From 7702d940ec9a27fd4ab9e3991fc582b369b5eedc Mon Sep 17 00:00:00 2001 From: Dimitry Andric Date: Thu, 8 Apr 2021 13:13:15 +0200 Subject: [PATCH] Avoid -pedantic warnings about using _Generic in __fp_type_select When compiling parts of math.h with clang using a C standard before C11, and using -pedantic, it will result in warnings similar to: bug254714.c:5:11: warning: '_Generic' is a C11 extension [-Wc11-extensions] return !isfinite(1.0); ^ /usr/include/math.h:111:21: note: expanded from macro 'isfinite' ^ /usr/include/math.h:82:39: note: expanded from macro '__fp_type_select' ^ This is because the block that enables use of _Generic is conditional not only on C11, but also on whether the compiler advertises support for C generic selections via __has_extension(c_generic_selections). To work around the warning without having to pessimize the code, use the __extension__ keyword, which is supported by both clang and gcc. While here, remove the check for __clang__, as _Generic has been supported for a long time by gcc too now. Reported by: yuri PR: 254714 MFC after: 1 week --- lib/msun/src/math.h | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/lib/msun/src/math.h b/lib/msun/src/math.h index fee69498708a..8156094313e4 100644 --- a/lib/msun/src/math.h +++ b/lib/msun/src/math.h @@ -77,9 +77,8 @@ extern const union __nan_un { #define FP_SUBNORMAL 0x08 #define FP_ZERO 0x10 -#if (__STDC_VERSION__ >= 201112L && defined(__clang__)) || \ - __has_extension(c_generic_selections) -#define __fp_type_select(x, f, d, ld) _Generic((x), \ +#if __STDC_VERSION__ >= 201112L || __has_extension(c_generic_selections) +#define __fp_type_select(x, f, d, ld) __extension__ _Generic((x), \ float: f(x), \ double: d(x), \ long double: ld(x), \