clang 17.0.0git
CheckObjCDealloc.cpp
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1//==- CheckObjCDealloc.cpp - Check ObjC -dealloc implementation --*- C++ -*-==//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This checker analyzes Objective-C -dealloc methods and their callees
10// to warn about improper releasing of instance variables that back synthesized
11// properties. It warns about missing releases in the following cases:
12// - When a class has a synthesized instance variable for a 'retain' or 'copy'
13// property and lacks a -dealloc method in its implementation.
14// - When a class has a synthesized instance variable for a 'retain'/'copy'
15// property but the ivar is not released in -dealloc by either -release
16// or by nilling out the property.
17//
18// It warns about extra releases in -dealloc (but not in callees) when a
19// synthesized instance variable is released in the following cases:
20// - When the property is 'assign' and is not 'readonly'.
21// - When the property is 'weak'.
22//
23// This checker only warns for instance variables synthesized to back
24// properties. Handling the more general case would require inferring whether
25// an instance variable is stored retained or not. For synthesized properties,
26// this is specified in the property declaration itself.
27//
28//===----------------------------------------------------------------------===//
29
32#include "clang/AST/Attr.h"
33#include "clang/AST/DeclObjC.h"
34#include "clang/AST/Expr.h"
35#include "clang/AST/ExprObjC.h"
47#include "llvm/Support/raw_ostream.h"
48#include <optional>
49
50using namespace clang;
51using namespace ento;
52
53/// Indicates whether an instance variable is required to be released in
54/// -dealloc.
56 /// The instance variable must be released, either by calling
57 /// -release on it directly or by nilling it out with a property setter.
59
60 /// The instance variable must not be directly released with -release.
62
63 /// The requirement for the instance variable could not be determined.
65};
66
67/// Returns true if the property implementation is synthesized and the
68/// type of the property is retainable.
70 const ObjCIvarDecl **ID,
71 const ObjCPropertyDecl **PD) {
72
74 return false;
75
76 (*ID) = I->getPropertyIvarDecl();
77 if (!(*ID))
78 return false;
79
80 QualType T = (*ID)->getType();
81 if (!T->isObjCRetainableType())
82 return false;
83
84 (*PD) = I->getPropertyDecl();
85 // Shouldn't be able to synthesize a property that doesn't exist.
86 assert(*PD);
87
88 return true;
89}
90
91namespace {
92
93class ObjCDeallocChecker
94 : public Checker<check::ASTDecl<ObjCImplementationDecl>,
95 check::PreObjCMessage, check::PostObjCMessage,
96 check::PreCall,
97 check::BeginFunction, check::EndFunction,
98 eval::Assume,
99 check::PointerEscape,
100 check::PreStmt<ReturnStmt>> {
101
102 mutable IdentifierInfo *NSObjectII, *SenTestCaseII, *XCTestCaseII,
103 *Block_releaseII, *CIFilterII;
104
105 mutable Selector DeallocSel, ReleaseSel;
106
107 std::unique_ptr<BugType> MissingReleaseBugType;
108 std::unique_ptr<BugType> ExtraReleaseBugType;
109 std::unique_ptr<BugType> MistakenDeallocBugType;
110
111public:
112 ObjCDeallocChecker();
113
114 void checkASTDecl(const ObjCImplementationDecl *D, AnalysisManager& Mgr,
115 BugReporter &BR) const;
116 void checkBeginFunction(CheckerContext &Ctx) const;
117 void checkPreObjCMessage(const ObjCMethodCall &M, CheckerContext &C) const;
118 void checkPreCall(const CallEvent &Call, CheckerContext &C) const;
119 void checkPostObjCMessage(const ObjCMethodCall &M, CheckerContext &C) const;
120
121 ProgramStateRef evalAssume(ProgramStateRef State, SVal Cond,
122 bool Assumption) const;
123
124 ProgramStateRef checkPointerEscape(ProgramStateRef State,
125 const InvalidatedSymbols &Escaped,
126 const CallEvent *Call,
127 PointerEscapeKind Kind) const;
128 void checkPreStmt(const ReturnStmt *RS, CheckerContext &C) const;
129 void checkEndFunction(const ReturnStmt *RS, CheckerContext &Ctx) const;
130
131private:
132 void diagnoseMissingReleases(CheckerContext &C) const;
133
134 bool diagnoseExtraRelease(SymbolRef ReleasedValue, const ObjCMethodCall &M,
135 CheckerContext &C) const;
136
137 bool diagnoseMistakenDealloc(SymbolRef DeallocedValue,
138 const ObjCMethodCall &M,
139 CheckerContext &C) const;
140
141 SymbolRef getValueReleasedByNillingOut(const ObjCMethodCall &M,
142 CheckerContext &C) const;
143
144 const ObjCIvarRegion *getIvarRegionForIvarSymbol(SymbolRef IvarSym) const;
145 SymbolRef getInstanceSymbolFromIvarSymbol(SymbolRef IvarSym) const;
146
148 findPropertyOnDeallocatingInstance(SymbolRef IvarSym,
149 CheckerContext &C) const;
150
152 getDeallocReleaseRequirement(const ObjCPropertyImplDecl *PropImpl) const;
153
154 bool isInInstanceDealloc(const CheckerContext &C, SVal &SelfValOut) const;
155 bool isInInstanceDealloc(const CheckerContext &C, const LocationContext *LCtx,
156 SVal &SelfValOut) const;
157 bool instanceDeallocIsOnStack(const CheckerContext &C,
158 SVal &InstanceValOut) const;
159
160 bool isSuperDeallocMessage(const ObjCMethodCall &M) const;
161
162 const ObjCImplDecl *getContainingObjCImpl(const LocationContext *LCtx) const;
163
164 const ObjCPropertyDecl *
165 findShadowedPropertyDecl(const ObjCPropertyImplDecl *PropImpl) const;
166
167 void transitionToReleaseValue(CheckerContext &C, SymbolRef Value) const;
168 ProgramStateRef removeValueRequiringRelease(ProgramStateRef State,
169 SymbolRef InstanceSym,
170 SymbolRef ValueSym) const;
171
172 void initIdentifierInfoAndSelectors(ASTContext &Ctx) const;
173
174 bool classHasSeparateTeardown(const ObjCInterfaceDecl *ID) const;
175
176 bool isReleasedByCIFilterDealloc(const ObjCPropertyImplDecl *PropImpl) const;
177 bool isNibLoadedIvarWithoutRetain(const ObjCPropertyImplDecl *PropImpl) const;
178};
179} // End anonymous namespace.
