Bug Summary

File:tools/clang/lib/CodeGen/CGObjC.cpp
Warning:line 2713, 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 -mrelocation-model pic -pic-level 2 -mthread-model posix -relaxed-aliasing -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-8/lib/clang/8.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/clang/lib/CodeGen -I /build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen -I /build/llvm-toolchain-snapshot-8~svn345461/tools/clang/include -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/include -I /build/llvm-toolchain-snapshot-8~svn345461/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/include/clang/8.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-8/lib/clang/8.0.0/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++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/clang/lib/CodeGen -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -fobjc-runtime=gcc -fno-common -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-10-27-211344-32123-1 -x c++ /build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp -faddrsig
1//===---- CGObjC.cpp - Emit LLVM Code for Objective-C ---------------------===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This contains code to emit Objective-C code as LLVM code.
11//
12//===----------------------------------------------------------------------===//
13
14#include "CGDebugInfo.h"
15#include "CGObjCRuntime.h"
16#include "CodeGenFunction.h"
17#include "CodeGenModule.h"
18#include "TargetInfo.h"
19#include "clang/AST/ASTContext.h"
20#include "clang/AST/DeclObjC.h"
21#include "clang/AST/StmtObjC.h"
22#include "clang/Basic/Diagnostic.h"
23#include "clang/CodeGen/CGFunctionInfo.h"
24#include "llvm/ADT/STLExtras.h"
25#include "llvm/IR/CallSite.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 assert(BoxingMethod && "BoxingMethod is null")((BoxingMethod && "BoxingMethod is null") ? static_cast
<void> (0) : __assert_fail ("BoxingMethod && \"BoxingMethod is null\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 65, __PRETTY_FUNCTION__))
;
66 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-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 66, __PRETTY_FUNCTION__))
;
67 Selector Sel = BoxingMethod->getSelector();
68
69 // Generate a reference to the class pointer, which will be the receiver.
70 // Assumes that the method was introduced in the class that should be
71 // messaged (avoids pulling it out of the result type).
72 CGObjCRuntime &Runtime = CGM.getObjCRuntime();
73 const ObjCInterfaceDecl *ClassDecl = BoxingMethod->getClassInterface();
74 llvm::Value *Receiver = Runtime.GetClass(*this, ClassDecl);
75
76 CallArgList Args;
77 const ParmVarDecl *ArgDecl = *BoxingMethod->param_begin();
78 QualType ArgQT = ArgDecl->getType().getUnqualifiedType();
79
80 // ObjCBoxedExpr supports boxing of structs and unions
81 // via [NSValue valueWithBytes:objCType:]
82 const QualType ValueType(SubExpr->getType().getCanonicalType());
83 if (ValueType->isObjCBoxableRecordType()) {
84 // Emit CodeGen for first parameter
85 // and cast value to correct type
86 Address Temporary = CreateMemTemp(SubExpr->getType());
87 EmitAnyExprToMem(SubExpr, Temporary, Qualifiers(), /*isInit*/ true);
88 Address BitCast = Builder.CreateBitCast(Temporary, ConvertType(ArgQT));
89 Args.add(RValue::get(BitCast.getPointer()), ArgQT);
90
91 // Create char array to store type encoding
92 std::string Str;
93 getContext().getObjCEncodingForType(ValueType, Str);
94 llvm::Constant *GV = CGM.GetAddrOfConstantCString(Str).getPointer();
95
96 // Cast type encoding to correct type
97 const ParmVarDecl *EncodingDecl = BoxingMethod->parameters()[1];
98 QualType EncodingQT = EncodingDecl->getType().getUnqualifiedType();
99 llvm::Value *Cast = Builder.CreateBitCast(GV, ConvertType(EncodingQT));
100
101 Args.add(RValue::get(Cast), EncodingQT);
102 } else {
103 Args.add(EmitAnyExpr(SubExpr), ArgQT);
104 }
105
106 RValue result = Runtime.GenerateMessageSend(
107 *this, ReturnValueSlot(), BoxingMethod->getReturnType(), Sel, Receiver,
108 Args, ClassDecl, BoxingMethod);
109 return Builder.CreateBitCast(result.getScalarVal(),
110 ConvertType(E->getType()));
111}
112
113llvm::Value *CodeGenFunction::EmitObjCCollectionLiteral(const Expr *E,
114 const ObjCMethodDecl *MethodWithObjects) {
115 ASTContext &Context = CGM.getContext();
116 const ObjCDictionaryLiteral *DLE = nullptr;
117 const ObjCArrayLiteral *ALE = dyn_cast<ObjCArrayLiteral>(E);
118 if (!ALE)
119 DLE = cast<ObjCDictionaryLiteral>(E);
120
121 // Optimize empty collections by referencing constants, when available.
122 uint64_t NumElements =
123 ALE ? ALE->getNumElements() : DLE->getNumElements();
124 if (NumElements == 0 && CGM.getLangOpts().ObjCRuntime.hasEmptyCollections()) {
125 StringRef ConstantName = ALE ? "__NSArray0__" : "__NSDictionary0__";
126 QualType IdTy(CGM.getContext().getObjCIdType());
127 llvm::Constant *Constant =
128 CGM.CreateRuntimeVariable(ConvertType(IdTy), ConstantName);
129 LValue LV = MakeNaturalAlignAddrLValue(Constant, IdTy);
130 llvm::Value *Ptr = EmitLoadOfScalar(LV, E->getBeginLoc());
131 cast<llvm::LoadInst>(Ptr)->setMetadata(
132 CGM.getModule().getMDKindID("invariant.load"),
133 llvm::MDNode::get(getLLVMContext(), None));
134 return Builder.CreateBitCast(Ptr, ConvertType(E->getType()));
135 }
136
137 // Compute the type of the array we're initializing.
138 llvm::APInt APNumElements(Context.getTypeSize(Context.getSizeType()),
139 NumElements);
140 QualType ElementType = Context.getObjCIdType().withConst();
141 QualType ElementArrayType
142 = Context.getConstantArrayType(ElementType, APNumElements,
143 ArrayType::Normal, /*IndexTypeQuals=*/0);
144
145 // Allocate the temporary array(s).
146 Address Objects = CreateMemTemp(ElementArrayType, "objects");
147 Address Keys = Address::invalid();
148 if (DLE)
149 Keys = CreateMemTemp(ElementArrayType, "keys");
150
151 // In ARC, we may need to do extra work to keep all the keys and
152 // values alive until after the call.
153 SmallVector<llvm::Value *, 16> NeededObjects;
154 bool TrackNeededObjects =
155 (getLangOpts().ObjCAutoRefCount &&
156 CGM.getCodeGenOpts().OptimizationLevel != 0);
157
158 // Perform the actual initialialization of the array(s).
159 for (uint64_t i = 0; i < NumElements; i++) {
160 if (ALE) {
161 // Emit the element and store it to the appropriate array slot.
162 const Expr *Rhs = ALE->getElement(i);
163 LValue LV = MakeAddrLValue(
164 Builder.CreateConstArrayGEP(Objects, i, getPointerSize()),
165 ElementType, AlignmentSource::Decl);
166
167 llvm::Value *value = EmitScalarExpr(Rhs);
168 EmitStoreThroughLValue(RValue::get(value), LV, true);
169 if (TrackNeededObjects) {
170 NeededObjects.push_back(value);
171 }
172 } else {
173 // Emit the key and store it to the appropriate array slot.
174 const Expr *Key = DLE->getKeyValueElement(i).Key;
175 LValue KeyLV = MakeAddrLValue(
176 Builder.CreateConstArrayGEP(Keys, i, getPointerSize()),
177 ElementType, AlignmentSource::Decl);
178 llvm::Value *keyValue = EmitScalarExpr(Key);
179 EmitStoreThroughLValue(RValue::get(keyValue), KeyLV, /*isInit=*/true);
180
181 // Emit the value and store it to the appropriate array slot.
182 const Expr *Value = DLE->getKeyValueElement(i).Value;
183 LValue ValueLV = MakeAddrLValue(
184 Builder.CreateConstArrayGEP(Objects, i, getPointerSize()),
185 ElementType, AlignmentSource::Decl);
186 llvm::Value *valueValue = EmitScalarExpr(Value);
187 EmitStoreThroughLValue(RValue::get(valueValue), ValueLV, /*isInit=*/true);
188 if (TrackNeededObjects) {
189 NeededObjects.push_back(keyValue);
190 NeededObjects.push_back(valueValue);
191 }
192 }
193 }
194
195 // Generate the argument list.
196 CallArgList Args;
197 ObjCMethodDecl::param_const_iterator PI = MethodWithObjects->param_begin();
198 const ParmVarDecl *argDecl = *PI++;
199 QualType ArgQT = argDecl->getType().getUnqualifiedType();
200 Args.add(RValue::get(Objects.getPointer()), ArgQT);
201 if (DLE) {
202 argDecl = *PI++;
203 ArgQT = argDecl->getType().getUnqualifiedType();
204 Args.add(RValue::get(Keys.getPointer()), ArgQT);
205 }
206 argDecl = *PI;
207 ArgQT = argDecl->getType().getUnqualifiedType();
208 llvm::Value *Count =
209 llvm::ConstantInt::get(CGM.getTypes().ConvertType(ArgQT), NumElements);
210 Args.add(RValue::get(Count), ArgQT);
211
212 // Generate a reference to the class pointer, which will be the receiver.
213 Selector Sel = MethodWithObjects->getSelector();
214 QualType ResultType = E->getType();
215 const ObjCObjectPointerType *InterfacePointerType
216 = ResultType->getAsObjCInterfacePointerType();
217 ObjCInterfaceDecl *Class
218 = InterfacePointerType->getObjectType()->getInterface();
219 CGObjCRuntime &Runtime = CGM.getObjCRuntime();
220 llvm::Value *Receiver = Runtime.GetClass(*this, Class);
221
222 // Generate the message send.
223 RValue result = Runtime.GenerateMessageSend(
224 *this, ReturnValueSlot(), MethodWithObjects->getReturnType(), Sel,
225 Receiver, Args, Class, MethodWithObjects);
226
227 // The above message send needs these objects, but in ARC they are
228 // passed in a buffer that is essentially __unsafe_unretained.
229 // Therefore we must prevent the optimizer from releasing them until
230 // after the call.
231 if (TrackNeededObjects) {
232 EmitARCIntrinsicUse(NeededObjects);
233 }
234
235 return Builder.CreateBitCast(result.getScalarVal(),
236 ConvertType(E->getType()));
237}
238
239llvm::Value *CodeGenFunction::EmitObjCArrayLiteral(const ObjCArrayLiteral *E) {
240 return EmitObjCCollectionLiteral(E, E->getArrayWithObjectsMethod());
241}
242
243llvm::Value *CodeGenFunction::EmitObjCDictionaryLiteral(
244 const ObjCDictionaryLiteral *E) {
245 return EmitObjCCollectionLiteral(E, E->getDictWithObjectsMethod());
246}
247
248/// Emit a selector.
249llvm::Value *CodeGenFunction::EmitObjCSelectorExpr(const ObjCSelectorExpr *E) {
250 // Untyped selector.
251 // Note that this implementation allows for non-constant strings to be passed
252 // as arguments to @selector(). Currently, the only thing preventing this
253 // behaviour is the type checking in the front end.
254 return CGM.getObjCRuntime().GetSelector(*this, E->getSelector());
255}
256
257llvm::Value *CodeGenFunction::EmitObjCProtocolExpr(const ObjCProtocolExpr *E) {
258 // FIXME: This should pass the Decl not the name.
259 return CGM.getObjCRuntime().GenerateProtocolRef(*this, E->getProtocol());
260}
261
262/// Adjust the type of an Objective-C object that doesn't match up due
263/// to type erasure at various points, e.g., related result types or the use
264/// of parameterized classes.
265static RValue AdjustObjCObjectType(CodeGenFunction &CGF, QualType ExpT,
266 RValue Result) {
267 if (!ExpT->isObjCRetainableType())
268 return Result;
269
270 // If the converted types are the same, we're done.
271 llvm::Type *ExpLLVMTy = CGF.ConvertType(ExpT);
272 if (ExpLLVMTy == Result.getScalarVal()->getType())
273 return Result;
274
275 // We have applied a substitution. Cast the rvalue appropriately.
276 return RValue::get(CGF.Builder.CreateBitCast(Result.getScalarVal(),
277 ExpLLVMTy));
278}
279
280/// Decide whether to extend the lifetime of the receiver of a
281/// returns-inner-pointer message.
282static bool
283shouldExtendReceiverForInnerPointerMessage(const ObjCMessageExpr *message) {
284 switch (message->getReceiverKind()) {
285
286 // For a normal instance message, we should extend unless the
287 // receiver is loaded from a variable with precise lifetime.
288 case ObjCMessageExpr::Instance: {
289 const Expr *receiver = message->getInstanceReceiver();
290
291 // Look through OVEs.
292 if (auto opaque = dyn_cast<OpaqueValueExpr>(receiver)) {
293 if (opaque->getSourceExpr())
294 receiver = opaque->getSourceExpr()->IgnoreParens();
295 }
296
297 const ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(receiver);
298 if (!ice || ice->getCastKind() != CK_LValueToRValue) return true;
299 receiver = ice->getSubExpr()->IgnoreParens();
300
301 // Look through OVEs.
302 if (auto opaque = dyn_cast<OpaqueValueExpr>(receiver)) {
303 if (opaque->getSourceExpr())
304 receiver = opaque->getSourceExpr()->IgnoreParens();
305 }
306
307 // Only __strong variables.
308 if (receiver->getType().getObjCLifetime() != Qualifiers::OCL_Strong)
309 return true;
310
311 // All ivars and fields have precise lifetime.
312 if (isa<MemberExpr>(receiver) || isa<ObjCIvarRefExpr>(receiver))
313 return false;
314
315 // Otherwise, check for variables.
316 const DeclRefExpr *declRef = dyn_cast<DeclRefExpr>(ice->getSubExpr());
317 if (!declRef) return true;
318 const VarDecl *var = dyn_cast<VarDecl>(declRef->getDecl());
319 if (!var) return true;
320
321 // All variables have precise lifetime except local variables with
322 // automatic storage duration that aren't specially marked.
323 return (var->hasLocalStorage() &&
324 !var->hasAttr<ObjCPreciseLifetimeAttr>());
325 }
326
327 case ObjCMessageExpr::Class:
328 case ObjCMessageExpr::SuperClass:
329 // It's never necessary for class objects.
330 return false;
331
332 case ObjCMessageExpr::SuperInstance:
333 // We generally assume that 'self' lives throughout a method call.
334 return false;
335 }
336
337 llvm_unreachable("invalid receiver kind")::llvm::llvm_unreachable_internal("invalid receiver kind", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 337)
;
338}
339
340/// Given an expression of ObjC pointer type, check whether it was
341/// immediately loaded from an ARC __weak l-value.
342static const Expr *findWeakLValue(const Expr *E) {
343 assert(E->getType()->isObjCRetainableType())((E->getType()->isObjCRetainableType()) ? static_cast<
void> (0) : __assert_fail ("E->getType()->isObjCRetainableType()"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 343, __PRETTY_FUNCTION__))
;
344 E = E->IgnoreParens();
345 if (auto CE = dyn_cast<CastExpr>(E)) {
346 if (CE->getCastKind() == CK_LValueToRValue) {
347 if (CE->getSubExpr()->getType().getObjCLifetime() == Qualifiers::OCL_Weak)
348 return CE->getSubExpr();
349 }
350 }
351
352 return nullptr;
353}
354
355RValue CodeGenFunction::EmitObjCMessageExpr(const ObjCMessageExpr *E,
356 ReturnValueSlot Return) {
357 // Only the lookup mechanism and first two arguments of the method
358 // implementation vary between runtimes. We can get the receiver and
359 // arguments in generic code.
360
361 bool isDelegateInit = E->isDelegateInitCall();
362
363 const ObjCMethodDecl *method = E->getMethodDecl();
364
365 // If the method is -retain, and the receiver's being loaded from
366 // a __weak variable, peephole the entire operation to objc_loadWeakRetained.
367 if (method && E->getReceiverKind() == ObjCMessageExpr::Instance &&
368 method->getMethodFamily() == OMF_retain) {
369 if (auto lvalueExpr = findWeakLValue(E->getInstanceReceiver())) {
370 LValue lvalue = EmitLValue(lvalueExpr);
371 llvm::Value *result = EmitARCLoadWeakRetained(lvalue.getAddress());
372 return AdjustObjCObjectType(*this, E->getType(), RValue::get(result));
373 }
374 }
375
376 // We don't retain the receiver in delegate init calls, and this is
377 // safe because the receiver value is always loaded from 'self',
378 // which we zero out. We don't want to Block_copy block receivers,
379 // though.
380 bool retainSelf =
381 (!isDelegateInit &&
382 CGM.getLangOpts().ObjCAutoRefCount &&
383 method &&
384 method->hasAttr<NSConsumesSelfAttr>());
385
386 CGObjCRuntime &Runtime = CGM.getObjCRuntime();
387 bool isSuperMessage = false;
388 bool isClassMessage = false;
389 ObjCInterfaceDecl *OID = nullptr;
390 // Find the receiver
391 QualType ReceiverType;
392 llvm::Value *Receiver = nullptr;
393 switch (E->getReceiverKind()) {
394 case ObjCMessageExpr::Instance:
395 ReceiverType = E->getInstanceReceiver()->getType();
396 if (retainSelf) {
397 TryEmitResult ter = tryEmitARCRetainScalarExpr(*this,
398 E->getInstanceReceiver());
399 Receiver = ter.getPointer();
400 if (ter.getInt()) retainSelf = false;
401 } else
402 Receiver = EmitScalarExpr(E->getInstanceReceiver());
403 break;
404
405 case ObjCMessageExpr::Class: {
406 ReceiverType = E->getClassReceiver();
407 const ObjCObjectType *ObjTy = ReceiverType->getAs<ObjCObjectType>();
408 assert(ObjTy && "Invalid Objective-C class message send")((ObjTy && "Invalid Objective-C class message send") ?
static_cast<void> (0) : __assert_fail ("ObjTy && \"Invalid Objective-C class message send\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 408, __PRETTY_FUNCTION__))
;
409 OID = ObjTy->getInterface();
410 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-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 410, __PRETTY_FUNCTION__))
;
411 Receiver = Runtime.GetClass(*this, OID);
412 isClassMessage = true;
413 break;
414 }
415
416 case ObjCMessageExpr::SuperInstance:
417 ReceiverType = E->getSuperType();
418 Receiver = LoadObjCSelf();
419 isSuperMessage = true;
420 break;
421
422 case ObjCMessageExpr::SuperClass:
423 ReceiverType = E->getSuperType();
424 Receiver = LoadObjCSelf();
425 isSuperMessage = true;
426 isClassMessage = true;
427 break;
428 }
429
430 if (retainSelf)
431 Receiver = EmitARCRetainNonBlock(Receiver);
432
433 // In ARC, we sometimes want to "extend the lifetime"
434 // (i.e. retain+autorelease) of receivers of returns-inner-pointer
435 // messages.
436 if (getLangOpts().ObjCAutoRefCount && method &&
437 method->hasAttr<ObjCReturnsInnerPointerAttr>() &&
438 shouldExtendReceiverForInnerPointerMessage(E))
439 Receiver = EmitARCRetainAutorelease(ReceiverType, Receiver);
440
441 QualType ResultType = method ? method->getReturnType() : E->getType();
442
443 CallArgList Args;
444 EmitCallArgs(Args, method, E->arguments(), /*AC*/AbstractCallee(method));
445
446 // For delegate init calls in ARC, do an unsafe store of null into
447 // self. This represents the call taking direct ownership of that
448 // value. We have to do this after emitting the other call
449 // arguments because they might also reference self, but we don't
450 // have to worry about any of them modifying self because that would
451 // be an undefined read and write of an object in unordered
452 // expressions.
