *STy, ArrayRef<Type *> ETypes);
-
- FunctionType *get(FunctionType *T) {
- return cast<FunctionType>(get((Type *)T));
- }
-
- /// Dump out the type map for debugging purposes.
- void dump() const {
- for (auto &Pair : MappedTypes) {
- dbgs() << "TypeMap: ";
- Pair.first->print(dbgs());
- dbgs() << " => ";
- Pair.second->print(dbgs());
- dbgs() << '\n';
- }
- }
-
-private:
- Type *remapType(Type *SrcTy) override { return get(SrcTy); }
-
- bool areTypesIsomorphic(Type *DstTy, Type *SrcTy);
-};
-}
-
-void TypeMapTy::addTypeMapping(Type *DstTy, Type *SrcTy) {
- 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 (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();
-}
-
-/// 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 we have an entry in the MappedTypes table, then we have our answer.
- Type *&Entry = MappedTypes[SrcTy];
- if (Entry)
- return Entry == DstTy;
-
- // Two identical types are clearly isomorphic. Remember this
- // non-speculatively.
- if (DstTy == 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.
- if (StructType *SSTy = dyn_cast<StructType>(SrcTy)) {
- // Mapping an opaque type to any struct, just keep the dest struct.
- if (SSTy->isOpaque()) {
- Entry = DstTy;
- SpeculativeTypes.push_back(SrcTy);
- return true;
- }
-
- // 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. 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)).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;
- } else if (StructType *DSTy = dyn_cast<StructType>(DstTy)) {
- StructType *SSTy = cast<StructType>(SrcTy);
- if (DSTy->isLiteral() != SSTy->isLiteral() ||
- DSTy->isPacked() != SSTy->isPacked())
- return false;
- } else if (ArrayType *DATy = dyn_cast<ArrayType>(DstTy)) {
- if (DATy->getNumElements() != cast<ArrayType>(SrcTy)->getNumElements())
- return false;
- } else if (VectorType *DVTy = dyn_cast<VectorType>(DstTy)) {
- if (DVTy->getNumElements() != cast<VectorType>(SrcTy)->getNumElements())
- return false;
- }
-
- // Otherwise, we speculate that these two types will line up and recursively
- // check the subelements.
- Entry = DstTy;
- SpeculativeTypes.push_back(SrcTy);
-
- 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;
-}
-
-void TypeMapTy::linkDefinedTypeBodies() {
- SmallVector<Type *, 16> Elements;
- for (StructType *SrcSTy : SrcDefinitionsToResolve) {
- StructType *DstSTy = cast<StructType>(MappedTypes[SrcSTy]);
- 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] = get(SrcSTy->getElementType(I));
-
- DstSTy->setBody(Elements, SrcSTy->isPacked());
- DstStructTypesSet.switchToNonOpaque(DstSTy);
- }
- SrcDefinitionsToResolve.clear();
- DstResolvedOpaqueTypes.clear();
-}
-
-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) {
- SmallPtrSet<StructType *, 8> Visited;
- return get(Ty, Visited);
-}
-
-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;
-
- // 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.
- 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;
- }
-
- if (StructType *OldT =
- DstStructTypesSet.findNonOpaque(ElementTypes, IsPacked)) {
- STy->setName("");
- return *Entry = OldT;
- }
-
- if (!AnyChange) {
- DstStructTypesSet.addNonOpaque(STy);
- return *Entry = Ty;
- }
-
- StructType *DTy = StructType::create(Ty->getContext());
- finishType(DTy, STy, ElementTypes);
- return *Entry = DTy;
- }
- }
-}
-
-//===----------------------------------------------------------------------===//
-// ModuleLinker implementation.
-//===----------------------------------------------------------------------===//
-
-namespace {
-class ModuleLinker;
-
-/// 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;
-
-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;
+ IRMover &Mover;
Module &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;
-
SetVector<GlobalValue *> ValuesToLink;
-
- DiagnosticHandlerFunction DiagnosticHandler;
+ StringSet<> Internalize;
/// For symbol clashes, prefer those from Src.
unsigned Flags;
/// as part of a different backend compilation process.
bool HasExportedFunctions = false;
- /// 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 = false;
-
- bool HasError = false;
+ /// Used as the callback for lazy linking.
+ /// The mover has just hit GV and we have to decide if it, and other members
+ /// of the same comdat, should be linked. Every member to be linked is passed
+ /// to Add.
+ void addLazyFor(GlobalValue &GV, IRMover::ValueAdder Add);
bool shouldOverrideFromSrc() { return Flags & Linker::OverrideFromSrc; }
bool shouldLinkOnlyNeeded() { return Flags & Linker::LinkOnlyNeeded; }
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(const GlobalValue *SGV, bool ForDefinition);
-
/// Check if we should promote the given local value to global scope.
bool doPromoteLocalToGlobal(const GlobalValue *SGV);
bool shouldLinkFromSource(bool &LinkFromSrc, const GlobalValue &Dest,
const GlobalValue &Src);
- /// Helper method for setting a message and returning an error code.
+ /// Should we have mover and linker error diag info?
bool emitError(const Twine &Message) {
- DiagnosticHandler(LinkDiagnosticInfo(DS_Error, Message));
- HasError = true;
+ Mover.getDiagnosticHandler()(LinkDiagnosticInfo(DS_Error, Message));
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,
/// 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) {
+ Module &DstM = Mover.getModule();
// 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 DGV;
}
- void computeTypeMapping();
-
bool linkIfNeeded(GlobalValue &GV);
- Constant *linkAppendingVarProto(GlobalVariable *DstGV,
- const GlobalVariable *SrcGV);
-
- Constant *linkGlobalValueProto(GlobalValue *GV);
- bool linkModuleFlagsMetadata();
-
- void linkGlobalInit(GlobalVariable &Dst, GlobalVariable &Src);
- bool linkFunctionBody(Function &Dst, Function &Src);
- void linkAliasBody(GlobalAlias &Dst, GlobalAlias &Src);
- bool linkGlobalValueBody(GlobalValue &Dst, GlobalValue &Src);
-
- /// Functions that take care of cloning a specific global value type
- /// into the destination module.
