Re: [RFC][python] Add support for commands implemented in Python

[Daniel Jacobowitz <drow@false.org>]

On Mon, Feb 02, 2009 at 11:13:25AM -0200, Thiago Jung Bauermann wrote:
> +@defmethod Command invoke argument from_tty
> +This method is called by @value{GDBN} when this command is invoked.
> +
> +@var{argument} is the argument to the command.  The argument
> +ordinarily is a string, but may be @code{None}, meaning that there was
> +no argument.

Any opinion on making it always a string?  The 'do I get NULL or an
empty string?' ambiguity shows up every time I write a new command in
C.  If you prefer None, let's document what whitespace trimming does
or does not happen before it is converted from a string to None.

> +@defmethod Command complete text word
> +This method is called by @value{GDBN} when the user attempts @key{TAB}
> +completion on this command.
> +
> +The arguments @var{text} and @var{word} are both strings.  @var{text}
> +holds the complete command line up to the cursor's location.
> +@var{word} holds the last word of the command line; this is computed
> +using a word-breaking heuristic.
> +
> +The @code{invoke} method can return several values:

Isn't this @code{complete} method?  Same problem repeated below.

> +/* A gdb command.  For the time being only ordinary commands (not
> +   set/show commands) are allowed.  */
> +struct cmdpy_object
> +{
> +  PyObject_HEAD
> +
> +  /* The corresponding gdb command object, or NULL if the command is
> +     no longer installed.  */
> +  struct cmd_list_element *command;
> +
> +  /* For a prefix command, this is the list of sub-commands.  */
> +  struct cmd_list_element *sub_list;
> +};

What's sub_list for?  There's *command->prefixlist too.  Overall, I'm
confused about why prefix commands are 'special' here.  When core GDB
adds a command, it doesn't need any new code to handle it as a prefix;
just calls add_prefix_cmd.  I'd expect to do the same here but fill in
a local FUN.

> +  /* Note: alias and user seem to be special; pseudo appears to be
> +     unused, and there is no reason to expose tui or xdb, I think.  */

Yes, alias and user are special.  User is where "define"'d commands
go; should there be a command to show all Python-defined
commands similar to "show user"?

The rest of the code looks fine.

-- 
Daniel Jacobowitz
CodeSourcery