From: Jordan Rose Date: Thu, 11 Oct 2012 16:06:21 +0000 (+0000) Subject: -Warc-repeated-use-of-weak: Check messages to property accessors as well. X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=7fffce781e6ecbf4058b24df7e5ae3037569aa56;p=clang -Warc-repeated-use-of-weak: Check messages to property accessors as well. Previously, [foo weakProp] was not being treated the same as foo.weakProp. Now, for every explicit message send, we check if it's a property access, and if so, if the property is weak. Then for every assignment of a message, we have to do the same thing again. This is a potentially expensive increase because determining whether a method is a property accessor requires searching through the methods it overrides. However, without it -Warc-repeated-use-of-weak will miss cases from people who prefer not to use dot syntax. If this turns out to be too expensive, we can try caching the result somewhere, or even lose precision by not checking superclass methods. The warning is off-by-default, though. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@165718 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/include/clang/Sema/ScopeInfo.h b/include/clang/Sema/ScopeInfo.h index 0592265ccd..7fbe07dc94 100644 --- a/include/clang/Sema/ScopeInfo.h +++ b/include/clang/Sema/ScopeInfo.h @@ -25,6 +25,7 @@ namespace clang { class Decl; class BlockDecl; class CXXMethodDecl; +class ObjCPropertyDecl; class IdentifierInfo; class LabelDecl; class ReturnStmt; @@ -34,6 +35,7 @@ class VarDecl; class DeclRefExpr; class ObjCIvarRefExpr; class ObjCPropertyRefExpr; +class ObjCMessageExpr; namespace sema { @@ -166,6 +168,7 @@ public: public: WeakObjectProfileTy(const ObjCPropertyRefExpr *RE); + WeakObjectProfileTy(const Expr *Base, const ObjCPropertyDecl *Property); WeakObjectProfileTy(const DeclRefExpr *RE); WeakObjectProfileTy(const ObjCIvarRefExpr *RE); @@ -261,6 +264,9 @@ public: template inline void recordUseOfWeak(const ExprT *E, bool IsRead = true); + void recordUseOfWeak(const ObjCMessageExpr *Msg, + const ObjCPropertyDecl *Prop); + /// Record that a given expression is a "safe" access of a weak object (e.g. /// assigning it to a strong variable.) /// diff --git a/lib/Sema/ScopeInfo.cpp b/lib/Sema/ScopeInfo.cpp index 76f967d588..c1d6629905 100644 --- a/lib/Sema/ScopeInfo.cpp +++ b/lib/Sema/ScopeInfo.cpp @@ -103,6 +103,14 @@ FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy( } } +FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy(const Expr *BaseE, + const ObjCPropertyDecl *Prop) + : Base(0, true), Property(Prop) { + if (BaseE) + Base = getBaseInfo(BaseE); + // else, this is a message accessing a property on super. +} + FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy( const DeclRefExpr *DRE) : Base(0, true), Property(DRE->getDecl()) { @@ -114,6 +122,14 @@ FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy( : Base(getBaseInfo(IvarE->getBase())), Property(IvarE->getDecl()) { } +void FunctionScopeInfo::recordUseOfWeak(const ObjCMessageExpr *Msg, + const ObjCPropertyDecl *Prop) { + assert(Msg && Prop); + WeakUseVector &Uses = + WeakObjectUses[WeakObjectProfileTy(Msg->getInstanceReceiver(), Prop)]; + Uses.push_back(WeakUseTy(Msg, Msg->getNumArgs() == 0)); +} + void FunctionScopeInfo::markSafeWeakUse(const