Clang does not know the -Wno-format-truncation option of (current) GCC,
but accepts unknown -W... options (exit core 0) but issues a warning
message on every invocation. So for example on macOS, where Clang is
used as "gcc", a new warning message was shown for every file to
compile, since we enabled -Wno-format-truncation in commit
1d527eaf:
warning: unknown warning option '-Wno-format-truncation' [-Wunknown-warning-option]
Clang no longer acceps unknown -W... options by enabling -Werror, which
this patch adds to the CFLAGS while testing for -Wno-format-truncation,
which fixes this issue.
This fixes commit
1d527eaf.
result=yes
AC_MSG_CHECKING([whether ${CC} accepts -Wno-format-truncation])
old_cflags="$CFLAGS"
- CFLAGS="$CFLAGS -Wno-format-truncation"
+ CFLAGS="$CFLAGS -Werror -Wno-format-truncation"
AC_LINK_IFELSE([AC_LANG_PROGRAM([],[])],[],[result=no])
echo $result
- if test "X$result" = "Xno"; then
+ if test "X$result" = "Xyes"; then
+ CFLAGS="$old_cflags -Wno-format-truncation"
+ else
CFLAGS="$old_cflags"
fi
])