- GlobalVariable *copyGlobalVariableProto(const GlobalVariable *SGVar);
- Function *copyFunctionProto(const Function *SF);
- GlobalValue *copyGlobalAliasProto(const GlobalAlias *SGA);
/// Helper methods to check if we are importing from or potentially
/// exporting from the current source module.
/// a local that is being promoted to global scope.
std::string getName(const GlobalValue *SGV);
+ /// Process globals so that they can be used in ThinLTO. This includes
+ /// promoting local variables so that they can be reference externally by
+ /// thin lto imported globals and converting strong external globals to
+ /// available_externally.
+ void processGlobalsForThinLTO();
+ void processGlobalForThinLTO(GlobalValue &GV);
+
/// 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.
void setVisibility(GlobalValue *NewGV, const GlobalValue *SGV,
const GlobalValue *DGV = nullptr);
- void linkNamedMDNodes();
-
public:
- ModuleLinker(Module &DstM, Linker::IdentifiedStructTypeSet &Set, Module &SrcM,
- DiagnosticHandlerFunction DiagnosticHandler, unsigned Flags,
+ ModuleLinker(IRMover &Mover, Module &SrcM, unsigned Flags,
const FunctionInfoIndex *Index = nullptr,
DenseSet<const GlobalValue *> *FunctionsToImport = nullptr)
- : DstM(DstM), SrcM(SrcM), TypeMap(Set), ValMaterializer(this),
- DiagnosticHandler(DiagnosticHandler), Flags(Flags), ImportIndex(Index),
+ : Mover(Mover), SrcM(SrcM), Flags(Flags), ImportIndex(Index),
ImportFunction(FunctionsToImport) {
assert((ImportIndex || !ImportFunction) &&
"Expect a FunctionInfoIndex when importing");
}
bool run();
- Value *materializeDeclFor(Value *V);
- void materializeInitFor(GlobalValue *New, GlobalValue *Old);
};
}
llvm_unreachable("unknown linkage type");
}
-/// Loop through the global variables in the src module and merge them into the
-/// dest module.
-GlobalVariable *
-ModuleLinker::copyGlobalVariableProto(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(), GlobalValue::ExternalLinkage,
- /*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(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()),
- GlobalValue::ExternalLinkage, getName(SF), &DstM);
-}
-
-/// Set up prototypes for any aliases that come over from the source module.
-GlobalValue *ModuleLinker::copyGlobalAliasProto(const GlobalAlias *SGA) {
- // 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(),
- GlobalValue::ExternalLinkage, getName(SGA), &DstM);
-}
-
static GlobalValue::VisibilityTypes
getMinVisibility(GlobalValue::VisibilityTypes A,
GlobalValue::VisibilityTypes B) {
NewGV->setVisibility(Visibility);
}
-GlobalValue *ModuleLinker::copyGlobalValueProto(const GlobalValue *SGV,
- bool ForDefinition) {
- GlobalValue *NewGV;
- if (auto *SGVar = dyn_cast<GlobalVariable>(SGV)) {
- NewGV = copyGlobalVariableProto(SGVar);
- } else if (auto *SF = dyn_cast<Function>(SGV)) {
- NewGV = copyFunctionProto(SF);
- } else {
- if (ForDefinition)
- NewGV = copyGlobalAliasProto(cast<GlobalAlias>(SGV));
- else
- NewGV = new GlobalVariable(
- DstM, TypeMap.get(SGV->getType()->getElementType()),
- /*isConstant*/ false, GlobalValue::ExternalLinkage,
- /*init*/ nullptr, getName(SGV),
- /*insertbefore*/ nullptr, SGV->getThreadLocalMode(),
- SGV->getType()->getAddressSpace());
- }
-
- if (ForDefinition)
- NewGV->setLinkage(getLinkage(SGV));
- else if (SGV->hasAvailableExternallyLinkage() || SGV->hasWeakLinkage() ||
- SGV->hasLinkOnceLinkage())
- NewGV->setLinkage(GlobalValue::ExternalWeakLinkage);
-
- copyGVAttributes(NewGV, SGV);
- 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;
-
- return linkGlobalValueProto(SGV);
-}
-
-void ValueMaterializerTy::materializeInitFor(GlobalValue *New,
- GlobalValue *Old) {
- return ModLinker->materializeInitFor(New, Old);
-}
-
-static bool shouldLazyLink(const GlobalValue &GV) {
- return GV.hasLocalLinkage() || GV.hasLinkOnceLinkage() ||
- GV.hasAvailableExternallyLinkage();
-}
-
-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 (!ValuesToLink.count(Old) && !shouldLazyLink(*Old))
- return;
-
- linkGlobalValueBody(*New, *Old);
-}
-
bool ModuleLinker::getComdatLeader(Module &M, StringRef ComdatName,
const GlobalVariable *&GVar) {
const GlobalValue *GVal = M.getNamedValue(ComdatName);
Comdat::SelectionKind Dst,
Comdat::SelectionKind &Result,
bool &LinkFromSrc) {
+ Module &DstM = Mover.getModule();
// The ability to mix Comdat::SelectionKind::Any with
// Comdat::SelectionKind::Largest is a behavior that comes from COFF.
bool DstAnyOrLargest = Dst == Comdat::SelectionKind::Any ||
bool ModuleLinker::getComdatResult(const Comdat *SrcC,
Comdat::SelectionKind &Result,
bool &LinkFromSrc) {
+ Module &DstM = Mover.getModule();
Comdat::SelectionKind SSK = SrcC->getSelectionKind();
StringRef ComdatName = SrcC->getName();
Module::ComdatSymTabType &ComdatSymTab = DstM.getComdatSymbolTable();
"': symbol multiply defined!");
}
-/// 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() {
- 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>(SGV.getType()->getElementType());
- TypeMap.addTypeMapping(DAT->getElementType(), SAT->getElementType());
- }
-
- 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 }".
