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

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//===---- CGObjC.cpp - Emit LLVM Code for Objective-C ---------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This contains code to emit Objective-C code as LLVM code.
//
//===----------------------------------------------------------------------===//
#include "CGDebugInfo.h"
#include "CGObjCRuntime.h"
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
#include "ConstantEmitter.h"
#include "TargetInfo.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Attr.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/StmtObjC.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/CodeGen/CGFunctionInfo.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/InlineAsm.h"
using namespace clang;
using namespace CodeGen;
typedef llvm::PointerIntPair<llvm::Value*,1,bool> TryEmitResult;
static TryEmitResult
tryEmitARCRetainScalarExpr(CodeGenFunction &CGF, const Expr *e);
static RValue AdjustObjCObjectType(CodeGenFunction &CGF,
QualType ET,
RValue Result);
/// Given the address of a variable of pointer type, find the correct
/// null to store into it.
static llvm::Constant *getNullForVariable(Address addr) {
llvm::Type *type = addr.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()).getPointer();
// FIXME: This bitcast should just be made an invariant on the Runtime.
return llvm::ConstantExpr::getBitCast(C, ConvertType(E->getType()));
}
/// EmitObjCBoxedExpr - This routine generates code to call
/// the appropriate expression boxing method. This will either be
/// one of +[NSNumber numberWith<Type>:], or +[NSString stringWithUTF8String:],
/// or [NSValue valueWithBytes:objCType:].
///
llvm::Value *
CodeGenFunction::EmitObjCBoxedExpr(const ObjCBoxedExpr *E) {
// Generate the correct selector for this literal's concrete type.
// Get the method.
const ObjCMethodDecl *BoxingMethod = E->getBoxingMethod();
const Expr *SubExpr = E->getSubExpr();
if (E->isExpressibleAsConstantInitializer()) {
ConstantEmitter ConstEmitter(CGM);
return ConstEmitter.tryEmitAbstract(E, E->getType());
}
assert(BoxingMethod->isClassMethod() && "BoxingMethod must be a class method");
Selector Sel = BoxingMethod->getSelector();
// Generate a reference to the class pointer, which will be the receiver.
// Assumes that the method was introduced in the class that should be
// messaged (avoids pulling it out of the result type).
CGObjCRuntime &Runtime = CGM.getObjCRuntime();
const ObjCInterfaceDecl *ClassDecl = BoxingMethod->getClassInterface();
llvm::Value *Receiver = Runtime.GetClass(*this, ClassDecl);
CallArgList Args;
const ParmVarDecl *ArgDecl = *BoxingMethod->param_begin();
QualType ArgQT = ArgDecl->getType().getUnqualifiedType();
// ObjCBoxedExpr supports boxing of structs and unions
// via [NSValue valueWithBytes:objCType:]
const QualType ValueType(SubExpr->getType().getCanonicalType());
if (ValueType->isObjCBoxableRecordType()) {
// Emit CodeGen for first parameter
// and cast value to correct type
Address Temporary = CreateMemTemp(SubExpr->getType());
EmitAnyExprToMem(SubExpr, Temporary, Qualifiers(), /*isInit*/ true);
Address BitCast = Builder.CreateBitCast(Temporary, ConvertType(ArgQT));
Args.add(RValue::get(BitCast.getPointer()), ArgQT);
// Create char array to store type encoding
std::string Str;
getContext().getObjCEncodingForType(ValueType, Str);
llvm::Constant *GV = CGM.GetAddrOfConstantCString(Str).getPointer();
// Cast type encoding to correct type
const ParmVarDecl *EncodingDecl = BoxingMethod->parameters()[1];
QualType EncodingQT = EncodingDecl->getType().getUnqualifiedType();
llvm::Value *Cast = Builder.CreateBitCast(GV, ConvertType(EncodingQT));
Args.add(RValue::get(Cast), EncodingQT);
} else {
Args.add(EmitAnyExpr(SubExpr), ArgQT);
}
RValue result = Runtime.GenerateMessageSend(
*this, ReturnValueSlot(), BoxingMethod->getReturnType(), Sel, Receiver,
Args, ClassDecl, BoxingMethod);
return Builder.CreateBitCast(result.getScalarVal(),
ConvertType(E->getType()));
}
llvm::Value *CodeGenFunction::EmitObjCCollectionLiteral(const Expr *E,
const ObjCMethodDecl *MethodWithObjects) {
ASTContext &Context = CGM.getContext();
const ObjCDictionaryLiteral *DLE = nullptr;
const ObjCArrayLiteral *ALE = dyn_cast<ObjCArrayLiteral>(E);
if (!ALE)
DLE = cast<ObjCDictionaryLiteral>(E);
// Optimize empty collections by referencing constants, when available.
uint64_t NumElements =
ALE ? ALE->getNumElements() : DLE->getNumElements();
if (NumElements == 0 && CGM.getLangOpts().ObjCRuntime.hasEmptyCollections()) {
StringRef ConstantName = ALE ? "__NSArray0__" : "__NSDictionary0__";
QualType IdTy(CGM.getContext().getObjCIdType());
llvm::Constant *Constant =
CGM.CreateRuntimeVariable(ConvertType(IdTy), ConstantName);
LValue LV = MakeNaturalAlignAddrLValue(Constant, IdTy);
llvm::Value *Ptr = EmitLoadOfScalar(LV, E->getBeginLoc());
cast<llvm::LoadInst>(Ptr)->setMetadata(
CGM.getModule().getMDKindID("invariant.load"),
llvm::MDNode::get(getLLVMContext(), None));
return Builder.CreateBitCast(Ptr, ConvertType(E->getType()));
}
// Compute the type of the array we're initializing.
llvm::APInt APNumElements(Context.getTypeSize(Context.getSizeType()),
NumElements);
QualType ElementType = Context.getObjCIdType().withConst();
QualType ElementArrayType
= Context.getConstantArrayType(ElementType, APNumElements, nullptr,
ArrayType::Normal, /*IndexTypeQuals=*/0);
// Allocate the temporary array(s).
Address Objects = CreateMemTemp(ElementArrayType, "objects");
Address Keys = Address::invalid();
if (DLE)
Keys = CreateMemTemp(ElementArrayType, "keys");
// In ARC, we may need to do extra work to keep all the keys and
// values alive until after the call.
SmallVector<llvm::Value *, 16> NeededObjects;
bool TrackNeededObjects =
(getLangOpts().ObjCAutoRefCount &&
CGM.getCodeGenOpts().OptimizationLevel != 0);
// Perform the actual initialialization of the array(s).
for (uint64_t i = 0; i < NumElements; i++) {
if (ALE) {
// Emit the element and store it to the appropriate array slot.
const Expr *Rhs = ALE->getElement(i);
LValue LV = MakeAddrLValue(Builder.CreateConstArrayGEP(Objects, i),
ElementType, AlignmentSource::Decl);
llvm::Value *value = EmitScalarExpr(Rhs);
EmitStoreThroughLValue(RValue::get(value), LV, true);
if (TrackNeededObjects) {
NeededObjects.push_back(value);
}
} else {
// Emit the key and store it to the appropriate array slot.
const Expr *Key = DLE->getKeyValueElement(i).Key;
LValue KeyLV = MakeAddrLValue(Builder.CreateConstArrayGEP(Keys, i),
ElementType, AlignmentSource::Decl);
llvm::Value *keyValue = EmitScalarExpr(Key);
EmitStoreThroughLValue(RValue::get(keyValue), KeyLV, /*isInit=*/true);
// Emit the value and store it to the appropriate array slot.
const Expr *Value = DLE->getKeyValueElement(i).Value;
LValue ValueLV = MakeAddrLValue(Builder.CreateConstArrayGEP(Objects, i),
ElementType, AlignmentSource::Decl);
llvm::Value *valueValue = EmitScalarExpr(Value);
EmitStoreThroughLValue(RValue::get(valueValue), ValueLV, /*isInit=*/true);
if (TrackNeededObjects) {
NeededObjects.push_back(keyValue);
NeededObjects.push_back(valueValue);
}
}
}
// Generate the argument list.
CallArgList Args;
ObjCMethodDecl::param_const_iterator PI = MethodWithObjects->param_begin();
const ParmVarDecl *argDecl = *PI++;
QualType ArgQT = argDecl->getType().getUnqualifiedType();
Args.add(RValue::get(Objects.getPointer()), ArgQT);
if (DLE) {
argDecl = *PI++;
ArgQT = argDecl->getType().getUnqualifiedType();
Args.add(RValue::get(Keys.getPointer()), ArgQT);
}
argDecl = *PI;
ArgQT = argDecl->getType().getUnqualifiedType();
llvm::Value *Count =
llvm::ConstantInt::get(CGM.getTypes().ConvertType(ArgQT), NumElements);
Args.add(RValue::get(Count), ArgQT);
// Generate a reference to the class pointer, which will be the receiver.
Selector Sel = MethodWithObjects->getSelector();
QualType ResultType = E->getType();
const ObjCObjectPointerType *InterfacePointerType
= ResultType->getAsObjCInterfacePointerType();
ObjCInterfaceDecl *Class
= InterfacePointerType->getObjectType()->getInterface();
CGObjCRuntime &Runtime = CGM.getObjCRuntime();
llvm::Value *Receiver = Runtime.GetClass(*this, Class);
// Generate the message send.
RValue result = Runtime.GenerateMessageSend(
*this, ReturnValueSlot(), MethodWithObjects->getReturnType(), Sel,
Receiver, Args, Class, MethodWithObjects);
// The above message send needs these objects, but in ARC they are
// passed in a buffer that is essentially __unsafe_unretained.
// Therefore we must prevent the optimizer from releasing them until
// after the call.
if (TrackNeededObjects) {
EmitARCIntrinsicUse(NeededObjects);
}
return Builder.CreateBitCast(result.getScalarVal(),
ConvertType(E->getType()));
}
llvm::Value *CodeGenFunction::EmitObjCArrayLiteral(const ObjCArrayLiteral *E) {
return EmitObjCCollectionLiteral(E, E->getArrayWithObjectsMethod());
}
llvm::Value *CodeGenFunction::EmitObjCDictionaryLiteral(
const ObjCDictionaryLiteral *E) {
return EmitObjCCollectionLiteral(E, E->getDictWithObjectsMethod());
}
/// 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(*this, E->getSelector());
}
llvm::Value *CodeGenFunction::EmitObjCProtocolExpr(const ObjCProtocolExpr *E) {
// FIXME: This should pass the Decl not the name.
return CGM.getObjCRuntime().GenerateProtocolRef(*this, E->getProtocol());
}
/// Adjust the type of an Objective-C object that doesn't match up due
/// to type erasure at various points, e.g., related result types or the use
/// of parameterized classes.
static RValue AdjustObjCObjectType(CodeGenFunction &CGF, QualType ExpT,
RValue Result) {
if (!ExpT->isObjCRetainableType())
return Result;
// If the converted types are the same, we're done.
llvm::Type *ExpLLVMTy = CGF.ConvertType(ExpT);
if (ExpLLVMTy == Result.getScalarVal()->getType())
return Result;
// We have applied a substitution. Cast the rvalue appropriately.
return RValue::get(CGF.Builder.CreateBitCast(Result.getScalarVal(),
ExpLLVMTy));
}
/// 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();
// Look through OVEs.
if (auto opaque = dyn_cast<OpaqueValueExpr>(receiver)) {
if (opaque->getSourceExpr())
receiver = opaque->getSourceExpr()->IgnoreParens();
}
const ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(receiver);
if (!ice || ice->getCastKind() != CK_LValueToRValue) return true;
receiver = ice->getSubExpr()->IgnoreParens();
// Look through OVEs.
if (auto opaque = dyn_cast<OpaqueValueExpr>(receiver)) {
if (opaque->getSourceExpr())
receiver = opaque->getSourceExpr()->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");
}
/// Given an expression of ObjC pointer type, check whether it was
/// immediately loaded from an ARC __weak l-value.
static const Expr *findWeakLValue(const Expr *E) {
assert(E->getType()->isObjCRetainableType());
E = E->IgnoreParens();
if (auto CE = dyn_cast<CastExpr>(E)) {
if (CE->getCastKind() == CK_LValueToRValue) {
if (CE->getSubExpr()->getType().getObjCLifetime() == Qualifiers::OCL_Weak)
return CE->getSubExpr();
}
}
return nullptr;
}
/// The ObjC runtime may provide entrypoints that are likely to be faster
/// than an ordinary message send of the appropriate selector.
