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-rw-r--r--lib/Linker/LinkModules.cpp1816
1 files changed, 742 insertions, 1074 deletions
diff --git a/lib/Linker/LinkModules.cpp b/lib/Linker/LinkModules.cpp
index f372db2403..d77062772e 100644
--- a/lib/Linker/LinkModules.cpp
+++ b/lib/Linker/LinkModules.cpp
@@ -9,337 +9,404 @@
//
// 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/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"
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;
-
- LinkerTypeMap(const LinkerTypeMap&); // DO NOT IMPLEMENT
- void operator=(const LinkerTypeMap&); // DO NOT IMPLEMENT
+class TypeMapTy : public ValueMapTypeRemapper {
+ /// MappedTypes - This is a mapping from a source type to a destination type
+ /// to use.
+ DenseMap<Type*, Type*> MappedTypes;
+
+ /// SpeculativeTypes - When checking to see if two subgraphs are isomorphic,
+ /// we speculatively add types to MappedTypes, but keep track of them here in
+ /// case we need to roll back.
+ SmallVector<Type*, 16> SpeculativeTypes;
+
+ /// DefinitionsToResolve - 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> DefinitionsToResolve;
public:
- LinkerTypeMap() {}
- ~LinkerTypeMap() {
- for (DenseMap<const Type*, PATypeHolder>::iterator I = TheMap.begin(),
- E = TheMap.end(); I != E; ++I)
- I->first->removeAbstractTypeUser(this);
- }
-
- /// 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;
- }
-
- /// 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;
- }
-
-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);
+
+ /// 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));}
+
+private:
+ Type *getImpl(Type *T);
+ /// remapType - Implement the ValueMapTypeRemapper interface.
+ Type *remapType(Type *SrcTy) {
+ return get(SrcTy);
}
+
+ bool areTypesIsomorphic(Type *DstTy, Type *SrcTy);
+};
+}
- /// 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);
+void TypeMapTy::addTypeMapping(Type *DstTy, Type *SrcTy) {
+ Type *&Entry = MappedTypes[SrcTy];
+ if (Entry) return;
+
+ if (DstTy == SrcTy) {
+ Entry = DstTy;
+ return;
}
-
- // for debugging...
- virtual void dump() const {
- dbgs() << "AbstractTypeSet!\n";
+
+ // 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();
}
-
-// 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);
-
- // 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;
-
- // 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())
- 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;
- }
- return false;
}
- case Type::StructTyID: {
- const StructType *DstST = cast<StructType>(DstTy);
- const StructType *SrcST = cast<StructType>(SrcTy);
- if (DstST->getNumContainedTypes() != SrcST->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;
+ }
- 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;
+ // Mapping a non-opaque source type to an opaque dest. Keep the dest, but
+ // fill it in later. This doesn't need to be speculative.
+ if (cast<StructType>(DstTy)->isOpaque()) {
+ Entry = DstTy;
+ DefinitionsToResolve.push_back(SSTy);
+ return true;
}
- 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);
+
+ // 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->isAnonymous() != SSTy->isAnonymous() ||
+ 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<ArrayType>(SrcTy)->getNumElements())
+ return false;
}
- 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);
+
+ 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;
+}
- // 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);
- }
+/// 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 DefinitionsToResolve vector.
+ while (!DefinitionsToResolve.empty()) {
+ StructType *SrcSTy = DefinitionsToResolve.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();
+ }
}
}
-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 (!DefinitionsToResolve.empty())
+ linkDefinedTypeBodies();
+ return Result;
+}
-// 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);
+/// 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)->isAnonymous()) {
+ // 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);
+ }
+
+ // 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: assert(0 && "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],
+ ArrayRef<Type*>(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())
+ return *Entry = STy;
+
+ // Otherwise we create a new type and resolve its body later. This will be
+ // resolved by the top level of get().
+ DefinitionsToResolve.push_back(STy);
+ return *Entry = StructType::createNamed(STy->getContext(), "");
+}
- // 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;
- }
- }
- // 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 implementation.
+//===----------------------------------------------------------------------===//
- return false;
+namespace {
+ /// ModuleLinker - This is an implementation class for the LinkModules
+ /// function, which is the entrypoint for this file.
+ class ModuleLinker {
+ Module *DstM, *SrcM;
+
+ TypeMapTy TypeMap;
+
+ /// 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;
+
+ public:
+ std::string ErrorMsg;
+
+ ModuleLinker(Module *dstM, Module *srcM) : DstM(dstM), SrcM(srcM) { }
+
+ bool run();
+
+ private:
+ /// emitError - Helper method for setting a message and returning an error
+ /// code.
+ bool emitError(const Twine &Message) {
+ ErrorMsg = Message.str();
+ return true;
+ }
+
+ /// getLinkageResult - This analyzes the two global values and determines
+ /// what the result will look like in the destination module.
+ bool getLinkageResult(GlobalValue *Dest, const GlobalValue *Src,
+ GlobalValue::LinkageTypes &LT, bool &LinkFromSrc);
+
+ /// getLinkedToGlobal - Given a global in the source module, return the
+ /// global in the destination module that is being linked to, if any.
+ GlobalValue *getLinkedToGlobal(GlobalValue *SrcGV) {
+ // If the source has no name it can't link. If it has local linkage,
+ // there is no name match-up going on.
