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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 "CGDebugInfo.h"
#include "CGObjCRuntime.h"
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
#include "TargetInfo.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/StmtObjC.h"
#include "clang/Basic/Diagnostic.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Target/TargetData.h"
#include "llvm/InlineAsm.h"
using namespace clang;
using namespace CodeGen;
typedef llvm::PointerIntPair<llvm::Value*,1,bool> TryEmitResult;
static TryEmitResult
tryEmitARCRetainScalarExpr(CodeGenFunction &CGF, const Expr *e);
/// Given the address of a variable of pointer type, find the correct
/// null to store into it.
static llvm::Constant *getNullForVariable(llvm::Value *addr) {
llvm::Type *type =
cast<llvm::PointerType>(addr->getType())->getElementType();
return llvm::ConstantPointerNull::get(cast<llvm::PointerType>(type));
}
/// Emits an instance of NSConstantString representing the object.
llvm::Value *CodeGenFunction::EmitObjCStringLiteral(const ObjCStringLiteral *E)
{
llvm::Constant *C =
CGM.getObjCRuntime().GenerateConstantString(E->getString());
// 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());
}
/// \brief Adjust the type of the result of an Objective-C message send
/// expression when the method has a related result type.
static RValue AdjustRelatedResultType(CodeGenFunction &CGF,
const Expr *E,
const ObjCMethodDecl *Method,
RValue Result) {
if (!Method)
return Result;
if (!Method->hasRelatedResultType() ||
CGF.getContext().hasSameType(E->getType(), Method->getResultType()) ||
!Result.isScalar())
return Result;
// We have applied a related result type. Cast the rvalue appropriately.
return RValue::get(CGF.Builder.CreateBitCast(Result.getScalarVal(),
CGF.ConvertType(E->getType())));
}
/// Decide whether to extend the lifetime of the receiver of a
/// returns-inner-pointer message.
static bool
shouldExtendReceiverForInnerPointerMessage(const ObjCMessageExpr *message) {
switch (message->getReceiverKind()) {
// For a normal instance message, we should extend unless the
// receiver is loaded from a variable with precise lifetime.
case ObjCMessageExpr::Instance: {
const Expr *receiver = message->getInstanceReceiver();
const ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(receiver);
if (!ice || ice->getCastKind() != CK_LValueToRValue) return true;
receiver = ice->getSubExpr()->IgnoreParens();
// Only __strong variables.
if (receiver->getType().getObjCLifetime() != Qualifiers::OCL_Strong)
return true;
// All ivars and fields have precise lifetime.
if (isa<MemberExpr>(receiver) || isa<ObjCIvarRefExpr>(receiver))
return false;
// Otherwise, check for variables.
const DeclRefExpr *declRef = dyn_cast<DeclRefExpr>(ice->getSubExpr());
if (!declRef) return true;
const VarDecl *var = dyn_cast<VarDecl>(declRef->getDecl());
if (!var) return true;
// All variables have precise lifetime except local variables with
// automatic storage duration that aren't specially marked.
return (var->hasLocalStorage() &&
!var->hasAttr<ObjCPreciseLifetimeAttr>());
}
case ObjCMessageExpr::Class:
case ObjCMessageExpr::SuperClass:
// It's never necessary for class objects.
return false;
case ObjCMessageExpr::SuperInstance:
// We generally assume that 'self' lives throughout a method call.
return false;
}
llvm_unreachable("invalid receiver kind");
}
RValue CodeGenFunction::EmitObjCMessageExpr(const ObjCMessageExpr *E,
ReturnValueSlot Return) {
// 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.
bool isDelegateInit = E->isDelegateInitCall();
const ObjCMethodDecl *method = E->getMethodDecl();
// We don't retain the receiver in delegate init calls, and this is
// safe because the receiver value is always loaded from 'self',
// which we zero out. We don't want to Block_copy block receivers,
// though.
bool retainSelf =
(!isDelegateInit &&
CGM.getLangOptions().ObjCAutoRefCount &&
method &&
method->hasAttr<NSConsumesSelfAttr>());
CGObjCRuntime &Runtime = CGM.getObjCRuntime();
bool isSuperMessage = false;
bool isClassMessage = false;
ObjCInterfaceDecl *OID = 0;
// Find the receiver
QualType ReceiverType;
llvm::Value *Receiver = 0;
switch (E->getReceiverKind()) {
case ObjCMessageExpr::Instance:
ReceiverType = E->getInstanceReceiver()->getType();
if (retainSelf) {
TryEmitResult ter = tryEmitARCRetainScalarExpr(*this,
E->getInstanceReceiver());
Receiver = ter.getPointer();
if (ter.getInt()) retainSelf = false;
} else
Receiver = EmitScalarExpr(E->getInstanceReceiver());
break;
case ObjCMessageExpr::Class: {
ReceiverType = E->getClassReceiver();
const ObjCObjectType *ObjTy = ReceiverType->getAs<ObjCObjectType>();
assert(ObjTy && "Invalid Objective-C class message send");
OID = ObjTy->getInterface();
assert(OID && "Invalid Objective-C class message send");
Receiver = Runtime.GetClass(Builder, OID);
isClassMessage = true;
break;
}
case ObjCMessageExpr::SuperInstance:
ReceiverType = E->getSuperType();
Receiver = LoadObjCSelf();
isSuperMessage = true;
break;
case ObjCMessageExpr::SuperClass:
ReceiverType = E->getSuperType();
Receiver = LoadObjCSelf();
isSuperMessage = true;
isClassMessage = true;
break;
}
if (retainSelf)
Receiver = EmitARCRetainNonBlock(Receiver);
// In ARC, we sometimes want to "extend the lifetime"
// (i.e. retain+autorelease) of receivers of returns-inner-pointer
// messages.
if (getLangOptions().ObjCAutoRefCount && method &&
method->hasAttr<ObjCReturnsInnerPointerAttr>() &&
shouldExtendReceiverForInnerPointerMessage(E))
Receiver = EmitARCRetainAutorelease(ReceiverType, Receiver);
QualType ResultType =
method ? method->getResultType() : E->getType();
CallArgList Args;
EmitCallArgs(Args, method, E->arg_begin(), E->arg_end());
// For delegate init calls in ARC, do an unsafe store of null into
// self. This represents the call taking direct ownership of that
// value. We have to do this after emitting the other call
// arguments because they might also reference self, but we don't
// have to worry about any of them modifying self because that would
// be an undefined read and write of an object in unordered
// expressions.
if (isDelegateInit) {
assert(getLangOptions().ObjCAutoRefCount &&
"delegate init calls should only be marked in ARC");
// Do an unsafe store of null into self.
llvm::Value *selfAddr =
LocalDeclMap[cast<ObjCMethodDecl>(CurCodeDecl)->getSelfDecl()];
assert(selfAddr && "no self entry for a delegate init call?");
Builder.CreateStore(getNullForVariable(selfAddr), selfAddr);
}
RValue result;
if (isSuperMessage) {
// super is only valid in an Objective-C method
const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
bool isCategoryImpl = isa<ObjCCategoryImplDecl>(OMD->getDeclContext());
result = Runtime.GenerateMessageSendSuper(*this, Return, ResultType,
E->getSelector(),
OMD->getClassInterface(),
isCategoryImpl,
Receiver,
isClassMessage,
Args,
method);
} else {
result = Runtime.GenerateMessageSend(*this, Return, ResultType,
E->getSelector(),
Receiver, Args, OID,
method);
}
// For delegate init calls in ARC, implicitly store the result of
// the call back into self. This takes ownership of the value.
if (isDelegateInit) {
llvm::Value *selfAddr =
LocalDeclMap[cast<ObjCMethodDecl>(CurCodeDecl)->getSelfDecl()];
llvm::Value *newSelf = result.getScalarVal();
// The delegate return type isn't necessarily a matching type; in
// fact, it's quite likely to be 'id'.
llvm::Type *selfTy =
cast<llvm::PointerType>(selfAddr->getType())->getElementType();
newSelf = Builder.CreateBitCast(newSelf, selfTy);
Builder.CreateStore(newSelf, selfAddr);
}
return AdjustRelatedResultType(*this, E, method, result);
}
namespace {
struct FinishARCDealloc : EHScopeStack::Cleanup {
void Emit(CodeGenFunction &CGF, Flags flags) {
const ObjCMethodDecl *method = cast<ObjCMethodDecl>(CGF.CurCodeDecl);
const ObjCImplDecl *impl = cast<ObjCImplDecl>(method->getDeclContext());
const ObjCInterfaceDecl *iface = impl->getClassInterface();
if (!iface->getSuperClass()) return;
bool isCategory = isa<ObjCCategoryImplDecl>(impl);
// Call [super dealloc] if we have a superclass.
llvm::Value *self = CGF.LoadObjCSelf();
CallArgList args;
CGF.CGM.getObjCRuntime().GenerateMessageSendSuper(CGF, ReturnValueSlot(),
CGF.getContext().VoidTy,
method->getSelector(),
iface,
isCategory,
self,
/*is class msg*/ false,
args,
method);
}
};
}
/// 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,
const ObjCContainerDecl *CD,
SourceLocation StartLoc) {
FunctionArgList args;
// Check if we should generate debug info for this method.
if (CGM.getModuleDebugInfo() && !OMD->hasAttr<NoDebugAttr>())
DebugInfo = CGM.getModuleDebugInfo();
llvm::Function *Fn = CGM.getObjCRuntime().GenerateMethod(OMD, CD);
const CGFunctionInfo &FI = CGM.getTypes().getFunctionInfo(OMD);
CGM.SetInternalFunctionAttributes(OMD, Fn, FI);
args.push_back(OMD->getSelfDecl());
args.push_back(OMD->getCmdDecl());
for (ObjCMethodDecl::param_const_iterator PI = OMD->param_begin(),
E = OMD->param_end(); PI != E; ++PI)
args.push_back(*PI);
CurGD = OMD;
StartFunction(OMD, OMD->getResultType(), Fn, FI, args, StartLoc);
// In ARC, certain methods get an extra cleanup.
if (CGM.getLangOptions().ObjCAutoRefCount &&
OMD->isInstanceMethod() &&
OMD->getSelector().isUnarySelector()) {
const IdentifierInfo *ident =
OMD->getSelector().getIdentifierInfoForSlot(0);
if (ident->isStr("dealloc"))
EHStack.pushCleanup<FinishARCDealloc>(getARCCleanupKind());
}
}
static llvm::Value *emitARCRetainLoadOfScalar(CodeGenFunction &CGF,
LValue lvalue, QualType type);
/// 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, OMD->getClassInterface(), OMD->getLocStart());
EmitStmt(OMD->getBody());
FinishFunction(OMD->getBodyRBrace());
}
/// emitStructGetterCall - Call the runtime function to load a property
/// into the return value slot.
static void emitStructGetterCall(CodeGenFunction &CGF, ObjCIvarDecl *ivar,
bool isAtomic, bool hasStrong) {
ASTContext &Context = CGF.getContext();
llvm::Value *src =
CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), CGF.LoadObjCSelf(),
ivar, 0).getAddress();
// objc_copyStruct (ReturnValue, &structIvar,
// sizeof (Type of Ivar), isAtomic, false);
CallArgList args;
llvm::Value *dest = CGF.Builder.CreateBitCast(CGF.ReturnValue, CGF.VoidPtrTy);
args.add(RValue::get(dest), Context.VoidPtrTy);
src = CGF.Builder.CreateBitCast(src, CGF.VoidPtrTy);
args.add(RValue::get(src), Context.VoidPtrTy);
CharUnits size = CGF.getContext().getTypeSizeInChars(ivar->getType());
args.add(RValue::get(CGF.CGM.getSize(size)), Context.getSizeType());
args.add(RValue::get(CGF.Builder.getInt1(isAtomic)), Context.BoolTy);
args.add(RValue::get(CGF.Builder.getInt1(hasStrong)), Context.BoolTy);
llvm::Value *fn = CGF.CGM.getObjCRuntime().GetGetStructFunction();
CGF.EmitCall(CGF.getTypes().getFunctionInfo(Context.VoidTy, args,
FunctionType::ExtInfo()),
fn, ReturnValueSlot(), args);
}
/// Determine whether the given architecture supports unaligned atomic
/// accesses. They don't have to be fast, just faster than a function
/// call and a mutex.
static bool hasUnalignedAtomics(llvm::Triple::ArchType arch) {
// FIXME: Allow unaligned atomic load/store on x86. (It is not
// currently supported by the backend.)
return 0;
}
/// Return the maximum size that permits atomic accesses for the given
/// architecture.
static CharUnits getMaxAtomicAccessSize(CodeGenModule &CGM,
llvm::Triple::ArchType arch) {
// ARM has 8-byte atomic accesses, but it's not clear whether we
// want to rely on them here.