- 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])))
- continue;
-
- // Check to see if the destination module has a struct with the prefix name.
- 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.
- TypeMap.linkDefinedTypeBodies();
-}
-
-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));
-}
-
-/// If there were any appending global variables, link them together now.
-/// Return true on error.
-Constant *ModuleLinker::linkAppendingVarProto(GlobalVariable *DstGV,
- const GlobalVariable *SrcGV) {
- Type *EltTy = cast<ArrayType>(TypeMap.get(SrcGV->getType()->getElementType()))
- ->getElementType();
-
- StringRef Name = SrcGV->getName();
- bool IsNewStructor = false;
- bool IsOldStructor = false;
- if (Name == "llvm.global_ctors" || Name == "llvm.global_dtors") {
- if (cast<StructType>(EltTy)->getNumElements() == 3)
- IsNewStructor = true;
- else
- IsOldStructor = true;
- }
-
- PointerType *VoidPtrTy = Type::getInt8Ty(SrcGV->getContext())->getPointerTo();
- if (IsOldStructor) {
- auto &ST = *cast<StructType>(EltTy);
- Type *Tys[3] = {ST.getElementType(0), ST.getElementType(1), VoidPtrTy};
- EltTy = StructType::get(SrcGV->getContext(), Tys, false);
- }
-
- if (DstGV) {
- ArrayType *DstTy = cast<ArrayType>(DstGV->getType()->getElementType());
-
- if (!SrcGV->hasAppendingLinkage() || !DstGV->hasAppendingLinkage()) {
- emitError(
- "Linking globals named '" + SrcGV->getName() +
- "': can only link appending global with another appending global!");
- return nullptr;
- }
-
- // Check to see that they two arrays agree on type.
- if (EltTy != DstTy->getElementType()) {
- emitError("Appending variables with different element types!");
- return nullptr;
- }
- if (DstGV->isConstant() != SrcGV->isConstant()) {
- emitError("Appending variables linked with different const'ness!");
- return nullptr;
- }
-
- if (DstGV->getAlignment() != SrcGV->getAlignment()) {
- emitError(
- "Appending variables with different alignment need to be linked!");
- return nullptr;
- }
-
- if (DstGV->getVisibility() != SrcGV->getVisibility()) {
- emitError(
- "Appending variables with different visibility need to be linked!");
- return nullptr;
- }
-
- if (DstGV->hasUnnamedAddr() != SrcGV->hasUnnamedAddr()) {
- emitError(
- "Appending variables with different unnamed_addr need to be linked!");
- return nullptr;
- }
-
- if (StringRef(DstGV->getSection()) != SrcGV->getSection()) {
- emitError(
- "Appending variables with different section name need to be linked!");
- return nullptr;
- }
- }
-
- SmallVector<Constant *, 16> DstElements;
- if (DstGV)
- getArrayElements(DstGV->getInitializer(), DstElements);
-
- SmallVector<Constant *, 16> SrcElements;
- getArrayElements(SrcGV->getInitializer(), SrcElements);
-
- if (IsNewStructor)
- SrcElements.erase(
- std::remove_if(SrcElements.begin(), SrcElements.end(),
- [this](Constant *E) {
- auto *Key = dyn_cast<GlobalValue>(
- E->getAggregateElement(2)->stripPointerCasts());
- return Key && !ValuesToLink.count(Key) &&
- !shouldLazyLink(*Key);
- }),
- SrcElements.end());
- uint64_t NewSize = DstElements.size() + SrcElements.size();
- ArrayType *NewType = ArrayType::get(EltTy, NewSize);
-
- // Create the new global variable.
- 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, SrcGV);
-
- Constant *Ret = ConstantExpr::getBitCast(NG, TypeMap.get(SrcGV->getType()));
-
- // Stop recursion.
- ValueMap[SrcGV] = Ret;
-
- for (auto *V : SrcElements) {
- Constant *NewV;
- if (IsOldStructor) {
- auto *S = cast<ConstantStruct>(V);
- auto *E1 = MapValue(S->getOperand(0), ValueMap, RF_MoveDistinctMDs,
- &TypeMap, &ValMaterializer);
- auto *E2 = MapValue(S->getOperand(1), ValueMap, RF_MoveDistinctMDs,
- &TypeMap, &ValMaterializer);
- Value *Null = Constant::getNullValue(VoidPtrTy);
- NewV =
- ConstantStruct::get(cast<StructType>(EltTy), E1, E2, Null, nullptr);
- } else {
- NewV =
- MapValue(V, ValueMap, RF_MoveDistinctMDs, &TypeMap, &ValMaterializer);
- }
- DstElements.push_back(NewV);
- }
-
- NG->setInitializer(ConstantArray::get(NewType, DstElements));
-
- // Replace any uses of the two global variables with uses of the new
- // global.
- if (DstGV) {
- DstGV->replaceAllUsesWith(ConstantExpr::getBitCast(NG, DstGV->getType()));
- DstGV->eraseFromParent();
- }
-
- return Ret;
-}
-
-Constant *ModuleLinker::linkGlobalValueProto(GlobalValue *SGV) {
- GlobalValue *DGV = getLinkedToGlobal(SGV);
-
- // Handle the ultra special appending linkage case first.
- assert(!DGV || SGV->hasAppendingLinkage() == DGV->hasAppendingLinkage());
- if (SGV->hasAppendingLinkage()) {
- // Should have prevented importing for appending linkage in linkIfNeeded.
- assert(!isPerformingImport());
- return linkAppendingVarProto(cast_or_null<GlobalVariable>(DGV),
- cast<GlobalVariable>(SGV));
- }
-
- bool LinkFromSrc = true;
- Comdat *C = nullptr;
- bool HasUnnamedAddr = SGV->hasUnnamedAddr();
-
- if (isPerformingImport() && !doImportAsDefinition(SGV)) {
- LinkFromSrc = false;
- } else if (const Comdat *SC = SGV->getComdat()) {
- Comdat::SelectionKind SK;
- std::tie(SK, LinkFromSrc) = ComdatsChosen[SC];
- C = DstM.getOrInsertComdat(SC->getName());
- C->setSelectionKind(SK);
- if (SGV->hasLocalLinkage())
- LinkFromSrc = true;
- } else if (DGV) {
- if (shouldLinkFromSource(LinkFromSrc, *DGV, *SGV))
- return nullptr;
- }
-
- if (DGV)
- HasUnnamedAddr = HasUnnamedAddr && DGV->hasUnnamedAddr();
-
- GlobalValue *NewGV;
- if (!LinkFromSrc && DGV) {
- NewGV = DGV;
- } else {
- // 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;
-
- NewGV = copyGlobalValueProto(SGV, LinkFromSrc);
- }
-
- setVisibility(NewGV, SGV, DGV);
- NewGV->setUnnamedAddr(HasUnnamedAddr);
-
- if (auto *NewGO = dyn_cast<GlobalObject>(NewGV)) {
- if (C && LinkFromSrc)
- NewGO->setComdat(C);
-
- if (DGV && DGV->hasCommonLinkage() && SGV->hasCommonLinkage())
- NewGO->setAlignment(std::max(DGV->getAlignment(), SGV->getAlignment()));
- }
-
- 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);
- }
-
- if (NewGV != DGV && DGV) {
- DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewGV, DGV->getType()));
- DGV->eraseFromParent();
- }
-
- return ConstantExpr::getBitCast(NewGV, TypeMap.get(SGV->getType()));
-}
-
-/// 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));
-}
-
-/// 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 (Argument &Arg : Src.args()) {
- DI->setName(Arg.getName()); // Copy the name over.
-
- // Add a mapping to our mapping.
- 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 (Argument &Arg : Src.args())
- ValueMap.erase(&Arg);
-
- Src.dematerialize();
- return false;
-}
-
-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 &Dst, GlobalValue &Src) {
- 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.lookup(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;
-}
-
-/// Insert all of the named MDNodes in Src into the Dest module.
-void ModuleLinker::linkNamedMDNodes() {
- const NamedMDNode *SrcModFlags = SrcM.getModuleFlagsMetadata();
- for (const NamedMDNode &NMD : SrcM.named_metadata()) {
- // Don't link module flags here. Do them separately.
- if (&NMD == SrcModFlags)
- continue;
- NamedMDNode *DestNMD = DstM.getOrInsertNamedMetadata(NMD.getName());
- // Add Src elements into Dest node.
- for (const MDNode *op : NMD.operands())
- DestNMD->addOperand(MapMetadata(
- op, ValueMap, RF_MoveDistinctMDs | RF_NullMapMissingGlobalValues,
- &TypeMap, &ValMaterializer));
- }
-}
-
-/// 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();
- if (!SrcModFlags)
- return false;
-
- // If the destination module doesn't have module flags yet, then just copy
- // over the source module's flags.
- NamedMDNode *DstModFlags = DstM.getOrInsertModuleFlagsMetadata();
- if (DstModFlags->getNumOperands() == 0) {
- for (unsigned I = 0, E = SrcModFlags->getNumOperands(); I != E; ++I)
- DstModFlags->addOperand(SrcModFlags->getOperand(I));
-
- return false;
- }
-
- // First build a map of the existing module flags and requirements.
- 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 = 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] = std::make_pair(Op, I);
- }
- }
-
- // Merge in the flags from the source module, and also collect its set of
- // requirements.
- for (unsigned I = 0, E = SrcModFlags->getNumOperands(); I != E; ++I) {
- MDNode *SrcOp = SrcModFlags->getOperand(I);
- ConstantInt *SrcBehavior =
- mdconst::extract<ConstantInt>(SrcOp->getOperand(0));
- MDString *ID = cast<MDString>(SrcOp->getOperand(1));
- 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 (SrcBehaviorValue == Module::Require) {
- // If the destination module does not already have this requirement, add
- // it.
- if (Requirements.insert(cast<MDNode>(SrcOp->getOperand(2)))) {
- DstModFlags->addOperand(SrcOp);
- }
- continue;
- }
-
- // If there is no existing flag with this ID, just add it.
- if (!DstOp) {
- Flags[ID] = std::make_pair(SrcOp, DstModFlags->getNumOperands());
- DstModFlags->addOperand(SrcOp);
- continue;
- }
-
- // Otherwise, perform a merge.
- ConstantInt *DstBehavior =
- mdconst::extract<ConstantInt>(DstOp->getOperand(0));
- unsigned DstBehaviorValue = DstBehavior->getZExtValue();
-
- // If either flag has override behavior, handle it first.
- if (DstBehaviorValue == Module::Override) {
- // Diagnose inconsistent flags which both have override behavior.
- if (SrcBehaviorValue == Module::Override &&
- SrcOp->getOperand(2) != DstOp->getOperand(2)) {
- emitError("linking module flags '" + ID->getString() +
- "': IDs have conflicting override values");
- }
- continue;
- } else if (SrcBehaviorValue == Module::Override) {
- // Update the destination flag to that of the source.
- DstModFlags->setOperand(DstIndex, SrcOp);
- Flags[ID].first = SrcOp;
- continue;
- }
-
- // Diagnose inconsistent merge behavior types.
- if (SrcBehaviorValue != DstBehaviorValue) {
- emitError("linking module flags '" + ID->getString() +
- "': IDs have conflicting behaviors");
- 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:
- llvm_unreachable("not possible");
- case Module::Error: {
- // Emit an error if the values differ.
- if (SrcOp->getOperand(2) != DstOp->getOperand(2)) {
- emitError("linking module flags '" + ID->getString() +
- "': IDs have conflicting values");
- }
- continue;
- }
- case Module::Warning: {
- // Emit a warning if the values differ.
