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//===------- CGObjCEtoile.cpp - Emit LLVM Code from ASTs for a Module --------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This provides Objective-C code generation targetting the Etoile runtime.
//
//===----------------------------------------------------------------------===//
#include "CGObjCRuntime.h"
#include "llvm/Module.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/IRBuilder.h"
#include "llvm/ADT/SmallVector.h"
namespace {
class CGObjCEtoile : public clang::CodeGen::CGObjCRuntime {
private:
llvm::Module &TheModule;
const llvm::Type *SelectorTy;
const llvm::PointerType *PtrToInt8Ty;
const llvm::Type *IMPTy;
const llvm::Type *IntTy;
const llvm::Type *PtrTy;
const llvm::Type *LongTy;
const llvm::Type *PtrToIntTy;
const llvm::Type *IdTy;
const llvm::Type *CallTy;
const llvm::Type *SlotTy;
const llvm::Type *LookupFunctionTy;
public:
CGObjCEtoile(llvm::Module &Mp,
const llvm::Type *LLVMIntType,
const llvm::Type *LLVMLongType);
virtual llvm::Value *generateMessageSend(llvm::IRBuilder &Builder,
const llvm::Type *ReturnTy,
llvm::Value *Sender,
llvm::Value *Receiver,
llvm::Value *Selector,
llvm::Value** ArgV,
unsigned ArgC);
llvm::Value *getSelector(llvm::IRBuilder &Builder,
llvm::Value *SelName,
llvm::Value *SelTypes);
virtual llvm::Function *MethodPreamble(const llvm::Type *ReturnTy,
const llvm::Type *SelfTy,
const llvm::Type **ArgTy,
unsigned ArgC,
bool isVarArg);
};
} // end anonymous namespace
CGObjCEtoile::CGObjCEtoile(llvm::Module &M,
const llvm::Type *LLVMIntType,
const llvm::Type *LLVMLongType) :
TheModule(M),
IntTy(LLVMIntType),
LongTy(LLVMLongType)
{
// C string type. Used in lots of places.
PtrToInt8Ty =
llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
// Get the selector Type.
SelectorTy = llvm::Type::Int32Ty;
PtrToIntTy = llvm::PointerType::getUnqual(IntTy);
PtrTy = llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
// Object type
llvm::PATypeHolder OpaqueObjTy = llvm::OpaqueType::get();
llvm::Type *OpaqueIdTy = llvm::PointerType::getUnqual(OpaqueObjTy);
IdTy = llvm::StructType::get(OpaqueIdTy, NULL);
llvm::cast<llvm::OpaqueType>(OpaqueObjTy.get())->refineAbstractTypeTo(IdTy);
IdTy = llvm::cast<llvm::StructType>(OpaqueObjTy.get());
IdTy = llvm::PointerType::getUnqual(IdTy);
// Call structure type.
llvm::PATypeHolder OpaqueSlotTy = llvm::OpaqueType::get();
CallTy = llvm::StructType::get(
llvm::PointerType::getUnqual(OpaqueSlotTy),
SelectorTy,
IdTy,
NULL);
//CallTy = llvm::PointerType::getUnqual(CallTy);
// IMP type
std::vector<const llvm::Type*> IMPArgs;
IMPArgs.push_back(IdTy);
IMPArgs.push_back(llvm::PointerType::getUnqual(CallTy));
IMPTy = llvm::FunctionType::get(IdTy, IMPArgs, true);
// Slot type
SlotTy = llvm::StructType::get(IntTy,
IMPTy,
PtrToInt8Ty,
PtrToInt8Ty,
llvm::Type::Int32Ty,
NULL);
llvm::cast<llvm::OpaqueType>(
OpaqueSlotTy.get())->refineAbstractTypeTo(SlotTy);
SlotTy = llvm::PointerType::getUnqual(
llvm::cast<llvm::StructType>(OpaqueSlotTy.get()));
// Lookup function type
std::vector<const llvm::Type*> LookupFunctionArgs;
LookupFunctionArgs.push_back(llvm::PointerType::getUnqual(IdTy));
LookupFunctionArgs.push_back(IdTy);
LookupFunctionArgs.push_back(SelectorTy);
LookupFunctionArgs.push_back(IdTy);
LookupFunctionTy =
llvm::FunctionType::get(SlotTy, LookupFunctionArgs, false);
LookupFunctionTy = llvm::PointerType::getUnqual(LookupFunctionTy);
}
/// Looks up the selector for the specified name / type pair.
llvm::Value *CGObjCEtoile::getSelector(llvm::IRBuilder &Builder,
llvm::Value *SelName,
llvm::Value *SelTypes)
{
// Look up the selector.
