Re: New ARI warning Sat Mar 19 01:54:11 UTC 2011

[Joel Brobecker <brobecker at adacore dot com>]

> This was a large diff, but in fact, there is only one new warning:
> 
> > gdb/i386-tdep.c:1693: obsolete: frame_register_read: Replace frame_register_read() with get_frame_register(), or possibly introduce a new method safe_get_frame_register()
> gdb/i386-tdep.c:1693:     && frame_register_read (this_frame, cache->saved_sp_reg, buf))

I just had a look at this ARI warning.  The comment on
frame_register_read says:

/* FIXME: cagney/2003-02-02: Should be deprecated or replaced with a
   function called get_frame_register_p().  This slightly weird (and
   older) variant of get_frame_register() returns zero (indicating the
   register value is unavailable/invalid) if either: the register
   isn't cached; or the register has been optimized out; or the
   register contents are unavailable (because they haven't been
   collected in a traceframe).  Problem is, neither check is exactly
   correct.  A register can't be optimized out (it may not have been
   saved as part of a function call); The fact that a register isn't
   in the register cache doesn't mean that the register isn't
   available (it could have been fetched from memory).  */

I have had this feeling that we have way too many ways to read/write
frame registers, but I'm wondering if this comment might not be
too zealous in this case. This function seems useful, because it
returns a status as opposed to get_frame_register, which has the exact
same profile except that it throws instead of returning. So I'm thinking
we should remove the "deprecation" fixme, and just keep the FIXME for
fixing whatever incorrectness might be left, and then remove this from
the ARI.

Thoughts?

-- 
Joel