453 if (isDelegateInit) {
454 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-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 455, __PRETTY_FUNCTION__))
455 "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-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 455, __PRETTY_FUNCTION__))
;
456
457 // Do an unsafe store of null into self.
458 Address selfAddr =
459 GetAddrOfLocalVar(cast<ObjCMethodDecl>(CurCodeDecl)->getSelfDecl());
460 Builder.CreateStore(getNullForVariable(selfAddr), selfAddr);
461 }
462
463 RValue result;
464 if (isSuperMessage) {
465 // super is only valid in an Objective-C method
466 const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
467 bool isCategoryImpl = isa<ObjCCategoryImplDecl>(OMD->getDeclContext());
468 result = Runtime.GenerateMessageSendSuper(*this, Return, ResultType,
469 E->getSelector(),
470 OMD->getClassInterface(),
471 isCategoryImpl,
472 Receiver,
473 isClassMessage,
474 Args,
475 method);
476 } else {
477 result = Runtime.GenerateMessageSend(*this, Return, ResultType,
478 E->getSelector(),
479 Receiver, Args, OID,
480 method);
481 }
482
483 // For delegate init calls in ARC, implicitly store the result of
484 // the call back into self. This takes ownership of the value.
485 if (isDelegateInit) {
486 Address selfAddr =
487 GetAddrOfLocalVar(cast<ObjCMethodDecl>(CurCodeDecl)->getSelfDecl());
488 llvm::Value *newSelf = result.getScalarVal();
489
490 // The delegate return type isn't necessarily a matching type; in
491 // fact, it's quite likely to be 'id'.
492 llvm::Type *selfTy = selfAddr.getElementType();
493 newSelf = Builder.CreateBitCast(newSelf, selfTy);
494
495 Builder.CreateStore(newSelf, selfAddr);
496 }
497
498 return AdjustObjCObjectType(*this, E->getType(), result);
499}
500
501namespace {
502struct FinishARCDealloc final : EHScopeStack::Cleanup {
503 void Emit(CodeGenFunction &CGF, Flags flags) override {
504 const ObjCMethodDecl *method = cast<ObjCMethodDecl>(CGF.CurCodeDecl);
505
506 const ObjCImplDecl *impl = cast<ObjCImplDecl>(method->getDeclContext());
507 const ObjCInterfaceDecl *iface = impl->getClassInterface();
508 if (!iface->getSuperClass()) return;
509
510 bool isCategory = isa<ObjCCategoryImplDecl>(impl);
511
512 // Call [super dealloc] if we have a superclass.
513 llvm::Value *self = CGF.LoadObjCSelf();
514
515 CallArgList args;
516 CGF.CGM.getObjCRuntime().GenerateMessageSendSuper(CGF, ReturnValueSlot(),
517 CGF.getContext().VoidTy,
518 method->getSelector(),
519 iface,
520 isCategory,
521 self,
522 /*is class msg*/ false,
523 args,
524 method);
525 }
526};
527}
528
529/// StartObjCMethod - Begin emission of an ObjCMethod. This generates
530/// the LLVM function and sets the other context used by
531/// CodeGenFunction.
532void CodeGenFunction::StartObjCMethod(const ObjCMethodDecl *OMD,
533 const ObjCContainerDecl *CD) {
534 SourceLocation StartLoc = OMD->getBeginLoc();
535 FunctionArgList args;
536 // Check if we should generate debug info for this method.
537 if (OMD->hasAttr<NoDebugAttr>())
538 DebugInfo = nullptr; // disable debug info indefinitely for this function
539
540 llvm::Function *Fn = CGM.getObjCRuntime().GenerateMethod(OMD, CD);
541
542 const CGFunctionInfo &FI = CGM.getTypes().arrangeObjCMethodDeclaration(OMD);
543 CGM.SetInternalFunctionAttributes(OMD, Fn, FI);
544
545 args.push_back(OMD->getSelfDecl());
546 args.push_back(OMD->getCmdDecl());
547
548 args.append(OMD->param_begin(), OMD->param_end());
549
550 CurGD = OMD;
551 CurEHLocation = OMD->getEndLoc();
552
553 StartFunction(OMD, OMD->getReturnType(), Fn, FI, args,
554 OMD->getLocation(), StartLoc);
555
556 // In ARC, certain methods get an extra cleanup.
557 if (CGM.getLangOpts().ObjCAutoRefCount &&
558 OMD->isInstanceMethod() &&
559 OMD->getSelector().isUnarySelector()) {
560 const IdentifierInfo *ident =
561 OMD->getSelector().getIdentifierInfoForSlot(0);
562 if (ident->isStr("dealloc"))
563 EHStack.pushCleanup<FinishARCDealloc>(getARCCleanupKind());
564 }
565}
566
567static llvm::Value *emitARCRetainLoadOfScalar(CodeGenFunction &CGF,
568 LValue lvalue, QualType type);
569
570/// Generate an Objective-C method. An Objective-C method is a C function with
571/// its pointer, name, and types registered in the class struture.
572void CodeGenFunction::GenerateObjCMethod(const ObjCMethodDecl *OMD) {
573 StartObjCMethod(OMD, OMD->getClassInterface());
574 PGO.assignRegionCounters(GlobalDecl(OMD), CurFn);
575 assert(isa<CompoundStmt>(OMD->getBody()))((isa<CompoundStmt>(OMD->getBody())) ? static_cast<
void> (0) : __assert_fail ("isa<CompoundStmt>(OMD->getBody())"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 575, __PRETTY_FUNCTION__))
;
576 incrementProfileCounter(OMD->getBody());
577 EmitCompoundStmtWithoutScope(*cast<CompoundStmt>(OMD->getBody()));
578 FinishFunction(OMD->getBodyRBrace());
579}
580
581/// emitStructGetterCall - Call the runtime function to load a property
582/// into the return value slot.
583static void emitStructGetterCall(CodeGenFunction &CGF, ObjCIvarDecl *ivar,
584 bool isAtomic, bool hasStrong) {
585 ASTContext &Context = CGF.getContext();
586
587 Address src =
588 CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), CGF.LoadObjCSelf(), ivar, 0)
589 .getAddress();
590
591 // objc_copyStruct (ReturnValue, &structIvar,
592 // sizeof (Type of Ivar), isAtomic, false);
593 CallArgList args;
594
595 Address dest = CGF.Builder.CreateBitCast(CGF.ReturnValue, CGF.VoidPtrTy);
596 args.add(RValue::get(dest.getPointer()), Context.VoidPtrTy);
597
598 src = CGF.Builder.CreateBitCast(src, CGF.VoidPtrTy);
599 args.add(RValue::get(src.getPointer()), Context.VoidPtrTy);
600
601 CharUnits size = CGF.getContext().getTypeSizeInChars(ivar->getType());
602 args.add(RValue::get(CGF.CGM.getSize(size)), Context.getSizeType());
603 args.add(RValue::get(CGF.Builder.getInt1(isAtomic)), Context.BoolTy);
604 args.add(RValue::get(CGF.Builder.getInt1(hasStrong)), Context.BoolTy);
605
606 llvm::Constant *fn = CGF.CGM.getObjCRuntime().GetGetStructFunction();
607 CGCallee callee = CGCallee::forDirect(fn);
608 CGF.EmitCall(CGF.getTypes().arrangeBuiltinFunctionCall(Context.VoidTy, args),
609 callee, ReturnValueSlot(), args);
610}
611
612/// Determine whether the given architecture supports unaligned atomic
613/// accesses. They don't have to be fast, just faster than a function
614/// call and a mutex.
615static bool hasUnalignedAtomics(llvm::Triple::ArchType arch) {
616 // FIXME: Allow unaligned atomic load/store on x86. (It is not
617 // currently supported by the backend.)
618 return 0;
619}
620
621/// Return the maximum size that permits atomic accesses for the given
622/// architecture.
623static CharUnits getMaxAtomicAccessSize(CodeGenModule &CGM,
624 llvm::Triple::ArchType arch) {
625 // ARM has 8-byte atomic accesses, but it's not clear whether we
626 // want to rely on them here.
627
628 // In the default case, just assume that any size up to a pointer is
629 // fine given adequate alignment.
630 return CharUnits::fromQuantity(CGM.PointerSizeInBytes);
631}
632
633namespace {
634 class PropertyImplStrategy {
635 public:
636 enum StrategyKind {
637 /// The 'native' strategy is to use the architecture's provided
638 /// reads and writes.
639 Native,
640
641 /// Use objc_setProperty and objc_getProperty.
642 GetSetProperty,
643
644 /// Use objc_setProperty for the setter, but use expression
645 /// evaluation for the getter.
646 SetPropertyAndExpressionGet,
647
648 /// Use objc_copyStruct.
649 CopyStruct,
650
651 /// The 'expression' strategy is to emit normal assignment or
652 /// lvalue-to-rvalue expressions.
653 Expression
654 };
655
656 StrategyKind getKind() const { return StrategyKind(Kind); }
657
658 bool hasStrongMember() const { return HasStrong; }
659 bool isAtomic() const { return IsAtomic; }
660 bool isCopy() const { return IsCopy; }
661
662 CharUnits getIvarSize() const { return IvarSize; }
663 CharUnits getIvarAlignment() const { return IvarAlignment; }
664
665 PropertyImplStrategy(CodeGenModule &CGM,
666 const ObjCPropertyImplDecl *propImpl);
667
668 private:
669 unsigned Kind : 8;
670 unsigned IsAtomic : 1;
671 unsigned IsCopy : 1;
672 unsigned HasStrong : 1;
673
674 CharUnits IvarSize;
675 CharUnits IvarAlignment;
676 };
677}
678
679/// Pick an implementation strategy for the given property synthesis.
680PropertyImplStrategy::PropertyImplStrategy(CodeGenModule &CGM,
681 const ObjCPropertyImplDecl *propImpl) {
682 const ObjCPropertyDecl *prop = propImpl->getPropertyDecl();
683 ObjCPropertyDecl::SetterKind setterKind = prop->getSetterKind();
684
685 IsCopy = (setterKind == ObjCPropertyDecl::Copy);
686 IsAtomic = prop->isAtomic();
687 HasStrong = false; // doesn't matter here.
688
689 // Evaluate the ivar's size and alignment.
690 ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
691 QualType ivarType = ivar->getType();
692 std::tie(IvarSize, IvarAlignment) =
693 CGM.getContext().getTypeInfoInChars(ivarType);
694
695 // If we have a copy property, we always have to use getProperty/setProperty.
696 // TODO: we could actually use setProperty and an expression for non-atomics.
697 if (IsCopy) {
698 Kind = GetSetProperty;
699 return;
700 }
701
702 // Handle retain.
703 if (setterKind == ObjCPropertyDecl::Retain) {
704 // In GC-only, there's nothing special that needs to be done.
705 if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) {
706 // fallthrough
707
708 // In ARC, if the property is non-atomic, use expression emission,
709 // which translates to objc_storeStrong. This isn't required, but
710 // it's slightly nicer.
711 } else if (CGM.getLangOpts().ObjCAutoRefCount && !IsAtomic) {
712 // Using standard expression emission for the setter is only
713 // acceptable if the ivar is __strong, which won't be true if
714 // the property is annotated with __attribute__((NSObject)).
715 // TODO: falling all the way back to objc_setProperty here is
716 // just laziness, though; we could still use objc_storeStrong
717 // if we hacked it right.
718 if (ivarType.getObjCLifetime() == Qualifiers::OCL_Strong)
719 Kind = Expression;
720 else
721 Kind = SetPropertyAndExpressionGet;
722 return;
723
724 // Otherwise, we need to at least use setProperty. However, if
725 // the property isn't atomic, we can use normal expression
726 // emission for the getter.
727 } else if (!IsAtomic) {
728 Kind = SetPropertyAndExpressionGet;
729 return;
730
731 // Otherwise, we have to use both setProperty and getProperty.
732 } else {
733 Kind = GetSetProperty;
734 return;
735 }
736 }
737
738 // If we're not atomic, just use expression accesses.
739 if (!IsAtomic) {
740 Kind = Expression;
741 return;
742 }
743
744 // Properties on bitfield ivars need to be emitted using expression
745 // accesses even if they're nominally atomic.
746 if (ivar->isBitField()) {
747 Kind = Expression;
748 return;
749 }
750
751 // GC-qualified or ARC-qualified ivars need to be emitted as
752 // expressions. This actually works out to being atomic anyway,
753 // except for ARC __strong, but that should trigger the above code.
754 if (ivarType.hasNonTrivialObjCLifetime() ||
755 (CGM.getLangOpts().getGC() &&
756 CGM.getContext().getObjCGCAttrKind(ivarType))) {
757 Kind = Expression;
758 return;
759 }
760
761 // Compute whether the ivar has strong members.
762 if (CGM.getLangOpts().getGC())
763 if (const RecordType *recordType = ivarType->getAs<RecordType>())
764 HasStrong = recordType->getDecl()->hasObjectMember();
765
766 // We can never access structs with object members with a native
767 // access, because we need to use write barriers. This is what
768 // objc_copyStruct is for.
769 if (HasStrong) {
770 Kind = CopyStruct;
771 return;
772 }
773
774 // Otherwise, this is target-dependent and based on the size and
775 // alignment of the ivar.
776
777 // If the size of the ivar is not a power of two, give up. We don't
778 // want to get into the business of doing compare-and-swaps.
779 if (!IvarSize.isPowerOfTwo()) {
780 Kind = CopyStruct;
781 return;
782 }
783
784 llvm::Triple::ArchType arch =
785 CGM.getTarget().getTriple().getArch();
786
787 // Most architectures require memory to fit within a single cache
788 // line, so the alignment has to be at least the size of the access.
789 // Otherwise we have to grab a lock.
790 if (IvarAlignment < IvarSize && !hasUnalignedAtomics(arch)) {
791 Kind = CopyStruct;
792 return;
793 }
794
795 // If the ivar's size exceeds the architecture's maximum atomic
796 // access size, we have to use CopyStruct.
797 if (IvarSize > getMaxAtomicAccessSize(CGM, arch)) {
798 Kind = CopyStruct;
799 return;
800 }
801
802 // Otherwise, we can use native loads and stores.
803 Kind = Native;
804}
805
806/// Generate an Objective-C property getter function.
807///
808/// The given Decl must be an ObjCImplementationDecl. \@synthesize
809/// is illegal within a category.
810void CodeGenFunction::GenerateObjCGetter(ObjCImplementationDecl *IMP,
811 const ObjCPropertyImplDecl *PID) {
812 llvm::Constant *AtomicHelperFn =
813 CodeGenFunction(CGM).GenerateObjCAtomicGetterCopyHelperFunction(PID);
814 const ObjCPropertyDecl *PD = PID->getPropertyDecl();
815 ObjCMethodDecl *OMD = PD->getGetterMethodDecl();
816 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-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 816, __PRETTY_FUNCTION__))
;
817 StartObjCMethod(OMD, IMP->getClassInterface());
818
819 generateObjCGetterBody(IMP, PID, OMD, AtomicHelperFn);
820
821 FinishFunction();
822}
823
824static bool hasTrivialGetExpr(const ObjCPropertyImplDecl *propImpl) {
825 const Expr *getter = propImpl->getGetterCXXConstructor();
826 if (!getter) return true;
827
828 // Sema only makes only of these when the ivar has a C++ class type,
829 // so the form is pretty constrained.
830
831 // If the property has a reference type, we might just be binding a
832 // reference, in which case the result will be a gl-value. We should
833 // treat this as a non-trivial operation.
834 if (getter->isGLValue())
835 return false;
836
837 // If we selected a trivial copy-constructor, we're okay.
838 if (const CXXConstructExpr *construct = dyn_cast<CXXConstructExpr>(getter))
839 return (construct->getConstructor()->isTrivial());
840
841 // The constructor might require cleanups (in which case it's never
842 // trivial).
843 assert(isa<ExprWithCleanups>(getter))((isa<ExprWithCleanups>(getter)) ? static_cast<void>
(0) : __assert_fail ("isa<ExprWithCleanups>(getter)", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 843, __PRETTY_FUNCTION__))
;
844 return false;
845}
846
847/// emitCPPObjectAtomicGetterCall - Call the runtime function to
848/// copy the ivar into the resturn slot.
849static void emitCPPObjectAtomicGetterCall(CodeGenFunction &CGF,
850 llvm::Value *returnAddr,
851 ObjCIvarDecl *ivar,
852 llvm::Constant *AtomicHelperFn) {
853 // objc_copyCppObjectAtomic (&returnSlot, &CppObjectIvar,
854 // AtomicHelperFn);
855 CallArgList args;
856
857 // The 1st argument is the return Slot.
858 args.add(RValue::get(returnAddr), CGF.getContext().VoidPtrTy);
859
860 // The 2nd argument is the address of the ivar.
861 llvm::Value *ivarAddr =
862 CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(),
863 CGF.LoadObjCSelf(), ivar, 0).getPointer();
864 ivarAddr = CGF.Builder.CreateBitCast(ivarAddr, CGF.Int8PtrTy);
865 args.add(RValue::get(ivarAddr), CGF.getContext().VoidPtrTy);
866
867 // Third argument is the helper function.
868 args.add(RValue::get(AtomicHelperFn), CGF.getContext().VoidPtrTy);
869
870 llvm::Constant *copyCppAtomicObjectFn =
871 CGF.CGM.getObjCRuntime().GetCppAtomicObjectGetFunction();
872 CGCallee callee = CGCallee::forDirect(copyCppAtomicObjectFn);
873 CGF.EmitCall(
874 CGF.getTypes().arrangeBuiltinFunctionCall(CGF.getContext().VoidTy, args),
875 callee, ReturnValueSlot(), args);
876}
877
878void
879CodeGenFunction::generateObjCGetterBody(const ObjCImplementationDecl *classImpl,
880 const ObjCPropertyImplDecl *propImpl,
881 const ObjCMethodDecl *GetterMethodDecl,
882 llvm::Constant *AtomicHelperFn) {
883 // If there's a non-trivial 'get' expression, we just have to emit that.
884 if (!hasTrivialGetExpr(propImpl)) {
885 if (!AtomicHelperFn) {
886 ReturnStmt ret(SourceLocation(), propImpl->getGetterCXXConstructor(),
887 /*nrvo*/ nullptr);
888 EmitReturnStmt(ret);
889 }
890 else {
891 ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
892 emitCPPObjectAtomicGetterCall(*this, ReturnValue.getPointer(),
893 ivar, AtomicHelperFn);
894 }
895 return;
896 }
897
898 const ObjCPropertyDecl *prop = propImpl->getPropertyDecl();
899 QualType propType = prop->getType();
900 ObjCMethodDecl *getterMethod = prop->getGetterMethodDecl();
901
902 ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
903
904 // Pick an implementation strategy.
905 PropertyImplStrategy strategy(CGM, propImpl);
906 switch (strategy.getKind()) {
907 case PropertyImplStrategy::Native: {
908 // We don't need to do anything for a zero-size struct.
909 if (strategy.getIvarSize().isZero())
910 return;
911
912 LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, 0);
913
914 // Currently, all atomic accesses have to be through integer
915 // types, so there's no point in trying to pick a prettier type.
916 uint64_t ivarSize = getContext().toBits(strategy.getIvarSize());
917 llvm::Type *bitcastType = llvm::Type::getIntNTy(getLLVMContext(), ivarSize);
918 bitcastType = bitcastType->getPointerTo(); // addrspace 0 okay
919
920 // Perform an atomic load. This does not impose ordering constraints.
921 Address ivarAddr = LV.getAddress();
922 ivarAddr = Builder.CreateBitCast(ivarAddr, bitcastType);
923 llvm::LoadInst *load = Builder.CreateLoad(ivarAddr, "load");
924 load->setAtomic(llvm::AtomicOrdering::Unordered);
925
926 // Store that value into the return address. Doing this with a
927 // bitcast is likely to produce some pretty ugly IR, but it's not
928 // the *most* terrible thing in the world.
