llvm-project/clang/lib/CodeGen/CGObjC.cpp

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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/ASTContext.h"
#include "clang/AST/DeclObjC.h"
#include "clang/Basic/Diagnostic.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Target/TargetData.h"
using namespace clang;
using namespace CodeGen;
/// Emits an instance of NSConstantString representing the object.
llvm::Value *CodeGenFunction::EmitObjCStringLiteral(const ObjCStringLiteral *E) {
std::string String(E->getString()->getStrData(), E->getString()->getByteLength());
llvm::Constant *C = CGM.getObjCRuntime().GenerateConstantString(String);
// FIXME: This bitcast should just be made an invariant on the Runtime.
return llvm::ConstantExpr::getBitCast(C, ConvertType(E->getType()));
}
/// 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::EmitObjCProtocolExpr(const ObjCProtocolExpr *E) {
// FIXME: This should pass the Decl not the name.
return CGM.getObjCRuntime().GenerateProtocolRef(Builder, E->getProtocol());
}
RValue 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;
bool isClassMessage = false;
// Find the receiver
llvm::Value *Receiver;
if (!ReceiverExpr) {
const ObjCInterfaceDecl *OID = E->getClassInfo().first;
// Very special case, super send in class method. The receiver is
// self (the class object) and the send uses super semantics.
if (!OID) {
assert(!strcmp(E->getClassName()->getName(), "super") &&
"Unexpected missing class interface in message send.");
isSuperMessage = true;
Receiver = LoadObjCSelf();
} else {
Receiver = Runtime.GetClass(Builder, OID);
}
isClassMessage = true;
} else if (isa<ObjCSuperExpr>(E->getReceiver())) {
isSuperMessage = true;
Receiver = LoadObjCSelf();
} else {
Receiver = EmitScalarExpr(E->getReceiver());
}
CallArgList Args;
for (CallExpr::const_arg_iterator i = E->arg_begin(), e = E->arg_end();
i != e; ++i)
Args.push_back(std::make_pair(EmitAnyExprToTemp(*i), (*i)->getType()));
if (isSuperMessage) {
// super is only valid in an Objective-C method
const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
return Runtime.GenerateMessageSendSuper(*this, E->getType(),
E->getSelector(),
OMD->getClassInterface(),
Receiver,
isClassMessage,
Args);
}
return Runtime.GenerateMessageSend(*this, E->getType(), E->getSelector(),
Receiver, isClassMessage, Args);
}
/// StartObjCMethod - Begin emission of an ObjCMethod. This generates
/// the LLVM function and sets the other context used by
/// CodeGenFunction.
void CodeGenFunction::StartObjCMethod(const ObjCMethodDecl *OMD) {
FunctionArgList Args;
llvm::Function *Fn = CGM.getObjCRuntime().GenerateMethod(OMD);
CGM.SetMethodAttributes(OMD, Fn);
Args.push_back(std::make_pair(OMD->getSelfDecl(),
OMD->getSelfDecl()->getType()));
Args.push_back(std::make_pair(OMD->getCmdDecl(),
OMD->getCmdDecl()->getType()));
for (unsigned i = 0, e = OMD->getNumParams(); i != e; ++i) {
ParmVarDecl *IPD = OMD->getParamDecl(i);
Args.push_back(std::make_pair(IPD, IPD->getType()));
}
StartFunction(OMD, OMD->getResultType(), Fn, Args, OMD->getLocEnd());
}
/// 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) {
StartObjCMethod(OMD);
EmitStmt(OMD->getBody());
FinishFunction(cast<CompoundStmt>(OMD->getBody())->getRBracLoc());
}
// FIXME: I wasn't sure about the synthesis approach. If we end up
// generating an AST for the whole body we can just fall back to
// having a GenerateFunction which takes the body Stmt.
/// GenerateObjCGetter - Generate an Objective-C property getter
/// function. The given Decl must be either an ObjCCategoryImplDecl
/// or an ObjCImplementationDecl.
void CodeGenFunction::GenerateObjCGetter(const ObjCPropertyImplDecl *PID) {
ObjCIvarDecl *Ivar = PID->getPropertyIvarDecl();
const ObjCPropertyDecl *PD = PID->getPropertyDecl();
ObjCMethodDecl *OMD = PD->getGetterMethodDecl();
assert(OMD && "Invalid call to generate getter (empty method)");
// FIXME: This is rather murky, we create this here since they will
// not have been created by Sema for us.
