[PATCH] Make ada_decode not use a static buffer

[Tom Tromey]

>>>>> "Christian" == Christian Biesinger via gdb-patches <gdb-patches@sourceware.org> writes:

Christian> This makes it safer to use in general, and also allows using it on a
Christian> background thread in the future.

Christian> Inspired by tromey's patch at:
Christian> https://github.com/tromey/gdb/commit/1226cbdfa436297a5dec054d94592c45891afa93
Christian> (however, implemented in a different way)

Sorry about the long delay on this.

Christian>  /* If ENCODED follows the GNAT entity encoding conventions, then return
Christian>     the decoded form of ENCODED.  Otherwise, return "<%s>" where "%s" is
Christian> -   replaced by ENCODED.
Christian> +   replaced by ENCODED.  */
 
Christian> -   The resulting string is valid until the next call of ada_decode.
Christian> -   If the string is unchanged by decoding, the original string pointer
Christian> -   is returned.  */

I wonder if the "unchanged" part is a useful optimization.
If so, then maybe my approach is preferred, though perhaps with
a new type -- something Pedro pointed out in review.

Something else he mentioned is that he came across a test case where
this function had a performance impact.  To test this, next week I'll
try out your patch on a large Ada program we have here to measure the
impact.  Hopefully it will show nothing, and we can just move forward.

On the whole I'm happy with your approach.

Tom