mirror of
https://github.com/autc04/Retro68.git
synced 2024-12-24 02:29:55 +00:00
48 lines
1.7 KiB
Plaintext
48 lines
1.7 KiB
Plaintext
|
|
dnl Check if the target supports weak.
|
|
AC_DEFUN([GCC_CHECK_ATTRIBUTE_WEAK], [
|
|
AC_CACHE_CHECK([whether the target supports weak],
|
|
ac_cv_have_attribute_weak, [
|
|
weakref_m4_saved_CFLAGS="$CFLAGS"
|
|
CFLAGS="$CFLAGS -Werror"
|
|
AC_TRY_COMPILE([void __attribute__((weak)) foo(void) { }],
|
|
[], ac_cv_have_attribute_weak=yes,
|
|
ac_cv_have_attribute_weak=no)
|
|
CFLAGS="$weakref_m4_saved_CFLAGS"])
|
|
if test x"$ac_cv_have_attribute_weak" = xyes; then
|
|
AC_DEFINE(HAVE_ATTRIBUTE_WEAK, 1,
|
|
[Define to 1 if the target supports __attribute__((weak)).])
|
|
fi])
|
|
|
|
dnl Check whether weak refs work like the ELF ones.
|
|
dnl This means that the weak reference works without having to satify
|
|
dnl linkage for the item.
|
|
dnl There are targets (at least Darwin) where we have fully functional
|
|
dnl weakrefs at runtime, but must supply the referenced item at link time.
|
|
AC_DEFUN([GCC_CHECK_ELF_STYLE_WEAKREF], [
|
|
AC_CACHE_CHECK([whether weak refs work like ELF],
|
|
ac_cv_have_elf_style_weakref, [
|
|
weakref_m4_saved_CFLAGS="$CFLAGS"
|
|
case "${host}" in
|
|
*-apple-darwin*) CFLAGS="$CFLAGS -Wl,-undefined,dynamic_lookup" ;;
|
|
*) ;;
|
|
esac
|
|
AC_RUN_IFELSE([AC_LANG_SOURCE([[
|
|
extern void fNotToBeFound(void) __attribute__((weak));
|
|
int main ()
|
|
{
|
|
if (fNotToBeFound)
|
|
return 1;
|
|
else
|
|
return 0;
|
|
}
|
|
]])], ac_cv_have_elf_style_weakref=yes, ac_cv_have_elf_style_weakref=no, [
|
|
case "${host}" in
|
|
*-apple-darwin[[89]]*) ac_cv_have_elf_style_weakref=no ;;
|
|
*) ac_cv_have_elf_style_weakref=yes;;
|
|
esac])CFLAGS="$weakref_m4_saved_CFLAGS"])
|
|
if test x"$ac_cv_have_elf_style_weakref" = xyes; then
|
|
AC_DEFINE(HAVE_ELF_STYLE_WEAKREF, 1, [Define to 1 if target has a weakref that works like the ELF one.])
|
|
fi])
|
|
|