Re: [mi] -list-features

[Vladimir Prus <ghost at cs dot msu dot su>]

On Friday 31 August 2007 13:18:17 Eli Zaretskii wrote:
> > From: Vladimir Prus <ghost@cs.msu.su>
> > Date: Fri, 31 Aug 2007 13:00:36 +0400
> > Cc: drow@false.org,
> >  gdb-patches@sources.redhat.com
> > 
> > > It is still ambiguous, because "a list of string" does not tell the
> > > whole story.  Is it
> > > 
> > >     foo bar baz
> > > or
> > >     "foo" "bar" "baz"
> > > or
> > >     foo,bar,baz
> > > or
> > >     {foo,bar,baz}
> > 
> > Well, in MI, "list of strings" is quite well defined.
> 
> I don't see such a definition.  I see a definition of "list", but if
> you want to rely on that, please add a cross-reference to that
> section, because the reader shouldn't be required to remember the
> syntax by heart.
> 
> > 		Example output:
> > 
> > 			^done,result=["feature1","feature2"]
> 
> This is much better, IMO; now it's perfectly clear what front ends
> should expect.

Here's the updated patch, including texinfo docs. OK?

- Volodya

--- gdb/doc/gdb.texinfo	(/mirrors/gdb_mainline)	(revision 4740)
+++ gdb/doc/gdb.texinfo	(/patches/gdb/list_features)	(revision 4740)
@@ -21236,6 +21236,37 @@ default shows this information when you 
 (gdb)
 @end smallexample
 
+@subheading The @code{-list-features} Command
+@findex -list-features
+
+Returns a list of particular features of the MI protocol that
+this version of gdb implements.  A feature can be a command,
+or a new field in an output of some command, or even an
+important bugfix.  While a frontend can sometimes detect presence
+of a feature at runtime, it is easier to perform detection at debugger
+startup. 
+
+The command returns a list of strings, with each string naming an
+available feature.  Each returned string is just a name, it does not
+have any internal structure.  The list of possible feature names 
+is given below.
+
+Example output:
+
+@smallexample
+(gdb) -list-features
+^done,result=["feature1","feature2"]
+@end smallexample
+
+The current list of features is:
+
+@itemize @minus
+@item
+@samp{frozen-varobjs}---indicates presence of the
+@code{-var-set-frozen} command, as well as possible presense of the
+@code{frozen} field in the output of @code{-varobj-create}.
+@end itemize
+
 @subheading The @code{-interpreter-exec} Command
 @findex -interpreter-exec
 
--- gdb/mi/mi-cmds.h	(/mirrors/gdb_mainline)	(revision 4740)
+++ gdb/mi/mi-cmds.h	(/patches/gdb/list_features)	(revision 4740)
@@ -91,6 +91,7 @@ extern mi_cmd_argv_ftype mi_cmd_gdb_exit
 extern mi_cmd_argv_ftype mi_cmd_inferior_tty_set;
 extern mi_cmd_argv_ftype mi_cmd_inferior_tty_show;
 extern mi_cmd_argv_ftype mi_cmd_interpreter_exec;
+extern mi_cmd_argv_ftype mi_cmd_list_features;
 extern mi_cmd_argv_ftype mi_cmd_stack_info_depth;
 extern mi_cmd_argv_ftype mi_cmd_stack_info_frame;
 extern mi_cmd_argv_ftype mi_cmd_stack_list_args;
--- gdb/mi/mi-main.c	(/mirrors/gdb_mainline)	(revision 4740)
+++ gdb/mi/mi-main.c	(/patches/gdb/list_features)	(revision 4740)
@@ -1075,6 +1075,25 @@ mi_cmd_enable_timings (char *command, ch
   return MI_CMD_ERROR;
 }
 
+enum mi_cmd_result
+mi_cmd_list_features (char *command, char **argv, int argc)
+{
+  if (argc == 0)
+    {
+      struct cleanup *cleanup = NULL;
+      cleanup = make_cleanup_ui_out_list_begin_end (uiout, "features");      
+
+      ui_out_field_string (uiout, NULL, "frozen-varobjs");
+      
+      do_cleanups (cleanup);
+
+      return MI_CMD_DONE;
+    }
+
+  error ("-list-features should be passed no arguments");
+  return MI_CMD_ERROR;
+}
+ 
 /* Execute a command within a safe environment.
    Return <0 for error; >=0 for ok.
 
--- gdb/mi/mi-cmds.c	(/mirrors/gdb_mainline)	(revision 4740)
+++ gdb/mi/mi-cmds.c	(/patches/gdb/list_features)	(revision 4740)
@@ -88,6 +88,7 @@ struct mi_cmd mi_cmds[] =
   { "inferior-tty-set", { NULL, 0 }, NULL, mi_cmd_inferior_tty_set},
   { "inferior-tty-show", { NULL, 0 }, NULL, mi_cmd_inferior_tty_show},
   { "interpreter-exec", { NULL, 0 }, 0, mi_cmd_interpreter_exec},
+  { "list-features", { NULL, 0 }, 0, mi_cmd_list_features},
   { "overlay-auto", { NULL, 0 }, NULL, NULL },
   { "overlay-list-mapping-state", { NULL, 0 }, NULL, NULL },
   { "overlay-list-overlays", { NULL, 0 }, NULL, NULL },

Property changes on: 
___________________________________________________________________
Name: svk:merge
 +e7755896-6108-0410-9592-8049d3e74e28:/mirrors/gdb/trunk:181223