Author: erichkeane Date: Thu Oct 19 08:58:58 2017 New Revision: 316166 URL: http://llvm.org/viewvc/llvm-project?rev=316166&view=rev Log: Fix nodiscard for volatile references
As reported here https://bugs.llvm.org/show_bug.cgi?id=34988 [[nodiscard]] warnings were not being suppressed for volatile-ref return values. Differential Revision: https://reviews.llvm.org/D39075 Modified: cfe/trunk/lib/AST/Expr.cpp cfe/trunk/test/CXX/dcl.dcl/dcl.attr/dcl.attr.nodiscard/p2.cpp Modified: cfe/trunk/lib/AST/Expr.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/Expr.cpp?rev=316166&r1=316165&r2=316166&view=diff ============================================================================== --- cfe/trunk/lib/AST/Expr.cpp (original) +++ cfe/trunk/lib/AST/Expr.cpp Thu Oct 19 08:58:58 2017 @@ -2298,7 +2298,8 @@ bool Expr::isUnusedResultAWarning(const const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CE->getSubExpr()->IgnoreParens()); if (!(DRE && isa<VarDecl>(DRE->getDecl()) && - cast<VarDecl>(DRE->getDecl())->hasLocalStorage())) { + cast<VarDecl>(DRE->getDecl())->hasLocalStorage()) && + !isa<CallExpr>(CE->getSubExpr()->IgnoreParens())) { return CE->getSubExpr()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx); } Modified: cfe/trunk/test/CXX/dcl.dcl/dcl.attr/dcl.attr.nodiscard/p2.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/dcl.dcl/dcl.attr/dcl.attr.nodiscard/p2.cpp?rev=316166&r1=316165&r2=316166&view=diff ============================================================================== --- cfe/trunk/test/CXX/dcl.dcl/dcl.attr/dcl.attr.nodiscard/p2.cpp (original) +++ cfe/trunk/test/CXX/dcl.dcl/dcl.attr/dcl.attr.nodiscard/p2.cpp Thu Oct 19 08:58:58 2017 @@ -9,21 +9,33 @@ enum [[nodiscard]] E {}; E get_e(); [[nodiscard]] int get_i(); +[[nodiscard]] volatile int &get_vi(); void f() { get_s(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} get_i(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} + get_vi(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} get_e(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} // Okay, warnings are not encouraged get_s_ref(); (void)get_s(); (void)get_i(); + (void)get_vi(); (void)get_e(); } +[[nodiscard]] volatile char &(*fp)(); +void g() { + fp(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} + + // OK, warning suppressed. + (void)fp(); +} #ifdef EXT // expected-warning@4 {{use of the 'nodiscard' attribute is a C++17 extension}} // expected-warning@8 {{use of the 'nodiscard' attribute is a C++17 extension}} // expected-warning@11 {{use of the 'nodiscard' attribute is a C++17 extension}} +// expected-warning@12 {{use of the 'nodiscard' attribute is a C++17 extension}} +// expected-warning@28 {{use of the 'nodiscard' attribute is a C++17 extension}} #endif _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits