* mail/rmail.el (rmail-show-message-1): When displaying a mime message,

[gnu-emacs] / configure.ac

diff --git a/configure.ac b/configure.ac
index 44709d47ab8bce8330298f2de0ed683cd9087639..d6925309d3dfa6889c2b237f8246f685bcaf8507 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -883,6 +883,7 @@ if test "$gl_gcc_warnings" != yes; then
      gl_WARN_ADD([-Wno-tautological-constant-out-of-range-compare])
      gl_WARN_ADD([-Wno-pointer-sign])
      gl_WARN_ADD([-Wno-string-plus-int])
+     gl_WARN_ADD([-Wno-unknown-attributes])
   fi
 else
   isystem='-isystem '
@@ -5027,11 +5028,29 @@ case "$opsys" in
    esac
    ;;
 
-  openbsd) LD_SWITCH_SYSTEM_TEMACS='-nopie' ;;
-
   *) LD_SWITCH_SYSTEM_TEMACS= ;;
 esac
 
+# -nopie fixes a temacs segfault on Gentoo, OpenBSD, and other systems
+# with "hardened" GCC configurations for some reason (Bug#18784).
+# We don't know why -nopie works, but not segfaulting is better than
+# segfaulting.  Use -Werror when trying -nopie, otherwise clang keeps
+# warning that it does not understand -nopie.
+AC_CACHE_CHECK([whether $CC accepts -nopie],
+  [emacs_cv_prog_cc_nopie],
+  [emacs_save_CFLAGS=$CFLAGS
+   emacs_save_LDFLAGS=$LDFLAGS
+   CFLAGS="$CFLAGS -Werror"
+   LDFLAGS="$LDFLAGS -nopie"
+   AC_LINK_IFELSE([AC_LANG_PROGRAM([], [])],
+     [emacs_cv_prog_cc_nopie=yes],
+     [emacs_cv_prog_cc_nopie=no])
+   CFLAGS=$emacs_save_CFLAGS
+   LDFLAGS=$emacs_save_LDFLAGS])
+if test "$emacs_cv_prog_cc_nopie" = yes; then
+  LD_SWITCH_SYSTEM_TEMACS="$LD_SWITCH_SYSTEM_TEMACS -nopie"
+fi
+
 if test x$ac_enable_profiling != x ; then
   case $opsys in
     *freebsd | gnu-linux) ;;