//
// This file implements the LLVM module linker.
//
-// Specifically, this:
-// * Merges global variables between the two modules
-// * Uninit + Uninit = Init, Init + Uninit = Init, Init + Init = Error if !=
-// * Merges functions between two modules
-//
//===----------------------------------------------------------------------===//
-#include "llvm/Linker.h"
-#include "llvm/Constants.h"
-#include "llvm/DerivedTypes.h"
-#include "llvm/LLVMContext.h"
-#include "llvm/Module.h"
-#include "llvm/TypeSymbolTable.h"
-#include "llvm/ValueSymbolTable.h"
-#include "llvm/Instructions.h"
-#include "llvm/Assembly/Writer.h"
+#include "llvm/Linker/Linker.h"
+#include "llvm-c/Linker.h"
+#include "llvm/ADT/Optional.h"
+#include "llvm/ADT/SetVector.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/TypeFinder.h"
+#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
-#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
-#include "llvm/Support/Path.h"
-#include "llvm/Transforms/Utils/ValueMapper.h"
-#include "llvm/ADT/DenseMap.h"
+#include "llvm/Transforms/Utils/Cloning.h"
+#include <cctype>
+#include <tuple>
using namespace llvm;
-// Error - Simple wrapper function to conditionally assign to E and return true.
-// This just makes error return conditions a little bit simpler...
-static inline bool Error(std::string *E, const Twine &Message) {
- if (E) *E = Message.str();
- return true;
-}
-// Function: ResolveTypes()
-//
-// Description:
-// Attempt to link the two specified types together.
-//
-// Inputs:
-// DestTy - The type to which we wish to resolve.
-// SrcTy - The original type which we want to resolve.
-//
-// Outputs:
-// DestST - The symbol table in which the new type should be placed.
-//
-// Return value:
-// true - There is an error and the types cannot yet be linked.
-// false - No errors.
-//
-static bool ResolveTypes(const Type *DestTy, const Type *SrcTy) {
- if (DestTy == SrcTy) return false; // If already equal, noop
- assert(DestTy && SrcTy && "Can't handle null types");
-
- if (const OpaqueType *OT = dyn_cast<OpaqueType>(DestTy)) {
- // Type _is_ in module, just opaque...
- const_cast<OpaqueType*>(OT)->refineAbstractTypeTo(SrcTy);
- } else if (const OpaqueType *OT = dyn_cast<OpaqueType>(SrcTy)) {
- const_cast<OpaqueType*>(OT)->refineAbstractTypeTo(DestTy);
- } else {
- return true; // Cannot link types... not-equal and neither is opaque.
- }
- return false;
-}
+//===----------------------------------------------------------------------===//
+// TypeMap implementation.
+//===----------------------------------------------------------------------===//
-/// LinkerTypeMap - This implements a map of types that is stable
-/// even if types are resolved/refined to other types. This is not a general
-/// purpose map, it is specific to the linker's use.
namespace {
-class LinkerTypeMap : public AbstractTypeUser {
- typedef DenseMap<const Type*, PATypeHolder> TheMapTy;
- TheMapTy TheMap;
+ typedef SmallPtrSet<StructType*, 32> TypeSet;
- LinkerTypeMap(const LinkerTypeMap&); // DO NOT IMPLEMENT
- void operator=(const LinkerTypeMap&); // DO NOT IMPLEMENT
-public:
- LinkerTypeMap() {}
- ~LinkerTypeMap() {
- for (DenseMap<const Type*, PATypeHolder>::iterator I = TheMap.begin(),
- E = TheMap.end(); I != E; ++I)
- I->first->removeAbstractTypeUser(this);
- }
+class TypeMapTy : public ValueMapTypeRemapper {
+ /// MappedTypes - This is a mapping from a source type to a destination type
+ /// to use.
+ DenseMap<Type*, Type*> MappedTypes;
- /// lookup - Return the value for the specified type or null if it doesn't
- /// exist.
- const Type *lookup(const Type *Ty) const {
- TheMapTy::const_iterator I = TheMap.find(Ty);
- if (I != TheMap.end()) return I->second;
- return 0;
- }
+ /// SpeculativeTypes - When checking to see if two subgraphs are isomorphic,
+ /// we speculatively add types to MappedTypes, but keep track of them here in
+ /// case we need to roll back.
+ SmallVector<Type*, 16> SpeculativeTypes;
- /// insert - This returns true if the pointer was new to the set, false if it
- /// was already in the set.
- bool insert(const Type *Src, const Type *Dst) {
- if (!TheMap.insert(std::make_pair(Src, PATypeHolder(Dst))).second)
- return false; // Already in map.
- if (Src->isAbstract())
- Src->addAbstractTypeUser(this);
- return true;
- }
+ /// SrcDefinitionsToResolve - This is a list of non-opaque structs in the
+ /// source module that are mapped to an opaque struct in the destination
+ /// module.
+ SmallVector<StructType*, 16> SrcDefinitionsToResolve;
-protected:
- /// refineAbstractType - The callback method invoked when an abstract type is
- /// resolved to another type. An object must override this method to update
- /// its internal state to reference NewType instead of OldType.
- ///
- virtual void refineAbstractType(const DerivedType *OldTy,
- const Type *NewTy) {
- TheMapTy::iterator I = TheMap.find(OldTy);
- const Type *DstTy = I->second;
-
- TheMap.erase(I);
- if (OldTy->isAbstract())
- OldTy->removeAbstractTypeUser(this);
-
- // Don't reinsert into the map if the key is concrete now.
- if (NewTy->isAbstract())
- insert(NewTy, DstTy);
- }
+ /// DstResolvedOpaqueTypes - This is the set of opaque types in the
+ /// destination modules who are getting a body from the source module.
+ SmallPtrSet<StructType*, 16> DstResolvedOpaqueTypes;
- /// The other case which AbstractTypeUsers must be aware of is when a type
- /// makes the transition from being abstract (where it has clients on it's
- /// AbstractTypeUsers list) to concrete (where it does not). This method
- /// notifies ATU's when this occurs for a type.
- virtual void typeBecameConcrete(const DerivedType *AbsTy) {
- TheMap.erase(AbsTy);
- AbsTy->removeAbstractTypeUser(this);
+public:
+ TypeMapTy(TypeSet &Set) : DstStructTypesSet(Set) {}
+
+ TypeSet &DstStructTypesSet;
+ /// addTypeMapping - Indicate that the specified type in the destination
+ /// module is conceptually equivalent to the specified type in the source
+ /// module.
+ void addTypeMapping(Type *DstTy, Type *SrcTy);
+
+ /// linkDefinedTypeBodies - Produce a body for an opaque type in the dest
+ /// module from a type definition in the source module.
+ void linkDefinedTypeBodies();
+
+ /// get - Return the mapped type to use for the specified input type from the
+ /// source module.
+ Type *get(Type *SrcTy);
+
+ FunctionType *get(FunctionType *T) {return cast<FunctionType>(get((Type*)T));}
+
+ /// dump - Dump out the type map for debugging purposes.
+ void dump() const {
+ for (DenseMap<Type*, Type*>::const_iterator
+ I = MappedTypes.begin(), E = MappedTypes.end(); I != E; ++I) {
+ dbgs() << "TypeMap: ";
+ I->first->print(dbgs());
+ dbgs() << " => ";
+ I->second->print(dbgs());
+ dbgs() << '\n';
+ }
}
- // for debugging...
- virtual void dump() const {
- dbgs() << "AbstractTypeSet!\n";
+private:
+ Type *getImpl(Type *T);
+ /// remapType - Implement the ValueMapTypeRemapper interface.
+ Type *remapType(Type *SrcTy) override {
+ return get(SrcTy);
}
+
+ bool areTypesIsomorphic(Type *DstTy, Type *SrcTy);
};
}
+void TypeMapTy::addTypeMapping(Type *DstTy, Type *SrcTy) {
+ Type *&Entry = MappedTypes[SrcTy];
+ if (Entry) return;
-// RecursiveResolveTypes - This is just like ResolveTypes, except that it
-// recurses down into derived types, merging the used types if the parent types
-// are compatible.
-static bool RecursiveResolveTypesI(const Type *DstTy, const Type *SrcTy,
- LinkerTypeMap &Pointers) {
- if (DstTy == SrcTy) return false; // If already equal, noop
-
- // If we found our opaque type, resolve it now!
- if (DstTy->isOpaqueTy() || SrcTy->isOpaqueTy())
- return ResolveTypes(DstTy, SrcTy);
+ if (DstTy == SrcTy) {
+ Entry = DstTy;
+ return;
+ }
- // Two types cannot be resolved together if they are of different primitive
- // type. For example, we cannot resolve an int to a float.
- if (DstTy->getTypeID() != SrcTy->getTypeID()) return true;
+ // Check to see if these types are recursively isomorphic and establish a
+ // mapping between them if so.
+ if (!areTypesIsomorphic(DstTy, SrcTy)) {
+ // Oops, they aren't isomorphic. Just discard this request by rolling out
+ // any speculative mappings we've established.
+ for (unsigned i = 0, e = SpeculativeTypes.size(); i != e; ++i)
+ MappedTypes.erase(SpeculativeTypes[i]);
+ }
+ SpeculativeTypes.clear();
+}
- // If neither type is abstract, then they really are just different types.
- if (!DstTy->isAbstract() && !SrcTy->isAbstract())
+/// areTypesIsomorphic - 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;
+ }
- // Otherwise, resolve the used type used by this derived type...
- switch (DstTy->getTypeID()) {
- default:
- return true;
- case Type::FunctionTyID: {
- const FunctionType *DstFT = cast<FunctionType>(DstTy);
- const FunctionType *SrcFT = cast<FunctionType>(SrcTy);
- if (DstFT->isVarArg() != SrcFT->isVarArg() ||
- DstFT->getNumContainedTypes() != SrcFT->getNumContainedTypes())
+ // 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;
+ }
- // Use TypeHolder's so recursive resolution won't break us.
- PATypeHolder ST(SrcFT), DT(DstFT);
- for (unsigned i = 0, e = DstFT->getNumContainedTypes(); i != e; ++i) {
- const Type *SE = ST->getContainedType(i), *DE = DT->getContainedType(i);
- if (SE != DE && RecursiveResolveTypesI(DE, SE, Pointers))
- 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. This doesn't need to be speculative. If
+ // this is the second (different) type that we're trying to map onto the
+ // same opaque type then we fail.
+ if (cast<StructType>(DstTy)->isOpaque()) {
+ // We can only map one source type onto the opaque destination type.
+ if (!DstResolvedOpaqueTypes.insert(cast<StructType>(DstTy)))
+ return false;
+ SrcDefinitionsToResolve.push_back(SSTy);
+ Entry = DstTy;
+ return true;
}
- return false;
}
- case Type::StructTyID: {
- const StructType *DstST = cast<StructType>(DstTy);
- const StructType *SrcST = cast<StructType>(SrcTy);
- if (DstST->getNumContainedTypes() != SrcST->getNumContainedTypes())
- return true;
- PATypeHolder ST(SrcST), DT(DstST);
- for (unsigned i = 0, e = DstST->getNumContainedTypes(); i != e; ++i) {
- const Type *SE = ST->getContainedType(i), *DE = DT->getContainedType(i);
- if (SE != DE && RecursiveResolveTypesI(DE, SE, Pointers))
- 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;
}
- case Type::ArrayTyID: {
- const ArrayType *DAT = cast<ArrayType>(DstTy);
- const ArrayType *SAT = cast<ArrayType>(SrcTy);
- if (DAT->getNumElements() != SAT->getNumElements()) return true;
- return RecursiveResolveTypesI(DAT->getElementType(), SAT->getElementType(),
- Pointers);
- }
- case Type::VectorTyID: {
- const VectorType *DVT = cast<VectorType>(DstTy);
- const VectorType *SVT = cast<VectorType>(SrcTy);
- if (DVT->getNumElements() != SVT->getNumElements()) return true;
- return RecursiveResolveTypesI(DVT->getElementType(), SVT->getElementType(),
- Pointers);
- }
- case Type::PointerTyID: {
- const PointerType *DstPT = cast<PointerType>(DstTy);
- const PointerType *SrcPT = cast<PointerType>(SrcTy);
- if (DstPT->getAddressSpace() != SrcPT->getAddressSpace())
- return true;
+ // Otherwise, we speculate that these two types will line up and recursively
+ // check the subelements.
+ Entry = DstTy;
+ SpeculativeTypes.push_back(SrcTy);
- // If this is a pointer type, check to see if we have already seen it. If
- // so, we are in a recursive branch. Cut off the search now. We cannot use
- // an associative container for this search, because the type pointers (keys
- // in the container) change whenever types get resolved.
- if (SrcPT->isAbstract())
- if (const Type *ExistingDestTy = Pointers.lookup(SrcPT))
- return ExistingDestTy != DstPT;
-
- if (DstPT->isAbstract())
- if (const Type *ExistingSrcTy = Pointers.lookup(DstPT))
- return ExistingSrcTy != SrcPT;
- // Otherwise, add the current pointers to the vector to stop recursion on
- // this pair.
- if (DstPT->isAbstract())
- Pointers.insert(DstPT, SrcPT);
- if (SrcPT->isAbstract())
- Pointers.insert(SrcPT, DstPT);
-
- return RecursiveResolveTypesI(DstPT->getElementType(),
- SrcPT->getElementType(), Pointers);
- }
+ for (unsigned i = 0, e = SrcTy->getNumContainedTypes(); i != e; ++i)
+ if (!areTypesIsomorphic(DstTy->getContainedType(i),
+ SrcTy->getContainedType(i)))
+ return false;
+
+ // If everything seems to have lined up, then everything is great.
+ return true;
+}
+
+/// linkDefinedTypeBodies - Produce a body for an opaque type in the dest
+/// module from a type definition in the source module.
+void TypeMapTy::linkDefinedTypeBodies() {
+ SmallVector<Type*, 16> Elements;
+ SmallString<16> TmpName;
+
+ // Note that processing entries in this loop (calling 'get') can add new
+ // entries to the SrcDefinitionsToResolve vector.
+ while (!SrcDefinitionsToResolve.empty()) {
+ StructType *SrcSTy = SrcDefinitionsToResolve.pop_back_val();
+ StructType *DstSTy = cast<StructType>(MappedTypes[SrcSTy]);
+
+ // TypeMap is a many-to-one mapping, if there were multiple types that
+ // provide a body for DstSTy then previous iterations of this loop may have
+ // already handled it. Just ignore this case.