- if (SrcOp->getOperand(2) != DstOp->getOperand(2)) {
- 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));
- 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<Metadata *, 16> Elts;
- MDNode *DstValue = cast<MDNode>(DstOp->getOperand(2));
- MDNode *SrcValue = cast<MDNode>(SrcOp->getOperand(2));
- 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;
- }
- }
- }
-
- // Check all of the requirements.
- for (unsigned I = 0, E = Requirements.size(); I != E; ++I) {
- MDNode *Requirement = Requirements[I];
- MDString *Flag = cast<MDString>(Requirement->getOperand(0));
- Metadata *ReqValue = Requirement->getOperand(1);
-
- MDNode *Op = Flags[Flag].first;
- if (!Op || Op->getOperand(2) != ReqValue) {
- emitError("linking module flags '" + Flag->getString() +
- "': does not have the required value");
- continue;
- }
- }
-
- return HasError;
-}
-
-// 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);
return false;
}
-bool ModuleLinker::run() {
- // Inherit the target data from the source module if the destination module
- // doesn't have one already.
- 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());
-
- Triple SrcTriple(SrcM.getTargetTriple()), DstTriple(DstM.getTargetTriple());
+void ModuleLinker::addLazyFor(GlobalValue &GV, IRMover::ValueAdder Add) {
+ // Add these to the internalize list
+ if (!GV.hasLinkOnceLinkage())
+ return;
- 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");
+ if (shouldInternalizeLinkedSymbols())
+ Internalize.insert(GV.getName());
+ Add(GV);
- DstM.setTargetTriple(mergeTriples(SrcTriple, DstTriple));
+ const Comdat *SC = GV.getComdat();
+ if (!SC)
+ return;
+ for (GlobalValue *GV2 : ComdatMembers[SC]) {
+ if (!GV2->hasLocalLinkage() && shouldInternalizeLinkedSymbols())
+ Internalize.insert(GV2->getName());
+ Add(*GV2);
+ }
+}
- // Append the module inline asm string.
- if (!SrcM.getModuleInlineAsm().empty()) {
- if (DstM.getModuleInlineAsm().empty())
- DstM.setModuleInlineAsm(SrcM.getModuleInlineAsm());
- else
- DstM.setModuleInlineAsm(DstM.getModuleInlineAsm() + "\n" +
- SrcM.getModuleInlineAsm());
+void ModuleLinker::processGlobalForThinLTO(GlobalValue &GV) {
+ if (GV.hasLocalLinkage() &&
+ (doPromoteLocalToGlobal(&GV) || isPerformingImport())) {
+ GV.setName(getName(&GV));
+ GV.setLinkage(getLinkage(&GV));
+ if (!GV.hasLocalLinkage())
+ GV.setVisibility(GlobalValue::HiddenVisibility);
+ if (isModuleExporting())
+ ValuesToLink.insert(&GV);
+ return;
}
+ GV.setLinkage(getLinkage(&GV));
+}
- // Loop over all of the linked values to compute type mappings.
- computeTypeMapping();
+void ModuleLinker::processGlobalsForThinLTO() {
+ for (GlobalVariable &GV : SrcM.globals())
+ processGlobalForThinLTO(GV);
+ for (Function &SF : SrcM)
+ processGlobalForThinLTO(SF);
+ for (GlobalAlias &GA : SrcM.aliases())
+ processGlobalForThinLTO(GA);
+}
- ComdatsChosen.clear();
+bool ModuleLinker::run() {
for (const auto &SMEC : SrcM.getComdatSymbolTable()) {
const Comdat &C = SMEC.getValue();
if (ComdatsChosen.count(&C))
if (linkIfNeeded(GA))
return true;
- for (GlobalValue *GV : ValuesToLink) {
- MapValue(GV, ValueMap, RF_MoveDistinctMDs, &TypeMap, &ValMaterializer);
- if (HasError)
- return true;
- }
+ processGlobalsForThinLTO();
- // Note that we are done linking global value bodies. This prevents
- // metadata linking from creating new references.
- DoneLinkingBodies = true;
+ for (unsigned I = 0; I < ValuesToLink.size(); ++I) {
+ GlobalValue *GV = ValuesToLink[I];
+ const Comdat *SC = GV->getComdat();
+ if (!SC)
+ continue;
+ for (GlobalValue *GV2 : ComdatMembers[SC])
+ ValuesToLink.insert(GV2);
+ }
- // Remap all of the named MDNodes in Src into the DstM module. We do this
- // after linking GlobalValues so that MDNodes that reference GlobalValues
- // are properly remapped.
- linkNamedMDNodes();
+ if (shouldInternalizeLinkedSymbols()) {
+ for (GlobalValue *GV : ValuesToLink)
+ Internalize.insert(GV->getName());
+ }
- // Merge the module flags into the DstM module.
