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From: Doug Evans <xdje42@gmail.com>
To: Joel Brobecker <brobecker@adacore.com>, Pedro Alves <palves@redhat.com>
Cc: "gdb-patches@sourceware.org" <gdb-patches@sourceware.org>
Subject: Re: [RFC] Empty result of "info types inner": Is this a bug?
Date: Tue, 06 Jan 2015 09:44:00 -0000	[thread overview]
Message-ID: <CAP9bCMQumyKnV8yzBheTxX=Ai4nCBqUNX=j=FpoyUO_k7=CmMA@mail.gmail.com> (raw)
In-Reply-To: <20150105030431.GE5445@adacore.com>

On Sun, Jan 4, 2015 at 7:04 PM, Joel Brobecker <brobecker@adacore.com> wrote:
>> Technically, it's a bug that the first "info types inner" didn't
>> print anything, but is this a bug we're willing to accept for
>> performance reasons? I want to make the case that the answer is "No."
>
> My inclination as well, and you'll probably see in dwarf2read.c
> a few added blocks of code that say "if (ada an some other langs),
> add children into global scope. That was for things such as putting
> a breakpoint on a nested subprogram, for instance.

For completeness sake,
another way to solve this particular bug is to traverse all the debug
info but not expand every (matching) symtab.
Yeah, it'll be slower, but info var/fun/types doesn't scale,
plus regexp matching means we have to make "o::b" find "foo::bar",
and is it better to try to make that scale, or provide the user with
something else that does scale for the common case(s)?
IOW, what are the common uses
of info var/fun/types and can we require a different argument besides
a simple regex such that the implementation can scale?
[We'd still keep info/var/types, but the implementation, while fixing
the bug under discussion, would not be intended to be fast for
large programs, and nor would it result in significantly increased
memory usage by gdb.  I can imagine it just walking all the DWARF
info but not expanding any symtabs.]

  reply	other threads:[~2015-01-06  9:44 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-04  8:54 Doug Evans
2015-01-05  3:04 ` Joel Brobecker
2015-01-06  9:44   ` Doug Evans [this message]
2015-01-07  8:55     ` Doug Evans
2015-01-05 17:08 ` Pedro Alves

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