Bug Summary

File:clang/lib/CodeGen/CGObjC.cpp
Warning:line 2986, column 3
Undefined or garbage value returned to caller

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name CGObjC.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mthread-model posix -mframe-pointer=none -relaxed-aliasing -fmath-errno -fno-rounding-math -masm-verbose -mconstructor-aliases -munwind-tables -target-cpu x86-64 -dwarf-column-info -fno-split-dwarf-inlining -debugger-tuning=gdb -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-11/lib/clang/11.0.0 -D CLANG_VENDOR="Debian " -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/tools/clang/lib/CodeGen -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/include -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/include -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-11/lib/clang/11.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/tools/clang/lib/CodeGen -fdebug-prefix-map=/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347=. -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fobjc-runtime=gcc -fno-common -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -o /tmp/scan-build-2020-03-09-184146-41876-1 -x c++ /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp
1//===---- CGObjC.cpp - Emit LLVM Code for Objective-C ---------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This contains code to emit Objective-C code as LLVM code.
10//
11//===----------------------------------------------------------------------===//
12
13#include "CGDebugInfo.h"
14#include "CGObjCRuntime.h"
15#include "CodeGenFunction.h"
16#include "CodeGenModule.h"
17#include "ConstantEmitter.h"
18#include "TargetInfo.h"
19#include "clang/AST/ASTContext.h"
20#include "clang/AST/Attr.h"
21#include "clang/AST/DeclObjC.h"
22#include "clang/AST/StmtObjC.h"
23#include "clang/Basic/Diagnostic.h"
24#include "clang/CodeGen/CGFunctionInfo.h"
25#include "llvm/ADT/STLExtras.h"
26#include "llvm/IR/DataLayout.h"
27#include "llvm/IR/InlineAsm.h"
28using namespace clang;
29using namespace CodeGen;
30
31typedef llvm::PointerIntPair<llvm::Value*,1,bool> TryEmitResult;
32static TryEmitResult
33tryEmitARCRetainScalarExpr(CodeGenFunction &CGF, const Expr *e);
34static RValue AdjustObjCObjectType(CodeGenFunction &CGF,
35 QualType ET,
36 RValue Result);
37
38/// Given the address of a variable of pointer type, find the correct
39/// null to store into it.
40static llvm::Constant *getNullForVariable(Address addr) {
41 llvm::Type *type = addr.getElementType();
42 return llvm::ConstantPointerNull::get(cast<llvm::PointerType>(type));
43}
44
45/// Emits an instance of NSConstantString representing the object.
46llvm::Value *CodeGenFunction::EmitObjCStringLiteral(const ObjCStringLiteral *E)
47{
48 llvm::Constant *C =
49 CGM.getObjCRuntime().GenerateConstantString(E->getString()).getPointer();
50 // FIXME: This bitcast should just be made an invariant on the Runtime.
51 return llvm::ConstantExpr::getBitCast(C, ConvertType(E->getType()));
52}
53
54/// EmitObjCBoxedExpr - This routine generates code to call
55/// the appropriate expression boxing method. This will either be
56/// one of +[NSNumber numberWith<Type>:], or +[NSString stringWithUTF8String:],
57/// or [NSValue valueWithBytes:objCType:].
58///
59llvm::Value *
60CodeGenFunction::EmitObjCBoxedExpr(const ObjCBoxedExpr *E) {
61 // Generate the correct selector for this literal's concrete type.
62 // Get the method.
63 const ObjCMethodDecl *BoxingMethod = E->getBoxingMethod();
64 const Expr *SubExpr = E->getSubExpr();
65
66 if (E->isExpressibleAsConstantInitializer()) {
67 ConstantEmitter ConstEmitter(CGM);
68 return ConstEmitter.tryEmitAbstract(E, E->getType());
69 }
70
71 assert(BoxingMethod->isClassMethod() && "BoxingMethod must be a class method")((BoxingMethod->isClassMethod() && "BoxingMethod must be a class method"
) ? static_cast<void> (0) : __assert_fail ("BoxingMethod->isClassMethod() && \"BoxingMethod must be a class method\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 71, __PRETTY_FUNCTION__))
;
72 Selector Sel = BoxingMethod->getSelector();
73
74 // Generate a reference to the class pointer, which will be the receiver.
75 // Assumes that the method was introduced in the class that should be
76 // messaged (avoids pulling it out of the result type).
77 CGObjCRuntime &Runtime = CGM.getObjCRuntime();
78 const ObjCInterfaceDecl *ClassDecl = BoxingMethod->getClassInterface();
79 llvm::Value *Receiver = Runtime.GetClass(*this, ClassDecl);
80
81 CallArgList Args;
82 const ParmVarDecl *ArgDecl = *BoxingMethod->param_begin();
83 QualType ArgQT = ArgDecl->getType().getUnqualifiedType();
84
85 // ObjCBoxedExpr supports boxing of structs and unions
86 // via [NSValue valueWithBytes:objCType:]
87 const QualType ValueType(SubExpr->getType().getCanonicalType());
88 if (ValueType->isObjCBoxableRecordType()) {
89 // Emit CodeGen for first parameter
90 // and cast value to correct type
91 Address Temporary = CreateMemTemp(SubExpr->getType());
92 EmitAnyExprToMem(SubExpr, Temporary, Qualifiers(), /*isInit*/ true);
93 Address BitCast = Builder.CreateBitCast(Temporary, ConvertType(ArgQT));
94 Args.add(RValue::get(BitCast.getPointer()), ArgQT);
95
96 // Create char array to store type encoding
97 std::string Str;
98 getContext().getObjCEncodingForType(ValueType, Str);
99 llvm::Constant *GV = CGM.GetAddrOfConstantCString(Str).getPointer();
100
101 // Cast type encoding to correct type
102 const ParmVarDecl *EncodingDecl = BoxingMethod->parameters()[1];
103 QualType EncodingQT = EncodingDecl->getType().getUnqualifiedType();
104 llvm::Value *Cast = Builder.CreateBitCast(GV, ConvertType(EncodingQT));
105
106 Args.add(RValue::get(Cast), EncodingQT);
107 } else {
108 Args.add(EmitAnyExpr(SubExpr), ArgQT);
109 }
110
111 RValue result = Runtime.GenerateMessageSend(
112 *this, ReturnValueSlot(), BoxingMethod->getReturnType(), Sel, Receiver,
113 Args, ClassDecl, BoxingMethod);
114 return Builder.CreateBitCast(result.getScalarVal(),
115 ConvertType(E->getType()));
116}
117
118llvm::Value *CodeGenFunction::EmitObjCCollectionLiteral(const Expr *E,
119 const ObjCMethodDecl *MethodWithObjects) {
120 ASTContext &Context = CGM.getContext();
121 const ObjCDictionaryLiteral *DLE = nullptr;
122 const ObjCArrayLiteral *ALE = dyn_cast<ObjCArrayLiteral>(E);
123 if (!ALE)
124 DLE = cast<ObjCDictionaryLiteral>(E);
125
126 // Optimize empty collections by referencing constants, when available.
127 uint64_t NumElements =
128 ALE ? ALE->getNumElements() : DLE->getNumElements();
129 if (NumElements == 0 && CGM.getLangOpts().ObjCRuntime.hasEmptyCollections()) {
130 StringRef ConstantName = ALE ? "__NSArray0__" : "__NSDictionary0__";
131 QualType IdTy(CGM.getContext().getObjCIdType());
132 llvm::Constant *Constant =
133 CGM.CreateRuntimeVariable(ConvertType(IdTy), ConstantName);
134 LValue LV = MakeNaturalAlignAddrLValue(Constant, IdTy);
135 llvm::Value *Ptr = EmitLoadOfScalar(LV, E->getBeginLoc());
136 cast<llvm::LoadInst>(Ptr)->setMetadata(
137 CGM.getModule().getMDKindID("invariant.load"),
138 llvm::MDNode::get(getLLVMContext(), None));
139 return Builder.CreateBitCast(Ptr, ConvertType(E->getType()));
140 }
141
142 // Compute the type of the array we're initializing.
143 llvm::APInt APNumElements(Context.getTypeSize(Context.getSizeType()),
144 NumElements);
145 QualType ElementType = Context.getObjCIdType().withConst();
146 QualType ElementArrayType
147 = Context.getConstantArrayType(ElementType, APNumElements, nullptr,
148 ArrayType::Normal, /*IndexTypeQuals=*/0);
149
150 // Allocate the temporary array(s).
151 Address Objects = CreateMemTemp(ElementArrayType, "objects");
152 Address Keys = Address::invalid();
153 if (DLE)
154 Keys = CreateMemTemp(ElementArrayType, "keys");
155
156 // In ARC, we may need to do extra work to keep all the keys and
157 // values alive until after the call.
158 SmallVector<llvm::Value *, 16> NeededObjects;
159 bool TrackNeededObjects =
160 (getLangOpts().ObjCAutoRefCount &&
161 CGM.getCodeGenOpts().OptimizationLevel != 0);
162
163 // Perform the actual initialialization of the array(s).
164 for (uint64_t i = 0; i < NumElements; i++) {
165 if (ALE) {
166 // Emit the element and store it to the appropriate array slot.
167 const Expr *Rhs = ALE->getElement(i);
168 LValue LV = MakeAddrLValue(Builder.CreateConstArrayGEP(Objects, i),
169 ElementType, AlignmentSource::Decl);
170
171 llvm::Value *value = EmitScalarExpr(Rhs);
172 EmitStoreThroughLValue(RValue::get(value), LV, true);
173 if (TrackNeededObjects) {
174 NeededObjects.push_back(value);
175 }
176 } else {
177 // Emit the key and store it to the appropriate array slot.
178 const Expr *Key = DLE->getKeyValueElement(i).Key;
179 LValue KeyLV = MakeAddrLValue(Builder.CreateConstArrayGEP(Keys, i),
180 ElementType, AlignmentSource::Decl);
181 llvm::Value *keyValue = EmitScalarExpr(Key);
182 EmitStoreThroughLValue(RValue::get(keyValue), KeyLV, /*isInit=*/true);
183
184 // Emit the value and store it to the appropriate array slot.
185 const Expr *Value = DLE->getKeyValueElement(i).Value;
186 LValue ValueLV = MakeAddrLValue(Builder.CreateConstArrayGEP(Objects, i),
187 ElementType, AlignmentSource::Decl);
188 llvm::Value *valueValue = EmitScalarExpr(Value);
189 EmitStoreThroughLValue(RValue::get(valueValue), ValueLV, /*isInit=*/true);
190 if (TrackNeededObjects) {
191 NeededObjects.push_back(keyValue);
192 NeededObjects.push_back(valueValue);
193 }
194 }
195 }
196
197 // Generate the argument list.
198 CallArgList Args;
199 ObjCMethodDecl::param_const_iterator PI = MethodWithObjects->param_begin();
200 const ParmVarDecl *argDecl = *PI++;
201 QualType ArgQT = argDecl->getType().getUnqualifiedType();
202 Args.add(RValue::get(Objects.getPointer()), ArgQT);
203 if (DLE) {
204 argDecl = *PI++;
205 ArgQT = argDecl->getType().getUnqualifiedType();
206 Args.add(RValue::get(Keys.getPointer()), ArgQT);
207 }
208 argDecl = *PI;
209 ArgQT = argDecl->getType().getUnqualifiedType();
210 llvm::Value *Count =
211 llvm::ConstantInt::get(CGM.getTypes().ConvertType(ArgQT), NumElements);
212 Args.add(RValue::get(Count), ArgQT);
213
214 // Generate a reference to the class pointer, which will be the receiver.
215 Selector Sel = MethodWithObjects->getSelector();
216 QualType ResultType = E->getType();
217 const ObjCObjectPointerType *InterfacePointerType
218 = ResultType->getAsObjCInterfacePointerType();
219 ObjCInterfaceDecl *Class
220 = InterfacePointerType->getObjectType()->getInterface();
221 CGObjCRuntime &Runtime = CGM.getObjCRuntime();
222 llvm::Value *Receiver = Runtime.GetClass(*this, Class);
223
224 // Generate the message send.
225 RValue result = Runtime.GenerateMessageSend(
226 *this, ReturnValueSlot(), MethodWithObjects->getReturnType(), Sel,
227 Receiver, Args, Class, MethodWithObjects);
228
229 // The above message send needs these objects, but in ARC they are
230 // passed in a buffer that is essentially __unsafe_unretained.
231 // Therefore we must prevent the optimizer from releasing them until
232 // after the call.
233 if (TrackNeededObjects) {
234 EmitARCIntrinsicUse(NeededObjects);
235 }
236
237 return Builder.CreateBitCast(result.getScalarVal(),
238 ConvertType(E->getType()));
239}
240
241llvm::Value *CodeGenFunction::EmitObjCArrayLiteral(const ObjCArrayLiteral *E) {
242 return EmitObjCCollectionLiteral(E, E->getArrayWithObjectsMethod());
243}
244
245llvm::Value *CodeGenFunction::EmitObjCDictionaryLiteral(
246 const ObjCDictionaryLiteral *E) {
247 return EmitObjCCollectionLiteral(E, E->getDictWithObjectsMethod());
248}
249
250/// Emit a selector.
251llvm::Value *CodeGenFunction::EmitObjCSelectorExpr(const ObjCSelectorExpr *E) {
252 // Untyped selector.
253 // Note that this implementation allows for non-constant strings to be passed
254 // as arguments to @selector(). Currently, the only thing preventing this
255 // behaviour is the type checking in the front end.
256 return CGM.getObjCRuntime().GetSelector(*this, E->getSelector());
257}
258
259llvm::Value *CodeGenFunction::EmitObjCProtocolExpr(const ObjCProtocolExpr *E) {
260 // FIXME: This should pass the Decl not the name.
261 return CGM.getObjCRuntime().GenerateProtocolRef(*this, E->getProtocol());
262}
263
264/// Adjust the type of an Objective-C object that doesn't match up due
265/// to type erasure at various points, e.g., related result types or the use
266/// of parameterized classes.
267static RValue AdjustObjCObjectType(CodeGenFunction &CGF, QualType ExpT,
268 RValue Result) {
269 if (!ExpT->isObjCRetainableType())
270 return Result;
271
272 // If the converted types are the same, we're done.
273 llvm::Type *ExpLLVMTy = CGF.ConvertType(ExpT);
274 if (ExpLLVMTy == Result.getScalarVal()->getType())
275 return Result;
276
277 // We have applied a substitution. Cast the rvalue appropriately.
278 return RValue::get(CGF.Builder.CreateBitCast(Result.getScalarVal(),
279 ExpLLVMTy));
280}
281
282/// Decide whether to extend the lifetime of the receiver of a
283/// returns-inner-pointer message.
284static bool
285shouldExtendReceiverForInnerPointerMessage(const ObjCMessageExpr *message) {
286 switch (message->getReceiverKind()) {
287
288 // For a normal instance message, we should extend unless the
289 // receiver is loaded from a variable with precise lifetime.
290 case ObjCMessageExpr::Instance: {
291 const Expr *receiver = message->getInstanceReceiver();
292
293 // Look through OVEs.
294 if (auto opaque = dyn_cast<OpaqueValueExpr>(receiver)) {
295 if (opaque->getSourceExpr())
296 receiver = opaque->getSourceExpr()->IgnoreParens();
297 }
298
299 const ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(receiver);
300 if (!ice || ice->getCastKind() != CK_LValueToRValue) return true;
301 receiver = ice->getSubExpr()->IgnoreParens();
302
303 // Look through OVEs.
304 if (auto opaque = dyn_cast<OpaqueValueExpr>(receiver)) {
305 if (opaque->getSourceExpr())
306 receiver = opaque->getSourceExpr()->IgnoreParens();
307 }
308
309 // Only __strong variables.
310 if (receiver->getType().getObjCLifetime() != Qualifiers::OCL_Strong)
311 return true;
312
313 // All ivars and fields have precise lifetime.
314 if (isa<MemberExpr>(receiver) || isa<ObjCIvarRefExpr>(receiver))
315 return false;
316
317 // Otherwise, check for variables.
318 const DeclRefExpr *declRef = dyn_cast<DeclRefExpr>(ice->getSubExpr());
319 if (!declRef) return true;
320 const VarDecl *var = dyn_cast<VarDecl>(declRef->getDecl());
321 if (!var) return true;
322
323 // All variables have precise lifetime except local variables with
324 // automatic storage duration that aren't specially marked.
325 return (var->hasLocalStorage() &&
326 !var->hasAttr<ObjCPreciseLifetimeAttr>());
327 }
328
329 case ObjCMessageExpr::Class:
330 case ObjCMessageExpr::SuperClass:
331 // It's never necessary for class objects.
332 return false;
333
334 case ObjCMessageExpr::SuperInstance:
335 // We generally assume that 'self' lives throughout a method call.
336 return false;
337 }
338
339 llvm_unreachable("invalid receiver kind")::llvm::llvm_unreachable_internal("invalid receiver kind", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 339)
;
340}
341
342/// Given an expression of ObjC pointer type, check whether it was
343/// immediately loaded from an ARC __weak l-value.
344static const Expr *findWeakLValue(const Expr *E) {
345 assert(E->getType()->isObjCRetainableType())((E->getType()->isObjCRetainableType()) ? static_cast<
void> (0) : __assert_fail ("E->getType()->isObjCRetainableType()"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 345, __PRETTY_FUNCTION__))
;
346 E = E->IgnoreParens();
347 if (auto CE = dyn_cast<CastExpr>(E)) {
348 if (CE->getCastKind() == CK_LValueToRValue) {
349 if (CE->getSubExpr()->getType().getObjCLifetime() == Qualifiers::OCL_Weak)
350 return CE->getSubExpr();
351 }
352 }
353
354 return nullptr;
355}
356
357/// The ObjC runtime may provide entrypoints that are likely to be faster
358/// than an ordinary message send of the appropriate selector.
359///
360/// The entrypoints are guaranteed to be equivalent to just sending the
361/// corresponding message. If the entrypoint is implemented naively as just a
362/// message send, using it is a trade-off: it sacrifices a few cycles of
363/// overhead to save a small amount of code. However, it's possible for
364/// runtimes to detect and special-case classes that use "standard"
365/// behavior; if that's dynamically a large proportion of all objects, using
366/// the entrypoint will also be faster than using a message send.
367///
368/// If the runtime does support a required entrypoint, then this method will
369/// generate a call and return the resulting value. Otherwise it will return
370/// None and the caller can generate a msgSend instead.
371static Optional<llvm::Value *>
372tryGenerateSpecializedMessageSend(CodeGenFunction &CGF, QualType ResultType,
373 llvm::Value *Receiver,
374 const CallArgList& Args, Selector Sel,
375 const ObjCMethodDecl *method,
376 bool isClassMessage) {
377 auto &CGM = CGF.CGM;
378 if (!CGM.getCodeGenOpts().ObjCConvertMessagesToRuntimeCalls)
379 return None;
380
381 auto &Runtime = CGM.getLangOpts().ObjCRuntime;
382 switch (Sel.getMethodFamily()) {
383 case OMF_alloc:
384 if (isClassMessage &&
385 Runtime.shouldUseRuntimeFunctionsForAlloc() &&
386 ResultType->isObjCObjectPointerType()) {
387 // [Foo alloc] -> objc_alloc(Foo) or
388 // [self alloc] -> objc_alloc(self)
389 if (Sel.isUnarySelector() && Sel.getNameForSlot(0) == "alloc")
390 return CGF.EmitObjCAlloc(Receiver, CGF.ConvertType(ResultType));
391 // [Foo allocWithZone:nil] -> objc_allocWithZone(Foo) or
392 // [self allocWithZone:nil] -> objc_allocWithZone(self)
393 if (Sel.isKeywordSelector() && Sel.getNumArgs() == 1 &&
394 Args.size() == 1 && Args.front().getType()->isPointerType() &&
395 Sel.getNameForSlot(0) == "allocWithZone") {
396 const llvm::Value* arg = Args.front().getKnownRValue().getScalarVal();
397 if (isa<llvm::ConstantPointerNull>(arg))
398 return CGF.EmitObjCAllocWithZone(Receiver,
399 CGF.ConvertType(ResultType));
400 return None;
401 }
402 }
403 break;
404
405 case OMF_autorelease:
406 if (ResultType->isObjCObjectPointerType() &&
407 CGM.getLangOpts().getGC() == LangOptions::NonGC &&
408 Runtime.shouldUseARCFunctionsForRetainRelease())
409 return CGF.EmitObjCAutorelease(Receiver, CGF.ConvertType(ResultType));
410 break;
411
412 case OMF_retain:
413 if (ResultType->isObjCObjectPointerType() &&
414 CGM.getLangOpts().getGC() == LangOptions::NonGC &&
415 Runtime.shouldUseARCFunctionsForRetainRelease())
416 return CGF.EmitObjCRetainNonBlock(Receiver, CGF.ConvertType(ResultType));
417 break;
418
419 case OMF_release:
420 if (ResultType->isVoidType() &&
421 CGM.getLangOpts().getGC() == LangOptions::NonGC &&
422 Runtime.shouldUseARCFunctionsForRetainRelease()) {
423 CGF.EmitObjCRelease(Receiver, ARCPreciseLifetime);
424 return nullptr;
425 }
426 break;
427
428 default:
429 break;
430 }
431 return None;
432}
433
434CodeGen::RValue CGObjCRuntime::GeneratePossiblySpecializedMessageSend(
435 CodeGenFunction &CGF, ReturnValueSlot Return, QualType ResultType,
436 Selector Sel, llvm::Value *Receiver, const CallArgList &Args,
437 const ObjCInterfaceDecl *OID, const ObjCMethodDecl *Method,
438 bool isClassMessage) {
439 if (Optional<llvm::Value *> SpecializedResult =
440 tryGenerateSpecializedMessageSend(CGF, ResultType, Receiver, Args,
441 Sel, Method, isClassMessage)) {
442 return RValue::get(SpecializedResult.getValue());
443 }
444 return GenerateMessageSend(CGF, Return, ResultType, Sel, Receiver, Args, OID,
445 Method);
446}
447
448/// Instead of '[[MyClass alloc] init]', try to generate
449/// 'objc_alloc_init(MyClass)'. This provides a code size improvement on the
450/// caller side, as well as the optimized objc_alloc.
451static Optional<llvm::Value *>
452tryEmitSpecializedAllocInit(CodeGenFunction &CGF, const ObjCMessageExpr *OME) {
453 auto &Runtime = CGF.getLangOpts().ObjCRuntime;
454 if (!Runtime.shouldUseRuntimeFunctionForCombinedAllocInit())
455 return None;
456
457 // Match the exact pattern '[[MyClass alloc] init]'.
