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 <[email protected]>
---
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
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 <[email protected]>
> ---
> 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
On Wed, Jan 13, 2021 at 11:08:36AM -0600, Josh Poimboeuf wrote:
> 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 <[email protected]>
> > ---
> > 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.
Yes, please. :)
--
Kees Cook
On Wed, 13 Jan 2021 11:08:36 -0600, Josh Poimboeuf said:
> The first patch has already been merged into Linus' tree, so this
> probably should be an incremental fix on top, with a Fixes: tag.
Gaah. v3 in a moment. :)