- if (linkModuleFlagsMetadata())
+ if (Mover.move(SrcM,
+ makeArrayRef(&*ValuesToLink.begin(), ValuesToLink.size()),
+ [this](GlobalValue &GV, IRMover::ValueAdder Add) {
+ addLazyFor(GV, Add);
+ }))
return true;
+ Module &DstM = Mover.getModule();
+ for (auto &P : Internalize) {
+ GlobalValue *GV = DstM.getNamedValue(P.first());
+ GV->setLinkage(GlobalValue::InternalLinkage);
+ }
return false;
}
-Linker::StructTypeKeyInfo::KeyTy::KeyTy(ArrayRef<Type *> E, bool P)
- : ETypes(E), IsPacked(P) {}
-
-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;
-}
-
-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;
-}
-
Linker::Linker(Module &M, DiagnosticHandlerFunction DiagnosticHandler)
- : Composite(M), DiagnosticHandler(DiagnosticHandler) {
- TypeFinder StructTypes;
- StructTypes.run(M, true);
- for (StructType *Ty : StructTypes) {
- if (Ty->isOpaque())
- IdentifiedStructTypes.addOpaque(Ty);
- else
- IdentifiedStructTypes.addNonOpaque(Ty);
- }
-}
+ : Mover(M, DiagnosticHandler) {}
bool Linker::linkInModule(Module &Src, unsigned Flags,
const FunctionInfoIndex *Index,
DenseSet<const GlobalValue *> *FunctionsToImport) {
- ModuleLinker TheLinker(Composite, IdentifiedStructTypes, Src,
- DiagnosticHandler, Flags, Index, FunctionsToImport);
- bool RetCode = TheLinker.run();
- Composite.dropTriviallyDeadConstantArrays();
- return RetCode;
+ ModuleLinker TheLinker(Mover, Src, Flags, Index, FunctionsToImport);
+ return TheLinker.run();
}
//===----------------------------------------------------------------------===//
-; RUN: llvm-link %s %S/Inputs/alias.ll -S -o - | FileCheck %s
-; RUN: llvm-link %S/Inputs/alias.ll %s -S -o - | FileCheck %s
+; RUN: llvm-link %s %S/Inputs/alias.ll -S -o - | FileCheck --check-prefix=C1 %s
+; RUN: llvm-link %S/Inputs/alias.ll %s -S -o - | FileCheck --check-prefix=C2 %s
+
+; FIXME:
+; The C1 direction is incorrect.
+; When moving an alias to an existing module and we want to discard the aliasee
+; (the C2 case), the IRMover knows to copy the aliasee as internal.
+; When moving a replacement to an aliasee to a module that has an alias (C1),
+; a replace all uses with blindly changes the alias.
+; The C1 case doesn't happen when using a system linker with a plugin because
+; the linker does full symbol resolution first.
+; Given that this is a problem only with llvm-link and its 1 module at a time
+; linking, it should probably learn to changes the aliases in the destination
+; before using the IRMover.
@foo = weak global i32 0
-; CHECK-DAG: @foo = alias i32, i32* @zed
+; C1-DAG: @foo = alias i32, i32* @zed
+; C2-DAG: @foo = alias i32, i32* @zed
@bar = alias i32, i32* @foo
-; CHECK-DAG: @bar = alias i32, i32* @foo
+; C1-DAG: @bar = alias i32, i32* @foo
+
+; C2-DAG: @foo.1 = internal global i32 0
+; C2-DAG: @bar = alias i32, i32* @foo.1
@foo2 = weak global i32 0
-; CHECK-DAG: @foo2 = alias i16, bitcast (i32* @zed to i16*)
+; C1-DAG: @foo2 = alias i16, bitcast (i32* @zed to i16*)
+; C2-DAG: @foo2 = alias i16, bitcast (i32* @zed to i16*)
@bar2 = alias i32, i32* @foo2
-; CHECK-DAG: @bar2 = alias i32, bitcast (i16* @foo2 to i32*)
+; C1-DAG: @bar2 = alias i32, bitcast (i16* @foo2 to i32*)
+
+; C2-DAG: @foo2.2 = internal global i32 0
+; C2-DAG: @bar2 = alias i32, i32* @foo2.2
-; CHECK-DAG: @zed = global i32 42
+; C1-DAG: @zed = global i32 42
+; C2-DAG: @zed = global i32 42
ret void
}
-; CHECK: declare void @foo(){{$}}
+; CHECK: declare extern_weak void @foo(){{$}}
#include "llvm/IR/LegacyPassManager.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Verifier.h"
-#include "llvm/Linker/Linker.h"
+#include "llvm/Linker/IRMover.h"
#include "llvm/MC/SubtargetFeature.h"
#include "llvm/Object/FunctionIndexObjectFile.h"
#include "llvm/Object/IRObjectFile.h"
void *handle;
std::vector<ld_plugin_symbol> syms;
};
+
+struct ResolutionInfo {
+ bool IsLinkonceOdr = true;
+ bool UnnamedAddr = true;
+ GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
+ bool CommonInternal = false;
+ bool UseCommon = false;
+ unsigned CommonSize = 0;
+ unsigned CommonAlign = 0;
+ claimed_file *CommonFile = nullptr;
+};
}
static ld_plugin_status discard_message(int level, const char *format, ...) {
static Reloc::Model RelocationModel = Reloc::Default;
static std::string output_name = "";
static std::list<claimed_file> Modules;
+static StringMap<ResolutionInfo> ResInfo;
static std::vector<std::string> Cleanup;
static llvm::TargetOptions TargetOpts;
diagnosticHandler(DI);
}
+static GlobalValue::VisibilityTypes
+getMinVisibility(GlobalValue::VisibilityTypes A,
+ GlobalValue::VisibilityTypes B) {
+ if (A == GlobalValue::HiddenVisibility)
+ return A;
+ if (B == GlobalValue::HiddenVisibility)
+ return B;
+ if (A == GlobalValue::ProtectedVisibility)
+ return A;
+ return B;
+}
+
/// Called by gold to see whether this file is one that our plugin can handle.
/// We'll try to open it and register all the symbols with add_symbol if
/// possible.
const GlobalValue *GV = Obj->getSymbolGV(Sym.getRawDataRefImpl());
+ ResolutionInfo &Res = ResInfo[sym.name];
+
sym.visibility = LDPV_DEFAULT;
if (GV) {
+ Res.UnnamedAddr &= GV->hasUnnamedAddr();
+ Res.IsLinkonceOdr &= GV->hasLinkOnceLinkage();
+ if (GV->hasCommonLinkage()) {
+ Res.CommonAlign = std::max(Res.CommonAlign, GV->getAlignment());
+ const DataLayout &DL = GV->getParent()->getDataLayout();
+ uint64_t Size = DL.getTypeAllocSize(GV->getType()->getElementType());
+ if (Size >= Res.CommonSize) {
+ Res.CommonSize = Size;
+ Res.CommonFile = &cf;
+ }
+ }
+ Res.Visibility = getMinVisibility(Res.Visibility, GV->getVisibility());
switch (GV->getVisibility()) {
case GlobalValue::DefaultVisibility:
sym.visibility = LDPV_DEFAULT;
return LDPS_OK;
}
-static void keepGlobalValue(GlobalValue &GV,
- std::vector<GlobalAlias *> &KeptAliases) {
- assert(!GV.hasLocalLinkage());
-
- if (auto *GA = dyn_cast<GlobalAlias>(&GV))
- KeptAliases.push_back(GA);
-
- switch (GV.getLinkage()) {
- default:
- break;
- case GlobalValue::LinkOnceAnyLinkage:
- GV.setLinkage(GlobalValue::WeakAnyLinkage);
- break;
- case GlobalValue::LinkOnceODRLinkage:
- GV.setLinkage(GlobalValue::WeakODRLinkage);
- break;
- }
-
- assert(!GV.isDiscardableIfUnused());
-}
-
static void internalize(GlobalValue &GV) {
if (GV.isDeclarationForLinker())
return; // We get here if there is a matching asm definition.
