From eedc73a224df61694fe4802ddec8eb9ad1822f32 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Tue, 28 Apr 2020 05:42:34 -0700
Subject: Check whether -fcf-protection=none -Wl,-z,ibt,-z,shstk work first

GCC_CET_HOST_FLAGS uses -Wl,-z,ibt,-z,shstk to check if Linux/x86 host
has Intel CET enabled by introducing an Intel CET violation on purpose.
To avoid false positive, check whether -Wl,-z,ibt,-z,shstk works first.
-fcf-protection=none is added to avoid false negative when -fcf-protection
is enabled by default.

config/

	PR bootstrap/94739
	* cet.m4 (GCC_CET_HOST_FLAGS): Add -fcf-protection=none to
	-Wl,-z,ibt,-z,shstk.  Check whether -fcf-protection=none
	-Wl,-z,ibt,-z,shstk works first.

libiberty/

	PR bootstrap/94739
	* configure: Regenerated.

lto-plugin/

	PR bootstrap/94739
	* configure: Regenerated.
---
 lto-plugin/ChangeLog |  5 +++++
 lto-plugin/configure | 35 ++++++++++++++++++++++++++++++-----
 2 files changed, 35 insertions(+), 5 deletions(-)

(limited to 'lto-plugin')

diff --git a/lto-plugin/ChangeLog b/lto-plugin/ChangeLog
index d5f7ef0329c..4ffbf122ebd 100644
--- a/lto-plugin/ChangeLog
+++ b/lto-plugin/ChangeLog
@@ -1,3 +1,8 @@
+2020-04-28  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR bootstrap/94739
+	* configure: Regenerated.
+
 2020-04-25  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR bootstrap/94739
diff --git a/lto-plugin/configure b/lto-plugin/configure
index e55b35ecf38..1baf6cc70b8 100755
--- a/lto-plugin/configure
+++ b/lto-plugin/configure
@@ -5741,9 +5741,33 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
     ;;
 esac
 
+save_CFLAGS="$CFLAGS"
+CFLAGS="$CFLAGS -fcf-protection=none"
+save_LDFLAGS="$LDFLAGS"
+LDFLAGS="$LDFLAGS -Wl,-z,ibt,-z,shstk"
+if test x$may_have_cet = xyes; then
+  # Check whether -fcf-protection=none -Wl,-z,ibt,-z,shstk work.
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+return 0;
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  may_have_cet=yes
+else
+  may_have_cet=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+fi
+
 if test x$may_have_cet = xyes; then
-  save_LDFLAGS="$LDFLAGS"
-  LDFLAGS="$LDFLAGS -Wl,-z,ibt,-z,shstk"
   if test "$cross_compiling" = yes; then :
   { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
 $as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
@@ -5789,7 +5813,6 @@ rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
   conftest.$ac_objext conftest.beam conftest.$ac_ext
 fi
 
-  LDFLAGS="$save_LDFLAGS"
   if test x$enable_cet = xno -a x$have_cet = xyes; then
     as_fn_error $? "Intel CET must be enabled on Intel CET enabled host" "$LINENO" 5
   fi
@@ -5802,6 +5825,8 @@ else
   { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
 $as_echo "no" >&6; }
 fi
+CFLAGS="$save_CFLAGS"
+LDFLAGS="$save_LDFLAGS"
 
 
 
@@ -11916,7 +11941,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11919 "configure"
+#line 11944 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -12022,7 +12047,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 12025 "configure"
+#line 12050 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
-- 
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