458 Selector Sel = OME->getSelector();
459 if (OME->getReceiverKind() != ObjCMessageExpr::Instance ||
460 !OME->getType()->isObjCObjectPointerType() || !Sel.isUnarySelector() ||
461 Sel.getNameForSlot(0) != "init")
462 return None;
463
464 // Okay, this is '[receiver init]', check if 'receiver' is '[cls alloc]'
465 // with 'cls' a Class.
466 auto *SubOME =
467 dyn_cast<ObjCMessageExpr>(OME->getInstanceReceiver()->IgnoreParenCasts());
468 if (!SubOME)
469 return None;
470 Selector SubSel = SubOME->getSelector();
471
472 if (!SubOME->getType()->isObjCObjectPointerType() ||
473 !SubSel.isUnarySelector() || SubSel.getNameForSlot(0) != "alloc")
474 return None;
475
476 llvm::Value *Receiver = nullptr;
477 switch (SubOME->getReceiverKind()) {
478 case ObjCMessageExpr::Instance:
479 if (!SubOME->getInstanceReceiver()->getType()->isObjCClassType())
480 return None;
481 Receiver = CGF.EmitScalarExpr(SubOME->getInstanceReceiver());
482 break;
483
484 case ObjCMessageExpr::Class: {
485 QualType ReceiverType = SubOME->getClassReceiver();
486 const ObjCObjectType *ObjTy = ReceiverType->castAs<ObjCObjectType>();
487 const ObjCInterfaceDecl *ID = ObjTy->getInterface();
488 assert(ID && "null interface should be impossible here")((ID && "null interface should be impossible here") ?
static_cast<void> (0) : __assert_fail ("ID && \"null interface should be impossible here\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 488, __PRETTY_FUNCTION__))
;
489 Receiver = CGF.CGM.getObjCRuntime().GetClass(CGF, ID);
490 break;
491 }
492 case ObjCMessageExpr::SuperInstance:
493 case ObjCMessageExpr::SuperClass:
494 return None;
495 }
496
497 return CGF.EmitObjCAllocInit(Receiver, CGF.ConvertType(OME->getType()));
498}
499
500RValue CodeGenFunction::EmitObjCMessageExpr(const ObjCMessageExpr *E,
501 ReturnValueSlot Return) {
502 // Only the lookup mechanism and first two arguments of the method
503 // implementation vary between runtimes. We can get the receiver and
504 // arguments in generic code.
505
506 bool isDelegateInit = E->isDelegateInitCall();
507
508 const ObjCMethodDecl *method = E->getMethodDecl();
509
510 // If the method is -retain, and the receiver's being loaded from
511 // a __weak variable, peephole the entire operation to objc_loadWeakRetained.
512 if (method && E->getReceiverKind() == ObjCMessageExpr::Instance &&
513 method->getMethodFamily() == OMF_retain) {
514 if (auto lvalueExpr = findWeakLValue(E->getInstanceReceiver())) {
515 LValue lvalue = EmitLValue(lvalueExpr);
516 llvm::Value *result = EmitARCLoadWeakRetained(lvalue.getAddress(*this));
517 return AdjustObjCObjectType(*this, E->getType(), RValue::get(result));
518 }
519 }
520
521 if (Optional<llvm::Value *> Val = tryEmitSpecializedAllocInit(*this, E))
522 return AdjustObjCObjectType(*this, E->getType(), RValue::get(*Val));
523
524 // We don't retain the receiver in delegate init calls, and this is
525 // safe because the receiver value is always loaded from 'self',
526 // which we zero out. We don't want to Block_copy block receivers,
527 // though.
528 bool retainSelf =
529 (!isDelegateInit &&
530 CGM.getLangOpts().ObjCAutoRefCount &&
531 method &&
532 method->hasAttr<NSConsumesSelfAttr>());
533
534 CGObjCRuntime &Runtime = CGM.getObjCRuntime();
535 bool isSuperMessage = false;
536 bool isClassMessage = false;
537 ObjCInterfaceDecl *OID = nullptr;
538 // Find the receiver
539 QualType ReceiverType;
540 llvm::Value *Receiver = nullptr;
541 switch (E->getReceiverKind()) {
542 case ObjCMessageExpr::Instance:
543 ReceiverType = E->getInstanceReceiver()->getType();
544 isClassMessage = ReceiverType->isObjCClassType();
545 if (retainSelf) {
546 TryEmitResult ter = tryEmitARCRetainScalarExpr(*this,
547 E->getInstanceReceiver());
548 Receiver = ter.getPointer();
549 if (ter.getInt()) retainSelf = false;
550 } else
551 Receiver = EmitScalarExpr(E->getInstanceReceiver());
552 break;
553
554 case ObjCMessageExpr::Class: {
555 ReceiverType = E->getClassReceiver();
556 OID = ReceiverType->castAs<ObjCObjectType>()->getInterface();
557 assert(OID && "Invalid Objective-C class message send")((OID && "Invalid Objective-C class message send") ? static_cast
<void> (0) : __assert_fail ("OID && \"Invalid Objective-C class message send\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 557, __PRETTY_FUNCTION__))
;
558 Receiver = Runtime.GetClass(*this, OID);
559 isClassMessage = true;
560 break;
561 }
562
563 case ObjCMessageExpr::SuperInstance:
564 ReceiverType = E->getSuperType();
565 Receiver = LoadObjCSelf();
566 isSuperMessage = true;
567 break;
568
569 case ObjCMessageExpr::SuperClass:
570 ReceiverType = E->getSuperType();
571 Receiver = LoadObjCSelf();
572 isSuperMessage = true;
573 isClassMessage = true;
574 break;
575 }
576
577 if (retainSelf)
578 Receiver = EmitARCRetainNonBlock(Receiver);
579
580 // In ARC, we sometimes want to "extend the lifetime"
581 // (i.e. retain+autorelease) of receivers of returns-inner-pointer
582 // messages.
583 if (getLangOpts().ObjCAutoRefCount && method &&
584 method->hasAttr<ObjCReturnsInnerPointerAttr>() &&
585 shouldExtendReceiverForInnerPointerMessage(E))
586 Receiver = EmitARCRetainAutorelease(ReceiverType, Receiver);
587
588 QualType ResultType = method ? method->getReturnType() : E->getType();
589
590 CallArgList Args;
591 EmitCallArgs(Args, method, E->arguments(), /*AC*/AbstractCallee(method));
592
593 // For delegate init calls in ARC, do an unsafe store of null into
594 // self. This represents the call taking direct ownership of that
595 // value. We have to do this after emitting the other call
596 // arguments because they might also reference self, but we don't
597 // have to worry about any of them modifying self because that would
598 // be an undefined read and write of an object in unordered
599 // expressions.
600 if (isDelegateInit) {
601 assert(getLangOpts().ObjCAutoRefCount &&((getLangOpts().ObjCAutoRefCount && "delegate init calls should only be marked in ARC"
) ? static_cast<void> (0) : __assert_fail ("getLangOpts().ObjCAutoRefCount && \"delegate init calls should only be marked in ARC\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 602, __PRETTY_FUNCTION__))
602 "delegate init calls should only be marked in ARC")((getLangOpts().ObjCAutoRefCount && "delegate init calls should only be marked in ARC"
) ? static_cast<void> (0) : __assert_fail ("getLangOpts().ObjCAutoRefCount && \"delegate init calls should only be marked in ARC\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 602, __PRETTY_FUNCTION__))
;
603
604 // Do an unsafe store of null into self.
605 Address selfAddr =
606 GetAddrOfLocalVar(cast<ObjCMethodDecl>(CurCodeDecl)->getSelfDecl());
607 Builder.CreateStore(getNullForVariable(selfAddr), selfAddr);
608 }
609
610 RValue result;
611 if (isSuperMessage) {
612 // super is only valid in an Objective-C method
613 const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
614 bool isCategoryImpl = isa<ObjCCategoryImplDecl>(OMD->getDeclContext());
615 result = Runtime.GenerateMessageSendSuper(*this, Return, ResultType,
616 E->getSelector(),
617 OMD->getClassInterface(),
618 isCategoryImpl,
619 Receiver,
620 isClassMessage,
621 Args,
622 method);
623 } else {
624 // Call runtime methods directly if we can.
625 result = Runtime.GeneratePossiblySpecializedMessageSend(
626 *this, Return, ResultType, E->getSelector(), Receiver, Args, OID,
627 method, isClassMessage);
628 }
629
630 // For delegate init calls in ARC, implicitly store the result of
631 // the call back into self. This takes ownership of the value.
632 if (isDelegateInit) {
633 Address selfAddr =
634 GetAddrOfLocalVar(cast<ObjCMethodDecl>(CurCodeDecl)->getSelfDecl());
635 llvm::Value *newSelf = result.getScalarVal();
636
637 // The delegate return type isn't necessarily a matching type; in
638 // fact, it's quite likely to be 'id'.
639 llvm::Type *selfTy = selfAddr.getElementType();
640 newSelf = Builder.CreateBitCast(newSelf, selfTy);
641
642 Builder.CreateStore(newSelf, selfAddr);
643 }
644
645 return AdjustObjCObjectType(*this, E->getType(), result);
646}
647
648namespace {
649struct FinishARCDealloc final : EHScopeStack::Cleanup {
650 void Emit(CodeGenFunction &CGF, Flags flags) override {
651 const ObjCMethodDecl *method = cast<ObjCMethodDecl>(CGF.CurCodeDecl);
652
653 const ObjCImplDecl *impl = cast<ObjCImplDecl>(method->getDeclContext());
654 const ObjCInterfaceDecl *iface = impl->getClassInterface();
655 if (!iface->getSuperClass()) return;
656
657 bool isCategory = isa<ObjCCategoryImplDecl>(impl);
658
659 // Call [super dealloc] if we have a superclass.
660 llvm::Value *self = CGF.LoadObjCSelf();
661
662 CallArgList args;
663 CGF.CGM.getObjCRuntime().GenerateMessageSendSuper(CGF, ReturnValueSlot(),
664 CGF.getContext().VoidTy,
665 method->getSelector(),
666 iface,
667 isCategory,
668 self,
669 /*is class msg*/ false,
670 args,
671 method);
672 }
673};
674}
675
676/// StartObjCMethod - Begin emission of an ObjCMethod. This generates
677/// the LLVM function and sets the other context used by
678/// CodeGenFunction.
679void CodeGenFunction::StartObjCMethod(const ObjCMethodDecl *OMD,
680 const ObjCContainerDecl *CD) {
681 SourceLocation StartLoc = OMD->getBeginLoc();
682 FunctionArgList args;
683 // Check if we should generate debug info for this method.
684 if (OMD->hasAttr<NoDebugAttr>())
685 DebugInfo = nullptr; // disable debug info indefinitely for this function
686
687 llvm::Function *Fn = CGM.getObjCRuntime().GenerateMethod(OMD, CD);
688
689 const CGFunctionInfo &FI = CGM.getTypes().arrangeObjCMethodDeclaration(OMD);
690 if (OMD->isDirectMethod()) {
691 Fn->setVisibility(llvm::Function::HiddenVisibility);
692 CGM.SetLLVMFunctionAttributes(OMD, FI, Fn);
693 CGM.SetLLVMFunctionAttributesForDefinition(OMD, Fn);
694 } else {
695 CGM.SetInternalFunctionAttributes(OMD, Fn, FI);
696 }
697
698 args.push_back(OMD->getSelfDecl());
699 args.push_back(OMD->getCmdDecl());
700
701 args.append(OMD->param_begin(), OMD->param_end());
702
703 CurGD = OMD;
704 CurEHLocation = OMD->getEndLoc();
705
706 StartFunction(OMD, OMD->getReturnType(), Fn, FI, args,
707 OMD->getLocation(), StartLoc);
708
709 if (OMD->isDirectMethod()) {
710 // This function is a direct call, it has to implement a nil check
711 // on entry.
712 //
713 // TODO: possibly have several entry points to elide the check
714 CGM.getObjCRuntime().GenerateDirectMethodPrologue(*this, Fn, OMD, CD);
715 }
716
717 // In ARC, certain methods get an extra cleanup.
718 if (CGM.getLangOpts().ObjCAutoRefCount &&
719 OMD->isInstanceMethod() &&
720 OMD->getSelector().isUnarySelector()) {
721 const IdentifierInfo *ident =
722 OMD->getSelector().getIdentifierInfoForSlot(0);
723 if (ident->isStr("dealloc"))
724 EHStack.pushCleanup<FinishARCDealloc>(getARCCleanupKind());
725 }
726}
727
728static llvm::Value *emitARCRetainLoadOfScalar(CodeGenFunction &CGF,
729 LValue lvalue, QualType type);
730
731/// Generate an Objective-C method. An Objective-C method is a C function with
732/// its pointer, name, and types registered in the class structure.
733void CodeGenFunction::GenerateObjCMethod(const ObjCMethodDecl *OMD) {
734 StartObjCMethod(OMD, OMD->getClassInterface());
735 PGO.assignRegionCounters(GlobalDecl(OMD), CurFn);
736 assert(isa<CompoundStmt>(OMD->getBody()))((isa<CompoundStmt>(OMD->getBody())) ? static_cast<
void> (0) : __assert_fail ("isa<CompoundStmt>(OMD->getBody())"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 736, __PRETTY_FUNCTION__))
;
737 incrementProfileCounter(OMD->getBody());
738 EmitCompoundStmtWithoutScope(*cast<CompoundStmt>(OMD->getBody()));
739 FinishFunction(OMD->getBodyRBrace());
740}
741
742/// emitStructGetterCall - Call the runtime function to load a property
743/// into the return value slot.
744static void emitStructGetterCall(CodeGenFunction &CGF, ObjCIvarDecl *ivar,
745 bool isAtomic, bool hasStrong) {
746 ASTContext &Context = CGF.getContext();
747
748 Address src =
749 CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), CGF.LoadObjCSelf(), ivar, 0)
750 .getAddress(CGF);
751
752 // objc_copyStruct (ReturnValue, &structIvar,
753 // sizeof (Type of Ivar), isAtomic, false);
754 CallArgList args;
755
756 Address dest = CGF.Builder.CreateBitCast(CGF.ReturnValue, CGF.VoidPtrTy);
757 args.add(RValue::get(dest.getPointer()), Context.VoidPtrTy);
758
759 src = CGF.Builder.CreateBitCast(src, CGF.VoidPtrTy);
760 args.add(RValue::get(src.getPointer()), Context.VoidPtrTy);
761
762 CharUnits size = CGF.getContext().getTypeSizeInChars(ivar->getType());
763 args.add(RValue::get(CGF.CGM.getSize(size)), Context.getSizeType());
764 args.add(RValue::get(CGF.Builder.getInt1(isAtomic)), Context.BoolTy);
765 args.add(RValue::get(CGF.Builder.getInt1(hasStrong)), Context.BoolTy);
766
767 llvm::FunctionCallee fn = CGF.CGM.getObjCRuntime().GetGetStructFunction();
768 CGCallee callee = CGCallee::forDirect(fn);
769 CGF.EmitCall(CGF.getTypes().arrangeBuiltinFunctionCall(Context.VoidTy, args),
770 callee, ReturnValueSlot(), args);
771}
772
773/// Determine whether the given architecture supports unaligned atomic
774/// accesses. They don't have to be fast, just faster than a function
775/// call and a mutex.
776static bool hasUnalignedAtomics(llvm::Triple::ArchType arch) {
777 // FIXME: Allow unaligned atomic load/store on x86. (It is not
778 // currently supported by the backend.)
779 return 0;
780}
781
782/// Return the maximum size that permits atomic accesses for the given
783/// architecture.
784static CharUnits getMaxAtomicAccessSize(CodeGenModule &CGM,
785 llvm::Triple::ArchType arch) {
786 // ARM has 8-byte atomic accesses, but it's not clear whether we
787 // want to rely on them here.
788
789 // In the default case, just assume that any size up to a pointer is
790 // fine given adequate alignment.
791 return CharUnits::fromQuantity(CGM.PointerSizeInBytes);
792}
793
794namespace {
795 class PropertyImplStrategy {
796 public:
797 enum StrategyKind {
798 /// The 'native' strategy is to use the architecture's provided
799 /// reads and writes.
800 Native,
801
802 /// Use objc_setProperty and objc_getProperty.
803 GetSetProperty,
804
805 /// Use objc_setProperty for the setter, but use expression
806 /// evaluation for the getter.
807 SetPropertyAndExpressionGet,
808
809 /// Use objc_copyStruct.
810 CopyStruct,
811
812 /// The 'expression' strategy is to emit normal assignment or
813 /// lvalue-to-rvalue expressions.
814 Expression
815 };
816
817 StrategyKind getKind() const { return StrategyKind(Kind); }
818
819 bool hasStrongMember() const { return HasStrong; }
820 bool isAtomic() const { return IsAtomic; }
821 bool isCopy() const { return IsCopy; }
822
823 CharUnits getIvarSize() const { return IvarSize; }
824 CharUnits getIvarAlignment() const { return IvarAlignment; }
825
826 PropertyImplStrategy(CodeGenModule &CGM,
827 const ObjCPropertyImplDecl *propImpl);
828
829 private:
830 unsigned Kind : 8;
831 unsigned IsAtomic : 1;
832 unsigned IsCopy : 1;
833 unsigned HasStrong : 1;
834
835 CharUnits IvarSize;
836 CharUnits IvarAlignment;
837 };
838}
839
840/// Pick an implementation strategy for the given property synthesis.
841PropertyImplStrategy::PropertyImplStrategy(CodeGenModule &CGM,
842 const ObjCPropertyImplDecl *propImpl) {
843 const ObjCPropertyDecl *prop = propImpl->getPropertyDecl();
844 ObjCPropertyDecl::SetterKind setterKind = prop->getSetterKind();
845
846 IsCopy = (setterKind == ObjCPropertyDecl::Copy);
847 IsAtomic = prop->isAtomic();
848 HasStrong = false; // doesn't matter here.
849
850 // Evaluate the ivar's size and alignment.
851 ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
852 QualType ivarType = ivar->getType();
853 std::tie(IvarSize, IvarAlignment) =
854 CGM.getContext().getTypeInfoInChars(ivarType);
855
856 // If we have a copy property, we always have to use getProperty/setProperty.
857 // TODO: we could actually use setProperty and an expression for non-atomics.
858 if (IsCopy) {
859 Kind = GetSetProperty;
860 return;
861 }
862
863 // Handle retain.
864 if (setterKind == ObjCPropertyDecl::Retain) {
865 // In GC-only, there's nothing special that needs to be done.
866 if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) {
867 // fallthrough
868
869 // In ARC, if the property is non-atomic, use expression emission,
870 // which translates to objc_storeStrong. This isn't required, but
871 // it's slightly nicer.
872 } else if (CGM.getLangOpts().ObjCAutoRefCount && !IsAtomic) {
873 // Using standard expression emission for the setter is only
874 // acceptable if the ivar is __strong, which won't be true if
875 // the property is annotated with __attribute__((NSObject)).
876 // TODO: falling all the way back to objc_setProperty here is
877 // just laziness, though; we could still use objc_storeStrong
878 // if we hacked it right.
879 if (ivarType.getObjCLifetime() == Qualifiers::OCL_Strong)
880 Kind = Expression;
881 else
882 Kind = SetPropertyAndExpressionGet;
883 return;
884
885 // Otherwise, we need to at least use setProperty. However, if
886 // the property isn't atomic, we can use normal expression
887 // emission for the getter.
888 } else if (!IsAtomic) {
889 Kind = SetPropertyAndExpressionGet;
890 return;
891
892 // Otherwise, we have to use both setProperty and getProperty.
893 } else {
894 Kind = GetSetProperty;
895 return;
896 }
897 }
898
899 // If we're not atomic, just use expression accesses.
900 if (!IsAtomic) {
901 Kind = Expression;
902 return;
903 }
904
905 // Properties on bitfield ivars need to be emitted using expression
906 // accesses even if they're nominally atomic.
907 if (ivar->isBitField()) {
908 Kind = Expression;
909 return;
910 }
911
912 // GC-qualified or ARC-qualified ivars need to be emitted as
913 // expressions. This actually works out to being atomic anyway,
914 // except for ARC __strong, but that should trigger the above code.
915 if (ivarType.hasNonTrivialObjCLifetime() ||
916 (CGM.getLangOpts().getGC() &&
917 CGM.getContext().getObjCGCAttrKind(ivarType))) {
918 Kind = Expression;
919 return;
920 }
921
922 // Compute whether the ivar has strong members.
923 if (CGM.getLangOpts().getGC())
924 if (const RecordType *recordType = ivarType->getAs<RecordType>())
925 HasStrong = recordType->getDecl()->hasObjectMember();
926
927 // We can never access structs with object members with a native
928 // access, because we need to use write barriers. This is what
929 // objc_copyStruct is for.
930 if (HasStrong) {
931 Kind = CopyStruct;
932 return;
933 }
934
935 // Otherwise, this is target-dependent and based on the size and
936 // alignment of the ivar.
937
938 // If the size of the ivar is not a power of two, give up. We don't
939 // want to get into the business of doing compare-and-swaps.
940 if (!IvarSize.isPowerOfTwo()) {
941 Kind = CopyStruct;
942 return;
943 }
944
945 llvm::Triple::ArchType arch =
946 CGM.getTarget().getTriple().getArch();
947
948 // Most architectures require memory to fit within a single cache
949 // line, so the alignment has to be at least the size of the access.
950 // Otherwise we have to grab a lock.
951 if (IvarAlignment < IvarSize && !hasUnalignedAtomics(arch)) {
952 Kind = CopyStruct;
953 return;
954 }
955
956 // If the ivar's size exceeds the architecture's maximum atomic
957 // access size, we have to use CopyStruct.
958 if (IvarSize > getMaxAtomicAccessSize(CGM, arch)) {
959 Kind = CopyStruct;
960 return;
961 }
962
963 // Otherwise, we can use native loads and stores.
964 Kind = Native;
965}
966
967/// Generate an Objective-C property getter function.
968///
969/// The given Decl must be an ObjCImplementationDecl. \@synthesize
970/// is illegal within a category.
971void CodeGenFunction::GenerateObjCGetter(ObjCImplementationDecl *IMP,
972 const ObjCPropertyImplDecl *PID) {
973 llvm::Constant *AtomicHelperFn =
974 CodeGenFunction(CGM).GenerateObjCAtomicGetterCopyHelperFunction(PID);
975 ObjCMethodDecl *OMD = PID->getGetterMethodDecl();
976 assert(OMD && "Invalid call to generate getter (empty method)")((OMD && "Invalid call to generate getter (empty method)"
) ? static_cast<void> (0) : __assert_fail ("OMD && \"Invalid call to generate getter (empty method)\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 976, __PRETTY_FUNCTION__))
;
977 StartObjCMethod(OMD, IMP->getClassInterface());
978
979 generateObjCGetterBody(IMP, PID, OMD, AtomicHelperFn);
980
981 FinishFunction(OMD->getEndLoc());
982}
983
984static bool hasTrivialGetExpr(const ObjCPropertyImplDecl *propImpl) {
985 const Expr *getter = propImpl->getGetterCXXConstructor();
986 if (!getter) return true;
987
988 // Sema only makes only of these when the ivar has a C++ class type,
989 // so the form is pretty constrained.
990
991 // If the property has a reference type, we might just be binding a
992 // reference, in which case the result will be a gl-value. We should
993 // treat this as a non-trivial operation.
994 if (getter->isGLValue())
995 return false;
996
997 // If we selected a trivial copy-constructor, we're okay.
998 if (const CXXConstructExpr *construct = dyn_cast<CXXConstructExpr>(getter))
999 return (construct->getConstructor()->isTrivial());
1000
1001 // The constructor might require cleanups (in which case it's never
1002 // trivial).
1003 assert(isa<ExprWithCleanups>(getter))((isa<ExprWithCleanups>(getter)) ? static_cast<void>
(0) : __assert_fail ("isa<ExprWithCleanups>(getter)", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 1003, __PRETTY_FUNCTION__))
;
1004 return false;
1005}
1006
1007/// emitCPPObjectAtomicGetterCall - Call the runtime function to
1008/// copy the ivar into the resturn slot.
1009static void emitCPPObjectAtomicGetterCall(CodeGenFunction &CGF,
1010 llvm::Value *returnAddr,
1011 ObjCIvarDecl *ivar,
1012 llvm::Constant *AtomicHelperFn) {
1013 // objc_copyCppObjectAtomic (&returnSlot, &CppObjectIvar,
1014 // AtomicHelperFn);
1015 CallArgList args;
1016
1017 // The 1st argument is the return Slot.
1018 args.add(RValue::get(returnAddr), CGF.getContext().VoidPtrTy);
1019
1020 // The 2nd argument is the address of the ivar.
1021 llvm::Value *ivarAddr =
1022 CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), CGF.LoadObjCSelf(), ivar, 0)
1023 .getPointer(CGF);
1024 ivarAddr = CGF.Builder.CreateBitCast(ivarAddr, CGF.Int8PtrTy);
1025 args.add(RValue::get(ivarAddr), CGF.getContext().VoidPtrTy);
1026
1027 // Third argument is the helper function.
1028 args.add(RValue::get(AtomicHelperFn), CGF.getContext().VoidPtrTy);
1029
1030 llvm::FunctionCallee copyCppAtomicObjectFn =
1031 CGF.CGM.getObjCRuntime().GetCppAtomicObjectGetFunction();
1032 CGCallee callee = CGCallee::forDirect(copyCppAtomicObjectFn);
1033 CGF.EmitCall(
1034 CGF.getTypes().arrangeBuiltinFunctionCall(CGF.getContext().VoidTy, args),
1035 callee, ReturnValueSlot(), args);
1036}
1037
1038void
1039CodeGenFunction::generateObjCGetterBody(const ObjCImplementationDecl *classImpl,
1040 const ObjCPropertyImplDecl *propImpl,
1041 const ObjCMethodDecl *GetterMethodDecl,
1042 llvm::Constant *AtomicHelperFn) {
1043 // If there's a non-trivial 'get' expression, we just have to emit that.
1044 if (!hasTrivialGetExpr(propImpl)) {
1045 if (!AtomicHelperFn) {
1046 auto *ret = ReturnStmt::Create(getContext(), SourceLocation(),
1047 propImpl->getGetterCXXConstructor(),
1048 /* NRVOCandidate=*/nullptr);
1049 EmitReturnStmt(*ret);
1050 }
1051 else {
1052 ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
1053 emitCPPObjectAtomicGetterCall(*this, ReturnValue.getPointer(),
1054 ivar, AtomicHelperFn);
1055 }
1056 return;
1057 }
1058
1059 const ObjCPropertyDecl *prop = propImpl->getPropertyDecl();
1060 QualType propType = prop->getType();
1061 ObjCMethodDecl *getterMethod = propImpl->getGetterMethodDecl();
1062
1063 ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
1064
1065 // Pick an implementation strategy.
1066 PropertyImplStrategy strategy(CGM, propImpl);
1067 switch (strategy.getKind()) {
1068 case PropertyImplStrategy::Native: {
1069 // We don't need to do anything for a zero-size struct.
1070 if (strategy.getIvarSize().isZero())
1071 return;
1072
1073 LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, 0);
1074
1075 // Currently, all atomic accesses have to be through integer
1076 // types, so there's no point in trying to pick a prettier type.
1077 uint64_t ivarSize = getContext().toBits(strategy.getIvarSize());
1078 llvm::Type *bitcastType = llvm::Type::getIntNTy(getLLVMContext(), ivarSize);
1079 bitcastType = bitcastType->getPointerTo(); // addrspace 0 okay
1080
1081 // Perform an atomic load. This does not impose ordering constraints.
1082 Address ivarAddr = LV.getAddress(*this);
1083 ivarAddr = Builder.CreateBitCast(ivarAddr, bitcastType);
1084 llvm::LoadInst *load = Builder.CreateLoad(ivarAddr, "load");
1085 load->setAtomic(llvm::AtomicOrdering::Unordered);
1086
1087 // Store that value into the return address. Doing this with a
1088 // bitcast is likely to produce some pretty ugly IR, but it's not
1089 // the *most* terrible thing in the world.
1090 llvm::Type *retTy = ConvertType(getterMethod->getReturnType());
1091 uint64_t retTySize = CGM.getDataLayout().getTypeSizeInBits(retTy);
1092 llvm::Value *ivarVal = load;
1093 if (ivarSize > retTySize) {
1094 llvm::Type *newTy = llvm::Type::getIntNTy(getLLVMContext(), retTySize);
1095 ivarVal = Builder.CreateTrunc(load, newTy);
1096 bitcastType = newTy->getPointerTo();
1097 }
1098 Builder.CreateStore(ivarVal,
1099 Builder.CreateBitCast(ReturnValue, bitcastType));
1100
1101 // Make sure we don't do an autorelease.
1102 AutoreleaseResult = false;
1103 return;
1104 }
1105
1106 case PropertyImplStrategy::GetSetProperty: {
1107 llvm::FunctionCallee getPropertyFn =
1108 CGM.getObjCRuntime().GetPropertyGetFunction();
1109 if (!getPropertyFn) {
1110 CGM.ErrorUnsupported(propImpl, "Obj-C getter requiring atomic copy");
1111 return;
1112 }
1113 CGCallee callee = CGCallee::forDirect(getPropertyFn);
1114
1115 // Return (ivar-type) objc_getProperty((id) self, _cmd, offset, true).
1116 // FIXME: Can't this be simpler? This might even be worse than the
1117 // corresponding gcc code.
1118 llvm::Value *cmd =
1119 Builder.CreateLoad(GetAddrOfLocalVar(getterMethod->getCmdDecl()), "cmd");
1120 llvm::Value *self = Builder.CreateBitCast(LoadObjCSelf(), VoidPtrTy);
1121 llvm::Value *ivarOffset =
1122 EmitIvarOffset(classImpl->getClassInterface(), ivar);
1123
1124 CallArgList args;
1125 args.add(RValue::get(self), getContext().getObjCIdType());
1126 args.add(RValue::get(cmd), getContext().getObjCSelType());
1127 args.add(RValue::get(ivarOffset), getContext().getPointerDiffType());
1128 args.add(RValue::get(Builder.getInt1(strategy.isAtomic())),
1129 getContext().BoolTy);
1130
1131 // FIXME: We shouldn't need to get the function info here, the
1132 // runtime already should have computed it to build the function.
1133 llvm::CallBase *CallInstruction;
1134 RValue RV = EmitCall(getTypes().arrangeBuiltinFunctionCall(
1135 getContext().getObjCIdType(), args),
1136 callee, ReturnValueSlot(), args, &CallInstruction);
1137 if (llvm::CallInst *call = dyn_cast<llvm::CallInst>(CallInstruction))
1138 call->setTailCall();
1139
1140 // We need to fix the type here. Ivars with copy & retain are
1141 // always objects so we don't need to worry about complex or
1142 // aggregates.
1143 RV = RValue::get(Builder.CreateBitCast(
1144 RV.getScalarVal(),
1145 getTypes().ConvertType(getterMethod->getReturnType())));
1146
1147 EmitReturnOfRValue(RV, propType);
1148
1149 // objc_getProperty does an autorelease, so we should suppress ours.
1150 AutoreleaseResult = false;
1151
1152 return;
1153 }
1154
1155 case PropertyImplStrategy::CopyStruct:
1156 emitStructGetterCall(*this, ivar, strategy.isAtomic(),
1157 strategy.hasStrongMember());
1158 return;
1159
1160 case PropertyImplStrategy::Expression:
1161 case PropertyImplStrategy::SetPropertyAndExpressionGet: {
1162 LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, 0);
1163
1164 QualType ivarType = ivar->getType();
1165 switch (getEvaluationKind(ivarType)) {
1166 case TEK_Complex: {
1167 ComplexPairTy pair = EmitLoadOfComplex(LV, SourceLocation());
1168 EmitStoreOfComplex(pair, MakeAddrLValue(ReturnValue, ivarType),
1169 /*init*/ true);
1170 return;
1171 }
1172 case TEK_Aggregate: {
1173 // The return value slot is guaranteed to not be aliased, but
1174 // that's not necessarily the same as "on the stack", so
1175 // we still potentially need objc_memmove_collectable.
1176 EmitAggregateCopy(/* Dest= */ MakeAddrLValue(ReturnValue, ivarType),
1177 /* Src= */ LV, ivarType, getOverlapForReturnValue());
1178 return;
1179 }
1180 case TEK_Scalar: {
1181 llvm::Value *value;
1182 if (propType->isReferenceType()) {
1183 value = LV.getAddress(*this).getPointer();
1184 } else {
1185 // We want to load and autoreleaseReturnValue ARC __weak ivars.
1186 if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) {
1187 if (getLangOpts().ObjCAutoRefCount) {
1188 value = emitARCRetainLoadOfScalar(*this, LV, ivarType);
1189 } else {
1190 value = EmitARCLoadWeak(LV.getAddress(*this));
1191 }
1192
1193 // Otherwise we want to do a simple load, suppressing the
1194 // final autorelease.
1195 } else {
1196 value = EmitLoadOfLValue(LV, SourceLocation()).getScalarVal();
1197 AutoreleaseResult = false;
1198 }
1199
1200 value = Builder.CreateBitCast(
1201 value, ConvertType(GetterMethodDecl->getReturnType()));
1202 }
1203
1204 EmitReturnOfRValue(RValue::get(value), propType);
1205 return;
1206 }
1207 }
1208 llvm_unreachable("bad evaluation kind")::llvm::llvm_unreachable_internal("bad evaluation kind", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 1208)
;
1209 }
1210
1211 }
1212 llvm_unreachable("bad @property implementation strategy!")::llvm::llvm_unreachable_internal("bad @property implementation strategy!"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 1212)
;
1213}
1214
1215/// emitStructSetterCall - Call the runtime function to store the value
1216/// from the first formal parameter into the given ivar.
1217static void emitStructSetterCall(CodeGenFunction &CGF, ObjCMethodDecl *OMD,
1218 ObjCIvarDecl *ivar) {
1219 // objc_copyStruct (&structIvar, &Arg,
1220 // sizeof (struct something), true, false);
1221 CallArgList args;
1222
1223 // The first argument is the address of the ivar.
1224 llvm::Value *ivarAddr =
1225 CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), CGF.LoadObjCSelf(), ivar, 0)
1226 .getPointer(CGF);
1227 ivarAddr = CGF.Builder.CreateBitCast(ivarAddr, CGF.Int8PtrTy);
1228 args.add(RValue::get(ivarAddr), CGF.getContext().VoidPtrTy);
1229
1230 // The second argument is the address of the parameter variable.
1231 ParmVarDecl *argVar = *OMD->param_begin();
1232 DeclRefExpr argRef(CGF.getContext(), argVar, false,
1233 argVar->getType().getNonReferenceType(), VK_LValue,
1234 SourceLocation());
1235 llvm::Value *argAddr = CGF.EmitLValue(&argRef).getPointer(CGF);
1236 argAddr = CGF.Builder.CreateBitCast(argAddr, CGF.Int8PtrTy);
1237 args.add(RValue::get(argAddr), CGF.getContext().VoidPtrTy);
1238
1239 // The third argument is the sizeof the type.
1240 llvm::Value *size =
1241 CGF.CGM.getSize(CGF.getContext().getTypeSizeInChars(ivar->getType()));
1242 args.add(RValue::get(size), CGF.getContext().getSizeType());
1243
1244 // The fourth argument is the 'isAtomic' flag.
1245 args.add(RValue::get(CGF.Builder.getTrue()), CGF.getContext().BoolTy);
1246
1247 // The fifth argument is the 'hasStrong' flag.
1248 // FIXME: should this really always be false?
1249 args.add(RValue::get(CGF.Builder.getFalse()), CGF.getContext().BoolTy);
1250
1251 llvm::FunctionCallee fn = CGF.CGM.getObjCRuntime().GetSetStructFunction();
1252 CGCallee callee = CGCallee::forDirect(fn);
1253 CGF.EmitCall(
1254 CGF.getTypes().arrangeBuiltinFunctionCall(CGF.getContext().VoidTy, args),
1255 callee, ReturnValueSlot(), args);
1256}
1257
1258/// emitCPPObjectAtomicSetterCall - Call the runtime function to store
1259/// the value from the first formal parameter into the given ivar, using
1260/// the Cpp API for atomic Cpp objects with non-trivial copy assignment.
1261static void emitCPPObjectAtomicSetterCall(CodeGenFunction &CGF,
1262 ObjCMethodDecl *OMD,
1263 ObjCIvarDecl *ivar,
1264 llvm::Constant *AtomicHelperFn) {
1265 // objc_copyCppObjectAtomic (&CppObjectIvar, &Arg,
1266 // AtomicHelperFn);
1267 CallArgList args;
1268
1269 // The first argument is the address of the ivar.
1270 llvm::Value *ivarAddr =
1271 CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), CGF.LoadObjCSelf(), ivar, 0)
1272 .getPointer(CGF);
1273 ivarAddr = CGF.Builder.CreateBitCast(ivarAddr, CGF.Int8PtrTy);
1274 args.add(RValue::get(ivarAddr), CGF.getContext().VoidPtrTy);
1275
1276 // The second argument is the address of the parameter variable.
1277 ParmVarDecl *argVar = *OMD->param_begin();
1278 DeclRefExpr argRef(CGF.getContext(), argVar, false,
1279 argVar->getType().getNonReferenceType(), VK_LValue,
1280 SourceLocation());
1281 llvm::Value *argAddr = CGF.EmitLValue(&argRef).getPointer(CGF);
1282 argAddr = CGF.Builder.CreateBitCast(argAddr, CGF.Int8PtrTy);
1283 args.add(RValue::get(argAddr), CGF.getContext().VoidPtrTy);
1284
1285 // Third argument is the helper function.
1286 args.add(RValue::get(AtomicHelperFn), CGF.getContext().VoidPtrTy);
1287
1288 llvm::FunctionCallee fn =
1289 CGF.CGM.getObjCRuntime().GetCppAtomicObjectSetFunction();
1290 CGCallee callee = CGCallee::forDirect(fn);
1291 CGF.EmitCall(
1292 CGF.getTypes().arrangeBuiltinFunctionCall(CGF.getContext().VoidTy, args),
1293 callee, ReturnValueSlot(), args);
1294}
1295
1296
1297static bool hasTrivialSetExpr(const ObjCPropertyImplDecl *PID) {
1298 Expr *setter = PID->getSetterCXXAssignment();
1299 if (!setter) return true;
1300
1301 // Sema only makes only of these when the ivar has a C++ class type,
1302 // so the form is pretty constrained.
1303
1304 // An operator call is trivial if the function it calls is trivial.
1305 // This also implies that there's nothing non-trivial going on with
1306 // the arguments, because operator= can only be trivial if it's a
1307 // synthesized assignment operator and therefore both parameters are
1308 // references.
1309 if (CallExpr *call = dyn_cast<CallExpr>(setter)) {
1310 if (const FunctionDecl *callee
1311 = dyn_cast_or_null<FunctionDecl>(call->getCalleeDecl()))
1312 if (callee->isTrivial())
1313 return true;
1314 return false;
1315 }
1316
1317 assert(isa<ExprWithCleanups>(setter))((isa<ExprWithCleanups>(setter)) ? static_cast<void>
(0) : __assert_fail ("isa<ExprWithCleanups>(setter)", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 1317, __PRETTY_FUNCTION__))
;
1318 return false;
1319}
1320
1321static bool UseOptimizedSetter(CodeGenModule &CGM) {
1322 if (CGM.getLangOpts().getGC() != LangOptions::NonGC)
1323 return false;
1324 return CGM.getLangOpts().ObjCRuntime.hasOptimizedSetter();
1325}
1326
1327void
1328CodeGenFunction::generateObjCSetterBody(const ObjCImplementationDecl *classImpl,
1329 const ObjCPropertyImplDecl *propImpl,
1330 llvm::Constant *AtomicHelperFn) {
1331 ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
1332 ObjCMethodDecl *setterMethod = propImpl->getSetterMethodDecl();
1333
1334 // Just use the setter expression if Sema gave us one and it's
1335 // non-trivial.
1336 if (!hasTrivialSetExpr(propImpl)) {
1337 if (!AtomicHelperFn)
1338 // If non-atomic, assignment is called directly.
1339 EmitStmt(propImpl->getSetterCXXAssignment());
1340 else
1341 // If atomic, assignment is called via a locking api.
1342 emitCPPObjectAtomicSetterCall(*this, setterMethod, ivar,
1343 AtomicHelperFn);
1344 return;
1345 }
1346
1347 PropertyImplStrategy strategy(CGM, propImpl);
1348 switch (strategy.getKind()) {
1349 case PropertyImplStrategy::Native: {
1350 // We don't need to do anything for a zero-size struct.
1351 if (strategy.getIvarSize().isZero())
1352 return;
1353
1354 Address argAddr = GetAddrOfLocalVar(*setterMethod->param_begin());
1355
1356 LValue ivarLValue =
1357 EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, /*quals*/ 0);
1358 Address ivarAddr = ivarLValue.getAddress(*this);
1359
1360 // Currently, all atomic accesses have to be through integer
1361 // types, so there's no point in trying to pick a prettier type.
1362 llvm::Type *bitcastType =
1363 llvm::Type::getIntNTy(getLLVMContext(),
1364 getContext().toBits(strategy.getIvarSize()));
1365
1366 // Cast both arguments to the chosen operation type.
1367 argAddr = Builder.CreateElementBitCast(argAddr, bitcastType);
1368 ivarAddr = Builder.CreateElementBitCast(ivarAddr, bitcastType);
1369
1370 // This bitcast load is likely to cause some nasty IR.
1371 llvm::Value *load = Builder.CreateLoad(argAddr);
1372
1373 // Perform an atomic store. There are no memory ordering requirements.
1374 llvm::StoreInst *store = Builder.CreateStore(load, ivarAddr);
1375 store->setAtomic(llvm::AtomicOrdering::Unordered);
1376 return;
1377 }
1378
1379 case PropertyImplStrategy::GetSetProperty:
1380 case PropertyImplStrategy::SetPropertyAndExpressionGet: {
1381
1382 llvm::FunctionCallee setOptimizedPropertyFn = nullptr;
1383 llvm::FunctionCallee setPropertyFn = nullptr;
1384 if (UseOptimizedSetter(CGM)) {
1385 // 10.8 and iOS 6.0 code and GC is off
1386 setOptimizedPropertyFn =
1387 CGM.getObjCRuntime().GetOptimizedPropertySetFunction(
1388 strategy.isAtomic(), strategy.isCopy());
1389 if (!setOptimizedPropertyFn) {
1390 CGM.ErrorUnsupported(propImpl, "Obj-C optimized setter - NYI");
1391 return;
1392 }
1393 }
1394 else {
1395 setPropertyFn = CGM.getObjCRuntime().GetPropertySetFunction();
1396 if (!setPropertyFn) {
1397 CGM.ErrorUnsupported(propImpl, "Obj-C setter requiring atomic copy");
1398 return;
1399 }
1400 }
1401
1402 // Emit objc_setProperty((id) self, _cmd, offset, arg,
1403 // <is-atomic>, <is-copy>).
1404 llvm::Value *cmd =
1405 Builder.CreateLoad(GetAddrOfLocalVar(setterMethod->getCmdDecl()));
1406 llvm::Value *self =
1407 Builder.CreateBitCast(LoadObjCSelf(), VoidPtrTy);
1408 llvm::Value *ivarOffset =
1409 EmitIvarOffset(classImpl->getClassInterface(), ivar);
1410 Address argAddr = GetAddrOfLocalVar(*setterMethod->param_begin());
1411 llvm::Value *arg = Builder.CreateLoad(argAddr, "arg");
1412 arg = Builder.CreateBitCast(arg, VoidPtrTy);
1413
1414 CallArgList args;
1415 args.add(RValue::get(self), getContext().getObjCIdType());
1416 args.add(RValue::get(cmd), getContext().getObjCSelType());
1417 if (setOptimizedPropertyFn) {
1418 args.add(RValue::get(arg), getContext().getObjCIdType());
1419 args.add(RValue::get(ivarOffset), getContext().getPointerDiffType());
1420 CGCallee callee = CGCallee::forDirect(setOptimizedPropertyFn);
1421 EmitCall(getTypes().arrangeBuiltinFunctionCall(getContext().VoidTy, args),
1422 callee, ReturnValueSlot(), args);
1423 } else {
1424 args.add(RValue::get(ivarOffset), getContext().getPointerDiffType());
1425 args.add(RValue::get(arg), getContext().getObjCIdType());
1426 args.add(RValue::get(Builder.getInt1(strategy.isAtomic())),
1427 getContext().BoolTy);
1428 args.add(RValue::get(Builder.getInt1(strategy.isCopy())),
1429 getContext().BoolTy);
1430 // FIXME: We shouldn't need to get the function info here, the runtime
1431 // already should have computed it to build the function.
1432 CGCallee callee = CGCallee::forDirect(setPropertyFn);
1433 EmitCall(getTypes().arrangeBuiltinFunctionCall(getContext().VoidTy, args),
1434 callee, ReturnValueSlot(), args);
1435 }
1436
1437 return;
1438 }
1439
1440 case PropertyImplStrategy::CopyStruct:
1441 emitStructSetterCall(*this, setterMethod, ivar);
1442 return;
1443
1444 case PropertyImplStrategy::Expression:
1445 break;
1446 }
1447
1448 // Otherwise, fake up some ASTs and emit a normal assignment.
1449 ValueDecl *selfDecl = setterMethod->getSelfDecl();
1450 DeclRefExpr self(getContext(), selfDecl, false, selfDecl->getType(),
1451 VK_LValue, SourceLocation());
1452 ImplicitCastExpr selfLoad(ImplicitCastExpr::OnStack,
1453 selfDecl->getType(), CK_LValueToRValue, &self,
1454 VK_RValue);
1455 ObjCIvarRefExpr ivarRef(ivar, ivar->getType().getNonReferenceType(),
1456 SourceLocation(), SourceLocation(),
1457 &selfLoad, true, true);
1458
1459 ParmVarDecl *argDecl = *setterMethod->param_begin();
1460 QualType argType = argDecl->getType().getNonReferenceType();
1461 DeclRefExpr arg(getContext(), argDecl, false, argType, VK_LValue,
1462 SourceLocation());
1463 ImplicitCastExpr argLoad(ImplicitCastExpr::OnStack,
1464 argType.getUnqualifiedType(), CK_LValueToRValue,
1465 &arg, VK_RValue);
1466
1467 // The property type can differ from the ivar type in some situations with
1468 // Objective-C pointer types, we can always bit cast the RHS in these cases.
1469 // The following absurdity is just to ensure well-formed IR.
1470 CastKind argCK = CK_NoOp;
1471 if (ivarRef.getType()->isObjCObjectPointerType()) {
1472 if (argLoad.getType()->isObjCObjectPointerType())
1473 argCK = CK_BitCast;
1474 else if (argLoad.getType()->isBlockPointerType())
1475 argCK = CK_BlockPointerToObjCPointerCast;
1476 else
1477 argCK = CK_CPointerToObjCPointerCast;
1478 } else if (ivarRef.getType()->isBlockPointerType()) {
1479 if (argLoad.getType()->isBlockPointerType())
1480 argCK = CK_BitCast;
1481 else
1482 argCK = CK_AnyPointerToBlockPointerCast;
1483 } else if (ivarRef.getType()->isPointerType()) {
1484 argCK = CK_BitCast;
1485 }
1486 ImplicitCastExpr argCast(ImplicitCastExpr::OnStack,
1487 ivarRef.getType(), argCK, &argLoad,
1488 VK_RValue);
1489 Expr *finalArg = &argLoad;
1490 if (!getContext().hasSameUnqualifiedType(ivarRef.getType(),
1491 argLoad.getType()))
1492 finalArg = &argCast;
1493
1494
1495 BinaryOperator assign(&ivarRef, finalArg, BO_Assign,
1496 ivarRef.getType(), VK_RValue, OK_Ordinary,
1497 SourceLocation(), FPOptions());
1498 EmitStmt(&assign);
1499}
1500
1501/// Generate an Objective-C property setter function.
1502///
1503/// The given Decl must be an ObjCImplementationDecl. \@synthesize
1504/// is illegal within a category.
1505void CodeGenFunction::GenerateObjCSetter(ObjCImplementationDecl *IMP,
1506 const ObjCPropertyImplDecl *PID) {
1507 llvm::Constant *AtomicHelperFn =
1508 CodeGenFunction(CGM).GenerateObjCAtomicSetterCopyHelperFunction(PID);
1509 ObjCMethodDecl *OMD = PID->getSetterMethodDecl();
1510 assert(OMD && "Invalid call to generate setter (empty method)")((OMD && "Invalid call to generate setter (empty method)"
) ? static_cast<void> (0) : __assert_fail ("OMD && \"Invalid call to generate setter (empty method)\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 1510, __PRETTY_FUNCTION__))
;
1511 StartObjCMethod(OMD, IMP->getClassInterface());
1512
1513 generateObjCSetterBody(IMP, PID, AtomicHelperFn);
1514
1515 FinishFunction(OMD->getEndLoc());
1516}
1517
1518namespace {
1519 struct DestroyIvar final : EHScopeStack::Cleanup {
1520 private:
1521 llvm::Value *addr;
1522 const ObjCIvarDecl *ivar;
1523 CodeGenFunction::Destroyer *destroyer;
1524 bool useEHCleanupForArray;
1525 public:
1526 DestroyIvar(llvm::Value *addr, const ObjCIvarDecl *ivar,
1527 CodeGenFunction::Destroyer *destroyer,
1528 bool useEHCleanupForArray)
1529 : addr(addr), ivar(ivar), destroyer(destroyer),
1530 useEHCleanupForArray(useEHCleanupForArray) {}
1531
1532 void Emit(CodeGenFunction &CGF, Flags flags) override {
1533 LValue lvalue
1534 = CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), addr, ivar, /*CVR*/ 0);
1535 CGF.emitDestroy(lvalue.getAddress(CGF), ivar->getType(), destroyer,
1536 flags.isForNormalCleanup() && useEHCleanupForArray);
1537 }
1538 };
1539}
1540
1541/// Like CodeGenFunction::destroyARCStrong, but do it with a call.
1542static void destroyARCStrongWithStore(CodeGenFunction &CGF,
1543 Address addr,
1544 QualType type) {
1545 llvm::Value *null = getNullForVariable(addr);
1546 CGF.EmitARCStoreStrongCall(addr, null, /*ignored*/ true);
1547}
1548
1549static void emitCXXDestructMethod(CodeGenFunction &CGF,
1550 ObjCImplementationDecl *impl) {
1551 CodeGenFunction::RunCleanupsScope scope(CGF);
1552
1553 llvm::Value *self = CGF.LoadObjCSelf();
1554
1555 const ObjCInterfaceDecl *iface = impl->getClassInterface();
1556 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin();
1557 ivar; ivar = ivar->getNextIvar()) {
1558 QualType type = ivar->getType();
1559
1560 // Check whether the ivar is a destructible type.
1561 QualType::DestructionKind dtorKind = type.isDestructedType();
1562 if (!dtorKind) continue;
1563
1564 CodeGenFunction::Destroyer *destroyer = nullptr;
1565
1566 // Use a call to objc_storeStrong to destroy strong ivars, for the
1567 // general benefit of the tools.
1568 if (dtorKind == QualType::DK_objc_strong_lifetime) {
1569 destroyer = destroyARCStrongWithStore;
1570
1571 // Otherwise use the default for the destruction kind.
1572 } else {
1573 destroyer = CGF.getDestroyer(dtorKind);
1574 }
1575
1576 CleanupKind cleanupKind = CGF.getCleanupKind(dtorKind);
1577
1578 CGF.EHStack.pushCleanup<DestroyIvar>(cleanupKind, self, ivar, destroyer,
1579 cleanupKind & EHCleanup);
1580 }
1581
1582 assert(scope.requiresCleanups() && "nothing to do in .cxx_destruct?")((scope.requiresCleanups() && "nothing to do in .cxx_destruct?"
) ? static_cast<void> (0) : __assert_fail ("scope.requiresCleanups() && \"nothing to do in .cxx_destruct?\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 1582, __PRETTY_FUNCTION__))
;
1583}
1584
1585void CodeGenFunction::GenerateObjCCtorDtorMethod(ObjCImplementationDecl *IMP,
1586 ObjCMethodDecl *MD,
1587 bool ctor) {
1588 MD->createImplicitParams(CGM.getContext(), IMP->getClassInterface());
1589 StartObjCMethod(MD, IMP->getClassInterface());
1590
1591 // Emit .cxx_construct.
1592 if (ctor) {
1593 // Suppress the final autorelease in ARC.
1594 AutoreleaseResult = false;
1595
1596 for (const auto *IvarInit : IMP->inits()) {
1597 FieldDecl *Field = IvarInit->getAnyMember();
1598 ObjCIvarDecl *Ivar = cast<ObjCIvarDecl>(Field);
1599 LValue LV = EmitLValueForIvar(TypeOfSelfObject(),
1600 LoadObjCSelf(), Ivar, 0);
1601 EmitAggExpr(IvarInit->getInit(),
1602 AggValueSlot::forLValue(LV, *this, AggValueSlot::IsDestructed,
1603 AggValueSlot::DoesNotNeedGCBarriers,
1604 AggValueSlot::IsNotAliased,
1605 AggValueSlot::DoesNotOverlap));
1606 }
1607 // constructor returns 'self'.
1608 CodeGenTypes &Types = CGM.getTypes();
1609 QualType IdTy(CGM.getContext().getObjCIdType());
1610 llvm::Value *SelfAsId =
1611 Builder.CreateBitCast(LoadObjCSelf(), Types.ConvertType(IdTy));
1612 EmitReturnOfRValue(RValue::get(SelfAsId), IdTy);
1613
1614 // Emit .cxx_destruct.
1615 } else {
1616 emitCXXDestructMethod(*this, IMP);
1617 }
1618 FinishFunction();
1619}
1620
1621llvm::Value *CodeGenFunction::LoadObjCSelf() {
1622 VarDecl *Self = cast<ObjCMethodDecl>(CurFuncDecl)->getSelfDecl();
1623 DeclRefExpr DRE(getContext(), Self,
1624 /*is enclosing local*/ (CurFuncDecl != CurCodeDecl),
1625 Self->getType(), VK_LValue, SourceLocation());
1626 return EmitLoadOfScalar(EmitDeclRefLValue(&DRE), SourceLocation());
1627}
1628
1629QualType CodeGenFunction::TypeOfSelfObject() {
1630 const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
1631 ImplicitParamDecl *selfDecl = OMD->getSelfDecl();
1632 const ObjCObjectPointerType *PTy = cast<ObjCObjectPointerType>(
1633 getContext().getCanonicalType(selfDecl->getType()));
1634 return PTy->getPointeeType();
1635}
1636
1637void CodeGenFunction::EmitObjCForCollectionStmt(const ObjCForCollectionStmt &S){
1638 llvm::FunctionCallee EnumerationMutationFnPtr =
1639 CGM.getObjCRuntime().EnumerationMutationFunction();
1640 if (!EnumerationMutationFnPtr) {
1641 CGM.ErrorUnsupported(&S, "Obj-C fast enumeration for this runtime");
1642 return;
1643 }
1644 CGCallee EnumerationMutationFn =
1645 CGCallee::forDirect(EnumerationMutationFnPtr);
1646
1647 CGDebugInfo *DI = getDebugInfo();
1648 if (DI)
1649 DI->EmitLexicalBlockStart(Builder, S.getSourceRange().getBegin());
1650
1651 RunCleanupsScope ForScope(*this);
1652
1653 // The local variable comes into scope immediately.
1654 AutoVarEmission variable = AutoVarEmission::invalid();
1655 if (const DeclStmt *SD = dyn_cast<DeclStmt>(S.getElement()))
1656 variable = EmitAutoVarAlloca(*cast<VarDecl>(SD->getSingleDecl()));
1657
1658 JumpDest LoopEnd = getJumpDestInCurrentScope("forcoll.end");
1659
1660 // Fast enumeration state.
1661 QualType StateTy = CGM.getObjCFastEnumerationStateType();
1662 Address StatePtr = CreateMemTemp(StateTy, "state.ptr");
1663 EmitNullInitialization(StatePtr, StateTy);
1664
1665 // Number of elements in the items array.
1666 static const unsigned NumItems = 16;
1667
1668 // Fetch the countByEnumeratingWithState:objects:count: selector.
1669 IdentifierInfo *II[] = {
1670 &CGM.getContext().Idents.get("countByEnumeratingWithState"),
1671 &CGM.getContext().Idents.get("objects"),
1672 &CGM.getContext().Idents.get("count")
1673 };
1674 Selector FastEnumSel =
1675 CGM.getContext().Selectors.getSelector(llvm::array_lengthof(II), &II[0]);
1676
1677 QualType ItemsTy =
1678 getContext().getConstantArrayType(getContext().getObjCIdType(),
1679 llvm::APInt(32, NumItems), nullptr,
1680 ArrayType::Normal, 0);
1681 Address ItemsPtr = CreateMemTemp(ItemsTy, "items.ptr");
1682
1683 // Emit the collection pointer. In ARC, we do a retain.
1684 llvm::Value *Collection;
1685 if (getLangOpts().ObjCAutoRefCount) {
1686 Collection = EmitARCRetainScalarExpr(S.getCollection());
1687
1688 // Enter a cleanup to do the release.
1689 EmitObjCConsumeObject(S.getCollection()->getType(), Collection);
1690 } else {
1691 Collection = EmitScalarExpr(S.getCollection());
1692 }
1693
1694 // The 'continue' label needs to appear within the cleanup for the
1695 // collection object.
1696 JumpDest AfterBody = getJumpDestInCurrentScope("forcoll.next");
1697
1698 // Send it our message:
1699 CallArgList Args;
1700
1701 // The first argument is a temporary of the enumeration-state type.
1702 Args.add(RValue::get(StatePtr.getPointer()),
1703 getContext().getPointerType(StateTy));
1704
1705 // The second argument is a temporary array with space for NumItems
1706 // pointers. We'll actually be loading elements from the array
1707 // pointer written into the control state; this buffer is so that
1708 // collections that *aren't* backed by arrays can still queue up
1709 // batches of elements.
1710 Args.add(RValue::get(ItemsPtr.getPointer()),
1711 getContext().getPointerType(ItemsTy));
1712
1713 // The third argument is the capacity of that temporary array.
1714 llvm::Type *NSUIntegerTy = ConvertType(getContext().getNSUIntegerType());
1715 llvm::Constant *Count = llvm::ConstantInt::get(NSUIntegerTy, NumItems);
1716 Args.add(RValue::get(Count), getContext().getNSUIntegerType());
1717
1718 // Start the enumeration.
1719 RValue CountRV =
1720 CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(),
1721 getContext().getNSUIntegerType(),
1722 FastEnumSel, Collection, Args);
1723
1724 // The initial number of objects that were returned in the buffer.
1725 llvm::Value *initialBufferLimit = CountRV.getScalarVal();
1726
1727 llvm::BasicBlock *EmptyBB = createBasicBlock("forcoll.empty");
1728 llvm::BasicBlock *LoopInitBB = createBasicBlock("forcoll.loopinit");
1729
1730 llvm::Value *zero = llvm::Constant::getNullValue(NSUIntegerTy);
1731
1732 // If the limit pointer was zero to begin with, the collection is
1733 // empty; skip all this. Set the branch weight assuming this has the same
1734 // probability of exiting the loop as any other loop exit.
1735 uint64_t EntryCount = getCurrentProfileCount();
1736 Builder.CreateCondBr(
1737 Builder.CreateICmpEQ(initialBufferLimit, zero, "iszero"), EmptyBB,
1738 LoopInitBB,
1739 createProfileWeights(EntryCount, getProfileCount(S.getBody())));
1740
1741 // Otherwise, initialize the loop.
1742 EmitBlock(LoopInitBB);
1743
1744 // Save the initial mutations value. This is the value at an
1745 // address that was written into the state object by
1746 // countByEnumeratingWithState:objects:count:.
1747 Address StateMutationsPtrPtr =
1748 Builder.CreateStructGEP(StatePtr, 2, "mutationsptr.ptr");
1749 llvm::Value *StateMutationsPtr
1750 = Builder.CreateLoad(StateMutationsPtrPtr, "mutationsptr");
1751
1752 llvm::Value *initialMutations =
1753 Builder.CreateAlignedLoad(StateMutationsPtr, getPointerAlign(),
1754 "forcoll.initial-mutations");
1755
1756 // Start looping. This is the point we return to whenever we have a
1757 // fresh, non-empty batch of objects.
1758 llvm::BasicBlock *LoopBodyBB = createBasicBlock("forcoll.loopbody");
1759 EmitBlock(LoopBodyBB);
1760
1761 // The current index into the buffer.
1762 llvm::PHINode *index = Builder.CreatePHI(NSUIntegerTy, 3, "forcoll.index");
1763 index->addIncoming(zero, LoopInitBB);
1764
1765 // The current buffer size.
1766 llvm::PHINode *count = Builder.CreatePHI(NSUIntegerTy, 3, "forcoll.count");
1767 count->addIncoming(initialBufferLimit, LoopInitBB);
1768
1769 incrementProfileCounter(&S);
1770
1771 // Check whether the mutations value has changed from where it was
1772 // at start. StateMutationsPtr should actually be invariant between
1773 // refreshes.
1774 StateMutationsPtr = Builder.CreateLoad(StateMutationsPtrPtr, "mutationsptr");
1775 llvm::Value *currentMutations
1776 = Builder.CreateAlignedLoad(StateMutationsPtr, getPointerAlign(),
1777 "statemutations");
1778
1779 llvm::BasicBlock *WasMutatedBB = createBasicBlock("forcoll.mutated");
1780 llvm::BasicBlock *WasNotMutatedBB = createBasicBlock("forcoll.notmutated");
1781
1782 Builder.CreateCondBr(Builder.CreateICmpEQ(currentMutations, initialMutations),
1783 WasNotMutatedBB, WasMutatedBB);
1784
1785 // If so, call the enumeration-mutation function.
1786 EmitBlock(WasMutatedBB);
1787 llvm::Value *V =
1788 Builder.CreateBitCast(Collection,
1789 ConvertType(getContext().getObjCIdType()));
1790 CallArgList Args2;
1791 Args2.add(RValue::get(V), getContext().getObjCIdType());
1792 // FIXME: We shouldn't need to get the function info here, the runtime already
1793 // should have computed it to build the function.
1794 EmitCall(
1795 CGM.getTypes().arrangeBuiltinFunctionCall(getContext().VoidTy, Args2),
1796 EnumerationMutationFn, ReturnValueSlot(), Args2);
1797
1798 // Otherwise, or if the mutation function returns, just continue.
1799 EmitBlock(WasNotMutatedBB);
1800
1801 // Initialize the element variable.
1802 RunCleanupsScope elementVariableScope(*this);
1803 bool elementIsVariable;
1804 LValue elementLValue;
1805 QualType elementType;
1806 if (const DeclStmt *SD = dyn_cast<DeclStmt>(S.getElement())) {
1807 // Initialize the variable, in case it's a __block variable or something.
1808 EmitAutoVarInit(variable);
1809
1810 const VarDecl *D = cast<VarDecl>(SD->getSingleDecl());
1811 DeclRefExpr tempDRE(getContext(), const_cast<VarDecl *>(D), false,
1812 D->getType(), VK_LValue, SourceLocation());
1813 elementLValue = EmitLValue(&tempDRE);
1814 elementType = D->getType();
1815 elementIsVariable = true;
1816
1817 if (D->isARCPseudoStrong())
1818 elementLValue.getQuals().setObjCLifetime(Qualifiers::OCL_ExplicitNone);
1819 } else {
1820 elementLValue = LValue(); // suppress warning
1821 elementType = cast<Expr>(S.getElement())->getType();
1822 elementIsVariable = false;
1823 }
1824 llvm::Type *convertedElementType = ConvertType(elementType);
1825
1826 // Fetch the buffer out of the enumeration state.
1827 // TODO: this pointer should actually be invariant between
1828 // refreshes, which would help us do certain loop optimizations.
1829 Address StateItemsPtr =
1830 Builder.CreateStructGEP(StatePtr, 1, "stateitems.ptr");
1831 llvm::Value *EnumStateItems =
1832 Builder.CreateLoad(StateItemsPtr, "stateitems");
1833
1834 // Fetch the value at the current index from the buffer.
1835 llvm::Value *CurrentItemPtr =
1836 Builder.CreateGEP(EnumStateItems, index, "currentitem.ptr");
1837 llvm::Value *CurrentItem =
1838 Builder.CreateAlignedLoad(CurrentItemPtr, getPointerAlign());
1839
1840 // Cast that value to the right type.
1841 CurrentItem = Builder.CreateBitCast(CurrentItem, convertedElementType,
1842 "currentitem");
1843
1844 // Make sure we have an l-value. Yes, this gets evaluated every
1845 // time through the loop.
1846 if (!elementIsVariable) {
1847 elementLValue = EmitLValue(cast<Expr>(S.getElement()));
1848 EmitStoreThroughLValue(RValue::get(CurrentItem), elementLValue);
1849 } else {
1850 EmitStoreThroughLValue(RValue::get(CurrentItem), elementLValue,
1851 /*isInit*/ true);
1852 }
1853
1854 // If we do have an element variable, this assignment is the end of
1855 // its initialization.
1856 if (elementIsVariable)
1857 EmitAutoVarCleanups(variable);
1858
1859 // Perform the loop body, setting up break and continue labels.
1860 BreakContinueStack.push_back(BreakContinue(LoopEnd, AfterBody));
1861 {
1862 RunCleanupsScope Scope(*this);
1863 EmitStmt(S.getBody());
1864 }
1865 BreakContinueStack.pop_back();
1866
1867 // Destroy the element variable now.
1868 elementVariableScope.ForceCleanup();
1869
1870 // Check whether there are more elements.
1871 EmitBlock(AfterBody.getBlock());
1872
1873 llvm::BasicBlock *FetchMoreBB = createBasicBlock("forcoll.refetch");
1874
1875 // First we check in the local buffer.
1876 llvm::Value *indexPlusOne =
1877 Builder.CreateAdd(index, llvm::ConstantInt::get(NSUIntegerTy, 1));
1878
1879 // If we haven't overrun the buffer yet, we can continue.
1880 // Set the branch weights based on the simplifying assumption that this is
1881 // like a while-loop, i.e., ignoring that the false branch fetches more
1882 // elements and then returns to the loop.
1883 Builder.CreateCondBr(
1884 Builder.CreateICmpULT(indexPlusOne, count), LoopBodyBB, FetchMoreBB,
1885 createProfileWeights(getProfileCount(S.getBody()), EntryCount));
1886
1887 index->addIncoming(indexPlusOne, AfterBody.getBlock());
1888 count->addIncoming(count, AfterBody.getBlock());
1889
1890 // Otherwise, we have to fetch more elements.
