+ # gcc --help=warnings outputs an unusual form for these options; list
+ # them here so that the above 'comm' command doesn't report a false match.
+ # Would prefer "min (PTRDIFF_MAX, SIZE_MAX)", but it must be a literal.
+ # Also, AC_COMPUTE_INT requires it to fit in a long; it is 2**63 on
+ # the only platforms where it does not fit in a long, so make that
+ # a special case.
+ AC_MSG_CHECKING([max safe object size])
+ AC_COMPUTE_INT([gl_alloc_max],
+ [LONG_MAX < (PTRDIFF_MAX < (size_t) -1 ? PTRDIFF_MAX : (size_t) -1)
+ ? -1
+ : PTRDIFF_MAX < (size_t) -1 ? (long) PTRDIFF_MAX : (long) (size_t) -1],
+ [[#include <limits.h>
+ #include <stddef.h>
+ #include <stdint.h>
+ ]],
+ [gl_alloc_max=2147483647])
+ case $gl_alloc_max in
+ -1) gl_alloc_max=9223372036854775807;;
+ esac
+ AC_MSG_RESULT([$gl_alloc_max])
+ gl_manywarn_set="$gl_manywarn_set -Walloc-size-larger-than=$gl_alloc_max"
+ gl_manywarn_set="$gl_manywarn_set -Warray-bounds=2"
+ gl_manywarn_set="$gl_manywarn_set -Wformat-overflow=2"
+ gl_manywarn_set="$gl_manywarn_set -Wformat-truncation=2"
+ gl_manywarn_set="$gl_manywarn_set -Wimplicit-fallthrough=5"
+ gl_manywarn_set="$gl_manywarn_set -Wnormalized=nfc"
+ gl_manywarn_set="$gl_manywarn_set -Wshift-overflow=2"
+ gl_manywarn_set="$gl_manywarn_set -Wstringop-overflow=2"
+ gl_manywarn_set="$gl_manywarn_set -Wunused-const-variable=2"
+ gl_manywarn_set="$gl_manywarn_set -Wvla-larger-than=4031"
+
+ # These are needed for older GCC versions.
+ if test -n "$GCC"; then
+ case `($CC --version) 2>/dev/null` in
+ 'gcc (GCC) '[[0-3]].* | \
+ 'gcc (GCC) '4.[[0-7]].*)
+ gl_manywarn_set="$gl_manywarn_set -fdiagnostics-show-option"
+ gl_manywarn_set="$gl_manywarn_set -funit-at-a-time"
+ ;;
+ esac
+ fi
+