929 llvm::Type *retTy = ConvertType(getterMethod->getReturnType());
930 uint64_t retTySize = CGM.getDataLayout().getTypeSizeInBits(retTy);
931 llvm::Value *ivarVal = load;
932 if (ivarSize > retTySize) {
933 llvm::Type *newTy = llvm::Type::getIntNTy(getLLVMContext(), retTySize);
934 ivarVal = Builder.CreateTrunc(load, newTy);
935 bitcastType = newTy->getPointerTo();
936 }
937 Builder.CreateStore(ivarVal,
938 Builder.CreateBitCast(ReturnValue, bitcastType));
939
940 // Make sure we don't do an autorelease.
941 AutoreleaseResult = false;
942 return;
943 }
944
945 case PropertyImplStrategy::GetSetProperty: {
946 llvm::Constant *getPropertyFn =
947 CGM.getObjCRuntime().GetPropertyGetFunction();
948 if (!getPropertyFn) {
949 CGM.ErrorUnsupported(propImpl, "Obj-C getter requiring atomic copy");
950 return;
951 }
952 CGCallee callee = CGCallee::forDirect(getPropertyFn);
953
954 // Return (ivar-type) objc_getProperty((id) self, _cmd, offset, true).
955 // FIXME: Can't this be simpler? This might even be worse than the
956 // corresponding gcc code.
957 llvm::Value *cmd =
958 Builder.CreateLoad(GetAddrOfLocalVar(getterMethod->getCmdDecl()), "cmd");
959 llvm::Value *self = Builder.CreateBitCast(LoadObjCSelf(), VoidPtrTy);
960 llvm::Value *ivarOffset =
961 EmitIvarOffset(classImpl->getClassInterface(), ivar);
962
963 CallArgList args;
964 args.add(RValue::get(self), getContext().getObjCIdType());
965 args.add(RValue::get(cmd), getContext().getObjCSelType());
966 args.add(RValue::get(ivarOffset), getContext().getPointerDiffType());
967 args.add(RValue::get(Builder.getInt1(strategy.isAtomic())),
968 getContext().BoolTy);
969
970 // FIXME: We shouldn't need to get the function info here, the
971 // runtime already should have computed it to build the function.
972 llvm::Instruction *CallInstruction;
973 RValue RV = EmitCall(
974 getTypes().arrangeBuiltinFunctionCall(propType, args),
975 callee, ReturnValueSlot(), args, &CallInstruction);
976 if (llvm::CallInst *call = dyn_cast<llvm::CallInst>(CallInstruction))
977 call->setTailCall();
978
979 // We need to fix the type here. Ivars with copy & retain are
980 // always objects so we don't need to worry about complex or
981 // aggregates.
982 RV = RValue::get(Builder.CreateBitCast(
983 RV.getScalarVal(),
984 getTypes().ConvertType(getterMethod->getReturnType())));
985
986 EmitReturnOfRValue(RV, propType);
987
988 // objc_getProperty does an autorelease, so we should suppress ours.
989 AutoreleaseResult = false;
990
991 return;
992 }
993
994 case PropertyImplStrategy::CopyStruct:
995 emitStructGetterCall(*this, ivar, strategy.isAtomic(),
996 strategy.hasStrongMember());
997 return;
998
999 case PropertyImplStrategy::Expression:
1000 case PropertyImplStrategy::SetPropertyAndExpressionGet: {
1001 LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, 0);
1002
1003 QualType ivarType = ivar->getType();
1004 switch (getEvaluationKind(ivarType)) {
1005 case TEK_Complex: {
1006 ComplexPairTy pair = EmitLoadOfComplex(LV, SourceLocation());
1007 EmitStoreOfComplex(pair, MakeAddrLValue(ReturnValue, ivarType),
1008 /*init*/ true);
1009 return;
1010 }
1011 case TEK_Aggregate: {
1012 // The return value slot is guaranteed to not be aliased, but
1013 // that's not necessarily the same as "on the stack", so
1014 // we still potentially need objc_memmove_collectable.
1015 EmitAggregateCopy(/* Dest= */ MakeAddrLValue(ReturnValue, ivarType),
1016 /* Src= */ LV, ivarType, overlapForReturnValue());
1017 return;
1018 }
1019 case TEK_Scalar: {
1020 llvm::Value *value;
1021 if (propType->isReferenceType()) {
1022 value = LV.getAddress().getPointer();
1023 } else {
1024 // We want to load and autoreleaseReturnValue ARC __weak ivars.
1025 if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) {
1026 if (getLangOpts().ObjCAutoRefCount) {
1027 value = emitARCRetainLoadOfScalar(*this, LV, ivarType);
1028 } else {
1029 value = EmitARCLoadWeak(LV.getAddress());
1030 }
1031
1032 // Otherwise we want to do a simple load, suppressing the
1033 // final autorelease.
1034 } else {
1035 value = EmitLoadOfLValue(LV, SourceLocation()).getScalarVal();
1036 AutoreleaseResult = false;
1037 }
1038
1039 value = Builder.CreateBitCast(
1040 value, ConvertType(GetterMethodDecl->getReturnType()));
1041 }
1042
1043 EmitReturnOfRValue(RValue::get(value), propType);
1044 return;
1045 }
1046 }
1047 llvm_unreachable("bad evaluation kind")::llvm::llvm_unreachable_internal("bad evaluation kind", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 1047)
;
1048 }
1049
1050 }
1051 llvm_unreachable("bad @property implementation strategy!")::llvm::llvm_unreachable_internal("bad @property implementation strategy!"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 1051)
;
1052}
1053
1054/// emitStructSetterCall - Call the runtime function to store the value
1055/// from the first formal parameter into the given ivar.
1056static void emitStructSetterCall(CodeGenFunction &CGF, ObjCMethodDecl *OMD,
1057 ObjCIvarDecl *ivar) {
1058 // objc_copyStruct (&structIvar, &Arg,
1059 // sizeof (struct something), true, false);
1060 CallArgList args;
1061
1062 // The first argument is the address of the ivar.
1063 llvm::Value *ivarAddr = CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(),
1064 CGF.LoadObjCSelf(), ivar, 0)
1065 .getPointer();
1066 ivarAddr = CGF.Builder.CreateBitCast(ivarAddr, CGF.Int8PtrTy);
1067 args.add(RValue::get(ivarAddr), CGF.getContext().VoidPtrTy);
1068
1069 // The second argument is the address of the parameter variable.
1070 ParmVarDecl *argVar = *OMD->param_begin();
1071 DeclRefExpr argRef(argVar, false, argVar->getType().getNonReferenceType(),
1072 VK_LValue, SourceLocation());
1073 llvm::Value *argAddr = CGF.EmitLValue(&argRef).getPointer();
1074 argAddr = CGF.Builder.CreateBitCast(argAddr, CGF.Int8PtrTy);
1075 args.add(RValue::get(argAddr), CGF.getContext().VoidPtrTy);
1076
1077 // The third argument is the sizeof the type.
1078 llvm::Value *size =
1079 CGF.CGM.getSize(CGF.getContext().getTypeSizeInChars(ivar->getType()));
1080 args.add(RValue::get(size), CGF.getContext().getSizeType());
1081
1082 // The fourth argument is the 'isAtomic' flag.
1083 args.add(RValue::get(CGF.Builder.getTrue()), CGF.getContext().BoolTy);
1084
1085 // The fifth argument is the 'hasStrong' flag.
1086 // FIXME: should this really always be false?
1087 args.add(RValue::get(CGF.Builder.getFalse()), CGF.getContext().BoolTy);
1088
1089 llvm::Constant *fn = CGF.CGM.getObjCRuntime().GetSetStructFunction();
1090 CGCallee callee = CGCallee::forDirect(fn);
1091 CGF.EmitCall(
1092 CGF.getTypes().arrangeBuiltinFunctionCall(CGF.getContext().VoidTy, args),
1093 callee, ReturnValueSlot(), args);
1094}
1095
1096/// emitCPPObjectAtomicSetterCall - Call the runtime function to store
1097/// the value from the first formal parameter into the given ivar, using
1098/// the Cpp API for atomic Cpp objects with non-trivial copy assignment.
1099static void emitCPPObjectAtomicSetterCall(CodeGenFunction &CGF,
1100 ObjCMethodDecl *OMD,
1101 ObjCIvarDecl *ivar,
1102 llvm::Constant *AtomicHelperFn) {
1103 // objc_copyCppObjectAtomic (&CppObjectIvar, &Arg,
1104 // AtomicHelperFn);
1105 CallArgList args;
1106
1107 // The first argument is the address of the ivar.
1108 llvm::Value *ivarAddr =
1109 CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(),
1110 CGF.LoadObjCSelf(), ivar, 0).getPointer();
1111 ivarAddr = CGF.Builder.CreateBitCast(ivarAddr, CGF.Int8PtrTy);
1112 args.add(RValue::get(ivarAddr), CGF.getContext().VoidPtrTy);
1113
1114 // The second argument is the address of the parameter variable.
1115 ParmVarDecl *argVar = *OMD->param_begin();
1116 DeclRefExpr argRef(argVar, false, argVar->getType().getNonReferenceType(),
1117 VK_LValue, SourceLocation());
1118 llvm::Value *argAddr = CGF.EmitLValue(&argRef).getPointer();
1119 argAddr = CGF.Builder.CreateBitCast(argAddr, CGF.Int8PtrTy);
1120 args.add(RValue::get(argAddr), CGF.getContext().VoidPtrTy);
1121
1122 // Third argument is the helper function.
1123 args.add(RValue::get(AtomicHelperFn), CGF.getContext().VoidPtrTy);
1124
1125 llvm::Constant *fn =
1126 CGF.CGM.getObjCRuntime().GetCppAtomicObjectSetFunction();
1127 CGCallee callee = CGCallee::forDirect(fn);
1128 CGF.EmitCall(
1129 CGF.getTypes().arrangeBuiltinFunctionCall(CGF.getContext().VoidTy, args),
1130 callee, ReturnValueSlot(), args);
1131}
1132
1133
1134static bool hasTrivialSetExpr(const ObjCPropertyImplDecl *PID) {
1135 Expr *setter = PID->getSetterCXXAssignment();
1136 if (!setter) return true;
1137
1138 // Sema only makes only of these when the ivar has a C++ class type,
1139 // so the form is pretty constrained.
1140
1141 // An operator call is trivial if the function it calls is trivial.
1142 // This also implies that there's nothing non-trivial going on with
1143 // the arguments, because operator= can only be trivial if it's a
1144 // synthesized assignment operator and therefore both parameters are
1145 // references.
1146 if (CallExpr *call = dyn_cast<CallExpr>(setter)) {
1147 if (const FunctionDecl *callee
1148 = dyn_cast_or_null<FunctionDecl>(call->getCalleeDecl()))
1149 if (callee->isTrivial())
1150 return true;
1151 return false;
1152 }
1153
1154 assert(isa<ExprWithCleanups>(setter))((isa<ExprWithCleanups>(setter)) ? static_cast<void>
(0) : __assert_fail ("isa<ExprWithCleanups>(setter)", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 1154, __PRETTY_FUNCTION__))
;
1155 return false;
1156}
1157
1158static bool UseOptimizedSetter(CodeGenModule &CGM) {
1159 if (CGM.getLangOpts().getGC() != LangOptions::NonGC)
1160 return false;
1161 return CGM.getLangOpts().ObjCRuntime.hasOptimizedSetter();
1162}
1163
1164void
1165CodeGenFunction::generateObjCSetterBody(const ObjCImplementationDecl *classImpl,
1166 const ObjCPropertyImplDecl *propImpl,
1167 llvm::Constant *AtomicHelperFn) {
1168 const ObjCPropertyDecl *prop = propImpl->getPropertyDecl();
1169 ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
1170 ObjCMethodDecl *setterMethod = prop->getSetterMethodDecl();
1171
1172 // Just use the setter expression if Sema gave us one and it's
1173 // non-trivial.
1174 if (!hasTrivialSetExpr(propImpl)) {
1175 if (!AtomicHelperFn)
1176 // If non-atomic, assignment is called directly.
1177 EmitStmt(propImpl->getSetterCXXAssignment());
1178 else
1179 // If atomic, assignment is called via a locking api.
1180 emitCPPObjectAtomicSetterCall(*this, setterMethod, ivar,
1181 AtomicHelperFn);
1182 return;
1183 }
1184
1185 PropertyImplStrategy strategy(CGM, propImpl);
1186 switch (strategy.getKind()) {
1187 case PropertyImplStrategy::Native: {
1188 // We don't need to do anything for a zero-size struct.
1189 if (strategy.getIvarSize().isZero())
1190 return;
1191
1192 Address argAddr = GetAddrOfLocalVar(*setterMethod->param_begin());
1193
1194 LValue ivarLValue =
1195 EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, /*quals*/ 0);
1196 Address ivarAddr = ivarLValue.getAddress();
1197
1198 // Currently, all atomic accesses have to be through integer
1199 // types, so there's no point in trying to pick a prettier type.
1200 llvm::Type *bitcastType =
1201 llvm::Type::getIntNTy(getLLVMContext(),
1202 getContext().toBits(strategy.getIvarSize()));
1203
1204 // Cast both arguments to the chosen operation type.
1205 argAddr = Builder.CreateElementBitCast(argAddr, bitcastType);
1206 ivarAddr = Builder.CreateElementBitCast(ivarAddr, bitcastType);
1207
1208 // This bitcast load is likely to cause some nasty IR.
1209 llvm::Value *load = Builder.CreateLoad(argAddr);
1210
1211 // Perform an atomic store. There are no memory ordering requirements.
1212 llvm::StoreInst *store = Builder.CreateStore(load, ivarAddr);
1213 store->setAtomic(llvm::AtomicOrdering::Unordered);
1214 return;
1215 }
1216
1217 case PropertyImplStrategy::GetSetProperty:
1218 case PropertyImplStrategy::SetPropertyAndExpressionGet: {
1219
1220 llvm::Constant *setOptimizedPropertyFn = nullptr;
1221 llvm::Constant *setPropertyFn = nullptr;
1222 if (UseOptimizedSetter(CGM)) {
1223 // 10.8 and iOS 6.0 code and GC is off
1224 setOptimizedPropertyFn =
1225 CGM.getObjCRuntime()
1226 .GetOptimizedPropertySetFunction(strategy.isAtomic(),
1227 strategy.isCopy());
1228 if (!setOptimizedPropertyFn) {
1229 CGM.ErrorUnsupported(propImpl, "Obj-C optimized setter - NYI");
1230 return;
1231 }
1232 }
1233 else {
1234 setPropertyFn = CGM.getObjCRuntime().GetPropertySetFunction();
1235 if (!setPropertyFn) {
1236 CGM.ErrorUnsupported(propImpl, "Obj-C setter requiring atomic copy");
1237 return;
1238 }
1239 }
1240
1241 // Emit objc_setProperty((id) self, _cmd, offset, arg,
1242 // <is-atomic>, <is-copy>).
1243 llvm::Value *cmd =
1244 Builder.CreateLoad(GetAddrOfLocalVar(setterMethod->getCmdDecl()));
1245 llvm::Value *self =
1246 Builder.CreateBitCast(LoadObjCSelf(), VoidPtrTy);
1247 llvm::Value *ivarOffset =
1248 EmitIvarOffset(classImpl->getClassInterface(), ivar);
1249 Address argAddr = GetAddrOfLocalVar(*setterMethod->param_begin());
1250 llvm::Value *arg = Builder.CreateLoad(argAddr, "arg");
1251 arg = Builder.CreateBitCast(arg, VoidPtrTy);
1252
1253 CallArgList args;
1254 args.add(RValue::get(self), getContext().getObjCIdType());
1255 args.add(RValue::get(cmd), getContext().getObjCSelType());
1256 if (setOptimizedPropertyFn) {
1257 args.add(RValue::get(arg), getContext().getObjCIdType());
1258 args.add(RValue::get(ivarOffset), getContext().getPointerDiffType());
1259 CGCallee callee = CGCallee::forDirect(setOptimizedPropertyFn);
1260 EmitCall(getTypes().arrangeBuiltinFunctionCall(getContext().VoidTy, args),
1261 callee, ReturnValueSlot(), args);
1262 } else {
1263 args.add(RValue::get(ivarOffset), getContext().getPointerDiffType());
1264 args.add(RValue::get(arg), getContext().getObjCIdType());
1265 args.add(RValue::get(Builder.getInt1(strategy.isAtomic())),
1266 getContext().BoolTy);
1267 args.add(RValue::get(Builder.getInt1(strategy.isCopy())),
1268 getContext().BoolTy);
1269 // FIXME: We shouldn't need to get the function info here, the runtime
1270 // already should have computed it to build the function.
1271 CGCallee callee = CGCallee::forDirect(setPropertyFn);
1272 EmitCall(getTypes().arrangeBuiltinFunctionCall(getContext().VoidTy, args),
1273 callee, ReturnValueSlot(), args);
1274 }
1275
1276 return;
1277 }
1278
1279 case PropertyImplStrategy::CopyStruct:
1280 emitStructSetterCall(*this, setterMethod, ivar);
1281 return;
1282
1283 case PropertyImplStrategy::Expression:
1284 break;
1285 }
1286
1287 // Otherwise, fake up some ASTs and emit a normal assignment.
1288 ValueDecl *selfDecl = setterMethod->getSelfDecl();
1289 DeclRefExpr self(selfDecl, false, selfDecl->getType(),
1290 VK_LValue, SourceLocation());
1291 ImplicitCastExpr selfLoad(ImplicitCastExpr::OnStack,
1292 selfDecl->getType(), CK_LValueToRValue, &self,
1293 VK_RValue);
1294 ObjCIvarRefExpr ivarRef(ivar, ivar->getType().getNonReferenceType(),
1295 SourceLocation(), SourceLocation(),
1296 &selfLoad, true, true);
1297
1298 ParmVarDecl *argDecl = *setterMethod->param_begin();
1299 QualType argType = argDecl->getType().getNonReferenceType();
1300 DeclRefExpr arg(argDecl, false, argType, VK_LValue, SourceLocation());
1301 ImplicitCastExpr argLoad(ImplicitCastExpr::OnStack,
1302 argType.getUnqualifiedType(), CK_LValueToRValue,
1303 &arg, VK_RValue);
1304
1305 // The property type can differ from the ivar type in some situations with
1306 // Objective-C pointer types, we can always bit cast the RHS in these cases.
1307 // The following absurdity is just to ensure well-formed IR.
1308 CastKind argCK = CK_NoOp;
1309 if (ivarRef.getType()->isObjCObjectPointerType()) {
1310 if (argLoad.getType()->isObjCObjectPointerType())
1311 argCK = CK_BitCast;
1312 else if (argLoad.getType()->isBlockPointerType())
1313 argCK = CK_BlockPointerToObjCPointerCast;
1314 else
1315 argCK = CK_CPointerToObjCPointerCast;
1316 } else if (ivarRef.getType()->isBlockPointerType()) {
1317 if (argLoad.getType()->isBlockPointerType())
1318 argCK = CK_BitCast;
1319 else
1320 argCK = CK_AnyPointerToBlockPointerCast;
1321 } else if (ivarRef.getType()->isPointerType()) {
1322 argCK = CK_BitCast;
1323 }
1324 ImplicitCastExpr argCast(ImplicitCastExpr::OnStack,
1325 ivarRef.getType(), argCK, &argLoad,
1326 VK_RValue);
1327 Expr *finalArg = &argLoad;
1328 if (!getContext().hasSameUnqualifiedType(ivarRef.getType(),
1329 argLoad.getType()))
1330 finalArg = &argCast;
1331
1332
1333 BinaryOperator assign(&ivarRef, finalArg, BO_Assign,
1334 ivarRef.getType(), VK_RValue, OK_Ordinary,
1335 SourceLocation(), FPOptions());
1336 EmitStmt(&assign);
1337}
1338
1339/// Generate an Objective-C property setter function.
1340///
1341/// The given Decl must be an ObjCImplementationDecl. \@synthesize
1342/// is illegal within a category.