OMD->createImplicitParams(getContext());
StartObjCMethod(OMD);
// Determine if we should use an objc_getProperty call for
// this. Non-atomic and properties with assign semantics are
// directly evaluated, and in gc-only mode we don't need it at all.
if (CGM.getLangOptions().getGCMode() != LangOptions::GCOnly &&
PD->getSetterKind() != ObjCPropertyDecl::Assign &&
!(PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_nonatomic)) {
llvm::Value *GetPropertyFn =
CGM.getObjCRuntime().GetPropertyGetFunction();
if (!GetPropertyFn) {
CGM.ErrorUnsupported(PID, "Obj-C getter requiring atomic copy");
FinishFunction();
return;
}
// Return (ivar-type) objc_getProperty((id) self, _cmd, offset, true).
// FIXME: Can't this be simpler? This might even be worse than the
// corresponding gcc code.
CodeGenTypes &Types = CGM.getTypes();
ValueDecl *Cmd = OMD->getCmdDecl();
llvm::Value *CmdVal = Builder.CreateLoad(LocalDeclMap[Cmd], "cmd");
QualType IdTy = getContext().getObjCIdType();
llvm::Value *SelfAsId =
Builder.CreateBitCast(LoadObjCSelf(), Types.ConvertType(IdTy));
llvm::Value *Offset = EmitIvarOffset(OMD->getClassInterface(), Ivar);
llvm::Value *True =
llvm::ConstantInt::get(Types.ConvertTypeForMem(getContext().BoolTy), 1);
CallArgList Args;
Args.push_back(std::make_pair(RValue::get(SelfAsId), IdTy));
Args.push_back(std::make_pair(RValue::get(CmdVal), Cmd->getType()));
Args.push_back(std::make_pair(RValue::get(Offset), getContext().LongTy));
Args.push_back(std::make_pair(RValue::get(True), getContext().BoolTy));
RValue RV = EmitCall(GetPropertyFn, PD->getType(), Args);
// We need to fix the type here. Ivars with copy & retain are
// always objects so we don't need to worry about complex or
// aggregates.
RV = RValue::get(Builder.CreateBitCast(RV.getScalarVal(),
Types.ConvertType(PD->getType())));
EmitReturnOfRValue(RV, PD->getType());
} else {
EmitReturnOfRValue(EmitLoadOfLValue(EmitLValueForIvar(LoadObjCSelf(),
Ivar, 0),
Ivar->getType()),
PD->getType());
}
FinishFunction();
}
/// GenerateObjCSetter - Generate an Objective-C property setter
/// function. The given Decl must be either an ObjCCategoryImplDecl
/// or an ObjCImplementationDecl.
void CodeGenFunction::GenerateObjCSetter(const ObjCPropertyImplDecl *PID) {
ObjCIvarDecl *Ivar = PID->getPropertyIvarDecl();
const ObjCPropertyDecl *PD = PID->getPropertyDecl();
ObjCMethodDecl *OMD = PD->getSetterMethodDecl();
assert(OMD && "Invalid call to generate setter (empty method)");
// FIXME: This is rather murky, we create this here since they will
// not have been created by Sema for us.
OMD->createImplicitParams(getContext());
StartObjCMethod(OMD);
bool IsCopy = PD->getSetterKind() == ObjCPropertyDecl::Copy;
bool IsAtomic =
!(PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_nonatomic);
// Determine if we should use an objc_setProperty call for
// this. Properties with 'copy' semantics always use it, as do
// non-atomic properties with 'release' semantics as long as we are
// not in gc-only mode.
if (IsCopy ||
(CGM.getLangOptions().getGCMode() != LangOptions::GCOnly &&
PD->getSetterKind() == ObjCPropertyDecl::Retain)) {
llvm::Value *SetPropertyFn =
CGM.getObjCRuntime().GetPropertySetFunction();
if (!SetPropertyFn) {
CGM.ErrorUnsupported(PID, "Obj-C getter requiring atomic copy");
FinishFunction();
return;
}
// Emit objc_setProperty((id) self, _cmd, offset, arg,
// <is-atomic>, <is-copy>).