1891 EmitBlock(FetchMoreBB);
1892
1893 CountRV =
1894 CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(),
1895 getContext().getNSUIntegerType(),
1896 FastEnumSel, Collection, Args);
1897
1898 // If we got a zero count, we're done.
1899 llvm::Value *refetchCount = CountRV.getScalarVal();
1900
1901 // (note that the message send might split FetchMoreBB)
1902 index->addIncoming(zero, Builder.GetInsertBlock());
1903 count->addIncoming(refetchCount, Builder.GetInsertBlock());
1904
1905 Builder.CreateCondBr(Builder.CreateICmpEQ(refetchCount, zero),
1906 EmptyBB, LoopBodyBB);
1907
1908 // No more elements.
1909 EmitBlock(EmptyBB);
1910
1911 if (!elementIsVariable) {
1912 // If the element was not a declaration, set it to be null.
1913
1914 llvm::Value *null = llvm::Constant::getNullValue(convertedElementType);
1915 elementLValue = EmitLValue(cast<Expr>(S.getElement()));
1916 EmitStoreThroughLValue(RValue::get(null), elementLValue);
1917 }
1918
1919 if (DI)
1920 DI->EmitLexicalBlockEnd(Builder, S.getSourceRange().getEnd());
1921
1922 ForScope.ForceCleanup();
1923 EmitBlock(LoopEnd.getBlock());
1924}
1925
1926void CodeGenFunction::EmitObjCAtTryStmt(const ObjCAtTryStmt &S) {
1927 CGM.getObjCRuntime().EmitTryStmt(*this, S);
1928}
1929
1930void CodeGenFunction::EmitObjCAtThrowStmt(const ObjCAtThrowStmt &S) {
1931 CGM.getObjCRuntime().EmitThrowStmt(*this, S);
1932}
1933
1934void CodeGenFunction::EmitObjCAtSynchronizedStmt(
1935 const ObjCAtSynchronizedStmt &S) {
1936 CGM.getObjCRuntime().EmitSynchronizedStmt(*this, S);
1937}
1938
1939namespace {
1940 struct CallObjCRelease final : EHScopeStack::Cleanup {
1941 CallObjCRelease(llvm::Value *object) : object(object) {}
1942 llvm::Value *object;
1943
1944 void Emit(CodeGenFunction &CGF, Flags flags) override {
1945 // Releases at the end of the full-expression are imprecise.
1946 CGF.EmitARCRelease(object, ARCImpreciseLifetime);
1947 }
1948 };
1949}
1950
1951/// Produce the code for a CK_ARCConsumeObject. Does a primitive
1952/// release at the end of the full-expression.
1953llvm::Value *CodeGenFunction::EmitObjCConsumeObject(QualType type,
1954 llvm::Value *object) {
1955 // If we're in a conditional branch, we need to make the cleanup
1956 // conditional.
1957 pushFullExprCleanup<CallObjCRelease>(getARCCleanupKind(), object);
1958 return object;
1959}
1960
1961llvm::Value *CodeGenFunction::EmitObjCExtendObjectLifetime(QualType type,
1962 llvm::Value *value) {
1963 return EmitARCRetainAutorelease(type, value);
1964}
1965
1966/// Given a number of pointers, inform the optimizer that they're
1967/// being intrinsically used up until this point in the program.
1968void CodeGenFunction::EmitARCIntrinsicUse(ArrayRef<llvm::Value*> values) {
1969 llvm::Function *&fn = CGM.getObjCEntrypoints().clang_arc_use;
1970 if (!fn)
1971 fn = CGM.getIntrinsic(llvm::Intrinsic::objc_clang_arc_use);
1972
1973 // This isn't really a "runtime" function, but as an intrinsic it
1974 // doesn't really matter as long as we align things up.
1975 EmitNounwindRuntimeCall(fn, values);
1976}
1977
1978static void setARCRuntimeFunctionLinkage(CodeGenModule &CGM, llvm::Value *RTF) {
1979 if (auto *F = dyn_cast<llvm::Function>(RTF)) {
1980 // If the target runtime doesn't naturally support ARC, emit weak
1981 // references to the runtime support library. We don't really
1982 // permit this to fail, but we need a particular relocation style.
1983 if (!CGM.getLangOpts().ObjCRuntime.hasNativeARC() &&
1984 !CGM.getTriple().isOSBinFormatCOFF()) {
1985 F->setLinkage(llvm::Function::ExternalWeakLinkage);
1986 }
1987 }
1988}
1989
1990static void setARCRuntimeFunctionLinkage(CodeGenModule &CGM,
1991 llvm::FunctionCallee RTF) {
1992 setARCRuntimeFunctionLinkage(CGM, RTF.getCallee());
1993}
1994
1995/// Perform an operation having the signature
1996/// i8* (i8*)
1997/// where a null input causes a no-op and returns null.
1998static llvm::Value *emitARCValueOperation(
1999 CodeGenFunction &CGF, llvm::Value *value, llvm::Type *returnType,
2000 llvm::Function *&fn, llvm::Intrinsic::ID IntID,
2001 llvm::CallInst::TailCallKind tailKind = llvm::CallInst::TCK_None) {
2002 if (isa<llvm::ConstantPointerNull>(value))
2003 return value;
2004
2005 if (!fn) {
2006 fn = CGF.CGM.getIntrinsic(IntID);
2007 setARCRuntimeFunctionLinkage(CGF.CGM, fn);
2008 }
2009
2010 // Cast the argument to 'id'.
2011 llvm::Type *origType = returnType ? returnType : value->getType();
2012 value = CGF.Builder.CreateBitCast(value, CGF.Int8PtrTy);
2013
2014 // Call the function.
2015 llvm::CallInst *call = CGF.EmitNounwindRuntimeCall(fn, value);
2016 call->setTailCallKind(tailKind);
2017
2018 // Cast the result back to the original type.
2019 return CGF.Builder.CreateBitCast(call, origType);
2020}
2021
2022/// Perform an operation having the following signature:
2023/// i8* (i8**)
2024static llvm::Value *emitARCLoadOperation(CodeGenFunction &CGF, Address addr,
2025 llvm::Function *&fn,
2026 llvm::Intrinsic::ID IntID) {
2027 if (!fn) {
2028 fn = CGF.CGM.getIntrinsic(IntID);
2029 setARCRuntimeFunctionLinkage(CGF.CGM, fn);
2030 }
2031
2032 // Cast the argument to 'id*'.
2033 llvm::Type *origType = addr.getElementType();
2034 addr = CGF.Builder.CreateBitCast(addr, CGF.Int8PtrPtrTy);
2035
2036 // Call the function.
2037 llvm::Value *result = CGF.EmitNounwindRuntimeCall(fn, addr.getPointer());
2038
2039 // Cast the result back to a dereference of the original type.
2040 if (origType != CGF.Int8PtrTy)
2041 result = CGF.Builder.CreateBitCast(result, origType);
2042
2043 return result;
2044}
2045
2046/// Perform an operation having the following signature:
2047/// i8* (i8**, i8*)
2048static llvm::Value *emitARCStoreOperation(CodeGenFunction &CGF, Address addr,
2049 llvm::Value *value,
2050 llvm::Function *&fn,
2051 llvm::Intrinsic::ID IntID,
2052 bool ignored) {
2053 assert(addr.getElementType() == value->getType())((addr.getElementType() == value->getType()) ? static_cast
<void> (0) : __assert_fail ("addr.getElementType() == value->getType()"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 2053, __PRETTY_FUNCTION__))
;
2054
2055 if (!fn) {
2056 fn = CGF.CGM.getIntrinsic(IntID);
2057 setARCRuntimeFunctionLinkage(CGF.CGM, fn);
2058 }
2059
2060 llvm::Type *origType = value->getType();
2061
2062 llvm::Value *args[] = {
2063 CGF.Builder.CreateBitCast(addr.getPointer(), CGF.Int8PtrPtrTy),
2064 CGF.Builder.CreateBitCast(value, CGF.Int8PtrTy)
2065 };
2066 llvm::CallInst *result = CGF.EmitNounwindRuntimeCall(fn, args);
2067
2068 if (ignored) return nullptr;
2069
2070 return CGF.Builder.CreateBitCast(result, origType);
2071}
2072
2073/// Perform an operation having the following signature:
2074/// void (i8**, i8**)
2075static void emitARCCopyOperation(CodeGenFunction &CGF, Address dst, Address src,
2076 llvm::Function *&fn,
2077 llvm::Intrinsic::ID IntID) {
2078 assert(dst.getType() == src.getType())((dst.getType() == src.getType()) ? static_cast<void> (
0) : __assert_fail ("dst.getType() == src.getType()", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 2078, __PRETTY_FUNCTION__))
;
2079
2080 if (!fn) {
2081 fn = CGF.CGM.getIntrinsic(IntID);
2082 setARCRuntimeFunctionLinkage(CGF.CGM, fn);
2083 }
2084
2085 llvm::Value *args[] = {
2086 CGF.Builder.CreateBitCast(dst.getPointer(), CGF.Int8PtrPtrTy),
2087 CGF.Builder.CreateBitCast(src.getPointer(), CGF.Int8PtrPtrTy)
2088 };
2089 CGF.EmitNounwindRuntimeCall(fn, args);
2090}
2091
2092/// Perform an operation having the signature
2093/// i8* (i8*)
2094/// where a null input causes a no-op and returns null.
2095static llvm::Value *emitObjCValueOperation(CodeGenFunction &CGF,
2096 llvm::Value *value,
2097 llvm::Type *returnType,
2098 llvm::FunctionCallee &fn,
2099 StringRef fnName) {
2100 if (isa<llvm::ConstantPointerNull>(value))
2101 return value;
2102
2103 if (!fn) {
2104 llvm::FunctionType *fnType =
2105 llvm::FunctionType::get(CGF.Int8PtrTy, CGF.Int8PtrTy, false);
2106 fn = CGF.CGM.CreateRuntimeFunction(fnType, fnName);
2107
2108 // We have Native ARC, so set nonlazybind attribute for performance
2109 if (llvm::Function *f = dyn_cast<llvm::Function>(fn.getCallee()))
2110 if (fnName == "objc_retain")
2111 f->addFnAttr(llvm::Attribute::NonLazyBind);
2112 }
2113
2114 // Cast the argument to 'id'.
2115 llvm::Type *origType = returnType ? returnType : value->getType();
2116 value = CGF.Builder.CreateBitCast(value, CGF.Int8PtrTy);
2117
2118 // Call the function.
2119 llvm::CallBase *Inst = CGF.EmitCallOrInvoke(fn, value);
2120
2121 // Cast the result back to the original type.
2122 return CGF.Builder.CreateBitCast(Inst, origType);
2123}
2124
2125/// Produce the code to do a retain. Based on the type, calls one of:
2126/// call i8* \@objc_retain(i8* %value)
2127/// call i8* \@objc_retainBlock(i8* %value)
2128llvm::Value *CodeGenFunction::EmitARCRetain(QualType type, llvm::Value *value) {
2129 if (type->isBlockPointerType())
2130 return EmitARCRetainBlock(value, /*mandatory*/ false);
2131 else
2132 return EmitARCRetainNonBlock(value);
2133}
2134
2135/// Retain the given object, with normal retain semantics.
2136/// call i8* \@objc_retain(i8* %value)
2137llvm::Value *CodeGenFunction::EmitARCRetainNonBlock(llvm::Value *value) {
2138 return emitARCValueOperation(*this, value, nullptr,
2139 CGM.getObjCEntrypoints().objc_retain,
2140 llvm::Intrinsic::objc_retain);
2141}
2142
2143/// Retain the given block, with _Block_copy semantics.
2144/// call i8* \@objc_retainBlock(i8* %value)
2145///
2146/// \param mandatory - If false, emit the call with metadata
2147/// indicating that it's okay for the optimizer to eliminate this call
2148/// if it can prove that the block never escapes except down the stack.
2149llvm::Value *CodeGenFunction::EmitARCRetainBlock(llvm::Value *value,
2150 bool mandatory) {
2151 llvm::Value *result
2152 = emitARCValueOperation(*this, value, nullptr,
2153 CGM.getObjCEntrypoints().objc_retainBlock,
2154 llvm::Intrinsic::objc_retainBlock);
2155
2156 // If the copy isn't mandatory, add !clang.arc.copy_on_escape to
2157 // tell the optimizer that it doesn't need to do this copy if the
2158 // block doesn't escape, where being passed as an argument doesn't
2159 // count as escaping.
2160 if (!mandatory && isa<llvm::Instruction>(result)) {
2161 llvm::CallInst *call
2162 = cast<llvm::CallInst>(result->stripPointerCasts());
2163 assert(call->getCalledValue() == CGM.getObjCEntrypoints().objc_retainBlock)((call->getCalledValue() == CGM.getObjCEntrypoints().objc_retainBlock
) ? static_cast<void> (0) : __assert_fail ("call->getCalledValue() == CGM.getObjCEntrypoints().objc_retainBlock"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 2163, __PRETTY_FUNCTION__))
;
2164
2165 call->setMetadata("clang.arc.copy_on_escape",
2166 llvm::MDNode::get(Builder.getContext(), None));
2167 }
2168
2169 return result;
2170}
2171
2172static void emitAutoreleasedReturnValueMarker(CodeGenFunction &CGF) {
2173 // Fetch the void(void) inline asm which marks that we're going to
2174 // do something with the autoreleased return value.
2175 llvm::InlineAsm *&marker
2176 = CGF.CGM.getObjCEntrypoints().retainAutoreleasedReturnValueMarker;
2177 if (!marker) {
2178 StringRef assembly
2179 = CGF.CGM.getTargetCodeGenInfo()
2180 .getARCRetainAutoreleasedReturnValueMarker();
2181
2182 // If we have an empty assembly string, there's nothing to do.
2183 if (assembly.empty()) {
2184
2185 // Otherwise, at -O0, build an inline asm that we're going to call
2186 // in a moment.
2187 } else if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) {
2188 llvm::FunctionType *type =
2189 llvm::FunctionType::get(CGF.VoidTy, /*variadic*/false);
2190
2191 marker = llvm::InlineAsm::get(type, assembly, "", /*sideeffects*/ true);
2192
2193 // If we're at -O1 and above, we don't want to litter the code
2194 // with this marker yet, so leave a breadcrumb for the ARC
2195 // optimizer to pick up.
2196 } else {
2197 const char *markerKey = "clang.arc.retainAutoreleasedReturnValueMarker";
2198 if (!CGF.CGM.getModule().getModuleFlag(markerKey)) {
2199 auto *str = llvm::MDString::get(CGF.getLLVMContext(), assembly);
2200 CGF.CGM.getModule().addModuleFlag(llvm::Module::Error, markerKey, str);
2201 }
2202 }
2203 }
2204
2205 // Call the marker asm if we made one, which we do only at -O0.
2206 if (marker)
2207 CGF.Builder.CreateCall(marker, None, CGF.getBundlesForFunclet(marker));
2208}
2209
2210/// Retain the given object which is the result of a function call.
2211/// call i8* \@objc_retainAutoreleasedReturnValue(i8* %value)
2212///
2213/// Yes, this function name is one character away from a different
2214/// call with completely different semantics.
2215llvm::Value *
2216CodeGenFunction::EmitARCRetainAutoreleasedReturnValue(llvm::Value *value) {
2217 emitAutoreleasedReturnValueMarker(*this);
2218 llvm::CallInst::TailCallKind tailKind =
2219 CGM.getTargetCodeGenInfo()
2220 .shouldSuppressTailCallsOfRetainAutoreleasedReturnValue()
2221 ? llvm::CallInst::TCK_NoTail
2222 : llvm::CallInst::TCK_None;
2223 return emitARCValueOperation(
2224 *this, value, nullptr,
2225 CGM.getObjCEntrypoints().objc_retainAutoreleasedReturnValue,
2226 llvm::Intrinsic::objc_retainAutoreleasedReturnValue, tailKind);
2227}
2228
2229/// Claim a possibly-autoreleased return value at +0. This is only
2230/// valid to do in contexts which do not rely on the retain to keep
2231/// the object valid for all of its uses; for example, when
2232/// the value is ignored, or when it is being assigned to an
2233/// __unsafe_unretained variable.
2234///
2235/// call i8* \@objc_unsafeClaimAutoreleasedReturnValue(i8* %value)
2236llvm::Value *
2237CodeGenFunction::EmitARCUnsafeClaimAutoreleasedReturnValue(llvm::Value *value) {
2238 emitAutoreleasedReturnValueMarker(*this);
2239 return emitARCValueOperation(*this, value, nullptr,
2240 CGM.getObjCEntrypoints().objc_unsafeClaimAutoreleasedReturnValue,
2241 llvm::Intrinsic::objc_unsafeClaimAutoreleasedReturnValue);
2242}
2243
2244/// Release the given object.
2245/// call void \@objc_release(i8* %value)
2246void CodeGenFunction::EmitARCRelease(llvm::Value *value,
2247 ARCPreciseLifetime_t precise) {
2248 if (isa<llvm::ConstantPointerNull>(value)) return;
2249
2250 llvm::Function *&fn = CGM.getObjCEntrypoints().objc_release;
2251 if (!fn) {
2252 fn = CGM.getIntrinsic(llvm::Intrinsic::objc_release);
2253 setARCRuntimeFunctionLinkage(CGM, fn);
2254 }
2255
2256 // Cast the argument to 'id'.
2257 value = Builder.CreateBitCast(value, Int8PtrTy);
2258
2259 // Call objc_release.
2260 llvm::CallInst *call = EmitNounwindRuntimeCall(fn, value);
2261
2262 if (precise == ARCImpreciseLifetime) {
2263 call->setMetadata("clang.imprecise_release",
2264 llvm::MDNode::get(Builder.getContext(), None));
2265 }
2266}
2267
2268/// Destroy a __strong variable.
2269///
2270/// At -O0, emit a call to store 'null' into the address;
2271/// instrumenting tools prefer this because the address is exposed,
2272/// but it's relatively cumbersome to optimize.
2273///
2274/// At -O1 and above, just load and call objc_release.
2275///
2276/// call void \@objc_storeStrong(i8** %addr, i8* null)
2277void CodeGenFunction::EmitARCDestroyStrong(Address addr,
2278 ARCPreciseLifetime_t precise) {
2279 if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
2280 llvm::Value *null = getNullForVariable(addr);
2281 EmitARCStoreStrongCall(addr, null, /*ignored*/ true);
2282 return;
2283 }
2284
2285 llvm::Value *value = Builder.CreateLoad(addr);
2286 EmitARCRelease(value, precise);
2287}
2288
2289/// Store into a strong object. Always calls this:
2290/// call void \@objc_storeStrong(i8** %addr, i8* %value)
2291llvm::Value *CodeGenFunction::EmitARCStoreStrongCall(Address addr,
2292 llvm::Value *value,
2293 bool ignored) {
2294 assert(addr.getElementType() == value->getType())((addr.getElementType() == value->getType()) ? static_cast
<void> (0) : __assert_fail ("addr.getElementType() == value->getType()"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 2294, __PRETTY_FUNCTION__))
;
2295
2296 llvm::Function *&fn = CGM.getObjCEntrypoints().objc_storeStrong;
2297 if (!fn) {
2298 fn = CGM.getIntrinsic(llvm::Intrinsic::objc_storeStrong);
2299 setARCRuntimeFunctionLinkage(CGM, fn);
2300 }
2301
2302 llvm::Value *args[] = {
2303 Builder.CreateBitCast(addr.getPointer(), Int8PtrPtrTy),
2304 Builder.CreateBitCast(value, Int8PtrTy)
2305 };
2306 EmitNounwindRuntimeCall(fn, args);
2307
2308 if (ignored) return nullptr;
2309 return value;
2310}
2311
2312/// Store into a strong object. Sometimes calls this:
2313/// call void \@objc_storeStrong(i8** %addr, i8* %value)
2314/// Other times, breaks it down into components.
2315llvm::Value *CodeGenFunction::EmitARCStoreStrong(LValue dst,
2316 llvm::Value *newValue,
2317 bool ignored) {
2318 QualType type = dst.getType();
2319 bool isBlock = type->isBlockPointerType();
2320
2321 // Use a store barrier at -O0 unless this is a block type or the
2322 // lvalue is inadequately aligned.
2323 if (shouldUseFusedARCCalls() &&
2324 !isBlock &&
2325 (dst.getAlignment().isZero() ||
2326 dst.getAlignment() >= CharUnits::fromQuantity(PointerAlignInBytes))) {
2327 return EmitARCStoreStrongCall(dst.getAddress(*this), newValue, ignored);
2328 }
2329
2330 // Otherwise, split it out.
2331
2332 // Retain the new value.
2333 newValue = EmitARCRetain(type, newValue);
2334
2335 // Read the old value.
2336 llvm::Value *oldValue = EmitLoadOfScalar(dst, SourceLocation());
2337
2338 // Store. We do this before the release so that any deallocs won't
2339 // see the old value.
2340 EmitStoreOfScalar(newValue, dst);
2341
2342 // Finally, release the old value.
2343 EmitARCRelease(oldValue, dst.isARCPreciseLifetime());
2344
2345 return newValue;
2346}
2347
2348/// Autorelease the given object.
2349/// call i8* \@objc_autorelease(i8* %value)
2350llvm::Value *CodeGenFunction::EmitARCAutorelease(llvm::Value *value) {
2351 return emitARCValueOperation(*this, value, nullptr,
2352 CGM.getObjCEntrypoints().objc_autorelease,
2353 llvm::Intrinsic::objc_autorelease);
2354}
2355
2356/// Autorelease the given object.
2357/// call i8* \@objc_autoreleaseReturnValue(i8* %value)
2358llvm::Value *
2359CodeGenFunction::EmitARCAutoreleaseReturnValue(llvm::Value *value) {
2360 return emitARCValueOperation(*this, value, nullptr,
2361 CGM.getObjCEntrypoints().objc_autoreleaseReturnValue,
2362 llvm::Intrinsic::objc_autoreleaseReturnValue,
2363 llvm::CallInst::TCK_Tail);
2364}
2365
2366/// Do a fused retain/autorelease of the given object.
2367/// call i8* \@objc_retainAutoreleaseReturnValue(i8* %value)
2368llvm::Value *
2369CodeGenFunction::EmitARCRetainAutoreleaseReturnValue(llvm::Value *value) {
2370 return emitARCValueOperation(*this, value, nullptr,
2371 CGM.getObjCEntrypoints().objc_retainAutoreleaseReturnValue,
2372 llvm::Intrinsic::objc_retainAutoreleaseReturnValue,
2373 llvm::CallInst::TCK_Tail);
2374}
2375
2376/// Do a fused retain/autorelease of the given object.