+ if (!DstSTy->isOpaque()) continue;
+ assert(!SrcSTy->isOpaque() && "Not resolving a definition?");
+
+ // Map the body of the source type over to a new body for the dest type.
+ Elements.resize(SrcSTy->getNumElements());
+ for (unsigned i = 0, e = Elements.size(); i != e; ++i)
+ Elements[i] = getImpl(SrcSTy->getElementType(i));
+
+ DstSTy->setBody(Elements, SrcSTy->isPacked());
+
+ // If DstSTy has no name or has a longer name than STy, then viciously steal
+ // STy's name.
+ if (!SrcSTy->hasName()) continue;
+ StringRef SrcName = SrcSTy->getName();
+
+ if (!DstSTy->hasName() || DstSTy->getName().size() > SrcName.size()) {
+ TmpName.insert(TmpName.end(), SrcName.begin(), SrcName.end());
+ SrcSTy->setName("");
+ DstSTy->setName(TmpName.str());
+ TmpName.clear();
+ }
}
+
+ DstResolvedOpaqueTypes.clear();
}
-static bool RecursiveResolveTypes(const Type *DestTy, const Type *SrcTy) {
- LinkerTypeMap PointerTypes;
- return RecursiveResolveTypesI(DestTy, SrcTy, PointerTypes);
+/// get - Return the mapped type to use for the specified input type from the
+/// source module.
+Type *TypeMapTy::get(Type *Ty) {
+ Type *Result = getImpl(Ty);
+
+ // If this caused a reference to any struct type, resolve it before returning.
+ if (!SrcDefinitionsToResolve.empty())
+ linkDefinedTypeBodies();
+ return Result;
}
+/// getImpl - This is the recursive version of get().
+Type *TypeMapTy::getImpl(Type *Ty) {
+ // If we already have an entry for this type, return it.
+ Type **Entry = &MappedTypes[Ty];
+ if (*Entry) return *Entry;
+
+ // If this is not a named struct type, then just map all of the elements and
+ // then rebuild the type from inside out.
+ if (!isa<StructType>(Ty) || cast<StructType>(Ty)->isLiteral()) {
+ // If there are no element types to map, then the type is itself. This is
+ // true for the anonymous {} struct, things like 'float', integers, etc.
+ if (Ty->getNumContainedTypes() == 0)
+ return *Entry = Ty;
+
+ // Remap all of the elements, keeping track of whether any of them change.
+ bool AnyChange = false;
+ SmallVector<Type*, 4> ElementTypes;
+ ElementTypes.resize(Ty->getNumContainedTypes());
+ for (unsigned i = 0, e = Ty->getNumContainedTypes(); i != e; ++i) {
+ ElementTypes[i] = getImpl(Ty->getContainedType(i));
+ AnyChange |= ElementTypes[i] != Ty->getContainedType(i);
+ }
-// LinkTypes - Go through the symbol table of the Src module and see if any
-// types are named in the src module that are not named in the Dst module.
-// Make sure there are no type name conflicts.
-static bool LinkTypes(Module *Dest, const Module *Src, std::string *Err) {
- TypeSymbolTable *DestST = &Dest->getTypeSymbolTable();
- const TypeSymbolTable *SrcST = &Src->getTypeSymbolTable();
-
- // Look for a type plane for Type's...
- TypeSymbolTable::const_iterator TI = SrcST->begin();
- TypeSymbolTable::const_iterator TE = SrcST->end();
- if (TI == TE) return false; // No named types, do nothing.
-
- // Some types cannot be resolved immediately because they depend on other
- // types being resolved to each other first. This contains a list of types we
- // are waiting to recheck.
- std::vector<std::string> DelayedTypesToResolve;
-
- for ( ; TI != TE; ++TI ) {
- const std::string &Name = TI->first;
- const Type *RHS = TI->second;
-
- // Check to see if this type name is already in the dest module.
- Type *Entry = DestST->lookup(Name);
-
- // If the name is just in the source module, bring it over to the dest.
- if (Entry == 0) {
- if (!Name.empty())
- DestST->insert(Name, const_cast<Type*>(RHS));
- } else if (ResolveTypes(Entry, RHS)) {
- // They look different, save the types 'till later to resolve.
- DelayedTypesToResolve.push_back(Name);
+ // If we found our type while recursively processing stuff, just use it.
+ Entry = &MappedTypes[Ty];
+ if (*Entry) return *Entry;
+
+ // If all of the element types mapped directly over, then the type is usable
+ // as-is.
+ if (!AnyChange)
+ return *Entry = Ty;
+
+ // Otherwise, rebuild a modified type.
+ switch (Ty->getTypeID()) {
+ default: llvm_unreachable("unknown derived type to remap");
+ case Type::ArrayTyID:
+ return *Entry = ArrayType::get(ElementTypes[0],
+ cast<ArrayType>(Ty)->getNumElements());
+ case Type::VectorTyID:
+ return *Entry = VectorType::get(ElementTypes[0],
+ cast<VectorType>(Ty)->getNumElements());
+ case Type::PointerTyID:
+ return *Entry = PointerType::get(ElementTypes[0],
+ cast<PointerType>(Ty)->getAddressSpace());
+ case Type::FunctionTyID:
+ return *Entry = FunctionType::get(ElementTypes[0],
+ makeArrayRef(ElementTypes).slice(1),
+ cast<FunctionType>(Ty)->isVarArg());
+ case Type::StructTyID:
+ // Note that this is only reached for anonymous structs.
+ return *Entry = StructType::get(Ty->getContext(), ElementTypes,
+ cast<StructType>(Ty)->isPacked());
}
}
- // Iteratively resolve types while we can...
- while (!DelayedTypesToResolve.empty()) {
- // Loop over all of the types, attempting to resolve them if possible...
- unsigned OldSize = DelayedTypesToResolve.size();
-
- // Try direct resolution by name...
- for (unsigned i = 0; i != DelayedTypesToResolve.size(); ++i) {
- const std::string &Name = DelayedTypesToResolve[i];
- Type *T1 = SrcST->lookup(Name);
- Type *T2 = DestST->lookup(Name);
- if (!ResolveTypes(T2, T1)) {
- // We are making progress!
- DelayedTypesToResolve.erase(DelayedTypesToResolve.begin()+i);
- --i;
- }
+ // Otherwise, this is an unmapped named struct. If the struct can be directly
+ // mapped over, just use it as-is. This happens in a case when the linked-in
+ // module has something like:
+ // %T = type {%T*, i32}
+ // @GV = global %T* null
+ // where T does not exist at all in the destination module.
+ //
+ // The other case we watch for is when the type is not in the destination
+ // module, but that it has to be rebuilt because it refers to something that
+ // is already mapped. For example, if the destination module has:
+ // %A = type { i32 }
+ // and the source module has something like
+ // %A' = type { i32 }
+ // %B = type { %A'* }
+ // @GV = global %B* null
+ // then we want to create a new type: "%B = type { %A*}" and have it take the
+ // pristine "%B" name from the source module.
+ //
+ // To determine which case this is, we have to recursively walk the type graph
+ // speculating that we'll be able to reuse it unmodified. Only if this is
+ // safe would we map the entire thing over. Because this is an optimization,
+ // and is not required for the prettiness of the linked module, we just skip
+ // it and always rebuild a type here.
+ StructType *STy = cast<StructType>(Ty);
+
+ // If the type is opaque, we can just use it directly.
+ if (STy->isOpaque()) {
+ // A named structure type from src module is used. Add it to the Set of
+ // identified structs in the destination module.
+ DstStructTypesSet.insert(STy);
+ return *Entry = STy;
+ }
+
+ // Otherwise we create a new type and resolve its body later. This will be
+ // resolved by the top level of get().
+ SrcDefinitionsToResolve.push_back(STy);
+ StructType *DTy = StructType::create(STy->getContext());
+ // A new identified structure type was created. Add it to the set of
+ // identified structs in the destination module.
+ DstStructTypesSet.insert(DTy);
+ DstResolvedOpaqueTypes.insert(DTy);
+ return *Entry = DTy;
+}
+
+//===----------------------------------------------------------------------===//
+// ModuleLinker implementation.
+//===----------------------------------------------------------------------===//
+
+namespace {
+ class ModuleLinker;
+
+ /// ValueMaterializerTy - Creates prototypes for functions that are lazily
+ /// linked on the fly. This speeds up linking for modules with many
+ /// lazily linked functions of which few get used.
+ class ValueMaterializerTy : public ValueMaterializer {
+ TypeMapTy &TypeMap;
+ Module *DstM;
+ std::vector<Function*> &LazilyLinkFunctions;
+ public:
+ ValueMaterializerTy(TypeMapTy &TypeMap, Module *DstM,
+ std::vector<Function*> &LazilyLinkFunctions) :
+ ValueMaterializer(), TypeMap(TypeMap), DstM(DstM),
+ LazilyLinkFunctions(LazilyLinkFunctions) {
}
- // Did we not eliminate any types?
- if (DelayedTypesToResolve.size() == OldSize) {
- // Attempt to resolve subelements of types. This allows us to merge these
- // two types: { int* } and { opaque* }
- for (unsigned i = 0, e = DelayedTypesToResolve.size(); i != e; ++i) {
- const std::string &Name = DelayedTypesToResolve[i];
- if (!RecursiveResolveTypes(SrcST->lookup(Name), DestST->lookup(Name))) {
- // We are making progress!
- DelayedTypesToResolve.erase(DelayedTypesToResolve.begin()+i);
-
- // Go back to the main loop, perhaps we can resolve directly by name
- // now...
- break;
- }
- }
+ Value *materializeValueFor(Value *V) override;
+ };
- // If we STILL cannot resolve the types, then there is something wrong.
- if (DelayedTypesToResolve.size() == OldSize) {
- // Remove the symbol name from the destination.
- DelayedTypesToResolve.pop_back();
- }
+ /// ModuleLinker - This is an implementation class for the LinkModules
+ /// function, which is the entrypoint for this file.
+ class ModuleLinker {
+ Module *DstM, *SrcM;
+
+ TypeMapTy TypeMap;
+ ValueMaterializerTy ValMaterializer;
+
+ /// ValueMap - Mapping of values from what they used to be in Src, to what
+ /// they are now in DstM. ValueToValueMapTy is a ValueMap, which involves
+ /// some overhead due to the use of Value handles which the Linker doesn't
+ /// actually need, but this allows us to reuse the ValueMapper code.
+ ValueToValueMapTy ValueMap;
+
+ struct AppendingVarInfo {
+ GlobalVariable *NewGV; // New aggregate global in dest module.
+ Constant *DstInit; // Old initializer from dest module.
+ Constant *SrcInit; // Old initializer from src module.
+ };
+
+ std::vector<AppendingVarInfo> AppendingVars;
+
+ unsigned Mode; // Mode to treat source module.
+
+ // Set of items not to link in from source.
+ SmallPtrSet<const Value*, 16> DoNotLinkFromSource;
+
+ // Vector of functions to lazily link in.
+ std::vector<Function*> LazilyLinkFunctions;
+
+ bool SuppressWarnings;
+
+ public:
+ std::string ErrorMsg;
+
+ ModuleLinker(Module *dstM, TypeSet &Set, Module *srcM, unsigned mode,
+ bool SuppressWarnings=false)
+ : DstM(dstM), SrcM(srcM), TypeMap(Set),
+ ValMaterializer(TypeMap, DstM, LazilyLinkFunctions), Mode(mode),
+ SuppressWarnings(SuppressWarnings) {}
+
+ bool run();
+
+ private:
+ /// emitError - Helper method for setting a message and returning an error
+ /// code.
+ bool emitError(const Twine &Message) {
+ ErrorMsg = Message.str();
+ return true;
}
- }
+ bool getComdatLeader(Module *M, StringRef ComdatName,
+ const GlobalVariable *&GVar);
+ bool computeResultingSelectionKind(StringRef ComdatName,
+ Comdat::SelectionKind Src,
+ Comdat::SelectionKind Dst,
+ Comdat::SelectionKind &Result,
+ bool &LinkFromSrc);
+ std::map<const Comdat *, std::pair<Comdat::SelectionKind, bool>>
+ ComdatsChosen;
+ bool getComdatResult(const Comdat *SrcC, Comdat::SelectionKind &SK,
+ bool &LinkFromSrc);
+
+ /// getLinkageResult - This analyzes the two global values and determines
+ /// what the result will look like in the destination module.
+ bool getLinkageResult(GlobalValue *Dest, const GlobalValue *Src,
+ GlobalValue::LinkageTypes <,
+ GlobalValue::VisibilityTypes &Vis,
+ bool &LinkFromSrc);
+
+ /// getLinkedToGlobal - Given a global in the source module, return the
+ /// global in the destination module that is being linked to, if any.
+ GlobalValue *getLinkedToGlobal(GlobalValue *SrcGV) {
+ // If the source has no name it can't link. If it has local linkage,
+ // there is no name match-up going on.
+ if (!SrcGV->hasName() || SrcGV->hasLocalLinkage())
+ return 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;
+ }
- return false;
+ void computeTypeMapping();
+
+ void upgradeMismatchedGlobalArray(StringRef Name);
+ void upgradeMismatchedGlobals();
+
+ bool linkAppendingVarProto(GlobalVariable *DstGV, GlobalVariable *SrcGV);
+ bool linkGlobalProto(GlobalVariable *SrcGV);
+ bool linkFunctionProto(Function *SrcF);
+ bool linkAliasProto(GlobalAlias *SrcA);
+ bool linkModuleFlagsMetadata();
+
+ void linkAppendingVarInit(const AppendingVarInfo &AVI);
+ void linkGlobalInits();
+ void linkFunctionBody(Function *Dst, Function *Src);
+ void linkAliasBodies();
+ void linkNamedMDNodes();
+ };
}
-/// ForceRenaming - The LLVM SymbolTable class autorenames globals that conflict
+/// forceRenaming - The LLVM SymbolTable class autorenames globals that conflict
/// in the symbol table. This is good for all clients except for us. Go
/// through the trouble to force this back.