// In the default case, just assume that any size up to a pointer is
// fine given adequate alignment.
return CharUnits::fromQuantity(CGM.PointerSizeInBytes);
}
namespace {
class PropertyImplStrategy {
public:
enum StrategyKind {
/// The 'native' strategy is to use the architecture's provided
/// reads and writes.
Native,
/// Use objc_setProperty and objc_getProperty.
GetSetProperty,
/// Use objc_setProperty for the setter, but use expression
/// evaluation for the getter.
SetPropertyAndExpressionGet,
/// Use objc_copyStruct.
CopyStruct,
/// The 'expression' strategy is to emit normal assignment or
/// lvalue-to-rvalue expressions.
Expression
};
StrategyKind getKind() const { return StrategyKind(Kind); }
bool hasStrongMember() const { return HasStrong; }
bool isAtomic() const { return IsAtomic; }
bool isCopy() const { return IsCopy; }
CharUnits getIvarSize() const { return IvarSize; }
CharUnits getIvarAlignment() const { return IvarAlignment; }
PropertyImplStrategy(CodeGenModule &CGM,
const ObjCPropertyImplDecl *propImpl);
private:
unsigned Kind : 8;
unsigned IsAtomic : 1;
unsigned IsCopy : 1;
unsigned HasStrong : 1;
CharUnits IvarSize;
CharUnits IvarAlignment;
};
}
/// Pick an implementation strategy for the the given property synthesis.
PropertyImplStrategy::PropertyImplStrategy(CodeGenModule &CGM,
const ObjCPropertyImplDecl *propImpl) {
const ObjCPropertyDecl *prop = propImpl->getPropertyDecl();
ObjCPropertyDecl::SetterKind setterKind = prop->getSetterKind();
IsCopy = (setterKind == ObjCPropertyDecl::Copy);
IsAtomic = prop->isAtomic();
HasStrong = false; // doesn't matter here.
// Evaluate the ivar's size and alignment.
ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
QualType ivarType = ivar->getType();
llvm::tie(IvarSize, IvarAlignment)
= CGM.getContext().getTypeInfoInChars(ivarType);
// If we have a copy property, we always have to use getProperty/setProperty.
// TODO: we could actually use setProperty and an expression for non-atomics.
if (IsCopy) {
Kind = GetSetProperty;
return;
}
// Handle retain.
if (setterKind == ObjCPropertyDecl::Retain) {
// In GC-only, there's nothing special that needs to be done.
if (CGM.getLangOptions().getGC() == LangOptions::GCOnly) {
// fallthrough
// In ARC, if the property is non-atomic, use expression emission,
// which translates to objc_storeStrong. This isn't required, but
// it's slightly nicer.
} else if (CGM.getLangOptions().ObjCAutoRefCount && !IsAtomic) {
Kind = Expression;
return;
// Otherwise, we need to at least use setProperty. However, if
// the property isn't atomic, we can use normal expression
// emission for the getter.
} else if (!IsAtomic) {
Kind = SetPropertyAndExpressionGet;
return;
// Otherwise, we have to use both setProperty and getProperty.
} else {
Kind = GetSetProperty;
return;
}
}
// If we're not atomic, just use expression accesses.
if (!IsAtomic) {
Kind = Expression;
return;
}
// Properties on bitfield ivars need to be emitted using expression
// accesses even if they're nominally atomic.
if (ivar->isBitField()) {
Kind = Expression;
return;
}
// GC-qualified or ARC-qualified ivars need to be emitted as
// expressions. This actually works out to being atomic anyway,
// except for ARC __strong, but that should trigger the above code.
if (ivarType.hasNonTrivialObjCLifetime() ||
(CGM.getLangOptions().getGC() &&
CGM.getContext().getObjCGCAttrKind(ivarType))) {
Kind = Expression;
return;
}
// Compute whether the ivar has strong members.
if (CGM.getLangOptions().getGC())
if (const RecordType *recordType = ivarType->getAs<RecordType>())
HasStrong = recordType->getDecl()->hasObjectMember();
// We can never access structs with object members with a native
// access, because we need to use write barriers. This is what
// objc_copyStruct is for.
if (HasStrong) {
Kind = CopyStruct;
return;
}
// Otherwise, this is target-dependent and based on the size and
// alignment of the ivar.
// If the size of the ivar is not a power of two, give up. We don't
// want to get into the business of doing compare-and-swaps.
if (!IvarSize.isPowerOfTwo()) {
Kind = CopyStruct;
return;
}
llvm::Triple::ArchType arch =
CGM.getContext().getTargetInfo().getTriple().getArch();
// Most architectures require memory to fit within a single cache
// line, so the alignment has to be at least the size of the access.
// Otherwise we have to grab a lock.
if (IvarAlignment < IvarSize && !hasUnalignedAtomics(arch)) {
Kind = CopyStruct;
return;
}
// If the ivar's size exceeds the architecture's maximum atomic
// access size, we have to use CopyStruct.
if (IvarSize > getMaxAtomicAccessSize(CGM, arch)) {
Kind = CopyStruct;
return;
}
// Otherwise, we can use native loads and stores.
Kind = Native;
}
/// GenerateObjCGetter - Generate an Objective-C property getter
/// function. The given Decl must be an ObjCImplementationDecl. @synthesize
/// is illegal within a category.
void CodeGenFunction::GenerateObjCGetter(ObjCImplementationDecl *IMP,
const ObjCPropertyImplDecl *PID) {
const ObjCPropertyDecl *PD = PID->getPropertyDecl();
ObjCMethodDecl *OMD = PD->getGetterMethodDecl();
assert(OMD && "Invalid call to generate getter (empty method)");
StartObjCMethod(OMD, IMP->getClassInterface(), PID->getLocStart());
generateObjCGetterBody(IMP, PID);
FinishFunction();
}
static bool hasTrivialGetExpr(const ObjCPropertyImplDecl *propImpl) {
const Expr *getter = propImpl->getGetterCXXConstructor();
if (!getter) return true;
// Sema only makes only of these when the ivar has a C++ class type,
// so the form is pretty constrained.
// If the property has a reference type, we might just be binding a
// reference, in which case the result will be a gl-value. We should
// treat this as a non-trivial operation.
if (getter->isGLValue())
return false;
// If we selected a trivial copy-constructor, we're okay.
if (const CXXConstructExpr *construct = dyn_cast<CXXConstructExpr>(getter))
return (construct->getConstructor()->isTrivial());
// The constructor might require cleanups (in which case it's never
// trivial).
assert(isa<ExprWithCleanups>(getter));
return false;
}
void
CodeGenFunction::generateObjCGetterBody(const ObjCImplementationDecl *classImpl,
const ObjCPropertyImplDecl *propImpl) {
// If there's a non-trivial 'get' expression, we just have to emit that.
if (!hasTrivialGetExpr(propImpl)) {
ReturnStmt ret(SourceLocation(), propImpl->getGetterCXXConstructor(),
/*nrvo*/ 0);
EmitReturnStmt(ret);
return;
}
const ObjCPropertyDecl *prop = propImpl->getPropertyDecl();
QualType propType = prop->getType();
ObjCMethodDecl *getterMethod = prop->getGetterMethodDecl();
ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
// Pick an implementation strategy.
PropertyImplStrategy strategy(CGM, propImpl);
switch (strategy.getKind()) {
case PropertyImplStrategy::Native: {
LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, 0);
// Currently, all atomic accesses have to be through integer
// types, so there's no point in trying to pick a prettier type.
llvm::Type *bitcastType =
llvm::Type::getIntNTy(getLLVMContext(),
getContext().toBits(strategy.getIvarSize()));
bitcastType = bitcastType->getPointerTo(); // addrspace 0 okay
// Perform an atomic load. This does not impose ordering constraints.
llvm::Value *ivarAddr = LV.getAddress();
ivarAddr = Builder.CreateBitCast(ivarAddr, bitcastType);
llvm::LoadInst *load = Builder.CreateLoad(ivarAddr, "load");
load->setAlignment(strategy.getIvarAlignment().getQuantity());
load->setAtomic(llvm::Unordered);
// Store that value into the return address. Doing this with a
// bitcast is likely to produce some pretty ugly IR, but it's not
// the *most* terrible thing in the world.
Builder.CreateStore(load, Builder.CreateBitCast(ReturnValue, bitcastType));
// Make sure we don't do an autorelease.
AutoreleaseResult = false;
return;
}
case PropertyImplStrategy::GetSetProperty: {
llvm::Value *getPropertyFn =
CGM.getObjCRuntime().GetPropertyGetFunction();
if (!getPropertyFn) {
CGM.ErrorUnsupported(propImpl, "Obj-C getter requiring atomic copy");
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.
llvm::Value *cmd =
Builder.CreateLoad(LocalDeclMap[getterMethod->getCmdDecl()], "cmd");
llvm::Value *self = Builder.CreateBitCast(LoadObjCSelf(), VoidPtrTy);
llvm::Value *ivarOffset =
EmitIvarOffset(classImpl->getClassInterface(), ivar);
CallArgList args;
args.add(RValue::get(self), getContext().getObjCIdType());
args.add(RValue::get(cmd), getContext().getObjCSelType());
args.add(RValue::get(ivarOffset), getContext().getPointerDiffType());
args.add(RValue::get(Builder.getInt1(strategy.isAtomic())),
getContext().BoolTy);
// FIXME: We shouldn't need to get the function info here, the
// runtime already should have computed it to build the function.
RValue RV = EmitCall(getTypes().getFunctionInfo(propType, args,
FunctionType::ExtInfo()),
getPropertyFn, ReturnValueSlot(), 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(),
getTypes().ConvertType(propType)));
EmitReturnOfRValue(RV, propType);
// objc_getProperty does an autorelease, so we should suppress ours.
AutoreleaseResult = false;
return;
}
case PropertyImplStrategy::CopyStruct:
emitStructGetterCall(*this, ivar, strategy.isAtomic(),
strategy.hasStrongMember());
return;
case PropertyImplStrategy::Expression:
case PropertyImplStrategy::SetPropertyAndExpressionGet: {
LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, 0);
QualType ivarType = ivar->getType();
if (ivarType->isAnyComplexType()) {
ComplexPairTy pair = LoadComplexFromAddr(LV.getAddress(),
LV.isVolatileQualified());
StoreComplexToAddr(pair, ReturnValue, LV.isVolatileQualified());
} else if (hasAggregateLLVMType(ivarType)) {
// The return value slot is guaranteed to not be aliased, but
// that's not necessarily the same as "on the stack", so
// we still potentially need objc_memmove_collectable.
