i386.c (ix86_supports_split_stack): -fsplit-stack requires assembler support for CFI directives.

gcc/:
	* config/i386/i386.c (ix86_supports_split_stack): -fsplit-stack
	requires assembler support for CFI directives.
libgcc/:
	* configure.ac: Test whether assembler supports CFI directives.
	* config.host: Only add t-stack and i386/t-stack-i386 to
	tmake_file if libgcc_cv_cfi is "yes".
	* configure: Rebuild.

From-SVN: r164671

6 files changed, 50 insertions, 1 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 07c71cd..6c7620e 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2010-09-27  Ian Lance Taylor  <iant@google.com>
+
+	* config/i386/i386.c (ix86_supports_split_stack): -fsplit-stack
+	requires assembler support for CFI directives.
+
 2010-09-27  Richard Henderson  <rth@redhat.com>
 
 	* dwarf2out.c (dwarf2out_cfi_label): Use ASM_OUTPUT_DEBUG_LABEL.
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 7d4126b..1d1c300 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -8415,6 +8415,14 @@ ix86_supports_split_stack (bool report ATTRIBUTE_UNUSED)
   if (report)
     error ("%<-fsplit-stack%> currently only supported on GNU/Linux");
   ret = false;
+#else
+  if (!dwarf2out_do_cfi_asm ())
+    {
+      if (report)
+	error ("%<-fsplit-stack%> requires "
+	       "assembler support for CFI directives");
+      ret = false;
+    }
 #endif
 
   return ret;
diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog
index 1bbebd9..c6ac0b4 100644
--- a/libgcc/ChangeLog
+++ b/libgcc/ChangeLog
@@ -1,5 +1,12 @@
 2010-09-27  Ian Lance Taylor  <iant@google.com>
 
+	* configure.ac: Test whether assembler supports CFI directives.
+	* config.host: Only add t-stack and i386/t-stack-i386 to
+	tmake_file if libgcc_cv_cfi is "yes".
+	* configure: Rebuild.
+
+2010-09-27  Ian Lance Taylor  <iant@google.com>
+
 	* generic-morestack.h: New file.
 	* generic-morestack.c: New file.
 	* generic-morestack-thread.c: New file.
diff --git a/libgcc/config.host b/libgcc/config.host
index 8476218..ab43da9 100644
--- a/libgcc/config.host
+++ b/libgcc/config.host
@@ -602,7 +602,10 @@ case ${host} in
 i[34567]86-*-linux* | x86_64-*-linux* | \
   i[34567]86-*-kfreebsd*-gnu | i[34567]86-*-knetbsd*-gnu | \
   i[34567]86-*-gnu*)
-	tmake_file="${tmake_file} t-tls t-stack i386/t-stack-i386"
+	tmake_file="${tmake_file} t-tls"
+	if test "$libgcc_cv_cfi" = "yes"; then
+		tmake_file="{$tmake_file} t-stack i386/t-stack-i386"
+	fi
 	;;
 esac
 
diff --git a/libgcc/configure b/libgcc/configure
index 5c8e3a0..56195bb 100644
--- a/libgcc/configure
+++ b/libgcc/configure
@@ -3707,6 +3707,26 @@ $as_echo "$libgcc_cv_fixed_point" >&6; }
 fixed_point=$libgcc_cv_fixed_point
 
 
+# Check for assembler CFI support.
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether assembler supports CFI directives" >&5
+$as_echo_n "checking whether assembler supports CFI directives... " >&6; }
+if test "${libgcc_cv_cfi+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+int i = __GCC_HAVE_DWARF2_CFI_ASM;
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  libgcc_cv_cfi=yes
+else
+  libgcc_cv_cfi=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libgcc_cv_cfi" >&5
+$as_echo "$libgcc_cv_cfi" >&6; }
+
 # Check 32bit or 64bit for x86.
 case ${host} in
 i?86*-*-* | x86_64*-*-*)
diff --git a/libgcc/configure.ac b/libgcc/configure.ac
index 6076637..6bb4844 100644
--- a/libgcc/configure.ac
+++ b/libgcc/configure.ac
@@ -135,6 +135,12 @@ AC_CACHE_CHECK([whether fixed-point is supported], [libgcc_cv_fixed_point],
 fixed_point=$libgcc_cv_fixed_point
 AC_SUBST(fixed_point)
 
+# Check for assembler CFI support.
+AC_CACHE_CHECK([whether assembler supports CFI directives], [libgcc_cv_cfi],
+	       [AC_COMPILE_IFELSE([int i = __GCC_HAVE_DWARF2_CFI_ASM;],
+				  [libgcc_cv_cfi=yes],
+				  [libgcc_cv_cfi=no])])
+
 # Check 32bit or 64bit for x86.
 case ${host} in
 i?86*-*-* | x86_64*-*-*)