linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Josh Poimboeuf <jpoimboe@redhat.com>
To: "Valdis Klētnieks" <valdis.kletnieks@vt.edu>
Cc: Kees Cook <keescook@chromium.org>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	linux-hardening@vger.kernel.org,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] gcc-plugins: fix gcc 11 indigestion with plugins...
Date: Wed, 13 Jan 2021 11:08:36 -0600	[thread overview]
Message-ID: <20210113170836.xvlq5xlmkjpi4zx7@treble> (raw)
In-Reply-To: <38485.1610500756@turing-police>

On Tue, Jan 12, 2021 at 08:19:16PM -0500, Valdis Klētnieks wrote:
> Fedora Rawhide has started including gcc 11,and the g++ compiler
> throws a wobbly when it hits scripts/gcc-plugins:
> 
>   HOSTCXX scripts/gcc-plugins/latent_entropy_plugin.so
> In file included from /usr/include/c++/11/type_traits:35,
>                  from /usr/lib/gcc/x86_64-redhat-linux/11/plugin/include/system.h:244,
>                  from /usr/lib/gcc/x86_64-redhat-linux/11/plugin/include/gcc-plugin.h:28,
>                  from scripts/gcc-plugins/gcc-common.h:7,
>                  from scripts/gcc-plugins/latent_entropy_plugin.c:78:
> /usr/include/c++/11/bits/c++0x_warning.h:32:2: error: #error This file requires compiler and library support for the ISO
>  C++ 2011 standard. This support must be enabled with the -std=c++11 or -std=gnu++11 compiler options.
>    32 | #error This file requires compiler and library support \
> 
> Patch is more complicated than would otherwise be needed, because
> older gcc (4.9, 5.4) have gnu++11 but throw an error due to a gcc bug
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69959
> 
> Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
> ---
> diff --git a/scripts/gcc-plugins/Makefile b/scripts/gcc-plugins/Makefile
> index d66949bfeba4..cc779973724a 100644
> --- a/scripts/gcc-plugins/Makefile
> +++ b/scripts/gcc-plugins/Makefile
> @@ -21,10 +21,13 @@ 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++98 \
> +		   -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-c++11-compat \
> +		   -ggdb -Wno-narrowing -Wno-unused-variable \
>  		   -Wno-format-diag
>  
>  plugin_ldflags	= -shared

The first patch has already been merged into Linus' tree, so this
probably should be an incremental fix on top, with a Fixes: tag.

-- 
Josh


  reply	other threads:[~2021-01-13 17:10 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-13  1:19 [PATCH v2] gcc-plugins: fix gcc 11 indigestion with plugins Valdis Klētnieks
2021-01-13 17:08 ` Josh Poimboeuf [this message]
2021-01-13 17:59   ` Kees Cook
2021-01-13 18:02   ` Valdis Klētnieks

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210113170836.xvlq5xlmkjpi4zx7@treble \
    --to=jpoimboe@redhat.com \
    --cc=geert@linux-m68k.org \
    --cc=keescook@chromium.org \
    --cc=linux-hardening@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=valdis.kletnieks@vt.edu \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).