EmitAggregateCopy(ReturnValue, LV.getAddress(), ivarType);
} else {
llvm::Value *value;
if (propType->isReferenceType()) {
value = LV.getAddress();
} else {
// We want to load and autoreleaseReturnValue ARC __weak ivars.
if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) {
value = emitARCRetainLoadOfScalar(*this, LV, ivarType);
// Otherwise we want to do a simple load, suppressing the
// final autorelease.
} else {
value = EmitLoadOfLValue(LV).getScalarVal();
AutoreleaseResult = false;
}
value = Builder.CreateBitCast(value, ConvertType(propType));
}
EmitReturnOfRValue(RValue::get(value), propType);
}
return;
}
}
llvm_unreachable("bad @property implementation strategy!");
}
/// emitStructSetterCall - Call the runtime function to store the value
/// from the first formal parameter into the given ivar.
static void emitStructSetterCall(CodeGenFunction &CGF, ObjCMethodDecl *OMD,
ObjCIvarDecl *ivar) {
// objc_copyStruct (&structIvar, &Arg,
// sizeof (struct something), true, false);
CallArgList args;
// The first argument is the address of the ivar.
llvm::Value *ivarAddr = CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(),
CGF.LoadObjCSelf(), ivar, 0)
.getAddress();
ivarAddr = CGF.Builder.CreateBitCast(ivarAddr, CGF.Int8PtrTy);
args.add(RValue::get(ivarAddr), CGF.getContext().VoidPtrTy);
// The second argument is the address of the parameter variable.
ParmVarDecl *argVar = *OMD->param_begin();
DeclRefExpr argRef(argVar, argVar->getType(), VK_LValue, SourceLocation());
llvm::Value *argAddr = CGF.EmitLValue(&argRef).getAddress();
argAddr = CGF.Builder.CreateBitCast(argAddr, CGF.Int8PtrTy);
args.add(RValue::get(argAddr), CGF.getContext().VoidPtrTy);
// The third argument is the sizeof the type.
llvm::Value *size =
CGF.CGM.getSize(CGF.getContext().getTypeSizeInChars(ivar->getType()));
args.add(RValue::get(size), CGF.getContext().getSizeType());
// The fourth argument is the 'isAtomic' flag.
args.add(RValue::get(CGF.Builder.getTrue()), CGF.getContext().BoolTy);
// The fifth argument is the 'hasStrong' flag.
// FIXME: should this really always be false?
args.add(RValue::get(CGF.Builder.getFalse()), CGF.getContext().BoolTy);
llvm::Value *copyStructFn = CGF.CGM.getObjCRuntime().GetSetStructFunction();
CGF.EmitCall(CGF.getTypes().getFunctionInfo(CGF.getContext().VoidTy, args,
FunctionType::ExtInfo()),
copyStructFn, ReturnValueSlot(), args);
}
static bool hasTrivialSetExpr(const ObjCPropertyImplDecl *PID) {
Expr *setter = PID->getSetterCXXAssignment();
if (!setter) return true;
// Sema only makes only of these when the ivar has a C++ class type,
// so the form is pretty constrained.
// An operator call is trivial if the function it calls is trivial.
// This also implies that there's nothing non-trivial going on with
// the arguments, because operator= can only be trivial if it's a
// synthesized assignment operator and therefore both parameters are
// references.
if (CallExpr *call = dyn_cast<CallExpr>(setter)) {
if (const FunctionDecl *callee
= dyn_cast_or_null<FunctionDecl>(call->getCalleeDecl()))
if (callee->isTrivial())
return true;
return false;
}
assert(isa<ExprWithCleanups>(setter));
return false;
}
void
CodeGenFunction::generateObjCSetterBody(const ObjCImplementationDecl *classImpl,
const ObjCPropertyImplDecl *propImpl) {
// Just use the setter expression if Sema gave us one and it's
// non-trivial. There's no way to do this atomically.
if (!hasTrivialSetExpr(propImpl)) {
EmitStmt(propImpl->getSetterCXXAssignment());
return;
}
const ObjCPropertyDecl *prop = propImpl->getPropertyDecl();
ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
ObjCMethodDecl *setterMethod = prop->getSetterMethodDecl();
PropertyImplStrategy strategy(CGM, propImpl);
switch (strategy.getKind()) {
case PropertyImplStrategy::Native: {
llvm::Value *argAddr = LocalDeclMap[*setterMethod->param_begin()];
LValue ivarLValue =
EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, /*quals*/ 0);
llvm::Value *ivarAddr = ivarLValue.getAddress();
// Currently, all atomic accesses have to be through integer
// types, so there's no point in trying to pick a prettier type.
llvm::Type *bitcastType =
llvm::Type::getIntNTy(getLLVMContext(),
getContext().toBits(strategy.getIvarSize()));
bitcastType = bitcastType->getPointerTo(); // addrspace 0 okay
// Cast both arguments to the chosen operation type.
argAddr = Builder.CreateBitCast(argAddr, bitcastType);
ivarAddr = Builder.CreateBitCast(ivarAddr, bitcastType);
// This bitcast load is likely to cause some nasty IR.
llvm::Value *load = Builder.CreateLoad(argAddr);
// Perform an atomic store. There are no memory ordering requirements.
llvm::StoreInst *store = Builder.CreateStore(load, ivarAddr);
store->setAlignment(strategy.getIvarAlignment().getQuantity());
store->setAtomic(llvm::Unordered);
return;
}
case PropertyImplStrategy::GetSetProperty:
case PropertyImplStrategy::SetPropertyAndExpressionGet: {
llvm::Value *setPropertyFn =
CGM.getObjCRuntime().GetPropertySetFunction();
if (!setPropertyFn) {
CGM.ErrorUnsupported(propImpl, "Obj-C setter requiring atomic copy");
return;
}
// Emit objc_setProperty((id) self, _cmd, offset, arg,
// <is-atomic>, <is-copy>).
llvm::Value *cmd =
Builder.CreateLoad(LocalDeclMap[setterMethod->getCmdDecl()]);
llvm::Value *self =
Builder.CreateBitCast(LoadObjCSelf(), VoidPtrTy);
llvm::Value *ivarOffset =
EmitIvarOffset(classImpl->getClassInterface(), ivar);
llvm::Value *arg = LocalDeclMap[*setterMethod->param_begin()];
arg = Builder.CreateBitCast(Builder.CreateLoad(arg, "arg"), VoidPtrTy);
CallArgList args;
args.add(RValue::get(self), getContext().getObjCIdType());
args.add(RValue::get(cmd), getContext().getObjCSelType());
args.add(RValue::get(ivarOffset), getContext().getPointerDiffType());
args.add(RValue::get(arg), getContext().getObjCIdType());
args.add(RValue::get(Builder.getInt1(strategy.isAtomic())),
getContext().BoolTy);
args.add(RValue::get(Builder.getInt1(strategy.isCopy())),
getContext().BoolTy);
// FIXME: We shouldn't need to get the function info here, the runtime
// already should have computed it to build the function.
EmitCall(getTypes().getFunctionInfo(getContext().VoidTy, args,
FunctionType::ExtInfo()),
setPropertyFn, ReturnValueSlot(), args);
return;
}
case PropertyImplStrategy::CopyStruct:
emitStructSetterCall(*this, setterMethod, ivar);
return;
case PropertyImplStrategy::Expression:
break;
}
// Otherwise, fake up some ASTs and emit a normal assignment.
ValueDecl *selfDecl = setterMethod->getSelfDecl();
DeclRefExpr self(selfDecl, selfDecl->getType(), VK_LValue, SourceLocation());
ImplicitCastExpr selfLoad(ImplicitCastExpr::OnStack,
selfDecl->getType(), CK_LValueToRValue, &self,
VK_RValue);
ObjCIvarRefExpr ivarRef(ivar, ivar->getType().getNonReferenceType(),
SourceLocation(), &selfLoad, true, true);
ParmVarDecl *argDecl = *setterMethod->param_begin();
QualType argType = argDecl->getType().getNonReferenceType();
DeclRefExpr arg(argDecl, argType, VK_LValue, SourceLocation());
ImplicitCastExpr argLoad(ImplicitCastExpr::OnStack,
argType.getUnqualifiedType(), CK_LValueToRValue,
&arg, VK_RValue);
// The property type can differ from the ivar type in some situations with
// Objective-C pointer types, we can always bit cast the RHS in these cases.
// The following absurdity is just to ensure well-formed IR.
CastKind argCK = CK_NoOp;
if (ivarRef.getType()->isObjCObjectPointerType()) {
if (argLoad.getType()->isObjCObjectPointerType())
argCK = CK_BitCast;
else if (argLoad.getType()->isBlockPointerType())
argCK = CK_BlockPointerToObjCPointerCast;
else
argCK = CK_CPointerToObjCPointerCast;
} else if (ivarRef.getType()->isBlockPointerType()) {
if (argLoad.getType()->isBlockPointerType())
argCK = CK_BitCast;
else
argCK = CK_AnyPointerToBlockPointerCast;
} else if (ivarRef.getType()->isPointerType()) {
argCK = CK_BitCast;
}
ImplicitCastExpr argCast(ImplicitCastExpr::OnStack,
ivarRef.getType(), argCK, &argLoad,
VK_RValue);
Expr *finalArg = &argLoad;
if (!getContext().hasSameUnqualifiedType(ivarRef.getType(),
argLoad.getType()))
finalArg = &argCast;
BinaryOperator assign(&ivarRef, finalArg, BO_Assign,
ivarRef.getType(), VK_RValue, OK_Ordinary,
SourceLocation());
EmitStmt(&assign);
}
/// GenerateObjCSetter - Generate an Objective-C property setter
/// function. The given Decl must be an ObjCImplementationDecl. @synthesize
/// is illegal within a category.
void CodeGenFunction::GenerateObjCSetter(ObjCImplementationDecl *IMP,
const ObjCPropertyImplDecl *PID) {
const ObjCPropertyDecl *PD = PID->getPropertyDecl();
ObjCMethodDecl *OMD = PD->getSetterMethodDecl();
assert(OMD && "Invalid call to generate setter (empty method)");
StartObjCMethod(OMD, IMP->getClassInterface(), PID->getLocStart());
generateObjCSetterBody(IMP, PID);
FinishFunction();
}
namespace {
struct DestroyIvar : EHScopeStack::Cleanup {
private:
llvm::Value *addr;
const ObjCIvarDecl *ivar;
CodeGenFunction::Destroyer &destroyer;
bool useEHCleanupForArray;
public:
DestroyIvar(llvm::Value *addr, const ObjCIvarDecl *ivar,
CodeGenFunction::Destroyer *destroyer,
bool useEHCleanupForArray)
: addr(addr), ivar(ivar), destroyer(*destroyer),
useEHCleanupForArray(useEHCleanupForArray) {}
void Emit(CodeGenFunction &CGF, Flags flags) {
LValue lvalue
= CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), addr, ivar, /*CVR*/ 0);
CGF.emitDestroy(lvalue.getAddress(), ivar->getType(), destroyer,
flags.isForNormalCleanup() && useEHCleanupForArray);
}
};
}
/// Like CodeGenFunction::destroyARCStrong, but do it with a call.
static void destroyARCStrongWithStore(CodeGenFunction &CGF,
llvm::Value *addr,
QualType type) {
llvm::Value *null = getNullForVariable(addr);
CGF.EmitARCStoreStrongCall(addr, null, /*ignored*/ true);
}
static void emitCXXDestructMethod(CodeGenFunction &CGF,
ObjCImplementationDecl *impl) {
CodeGenFunction::RunCleanupsScope scope(CGF);
llvm::Value *self = CGF.LoadObjCSelf();
const ObjCInterfaceDecl *iface = impl->getClassInterface();
for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin();
ivar; ivar = ivar->getNextIvar()) {
QualType type = ivar->getType();
// Check whether the ivar is a destructible type.
