Add mi_getopt_allow_unknown

This patch is to add a new function mi_getopt_allow_unknown, which
returns -1 silently (without throwing error) when unknown option is
met, and use this function to parse options for command
'-stack-list-arguments'.

gdb/
	* mi/mi-cmd-stack.c (parse_no_frames_option): Remove.
	(mi_cmd_stack_list_args): Use mi_getopt_silent to handle
	options.
	* mi/mi-getopt.c (mi_getopt): Remove.
	(mi_getopt_1): Renamed from mi_getopt.  Add one parameter
	'error_on_unknown'.
	(mi_getopt): Call mi_getopt_1.
	(mi_getopt_silent): New.
	* mi/mi-getopt.h (mi_getopt_silent): Declare.

3 files changed, 66 insertions, 27 deletions

diff --git a/gdb/mi/mi-cmd-stack.c b/gdb/mi/mi-cmd-stack.c
index e542fc19432..2df97e2f467 100644
--- a/gdb/mi/mi-cmd-stack.c
+++ b/gdb/mi/mi-cmd-stack.c
@@ -54,17 +54,6 @@ mi_cmd_enable_frame_filters (char *command, char **argv, int argc)
   frame_filters = 1;
 }
 
-/* Parse the --no-frame-filters option in commands where we cannot use
-   mi_getopt. */
-static int
-parse_no_frames_option (const char *arg)
-{
-  if (arg && (strcmp (arg, "--no-frame-filters") == 0))
-    return 1;
-
-  return 0;
-}
-
 /* Print a list of the stack frames.  Args can be none, in which case
    we want to print the whole backtrace, or a pair of numbers
    specifying the frame numbers at which to start and stop the
@@ -284,19 +273,42 @@ mi_cmd_stack_list_args (char *command, char **argv, int argc)
   enum print_values print_values;
   struct ui_out *uiout = current_uiout;
   int raw_arg = 0;
+  int oind = 0;
   enum py_bt_status result = PY_BT_ERROR;
+  enum opt
+  {
+    NO_FRAME_FILTERS,
+  };
+  static const struct mi_opt opts[] =
+    {
+      {"-no-frame-filters", NO_FRAME_FILTERS, 0},
+      { 0, 0, 0 }
+    };
 
-  if (argc > 0)
-    raw_arg = parse_no_frames_option (argv[0]);
+  while (1)
+    {
+      char *oarg;
+      int opt = mi_getopt_allow_unknown ("-stack-list-args", argc, argv,
+					 opts, &oind, &oarg);
+
+      if (opt < 0)
+	break;
+      switch ((enum opt) opt)
+	{
+	case NO_FRAME_FILTERS:
+	  raw_arg = oind;
+	  break;
+	}
+    }
 
-  if (argc < 1 || (argc > 3 && ! raw_arg) || (argc == 2 && ! raw_arg))
-    error (_("-stack-list-arguments: Usage: " \
+  if (argc - oind != 1 && argc - oind != 3)
+    error (_("-stack-list-arguments: Usage: "	\
 	     "[--no-frame-filters] PRINT_VALUES [FRAME_LOW FRAME_HIGH]"));
 
-  if (argc >= 3)
+  if (argc - oind == 3)
     {
-      frame_low = atoi (argv[1 + raw_arg]);
-      frame_high = atoi (argv[2 + raw_arg]);
+      frame_low = atoi (argv[1 + oind]);
+      frame_high = atoi (argv[2 + oind]);
     }
   else
     {
@@ -306,7 +318,7 @@ mi_cmd_stack_list_args (char *command, char **argv, int argc)
       frame_high = -1;
     }
 
-  print_values = mi_parse_print_values (argv[raw_arg]);
+  print_values = mi_parse_print_values (argv[oind]);
 
   /* Let's position fi on the frame at which to start the
      display. Could be the innermost frame if the whole stack needs
diff --git a/gdb/mi/mi-getopt.c b/gdb/mi/mi-getopt.c
index a1e2ccc5874..f2072495a96 100644
--- a/gdb/mi/mi-getopt.c
+++ b/gdb/mi/mi-getopt.c
@@ -21,11 +21,14 @@
 #include "mi-getopt.h"
 #include "gdb_string.h"
 
-int
-mi_getopt (const char *prefix,
-	   int argc, char **argv,
-	   const struct mi_opt *opts,
-	   int *oind, char **oarg)
+/* See comments about mi_getopt and mi_getopt_silent in mi-getopt.h.
+   When there is an unknown option, if ERROR_ON_UNKNOWN is true,
+   throw an error, otherwise return -1.  */
+
+static int
+mi_getopt_1 (const char *prefix, int argc, char **argv,
+	     const struct mi_opt *opts, int *oind, char **oarg,
+	     int error_on_unknown)
 {
   char *arg;
   const struct mi_opt *opt;
@@ -71,7 +74,27 @@ mi_getopt (const char *prefix,
 	  return opt->index;
 	}
     }
-  error (_("%s: Unknown option ``%s''"), prefix, arg + 1);
+
+  if (error_on_unknown)
+    error (_("%s: Unknown option ``%s''"), prefix, arg + 1);
+  else
+    return -1;
+}
+
+int
+mi_getopt (const char *prefix,
+	   int argc, char **argv,
+	   const struct mi_opt *opts,
+	   int *oind, char **oarg)
+{
+  return mi_getopt_1 (prefix, argc, argv, opts, oind, oarg, 1);
+}
+
+int
+mi_getopt_allow_unknown (const char *prefix, int argc, char **argv,
+			 const struct mi_opt *opts, int *oind, char **oarg)
+{
+  return mi_getopt_1 (prefix, argc, argv, opts, oind, oarg, 0);
 }
 
 int 
diff --git a/gdb/mi/mi-getopt.h b/gdb/mi/mi-getopt.h
index 960035318ee..7db0bf4c35a 100644
--- a/gdb/mi/mi-getopt.h
+++ b/gdb/mi/mi-getopt.h
@@ -46,11 +46,15 @@ struct mi_opt
    If ARGV[OPTIND] is not an option, -1 is returned and OPTIND updated
    to specify the non-option argument.  OPTARG is set to NULL.
 
-   mi_getopt() calls ``error("%s: Unknown option %c", prefix,
-   option)'' if an unknown option is encountered.  */
+   If an unknown option is encountered, mi_getopt() calls
+   ``error("%s: Unknown option %c", prefix, option)'' while
+   mi_getopt_allow_unknown returns -1.  */
 
 extern int mi_getopt (const char *prefix, int argc, char **argv,
 		      const struct mi_opt *opt, int *optind, char **optarg);
+extern int mi_getopt_allow_unknown (const char *prefix, int argc,
+				    char **argv, const struct mi_opt *opts,
+				    int *oind, char **oarg);
 
 /* mi_valid_noargs determines if ARGC/ARGV are a valid set of
    parameters to satisfy an MI function that is not supposed to