invoke.texi (fms-extensions): Document changed behavior for ms-abi targets.

	* doc/invoke.texi (fms-extensions): Document changed
	behavior for ms-abi targets.
	* config/i386/i386.c (ix86_option_override_internal):
	Set default value of option -fms-extension for ms-abi targets.

From-SVN: r202429

gcc/ChangeLog

+2013-09-10  Kai Tietz  <ktietz@redhat.com>
+
+	* doc/invoke.texi (fms-extensions): Document changed
+	behavior for ms-abi targets.
+	* config/i386/i386.c (ix86_option_override_internal):
+	Set default value of option -fms-extension for ms-abi targets.
+
 2013-09-10  Michael Zolotukhin  <michael.v.zolotukhin@gmail.com>
 
 	* config/i386/i386.c (ix86_expand_movmem): Fix epilogue generation.

gcc/config/i386/i386.c

@@ -3357,6 +3357,12 @@ ix86_option_override_internal (bool main_args_p)
   if (!global_options_set.x_ix86_abi)
     ix86_abi = DEFAULT_ABI;
 
+  /* For targets using ms ABI enable ms-extensions, if not
+     explicit turned off.  For non-ms ABI we turn off this
+     option.  */
+  if (!global_options_set.x_flag_ms_extensions)
+    flag_ms_extensions = (MS_ABI == DEFAULT_ABI);
+
   if (global_options_set.x_ix86_cmodel)
     {
       switch (ix86_cmodel)

gcc/doc/invoke.texi

@@ -1856,6 +1856,8 @@ Some cases of unnamed fields in structures and unions are only
 accepted with this option.  @xref{Unnamed Fields,,Unnamed struct/union
 fields within structs/unions}, for details.
 
+Note that this option is off for all targets but i?86 and x86_64
+targets using ms-abi.
 @item -fplan9-extensions
 Accept some non-standard constructs used in Plan 9 code.