1343void CodeGenFunction::GenerateObjCSetter(ObjCImplementationDecl *IMP,
1344 const ObjCPropertyImplDecl *PID) {
1345 llvm::Constant *AtomicHelperFn =
1346 CodeGenFunction(CGM).GenerateObjCAtomicSetterCopyHelperFunction(PID);
1347 const ObjCPropertyDecl *PD = PID->getPropertyDecl();
1348 ObjCMethodDecl *OMD = PD->getSetterMethodDecl();
1349 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-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 1349, __PRETTY_FUNCTION__))
;
1350 StartObjCMethod(OMD, IMP->getClassInterface());
1351
1352 generateObjCSetterBody(IMP, PID, AtomicHelperFn);
1353
1354 FinishFunction();
1355}
1356
1357namespace {
1358 struct DestroyIvar final : EHScopeStack::Cleanup {
1359 private:
1360 llvm::Value *addr;
1361 const ObjCIvarDecl *ivar;
1362 CodeGenFunction::Destroyer *destroyer;
1363 bool useEHCleanupForArray;
1364 public:
1365 DestroyIvar(llvm::Value *addr, const ObjCIvarDecl *ivar,
1366 CodeGenFunction::Destroyer *destroyer,
1367 bool useEHCleanupForArray)
1368 : addr(addr), ivar(ivar), destroyer(destroyer),
1369 useEHCleanupForArray(useEHCleanupForArray) {}
1370
1371 void Emit(CodeGenFunction &CGF, Flags flags) override {
1372 LValue lvalue
1373 = CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), addr, ivar, /*CVR*/ 0);
1374 CGF.emitDestroy(lvalue.getAddress(), ivar->getType(), destroyer,
1375 flags.isForNormalCleanup() && useEHCleanupForArray);
1376 }
1377 };
1378}
1379
1380/// Like CodeGenFunction::destroyARCStrong, but do it with a call.
1381static void destroyARCStrongWithStore(CodeGenFunction &CGF,
1382 Address addr,
1383 QualType type) {
1384 llvm::Value *null = getNullForVariable(addr);
1385 CGF.EmitARCStoreStrongCall(addr, null, /*ignored*/ true);
1386}
1387
1388static void emitCXXDestructMethod(CodeGenFunction &CGF,
1389 ObjCImplementationDecl *impl) {
1390 CodeGenFunction::RunCleanupsScope scope(CGF);
1391
1392 llvm::Value *self = CGF.LoadObjCSelf();
1393
1394 const ObjCInterfaceDecl *iface = impl->getClassInterface();
1395 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin();
1396 ivar; ivar = ivar->getNextIvar()) {
1397 QualType type = ivar->getType();
1398
1399 // Check whether the ivar is a destructible type.
1400 QualType::DestructionKind dtorKind = type.isDestructedType();
1401 if (!dtorKind) continue;
1402
1403 CodeGenFunction::Destroyer *destroyer = nullptr;
1404
1405 // Use a call to objc_storeStrong to destroy strong ivars, for the
1406 // general benefit of the tools.
1407 if (dtorKind == QualType::DK_objc_strong_lifetime) {
1408 destroyer = destroyARCStrongWithStore;
1409
1410 // Otherwise use the default for the destruction kind.
1411 } else {
1412 destroyer = CGF.getDestroyer(dtorKind);
1413 }
1414
1415 CleanupKind cleanupKind = CGF.getCleanupKind(dtorKind);
1416
1417 CGF.EHStack.pushCleanup<DestroyIvar>(cleanupKind, self, ivar, destroyer,
1418 cleanupKind & EHCleanup);
1419 }
1420
1421 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-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 1421, __PRETTY_FUNCTION__))
;
1422}
1423
1424void CodeGenFunction::GenerateObjCCtorDtorMethod(ObjCImplementationDecl *IMP,
1425 ObjCMethodDecl *MD,
1426 bool ctor) {
1427 MD->createImplicitParams(CGM.getContext(), IMP->getClassInterface());
1428 StartObjCMethod(MD, IMP->getClassInterface());
1429
1430 // Emit .cxx_construct.
1431 if (ctor) {
1432 // Suppress the final autorelease in ARC.
1433 AutoreleaseResult = false;
1434
1435 for (const auto *IvarInit : IMP->inits()) {
1436 FieldDecl *Field = IvarInit->getAnyMember();
1437 ObjCIvarDecl *Ivar = cast<ObjCIvarDecl>(Field);
1438 LValue LV = EmitLValueForIvar(TypeOfSelfObject(),
1439 LoadObjCSelf(), Ivar, 0);
1440 EmitAggExpr(IvarInit->getInit(),
1441 AggValueSlot::forLValue(LV, AggValueSlot::IsDestructed,
1442 AggValueSlot::DoesNotNeedGCBarriers,
1443 AggValueSlot::IsNotAliased,
1444 AggValueSlot::DoesNotOverlap));
1445 }
1446 // constructor returns 'self'.
1447 CodeGenTypes &Types = CGM.getTypes();
1448 QualType IdTy(CGM.getContext().getObjCIdType());
1449 llvm::Value *SelfAsId =
1450 Builder.CreateBitCast(LoadObjCSelf(), Types.ConvertType(IdTy));
1451 EmitReturnOfRValue(RValue::get(SelfAsId), IdTy);
1452
1453 // Emit .cxx_destruct.
1454 } else {
1455 emitCXXDestructMethod(*this, IMP);
1456 }
1457 FinishFunction();
1458}
1459
1460llvm::Value *CodeGenFunction::LoadObjCSelf() {
1461 VarDecl *Self = cast<ObjCMethodDecl>(CurFuncDecl)->getSelfDecl();
1462 DeclRefExpr DRE(Self, /*is enclosing local*/ (CurFuncDecl != CurCodeDecl),
1463 Self->getType(), VK_LValue, SourceLocation());
1464 return EmitLoadOfScalar(EmitDeclRefLValue(&DRE), SourceLocation());
1465}
1466
1467QualType CodeGenFunction::TypeOfSelfObject() {
1468 const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
1469 ImplicitParamDecl *selfDecl = OMD->getSelfDecl();
1470 const ObjCObjectPointerType *PTy = cast<ObjCObjectPointerType>(
1471 getContext().getCanonicalType(selfDecl->getType()));
1472 return PTy->getPointeeType();
1473}
1474
1475void CodeGenFunction::EmitObjCForCollectionStmt(const ObjCForCollectionStmt &S){
1476 llvm::Constant *EnumerationMutationFnPtr =
1477 CGM.getObjCRuntime().EnumerationMutationFunction();
1478 if (!EnumerationMutationFnPtr) {
1479 CGM.ErrorUnsupported(&S, "Obj-C fast enumeration for this runtime");
1480 return;
1481 }
1482 CGCallee EnumerationMutationFn =
1483 CGCallee::forDirect(EnumerationMutationFnPtr);
1484
1485 CGDebugInfo *DI = getDebugInfo();
1486 if (DI)
1487 DI->EmitLexicalBlockStart(Builder, S.getSourceRange().getBegin());
1488
1489 RunCleanupsScope ForScope(*this);
1490
1491 // The local variable comes into scope immediately.
1492 AutoVarEmission variable = AutoVarEmission::invalid();
1493 if (const DeclStmt *SD = dyn_cast<DeclStmt>(S.getElement()))
1494 variable = EmitAutoVarAlloca(*cast<VarDecl>(SD->getSingleDecl()));
1495
1496 JumpDest LoopEnd = getJumpDestInCurrentScope("forcoll.end");
1497
1498 // Fast enumeration state.
1499 QualType StateTy = CGM.getObjCFastEnumerationStateType();
1500 Address StatePtr = CreateMemTemp(StateTy, "state.ptr");
1501 EmitNullInitialization(StatePtr, StateTy);
1502
1503 // Number of elements in the items array.
1504 static const unsigned NumItems = 16;
1505
1506 // Fetch the countByEnumeratingWithState:objects:count: selector.
1507 IdentifierInfo *II[] = {
1508 &CGM.getContext().Idents.get("countByEnumeratingWithState"),
1509 &CGM.getContext().Idents.get("objects"),
1510 &CGM.getContext().Idents.get("count")
1511 };
1512 Selector FastEnumSel =
1513 CGM.getContext().Selectors.getSelector(llvm::array_lengthof(II), &II[0]);
1514
1515 QualType ItemsTy =
1516 getContext().getConstantArrayType(getContext().getObjCIdType(),
1517 llvm::APInt(32, NumItems),
1518 ArrayType::Normal, 0);
1519 Address ItemsPtr = CreateMemTemp(ItemsTy, "items.ptr");
1520
1521 // Emit the collection pointer. In ARC, we do a retain.
1522 llvm::Value *Collection;
1523 if (getLangOpts().ObjCAutoRefCount) {
1524 Collection = EmitARCRetainScalarExpr(S.getCollection());
1525
1526 // Enter a cleanup to do the release.
1527 EmitObjCConsumeObject(S.getCollection()->getType(), Collection);
1528 } else {
1529 Collection = EmitScalarExpr(S.getCollection());
1530 }
1531
1532 // The 'continue' label needs to appear within the cleanup for the
1533 // collection object.
1534 JumpDest AfterBody = getJumpDestInCurrentScope("forcoll.next");
1535
1536 // Send it our message:
1537 CallArgList Args;
1538
1539 // The first argument is a temporary of the enumeration-state type.
1540 Args.add(RValue::get(StatePtr.getPointer()),
1541 getContext().getPointerType(StateTy));
1542
1543 // The second argument is a temporary array with space for NumItems
1544 // pointers. We'll actually be loading elements from the array
1545 // pointer written into the control state; this buffer is so that
1546 // collections that *aren't* backed by arrays can still queue up
1547 // batches of elements.
1548 Args.add(RValue::get(ItemsPtr.getPointer()),
1549 getContext().getPointerType(ItemsTy));
1550
1551 // The third argument is the capacity of that temporary array.
1552 llvm::Type *NSUIntegerTy = ConvertType(getContext().getNSUIntegerType());
1553 llvm::Constant *Count = llvm::ConstantInt::get(NSUIntegerTy, NumItems);
1554 Args.add(RValue::get(Count), getContext().getNSUIntegerType());
1555
1556 // Start the enumeration.
1557 RValue CountRV =
1558 CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(),
1559 getContext().getNSUIntegerType(),
1560 FastEnumSel, Collection, Args);
1561
1562 // The initial number of objects that were returned in the buffer.
1563 llvm::Value *initialBufferLimit = CountRV.getScalarVal();
1564
1565 llvm::BasicBlock *EmptyBB = createBasicBlock("forcoll.empty");
1566 llvm::BasicBlock *LoopInitBB = createBasicBlock("forcoll.loopinit");
1567
1568 llvm::Value *zero = llvm::Constant::getNullValue(NSUIntegerTy);
1569
1570 // If the limit pointer was zero to begin with, the collection is
1571 // empty; skip all this. Set the branch weight assuming this has the same
1572 // probability of exiting the loop as any other loop exit.
1573 uint64_t EntryCount = getCurrentProfileCount();
1574 Builder.CreateCondBr(
1575 Builder.CreateICmpEQ(initialBufferLimit, zero, "iszero"), EmptyBB,
1576 LoopInitBB,
1577 createProfileWeights(EntryCount, getProfileCount(S.getBody())));
1578
1579 // Otherwise, initialize the loop.
1580 EmitBlock(LoopInitBB);
1581
1582 // Save the initial mutations value. This is the value at an
1583 // address that was written into the state object by
1584 // countByEnumeratingWithState:objects:count:.
1585 Address StateMutationsPtrPtr = Builder.CreateStructGEP(
1586 StatePtr, 2, 2 * getPointerSize(), "mutationsptr.ptr");
1587 llvm::Value *StateMutationsPtr
1588 = Builder.CreateLoad(StateMutationsPtrPtr, "mutationsptr");
1589
1590 llvm::Value *initialMutations =
1591 Builder.CreateAlignedLoad(StateMutationsPtr, getPointerAlign(),
1592 "forcoll.initial-mutations");
1593
1594 // Start looping. This is the point we return to whenever we have a
1595 // fresh, non-empty batch of objects.
1596 llvm::BasicBlock *LoopBodyBB = createBasicBlock("forcoll.loopbody");
1597 EmitBlock(LoopBodyBB);
1598
1599 // The current index into the buffer.
1600 llvm::PHINode *index = Builder.CreatePHI(NSUIntegerTy, 3, "forcoll.index");
1601 index->addIncoming(zero, LoopInitBB);
1602
1603 // The current buffer size.
1604 llvm::PHINode *count = Builder.CreatePHI(NSUIntegerTy, 3, "forcoll.count");
1605 count->addIncoming(initialBufferLimit, LoopInitBB);
1606
1607 incrementProfileCounter(&S);
1608
1609 // Check whether the mutations value has changed from where it was
1610 // at start. StateMutationsPtr should actually be invariant between
1611 // refreshes.
1612 StateMutationsPtr = Builder.CreateLoad(StateMutationsPtrPtr, "mutationsptr");
1613 llvm::Value *currentMutations
1614 = Builder.CreateAlignedLoad(StateMutationsPtr, getPointerAlign(),
1615 "statemutations");
1616
1617 llvm::BasicBlock *WasMutatedBB = createBasicBlock("forcoll.mutated");
1618 llvm::BasicBlock *WasNotMutatedBB = createBasicBlock("forcoll.notmutated");
1619
1620 Builder.CreateCondBr(Builder.CreateICmpEQ(currentMutations, initialMutations),
1621 WasNotMutatedBB, WasMutatedBB);
1622
1623 // If so, call the enumeration-mutation function.
1624 EmitBlock(WasMutatedBB);
1625 llvm::Value *V =
1626 Builder.CreateBitCast(Collection,
1627 ConvertType(getContext().getObjCIdType()));
1628 CallArgList Args2;
1629 Args2.add(RValue::get(V), getContext().getObjCIdType());
1630 // FIXME: We shouldn't need to get the function info here, the runtime already
1631 // should have computed it to build the function.
1632 EmitCall(
1633 CGM.getTypes().arrangeBuiltinFunctionCall(getContext().VoidTy, Args2),
1634 EnumerationMutationFn, ReturnValueSlot(), Args2);
1635
1636 // Otherwise, or if the mutation function returns, just continue.
1637 EmitBlock(WasNotMutatedBB);
1638
1639 // Initialize the element variable.
1640 RunCleanupsScope elementVariableScope(*this);
1641 bool elementIsVariable;
1642 LValue elementLValue;
1643 QualType elementType;
1644 if (const DeclStmt *SD = dyn_cast<DeclStmt>(S.getElement())) {
1645 // Initialize the variable, in case it's a __block variable or something.
1646 EmitAutoVarInit(variable);
1647
1648 const VarDecl* D = cast<VarDecl>(SD->getSingleDecl());
1649 DeclRefExpr tempDRE(const_cast<VarDecl*>(D), false, D->getType(),
1650 VK_LValue, SourceLocation());
1651 elementLValue = EmitLValue(&tempDRE);
1652 elementType = D->getType();
1653 elementIsVariable = true;
1654
1655 if (D->isARCPseudoStrong())
1656 elementLValue.getQuals().setObjCLifetime(Qualifiers::OCL_ExplicitNone);
1657 } else {
1658 elementLValue = LValue(); // suppress warning
1659 elementType = cast<Expr>(S.getElement())->getType();
1660 elementIsVariable = false;
1661 }
1662 llvm::Type *convertedElementType = ConvertType(elementType);
1663
1664 // Fetch the buffer out of the enumeration state.
1665 // TODO: this pointer should actually be invariant between
1666 // refreshes, which would help us do certain loop optimizations.
1667 Address StateItemsPtr = Builder.CreateStructGEP(
1668 StatePtr, 1, getPointerSize(), "stateitems.ptr");
1669 llvm::Value *EnumStateItems =
1670 Builder.CreateLoad(StateItemsPtr, "stateitems");
1671
1672 // Fetch the value at the current index from the buffer.
1673 llvm::Value *CurrentItemPtr =
1674 Builder.CreateGEP(EnumStateItems, index, "currentitem.ptr");
1675 llvm::Value *CurrentItem =
1676 Builder.CreateAlignedLoad(CurrentItemPtr, getPointerAlign());
1677
1678 // Cast that value to the right type.
1679 CurrentItem = Builder.CreateBitCast(CurrentItem, convertedElementType,
1680 "currentitem");
1681
1682 // Make sure we have an l-value. Yes, this gets evaluated every
1683 // time through the loop.
1684 if (!elementIsVariable) {
1685 elementLValue = EmitLValue(cast<Expr>(S.getElement()));
1686 EmitStoreThroughLValue(RValue::get(CurrentItem), elementLValue);
1687 } else {
1688 EmitStoreThroughLValue(RValue::get(CurrentItem), elementLValue,
1689 /*isInit*/ true);
1690 }
1691
1692 // If we do have an element variable, this assignment is the end of
1693 // its initialization.
1694 if (elementIsVariable)
1695 EmitAutoVarCleanups(variable);
1696
1697 // Perform the loop body, setting up break and continue labels.
1698 BreakContinueStack.push_back(BreakContinue(LoopEnd, AfterBody));
1699 {
1700 RunCleanupsScope Scope(*this);
1701 EmitStmt(S.getBody());
1702 }
1703 BreakContinueStack.pop_back();
1704
1705 // Destroy the element variable now.
1706 elementVariableScope.ForceCleanup();
1707
1708 // Check whether there are more elements.
1709 EmitBlock(AfterBody.getBlock());
1710
1711 llvm::BasicBlock *FetchMoreBB = createBasicBlock("forcoll.refetch");
1712
1713 // First we check in the local buffer.
1714 llvm::Value *indexPlusOne =
1715 Builder.CreateAdd(index, llvm::ConstantInt::get(NSUIntegerTy, 1));
1716
1717 // If we haven't overrun the buffer yet, we can continue.
1718 // Set the branch weights based on the simplifying assumption that this is
1719 // like a while-loop, i.e., ignoring that the false branch fetches more
1720 // elements and then returns to the loop.
1721 Builder.CreateCondBr(
1722 Builder.CreateICmpULT(indexPlusOne, count), LoopBodyBB, FetchMoreBB,
1723 createProfileWeights(getProfileCount(S.getBody()), EntryCount));
1724
1725 index->addIncoming(indexPlusOne, AfterBody.getBlock());
1726 count->addIncoming(count, AfterBody.getBlock());
1727
1728 // Otherwise, we have to fetch more elements.
1729 EmitBlock(FetchMoreBB);
1730
1731 CountRV =
1732 CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(),
1733 getContext().getNSUIntegerType(),
1734 FastEnumSel, Collection, Args);
1735
1736 // If we got a zero count, we're done.
1737 llvm::Value *refetchCount = CountRV.getScalarVal();
1738
1739 // (note that the message send might split FetchMoreBB)
1740 index->addIncoming(zero, Builder.GetInsertBlock());
1741 count->addIncoming(refetchCount, Builder.GetInsertBlock());
1742
1743 Builder.CreateCondBr(Builder.CreateICmpEQ(refetchCount, zero),
1744 EmptyBB, LoopBodyBB);
1745
1746 // No more elements.
1747 EmitBlock(EmptyBB);
1748
1749 if (!elementIsVariable) {
1750 // If the element was not a declaration, set it to be null.