180
181
182/// Maps from the symbol for a class instance to the set of
183/// symbols remaining that must be released in -dealloc.
185REGISTER_MAP_WITH_PROGRAMSTATE(UnreleasedIvarMap, SymbolRef, SymbolSet)
186
187
188/// An AST check that diagnose when the class requires a -dealloc method and
189/// is missing one.
190void ObjCDeallocChecker::checkASTDecl(const ObjCImplementationDecl *D,
191 AnalysisManager &Mgr,
192 BugReporter &BR) const {
193 assert(Mgr.getLangOpts().getGC() != LangOptions::GCOnly);
194 assert(!Mgr.getLangOpts().ObjCAutoRefCount);
195 initIdentifierInfoAndSelectors(Mgr.getASTContext());
196
198 // If the class is known to have a lifecycle with a separate teardown method
199 // then it may not require a -dealloc method.
200 if (classHasSeparateTeardown(ID))
201 return;
202
203 // Does the class contain any synthesized properties that are retainable?
204 // If not, skip the check entirely.
205 const ObjCPropertyImplDecl *PropImplRequiringRelease = nullptr;
206 bool HasOthers = false;
207 for (const auto *I : D->property_impls()) {
208 if (getDeallocReleaseRequirement(I) == ReleaseRequirement::MustRelease) {
209 if (!PropImplRequiringRelease)
210 PropImplRequiringRelease = I;
211 else {
212 HasOthers = true;
213 break;
214 }
215 }
216 }
217
218 if (!PropImplRequiringRelease)
219 return;
220
221 const ObjCMethodDecl *MD = nullptr;
222
223 // Scan the instance methods for "dealloc".
224 for (const auto *I : D->instance_methods()) {
225 if (I->getSelector() == DeallocSel) {
226 MD = I;
227 break;
228 }
229 }
230
231 if (!MD) { // No dealloc found.
232 const char* Name = "Missing -dealloc";
233
234 std::string Buf;
235 llvm::raw_string_ostream OS(Buf);
236 OS << "'" << *D << "' lacks a 'dealloc' instance method but "
237 << "must release '" << *PropImplRequiringRelease->getPropertyIvarDecl()
238 << "'";
239
240 if (HasOthers)
241 OS << " and others";
244
246 OS.str(), DLoc);
247 return;
248 }
249}
250
251/// If this is the beginning of -dealloc, mark the values initially stored in
252/// instance variables that must be released by the end of -dealloc
253/// as unreleased in the state.
254void ObjCDeallocChecker::checkBeginFunction(
255 CheckerContext &C) const {
256 initIdentifierInfoAndSelectors(C.getASTContext());
257
258 // Only do this if the current method is -dealloc.
259 SVal SelfVal;
260 if (!isInInstanceDealloc(C, SelfVal))
261 return;
262
263 SymbolRef SelfSymbol = SelfVal.getAsSymbol();
264
265 const LocationContext *LCtx = C.getLocationContext();
266 ProgramStateRef InitialState = C.getState();
267
268 ProgramStateRef State = InitialState;
269
270 SymbolSet::Factory &F = State->getStateManager().get_context<SymbolSet>();
271
272 // Symbols that must be released by the end of the -dealloc;
273 SymbolSet RequiredReleases = F.getEmptySet();
274
275 // If we're an inlined -dealloc, we should add our symbols to the existing
276 // set from our subclass.
277 if (const SymbolSet *CurrSet = State->get<UnreleasedIvarMap>(SelfSymbol))
278 RequiredReleases = *CurrSet;
279
280 for (auto *PropImpl : getContainingObjCImpl(LCtx)->property_impls()) {
281 ReleaseRequirement Requirement = getDeallocReleaseRequirement(PropImpl);
282 if (Requirement != ReleaseRequirement::MustRelease)
283 continue;
284
285 SVal LVal = State->getLValue(PropImpl->getPropertyIvarDecl(), SelfVal);
286 std::optional<Loc> LValLoc = LVal.getAs<Loc>();
287 if (!LValLoc)
288 continue;
289
290 SVal InitialVal = State->getSVal(*LValLoc);
291 SymbolRef Symbol = InitialVal.getAsSymbol();
292 if (!Symbol || !isa<SymbolRegionValue>(Symbol))
293 continue;
294
295 // Mark the value as requiring a release.
296 RequiredReleases = F.add(RequiredReleases, Symbol);
297 }
298
299 if (!RequiredReleases.isEmpty()) {
300 State = State->set<UnreleasedIvarMap>(SelfSymbol, RequiredReleases);
301 }
302
303 if (State != InitialState) {
304 C.addTransition(State);
305 }
306}
307
308/// Given a symbol for an ivar, return the ivar region it was loaded from.
309/// Returns nullptr if the instance symbol cannot be found.
310const ObjCIvarRegion *
311ObjCDeallocChecker::getIvarRegionForIvarSymbol(SymbolRef IvarSym) const {
312 return dyn_cast_or_null<ObjCIvarRegion>(IvarSym->getOriginRegion());
313}
314
315/// Given a symbol for an ivar, return a symbol for the instance containing
316/// the ivar. Returns nullptr if the instance symbol cannot be found.
318ObjCDeallocChecker::getInstanceSymbolFromIvarSymbol(SymbolRef IvarSym) const {
319
320 const ObjCIvarRegion *IvarRegion = getIvarRegionForIvarSymbol(IvarSym);
321 if (!IvarRegion)
322 return nullptr;
323
324 return IvarRegion->getSymbolicBase()->getSymbol();
325}
326
327/// If we are in -dealloc or -dealloc is on the stack, handle the call if it is
328/// a release or a nilling-out property setter.
329void ObjCDeallocChecker::checkPreObjCMessage(
330 const ObjCMethodCall &M, CheckerContext &C) const {
331 // Only run if -dealloc is on the stack.
332 SVal DeallocedInstance;
333 if (!instanceDeallocIsOnStack(C, DeallocedInstance))
334 return;
335
336 SymbolRef ReleasedValue = nullptr;
337
338 if (M.getSelector() == ReleaseSel) {
339 ReleasedValue = M.getReceiverSVal().getAsSymbol();
340 } else if (M.getSelector() == DeallocSel && !M.isReceiverSelfOrSuper()) {
341 if (diagnoseMistakenDealloc(M.getReceiverSVal().getAsSymbol(), M, C))
342 return;
343 }
344
345 if (ReleasedValue) {
346 // An instance variable symbol was released with -release:
347 // [_property release];
348 if (diagnoseExtraRelease(ReleasedValue,M, C))
349 return;
350 } else {
351 // An instance variable symbol was released nilling out its property:
352 // self.property = nil;
353 ReleasedValue = getValueReleasedByNillingOut(M, C);
354 }
355
356 if (!ReleasedValue)
357 return;
358
359 transitionToReleaseValue(C, ReleasedValue);
360}
361
362/// If we are in -dealloc or -dealloc is on the stack, handle the call if it is
363/// call to Block_release().
