From: Wei-min Pan <weimin.pan@oracle.com>
To: Joel Brobecker <brobecker@adacore.com>
Cc: gdb-patches@sourceware.org
Subject: Re: [PATCH PR gdb/20057] Internal error on trying to set {char[]}$pc="string"
Date: Thu, 25 Jan 2018 22:24:00 -0000 [thread overview]
Message-ID: <1dfc87b0-353d-3388-a427-fee247dc79a5@oracle.com> (raw)
In-Reply-To: <20180125041431.tghhxefsgxnxh3l3@adacore.com>
On 1/24/2018 8:14 PM, Joel Brobecker wrote:
>> To support C99 VLA, function value_from_contents_and_address() was
>> modified to add a call to resolve_dynamic_type(), which in turn
>> calls resolve_dynamic_array() to resolve the dynamic array bounds
>> to static values. But the problem arises when function copy_type(),
>> called by resolve_dynamic_array(), expects the type to be copied
>> to have an associated objfile from which the new type is allocated,
>> or asserts. Since type char[] doesn't have an associated objfile
>> when the following gdb command:
>>
>> (gdb) set {char[]}$pc="hello"
>>
>> was issued, gdb asserts.
>>
>> The gdb_assert (TYPE_OBJFILE_OWNED (type)) line in copy_type() doesn't
>> look necessary or correct since space needed for the new type could be
>> allocated from either the type's objfile if it exists or gdbarch if
>> it doesn't, similar to what alloc_type_copy(), which is called after
>> gdb_assert() in copy_type(), does. Removing gdb_assert() fixes the
>> problem.
> I think removing the assert just shifts the issue elsewhere.
> Basically, you want the lifetime of the new type to match
> the lifetime of the object using it. The gdbarch structure
> has a lifetime that's different from objfiles.
Is there any reason why the gdbarch structure, which won't be freed until
the corresponding architecture is, needs to have a lifetime that matches
the objfiles?
> I happen to have hit the same issue as you, but from an Ada expression,
> and sent it a fix not long ago:
> https://www.sourceware.org/ml/gdb-patches/2018-01/msg00240.html
>
> Does it fix your problem too?
>
Yes, it does fix my problem of gdb asserting on the "set
{char[]}$pc="hi"" command, as
reported in the PR, but still asserts on a slightly modified "set
{unsigned char[]}$pc="hi"
command.
Thanks.
next prev parent reply other threads:[~2018-01-25 22:24 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-25 2:12 Weimin Pan
2018-01-25 4:14 ` Joel Brobecker
2018-01-25 22:24 ` Wei-min Pan [this message]
2018-01-31 7:45 ` Joel Brobecker
2018-02-01 1:46 ` Wei-min Pan
2018-02-01 8:00 ` Joel Brobecker
2018-02-02 1:14 ` Wei-min Pan
2018-11-14 23:38 ` Wei-min Pan
2018-11-14 23:51 ` Joel Brobecker
2018-11-15 0:16 ` Wei-min Pan
2018-11-29 19:18 ` Tom Tromey
2018-11-29 21:10 ` Wei-min Pan
2018-11-29 21:52 ` Tom Tromey
2018-11-29 23:26 ` Wei-min Pan
2018-11-30 15:37 ` Tom Tromey
2018-11-30 17:31 ` Wei-min Pan
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1dfc87b0-353d-3388-a427-fee247dc79a5@oracle.com \
--to=weimin.pan@oracle.com \
--cc=brobecker@adacore.com \
--cc=gdb-patches@sourceware.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).