[clang] [clang] Suggest using __VA_OPT__(,) instead of GNU zero variadic macro argument (PR #188624)

[via cfe-commits]

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@@ -0,0 +1,13 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s -Wgnu-zero-variadic-macro-arguments -std=c23
+// RUN: %clang_cc1 -fsyntax-only -fdiagnostics-parseable-fixits %s -Wgnu-zero-variadic-macro-arguments -std=c23 2>&1 | FileCheck %s
+// RUN: %clang_cc1 -fsyntax-only -verify %s -Wgnu-zero-variadic-macro-arguments -xc++ -std=c++20
+// RUN: %clang_cc1 -fsyntax-only -fdiagnostics-parseable-fixits %s -Wgnu-zero-variadic-macro-arguments -xc++ -std=c++20 2>&1 | FileCheck %s
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serge-sans-paille wrote:

yeah, we already have `clang/test/Lexer/gnu-flags.c`

https://github.com/llvm/llvm-project/pull/188624