diff options
Diffstat (limited to 'm4')
-rw-r--r-- | m4/attributes.m4 | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/m4/attributes.m4 b/m4/attributes.m4 index 45ea789..e86456a 100644 --- a/m4/attributes.m4 +++ b/m4/attributes.m4 @@ -99,6 +99,31 @@ AC_DEFUN([CC_CHECK_LDFLAGS], [ [$2], [$3]) ]) +dnl define the LDFLAGS_NOUNDEFINED variable with the correct value for +dnl the current linker to avoid undefined references in a shared object. +AC_DEFUN([CC_NOUNDEFINED], [ + dnl We check $host for which systems to enable this for. + AC_REQUIRE([AC_CANONICAL_HOST]) + + case $host in + dnl FreeBSD (et al.) does not complete linking for shared objects when pthreads + dnl are requested, as different implementations are present; to avoid problems + dnl use -Wl,-z,defs only for those platform not behaving this way. + *-freebsd*) ;; + *) + dnl First of all check for the --no-undefined variant of GNU ld. This allows + dnl for a much more readable commandline, so that people can understand what + dnl it does without going to look for what the heck -z defs does. + for possible_flags in "-Wl,--no-undefined" "-Wl,-z,defs"; do + CC_CHECK_LDFLAGS([$possible_flags], [LDFLAGS_NOUNDEFINED="$possible_flags"]) + break + done + ;; + esac + + AC_SUBST([LDFLAGS_NOUNDEFINED]) +]) + dnl Check for a -Werror flag or equivalent. -Werror is the GCC dnl and ICC flag that tells the compiler to treat all the warnings dnl as fatal. We usually need this option to make sure that some |