diff options
| -rw-r--r-- | include/clang/Basic/DiagnosticGroups.td | 3 | ||||
| -rw-r--r-- | include/clang/Basic/DiagnosticSemaKinds.td | 4 | ||||
| -rw-r--r-- | lib/Sema/SemaExpr.cpp | 25 | ||||
| -rw-r--r-- | test/Sema/warn-self-assign-memvar.mm | 66 | ||||
| -rw-r--r-- | test/SemaObjC/provisional-ivar-lookup.m | 2 |
5 files changed, 97 insertions, 3 deletions
diff --git a/include/clang/Basic/DiagnosticGroups.td b/include/clang/Basic/DiagnosticGroups.td index a99eb1d486..ab2cd1b08b 100644 --- a/include/clang/Basic/DiagnosticGroups.td +++ b/include/clang/Basic/DiagnosticGroups.td @@ -169,7 +169,8 @@ def ReturnTypeCLinkage : DiagGroup<"return-type-c-linkage">; def ReturnType : DiagGroup<"return-type", [ReturnTypeCLinkage]>; def BindToTemporaryCopy : DiagGroup<"bind-to-temporary-copy", [CXX98CompatBindToTemporaryCopy]>; -def SelfAssignment : DiagGroup<"self-assign">; +def SelfAssignmentMemvar : DiagGroup<"self-assign-memvar">; +def SelfAssignment : DiagGroup<"self-assign", [SelfAssignmentMemvar]>; def SemiBeforeMethodBody : DiagGroup<"semicolon-before-method-body">; def Sentinel : DiagGroup<"sentinel">; def MissingMethodReturnType : DiagGroup<"missing-method-return-type">; diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td index 91f90ca19e..0b3a8ed698 100644 --- a/include/clang/Basic/DiagnosticSemaKinds.td +++ b/include/clang/Basic/DiagnosticSemaKinds.td @@ -5274,6 +5274,10 @@ def warn_stringcompare : Warning< "unspecified (use strncmp instead)">, InGroup<DiagGroup<"string-compare">>; +def warn_identity_memvar_assign : Warning< + "assigning %select{member variable|instance variable}0 to itself">, + InGroup<SelfAssignmentMemvar>; + // Generic selections. def err_assoc_type_incomplete : Error< "type %0 in generic association incomplete">; diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp index a6051d6ccc..cd3c93b720 100644 --- a/lib/Sema/SemaExpr.cpp +++ b/lib/Sema/SemaExpr.cpp @@ -7558,7 +7558,27 @@ static bool CheckForModifiableLvalue(Expr *E, SourceLocation Loc, Sema &S) { return true; } +static void CheckIdentityMemvarAssignment(Expr *LHSExpr, Expr *RHSExpr, + SourceLocation Loc, + Sema &Sema) { + // C / C++ memvars + MemberExpr *ML = dyn_cast<MemberExpr>(LHSExpr); + MemberExpr *MR = dyn_cast<MemberExpr>(RHSExpr); + if (ML && MR && ML->getMemberDecl() == MR->getMemberDecl()) { + if (isa<CXXThisExpr>(ML->getBase()) && isa<CXXThisExpr>(MR->getBase())) + Sema.Diag(Loc, diag::warn_identity_memvar_assign) << 0; + } + // Objective-C memvars + ObjCIvarRefExpr *OL = dyn_cast<ObjCIvarRefExpr>(LHSExpr); + ObjCIvarRefExpr *OR = dyn_cast<ObjCIvarRefExpr>(RHSExpr); + if (OL && OR && OL->getDecl() == OR->getDecl()) { + DeclRefExpr *RL = dyn_cast<DeclRefExpr>(OL->getBase()->IgnoreImpCasts()); + DeclRefExpr *RR = dyn_cast<DeclRefExpr>(OR->getBase()->IgnoreImpCasts()); + if (RL && RR && RL->getDecl() == RR->getDecl()) + Sema.Diag(Loc, diag::warn_identity_memvar_assign) << 1; + } +} // C99 6.5.16.1 QualType Sema::CheckAssignmentOperands(Expr *LHSExpr, ExprResult &RHS, @@ -7575,6 +7595,10 @@ QualType Sema::CheckAssignmentOperands(Expr *LHSExpr, ExprResult &RHS, CompoundType; AssignConvertType ConvTy; if (CompoundType.isNull()) { + Expr *RHSCheck = RHS.get(); + + CheckIdentityMemvarAssignment(LHSExpr, RHSCheck, Loc, *this); + QualType LHSTy(LHSType); ConvTy = CheckSingleAssignmentConstraints(LHSTy, RHS); if (RHS.isInvalid()) @@ -7595,7 +7619,6 @@ QualType Sema::CheckAssignmentOperands(Expr *LHSExpr, ExprResult &RHS, // If the RHS is a unary plus or minus, check to see if they = and + are // right next to each other. If so, the user may have typo'd "x =+ 4" // instead of "x += 4". - Expr *RHSCheck = RHS.get(); if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(RHSCheck)) RHSCheck = ICE->getSubExpr(); if (UnaryOperator *UO = dyn_cast<UnaryOperator>(RHSCheck)) { diff --git a/test/Sema/warn-self-assign-memvar.mm b/test/Sema/warn-self-assign-memvar.mm new file mode 100644 index 0000000000..8c6fb0a5a0 --- /dev/null +++ b/test/Sema/warn-self-assign-memvar.mm @@ -0,0 +1,66 @@ +// RUN: %clang_cc1 -fsyntax-only -verify %s + +class S { + public: + int a_; + void s(int a) { + a_ = a_; // expected-warning {{assigning member variable to itself}} + + // Don't really care about this one either way. + this->a_ = a_; // expected-warning {{assigning member variable to itself}} + + a_ += a_; // Shouldn't warn. + } +}; + +void f0(S* s) { + // Would be nice to have, but not important. + s->a_ = s->a_; +} + +void f1(S* s, S* t) { + // Shouldn't warn. + t->a_ = s->a_; +} + +struct T { + S* s_; +}; + +void f2(T* t) { + // Would be nice to have, but even less important. + t->s_->a_ = t->s_->a_; +} + +void f3(T* t, T* t2) { + // Shouldn't warn. + t2->s_->a_ = t->s_->a_; +} + +void f4(int i) { + // This is a common pattern to silence "parameter unused". Shouldn't warn. + i = i; + + int j = 0; + j = j; // Likewise. +} + +@interface I { + int a_; +} +@end + +@implementation I +- (void)setA:(int)a { + a_ = a_; // expected-warning {{assigning instance variable to itself}} +} + +- (void)foo:(I*)i { + // Don't care much about this warning. + i->a_ = i->a_; // expected-warning {{assigning instance variable to itself}} + + // Shouldn't warn. + a_ = i->a_; + i->a_ = a_; +} +@end diff --git a/test/SemaObjC/provisional-ivar-lookup.m b/test/SemaObjC/provisional-ivar-lookup.m index 2ec23a55c3..7460fc2e20 100644 --- a/test/SemaObjC/provisional-ivar-lookup.m +++ b/test/SemaObjC/provisional-ivar-lookup.m @@ -36,7 +36,7 @@ @synthesize PROP=PROP; - (void)setPROP:(int)value { - PROP = PROP; // OK + PROP = value; // OK } @end |