btrfs-progs/m4/ax_gcc_version.m4
Jeff Mahoney eb7b42003a btrfs-progs: build: detect whether -std=gnu90 is supported
GCC releases prior to 4.5.0 don't support -std=gnu90 so btrfs-progs won't
build at all on older distros.  We can detect whether the compiler
supports -std=gnu90 and fall back to -std=gnu89 if it doesn't.

AX_CHECK_COMPILE_FLAG is the right way to do this, but it depends on
autoconf 2.64.  AX_GCC_VERSION has been deprecated, so we'll use that
only for earlier autoconf versions so we can drop it when we drop
support for older autoconf releases.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-06-07 16:37:35 +02:00

38 lines
1.1 KiB
Plaintext

dnl @synopsis AX_GCC_VERSION(MAJOR, MINOR, PATCHLEVEL, [ACTION-SUCCESS], [ACTION-FAILURE])
dnl @summary check wither gcc is at least version MAJOR.MINOR.PATCHLEVEL
dnl @category InstalledPackages
dnl
dnl Check whether we are using gcc and, if so, whether its version
dnl is at least MAJOR.MINOR.PATCHLEVEL
dnl
dnl ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on
dnl success/failure.
dnl
dnl @version 2005-05-30
dnl @license GPLWithACException
dnl @author Steven G. Johnson <stevenj@alum.mit.edu> and Matteo Frigo.
AC_DEFUN([AX_GCC_VERSION],
[
AC_REQUIRE([AC_PROG_CC])
AC_CACHE_CHECK(whether we are using gcc $1.$2.$3 or later, ax_cv_gcc_$1_$2_$3,
[
ax_cv_gcc_$1_$2_$3=no
if test "$GCC" = "yes"; then
dnl The semicolon after "yes" below is to pacify NeXT's syntax-checking cpp.
AC_EGREP_CPP(yes, [
#ifdef __GNUC__
# if (__GNUC__ > $1) || (__GNUC__ == $1 && __GNUC_MINOR__ > $2) \
|| (__GNUC__ == $1 && __GNUC_MINOR__ == $2 && __GNUC_PATCHLEVEL__ >= $3)
yes;
# endif
#endif
], [ax_cv_gcc_$1_$2_$3=yes])
fi
])
if test "$ax_cv_gcc_$1_$2_$3" = yes; then
m4_default([$4], :)
else
m4_default([$5], :)
fi
])