Arch Linux

Description:

When compiling a custom LTS kernel with CONFIG_GCC_PLUGINS and the latest version of gcc, the following check in "scripts/gcc-plugins/Kconfig" will fail:

depends on $(success,$(srctree)/scripts/gcc-plugin.sh $(CC))

causing the selected plugins not to be compiled.
This is due to the use of the C++98 standard which leads to incompatibility issues at compile time with GCC 11:

/usr/include/c++/11.1.0/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.

Thus this is necessary to patch the "scripts/gcc-plugin.sh" file and the "scripts/gcc-plugins/Makefile" in order to be able to compile the plugins.

--- scripts/gcc-plugin.sh
+++ scripts/gcc-plugin.sh
@@ -11 +11 @@
-$HOSTCC -c -x c++ -std=gnu++98 - -fsyntax-only -I $srctree/gcc-plugins -I $gccplugins_dir/include 2>/dev/null <<EOF
+$HOSTCC -c -x c++ -std=gnu++11 - -fsyntax-only -I $srctree/gcc-plugins -I $gccplugins_dir/include 2>/dev/null <<EOF

--- scripts/gcc-plugins/Makefile
+++ scripts/gcc-plugins/Makefile
@@ -25 +25 @@
- -I $(GCC_PLUGINS_DIR)/include -I $(obj) -std=gnu++98 \
+ -I $(GCC_PLUGINS_DIR)/include -I $(obj) -std=gnu++11 \
@@ -27 +27 @@
- -ggdb -Wno-narrowing -Wno-unused-variable -Wno-c++11-compat \
+ -ggdb -Wno-narrowing -Wno-unused-variable \


Additional info:
https://www.spinics.net/linux/fedora/fedora-kernel/msg10398.html