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//===---- CGBuiltin.cpp - Emit LLVM Code for builtins ---------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This contains code to emit Objective-C code as LLVM code.
//
//===----------------------------------------------------------------------===//
#include "CGObjCRuntime.h"
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
#include "clang/AST/ExprObjC.h"
#include "llvm/Constant.h"
#include "llvm/Function.h"
using namespace clang;
using namespace CodeGen;
/// Emits an instance of NSConstantString representing the object.
llvm::Value *CodeGenFunction::EmitObjCStringLiteral(const ObjCStringLiteral *E){
return CGM.getObjCRuntime()->GenerateConstantString(
E->getString()->getStrData(), E->getString()->getByteLength());
}
/// Emit a selector.
llvm::Value *CodeGenFunction::EmitObjCSelectorExpr(const ObjCSelectorExpr *E) {
// Untyped selector.
// Note that this implementation allows for non-constant strings to be passed
// as arguments to @selector(). Currently, the only thing preventing this
// behaviour is the type checking in the front end.
return CGM.getObjCRuntime()->GetSelector(Builder, E->getSelector());
}
llvm::Value *CodeGenFunction::EmitObjCMessageExpr(const ObjCMessageExpr *E) {
// Only the lookup mechanism and first two arguments of the method
// implementation vary between runtimes. We can get the receiver and
// arguments in generic code.
CGObjCRuntime *Runtime = CGM.getObjCRuntime();
const Expr *ReceiverExpr = E->getReceiver();
bool isSuperMessage = false;
// Find the receiver
llvm::Value *Receiver;
if (!ReceiverExpr) {
const char * classname = E->getClassName()->getName();
if (!strcmp(classname, "super")) {
classname = E->getMethodDecl()->getClassInterface()->getName();
}
llvm::Value *ClassName = CGM.GetAddrOfConstantString(classname);
ClassName = Builder.CreateStructGEP(ClassName, 0);
Receiver = Runtime->LookupClass(Builder, ClassName);
} else if (isa<PreDefinedExpr>(E->getReceiver())) {
assert(cast<PreDefinedExpr>(E->getReceiver())->getIdentType() ==
PreDefinedExpr::ObjCSuper);
isSuperMessage = true;
Receiver = LoadObjCSelf();
} else {
Receiver = EmitScalarExpr(E->getReceiver());
}
// Process the arguments
unsigned ArgC = E->getNumArgs();
llvm::SmallVector<llvm::Value*, 16> Args;
for (unsigned i = 0; i != ArgC; ++i) {
const Expr *ArgExpr = E->getArg(i);
QualType ArgTy = ArgExpr->getType();
if (!hasAggregateLLVMType(ArgTy)) {
// Scalar argument is passed by-value.
Args.push_back(EmitScalarExpr(ArgExpr));
} else if (ArgTy->isAnyComplexType()) {
// Make a temporary alloca to pass the argument.
llvm::Value *DestMem = CreateTempAlloca(ConvertType(ArgTy));
EmitComplexExprIntoAddr(ArgExpr, DestMem, false);
Args.push_back(DestMem);
} else {
llvm::Value *DestMem = CreateTempAlloca(ConvertType(ArgTy));
EmitAggExpr(ArgExpr, DestMem, false);
Args.push_back(DestMem);
}
}
if (isSuperMessage) {
// super is only valid in an Objective-C method
const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
const char *SuperClass =
OMD->getClassInterface()->getSuperClass()->getName();
return Runtime->GenerateMessageSendSuper(Builder, ConvertType(E->getType()),
Receiver, SuperClass,
Receiver, E->getSelector(),
&Args[0], Args.size());
}
return Runtime->GenerateMessageSend(Builder, ConvertType(E->getType()),
LoadObjCSelf(),
Receiver, E->getSelector(),
&Args[0], Args.size());
}
/// Generate an Objective-C method. An Objective-C method is a C function with
/// its pointer, name, and types registered in the class struture.
void CodeGenFunction::GenerateObjCMethod(const ObjCMethodDecl *OMD) {
llvm::SmallVector<const llvm::Type *, 16> ParamTypes;
for (unsigned i=0 ; i<OMD->param_size() ; i++) {
const llvm::Type *Ty = ConvertType(OMD->getParamDecl(i)->getType());
if (Ty->isFirstClassType())
ParamTypes.push_back(Ty);
else
ParamTypes.push_back(llvm::PointerType::getUnqual(Ty));
}
std::string CategoryName = "";
if (ObjCCategoryImplDecl *OCD =
dyn_cast<ObjCCategoryImplDecl>(OMD->getMethodContext())) {
CategoryName = OCD->getName();
}
const llvm::Type *ReturnTy =
CGM.getTypes().ConvertReturnType(OMD->getResultType());
CurFn = CGM.getObjCRuntime()->MethodPreamble(
OMD->getClassInterface()->getName(),
CategoryName,
OMD->getSelector().getName(),
ReturnTy,
llvm::PointerType::getUnqual(
llvm::Type::Int32Ty),
ParamTypes.begin(),
OMD->param_size(),
!OMD->isInstance(),
OMD->isVariadic());
llvm::BasicBlock *EntryBB = llvm::BasicBlock::Create("entry", CurFn);
// Create a marker to make it easy to insert allocas into the entryblock
// later. Don't create this with the builder, because we don't want it
// folded.
llvm::Value *Undef = llvm::UndefValue::get(llvm::Type::Int32Ty);
AllocaInsertPt = new llvm::BitCastInst(Undef, llvm::Type::Int32Ty, "allocapt",
EntryBB);
FnRetTy = OMD->getResultType();
CurFuncDecl = OMD;
Builder.SetInsertPoint(EntryBB);
// Emit allocs for param decls. Give the LLVM Argument nodes names.
llvm::Function::arg_iterator AI = CurFn->arg_begin();
if (hasAggregateLLVMType(OMD->getResultType())) {
++AI;
}
// Add implicit parameters to the decl map.
// TODO: Add something to AST to let the runtime specify the names and types
// of these.
llvm::Value *&SelfEntry = LocalDeclMap[OMD->getSelfDecl()];
const llvm::Type *IPTy = AI->getType();
llvm::Value *DeclPtr = new llvm::AllocaInst(IPTy, 0, AI->getName() +
".addr", AllocaInsertPt);
// Store the initial value into the alloca.
Builder.CreateStore(AI, DeclPtr);
SelfEntry = DeclPtr;
++AI;
llvm::Value *&CmdEntry = LocalDeclMap[OMD->getCmdDecl()];
IPTy = AI->getType();
DeclPtr = new llvm::AllocaInst(IPTy, 0, AI->getName() +
".addr", AllocaInsertPt);
// Store the initial value into the alloca.
Builder.CreateStore(AI, DeclPtr);
CmdEntry = DeclPtr;
for (unsigned i = 0, e = OMD->getNumParams(); i != e; ++i, ++AI) {
assert(AI != CurFn->arg_end() && "Argument mismatch!");
EmitParmDecl(*OMD->getParamDecl(i), AI);
}
GenerateFunction(OMD->getBody());
}
llvm::Value *CodeGenFunction::LoadObjCSelf(void)
{
if (const ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(CurFuncDecl)) {
ValueDecl *Decl = OMD->getSelfDecl();
llvm::Value *SelfPtr = LocalDeclMap[&(*(Decl))];
return Builder.CreateLoad(SelfPtr, "self");
}
return NULL;
}
CGObjCRuntime::~CGObjCRuntime() {}
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