1751
1752 llvm::Value *null = llvm::Constant::getNullValue(convertedElementType);
1753 elementLValue = EmitLValue(cast<Expr>(S.getElement()));
1754 EmitStoreThroughLValue(RValue::get(null), elementLValue);
1755 }
1756
1757 if (DI)
1758 DI->EmitLexicalBlockEnd(Builder, S.getSourceRange().getEnd());
1759
1760 ForScope.ForceCleanup();
1761 EmitBlock(LoopEnd.getBlock());
1762}
1763
1764void CodeGenFunction::EmitObjCAtTryStmt(const ObjCAtTryStmt &S) {
1765 CGM.getObjCRuntime().EmitTryStmt(*this, S);
1766}
1767
1768void CodeGenFunction::EmitObjCAtThrowStmt(const ObjCAtThrowStmt &S) {
1769 CGM.getObjCRuntime().EmitThrowStmt(*this, S);
1770}
1771
1772void CodeGenFunction::EmitObjCAtSynchronizedStmt(
1773 const ObjCAtSynchronizedStmt &S) {
1774 CGM.getObjCRuntime().EmitSynchronizedStmt(*this, S);
1775}
1776
1777namespace {
1778 struct CallObjCRelease final : EHScopeStack::Cleanup {
1779 CallObjCRelease(llvm::Value *object) : object(object) {}
1780 llvm::Value *object;
1781
1782 void Emit(CodeGenFunction &CGF, Flags flags) override {
1783 // Releases at the end of the full-expression are imprecise.
1784 CGF.EmitARCRelease(object, ARCImpreciseLifetime);
1785 }
1786 };
1787}
1788
1789/// Produce the code for a CK_ARCConsumeObject. Does a primitive
1790/// release at the end of the full-expression.
1791llvm::Value *CodeGenFunction::EmitObjCConsumeObject(QualType type,
1792 llvm::Value *object) {
1793 // If we're in a conditional branch, we need to make the cleanup
1794 // conditional.
1795 pushFullExprCleanup<CallObjCRelease>(getARCCleanupKind(), object);
1796 return object;
1797}
1798
1799llvm::Value *CodeGenFunction::EmitObjCExtendObjectLifetime(QualType type,
1800 llvm::Value *value) {
1801 return EmitARCRetainAutorelease(type, value);
1802}
1803
1804/// Given a number of pointers, inform the optimizer that they're
1805/// being intrinsically used up until this point in the program.
1806void CodeGenFunction::EmitARCIntrinsicUse(ArrayRef<llvm::Value*> values) {
1807 llvm::Constant *&fn = CGM.getObjCEntrypoints().clang_arc_use;
1808 if (!fn) {
1809 llvm::FunctionType *fnType =
1810 llvm::FunctionType::get(CGM.VoidTy, None, true);
1811 fn = CGM.CreateRuntimeFunction(fnType, "clang.arc.use");
1812 }
1813
1814 // This isn't really a "runtime" function, but as an intrinsic it
1815 // doesn't really matter as long as we align things up.
1816 EmitNounwindRuntimeCall(fn, values);
1817}
1818
1819
1820static llvm::Constant *createARCRuntimeFunction(CodeGenModule &CGM,
1821 llvm::FunctionType *FTy,
1822 StringRef Name) {
1823 llvm::Constant *RTF = CGM.CreateRuntimeFunction(FTy, Name);
1824
1825 if (auto *F = dyn_cast<llvm::Function>(RTF)) {
1826 // If the target runtime doesn't naturally support ARC, emit weak
1827 // references to the runtime support library. We don't really
1828 // permit this to fail, but we need a particular relocation style.
1829 if (!CGM.getLangOpts().ObjCRuntime.hasNativeARC() &&
1830 !CGM.getTriple().isOSBinFormatCOFF()) {
1831 F->setLinkage(llvm::Function::ExternalWeakLinkage);
1832 } else if (Name == "objc_retain" || Name == "objc_release") {
1833 // If we have Native ARC, set nonlazybind attribute for these APIs for
1834 // performance.
1835 F->addFnAttr(llvm::Attribute::NonLazyBind);
1836 }
1837 }
1838
1839 return RTF;
1840}
1841
1842/// Perform an operation having the signature
1843/// i8* (i8*)
1844/// where a null input causes a no-op and returns null.
1845static llvm::Value *emitARCValueOperation(CodeGenFunction &CGF,
1846 llvm::Value *value,
1847 llvm::Constant *&fn,
1848 StringRef fnName,
1849 bool isTailCall = false) {
1850 if (isa<llvm::ConstantPointerNull>(value))
1851 return value;
1852
1853 if (!fn) {
1854 llvm::FunctionType *fnType =
1855 llvm::FunctionType::get(CGF.Int8PtrTy, CGF.Int8PtrTy, false);
1856 fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName);
1857 }
1858
1859 // Cast the argument to 'id'.
1860 llvm::Type *origType = value->getType();
1861 value = CGF.Builder.CreateBitCast(value, CGF.Int8PtrTy);
1862
1863 // Call the function.
1864 llvm::CallInst *call = CGF.EmitNounwindRuntimeCall(fn, value);
1865 if (isTailCall)
1866 call->setTailCall();
1867
1868 // Cast the result back to the original type.
1869 return CGF.Builder.CreateBitCast(call, origType);
1870}
1871
1872/// Perform an operation having the following signature:
1873/// i8* (i8**)
1874static llvm::Value *emitARCLoadOperation(CodeGenFunction &CGF,
1875 Address addr,
1876 llvm::Constant *&fn,
1877 StringRef fnName) {
1878 if (!fn) {
1879 llvm::FunctionType *fnType =
1880 llvm::FunctionType::get(CGF.Int8PtrTy, CGF.Int8PtrPtrTy, false);
1881 fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName);
1882 }
1883
1884 // Cast the argument to 'id*'.
1885 llvm::Type *origType = addr.getElementType();
1886 addr = CGF.Builder.CreateBitCast(addr, CGF.Int8PtrPtrTy);
1887
1888 // Call the function.
1889 llvm::Value *result = CGF.EmitNounwindRuntimeCall(fn, addr.getPointer());
1890
1891 // Cast the result back to a dereference of the original type.
1892 if (origType != CGF.Int8PtrTy)
1893 result = CGF.Builder.CreateBitCast(result, origType);
1894
1895 return result;
1896}
1897
1898/// Perform an operation having the following signature:
1899/// i8* (i8**, i8*)
1900static llvm::Value *emitARCStoreOperation(CodeGenFunction &CGF,
1901 Address addr,
1902 llvm::Value *value,
1903 llvm::Constant *&fn,
1904 StringRef fnName,
1905 bool ignored) {
1906 assert(addr.getElementType() == value->getType())((addr.getElementType() == value->getType()) ? static_cast
<void> (0) : __assert_fail ("addr.getElementType() == value->getType()"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 1906, __PRETTY_FUNCTION__))
;
1907
1908 if (!fn) {
1909 llvm::Type *argTypes[] = { CGF.Int8PtrPtrTy, CGF.Int8PtrTy };
1910
1911 llvm::FunctionType *fnType
1912 = llvm::FunctionType::get(CGF.Int8PtrTy, argTypes, false);
1913 fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName);
1914 }
1915
1916 llvm::Type *origType = value->getType();
1917
1918 llvm::Value *args[] = {
1919 CGF.Builder.CreateBitCast(addr.getPointer(), CGF.Int8PtrPtrTy),
1920 CGF.Builder.CreateBitCast(value, CGF.Int8PtrTy)
1921 };
1922 llvm::CallInst *result = CGF.EmitNounwindRuntimeCall(fn, args);
1923
1924 if (ignored) return nullptr;
1925
1926 return CGF.Builder.CreateBitCast(result, origType);
1927}
1928
1929/// Perform an operation having the following signature:
1930/// void (i8**, i8**)
1931static void emitARCCopyOperation(CodeGenFunction &CGF,
1932 Address dst,
1933 Address src,
1934 llvm::Constant *&fn,
1935 StringRef fnName) {
1936 assert(dst.getType() == src.getType())((dst.getType() == src.getType()) ? static_cast<void> (
0) : __assert_fail ("dst.getType() == src.getType()", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 1936, __PRETTY_FUNCTION__))
;
1937
1938 if (!fn) {
1939 llvm::Type *argTypes[] = { CGF.Int8PtrPtrTy, CGF.Int8PtrPtrTy };
1940
1941 llvm::FunctionType *fnType
1942 = llvm::FunctionType::get(CGF.Builder.getVoidTy(), argTypes, false);
1943 fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName);
1944 }
1945
1946 llvm::Value *args[] = {
1947 CGF.Builder.CreateBitCast(dst.getPointer(), CGF.Int8PtrPtrTy),
1948 CGF.Builder.CreateBitCast(src.getPointer(), CGF.Int8PtrPtrTy)
1949 };
1950 CGF.EmitNounwindRuntimeCall(fn, args);
1951}
1952
1953/// Produce the code to do a retain. Based on the type, calls one of:
1954/// call i8* \@objc_retain(i8* %value)
1955/// call i8* \@objc_retainBlock(i8* %value)
1956llvm::Value *CodeGenFunction::EmitARCRetain(QualType type, llvm::Value *value) {
1957 if (type->isBlockPointerType())
1958 return EmitARCRetainBlock(value, /*mandatory*/ false);
1959 else
1960 return EmitARCRetainNonBlock(value);
1961}
1962
1963/// Retain the given object, with normal retain semantics.
1964/// call i8* \@objc_retain(i8* %value)
1965llvm::Value *CodeGenFunction::EmitARCRetainNonBlock(llvm::Value *value) {
1966 return emitARCValueOperation(*this, value,
1967 CGM.getObjCEntrypoints().objc_retain,
1968 "objc_retain");
1969}
1970
1971/// Retain the given block, with _Block_copy semantics.
1972/// call i8* \@objc_retainBlock(i8* %value)
1973///
1974/// \param mandatory - If false, emit the call with metadata
1975/// indicating that it's okay for the optimizer to eliminate this call
1976/// if it can prove that the block never escapes except down the stack.
1977llvm::Value *CodeGenFunction::EmitARCRetainBlock(llvm::Value *value,
1978 bool mandatory) {
1979 llvm::Value *result
1980 = emitARCValueOperation(*this, value,
1981 CGM.getObjCEntrypoints().objc_retainBlock,
1982 "objc_retainBlock");
1983
1984 // If the copy isn't mandatory, add !clang.arc.copy_on_escape to
1985 // tell the optimizer that it doesn't need to do this copy if the
1986 // block doesn't escape, where being passed as an argument doesn't
1987 // count as escaping.
1988 if (!mandatory && isa<llvm::Instruction>(result)) {
1989 llvm::CallInst *call
1990 = cast<llvm::CallInst>(result->stripPointerCasts());
1991 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-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 1991, __PRETTY_FUNCTION__))
;
1992
1993 call->setMetadata("clang.arc.copy_on_escape",
1994 llvm::MDNode::get(Builder.getContext(), None));
1995 }
1996
1997 return result;
1998}
1999
2000static void emitAutoreleasedReturnValueMarker(CodeGenFunction &CGF) {
2001 // Fetch the void(void) inline asm which marks that we're going to
2002 // do something with the autoreleased return value.
2003 llvm::InlineAsm *&marker
2004 = CGF.CGM.getObjCEntrypoints().retainAutoreleasedReturnValueMarker;
2005 if (!marker) {
2006 StringRef assembly
2007 = CGF.CGM.getTargetCodeGenInfo()
2008 .getARCRetainAutoreleasedReturnValueMarker();
2009
2010 // If we have an empty assembly string, there's nothing to do.
2011 if (assembly.empty()) {
2012
2013 // Otherwise, at -O0, build an inline asm that we're going to call
2014 // in a moment.
2015 } else if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) {
2016 llvm::FunctionType *type =
2017 llvm::FunctionType::get(CGF.VoidTy, /*variadic*/false);
2018
2019 marker = llvm::InlineAsm::get(type, assembly, "", /*sideeffects*/ true);
2020
2021 // If we're at -O1 and above, we don't want to litter the code
2022 // with this marker yet, so leave a breadcrumb for the ARC
2023 // optimizer to pick up.
2024 } else {
2025 llvm::NamedMDNode *metadata =
2026 CGF.CGM.getModule().getOrInsertNamedMetadata(
2027 "clang.arc.retainAutoreleasedReturnValueMarker");
2028 assert(metadata->getNumOperands() <= 1)((metadata->getNumOperands() <= 1) ? static_cast<void
> (0) : __assert_fail ("metadata->getNumOperands() <= 1"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 2028, __PRETTY_FUNCTION__))
;
2029 if (metadata->getNumOperands() == 0) {
2030 auto &ctx = CGF.getLLVMContext();
2031 metadata->addOperand(llvm::MDNode::get(ctx,
2032 llvm::MDString::get(ctx, assembly)));
2033 }
2034 }
2035 }
2036
2037 // Call the marker asm if we made one, which we do only at -O0.
2038 if (marker)
2039 CGF.Builder.CreateCall(marker, None, CGF.getBundlesForFunclet(marker));
2040}
2041
2042/// Retain the given object which is the result of a function call.
2043/// call i8* \@objc_retainAutoreleasedReturnValue(i8* %value)
2044///
2045/// Yes, this function name is one character away from a different
2046/// call with completely different semantics.
2047llvm::Value *
2048CodeGenFunction::EmitARCRetainAutoreleasedReturnValue(llvm::Value *value) {
2049 emitAutoreleasedReturnValueMarker(*this);
2050 return emitARCValueOperation(*this, value,
2051 CGM.getObjCEntrypoints().objc_retainAutoreleasedReturnValue,
2052 "objc_retainAutoreleasedReturnValue");
2053}
2054
2055/// Claim a possibly-autoreleased return value at +0. This is only
2056/// valid to do in contexts which do not rely on the retain to keep
2057/// the object valid for all of its uses; for example, when
2058/// the value is ignored, or when it is being assigned to an
2059/// __unsafe_unretained variable.
2060///
2061/// call i8* \@objc_unsafeClaimAutoreleasedReturnValue(i8* %value)
2062llvm::Value *
2063CodeGenFunction::EmitARCUnsafeClaimAutoreleasedReturnValue(llvm::Value *value) {
2064 emitAutoreleasedReturnValueMarker(*this);
2065 return emitARCValueOperation(*this, value,
2066 CGM.getObjCEntrypoints().objc_unsafeClaimAutoreleasedReturnValue,
2067 "objc_unsafeClaimAutoreleasedReturnValue");
2068}
2069
2070/// Release the given object.
2071/// call void \@objc_release(i8* %value)
2072void CodeGenFunction::EmitARCRelease(llvm::Value *value,
2073 ARCPreciseLifetime_t precise) {
2074 if (isa<llvm::ConstantPointerNull>(value)) return;
2075
2076 llvm::Constant *&fn = CGM.getObjCEntrypoints().objc_release;
2077 if (!fn) {
2078 llvm::FunctionType *fnType =
2079 llvm::FunctionType::get(Builder.getVoidTy(), Int8PtrTy, false);
2080 fn = createARCRuntimeFunction(CGM, fnType, "objc_release");
2081 }
2082
2083 // Cast the argument to 'id'.
2084 value = Builder.CreateBitCast(value, Int8PtrTy);
2085
2086 // Call objc_release.
2087 llvm::CallInst *call = EmitNounwindRuntimeCall(fn, value);
2088
2089 if (precise == ARCImpreciseLifetime) {
2090 call->setMetadata("clang.imprecise_release",
2091 llvm::MDNode::get(Builder.getContext(), None));
2092 }
2093}
2094
2095/// Destroy a __strong variable.
2096///
2097/// At -O0, emit a call to store 'null' into the address;
2098/// instrumenting tools prefer this because the address is exposed,
2099/// but it's relatively cumbersome to optimize.
2100///
2101/// At -O1 and above, just load and call objc_release.
2102///
2103/// call void \@objc_storeStrong(i8** %addr, i8* null)
2104void CodeGenFunction::EmitARCDestroyStrong(Address addr,
2105 ARCPreciseLifetime_t precise) {
2106 if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
2107 llvm::Value *null = getNullForVariable(addr);
2108 EmitARCStoreStrongCall(addr, null, /*ignored*/ true);
2109 return;
2110 }
2111
2112 llvm::Value *value = Builder.CreateLoad(addr);
2113 EmitARCRelease(value, precise);
2114}
2115
2116/// Store into a strong object. Always calls this:
2117/// call void \@objc_storeStrong(i8** %addr, i8* %value)
2118llvm::Value *CodeGenFunction::EmitARCStoreStrongCall(Address addr,
2119 llvm::Value *value,
2120 bool ignored) {
2121 assert(addr.getElementType() == value->getType())((addr.getElementType() == value->getType()) ? static_cast
<void> (0) : __assert_fail ("addr.getElementType() == value->getType()"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 2121, __PRETTY_FUNCTION__))
;
2122
2123 llvm::Constant *&fn = CGM.getObjCEntrypoints().objc_storeStrong;
2124 if (!fn) {
2125 llvm::Type *argTypes[] = { Int8PtrPtrTy, Int8PtrTy };
2126 llvm::FunctionType *fnType
2127 = llvm::FunctionType::get(Builder.getVoidTy(), argTypes, false);
2128 fn = createARCRuntimeFunction(CGM, fnType, "objc_storeStrong");
2129 }
2130
2131 llvm::Value *args[] = {
2132 Builder.CreateBitCast(addr.getPointer(), Int8PtrPtrTy),
2133 Builder.CreateBitCast(value, Int8PtrTy)
2134 };
2135 EmitNounwindRuntimeCall(fn, args);
2136
2137 if (ignored) return nullptr;
2138 return value;
2139}
2140
2141/// Store into a strong object. Sometimes calls this:
2142/// call void \@objc_storeStrong(i8** %addr, i8* %value)
2143/// Other times, breaks it down into components.
2144llvm::Value *CodeGenFunction::EmitARCStoreStrong(LValue dst,
2145 llvm::Value *newValue,
2146 bool ignored) {
2147 QualType type = dst.getType();
2148 bool isBlock = type->isBlockPointerType();
2149
2150 // Use a store barrier at -O0 unless this is a block type or the
2151 // lvalue is inadequately aligned.
2152 if (shouldUseFusedARCCalls() &&
2153 !isBlock &&
2154 (dst.getAlignment().isZero() ||
2155 dst.getAlignment() >= CharUnits::fromQuantity(PointerAlignInBytes))) {
2156 return EmitARCStoreStrongCall(dst.getAddress(), newValue, ignored);
2157 }
2158
2159 // Otherwise, split it out.
2160
2161 // Retain the new value.
2162 newValue = EmitARCRetain(type, newValue);
2163
2164 // Read the old value.
2165 llvm::Value *oldValue = EmitLoadOfScalar(dst, SourceLocation());
2166
2167 // Store. We do this before the release so that any deallocs won't
2168 // see the old value.
2169 EmitStoreOfScalar(newValue, dst);
2170
2171 // Finally, release the old value.
2172 EmitARCRelease(oldValue, dst.isARCPreciseLifetime());
2173
2174 return newValue;
2175}
2176
2177/// Autorelease the given object.
2178/// call i8* \@objc_autorelease(i8* %value)
2179llvm::Value *CodeGenFunction::EmitARCAutorelease(llvm::Value *value) {
2180 return emitARCValueOperation(*this, value,
2181 CGM.getObjCEntrypoints().objc_autorelease,
2182 "objc_autorelease");
2183}
2184
2185/// Autorelease the given object.
2186/// call i8* \@objc_autoreleaseReturnValue(i8* %value)
2187llvm::Value *
2188CodeGenFunction::EmitARCAutoreleaseReturnValue(llvm::Value *value) {
2189 return emitARCValueOperation(*this, value,
2190 CGM.getObjCEntrypoints().objc_autoreleaseReturnValue,
2191 "objc_autoreleaseReturnValue",
2192 /*isTailCall*/ true);
2193}
2194
2195/// Do a fused retain/autorelease of the given object.
2196/// call i8* \@objc_retainAutoreleaseReturnValue(i8* %value)
2197llvm::Value *
2198CodeGenFunction::EmitARCRetainAutoreleaseReturnValue(llvm::Value *value) {
2199 return emitARCValueOperation(*this, value,
2200 CGM.getObjCEntrypoints().objc_retainAutoreleaseReturnValue,
2201 "objc_retainAutoreleaseReturnValue",
2202 /*isTailCall*/ true);
2203}
2204
2205/// Do a fused retain/autorelease of the given object.
