How to enable c11 on later versions of gcc?

Question

I currently use gcc 4.6.3. My understanding is that gcc by default uses the gnu89 standard and I would like to enable C11, the latest

Answer 1

The correct option is -std=c11.

However, it is not available in gcc 4.6. You need at least gcc 4.7 to have this option supported. In some older versions like gcc 4.6, the option -std=c1x was available with experimental (i.e., very limited) support of C11.

Note that the current version of gcc is gcc 8.2.

Answer 2

Just to let you know GCC 4.9.x has far more complete support than older versions. If you really need to use this feature, please switch to anything 4.8+ Here is the support status -- https://gcc.gnu.org/wiki/C11Status

Answer 3

gcc 5.2.0 works with command line option ‘-std=c11’

Answer 4

Inside a .spec file :

%define gcc_ver %(if [[ $(gcc -dumpversion) > 4.7 ]]; then echo 1; else echo 0; fi)
# Do we use c11 ?
%if 0%{?gcc_ver} < 1
  %global std_c11 0
%else
  %global std_c11 1
%endif

# if the configure of the package supports it add :
%if %{std_c11}
  --enable-cxx11 \
%endif