-static void ForceRenaming(GlobalValue *GV, const std::string &Name) {
- assert(GV->getName() != Name && "Can't force rename to self");
- ValueSymbolTable &ST = GV->getParent()->getValueSymbolTable();
+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 = cast_or_null<GlobalValue>(ST.lookup(Name))) {
- assert(ConflictGV->hasLocalLinkage() &&
- "Not conflicting with a static global, should link instead!");
+ 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");
+ assert(ConflictGV->getName() != Name && "forceRenaming didn't work");
} else {
GV->setName(Name); // Force the name back
}
}
-/// CopyGVAttributes - copy additional attributes (those not needed to construct
+/// copyGVAttributes - copy additional attributes (those not needed to construct
/// a GlobalValue) from the SrcGV to the DestGV.
-static void CopyGVAttributes(GlobalValue *DestGV, const GlobalValue *SrcGV) {
+static void copyGVAttributes(GlobalValue *DestGV, const GlobalValue *SrcGV) {
// Use the maximum alignment, rather than just copying the alignment of SrcGV.
- unsigned Alignment = std::max(DestGV->getAlignment(), SrcGV->getAlignment());
+ auto *DestGO = dyn_cast<GlobalObject>(DestGV);
+ unsigned Alignment;
+ if (DestGO)
+ Alignment = std::max(DestGO->getAlignment(), SrcGV->getAlignment());
+
DestGV->copyAttributesFrom(SrcGV);
- DestGV->setAlignment(Alignment);
+
+ if (DestGO)
+ DestGO->setAlignment(Alignment);
+
+ forceRenaming(DestGV, SrcGV->getName());
}
-/// GetLinkageResult - This analyzes the two global values and determines what
-/// the result will look like in the destination module. In particular, it
-/// computes the resultant linkage type, computes whether the global in the
-/// source should be copied over to the destination (replacing the existing
-/// one), and computes whether this linkage is an error or not. It also performs
-/// visibility checks: we cannot link together two symbols with different
-/// visibilities.
-static bool GetLinkageResult(GlobalValue *Dest, const GlobalValue *Src,
- GlobalValue::LinkageTypes <, bool &LinkFromSrc,
- std::string *Err) {
- assert((!Dest || !Src->hasLocalLinkage()) &&
- "If Src has internal linkage, Dest shouldn't be set!");
- if (!Dest) {
- // Linking something to nothing.
+static bool isLessConstraining(GlobalValue::VisibilityTypes a,
+ GlobalValue::VisibilityTypes b) {
+ if (a == GlobalValue::HiddenVisibility)
+ return false;
+ if (b == GlobalValue::HiddenVisibility)
+ return true;
+ if (a == GlobalValue::ProtectedVisibility)
+ return false;
+ if (b == GlobalValue::ProtectedVisibility)
+ return true;
+ return false;
+}
+
+Value *ValueMaterializerTy::materializeValueFor(Value *V) {
+ Function *SF = dyn_cast<Function>(V);
+ if (!SF)
+ return nullptr;
+
+ Function *DF = Function::Create(TypeMap.get(SF->getFunctionType()),
+ SF->getLinkage(), SF->getName(), DstM);
+ copyGVAttributes(DF, SF);
+
+ if (Comdat *SC = SF->getComdat()) {
+ Comdat *DC = DstM->getOrInsertComdat(SC->getName());
+ DF->setComdat(DC);
+ }
+
+ LazilyLinkFunctions.push_back(SF);
+ return DF;
+}
+
+bool ModuleLinker::getComdatLeader(Module *M, StringRef ComdatName,
+ const GlobalVariable *&GVar) {
+ const GlobalValue *GVal = M->getNamedValue(ComdatName);
+ if (const auto *GA = dyn_cast_or_null<GlobalAlias>(GVal)) {
+ GVal = GA->getBaseObject();
+ if (!GVal)
+ // We cannot resolve the size of the aliasee yet.
+ return emitError("Linking COMDATs named '" + ComdatName +
+ "': COMDAT key involves incomputable alias size.");
+ }
+
+ GVar = dyn_cast_or_null<GlobalVariable>(GVal);
+ if (!GVar)
+ return emitError(
+ "Linking COMDATs named '" + ComdatName +
+ "': GlobalVariable required for data dependent selection!");
+
+ return false;
+}
+
+bool ModuleLinker::computeResultingSelectionKind(StringRef ComdatName,
+ Comdat::SelectionKind Src,
+ Comdat::SelectionKind Dst,
+ Comdat::SelectionKind &Result,
+ bool &LinkFromSrc) {
+ // The ability to mix Comdat::SelectionKind::Any with
+ // Comdat::SelectionKind::Largest is a behavior that comes from COFF.
+ bool DstAnyOrLargest = Dst == Comdat::SelectionKind::Any ||
+ Dst == Comdat::SelectionKind::Largest;
+ bool SrcAnyOrLargest = Src == Comdat::SelectionKind::Any ||
+ Src == Comdat::SelectionKind::Largest;
+ if (DstAnyOrLargest && SrcAnyOrLargest) {
+ if (Dst == Comdat::SelectionKind::Largest ||
+ Src == Comdat::SelectionKind::Largest)
+ Result = Comdat::SelectionKind::Largest;
+ else
+ Result = Comdat::SelectionKind::Any;
+ } else if (Src == Dst) {
+ Result = Dst;
+ } else {
+ return emitError("Linking COMDATs named '" + ComdatName +
+ "': invalid selection kinds!");
+ }
+
+ switch (Result) {
+ case Comdat::SelectionKind::Any:
+ // Go with Dst.
+ LinkFromSrc = false;
+ break;
+ case Comdat::SelectionKind::NoDuplicates:
+ return emitError("Linking COMDATs named '" + ComdatName +
+ "': noduplicates has been violated!");
+ case Comdat::SelectionKind::ExactMatch:
+ case Comdat::SelectionKind::Largest:
+ case Comdat::SelectionKind::SameSize: {
+ const GlobalVariable *DstGV;
+ const GlobalVariable *SrcGV;
+ if (getComdatLeader(DstM, ComdatName, DstGV) ||
+ getComdatLeader(SrcM, ComdatName, SrcGV))
+ return true;
+
+ const DataLayout *DstDL = DstM->getDataLayout();
+ const DataLayout *SrcDL = SrcM->getDataLayout();
+ if (!DstDL || !SrcDL) {
+ return emitError(
+ "Linking COMDATs named '" + ComdatName +
+ "': can't do size dependent selection without DataLayout!");
+ }
+ uint64_t DstSize =
+ DstDL->getTypeAllocSize(DstGV->getType()->getPointerElementType());
+ uint64_t SrcSize =
+ SrcDL->getTypeAllocSize(SrcGV->getType()->getPointerElementType());
+ if (Result == Comdat::SelectionKind::ExactMatch) {
+ if (SrcGV->getInitializer() != DstGV->getInitializer())
+ return emitError("Linking COMDATs named '" + ComdatName +
+ "': ExactMatch violated!");
+ LinkFromSrc = false;
+ } else if (Result == Comdat::SelectionKind::Largest) {
+ LinkFromSrc = SrcSize > DstSize;
+ } else if (Result == Comdat::SelectionKind::SameSize) {
+ if (SrcSize != DstSize)
+ return emitError("Linking COMDATs named '" + ComdatName +
+ "': SameSize violated!");
+ LinkFromSrc = false;
+ } else {
+ llvm_unreachable("unknown selection kind");
+ }
+ break;
+ }
+ }
+
+ return false;
+}
+
+bool ModuleLinker::getComdatResult(const Comdat *SrcC,
+ Comdat::SelectionKind &Result,
+ bool &LinkFromSrc) {
+ Comdat::SelectionKind SSK = SrcC->getSelectionKind();
+ StringRef ComdatName = SrcC->getName();
+ Module::ComdatSymTabType &ComdatSymTab = DstM->getComdatSymbolTable();
+ Module::ComdatSymTabType::iterator DstCI = ComdatSymTab.find(ComdatName);
+
+ if (DstCI == ComdatSymTab.end()) {
+ // Use the comdat if it is only available in one of the modules.
LinkFromSrc = true;
- LT = Src->getLinkage();
- } else if (Src->isDeclaration()) {
+ Result = SSK;
+ return false;
+ }
+
+ const Comdat *DstC = &DstCI->second;
+ Comdat::SelectionKind DSK = DstC->getSelectionKind();
+ return computeResultingSelectionKind(ComdatName, SSK, DSK, Result,
+ LinkFromSrc);
+}
+
+// FIXME: Duplicated from the gold plugin. This should be refactored somewhere.
+static bool isDeclaration(const GlobalValue &V) {
+ if (V.hasAvailableExternallyLinkage())
+ return true;
+
+ if (V.isMaterializable())
+ return false;
+
+ return V.isDeclaration();
+}
+
+/// This analyzes the two global values and determines what the result will look
+/// like in the destination module. In particular, it computes the resultant
+/// linkage type and visibility, computes whether the global in the source
+/// should be copied over to the destination (replacing the existing one), and
+/// computes whether this linkage is an error or not.
+bool ModuleLinker::getLinkageResult(GlobalValue *Dest, const GlobalValue *Src,
+ GlobalValue::LinkageTypes <,
+ GlobalValue::VisibilityTypes &Vis,
+ bool &LinkFromSrc) {
+ assert(Dest && "Must have two globals being queried");
+ assert(!Src->hasLocalLinkage() &&
+ "If Src has internal linkage, Dest shouldn't be set!");
+
+ bool SrcIsDeclaration = isDeclaration(*Src);
+ bool DestIsDeclaration = isDeclaration(*Dest);
+
+ if (SrcIsDeclaration) {
// If Src is external or if both Src & Dest are external.. Just link the
// external globals, we aren't adding anything.
- if (Src->hasDLLImportLinkage()) {
- // If one of GVs has DLLImport linkage, result should be dllimport'ed.
- if (Dest->isDeclaration()) {
+ if (Src->hasDLLImportStorageClass()) {
+ // If one of GVs is marked as DLLImport, result should be dllimport'ed.
+ if (DestIsDeclaration) {
LinkFromSrc = true;
LT = Src->getLinkage();
}
LinkFromSrc = false;
LT = Dest->getLinkage();
}
- } else if (Dest->isDeclaration() && !Dest->hasDLLImportLinkage()) {
+ } else if (DestIsDeclaration) {
// If Dest is external but Src is not:
LinkFromSrc = true;
LT = Src->getLinkage();
- } else if (Src->hasAppendingLinkage() || Dest->hasAppendingLinkage()) {
- if (Src->getLinkage() != Dest->getLinkage())
- return Error(Err, "Linking globals named '" + Src->getName() +
- "': can only link appending global with another appending global!");
- LinkFromSrc = true; // Special cased.
- LT = Src->getLinkage();
} else if (Src->isWeakForLinker()) {
- // At this point we know that Dest has LinkOnce, External*, Weak, Common,
- // or DLL* linkage.
- if (Dest->hasExternalWeakLinkage() ||
- Dest->hasAvailableExternallyLinkage() ||
- (Dest->hasLinkOnceLinkage() &&
- (Src->hasWeakLinkage() || Src->hasCommonLinkage()))) {
+ assert(!Dest->hasExternalWeakLinkage());
+ assert(!Dest->hasAvailableExternallyLinkage());
+ if (Dest->hasLinkOnceLinkage() &&
+ (Src->hasWeakLinkage() || Src->hasCommonLinkage())) {
LinkFromSrc = true;
LT = Src->getLinkage();
} else {
LT = Dest->getLinkage();
}
} else if (Dest->isWeakForLinker()) {
- // At this point we know that Src has External* or DLL* linkage.
- if (Src->hasExternalWeakLinkage()) {
- LinkFromSrc = false;
- LT = Dest->getLinkage();
- } else {
- LinkFromSrc = true;
- LT = GlobalValue::ExternalLinkage;
- }
+ assert(!Src->hasExternalWeakLinkage());
+ LinkFromSrc = true;
+ LT = GlobalValue::ExternalLinkage;
} else {
- assert((Dest->hasExternalLinkage() ||
- Dest->hasDLLImportLinkage() ||
- Dest->hasDLLExportLinkage() ||
- Dest->hasExternalWeakLinkage()) &&
- (Src->hasExternalLinkage() ||
- Src->hasDLLImportLinkage() ||
- Src->hasDLLExportLinkage() ||
- Src->hasExternalWeakLinkage()) &&
+ assert(!Src->hasExternalWeakLinkage());
+ assert(!Dest->hasExternalWeakLinkage());
+ assert(Dest->hasExternalLinkage() && Src->hasExternalLinkage() &&
"Unexpected linkage type!");
- return Error(Err, "Linking globals named '" + Src->getName() +
- "': symbol multiply defined!");
+ return emitError("Linking globals named '" + Src->getName() +
+ "': symbol multiply defined!");
}
- // Check visibility
- if (Dest && Src->getVisibility() != Dest->getVisibility() &&
- !Src->isDeclaration() && !Dest->isDeclaration() &&
- !Src->hasAvailableExternallyLinkage() &&
- !Dest->hasAvailableExternallyLinkage())
- return Error(Err, "Linking globals named '" + Src->getName() +
- "': symbols have different visibilities!");
+ // Compute the visibility. We follow the rules in the System V Application
+ // Binary Interface.
+ assert(!GlobalValue::isLocalLinkage(LT) &&
+ "Symbols with local linkage should not be merged");
+ Vis = isLessConstraining(Src->getVisibility(), Dest->getVisibility()) ?
+ Dest->getVisibility() : Src->getVisibility();
return false;
}
-// Insert all of the named mdnoes in Src into the Dest module.
-static void LinkNamedMDNodes(Module *Dest, Module *Src,
- ValueToValueMapTy &ValueMap) {
- for (Module::const_named_metadata_iterator I = Src->named_metadata_begin(),
- E = Src->named_metadata_end(); I != E; ++I) {
- const NamedMDNode *SrcNMD = I;
- NamedMDNode *DestNMD = Dest->getOrInsertNamedMetadata(SrcNMD->getName());
- // Add Src elements into Dest node.
- for (unsigned i = 0, e = SrcNMD->getNumOperands(); i != e; ++i)
- DestNMD->addOperand(cast<MDNode>(MapValue(SrcNMD->getOperand(i),
- ValueMap)));
+/// computeTypeMapping - Loop over all of the linked values to compute type
+/// mappings. For example, if we link "extern Foo *x" and "Foo *x = NULL", then
+/// we have two struct types 'Foo' but one got renamed when the module was
+/// loaded into the same LLVMContext.