// FIXME: Can't this be simpler? This might even be worse than the
// corresponding gcc code.
CodeGenTypes &Types = CGM.getTypes();
ValueDecl *Cmd = OMD->getCmdDecl();
llvm::Value *CmdVal = Builder.CreateLoad(LocalDeclMap[Cmd], "cmd");
QualType IdTy = getContext().getObjCIdType();
llvm::Value *SelfAsId =
Builder.CreateBitCast(LoadObjCSelf(), Types.ConvertType(IdTy));
llvm::Value *Offset = EmitIvarOffset(OMD->getClassInterface(), Ivar);
llvm::Value *Arg = LocalDeclMap[OMD->getParamDecl(0)];
llvm::Value *ArgAsId =
Builder.CreateBitCast(Builder.CreateLoad(Arg, "arg"),
Types.ConvertType(IdTy));
llvm::Value *True =
llvm::ConstantInt::get(Types.ConvertTypeForMem(getContext().BoolTy), 1);
llvm::Value *False =
llvm::ConstantInt::get(Types.ConvertTypeForMem(getContext().BoolTy), 0);
CallArgList Args;
Args.push_back(std::make_pair(RValue::get(SelfAsId), IdTy));
Args.push_back(std::make_pair(RValue::get(CmdVal), Cmd->getType()));
Args.push_back(std::make_pair(RValue::get(Offset), getContext().LongTy));
Args.push_back(std::make_pair(RValue::get(ArgAsId), IdTy));
Args.push_back(std::make_pair(RValue::get(IsAtomic ? True : False),
getContext().BoolTy));
Args.push_back(std::make_pair(RValue::get(IsCopy ? True : False),
getContext().BoolTy));
EmitCall(SetPropertyFn, PD->getType(), Args);
} else {
SourceLocation Loc = PD->getLocation();
ValueDecl *Self = OMD->getSelfDecl();
ObjCIvarDecl *Ivar = PID->getPropertyIvarDecl();
DeclRefExpr Base(Self, Self->getType(), Loc);
ParmVarDecl *ArgDecl = OMD->getParamDecl(0);
DeclRefExpr Arg(ArgDecl, ArgDecl->getType(), Loc);
ObjCIvarRefExpr IvarRef(Ivar, Ivar->getType(), Loc, &Base,
true, true);
BinaryOperator Assign(&IvarRef, &Arg, BinaryOperator::Assign,
Ivar->getType(), Loc);
EmitStmt(&Assign);
}
FinishFunction();
}
llvm::Value *CodeGenFunction::LoadObjCSelf() {
const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
return Builder.CreateLoad(LocalDeclMap[OMD->getSelfDecl()], "self");
}
RValue CodeGenFunction::EmitObjCPropertyGet(const ObjCPropertyRefExpr *E) {
// Determine getter selector.
Selector S;
if (E->getKind() == ObjCPropertyRefExpr::MethodRef) {
S = E->getGetterMethod()->getSelector();
} else {
S = E->getProperty()->getGetterName();
}
return CGM.getObjCRuntime().
GenerateMessageSend(*this, E->getType(), S,
EmitScalarExpr(E->getBase()),
false, CallArgList());
}
void CodeGenFunction::EmitObjCPropertySet(const ObjCPropertyRefExpr *E,
RValue Src) {
Selector S;
if (E->getKind() == ObjCPropertyRefExpr::MethodRef) {
ObjCMethodDecl *Setter = E->getSetterMethod();
if (Setter) {
S = Setter->getSelector();
} else {
// FIXME: This should be diagnosed by sema.
SourceRange Range = E->getSourceRange();
CGM.getDiags().Report(getContext().getFullLoc(E->getLocStart()),
diag::err_typecheck_assign_const, 0, 0,
&Range, 1);
return;
}
} else {
S = E->getProperty()->getSetterName();
}
CallArgList Args;
Args.push_back(std::make_pair(Src, E->getType()));
CGM.getObjCRuntime().GenerateMessageSend(*this, getContext().VoidTy, S,
EmitScalarExpr(E->getBase()),
false, Args);
}
void CodeGenFunction::EmitObjCForCollectionStmt(const ObjCForCollectionStmt &S)
{
llvm::Function *EnumerationMutationFn =
CGM.getObjCRuntime().EnumerationMutationFunction();
llvm::Value *DeclAddress;
QualType ElementTy;
if (!EnumerationMutationFn) {
CGM.ErrorUnsupported(&S, "Obj-C fast enumeration for this runtime");
return;
}
if (const DeclStmt *SD = dyn_cast<DeclStmt>(S.getElement())) {
EmitStmt(SD);
assert(HaveInsertPoint() && "DeclStmt destroyed insert point!");
const ScopedDecl* D = SD->getSolitaryDecl();
ElementTy = cast<ValueDecl>(D)->getType();
DeclAddress = LocalDeclMap[D];
} else {
ElementTy = cast<Expr>(S.getElement())->getType();
DeclAddress = 0;
}
// Fast enumeration state.