2206/// call i8* \@objc_retainAutorelease(i8* %value)
2207/// or
2208/// %retain = call i8* \@objc_retainBlock(i8* %value)
2209/// call i8* \@objc_autorelease(i8* %retain)
2210llvm::Value *CodeGenFunction::EmitARCRetainAutorelease(QualType type,
2211 llvm::Value *value) {
2212 if (!type->isBlockPointerType())
2213 return EmitARCRetainAutoreleaseNonBlock(value);
2214
2215 if (isa<llvm::ConstantPointerNull>(value)) return value;
2216
2217 llvm::Type *origType = value->getType();
2218 value = Builder.CreateBitCast(value, Int8PtrTy);
2219 value = EmitARCRetainBlock(value, /*mandatory*/ true);
2220 value = EmitARCAutorelease(value);
2221 return Builder.CreateBitCast(value, origType);
2222}
2223
2224/// Do a fused retain/autorelease of the given object.
2225/// call i8* \@objc_retainAutorelease(i8* %value)
2226llvm::Value *
2227CodeGenFunction::EmitARCRetainAutoreleaseNonBlock(llvm::Value *value) {
2228 return emitARCValueOperation(*this, value,
2229 CGM.getObjCEntrypoints().objc_retainAutorelease,
2230 "objc_retainAutorelease");
2231}
2232
2233/// i8* \@objc_loadWeak(i8** %addr)
2234/// Essentially objc_autorelease(objc_loadWeakRetained(addr)).
2235llvm::Value *CodeGenFunction::EmitARCLoadWeak(Address addr) {
2236 return emitARCLoadOperation(*this, addr,
2237 CGM.getObjCEntrypoints().objc_loadWeak,
2238 "objc_loadWeak");
2239}
2240
2241/// i8* \@objc_loadWeakRetained(i8** %addr)
2242llvm::Value *CodeGenFunction::EmitARCLoadWeakRetained(Address addr) {
2243 return emitARCLoadOperation(*this, addr,
2244 CGM.getObjCEntrypoints().objc_loadWeakRetained,
2245 "objc_loadWeakRetained");
2246}
2247
2248/// i8* \@objc_storeWeak(i8** %addr, i8* %value)
2249/// Returns %value.
2250llvm::Value *CodeGenFunction::EmitARCStoreWeak(Address addr,
2251 llvm::Value *value,
2252 bool ignored) {
2253 return emitARCStoreOperation(*this, addr, value,
2254 CGM.getObjCEntrypoints().objc_storeWeak,
2255 "objc_storeWeak", ignored);
2256}
2257
2258/// i8* \@objc_initWeak(i8** %addr, i8* %value)
2259/// Returns %value. %addr is known to not have a current weak entry.
2260/// Essentially equivalent to:
2261/// *addr = nil; objc_storeWeak(addr, value);
2262void CodeGenFunction::EmitARCInitWeak(Address addr, llvm::Value *value) {
2263 // If we're initializing to null, just write null to memory; no need
2264 // to get the runtime involved. But don't do this if optimization
2265 // is enabled, because accounting for this would make the optimizer
2266 // much more complicated.
2267 if (isa<llvm::ConstantPointerNull>(value) &&
2268 CGM.getCodeGenOpts().OptimizationLevel == 0) {
2269 Builder.CreateStore(value, addr);
2270 return;
2271 }
2272
2273 emitARCStoreOperation(*this, addr, value,
2274 CGM.getObjCEntrypoints().objc_initWeak,
2275 "objc_initWeak", /*ignored*/ true);
2276}
2277
2278/// void \@objc_destroyWeak(i8** %addr)
2279/// Essentially objc_storeWeak(addr, nil).
2280void CodeGenFunction::EmitARCDestroyWeak(Address addr) {
2281 llvm::Constant *&fn = CGM.getObjCEntrypoints().objc_destroyWeak;
2282 if (!fn) {
2283 llvm::FunctionType *fnType =
2284 llvm::FunctionType::get(Builder.getVoidTy(), Int8PtrPtrTy, false);
2285 fn = createARCRuntimeFunction(CGM, fnType, "objc_destroyWeak");
2286 }
2287
2288 // Cast the argument to 'id*'.
2289 addr = Builder.CreateBitCast(addr, Int8PtrPtrTy);
2290
2291 EmitNounwindRuntimeCall(fn, addr.getPointer());
2292}
2293
2294/// void \@objc_moveWeak(i8** %dest, i8** %src)
2295/// Disregards the current value in %dest. Leaves %src pointing to nothing.
2296/// Essentially (objc_copyWeak(dest, src), objc_destroyWeak(src)).
2297void CodeGenFunction::EmitARCMoveWeak(Address dst, Address src) {
2298 emitARCCopyOperation(*this, dst, src,
2299 CGM.getObjCEntrypoints().objc_moveWeak,
2300 "objc_moveWeak");
2301}
2302
2303/// void \@objc_copyWeak(i8** %dest, i8** %src)
2304/// Disregards the current value in %dest. Essentially
2305/// objc_release(objc_initWeak(dest, objc_readWeakRetained(src)))
2306void CodeGenFunction::EmitARCCopyWeak(Address dst, Address src) {
2307 emitARCCopyOperation(*this, dst, src,
2308 CGM.getObjCEntrypoints().objc_copyWeak,
2309 "objc_copyWeak");
2310}
2311
2312void CodeGenFunction::emitARCCopyAssignWeak(QualType Ty, Address DstAddr,
2313 Address SrcAddr) {
2314 llvm::Value *Object = EmitARCLoadWeakRetained(SrcAddr);
2315 Object = EmitObjCConsumeObject(Ty, Object);
2316 EmitARCStoreWeak(DstAddr, Object, false);
2317}
2318
2319void CodeGenFunction::emitARCMoveAssignWeak(QualType Ty, Address DstAddr,
2320 Address SrcAddr) {
2321 llvm::Value *Object = EmitARCLoadWeakRetained(SrcAddr);
2322 Object = EmitObjCConsumeObject(Ty, Object);
2323 EmitARCStoreWeak(DstAddr, Object, false);
2324 EmitARCDestroyWeak(SrcAddr);
2325}
2326
2327/// Produce the code to do a objc_autoreleasepool_push.
2328/// call i8* \@objc_autoreleasePoolPush(void)
2329llvm::Value *CodeGenFunction::EmitObjCAutoreleasePoolPush() {
2330 llvm::Constant *&fn = CGM.getObjCEntrypoints().objc_autoreleasePoolPush;
2331 if (!fn) {
2332 llvm::FunctionType *fnType =
2333 llvm::FunctionType::get(Int8PtrTy, false);
2334 fn = createARCRuntimeFunction(CGM, fnType, "objc_autoreleasePoolPush");
2335 }
2336
2337 return EmitNounwindRuntimeCall(fn);
2338}
2339
2340/// Produce the code to do a primitive release.
2341/// call void \@objc_autoreleasePoolPop(i8* %ptr)
2342void CodeGenFunction::EmitObjCAutoreleasePoolPop(llvm::Value *value) {
2343 assert(value->getType() == Int8PtrTy)((value->getType() == Int8PtrTy) ? static_cast<void>
(0) : __assert_fail ("value->getType() == Int8PtrTy", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 2343, __PRETTY_FUNCTION__))
;
2344
2345 llvm::Constant *&fn = CGM.getObjCEntrypoints().objc_autoreleasePoolPop;
2346 if (!fn) {
2347 llvm::FunctionType *fnType =
2348 llvm::FunctionType::get(Builder.getVoidTy(), Int8PtrTy, false);
2349
2350 // We don't want to use a weak import here; instead we should not
2351 // fall into this path.
2352 fn = createARCRuntimeFunction(CGM, fnType, "objc_autoreleasePoolPop");
2353 }
2354
2355 // objc_autoreleasePoolPop can throw.
2356 EmitRuntimeCallOrInvoke(fn, value);
2357}
2358
2359/// Produce the code to do an MRR version objc_autoreleasepool_push.
2360/// Which is: [[NSAutoreleasePool alloc] init];
2361/// Where alloc is declared as: + (id) alloc; in NSAutoreleasePool class.
2362/// init is declared as: - (id) init; in its NSObject super class.
2363///
2364llvm::Value *CodeGenFunction::EmitObjCMRRAutoreleasePoolPush() {
2365 CGObjCRuntime &Runtime = CGM.getObjCRuntime();
2366 llvm::Value *Receiver = Runtime.EmitNSAutoreleasePoolClassRef(*this);
2367 // [NSAutoreleasePool alloc]
2368 IdentifierInfo *II = &CGM.getContext().Idents.get("alloc");
2369 Selector AllocSel = getContext().Selectors.getSelector(0, &II);
2370 CallArgList Args;
2371 RValue AllocRV =
2372 Runtime.GenerateMessageSend(*this, ReturnValueSlot(),
2373 getContext().getObjCIdType(),
2374 AllocSel, Receiver, Args);
2375
2376 // [Receiver init]
2377 Receiver = AllocRV.getScalarVal();
2378 II = &CGM.getContext().Idents.get("init");
2379 Selector InitSel = getContext().Selectors.getSelector(0, &II);
2380 RValue InitRV =
2381 Runtime.GenerateMessageSend(*this, ReturnValueSlot(),
2382 getContext().getObjCIdType(),
2383 InitSel, Receiver, Args);
2384 return InitRV.getScalarVal();
2385}
2386
2387/// Produce the code to do a primitive release.
2388/// [tmp drain];
2389void CodeGenFunction::EmitObjCMRRAutoreleasePoolPop(llvm::Value *Arg) {
2390 IdentifierInfo *II = &CGM.getContext().Idents.get("drain");
2391 Selector DrainSel = getContext().Selectors.getSelector(0, &II);
2392 CallArgList Args;
2393 CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(),
2394 getContext().VoidTy, DrainSel, Arg, Args);
2395}
2396
2397void CodeGenFunction::destroyARCStrongPrecise(CodeGenFunction &CGF,
2398 Address addr,
2399 QualType type) {
2400 CGF.EmitARCDestroyStrong(addr, ARCPreciseLifetime);
2401}
2402
2403void CodeGenFunction::destroyARCStrongImprecise(CodeGenFunction &CGF,
2404 Address addr,
2405 QualType type) {
2406 CGF.EmitARCDestroyStrong(addr, ARCImpreciseLifetime);
2407}
2408
2409void CodeGenFunction::destroyARCWeak(CodeGenFunction &CGF,
2410 Address addr,
2411 QualType type) {
2412 CGF.EmitARCDestroyWeak(addr);
2413}
2414
2415void CodeGenFunction::emitARCIntrinsicUse(CodeGenFunction &CGF, Address addr,
2416 QualType type) {
2417 llvm::Value *value = CGF.Builder.CreateLoad(addr);
2418 CGF.EmitARCIntrinsicUse(value);
2419}
2420
2421namespace {
2422 struct CallObjCAutoreleasePoolObject final : EHScopeStack::Cleanup {
2423 llvm::Value *Token;
2424
2425 CallObjCAutoreleasePoolObject(llvm::Value *token) : Token(token) {}
2426
2427 void Emit(CodeGenFunction &CGF, Flags flags) override {
2428 CGF.EmitObjCAutoreleasePoolPop(Token);
2429 }
2430 };
2431 struct CallObjCMRRAutoreleasePoolObject final : EHScopeStack::Cleanup {
2432 llvm::Value *Token;
2433
2434 CallObjCMRRAutoreleasePoolObject(llvm::Value *token) : Token(token) {}
2435
2436 void Emit(CodeGenFunction &CGF, Flags flags) override {
2437 CGF.EmitObjCMRRAutoreleasePoolPop(Token);
2438 }
2439 };
2440}
2441
2442void CodeGenFunction::EmitObjCAutoreleasePoolCleanup(llvm::Value *Ptr) {
2443 if (CGM.getLangOpts().ObjCAutoRefCount)
2444 EHStack.pushCleanup<CallObjCAutoreleasePoolObject>(NormalCleanup, Ptr);
2445 else
2446 EHStack.pushCleanup<CallObjCMRRAutoreleasePoolObject>(NormalCleanup, Ptr);
2447}
2448
2449static TryEmitResult tryEmitARCRetainLoadOfScalar(CodeGenFunction &CGF,
2450 LValue lvalue,
2451 QualType type) {
2452 switch (type.getObjCLifetime()) {
2453 case Qualifiers::OCL_None:
2454 case Qualifiers::OCL_ExplicitNone:
2455 case Qualifiers::OCL_Strong:
2456 case Qualifiers::OCL_Autoreleasing:
2457 return TryEmitResult(CGF.EmitLoadOfLValue(lvalue,
2458 SourceLocation()).getScalarVal(),
2459 false);
2460
2461 case Qualifiers::OCL_Weak:
2462 return TryEmitResult(CGF.EmitARCLoadWeakRetained(lvalue.getAddress()),
2463 true);
2464 }
2465
2466 llvm_unreachable("impossible lifetime!")::llvm::llvm_unreachable_internal("impossible lifetime!", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 2466)
;
2467}
2468
2469static TryEmitResult tryEmitARCRetainLoadOfScalar(CodeGenFunction &CGF,
2470 const Expr *e) {
2471 e = e->IgnoreParens();
2472 QualType type = e->getType();
2473
2474 // If we're loading retained from a __strong xvalue, we can avoid
2475 // an extra retain/release pair by zeroing out the source of this
2476 // "move" operation.
2477 if (e->isXValue() &&
2478 !type.isConstQualified() &&
2479 type.getObjCLifetime() == Qualifiers::OCL_Strong) {
2480 // Emit the lvalue.
2481 LValue lv = CGF.EmitLValue(e);
2482
2483 // Load the object pointer.
2484 llvm::Value *result = CGF.EmitLoadOfLValue(lv,
2485 SourceLocation()).getScalarVal();
2486
2487 // Set the source pointer to NULL.
2488 CGF.EmitStoreOfScalar(getNullForVariable(lv.getAddress()), lv);
2489
2490 return TryEmitResult(result, true);
2491 }
2492
2493 // As a very special optimization, in ARC++, if the l-value is the
2494 // result of a non-volatile assignment, do a simple retain of the
2495 // result of the call to objc_storeWeak instead of reloading.
2496 if (CGF.getLangOpts().CPlusPlus &&
2497 !type.isVolatileQualified() &&
2498 type.getObjCLifetime() == Qualifiers::OCL_Weak &&
2499 isa<BinaryOperator>(e) &&
2500 cast<BinaryOperator>(e)->getOpcode() == BO_Assign)
2501 return TryEmitResult(CGF.EmitScalarExpr(e), false);
2502
2503 return tryEmitARCRetainLoadOfScalar(CGF, CGF.EmitLValue(e), type);
2504}
2505
2506typedef llvm::function_ref<llvm::Value *(CodeGenFunction &CGF,
2507 llvm::Value *value)>
2508 ValueTransform;
2509
2510/// Insert code immediately after a call.
2511static llvm::Value *emitARCOperationAfterCall(CodeGenFunction &CGF,
2512 llvm::Value *value,
2513 ValueTransform doAfterCall,
2514 ValueTransform doFallback) {
2515 if (llvm::CallInst *call = dyn_cast<llvm::CallInst>(value)) {
2516 CGBuilderTy::InsertPoint ip = CGF.Builder.saveIP();
2517
2518 // Place the retain immediately following the call.
2519 CGF.Builder.SetInsertPoint(call->getParent(),
2520 ++llvm::BasicBlock::iterator(call));
2521 value = doAfterCall(CGF, value);
2522
2523 CGF.Builder.restoreIP(ip);
2524 return value;
2525 } else if (llvm::InvokeInst *invoke = dyn_cast<llvm::InvokeInst>(value)) {
2526 CGBuilderTy::InsertPoint ip = CGF.Builder.saveIP();
2527
2528 // Place the retain at the beginning of the normal destination block.
2529 llvm::BasicBlock *BB = invoke->getNormalDest();
2530 CGF.Builder.SetInsertPoint(BB, BB->begin());
2531 value = doAfterCall(CGF, value);
2532
2533 CGF.Builder.restoreIP(ip);
2534 return value;
2535
2536 // Bitcasts can arise because of related-result returns. Rewrite
2537 // the operand.
2538 } else if (llvm::BitCastInst *bitcast = dyn_cast<llvm::BitCastInst>(value)) {
2539 llvm::Value *operand = bitcast->getOperand(0);
2540 operand = emitARCOperationAfterCall(CGF, operand, doAfterCall, doFallback);
2541 bitcast->setOperand(0, operand);
2542 return bitcast;
2543
2544 // Generic fall-back case.
2545 } else {
2546 // Retain using the non-block variant: we never need to do a copy
2547 // of a block that's been returned to us.
2548 return doFallback(CGF, value);
2549 }
2550}
2551
2552/// Given that the given expression is some sort of call (which does
2553/// not return retained), emit a retain following it.
2554static llvm::Value *emitARCRetainCallResult(CodeGenFunction &CGF,
2555 const Expr *e) {
2556 llvm::Value *value = CGF.EmitScalarExpr(e);
2557 return emitARCOperationAfterCall(CGF, value,
2558 [](CodeGenFunction &CGF, llvm::Value *value) {
2559 return CGF.EmitARCRetainAutoreleasedReturnValue(value);
2560 },
2561 [](CodeGenFunction &CGF, llvm::Value *value) {
2562 return CGF.EmitARCRetainNonBlock(value);
2563 });
2564}
2565
2566/// Given that the given expression is some sort of call (which does
2567/// not return retained), perform an unsafeClaim following it.
2568static llvm::Value *emitARCUnsafeClaimCallResult(CodeGenFunction &CGF,
2569 const Expr *e) {
2570 llvm::Value *value = CGF.EmitScalarExpr(e);
2571 return emitARCOperationAfterCall(CGF, value,
2572 [](CodeGenFunction &CGF, llvm::Value *value) {
2573 return CGF.EmitARCUnsafeClaimAutoreleasedReturnValue(value);
2574 },
2575 [](CodeGenFunction &CGF, llvm::Value *value) {
2576 return value;
2577 });
2578}
2579
2580llvm::Value *CodeGenFunction::EmitARCReclaimReturnedObject(const Expr *E,
2581 bool allowUnsafeClaim) {
2582 if (allowUnsafeClaim &&
2583 CGM.getLangOpts().ObjCRuntime.hasARCUnsafeClaimAutoreleasedReturnValue()) {
2584 return emitARCUnsafeClaimCallResult(*this, E);
2585 } else {
2586 llvm::Value *value = emitARCRetainCallResult(*this, E);
2587 return EmitObjCConsumeObject(E->getType(), value);
2588 }
2589}
2590
2591/// Determine whether it might be important to emit a separate
2592/// objc_retain_block on the result of the given expression, or
2593/// whether it's okay to just emit it in a +1 context.
2594static bool shouldEmitSeparateBlockRetain(const Expr *e) {
2595 assert(e->getType()->isBlockPointerType())((e->getType()->isBlockPointerType()) ? static_cast<
void> (0) : __assert_fail ("e->getType()->isBlockPointerType()"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 2595, __PRETTY_FUNCTION__))
;
2596 e = e->IgnoreParens();
2597
2598 // For future goodness, emit block expressions directly in +1
2599 // contexts if we can.
2600 if (isa<BlockExpr>(e))
2601 return false;
2602
2603 if (const CastExpr *cast = dyn_cast<CastExpr>(e)) {
2604 switch (cast->getCastKind()) {
2605 // Emitting these operations in +1 contexts is goodness.
2606 case CK_LValueToRValue:
2607 case CK_ARCReclaimReturnedObject:
2608 case CK_ARCConsumeObject:
2609 case CK_ARCProduceObject:
2610 return false;
2611
2612 // These operations preserve a block type.
2613 case CK_NoOp:
2614 case CK_BitCast:
2615 return shouldEmitSeparateBlockRetain(cast->getSubExpr());
2616
2617 // These operations are known to be bad (or haven't been considered).