+void ModuleLinker::computeTypeMapping() {
+ // Incorporate globals.
+ for (Module::global_iterator I = SrcM->global_begin(),
+ E = SrcM->global_end(); I != E; ++I) {
+ GlobalValue *DGV = getLinkedToGlobal(I);
+ if (!DGV) continue;
+
+ if (!DGV->hasAppendingLinkage() || !I->hasAppendingLinkage()) {
+ TypeMap.addTypeMapping(DGV->getType(), I->getType());
+ continue;
+ }
+
+ // Unify the element type of appending arrays.
+ ArrayType *DAT = cast<ArrayType>(DGV->getType()->getElementType());
+ ArrayType *SAT = cast<ArrayType>(I->getType()->getElementType());
+ TypeMap.addTypeMapping(DAT->getElementType(), SAT->getElementType());
}
-}
-// LinkGlobals - Loop through the global variables in the src module and merge
-// them into the dest module.
-static bool LinkGlobals(Module *Dest, const Module *Src,
- ValueToValueMapTy &ValueMap,
- std::multimap<std::string, GlobalVariable *> &AppendingVars,
- std::string *Err) {
- ValueSymbolTable &DestSymTab = Dest->getValueSymbolTable();
+ // Incorporate functions.
+ for (Module::iterator I = SrcM->begin(), E = SrcM->end(); I != E; ++I) {
+ if (GlobalValue *DGV = getLinkedToGlobal(I))
+ TypeMap.addTypeMapping(DGV->getType(), I->getType());
+ }
- // Loop over all of the globals in the src module, mapping them over as we go
- for (Module::const_global_iterator I = Src->global_begin(),
- E = Src->global_end(); I != E; ++I) {
- const GlobalVariable *SGV = I;
- GlobalValue *DGV = 0;
-
- // Check to see if may have to link the global with the global, alias or
- // function.
- if (SGV->hasName() && !SGV->hasLocalLinkage())
- DGV = cast_or_null<GlobalValue>(DestSymTab.lookup(SGV->getName()));
-
- // If we found a global with the same name in the dest module, but it has
- // internal linkage, we are really not doing any linkage here.
- if (DGV && DGV->hasLocalLinkage())
- DGV = 0;
-
- // If types don't agree due to opaque types, try to resolve them.
- if (DGV && DGV->getType() != SGV->getType())
- RecursiveResolveTypes(SGV->getType(), DGV->getType());
-
- assert((SGV->hasInitializer() || SGV->hasExternalWeakLinkage() ||
- SGV->hasExternalLinkage() || SGV->hasDLLImportLinkage()) &&
- "Global must either be external or have an initializer!");
-
- GlobalValue::LinkageTypes NewLinkage = GlobalValue::InternalLinkage;
- bool LinkFromSrc = false;
- if (GetLinkageResult(DGV, SGV, NewLinkage, LinkFromSrc, Err))
- return true;
+ // Incorporate types by name, scanning all the types in the source module.
+ // At this point, the destination module may have a type "%foo = { i32 }" for
+ // example. When the source module got loaded into the same LLVMContext, if
+ // it had the same type, it would have been renamed to "%foo.42 = { i32 }".
+ TypeFinder SrcStructTypes;
+ SrcStructTypes.run(*SrcM, true);
+ SmallPtrSet<StructType*, 32> SrcStructTypesSet(SrcStructTypes.begin(),
+ SrcStructTypes.end());
+
+ for (unsigned i = 0, e = SrcStructTypes.size(); i != e; ++i) {
+ StructType *ST = SrcStructTypes[i];
+ if (!ST->hasName()) continue;
+
+ // 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;
- if (DGV == 0) {
- // No linking to be performed, simply create an identical version of the
- // symbol over in the dest module... the initializer will be filled in
- // later by LinkGlobalInits.
- GlobalVariable *NewDGV =
- new GlobalVariable(*Dest, SGV->getType()->getElementType(),
- SGV->isConstant(), SGV->getLinkage(), /*init*/0,
- SGV->getName(), 0, false,
- SGV->getType()->getAddressSpace());
- // Propagate alignment, visibility and section info.
- CopyGVAttributes(NewDGV, SGV);
- NewDGV->setUnnamedAddr(SGV->hasUnnamedAddr());
-
- // If the LLVM runtime renamed the global, but it is an externally visible
- // symbol, DGV must be an existing global with internal linkage. Rename
- // it.
- if (!NewDGV->hasLocalLinkage() && NewDGV->getName() != SGV->getName())
- ForceRenaming(NewDGV, SGV->getName());
+ // Check to see if the destination module has a struct with the prefix name.
+ if (StructType *DST = DstM->getTypeByName(ST->getName().substr(0, DotPos)))
+ // Don't use it if this actually came from the source module. They're in
+ // the same LLVMContext after all. Also don't use it unless the type is
+ // actually used in the destination module. This can happen in situations
+ // like this:
+ //
+ // Module A Module B
+ // -------- --------
+ // %Z = type { %A } %B = type { %C.1 }
+ // %A = type { %B.1, [7 x i8] } %C.1 = type { i8* }
+ // %B.1 = type { %C } %A.2 = type { %B.3, [5 x i8] }
+ // %C = type { i8* } %B.3 = type { %C.1 }
+ //
+ // When we link Module B with Module A, the '%B' in Module B is
+ // used. However, that would then use '%C.1'. But when we process '%C.1',
+ // we prefer to take the '%C' version. So we are then left with both
+ // '%C.1' and '%C' being used for the same types. This leads to some
+ // variables using one type and some using the other.
+ if (!SrcStructTypesSet.count(DST) && TypeMap.DstStructTypesSet.count(DST))
+ TypeMap.addTypeMapping(DST, ST);
+ }
- // Make sure to remember this mapping.
- ValueMap[SGV] = NewDGV;
+ // Don't bother incorporating aliases, they aren't generally typed well.
- // Keep track that this is an appending variable.
- if (SGV->hasAppendingLinkage())
- AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV));
- continue;
- }
+ // 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();
+}
- bool HasUnnamedAddr = SGV->hasUnnamedAddr() && DGV->hasUnnamedAddr();
-
- // If the visibilities of the symbols disagree and the destination is a
- // prototype, take the visibility of its input.
- if (DGV->isDeclaration())
- DGV->setVisibility(SGV->getVisibility());
-
- if (DGV->hasAppendingLinkage()) {
- // No linking is performed yet. Just insert a new copy of the global, and
- // keep track of the fact that it is an appending variable in the
- // AppendingVars map. The name is cleared out so that no linkage is
- // performed.
- GlobalVariable *NewDGV =
- new GlobalVariable(*Dest, SGV->getType()->getElementType(),
- SGV->isConstant(), SGV->getLinkage(), /*init*/0,
- "", 0, false,
- SGV->getType()->getAddressSpace());
-
- // Set alignment allowing CopyGVAttributes merge it with alignment of SGV.
- NewDGV->setAlignment(DGV->getAlignment());
- // Propagate alignment, section and visibility info.
- CopyGVAttributes(NewDGV, SGV);
-
- // Make sure to remember this mapping...
- ValueMap[SGV] = NewDGV;
-
- // Keep track that this is an appending variable...
- AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV));
- continue;
+static void upgradeGlobalArray(GlobalVariable *GV) {
+ ArrayType *ATy = cast<ArrayType>(GV->getType()->getElementType());
+ StructType *OldTy = cast<StructType>(ATy->getElementType());
+ assert(OldTy->getNumElements() == 2 && "Expected to upgrade from 2 elements");
+
+ // Get the upgraded 3 element type.
+ PointerType *VoidPtrTy = Type::getInt8Ty(GV->getContext())->getPointerTo();
+ Type *Tys[3] = {OldTy->getElementType(0), OldTy->getElementType(1),
+ VoidPtrTy};
+ StructType *NewTy = StructType::get(GV->getContext(), Tys, false);
+
+ // Build new constants with a null third field filled in.
+ Constant *OldInitC = GV->getInitializer();
+ ConstantArray *OldInit = dyn_cast<ConstantArray>(OldInitC);
+ if (!OldInit && !isa<ConstantAggregateZero>(OldInitC))
+ // Invalid initializer; give up.
+ return;
+ std::vector<Constant *> Initializers;
+ if (OldInit && OldInit->getNumOperands()) {
+ Value *Null = Constant::getNullValue(VoidPtrTy);
+ for (Use &U : OldInit->operands()) {
+ ConstantStruct *Init = cast<ConstantStruct>(U.get());
+ Initializers.push_back(ConstantStruct::get(
+ NewTy, Init->getOperand(0), Init->getOperand(1), Null, nullptr));
}
+ }
+ assert(Initializers.size() == ATy->getNumElements() &&
+ "Failed to copy all array elements");
+
+ // Replace the old GV with a new one.
+ ATy = ArrayType::get(NewTy, Initializers.size());
+ Constant *NewInit = ConstantArray::get(ATy, Initializers);
+ GlobalVariable *NewGV = new GlobalVariable(
+ *GV->getParent(), ATy, GV->isConstant(), GV->getLinkage(), NewInit, "",
+ GV, GV->getThreadLocalMode(), GV->getType()->getAddressSpace(),
+ GV->isExternallyInitialized());
+ NewGV->copyAttributesFrom(GV);
+ NewGV->takeName(GV);
+ assert(GV->use_empty() && "program cannot use initializer list");
+ GV->eraseFromParent();
+}
- if (LinkFromSrc) {
- if (isa<GlobalAlias>(DGV))
- return Error(Err, "Global-Alias Collision on '" + SGV->getName() +
- "': symbol multiple defined");
-
- // If the types don't match, and if we are to link from the source, nuke
- // DGV and create a new one of the appropriate type. Note that the thing
- // we are replacing may be a function (if a prototype, weak, etc) or a
- // global variable.
- GlobalVariable *NewDGV =
- new GlobalVariable(*Dest, SGV->getType()->getElementType(),
- SGV->isConstant(), NewLinkage, /*init*/0,
- DGV->getName(), 0, false,
- SGV->getType()->getAddressSpace());
-
- // Set the unnamed_addr.
- NewDGV->setUnnamedAddr(HasUnnamedAddr);
-
- // Propagate alignment, section, and visibility info.
- CopyGVAttributes(NewDGV, SGV);
- DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewDGV,
- DGV->getType()));
-
- // DGV will conflict with NewDGV because they both had the same
- // name. We must erase this now so ForceRenaming doesn't assert
- // because DGV might not have internal linkage.
- if (GlobalVariable *Var = dyn_cast<GlobalVariable>(DGV))
- Var->eraseFromParent();
- else
- cast<Function>(DGV)->eraseFromParent();
-
- // If the symbol table renamed the global, but it is an externally visible
- // symbol, DGV must be an existing global with internal linkage. Rename.
- if (NewDGV->getName() != SGV->getName() && !NewDGV->hasLocalLinkage())
- ForceRenaming(NewDGV, SGV->getName());
-
- // Inherit const as appropriate.
- NewDGV->setConstant(SGV->isConstant());
+void ModuleLinker::upgradeMismatchedGlobalArray(StringRef Name) {
+ // Look for the global arrays.
+ auto *DstGV = dyn_cast_or_null<GlobalVariable>(DstM->getNamedValue(Name));
+ if (!DstGV)
+ return;
+ auto *SrcGV = dyn_cast_or_null<GlobalVariable>(SrcM->getNamedValue(Name));
+ if (!SrcGV)
+ return;
+
+ // Check if the types already match.
+ auto *DstTy = cast<ArrayType>(DstGV->getType()->getElementType());
+ auto *SrcTy =
+ cast<ArrayType>(TypeMap.get(SrcGV->getType()->getElementType()));
+ if (DstTy == SrcTy)
+ return;
+
+ // Grab the element types. We can only upgrade an array of a two-field
+ // struct. Only bother if the other one has three-fields.
+ auto *DstEltTy = cast<StructType>(DstTy->getElementType());
+ auto *SrcEltTy = cast<StructType>(SrcTy->getElementType());
+ if (DstEltTy->getNumElements() == 2 && SrcEltTy->getNumElements() == 3) {
+ upgradeGlobalArray(DstGV);
+ return;
+ }
+ if (DstEltTy->getNumElements() == 3 && SrcEltTy->getNumElements() == 2)
+ upgradeGlobalArray(SrcGV);
- // Make sure to remember this mapping.
- ValueMap[SGV] = NewDGV;
- continue;
- }
+ // We can't upgrade any other differences.
+}
- // Not "link from source", keep the one in the DestModule and remap the
- // input onto it.
-
- // Special case for const propagation.
- if (GlobalVariable *DGVar = dyn_cast<GlobalVariable>(DGV))
- if (DGVar->isDeclaration() && SGV->isConstant() && !DGVar->isConstant())
- DGVar->setConstant(true);
-
- // SGV is global, but DGV is alias.
- if (isa<GlobalAlias>(DGV)) {
- // The only valid mappings are:
- // - SGV is external declaration, which is effectively a no-op.
- // - SGV is weak, when we just need to throw SGV out.
- if (!SGV->isDeclaration() && !SGV->isWeakForLinker())
- return Error(Err, "Global-Alias Collision on '" + SGV->getName() +
- "': symbol multiple defined");
- }
+void ModuleLinker::upgradeMismatchedGlobals() {
+ upgradeMismatchedGlobalArray("llvm.global_ctors");
+ upgradeMismatchedGlobalArray("llvm.global_dtors");
+}
- // Set calculated linkage and unnamed_addr
- DGV->setLinkage(NewLinkage);
- DGV->setUnnamedAddr(HasUnnamedAddr);
+/// linkAppendingVarProto - If there were any appending global variables, link
+/// them together now. Return true on error.
+bool ModuleLinker::linkAppendingVarProto(GlobalVariable *DstGV,
+ GlobalVariable *SrcGV) {
+
+ if (!SrcGV->hasAppendingLinkage() || !DstGV->hasAppendingLinkage())
+ return emitError("Linking globals named '" + SrcGV->getName() +
+ "': can only link appending global with another appending global!");
+
+ ArrayType *DstTy = cast<ArrayType>(DstGV->getType()->getElementType());
+ ArrayType *SrcTy =
+ cast<ArrayType>(TypeMap.get(SrcGV->getType()->getElementType()));
+ Type *EltTy = DstTy->getElementType();
+
+ // Check to see that they two arrays agree on type.