364void ObjCDeallocChecker::checkPreCall(const CallEvent &Call,
365 CheckerContext &C) const {
366 const IdentifierInfo *II = Call.getCalleeIdentifier();
367 if (II != Block_releaseII)
368 return;
369
370 if (Call.getNumArgs() != 1)
371 return;
372
373 SymbolRef ReleasedValue = Call.getArgSVal(0).getAsSymbol();
374 if (!ReleasedValue)
375 return;
376
377 transitionToReleaseValue(C, ReleasedValue);
378}
379/// If the message was a call to '[super dealloc]', diagnose any missing
380/// releases.
381void ObjCDeallocChecker::checkPostObjCMessage(
382 const ObjCMethodCall &M, CheckerContext &C) const {
383 // We perform this check post-message so that if the super -dealloc
384 // calls a helper method and that this class overrides, any ivars released in
385 // the helper method will be recorded before checking.
386 if (isSuperDeallocMessage(M))
387 diagnoseMissingReleases(C);
388}
389
390/// Check for missing releases even when -dealloc does not call
391/// '[super dealloc]'.
392void ObjCDeallocChecker::checkEndFunction(
393 const ReturnStmt *RS, CheckerContext &C) const {
394 diagnoseMissingReleases(C);
395}
396
397/// Check for missing releases on early return.
398void ObjCDeallocChecker::checkPreStmt(
399 const ReturnStmt *RS, CheckerContext &C) const {
400 diagnoseMissingReleases(C);
401}
402
403/// When a symbol is assumed to be nil, remove it from the set of symbols
404/// require to be nil.
405ProgramStateRef ObjCDeallocChecker::evalAssume(ProgramStateRef State, SVal Cond,
406 bool Assumption) const {
407 if (State->get<UnreleasedIvarMap>().isEmpty())
408 return State;
409
410 auto *CondBSE = dyn_cast_or_null<BinarySymExpr>(Cond.getAsSymbol());
411 if (!CondBSE)
412 return State;
413
414 BinaryOperator::Opcode OpCode = CondBSE->getOpcode();
415 if (Assumption) {
416 if (OpCode != BO_EQ)
417 return State;
418 } else {
419 if (OpCode != BO_NE)
420 return State;
421 }
422
423 SymbolRef NullSymbol = nullptr;
424 if (auto *SIE = dyn_cast<SymIntExpr>(CondBSE)) {
425 const llvm::APInt &RHS = SIE->getRHS();
426 if (RHS != 0)
427 return State;
428 NullSymbol = SIE->getLHS();
429 } else if (auto *SIE = dyn_cast<IntSymExpr>(CondBSE)) {
430 const llvm::APInt &LHS = SIE->getLHS();
431 if (LHS != 0)
432 return State;
433 NullSymbol = SIE->getRHS();
434 } else {
435 return State;
436 }
437
438 SymbolRef InstanceSymbol = getInstanceSymbolFromIvarSymbol(NullSymbol);
439 if (!InstanceSymbol)
440 return State;
441
442 State = removeValueRequiringRelease(State, InstanceSymbol, NullSymbol);
443
444 return State;
445}
446
447/// If a symbol escapes conservatively assume unseen code released it.
448ProgramStateRef ObjCDeallocChecker::checkPointerEscape(
449 ProgramStateRef State, const InvalidatedSymbols &Escaped,
450 const CallEvent *Call, PointerEscapeKind Kind) const {
451
452 if (State->get<UnreleasedIvarMap>().isEmpty())
453 return State;
454
455 // Don't treat calls to '[super dealloc]' as escaping for the purposes
456 // of this checker. Because the checker diagnoses missing releases in the
457 // post-message handler for '[super dealloc], escaping here would cause
458 // the checker to never warn.
459 auto *OMC = dyn_cast_or_null<ObjCMethodCall>(Call);
460 if (OMC && isSuperDeallocMessage(*OMC))
461 return State;
462
463 for (const auto &Sym : Escaped) {
464 if (!Call || (Call && !Call->isInSystemHeader())) {
465 // If Sym is a symbol for an object with instance variables that
466 // must be released, remove these obligations when the object escapes
467 // unless via a call to a system function. System functions are
468 // very unlikely to release instance variables on objects passed to them,
469 // and are frequently called on 'self' in -dealloc (e.g., to remove
470 // observers) -- we want to avoid false negatives from escaping on
471 // them.
472 State = State->remove<UnreleasedIvarMap>(Sym);
473 }
474
475
476 SymbolRef InstanceSymbol = getInstanceSymbolFromIvarSymbol(Sym);
477 if (!InstanceSymbol)
478 continue;
479
480 State = removeValueRequiringRelease(State, InstanceSymbol, Sym);
481 }
482
483 return State;
484}
485
486/// Report any unreleased instance variables for the current instance being
487/// dealloced.
488void ObjCDeallocChecker::diagnoseMissingReleases(CheckerContext &C) const {
489 ProgramStateRef State = C.getState();
490
491 SVal SelfVal;
492 if (!isInInstanceDealloc(C, SelfVal))
493 return;
494
495 const MemRegion *SelfRegion = SelfVal.castAs<loc::MemRegionVal>().getRegion();
496 const LocationContext *LCtx = C.getLocationContext();
497
498 ExplodedNode *ErrNode = nullptr;
499
500 SymbolRef SelfSym = SelfVal.getAsSymbol();
501 if (!SelfSym)
502 return;
503
504 const SymbolSet *OldUnreleased = State->get<UnreleasedIvarMap>(SelfSym);
505 if (!OldUnreleased)
506 return;
507
508 SymbolSet NewUnreleased = *OldUnreleased;
509 SymbolSet::Factory &F = State->getStateManager().get_context<SymbolSet>();
510
511 ProgramStateRef InitialState = State;
512
513 for (auto *IvarSymbol : *OldUnreleased) {
514 const TypedValueRegion *TVR =
515 cast<SymbolRegionValue>(IvarSymbol)->getRegion();
516 const ObjCIvarRegion *IvarRegion = cast<ObjCIvarRegion>(TVR);
517
518 // Don't warn if the ivar is not for this instance.