GV.setLinkage(GlobalValue::InternalLinkage);
}
-static void drop(GlobalValue &GV) {
- if (auto *F = dyn_cast<Function>(&GV)) {
- F->deleteBody();
- F->setComdat(nullptr); // Should deleteBody do this?
- return;
- }
-
- if (auto *Var = dyn_cast<GlobalVariable>(&GV)) {
- Var->setInitializer(nullptr);
- Var->setLinkage(
- GlobalValue::ExternalLinkage); // Should setInitializer do this?
- Var->setComdat(nullptr); // and this?
- return;
- }
-
- auto &Alias = cast<GlobalAlias>(GV);
- Module &M = *Alias.getParent();
- PointerType &Ty = *cast<PointerType>(Alias.getType());
- GlobalValue::LinkageTypes L = Alias.getLinkage();
- auto *Var =
- new GlobalVariable(M, Ty.getElementType(), /*isConstant*/ false, L,
- /*Initializer*/ nullptr);
- Var->takeName(&Alias);
- Alias.replaceAllUsesWith(Var);
- Alias.eraseFromParent();
-}
-
static const char *getResolutionName(ld_plugin_symbol_resolution R) {
switch (R) {
case LDPR_UNKNOWN:
llvm_unreachable("Unknown resolution");
}
-namespace {
-class LocalValueMaterializer final : public ValueMaterializer {
- DenseSet<GlobalValue *> &Dropped;
- DenseMap<GlobalObject *, GlobalObject *> LocalVersions;
-
-public:
- LocalValueMaterializer(DenseSet<GlobalValue *> &Dropped) : Dropped(Dropped) {}
- Value *materializeDeclFor(Value *V) override;
-};
-}
-
-Value *LocalValueMaterializer::materializeDeclFor(Value *V) {
- auto *GO = dyn_cast<GlobalObject>(V);
- if (!GO)
- return nullptr;
-
- auto I = LocalVersions.find(GO);
- if (I != LocalVersions.end())
- return I->second;
-
- if (!Dropped.count(GO))
- return nullptr;
-
- Module &M = *GO->getParent();
- GlobalValue::LinkageTypes L = GO->getLinkage();
- GlobalObject *Declaration;
- if (auto *F = dyn_cast<Function>(GO)) {
- Declaration = Function::Create(F->getFunctionType(), L, "", &M);
- } else {
- auto *Var = cast<GlobalVariable>(GO);
- Declaration = new GlobalVariable(M, Var->getType()->getElementType(),
- Var->isConstant(), L,
- /*Initializer*/ nullptr);
- }
- Declaration->takeName(GO);
- Declaration->copyAttributesFrom(GO);
-
- GO->setLinkage(GlobalValue::InternalLinkage);
- GO->setName(Declaration->getName());
- Dropped.erase(GO);
- GO->replaceAllUsesWith(Declaration);
-
- LocalVersions[Declaration] = GO;
-
- return GO;
-}
-
-static Constant *mapConstantToLocalCopy(Constant *C, ValueToValueMapTy &VM,
- LocalValueMaterializer *Materializer) {
- return MapValue(C, VM, RF_IgnoreMissingEntries, nullptr, Materializer);
-}
-
static void freeSymName(ld_plugin_symbol &Sym) {
free(Sym.name);
free(Sym.comdat_key);
static std::unique_ptr<Module>
getModuleForFile(LLVMContext &Context, claimed_file &F,
ld_plugin_input_file &Info, raw_fd_ostream *ApiFile,
- StringSet<> &Internalize, StringSet<> &Maybe) {
+ StringSet<> &Internalize, StringSet<> &Maybe,
+ std::vector<GlobalValue *> &Keep) {
if (get_symbols(F.handle, F.syms.size(), F.syms.data()) != LDPS_OK)
message(LDPL_FATAL, "Failed to get symbol information");
SmallPtrSet<GlobalValue *, 8> Used;
collectUsedGlobalVariables(M, Used, /*CompilerUsed*/ false);
- DenseSet<GlobalValue *> Drop;
- std::vector<GlobalAlias *> KeptAliases;
-
unsigned SymNum = 0;
for (auto &ObjSym : Obj.symbols()) {
+ GlobalValue *GV = Obj.getSymbolGV(ObjSym.getRawDataRefImpl());
+ if (GV && GV->hasAppendingLinkage())
+ Keep.push_back(GV);
+
if (shouldSkip(ObjSym.getFlags()))
continue;
ld_plugin_symbol &Sym = F.syms[SymNum];
if (options::generate_api_file)
*ApiFile << Sym.name << ' ' << getResolutionName(Resolution) << '\n';
- GlobalValue *GV = Obj.getSymbolGV(ObjSym.getRawDataRefImpl());
if (!GV) {
freeSymName(Sym);
continue; // Asm symbol.
}
- if (Resolution != LDPR_PREVAILING_DEF_IRONLY && GV->hasCommonLinkage()) {
- // Common linkage is special. There is no single symbol that wins the
- // resolution. Instead we have to collect the maximum alignment and size.