+ if (EltTy != SrcTy->getElementType())
+ return emitError("Appending variables with different element types!");
+ if (DstGV->isConstant() != SrcGV->isConstant())
+ return emitError("Appending variables linked with different const'ness!");
+
+ if (DstGV->getAlignment() != SrcGV->getAlignment())
+ return emitError(
+ "Appending variables with different alignment need to be linked!");
+
+ if (DstGV->getVisibility() != SrcGV->getVisibility())
+ return emitError(
+ "Appending variables with different visibility need to be linked!");
+
+ if (DstGV->hasUnnamedAddr() != SrcGV->hasUnnamedAddr())
+ return emitError(
+ "Appending variables with different unnamed_addr need to be linked!");
+
+ if (StringRef(DstGV->getSection()) != SrcGV->getSection())
+ return emitError(
+ "Appending variables with different section name need to be linked!");
+
+ uint64_t NewSize = DstTy->getNumElements() + SrcTy->getNumElements();
+ ArrayType *NewType = ArrayType::get(EltTy, NewSize);
+
+ // Create the new global variable.
+ GlobalVariable *NG =
+ new GlobalVariable(*DstGV->getParent(), NewType, SrcGV->isConstant(),
+ DstGV->getLinkage(), /*init*/nullptr, /*name*/"", DstGV,
+ DstGV->getThreadLocalMode(),
+ DstGV->getType()->getAddressSpace());
+
+ // Propagate alignment, visibility and section info.
+ copyGVAttributes(NG, DstGV);
+
+ AppendingVarInfo AVI;
+ AVI.NewGV = NG;
+ AVI.DstInit = DstGV->getInitializer();
+ AVI.SrcInit = SrcGV->getInitializer();
+ AppendingVars.push_back(AVI);
+
+ // Replace any uses of the two global variables with uses of the new
+ // global.
+ ValueMap[SrcGV] = ConstantExpr::getBitCast(NG, TypeMap.get(SrcGV->getType()));
+
+ DstGV->replaceAllUsesWith(ConstantExpr::getBitCast(NG, DstGV->getType()));
+ DstGV->eraseFromParent();
+
+ // Track the source variable so we don't try to link it.
+ DoNotLinkFromSource.insert(SrcGV);
- // Make sure to remember this mapping...
- ValueMap[SGV] = ConstantExpr::getBitCast(DGV, SGV->getType());
- }
return false;
}
-static GlobalValue::LinkageTypes
-CalculateAliasLinkage(const GlobalValue *SGV, const GlobalValue *DGV) {
- GlobalValue::LinkageTypes SL = SGV->getLinkage();
- GlobalValue::LinkageTypes DL = DGV->getLinkage();
- if (SL == GlobalValue::ExternalLinkage || DL == GlobalValue::ExternalLinkage)
- return GlobalValue::ExternalLinkage;
- else if (SL == GlobalValue::WeakAnyLinkage ||
- DL == GlobalValue::WeakAnyLinkage)
- return GlobalValue::WeakAnyLinkage;
- else if (SL == GlobalValue::WeakODRLinkage ||
- DL == GlobalValue::WeakODRLinkage)
- return GlobalValue::WeakODRLinkage;
- else if (SL == GlobalValue::InternalLinkage &&
- DL == GlobalValue::InternalLinkage)
- return GlobalValue::InternalLinkage;
- else if (SL == GlobalValue::LinkerPrivateLinkage &&
- DL == GlobalValue::LinkerPrivateLinkage)
- return GlobalValue::LinkerPrivateLinkage;
- else if (SL == GlobalValue::LinkerPrivateWeakLinkage &&
- DL == GlobalValue::LinkerPrivateWeakLinkage)
- return GlobalValue::LinkerPrivateWeakLinkage;
- else if (SL == GlobalValue::LinkerPrivateWeakDefAutoLinkage &&
- DL == GlobalValue::LinkerPrivateWeakDefAutoLinkage)
- return GlobalValue::LinkerPrivateWeakDefAutoLinkage;
- else {
- assert (SL == GlobalValue::PrivateLinkage &&
- DL == GlobalValue::PrivateLinkage && "Unexpected linkage type");
- return GlobalValue::PrivateLinkage;
+/// linkGlobalProto - Loop through the global variables in the src module and
+/// merge them into the dest module.
+bool ModuleLinker::linkGlobalProto(GlobalVariable *SGV) {
+ GlobalValue *DGV = getLinkedToGlobal(SGV);
+ llvm::Optional<GlobalValue::VisibilityTypes> NewVisibility;
+ bool HasUnnamedAddr = SGV->hasUnnamedAddr();
+
+ bool LinkFromSrc = false;
+ Comdat *DC = nullptr;
+ if (const Comdat *SC = SGV->getComdat()) {
+ Comdat::SelectionKind SK;
+ std::tie(SK, LinkFromSrc) = ComdatsChosen[SC];
+ DC = DstM->getOrInsertComdat(SC->getName());
+ DC->setSelectionKind(SK);
}
-}
-// LinkAlias - Loop through the alias in the src module and link them into the
-// dest module. We're assuming, that all functions/global variables were already
-// linked in.
-static bool LinkAlias(Module *Dest, const Module *Src,
- ValueToValueMapTy &ValueMap,
- std::string *Err) {
- // Loop over all alias in the src module
- for (Module::const_alias_iterator I = Src->alias_begin(),
- E = Src->alias_end(); I != E; ++I) {
- const GlobalAlias *SGA = I;
- const GlobalValue *SAliasee = SGA->getAliasedGlobal();
- GlobalAlias *NewGA = NULL;
-
- // Globals were already linked, thus we can just query ValueMap for variant
- // of SAliasee in Dest.
- ValueToValueMapTy::const_iterator VMI = ValueMap.find(SAliasee);
- assert(VMI != ValueMap.end() && "Aliasee not linked");
- GlobalValue* DAliasee = cast<GlobalValue>(VMI->second);
- GlobalValue* DGV = NULL;
-
- // Fixup aliases to bitcasts. Note that aliases to GEPs are still broken
- // by this, but aliases to GEPs are broken to a lot of other things, so
- // it's less important.
- Constant *DAliaseeConst = DAliasee;
- if (SGA->getType() != DAliasee->getType())
- DAliaseeConst = ConstantExpr::getBitCast(DAliasee, SGA->getType());
-
- // Try to find something 'similar' to SGA in destination module.
- if (!DGV && !SGA->hasLocalLinkage()) {
- DGV = Dest->getNamedAlias(SGA->getName());
-
- // If types don't agree due to opaque types, try to resolve them.
- if (DGV && DGV->getType() != SGA->getType())
- RecursiveResolveTypes(SGA->getType(), DGV->getType());
+ if (DGV) {
+ if (!DC) {
+ // Concatenation of appending linkage variables is magic and handled later.
+ if (DGV->hasAppendingLinkage() || SGV->hasAppendingLinkage())
+ return linkAppendingVarProto(cast<GlobalVariable>(DGV), SGV);
+
+ // Determine whether linkage of these two globals follows the source
+ // module's definition or the destination module's definition.
+ GlobalValue::LinkageTypes NewLinkage = GlobalValue::InternalLinkage;
+ GlobalValue::VisibilityTypes NV;
+ if (getLinkageResult(DGV, SGV, NewLinkage, NV, LinkFromSrc))
+ return true;
+ NewVisibility = NV;
+ HasUnnamedAddr = HasUnnamedAddr && DGV->hasUnnamedAddr();
+
+ // If we're not linking from the source, then keep the definition that we
+ // have.
+ if (!LinkFromSrc) {
+ // Special case for const propagation.
+ if (GlobalVariable *DGVar = dyn_cast<GlobalVariable>(DGV))
+ if (DGVar->isDeclaration() && SGV->isConstant() &&
+ !DGVar->isConstant())
+ DGVar->setConstant(true);
+
+ // Set calculated linkage, visibility and unnamed_addr.
+ DGV->setLinkage(NewLinkage);
+ DGV->setVisibility(*NewVisibility);
+ DGV->setUnnamedAddr(HasUnnamedAddr);
+ }
}
- if (!DGV && !SGA->hasLocalLinkage()) {
- DGV = Dest->getGlobalVariable(SGA->getName());
+ if (!LinkFromSrc) {
+ // Make sure to remember this mapping.
+ ValueMap[SGV] = ConstantExpr::getBitCast(DGV,TypeMap.get(SGV->getType()));
+
+ // Track the source global so that we don't attempt to copy it over when
+ // processing global initializers.
+ DoNotLinkFromSource.insert(SGV);
- // If types don't agree due to opaque types, try to resolve them.
- if (DGV && DGV->getType() != SGA->getType())
- RecursiveResolveTypes(SGA->getType(), DGV->getType());
+ return false;
}
+ }
+
+ // If the Comdat this variable was inside of wasn't selected, skip it.
+ if (DC && !DGV && !LinkFromSrc) {
+ DoNotLinkFromSource.insert(SGV);
+ return false;
+ }
+
+ // No linking to be performed or linking from the source: simply create an
+ // identical version of the symbol over in the dest module... the
+ // initializer will be filled in later by LinkGlobalInits.
+ GlobalVariable *NewDGV =
+ new GlobalVariable(*DstM, TypeMap.get(SGV->getType()->getElementType()),
+ SGV->isConstant(), SGV->getLinkage(), /*init*/nullptr,
+ SGV->getName(), /*insertbefore*/nullptr,
+ SGV->getThreadLocalMode(),
+ SGV->getType()->getAddressSpace());
+ // Propagate alignment, visibility and section info.
+ copyGVAttributes(NewDGV, SGV);
+ if (NewVisibility)
+ NewDGV->setVisibility(*NewVisibility);
+ NewDGV->setUnnamedAddr(HasUnnamedAddr);
+
+ if (DC)
+ NewDGV->setComdat(DC);
+
+ if (DGV) {
+ DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewDGV, DGV->getType()));
+ DGV->eraseFromParent();
+ }
+
+ // Make sure to remember this mapping.
+ ValueMap[SGV] = NewDGV;
+ return false;
+}
- if (!DGV && !SGA->hasLocalLinkage()) {
- DGV = Dest->getFunction(SGA->getName());
+/// linkFunctionProto - Link the function in the source module into the
+/// destination module if needed, setting up mapping information.
+bool ModuleLinker::linkFunctionProto(Function *SF) {
+ GlobalValue *DGV = getLinkedToGlobal(SF);
+ llvm::Optional<GlobalValue::VisibilityTypes> NewVisibility;
+ bool HasUnnamedAddr = SF->hasUnnamedAddr();
+
+ bool LinkFromSrc = false;
+ Comdat *DC = nullptr;
+ if (const Comdat *SC = SF->getComdat()) {
+ Comdat::SelectionKind SK;
+ std::tie(SK, LinkFromSrc) = ComdatsChosen[SC];
+ DC = DstM->getOrInsertComdat(SC->getName());
+ DC->setSelectionKind(SK);
+ }
- // If types don't agree due to opaque types, try to resolve them.
- if (DGV && DGV->getType() != SGA->getType())
- RecursiveResolveTypes(SGA->getType(), DGV->getType());
+ if (DGV) {
+ if (!DC) {
+ GlobalValue::LinkageTypes NewLinkage = GlobalValue::InternalLinkage;
+ GlobalValue::VisibilityTypes NV;
+ if (getLinkageResult(DGV, SF, NewLinkage, NV, LinkFromSrc))
+ return true;
+ NewVisibility = NV;
+ HasUnnamedAddr = HasUnnamedAddr && DGV->hasUnnamedAddr();
+
+ if (!LinkFromSrc) {
+ // Set calculated linkage
+ DGV->setLinkage(NewLinkage);
+ DGV->setVisibility(*NewVisibility);
+ DGV->setUnnamedAddr(HasUnnamedAddr);
+ }
}
- // No linking to be performed on internal stuff.
- if (DGV && DGV->hasLocalLinkage())
- DGV = NULL;
-
- if (GlobalAlias *DGA = dyn_cast_or_null<GlobalAlias>(DGV)) {
- // Types are known to be the same, check whether aliasees equal. As
- // globals are already linked we just need query ValueMap to find the
- // mapping.
- if (DAliasee == DGA->getAliasedGlobal()) {
- // This is just two copies of the same alias. Propagate linkage, if
- // necessary.
- DGA->setLinkage(CalculateAliasLinkage(SGA, DGA));
-
- NewGA = DGA;
- // Proceed to 'common' steps
- } else
- return Error(Err, "Alias Collision on '" + SGA->getName()+
- "': aliases have different aliasees");
- } else if (GlobalVariable *DGVar = dyn_cast_or_null<GlobalVariable>(DGV)) {
- // The only allowed way is to link alias with external declaration or weak
- // symbol..
- if (DGVar->isDeclaration() || DGVar->isWeakForLinker()) {
- // But only if aliasee is global too...
- if (!isa<GlobalVariable>(DAliasee))
- return Error(Err, "Global-Alias Collision on '" + SGA->getName() +
- "': aliasee is not global variable");
-
- NewGA = new GlobalAlias(SGA->getType(), SGA->getLinkage(),
- SGA->getName(), DAliaseeConst, Dest);
- CopyGVAttributes(NewGA, SGA);
-
- // Any uses of DGV need to change to NewGA, with cast, if needed.
- if (SGA->getType() != DGVar->getType())
- DGVar->replaceAllUsesWith(ConstantExpr::getBitCast(NewGA,
- DGVar->getType()));
- else
- DGVar->replaceAllUsesWith(NewGA);
-
- // DGVar will conflict with NewGA because they both had the same
- // name. We must erase this now so ForceRenaming doesn't assert
- // because DGV might not have internal linkage.
- DGVar->eraseFromParent();
-
- // Proceed to 'common' steps
- } else
- return Error(Err, "Global-Alias Collision on '" + SGA->getName() +
- "': symbol multiple defined");
- } else if (Function *DF = dyn_cast_or_null<Function>(DGV)) {
- // The only allowed way is to link alias with external declaration or weak
- // symbol...
- if (DF->isDeclaration() || DF->isWeakForLinker()) {
- // But only if aliasee is function too...