Expr *E) { E = E->IgnoreParenCasts(); @@ -138,11 +154,21 @@ void FunctionScopeInfo::markSafeWeakUse(const Expr *E) { // Has this weak object been seen before? FunctionScopeInfo::WeakObjectUseMap::iterator Uses; if (const ObjCPropertyRefExpr *RefExpr = dyn_cast(E)) - Uses = WeakObjectUses.find(FunctionScopeInfo::WeakObjectProfileTy(RefExpr)); + Uses = WeakObjectUses.find(WeakObjectProfileTy(RefExpr)); else if (const ObjCIvarRefExpr *IvarE = dyn_cast(E)) - Uses = WeakObjectUses.find(FunctionScopeInfo::WeakObjectProfileTy(IvarE)); + Uses = WeakObjectUses.find(WeakObjectProfileTy(IvarE)); else if (const DeclRefExpr *DRE = dyn_cast(E)) - Uses = WeakObjectUses.find(FunctionScopeInfo::WeakObjectProfileTy(DRE)); + Uses = WeakObjectUses.find(WeakObjectProfileTy(DRE)); + else if (const ObjCMessageExpr *MsgE = dyn_cast(MsgE)) { + Uses = WeakObjectUses.end(); + if (const ObjCMethodDecl *MD = MsgE->getMethodDecl()) { + if (const ObjCPropertyDecl *Prop = MD->findPropertyDecl()) { + Uses = + WeakObjectUses.find(WeakObjectProfileTy(MsgE->getInstanceReceiver(), + Prop)); + } + } + } else return; diff --git a/lib/Sema/SemaExprObjC.cpp b/lib/Sema/SemaExprObjC.cpp index 1bb4df0483..3f9c14c685 100644 --- a/lib/Sema/SemaExprObjC.cpp +++ b/lib/Sema/SemaExprObjC.cpp @@ -2434,6 +2434,24 @@ ExprResult Sema::BuildInstanceMessage(Expr *Receiver, // In ARC, check for message sends which are likely to introduce // retain cycles. checkRetainCycles(Result); + + if (!isImplicit && Method) { + if (const ObjCPropertyDecl *Prop = Method->findPropertyDecl()) { + bool IsWeak = + Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_weak; + if (!IsWeak && Sel.isUnarySelector()) + IsWeak = ReturnType.getObjCLifetime() & Qualifiers::OCL_Weak; + + if (IsWeak) { + DiagnosticsEngine::Level Level = + Diags.getDiagnosticLevel(diag::warn_arc_repeated_use_of_weak, + LBracLoc); + if (Level != DiagnosticsEngine::Ignored) + getCurFunction()->recordUseOfWeak(Result, Prop); + + } + } + } } return MaybeBindToTemporary(Result); diff --git a/test/SemaObjC/arc-repeated-weak.mm b/test/SemaObjC/arc-repeated-weak.mm index 1c6578ef13..ca13e20dcf 100644 --- a/test/SemaObjC/arc-repeated-weak.mm +++ b/test/SemaObjC/arc-repeated-weak.mm @@ -99,6 +99,29 @@ void globals() { use(a); // expected-note{{also accessed here}} } +void messageGetter(Test *a) { + use([a weakProp]); // expected-warning{{weak property 'weakProp' is accessed multiple times}} + use([a weakProp]); // expected-note{{also accessed here}} +} + +void messageSetter(Test *a) { + [a setWeakProp:get()]; // no-warning + [a setWeakProp:get()]; // no-warning +} + +void messageSetterAndGetter(Test *a) { + [a setWeakProp:get()]; // expected-note{{also accessed here}} + use([a weakProp]); // expected-warning{{weak property 'weakProp' is accessed multiple times}} +} + +void mixDotAndMessageSend(Test *a, Test *b) { + use(a.weakProp); // expected-warning{{weak property 'weakProp' is accessed multiple times}} + use([a weakProp]); // expected-note{{also accessed here}} + + use([b weakProp]); // expected-warning{{weak property 'weakProp' is accessed multiple times}} + use(b.weakProp); // expected-note{{also accessed here}} +} + void assignToStrongWrongInit(Test *a) { id val = a.weakProp; // expected-note{{also accessed here}}