Re: Follow-up to earlier question

Robert Goldman <[email protected]> Fri, 27 Mar 2026 17:35:06 -0500
Newsgroups gmane.lisp.steel-bank.general
Message-ID <[email protected]>
--===============0332577508730574125==
Content-Type: multipart/alternative;
 boundary="=_MailMate_6EAF10C9-D28E-4475-B8E5-4EE57CE21FC9_="


--=_MailMate_6EAF10C9-D28E-4475-B8E5-4EE57CE21FC9_=
Content-Type: text/plain; format=flowed

I just tried this with the patch and got some bindings, but I'm not sure 
what they mean:

```
0] (sb-vm:ldb-monitor)
Welcome to LDB, a low-level debugger for the Lisp runtime environment.
ldb> bindings
slot      4: *ALLOW-INSTRUMENTING*          ffffffffffffffff
slot      5: *INLINE-EXPANSIONS*            ffffffffffffffff
slot      6: *VALUES-TYPE-OKAY*             ffffffffffffffff
slot      7: *CURRENT-COMPONENT*            ffffffffffffffff
slot      8: *PRINT-IR-NODES-PRETTY*        ffffffffffffffff
slot      9: *PRINT-IR-NODES-PRETTY*        ffffffffffffffff
slot     10: *ALIEN-TYPE-MATCHES*           ffffffffffffffff
slot     11: *ALIEN-TYPE-MATCHES*           ffffffffffffffff
slot     12: *INLINE-EXPANSIONS*            ffffffffffffffff
slot     13: *ALLOW-INSTRUMENTING*          ffffffffffffffff
CORRUPTION WARNING in SBCL pid 4914 pthread 0x1f6b6a240:
Memory fault at 0x18 (pc=0x102477a2c)
The integrity of this image is possibly compromised.
Continuing with fingers crossed.
X
```

I got kicked out of LDB -- I didn't do anything to exit it.


On 27 Mar 2026, at 11:37, Douglas Katzman wrote:

> Algorithmic improvements in the pretty-printer could potentially 
> decrease
> its use of special vars. However, user-defined print-object methods 
> could
> be to blame.  The size to which you increased the binding stack (10x 
> over
> the default) should have allowed *640 thousand* bindings. I am curious 
> to
> know which vars are on the stack so I concocted a patch to ldb-monitor
> which can tell you.  Try rebuilding with the patch (which requires the
> latest unreleased SBCL), entering ldb-monitor, executing the added
> 'bindings' command, and then you will see output resembling the 
> following:
> ldb> *bindings*
> slot      4: *                              ffffffffffffffff
> slot      5: **                             ffffffffffffffff
> slot      6: ***                            ffffffffffffffff
> ...
> slot    146: *ERROR-OUTPUT*                 ffffffffffffffff
> slot    148: *READ-SUPPRESS*                5200000fff97
> slot    149: *SUPPRESS-FRAME-PRINT*         ffffffffffffffff
>
>>


--=_MailMate_6EAF10C9-D28E-4475-B8E5-4EE57CE21FC9_=
Content-Type: text/html
Content-Transfer-Encoding: quoted-printable

