libffi: Add --enable-cet to configure

When --enable-cet is used to configure GCC, enable Intel CET in libffi.

	* Makefile.am (AM_CFLAGS): Add $(CET_FLAGS).
	(AM_CCASFLAGS): Likewise.
	* configure.ac (CET_FLAGS): Add GCC_CET_FLAGS and AC_SUBST.
	* Makefile.in: Regenerate.
	* aclocal.m4: Likewise.
	* configure: Likewise.
	* include/Makefile.in: Likewise.
	* man/Makefile.in: Likewise.
	* testsuite/Makefile.in: Likewise.

1 files changed, 94 insertions, 3 deletions

diff --git a/libffi/configure b/libffi/configure
index 4bababb..575641c 100755
--- a/libffi/configure
+++ b/libffi/configure
@@ -692,6 +692,7 @@ am__fastdepCCAS_TRUE
 CCASDEPMODE
 CCASFLAGS
 CCAS
+CET_FLAGS
 am__fastdepCXX_FALSE
 am__fastdepCXX_TRUE
 CXXDEPMODE
@@ -802,6 +803,7 @@ enable_multilib
 enable_silent_rules
 enable_generated_files_in_srcdir
 enable_dependency_tracking
+enable_cet
 enable_shared
 enable_static
 with_pic
@@ -1457,6 +1459,7 @@ Optional Features:
                           do not reject slow dependency extractors
   --disable-dependency-tracking
                           speeds up one-time build
+  --enable-cet            enable Intel CET in target libraries [default=auto]
   --enable-shared[=PKGS]  build shared libraries [default=yes]
   --enable-static[=PKGS]  build static libraries [default=yes]
   --enable-fast-install[=PKGS]
@@ -4877,6 +4880,95 @@ CFLAGS=$save_CFLAGS
 
 
 
+# Add CET specific flags if CET is enabled
+
+ # Check whether --enable-cet was given.
+if test "${enable_cet+set}" = set; then :
+  enableval=$enable_cet;
+      case "$enableval" in
+       yes|no|auto) ;;
+       *) as_fn_error $? "Unknown argument to enable/disable cet" "$LINENO" 5 ;;
+                          esac
+
+else
+  enable_cet=auto
+fi
+
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for CET support" >&5
+$as_echo_n "checking for CET support... " >&6; }
+
+# NB: Avoid nested save_CFLAGS and save_LDFLAGS.
+case "$host" in
+  i[34567]86-*-linux* | x86_64-*-linux*)
+    case "$enable_cet" in
+      auto)
+	# Check if target supports multi-byte NOPs
+	# and if compiler and assembler support CET insn.
+	cet_save_CFLAGS="$CFLAGS"
+	CFLAGS="$CFLAGS -fcf-protection"
+	cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+#if !defined(__SSE2__)
+#error target does not support multi-byte NOPs
+#else
+asm ("setssbsy");
+#endif
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  enable_cet=yes
+else
+  enable_cet=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+	CFLAGS="$cet_save_CFLAGS"
+	;;
+      yes)
+	# Check if assembler supports CET.
+	cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+asm ("setssbsy");
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+
+else
+  as_fn_error $? "assembler with CET support is required for --enable-cet" "$LINENO" 5
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+	;;
+    esac
+    ;;
+  *)
+    enable_cet=no
+    ;;
+esac
+if test x$enable_cet = xyes; then
+  CET_FLAGS="-fcf-protection -mshstk"
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+
 # By default we simply use the C compiler to build assembly code.
 
 test "${CCAS+set}" = set || CCAS=$CC
@@ -6903,7 +6995,6 @@ fi
 
 
 
-
 # Check whether --enable-libtool-lock was given.
 if test "${enable_libtool_lock+set}" = set; then :
   enableval=$enable_libtool_lock;
@@ -11481,7 +11572,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11484 "configure"
+#line 11575 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -11587,7 +11678,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11590 "configure"
+#line 11681 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H