///
/// The entrypoints are guaranteed to be equivalent to just sending the
/// corresponding message. If the entrypoint is implemented naively as just a
/// message send, using it is a trade-off: it sacrifices a few cycles of
/// overhead to save a small amount of code. However, it's possible for
/// runtimes to detect and special-case classes that use "standard"
/// behavior; if that's dynamically a large proportion of all objects, using
/// the entrypoint will also be faster than using a message send.
///
/// If the runtime does support a required entrypoint, then this method will
/// generate a call and return the resulting value. Otherwise it will return
/// None and the caller can generate a msgSend instead.
static Optional<llvm::Value *>
tryGenerateSpecializedMessageSend(CodeGenFunction &CGF, QualType ResultType,
llvm::Value *Receiver,
const CallArgList& Args, Selector Sel,
const ObjCMethodDecl *method,
bool isClassMessage) {
auto &CGM = CGF.CGM;
if (!CGM.getCodeGenOpts().ObjCConvertMessagesToRuntimeCalls)
return None;
auto &Runtime = CGM.getLangOpts().ObjCRuntime;
switch (Sel.getMethodFamily()) {
case OMF_alloc:
if (isClassMessage &&
Runtime.shouldUseRuntimeFunctionsForAlloc() &&
ResultType->isObjCObjectPointerType()) {
// [Foo alloc] -> objc_alloc(Foo) or
// [self alloc] -> objc_alloc(self)
if (Sel.isUnarySelector() && Sel.getNameForSlot(0) == "alloc")
return CGF.EmitObjCAlloc(Receiver, CGF.ConvertType(ResultType));
// [Foo allocWithZone:nil] -> objc_allocWithZone(Foo) or
// [self allocWithZone:nil] -> objc_allocWithZone(self)
if (Sel.isKeywordSelector() && Sel.getNumArgs() == 1 &&
Args.size() == 1 && Args.front().getType()->isPointerType() &&
Sel.getNameForSlot(0) == "allocWithZone") {
const llvm::Value* arg = Args.front().getKnownRValue().getScalarVal();
if (isa<llvm::ConstantPointerNull>(arg))
return CGF.EmitObjCAllocWithZone(Receiver,
CGF.ConvertType(ResultType));
return None;
}
}
break;
case OMF_autorelease:
if (ResultType->isObjCObjectPointerType() &&
CGM.getLangOpts().getGC() == LangOptions::NonGC &&
Runtime.shouldUseARCFunctionsForRetainRelease())
return CGF.EmitObjCAutorelease(Receiver, CGF.ConvertType(ResultType));
break;
case OMF_retain:
if (ResultType->isObjCObjectPointerType() &&
CGM.getLangOpts().getGC() == LangOptions::NonGC &&
Runtime.shouldUseARCFunctionsForRetainRelease())
return CGF.EmitObjCRetainNonBlock(Receiver, CGF.ConvertType(ResultType));
break;
case OMF_release:
if (ResultType->isVoidType() &&
CGM.getLangOpts().getGC() == LangOptions::NonGC &&
Runtime.shouldUseARCFunctionsForRetainRelease()) {
CGF.EmitObjCRelease(Receiver, ARCPreciseLifetime);
return nullptr;
}
break;
default:
break;
}
return None;
}
CodeGen::RValue CGObjCRuntime::GeneratePossiblySpecializedMessageSend(
CodeGenFunction &CGF, ReturnValueSlot Return, QualType ResultType,
Selector Sel, llvm::Value *Receiver, const CallArgList &Args,
const ObjCInterfaceDecl *OID, const ObjCMethodDecl *Method,
bool isClassMessage) {
if (Optional<llvm::Value *> SpecializedResult =
tryGenerateSpecializedMessageSend(CGF, ResultType, Receiver, Args,
Sel, Method, isClassMessage)) {
return RValue::get(SpecializedResult.getValue());
}
return GenerateMessageSend(CGF, Return, ResultType, Sel, Receiver, Args, OID,
Method);
}
/// Instead of '[[MyClass alloc] init]', try to generate
/// 'objc_alloc_init(MyClass)'. This provides a code size improvement on the
/// caller side, as well as the optimized objc_alloc.
static Optional<llvm::Value *>
tryEmitSpecializedAllocInit(CodeGenFunction &CGF, const ObjCMessageExpr *OME) {
auto &Runtime = CGF.getLangOpts().ObjCRuntime;
if (!Runtime.shouldUseRuntimeFunctionForCombinedAllocInit())
return None;
// Match the exact pattern '[[MyClass alloc] init]'.
Selector Sel = OME->getSelector();
if (OME->getReceiverKind() != ObjCMessageExpr::Instance ||
!OME->getType()->isObjCObjectPointerType() || !Sel.isUnarySelector() ||
Sel.getNameForSlot(0) != "init")
return None;
// Okay, this is '[receiver init]', check if 'receiver' is '[cls alloc]'
// with 'cls' a Class.
auto *SubOME =
dyn_cast<ObjCMessageExpr>(OME->getInstanceReceiver()->IgnoreParenCasts());
if (!SubOME)
return None;
Selector SubSel = SubOME->getSelector();
if (!SubOME->getType()->isObjCObjectPointerType() ||
!SubSel.isUnarySelector() || SubSel.getNameForSlot(0) != "alloc")
return None;
llvm::Value *Receiver = nullptr;
switch (SubOME->getReceiverKind()) {
case ObjCMessageExpr::Instance:
if (!SubOME->getInstanceReceiver()->getType()->isObjCClassType())
return None;
Receiver = CGF.EmitScalarExpr(SubOME->getInstanceReceiver());
break;
case ObjCMessageExpr::Class: {
QualType ReceiverType = SubOME->getClassReceiver();
const ObjCObjectType *ObjTy = ReceiverType->castAs<ObjCObjectType>();
const ObjCInterfaceDecl *ID = ObjTy->getInterface();
assert(ID && "null interface should be impossible here");
Receiver = CGF.CGM.getObjCRuntime().GetClass(CGF, ID);
break;
}
case ObjCMessageExpr::SuperInstance:
case ObjCMessageExpr::SuperClass:
return None;
}
return CGF.EmitObjCAllocInit(Receiver, CGF.ConvertType(OME->getType()));
}
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();
// If the method is -retain, and the receiver's being loaded from
// a __weak variable, peephole the entire operation to objc_loadWeakRetained.
if (method && E->getReceiverKind() == ObjCMessageExpr::Instance &&
method->getMethodFamily() == OMF_retain) {
if (auto lvalueExpr = findWeakLValue(E->getInstanceReceiver())) {
LValue lvalue = EmitLValue(lvalueExpr);
llvm::Value *result = EmitARCLoadWeakRetained(lvalue.getAddress(*this));
return AdjustObjCObjectType(*this, E->getType(), RValue::get(result));
}
}
if (Optional<llvm::Value *> Val = tryEmitSpecializedAllocInit(*this, E))
return AdjustObjCObjectType(*this, E->getType(), RValue::get(*Val));
// 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.getLangOpts().ObjCAutoRefCount &&
method &&
method->hasAttr<NSConsumesSelfAttr>());
CGObjCRuntime &Runtime = CGM.getObjCRuntime();
bool isSuperMessage = false;
bool isClassMessage = false;
ObjCInterfaceDecl *OID = nullptr;
// Find the receiver
QualType ReceiverType;
llvm::Value *Receiver = nullptr;
switch (E->getReceiverKind()) {
case ObjCMessageExpr::Instance:
ReceiverType = E->getInstanceReceiver()->getType();
isClassMessage = ReceiverType->isObjCClassType();
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();
OID = ReceiverType->castAs<ObjCObjectType>()->getInterface();
assert(OID && "Invalid Objective-C class message send");
Receiver = Runtime.GetClass(*this, 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 (getLangOpts().ObjCAutoRefCount && method &&
method->hasAttr<ObjCReturnsInnerPointerAttr>() &&
shouldExtendReceiverForInnerPointerMessage(E))
Receiver = EmitARCRetainAutorelease(ReceiverType, Receiver);
QualType ResultType = method ? method->getReturnType() : E->getType();
CallArgList Args;
EmitCallArgs(Args, method, E->arguments(), /*AC*/AbstractCallee(method));
// 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(getLangOpts().ObjCAutoRefCount &&
"delegate init calls should only be marked in ARC");
// Do an unsafe store of null into self.
Address selfAddr =
GetAddrOfLocalVar(cast<ObjCMethodDecl>(CurCodeDecl)->getSelfDecl());
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 {
// Call runtime methods directly if we can.
result = Runtime.GeneratePossiblySpecializedMessageSend(
*this, Return, ResultType, E->getSelector(), Receiver, Args, OID,
method, isClassMessage);
}
// For delegate init calls in ARC, implicitly store the result of
// the call back into self. This takes ownership of the value.
if (isDelegateInit) {
Address selfAddr =
GetAddrOfLocalVar(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 = selfAddr.getElementType();
newSelf = Builder.CreateBitCast(newSelf, selfTy);
Builder.CreateStore(newSelf, selfAddr);
}
return AdjustObjCObjectType(*this, E->getType(), result);
}
namespace {
struct FinishARCDealloc final : EHScopeStack::Cleanup {
void Emit(CodeGenFunction &CGF, Flags flags) override {
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 = OMD->getBeginLoc();
FunctionArgList args;
// Check if we should generate debug info for this method.
if (OMD->hasAttr<NoDebugAttr>())
DebugInfo = nullptr; // disable debug info indefinitely for this function
llvm::Function *Fn = CGM.getObjCRuntime().GenerateMethod(OMD, CD);
const CGFunctionInfo &FI = CGM.getTypes().arrangeObjCMethodDeclaration(OMD);
if (OMD->isDirectMethod()) {
Fn->setVisibility(llvm::Function::HiddenVisibility);
CGM.SetLLVMFunctionAttributes(OMD, FI, Fn);
CGM.SetLLVMFunctionAttributesForDefinition(OMD, Fn);
} else {
CGM.SetInternalFunctionAttributes(OMD, Fn, FI);
}
args.push_back(OMD->getSelfDecl());
args.push_back(OMD->getCmdDecl());
args.append(OMD->param_begin(), OMD->param_end());
CurGD = OMD;
CurEHLocation = OMD->getEndLoc();
StartFunction(OMD, OMD->getReturnType(), Fn, FI, args,
OMD->getLocation(), StartLoc);
if (OMD->isDirectMethod()) {
// This function is a direct call, it has to implement a nil check
// on entry.
//
// TODO: possibly have several entry points to elide the check
CGM.getObjCRuntime().GenerateDirectMethodPrologue(*this, Fn, OMD, CD);
}
// In ARC, certain methods get an extra cleanup.
if (CGM.getLangOpts().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 structure.
void CodeGenFunction::GenerateObjCMethod(const ObjCMethodDecl *OMD) {
StartObjCMethod(OMD, OMD->getClassInterface());
PGO.assignRegionCounters(GlobalDecl(OMD), CurFn);
assert(isa<CompoundStmt>(OMD->getBody()));
incrementProfileCounter(OMD->getBody());
EmitCompoundStmtWithoutScope(*cast<CompoundStmt>(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();
Address src =
CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), CGF.LoadObjCSelf(), ivar, 0)
.getAddress(CGF);
// objc_copyStruct (ReturnValue, &structIvar,
// sizeof (Type of Ivar), isAtomic, false);
CallArgList args;
Address dest = CGF.Builder.CreateBitCast(CGF.ReturnValue, CGF.VoidPtrTy);
args.add(RValue::get(dest.getPointer()), Context.VoidPtrTy);
src = CGF.Builder.CreateBitCast(src, CGF.VoidPtrTy);
args.add(RValue::get(src.getPointer()), 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::FunctionCallee fn = CGF.CGM.getObjCRuntime().GetGetStructFunction();
CGCallee callee = CGCallee::forDirect(fn);
CGF.EmitCall(CGF.getTypes().arrangeBuiltinFunctionCall(Context.VoidTy, args),
callee, 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 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();
std::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.getLangOpts().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.getLangOpts().ObjCAutoRefCount && !IsAtomic) {
// Using standard expression emission for the setter is only
// acceptable if the ivar is __strong, which won't be true if
// the property is annotated with __attribute__((NSObject)).