2377/// call i8* \@objc_retainAutorelease(i8* %value)
2378/// or
2379/// %retain = call i8* \@objc_retainBlock(i8* %value)
2380/// call i8* \@objc_autorelease(i8* %retain)
2381llvm::Value *CodeGenFunction::EmitARCRetainAutorelease(QualType type,
2382 llvm::Value *value) {
2383 if (!type->isBlockPointerType())
2384 return EmitARCRetainAutoreleaseNonBlock(value);
2385
2386 if (isa<llvm::ConstantPointerNull>(value)) return value;
2387
2388 llvm::Type *origType = value->getType();
2389 value = Builder.CreateBitCast(value, Int8PtrTy);
2390 value = EmitARCRetainBlock(value, /*mandatory*/ true);
2391 value = EmitARCAutorelease(value);
2392 return Builder.CreateBitCast(value, origType);
2393}
2394
2395/// Do a fused retain/autorelease of the given object.
2396/// call i8* \@objc_retainAutorelease(i8* %value)
2397llvm::Value *
2398CodeGenFunction::EmitARCRetainAutoreleaseNonBlock(llvm::Value *value) {
2399 return emitARCValueOperation(*this, value, nullptr,
2400 CGM.getObjCEntrypoints().objc_retainAutorelease,
2401 llvm::Intrinsic::objc_retainAutorelease);
2402}
2403
2404/// i8* \@objc_loadWeak(i8** %addr)
2405/// Essentially objc_autorelease(objc_loadWeakRetained(addr)).
2406llvm::Value *CodeGenFunction::EmitARCLoadWeak(Address addr) {
2407 return emitARCLoadOperation(*this, addr,
2408 CGM.getObjCEntrypoints().objc_loadWeak,
2409 llvm::Intrinsic::objc_loadWeak);
2410}
2411
2412/// i8* \@objc_loadWeakRetained(i8** %addr)
2413llvm::Value *CodeGenFunction::EmitARCLoadWeakRetained(Address addr) {
2414 return emitARCLoadOperation(*this, addr,
2415 CGM.getObjCEntrypoints().objc_loadWeakRetained,
2416 llvm::Intrinsic::objc_loadWeakRetained);
2417}
2418
2419/// i8* \@objc_storeWeak(i8** %addr, i8* %value)
2420/// Returns %value.
2421llvm::Value *CodeGenFunction::EmitARCStoreWeak(Address addr,
2422 llvm::Value *value,
2423 bool ignored) {
2424 return emitARCStoreOperation(*this, addr, value,
2425 CGM.getObjCEntrypoints().objc_storeWeak,
2426 llvm::Intrinsic::objc_storeWeak, ignored);
2427}
2428
2429/// i8* \@objc_initWeak(i8** %addr, i8* %value)
2430/// Returns %value. %addr is known to not have a current weak entry.
2431/// Essentially equivalent to:
2432/// *addr = nil; objc_storeWeak(addr, value);
2433void CodeGenFunction::EmitARCInitWeak(Address addr, llvm::Value *value) {
2434 // If we're initializing to null, just write null to memory; no need
2435 // to get the runtime involved. But don't do this if optimization
2436 // is enabled, because accounting for this would make the optimizer
2437 // much more complicated.
2438 if (isa<llvm::ConstantPointerNull>(value) &&
2439 CGM.getCodeGenOpts().OptimizationLevel == 0) {
2440 Builder.CreateStore(value, addr);
2441 return;
2442 }
2443
2444 emitARCStoreOperation(*this, addr, value,
2445 CGM.getObjCEntrypoints().objc_initWeak,
2446 llvm::Intrinsic::objc_initWeak, /*ignored*/ true);
2447}
2448
2449/// void \@objc_destroyWeak(i8** %addr)
2450/// Essentially objc_storeWeak(addr, nil).
2451void CodeGenFunction::EmitARCDestroyWeak(Address addr) {
2452 llvm::Function *&fn = CGM.getObjCEntrypoints().objc_destroyWeak;
2453 if (!fn) {
2454 fn = CGM.getIntrinsic(llvm::Intrinsic::objc_destroyWeak);
2455 setARCRuntimeFunctionLinkage(CGM, fn);
2456 }
2457
2458 // Cast the argument to 'id*'.
2459 addr = Builder.CreateBitCast(addr, Int8PtrPtrTy);
2460
2461 EmitNounwindRuntimeCall(fn, addr.getPointer());
2462}
2463
2464/// void \@objc_moveWeak(i8** %dest, i8** %src)
2465/// Disregards the current value in %dest. Leaves %src pointing to nothing.
2466/// Essentially (objc_copyWeak(dest, src), objc_destroyWeak(src)).
2467void CodeGenFunction::EmitARCMoveWeak(Address dst, Address src) {
2468 emitARCCopyOperation(*this, dst, src,
2469 CGM.getObjCEntrypoints().objc_moveWeak,
2470 llvm::Intrinsic::objc_moveWeak);
2471}
2472
2473/// void \@objc_copyWeak(i8** %dest, i8** %src)
2474/// Disregards the current value in %dest. Essentially
2475/// objc_release(objc_initWeak(dest, objc_readWeakRetained(src)))
2476void CodeGenFunction::EmitARCCopyWeak(Address dst, Address src) {
2477 emitARCCopyOperation(*this, dst, src,
2478 CGM.getObjCEntrypoints().objc_copyWeak,
2479 llvm::Intrinsic::objc_copyWeak);
2480}
2481
2482void CodeGenFunction::emitARCCopyAssignWeak(QualType Ty, Address DstAddr,
2483 Address SrcAddr) {
2484 llvm::Value *Object = EmitARCLoadWeakRetained(SrcAddr);
2485 Object = EmitObjCConsumeObject(Ty, Object);
2486 EmitARCStoreWeak(DstAddr, Object, false);
2487}
2488
2489void CodeGenFunction::emitARCMoveAssignWeak(QualType Ty, Address DstAddr,
2490 Address SrcAddr) {
2491 llvm::Value *Object = EmitARCLoadWeakRetained(SrcAddr);
2492 Object = EmitObjCConsumeObject(Ty, Object);
2493 EmitARCStoreWeak(DstAddr, Object, false);
2494 EmitARCDestroyWeak(SrcAddr);
2495}
2496
2497/// Produce the code to do a objc_autoreleasepool_push.
2498/// call i8* \@objc_autoreleasePoolPush(void)
2499llvm::Value *CodeGenFunction::EmitObjCAutoreleasePoolPush() {
2500 llvm::Function *&fn = CGM.getObjCEntrypoints().objc_autoreleasePoolPush;
2501 if (!fn) {
2502 fn = CGM.getIntrinsic(llvm::Intrinsic::objc_autoreleasePoolPush);
2503 setARCRuntimeFunctionLinkage(CGM, fn);
2504 }
2505
2506 return EmitNounwindRuntimeCall(fn);
2507}
2508
2509/// Produce the code to do a primitive release.
2510/// call void \@objc_autoreleasePoolPop(i8* %ptr)
2511void CodeGenFunction::EmitObjCAutoreleasePoolPop(llvm::Value *value) {
2512 assert(value->getType() == Int8PtrTy)((value->getType() == Int8PtrTy) ? static_cast<void>
(0) : __assert_fail ("value->getType() == Int8PtrTy", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 2512, __PRETTY_FUNCTION__))
;
2513
2514 if (getInvokeDest()) {
2515 // Call the runtime method not the intrinsic if we are handling exceptions
2516 llvm::FunctionCallee &fn =
2517 CGM.getObjCEntrypoints().objc_autoreleasePoolPopInvoke;
2518 if (!fn) {
2519 llvm::FunctionType *fnType =
2520 llvm::FunctionType::get(Builder.getVoidTy(), Int8PtrTy, false);
2521 fn = CGM.CreateRuntimeFunction(fnType, "objc_autoreleasePoolPop");
2522 setARCRuntimeFunctionLinkage(CGM, fn);
2523 }
2524
2525 // objc_autoreleasePoolPop can throw.
2526 EmitRuntimeCallOrInvoke(fn, value);
2527 } else {
2528 llvm::FunctionCallee &fn = CGM.getObjCEntrypoints().objc_autoreleasePoolPop;
2529 if (!fn) {
2530 fn = CGM.getIntrinsic(llvm::Intrinsic::objc_autoreleasePoolPop);
2531 setARCRuntimeFunctionLinkage(CGM, fn);
2532 }
2533
2534 EmitRuntimeCall(fn, value);
2535 }
2536}
2537
2538/// Produce the code to do an MRR version objc_autoreleasepool_push.
2539/// Which is: [[NSAutoreleasePool alloc] init];
2540/// Where alloc is declared as: + (id) alloc; in NSAutoreleasePool class.
2541/// init is declared as: - (id) init; in its NSObject super class.
2542///
2543llvm::Value *CodeGenFunction::EmitObjCMRRAutoreleasePoolPush() {
2544 CGObjCRuntime &Runtime = CGM.getObjCRuntime();
2545 llvm::Value *Receiver = Runtime.EmitNSAutoreleasePoolClassRef(*this);
2546 // [NSAutoreleasePool alloc]
2547 IdentifierInfo *II = &CGM.getContext().Idents.get("alloc");
2548 Selector AllocSel = getContext().Selectors.getSelector(0, &II);
2549 CallArgList Args;
2550 RValue AllocRV =
2551 Runtime.GenerateMessageSend(*this, ReturnValueSlot(),
2552 getContext().getObjCIdType(),
2553 AllocSel, Receiver, Args);
2554
2555 // [Receiver init]
2556 Receiver = AllocRV.getScalarVal();
2557 II = &CGM.getContext().Idents.get("init");
2558 Selector InitSel = getContext().Selectors.getSelector(0, &II);
2559 RValue InitRV =
2560 Runtime.GenerateMessageSend(*this, ReturnValueSlot(),
2561 getContext().getObjCIdType(),
2562 InitSel, Receiver, Args);
2563 return InitRV.getScalarVal();
2564}
2565
2566/// Allocate the given objc object.
2567/// call i8* \@objc_alloc(i8* %value)
2568llvm::Value *CodeGenFunction::EmitObjCAlloc(llvm::Value *value,
2569 llvm::Type *resultType) {
2570 return emitObjCValueOperation(*this, value, resultType,
2571 CGM.getObjCEntrypoints().objc_alloc,
2572 "objc_alloc");
2573}
2574
2575/// Allocate the given objc object.
2576/// call i8* \@objc_allocWithZone(i8* %value)
2577llvm::Value *CodeGenFunction::EmitObjCAllocWithZone(llvm::Value *value,
2578 llvm::Type *resultType) {
2579 return emitObjCValueOperation(*this, value, resultType,
2580 CGM.getObjCEntrypoints().objc_allocWithZone,
2581 "objc_allocWithZone");
2582}
2583
2584llvm::Value *CodeGenFunction::EmitObjCAllocInit(llvm::Value *value,
2585 llvm::Type *resultType) {
2586 return emitObjCValueOperation(*this, value, resultType,
2587 CGM.getObjCEntrypoints().objc_alloc_init,
2588 "objc_alloc_init");
2589}
2590
2591/// Produce the code to do a primitive release.
2592/// [tmp drain];
2593void CodeGenFunction::EmitObjCMRRAutoreleasePoolPop(llvm::Value *Arg) {
2594 IdentifierInfo *II = &CGM.getContext().Idents.get("drain");
2595 Selector DrainSel = getContext().Selectors.getSelector(0, &II);
2596 CallArgList Args;
2597 CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(),
2598 getContext().VoidTy, DrainSel, Arg, Args);
2599}
2600
2601void CodeGenFunction::destroyARCStrongPrecise(CodeGenFunction &CGF,
2602 Address addr,
2603 QualType type) {
2604 CGF.EmitARCDestroyStrong(addr, ARCPreciseLifetime);
2605}
2606
2607void CodeGenFunction::destroyARCStrongImprecise(CodeGenFunction &CGF,
2608 Address addr,
2609 QualType type) {
2610 CGF.EmitARCDestroyStrong(addr, ARCImpreciseLifetime);
2611}
2612
2613void CodeGenFunction::destroyARCWeak(CodeGenFunction &CGF,
2614 Address addr,
2615 QualType type) {
2616 CGF.EmitARCDestroyWeak(addr);
2617}
2618
2619void CodeGenFunction::emitARCIntrinsicUse(CodeGenFunction &CGF, Address addr,
2620 QualType type) {
2621 llvm::Value *value = CGF.Builder.CreateLoad(addr);
2622 CGF.EmitARCIntrinsicUse(value);
2623}
2624
2625/// Autorelease the given object.
2626/// call i8* \@objc_autorelease(i8* %value)
2627llvm::Value *CodeGenFunction::EmitObjCAutorelease(llvm::Value *value,
2628 llvm::Type *returnType) {
2629 return emitObjCValueOperation(
2630 *this, value, returnType,
2631 CGM.getObjCEntrypoints().objc_autoreleaseRuntimeFunction,
2632 "objc_autorelease");
2633}
2634
2635/// Retain the given object, with normal retain semantics.
2636/// call i8* \@objc_retain(i8* %value)
2637llvm::Value *CodeGenFunction::EmitObjCRetainNonBlock(llvm::Value *value,
2638 llvm::Type *returnType) {
2639 return emitObjCValueOperation(
2640 *this, value, returnType,
2641 CGM.getObjCEntrypoints().objc_retainRuntimeFunction, "objc_retain");
2642}
2643
2644/// Release the given object.
2645/// call void \@objc_release(i8* %value)
2646void CodeGenFunction::EmitObjCRelease(llvm::Value *value,
2647 ARCPreciseLifetime_t precise) {
2648 if (isa<llvm::ConstantPointerNull>(value)) return;
2649
2650 llvm::FunctionCallee &fn =
2651 CGM.getObjCEntrypoints().objc_releaseRuntimeFunction;
2652 if (!fn) {
2653 llvm::FunctionType *fnType =
2654 llvm::FunctionType::get(Builder.getVoidTy(), Int8PtrTy, false);
2655 fn = CGM.CreateRuntimeFunction(fnType, "objc_release");
2656 setARCRuntimeFunctionLinkage(CGM, fn);
2657 // We have Native ARC, so set nonlazybind attribute for performance
2658 if (llvm::Function *f = dyn_cast<llvm::Function>(fn.getCallee()))
2659 f->addFnAttr(llvm::Attribute::NonLazyBind);
2660 }
2661
2662 // Cast the argument to 'id'.
2663 value = Builder.CreateBitCast(value, Int8PtrTy);
2664
2665 // Call objc_release.
2666 llvm::CallBase *call = EmitCallOrInvoke(fn, value);
2667
2668 if (precise == ARCImpreciseLifetime) {
2669 call->setMetadata("clang.imprecise_release",
2670 llvm::MDNode::get(Builder.getContext(), None));
2671 }
2672}
2673
2674namespace {
2675 struct CallObjCAutoreleasePoolObject final : EHScopeStack::Cleanup {
2676 llvm::Value *Token;
2677
2678 CallObjCAutoreleasePoolObject(llvm::Value *token) : Token(token) {}
2679
2680 void Emit(CodeGenFunction &CGF, Flags flags) override {
2681 CGF.EmitObjCAutoreleasePoolPop(Token);
2682 }
2683 };
2684 struct CallObjCMRRAutoreleasePoolObject final : EHScopeStack::Cleanup {
2685 llvm::Value *Token;
2686
2687 CallObjCMRRAutoreleasePoolObject(llvm::Value *token) : Token(token) {}
2688
2689 void Emit(CodeGenFunction &CGF, Flags flags) override {
2690 CGF.EmitObjCMRRAutoreleasePoolPop(Token);
2691 }
2692 };
2693}
2694
2695void CodeGenFunction::EmitObjCAutoreleasePoolCleanup(llvm::Value *Ptr) {
2696 if (CGM.getLangOpts().ObjCAutoRefCount)
2697 EHStack.pushCleanup<CallObjCAutoreleasePoolObject>(NormalCleanup, Ptr);
2698 else
2699 EHStack.pushCleanup<CallObjCMRRAutoreleasePoolObject>(NormalCleanup, Ptr);
2700}
2701
2702static bool shouldRetainObjCLifetime(Qualifiers::ObjCLifetime lifetime) {
2703 switch (lifetime) {
2704 case Qualifiers::OCL_None:
2705 case Qualifiers::OCL_ExplicitNone:
2706 case Qualifiers::OCL_Strong:
2707 case Qualifiers::OCL_Autoreleasing:
2708 return true;
2709
2710 case Qualifiers::OCL_Weak:
2711 return false;
2712 }
2713
2714 llvm_unreachable("impossible lifetime!")::llvm::llvm_unreachable_internal("impossible lifetime!", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 2714)
;
2715}
2716
2717static TryEmitResult tryEmitARCRetainLoadOfScalar(CodeGenFunction &CGF,
2718 LValue lvalue,
2719 QualType type) {
2720 llvm::Value *result;
2721 bool shouldRetain = shouldRetainObjCLifetime(type.getObjCLifetime());
2722 if (shouldRetain) {
2723 result = CGF.EmitLoadOfLValue(lvalue, SourceLocation()).getScalarVal();
2724 } else {
2725 assert(type.getObjCLifetime() == Qualifiers::OCL_Weak)((type.getObjCLifetime() == Qualifiers::OCL_Weak) ? static_cast
<void> (0) : __assert_fail ("type.getObjCLifetime() == Qualifiers::OCL_Weak"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 2725, __PRETTY_FUNCTION__))
;
2726 result = CGF.EmitARCLoadWeakRetained(lvalue.getAddress(CGF));
2727 }
2728 return TryEmitResult(result, !shouldRetain);
2729}
2730
2731static TryEmitResult tryEmitARCRetainLoadOfScalar(CodeGenFunction &CGF,
2732 const Expr *e) {
2733 e = e->IgnoreParens();
2734 QualType type = e->getType();
2735
2736 // If we're loading retained from a __strong xvalue, we can avoid
2737 // an extra retain/release pair by zeroing out the source of this
2738 // "move" operation.
2739 if (e->isXValue() &&
2740 !type.isConstQualified() &&
2741 type.getObjCLifetime() == Qualifiers::OCL_Strong) {
2742 // Emit the lvalue.
2743 LValue lv = CGF.EmitLValue(e);
2744
2745 // Load the object pointer.
2746 llvm::Value *result = CGF.EmitLoadOfLValue(lv,
2747 SourceLocation()).getScalarVal();
2748
2749 // Set the source pointer to NULL.
2750 CGF.EmitStoreOfScalar(getNullForVariable(lv.getAddress(CGF)), lv);
2751
2752 return TryEmitResult(result, true);
2753 }
2754
2755 // As a very special optimization, in ARC++, if the l-value is the
2756 // result of a non-volatile assignment, do a simple retain of the
2757 // result of the call to objc_storeWeak instead of reloading.
2758 if (CGF.getLangOpts().CPlusPlus &&
2759 !type.isVolatileQualified() &&
2760 type.getObjCLifetime() == Qualifiers::OCL_Weak &&
2761 isa<BinaryOperator>(e) &&
2762 cast<BinaryOperator>(e)->getOpcode() == BO_Assign)
2763 return TryEmitResult(CGF.EmitScalarExpr(e), false);
2764
2765 // Try to emit code for scalar constant instead of emitting LValue and
2766 // loading it because we are not guaranteed to have an l-value. One of such
2767 // cases is DeclRefExpr referencing non-odr-used constant-evaluated variable.
2768 if (const auto *decl_expr = dyn_cast<DeclRefExpr>(e)) {
2769 auto *DRE = const_cast<DeclRefExpr *>(decl_expr);
2770 if (CodeGenFunction::ConstantEmission constant = CGF.tryEmitAsConstant(DRE))
2771 return TryEmitResult(CGF.emitScalarConstant(constant, DRE),
2772 !shouldRetainObjCLifetime(type.getObjCLifetime()));
2773 }
2774
2775 return tryEmitARCRetainLoadOfScalar(CGF, CGF.EmitLValue(e), type);
2776}
2777
2778typedef llvm::function_ref<llvm::Value *(CodeGenFunction &CGF,
2779 llvm::Value *value)>
2780 ValueTransform;
2781
2782/// Insert code immediately after a call.
2783static llvm::Value *emitARCOperationAfterCall(CodeGenFunction &CGF,
2784 llvm::Value *value,
2785 ValueTransform doAfterCall,
2786 ValueTransform doFallback) {
2787 if (llvm::CallInst *call = dyn_cast<llvm::CallInst>(value)) {
2788 CGBuilderTy::InsertPoint ip = CGF.Builder.saveIP();
2789
2790 // Place the retain immediately following the call.
2791 CGF.Builder.SetInsertPoint(call->getParent(),
2792 ++llvm::BasicBlock::iterator(call));
2793 value = doAfterCall(CGF, value);
2794
2795 CGF.Builder.restoreIP(ip);
2796 return value;
2797 } else if (llvm::InvokeInst *invoke = dyn_cast<llvm::InvokeInst>(value)) {
2798 CGBuilderTy::InsertPoint ip = CGF.Builder.saveIP();
2799
2800 // Place the retain at the beginning of the normal destination block.
2801 llvm::BasicBlock *BB = invoke->getNormalDest();
2802 CGF.Builder.SetInsertPoint(BB, BB->begin());
2803 value = doAfterCall(CGF, value);
2804
2805 CGF.Builder.restoreIP(ip);
2806 return value;
2807
2808 // Bitcasts can arise because of related-result returns. Rewrite
2809 // the operand.
2810 } else if (llvm::BitCastInst *bitcast = dyn_cast<llvm::BitCastInst>(value)) {
2811 llvm::Value *operand = bitcast->getOperand(0);
2812 operand = emitARCOperationAfterCall(CGF, operand, doAfterCall, doFallback);
2813 bitcast->setOperand(0, operand);
2814 return bitcast;
2815
2816 // Generic fall-back case.
2817 } else {
2818 // Retain using the non-block variant: we never need to do a copy
2819 // of a block that's been returned to us.
2820 return doFallback(CGF, value);
2821 }
2822}
2823
2824/// Given that the given expression is some sort of call (which does
2825/// not return retained), emit a retain following it.
