Author: YingChi Long Date: 2022-08-16T20:44:38+08:00 New Revision: ccbc22cd8976c285d76e9f66dd5cac2fe908d084
URL: https://github.com/llvm/llvm-project/commit/ccbc22cd8976c285d76e9f66dd5cac2fe908d084 DIFF: https://github.com/llvm/llvm-project/commit/ccbc22cd8976c285d76e9f66dd5cac2fe908d084.diff LOG: [Sema] fix false -Wcomma being emitted from void returning functions Fixes https://github.com/llvm/llvm-project/issues/57151 Reviewed By: aaron.ballman Differential Revision: https://reviews.llvm.org/D131892 Added: Modified: clang/docs/ReleaseNotes.rst clang/lib/Sema/SemaExpr.cpp clang/test/SemaCXX/warn-comma-operator.cpp Removed: ################################################################################ diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index ded0b39c27ea5..1da6015ad1610 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -73,7 +73,8 @@ Bug Fixes number of arguments cause an assertion fault. - Fix multi-level pack expansion of undeclared function parameters. This fixes `Issue 56094 <https://github.com/llvm/llvm-project/issues/56094>`_. - +- Fix `#57151 <https://github.com/llvm/llvm-project/issues/57151>`_. + ``-Wcomma`` is emitted for void returning functions. Improvements to Clang's diagnostics ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp index 03f5ec9848e1f..a2a2e1ed85fc3 100644 --- a/clang/lib/Sema/SemaExpr.cpp +++ b/clang/lib/Sema/SemaExpr.cpp @@ -13957,8 +13957,10 @@ QualType Sema::CheckAssignmentOperands(Expr *LHSExpr, ExprResult &RHS, return getLangOpts().CPlusPlus ? LHSType : LHSType.getAtomicUnqualifiedType(); } -// Only ignore explicit casts to void. -static bool IgnoreCommaOperand(const Expr *E) { +// Scenarios to ignore if expression E is: +// 1. an explicit cast expression into void +// 2. a function call expression that returns void +static bool IgnoreCommaOperand(const Expr *E, const ASTContext &Context) { E = E->IgnoreParens(); if (const CastExpr *CE = dyn_cast<CastExpr>(E)) { @@ -13973,6 +13975,8 @@ static bool IgnoreCommaOperand(const Expr *E) { } } + if (const auto *CE = dyn_cast<CallExpr>(E)) + return CE->getCallReturnType(Context)->isVoidType(); return false; } @@ -14014,7 +14018,7 @@ void Sema::DiagnoseCommaOperator(const Expr *LHS, SourceLocation Loc) { } // Only allow some expressions on LHS to not warn. - if (IgnoreCommaOperand(LHS)) + if (IgnoreCommaOperand(LHS, Context)) return; Diag(Loc, diag::warn_comma_operator); diff --git a/clang/test/SemaCXX/warn-comma-operator.cpp b/clang/test/SemaCXX/warn-comma-operator.cpp index 635ce01b1c9cf..75148cb416fdb 100644 --- a/clang/test/SemaCXX/warn-comma-operator.cpp +++ b/clang/test/SemaCXX/warn-comma-operator.cpp @@ -140,6 +140,27 @@ void test_nested_fixits(void) { // CHECK: fix-it:{{.*}}:{[[@LINE-8]]:46-[[@LINE-8]]:46}:")" } + +void void_func(); +int int_func() { return 0; } + +void void_function_comma(){ + void_func(), int_func(); // expected no -Wcomma because of the returning type `void` + // Reported by https://github.com/llvm/llvm-project/issues/57151 + // Descriptions about -Wcomma: https://reviews.llvm.org/D3976 +} + +typedef void Void; +Void typedef_func(); + +void whatever() { + // We don't get confused about type aliases. + typedef_func(), int_func(); + // Even function pointers don't confuse us. + void (*fp)() = void_func; + fp(), int_func(); +} + #ifdef __cplusplus class S2 { public: @@ -296,4 +317,23 @@ void test_dependent_cast() { (void)T{}, 0; static_cast<void>(T{}), 0; } + +namespace { + +// issue #57151 + +struct S { + void mem() {} +}; + +void whatever() { + struct S s; + // Member function calls also work as expected. + s.mem(), int_func(); + // As do lambda calls. + []() { return; }(), int_func(); +} + +} // namespace + #endif // ifdef __cplusplus _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