QualType::DestructionKind dtorKind = type.isDestructedType();
if (!dtorKind) continue;
CodeGenFunction::Destroyer *destroyer = 0;
// Use a call to objc_storeStrong to destroy strong ivars, for the
// general benefit of the tools.
if (dtorKind == QualType::DK_objc_strong_lifetime) {
destroyer = &destroyARCStrongWithStore;
// Otherwise use the default for the destruction kind.
} else {
destroyer = &CGF.getDestroyer(dtorKind);
}
CleanupKind cleanupKind = CGF.getCleanupKind(dtorKind);
CGF.EHStack.pushCleanup<DestroyIvar>(cleanupKind, self, ivar, destroyer,
cleanupKind & EHCleanup);
}
assert(scope.requiresCleanups() && "nothing to do in .cxx_destruct?");
}
void CodeGenFunction::GenerateObjCCtorDtorMethod(ObjCImplementationDecl *IMP,
ObjCMethodDecl *MD,
bool ctor) {
MD->createImplicitParams(CGM.getContext(), IMP->getClassInterface());
StartObjCMethod(MD, IMP->getClassInterface(), MD->getLocStart());
// Emit .cxx_construct.
if (ctor) {
// Suppress the final autorelease in ARC.
AutoreleaseResult = false;
SmallVector<CXXCtorInitializer *, 8> IvarInitializers;
for (ObjCImplementationDecl::init_const_iterator B = IMP->init_begin(),
E = IMP->init_end(); B != E; ++B) {
CXXCtorInitializer *IvarInit = (*B);
FieldDecl *Field = IvarInit->getAnyMember();
ObjCIvarDecl *Ivar = cast<ObjCIvarDecl>(Field);
LValue LV = EmitLValueForIvar(TypeOfSelfObject(),
LoadObjCSelf(), Ivar, 0);
EmitAggExpr(IvarInit->getInit(),
AggValueSlot::forLValue(LV, AggValueSlot::IsDestructed,
AggValueSlot::DoesNotNeedGCBarriers,
AggValueSlot::IsNotAliased));
}
// constructor returns 'self'.
CodeGenTypes &Types = CGM.getTypes();
QualType IdTy(CGM.getContext().getObjCIdType());
llvm::Value *SelfAsId =
Builder.CreateBitCast(LoadObjCSelf(), Types.ConvertType(IdTy));
EmitReturnOfRValue(RValue::get(SelfAsId), IdTy);
// Emit .cxx_destruct.
} else {
emitCXXDestructMethod(*this, IMP);
}
FinishFunction();
}
bool CodeGenFunction::IndirectObjCSetterArg(const CGFunctionInfo &FI) {
CGFunctionInfo::const_arg_iterator it = FI.arg_begin();
it++; it++;
const ABIArgInfo &AI = it->info;
// FIXME. Is this sufficient check?
return (AI.getKind() == ABIArgInfo::Indirect);
}
bool CodeGenFunction::IvarTypeWithAggrGCObjects(QualType Ty) {
if (CGM.getLangOptions().getGC() == LangOptions::NonGC)
return false;
if (const RecordType *FDTTy = Ty.getTypePtr()->getAs<RecordType>())
return FDTTy->getDecl()->hasObjectMember();
return false;
}
llvm::Value *CodeGenFunction::LoadObjCSelf() {
const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
return Builder.CreateLoad(LocalDeclMap[OMD->getSelfDecl()], "self");
}
QualType CodeGenFunction::TypeOfSelfObject() {
const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
ImplicitParamDecl *selfDecl = OMD->getSelfDecl();
const ObjCObjectPointerType *PTy = cast<ObjCObjectPointerType>(
getContext().getCanonicalType(selfDecl->getType()));
return PTy->getPointeeType();
}
void CodeGenFunction::EmitObjCForCollectionStmt(const ObjCForCollectionStmt &S){
llvm::Constant *EnumerationMutationFn =
CGM.getObjCRuntime().EnumerationMutationFunction();
if (!EnumerationMutationFn) {
CGM.ErrorUnsupported(&S, "Obj-C fast enumeration for this runtime");
return;
}
CGDebugInfo *DI = getDebugInfo();
if (DI)
DI->EmitLexicalBlockStart(Builder, S.getSourceRange().getBegin());
// The local variable comes into scope immediately.
AutoVarEmission variable = AutoVarEmission::invalid();
if (const DeclStmt *SD = dyn_cast<DeclStmt>(S.getElement()))
variable = EmitAutoVarAlloca(*cast<VarDecl>(SD->getSingleDecl()));
JumpDest LoopEnd = getJumpDestInCurrentScope("forcoll.end");
// Fast enumeration state.
QualType StateTy = CGM.getObjCFastEnumerationStateType();
llvm::Value *StatePtr = CreateMemTemp(StateTy, "state.ptr");
EmitNullInitialization(StatePtr, StateTy);
// Number of elements in the items array.
static const unsigned NumItems = 16;
// Fetch the countByEnumeratingWithState:objects:count: selector.
IdentifierInfo *II[] = {
&CGM.getContext().Idents.get("countByEnumeratingWithState"),
&CGM.getContext().Idents.get("objects"),
&CGM.getContext().Idents.get("count")
};
Selector FastEnumSel =
CGM.getContext().Selectors.getSelector(llvm::array_lengthof(II), &II[0]);
QualType ItemsTy =
getContext().getConstantArrayType(getContext().getObjCIdType(),
llvm::APInt(32, NumItems),
ArrayType::Normal, 0);
llvm::Value *ItemsPtr = CreateMemTemp(ItemsTy, "items.ptr");
// Emit the collection pointer. In ARC, we do a retain.
llvm::Value *Collection;
if (getLangOptions().ObjCAutoRefCount) {
Collection = EmitARCRetainScalarExpr(S.getCollection());
// Enter a cleanup to do the release.
EmitObjCConsumeObject(S.getCollection()->getType(), Collection);
} else {
Collection = EmitScalarExpr(S.getCollection());
}
// The 'continue' label needs to appear within the cleanup for the
// collection object.
JumpDest AfterBody = getJumpDestInCurrentScope("forcoll.next");
// Send it our message:
CallArgList Args;
// The first argument is a temporary of the enumeration-state type.
Args.add(RValue::get(StatePtr), getContext().getPointerType(StateTy));
// The second argument is a temporary array with space for NumItems
// pointers. We'll actually be loading elements from the array
// pointer written into the control state; this buffer is so that
// collections that *aren't* backed by arrays can still queue up
// batches of elements.
Args.add(RValue::get(ItemsPtr), getContext().getPointerType(ItemsTy));
// The third argument is the capacity of that temporary array.
llvm::Type *UnsignedLongLTy = ConvertType(getContext().UnsignedLongTy);
llvm::Constant *Count = llvm::ConstantInt::get(UnsignedLongLTy, NumItems);
Args.add(RValue::get(Count), getContext().UnsignedLongTy);
// Start the enumeration.
RValue CountRV =
CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(),
getContext().UnsignedLongTy,
FastEnumSel,
Collection, Args);
// The initial number of objects that were returned in the buffer.
llvm::Value *initialBufferLimit = CountRV.getScalarVal();
llvm::BasicBlock *EmptyBB = createBasicBlock("forcoll.empty");
llvm::BasicBlock *LoopInitBB = createBasicBlock("forcoll.loopinit");
llvm::Value *zero = llvm::Constant::getNullValue(UnsignedLongLTy);
// If the limit pointer was zero to begin with, the collection is
// empty; skip all this.
Builder.CreateCondBr(Builder.CreateICmpEQ(initialBufferLimit, zero, "iszero"),
EmptyBB, LoopInitBB);
// Otherwise, initialize the loop.
EmitBlock(LoopInitBB);
// Save the initial mutations value. This is the value at an
// address that was written into the state object by
// countByEnumeratingWithState:objects:count:.
llvm::Value *StateMutationsPtrPtr =
Builder.CreateStructGEP(StatePtr, 2, "mutationsptr.ptr");
llvm::Value *StateMutationsPtr = Builder.CreateLoad(StateMutationsPtrPtr,
"mutationsptr");
llvm::Value *initialMutations =
Builder.CreateLoad(StateMutationsPtr, "forcoll.initial-mutations");
// Start looping. This is the point we return to whenever we have a
// fresh, non-empty batch of objects.
llvm::BasicBlock *LoopBodyBB = createBasicBlock("forcoll.loopbody");
EmitBlock(LoopBodyBB);
// The current index into the buffer.
llvm::PHINode *index = Builder.CreatePHI(UnsignedLongLTy, 3, "forcoll.index");
index->addIncoming(zero, LoopInitBB);
// The current buffer size.
llvm::PHINode *count = Builder.CreatePHI(UnsignedLongLTy, 3, "forcoll.count");
count->addIncoming(initialBufferLimit, LoopInitBB);
// Check whether the mutations value has changed from where it was
// at start. StateMutationsPtr should actually be invariant between
// refreshes.
StateMutationsPtr = Builder.CreateLoad(StateMutationsPtrPtr, "mutationsptr");
llvm::Value *currentMutations
= Builder.CreateLoad(StateMutationsPtr, "statemutations");
llvm::BasicBlock *WasMutatedBB = createBasicBlock("forcoll.mutated");
llvm::BasicBlock *WasNotMutatedBB = createBasicBlock("forcoll.notmutated");
Builder.CreateCondBr(Builder.CreateICmpEQ(currentMutations, initialMutations),
WasNotMutatedBB, WasMutatedBB);
// If so, call the enumeration-mutation function.
EmitBlock(WasMutatedBB);
llvm::Value *V =
Builder.CreateBitCast(Collection,
ConvertType(getContext().getObjCIdType()));
CallArgList Args2;
Args2.add(RValue::get(V), getContext().getObjCIdType());
// FIXME: We shouldn't need to get the function info here, the runtime already
// should have computed it to build the function.
EmitCall(CGM.getTypes().getFunctionInfo(getContext().VoidTy, Args2,
FunctionType::ExtInfo()),
EnumerationMutationFn, ReturnValueSlot(), Args2);
// Otherwise, or if the mutation function returns, just continue.
EmitBlock(WasNotMutatedBB);
// Initialize the element variable.
RunCleanupsScope elementVariableScope(*this);
bool elementIsVariable;
LValue elementLValue;
QualType elementType;
if (const DeclStmt *SD = dyn_cast<DeclStmt>(S.getElement())) {
// Initialize the variable, in case it's a __block variable or something.
