From: Wenji Huang <wenji.huang@oracle.com>
To: fche@redhat.com
Cc: "systemtap@sourceware.org" <systemtap@sourceware.org>
Subject: Re: [RFC PATCH] Fix segmentation fault of listing kprocess.create
Date: Fri, 06 Nov 2009 01:08:00 -0000 [thread overview]
Message-ID: <4AF37691.6000601@oracle.com> (raw)
In-Reply-To: <y0mfx8txdpe.fsf@fche.csb>
fche@redhat.com wrote:
>>> /* trick from visit_target_symbol_context */
>>> target_symbol *tsym = new target_symbol;
>>> token *t = new token;
>>> tsym->tok = t;
>>> tsym->base_name = "$";
>>> tsym->base_name += arg_name;
>
> Right, such an empty token should not exist. (We may be able to
> remove this default constructor and force clients to fill in the
> fields immediately.)
>
> When synthesizing new parse tree structures, the token pointer
> assigned to the new objects usually relates to the original
> script-level object that caused the synthesis. So for example in a
> return probe that uses a saved entry-time $var, a whole new synthetic
> probe and global variables could all be assigned to the same "$var"
> token.
>
> Perhaps the recently introduced saveargs() function should be supplied
> with an appropriate token*, for examples q.base_probe->tok.
The empty token is from my patch for 10820, sorry for the
error. Maybe the following patch can fix that.
Regards,
Wenji
diff --git a/tapsets.cxx b/tapsets.cxx
index d2c3334..17e315e 100644
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -2928,6 +2928,14 @@ dwarf_derived_probe::saveargs(dwarf_query& q,
Dwarf_Die* scope_die, dwarf_var_ex
/* trick from visit_target_symbol_context */
target_symbol *tsym = new target_symbol;
token *t = new token;
+ /* We hypothesize accessing the argument
+ * The source_loc will be base_loc since no real one */
+ t->content = "$";
+ t->content += arg_name;
+ t->type = tok_identifier;
+ t->location.file = q.base_loc->tok->location.file;
+ t->location.column = q.base_loc->tok->location.column;
+ t->location.line = q.base_loc->tok->location.line;
tsym->tok = t;
tsym->base_name = "$";
tsym->base_name += arg_name;
next prev parent reply other threads:[~2009-11-06 1:08 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-05 5:03 Wenji Huang
2009-11-05 7:00 ` Wenji Huang
2009-11-05 7:36 ` Wenji Huang
2009-11-05 14:12 ` Frank Ch. Eigler
2009-11-06 1:08 ` Wenji Huang [this message]
2009-11-06 11:19 ` Frank Ch. Eigler
2009-11-07 0:14 ` Josh Stone
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=4AF37691.6000601@oracle.com \
--to=wenji.huang@oracle.com \
--cc=fche@redhat.com \
--cc=systemtap@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).