// TODO: falling all the way back to objc_setProperty here is
// just laziness, though; we could still use objc_storeStrong
// if we hacked it right.
if (ivarType.getObjCLifetime() == Qualifiers::OCL_Strong)
Kind = Expression;
else
Kind = SetPropertyAndExpressionGet;
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.getLangOpts().getGC() &&
CGM.getContext().getObjCGCAttrKind(ivarType))) {
Kind = Expression;
return;
}
// Compute whether the ivar has strong members.
if (CGM.getLangOpts().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.getTarget().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;
}
/// 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) {
llvm::Constant *AtomicHelperFn =
CodeGenFunction(CGM).GenerateObjCAtomicGetterCopyHelperFunction(PID);
ObjCMethodDecl *OMD = PID->getGetterMethodDecl();
assert(OMD && "Invalid call to generate getter (empty method)");
StartObjCMethod(OMD, IMP->getClassInterface());
generateObjCGetterBody(IMP, PID, OMD, AtomicHelperFn);
FinishFunction(OMD->getEndLoc());
}
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;
}
/// emitCPPObjectAtomicGetterCall - Call the runtime function to
/// copy the ivar into the resturn slot.
static void emitCPPObjectAtomicGetterCall(CodeGenFunction &CGF,
llvm::Value *returnAddr,
ObjCIvarDecl *ivar,
llvm::Constant *AtomicHelperFn) {
// objc_copyCppObjectAtomic (&returnSlot, &CppObjectIvar,
// AtomicHelperFn);
CallArgList args;
// The 1st argument is the return Slot.
args.add(RValue::get(returnAddr), CGF.getContext().VoidPtrTy);
// The 2nd argument is the address of the ivar.
llvm::Value *ivarAddr =
CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), CGF.LoadObjCSelf(), ivar, 0)
.getPointer(CGF);
ivarAddr = CGF.Builder.CreateBitCast(ivarAddr, CGF.Int8PtrTy);
args.add(RValue::get(ivarAddr), CGF.getContext().VoidPtrTy);
// Third argument is the helper function.
args.add(RValue::get(AtomicHelperFn), CGF.getContext().VoidPtrTy);
llvm::FunctionCallee copyCppAtomicObjectFn =
CGF.CGM.getObjCRuntime().GetCppAtomicObjectGetFunction();
CGCallee callee = CGCallee::forDirect(copyCppAtomicObjectFn);
CGF.EmitCall(
CGF.getTypes().arrangeBuiltinFunctionCall(CGF.getContext().VoidTy, args),
callee, ReturnValueSlot(), args);
}
void
CodeGenFunction::generateObjCGetterBody(const ObjCImplementationDecl *classImpl,
const ObjCPropertyImplDecl *propImpl,
const ObjCMethodDecl *GetterMethodDecl,
llvm::Constant *AtomicHelperFn) {
// If there's a non-trivial 'get' expression, we just have to emit that.
if (!hasTrivialGetExpr(propImpl)) {
if (!AtomicHelperFn) {
auto *ret = ReturnStmt::Create(getContext(), SourceLocation(),
propImpl->getGetterCXXConstructor(),
/* NRVOCandidate=*/nullptr);
EmitReturnStmt(*ret);
}
else {
ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
emitCPPObjectAtomicGetterCall(*this, ReturnValue.getPointer(),
ivar, AtomicHelperFn);
}
return;
}
const ObjCPropertyDecl *prop = propImpl->getPropertyDecl();
QualType propType = prop->getType();
ObjCMethodDecl *getterMethod = propImpl->getGetterMethodDecl();
ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
// Pick an implementation strategy.
PropertyImplStrategy strategy(CGM, propImpl);
switch (strategy.getKind()) {
case PropertyImplStrategy::Native: {
// We don't need to do anything for a zero-size struct.
if (strategy.getIvarSize().isZero())
return;
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.
uint64_t ivarSize = getContext().toBits(strategy.getIvarSize());
llvm::Type *bitcastType = llvm::Type::getIntNTy(getLLVMContext(), ivarSize);
bitcastType = bitcastType->getPointerTo(); // addrspace 0 okay
// Perform an atomic load. This does not impose ordering constraints.
Address ivarAddr = LV.getAddress(*this);
ivarAddr = Builder.CreateBitCast(ivarAddr, bitcastType);
llvm::LoadInst *load = Builder.CreateLoad(ivarAddr, "load");
load->setAtomic(llvm::AtomicOrdering::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.
llvm::Type *retTy = ConvertType(getterMethod->getReturnType());
uint64_t retTySize = CGM.getDataLayout().getTypeSizeInBits(retTy);
llvm::Value *ivarVal = load;
if (ivarSize > retTySize) {
llvm::Type *newTy = llvm::Type::getIntNTy(getLLVMContext(), retTySize);
ivarVal = Builder.CreateTrunc(load, newTy);
bitcastType = newTy->getPointerTo();
}
Builder.CreateStore(ivarVal,
Builder.CreateBitCast(ReturnValue, bitcastType));
// Make sure we don't do an autorelease.
AutoreleaseResult = false;
return;
}
case PropertyImplStrategy::GetSetProperty: {
llvm::FunctionCallee getPropertyFn =
CGM.getObjCRuntime().GetPropertyGetFunction();
if (!getPropertyFn) {
CGM.ErrorUnsupported(propImpl, "Obj-C getter requiring atomic copy");
return;
}
CGCallee callee = CGCallee::forDirect(getPropertyFn);
// 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(GetAddrOfLocalVar(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.
llvm::CallBase *CallInstruction;
RValue RV = EmitCall(getTypes().arrangeBuiltinFunctionCall(
getContext().getObjCIdType(), args),
callee, ReturnValueSlot(), args, &CallInstruction);
if (llvm::CallInst *call = dyn_cast<llvm::CallInst>(CallInstruction))
call->setTailCall();
// 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(getterMethod->getReturnType())));
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();
switch (getEvaluationKind(ivarType)) {
case TEK_Complex: {
ComplexPairTy pair = EmitLoadOfComplex(LV, SourceLocation());
EmitStoreOfComplex(pair, MakeAddrLValue(ReturnValue, ivarType),
/*init*/ true);
return;
}
case TEK_Aggregate: {
// 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(/* Dest= */ MakeAddrLValue(ReturnValue, ivarType),
/* Src= */ LV, ivarType, getOverlapForReturnValue());
return;
}
case TEK_Scalar: {
llvm::Value *value;
if (propType->isReferenceType()) {
value = LV.getAddress(*this).getPointer();
} else {
// We want to load and autoreleaseReturnValue ARC __weak ivars.
if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) {
if (getLangOpts().ObjCAutoRefCount) {
value = emitARCRetainLoadOfScalar(*this, LV, ivarType);
} else {
value = EmitARCLoadWeak(LV.getAddress(*this));
}
// Otherwise we want to do a simple load, suppressing the
// final autorelease.
} else {
value = EmitLoadOfLValue(LV, SourceLocation()).getScalarVal();
AutoreleaseResult = false;
}
value = Builder.CreateBitCast(
value, ConvertType(GetterMethodDecl->getReturnType()));
}
EmitReturnOfRValue(RValue::get(value), propType);
return;
}
}
llvm_unreachable("bad evaluation kind");
}
}
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)
.getPointer(CGF);
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(CGF.getContext(), argVar, false,
argVar->getType().getNonReferenceType(), VK_LValue,
SourceLocation());
llvm::Value *argAddr = CGF.EmitLValue(&argRef).getPointer(CGF);
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::FunctionCallee fn = CGF.CGM.getObjCRuntime().GetSetStructFunction();
CGCallee callee = CGCallee::forDirect(fn);
CGF.EmitCall(
CGF.getTypes().arrangeBuiltinFunctionCall(CGF.getContext().VoidTy, args),
callee, ReturnValueSlot(), args);
}
/// emitCPPObjectAtomicSetterCall - Call the runtime function to store
/// the value from the first formal parameter into the given ivar, using
/// the Cpp API for atomic Cpp objects with non-trivial copy assignment.
static void emitCPPObjectAtomicSetterCall(CodeGenFunction &CGF,
ObjCMethodDecl *OMD,
ObjCIvarDecl *ivar,
llvm::Constant *AtomicHelperFn) {
// objc_copyCppObjectAtomic (&CppObjectIvar, &Arg,
// AtomicHelperFn);
CallArgList args;
// The first argument is the address of the ivar.
llvm::Value *ivarAddr =
CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), CGF.LoadObjCSelf(), ivar, 0)
.getPointer(CGF);
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(CGF.getContext(), argVar, false,
argVar->getType().getNonReferenceType(), VK_LValue,
SourceLocation());
llvm::Value *argAddr = CGF.EmitLValue(&argRef).getPointer(CGF);
argAddr = CGF.Builder.CreateBitCast(argAddr, CGF.Int8PtrTy);
args.add(RValue::get(argAddr), CGF.getContext().VoidPtrTy);
// Third argument is the helper function.
args.add(RValue::get(AtomicHelperFn), CGF.getContext().VoidPtrTy);
llvm::FunctionCallee fn =
CGF.CGM.getObjCRuntime().GetCppAtomicObjectSetFunction();
CGCallee callee = CGCallee::forDirect(fn);
CGF.EmitCall(
CGF.getTypes().arrangeBuiltinFunctionCall(CGF.getContext().VoidTy, args),
callee, 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;
}
static bool UseOptimizedSetter(CodeGenModule &CGM) {
if (CGM.getLangOpts().getGC() != LangOptions::NonGC)
return false;
return CGM.getLangOpts().ObjCRuntime.hasOptimizedSetter();
}
void
CodeGenFunction::generateObjCSetterBody(const ObjCImplementationDecl *classImpl,
const ObjCPropertyImplDecl *propImpl,
llvm::Constant *AtomicHelperFn) {
ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
ObjCMethodDecl *setterMethod = propImpl->getSetterMethodDecl();
// Just use the setter expression if Sema gave us one and it's
// non-trivial.
if (!hasTrivialSetExpr(propImpl)) {
if (!AtomicHelperFn)
// If non-atomic, assignment is called directly.
EmitStmt(propImpl->getSetterCXXAssignment());
else
// If atomic, assignment is called via a locking api.
emitCPPObjectAtomicSetterCall(*this, setterMethod, ivar,
AtomicHelperFn);
return;
}
PropertyImplStrategy strategy(CGM, propImpl);
switch (strategy.getKind()) {
case PropertyImplStrategy::Native: {
// We don't need to do anything for a zero-size struct.
if (strategy.getIvarSize().isZero())
return;
Address argAddr = GetAddrOfLocalVar(*setterMethod->param_begin());
LValue ivarLValue =
EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, /*quals*/ 0);
Address ivarAddr = ivarLValue.getAddress(*this);
// 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()));
// Cast both arguments to the chosen operation type.
argAddr = Builder.CreateElementBitCast(argAddr, bitcastType);
ivarAddr = Builder.CreateElementBitCast(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->setAtomic(llvm::AtomicOrdering::Unordered);
return;
}
case PropertyImplStrategy::GetSetProperty:
case PropertyImplStrategy::SetPropertyAndExpressionGet: {
llvm::FunctionCallee setOptimizedPropertyFn = nullptr;
llvm::FunctionCallee setPropertyFn = nullptr;
if (UseOptimizedSetter(CGM)) {
// 10.8 and iOS 6.0 code and GC is off
setOptimizedPropertyFn =
CGM.getObjCRuntime().GetOptimizedPropertySetFunction(
strategy.isAtomic(), strategy.isCopy());
if (!setOptimizedPropertyFn) {
CGM.ErrorUnsupported(propImpl, "Obj-C optimized setter - NYI");
return;
}
}
else {
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(GetAddrOfLocalVar(setterMethod->getCmdDecl()));
llvm::Value *self =
Builder.CreateBitCast(LoadObjCSelf(), VoidPtrTy);
llvm::Value *ivarOffset =
EmitIvarOffset(classImpl->getClassInterface(), ivar);
Address argAddr = GetAddrOfLocalVar(*setterMethod->param_begin());
llvm::Value *arg = Builder.CreateLoad(argAddr, "arg");
arg = Builder.CreateBitCast(arg, VoidPtrTy);
CallArgList args;
args.add(RValue::get(self), getContext().getObjCIdType());
args.add(RValue::get(cmd), getContext().getObjCSelType());
if (setOptimizedPropertyFn) {
args.add(RValue::get(arg), getContext().getObjCIdType());
args.add(RValue::get(ivarOffset), getContext().getPointerDiffType());
CGCallee callee = CGCallee::forDirect(setOptimizedPropertyFn);
EmitCall(getTypes().arrangeBuiltinFunctionCall(getContext().VoidTy, args),
callee, ReturnValueSlot(), args);
} else {
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.