- if (!isa<Function>(DAliasee))
- return Error(Err, "Function-Alias Collision on '" + SGA->getName() +
- "': aliasee is not function");
-
- NewGA = new GlobalAlias(SGA->getType(), SGA->getLinkage(),
- SGA->getName(), DAliaseeConst, Dest);
- CopyGVAttributes(NewGA, SGA);
-
- // Any uses of DF need to change to NewGA, with cast, if needed.
- if (SGA->getType() != DF->getType())
- DF->replaceAllUsesWith(ConstantExpr::getBitCast(NewGA,
- DF->getType()));
- else
- DF->replaceAllUsesWith(NewGA);
-
- // DF will conflict with NewGA because they both had the same
- // name. We must erase this now so ForceRenaming doesn't assert
- // because DF might not have internal linkage.
- DF->eraseFromParent();
-
- // Proceed to 'common' steps
- } else
- return Error(Err, "Function-Alias Collision on '" + SGA->getName() +
- "': symbol multiple defined");
- } else {
- // No linking to be performed, simply create an identical version of the
- // alias over in the dest module...
- NewGA = new GlobalAlias(SGA->getType(), SGA->getLinkage(),
- SGA->getName(), DAliaseeConst, Dest);
- CopyGVAttributes(NewGA, SGA);
+ if (!LinkFromSrc) {
+ // Make sure to remember this mapping.
+ ValueMap[SF] = ConstantExpr::getBitCast(DGV, TypeMap.get(SF->getType()));
+
+ // Track the function from the source module so we don't attempt to remap
+ // it.
+ DoNotLinkFromSource.insert(SF);
- // Proceed to 'common' steps
+ return false;
}
+ }
- assert(NewGA && "No alias was created in destination module!");
+ // If the function is to be lazily linked, don't create it just yet.
+ // The ValueMaterializerTy will deal with creating it if it's used.
+ if (!DGV && (SF->hasLocalLinkage() || SF->hasLinkOnceLinkage() ||
+ SF->hasAvailableExternallyLinkage())) {
+ DoNotLinkFromSource.insert(SF);
+ return false;
+ }
- // If the symbol table renamed the alias, but it is an externally visible
- // symbol, DGA must be an global value with internal linkage. Rename it.
- if (NewGA->getName() != SGA->getName() &&
- !NewGA->hasLocalLinkage())
- ForceRenaming(NewGA, SGA->getName());
+ // If the Comdat this function was inside of wasn't selected, skip it.
+ if (DC && !DGV && !LinkFromSrc) {
+ DoNotLinkFromSource.insert(SF);
+ return false;
+ }
- // Remember this mapping so uses in the source module get remapped
- // later by MapValue.
- ValueMap[SGA] = NewGA;
+ // If there is no linkage to be performed or we are linking from the source,
+ // bring SF over.
+ Function *NewDF = Function::Create(TypeMap.get(SF->getFunctionType()),
+ SF->getLinkage(), SF->getName(), DstM);
+ copyGVAttributes(NewDF, SF);
+ if (NewVisibility)
+ NewDF->setVisibility(*NewVisibility);
+ NewDF->setUnnamedAddr(HasUnnamedAddr);
+
+ if (DC)
+ NewDF->setComdat(DC);
+
+ if (DGV) {
+ // Any uses of DF need to change to NewDF, with cast.
+ DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewDF, DGV->getType()));
+ DGV->eraseFromParent();
}
+ ValueMap[SF] = NewDF;
return false;
}
+/// LinkAliasProto - Set up prototypes for any aliases that come over from the
+/// source module.
+bool ModuleLinker::linkAliasProto(GlobalAlias *SGA) {
+ GlobalValue *DGV = getLinkedToGlobal(SGA);
+ llvm::Optional<GlobalValue::VisibilityTypes> NewVisibility;
+ bool HasUnnamedAddr = SGA->hasUnnamedAddr();
+
+ bool LinkFromSrc = false;
+ Comdat *DC = nullptr;
+ if (const Comdat *SC = SGA->getComdat()) {
+ Comdat::SelectionKind SK;
+ std::tie(SK, LinkFromSrc) = ComdatsChosen[SC];
+ DC = DstM->getOrInsertComdat(SC->getName());
+ DC->setSelectionKind(SK);
+ }
-// LinkGlobalInits - Update the initializers in the Dest module now that all
-// globals that may be referenced are in Dest.
-static bool LinkGlobalInits(Module *Dest, const Module *Src,
- ValueToValueMapTy &ValueMap,
- std::string *Err) {
- // Loop over all of the globals in the src module, mapping them over as we go
- for (Module::const_global_iterator I = Src->global_begin(),
- E = Src->global_end(); I != E; ++I) {
- const GlobalVariable *SGV = I;
-
- if (SGV->hasInitializer()) { // Only process initialized GV's
- // Figure out what the initializer looks like in the dest module.
- Constant *SInit =
- cast<Constant>(MapValue(SGV->getInitializer(), ValueMap));
- // Grab destination global variable or alias.
- GlobalValue *DGV = cast<GlobalValue>(ValueMap[SGV]->stripPointerCasts());
-
- // If dest if global variable, check that initializers match.
- if (GlobalVariable *DGVar = dyn_cast<GlobalVariable>(DGV)) {
- if (DGVar->hasInitializer()) {
- if (SGV->hasExternalLinkage()) {
- if (DGVar->getInitializer() != SInit)
- return Error(Err, "Global Variable Collision on '" +
- SGV->getName() +
- "': global variables have different initializers");
- } else if (DGVar->isWeakForLinker()) {
- // Nothing is required, mapped values will take the new global
- // automatically.
- } else if (SGV->isWeakForLinker()) {
- // Nothing is required, mapped values will take the new global
- // automatically.
- } else if (DGVar->hasAppendingLinkage()) {
- llvm_unreachable("Appending linkage unimplemented!");
- } else {
- llvm_unreachable("Unknown linkage!");
- }
- } else {
- // Copy the initializer over now...
- DGVar->setInitializer(SInit);
- }
- } else {
- // Destination is alias, the only valid situation is when source is
- // weak. Also, note, that we already checked linkage in LinkGlobals(),
- // thus we assert here.
- // FIXME: Should we weaken this assumption, 'dereference' alias and
- // check for initializer of aliasee?
- assert(SGV->isWeakForLinker());
+ if (DGV) {
+ if (!DC) {
+ GlobalValue::LinkageTypes NewLinkage = GlobalValue::InternalLinkage;
+ GlobalValue::VisibilityTypes NV;
+ if (getLinkageResult(DGV, SGA, NewLinkage, NV, LinkFromSrc))
+ return true;
+ NewVisibility = NV;
+ HasUnnamedAddr = HasUnnamedAddr && DGV->hasUnnamedAddr();
+
+ if (!LinkFromSrc) {
+ // Set calculated linkage.
+ DGV->setLinkage(NewLinkage);
+ DGV->setVisibility(*NewVisibility);
+ DGV->setUnnamedAddr(HasUnnamedAddr);
}
}
+
+ if (!LinkFromSrc) {
+ // Make sure to remember this mapping.
+ ValueMap[SGA] = ConstantExpr::getBitCast(DGV,TypeMap.get(SGA->getType()));
+
+ // Track the alias from the source module so we don't attempt to remap it.
+ DoNotLinkFromSource.insert(SGA);
+
+ return false;
+ }
+ }
+
+ // If the Comdat this alias was inside of wasn't selected, skip it.
+ if (DC && !DGV && !LinkFromSrc) {
+ DoNotLinkFromSource.insert(SGA);
+ return false;
}
+
+ // If there is no linkage to be performed or we're linking from the source,
+ // bring over SGA.
+ auto *PTy = cast<PointerType>(TypeMap.get(SGA->getType()));
+ auto *NewDA =
+ GlobalAlias::create(PTy->getElementType(), PTy->getAddressSpace(),
+ SGA->getLinkage(), SGA->getName(), DstM);
+ copyGVAttributes(NewDA, SGA);
+ if (NewVisibility)
+ NewDA->setVisibility(*NewVisibility);
+ NewDA->setUnnamedAddr(HasUnnamedAddr);
+
+ if (DGV) {
+ // Any uses of DGV need to change to NewDA, with cast.
+ DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewDA, DGV->getType()));
+ DGV->eraseFromParent();
+ }
+
+ ValueMap[SGA] = NewDA;
return false;
}
-// LinkFunctionProtos - Link the functions together between the two modules,
-// without doing function bodies... this just adds external function prototypes
-// to the Dest function...
-//
-static bool LinkFunctionProtos(Module *Dest, const Module *Src,
- ValueToValueMapTy &ValueMap,
- std::string *Err) {
- ValueSymbolTable &DestSymTab = Dest->getValueSymbolTable();
-
- // Loop over all of the functions in the src module, mapping them over
- for (Module::const_iterator I = Src->begin(), E = Src->end(); I != E; ++I) {
- const Function *SF = I; // SrcFunction
- GlobalValue *DGV = 0;
-
- // Check to see if may have to link the function with the global, alias or
- // function.
- if (SF->hasName() && !SF->hasLocalLinkage())
- DGV = cast_or_null<GlobalValue>(DestSymTab.lookup(SF->getName()));
-
- // If we found a global with the same name in the dest module, but it has
- // internal linkage, we are really not doing any linkage here.
- if (DGV && DGV->hasLocalLinkage())
- DGV = 0;
-
- // If types don't agree due to opaque types, try to resolve them.
- if (DGV && DGV->getType() != SF->getType())
- RecursiveResolveTypes(SF->getType(), DGV->getType());
-
- GlobalValue::LinkageTypes NewLinkage = GlobalValue::InternalLinkage;
- bool LinkFromSrc = false;
- if (GetLinkageResult(DGV, SF, NewLinkage, LinkFromSrc, Err))
- return true;
+static void getArrayElements(Constant *C, SmallVectorImpl<Constant*> &Dest) {
+ unsigned NumElements = cast<ArrayType>(C->getType())->getNumElements();
- // If there is no linkage to be performed, just bring over SF without
- // modifying it.
- if (DGV == 0) {
- // Function does not already exist, simply insert an function signature
- // identical to SF into the dest module.
- Function *NewDF = Function::Create(SF->getFunctionType(),
- SF->getLinkage(),
- SF->getName(), Dest);
- CopyGVAttributes(NewDF, SF);
-
- // If the LLVM runtime renamed the function, but it is an externally
- // visible symbol, DF must be an existing function with internal linkage.
- // Rename it.
- if (!NewDF->hasLocalLinkage() && NewDF->getName() != SF->getName())
- ForceRenaming(NewDF, SF->getName());
-
- // ... and remember this mapping...
- ValueMap[SF] = NewDF;
- continue;
- }
+ for (unsigned i = 0; i != NumElements; ++i)
+ Dest.push_back(C->getAggregateElement(i));
+}
- // If the visibilities of the symbols disagree and the destination is a
- // prototype, take the visibility of its input.
- if (DGV->isDeclaration())
- DGV->setVisibility(SF->getVisibility());
-
- if (LinkFromSrc) {
- if (isa<GlobalAlias>(DGV))
- return Error(Err, "Function-Alias Collision on '" + SF->getName() +
- "': symbol multiple defined");
-
- // We have a definition of the same name but different type in the
- // source module. Copy the prototype to the destination and replace
- // uses of the destination's prototype with the new prototype.
- Function *NewDF = Function::Create(SF->getFunctionType(), NewLinkage,
- SF->getName(), Dest);
- CopyGVAttributes(NewDF, SF);
-
- // Any uses of DF need to change to NewDF, with cast
- DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewDF,
- DGV->getType()));
-
- // DF will conflict with NewDF because they both had the same. We must
- // erase this now so ForceRenaming doesn't assert because DF might
- // not have internal linkage.
- if (GlobalVariable *Var = dyn_cast<GlobalVariable>(DGV))
- Var->eraseFromParent();
- else
- cast<Function>(DGV)->eraseFromParent();
-
- // If the symbol table renamed the function, but it is an externally
- // visible symbol, DF must be an existing function with internal
- // linkage. Rename it.
- if (NewDF->getName() != SF->getName() && !NewDF->hasLocalLinkage())
- ForceRenaming(NewDF, SF->getName());
-
- // Remember this mapping so uses in the source module get remapped
- // later by MapValue.
- ValueMap[SF] = NewDF;
- continue;
- }
+void ModuleLinker::linkAppendingVarInit(const AppendingVarInfo &AVI) {
+ // Merge the initializer.
+ SmallVector<Constant *, 16> DstElements;
+ getArrayElements(AVI.DstInit, DstElements);
+
+ SmallVector<Constant *, 16> SrcElements;
+ getArrayElements(AVI.SrcInit, SrcElements);
- // Not "link from source", keep the one in the DestModule and remap the
- // input onto it.
+ ArrayType *NewType = cast<ArrayType>(AVI.NewGV->getType()->getElementType());
- if (isa<GlobalAlias>(DGV)) {
- // The only valid mappings are:
- // - SF is external declaration, which is effectively a no-op.
- // - SF is weak, when we just need to throw SF out.
- if (!SF->isDeclaration() && !SF->isWeakForLinker())
- return Error(Err, "Function-Alias Collision on '" + SF->getName() +
- "': symbol multiple defined");
+ StringRef Name = AVI.NewGV->getName();
+ bool IsNewStructor =
+ (Name == "llvm.global_ctors" || Name == "llvm.global_dtors") &&
+ cast<StructType>(NewType->getElementType())->getNumElements() == 3;
+
+ for (auto *V : SrcElements) {
+ if (IsNewStructor) {
+ Constant *Key = V->getAggregateElement(2);
+ if (DoNotLinkFromSource.count(Key))
+ continue;
}
+ DstElements.push_back(
+ MapValue(V, ValueMap, RF_None, &TypeMap, &ValMaterializer));
+ }
+ if (IsNewStructor) {
+ NewType = ArrayType::get(NewType->getElementType(), DstElements.size());
+ AVI.NewGV->mutateType(PointerType::get(NewType, 0));
+ }
- // Set calculated linkage
- DGV->setLinkage(NewLinkage);
+ AVI.NewGV->setInitializer(ConstantArray::get(NewType, DstElements));
+}
- // Make sure to remember this mapping.
- ValueMap[SF] = ConstantExpr::getBitCast(DGV, SF->getType());
+/// linkGlobalInits - Update the initializers in the Dest module now that all
+/// globals that may be referenced are in Dest.