519 if (SelfRegion != IvarRegion->getSuperRegion())
520 continue;
521
522 const ObjCIvarDecl *IvarDecl = IvarRegion->getDecl();
523 // Prevent an inlined call to -dealloc in a super class from warning
524 // about the values the subclass's -dealloc should release.
525 if (IvarDecl->getContainingInterface() !=
526 cast<ObjCMethodDecl>(LCtx->getDecl())->getClassInterface())
527 continue;
528
529 // Prevents diagnosing multiple times for the same instance variable
530 // at, for example, both a return and at the end of the function.
531 NewUnreleased = F.remove(NewUnreleased, IvarSymbol);
532
533 if (State->getStateManager()
534 .getConstraintManager()
535 .isNull(State, IvarSymbol)
536 .isConstrainedTrue()) {
537 continue;
538 }
539
540 // A missing release manifests as a leak, so treat as a non-fatal error.
541 if (!ErrNode)
542 ErrNode = C.generateNonFatalErrorNode();
543 // If we've already reached this node on another path, return without
544 // diagnosing.
545 if (!ErrNode)
546 return;
547
548 std::string Buf;
549 llvm::raw_string_ostream OS(Buf);
550
551 const ObjCInterfaceDecl *Interface = IvarDecl->getContainingInterface();
552 // If the class is known to have a lifecycle with teardown that is
553 // separate from -dealloc, do not warn about missing releases. We
554 // suppress here (rather than not tracking for instance variables in
555 // such classes) because these classes are rare.
556 if (classHasSeparateTeardown(Interface))
557 return;
558
559 ObjCImplDecl *ImplDecl = Interface->getImplementation();
560
561 const ObjCPropertyImplDecl *PropImpl =
562 ImplDecl->FindPropertyImplIvarDecl(IvarDecl->getIdentifier());
563
564 const ObjCPropertyDecl *PropDecl = PropImpl->getPropertyDecl();
565
566 assert(PropDecl->getSetterKind() == ObjCPropertyDecl::Copy ||
568
569 OS << "The '" << *IvarDecl << "' ivar in '" << *ImplDecl
570 << "' was ";
571
572 if (PropDecl->getSetterKind() == ObjCPropertyDecl::Retain)
573 OS << "retained";
574 else
575 OS << "copied";
576
577 OS << " by a synthesized property but not released"
578 " before '[super dealloc]'";
579
580 auto BR = std::make_unique<PathSensitiveBugReport>(*MissingReleaseBugType,
581 OS.str(), ErrNode);
582 C.emitReport(std::move(BR));
583 }
584
585 if (NewUnreleased.isEmpty()) {
586 State = State->remove<UnreleasedIvarMap>(SelfSym);
587 } else {
588 State = State->set<UnreleasedIvarMap>(SelfSym, NewUnreleased);
589 }
590
591 if (ErrNode) {
592 C.addTransition(State, ErrNode);
593 } else if (State != InitialState) {
594 C.addTransition(State);
595 }
596
597 // Make sure that after checking in the top-most frame the list of
598 // tracked ivars is empty. This is intended to detect accidental leaks in
599 // the UnreleasedIvarMap program state.
600 assert(!LCtx->inTopFrame() || State->get<UnreleasedIvarMap>().isEmpty());
601}
602
603/// Given a symbol, determine whether the symbol refers to an ivar on
604/// the top-most deallocating instance. If so, find the property for that
605/// ivar, if one exists. Otherwise return null.
607ObjCDeallocChecker::findPropertyOnDeallocatingInstance(
608 SymbolRef IvarSym, CheckerContext &C) const {
609 SVal DeallocedInstance;
610 if (!isInInstanceDealloc(C, DeallocedInstance))
611 return nullptr;
612
613 // Try to get the region from which the ivar value was loaded.
614 auto *IvarRegion = getIvarRegionForIvarSymbol(IvarSym);
615 if (!IvarRegion)
616 return nullptr;
617
618 // Don't try to find the property if the ivar was not loaded from the
619 // given instance.
620 if (DeallocedInstance.castAs<loc::MemRegionVal>().getRegion() !=
621 IvarRegion->getSuperRegion())
622 return nullptr;
623
624 const LocationContext *LCtx = C.getLocationContext();
625 const ObjCIvarDecl *IvarDecl = IvarRegion->getDecl();
626
627 const ObjCImplDecl *Container = getContainingObjCImpl(LCtx);
628 const ObjCPropertyImplDecl *PropImpl =
629 Container->FindPropertyImplIvarDecl(IvarDecl->getIdentifier());
630 return PropImpl;
631}
632
633/// Emits a warning if the current context is -dealloc and ReleasedValue
634/// must not be directly released in a -dealloc. Returns true if a diagnostic
635/// was emitted.
636bool ObjCDeallocChecker::diagnoseExtraRelease(SymbolRef ReleasedValue,
637 const ObjCMethodCall &M,
638 CheckerContext &C) const {
639 // Try to get the region from which the released value was loaded.
640 // Note that, unlike diagnosing for missing releases, here we don't track
641 // values that must not be released in the state. This is because even if
642 // these values escape, it is still an error under the rules of MRR to
643 // release them in -dealloc.
644 const ObjCPropertyImplDecl *PropImpl =
645 findPropertyOnDeallocatingInstance(ReleasedValue, C);
646
647 if (!PropImpl)
648 return false;
649
650 // If the ivar belongs to a property that must not be released directly
651 // in dealloc, emit a warning.
652 if (getDeallocReleaseRequirement(PropImpl) !=
654 return false;
655 }
656
657 // If the property is readwrite but it shadows a read-only property in its
658 // external interface, treat the property a read-only. If the outside
659 // world cannot write to a property then the internal implementation is free
660 // to make its own convention about whether the value is stored retained
661 // or not. We look up the shadow here rather than in
662 // getDeallocReleaseRequirement() because doing so can be expensive.