if(SelTypes == 0) {
SelTypes = llvm::ConstantPointerNull::get(PtrToInt8Ty);
}
llvm::Constant *SelFunction =
TheModule.getOrInsertFunction("lookup_typed_selector",
SelectorTy,
PtrToInt8Ty,
PtrToInt8Ty,
NULL);
llvm::SmallVector<llvm::Value*, 2> Args;
Args.push_back(SelName);
Args.push_back(SelTypes);
return Builder.CreateCall(SelFunction, Args.begin(), Args.end());
}
static void SetField(llvm::IRBuilder &Builder, llvm::Value *Structure,
unsigned Index, llvm::Value *Value) {
llvm::Value *element_ptr = Builder.CreateStructGEP(Structure, Index);
Builder.CreateStore(Value, element_ptr);
}
// Generate code for a message send expression on the Etoile runtime.
// BIG FAT WARNING: Much of this code will need factoring out later.
llvm::Value *CGObjCEtoile::generateMessageSend(llvm::IRBuilder &Builder,
const llvm::Type *ReturnTy,
llvm::Value *Sender,
llvm::Value *Receiver,
llvm::Value *Selector,
llvm::Value** ArgV,
unsigned ArgC) {
// FIXME: Selectors should be statically cached, not looked up on every call.
llvm::Value *cmd = getSelector(Builder, Selector, 0);
// TODO: [Polymorphic] inline caching
// Get the lookup function for this object:
llvm::Value *ObjAddr = Builder.CreateBitCast(Receiver, PtrToInt8Ty);
llvm::Value *FunctionOffset = new llvm::GlobalVariable(llvm::Type::Int32Ty,
false,
llvm::GlobalValue::ExternalLinkage,
0,
"lookup_offset",
&TheModule);
FunctionOffset = Builder.CreateLoad(FunctionOffset);
llvm::Value *Tag = Builder.CreateGEP(ObjAddr, FunctionOffset);
llvm::Value *Lookup = Builder.CreateBitCast(Tag, LookupFunctionTy);
// TODO: Remove this when the caller is providing sensible sender info
if(Sender == 0) {
Sender = llvm::ConstantPointerNull::get((llvm::PointerType*)IdTy);
}
Receiver = Builder.CreateBitCast(Receiver, IdTy);
llvm::Value *ReceiverAddr = Builder.CreateAlloca(IdTy);
Builder.CreateStore(Receiver, ReceiverAddr);
// Look up the method implementation.
llvm::SmallVector<llvm::Value*, 4> LookupArgs;
LookupArgs.push_back(ReceiverAddr);
LookupArgs.push_back(Receiver);
LookupArgs.push_back(cmd);
LookupArgs.push_back(Sender);
llvm::Value *Slot = Builder.CreateCall(Lookup,
LookupArgs.begin(),
LookupArgs.end());
// Create the call structure
llvm::Value *Call = Builder.CreateAlloca(CallTy);
SetField(Builder, Call, 0, Slot);
SetField(Builder, Call, 1, cmd);
SetField(Builder, Call, 2, Sender);
// Get the IMP from the slot and call it
// TODO: Property load / store optimisations
llvm::Value *IMP = Builder.CreateStructGEP(Slot, 1);
// If the return type of the IMP is wrong, cast it so it isn't.
if(ReturnTy != IdTy) {
std::vector<const llvm::Type*> IMPArgs;
IMPArgs.push_back(IdTy);
IMPArgs.push_back(llvm::PointerType::getUnqual(CallTy));
llvm::Type *NewIMPTy = llvm::FunctionType::get(ReturnTy, IMPArgs, true);
IMP = Builder.CreateBitCast(IMP, llvm::PointerType::getUnqual(NewIMPTy));
}
llvm::SmallVector<llvm::Value*, 16> Args;
Args.push_back(Receiver);
Args.push_back(Call);
Args.insert(Args.end(), ArgV, ArgV+ArgC);
return Builder.CreateCall(IMP, Args.begin(), Args.end());
}
/// Generates an LLVM Function object corresponding to the Objective-C method,
/// including the implicit arguments.
llvm::Function *CGObjCEtoile::MethodPreamble(
const llvm::Type *ReturnTy,
const llvm::Type *SelfTy,
const llvm::Type **ArgTy,
unsigned ArgC,
bool isVarArg) {
std::vector<const llvm::Type*> Args;
//Args.push_back(SelfTy);
Args.push_back(IdTy);
Args.push_back(llvm::PointerType::getUnqual(CallTy));
for (unsigned i=0; i<ArgC ;
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