QualType StateTy = getContext().getObjCFastEnumerationStateType();
llvm::AllocaInst *StatePtr = CreateTempAlloca(ConvertType(StateTy),
"state.ptr");
StatePtr->setAlignment(getContext().getTypeAlign(StateTy) >> 3);
EmitMemSetToZero(StatePtr, StateTy);
// Number of elements in the items array.
static const unsigned NumItems = 16;
// Get selector
llvm::SmallVector<IdentifierInfo*, 3> II;
II.push_back(&CGM.getContext().Idents.get("countByEnumeratingWithState"));
II.push_back(&CGM.getContext().Idents.get("objects"));
II.push_back(&CGM.getContext().Idents.get("count"));
Selector FastEnumSel = CGM.getContext().Selectors.getSelector(II.size(),
&II[0]);
QualType ItemsTy =
getContext().getConstantArrayType(getContext().getObjCIdType(),
llvm::APInt(32, NumItems),
ArrayType::Normal, 0);
llvm::Value *ItemsPtr = CreateTempAlloca(ConvertType(ItemsTy), "items.ptr");
llvm::Value *Collection = EmitScalarExpr(S.getCollection());
CallArgList Args;
Args.push_back(std::make_pair(RValue::get(StatePtr),
getContext().getPointerType(StateTy)));
Args.push_back(std::make_pair(RValue::get(ItemsPtr),
getContext().getPointerType(ItemsTy)));
const llvm::Type *UnsignedLongLTy = ConvertType(getContext().UnsignedLongTy);
llvm::Constant *Count = llvm::ConstantInt::get(UnsignedLongLTy, NumItems);
Args.push_back(std::make_pair(RValue::get(Count),
getContext().UnsignedLongTy));
RValue CountRV =
CGM.getObjCRuntime().GenerateMessageSend(*this,
getContext().UnsignedLongTy,
FastEnumSel,
Collection, false, Args);
llvm::Value *LimitPtr = CreateTempAlloca(UnsignedLongLTy, "limit.ptr");
Builder.CreateStore(CountRV.getScalarVal(), LimitPtr);
llvm::BasicBlock *NoElements = createBasicBlock("noelements");
llvm::BasicBlock *SetStartMutations = createBasicBlock("setstartmutations");
llvm::Value *Limit = Builder.CreateLoad(LimitPtr);
llvm::Value *Zero = llvm::Constant::getNullValue(UnsignedLongLTy);
llvm::Value *IsZero = Builder.CreateICmpEQ(Limit, Zero, "iszero");
Builder.CreateCondBr(IsZero, NoElements, SetStartMutations);
EmitBlock(SetStartMutations);
llvm::Value *StartMutationsPtr =
CreateTempAlloca(UnsignedLongLTy);
llvm::Value *StateMutationsPtrPtr =
Builder.CreateStructGEP(StatePtr, 2, "mutationsptr.ptr");
llvm::Value *StateMutationsPtr = Builder.CreateLoad(StateMutationsPtrPtr,
"mutationsptr");
llvm::Value *StateMutations = Builder.CreateLoad(StateMutationsPtr,
"mutations");
Builder.CreateStore(StateMutations, StartMutationsPtr);
llvm::BasicBlock *LoopStart = createBasicBlock("loopstart");
EmitBlock(LoopStart);
llvm::Value *CounterPtr = CreateTempAlloca(UnsignedLongLTy, "counter.ptr");
Builder.CreateStore(Zero, CounterPtr);
llvm::BasicBlock *LoopBody = createBasicBlock("loopbody");
EmitBlock(LoopBody);
StateMutationsPtr = Builder.CreateLoad(StateMutationsPtrPtr, "mutationsptr");
StateMutations = Builder.CreateLoad(StateMutationsPtr, "statemutations");
llvm::Value *StartMutations = Builder.CreateLoad(StartMutationsPtr,
