public inbox for systemtap@sourceware.org
 help / color / mirror / Atom feed
From: "jistone at redhat dot com" <sourceware-bugzilla@sourceware.org>
To: systemtap@sources.redhat.com
Subject: [Bug tapsets/10475] New: pointer-array confused about array element size
Date: Mon, 03 Aug 2009 21:13:00 -0000	[thread overview]
Message-ID: <20090803211253.10475.jistone@redhat.com> (raw)

When the referenced type of a pointer is an indirect modifier (const, volatile,
etc.), loc2c fails to determine the byte size of the elements when you try to
use the pointer like an array.  For example, the kernel function do_filp_open
has a parameter "const char *pathname":

$ stap -p2 -ve 'probe kernel.function("do_filp_open"){ println($pathname[0]) }'
Pass 1: parsed user script and 58 library script(s) in 230usr/20sys/251real ms.
semantic error: confused about array element size: identifier '$pathname' at
<input>:1:48
        source: probe kernel.function("do_filp_open"){ println($pathname[0]) }
                                                               ^
Pass 2: analyzed script: 1 probe(s), 0 function(s), 0 embed(s), 0 global(s) in
430usr/30sys/474real ms.
Pass 2: analysis failed.  Try again with another '--vp 01' option.

I believe this is because array_stride() is getting a DW_TAG_const_type die,
which doesn't directly have a byte size.  We need iterate down to the real type
which has a defined byte size.

-- 
           Summary: pointer-array confused about array element size
           Product: systemtap
           Version: unspecified
            Status: NEW
          Severity: normal
          Priority: P2
         Component: tapsets
        AssignedTo: systemtap at sources dot redhat dot com
        ReportedBy: jistone at redhat dot com


http://sourceware.org/bugzilla/show_bug.cgi?id=10475

------- You are receiving this mail because: -------
You are the assignee for the bug, or are watching the assignee.

             reply	other threads:[~2009-08-03 21:13 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-08-03 21:13 jistone at redhat dot com [this message]
2009-08-03 21:13 ` [Bug tapsets/10475] " jistone at redhat dot com

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=20090803211253.10475.jistone@redhat.com \
    --to=sourceware-bugzilla@sourceware.org \
    --cc=systemtap@sources.redhat.com \
    /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).