CGCallee callee = CGCallee::forDirect(setPropertyFn);
EmitCall(getTypes().arrangeBuiltinFunctionCall(getContext().VoidTy, args),
callee, 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(getContext(), selfDecl, false, selfDecl->getType(),
VK_LValue, SourceLocation());
ImplicitCastExpr selfLoad(ImplicitCastExpr::OnStack,
selfDecl->getType(), CK_LValueToRValue, &self,
VK_RValue);
ObjCIvarRefExpr ivarRef(ivar, ivar->getType().getNonReferenceType(),
SourceLocation(), SourceLocation(),
&selfLoad, true, true);
ParmVarDecl *argDecl = *setterMethod->param_begin();
QualType argType = argDecl->getType().getNonReferenceType();
DeclRefExpr arg(getContext(), argDecl, false, 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 = BinaryOperator::Create(
getContext(), &ivarRef, finalArg, BO_Assign, ivarRef.getType(), VK_RValue,
OK_Ordinary, SourceLocation(),
FPOptions(getContext().getLangOpts()));
EmitStmt(assign);
}
/// 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) {
llvm::Constant *AtomicHelperFn =
CodeGenFunction(CGM).GenerateObjCAtomicSetterCopyHelperFunction(PID);
ObjCMethodDecl *OMD = PID->getSetterMethodDecl();
assert(OMD && "Invalid call to generate setter (empty method)");
StartObjCMethod(OMD, IMP->getClassInterface());
generateObjCSetterBody(IMP, PID, AtomicHelperFn);
FinishFunction(OMD->getEndLoc());
}
namespace {
struct DestroyIvar final : 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) override {
LValue lvalue
= CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), addr, ivar, /*CVR*/ 0);
CGF.emitDestroy(lvalue.getAddress(CGF), ivar->getType(), destroyer,
flags.isForNormalCleanup() && useEHCleanupForArray);
}
};
}
/// Like CodeGenFunction::destroyARCStrong, but do it with a call.
static void destroyARCStrongWithStore(CodeGenFunction &CGF,
Address 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 = nullptr;
// 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());
// Emit .cxx_construct.
if (ctor) {
// Suppress the final autorelease in ARC.
AutoreleaseResult = false;
for (const auto *IvarInit : IMP->inits()) {
FieldDecl *Field = IvarInit->getAnyMember();
ObjCIvarDecl *Ivar = cast<ObjCIvarDecl>(Field);
LValue LV = EmitLValueForIvar(TypeOfSelfObject(),
LoadObjCSelf(), Ivar, 0);
EmitAggExpr(IvarInit->getInit(),
AggValueSlot::forLValue(LV, *this, AggValueSlot::IsDestructed,
AggValueSlot::DoesNotNeedGCBarriers,
AggValueSlot::IsNotAliased,
AggValueSlot::DoesNotOverlap));
}
// 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();
}
llvm::Value *CodeGenFunction::LoadObjCSelf() {
VarDecl *Self = cast<ObjCMethodDecl>(CurFuncDecl)->getSelfDecl();
DeclRefExpr DRE(getContext(), Self,
/*is enclosing local*/ (CurFuncDecl != CurCodeDecl),
Self->getType(), VK_LValue, SourceLocation());
return EmitLoadOfScalar(EmitDeclRefLValue(&DRE), SourceLocation());
}
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::FunctionCallee EnumerationMutationFnPtr =
CGM.getObjCRuntime().EnumerationMutationFunction();
if (!EnumerationMutationFnPtr) {
CGM.ErrorUnsupported(&S, "Obj-C fast enumeration for this runtime");
return;
}
CGCallee EnumerationMutationFn =
CGCallee::forDirect(EnumerationMutationFnPtr);
CGDebugInfo *DI = getDebugInfo();
if (DI)
DI->EmitLexicalBlockStart(Builder, S.getSourceRange().getBegin());
RunCleanupsScope ForScope(*this);
// 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();
Address 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), nullptr,
ArrayType::Normal, 0);
Address ItemsPtr = CreateMemTemp(ItemsTy, "items.ptr");
// Emit the collection pointer. In ARC, we do a retain.
llvm::Value *Collection;
if (getLangOpts().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.getPointer()),
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.getPointer()),
getContext().getPointerType(ItemsTy));
// The third argument is the capacity of that temporary array.
llvm::Type *NSUIntegerTy = ConvertType(getContext().getNSUIntegerType());
llvm::Constant *Count = llvm::ConstantInt::get(NSUIntegerTy, NumItems);
Args.add(RValue::get(Count), getContext().getNSUIntegerType());
// Start the enumeration.
RValue CountRV =
CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(),
getContext().getNSUIntegerType(),
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(NSUIntegerTy);
// If the limit pointer was zero to begin with, the collection is
// empty; skip all this. Set the branch weight assuming this has the same
// probability of exiting the loop as any other loop exit.
uint64_t EntryCount = getCurrentProfileCount();
Builder.CreateCondBr(
Builder.CreateICmpEQ(initialBufferLimit, zero, "iszero"), EmptyBB,
LoopInitBB,
createProfileWeights(EntryCount, getProfileCount(S.getBody())));
// 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:.
Address StateMutationsPtrPtr =
Builder.CreateStructGEP(StatePtr, 2, "mutationsptr.ptr");
llvm::Value *StateMutationsPtr
= Builder.CreateLoad(StateMutationsPtrPtr, "mutationsptr");
llvm::Value *initialMutations =
Builder.CreateAlignedLoad(StateMutationsPtr, getPointerAlign(),
"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(NSUIntegerTy, 3, "forcoll.index");
index->addIncoming(zero, LoopInitBB);
// The current buffer size.
llvm::PHINode *count = Builder.CreatePHI(NSUIntegerTy, 3, "forcoll.count");
count->addIncoming(initialBufferLimit, LoopInitBB);
incrementProfileCounter(&S);
// 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.CreateAlignedLoad(StateMutationsPtr, getPointerAlign(),
"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().arrangeBuiltinFunctionCall(getContext().VoidTy, Args2),
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(getContext(), const_cast<VarDecl *>(D), false,
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.
Address 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.CreateAlignedLoad(CurrentItemPtr, getPointerAlign());
// 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 {
EmitStoreThroughLValue(RValue::get(CurrentItem), elementLValue,
/*isInit*/ true);
}
// 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(NSUIntegerTy, 1));
// If we haven't overrun the buffer yet, we can continue.
// Set the branch weights based on the simplifying assumption that this is
// like a while-loop, i.e., ignoring that the false branch fetches more
// elements and then returns to the loop.
Builder.CreateCondBr(
Builder.CreateICmpULT(indexPlusOne, count), LoopBodyBB, FetchMoreBB,
createProfileWeights(getProfileCount(S.getBody()), EntryCount));
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().getNSUIntegerType(),
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());
ForScope.ForceCleanup();
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);
}
namespace {
struct CallObjCRelease final : EHScopeStack::Cleanup {
CallObjCRelease(llvm::Value *object) : object(object) {}
llvm::Value *object;
void Emit(CodeGenFunction &CGF, Flags flags) override {
// Releases at the end of the full-expression are imprecise.
CGF.EmitARCRelease(object, ARCImpreciseLifetime);
}
};
}
/// 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);
}
/// Given a number of pointers, inform the optimizer that they're
/// being intrinsically used up until this point in the program.
void CodeGenFunction::EmitARCIntrinsicUse(ArrayRef<llvm::Value*> values) {
llvm::Function *&fn = CGM.getObjCEntrypoints().clang_arc_use;
if (!fn)
fn = CGM.getIntrinsic(llvm::Intrinsic::objc_clang_arc_use);
// This isn't really a "runtime" function, but as an intrinsic it
// doesn't really matter as long as we align things up.
EmitNounwindRuntimeCall(fn, values);
}
static void setARCRuntimeFunctionLinkage(CodeGenModule &CGM, llvm::Value *RTF) {
if (auto *F = dyn_cast<llvm::Function>(RTF)) {
// If the target runtime doesn't naturally support ARC, emit weak
// references to the runtime support library. We don't really
// permit this to fail, but we need a particular relocation style.
if (!CGM.getLangOpts().ObjCRuntime.hasNativeARC() &&
!CGM.getTriple().isOSBinFormatCOFF()) {
F->setLinkage(llvm::Function::ExternalWeakLinkage);
}
}
}
static void setARCRuntimeFunctionLinkage(CodeGenModule &CGM,
llvm::FunctionCallee RTF) {
setARCRuntimeFunctionLinkage(CGM, RTF.getCallee());
}
/// 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::Type *returnType,
llvm::Function *&fn, llvm::Intrinsic::ID IntID,
llvm::CallInst::TailCallKind tailKind = llvm::CallInst::TCK_None) {
if (isa<llvm::ConstantPointerNull>(value))
return value;
if (!fn) {
fn = CGF.CGM.getIntrinsic(IntID);
setARCRuntimeFunctionLinkage(CGF.CGM, fn);
}
// Cast the argument to 'id'.
llvm::Type *origType = returnType ? returnType : value->getType();
value = CGF.Builder.CreateBitCast(value, CGF.Int8PtrTy);
// Call the function.
llvm::CallInst *call = CGF.EmitNounwindRuntimeCall(fn, value);
call->setTailCallKind(tailKind);
// 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, Address addr,
llvm::Function *&fn,
llvm::Intrinsic::ID IntID) {
if (!fn) {
fn = CGF.CGM.getIntrinsic(IntID);
setARCRuntimeFunctionLinkage(CGF.CGM, fn);
}
// Cast the argument to 'id*'.
llvm::Type *origType = addr.getElementType();
addr = CGF.Builder.CreateBitCast(addr, CGF.Int8PtrPtrTy);
// Call the function.
llvm::Value *result = CGF.EmitNounwindRuntimeCall(fn, addr.getPointer());
// Cast the result back to a dereference of the original type.
if (origType != CGF.Int8PtrTy)
result = CGF.Builder.CreateBitCast(result, origType);
return result;
}
/// Perform an operation having the following signature:
/// i8* (i8**, i8*)
static llvm::Value *emitARCStoreOperation(CodeGenFunction &CGF, Address addr,
llvm::Value *value,
llvm::Function *&fn,
llvm::Intrinsic::ID IntID,
bool ignored) {
assert(addr.getElementType() == value->getType());
if (!fn) {
fn = CGF.CGM.getIntrinsic(IntID);
setARCRuntimeFunctionLinkage(CGF.CGM, fn);
}
llvm::Type *origType = value->getType();
llvm::Value *args[] = {
CGF.Builder.CreateBitCast(addr.getPointer(), CGF.Int8PtrPtrTy),
CGF.Builder.CreateBitCast(value, CGF.Int8PtrTy)
};
llvm::CallInst *result = CGF.EmitNounwindRuntimeCall(fn, args);
if (ignored) return nullptr;
return CGF.Builder.CreateBitCast(result, origType);
}
/// Perform an operation having the following signature:
/// void (i8**, i8**)
static void emitARCCopyOperation(CodeGenFunction &CGF, Address dst, Address src,
llvm::Function *&fn,
llvm::Intrinsic::ID IntID) {
assert(dst.getType() == src.getType());
if (!fn) {
fn = CGF.CGM.getIntrinsic(IntID);
setARCRuntimeFunctionLinkage(CGF.CGM, fn);
}
llvm::Value *args[] = {
CGF.Builder.CreateBitCast(dst.getPointer(), CGF.Int8PtrPtrTy),
CGF.Builder.CreateBitCast(src.getPointer(), CGF.Int8PtrPtrTy)
};
CGF.EmitNounwindRuntimeCall(fn, args);
}
/// Perform an operation having the signature
/// i8* (i8*)
/// where a null input causes a no-op and returns null.
