On 1/25/18, Ferenc Wágner <wferi@xxxxxxx> wrote: > Jeffrey Walton <noloader@xxxxxxxxx> writes: > >> AC_MSG_CHECKING([if $LDNAME supports $LDFLAGS]) >> AC_COMPILE_IFELSE([AC_LANG_PROGRAM([])], >> [AC_MSG_RESULT([yes]); AC_SUBST([tr_RESULT], [1])], >> [AC_MSG_RESULT([no]); AC_SUBST([tr_RESULT], [0])] >> ) > > Thanks for the example! Why is AC_COMPILE_IFELSE enough? It isn't. You will definitely should use AC_LINK_IFELSE to test if the linker accepts the option. By itself that won't tell you if the option actually did anything useful but that likely won't matter for this test. > Don't you have to invoke the linker itself to see if it accepts the > option passed through? And is the "-Wl," part applicable to most/all > compilers? There may exist toolchains where this won't work. They probably don't support as-needed anyway. I wouldn't worry about it at all, since normally this feature is strictly optional and the consequence of a false negative on the test is essentially zero (the as-needed flag won't be set, the build will work fine anyway, and your users are happy). This is in line with the Autoconf philosophy. Cheers, Nick _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx https://lists.gnu.org/mailman/listinfo/autoconf