2618 case CK_AnyPointerToBlockPointerCast:
2619 default:
2620 return true;
2621 }
2622 }
2623
2624 return true;
2625}
2626
2627namespace {
2628/// A CRTP base class for emitting expressions of retainable object
2629/// pointer type in ARC.
2630template <typename Impl, typename Result> class ARCExprEmitter {
2631protected:
2632 CodeGenFunction &CGF;
2633 Impl &asImpl() { return *static_cast<Impl*>(this); }
2634
2635 ARCExprEmitter(CodeGenFunction &CGF) : CGF(CGF) {}
2636
2637public:
2638 Result visit(const Expr *e);
2639 Result visitCastExpr(const CastExpr *e);
2640 Result visitPseudoObjectExpr(const PseudoObjectExpr *e);
2641 Result visitBinaryOperator(const BinaryOperator *e);
2642 Result visitBinAssign(const BinaryOperator *e);
2643 Result visitBinAssignUnsafeUnretained(const BinaryOperator *e);
2644 Result visitBinAssignAutoreleasing(const BinaryOperator *e);
2645 Result visitBinAssignWeak(const BinaryOperator *e);
2646 Result visitBinAssignStrong(const BinaryOperator *e);
2647
2648 // Minimal implementation:
2649 // Result visitLValueToRValue(const Expr *e)
2650 // Result visitConsumeObject(const Expr *e)
2651 // Result visitExtendBlockObject(const Expr *e)
2652 // Result visitReclaimReturnedObject(const Expr *e)
2653 // Result visitCall(const Expr *e)
2654 // Result visitExpr(const Expr *e)
2655 //
2656 // Result emitBitCast(Result result, llvm::Type *resultType)
2657 // llvm::Value *getValueOfResult(Result result)
2658};
2659}
2660
2661/// Try to emit a PseudoObjectExpr under special ARC rules.
2662///
2663/// This massively duplicates emitPseudoObjectRValue.
2664template <typename Impl, typename Result>
2665Result
2666ARCExprEmitter<Impl,Result>::visitPseudoObjectExpr(const PseudoObjectExpr *E) {
2667 SmallVector<CodeGenFunction::OpaqueValueMappingData, 4> opaques;
2668
2669 // Find the result expression.
2670 const Expr *resultExpr = E->getResultExpr();
2671 assert(resultExpr)((resultExpr) ? static_cast<void> (0) : __assert_fail (
"resultExpr", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 2671, __PRETTY_FUNCTION__))
;
2672 Result result;
11
'result' declared without an initial value
2673
2674 for (PseudoObjectExpr::const_semantics_iterator
13
Loop condition is false. Execution continues on line 2710
2675 i = E->semantics_begin(), e = E->semantics_end(); i != e; ++i) {
12
Assuming 'i' is equal to 'e'
2676 const Expr *semantic = *i;
2677
2678 // If this semantic expression is an opaque value, bind it
2679 // to the result of its source expression.
2680 if (const OpaqueValueExpr *ov = dyn_cast<OpaqueValueExpr>(semantic)) {
2681 typedef CodeGenFunction::OpaqueValueMappingData OVMA;
2682 OVMA opaqueData;
2683
2684 // If this semantic is the result of the pseudo-object
2685 // expression, try to evaluate the source as +1.
2686 if (ov == resultExpr) {
2687 assert(!OVMA::shouldBindAsLValue(ov))((!OVMA::shouldBindAsLValue(ov)) ? static_cast<void> (0
) : __assert_fail ("!OVMA::shouldBindAsLValue(ov)", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 2687, __PRETTY_FUNCTION__))
;
2688 result = asImpl().visit(ov->getSourceExpr());
2689 opaqueData = OVMA::bind(CGF, ov,
2690 RValue::get(asImpl().getValueOfResult(result)));
2691
2692 // Otherwise, just bind it.
2693 } else {
2694 opaqueData = OVMA::bind(CGF, ov, ov->getSourceExpr());
2695 }
2696 opaques.push_back(opaqueData);
2697
2698 // Otherwise, if the expression is the result, evaluate it
2699 // and remember the result.
2700 } else if (semantic == resultExpr) {
2701 result = asImpl().visit(semantic);
2702
2703 // Otherwise, evaluate the expression in an ignored context.
2704 } else {
2705 CGF.EmitIgnoredExpr(semantic);
2706 }
2707 }
2708
2709 // Unbind all the opaques now.
2710 for (unsigned i = 0, e = opaques.size(); i != e; ++i)
14
Assuming 'i' is equal to 'e'
15
Loop condition is false. Execution continues on line 2713
2711 opaques[i].unbind(CGF);
2712
2713 return result;
16
Undefined or garbage value returned to caller
2714}
2715
2716template <typename Impl, typename Result>
2717Result ARCExprEmitter<Impl,Result>::visitCastExpr(const CastExpr *e) {
2718 switch (e->getCastKind()) {
2719
2720 // No-op casts don't change the type, so we just ignore them.
2721 case CK_NoOp:
2722 return asImpl().visit(e->getSubExpr());
2723
2724 // These casts can change the type.
2725 case CK_CPointerToObjCPointerCast:
2726 case CK_BlockPointerToObjCPointerCast:
2727 case CK_AnyPointerToBlockPointerCast:
2728 case CK_BitCast: {
2729 llvm::Type *resultType = CGF.ConvertType(e->getType());
2730 assert(e->getSubExpr()->getType()->hasPointerRepresentation())((e->getSubExpr()->getType()->hasPointerRepresentation
()) ? static_cast<void> (0) : __assert_fail ("e->getSubExpr()->getType()->hasPointerRepresentation()"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 2730, __PRETTY_FUNCTION__))
;
2731 Result result = asImpl().visit(e->getSubExpr());
2732 return asImpl().emitBitCast(result, resultType);
2733 }
2734
2735 // Handle some casts specially.
2736 case CK_LValueToRValue:
2737 return asImpl().visitLValueToRValue(e->getSubExpr());
2738 case CK_ARCConsumeObject:
2739 return asImpl().visitConsumeObject(e->getSubExpr());
2740 case CK_ARCExtendBlockObject:
2741 return asImpl().visitExtendBlockObject(e->getSubExpr());
2742 case CK_ARCReclaimReturnedObject:
2743 return asImpl().visitReclaimReturnedObject(e->getSubExpr());
2744
2745 // Otherwise, use the default logic.
2746 default:
2747 return asImpl().visitExpr(e);
2748 }
2749}
2750
2751template <typename Impl, typename Result>
2752Result
2753ARCExprEmitter<Impl,Result>::visitBinaryOperator(const BinaryOperator *e) {
2754 switch (e->getOpcode()) {
2755 case BO_Comma:
2756 CGF.EmitIgnoredExpr(e->getLHS());
2757 CGF.EnsureInsertPoint();
2758 return asImpl().visit(e->getRHS());
2759
2760 case BO_Assign:
2761 return asImpl().visitBinAssign(e);
2762
2763 default:
2764 return asImpl().visitExpr(e);
2765 }
2766}
2767
2768template <typename Impl, typename Result>
2769Result ARCExprEmitter<Impl,Result>::visitBinAssign(const BinaryOperator *e) {
2770 switch (e->getLHS()->getType().getObjCLifetime()) {
2771 case Qualifiers::OCL_ExplicitNone:
2772 return asImpl().visitBinAssignUnsafeUnretained(e);
2773
2774 case Qualifiers::OCL_Weak:
2775 return asImpl().visitBinAssignWeak(e);
2776
2777 case Qualifiers::OCL_Autoreleasing:
2778 return asImpl().visitBinAssignAutoreleasing(e);
2779
2780 case Qualifiers::OCL_Strong:
2781 return asImpl().visitBinAssignStrong(e);
2782
2783 case Qualifiers::OCL_None:
2784 return asImpl().visitExpr(e);
2785 }
2786 llvm_unreachable("bad ObjC ownership qualifier")::llvm::llvm_unreachable_internal("bad ObjC ownership qualifier"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 2786)
;
2787}
2788
2789/// The default rule for __unsafe_unretained emits the RHS recursively,
2790/// stores into the unsafe variable, and propagates the result outward.
2791template <typename Impl, typename Result>
2792Result ARCExprEmitter<Impl,Result>::
2793 visitBinAssignUnsafeUnretained(const BinaryOperator *e) {
2794 // Recursively emit the RHS.
2795 // For __block safety, do this before emitting the LHS.
2796 Result result = asImpl().visit(e->getRHS());
2797
2798 // Perform the store.
2799 LValue lvalue =
2800 CGF.EmitCheckedLValue(e->getLHS(), CodeGenFunction::TCK_Store);
2801 CGF.EmitStoreThroughLValue(RValue::get(asImpl().getValueOfResult(result)),
2802 lvalue);
2803
2804 return result;
2805}
2806
2807template <typename Impl, typename Result>
2808Result
2809ARCExprEmitter<Impl,Result>::visitBinAssignAutoreleasing(const BinaryOperator *e) {
2810 return asImpl().visitExpr(e);
2811}
2812
2813template <typename Impl, typename Result>
2814Result
2815ARCExprEmitter<Impl,Result>::visitBinAssignWeak(const BinaryOperator *e) {
2816 return asImpl().visitExpr(e);
2817}
2818
2819template <typename Impl, typename Result>
2820Result
2821ARCExprEmitter<Impl,Result>::visitBinAssignStrong(const BinaryOperator *e) {
2822 return asImpl().visitExpr(e);
2823}
2824
2825/// The general expression-emission logic.
2826template <typename Impl, typename Result>
2827Result ARCExprEmitter<Impl,Result>::visit(const Expr *e) {
2828 // We should *never* see a nested full-expression here, because if
2829 // we fail to emit at +1, our caller must not retain after we close
2830 // out the full-expression. This isn't as important in the unsafe
2831 // emitter.
2832 assert(!isa<ExprWithCleanups>(e))((!isa<ExprWithCleanups>(e)) ? static_cast<void> (
0) : __assert_fail ("!isa<ExprWithCleanups>(e)", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 2832, __PRETTY_FUNCTION__))
;
2833
2834 // Look through parens, __extension__, generic selection, etc.
2835 e = e->IgnoreParens();
2836
2837 // Handle certain kinds of casts.
2838 if (const CastExpr *ce = dyn_cast<CastExpr>(e)) {
7
Taking false branch
2839 return asImpl().visitCastExpr(ce);
2840
2841 // Handle the comma operator.
2842 } else if (auto op = dyn_cast<BinaryOperator>(e)) {
8
Taking false branch
2843 return asImpl().visitBinaryOperator(op);
2844
2845 // TODO: handle conditional operators here
2846
2847 // For calls and message sends, use the retained-call logic.
2848 // Delegate inits are a special case in that they're the only
2849 // returns-retained expression that *isn't* surrounded by
2850 // a consume.
2851 } else if (isa<CallExpr>(e) ||
2852 (isa<ObjCMessageExpr>(e) &&
2853 !cast<ObjCMessageExpr>(e)->isDelegateInitCall())) {
2854 return asImpl().visitCall(e);
2855
2856 // Look through pseudo-object expressions.
2857 } else if (const PseudoObjectExpr *pseudo = dyn_cast<PseudoObjectExpr>(e)) {
9
Taking true branch
2858 return asImpl().visitPseudoObjectExpr(pseudo);
10
Calling 'ARCExprEmitter::visitPseudoObjectExpr'
2859 }
2860
2861 return asImpl().visitExpr(e);
2862}
2863
2864namespace {
2865
2866/// An emitter for +1 results.
2867struct ARCRetainExprEmitter :
2868 public ARCExprEmitter<ARCRetainExprEmitter, TryEmitResult> {
2869
2870 ARCRetainExprEmitter(CodeGenFunction &CGF) : ARCExprEmitter(CGF) {}
2871
2872 llvm::Value *getValueOfResult(TryEmitResult result) {
2873 return result.getPointer();
2874 }
2875
2876 TryEmitResult emitBitCast(TryEmitResult result, llvm::Type *resultType) {
2877 llvm::Value *value = result.getPointer();
2878 value = CGF.Builder.CreateBitCast(value, resultType);
2879 result.setPointer(value);
2880 return result;
2881 }
2882
2883 TryEmitResult visitLValueToRValue(const Expr *e) {
2884 return tryEmitARCRetainLoadOfScalar(CGF, e);
2885 }
2886
2887 /// For consumptions, just emit the subexpression and thus elide
2888 /// the retain/release pair.
2889 TryEmitResult visitConsumeObject(const Expr *e) {
2890 llvm::Value *result = CGF.EmitScalarExpr(e);
2891 return TryEmitResult(result, true);
2892 }
2893
2894 /// Block extends are net +0. Naively, we could just recurse on
2895 /// the subexpression, but actually we need to ensure that the
2896 /// value is copied as a block, so there's a little filter here.
2897 TryEmitResult visitExtendBlockObject(const Expr *e) {
2898 llvm::Value *result; // will be a +0 value
2899
2900 // If we can't safely assume the sub-expression will produce a
2901 // block-copied value, emit the sub-expression at +0.
2902 if (shouldEmitSeparateBlockRetain(e)) {
2903 result = CGF.EmitScalarExpr(e);
2904
2905 // Otherwise, try to emit the sub-expression at +1 recursively.
2906 } else {
2907 TryEmitResult subresult = asImpl().visit(e);
2908
2909 // If that produced a retained value, just use that.
2910 if (subresult.getInt()) {
2911 return subresult;
2912 }
2913
2914 // Otherwise it's +0.
2915 result = subresult.getPointer();
2916 }
2917
2918 // Retain the object as a block.
2919 result = CGF.EmitARCRetainBlock(result, /*mandatory*/ true);
2920 return TryEmitResult(result, true);
2921 }
2922
2923 /// For reclaims, emit the subexpression as a retained call and
2924 /// skip the consumption.
2925 TryEmitResult visitReclaimReturnedObject(const Expr *e) {
2926 llvm::Value *result = emitARCRetainCallResult(CGF, e);
2927 return TryEmitResult(result, true);
2928 }
2929
2930 /// When we have an undecorated call, retroactively do a claim.
2931 TryEmitResult visitCall(const Expr *e) {
2932 llvm::Value *result = emitARCRetainCallResult(CGF, e);
2933 return TryEmitResult(result, true);
2934 }
2935
2936 // TODO: maybe special-case visitBinAssignWeak?
2937
2938 TryEmitResult visitExpr(const Expr *e) {
2939 // We didn't find an obvious production, so emit what we've got and
2940 // tell the caller that we didn't manage to retain.
2941 llvm::Value *result = CGF.EmitScalarExpr(e);
2942 return TryEmitResult(result, false);
2943 }
2944};
2945}
2946
2947static TryEmitResult
2948tryEmitARCRetainScalarExpr(CodeGenFunction &CGF, const Expr *e) {
2949 return ARCRetainExprEmitter(CGF).visit(e);
2950}
2951
2952static llvm::Value *emitARCRetainLoadOfScalar(CodeGenFunction &CGF,
2953 LValue lvalue,
2954 QualType type) {
2955 TryEmitResult result = tryEmitARCRetainLoadOfScalar(CGF, lvalue, type);
2956 llvm::Value *value = result.getPointer();
2957 if (!result.getInt())
2958 value = CGF.EmitARCRetain(type, value);
2959 return value;
2960}
2961
2962/// EmitARCRetainScalarExpr - Semantically equivalent to
2963/// EmitARCRetainObject(e->getType(), EmitScalarExpr(e)), but making a
2964/// best-effort attempt to peephole expressions that naturally produce
2965/// retained objects.
2966llvm::Value *CodeGenFunction::EmitARCRetainScalarExpr(const Expr *e) {
2967 // The retain needs to happen within the full-expression.
2968 if (const ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(e)) {
2969 enterFullExpression(cleanups);
2970 RunCleanupsScope scope(*this);
2971 return EmitARCRetainScalarExpr(cleanups->getSubExpr());
2972 }
2973
2974 TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e);
2975 llvm::Value *value = result.getPointer();
2976 if (!result.getInt())
2977 value = EmitARCRetain(e->getType(), value);
2978 return value;
2979}
2980
2981llvm::Value *
2982CodeGenFunction::EmitARCRetainAutoreleaseScalarExpr(const Expr *e) {
2983 // The retain needs to happen within the full-expression.
2984 if (const ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(e)) {
2985 enterFullExpression(cleanups);
2986 RunCleanupsScope scope(*this);
2987 return EmitARCRetainAutoreleaseScalarExpr(cleanups->getSubExpr());
2988 }
2989
2990 TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e);
2991 llvm::Value *value = result.getPointer();
2992 if (result.getInt())
2993 value = EmitARCAutorelease(value);
2994 else
2995 value = EmitARCRetainAutorelease(e->getType(), value);
2996 return value;
2997}
2998
2999llvm::Value *CodeGenFunction::EmitARCExtendBlockObject(const Expr *e) {
3000 llvm::Value *result;
3001 bool doRetain;
3002
3003 if (shouldEmitSeparateBlockRetain(e)) {
3004 result = EmitScalarExpr(e);
3005 doRetain = true;
3006 } else {
3007 TryEmitResult subresult = tryEmitARCRetainScalarExpr(*this, e);
3008 result = subresult.getPointer();
3009 doRetain = !subresult.getInt();
3010 }
3011
3012 if (doRetain)
3013 result = EmitARCRetainBlock(result, /*mandatory*/ true);
3014 return EmitObjCConsumeObject(e->getType(), result);
3015}
3016
3017llvm::Value *CodeGenFunction::EmitObjCThrowOperand(const Expr *expr) {
3018 // In ARC, retain and autorelease the expression.
3019 if (getLangOpts().ObjCAutoRefCount) {
3020 // Do so before running any cleanups for the full-expression.
3021 // EmitARCRetainAutoreleaseScalarExpr does this for us.
3022 return EmitARCRetainAutoreleaseScalarExpr(expr);
3023 }
3024
3025 // Otherwise, use the normal scalar-expression emission. The
3026 // exception machinery doesn't do anything special with the
3027 // exception like retaining it, so there's no safety associated with
3028 // only running cleanups after the throw has started, and when it
3029 // matters it tends to be substantially inferior code.
3030 return EmitScalarExpr(expr);
3031}
3032
3033namespace {
3034
3035/// An emitter for assigning into an __unsafe_unretained context.
3036struct ARCUnsafeUnretainedExprEmitter :
3037 public ARCExprEmitter<ARCUnsafeUnretainedExprEmitter, llvm::Value*> {
3038
3039 ARCUnsafeUnretainedExprEmitter(CodeGenFunction &CGF) : ARCExprEmitter(CGF) {}
3040
3041 llvm::Value *getValueOfResult(llvm::Value *value) {
3042 return value;
3043 }
3044
3045 llvm::Value *emitBitCast(llvm::Value *value, llvm::Type *resultType) {
3046 return CGF.Builder.CreateBitCast(value, resultType);
3047 }
3048
3049 llvm::Value *visitLValueToRValue(const Expr *e) {
3050 return CGF.EmitScalarExpr(e);
3051 }
3052
3053 /// For consumptions, just emit the subexpression and perform the
3054 /// consumption like normal.
3055 llvm::Value *visitConsumeObject(const Expr *e) {
3056 llvm::Value *value = CGF.EmitScalarExpr(e);
3057 return CGF.EmitObjCConsumeObject(e->getType(), value);
3058 }
3059
3060 /// No special logic for block extensions. (This probably can't
3061 /// actually happen in this emitter, though.)
3062 llvm::Value *visitExtendBlockObject(const Expr *e) {
3063 return CGF.EmitARCExtendBlockObject(e);
3064 }
3065
3066 /// For reclaims, perform an unsafeClaim if that's enabled.
3067 llvm::Value *visitReclaimReturnedObject(const Expr *e) {
3068 return CGF.EmitARCReclaimReturnedObject(e, /*unsafe*/ true);
3069 }
3070
3071 /// When we have an undecorated call, just emit it without adding
3072 /// the unsafeClaim.