EmitAutoVarInit(variable);
const VarDecl* D = cast<VarDecl>(SD->getSingleDecl());
DeclRefExpr tempDRE(const_cast<VarDecl*>(D), D->getType(),
VK_LValue, SourceLocation());
elementLValue = EmitLValue(&tempDRE);
elementType = D->getType();
elementIsVariable = true;
if (D->isARCPseudoStrong())
elementLValue.getQuals().setObjCLifetime(Qualifiers::OCL_ExplicitNone);
} else {
elementLValue = LValue(); // suppress warning
elementType = cast<Expr>(S.getElement())->getType();
elementIsVariable = false;
}
llvm::Type *convertedElementType = ConvertType(elementType);
// Fetch the buffer out of the enumeration state.
// TODO: this pointer should actually be invariant between
// refreshes, which would help us do certain loop optimizations.
llvm::Value *StateItemsPtr =
Builder.CreateStructGEP(StatePtr, 1, "stateitems.ptr");
llvm::Value *EnumStateItems =
Builder.CreateLoad(StateItemsPtr, "stateitems");
// Fetch the value at the current index from the buffer.
llvm::Value *CurrentItemPtr =
Builder.CreateGEP(EnumStateItems, index, "currentitem.ptr");
llvm::Value *CurrentItem = Builder.CreateLoad(CurrentItemPtr);
// Cast that value to the right type.
CurrentItem = Builder.CreateBitCast(CurrentItem, convertedElementType,
"currentitem");
// Make sure we have an l-value. Yes, this gets evaluated every
// time through the loop.
if (!elementIsVariable) {
elementLValue = EmitLValue(cast<Expr>(S.getElement()));
EmitStoreThroughLValue(RValue::get(CurrentItem), elementLValue);
} else {
EmitScalarInit(CurrentItem, elementLValue);
}
// If we do have an element variable, this assignment is the end of
// its initialization.
if (elementIsVariable)
EmitAutoVarCleanups(variable);
// Perform the loop body, setting up break and continue labels.
BreakContinueStack.push_back(BreakContinue(LoopEnd, AfterBody));
{
RunCleanupsScope Scope(*this);
EmitStmt(S.getBody());
}
BreakContinueStack.pop_back();
// Destroy the element variable now.
elementVariableScope.ForceCleanup();
// Check whether there are more elements.
EmitBlock(AfterBody.getBlock());
llvm::BasicBlock *FetchMoreBB = createBasicBlock("forcoll.refetch");
// First we check in the local buffer.
llvm::Value *indexPlusOne
= Builder.CreateAdd(index, llvm::ConstantInt::get(UnsignedLongLTy, 1));
// If we haven't overrun the buffer yet, we can continue.
Builder.CreateCondBr(Builder.CreateICmpULT(indexPlusOne, count),
LoopBodyBB, FetchMoreBB);
index->addIncoming(indexPlusOne, AfterBody.getBlock());
count->addIncoming(count, AfterBody.getBlock());
// Otherwise, we have to fetch more elements.
EmitBlock(FetchMoreBB);
CountRV =
CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(),
getContext().UnsignedLongTy,
FastEnumSel,
Collection, Args);
// If we got a zero count, we're done.
llvm::Value *refetchCount = CountRV.getScalarVal();
// (note that the message send might split FetchMoreBB)
index->addIncoming(zero, Builder.GetInsertBlock());
count->addIncoming(refetchCount, Builder.GetInsertBlock());
Builder.CreateCondBr(Builder.CreateICmpEQ(refetchCount, zero),
EmptyBB, LoopBodyBB);
// No more elements.
EmitBlock(EmptyBB);
if (!elementIsVariable) {
// If the element was not a declaration, set it to be null.
llvm::Value *null = llvm::Constant::getNullValue(convertedElementType);
elementLValue = EmitLValue(cast<Expr>(S.getElement()));
EmitStoreThroughLValue(RValue::get(null), elementLValue);
}
if (DI)
DI->EmitLexicalBlockEnd(Builder, S.getSourceRange().getEnd());
// Leave the cleanup we entered in ARC.
if (getLangOptions().ObjCAutoRefCount)
PopCleanupBlock();
EmitBlock(LoopEnd.getBlock());
}
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);
}
/// Produce the code for a CK_ARCProduceObject. Just does a
/// primitive retain.
llvm::Value *CodeGenFunction::EmitObjCProduceObject(QualType type,
llvm::Value *value) {
return EmitARCRetain(type, value);
}
namespace {
struct CallObjCRelease : EHScopeStack::Cleanup {
CallObjCRelease(llvm::Value *object) : object(object) {}
llvm::Value *object;
void Emit(CodeGenFunction &CGF, Flags flags) {
CGF.EmitARCRelease(object, /*precise*/ true);
}
};
}
/// Produce the code for a CK_ARCConsumeObject. Does a primitive
/// release at the end of the full-expression.
llvm::Value *CodeGenFunction::EmitObjCConsumeObject(QualType type,
llvm::Value *object) {
// If we're in a conditional branch, we need to make the cleanup
// conditional.
pushFullExprCleanup<CallObjCRelease>(getARCCleanupKind(), object);
return object;
}
llvm::Value *CodeGenFunction::EmitObjCExtendObjectLifetime(QualType type,
llvm::Value *value) {
return EmitARCRetainAutorelease(type, value);
}
static llvm::Constant *createARCRuntimeFunction(CodeGenModule &CGM,
llvm::FunctionType *type,
StringRef fnName) {
llvm::Constant *fn = CGM.CreateRuntimeFunction(type, fnName);
// In -fobjc-no-arc-runtime, emit weak references to the runtime
// support library.
if (!CGM.getCodeGenOpts().ObjCRuntimeHasARC)
if (llvm::Function *f = dyn_cast<llvm::Function>(fn))
f->setLinkage(llvm::Function::ExternalWeakLinkage);
return fn;
}
/// Perform an operation having the signature
/// i8* (i8*)
/// where a null input causes a no-op and returns null.
static llvm::Value *emitARCValueOperation(CodeGenFunction &CGF,
llvm::Value *value,
llvm::Constant *&fn,
StringRef fnName) {
if (isa<llvm::ConstantPointerNull>(value)) return value;
if (!fn) {
std::vector<llvm::Type*> args(1, CGF.Int8PtrTy);
llvm::FunctionType *fnType =
llvm::FunctionType::get(CGF.Int8PtrTy, args, false);
fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName);
}
// Cast the argument to 'id'.
llvm::Type *origType = value->getType();
value = CGF.Builder.CreateBitCast(value, CGF.Int8PtrTy);
// Call the function.
llvm::CallInst *call = CGF.Builder.CreateCall(fn, value);
call->setDoesNotThrow();
// Cast the result back to the original type.
return CGF.Builder.CreateBitCast(call, origType);
}
/// Perform an operation having the following signature:
/// i8* (i8**)
static llvm::Value *emitARCLoadOperation(CodeGenFunction &CGF,
llvm::Value *addr,
llvm::Constant *&fn,
StringRef fnName) {
if (!fn) {
std::vector<llvm::Type*> args(1, CGF.Int8PtrPtrTy);
llvm::FunctionType *fnType =
llvm::FunctionType::get(CGF.Int8PtrTy, args, false);
fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName);
}
// Cast the argument to 'id*'.
llvm::Type *origType = addr->getType();
addr = CGF.Builder.CreateBitCast(addr, CGF.Int8PtrPtrTy);
// Call the function.
llvm::CallInst *call = CGF.Builder.CreateCall(fn, addr);
call->setDoesNotThrow();
// Cast the result back to a dereference of the original type.
llvm::Value *result = call;
if (origType != CGF.Int8PtrPtrTy)
result = CGF.Builder.CreateBitCast(result,
cast<llvm::PointerType>(origType)->getElementType());
return result;
}
/// Perform an operation having the following signature:
/// i8* (i8**, i8*)
static llvm::Value *emitARCStoreOperation(CodeGenFunction &CGF,
llvm::Value *addr,
llvm::Value *value,
llvm::Constant *&fn,
StringRef fnName,
bool ignored) {
assert(cast<llvm::PointerType>(addr->getType())->getElementType()
== value->getType());
if (!fn) {
llvm::Type *argTypes[] = { CGF.Int8PtrPtrTy, CGF.Int8PtrTy };
llvm::FunctionType *fnType
= llvm::FunctionType::get(CGF.Int8PtrTy, argTypes, false);
fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName);
}
llvm::Type *origType = value->getType();
addr = CGF.Builder.CreateBitCast(addr, CGF.Int8PtrPtrTy);
value = CGF.Builder.CreateBitCast(value, CGF.Int8PtrTy);
llvm::CallInst *result = CGF.Builder.CreateCall2(fn, addr, value);
result->setDoesNotThrow();
if (ignored) return 0;
return CGF.Builder.CreateBitCast(result, origType);
}
/// Perform an operation having the following signature:
/// void (i8**, i8**)
static void emitARCCopyOperation(CodeGenFunction &CGF,
llvm::Value *dst,
llvm::Value *src,
llvm::Constant *&fn,
StringRef fnName) {
assert(dst->getType() == src->getType());
if (!fn) {
std::vector<llvm::Type*> argTypes(2, CGF.Int8PtrPtrTy);
llvm::FunctionType *fnType
= llvm::FunctionType::get(CGF.Builder.getVoidTy(), argTypes, false);
fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName);
}
dst = CGF.Builder.CreateBitCast(dst, CGF.Int8PtrPtrTy);
src = CGF.Builder.CreateBitCast(src, CGF.Int8PtrPtrTy);
llvm::CallInst *result = CGF.Builder.CreateCall2(fn, dst, src);
result->setDoesNotThrow();
}
/// Produce the code to do a retain. Based on the type, calls one of:
/// call i8* @objc_retain(i8* %value)
/// call i8* @objc_retainBlock(i8* %value)
llvm::Value *CodeGenFunction::EmitARCRetain(QualType type, llvm::Value *value) {
if (type->isBlockPointerType())
return EmitARCRetainBlock(value, /*mandatory*/ false);
else
return EmitARCRetainNonBlock(value);
}
/// Retain the given object, with normal retain semantics.
/// call i8* @objc_retain(i8* %value)
llvm::Value *CodeGenFunction::EmitARCRetainNonBlock(llvm::Value *value) {
return emitARCValueOperation(*this, value,
CGM.getARCEntrypoints().objc_retain,
"objc_retain");
}
/// Retain the given block, with _Block_copy semantics.
/// call i8* @objc_retainBlock(i8* %value)
///
/// \param mandatory - If false, emit the call with metadata
/// indicating that it's okay for the optimizer to eliminate this call
/// if it can prove that the block never escapes except down the stack.
llvm::Value *CodeGenFunction::EmitARCRetainBlock(llvm::Value *value,
bool mandatory) {
llvm::Value *result
= emitARCValueOperation(*this, value,
CGM.getARCEntrypoints().objc_retainBlock,
"objc_retainBlock");
// If the copy isn't mandatory, add !clang.arc.copy_on_escape to
// tell the optimizer that it doesn't need to do this copy if the
// block doesn't escape, where being passed as an argument doesn't
// count as escaping.
if (!mandatory && isa<llvm::Instruction>(result)) {
llvm::CallInst *call
= cast<llvm::CallInst>(result->stripPointerCasts());
assert(call->getCalledValue() == CGM.getARCEntrypoints().objc_retainBlock);
SmallVector<llvm::Value*,1> args;
call->setMetadata("clang.arc.copy_on_escape",
llvm::MDNode::get(Builder.getContext(), args));
}
return result;
}
/// Retain the given object which is the result of a function call.
