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From: Kelley Cook <KelleyCook@comcast.net>
To: gcc@gcc.gnu.org
Cc: gcc-patches@gcc.gnu.org
Subject: [wwwdocs] segfault.html (was Synthetic register related: Seg fault) - segfault.html [1/1]
Date: Thu, 16 Jan 2003 18:03:00 -0000	[thread overview]
Message-ID: <MPG.1890abeecfadb0a1989683@news.gmane.org> (raw)
In-Reply-To: <20030115194943.A16830@hg.cs.mu.OZ.AU>

[-- Attachment #1: Type: text/plain, Size: 523 bytes --]

[This followup was posted to gmane.comp.gcc.devel and a copy 
was sent to the cited author.]

In article <20030115194943.A16830@hg.cs.mu.OZ.AU>, 
fjh@cs.mu.OZ.AU says...
> On 15-Jan-2003, Andy Walker <ja_walker@earthlink.net> wrote:
> > What would be the best approach to hunting down flaws that cause things like 
> > this Segmentation fault?

I'm pretty sure this would make a good web page addition.  
Likely should be linked onto the bugs.html page.

So here it is.

Passed validator.w3.org as XHTML 1.0 transitional.


[-- Attachment #2: HTMLized version of segfault instructions --]
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <meta http-equiv="content-type" content="text/html; charset=ISO-8859-1" />
    <title>
      An approach to hunting down compiler flaws that cause things like
      Segmentation faults
    </title>
    <style type="text/css">
      code {color: red}
    </style>
  </head>
  <body>
    <h1>
      An approach to hunting down compiler flaws that cause things like
      Segmentation faults
    </h1>
    <address>
      By: Fergus Henderson &lt;fjh@cs.mu.OZ.AU&gt;
    </address>
    <hr />
    <p>
      Configure GCC with <code>--enable-checking</code>.&nbsp; Compile it with
      <code>-g</code> so that you can use gdb.
    </p>
    <p>
      Compile your test case with <code>-v -da -Q</code>.
    </p>
    <ul>
      <li>
        <code>-Q</code> will show which function in the test case is causing
        it to crash.
      </li>
      <li>
        <code>-v</code> shows how `cc1' was invoked (useful for invoking cc1
        manually in gdb).
      </li>
      <li>
        <code>-da</code> dumps the RTL to a file after each stage.
      </li>
    </ul>
    <p>
      Next, use gdb to get a stack trace.&nbsp; Compile the compiler with
      debugging enabled (<code>-g</code>), use the <code>-v</code> option to see how cc1 is getting
      invoked, and then do
    </p>
     
    <div style="margin-left: 40px;">
      bash$ <code>gdb cc1</code><br />
       gdb&gt; <code>run &lt;arguments&gt;</code><br />
       &hellip; (it will stop at the Seg fault)<br />
       gdb&gt; <code>where</code><br />
       &hellip;<br />
       gdb&gt; <code>list</code>
    </div>
     
    <p>
      Print out the values of interesting variables (e.g. the ones in the
      statement which got a segmentation fault).
    </p>
    <p>
      You can use the <code>pt</code> and <code>pr</code> macros from the
      gdbinit.in file to display them.&nbsp; For example, if there is a value
      of type <code>tree</code> named <code>t</code>, and a value of type
      <code>rtx</code> named <code>r</code>, you can use these commands:
    </p>
     
    <div style="margin-left: 40px;">
      gdb&gt; <code>source .gdbinit</code><br />
       gdb&gt; <code>print t</code><br />
       gdb&gt; <code>pt</code><br />
       gdb&gt; <code>print r</code><br />
       gdb&gt; <code>pr</code><br />
       gdb&gt; <code>pt</code><br />
    </div>
  </body>
</html>

  parent reply	other threads:[~2003-01-16 16:46 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-01-15 18:43 Synthetic register related: Seg fault Andy Walker
2003-01-15 19:46 ` Fergus Henderson
2003-01-15 20:01   ` Lars Segerlund
2003-01-16 18:03   ` Kelley Cook [this message]
2003-01-16 19:33     ` [wwwdocs] segfault.html (was Synthetic register related: Seg fault) - segfault.html [1/1] Janis Johnson
2003-01-16 20:06       ` Joseph S. Myers
2003-01-16 21:03         ` Janis Johnson

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