- // The IR linker does that for us if we just pass it every common GV.
- // We still have to keep track of LDPR_PREVAILING_DEF_IRONLY so we
- // internalize once the IR linker has done its job.
- freeSymName(Sym);
- continue;
+ ResolutionInfo &Res = ResInfo[Sym.name];
+ if (Resolution == LDPR_PREVAILING_DEF_IRONLY_EXP && !Res.IsLinkonceOdr)
+ Resolution = LDPR_PREVAILING_DEF;
+
+ GV->setUnnamedAddr(Res.UnnamedAddr);
+ GV->setVisibility(Res.Visibility);
+
+ // Override gold's resolution for common symbols. We want the largest
+ // one to win.
+ if (GV->hasCommonLinkage()) {
+ cast<GlobalVariable>(GV)->setAlignment(Res.CommonAlign);
+ if (Resolution == LDPR_PREVAILING_DEF_IRONLY)
+ Res.CommonInternal = true;
+
+ if (Resolution == LDPR_PREVAILING_DEF_IRONLY ||
+ Resolution == LDPR_PREVAILING_DEF)
+ Res.UseCommon = true;
+
+ if (Res.CommonFile == &F && Res.UseCommon) {
+ if (Res.CommonInternal)
+ Resolution = LDPR_PREVAILING_DEF_IRONLY;
+ else
+ Resolution = LDPR_PREVAILING_DEF;
+ } else {
+ Resolution = LDPR_PREEMPTED_IR;
+ }
}
switch (Resolution) {
case LDPR_RESOLVED_IR:
case LDPR_RESOLVED_EXEC:
case LDPR_RESOLVED_DYN:
- assert(GV->isDeclarationForLinker());
+ case LDPR_PREEMPTED_IR:
+ case LDPR_PREEMPTED_REG:
break;
case LDPR_UNDEF:
- if (!GV->isDeclarationForLinker()) {
+ if (!GV->isDeclarationForLinker())
assert(GV->hasComdat());
- Drop.insert(GV);
- }
break;
case LDPR_PREVAILING_DEF_IRONLY: {
- keepGlobalValue(*GV, KeptAliases);
- if (!Used.count(GV)) {
- // Since we use the regular lib/Linker, we cannot just internalize GV
- // now or it will not be copied to the merged module. Instead we force
- // it to be copied and then internalize it.
+ Keep.push_back(GV);
+ // The IR linker has to be able to map this value to a declaration,
+ // so we can only internalize after linking.
+ if (!Used.count(GV))
Internalize.insert(GV->getName());
- }
break;
}
case LDPR_PREVAILING_DEF:
- keepGlobalValue(*GV, KeptAliases);
- break;
-
- case LDPR_PREEMPTED_IR:
- // Gold might have selected a linkonce_odr and preempted a weak_odr.
- // In that case we have to make sure we don't end up internalizing it.
- if (!GV->isDiscardableIfUnused())
- Maybe.erase(GV->getName());
-
- // fall-through
- case LDPR_PREEMPTED_REG:
- Drop.insert(GV);
+ Keep.push_back(GV);
+ // There is a non IR use, so we have to force optimizations to keep this.
+ switch (GV->getLinkage()) {
+ default:
+ break;
+ case GlobalValue::LinkOnceAnyLinkage:
+ GV->setLinkage(GlobalValue::WeakAnyLinkage);
+ break;
+ case GlobalValue::LinkOnceODRLinkage:
+ GV->setLinkage(GlobalValue::WeakODRLinkage);
+ break;
+ }
break;
case LDPR_PREVAILING_DEF_IRONLY_EXP: {
// reason is that this GV might have a copy in another module
// and in that module the address might be significant, but that
// copy will be LDPR_PREEMPTED_IR.
- if (GV->hasLinkOnceODRLinkage())
- Maybe.insert(GV->getName());
- keepGlobalValue(*GV, KeptAliases);
+ Maybe.insert(GV->getName());
+ Keep.push_back(GV);
break;
}
}
freeSymName(Sym);
}
- ValueToValueMapTy VM;
- LocalValueMaterializer Materializer(Drop);
- for (GlobalAlias *GA : KeptAliases) {
- // Gold told us to keep GA. It is possible that a GV usied in the aliasee
- // expression is being dropped. If that is the case, that GV must be copied.
- Constant *Aliasee = GA->getAliasee();
- Constant *Replacement = mapConstantToLocalCopy(Aliasee, VM, &Materializer);
- GA->setAliasee(Replacement);
- }
-
- for (auto *GV : Drop)
- drop(*GV);
-
return Obj.takeModule();
}
Context.setDiagnosticHandler(diagnosticHandlerForContext, nullptr, true);
std::unique_ptr<Module> Combined(new Module("ld-temp.o", Context));
- Linker L(*Combined, diagnosticHandler);
+ IRMover L(*Combined, diagnosticHandler);
std::string DefaultTriple = sys::getDefaultTargetTriple();
ld_plugin_input_file File;
if (get_input_file(F.handle, &File) != LDPS_OK)
message(LDPL_FATAL, "Failed to get file information");
+ std::vector<GlobalValue *> Keep;
std::unique_ptr<Module> M =
- getModuleForFile(Context, F, File, ApiFile, Internalize, Maybe);
+ getModuleForFile(Context, F, File, ApiFile, Internalize, Maybe, Keep);
if (!options::triple.empty())
M->setTargetTriple(options::triple.c_str());
- else if (M->getTargetTriple().empty()) {
+ else if (M->getTargetTriple().empty())
M->setTargetTriple(DefaultTriple);
- }
- if (L.linkInModule(*M))
+ if (L.move(*M, Keep, [](GlobalValue &, IRMover::ValueAdder) {}))
message(LDPL_FATAL, "Failed to link module");
if (release_input_file(F.handle) != LDPS_OK)
message(LDPL_FATAL, "Failed to release file information");
projects / oota-llvm.git / commitdiff