2826static llvm::Value *emitARCRetainCallResult(CodeGenFunction &CGF,
2827 const Expr *e) {
2828 llvm::Value *value = CGF.EmitScalarExpr(e);
2829 return emitARCOperationAfterCall(CGF, value,
2830 [](CodeGenFunction &CGF, llvm::Value *value) {
2831 return CGF.EmitARCRetainAutoreleasedReturnValue(value);
2832 },
2833 [](CodeGenFunction &CGF, llvm::Value *value) {
2834 return CGF.EmitARCRetainNonBlock(value);
2835 });
2836}
2837
2838/// Given that the given expression is some sort of call (which does
2839/// not return retained), perform an unsafeClaim following it.
2840static llvm::Value *emitARCUnsafeClaimCallResult(CodeGenFunction &CGF,
2841 const Expr *e) {
2842 llvm::Value *value = CGF.EmitScalarExpr(e);
2843 return emitARCOperationAfterCall(CGF, value,
2844 [](CodeGenFunction &CGF, llvm::Value *value) {
2845 return CGF.EmitARCUnsafeClaimAutoreleasedReturnValue(value);
2846 },
2847 [](CodeGenFunction &CGF, llvm::Value *value) {
2848 return value;
2849 });
2850}
2851
2852llvm::Value *CodeGenFunction::EmitARCReclaimReturnedObject(const Expr *E,
2853 bool allowUnsafeClaim) {
2854 if (allowUnsafeClaim &&
2855 CGM.getLangOpts().ObjCRuntime.hasARCUnsafeClaimAutoreleasedReturnValue()) {
2856 return emitARCUnsafeClaimCallResult(*this, E);
2857 } else {
2858 llvm::Value *value = emitARCRetainCallResult(*this, E);
2859 return EmitObjCConsumeObject(E->getType(), value);
2860 }
2861}
2862
2863/// Determine whether it might be important to emit a separate
2864/// objc_retain_block on the result of the given expression, or
2865/// whether it's okay to just emit it in a +1 context.
2866static bool shouldEmitSeparateBlockRetain(const Expr *e) {
2867 assert(e->getType()->isBlockPointerType())((e->getType()->isBlockPointerType()) ? static_cast<
void> (0) : __assert_fail ("e->getType()->isBlockPointerType()"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 2867, __PRETTY_FUNCTION__))
;
2868 e = e->IgnoreParens();
2869
2870 // For future goodness, emit block expressions directly in +1
2871 // contexts if we can.
2872 if (isa<BlockExpr>(e))
2873 return false;
2874
2875 if (const CastExpr *cast = dyn_cast<CastExpr>(e)) {
2876 switch (cast->getCastKind()) {
2877 // Emitting these operations in +1 contexts is goodness.
2878 case CK_LValueToRValue:
2879 case CK_ARCReclaimReturnedObject:
2880 case CK_ARCConsumeObject:
2881 case CK_ARCProduceObject:
2882 return false;
2883
2884 // These operations preserve a block type.
2885 case CK_NoOp:
2886 case CK_BitCast:
2887 return shouldEmitSeparateBlockRetain(cast->getSubExpr());
2888
2889 // These operations are known to be bad (or haven't been considered).
2890 case CK_AnyPointerToBlockPointerCast:
2891 default:
2892 return true;
2893 }
2894 }
2895
2896 return true;
2897}
2898
2899namespace {
2900/// A CRTP base class for emitting expressions of retainable object
2901/// pointer type in ARC.
2902template <typename Impl, typename Result> class ARCExprEmitter {
2903protected:
2904 CodeGenFunction &CGF;
2905 Impl &asImpl() { return *static_cast<Impl*>(this); }
2906
2907 ARCExprEmitter(CodeGenFunction &CGF) : CGF(CGF) {}
2908
2909public:
2910 Result visit(const Expr *e);
2911 Result visitCastExpr(const CastExpr *e);
2912 Result visitPseudoObjectExpr(const PseudoObjectExpr *e);
2913 Result visitBlockExpr(const BlockExpr *e);
2914 Result visitBinaryOperator(const BinaryOperator *e);
2915 Result visitBinAssign(const BinaryOperator *e);
2916 Result visitBinAssignUnsafeUnretained(const BinaryOperator *e);
2917 Result visitBinAssignAutoreleasing(const BinaryOperator *e);
2918 Result visitBinAssignWeak(const BinaryOperator *e);
2919 Result visitBinAssignStrong(const BinaryOperator *e);
2920
2921 // Minimal implementation:
2922 // Result visitLValueToRValue(const Expr *e)
2923 // Result visitConsumeObject(const Expr *e)
2924 // Result visitExtendBlockObject(const Expr *e)
2925 // Result visitReclaimReturnedObject(const Expr *e)
2926 // Result visitCall(const Expr *e)
2927 // Result visitExpr(const Expr *e)
2928 //
2929 // Result emitBitCast(Result result, llvm::Type *resultType)
2930 // llvm::Value *getValueOfResult(Result result)
2931};
2932}
2933
2934/// Try to emit a PseudoObjectExpr under special ARC rules.
2935///
2936/// This massively duplicates emitPseudoObjectRValue.
2937template <typename Impl, typename Result>
2938Result
2939ARCExprEmitter<Impl,Result>::visitPseudoObjectExpr(const PseudoObjectExpr *E) {
2940 SmallVector<CodeGenFunction::OpaqueValueMappingData, 4> opaques;
2941
2942 // Find the result expression.
2943 const Expr *resultExpr = E->getResultExpr();
2944 assert(resultExpr)((resultExpr) ? static_cast<void> (0) : __assert_fail (
"resultExpr", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 2944, __PRETTY_FUNCTION__))
;
19
Assuming 'resultExpr' is non-null
20
'?' condition is true
2945 Result result;
21
'result' declared without an initial value
2946
2947 for (PseudoObjectExpr::const_semantics_iterator
23
Loop condition is false. Execution continues on line 2983
2948 i = E->semantics_begin(), e = E->semantics_end(); i != e; ++i) {
22
Assuming 'i' is equal to 'e'
2949 const Expr *semantic = *i;
2950
2951 // If this semantic expression is an opaque value, bind it
2952 // to the result of its source expression.
2953 if (const OpaqueValueExpr *ov = dyn_cast<OpaqueValueExpr>(semantic)) {
2954 typedef CodeGenFunction::OpaqueValueMappingData OVMA;
2955 OVMA opaqueData;
2956
2957 // If this semantic is the result of the pseudo-object
2958 // expression, try to evaluate the source as +1.
2959 if (ov == resultExpr) {
2960 assert(!OVMA::shouldBindAsLValue(ov))((!OVMA::shouldBindAsLValue(ov)) ? static_cast<void> (0
) : __assert_fail ("!OVMA::shouldBindAsLValue(ov)", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 2960, __PRETTY_FUNCTION__))
;
2961 result = asImpl().visit(ov->getSourceExpr());
2962 opaqueData = OVMA::bind(CGF, ov,
2963 RValue::get(asImpl().getValueOfResult(result)));
2964
2965 // Otherwise, just bind it.
2966 } else {
2967 opaqueData = OVMA::bind(CGF, ov, ov->getSourceExpr());
2968 }
2969 opaques.push_back(opaqueData);
2970
2971 // Otherwise, if the expression is the result, evaluate it
2972 // and remember the result.
2973 } else if (semantic == resultExpr) {
2974 result = asImpl().visit(semantic);
2975
2976 // Otherwise, evaluate the expression in an ignored context.
2977 } else {
2978 CGF.EmitIgnoredExpr(semantic);
2979 }
2980 }
2981
2982 // Unbind all the opaques now.
2983 for (unsigned i = 0, e = opaques.size(); i != e; ++i)
24
Assuming 'i' is equal to 'e'
25
Loop condition is false. Execution continues on line 2986
2984 opaques[i].unbind(CGF);
2985
2986 return result;
26
Undefined or garbage value returned to caller
2987}
2988
2989template <typename Impl, typename Result>
2990Result ARCExprEmitter<Impl, Result>::visitBlockExpr(const BlockExpr *e) {
2991 // The default implementation just forwards the expression to visitExpr.
2992 return asImpl().visitExpr(e);
2993}
2994
2995template <typename Impl, typename Result>
2996Result ARCExprEmitter<Impl,Result>::visitCastExpr(const CastExpr *e) {
2997 switch (e->getCastKind()) {
2998
2999 // No-op casts don't change the type, so we just ignore them.
3000 case CK_NoOp:
3001 return asImpl().visit(e->getSubExpr());
3002
3003 // These casts can change the type.
3004 case CK_CPointerToObjCPointerCast:
3005 case CK_BlockPointerToObjCPointerCast:
3006 case CK_AnyPointerToBlockPointerCast:
3007 case CK_BitCast: {
3008 llvm::Type *resultType = CGF.ConvertType(e->getType());
3009 assert(e->getSubExpr()->getType()->hasPointerRepresentation())((e->getSubExpr()->getType()->hasPointerRepresentation
()) ? static_cast<void> (0) : __assert_fail ("e->getSubExpr()->getType()->hasPointerRepresentation()"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 3009, __PRETTY_FUNCTION__))
;
3010 Result result = asImpl().visit(e->getSubExpr());
3011 return asImpl().emitBitCast(result, resultType);
3012 }
3013
3014 // Handle some casts specially.
3015 case CK_LValueToRValue:
3016 return asImpl().visitLValueToRValue(e->getSubExpr());
3017 case CK_ARCConsumeObject:
3018 return asImpl().visitConsumeObject(e->getSubExpr());
3019 case CK_ARCExtendBlockObject:
3020 return asImpl().visitExtendBlockObject(e->getSubExpr());
3021 case CK_ARCReclaimReturnedObject:
3022 return asImpl().visitReclaimReturnedObject(e->getSubExpr());
3023
3024 // Otherwise, use the default logic.
3025 default:
3026 return asImpl().visitExpr(e);
3027 }
3028}
3029
3030template <typename Impl, typename Result>
3031Result
3032ARCExprEmitter<Impl,Result>::visitBinaryOperator(const BinaryOperator *e) {
3033 switch (e->getOpcode()) {
3034 case BO_Comma:
3035 CGF.EmitIgnoredExpr(e->getLHS());
3036 CGF.EnsureInsertPoint();
3037 return asImpl().visit(e->getRHS());
3038
3039 case BO_Assign:
3040 return asImpl().visitBinAssign(e);
3041
3042 default:
3043 return asImpl().visitExpr(e);
3044 }
3045}
3046
3047template <typename Impl, typename Result>
3048Result ARCExprEmitter<Impl,Result>::visitBinAssign(const BinaryOperator *e) {
3049 switch (e->getLHS()->getType().getObjCLifetime()) {
3050 case Qualifiers::OCL_ExplicitNone:
3051 return asImpl().visitBinAssignUnsafeUnretained(e);
3052
3053 case Qualifiers::OCL_Weak:
3054 return asImpl().visitBinAssignWeak(e);
3055
3056 case Qualifiers::OCL_Autoreleasing:
3057 return asImpl().visitBinAssignAutoreleasing(e);
3058
3059 case Qualifiers::OCL_Strong:
3060 return asImpl().visitBinAssignStrong(e);
3061
3062 case Qualifiers::OCL_None:
3063 return asImpl().visitExpr(e);
3064 }
3065 llvm_unreachable("bad ObjC ownership qualifier")::llvm::llvm_unreachable_internal("bad ObjC ownership qualifier"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 3065)
;
3066}
3067
3068/// The default rule for __unsafe_unretained emits the RHS recursively,
3069/// stores into the unsafe variable, and propagates the result outward.
3070template <typename Impl, typename Result>
3071Result ARCExprEmitter<Impl,Result>::
3072 visitBinAssignUnsafeUnretained(const BinaryOperator *e) {
3073 // Recursively emit the RHS.
3074 // For __block safety, do this before emitting the LHS.
3075 Result result = asImpl().visit(e->getRHS());
3076
3077 // Perform the store.
3078 LValue lvalue =
3079 CGF.EmitCheckedLValue(e->getLHS(), CodeGenFunction::TCK_Store);
3080 CGF.EmitStoreThroughLValue(RValue::get(asImpl().getValueOfResult(result)),
3081 lvalue);
3082
3083 return result;
3084}
3085
3086template <typename Impl, typename Result>
3087Result
3088ARCExprEmitter<Impl,Result>::visitBinAssignAutoreleasing(const BinaryOperator *e) {
3089 return asImpl().visitExpr(e);
3090}
3091
3092template <typename Impl, typename Result>
3093Result
3094ARCExprEmitter<Impl,Result>::visitBinAssignWeak(const BinaryOperator *e) {
3095 return asImpl().visitExpr(e);
3096}
3097
3098template <typename Impl, typename Result>
3099Result
3100ARCExprEmitter<Impl,Result>::visitBinAssignStrong(const BinaryOperator *e) {
3101 return asImpl().visitExpr(e);
3102}
3103
3104/// The general expression-emission logic.
3105template <typename Impl, typename Result>
3106Result ARCExprEmitter<Impl,Result>::visit(const Expr *e) {
3107 // We should *never* see a nested full-expression here, because if
3108 // we fail to emit at +1, our caller must not retain after we close
3109 // out the full-expression. This isn't as important in the unsafe
3110 // emitter.
3111 assert(!isa<ExprWithCleanups>(e))((!isa<ExprWithCleanups>(e)) ? static_cast<void> (
0) : __assert_fail ("!isa<ExprWithCleanups>(e)", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 3111, __PRETTY_FUNCTION__))
;
8
Assuming 'e' is not a 'ExprWithCleanups'
9
'?' condition is true
3112
3113 // Look through parens, __extension__, generic selection, etc.
3114 e = e->IgnoreParens();
3115
3116 // Handle certain kinds of casts.
3117 if (const CastExpr *ce
10.1
'ce' is null
= dyn_cast<CastExpr>(e)) {
10
Assuming 'e' is not a 'CastExpr'
11
Taking false branch
3118 return asImpl().visitCastExpr(ce);
3119
3120 // Handle the comma operator.
3121 } else if (auto op
12.1
'op' is null
= dyn_cast<BinaryOperator>(e)) {
12
Assuming 'e' is not a 'BinaryOperator'
13
Taking false branch
3122 return asImpl().visitBinaryOperator(op);
3123
3124 // TODO: handle conditional operators here
3125
3126 // For calls and message sends, use the retained-call logic.
3127 // Delegate inits are a special case in that they're the only
3128 // returns-retained expression that *isn't* surrounded by
3129 // a consume.
3130 } else if (isa<CallExpr>(e) ||
14
Assuming 'e' is not a 'CallExpr'
3131 (isa<ObjCMessageExpr>(e) &&
15
Assuming 'e' is not a 'ObjCMessageExpr'
3132 !cast<ObjCMessageExpr>(e)->isDelegateInitCall())) {
3133 return asImpl().visitCall(e);
3134
3135 // Look through pseudo-object expressions.
3136 } else if (const PseudoObjectExpr *pseudo
16.1
'pseudo' is non-null
= dyn_cast<PseudoObjectExpr>(e)) {
16
Assuming 'e' is a 'PseudoObjectExpr'
17
Taking true branch
3137 return asImpl().visitPseudoObjectExpr(pseudo);
18
Calling 'ARCExprEmitter::visitPseudoObjectExpr'
3138 } else if (auto *be = dyn_cast<BlockExpr>(e))
3139 return asImpl().visitBlockExpr(be);
3140
3141 return asImpl().visitExpr(e);
3142}
3143
3144namespace {
3145
3146/// An emitter for +1 results.
3147struct ARCRetainExprEmitter :
3148 public ARCExprEmitter<ARCRetainExprEmitter, TryEmitResult> {
3149
3150 ARCRetainExprEmitter(CodeGenFunction &CGF) : ARCExprEmitter(CGF) {}
3151
3152 llvm::Value *getValueOfResult(TryEmitResult result) {
3153 return result.getPointer();
3154 }
3155
3156 TryEmitResult emitBitCast(TryEmitResult result, llvm::Type *resultType) {
3157 llvm::Value *value = result.getPointer();
3158 value = CGF.Builder.CreateBitCast(value, resultType);
3159 result.setPointer(value);
3160 return result;
3161 }
3162
3163 TryEmitResult visitLValueToRValue(const Expr *e) {
3164 return tryEmitARCRetainLoadOfScalar(CGF, e);
3165 }
3166
3167 /// For consumptions, just emit the subexpression and thus elide
3168 /// the retain/release pair.
3169 TryEmitResult visitConsumeObject(const Expr *e) {
3170 llvm::Value *result = CGF.EmitScalarExpr(e);
3171 return TryEmitResult(result, true);
3172 }
3173
3174 TryEmitResult visitBlockExpr(const BlockExpr *e) {
3175 TryEmitResult result = visitExpr(e);
3176 // Avoid the block-retain if this is a block literal that doesn't need to be
3177 // copied to the heap.
3178 if (e->getBlockDecl()->canAvoidCopyToHeap())
3179 result.setInt(true);
3180 return result;
3181 }
3182
3183 /// Block extends are net +0. Naively, we could just recurse on
3184 /// the subexpression, but actually we need to ensure that the
3185 /// value is copied as a block, so there's a little filter here.
3186 TryEmitResult visitExtendBlockObject(const Expr *e) {
3187 llvm::Value *result; // will be a +0 value
3188
3189 // If we can't safely assume the sub-expression will produce a
3190 // block-copied value, emit the sub-expression at +0.
3191 if (shouldEmitSeparateBlockRetain(e)) {
3192 result = CGF.EmitScalarExpr(e);
3193
3194 // Otherwise, try to emit the sub-expression at +1 recursively.
3195 } else {
3196 TryEmitResult subresult = asImpl().visit(e);
3197
3198 // If that produced a retained value, just use that.
3199 if (subresult.getInt()) {
3200 return subresult;
3201 }
3202
3203 // Otherwise it's +0.
3204 result = subresult.getPointer();
3205 }
3206
3207 // Retain the object as a block.
3208 result = CGF.EmitARCRetainBlock(result, /*mandatory*/ true);
3209 return TryEmitResult(result, true);
3210 }
3211
3212 /// For reclaims, emit the subexpression as a retained call and
3213 /// skip the consumption.
3214 TryEmitResult visitReclaimReturnedObject(const Expr *e) {
3215 llvm::Value *result = emitARCRetainCallResult(CGF, e);
3216 return TryEmitResult(result, true);
3217 }
3218
3219 /// When we have an undecorated call, retroactively do a claim.
3220 TryEmitResult visitCall(const Expr *e) {
3221 llvm::Value *result = emitARCRetainCallResult(CGF, e);
3222 return TryEmitResult(result, true);
3223 }
3224
3225 // TODO: maybe special-case visitBinAssignWeak?
3226
3227 TryEmitResult visitExpr(const Expr *e) {
3228 // We didn't find an obvious production, so emit what we've got and
3229 // tell the caller that we didn't manage to retain.
3230 llvm::Value *result = CGF.EmitScalarExpr(e);
3231 return TryEmitResult(result, false);
3232 }
3233};
3234}
3235
3236static TryEmitResult
3237tryEmitARCRetainScalarExpr(CodeGenFunction &CGF, const Expr *e) {
3238 return ARCRetainExprEmitter(CGF).visit(e);
3239}
3240
3241static llvm::Value *emitARCRetainLoadOfScalar(CodeGenFunction &CGF,
3242 LValue lvalue,
3243 QualType type) {
3244 TryEmitResult result = tryEmitARCRetainLoadOfScalar(CGF, lvalue, type);
3245 llvm::Value *value = result.getPointer();
3246 if (!result.getInt())
3247 value = CGF.EmitARCRetain(type, value);
3248 return value;
3249}
3250
3251/// EmitARCRetainScalarExpr - Semantically equivalent to
3252/// EmitARCRetainObject(e->getType(), EmitScalarExpr(e)), but making a
3253/// best-effort attempt to peephole expressions that naturally produce
3254/// retained objects.
3255llvm::Value *CodeGenFunction::EmitARCRetainScalarExpr(const Expr *e) {
3256 // The retain needs to happen within the full-expression.
3257 if (const ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(e)) {
3258 enterFullExpression(cleanups);
3259 RunCleanupsScope scope(*this);
3260 return EmitARCRetainScalarExpr(cleanups->getSubExpr());
3261 }
3262
3263 TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e);
3264 llvm::Value *value = result.getPointer();
3265 if (!result.getInt())
3266 value = EmitARCRetain(e->getType(), value);
3267 return value;
3268}
3269
3270llvm::Value *
3271CodeGenFunction::EmitARCRetainAutoreleaseScalarExpr(const Expr *e) {
3272 // The retain needs to happen within the full-expression.
3273 if (const ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(e)) {
3274 enterFullExpression(cleanups);
3275 RunCleanupsScope scope(*this);
3276 return EmitARCRetainAutoreleaseScalarExpr(cleanups->getSubExpr());
3277 }
3278
3279 TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e);
3280 llvm::Value *value = result.getPointer();
3281 if (result.getInt())
3282 value = EmitARCAutorelease(value);
3283 else
3284 value = EmitARCRetainAutorelease(e->getType(), value);
3285 return value;
3286}
3287
3288llvm::Value *CodeGenFunction::EmitARCExtendBlockObject(const Expr *e) {
3289 llvm::Value *result;
3290 bool doRetain;
3291
3292 if (shouldEmitSeparateBlockRetain(e)) {
3293 result = EmitScalarExpr(e);
3294 doRetain = true;
3295 } else {
3296 TryEmitResult subresult = tryEmitARCRetainScalarExpr(*this, e);
3297 result = subresult.getPointer();
3298 doRetain = !subresult.getInt();
3299 }
3300
3301 if (doRetain)
3302 result = EmitARCRetainBlock(result, /*mandatory*/ true);
3303 return EmitObjCConsumeObject(e->getType(), result);
3304}
3305
3306llvm::Value *CodeGenFunction::EmitObjCThrowOperand(const Expr *expr) {
3307 // In ARC, retain and autorelease the expression.
3308 if (getLangOpts().ObjCAutoRefCount) {
3309 // Do so before running any cleanups for the full-expression.
3310 // EmitARCRetainAutoreleaseScalarExpr does this for us.
3311 return EmitARCRetainAutoreleaseScalarExpr(expr);
3312 }
3313
3314 // Otherwise, use the normal scalar-expression emission. The
3315 // exception machinery doesn't do anything special with the
3316 // exception like retaining it, so there's no safety associated with
3317 // only running cleanups after the throw has started, and when it
3318 // matters it tends to be substantially inferior code.
3319 return EmitScalarExpr(expr);
3320}
3321
3322namespace {
3323
3324/// An emitter for assigning into an __unsafe_unretained context.