+ if (!SrcGV->hasName() || SrcGV->hasLocalLinkage())
+ return 0;
+
+ // Otherwise see if we have a match in the destination module's symtab.
+ GlobalValue *DGV = DstM->getNamedValue(SrcGV->getName());
+ if (DGV == 0) return 0;
+
+ // If we found a global with the same name in the dest module, but it has
+ // internal linkage, we are really not doing any linkage here.
+ if (DGV->hasLocalLinkage())
+ return 0;
+
+ // Otherwise, we do in fact link to the destination global.
+ return DGV;
+ }
+
+ void computeTypeMapping();
+
+ bool linkAppendingVarProto(GlobalVariable *DstGV, GlobalVariable *SrcGV);
+ bool linkGlobalProto(GlobalVariable *SrcGV);
+ bool linkFunctionProto(Function *SrcF);
+ bool linkAliasProto(GlobalAlias *SrcA);
+
+ 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
}
@@ -352,30 +419,35 @@ static void CopyGVAttributes(GlobalValue *DestGV, const GlobalValue *SrcGV) {
unsigned Alignment = std::max(DestGV->getAlignment(), SrcGV->getAlignment());
DestGV->copyAttributesFrom(SrcGV);
DestGV->setAlignment(Alignment);
+
+ forceRenaming(DestGV, SrcGV->getName());
}
-/// GetLinkageResult - This analyzes the two global values and determines what
+/// 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 &LT, bool &LinkFromSrc,
- std::string *Err) {
- assert((!Dest || !Src->hasLocalLinkage()) &&
+bool ModuleLinker::getLinkageResult(GlobalValue *Dest, const GlobalValue *Src,
+ GlobalValue::LinkageTypes &LT,
+ bool &LinkFromSrc) {
+ assert(Dest && "Must have two globals being queried");
+ assert(!Src->hasLocalLinkage() &&
"If Src has internal linkage, Dest shouldn't be set!");
- if (!Dest) {
- // Linking something to nothing.
- LinkFromSrc = true;
- LT = Src->getLinkage();
- } else if (Src->isDeclaration()) {
+
+ // FIXME: GlobalAlias::isDeclaration is broken, should always be
+ // false.
+ bool SrcIsDeclaration = Src->isDeclaration() && !isa<GlobalAlias>(Src);
+ bool DestIsDeclaration = Dest->isDeclaration() && !isa<GlobalAlias>(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 (DestIsDeclaration) {
LinkFromSrc = true;
LT = Src->getLinkage();
}
@@ -387,16 +459,10 @@ static bool GetLinkageResult(GlobalValue *Dest, const GlobalValue *Src,
LinkFromSrc = false;
LT = Dest->getLinkage();
}
- } else if (Dest->isDeclaration() && !Dest->hasDLLImportLinkage()) {
+ } else if (DestIsDeclaration && !Dest->hasDLLImportLinkage()) {
// 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.
@@ -420,883 +486,485 @@ static bool GetLinkageResult(GlobalValue *Dest, const GlobalValue *Src,
LT = GlobalValue::ExternalLinkage;
}
} else {
- assert((Dest->hasExternalLinkage() ||
- Dest->hasDLLImportLinkage() ||
- Dest->hasDLLExportLinkage() ||
- Dest->hasExternalWeakLinkage()) &&
- (Src->hasExternalLinkage() ||
- Src->hasDLLImportLinkage() ||
- Src->hasDLLExportLinkage() ||
- Src->hasExternalWeakLinkage()) &&
+ assert((Dest->hasExternalLinkage() || Dest->hasDLLImportLinkage() ||
+ Dest->hasDLLExportLinkage() || Dest->hasExternalWeakLinkage()) &&
+ (Src->hasExternalLinkage() || Src->hasDLLImportLinkage() ||
+ Src->hasDLLExportLinkage() || Src->hasExternalWeakLinkage()) &&
"Unexpected linkage type!");
- return Error(Err, "Linking globals named '" + Src->getName() +
+ return emitError("Linking globals named '" + Src->getName() +
"': symbol multiply defined!");
}
// Check visibility
- if (Dest && Src->getVisibility() != Dest->getVisibility() &&
- !Src->isDeclaration() && !Dest->isDeclaration() &&
+ if (Src->getVisibility() != Dest->getVisibility() &&
+ !SrcIsDeclaration && !DestIsDeclaration &&
!Src->hasAvailableExternallyLinkage() &&
!Dest->hasAvailableExternallyLinkage())
- return Error(Err, "Linking globals named '" + Src->getName() +
+ return emitError("Linking globals named '" + Src->getName() +
"': symbols have different visibilities!");
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 == 0) 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());
}
+
+ // 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());
+ }
+
+ // Don't bother incorporating aliases, they aren't generally typed well.
+
+ // 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();
}
-// 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();
-
- // 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!");
+/// 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->getSection() != SrcGV->getSection())
+ return emitError(
+ "Appending variables with different section name need to be linked!");
+
+ uint64_t NewSize = DstTy->getNumElements() + SrcTy->getNumElements();
+ ArrayType *NewType = ArrayType::get(EltTy, NewSize);
+
+ // Create the new global variable.
+ GlobalVariable *NG =
+ new GlobalVariable(*DstGV->getParent(), NewType, SrcGV->isConstant(),
+ DstGV->getLinkage(), /*init*/0, /*name*/"", DstGV,
+ DstGV->isThreadLocal(),
+ DstGV->getType()->getAddressSpace());
+