static llvm::Value *emitObjCValueOperation(CodeGenFunction &CGF,
llvm::Value *value,
llvm::Type *returnType,
llvm::FunctionCallee &fn,
StringRef fnName) {
if (isa<llvm::ConstantPointerNull>(value))
return value;
if (!fn) {
llvm::FunctionType *fnType =
llvm::FunctionType::get(CGF.Int8PtrTy, CGF.Int8PtrTy, false);
fn = CGF.CGM.CreateRuntimeFunction(fnType, fnName);
// We have Native ARC, so set nonlazybind attribute for performance
if (llvm::Function *f = dyn_cast<llvm::Function>(fn.getCallee()))
if (fnName == "objc_retain")
f->addFnAttr(llvm::Attribute::NonLazyBind);
}
// Cast the argument to 'id'.
llvm::Type *origType = returnType ? returnType : value->getType();
value = CGF.Builder.CreateBitCast(value, CGF.Int8PtrTy);
// Call the function.
llvm::CallBase *Inst = CGF.EmitCallOrInvoke(fn, value);
// Cast the result back to the original type.
return CGF.Builder.CreateBitCast(Inst, origType);
}
/// 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, nullptr,
CGM.getObjCEntrypoints().objc_retain,
llvm::Intrinsic::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, nullptr,
CGM.getObjCEntrypoints().objc_retainBlock,
llvm::Intrinsic::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->getCalledOperand() ==
CGM.getObjCEntrypoints().objc_retainBlock);
call->setMetadata("clang.arc.copy_on_escape",
llvm::MDNode::get(Builder.getContext(), None));
}
return result;
}
static void emitAutoreleasedReturnValueMarker(CodeGenFunction &CGF) {
// Fetch the void(void) inline asm which marks that we're going to
// do something with the autoreleased return value.
llvm::InlineAsm *&marker
= CGF.CGM.getObjCEntrypoints().retainAutoreleasedReturnValueMarker;
if (!marker) {
StringRef assembly
= CGF.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 (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) {
llvm::FunctionType *type =
llvm::FunctionType::get(CGF.VoidTy, /*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 {
const char *markerKey = "clang.arc.retainAutoreleasedReturnValueMarker";
if (!CGF.CGM.getModule().getModuleFlag(markerKey)) {
auto *str = llvm::MDString::get(CGF.getLLVMContext(), assembly);
CGF.CGM.getModule().addModuleFlag(llvm::Module::Error, markerKey, str);
}
}
}
// Call the marker asm if we made one, which we do only at -O0.
if (marker)
CGF.Builder.CreateCall(marker, None, CGF.getBundlesForFunclet(marker));
}
/// 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) {
emitAutoreleasedReturnValueMarker(*this);
llvm::CallInst::TailCallKind tailKind =
CGM.getTargetCodeGenInfo()
.shouldSuppressTailCallsOfRetainAutoreleasedReturnValue()
? llvm::CallInst::TCK_NoTail
: llvm::CallInst::TCK_None;
return emitARCValueOperation(
*this, value, nullptr,
CGM.getObjCEntrypoints().objc_retainAutoreleasedReturnValue,
llvm::Intrinsic::objc_retainAutoreleasedReturnValue, tailKind);
}
/// Claim a possibly-autoreleased return value at +0. This is only
/// valid to do in contexts which do not rely on the retain to keep
/// the object valid for all of its uses; for example, when
/// the value is ignored, or when it is being assigned to an
/// __unsafe_unretained variable.
///
/// call i8* \@objc_unsafeClaimAutoreleasedReturnValue(i8* %value)
llvm::Value *
CodeGenFunction::EmitARCUnsafeClaimAutoreleasedReturnValue(llvm::Value *value) {
emitAutoreleasedReturnValueMarker(*this);
return emitARCValueOperation(*this, value, nullptr,
CGM.getObjCEntrypoints().objc_unsafeClaimAutoreleasedReturnValue,
llvm::Intrinsic::objc_unsafeClaimAutoreleasedReturnValue);
}
/// Release the given object.
/// call void \@objc_release(i8* %value)
void CodeGenFunction::EmitARCRelease(llvm::Value *value,
ARCPreciseLifetime_t precise) {
if (isa<llvm::ConstantPointerNull>(value)) return;
llvm::Function *&fn = CGM.getObjCEntrypoints().objc_release;
if (!fn) {
fn = CGM.getIntrinsic(llvm::Intrinsic::objc_release);
setARCRuntimeFunctionLinkage(CGM, fn);
}
// Cast the argument to 'id'.
value = Builder.CreateBitCast(value, Int8PtrTy);
// Call objc_release.
llvm::CallInst *call = EmitNounwindRuntimeCall(fn, value);
if (precise == ARCImpreciseLifetime) {
call->setMetadata("clang.imprecise_release",
llvm::MDNode::get(Builder.getContext(), None));
}
}
/// Destroy a __strong variable.
///
/// At -O0, emit a call to store 'null' into the address;
/// instrumenting tools prefer this because the address is exposed,
/// but it's relatively cumbersome to optimize.
///
/// At -O1 and above, just load and call objc_release.
///
/// call void \@objc_storeStrong(i8** %addr, i8* null)
void CodeGenFunction::EmitARCDestroyStrong(Address addr,
ARCPreciseLifetime_t precise) {
if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
llvm::Value *null = getNullForVariable(addr);
EmitARCStoreStrongCall(addr, null, /*ignored*/ true);
return;
}
llvm::Value *value = Builder.CreateLoad(addr);
EmitARCRelease(value, precise);
}
/// Store into a strong object. Always calls this:
/// call void \@objc_storeStrong(i8** %addr, i8* %value)
llvm::Value *CodeGenFunction::EmitARCStoreStrongCall(Address addr,
llvm::Value *value,
bool ignored) {
assert(addr.getElementType() == value->getType());
llvm::Function *&fn = CGM.getObjCEntrypoints().objc_storeStrong;
if (!fn) {
fn = CGM.getIntrinsic(llvm::Intrinsic::objc_storeStrong);
setARCRuntimeFunctionLinkage(CGM, fn);
}
llvm::Value *args[] = {
Builder.CreateBitCast(addr.getPointer(), Int8PtrPtrTy),
Builder.CreateBitCast(value, Int8PtrTy)
};
EmitNounwindRuntimeCall(fn, args);
if (ignored) return nullptr;
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().isZero() ||
dst.getAlignment() >= CharUnits::fromQuantity(PointerAlignInBytes))) {
return EmitARCStoreStrongCall(dst.getAddress(*this), newValue, ignored);
}
// Otherwise, split it out.
// Retain the new value.
newValue = EmitARCRetain(type, newValue);
// Read the old value.
llvm::Value *oldValue = EmitLoadOfScalar(dst, SourceLocation());
// 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, dst.isARCPreciseLifetime());
return newValue;
}
/// Autorelease the given object.
/// call i8* \@objc_autorelease(i8* %value)
llvm::Value *CodeGenFunction::EmitARCAutorelease(llvm::Value *value) {
return emitARCValueOperation(*this, value, nullptr,
CGM.getObjCEntrypoints().objc_autorelease,
llvm::Intrinsic::objc_autorelease);
}
/// Autorelease the given object.
/// call i8* \@objc_autoreleaseReturnValue(i8* %value)
llvm::Value *
CodeGenFunction::EmitARCAutoreleaseReturnValue(llvm::Value *value) {
return emitARCValueOperation(*this, value, nullptr,
CGM.getObjCEntrypoints().objc_autoreleaseReturnValue,
llvm::Intrinsic::objc_autoreleaseReturnValue,
llvm::CallInst::TCK_Tail);
}
/// 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, nullptr,
CGM.getObjCEntrypoints().objc_retainAutoreleaseReturnValue,
llvm::Intrinsic::objc_retainAutoreleaseReturnValue,
llvm::CallInst::TCK_Tail);
}
/// 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, nullptr,
CGM.getObjCEntrypoints().objc_retainAutorelease,
llvm::Intrinsic::objc_retainAutorelease);
}
/// i8* \@objc_loadWeak(i8** %addr)
/// Essentially objc_autorelease(objc_loadWeakRetained(addr)).
llvm::Value *CodeGenFunction::EmitARCLoadWeak(Address addr) {
return emitARCLoadOperation(*this, addr,
CGM.getObjCEntrypoints().objc_loadWeak,
llvm::Intrinsic::objc_loadWeak);
}
/// i8* \@objc_loadWeakRetained(i8** %addr)
llvm::Value *CodeGenFunction::EmitARCLoadWeakRetained(Address addr) {
return emitARCLoadOperation(*this, addr,
CGM.getObjCEntrypoints().objc_loadWeakRetained,
llvm::Intrinsic::objc_loadWeakRetained);
}
/// i8* \@objc_storeWeak(i8** %addr, i8* %value)
/// Returns %value.
llvm::Value *CodeGenFunction::EmitARCStoreWeak(Address addr,
llvm::Value *value,
bool ignored) {
return emitARCStoreOperation(*this, addr, value,
CGM.getObjCEntrypoints().objc_storeWeak,
llvm::Intrinsic::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(Address 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.getObjCEntrypoints().objc_initWeak,
llvm::Intrinsic::objc_initWeak, /*ignored*/ true);
}
/// void \@objc_destroyWeak(i8** %addr)
/// Essentially objc_storeWeak(addr, nil).
void CodeGenFunction::EmitARCDestroyWeak(Address addr) {
llvm::Function *&fn = CGM.getObjCEntrypoints().objc_destroyWeak;
if (!fn) {
fn = CGM.getIntrinsic(llvm::Intrinsic::objc_destroyWeak);
setARCRuntimeFunctionLinkage(CGM, fn);
}
// Cast the argument to 'id*'.
addr = Builder.CreateBitCast(addr, Int8PtrPtrTy);
EmitNounwindRuntimeCall(fn, addr.getPointer());
}
/// 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(Address dst, Address src) {
emitARCCopyOperation(*this, dst, src,
CGM.getObjCEntrypoints().objc_moveWeak,
llvm::Intrinsic::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(Address dst, Address src) {
emitARCCopyOperation(*this, dst, src,
CGM.getObjCEntrypoints().objc_copyWeak,
llvm::Intrinsic::objc_copyWeak);
}
void CodeGenFunction::emitARCCopyAssignWeak(QualType Ty, Address DstAddr,
Address SrcAddr) {
llvm::Value *Object = EmitARCLoadWeakRetained(SrcAddr);
Object = EmitObjCConsumeObject(Ty, Object);
EmitARCStoreWeak(DstAddr, Object, false);
}
void CodeGenFunction::emitARCMoveAssignWeak(QualType Ty, Address DstAddr,
Address SrcAddr) {
llvm::Value *Object = EmitARCLoadWeakRetained(SrcAddr);
Object = EmitObjCConsumeObject(Ty, Object);
EmitARCStoreWeak(DstAddr, Object, false);
EmitARCDestroyWeak(SrcAddr);
}
/// Produce the code to do a objc_autoreleasepool_push.
/// call i8* \@objc_autoreleasePoolPush(void)
llvm::Value *CodeGenFunction::EmitObjCAutoreleasePoolPush() {
llvm::Function *&fn = CGM.getObjCEntrypoints().objc_autoreleasePoolPush;
if (!fn) {
fn = CGM.getIntrinsic(llvm::Intrinsic::objc_autoreleasePoolPush);
setARCRuntimeFunctionLinkage(CGM, fn);
}
return EmitNounwindRuntimeCall(fn);
}
/// Produce the code to do a primitive release.
/// call void \@objc_autoreleasePoolPop(i8* %ptr)
void CodeGenFunction::EmitObjCAutoreleasePoolPop(llvm::Value *value) {
assert(value->getType() == Int8PtrTy);
if (getInvokeDest()) {
// Call the runtime method not the intrinsic if we are handling exceptions
llvm::FunctionCallee &fn =
CGM.getObjCEntrypoints().objc_autoreleasePoolPopInvoke;
if (!fn) {
llvm::FunctionType *fnType =
llvm::FunctionType::get(Builder.getVoidTy(), Int8PtrTy, false);
fn = CGM.CreateRuntimeFunction(fnType, "objc_autoreleasePoolPop");
setARCRuntimeFunctionLinkage(CGM, fn);
}
// objc_autoreleasePoolPop can throw.