<!DOCTYPE html>
<html>
<head>
<meta http-equiv=3D"Content-Type" content=3D"text/xhtml; charset=3Dutf-8"=
>
</head>
<body><div style=3D"font-family: sans-serif;"><div class=3D"markdown" sty=
le=3D"white-space: normal;">
<p dir=3D"auto">I just tried this with the patch and got some bindings, b=
ut I'm not sure what they mean:</p>
<pre style=3D"margin-left: 15px; margin-right: 15px; padding: 5px; backgr=
ound-color: #F7F7F7; border-radius: 5px 5px 5px 5px; overflow-x: auto; ma=
x-width: 90vw;"><code style=3D"margin: 0 0; border-radius: 3px; backgroun=
d-color: #F7F7F7; padding: 0px;">0] (sb-vm:ldb-monitor)
Welcome to LDB, a low-level debugger for the Lisp runtime environment.
ldb&gt; bindings
slot      4: *ALLOW-INSTRUMENTING*          ffffffffffffffff
slot      5: *INLINE-EXPANSIONS*            ffffffffffffffff
slot      6: *VALUES-TYPE-OKAY*             ffffffffffffffff
slot      7: *CURRENT-COMPONENT*            ffffffffffffffff
slot      8: *PRINT-IR-NODES-PRETTY*        ffffffffffffffff
slot      9: *PRINT-IR-NODES-PRETTY*        ffffffffffffffff
slot     10: *ALIEN-TYPE-MATCHES*           ffffffffffffffff
slot     11: *ALIEN-TYPE-MATCHES*           ffffffffffffffff
slot     12: *INLINE-EXPANSIONS*            ffffffffffffffff
slot     13: *ALLOW-INSTRUMENTING*          ffffffffffffffff
CORRUPTION WARNING in SBCL pid 4914 pthread 0x1f6b6a240:
Memory fault at 0x18 (pc=3D0x102477a2c)
The integrity of this image is possibly compromised.
Continuing with fingers crossed.
X
</code></pre>
<p dir=3D"auto">I got kicked out of LDB -- I didn't do anything to exit i=
t.</p>
<p dir=3D"auto">On 27 Mar 2026, at 11:37, Douglas Katzman wrote:</p>
</div><blockquote class=3D"embedded" style=3D"margin: 0 0 5px; padding-le=
ft: 5px; border-left: 2px solid #777777; color: #777777;"><div id=3D"C63C=
0ACE-CA42-4CCC-B830-11944BF3F41E">

<div dir=3D"ltr">
<div dir=3D"ltr">
<div>Algorithmic improvements in the pretty-printer could potentially dec=
rease its use of special vars. However, user-defined print-object methods=
 could be to blame.&nbsp; The size to which&nbsp;you increased&nbsp;the b=
inding stack (10x over the default) should have allowed <i>640 thousand</=
i> bindings. I am curious to know which vars are on the stack so I concoc=
ted a patch to ldb-monitor which can tell you.&nbsp; Try rebuilding&nbsp;=
with the patch (which requires the latest unreleased SBCL), entering ldb-=
monitor, executing the added 'bindings' command, and then you will see ou=
tput resembling the following:</div>
<div><font face=3D"monospace">ldb&gt; <b>bindings</b></font></div>
<div><font face=3D"monospace">slot &nbsp; &nbsp; &nbsp;4: * &nbsp; &nbsp;=
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &n=
bsp; &nbsp; &nbsp;ffffffffffffffff<br>
slot &nbsp; &nbsp; &nbsp;5: ** &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; =
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; ffffffffffffffff<=
br>
slot &nbsp; &nbsp; &nbsp;6: *** &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;=
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;ffffffffffffffff<=
/font></div>
<div><font face=3D"monospace">...</font></div>
<font face=3D"monospace">slot &nbsp; &nbsp;146: *ERROR-OUTPUT* &nbsp; &nb=
sp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; ffffffffffffffff<br>
slot &nbsp; &nbsp;148: *READ-SUPPRESS* &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;=
 &nbsp; &nbsp; &nbsp;5200000fff97<br>
slot &nbsp; &nbsp;149: *SUPPRESS-FRAME-PRINT* &nbsp; &nbsp; &nbsp; &nbsp;=
 ffffffffffffffff</font>
<div>
<div class=3D"gmail_quote">
<blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;borde=
r-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
<div style=3D"font-family:sans-serif">
<div style=3D"white-space:normal"></div>
</div>
</div>
</blockquote>
</div>
</div>
</div>
</div></div></blockquote>
<div class=3D"markdown" style=3D"white-space: normal;">

</div>
</div>
</body>

</html>

--=_MailMate_6EAF10C9-D28E-4475-B8E5-4EE57CE21FC9_=--


--===============0332577508730574125==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: inline


--===============0332577508730574125==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

_______________________________________________
Sbcl-help mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/sbcl-help

--===============0332577508730574125==--