663 const ObjCPropertyDecl *PropDecl = findShadowedPropertyDecl(PropImpl);
664 if (PropDecl) {
665 if (PropDecl->isReadOnly())
666 return false;
667 } else {
668 PropDecl = PropImpl->getPropertyDecl();
669 }
670
671 ExplodedNode *ErrNode = C.generateNonFatalErrorNode();
672 if (!ErrNode)
673 return false;
674
675 std::string Buf;
676 llvm::raw_string_ostream OS(Buf);
677
678 assert(PropDecl->getSetterKind() == ObjCPropertyDecl::Weak ||
679 (PropDecl->getSetterKind() == ObjCPropertyDecl::Assign &&
680 !PropDecl->isReadOnly()) ||
681 isReleasedByCIFilterDealloc(PropImpl)
682 );
683
684 const ObjCImplDecl *Container = getContainingObjCImpl(C.getLocationContext());
685 OS << "The '" << *PropImpl->getPropertyIvarDecl()
686 << "' ivar in '" << *Container;
687
688
689 if (isReleasedByCIFilterDealloc(PropImpl)) {
690 OS << "' will be released by '-[CIFilter dealloc]' but also released here";
691 } else {
692 OS << "' was synthesized for ";
693
694 if (PropDecl->getSetterKind() == ObjCPropertyDecl::Weak)
695 OS << "a weak";
696 else
697 OS << "an assign, readwrite";
698
699 OS << " property but was released in 'dealloc'";
700 }
701
702 auto BR = std::make_unique<PathSensitiveBugReport>(*ExtraReleaseBugType,
703 OS.str(), ErrNode);
704 BR->addRange(M.getOriginExpr()->getSourceRange());
705
706 C.emitReport(std::move(BR));
707
708 return true;
709}
710
711/// Emits a warning if the current context is -dealloc and DeallocedValue
712/// must not be directly dealloced in a -dealloc. Returns true if a diagnostic
713/// was emitted.
714bool ObjCDeallocChecker::diagnoseMistakenDealloc(SymbolRef DeallocedValue,
715 const ObjCMethodCall &M,
716 CheckerContext &C) const {
717 // TODO: Apart from unknown/undefined receivers, this may happen when
718 // dealloc is called as a class method. Should we warn?
719 if (!DeallocedValue)
720 return false;
721
722 // Find the property backing the instance variable that M
723 // is dealloc'ing.
724 const ObjCPropertyImplDecl *PropImpl =
725 findPropertyOnDeallocatingInstance(DeallocedValue, C);
726 if (!PropImpl)
727 return false;
728
729 if (getDeallocReleaseRequirement(PropImpl) !=
731 return false;
732 }
733
734 ExplodedNode *ErrNode = C.generateErrorNode();
735 if (!ErrNode)
736 return false;
737
738 std::string Buf;
739 llvm::raw_string_ostream OS(Buf);
740
741 OS << "'" << *PropImpl->getPropertyIvarDecl()
742 << "' should be released rather than deallocated";
743
744 auto BR = std::make_unique<PathSensitiveBugReport>(*MistakenDeallocBugType,
745 OS.str(), ErrNode);
746 BR->addRange(M.getOriginExpr()->getSourceRange());
747
748 C.emitReport(std::move(BR));
749
750 return true;
751}
752
753ObjCDeallocChecker::ObjCDeallocChecker()
754 : NSObjectII(nullptr), SenTestCaseII(nullptr), XCTestCaseII(nullptr),
755 CIFilterII(nullptr) {
756
757 MissingReleaseBugType.reset(
758 new BugType(this, "Missing ivar release (leak)",
760
761 ExtraReleaseBugType.reset(
762 new BugType(this, "Extra ivar release",
764
765 MistakenDeallocBugType.reset(
766 new BugType(this, "Mistaken dealloc",
768}
769
770void ObjCDeallocChecker::initIdentifierInfoAndSelectors(
771 ASTContext &Ctx) const {
772 if (NSObjectII)
773 return;
774
775 NSObjectII = &Ctx.Idents.get("NSObject");
776 SenTestCaseII = &Ctx.Idents.get("SenTestCase");
777 XCTestCaseII = &Ctx.Idents.get("XCTestCase");
778 Block_releaseII = &Ctx.Idents.get("_Block_release");
779 CIFilterII = &Ctx.Idents.get("CIFilter");
780
781 IdentifierInfo *DeallocII = &Ctx.Idents.get("dealloc");
782 IdentifierInfo *ReleaseII = &Ctx.Idents.get("release");
783 DeallocSel = Ctx.Selectors.getSelector(0, &DeallocII);
784 ReleaseSel = Ctx.Selectors.getSelector(0, &ReleaseII);
785}
786
787/// Returns true if M is a call to '[super dealloc]'.
788bool ObjCDeallocChecker::isSuperDeallocMessage(
789 const ObjCMethodCall &M) const {
791 return false;
792
793 return M.getSelector() == DeallocSel;
794}
795
796/// Returns the ObjCImplDecl containing the method declaration in LCtx.
797const ObjCImplDecl *
798ObjCDeallocChecker::getContainingObjCImpl(const LocationContext *LCtx) const {
799 auto *MD = cast<ObjCMethodDecl>(LCtx->getDecl());
800 return cast<ObjCImplDecl>(MD->getDeclContext());
801}
802
803/// Returns the property that shadowed by PropImpl if one exists and
804/// nullptr otherwise.
805const ObjCPropertyDecl *ObjCDeallocChecker::findShadowedPropertyDecl(
806 const ObjCPropertyImplDecl *PropImpl) const {
807 const ObjCPropertyDecl *PropDecl = PropImpl->getPropertyDecl();
808
809 // Only readwrite properties can shadow.
810 if (PropDecl->isReadOnly())
811 return nullptr;
812
813 auto *CatDecl = dyn_cast<ObjCCategoryDecl>(PropDecl->getDeclContext());
814
815 // Only class extensions can contain shadowing properties.
816 if (!CatDecl || !CatDecl->IsClassExtension())
817 return nullptr;
818
819 IdentifierInfo *ID = PropDecl->getIdentifier();
820 DeclContext::lookup_result R = CatDecl->getClassInterface()->lookup(ID);
821 for (DeclContext::lookup_iterator I = R.begin(), E = R.end(); I != E; ++I) {
822 auto *ShadowedPropDecl = dyn_cast<ObjCPropertyDecl>(*I);
823 if (!ShadowedPropDecl)
824 continue;
825
826 if (ShadowedPropDecl->isInstanceProperty()) {
827 assert(ShadowedPropDecl->isReadOnly());
828 return ShadowedPropDecl;
829 }
830 }
831
832 return nullptr;
833}
834
835/// Add a transition noting the release of the given value.