"mutations");
llvm::Value *MutationsEqual = Builder.CreateICmpEQ(StateMutations,
StartMutations,
"tobool");
llvm::BasicBlock *WasMutated = createBasicBlock("wasmutated");
llvm::BasicBlock *WasNotMutated = createBasicBlock("wasnotmutated");
Builder.CreateCondBr(MutationsEqual, WasNotMutated, WasMutated);
EmitBlock(WasMutated);
llvm::Value *V =
Builder.CreateBitCast(Collection,
ConvertType(getContext().getObjCIdType()),
"tmp");
Builder.CreateCall(EnumerationMutationFn, V);
EmitBlock(WasNotMutated);
llvm::Value *StateItemsPtr =
Builder.CreateStructGEP(StatePtr, 1, "stateitems.ptr");
llvm::Value *Counter = Builder.CreateLoad(CounterPtr, "counter");
llvm::Value *EnumStateItems = Builder.CreateLoad(StateItemsPtr,
"stateitems");
llvm::Value *CurrentItemPtr =
Builder.CreateGEP(EnumStateItems, Counter, "currentitem.ptr");
llvm::Value *CurrentItem = Builder.CreateLoad(CurrentItemPtr, "currentitem");
// Cast the item to the right type.
CurrentItem = Builder.CreateBitCast(CurrentItem,
ConvertType(ElementTy), "tmp");
if (!DeclAddress) {
LValue LV = EmitLValue(cast<Expr>(S.getElement()));
// Set the value to null.
Builder.CreateStore(CurrentItem, LV.getAddress());
} else
Builder.CreateStore(CurrentItem, DeclAddress);
// Increment the counter.
Counter = Builder.CreateAdd(Counter,
llvm::ConstantInt::get(UnsignedLongLTy, 1));
Builder.CreateStore(Counter, CounterPtr);
llvm::BasicBlock *LoopEnd = createBasicBlock("loopend");
llvm::BasicBlock *AfterBody = createBasicBlock("afterbody");
BreakContinueStack.push_back(BreakContinue(LoopEnd, AfterBody));
EmitStmt(S.getBody());
BreakContinueStack.pop_back();
EmitBlock(AfterBody);
llvm::BasicBlock *FetchMore = createBasicBlock("fetchmore");
llvm::Value *IsLess = Builder.CreateICmpULT(Counter, Limit, "isless");
Builder.CreateCondBr(IsLess, LoopBody, FetchMore);
// Fetch more elements.
EmitBlock(FetchMore);
CountRV =
CGM.getObjCRuntime().GenerateMessageSend(*this,
getContext().UnsignedLongTy,
FastEnumSel,
Collection, false, Args);
Builder.CreateStore(CountRV.getScalarVal(), LimitPtr);
Limit = Builder.CreateLoad(LimitPtr);
IsZero = Builder.CreateICmpEQ(Limit, Zero, "iszero");
Builder.CreateCondBr(IsZero, NoElements, LoopStart);
// No more elements.
EmitBlock(NoElements);
if (!DeclAddress) {
// If the element was not a declaration, set it to be null.
LValue LV = EmitLValue(cast<Expr>(S.getElement()));
// Set the value to null.
Builder.CreateStore(llvm::Constant::getNullValue(ConvertType(ElementTy)),
LV.getAddress());
}
EmitBlock(LoopEnd);
}
void CodeGenFunction::EmitObjCAtTryStmt(const ObjCAtTryStmt &S)
{
CGM.getObjCRuntime().EmitTryStmt(*this, S);
}
void CodeGenFunction::EmitObjCAtThrowStmt(const ObjCAtThrowStmt &S)
{
CGM.getObjCRuntime().EmitThrowStmt(*this, S);
}
void CodeGenFunction::EmitObjCAtSynchronizedStmt(
const ObjCAtSynchronizedStmt &S)
{
CGM.getObjCRuntime().EmitSynchronizedStmt(*this, S);
}
CGObjCRuntime::~CGObjCRuntime() {}