https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95413
--- Comment #6 from H.J. Lu <hjl.tools at gmail dot com> ---
I am testing this:
diff --git a/config/cet.m4 b/config/cet.m4
index 2bb2c8a95ac..911fbd46475 100644
--- a/config/cet.m4
+++ b/config/cet.m4
@@ -7,13 +7,14 @@ GCC_ENABLE(cet, auto, ,[enable Intel CET in target
libraries],
permit yes|no|auto)
AC_MSG_CHECKING([for CET support])
+# 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 assembler supports CET insn.
- save_CFLAGS="$CFLAGS"
+ cet_save_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS -fcf-protection"
AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM(
@@ -27,7 +28,7 @@ asm ("setssbsy");
])],
[enable_cet=yes],
[enable_cet=no])
- CFLAGS="$save_CFLAGS"
+ CFLAGS="$cet_save_CFLAGS"
;;
yes)
# Check if assembler supports CET.
@@ -64,7 +65,7 @@ AC_MSG_CHECKING([for CET support])
case "$host" in
i[[34567]]86-*-linux* | x86_64-*-linux*)
may_have_cet=yes
- save_CFLAGS="$CFLAGS"
+ cet_save_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS -fcf-protection"
case "$enable_cet" in
auto)
@@ -93,7 +94,7 @@ asm ("setssbsy");
[AC_MSG_ERROR([assembler with CET support is required for
--enable-cet])])
;;
esac
- CFLAGS="$save_CFLAGS"
+ CFLAGS="$cet_save_CFLAGS"
;;
*)
may_have_cet=no
@@ -101,9 +102,9 @@ asm ("setssbsy");
;;
esac
-save_CFLAGS="$CFLAGS"
+cet_save_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS -fcf-protection=none"
-save_LDFLAGS="$LDFLAGS"
+cet_save_LDFLAGS="$LDFLAGS"
LDFLAGS="$LDFLAGS -Wl,-z,ibt,-z,shstk"
if test x$may_have_cet = xyes; then
# Check whether -fcf-protection=none -Wl,-z,ibt,-z,shstk work.
@@ -159,6 +160,6 @@ if test x$enable_cet = xyes; then
else
AC_MSG_RESULT([no])
fi
-CFLAGS="$save_CFLAGS"
-LDFLAGS="$save_LDFLAGS"
+CFLAGS="$cet_save_CFLAGS"
+LDFLAGS="$cet_save_LDFLAGS"
])