/// call i8* @objc_retainAutoreleasedReturnValue(i8* %value)
///
/// Yes, this function name is one character away from a different
/// call with completely different semantics.
llvm::Value *
CodeGenFunction::EmitARCRetainAutoreleasedReturnValue(llvm::Value *value) {
// Fetch the void(void) inline asm which marks that we're going to
// retain the autoreleased return value.
llvm::InlineAsm *&marker
= CGM.getARCEntrypoints().retainAutoreleasedReturnValueMarker;
if (!marker) {
StringRef assembly
= CGM.getTargetCodeGenInfo()
.getARCRetainAutoreleasedReturnValueMarker();
// If we have an empty assembly string, there's nothing to do.
if (assembly.empty()) {
// Otherwise, at -O0, build an inline asm that we're going to call
// in a moment.
} else if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
llvm::FunctionType *type =
llvm::FunctionType::get(llvm::Type::getVoidTy(getLLVMContext()),
/*variadic*/ false);
marker = llvm::InlineAsm::get(type, assembly, "", /*sideeffects*/ true);
// If we're at -O1 and above, we don't want to litter the code
// with this marker yet, so leave a breadcrumb for the ARC
// optimizer to pick up.
} else {
llvm::NamedMDNode *metadata =
CGM.getModule().getOrInsertNamedMetadata(
"clang.arc.retainAutoreleasedReturnValueMarker");
assert(metadata->getNumOperands() <= 1);
if (metadata->getNumOperands() == 0) {
llvm::Value *string = llvm::MDString::get(getLLVMContext(), assembly);
metadata->addOperand(llvm::MDNode::get(getLLVMContext(), string));
}
}
}
// Call the marker asm if we made one, which we do only at -O0.
if (marker) Builder.CreateCall(marker);
return emitARCValueOperation(*this, value,
CGM.getARCEntrypoints().objc_retainAutoreleasedReturnValue,
"objc_retainAutoreleasedReturnValue");
}
/// Release the given object.
/// call void @objc_release(i8* %value)
void CodeGenFunction::EmitARCRelease(llvm::Value *value, bool precise) {
if (isa<llvm::ConstantPointerNull>(value)) return;
llvm::Constant *&fn = CGM.getARCEntrypoints().objc_release;
if (!fn) {
std::vector<llvm::Type*> args(1, Int8PtrTy);
llvm::FunctionType *fnType =
llvm::FunctionType::get(Builder.getVoidTy(), args, false);
fn = createARCRuntimeFunction(CGM, fnType, "objc_release");
}
// Cast the argument to 'id'.
value = Builder.CreateBitCast(value, Int8PtrTy);
// Call objc_release.
llvm::CallInst *call = Builder.CreateCall(fn, value);
call->setDoesNotThrow();
if (!precise) {
SmallVector<llvm::Value*,1> args;
call->setMetadata("clang.imprecise_release",
llvm::MDNode::get(Builder.getContext(), args));
}
}
/// Store into a strong object. Always calls this:
/// call void @objc_storeStrong(i8** %addr, i8* %value)
llvm::Value *CodeGenFunction::EmitARCStoreStrongCall(llvm::Value *addr,
llvm::Value *value,
bool ignored) {
assert(cast<llvm::PointerType>(addr->getType())->getElementType()
== value->getType());
llvm::Constant *&fn = CGM.getARCEntrypoints().objc_storeStrong;
if (!fn) {
llvm::Type *argTypes[] = { Int8PtrPtrTy, Int8PtrTy };
llvm::FunctionType *fnType
= llvm::FunctionType::get(Builder.getVoidTy(), argTypes, false);
fn = createARCRuntimeFunction(CGM, fnType, "objc_storeStrong");
}
addr = Builder.CreateBitCast(addr, Int8PtrPtrTy);
llvm::Value *castValue = Builder.CreateBitCast(value, Int8PtrTy);
Builder.CreateCall2(fn, addr, castValue)->setDoesNotThrow();
if (ignored) return 0;
return value;
}
/// Store into a strong object. Sometimes calls this:
/// call void @objc_storeStrong(i8** %addr, i8* %value)
/// Other times, breaks it down into components.
llvm::Value *CodeGenFunction::EmitARCStoreStrong(LValue dst,
llvm::Value *newValue,
bool ignored) {
QualType type = dst.getType();
bool isBlock = type->isBlockPointerType();
// Use a store barrier at -O0 unless this is a block type or the
// lvalue is inadequately aligned.
if (shouldUseFusedARCCalls() &&
!isBlock &&
!(dst.getAlignment() && dst.getAlignment() < PointerAlignInBytes)) {
return EmitARCStoreStrongCall(dst.getAddress(), newValue, ignored);
}
// Otherwise, split it out.
// Retain the new value.
newValue = EmitARCRetain(type, newValue);
// Read the old value.
llvm::Value *oldValue = EmitLoadOfScalar(dst);
// Store. We do this before the release so that any deallocs won't
// see the old value.
EmitStoreOfScalar(newValue, dst);
// Finally, release the old value.
EmitARCRelease(oldValue, /*precise*/ false);
return newValue;
}
/// Autorelease the given object.
/// call i8* @objc_autorelease(i8* %value)
llvm::Value *CodeGenFunction::EmitARCAutorelease(llvm::Value *value) {
return emitARCValueOperation(*this, value,
CGM.getARCEntrypoints().objc_autorelease,
"objc_autorelease");
}
/// Autorelease the given object.
/// call i8* @objc_autoreleaseReturnValue(i8* %value)
llvm::Value *
CodeGenFunction::EmitARCAutoreleaseReturnValue(llvm::Value *value) {
return emitARCValueOperation(*this, value,
CGM.getARCEntrypoints().objc_autoreleaseReturnValue,
"objc_autoreleaseReturnValue");
}
/// Do a fused retain/autorelease of the given object.
/// call i8* @objc_retainAutoreleaseReturnValue(i8* %value)
llvm::Value *
CodeGenFunction::EmitARCRetainAutoreleaseReturnValue(llvm::Value *value) {
return emitARCValueOperation(*this, value,
CGM.getARCEntrypoints().objc_retainAutoreleaseReturnValue,
"objc_retainAutoreleaseReturnValue");
}
/// Do a fused retain/autorelease of the given object.
/// call i8* @objc_retainAutorelease(i8* %value)
/// or
/// %retain = call i8* @objc_retainBlock(i8* %value)
/// call i8* @objc_autorelease(i8* %retain)
llvm::Value *CodeGenFunction::EmitARCRetainAutorelease(QualType type,
llvm::Value *value) {
if (!type->isBlockPointerType())
return EmitARCRetainAutoreleaseNonBlock(value);
if (isa<llvm::ConstantPointerNull>(value)) return value;
llvm::Type *origType = value->getType();
value = Builder.CreateBitCast(value, Int8PtrTy);
value = EmitARCRetainBlock(value, /*mandatory*/ true);
value = EmitARCAutorelease(value);
return Builder.CreateBitCast(value, origType);
}
/// Do a fused retain/autorelease of the given object.
/// call i8* @objc_retainAutorelease(i8* %value)
llvm::Value *
CodeGenFunction::EmitARCRetainAutoreleaseNonBlock(llvm::Value *value) {
return emitARCValueOperation(*this, value,
CGM.getARCEntrypoints().objc_retainAutorelease,
"objc_retainAutorelease");
}
/// i8* @objc_loadWeak(i8** %addr)
/// Essentially objc_autorelease(objc_loadWeakRetained(addr)).
llvm::Value *CodeGenFunction::EmitARCLoadWeak(llvm::Value *addr) {
return emitARCLoadOperation(*this, addr,
CGM.getARCEntrypoints().objc_loadWeak,
"objc_loadWeak");
}
/// i8* @objc_loadWeakRetained(i8** %addr)
llvm::Value *CodeGenFunction::EmitARCLoadWeakRetained(llvm::Value *addr) {
return emitARCLoadOperation(*this, addr,
CGM.getARCEntrypoints().objc_loadWeakRetained,
"objc_loadWeakRetained");
}
/// i8* @objc_storeWeak(i8** %addr, i8* %value)
/// Returns %value.
llvm::Value *CodeGenFunction::EmitARCStoreWeak(llvm::Value *addr,
llvm::Value *value,
bool ignored) {
return emitARCStoreOperation(*this, addr, value,
CGM.getARCEntrypoints().objc_storeWeak,
"objc_storeWeak", ignored);
}
/// i8* @objc_initWeak(i8** %addr, i8* %value)
/// Returns %value. %addr is known to not have a current weak entry.
/// Essentially equivalent to:
/// *addr = nil; objc_storeWeak(addr, value);
void CodeGenFunction::EmitARCInitWeak(llvm::Value *addr, llvm::Value *value) {
// If we're initializing to null, just write null to memory; no need
// to get the runtime involved. But don't do this if optimization
// is enabled, because accounting for this would make the optimizer
// much more complicated.
if (isa<llvm::ConstantPointerNull>(value) &&
CGM.getCodeGenOpts().OptimizationLevel == 0) {
Builder.CreateStore(value, addr);
return;
}
emitARCStoreOperation(*this, addr, value,
CGM.getARCEntrypoints().objc_initWeak,
"objc_initWeak", /*ignored*/ true);
}
/// void @objc_destroyWeak(i8** %addr)
/// Essentially objc_storeWeak(addr, nil).
void CodeGenFunction::EmitARCDestroyWeak(llvm::Value *addr) {
llvm::Constant *&fn = CGM.getARCEntrypoints().objc_destroyWeak;
if (!fn) {
std::vector<llvm::Type*> args(1, Int8PtrPtrTy);
llvm::FunctionType *fnType =
llvm::FunctionType::get(Builder.getVoidTy(), args, false);
fn = createARCRuntimeFunction(CGM, fnType, "objc_destroyWeak");
}
// Cast the argument to 'id*'.
addr = Builder.CreateBitCast(addr, Int8PtrPtrTy);
llvm::CallInst *call = Builder.CreateCall(fn, addr);
call->setDoesNotThrow();
}
/// void @objc_moveWeak(i8** %dest, i8** %src)
/// Disregards the current value in %dest. Leaves %src pointing to nothing.
/// Essentially (objc_copyWeak(dest, src), objc_destroyWeak(src)).
void CodeGenFunction::EmitARCMoveWeak(llvm::Value *dst, llvm::Value *src) {
emitARCCopyOperation(*this, dst, src,
CGM.getARCEntrypoints().objc_moveWeak,
"objc_moveWeak");
}
/// void @objc_copyWeak(i8** %dest, i8** %src)
/// Disregards the current value in %dest. Essentially
/// objc_release(objc_initWeak(dest, objc_readWeakRetained(src)))
void CodeGenFunction::EmitARCCopyWeak(llvm::Value *dst, llvm::Value *src) {
emitARCCopyOperation(*this, dst, src,
CGM.getARCEntrypoints().objc_copyWeak,
"objc_copyWeak");
}
/// Produce the code to do a objc_autoreleasepool_push.
/// call i8* @objc_autoreleasePoolPush(void)
llvm::Value *CodeGenFunction::EmitObjCAutoreleasePoolPush() {
llvm::Constant *&fn = CGM.getRREntrypoints().objc_autoreleasePoolPush;
if (!fn) {
llvm::FunctionType *fnType =
llvm::FunctionType::get(Int8PtrTy, false);
fn = createARCRuntimeFunction(CGM, fnType, "objc_autoreleasePoolPush");
}
llvm::CallInst *call = Builder.CreateCall(fn);
call->setDoesNotThrow();
return call;
}
/// Produce the code to do a primitive release.
