diff options
Diffstat (limited to 'config/always-no-unused-but-set-variable.m4')
| -rw-r--r-- | config/always-no-unused-but-set-variable.m4 | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/config/always-no-unused-but-set-variable.m4 b/config/always-no-unused-but-set-variable.m4 new file mode 100644 index 000000000..0e2634da2 --- /dev/null +++ b/config/always-no-unused-but-set-variable.m4 @@ -0,0 +1,27 @@ +dnl # +dnl # Check if gcc supports -Wno-unused-but-set-variable option. +dnl # +dnl # We actually invoke gcc with the -Wunused-but-set-variable option +dnl # and infer the 'no-' version does or doesn't exist based upon +dnl # the results. This is required because when checking any of +dnl # no- prefixed options gcc always returns success. +dnl # +AC_DEFUN([ZFS_AC_CONFIG_ALWAYS_NO_UNUSED_BUT_SET_VARIABLE], [ + AC_MSG_CHECKING([for -Wno-unused-but-set-variable support]) + + saved_flags="$CFLAGS" + CFLAGS="$CFLAGS -Wunused-but-set-variable" + + AC_RUN_IFELSE(AC_LANG_PROGRAM( [], []), + [ + NO_UNUSED_BUT_SET_VARIABLE=-Wno-unused-but-set-variable + AC_MSG_RESULT([yes]) + ], + [ + NO_UNUSED_BUT_SET_VARIABLE= + AC_MSG_RESULT([no]) + ]) + + CFLAGS="$saved_flags" + AC_SUBST([NO_UNUSED_BUT_SET_VARIABLE]) +]) |