836void ObjCDeallocChecker::transitionToReleaseValue(CheckerContext &C,
837 SymbolRef Value) const {
838 assert(Value);
839 SymbolRef InstanceSym = getInstanceSymbolFromIvarSymbol(Value);
840 if (!InstanceSym)
841 return;
842 ProgramStateRef InitialState = C.getState();
843
844 ProgramStateRef ReleasedState =
845 removeValueRequiringRelease(InitialState, InstanceSym, Value);
846
847 if (ReleasedState != InitialState) {
848 C.addTransition(ReleasedState);
849 }
850}
851
852/// Remove the Value requiring a release from the tracked set for
853/// Instance and return the resultant state.
854ProgramStateRef ObjCDeallocChecker::removeValueRequiringRelease(
855 ProgramStateRef State, SymbolRef Instance, SymbolRef Value) const {
856 assert(Instance);
857 assert(Value);
858 const ObjCIvarRegion *RemovedRegion = getIvarRegionForIvarSymbol(Value);
859 if (!RemovedRegion)
860 return State;
861
862 const SymbolSet *Unreleased = State->get<UnreleasedIvarMap>(Instance);
863 if (!Unreleased)
864 return State;
865
866 // Mark the value as no longer requiring a release.
867 SymbolSet::Factory &F = State->getStateManager().get_context<SymbolSet>();
868 SymbolSet NewUnreleased = *Unreleased;
869 for (auto &Sym : *Unreleased) {
870 const ObjCIvarRegion *UnreleasedRegion = getIvarRegionForIvarSymbol(Sym);
871 assert(UnreleasedRegion);
872 if (RemovedRegion->getDecl() == UnreleasedRegion->getDecl()) {
873 NewUnreleased = F.remove(NewUnreleased, Sym);
874 }
875 }
876
877 if (NewUnreleased.isEmpty()) {
878 return State->remove<UnreleasedIvarMap>(Instance);
879 }
880
881 return State->set<UnreleasedIvarMap>(Instance, NewUnreleased);
882}
883
884/// Determines whether the instance variable for \p PropImpl must or must not be
885/// released in -dealloc or whether it cannot be determined.
886ReleaseRequirement ObjCDeallocChecker::getDeallocReleaseRequirement(
887 const ObjCPropertyImplDecl *PropImpl) const {
888 const ObjCIvarDecl *IvarDecl;
889 const ObjCPropertyDecl *PropDecl;
890 if (!isSynthesizedRetainableProperty(PropImpl, &IvarDecl, &PropDecl))
892
894
895 switch (SK) {
896 // Retain and copy setters retain/copy their values before storing and so
897 // the value in their instance variables must be released in -dealloc.
900 if (isReleasedByCIFilterDealloc(PropImpl))
902
903 if (isNibLoadedIvarWithoutRetain(PropImpl))
905
907
910
912 // It is common for the ivars for read-only assign properties to
913 // always be stored retained, so their release requirement cannot be
914 // be determined.
915 if (PropDecl->isReadOnly())
917
919 }
920 llvm_unreachable("Unrecognized setter kind");
921}
922
923/// Returns the released value if M is a call a setter that releases
924/// and nils out its underlying instance variable.
926ObjCDeallocChecker::getValueReleasedByNillingOut(const ObjCMethodCall &M,
927 CheckerContext &C) const {
928 SVal ReceiverVal = M.getReceiverSVal();
929 if (!ReceiverVal.isValid())
930 return nullptr;
931
932 if (M.getNumArgs() == 0)
933 return nullptr;
934
936 return nullptr;
937
938 // Is the first argument nil?
939 SVal Arg = M.getArgSVal(0);
940 ProgramStateRef notNilState, nilState;
941 std::tie(notNilState, nilState) =
942 M.getState()->assume(Arg.castAs<DefinedOrUnknownSVal>());
943 if (!(nilState && !notNilState))
944 return nullptr;
945
946 const ObjCPropertyDecl *Prop = M.getAccessedProperty();
947 if (!Prop)
948 return nullptr;
949
950 ObjCIvarDecl *PropIvarDecl = Prop->getPropertyIvarDecl();
951 if (!PropIvarDecl)
952 return nullptr;
953
954 ProgramStateRef State = C.getState();
955
956 SVal LVal = State->getLValue(PropIvarDecl, ReceiverVal);
957 std::optional<Loc> LValLoc = LVal.getAs<Loc>();
958 if (!LValLoc)
959 return nullptr;
960
961 SVal CurrentValInIvar = State->getSVal(*LValLoc);
962 return CurrentValInIvar.getAsSymbol();
963}
964
965/// Returns true if the current context is a call to -dealloc and false
966/// otherwise. If true, it also sets SelfValOut to the value of
967/// 'self'.
968bool ObjCDeallocChecker::isInInstanceDealloc(const CheckerContext &C,
969 SVal &SelfValOut) const {
970 return isInInstanceDealloc(C, C.getLocationContext(), SelfValOut);
971}
972
973/// Returns true if LCtx is a call to -dealloc and false
974/// otherwise. If true, it also sets SelfValOut to the value of
975/// 'self'.
976bool ObjCDeallocChecker::isInInstanceDealloc(const CheckerContext &C,
977 const LocationContext *LCtx,
978 SVal &SelfValOut) const {
979 auto *MD = dyn_cast<ObjCMethodDecl>(LCtx->getDecl());
980 if (!MD || !MD->isInstanceMethod() || MD->getSelector() != DeallocSel)
981 return false;
982
983 const ImplicitParamDecl *SelfDecl = LCtx->getSelfDecl();
984 assert(SelfDecl && "No self in -dealloc?");
985
986 ProgramStateRef State = C.getState();
987 SelfValOut = State->getSVal(State->getRegion(SelfDecl, LCtx));
988 return true;
989}
990
991/// Returns true if there is a call to -dealloc anywhere on the stack and false
992/// otherwise. If true, it also sets InstanceValOut to the value of
993/// 'self' in the frame for -dealloc.
994bool ObjCDeallocChecker::instanceDeallocIsOnStack(const CheckerContext &C,
995 SVal &InstanceValOut) const {
996 const LocationContext *LCtx = C.getLocationContext();
997
998 while (LCtx) {
999 if (isInInstanceDealloc(C, LCtx, InstanceValOut))
1000 return true;
1001
1002 LCtx = LCtx->getParent();
1003 }
1004
1005 return false;
1006}
1007
1008/// Returns true if the ID is a class in which is known to have
1009/// a separate teardown lifecycle. In this case, -dealloc warnings
1010/// about missing releases should be suppressed.