EmitRuntimeCallOrInvoke(fn, value);
} else {
llvm::FunctionCallee &fn = CGM.getObjCEntrypoints().objc_autoreleasePoolPop;
if (!fn) {
fn = CGM.getIntrinsic(llvm::Intrinsic::objc_autoreleasePoolPop);
setARCRuntimeFunctionLinkage(CGM, fn);
}
EmitRuntimeCall(fn, value);
}
}
/// 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(*this);
// [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();
}
/// Allocate the given objc object.
/// call i8* \@objc_alloc(i8* %value)
llvm::Value *CodeGenFunction::EmitObjCAlloc(llvm::Value *value,
llvm::Type *resultType) {
return emitObjCValueOperation(*this, value, resultType,
CGM.getObjCEntrypoints().objc_alloc,
"objc_alloc");
}
/// Allocate the given objc object.
/// call i8* \@objc_allocWithZone(i8* %value)
llvm::Value *CodeGenFunction::EmitObjCAllocWithZone(llvm::Value *value,
llvm::Type *resultType) {
return emitObjCValueOperation(*this, value, resultType,
CGM.getObjCEntrypoints().objc_allocWithZone,
"objc_allocWithZone");
}
llvm::Value *CodeGenFunction::EmitObjCAllocInit(llvm::Value *value,
llvm::Type *resultType) {
return emitObjCValueOperation(*this, value, resultType,
CGM.getObjCEntrypoints().objc_alloc_init,
"objc_alloc_init");
}
/// 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,
Address addr,
QualType type) {
CGF.EmitARCDestroyStrong(addr, ARCPreciseLifetime);
}
void CodeGenFunction::destroyARCStrongImprecise(CodeGenFunction &CGF,
Address addr,
QualType type) {
CGF.EmitARCDestroyStrong(addr, ARCImpreciseLifetime);
}
void CodeGenFunction::destroyARCWeak(CodeGenFunction &CGF,
Address addr,
QualType type) {
CGF.EmitARCDestroyWeak(addr);
}
void CodeGenFunction::emitARCIntrinsicUse(CodeGenFunction &CGF, Address addr,
QualType type) {
llvm::Value *value = CGF.Builder.CreateLoad(addr);
CGF.EmitARCIntrinsicUse(value);
}
/// Autorelease the given object.
/// call i8* \@objc_autorelease(i8* %value)
llvm::Value *CodeGenFunction::EmitObjCAutorelease(llvm::Value *value,
llvm::Type *returnType) {
return emitObjCValueOperation(
*this, value, returnType,
CGM.getObjCEntrypoints().objc_autoreleaseRuntimeFunction,
"objc_autorelease");
}
/// Retain the given object, with normal retain semantics.
/// call i8* \@objc_retain(i8* %value)
llvm::Value *CodeGenFunction::EmitObjCRetainNonBlock(llvm::Value *value,
llvm::Type *returnType) {
return emitObjCValueOperation(
*this, value, returnType,
CGM.getObjCEntrypoints().objc_retainRuntimeFunction, "objc_retain");
}
/// Release the given object.
/// call void \@objc_release(i8* %value)
void CodeGenFunction::EmitObjCRelease(llvm::Value *value,
ARCPreciseLifetime_t precise) {
if (isa<llvm::ConstantPointerNull>(value)) return;
llvm::FunctionCallee &fn =
CGM.getObjCEntrypoints().objc_releaseRuntimeFunction;
if (!fn) {
llvm::FunctionType *fnType =
llvm::FunctionType::get(Builder.getVoidTy(), Int8PtrTy, false);
fn = CGM.CreateRuntimeFunction(fnType, "objc_release");
setARCRuntimeFunctionLinkage(CGM, fn);
// We have Native ARC, so set nonlazybind attribute for performance
if (llvm::Function *f = dyn_cast<llvm::Function>(fn.getCallee()))
f->addFnAttr(llvm::Attribute::NonLazyBind);
}
// Cast the argument to 'id'.
value = Builder.CreateBitCast(value, Int8PtrTy);
// Call objc_release.
llvm::CallBase *call = EmitCallOrInvoke(fn, value);
if (precise == ARCImpreciseLifetime) {
call->setMetadata("clang.imprecise_release",
llvm::MDNode::get(Builder.getContext(), None));
}
}
namespace {
struct CallObjCAutoreleasePoolObject final : EHScopeStack::Cleanup {
llvm::Value *Token;
CallObjCAutoreleasePoolObject(llvm::Value *token) : Token(token) {}
void Emit(CodeGenFunction &CGF, Flags flags) override {
CGF.EmitObjCAutoreleasePoolPop(Token);
}
};
struct CallObjCMRRAutoreleasePoolObject final : EHScopeStack::Cleanup {
llvm::Value *Token;
CallObjCMRRAutoreleasePoolObject(llvm::Value *token) : Token(token) {}
void Emit(CodeGenFunction &CGF, Flags flags) override {
CGF.EmitObjCMRRAutoreleasePoolPop(Token);
}
};
}
void CodeGenFunction::EmitObjCAutoreleasePoolCleanup(llvm::Value *Ptr) {
if (CGM.getLangOpts().ObjCAutoRefCount)
EHStack.pushCleanup<CallObjCAutoreleasePoolObject>(NormalCleanup, Ptr);
else
EHStack.pushCleanup<CallObjCMRRAutoreleasePoolObject>(NormalCleanup, Ptr);
}
static bool shouldRetainObjCLifetime(Qualifiers::ObjCLifetime lifetime) {
switch (lifetime) {
case Qualifiers::OCL_None:
case Qualifiers::OCL_ExplicitNone:
case Qualifiers::OCL_Strong:
case Qualifiers::OCL_Autoreleasing:
return true;
case Qualifiers::OCL_Weak:
return false;
}
llvm_unreachable("impossible lifetime!");
}
static TryEmitResult tryEmitARCRetainLoadOfScalar(CodeGenFunction &CGF,
LValue lvalue,
QualType type) {
llvm::Value *result;
bool shouldRetain = shouldRetainObjCLifetime(type.getObjCLifetime());
if (shouldRetain) {
result = CGF.EmitLoadOfLValue(lvalue, SourceLocation()).getScalarVal();
} else {
assert(type.getObjCLifetime() == Qualifiers::OCL_Weak);
result = CGF.EmitARCLoadWeakRetained(lvalue.getAddress(CGF));
}
return TryEmitResult(result, !shouldRetain);
}
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,
SourceLocation()).getScalarVal();
// Set the source pointer to NULL.
CGF.EmitStoreOfScalar(getNullForVariable(lv.getAddress(CGF)), 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.getLangOpts().CPlusPlus &&
!type.isVolatileQualified() &&
type.getObjCLifetime() == Qualifiers::OCL_Weak &&
isa<BinaryOperator>(e) &&
cast<BinaryOperator>(e)->getOpcode() == BO_Assign)
return TryEmitResult(CGF.EmitScalarExpr(e), false);
// Try to emit code for scalar constant instead of emitting LValue and
// loading it because we are not guaranteed to have an l-value. One of such
// cases is DeclRefExpr referencing non-odr-used constant-evaluated variable.
if (const auto *decl_expr = dyn_cast<DeclRefExpr>(e)) {
auto *DRE = const_cast<DeclRefExpr *>(decl_expr);
if (CodeGenFunction::ConstantEmission constant = CGF.tryEmitAsConstant(DRE))
return TryEmitResult(CGF.emitScalarConstant(constant, DRE),
!shouldRetainObjCLifetime(type.getObjCLifetime()));
}
return tryEmitARCRetainLoadOfScalar(CGF, CGF.EmitLValue(e), type);
}
typedef llvm::function_ref<llvm::Value *(CodeGenFunction &CGF,
llvm::Value *value)>
ValueTransform;
/// Insert code immediately after a call.
static llvm::Value *emitARCOperationAfterCall(CodeGenFunction &CGF,
llvm::Value *value,
ValueTransform doAfterCall,
ValueTransform doFallback) {
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 = doAfterCall(CGF, 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 = doAfterCall(CGF, 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 = emitARCOperationAfterCall(CGF, operand, doAfterCall, doFallback);
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 doFallback(CGF, value);
}
}
/// Given that the given expression is some sort of call (which does
/// not return retained), emit a retain following it.
static llvm::Value *emitARCRetainCallResult(CodeGenFunction &CGF,
const Expr *e) {
llvm::Value *value = CGF.EmitScalarExpr(e);
return emitARCOperationAfterCall(CGF, value,
[](CodeGenFunction &CGF, llvm::Value *value) {
return CGF.EmitARCRetainAutoreleasedReturnValue(value);
},
[](CodeGenFunction &CGF, llvm::Value *value) {
return CGF.EmitARCRetainNonBlock(value);
});
}
/// Given that the given expression is some sort of call (which does
/// not return retained), perform an unsafeClaim following it.
static llvm::Value *emitARCUnsafeClaimCallResult(CodeGenFunction &CGF,
const Expr *e) {
llvm::Value *value = CGF.EmitScalarExpr(e);
return emitARCOperationAfterCall(CGF, value,
[](CodeGenFunction &CGF, llvm::Value *value) {
return CGF.EmitARCUnsafeClaimAutoreleasedReturnValue(value);
},
[](CodeGenFunction &CGF, llvm::Value *value) {
return value;
});
}
llvm::Value *CodeGenFunction::EmitARCReclaimReturnedObject(const Expr *E,
bool allowUnsafeClaim) {
if (allowUnsafeClaim &&
CGM.getLangOpts().ObjCRuntime.hasARCUnsafeClaimAutoreleasedReturnValue()) {
return emitARCUnsafeClaimCallResult(*this, E);
} else {
llvm::Value *value = emitARCRetainCallResult(*this, E);
return EmitObjCConsumeObject(E->getType(), 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;
}
namespace {
/// A CRTP base class for emitting expressions of retainable object
/// pointer type in ARC.
template <typename Impl, typename Result> class ARCExprEmitter {
protected:
CodeGenFunction &CGF;
Impl &asImpl() { return *static_cast<Impl*>(this); }
ARCExprEmitter(CodeGenFunction &CGF) : CGF(CGF) {}
public:
Result visit(const Expr *e);
Result visitCastExpr(const CastExpr *e);
Result visitPseudoObjectExpr(const PseudoObjectExpr *e);
Result visitBlockExpr(const BlockExpr *e);
Result visitBinaryOperator(const BinaryOperator *e);
Result visitBinAssign(const BinaryOperator *e);
Result visitBinAssignUnsafeUnretained(const BinaryOperator *e);
Result visitBinAssignAutoreleasing(const BinaryOperator *e);
Result visitBinAssignWeak(const BinaryOperator *e);
Result visitBinAssignStrong(const BinaryOperator *e);
// Minimal implementation:
// Result visitLValueToRValue(const Expr *e)
// Result visitConsumeObject(const Expr *e)
// Result visitExtendBlockObject(const Expr *e)
// Result visitReclaimReturnedObject(const Expr *e)
// Result visitCall(const Expr *e)
// Result visitExpr(const Expr *e)
//
// Result emitBitCast(Result result, llvm::Type *resultType)
// llvm::Value *getValueOfResult(Result result)
};
}
/// Try to emit a PseudoObjectExpr under special ARC rules.