3073 llvm::Value *visitCall(const Expr *e) {
3074 return CGF.EmitScalarExpr(e);
3075 }
3076
3077 /// Just do normal scalar emission in the default case.
3078 llvm::Value *visitExpr(const Expr *e) {
3079 return CGF.EmitScalarExpr(e);
3080 }
3081};
3082}
3083
3084static llvm::Value *emitARCUnsafeUnretainedScalarExpr(CodeGenFunction &CGF,
3085 const Expr *e) {
3086 return ARCUnsafeUnretainedExprEmitter(CGF).visit(e);
6
Calling 'ARCExprEmitter::visit'
3087}
3088
3089/// EmitARCUnsafeUnretainedScalarExpr - Semantically equivalent to
3090/// immediately releasing the resut of EmitARCRetainScalarExpr, but
3091/// avoiding any spurious retains, including by performing reclaims
3092/// with objc_unsafeClaimAutoreleasedReturnValue.
3093llvm::Value *CodeGenFunction::EmitARCUnsafeUnretainedScalarExpr(const Expr *e) {
3094 // Look through full-expressions.
3095 if (const ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(e)) {
4
Taking false branch
3096 enterFullExpression(cleanups);
3097 RunCleanupsScope scope(*this);
3098 return emitARCUnsafeUnretainedScalarExpr(*this, cleanups->getSubExpr());
3099 }
3100
3101 return emitARCUnsafeUnretainedScalarExpr(*this, e);
5
Calling 'emitARCUnsafeUnretainedScalarExpr'
3102}
3103
3104std::pair<LValue,llvm::Value*>
3105CodeGenFunction::EmitARCStoreUnsafeUnretained(const BinaryOperator *e,
3106 bool ignored) {
3107 // Evaluate the RHS first. If we're ignoring the result, assume
3108 // that we can emit at an unsafe +0.
3109 llvm::Value *value;
3110 if (ignored) {
1
Assuming 'ignored' is not equal to 0
2
Taking true branch
3111 value = EmitARCUnsafeUnretainedScalarExpr(e->getRHS());
3
Calling 'CodeGenFunction::EmitARCUnsafeUnretainedScalarExpr'
3112 } else {
3113 value = EmitScalarExpr(e->getRHS());
3114 }
3115
3116 // Emit the LHS and perform the store.
3117 LValue lvalue = EmitLValue(e->getLHS());
3118 EmitStoreOfScalar(value, lvalue);
3119
3120 return std::pair<LValue,llvm::Value*>(std::move(lvalue), value);
3121}
3122
3123std::pair<LValue,llvm::Value*>
3124CodeGenFunction::EmitARCStoreStrong(const BinaryOperator *e,
3125 bool ignored) {
3126 // Evaluate the RHS first.
3127 TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e->getRHS());
3128 llvm::Value *value = result.getPointer();
3129
3130 bool hasImmediateRetain = result.getInt();
3131
3132 // If we didn't emit a retained object, and the l-value is of block
3133 // type, then we need to emit the block-retain immediately in case
3134 // it invalidates the l-value.
3135 if (!hasImmediateRetain && e->getType()->isBlockPointerType()) {
3136 value = EmitARCRetainBlock(value, /*mandatory*/ false);
3137 hasImmediateRetain = true;
3138 }
3139
3140 LValue lvalue = EmitLValue(e->getLHS());
3141
3142 // If the RHS was emitted retained, expand this.
3143 if (hasImmediateRetain) {
3144 llvm::Value *oldValue = EmitLoadOfScalar(lvalue, SourceLocation());
3145 EmitStoreOfScalar(value, lvalue);
3146 EmitARCRelease(oldValue, lvalue.isARCPreciseLifetime());
3147 } else {
3148 value = EmitARCStoreStrong(lvalue, value, ignored);
3149 }
3150
3151 return std::pair<LValue,llvm::Value*>(lvalue, value);
3152}
3153
3154std::pair<LValue,llvm::Value*>
3155CodeGenFunction::EmitARCStoreAutoreleasing(const BinaryOperator *e) {
3156 llvm::Value *value = EmitARCRetainAutoreleaseScalarExpr(e->getRHS());
3157 LValue lvalue = EmitLValue(e->getLHS());
3158
3159 EmitStoreOfScalar(value, lvalue);
3160
3161 return std::pair<LValue,llvm::Value*>(lvalue, value);
3162}
3163
3164void CodeGenFunction::EmitObjCAutoreleasePoolStmt(
3165 const ObjCAutoreleasePoolStmt &ARPS) {
3166 const Stmt *subStmt = ARPS.getSubStmt();
3167 const CompoundStmt &S = cast<CompoundStmt>(*subStmt);
3168
3169 CGDebugInfo *DI = getDebugInfo();
3170 if (DI)
3171 DI->EmitLexicalBlockStart(Builder, S.getLBracLoc());
3172
3173 // Keep track of the current cleanup stack depth.
3174 RunCleanupsScope Scope(*this);
3175 if (CGM.getLangOpts().ObjCRuntime.hasNativeARC()) {
3176 llvm::Value *token = EmitObjCAutoreleasePoolPush();
3177 EHStack.pushCleanup<CallObjCAutoreleasePoolObject>(NormalCleanup, token);
3178 } else {
3179 llvm::Value *token = EmitObjCMRRAutoreleasePoolPush();
3180 EHStack.pushCleanup<CallObjCMRRAutoreleasePoolObject>(NormalCleanup, token);
3181 }
3182
3183 for (const auto *I : S.body())
3184 EmitStmt(I);
3185
3186 if (DI)
3187 DI->EmitLexicalBlockEnd(Builder, S.getRBracLoc());
3188}
3189
3190/// EmitExtendGCLifetime - Given a pointer to an Objective-C object,
3191/// make sure it survives garbage collection until this point.
3192void CodeGenFunction::EmitExtendGCLifetime(llvm::Value *object) {
3193 // We just use an inline assembly.
3194 llvm::FunctionType *extenderType
3195 = llvm::FunctionType::get(VoidTy, VoidPtrTy, RequiredArgs::All);
3196 llvm::Value *extender
3197 = llvm::InlineAsm::get(extenderType,
3198 /* assembly */ "",
3199 /* constraints */ "r",
3200 /* side effects */ true);
3201
3202 object = Builder.CreateBitCast(object, VoidPtrTy);
3203 EmitNounwindRuntimeCall(extender, object);
3204}
3205
3206/// GenerateObjCAtomicSetterCopyHelperFunction - Given a c++ object type with
3207/// non-trivial copy assignment function, produce following helper function.
3208/// static void copyHelper(Ty *dest, const Ty *source) { *dest = *source; }
3209///
3210llvm::Constant *
3211CodeGenFunction::GenerateObjCAtomicSetterCopyHelperFunction(
3212 const ObjCPropertyImplDecl *PID) {
3213 if (!getLangOpts().CPlusPlus ||
3214 !getLangOpts().ObjCRuntime.hasAtomicCopyHelper())
3215 return nullptr;
3216 QualType Ty = PID->getPropertyIvarDecl()->getType();
3217 if (!Ty->isRecordType())
3218 return nullptr;
3219 const ObjCPropertyDecl *PD = PID->getPropertyDecl();
3220 if ((!(PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_atomic)))
3221 return nullptr;
3222 llvm::Constant *HelperFn = nullptr;
3223 if (hasTrivialSetExpr(PID))
3224 return nullptr;
3225 assert(PID->getSetterCXXAssignment() && "SetterCXXAssignment - null")((PID->getSetterCXXAssignment() && "SetterCXXAssignment - null"
) ? static_cast<void> (0) : __assert_fail ("PID->getSetterCXXAssignment() && \"SetterCXXAssignment - null\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 3225, __PRETTY_FUNCTION__))
;
3226 if ((HelperFn = CGM.getAtomicSetterHelperFnMap(Ty)))
3227 return HelperFn;
3228
3229 ASTContext &C = getContext();
3230 IdentifierInfo *II
3231 = &CGM.getContext().Idents.get("__assign_helper_atomic_property_");
3232 FunctionDecl *FD = FunctionDecl::Create(C,
3233 C.getTranslationUnitDecl(),
3234 SourceLocation(),
3235 SourceLocation(), II, C.VoidTy,
3236 nullptr, SC_Static,
3237 false,
3238 false);
3239
3240 QualType DestTy = C.getPointerType(Ty);
3241 QualType SrcTy = Ty;
3242 SrcTy.addConst();
3243 SrcTy = C.getPointerType(SrcTy);
3244
3245 FunctionArgList args;
3246 ImplicitParamDecl DstDecl(getContext(), FD, SourceLocation(), /*Id=*/nullptr,
3247 DestTy, ImplicitParamDecl::Other);
3248 args.push_back(&DstDecl);
3249 ImplicitParamDecl SrcDecl(getContext(), FD, SourceLocation(), /*Id=*/nullptr,
3250 SrcTy, ImplicitParamDecl::Other);
3251 args.push_back(&SrcDecl);
3252
3253 const CGFunctionInfo &FI =
3254 CGM.getTypes().arrangeBuiltinFunctionDeclaration(C.VoidTy, args);
3255
3256 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
3257
3258 llvm::Function *Fn =
3259 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
3260 "__assign_helper_atomic_property_",
3261 &CGM.getModule());
3262
3263 CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, FI);
3264
3265 StartFunction(FD, C.VoidTy, Fn, FI, args);
3266
3267 DeclRefExpr DstExpr(&DstDecl, false, DestTy,
3268 VK_RValue, SourceLocation());
3269 UnaryOperator DST(&DstExpr, UO_Deref, DestTy->getPointeeType(),
3270 VK_LValue, OK_Ordinary, SourceLocation(), false);
3271
3272 DeclRefExpr SrcExpr(&SrcDecl, false, SrcTy,
3273 VK_RValue, SourceLocation());
3274 UnaryOperator SRC(&SrcExpr, UO_Deref, SrcTy->getPointeeType(),
3275 VK_LValue, OK_Ordinary, SourceLocation(), false);
3276
3277 Expr *Args[2] = { &DST, &SRC };
3278 CallExpr *CalleeExp = cast<CallExpr>(PID->getSetterCXXAssignment());
3279 CXXOperatorCallExpr TheCall(C, OO_Equal, CalleeExp->getCallee(),
3280 Args, DestTy->getPointeeType(),
3281 VK_LValue, SourceLocation(), FPOptions());
3282
3283 EmitStmt(&TheCall);
3284
3285 FinishFunction();
3286 HelperFn = llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
3287 CGM.setAtomicSetterHelperFnMap(Ty, HelperFn);
3288 return HelperFn;
3289}
3290
3291llvm::Constant *
3292CodeGenFunction::GenerateObjCAtomicGetterCopyHelperFunction(
3293 const ObjCPropertyImplDecl *PID) {
3294 if (!getLangOpts().CPlusPlus ||
3295 !getLangOpts().ObjCRuntime.hasAtomicCopyHelper())
3296 return nullptr;
3297 const ObjCPropertyDecl *PD = PID->getPropertyDecl();
3298 QualType Ty = PD->getType();
3299 if (!Ty->isRecordType())
3300 return nullptr;
3301 if ((!(PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_atomic)))
3302 return nullptr;
3303 llvm::Constant *HelperFn = nullptr;
3304
3305 if (hasTrivialGetExpr(PID))
3306 return nullptr;
3307 assert(PID->getGetterCXXConstructor() && "getGetterCXXConstructor - null")((PID->getGetterCXXConstructor() && "getGetterCXXConstructor - null"
) ? static_cast<void> (0) : __assert_fail ("PID->getGetterCXXConstructor() && \"getGetterCXXConstructor - null\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 3307, __PRETTY_FUNCTION__))
;
3308 if ((HelperFn = CGM.getAtomicGetterHelperFnMap(Ty)))
3309 return HelperFn;
3310
3311
3312 ASTContext &C = getContext();
3313 IdentifierInfo *II
3314 = &CGM.getContext().Idents.get("__copy_helper_atomic_property_");
3315 FunctionDecl *FD = FunctionDecl::Create(C,
3316 C.getTranslationUnitDecl(),
3317 SourceLocation(),
3318 SourceLocation(), II, C.VoidTy,
3319 nullptr, SC_Static,
3320 false,
3321 false);
3322
3323 QualType DestTy = C.getPointerType(Ty);
3324 QualType SrcTy = Ty;
3325 SrcTy.addConst();
3326 SrcTy = C.getPointerType(SrcTy);
3327
3328 FunctionArgList args;
3329 ImplicitParamDecl DstDecl(getContext(), FD, SourceLocation(), /*Id=*/nullptr,
3330 DestTy, ImplicitParamDecl::Other);
3331 args.push_back(&DstDecl);
3332 ImplicitParamDecl SrcDecl(getContext(), FD, SourceLocation(), /*Id=*/nullptr,
3333 SrcTy, ImplicitParamDecl::Other);
3334 args.push_back(&SrcDecl);
3335
3336 const CGFunctionInfo &FI =
3337 CGM.getTypes().arrangeBuiltinFunctionDeclaration(C.VoidTy, args);
3338
3339 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
3340
3341 llvm::Function *Fn =
3342 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
3343 "__copy_helper_atomic_property_", &CGM.getModule());
3344
3345 CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, FI);
3346
3347 StartFunction(FD, C.VoidTy, Fn, FI, args);
3348
3349 DeclRefExpr SrcExpr(&SrcDecl, false, SrcTy,
3350 VK_RValue, SourceLocation());
3351
3352 UnaryOperator SRC(&SrcExpr, UO_Deref, SrcTy->getPointeeType(),
3353 VK_LValue, OK_Ordinary, SourceLocation(), false);
3354
3355 CXXConstructExpr *CXXConstExpr =
3356 cast<CXXConstructExpr>(PID->getGetterCXXConstructor());
3357
3358 SmallVector<Expr*, 4> ConstructorArgs;
3359 ConstructorArgs.push_back(&SRC);
3360 ConstructorArgs.append(std::next(CXXConstExpr->arg_begin()),
3361 CXXConstExpr->arg_end());
3362
3363 CXXConstructExpr *TheCXXConstructExpr =
3364 CXXConstructExpr::Create(C, Ty, SourceLocation(),
3365 CXXConstExpr->getConstructor(),
3366 CXXConstExpr->isElidable(),
3367 ConstructorArgs,
3368 CXXConstExpr->hadMultipleCandidates(),
3369 CXXConstExpr->isListInitialization(),
3370 CXXConstExpr->isStdInitListInitialization(),
3371 CXXConstExpr->requiresZeroInitialization(),
3372 CXXConstExpr->getConstructionKind(),
3373 SourceRange());
3374
3375 DeclRefExpr DstExpr(&DstDecl, false, DestTy,
3376 VK_RValue, SourceLocation());
3377
3378 RValue DV = EmitAnyExpr(&DstExpr);
3379 CharUnits Alignment
3380 = getContext().getTypeAlignInChars(TheCXXConstructExpr->getType());
3381 EmitAggExpr(TheCXXConstructExpr,
3382 AggValueSlot::forAddr(Address(DV.getScalarVal(), Alignment),
3383 Qualifiers(),
3384 AggValueSlot::IsDestructed,
3385 AggValueSlot::DoesNotNeedGCBarriers,
3386 AggValueSlot::IsNotAliased,
3387 AggValueSlot::DoesNotOverlap));
3388
3389 FinishFunction();
3390 HelperFn = llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
3391 CGM.setAtomicGetterHelperFnMap(Ty, HelperFn);
3392 return HelperFn;
3393}
3394
3395llvm::Value *
3396CodeGenFunction::EmitBlockCopyAndAutorelease(llvm::Value *Block, QualType Ty) {
3397 // Get selectors for retain/autorelease.
3398 IdentifierInfo *CopyID = &getContext().Idents.get("copy");
3399 Selector CopySelector =
3400 getContext().Selectors.getNullarySelector(CopyID);
3401 IdentifierInfo *AutoreleaseID = &getContext().Idents.get("autorelease");
3402 Selector AutoreleaseSelector =
3403 getContext().Selectors.getNullarySelector(AutoreleaseID);
3404
3405 // Emit calls to retain/autorelease.
3406 CGObjCRuntime &Runtime = CGM.getObjCRuntime();
3407 llvm::Value *Val = Block;
3408 RValue Result;
3409 Result = Runtime.GenerateMessageSend(*this, ReturnValueSlot(),
3410 Ty, CopySelector,
3411 Val, CallArgList(), nullptr, nullptr);
3412 Val = Result.getScalarVal();
3413 Result = Runtime.GenerateMessageSend(*this, ReturnValueSlot(),
3414 Ty, AutoreleaseSelector,
3415 Val, CallArgList(), nullptr, nullptr);
3416 Val = Result.getScalarVal();
3417 return Val;
3418}
3419
3420llvm::Value *
3421CodeGenFunction::EmitBuiltinAvailable(ArrayRef<llvm::Value *> Args) {
3422 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-8~svn345461/tools/clang/lib/CodeGen/CGObjC.cpp"
, 3422, __PRETTY_FUNCTION__))
;
3423
3424 if (!CGM.IsOSVersionAtLeastFn) {
3425 llvm::FunctionType *FTy =
3426 llvm::FunctionType::get(Int32Ty, {Int32Ty, Int32Ty, Int32Ty}, false);
3427 CGM.IsOSVersionAtLeastFn =
3428 CGM.CreateRuntimeFunction(FTy, "__isOSVersionAtLeast");
3429 }
3430
3431 llvm::Value *CallRes =
3432 EmitNounwindRuntimeCall(CGM.IsOSVersionAtLeastFn, Args);
3433
3434 return Builder.CreateICmpNE(CallRes, llvm::Constant::getNullValue(Int32Ty));
3435}
3436
3437void CodeGenModule::emitAtAvailableLinkGuard() {
3438 if (!IsOSVersionAtLeastFn)
3439 return;
3440 // @available requires CoreFoundation only on Darwin.
3441 if (!Target.getTriple().isOSDarwin())
3442 return;
3443 // Add -framework CoreFoundation to the linker commands. We still want to
3444 // emit the core foundation reference down below because otherwise if
3445 // CoreFoundation is not used in the code, the linker won't link the
3446 // framework.
3447 auto &Context = getLLVMContext();
3448 llvm::Metadata *Args[2] = {llvm::MDString::get(Context, "-framework"),
3449 llvm::MDString::get(Context, "CoreFoundation")};
3450 LinkerOptionsMetadata.push_back(llvm::MDNode::get(Context, Args));
3451 // Emit a reference to a symbol from CoreFoundation to ensure that
3452 // CoreFoundation is linked into the final binary.
3453 llvm::FunctionType *FTy =
3454 llvm::FunctionType::get(Int32Ty, {VoidPtrTy}, false);
3455 llvm::Constant *CFFunc =
3456 CreateRuntimeFunction(FTy, "CFBundleGetVersionNumber");
3457
3458 llvm::FunctionType *CheckFTy = llvm::FunctionType::get(VoidTy, {}, false);
3459 llvm::Function *CFLinkCheckFunc = cast<llvm::Function>(CreateBuiltinFunction(
3460 CheckFTy, "__clang_at_available_requires_core_foundation_framework"));
3461 CFLinkCheckFunc->setLinkage(llvm::GlobalValue::LinkOnceAnyLinkage);
3462 CFLinkCheckFunc->setVisibility(llvm::GlobalValue::HiddenVisibility);
3463 CodeGenFunction CGF(*this);
3464 CGF.Builder.SetInsertPoint(CGF.createBasicBlock("", CFLinkCheckFunc));
3465 CGF.EmitNounwindRuntimeCall(CFFunc, llvm::Constant::getNullValue(VoidPtrTy));
3466 CGF.Builder.CreateUnreachable();
3467 addCompilerUsedGlobal(CFLinkCheckFunc);
3468}
3469
3470CGObjCRuntime::~CGObjCRuntime() {}