1011bool ObjCDeallocChecker::classHasSeparateTeardown(
1012 const ObjCInterfaceDecl *ID) const {
1013 // Suppress if the class is not a subclass of NSObject.
1014 for ( ; ID ; ID = ID->getSuperClass()) {
1015 IdentifierInfo *II = ID->getIdentifier();
1016
1017 if (II == NSObjectII)
1018 return false;
1019
1020 // FIXME: For now, ignore classes that subclass SenTestCase and XCTestCase,
1021 // as these don't need to implement -dealloc. They implement tear down in
1022 // another way, which we should try and catch later.
1023 // http://llvm.org/bugs/show_bug.cgi?id=3187
1024 if (II == XCTestCaseII || II == SenTestCaseII)
1025 return true;
1026 }
1027
1028 return true;
1029}
1030
1031/// The -dealloc method in CIFilter highly unusual in that is will release
1032/// instance variables belonging to its *subclasses* if the variable name
1033/// starts with "input" or backs a property whose name starts with "input".
1034/// Subclasses should not release these ivars in their own -dealloc method --
1035/// doing so could result in an over release.
1036///
1037/// This method returns true if the property will be released by
1038/// -[CIFilter dealloc].
1039bool ObjCDeallocChecker::isReleasedByCIFilterDealloc(
1040 const ObjCPropertyImplDecl *PropImpl) const {
1041 assert(PropImpl->getPropertyIvarDecl());
1042 StringRef PropName = PropImpl->getPropertyDecl()->getName();
1043 StringRef IvarName = PropImpl->getPropertyIvarDecl()->getName();
1044
1045 const char *ReleasePrefix = "input";
1046 if (!(PropName.startswith(ReleasePrefix) ||
1047 IvarName.startswith(ReleasePrefix))) {
1048 return false;
1049 }
1050
1051 const ObjCInterfaceDecl *ID =
1053 for ( ; ID ; ID = ID->getSuperClass()) {
1054 IdentifierInfo *II = ID->getIdentifier();
1055 if (II == CIFilterII)
1056 return true;
1057 }
1058
1059 return false;
1060}
1061
1062/// Returns whether the ivar backing the property is an IBOutlet that
1063/// has its value set by nib loading code without retaining the value.
1064///
1065/// On macOS, if there is no setter, the nib-loading code sets the ivar
1066/// directly, without retaining the value,
1067///
1068/// On iOS and its derivatives, the nib-loading code will call
1069/// -setValue:forKey:, which retains the value before directly setting the ivar.
1070bool ObjCDeallocChecker::isNibLoadedIvarWithoutRetain(
1071 const ObjCPropertyImplDecl *PropImpl) const {
1072 const ObjCIvarDecl *IvarDecl = PropImpl->getPropertyIvarDecl();
1073 if (!IvarDecl->hasAttr<IBOutletAttr>())
1074 return false;
1075
1076 const llvm::Triple &Target =
1077 IvarDecl->getASTContext().getTargetInfo().getTriple();
1078
1079 if (!Target.isMacOSX())
1080 return false;
1081
1082 if (PropImpl->getPropertyDecl()->getSetterMethodDecl())
1083 return false;
1084
1085 return true;
1086}
1087
1088void ento::registerObjCDeallocChecker(CheckerManager &Mgr) {
1089 Mgr.registerChecker<ObjCDeallocChecker>();
1090}
1091
1092bool ento::shouldRegisterObjCDeallocChecker(const CheckerManager &mgr) {
1093 // These checker only makes sense under MRR.
1094 const LangOptions &LO = mgr.getLangOpts();
1095 return LO.getGC() != LangOptions::GCOnly && !LO.ObjCAutoRefCount;
1096}
ReleaseRequirement
Indicates whether an instance variable is required to be released in -dealloc.
@ MustNotReleaseDirectly
The instance variable must not be directly released with -release.
@ Unknown
The requirement for the instance variable could not be determined.
@ MustRelease
The instance variable must be released, either by calling -release on it directly or by nilling it ou...
static bool isSynthesizedRetainableProperty(const ObjCPropertyImplDecl *I, const ObjCIvarDecl **ID, const ObjCPropertyDecl **PD)
Returns true if the property implementation is synthesized and the type of the property is retainable...
Defines the clang::LangOptions interface.
#define REGISTER_MAP_WITH_PROGRAMSTATE(Name, Key, Value)
Declares an immutable map of type NameTy, suitable for placement into the ProgramState.
#define REGISTER_SET_FACTORY_WITH_PROGRAMSTATE(Name, Elem)
Declares an immutable set type Name and registers the factory for such sets in the program state,...
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:182
IdentifierTable & Idents
Definition: ASTContext.h:630
SelectorTable & Selectors
Definition: ASTContext.h:631
const TargetInfo & getTargetInfo() const
Definition: ASTContext.h:743
The results of name lookup within a DeclContext.
Definition: DeclBase.h:1347
ASTContext & getASTContext() const LLVM_READONLY
Definition: DeclBase.cpp:429
DeclContext * getDeclContext()
Definition: DeclBase.h:441
bool hasAttr() const
Definition: DeclBase.h:560
QualType getType() const
Definition: Expr.h:142
One of these records is kept for each identifier that is lexed.
IdentifierInfo & get(StringRef Name)
Return the identifier token info for the specified named identifier.
Keeps track of the various options that can be enabled, which controls the dialect of C or C++ that i...
Definition: LangOptions.h:82
It wraps the AnalysisDeclContext to represent both the call stack with the help of StackFrameContext ...
const Decl * getDecl() const
const LocationContext * getParent() const
It might return null.
virtual bool inTopFrame() const
const ImplicitParamDecl * getSelfDecl() const
IdentifierInfo * getIdentifier() const
Get the identifier that names this declaration, if there is one.
Definition: Decl.h:268
StringRef getName() const
Get the name of identifier for this declaration as a StringRef.
Definition: Decl.h:274
instmeth_range instance_methods() const
Definition: DeclObjC.h:1026
propimpl_range property_impls() const
Definition: DeclObjC.h:2499
const ObjCInterfaceDecl * getClassInterface() const
Definition: DeclObjC.h:2472
ObjCPropertyImplDecl * FindPropertyImplIvarDecl(IdentifierInfo *ivarId) const
FindPropertyImplIvarDecl - This method lookup the ivar in the list of properties implemented in this ...
Definition: DeclObjC.cpp:2247
ObjCImplementationDecl - Represents a class definition - this is where method definitions are specifi...
Definition: DeclObjC.h:2584
Represents an ObjC class declaration.