///
/// This massively duplicates emitPseudoObjectRValue.
template <typename Impl, typename Result>
Result
ARCExprEmitter<Impl,Result>::visitPseudoObjectExpr(const PseudoObjectExpr *E) {
SmallVector<CodeGenFunction::OpaqueValueMappingData, 4> opaques;
// Find the result expression.
const Expr *resultExpr = E->getResultExpr();
assert(resultExpr);
Result 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 = asImpl().visit(ov->getSourceExpr());
opaqueData = OVMA::bind(CGF, ov,
RValue::get(asImpl().getValueOfResult(result)));
// 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 = asImpl().visit(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;
}
template <typename Impl, typename Result>
Result ARCExprEmitter<Impl, Result>::visitBlockExpr(const BlockExpr *e) {
// The default implementation just forwards the expression to visitExpr.
return asImpl().visitExpr(e);
}
template <typename Impl, typename Result>
Result ARCExprEmitter<Impl,Result>::visitCastExpr(const CastExpr *e) {
switch (e->getCastKind()) {
// No-op casts don't change the type, so we just ignore them.
case CK_NoOp:
return asImpl().visit(e->getSubExpr());
// These casts can change the type.
case CK_CPointerToObjCPointerCast:
case CK_BlockPointerToObjCPointerCast:
case CK_AnyPointerToBlockPointerCast:
case CK_BitCast: {
llvm::Type *resultType = CGF.ConvertType(e->getType());
assert(e->getSubExpr()->getType()->hasPointerRepresentation());
Result result = asImpl().visit(e->getSubExpr());
return asImpl().emitBitCast(result, resultType);
}
// Handle some casts specially.
case CK_LValueToRValue:
return asImpl().visitLValueToRValue(e->getSubExpr());
case CK_ARCConsumeObject:
return asImpl().visitConsumeObject(e->getSubExpr());
case CK_ARCExtendBlockObject:
return asImpl().visitExtendBlockObject(e->getSubExpr());
case CK_ARCReclaimReturnedObject:
return asImpl().visitReclaimReturnedObject(e->getSubExpr());
// Otherwise, use the default logic.
default:
return asImpl().visitExpr(e);
}
}
template <typename Impl, typename Result>
Result
ARCExprEmitter<Impl,Result>::visitBinaryOperator(const BinaryOperator *e) {
switch (e->getOpcode()) {
case BO_Comma:
CGF.EmitIgnoredExpr(e->getLHS());
CGF.EnsureInsertPoint();
return asImpl().visit(e->getRHS());
case BO_Assign:
return asImpl().visitBinAssign(e);
default:
return asImpl().visitExpr(e);
}
}
template <typename Impl, typename Result>
Result ARCExprEmitter<Impl,Result>::visitBinAssign(const BinaryOperator *e) {
switch (e->getLHS()->getType().getObjCLifetime()) {
case Qualifiers::OCL_ExplicitNone:
return asImpl().visitBinAssignUnsafeUnretained(e);
case Qualifiers::OCL_Weak:
return asImpl().visitBinAssignWeak(e);
case Qualifiers::OCL_Autoreleasing:
return asImpl().visitBinAssignAutoreleasing(e);
case Qualifiers::OCL_Strong:
return asImpl().visitBinAssignStrong(e);
case Qualifiers::OCL_None:
return asImpl().visitExpr(e);
}
llvm_unreachable("bad ObjC ownership qualifier");
}
/// The default rule for __unsafe_unretained emits the RHS recursively,
/// stores into the unsafe variable, and propagates the result outward.
template <typename Impl, typename Result>
Result ARCExprEmitter<Impl,Result>::
visitBinAssignUnsafeUnretained(const BinaryOperator *e) {
// Recursively emit the RHS.
// For __block safety, do this before emitting the LHS.
Result result = asImpl().visit(e->getRHS());
// Perform the store.
LValue lvalue =
CGF.EmitCheckedLValue(e->getLHS(), CodeGenFunction::TCK_Store);
CGF.EmitStoreThroughLValue(RValue::get(asImpl().getValueOfResult(result)),
lvalue);
return result;
}
template <typename Impl, typename Result>
Result
ARCExprEmitter<Impl,Result>::visitBinAssignAutoreleasing(const BinaryOperator *e) {
return asImpl().visitExpr(e);
}
template <typename Impl, typename Result>
Result
ARCExprEmitter<Impl,Result>::visitBinAssignWeak(const BinaryOperator *e) {
return asImpl().visitExpr(e);
}
template <typename Impl, typename Result>
Result
ARCExprEmitter<Impl,Result>::visitBinAssignStrong(const BinaryOperator *e) {
return asImpl().visitExpr(e);
}
/// The general expression-emission logic.
template <typename Impl, typename Result>
Result ARCExprEmitter<Impl,Result>::visit(const Expr *e) {
// We should *never* see a nested full-expression here, because if
// we fail to emit at +1, our caller must not retain after we close
// out the full-expression. This isn't as important in the unsafe
// emitter.
assert(!isa<ExprWithCleanups>(e));
// Look through parens, __extension__, generic selection, etc.
e = e->IgnoreParens();
// Handle certain kinds of casts.
if (const CastExpr *ce = dyn_cast<CastExpr>(e)) {
return asImpl().visitCastExpr(ce);
// Handle the comma operator.
} else if (auto op = dyn_cast<BinaryOperator>(e)) {
return asImpl().visitBinaryOperator(op);
// TODO: handle conditional operators here
// 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())) {
return asImpl().visitCall(e);
// Look through pseudo-object expressions.
} else if (const PseudoObjectExpr *pseudo = dyn_cast<PseudoObjectExpr>(e)) {
return asImpl().visitPseudoObjectExpr(pseudo);
} else if (auto *be = dyn_cast<BlockExpr>(e))
return asImpl().visitBlockExpr(be);
return asImpl().visitExpr(e);
}
namespace {
/// An emitter for +1 results.
struct ARCRetainExprEmitter :
public ARCExprEmitter<ARCRetainExprEmitter, TryEmitResult> {
ARCRetainExprEmitter(CodeGenFunction &CGF) : ARCExprEmitter(CGF) {}
llvm::Value *getValueOfResult(TryEmitResult result) {
return result.getPointer();
}
TryEmitResult emitBitCast(TryEmitResult result, llvm::Type *resultType) {
llvm::Value *value = result.getPointer();
value = CGF.Builder.CreateBitCast(value, resultType);
result.setPointer(value);
return result;
}
TryEmitResult visitLValueToRValue(const Expr *e) {
return tryEmitARCRetainLoadOfScalar(CGF, e);
}
/// For consumptions, just emit the subexpression and thus elide
/// the retain/release pair.
TryEmitResult visitConsumeObject(const Expr *e) {
llvm::Value *result = CGF.EmitScalarExpr(e);
return TryEmitResult(result, true);
}
TryEmitResult visitBlockExpr(const BlockExpr *e) {
TryEmitResult result = visitExpr(e);
// Avoid the block-retain if this is a block literal that doesn't need to be
// copied to the heap.
if (e->getBlockDecl()->canAvoidCopyToHeap())
result.setInt(true);
return result;
}
/// 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.
TryEmitResult visitExtendBlockObject(const Expr *e) {
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(e)) {
result = CGF.EmitScalarExpr(e);
// Otherwise, try to emit the sub-expression at +1 recursively.
} else {
TryEmitResult subresult = asImpl().visit(e);
// If that produced a retained value, just use that.
if (subresult.getInt()) {
return subresult;
}
// Otherwise it's +0.
result = subresult.getPointer();
}
// Retain the object as a block.
result = CGF.EmitARCRetainBlock(result, /*mandatory*/ true);
return TryEmitResult(result, true);
}
/// For reclaims, emit the subexpression as a retained call and
/// skip the consumption.
TryEmitResult visitReclaimReturnedObject(const Expr *e) {
llvm::Value *result = emitARCRetainCallResult(CGF, e);
return TryEmitResult(result, true);
}
/// When we have an undecorated call, retroactively do a claim.
TryEmitResult visitCall(const Expr *e) {
llvm::Value *result = emitARCRetainCallResult(CGF, e);
return TryEmitResult(result, true);
}
// TODO: maybe special-case visitBinAssignWeak?
TryEmitResult visitExpr(const Expr *e) {
// 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);
return TryEmitResult(result, false);
}
};
}
static TryEmitResult
tryEmitARCRetainScalarExpr(CodeGenFunction &CGF, const Expr *e) {
return ARCRetainExprEmitter(CGF).visit(e);
}
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) {
// The retain needs to happen within the full-expression.
if (const ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(e)) {
RunCleanupsScope scope(*this);
return EmitARCRetainScalarExpr(cleanups->getSubExpr());
}
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) {
// The retain needs to happen within the full-expression.
if (const ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(e)) {
RunCleanupsScope scope(*this);
return EmitARCRetainAutoreleaseScalarExpr(cleanups->getSubExpr());
}
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 (getLangOpts().ObjCAutoRefCount) {
// Do so before running any cleanups for the full-expression.
// EmitARCRetainAutoreleaseScalarExpr does this for us.
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);
}
namespace {
/// An emitter for assigning into an __unsafe_unretained context.
struct ARCUnsafeUnretainedExprEmitter :
public ARCExprEmitter<ARCUnsafeUnretainedExprEmitter, llvm::Value*> {
ARCUnsafeUnretainedExprEmitter(CodeGenFunction &CGF) : ARCExprEmitter(CGF) {}
llvm::Value *getValueOfResult(llvm::Value *value) {
return value;
}
llvm::Value *emitBitCast(llvm::Value *value, llvm::Type *resultType) {
return CGF.Builder.CreateBitCast(value, resultType);
}
llvm::Value *visitLValueToRValue(const Expr *e) {
return CGF.EmitScalarExpr(e);
}
/// For consumptions, just emit the subexpression and perform the
/// consumption like normal.
llvm::Value *visitConsumeObject(const Expr *e) {
llvm::Value *value = CGF.EmitScalarExpr(e);
return CGF.EmitObjCConsumeObject(e->getType(), value);
}
/// No special logic for block extensions. (This probably can't
/// actually happen in this emitter, though.)
llvm::Value *visitExtendBlockObject(const Expr *e) {
return CGF.EmitARCExtendBlockObject(e);
}
/// For reclaims, perform an unsafeClaim if that's enabled.
llvm::Value *visitReclaimReturnedObject(const Expr *e) {
return CGF.EmitARCReclaimReturnedObject(e, /*unsafe*/ true);
}
/// When we have an undecorated call, just emit it without adding
/// the unsafeClaim.
llvm::Value *visitCall(const Expr *e) {
return CGF.EmitScalarExpr(e);
}
/// Just do normal scalar emission in the default case.
llvm::Value *visitExpr(const Expr *e) {
return CGF.EmitScalarExpr(e);
}
};
}
static llvm::Value *emitARCUnsafeUnretainedScalarExpr(CodeGenFunction &CGF,
const Expr *e) {
return ARCUnsafeUnretainedExprEmitter(CGF).visit(e);
}
/// EmitARCUnsafeUnretainedScalarExpr - Semantically equivalent to
/// immediately releasing the resut of EmitARCRetainScalarExpr, but
/// avoiding any spurious retains, including by performing reclaims
/// with objc_unsafeClaimAutoreleasedReturnValue.
llvm::Value *CodeGenFunction::EmitARCUnsafeUnretainedScalarExpr(const Expr *e) {
// Look through full-expressions.
if (const ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(e)) {
RunCleanupsScope scope(*this);
return emitARCUnsafeUnretainedScalarExpr(*this, cleanups->getSubExpr());
}
return emitARCUnsafeUnretainedScalarExpr(*this, e);
}
std::pair<LValue,llvm::Value*>
CodeGenFunction::EmitARCStoreUnsafeUnretained(const BinaryOperator *e,
bool ignored) {
// Evaluate the RHS first. If we're ignoring the result, assume
// that we can emit at an unsafe +0.
llvm::Value *value;
if (ignored) {
value = EmitARCUnsafeUnretainedScalarExpr(e->getRHS());
} else {
value = EmitScalarExpr(e->getRHS());
}
// Emit the LHS and perform the store.
LValue lvalue = EmitLValue(e->getLHS());
EmitStoreOfScalar(value, lvalue);
return std::pair<LValue,llvm::Value*>(std::move(lvalue), value);
}
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, SourceLocation());
EmitStoreOfScalar(value, lvalue);
EmitARCRelease(oldValue, lvalue.isARCPreciseLifetime());
} 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);
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.getLangOpts().ObjCRuntime.hasNativeARC()) {
llvm::Value *token = EmitObjCAutoreleasePoolPush();
EHStack.pushCleanup<CallObjCAutoreleasePoolObject>(NormalCleanup, token);
} else {
llvm::Value *token = EmitObjCMRRAutoreleasePoolPush();
EHStack.pushCleanup<CallObjCMRRAutoreleasePoolObject>(NormalCleanup, token);
}
for (const auto *I : S.body())
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, RequiredArgs::All);
llvm::InlineAsm *extender = llvm::InlineAsm::get(extenderType,
/* assembly */ "",
/* constraints */ "r",
/* side effects */ true);
object = Builder.CreateBitCast(object, VoidPtrTy);
EmitNounwindRuntimeCall(extender, object);
}
/// GenerateObjCAtomicSetterCopyHelperFunction - Given a c++ object type with
/// non-trivial copy assignment function, produce following helper function.
