Enable building libbacktrace with Intel CET

libbacktrace/
	* configure.ac: Add CET_FLAGS to EXTRA_FLAGS.
	* aclocal.m4: Regenerate.
	* Makefile.in: Likewise.
	* configure: Likewise.

From-SVN: r254892

libbacktrace/ChangeLog

@@ -1,3 +1,10 @@
+2017-11-17  Igor Tsimbalist  <igor.v.tsimbalist@intel.com>
+
+	* configure.ac: Add CET_FLAGS to EXTRA_FLAGS.
+	* aclocal.m4: Regenerate.
+	* Makefile.in: Likewise.
+	* configure: Likewise.
+
 2017-10-06  Ian Lance Taylor  <iant@golang.org>
 
 	* ztest.c (test_large): Pass unsigned long *, not size_t *, to

libbacktrace/Makefile.in

@@ -95,7 +95,9 @@ DIST_COMMON = README ChangeLog $(srcdir)/Makefile.in \
 	$(am__configure_deps) $(srcdir)/config.h.in \
 	$(srcdir)/../mkinstalldirs $(srcdir)/backtrace-supported.h.in
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
-am__aclocal_m4_deps = $(top_srcdir)/../config/lead-dot.m4 \
+am__aclocal_m4_deps = $(top_srcdir)/../config/cet.m4 \
+	$(top_srcdir)/../config/enable.m4 \
+	$(top_srcdir)/../config/lead-dot.m4 \
 	$(top_srcdir)/../config/multi.m4 \
 	$(top_srcdir)/../config/override.m4 \
 	$(top_srcdir)/../config/stdint.m4 \

libbacktrace/aclocal.m4

@@ -670,6 +670,8 @@ AC_SUBST([am__tar])
 AC_SUBST([am__untar])
 ]) # _AM_PROG_TAR
 
+m4_include([../config/cet.m4])
+m4_include([../config/enable.m4])
 m4_include([../config/lead-dot.m4])
 m4_include([../config/multi.m4])
 m4_include([../config/override.m4])

libbacktrace/configure

@@ -743,6 +743,7 @@ enable_fast_install
 with_gnu_ld
 enable_libtool_lock
 enable_largefile
+enable_cet
 with_system_libunwind
 enable_host_shared
 '
@@ -1385,6 +1386,8 @@ Optional Features:
                           optimize for fast installation [default=yes]
   --disable-libtool-lock  avoid locking (might break parallel builds)
   --disable-largefile     omit support for large files
+  --enable-cet            enable Intel CET in target libraries
+                          [default=default]
   --enable-host-shared    build host code as shared libraries
 
 Optional Packages:
@@ -11146,7 +11149,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11149 "configure"
+#line 11152 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -11252,7 +11255,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11255 "configure"
+#line 11258 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -11784,6 +11787,77 @@ $as_echo "$libbacktrace_cv_c_random_seed_string" >&6; }
   fi
 fi
 
+if test -n "${with_target_subdir}"; then
+  # Add CET specific flags is Intel CET is enabled.
+   # Check whether --enable-cet was given.
+if test "${enable_cet+set}" = set; then :
+  enableval=$enable_cet;
+      case "$enableval" in
+       yes|no|default) ;;
+       *) as_fn_error "Unknown argument to enable/disable cet" "$LINENO" 5 ;;
+                          esac
+
+else
+  enable_cet=default
+fi
+
+
+case "$host" in
+  i[34567]86-*-linux* | x86_64-*-linux*)
+    case "$enable_cet" in
+      default)
+	# Check if assembler supports CET.
+	cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+asm ("setssbsy");
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  enable_cet=yes
+else
+  enable_cet=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+	;;
+      yes)
+	# Check if assembler supports CET.
+	cat confdefs.h - <<_ACEOF >conftest.$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$enable_cet = xyes; then
+  CET_FLAGS="-fcf-protection -mcet"
+fi
+
+  EXTRA_FLAGS="$EXTRA_FLAGS $CET_FLAGS"
+fi
+
 
 ac_ext=c
 ac_cpp='$CPP $CPPFLAGS'

libbacktrace/configure.ac

@@ -130,6 +130,12 @@ else
     EXTRA_FLAGS="$EXTRA_FLAGS -frandom-seed=\$@"
   fi
 fi
+
+if test -n "${with_target_subdir}"; then
+  # Add CET specific flags is Intel CET is enabled.
+  GCC_CET_FLAGS(CET_FLAGS)
+  EXTRA_FLAGS="$EXTRA_FLAGS $CET_FLAGS"
+fi
 AC_SUBST(EXTRA_FLAGS)
 
 ACX_PROG_CC_WARNING_OPTS([-W -Wall -Wwrite-strings -Wstrict-prototypes \