/// call void @objc_autoreleasePoolPop(i8* %ptr)
void CodeGenFunction::EmitObjCAutoreleasePoolPop(llvm::Value *value) {
assert(value->getType() == Int8PtrTy);
llvm::Constant *&fn = CGM.getRREntrypoints().objc_autoreleasePoolPop;
if (!fn) {
std::vector<llvm::Type*> args(1, Int8PtrTy);
llvm::FunctionType *fnType =
llvm::FunctionType::get(Builder.getVoidTy(), args, false);
// We don't want to use a weak import here; instead we should not
// fall into this path.
fn = createARCRuntimeFunction(CGM, fnType, "objc_autoreleasePoolPop");
}
llvm::CallInst *call = Builder.CreateCall(fn, value);
call->setDoesNotThrow();
}
/// Produce the code to do an MRR version objc_autoreleasepool_push.
/// Which is: [[NSAutoreleasePool alloc] init];
/// Where alloc is declared as: + (id) alloc; in NSAutoreleasePool class.
/// init is declared as: - (id) init; in its NSObject super class.
///
llvm::Value *CodeGenFunction::EmitObjCMRRAutoreleasePoolPush() {
CGObjCRuntime &Runtime = CGM.getObjCRuntime();
llvm::Value *Receiver = Runtime.EmitNSAutoreleasePoolClassRef(Builder);
// [NSAutoreleasePool alloc]
IdentifierInfo *II = &CGM.getContext().Idents.get("alloc");
Selector AllocSel = getContext().Selectors.getSelector(0, &II);
CallArgList Args;
RValue AllocRV =
Runtime.GenerateMessageSend(*this, ReturnValueSlot(),
getContext().getObjCIdType(),
AllocSel, Receiver, Args);
// [Receiver init]
Receiver = AllocRV.getScalarVal();
II = &CGM.getContext().Idents.get("init");
Selector InitSel = getContext().Selectors.getSelector(0, &II);
RValue InitRV =
Runtime.GenerateMessageSend(*this, ReturnValueSlot(),
getContext().getObjCIdType(),
InitSel, Receiver, Args);
return InitRV.getScalarVal();
}
/// Produce the code to do a primitive release.
/// [tmp drain];
void CodeGenFunction::EmitObjCMRRAutoreleasePoolPop(llvm::Value *Arg) {
IdentifierInfo *II = &CGM.getContext().Idents.get("drain");
Selector DrainSel = getContext().Selectors.getSelector(0, &II);
CallArgList Args;
CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(),
getContext().VoidTy, DrainSel, Arg, Args);
}
void CodeGenFunction::destroyARCStrongPrecise(CodeGenFunction &CGF,
llvm::Value *addr,
QualType type) {
llvm::Value *ptr = CGF.Builder.CreateLoad(addr, "strongdestroy");
CGF.EmitARCRelease(ptr, /*precise*/ true);
}
void CodeGenFunction::destroyARCStrongImprecise(CodeGenFunction &CGF,
llvm::Value *addr,
QualType type) {
llvm::Value *ptr = CGF.Builder.CreateLoad(addr, "strongdestroy");
CGF.EmitARCRelease(ptr, /*precise*/ false);
}
void CodeGenFunction::destroyARCWeak(CodeGenFunction &CGF,
llvm::Value *addr,
QualType type) {
CGF.EmitARCDestroyWeak(addr);
}
namespace {
struct CallObjCAutoreleasePoolObject : EHScopeStack::Cleanup {
llvm::Value *Token;
CallObjCAutoreleasePoolObject(llvm::Value *token) : Token(token) {}
void Emit(CodeGenFunction &CGF, Flags flags) {
CGF.EmitObjCAutoreleasePoolPop(Token);
}
};
struct CallObjCMRRAutoreleasePoolObject : EHScopeStack::Cleanup {
llvm::Value *Token;
CallObjCMRRAutoreleasePoolObject(llvm::Value *token) : Token(token) {}
void Emit(CodeGenFunction &CGF, Flags flags) {
CGF.EmitObjCMRRAutoreleasePoolPop(Token);
}
};
}
void CodeGenFunction::EmitObjCAutoreleasePoolCleanup(llvm::Value *Ptr) {
if (CGM.getLangOptions().ObjCAutoRefCount)
EHStack.pushCleanup<CallObjCAutoreleasePoolObject>(NormalCleanup, Ptr);
else
EHStack.pushCleanup<CallObjCMRRAutoreleasePoolObject>(NormalCleanup, Ptr);
}
static TryEmitResult tryEmitARCRetainLoadOfScalar(CodeGenFunction &CGF,
LValue lvalue,
QualType type) {
switch (type.getObjCLifetime()) {
case Qualifiers::OCL_None:
case Qualifiers::OCL_ExplicitNone:
case Qualifiers::OCL_Strong:
case Qualifiers::OCL_Autoreleasing:
return TryEmitResult(CGF.EmitLoadOfLValue(lvalue).getScalarVal(),
false);
case Qualifiers::OCL_Weak:
return TryEmitResult(CGF.EmitARCLoadWeakRetained(lvalue.getAddress()),
true);
}
llvm_unreachable("impossible lifetime!");
return TryEmitResult();
}
static TryEmitResult tryEmitARCRetainLoadOfScalar(CodeGenFunction &CGF,
const Expr *e) {
e = e->IgnoreParens();
QualType type = e->getType();
// If we're loading retained from a __strong xvalue, we can avoid
// an extra retain/release pair by zeroing out the source of this
// "move" operation.
if (e->isXValue() &&
!type.isConstQualified() &&
type.getObjCLifetime() == Qualifiers::OCL_Strong) {
// Emit the lvalue.
LValue lv = CGF.EmitLValue(e);
// Load the object pointer.
llvm::Value *result = CGF.EmitLoadOfLValue(lv).getScalarVal();
// Set the source pointer to NULL.
CGF.EmitStoreOfScalar(getNullForVariable(lv.getAddress()), lv);
return TryEmitResult(result, true);
}
// As a very special optimization, in ARC++, if the l-value is the
// result of a non-volatile assignment, do a simple retain of the
// result of the call to objc_storeWeak instead of reloading.
if (CGF.getLangOptions().CPlusPlus &&
!type.isVolatileQualified() &&
type.getObjCLifetime() == Qualifiers::OCL_Weak &&
isa<BinaryOperator>(e) &&
cast<BinaryOperator>(e)->getOpcode() == BO_Assign)
return TryEmitResult(CGF.EmitScalarExpr(e), false);
return tryEmitARCRetainLoadOfScalar(CGF, CGF.EmitLValue(e), type);
}
static llvm::Value *emitARCRetainAfterCall(CodeGenFunction &CGF,
llvm::Value *value);
/// Given that the given expression is some sort of call (which does
/// not return retained), emit a retain following it.
static llvm::Value *emitARCRetainCall(CodeGenFunction &CGF, const Expr *e) {
llvm::Value *value = CGF.EmitScalarExpr(e);
return emitARCRetainAfterCall(CGF, value);
}
static llvm::Value *emitARCRetainAfterCall(CodeGenFunction &CGF,
llvm::Value *value) {
if (llvm::CallInst *call = dyn_cast<llvm::CallInst>(value)) {
CGBuilderTy::InsertPoint ip = CGF.Builder.saveIP();
// Place the retain immediately following the call.
CGF.Builder.SetInsertPoint(call->getParent(),
++llvm::BasicBlock::iterator(call));
value = CGF.EmitARCRetainAutoreleasedReturnValue(value);
CGF.Builder.restoreIP(ip);
return value;
} else if (llvm::InvokeInst *invoke = dyn_cast<llvm::InvokeInst>(value)) {
CGBuilderTy::InsertPoint ip = CGF.Builder.saveIP();
// Place the retain at the beginning of the normal destination block.
llvm::BasicBlock *BB = invoke->getNormalDest();
CGF.Builder.SetInsertPoint(BB, BB->begin());
value = CGF.EmitARCRetainAutoreleasedReturnValue(value);
CGF.Builder.restoreIP(ip);
return value;
// Bitcasts can arise because of related-result returns. Rewrite
// the operand.
} else if (llvm::BitCastInst *bitcast = dyn_cast<llvm::BitCastInst>(value)) {
llvm::Value *operand = bitcast->getOperand(0);
operand = emitARCRetainAfterCall(CGF, operand);
bitcast->setOperand(0, operand);
return bitcast;
// Generic fall-back case.
} else {
// Retain using the non-block variant: we never need to do a copy
// of a block that's been returned to us.
return CGF.EmitARCRetainNonBlock(value);
}
}
/// Determine whether it might be important to emit a separate
/// objc_retain_block on the result of the given expression, or
/// whether it's okay to just emit it in a +1 context.
static bool shouldEmitSeparateBlockRetain(const Expr *e) {
assert(e->getType()->isBlockPointerType());
e = e->IgnoreParens();
// For future goodness, emit block expressions directly in +1
// contexts if we can.
if (isa<BlockExpr>(e))
return false;
if (const CastExpr *cast = dyn_cast<CastExpr>(e)) {
switch (cast->getCastKind()) {
// Emitting these operations in +1 contexts is goodness.
case CK_LValueToRValue:
case CK_ARCReclaimReturnedObject:
case CK_ARCConsumeObject:
case CK_ARCProduceObject:
return false;
// These operations preserve a block type.
case CK_NoOp:
case CK_BitCast:
return shouldEmitSeparateBlockRetain(cast->getSubExpr());
// These operations are known to be bad (or haven't been considered).
case CK_AnyPointerToBlockPointerCast:
default:
return true;
}
}
return true;
}
/// Try to emit a PseudoObjectExpr at +1.
///
/// This massively duplicates emitPseudoObjectRValue.
static TryEmitResult tryEmitARCRetainPseudoObject(CodeGenFunction &CGF,
const PseudoObjectExpr *E) {
llvm::SmallVector<CodeGenFunction::OpaqueValueMappingData, 4> opaques;
// Find the result expression.
const Expr *resultExpr = E->getResultExpr();
assert(resultExpr);
TryEmitResult result;
for (PseudoObjectExpr::const_semantics_iterator
i = E->semantics_begin(), e = E->semantics_end(); i != e; ++i) {
const Expr *semantic = *i;
// If this semantic expression is an opaque value, bind it
// to the result of its source expression.
if (const OpaqueValueExpr *ov = dyn_cast<OpaqueValueExpr>(semantic)) {
typedef CodeGenFunction::OpaqueValueMappingData OVMA;
OVMA opaqueData;
// If this semantic is the result of the pseudo-object
// expression, try to evaluate the source as +1.
if (ov == resultExpr) {
assert(!OVMA::shouldBindAsLValue(ov));
result = tryEmitARCRetainScalarExpr(CGF, ov->getSourceExpr());
opaqueData = OVMA::bind(CGF, ov, RValue::get(result.getPointer()));
// Otherwise, just bind it.
} else {
opaqueData = OVMA::bind(CGF, ov, ov->getSourceExpr());
}
opaques.push_back(opaqueData);
// Otherwise, if the expression is the result, evaluate it
// and remember the result.
} else if (semantic == resultExpr) {
result = tryEmitARCRetainScalarExpr(CGF, semantic);
// Otherwise, evaluate the expression in an ignored context.