/// static void copyHelper(Ty *dest, const Ty *source) { *dest = *source; }
///
llvm::Constant *
CodeGenFunction::GenerateObjCAtomicSetterCopyHelperFunction(
const ObjCPropertyImplDecl *PID) {
if (!getLangOpts().CPlusPlus ||
!getLangOpts().ObjCRuntime.hasAtomicCopyHelper())
return nullptr;
QualType Ty = PID->getPropertyIvarDecl()->getType();
if (!Ty->isRecordType())
return nullptr;
const ObjCPropertyDecl *PD = PID->getPropertyDecl();
if ((!(PD->getPropertyAttributes() & ObjCPropertyAttribute::kind_atomic)))
return nullptr;
llvm::Constant *HelperFn = nullptr;
if (hasTrivialSetExpr(PID))
return nullptr;
assert(PID->getSetterCXXAssignment() && "SetterCXXAssignment - null");
if ((HelperFn = CGM.getAtomicSetterHelperFnMap(Ty)))
return HelperFn;
ASTContext &C = getContext();
IdentifierInfo *II
= &CGM.getContext().Idents.get("__assign_helper_atomic_property_");
QualType ReturnTy = C.VoidTy;
QualType DestTy = C.getPointerType(Ty);
QualType SrcTy = Ty;
SrcTy.addConst();
SrcTy = C.getPointerType(SrcTy);
SmallVector<QualType, 2> ArgTys;
ArgTys.push_back(DestTy);
ArgTys.push_back(SrcTy);
QualType FunctionTy = C.getFunctionType(ReturnTy, ArgTys, {});
FunctionDecl *FD = FunctionDecl::Create(
C, C.getTranslationUnitDecl(), SourceLocation(), SourceLocation(), II,
FunctionTy, nullptr, SC_Static, false, false);
FunctionArgList args;
ImplicitParamDecl DstDecl(C, FD, SourceLocation(), /*Id=*/nullptr, DestTy,
ImplicitParamDecl::Other);
args.push_back(&DstDecl);
ImplicitParamDecl SrcDecl(C, FD, SourceLocation(), /*Id=*/nullptr, SrcTy,
ImplicitParamDecl::Other);
args.push_back(&SrcDecl);
const CGFunctionInfo &FI =
CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
llvm::Function *Fn =
llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
"__assign_helper_atomic_property_",
&CGM.getModule());
CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, FI);
StartFunction(FD, ReturnTy, Fn, FI, args);
DeclRefExpr DstExpr(C, &DstDecl, false, DestTy, VK_RValue, SourceLocation());
UnaryOperator *DST = UnaryOperator::Create(
C, &DstExpr, UO_Deref, DestTy->getPointeeType(), VK_LValue, OK_Ordinary,
SourceLocation(), false, FPOptions(C.getLangOpts()));
DeclRefExpr SrcExpr(C, &SrcDecl, false, SrcTy, VK_RValue, SourceLocation());
UnaryOperator *SRC = UnaryOperator::Create(
C, &SrcExpr, UO_Deref, SrcTy->getPointeeType(), VK_LValue, OK_Ordinary,
SourceLocation(), false, FPOptions(C.getLangOpts()));
Expr *Args[2] = {DST, SRC};
CallExpr *CalleeExp = cast<CallExpr>(PID->getSetterCXXAssignment());
CXXOperatorCallExpr *TheCall = CXXOperatorCallExpr::Create(
C, OO_Equal, CalleeExp->getCallee(), Args, DestTy->getPointeeType(),
VK_LValue, SourceLocation(), FPOptions(C.getLangOpts()));
EmitStmt(TheCall);
FinishFunction();
HelperFn = llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
CGM.setAtomicSetterHelperFnMap(Ty, HelperFn);
return HelperFn;
}
llvm::Constant *
CodeGenFunction::GenerateObjCAtomicGetterCopyHelperFunction(
const ObjCPropertyImplDecl *PID) {
if (!getLangOpts().CPlusPlus ||
!getLangOpts().ObjCRuntime.hasAtomicCopyHelper())
return nullptr;
const ObjCPropertyDecl *PD = PID->getPropertyDecl();
QualType Ty = PD->getType();
if (!Ty->isRecordType())
return nullptr;
if ((!(PD->getPropertyAttributes() & ObjCPropertyAttribute::kind_atomic)))
return nullptr;
llvm::Constant *HelperFn = nullptr;
if (hasTrivialGetExpr(PID))
return nullptr;
assert(PID->getGetterCXXConstructor() && "getGetterCXXConstructor - null");
if ((HelperFn = CGM.getAtomicGetterHelperFnMap(Ty)))
return HelperFn;
ASTContext &C = getContext();
IdentifierInfo *II =
&CGM.getContext().Idents.get("__copy_helper_atomic_property_");
QualType ReturnTy = C.VoidTy;
QualType DestTy = C.getPointerType(Ty);
QualType SrcTy = Ty;
SrcTy.addConst();
SrcTy = C.getPointerType(SrcTy);
SmallVector<QualType, 2> ArgTys;
ArgTys.push_back(DestTy);
ArgTys.push_back(SrcTy);
QualType FunctionTy = C.getFunctionType(ReturnTy, ArgTys, {});
FunctionDecl *FD = FunctionDecl::Create(
C, C.getTranslationUnitDecl(), SourceLocation(), SourceLocation(), II,
FunctionTy, nullptr, SC_Static, false, false);
FunctionArgList args;
ImplicitParamDecl DstDecl(C, FD, SourceLocation(), /*Id=*/nullptr, DestTy,
ImplicitParamDecl::Other);
args.push_back(&DstDecl);
ImplicitParamDecl SrcDecl(C, FD, SourceLocation(), /*Id=*/nullptr, SrcTy,
ImplicitParamDecl::Other);
args.push_back(&SrcDecl);
const CGFunctionInfo &FI =
CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
llvm::Function *Fn = llvm::Function::Create(
LTy, llvm::GlobalValue::InternalLinkage, "__copy_helper_atomic_property_",
&CGM.getModule());
CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, FI);
StartFunction(FD, ReturnTy, Fn, FI, args);
DeclRefExpr SrcExpr(getContext(), &SrcDecl, false, SrcTy, VK_RValue,
SourceLocation());
UnaryOperator *SRC = UnaryOperator::Create(
C, &SrcExpr, UO_Deref, SrcTy->getPointeeType(), VK_LValue, OK_Ordinary,
SourceLocation(), false, FPOptions(C.getLangOpts()));
CXXConstructExpr *CXXConstExpr =
cast<CXXConstructExpr>(PID->getGetterCXXConstructor());
SmallVector<Expr*, 4> ConstructorArgs;
ConstructorArgs.push_back(SRC);
ConstructorArgs.append(std::next(CXXConstExpr->arg_begin()),
CXXConstExpr->arg_end());
CXXConstructExpr *TheCXXConstructExpr =
CXXConstructExpr::Create(C, Ty, SourceLocation(),
CXXConstExpr->getConstructor(),
CXXConstExpr->isElidable(),
ConstructorArgs,
CXXConstExpr->hadMultipleCandidates(),
CXXConstExpr->isListInitialization(),
CXXConstExpr->isStdInitListInitialization(),
CXXConstExpr->requiresZeroInitialization(),
CXXConstExpr->getConstructionKind(),
SourceRange());
DeclRefExpr DstExpr(getContext(), &DstDecl, false, DestTy, VK_RValue,
SourceLocation());
RValue DV = EmitAnyExpr(&DstExpr);
CharUnits Alignment
= getContext().getTypeAlignInChars(TheCXXConstructExpr->getType());
EmitAggExpr(TheCXXConstructExpr,
AggValueSlot::forAddr(Address(DV.getScalarVal(), Alignment),
Qualifiers(),
AggValueSlot::IsDestructed,
AggValueSlot::DoesNotNeedGCBarriers,
AggValueSlot::IsNotAliased,
AggValueSlot::DoesNotOverlap));
FinishFunction();
HelperFn = llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
CGM.setAtomicGetterHelperFnMap(Ty, HelperFn);
return HelperFn;
}
llvm::Value *
CodeGenFunction::EmitBlockCopyAndAutorelease(llvm::Value *Block, QualType Ty) {
// Get selectors for retain/autorelease.
IdentifierInfo *CopyID = &getContext().Idents.get("copy");
Selector CopySelector =
getContext().Selectors.getNullarySelector(CopyID);
IdentifierInfo *AutoreleaseID = &getContext().Idents.get("autorelease");
Selector AutoreleaseSelector =
getContext().Selectors.getNullarySelector(AutoreleaseID);
// Emit calls to retain/autorelease.
CGObjCRuntime &Runtime = CGM.getObjCRuntime();
llvm::Value *Val = Block;
RValue Result;
Result = Runtime.GenerateMessageSend(*this, ReturnValueSlot(),
Ty, CopySelector,
Val, CallArgList(), nullptr, nullptr);
Val = Result.getScalarVal();
Result = Runtime.GenerateMessageSend(*this, ReturnValueSlot(),
Ty, AutoreleaseSelector,
Val, CallArgList(), nullptr, nullptr);
Val = Result.getScalarVal();
return Val;
}
llvm::Value *
CodeGenFunction::EmitBuiltinAvailable(ArrayRef<llvm::Value *> Args) {
assert(Args.size() == 3 && "Expected 3 argument here!");
if (!CGM.IsOSVersionAtLeastFn) {
llvm::FunctionType *FTy =
llvm::FunctionType::get(Int32Ty, {Int32Ty, Int32Ty, Int32Ty}, false);
CGM.IsOSVersionAtLeastFn =
CGM.CreateRuntimeFunction(FTy, "__isOSVersionAtLeast");
}
llvm::Value *CallRes =
EmitNounwindRuntimeCall(CGM.IsOSVersionAtLeastFn, Args);
return Builder.CreateICmpNE(CallRes, llvm::Constant::getNullValue(Int32Ty));
}
void CodeGenModule::emitAtAvailableLinkGuard() {
if (!IsOSVersionAtLeastFn)
return;
// @available requires CoreFoundation only on Darwin.
if (!Target.getTriple().isOSDarwin())
return;
// Add -framework CoreFoundation to the linker commands. We still want to
// emit the core foundation reference down below because otherwise if
// CoreFoundation is not used in the code, the linker won't link the
// framework.
auto &Context = getLLVMContext();
llvm::Metadata *Args[2] = {llvm::MDString::get(Context, "-framework"),
llvm::MDString::get(Context, "CoreFoundation")};
LinkerOptionsMetadata.push_back(llvm::MDNode::get(Context, Args));
// Emit a reference to a symbol from CoreFoundation to ensure that
// CoreFoundation is linked into the final binary.
llvm::FunctionType *FTy =
llvm::FunctionType::get(Int32Ty, {VoidPtrTy}, false);
llvm::FunctionCallee CFFunc =
CreateRuntimeFunction(FTy, "CFBundleGetVersionNumber");
llvm::FunctionType *CheckFTy = llvm::FunctionType::get(VoidTy, {}, false);
llvm::FunctionCallee CFLinkCheckFuncRef = CreateRuntimeFunction(
CheckFTy, "__clang_at_available_requires_core_foundation_framework",
llvm::AttributeList(), /*Local=*/true);
llvm::Function *CFLinkCheckFunc =
cast<llvm::Function>(CFLinkCheckFuncRef.getCallee()->stripPointerCasts());
if (CFLinkCheckFunc->empty()) {
CFLinkCheckFunc->setLinkage(llvm::GlobalValue::LinkOnceAnyLinkage);
CFLinkCheckFunc->setVisibility(llvm::GlobalValue::HiddenVisibility);
CodeGenFunction CGF(*this);
CGF.Builder.SetInsertPoint(CGF.createBasicBlock("", CFLinkCheckFunc));
CGF.EmitNounwindRuntimeCall(CFFunc,
llvm::Constant::getNullValue(VoidPtrTy));
CGF.Builder.CreateUnreachable();
addCompilerUsedGlobal(CFLinkCheckFunc);
}
}
CGObjCRuntime::~CGObjCRuntime() {}
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