3325struct ARCUnsafeUnretainedExprEmitter :
3326 public ARCExprEmitter<ARCUnsafeUnretainedExprEmitter, llvm::Value*> {
3327
3328 ARCUnsafeUnretainedExprEmitter(CodeGenFunction &CGF) : ARCExprEmitter(CGF) {}
3329
3330 llvm::Value *getValueOfResult(llvm::Value *value) {
3331 return value;
3332 }
3333
3334 llvm::Value *emitBitCast(llvm::Value *value, llvm::Type *resultType) {
3335 return CGF.Builder.CreateBitCast(value, resultType);
3336 }
3337
3338 llvm::Value *visitLValueToRValue(const Expr *e) {
3339 return CGF.EmitScalarExpr(e);
3340 }
3341
3342 /// For consumptions, just emit the subexpression and perform the
3343 /// consumption like normal.
3344 llvm::Value *visitConsumeObject(const Expr *e) {
3345 llvm::Value *value = CGF.EmitScalarExpr(e);
3346 return CGF.EmitObjCConsumeObject(e->getType(), value);
3347 }
3348
3349 /// No special logic for block extensions. (This probably can't
3350 /// actually happen in this emitter, though.)
3351 llvm::Value *visitExtendBlockObject(const Expr *e) {
3352 return CGF.EmitARCExtendBlockObject(e);
3353 }
3354
3355 /// For reclaims, perform an unsafeClaim if that's enabled.
3356 llvm::Value *visitReclaimReturnedObject(const Expr *e) {
3357 return CGF.EmitARCReclaimReturnedObject(e, /*unsafe*/ true);
3358 }
3359
3360 /// When we have an undecorated call, just emit it without adding
3361 /// the unsafeClaim.
3362 llvm::Value *visitCall(const Expr *e) {
3363 return CGF.EmitScalarExpr(e);
3364 }
3365
3366 /// Just do normal scalar emission in the default case.
3367 llvm::Value *visitExpr(const Expr *e) {
3368 return CGF.EmitScalarExpr(e);
3369 }
3370};
3371}
3372
3373static llvm::Value *emitARCUnsafeUnretainedScalarExpr(CodeGenFunction &CGF,
3374 const Expr *e) {
3375 return ARCUnsafeUnretainedExprEmitter(CGF).visit(e);
7
Calling 'ARCExprEmitter::visit'
3376}
3377
3378/// EmitARCUnsafeUnretainedScalarExpr - Semantically equivalent to
3379/// immediately releasing the resut of EmitARCRetainScalarExpr, but
3380/// avoiding any spurious retains, including by performing reclaims
3381/// with objc_unsafeClaimAutoreleasedReturnValue.
3382llvm::Value *CodeGenFunction::EmitARCUnsafeUnretainedScalarExpr(const Expr *e) {
3383 // Look through full-expressions.
3384 if (const ExprWithCleanups *cleanups
4.1
'cleanups' is null
= dyn_cast<ExprWithCleanups>(e)) {
4
Assuming 'e' is not a 'ExprWithCleanups'
5
Taking false branch
3385 enterFullExpression(cleanups);
3386 RunCleanupsScope scope(*this);
3387 return emitARCUnsafeUnretainedScalarExpr(*this, cleanups->getSubExpr());
3388 }
3389
3390 return emitARCUnsafeUnretainedScalarExpr(*this, e);
6
Calling 'emitARCUnsafeUnretainedScalarExpr'
3391}
3392
3393std::pair<LValue,llvm::Value*>
3394CodeGenFunction::EmitARCStoreUnsafeUnretained(const BinaryOperator *e,
3395 bool ignored) {
3396 // Evaluate the RHS first. If we're ignoring the result, assume
3397 // that we can emit at an unsafe +0.
3398 llvm::Value *value;
3399 if (ignored) {
1
Assuming 'ignored' is true
2
Taking true branch
3400 value = EmitARCUnsafeUnretainedScalarExpr(e->getRHS());
3
Calling 'CodeGenFunction::EmitARCUnsafeUnretainedScalarExpr'
3401 } else {
3402 value = EmitScalarExpr(e->getRHS());
3403 }
3404
3405 // Emit the LHS and perform the store.
3406 LValue lvalue = EmitLValue(e->getLHS());
3407 EmitStoreOfScalar(value, lvalue);
3408
3409 return std::pair<LValue,llvm::Value*>(std::move(lvalue), value);
3410}
3411
3412std::pair<LValue,llvm::Value*>
3413CodeGenFunction::EmitARCStoreStrong(const BinaryOperator *e,
3414 bool ignored) {
3415 // Evaluate the RHS first.
3416 TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e->getRHS());
3417 llvm::Value *value = result.getPointer();
3418
3419 bool hasImmediateRetain = result.getInt();
3420
3421 // If we didn't emit a retained object, and the l-value is of block
3422 // type, then we need to emit the block-retain immediately in case
3423 // it invalidates the l-value.
3424 if (!hasImmediateRetain && e->getType()->isBlockPointerType()) {
3425 value = EmitARCRetainBlock(value, /*mandatory*/ false);
3426 hasImmediateRetain = true;
3427 }
3428
3429 LValue lvalue = EmitLValue(e->getLHS());
3430
3431 // If the RHS was emitted retained, expand this.
3432 if (hasImmediateRetain) {
3433 llvm::Value *oldValue = EmitLoadOfScalar(lvalue, SourceLocation());
3434 EmitStoreOfScalar(value, lvalue);
3435 EmitARCRelease(oldValue, lvalue.isARCPreciseLifetime());
3436 } else {
3437 value = EmitARCStoreStrong(lvalue, value, ignored);
3438 }
3439
3440 return std::pair<LValue,llvm::Value*>(lvalue, value);
3441}
3442
3443std::pair<LValue,llvm::Value*>
3444CodeGenFunction::EmitARCStoreAutoreleasing(const BinaryOperator *e) {
3445 llvm::Value *value = EmitARCRetainAutoreleaseScalarExpr(e->getRHS());
3446 LValue lvalue = EmitLValue(e->getLHS());
3447
3448 EmitStoreOfScalar(value, lvalue);
3449
3450 return std::pair<LValue,llvm::Value*>(lvalue, value);
3451}
3452
3453void CodeGenFunction::EmitObjCAutoreleasePoolStmt(
3454 const ObjCAutoreleasePoolStmt &ARPS) {
3455 const Stmt *subStmt = ARPS.getSubStmt();
3456 const CompoundStmt &S = cast<CompoundStmt>(*subStmt);
3457
3458 CGDebugInfo *DI = getDebugInfo();
3459 if (DI)
3460 DI->EmitLexicalBlockStart(Builder, S.getLBracLoc());
3461
3462 // Keep track of the current cleanup stack depth.
3463 RunCleanupsScope Scope(*this);
3464 if (CGM.getLangOpts().ObjCRuntime.hasNativeARC()) {
3465 llvm::Value *token = EmitObjCAutoreleasePoolPush();
3466 EHStack.pushCleanup<CallObjCAutoreleasePoolObject>(NormalCleanup, token);
3467 } else {
3468 llvm::Value *token = EmitObjCMRRAutoreleasePoolPush();
3469 EHStack.pushCleanup<CallObjCMRRAutoreleasePoolObject>(NormalCleanup, token);
3470 }
3471
3472 for (const auto *I : S.body())
3473 EmitStmt(I);
3474
3475 if (DI)
3476 DI->EmitLexicalBlockEnd(Builder, S.getRBracLoc());
3477}
3478
3479/// EmitExtendGCLifetime - Given a pointer to an Objective-C object,
3480/// make sure it survives garbage collection until this point.
3481void CodeGenFunction::EmitExtendGCLifetime(llvm::Value *object) {
3482 // We just use an inline assembly.
3483 llvm::FunctionType *extenderType
3484 = llvm::FunctionType::get(VoidTy, VoidPtrTy, RequiredArgs::All);
3485 llvm::InlineAsm *extender = llvm::InlineAsm::get(extenderType,
3486 /* assembly */ "",
3487 /* constraints */ "r",
3488 /* side effects */ true);
3489
3490 object = Builder.CreateBitCast(object, VoidPtrTy);
3491 EmitNounwindRuntimeCall(extender, object);
3492}
3493
3494/// GenerateObjCAtomicSetterCopyHelperFunction - Given a c++ object type with
3495/// non-trivial copy assignment function, produce following helper function.
3496/// static void copyHelper(Ty *dest, const Ty *source) { *dest = *source; }
3497///
3498llvm::Constant *
3499CodeGenFunction::GenerateObjCAtomicSetterCopyHelperFunction(
3500 const ObjCPropertyImplDecl *PID) {
3501 if (!getLangOpts().CPlusPlus ||
3502 !getLangOpts().ObjCRuntime.hasAtomicCopyHelper())
3503 return nullptr;
3504 QualType Ty = PID->getPropertyIvarDecl()->getType();
3505 if (!Ty->isRecordType())
3506 return nullptr;
3507 const ObjCPropertyDecl *PD = PID->getPropertyDecl();
3508 if ((!(PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_atomic)))
3509 return nullptr;
3510 llvm::Constant *HelperFn = nullptr;
3511 if (hasTrivialSetExpr(PID))
3512 return nullptr;
3513 assert(PID->getSetterCXXAssignment() && "SetterCXXAssignment - null")((PID->getSetterCXXAssignment() && "SetterCXXAssignment - null"
) ? static_cast<void> (0) : __assert_fail ("PID->getSetterCXXAssignment() && \"SetterCXXAssignment - null\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 3513, __PRETTY_FUNCTION__))
;
3514 if ((HelperFn = CGM.getAtomicSetterHelperFnMap(Ty)))
3515 return HelperFn;
3516
3517 ASTContext &C = getContext();
3518 IdentifierInfo *II
3519 = &CGM.getContext().Idents.get("__assign_helper_atomic_property_");
3520
3521 QualType ReturnTy = C.VoidTy;
3522 QualType DestTy = C.getPointerType(Ty);
3523 QualType SrcTy = Ty;
3524 SrcTy.addConst();
3525 SrcTy = C.getPointerType(SrcTy);
3526
3527 SmallVector<QualType, 2> ArgTys;
3528 ArgTys.push_back(DestTy);
3529 ArgTys.push_back(SrcTy);
3530 QualType FunctionTy = C.getFunctionType(ReturnTy, ArgTys, {});
3531
3532 FunctionDecl *FD = FunctionDecl::Create(
3533 C, C.getTranslationUnitDecl(), SourceLocation(), SourceLocation(), II,
3534 FunctionTy, nullptr, SC_Static, false, false);
3535
3536 FunctionArgList args;
3537 ImplicitParamDecl DstDecl(C, FD, SourceLocation(), /*Id=*/nullptr, DestTy,
3538 ImplicitParamDecl::Other);
3539 args.push_back(&DstDecl);
3540 ImplicitParamDecl SrcDecl(C, FD, SourceLocation(), /*Id=*/nullptr, SrcTy,
3541 ImplicitParamDecl::Other);
3542 args.push_back(&SrcDecl);
3543
3544 const CGFunctionInfo &FI =
3545 CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
3546
3547 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
3548
3549 llvm::Function *Fn =
3550 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
3551 "__assign_helper_atomic_property_",
3552 &CGM.getModule());
3553
3554 CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, FI);
3555
3556 StartFunction(FD, ReturnTy, Fn, FI, args);
3557
3558 DeclRefExpr DstExpr(getContext(), &DstDecl, false, DestTy, VK_RValue,
3559 SourceLocation());
3560 UnaryOperator DST(&DstExpr, UO_Deref, DestTy->getPointeeType(),
3561 VK_LValue, OK_Ordinary, SourceLocation(), false);
3562
3563 DeclRefExpr SrcExpr(getContext(), &SrcDecl, false, SrcTy, VK_RValue,
3564 SourceLocation());
3565 UnaryOperator SRC(&SrcExpr, UO_Deref, SrcTy->getPointeeType(),
3566 VK_LValue, OK_Ordinary, SourceLocation(), false);
3567
3568 Expr *Args[2] = { &DST, &SRC };
3569 CallExpr *CalleeExp = cast<CallExpr>(PID->getSetterCXXAssignment());
3570 CXXOperatorCallExpr *TheCall = CXXOperatorCallExpr::Create(
3571 C, OO_Equal, CalleeExp->getCallee(), Args, DestTy->getPointeeType(),
3572 VK_LValue, SourceLocation(), FPOptions());
3573
3574 EmitStmt(TheCall);
3575
3576 FinishFunction();
3577 HelperFn = llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
3578 CGM.setAtomicSetterHelperFnMap(Ty, HelperFn);
3579 return HelperFn;
3580}
3581
3582llvm::Constant *
3583CodeGenFunction::GenerateObjCAtomicGetterCopyHelperFunction(
3584 const ObjCPropertyImplDecl *PID) {
3585 if (!getLangOpts().CPlusPlus ||
3586 !getLangOpts().ObjCRuntime.hasAtomicCopyHelper())
3587 return nullptr;
3588 const ObjCPropertyDecl *PD = PID->getPropertyDecl();
3589 QualType Ty = PD->getType();
3590 if (!Ty->isRecordType())
3591 return nullptr;
3592 if ((!(PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_atomic)))
3593 return nullptr;
3594 llvm::Constant *HelperFn = nullptr;
3595 if (hasTrivialGetExpr(PID))
3596 return nullptr;
3597 assert(PID->getGetterCXXConstructor() && "getGetterCXXConstructor - null")((PID->getGetterCXXConstructor() && "getGetterCXXConstructor - null"
) ? static_cast<void> (0) : __assert_fail ("PID->getGetterCXXConstructor() && \"getGetterCXXConstructor - null\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 3597, __PRETTY_FUNCTION__))
;
3598 if ((HelperFn = CGM.getAtomicGetterHelperFnMap(Ty)))
3599 return HelperFn;
3600
3601 ASTContext &C = getContext();
3602 IdentifierInfo *II =
3603 &CGM.getContext().Idents.get("__copy_helper_atomic_property_");
3604
3605 QualType ReturnTy = C.VoidTy;
3606 QualType DestTy = C.getPointerType(Ty);
3607 QualType SrcTy = Ty;
3608 SrcTy.addConst();
3609 SrcTy = C.getPointerType(SrcTy);
3610
3611 SmallVector<QualType, 2> ArgTys;
3612 ArgTys.push_back(DestTy);
3613 ArgTys.push_back(SrcTy);
3614 QualType FunctionTy = C.getFunctionType(ReturnTy, ArgTys, {});
3615
3616 FunctionDecl *FD = FunctionDecl::Create(
3617 C, C.getTranslationUnitDecl(), SourceLocation(), SourceLocation(), II,
3618 FunctionTy, nullptr, SC_Static, false, false);
3619
3620 FunctionArgList args;
3621 ImplicitParamDecl DstDecl(C, FD, SourceLocation(), /*Id=*/nullptr, DestTy,
3622 ImplicitParamDecl::Other);
3623 args.push_back(&DstDecl);
3624 ImplicitParamDecl SrcDecl(C, FD, SourceLocation(), /*Id=*/nullptr, SrcTy,
3625 ImplicitParamDecl::Other);
3626 args.push_back(&SrcDecl);
3627
3628 const CGFunctionInfo &FI =
3629 CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
3630
3631 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
3632
3633 llvm::Function *Fn = llvm::Function::Create(
3634 LTy, llvm::GlobalValue::InternalLinkage, "__copy_helper_atomic_property_",
3635 &CGM.getModule());
3636
3637 CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, FI);
3638
3639 StartFunction(FD, ReturnTy, Fn, FI, args);
3640
3641 DeclRefExpr SrcExpr(getContext(), &SrcDecl, false, SrcTy, VK_RValue,
3642 SourceLocation());
3643
3644 UnaryOperator SRC(&SrcExpr, UO_Deref, SrcTy->getPointeeType(),
3645 VK_LValue, OK_Ordinary, SourceLocation(), false);
3646
3647 CXXConstructExpr *CXXConstExpr =
3648 cast<CXXConstructExpr>(PID->getGetterCXXConstructor());
3649
3650 SmallVector<Expr*, 4> ConstructorArgs;
3651 ConstructorArgs.push_back(&SRC);
3652 ConstructorArgs.append(std::next(CXXConstExpr->arg_begin()),
3653 CXXConstExpr->arg_end());
3654
3655 CXXConstructExpr *TheCXXConstructExpr =
3656 CXXConstructExpr::Create(C, Ty, SourceLocation(),
3657 CXXConstExpr->getConstructor(),
3658 CXXConstExpr->isElidable(),
3659 ConstructorArgs,
3660 CXXConstExpr->hadMultipleCandidates(),
3661 CXXConstExpr->isListInitialization(),
3662 CXXConstExpr->isStdInitListInitialization(),
3663 CXXConstExpr->requiresZeroInitialization(),
3664 CXXConstExpr->getConstructionKind(),
3665 SourceRange());
3666
3667 DeclRefExpr DstExpr(getContext(), &DstDecl, false, DestTy, VK_RValue,
3668 SourceLocation());
3669
3670 RValue DV = EmitAnyExpr(&DstExpr);
3671 CharUnits Alignment
3672 = getContext().getTypeAlignInChars(TheCXXConstructExpr->getType());
3673 EmitAggExpr(TheCXXConstructExpr,
3674 AggValueSlot::forAddr(Address(DV.getScalarVal(), Alignment),
3675 Qualifiers(),
3676 AggValueSlot::IsDestructed,
3677 AggValueSlot::DoesNotNeedGCBarriers,
3678 AggValueSlot::IsNotAliased,
3679 AggValueSlot::DoesNotOverlap));
3680
3681 FinishFunction();
3682 HelperFn = llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
3683 CGM.setAtomicGetterHelperFnMap(Ty, HelperFn);
3684 return HelperFn;
3685}
3686
3687llvm::Value *
3688CodeGenFunction::EmitBlockCopyAndAutorelease(llvm::Value *Block, QualType Ty) {
3689 // Get selectors for retain/autorelease.
3690 IdentifierInfo *CopyID = &getContext().Idents.get("copy");
3691 Selector CopySelector =
3692 getContext().Selectors.getNullarySelector(CopyID);
3693 IdentifierInfo *AutoreleaseID = &getContext().Idents.get("autorelease");
3694 Selector AutoreleaseSelector =
3695 getContext().Selectors.getNullarySelector(AutoreleaseID);
3696
3697 // Emit calls to retain/autorelease.
3698 CGObjCRuntime &Runtime = CGM.getObjCRuntime();
3699 llvm::Value *Val = Block;
3700 RValue Result;
3701 Result = Runtime.GenerateMessageSend(*this, ReturnValueSlot(),
3702 Ty, CopySelector,
3703 Val, CallArgList(), nullptr, nullptr);
3704 Val = Result.getScalarVal();
3705 Result = Runtime.GenerateMessageSend(*this, ReturnValueSlot(),
3706 Ty, AutoreleaseSelector,
3707 Val, CallArgList(), nullptr, nullptr);
3708 Val = Result.getScalarVal();
3709 return Val;
3710}
3711
3712llvm::Value *
3713CodeGenFunction::EmitBuiltinAvailable(ArrayRef<llvm::Value *> Args) {
3714 assert(Args.size() == 3 && "Expected 3 argument here!")((Args.size() == 3 && "Expected 3 argument here!") ? static_cast
<void> (0) : __assert_fail ("Args.size() == 3 && \"Expected 3 argument here!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGObjC.cpp"
, 3714, __PRETTY_FUNCTION__))
;
3715
3716 if (!CGM.IsOSVersionAtLeastFn) {
3717 llvm::FunctionType *FTy =
3718 llvm::FunctionType::get(Int32Ty, {Int32Ty, Int32Ty, Int32Ty}, false);
3719 CGM.IsOSVersionAtLeastFn =
3720 CGM.CreateRuntimeFunction(FTy, "__isOSVersionAtLeast");
3721 }
3722
3723 llvm::Value *CallRes =
3724 EmitNounwindRuntimeCall(CGM.IsOSVersionAtLeastFn, Args);
3725
3726 return Builder.CreateICmpNE(CallRes, llvm::Constant::getNullValue(Int32Ty));
3727}
3728
3729void CodeGenModule::emitAtAvailableLinkGuard() {
3730 if (!IsOSVersionAtLeastFn)
3731 return;
3732 // @available requires CoreFoundation only on Darwin.
3733 if (!Target.getTriple().isOSDarwin())
3734 return;
3735 // Add -framework CoreFoundation to the linker commands. We still want to
3736 // emit the core foundation reference down below because otherwise if
3737 // CoreFoundation is not used in the code, the linker won't link the
3738 // framework.
3739 auto &Context = getLLVMContext();
3740 llvm::Metadata *Args[2] = {llvm::MDString::get(Context, "-framework"),
3741 llvm::MDString::get(Context, "CoreFoundation")};
3742 LinkerOptionsMetadata.push_back(llvm::MDNode::get(Context, Args));
3743 // Emit a reference to a symbol from CoreFoundation to ensure that
3744 // CoreFoundation is linked into the final binary.
3745 llvm::FunctionType *FTy =
3746 llvm::FunctionType::get(Int32Ty, {VoidPtrTy}, false);
3747 llvm::FunctionCallee CFFunc =
3748 CreateRuntimeFunction(FTy, "CFBundleGetVersionNumber");
3749
3750 llvm::FunctionType *CheckFTy = llvm::FunctionType::get(VoidTy, {}, false);
3751 llvm::FunctionCallee CFLinkCheckFuncRef = CreateRuntimeFunction(
3752 CheckFTy, "__clang_at_available_requires_core_foundation_framework",
3753 llvm::AttributeList(), /*Local=*/true);
3754 llvm::Function *CFLinkCheckFunc =
3755 cast<llvm::Function>(CFLinkCheckFuncRef.getCallee()->stripPointerCasts());
3756 if (CFLinkCheckFunc->empty()) {
3757 CFLinkCheckFunc->setLinkage(llvm::GlobalValue::LinkOnceAnyLinkage);
3758 CFLinkCheckFunc->setVisibility(llvm::GlobalValue::HiddenVisibility);
3759 CodeGenFunction CGF(*this);
3760 CGF.Builder.SetInsertPoint(CGF.createBasicBlock("", CFLinkCheckFunc));
3761 CGF.EmitNounwindRuntimeCall(CFFunc,
3762 llvm::Constant::getNullValue(VoidPtrTy));
3763 CGF.Builder.CreateUnreachable();
3764 addCompilerUsedGlobal(CFLinkCheckFunc);
3765 }
3766}
3767
3768CGObjCRuntime::~CGObjCRuntime() {}