configure: Use -std=gnu11

Now that the minimum gcc version is 7.5, we can use C11.
This will allow lots of cleanups to the code, currently
hidden behind macros in include/qemu/compiler.h.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210614233143.1221879-2-richard.henderson@linaro.org>

configure

@@ -159,7 +159,7 @@ update_cxxflags() {
     # options which some versions of GCC's C++ compiler complain about
     # because they only make sense for C programs.
     QEMU_CXXFLAGS="$QEMU_CXXFLAGS -D__STDC_LIMIT_MACROS -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS"
-    CONFIGURE_CXXFLAGS=$(echo "$CONFIGURE_CFLAGS" | sed s/-std=gnu99/-std=gnu++11/)
+    CONFIGURE_CXXFLAGS=$(echo "$CONFIGURE_CFLAGS" | sed s/-std=gnu11/-std=gnu++11/)
     for arg in $QEMU_CFLAGS; do
         case $arg in
             -Wstrict-prototypes|-Wmissing-prototypes|-Wnested-externs|\
@@ -538,7 +538,7 @@ QEMU_CFLAGS="-Wstrict-prototypes -Wredundant-decls $QEMU_CFLAGS"
 QEMU_CFLAGS="-D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE $QEMU_CFLAGS"
 
 # Flags that are needed during configure but later taken care of by Meson
-CONFIGURE_CFLAGS="-std=gnu99 -Wall"
+CONFIGURE_CFLAGS="-std=gnu11 -Wall"
 CONFIGURE_LDFLAGS=
 
 

meson.build

@@ -1,5 +1,5 @@
 project('qemu', ['c'], meson_version: '>=0.55.0',
-        default_options: ['warning_level=1', 'c_std=gnu99', 'cpp_std=gnu++11', 'b_colorout=auto'] +
+        default_options: ['warning_level=1', 'c_std=gnu11', 'cpp_std=gnu++11', 'b_colorout=auto'] +
                          (meson.version().version_compare('>=0.56.0') ? [ 'b_staticpic=false' ] : []),
         version: run_command('head', meson.source_root() / 'VERSION').stdout().strip())