} else {
CGF.EmitIgnoredExpr(semantic);
}
}
// Unbind all the opaques now.
for (unsigned i = 0, e = opaques.size(); i != e; ++i)
opaques[i].unbind(CGF);
return result;
}
static TryEmitResult
tryEmitARCRetainScalarExpr(CodeGenFunction &CGF, const Expr *e) {
// Look through cleanups.
if (const ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(e)) {
CGF.enterFullExpression(cleanups);
CodeGenFunction::RunCleanupsScope scope(CGF);
return tryEmitARCRetainScalarExpr(CGF, cleanups->getSubExpr());
}
// The desired result type, if it differs from the type of the
// ultimate opaque expression.
llvm::Type *resultType = 0;
while (true) {
e = e->IgnoreParens();
// There's a break at the end of this if-chain; anything
// that wants to keep looping has to explicitly continue.
if (const CastExpr *ce = dyn_cast<CastExpr>(e)) {
switch (ce->getCastKind()) {
// No-op casts don't change the type, so we just ignore them.
case CK_NoOp:
e = ce->getSubExpr();
continue;
case CK_LValueToRValue: {
TryEmitResult loadResult
= tryEmitARCRetainLoadOfScalar(CGF, ce->getSubExpr());
if (resultType) {
llvm::Value *value = loadResult.getPointer();
value = CGF.Builder.CreateBitCast(value, resultType);
loadResult.setPointer(value);
}
return loadResult;
}
// These casts can change the type, so remember that and
// soldier on. We only need to remember the outermost such
// cast, though.
case CK_CPointerToObjCPointerCast:
case CK_BlockPointerToObjCPointerCast:
case CK_AnyPointerToBlockPointerCast:
case CK_BitCast:
if (!resultType)
resultType = CGF.ConvertType(ce->getType());
e = ce->getSubExpr();
assert(e->getType()->hasPointerRepresentation());
continue;
// For consumptions, just emit the subexpression and thus elide
// the retain/release pair.
case CK_ARCConsumeObject: {
llvm::Value *result = CGF.EmitScalarExpr(ce->getSubExpr());
if (resultType) result = CGF.Builder.CreateBitCast(result, resultType);
return TryEmitResult(result, true);
}
// Block extends are net +0. Naively, we could just recurse on
// the subexpression, but actually we need to ensure that the
// value is copied as a block, so there's a little filter here.
case CK_ARCExtendBlockObject: {
llvm::Value *result; // will be a +0 value
// If we can't safely assume the sub-expression will produce a
// block-copied value, emit the sub-expression at +0.
if (shouldEmitSeparateBlockRetain(ce->getSubExpr())) {
result = CGF.EmitScalarExpr(ce->getSubExpr());
// Otherwise, try to emit the sub-expression at +1 recursively.
} else {
TryEmitResult subresult
= tryEmitARCRetainScalarExpr(CGF, ce->getSubExpr());
result = subresult.getPointer();
// If that produced a retained value, just use that,
// possibly casting down.
if (subresult.getInt()) {
if (resultType)
result = CGF.Builder.CreateBitCast(result, resultType);
return TryEmitResult(result, true);
}
// Otherwise it's +0.
}
// Retain the object as a block, then cast down.
result = CGF.EmitARCRetainBlock(result, /*mandatory*/ true);
if (resultType) result = CGF.Builder.CreateBitCast(result, resultType);
return TryEmitResult(result, true);
}
// For reclaims, emit the subexpression as a retained call and
// skip the consumption.
case CK_ARCReclaimReturnedObject: {
llvm::Value *result = emitARCRetainCall(CGF, ce->getSubExpr());
if (resultType) result = CGF.Builder.CreateBitCast(result, resultType);
return TryEmitResult(result, true);
}
default:
break;
}
// Skip __extension__.
} else if (const UnaryOperator *op = dyn_cast<UnaryOperator>(e)) {
if (op->getOpcode() == UO_Extension) {
e = op->getSubExpr();
continue;
}
// For calls and message sends, use the retained-call logic.
// Delegate inits are a special case in that they're the only
// returns-retained expression that *isn't* surrounded by
// a consume.
} else if (isa<CallExpr>(e) ||
(isa<ObjCMessageExpr>(e) &&
!cast<ObjCMessageExpr>(e)->isDelegateInitCall())) {
llvm::Value *result = emitARCRetainCall(CGF, e);
if (resultType) result = CGF.Builder.CreateBitCast(result, resultType);
return TryEmitResult(result, true);
// Look through pseudo-object expressions.
} else if (const PseudoObjectExpr *pseudo = dyn_cast<PseudoObjectExpr>(e)) {
TryEmitResult result
= tryEmitARCRetainPseudoObject(CGF, pseudo);
if (resultType) {
llvm::Value *value = result.getPointer();
value = CGF.Builder.CreateBitCast(value, resultType);
result.setPointer(value);
}
return result;
}
// Conservatively halt the search at any other expression kind.
break;
}
// We didn't find an obvious production, so emit what we've got and
// tell the caller that we didn't manage to retain.
llvm::Value *result = CGF.EmitScalarExpr(e);
if (resultType) result = CGF.Builder.CreateBitCast(result, resultType);
return TryEmitResult(result, false);
}
static llvm::Value *emitARCRetainLoadOfScalar(CodeGenFunction &CGF,
LValue lvalue,
QualType type) {
TryEmitResult result = tryEmitARCRetainLoadOfScalar(CGF, lvalue, type);
llvm::Value *value = result.getPointer();
if (!result.getInt())
value = CGF.EmitARCRetain(type, value);
return value;
}
/// EmitARCRetainScalarExpr - Semantically equivalent to
/// EmitARCRetainObject(e->getType(), EmitScalarExpr(e)), but making a
/// best-effort attempt to peephole expressions that naturally produce
/// retained objects.
llvm::Value *CodeGenFunction::EmitARCRetainScalarExpr(const Expr *e) {
TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e);
llvm::Value *value = result.getPointer();
if (!result.getInt())
value = EmitARCRetain(e->getType(), value);
return value;
}
llvm::Value *
CodeGenFunction::EmitARCRetainAutoreleaseScalarExpr(const Expr *e) {
TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e);
llvm::Value *value = result.getPointer();
if (result.getInt())
value = EmitARCAutorelease(value);
else
value = EmitARCRetainAutorelease(e->getType(), value);
return value;
}
llvm::Value *CodeGenFunction::EmitARCExtendBlockObject(const Expr *e) {
llvm::Value *result;
bool doRetain;
if (shouldEmitSeparateBlockRetain(e)) {
result = EmitScalarExpr(e);
doRetain = true;
} else {
TryEmitResult subresult = tryEmitARCRetainScalarExpr(*this, e);
result = subresult.getPointer();
doRetain = !subresult.getInt();
}
if (doRetain)
result = EmitARCRetainBlock(result, /*mandatory*/ true);
return EmitObjCConsumeObject(e->getType(), result);
}
llvm::Value *CodeGenFunction::EmitObjCThrowOperand(const Expr *expr) {
// In ARC, retain and autorelease the expression.
if (getLangOptions().ObjCAutoRefCount) {
// Do so before running any cleanups for the full-expression.
// tryEmitARCRetainScalarExpr does make an effort to do things
// inside cleanups, but there are crazy cases like
// @throw A().foo;
// where a full retain+autorelease is required and would
// otherwise happen after the destructor for the temporary.
if (const ExprWithCleanups *ewc = dyn_cast<ExprWithCleanups>(expr)) {
enterFullExpression(ewc);
expr = ewc->getSubExpr();
}
CodeGenFunction::RunCleanupsScope cleanups(*this);
return EmitARCRetainAutoreleaseScalarExpr(expr);
}
// Otherwise, use the normal scalar-expression emission. The
// exception machinery doesn't do anything special with the
// exception like retaining it, so there's no safety associated with
// only running cleanups after the throw has started, and when it
// matters it tends to be substantially inferior code.
return EmitScalarExpr(expr);
}
std::pair<LValue,llvm::Value*>
CodeGenFunction::EmitARCStoreStrong(const BinaryOperator *e,
bool ignored) {
// Evaluate the RHS first.
TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e->getRHS());
llvm::Value *value = result.getPointer();
bool hasImmediateRetain = result.getInt();
// If we didn't emit a retained object, and the l-value is of block
// type, then we need to emit the block-retain immediately in case
// it invalidates the l-value.
if (!hasImmediateRetain && e->getType()->isBlockPointerType()) {
value = EmitARCRetainBlock(value, /*mandatory*/ false);
hasImmediateRetain = true;
}
LValue lvalue = EmitLValue(e->getLHS());
// If the RHS was emitted retained, expand this.
if (hasImmediateRetain) {
llvm::Value *oldValue =
EmitLoadOfScalar(lvalue.getAddress(), lvalue.isVolatileQualified(),
lvalue.getAlignment(), e->getType(),
lvalue.getTBAAInfo());
EmitStoreOfScalar(value, lvalue.getAddress(),
lvalue.isVolatileQualified(), lvalue.getAlignment(),
e->getType(), lvalue.getTBAAInfo());
EmitARCRelease(oldValue, /*precise*/ false);
} else {
value = EmitARCStoreStrong(lvalue, value, ignored);
}
return std::pair<LValue,llvm::Value*>(lvalue, value);
}
std::pair<LValue,llvm::Value*>
CodeGenFunction::EmitARCStoreAutoreleasing(const BinaryOperator *e) {
llvm::Value *value = EmitARCRetainAutoreleaseScalarExpr(e->getRHS());
LValue lvalue = EmitLValue(e->getLHS());
EmitStoreOfScalar(value, lvalue.getAddress(),
lvalue.isVolatileQualified(), lvalue.getAlignment(),
e->getType(), lvalue.getTBAAInfo());
return std::pair<LValue,llvm::Value*>(lvalue, value);
}
void CodeGenFunction::EmitObjCAutoreleasePoolStmt(
const ObjCAutoreleasePoolStmt &ARPS) {
const Stmt *subStmt = ARPS.getSubStmt();
const CompoundStmt &S = cast<CompoundStmt>(*subStmt);
CGDebugInfo *DI = getDebugInfo();
if (DI)
DI->EmitLexicalBlockStart(Builder, S.getLBracLoc());
// Keep track of the current cleanup stack depth.
RunCleanupsScope Scope(*this);
if (CGM.getCodeGenOpts().ObjCRuntimeHasARC) {
llvm::Value *token = EmitObjCAutoreleasePoolPush();
EHStack.pushCleanup<CallObjCAutoreleasePoolObject>(NormalCleanup, token);
} else {
llvm::Value *token = EmitObjCMRRAutoreleasePoolPush();
EHStack.pushCleanup<CallObjCMRRAutoreleasePoolObject>(NormalCleanup, token);
}
for (CompoundStmt::const_body_iterator I = S.body_begin(),
E = S.body_end(); I != E; ++I)
EmitStmt(*I);
if (DI)
DI->EmitLexicalBlockEnd(Builder, S.getRBracLoc());
}
/// EmitExtendGCLifetime - Given a pointer to an Objective-C object,
/// make sure it survives garbage collection until this point.
void CodeGenFunction::EmitExtendGCLifetime(llvm::Value *object) {
// We just use an inline assembly.
llvm::FunctionType *extenderType
= llvm::FunctionType::get(VoidTy, VoidPtrTy, /*variadic*/ false);
llvm::Value *extender
= llvm::InlineAsm::get(extenderType,
/* assembly */ "",
/* constraints */ "r",
/* side effects */ true);
object = Builder.CreateBitCast(object, VoidPtrTy);
Builder.CreateCall(extender, object)->setDoesNotThrow();
}
CGObjCRuntime::~CGObjCRuntime() {}
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