lkml.org 
[lkml]   [2021]   [Mar]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH RESEND] gcc-plugins: avoid errors with -std=gnu++11 on old gcc
On Mon, Mar 08, 2021 at 03:40:21AM -0500, Valdis Klētnieks wrote:
> It turns out that older gcc (4.9 and 5.4) have gnu++11 support, but
> due to a gcc bug fixed in gcc6, throw errors during the build.
> The relevant gcc bug is https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69959
>
> Version the option based on what gcc we're using.

Is there a better way to detect this than with version checking?

-Kees

>
> Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
> Fixes: 27c287b41659 ("gcc-plugins: fix gcc 11 indigestion with plugins...")
> ---
> diff --git a/scripts/gcc-plugins/Makefile b/scripts/gcc-plugins/Makefile
> index b5487cce69e8..cc779973724a 100644
> --- a/scripts/gcc-plugins/Makefile
> +++ b/scripts/gcc-plugins/Makefile
> @@ -21,8 +21,11 @@ always-y += $(GCC_PLUGIN)
>
> GCC_PLUGINS_DIR = $(shell $(CC) -print-file-name=plugin)
>
> +# need gnu++11 for gcc 11, but 4.9 and 5.4 need gnu++98
> +GCC_FLAVOR = $(call cc-ifversion, -ge, 1100, 11, 98)
> +
> plugin_cxxflags = -Wp,-MMD,$(depfile) $(KBUILD_HOSTCXXFLAGS) -fPIC \
> - -I $(GCC_PLUGINS_DIR)/include -I $(obj) -std=gnu++11 \
> + -I $(GCC_PLUGINS_DIR)/include -I $(obj) -std=gnu++$(GCC_FLAVOR) \
> -fno-rtti -fno-exceptions -fasynchronous-unwind-tables \
> -ggdb -Wno-narrowing -Wno-unused-variable \
> -Wno-format-diag
>
>

--
Kees Cook

\
 
 \ /
  Last update: 2021-03-18 06:55    [W:0.104 / U:0.028 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site