+void ModuleLinker::linkGlobalInits() {
+ // Loop over all of the globals in the src module, mapping them over as we go
+ for (Module::const_global_iterator I = SrcM->global_begin(),
+ E = SrcM->global_end(); I != E; ++I) {
+
+ // Only process initialized GV's or ones not already in dest.
+ if (!I->hasInitializer() || DoNotLinkFromSource.count(I)) continue;
+
+ // Grab destination global variable.
+ GlobalVariable *DGV = cast<GlobalVariable>(ValueMap[I]);
+ // Figure out what the initializer looks like in the dest module.
+ DGV->setInitializer(MapValue(I->getInitializer(), ValueMap,
+ RF_None, &TypeMap, &ValMaterializer));
}
- return false;
}
-// LinkFunctionBody - Copy the source function over into the dest function and
-// fix up references to values. At this point we know that Dest is an external
-// function, and that Src is not.
-static bool LinkFunctionBody(Function *Dest, Function *Src,
- ValueToValueMapTy &ValueMap,
- std::string *Err) {
- assert(Src && Dest && Dest->isDeclaration() && !Src->isDeclaration());
+/// linkFunctionBody - Copy the source function over into the dest function and
+/// fix up references to values. At this point we know that Dest is an external
+/// function, and that Src is not.
+void ModuleLinker::linkFunctionBody(Function *Dst, Function *Src) {
+ assert(Src && Dst && Dst->isDeclaration() && !Src->isDeclaration());
// Go through and convert function arguments over, remembering the mapping.
- Function::arg_iterator DI = Dest->arg_begin();
+ Function::arg_iterator DI = Dst->arg_begin();
for (Function::arg_iterator I = Src->arg_begin(), E = Src->arg_end();
I != E; ++I, ++DI) {
- DI->setName(I->getName()); // Copy the name information over...
+ DI->setName(I->getName()); // Copy the name over.
- // Add a mapping to our local map
+ // Add a mapping to our mapping.
ValueMap[I] = DI;
}
- // Splice the body of the source function into the dest function.
- Dest->getBasicBlockList().splice(Dest->end(), Src->getBasicBlockList());
+ if (Mode == Linker::DestroySource) {
+ // Splice the body of the source function into the dest function.
+ Dst->getBasicBlockList().splice(Dst->end(), Src->getBasicBlockList());
- // At this point, all of the instructions and values of the function are now
- // copied over. The only problem is that they are still referencing values in
- // the Source function as operands. Loop through all of the operands of the
- // functions and patch them up to point to the local versions.
- for (Function::iterator BB = Dest->begin(), BE = Dest->end(); BB != BE; ++BB)
- for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
- RemapInstruction(I, ValueMap, RF_IgnoreMissingEntries);
+ // At this point, all of the instructions and values of the function are now
+ // copied over. The only problem is that they are still referencing values in
+ // the Source function as operands. Loop through all of the operands of the
+ // functions and patch them up to point to the local versions.
+ for (Function::iterator BB = Dst->begin(), BE = Dst->end(); BB != BE; ++BB)
+ for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
+ RemapInstruction(I, ValueMap, RF_IgnoreMissingEntries,
+ &TypeMap, &ValMaterializer);
+
+ } else {
+ // Clone the body of the function into the dest function.
+ SmallVector<ReturnInst*, 8> Returns; // Ignore returns.
+ CloneFunctionInto(Dst, Src, ValueMap, false, Returns, "", nullptr,
+ &TypeMap, &ValMaterializer);
+ }
// There is no need to map the arguments anymore.
for (Function::arg_iterator I = Src->arg_begin(), E = Src->arg_end();
I != E; ++I)
ValueMap.erase(I);
- return false;
}
+/// linkAliasBodies - Insert all of the aliases in Src into the Dest module.
+void ModuleLinker::linkAliasBodies() {
+ for (Module::alias_iterator I = SrcM->alias_begin(), E = SrcM->alias_end();
+ I != E; ++I) {
+ if (DoNotLinkFromSource.count(I))
+ continue;
+ if (Constant *Aliasee = I->getAliasee()) {
+ GlobalAlias *DA = cast<GlobalAlias>(ValueMap[I]);
+ Constant *Val =
+ MapValue(Aliasee, ValueMap, RF_None, &TypeMap, &ValMaterializer);
+ DA->setAliasee(Val);
+ }
+ }
+}
-// LinkFunctionBodies - Link in the function bodies that are defined in the
-// source module into the DestModule. This consists basically of copying the
-// function over and fixing up references to values.
-static bool LinkFunctionBodies(Module *Dest, Module *Src,
- ValueToValueMapTy &ValueMap,
- std::string *Err) {
+/// linkNamedMDNodes - Insert all of the named MDNodes in Src into the Dest
+/// module.
+void ModuleLinker::linkNamedMDNodes() {
+ const NamedMDNode *SrcModFlags = SrcM->getModuleFlagsMetadata();
+ for (Module::const_named_metadata_iterator I = SrcM->named_metadata_begin(),
+ E = SrcM->named_metadata_end(); I != E; ++I) {
+ // Don't link module flags here. Do them separately.
+ if (&*I == SrcModFlags) continue;
+ NamedMDNode *DestNMD = DstM->getOrInsertNamedMetadata(I->getName());
+ // Add Src elements into Dest node.
+ for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i)
+ DestNMD->addOperand(MapValue(I->getOperand(i), ValueMap,
+ RF_None, &TypeMap, &ValMaterializer));
+ }
+}
- // Loop over all of the functions in the src module, mapping them over as we
- // go
- for (Module::iterator SF = Src->begin(), E = Src->end(); SF != E; ++SF) {
- if (!SF->isDeclaration()) { // No body if function is external
- Function *DF = dyn_cast<Function>(ValueMap[SF]); // Destination function
+/// linkModuleFlagsMetadata - 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;
- // DF not external SF external?
- if (DF && DF->isDeclaration())
- // Only provide the function body if there isn't one already.
- if (LinkFunctionBody(DF, SF, ValueMap, Err))
- return true;
+ // 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*, MDNode*> Flags;
+ SmallSetVector<MDNode*, 16> Requirements;
+ for (unsigned I = 0, E = DstModFlags->getNumOperands(); I != E; ++I) {
+ MDNode *Op = DstModFlags->getOperand(I);
+ ConstantInt *Behavior = cast<ConstantInt>(Op->getOperand(0));
+ MDString *ID = cast<MDString>(Op->getOperand(1));
+
+ if (Behavior->getZExtValue() == Module::Require) {
+ Requirements.insert(cast<MDNode>(Op->getOperand(2)));
+ } else {
+ Flags[ID] = Op;
}
}
- return false;
-}
-// LinkAppendingVars - If there were any appending global variables, link them
-// together now. Return true on error.
-static bool LinkAppendingVars(Module *M,
- std::multimap<std::string, GlobalVariable *> &AppendingVars,
- std::string *ErrorMsg) {
- if (AppendingVars.empty()) return false; // Nothing to do.
-
- // Loop over the multimap of appending vars, processing any variables with the
- // same name, forming a new appending global variable with both of the
- // initializers merged together, then rewrite references to the old variables
- // and delete them.
- std::vector<Constant*> Inits;
- while (AppendingVars.size() > 1) {
- // Get the first two elements in the map...
- std::multimap<std::string,
- GlobalVariable*>::iterator Second = AppendingVars.begin(), First=Second++;
-
- // If the first two elements are for different names, there is no pair...
- // Otherwise there is a pair, so link them together...
- if (First->first == Second->first) {
- GlobalVariable *G1 = First->second, *G2 = Second->second;
- const ArrayType *T1 = cast<ArrayType>(G1->getType()->getElementType());
- const ArrayType *T2 = cast<ArrayType>(G2->getType()->getElementType());
-
- // Check to see that they two arrays agree on type...
- if (T1->getElementType() != T2->getElementType())
- return Error(ErrorMsg,
- "Appending variables with different element types need to be linked!");
- if (G1->isConstant() != G2->isConstant())
- return Error(ErrorMsg,
- "Appending variables linked with different const'ness!");
-
- if (G1->getAlignment() != G2->getAlignment())
- return Error(ErrorMsg,
- "Appending variables with different alignment need to be linked!");
-
- if (G1->getVisibility() != G2->getVisibility())
- return Error(ErrorMsg,
- "Appending variables with different visibility need to be linked!");
-
- if (G1->getSection() != G2->getSection())
- return Error(ErrorMsg,
- "Appending variables with different section name need to be linked!");
-
- unsigned NewSize = T1->getNumElements() + T2->getNumElements();
- ArrayType *NewType = ArrayType::get(T1->getElementType(),
- NewSize);
-
- G1->setName(""); // Clear G1's name in case of a conflict!
-
- // Create the new global variable...
- GlobalVariable *NG =
- new GlobalVariable(*M, NewType, G1->isConstant(), G1->getLinkage(),
- /*init*/0, First->first, 0, G1->isThreadLocal(),
- G1->getType()->getAddressSpace());
-
- // Propagate alignment, visibility and section info.
- CopyGVAttributes(NG, G1);
-
- // Merge the initializer...
- Inits.reserve(NewSize);
- if (ConstantArray *I = dyn_cast<ConstantArray>(G1->getInitializer())) {
- for (unsigned i = 0, e = T1->getNumElements(); i != e; ++i)
- Inits.push_back(I->getOperand(i));
- } else {
- assert(isa<ConstantAggregateZero>(G1->getInitializer()));
- Constant *CV = Constant::getNullValue(T1->getElementType());
- for (unsigned i = 0, e = T1->getNumElements(); i != e; ++i)
- Inits.push_back(CV);
+ // Merge in the flags from the source module, and also collect its set of
+ // requirements.
+ bool HasErr = false;
+ for (unsigned I = 0, E = SrcModFlags->getNumOperands(); I != E; ++I) {
+ MDNode *SrcOp = SrcModFlags->getOperand(I);
+ ConstantInt *SrcBehavior = cast<ConstantInt>(SrcOp->getOperand(0));
+ MDString *ID = cast<MDString>(SrcOp->getOperand(1));
+ MDNode *DstOp = 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] = SrcOp;
+ DstModFlags->addOperand(SrcOp);
+ continue;
+ }
+
+ // Otherwise, perform a merge.
+ ConstantInt *DstBehavior = cast<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)) {
+ HasErr |= emitError("linking module flags '" + ID->getString() +
+ "': IDs have conflicting override values");
}
- if (ConstantArray *I = dyn_cast<ConstantArray>(G2->getInitializer())) {
- for (unsigned i = 0, e = T2->getNumElements(); i != e; ++i)
- Inits.push_back(I->getOperand(i));
- } else {
- assert(isa<ConstantAggregateZero>(G2->getInitializer()));
- Constant *CV = Constant::getNullValue(T2->getElementType());
- for (unsigned i = 0, e = T2->getNumElements(); i != e; ++i)
- Inits.push_back(CV);
+ continue;
+ } else if (SrcBehaviorValue == Module::Override) {
+ // Update the destination flag to that of the source.
+ DstOp->replaceOperandWith(0, SrcBehavior);
+ DstOp->replaceOperandWith(2, SrcOp->getOperand(2));
+ continue;
+ }
+
+ // Diagnose inconsistent merge behavior types.
+ if (SrcBehaviorValue != DstBehaviorValue) {
+ HasErr |= emitError("linking module flags '" + ID->getString() +
+ "': IDs have conflicting behaviors");
+ continue;
+ }
+
+ // 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)) {
+ HasErr |= emitError("linking module flags '" + ID->getString() +
+ "': IDs have conflicting values");
}
- NG->setInitializer(ConstantArray::get(NewType, Inits));
- Inits.clear();
-
- // Replace any uses of the two global variables with uses of the new
- // global...
-
- // FIXME: This should rewrite simple/straight-forward uses such as
- // getelementptr instructions to not use the Cast!
- G1->replaceAllUsesWith(ConstantExpr::getBitCast(NG,
- G1->getType()));
- G2->replaceAllUsesWith(ConstantExpr::getBitCast(NG,
- G2->getType()));
-
- // Remove the two globals from the module now...
- M->getGlobalList().erase(G1);
- M->getGlobalList().erase(G2);
-
- // Put the new global into the AppendingVars map so that we can handle
- // linking of more than two vars...
- Second->second = NG;
+ continue;
+ }
+ case Module::Warning: {
+ // Emit a warning if the values differ.
+ if (SrcOp->getOperand(2) != DstOp->getOperand(2)) {
+ if (!SuppressWarnings) {
+ errs() << "WARNING: linking module flags '" << ID->getString()
+ << "': IDs have conflicting values";
+ }
+ }
+ continue;
+ }
+ case Module::Append: {
+ MDNode *DstValue = cast<MDNode>(DstOp->getOperand(2));
+ MDNode *SrcValue = cast<MDNode>(SrcOp->getOperand(2));
+ unsigned NumOps = DstValue->getNumOperands() + SrcValue->getNumOperands();
+ Value **VP, **Values = VP = new Value*[NumOps];
+ for (unsigned i = 0, e = DstValue->getNumOperands(); i != e; ++i, ++VP)
+ *VP = DstValue->getOperand(i);
+ for (unsigned i = 0, e = SrcValue->getNumOperands(); i != e; ++i, ++VP)
+ *VP = SrcValue->getOperand(i);
+ DstOp->replaceOperandWith(2, MDNode::get(DstM->getContext(),
+ ArrayRef<Value*>(Values,
+ NumOps)));
+ delete[] Values;
+ break;
+ }
+ case Module::AppendUnique: {
+ SmallSetVector<Value*, 16> Elts;
+ MDNode *DstValue = cast<MDNode>(DstOp->getOperand(2));
+ MDNode *SrcValue = cast<MDNode>(SrcOp->getOperand(2));
+ for (unsigned i = 0, e = DstValue->getNumOperands(); i != e; ++i)
+ Elts.insert(DstValue->getOperand(i));
+ for (unsigned i = 0, e = SrcValue->getNumOperands(); i != e; ++i)
+ Elts.insert(SrcValue->getOperand(i));
+ DstOp->replaceOperandWith(2, MDNode::get(DstM->getContext(),
+ ArrayRef<Value*>(Elts.begin(),
+ Elts.end())));
+ break;
+ }
}
- AppendingVars.erase(First);
}
- return false;
-}
+ // 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));
+ Value *ReqValue = Requirement->getOperand(1);
-static bool ResolveAliases(Module *Dest) {
- for (Module::alias_iterator I = Dest->alias_begin(), E = Dest->alias_end();
- I != E; ++I)
- // We can't sue resolveGlobalAlias here because we need to preserve
- // bitcasts and GEPs.
- if (const Constant *C = I->getAliasee()) {
- while (dyn_cast<GlobalAlias>(C))
- C = cast<GlobalAlias>(C)->getAliasee();
- const GlobalValue *GV = dyn_cast<GlobalValue>(C);
- if (C != I && !(GV && GV->isDeclaration()))
- I->replaceAllUsesWith(const_cast<Constant*>(C));
+ MDNode *Op = Flags[Flag];
+ if (!Op || Op->getOperand(2) != ReqValue) {
+ HasErr |= emitError("linking module flags '" + Flag->getString() +
+ "': does not have the required value");
+ continue;
}
+ }
- return false;
+ return HasErr;
}
-// LinkModules - This function links two modules together, with the resulting
-// left module modified to be the composite of the two input modules. If an
-// error occurs, true is returned and ErrorMsg (if not null) is set to indicate
-// the problem. Upon failure, the Dest module could be in a modified state, and
-// shouldn't be relied on to be consistent.
-bool
-Linker::LinkModules(Module *Dest, Module *Src, std::string *ErrorMsg) {
- assert(Dest != 0 && "Invalid Destination module");
- assert(Src != 0 && "Invalid Source Module");
-
- if (Dest->getDataLayout().empty()) {
- if (!Src->getDataLayout().empty()) {
- Dest->setDataLayout(Src->getDataLayout());
- } else {
- std::string DataLayout;
+bool ModuleLinker::run() {
+ assert(DstM && "Null destination module");
+ assert(SrcM && "Null source module");
- if (Dest->getEndianness() == Module::AnyEndianness) {
- if (Src->getEndianness() == Module::BigEndian)
- DataLayout.append("E");
- else if (Src->getEndianness() == Module::LittleEndian)
- DataLayout.append("e");
- }
+ // Inherit the target data from the source module if the destination module
+ // doesn't have one already.
+ if (!DstM->getDataLayout() && SrcM->getDataLayout())
+ DstM->setDataLayout(SrcM->getDataLayout());
- if (Dest->getPointerSize() == Module::AnyPointerSize) {
- if (Src->getPointerSize() == Module::Pointer64)
- DataLayout.append(DataLayout.length() == 0 ? "p:64:64" : "-p:64:64");
- else if (Src->getPointerSize() == Module::Pointer32)
- DataLayout.append(DataLayout.length() == 0 ? "p:32:32" : "-p:32:32");
- }
- Dest->setDataLayout(DataLayout);
+ // Copy the target triple from the source to dest if the dest's is empty.
+ if (DstM->getTargetTriple().empty() && !SrcM->getTargetTriple().empty())
+ DstM->setTargetTriple(SrcM->getTargetTriple());
+
+ if (SrcM->getDataLayout() && DstM->getDataLayout() &&
+ *SrcM->getDataLayout() != *DstM->getDataLayout()) {
+ if (!SuppressWarnings) {
+ errs() << "WARNING: 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 (Dest->getTargetTriple().empty() && !Src->getTargetTriple().empty())
- Dest->setTargetTriple(Src->getTargetTriple());
-
- if (!Src->getDataLayout().empty() && !Dest->getDataLayout().empty() &&
- Src->getDataLayout() != Dest->getDataLayout())
- errs() << "WARNING: Linking two modules of different data layouts!\n";
- if (!Src->getTargetTriple().empty() &&
- Dest->getTargetTriple() != Src->getTargetTriple()) {
- errs() << "WARNING: Linking two modules of different target triples: ";
- if (!Src->getModuleIdentifier().empty())
- errs() << Src->getModuleIdentifier() << ": ";
- errs() << "'" << Src->getTargetTriple() << "' and '"
- << Dest->getTargetTriple() << "'\n";
+ if (!SrcM->getTargetTriple().empty() &&
+ DstM->getTargetTriple() != SrcM->getTargetTriple()) {
+ if (!SuppressWarnings) {
+ errs() << "WARNING: Linking two modules of different target triples: "
+ << SrcM->getModuleIdentifier() << "' is '"
+ << SrcM->getTargetTriple() << "' whereas '"
+ << DstM->getModuleIdentifier() << "' is '"
+ << DstM->getTargetTriple() << "'\n";
+ }
}
// Append the module inline asm string.
- if (!Src->getModuleInlineAsm().empty()) {
- if (Dest->getModuleInlineAsm().empty())
- Dest->setModuleInlineAsm(Src->getModuleInlineAsm());
+ if (!SrcM->getModuleInlineAsm().empty()) {
+ if (DstM->getModuleInlineAsm().empty())
+ DstM->setModuleInlineAsm(SrcM->getModuleInlineAsm());
else
- Dest->setModuleInlineAsm(Dest->getModuleInlineAsm()+"\n"+
- Src->getModuleInlineAsm());
+ DstM->setModuleInlineAsm(DstM->getModuleInlineAsm()+"\n"+
+ SrcM->getModuleInlineAsm());
}
- // Update the destination module's dependent libraries list with the libraries
- // from the source module. There's no opportunity for duplicates here as the
- // Module ensures that duplicate insertions are discarded.
- for (Module::lib_iterator SI = Src->lib_begin(), SE = Src->lib_end();
- SI != SE; ++SI)
- Dest->addLibrary(*SI);
-
- // LinkTypes - Go through the symbol table of the Src module and see if any
- // types are named in the src module that are not named in the Dst module.
- // Make sure there are no type name conflicts.
- if (LinkTypes(Dest, Src, ErrorMsg))
- return true;
+ // Loop over all of the linked values to compute type mappings.
+ computeTypeMapping();
- // ValueMap - Mapping of values from what they used to be in Src, to what they
- // are now in Dest. 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;
-
- // AppendingVars - Keep track of global variables in the destination module
- // with appending linkage. After the module is linked together, they are
- // appended and the module is rewritten.
- std::multimap<std::string, GlobalVariable *> AppendingVars;
- for (Module::global_iterator I = Dest->global_begin(), E = Dest->global_end();
- I != E; ++I) {
- // Add all of the appending globals already in the Dest module to
- // AppendingVars.
- if (I->hasAppendingLinkage())
- AppendingVars.insert(std::make_pair(I->getName(), I));
+ ComdatsChosen.clear();
+ for (const StringMapEntry<llvm::Comdat> &SMEC : SrcM->getComdatSymbolTable()) {
+ const Comdat &C = SMEC.getValue();
+ if (ComdatsChosen.count(&C))
+ continue;
+ Comdat::SelectionKind SK;
+ bool LinkFromSrc;
+ if (getComdatResult(&C, SK, LinkFromSrc))
+ return true;
+ ComdatsChosen[&C] = std::make_pair(SK, LinkFromSrc);
}
- // Insert all of the globals in src into the Dest module... without linking
+ // Upgrade mismatched global arrays.
+ upgradeMismatchedGlobals();
+
+ // Insert all of the globals in src into the DstM module... without linking
// initializers (which could refer to functions not yet mapped over).
- if (LinkGlobals(Dest, Src, ValueMap, AppendingVars, ErrorMsg))
- return true;
+ for (Module::global_iterator I = SrcM->global_begin(),
+ E = SrcM->global_end(); I != E; ++I)
+ if (linkGlobalProto(I))
+ return true;
// Link the functions together between the two modules, without doing function
- // bodies... this just adds external function prototypes to the Dest
+ // bodies... this just adds external function prototypes to the DstM
// function... We do this so that when we begin processing function bodies,
// all of the global values that may be referenced are available in our
// ValueMap.
- if (LinkFunctionProtos(Dest, Src, ValueMap, ErrorMsg))
- return true;
+ for (Module::iterator I = SrcM->begin(), E = SrcM->end(); I != E; ++I)
+ if (linkFunctionProto(I))
+ return true;
- // If there were any alias, link them now. We really need to do this now,
- // because all of the aliases that may be referenced need to be available in
- // ValueMap
- if (LinkAlias(Dest, Src, ValueMap, ErrorMsg)) return true;
+ // If there were any aliases, link them now.
+ for (Module::alias_iterator I = SrcM->alias_begin(),
+ E = SrcM->alias_end(); I != E; ++I)
+ if (linkAliasProto(I))
+ return true;
- // Update the initializers in the Dest module now that all globals that may
- // be referenced are in Dest.
- if (LinkGlobalInits(Dest, Src, ValueMap, ErrorMsg)) return true;
+ for (unsigned i = 0, e = AppendingVars.size(); i != e; ++i)
+ linkAppendingVarInit(AppendingVars[i]);
- // Link in the function bodies that are defined in the source module into the
- // DestModule. This consists basically of copying the function over and
- // fixing up references to values.
- if (LinkFunctionBodies(Dest, Src, ValueMap, ErrorMsg)) return true;
+ // Link in the function bodies that are defined in the source module into
+ // DstM.
+ for (Module::iterator SF = SrcM->begin(), E = SrcM->end(); SF != E; ++SF) {
+ // Skip if not linking from source.
+ if (DoNotLinkFromSource.count(SF)) continue;
+
+ Function *DF = cast<Function>(ValueMap[SF]);
+ if (SF->hasPrefixData()) {
+ // Link in the prefix data.
+ DF->setPrefixData(MapValue(
+ SF->getPrefixData(), ValueMap, RF_None, &TypeMap, &ValMaterializer));
+ }
+
+ // Skip if no body (function is external) or materialize.
+ if (SF->isDeclaration()) {
+ if (!SF->isMaterializable())
+ continue;
+ if (SF->Materialize(&ErrorMsg))
+ return true;
+ }
- // If there were any appending global variables, link them together now.
- if (LinkAppendingVars(Dest, AppendingVars, ErrorMsg)) return true;
+ linkFunctionBody(DF, SF);
+ SF->Dematerialize();
+ }
- // Resolve all uses of aliases with aliasees
- if (ResolveAliases(Dest)) return true;
+ // Resolve all uses of aliases with aliasees.
+ linkAliasBodies();
- // Remap all of the named mdnoes in Src into the Dest module. We do this
+ // 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(Dest, Src, ValueMap);
+ linkNamedMDNodes();
+
+ // Merge the module flags into the DstM module.
+ if (linkModuleFlagsMetadata())
+ return true;
- // If the source library's module id is in the dependent library list of the
- // destination library, remove it since that module is now linked in.
- const std::string &modId = Src->getModuleIdentifier();
- if (!modId.empty())
- Dest->removeLibrary(sys::path::stem(modId));
+ // Update the initializers in the DstM module now that all globals that may
+ // be referenced are in DstM.
+ linkGlobalInits();
+
+ // Process vector of lazily linked in functions.
+ bool LinkedInAnyFunctions;
+ do {
+ LinkedInAnyFunctions = false;
+
+ for(std::vector<Function*>::iterator I = LazilyLinkFunctions.begin(),
+ E = LazilyLinkFunctions.end(); I != E; ++I) {
+ Function *SF = *I;
+ if (!SF)
+ continue;
+
+ Function *DF = cast<Function>(ValueMap[SF]);
+ if (SF->hasPrefixData()) {
+ // Link in the prefix data.
+ DF->setPrefixData(MapValue(SF->getPrefixData(),
+ ValueMap,
+ RF_None,
+ &TypeMap,
+ &ValMaterializer));
+ }
+
+ // Materialize if necessary.
+ if (SF->isDeclaration()) {
+ if (!SF->isMaterializable())
+ continue;
+ if (SF->Materialize(&ErrorMsg))
+ return true;
+ }
+
+ // Erase from vector *before* the function body is linked - linkFunctionBody could
+ // invalidate I.
+ LazilyLinkFunctions.erase(I);
+
+ // Link in function body.
+ linkFunctionBody(DF, SF);
+ SF->Dematerialize();
+
+ // Set flag to indicate we may have more functions to lazily link in
+ // since we linked in a function.
+ LinkedInAnyFunctions = true;
+ break;
+ }
+ } while (LinkedInAnyFunctions);
+
+ // Now that all of the types from the source are used, resolve any structs
+ // copied over to the dest that didn't exist there.
+ TypeMap.linkDefinedTypeBodies();
return false;
}
-// vim: sw=2
+Linker::Linker(Module *M, bool SuppressWarnings)
+ : Composite(M), SuppressWarnings(SuppressWarnings) {
+ TypeFinder StructTypes;
+ StructTypes.run(*M, true);
+ IdentifiedStructTypes.insert(StructTypes.begin(), StructTypes.end());
+}
+
+Linker::~Linker() {
+}
+
+void Linker::deleteModule() {
+ delete Composite;
+ Composite = nullptr;
+}
+
+bool Linker::linkInModule(Module *Src, unsigned Mode, std::string *ErrorMsg) {
+ ModuleLinker TheLinker(Composite, IdentifiedStructTypes, Src, Mode,
+ SuppressWarnings);
+ if (TheLinker.run()) {
+ if (ErrorMsg)
+ *ErrorMsg = TheLinker.ErrorMsg;
+ return true;
+ }
+ return false;
+}
+
+//===----------------------------------------------------------------------===//
+// LinkModules entrypoint.
+//===----------------------------------------------------------------------===//
+
+/// LinkModules - This function links two modules together, with the resulting
+/// Dest module modified to be the composite of the two input modules. If an
+/// error occurs, true is returned and ErrorMsg (if not null) is set to indicate
+/// the problem. Upon failure, the Dest module could be in a modified state,
+/// and shouldn't be relied on to be consistent.
+bool Linker::LinkModules(Module *Dest, Module *Src, unsigned Mode,
+ std::string *ErrorMsg) {
+ Linker L(Dest);
+ return L.linkInModule(Src, Mode, ErrorMsg);
+}
+
+//===----------------------------------------------------------------------===//
+// C API.
+//===----------------------------------------------------------------------===//
+
+LLVMBool LLVMLinkModules(LLVMModuleRef Dest, LLVMModuleRef Src,
+ LLVMLinkerMode Mode, char **OutMessages) {
+ std::string Messages;
+ LLVMBool Result = Linker::LinkModules(unwrap(Dest), unwrap(Src),
+ Mode, OutMessages? &Messages : nullptr);
+ if (OutMessages)
+ *OutMessages = strdup(Messages.c_str());
+ return Result;
+}
projects / oota-llvm.git / blobdiff