Definition: DeclObjC.h:1147
ObjCImplementationDecl * getImplementation() const
Definition: DeclObjC.cpp:1635
ObjCIvarDecl - Represents an ObjC instance variable.
Definition: DeclObjC.h:1939
ObjCInterfaceDecl * getContainingInterface()
Return the class interface that this ivar is logically contained in; this is either the interface whe...
Definition: DeclObjC.cpp:1881
@ SuperInstance
The receiver is the instance of the superclass object.
Definition: ExprObjC.h:1097
ReceiverKind getReceiverKind() const
Determine the kind of receiver that this message is being sent to.
Definition: ExprObjC.h:1224
ObjCMethodDecl - Represents an instance or class method declaration.
Definition: DeclObjC.h:138
Selector getSelector() const
Definition: DeclObjC.h:329
bool isInstanceMethod() const
Definition: DeclObjC.h:428
Represents one property declaration in an Objective-C interface.
Definition: DeclObjC.h:729
ObjCMethodDecl * getSetterMethodDecl() const
Definition: DeclObjC.h:897
bool isReadOnly() const
isReadOnly - Return true iff the property has a setter.
Definition: DeclObjC.h:831
ObjCIvarDecl * getPropertyIvarDecl() const
Definition: DeclObjC.h:917
SetterKind getSetterKind() const
getSetterKind - Return the method used for doing assignment in the property setter.
Definition: DeclObjC.h:866
ObjCPropertyImplDecl - Represents implementation declaration of a property in a class or category imp...
Definition: DeclObjC.h:2789
ObjCIvarDecl * getPropertyIvarDecl() const
Definition: DeclObjC.h:2862
Kind getPropertyImplementation() const
Definition: DeclObjC.h:2858
ObjCPropertyDecl * getPropertyDecl() const
Definition: DeclObjC.h:2853
A (possibly-)qualified type.
Definition: Type.h:736
ReturnStmt - This represents a return, optionally of an expression: return; return 4;.
Definition: Stmt.h:2835
Selector getSelector(unsigned NumArgs, IdentifierInfo **IIV)
Can create any sort of selector.
Smart pointer class that efficiently represents Objective-C method names.
SourceRange getSourceRange() const LLVM_READONLY
SourceLocation tokens are not useful in isolation - they are low level value objects created/interpre...
Definition: Stmt.cpp:325
const llvm::Triple & getTriple() const
Returns the target triple of the primary target.
Definition: TargetInfo.h:1197
bool isObjCRetainableType() const
Definition: Type.cpp:4549
const LangOptions & getLangOpts() const
ASTContext & getASTContext() override
BugReporter is a utility class for generating PathDiagnostics for analysis.
Definition: BugReporter.h:585
const SourceManager & getSourceManager()
Definition: BugReporter.h:616
void EmitBasicReport(const Decl *DeclWithIssue, const CheckerBase *Checker, StringRef BugName, StringRef BugCategory, StringRef BugStr, PathDiagnosticLocation Loc, ArrayRef< SourceRange > Ranges=std::nullopt, ArrayRef< FixItHint > Fixits=std::nullopt)
Represents an abstract call to a function or method along a particular path.
Definition: CallEvent.h:149
const ProgramStateRef & getState() const
The state in which the call is being evaluated.
Definition: CallEvent.h:230
virtual SVal getArgSVal(unsigned Index) const
Returns the value of a given argument at the time of the call.
Definition: CallEvent.cpp:308
CHECKER * registerChecker(AT &&... Args)
Used to register checkers.
const LangOptions & getLangOpts() const
MemRegion - The root abstract class for all memory regions.
Definition: MemRegion.h:95
const SymbolicRegion * getSymbolicBase() const
If this is a symbolic region, returns the region.
Definition: MemRegion.cpp:1365
LLVM_ATTRIBUTE_RETURNS_NONNULL const ObjCIvarDecl * getDecl() const override
Definition: MemRegion.cpp:169
Represents any expression that calls an Objective-C method.
Definition: CallEvent.h:1163
const Expr * getArgExpr(unsigned Index) const override
Returns the expression associated with a given argument.
Definition: CallEvent.h:1200
unsigned getNumArgs() const override
Returns the number of arguments (explicit and implicit).
Definition: CallEvent.h:1196
const ObjCMessageExpr * getOriginExpr() const override
Returns the expression whose value will be the result of this call.
Definition: CallEvent.h:1188
SVal getReceiverSVal() const
Returns the value of the receiver at the time of this call.
Definition: CallEvent.cpp:979
bool isReceiverSelfOrSuper() const
Checks if the receiver refers to 'self' or 'super'.
Definition: CallEvent.cpp:995
Selector getSelector() const
Definition: CallEvent.h:1212
const ObjCPropertyDecl * getAccessedProperty() const
Definition: CallEvent.cpp:1084
static PathDiagnosticLocation createBegin(const Decl *D, const SourceManager &SM)
Create a location for the beginning of the declaration.
SVal - This represents a symbolic expression, which can be either an L-value or an R-value.
Definition: SVals.h:72
SymbolRef getAsSymbol(bool IncludeBaseRegions=false) const
If this SVal wraps a symbol return that SymbolRef.
Definition: SVals.cpp:104
std::optional< T > getAs() const
Convert to the specified SVal type, returning std::nullopt if this SVal is not of the desired type.
Definition: SVals.h:103
bool isValid() const
Definition: SVals.h:136
T castAs() const
Convert to the specified SVal type, asserting that this SVal is of the desired type.
Definition: SVals.h:99
LLVM_ATTRIBUTE_RETURNS_NONNULL const MemRegion * getSuperRegion() const
Definition: MemRegion.h:455
Symbolic value.
Definition: SymExpr.h:29
virtual const MemRegion * getOriginRegion() const
Find the region from which this symbol originates.
Definition: SymExpr.h:102
SymbolRef getSymbol() const
It might return null.
Definition: MemRegion.h:789
TypedValueRegion - An abstract class representing regions having a typed value.
Definition: MemRegion.h:531
const MemRegion * getRegion() const
Get the underlining region.
Definition: SVals.h:512
Defines the clang::TargetInfo interface.
const char *const CoreFoundationObjectiveC
const char *const MemoryRefCount
PointerEscapeKind
Describes the different reasons a pointer escapes during analysis.
bool Call(InterpState &S, CodePtr OpPC, const Function *Func)
Definition: Interp.h:1584
BinaryOperatorKind
@ C
Languages that the frontend can parse and compile.