[RFA] mips-tdep.c: Make ``show mips abi'' more useful

[Kevin Buettner <kevinb@redhat.com>]

By default, the command ``show mips abi'' will print the following:

    The ABI used by this program is "auto".

This information is not as useful as it could be.  In such cases, it
would also be nice to know what GDB has determined the actual ABI to
be.  The patch below adds a callback to augment the information provided
by the ``show mips abi command''.  E.g,

    (gdb) file hello-n64-shared
    Reading symbols from hello-n64-shared...done.
    (gdb) show mips abi
    The ABI used by this program is "auto".
    Current ABI is "n64".

Okay?

(BTW, ``show language'' and some other commands in language.c use a
similar mechanism for providing additional information.  It might
be cleaner though to implement ``show mips abi'' in a fashion similar
to the way that ``show osabi'' is implemented.)

	* mips-tdep.c (mips_abi_show): New function.
	(_initialize_mips_tdep): Add callback for ``show mips abi''.

Index: mips-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/mips-tdep.c,v
retrieving revision 1.163
diff -u -p -r1.163 mips-tdep.c
--- mips-tdep.c	20 Feb 2003 16:35:51 -0000	1.163
+++ mips-tdep.c	26 Feb 2003 02:29:04 -0000
@@ -6066,6 +6066,26 @@ mips_abi_update (char *ignore_args, int 
   gdbarch_update_p (info);
 }
 
+/* Callback for command ``show mips abi''.  Print out which ABI is in
+   use when the global mips abi is set to "auto".  */
+
+static void
+mips_abi_show (char *ignore_args, int from_tty, 
+		 struct cmd_list_element *c)
+{
+  if (global_mips_abi () == MIPS_ABI_UNKNOWN
+      && gdbarch_bfd_arch_info (current_gdbarch)->arch == bfd_arch_mips)
+    {
+      enum mips_abi abi = mips_abi (current_gdbarch);
+      const char *abi_str;
+      if (abi == MIPS_ABI_UNKNOWN)
+	abi_str = "unknown";
+      else
+	abi_str = mips_abi_strings[abi];
+      fprintf_filtered (gdb_stdout, "Current ABI is \"%s\".\n", abi_str);
+    }
+}
+
 static void
 mips_dump_tdep (struct gdbarch *current_gdbarch, struct ui_file *file)
 {
@@ -6451,7 +6471,7 @@ void
 _initialize_mips_tdep (void)
 {
   static struct cmd_list_element *mipsfpulist = NULL;
-  struct cmd_list_element *c;
+  struct cmd_list_element *c, *c2;
 
   mips_abi_string = mips_abi_strings [MIPS_ABI_UNKNOWN];
   if (MIPS_ABI_LAST + 1
@@ -6513,8 +6533,9 @@ This option can be set to one of:\n\
      "  eabi32\n"
      "  eabi64",
      &setmipscmdlist);
-  add_show_from_set (c, &showmipscmdlist);
+  c2 = add_show_from_set (c, &showmipscmdlist);
   set_cmd_sfunc (c, mips_abi_update);
+  set_cmd_sfunc (c2, mips_abi_show);
 
   /* Let the user turn off floating point and set the fence post for
      heuristic_proc_start.  */