From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.5 required=5.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,HTML_MESSAGE,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: from minnie.tuhs.org (minnie.tuhs.org [IPv6:2600:3c01:e000:146::1]) by inbox.vuxu.org (Postfix) with ESMTP id 7542326BED for ; Wed, 22 May 2024 17:38:02 +0200 (CEST) Received: from minnie.tuhs.org (localhost [IPv6:::1]) by minnie.tuhs.org (Postfix) with ESMTP id E6D9643AEC; Thu, 23 May 2024 01:37:56 +1000 (AEST) Received: from mail-pj1-x1029.google.com (mail-pj1-x1029.google.com [IPv6:2607:f8b0:4864:20::1029]) by minnie.tuhs.org (Postfix) with ESMTPS id C636B43ADA for ; Thu, 23 May 2024 01:37:50 +1000 (AEST) Received: by mail-pj1-x1029.google.com with SMTP id 98e67ed59e1d1-2b8a13416d0so1240045a91.3 for ; Wed, 22 May 2024 08:37:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1716392270; x=1716997070; darn=tuhs.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=GUd/Y7LAoteIniJ47Se4mEy+vNqkDZ7Y8U3ISx4St5c=; b=LP8vI0ipeqIBtroMynXjkQWeSwOaZv27L+UoXEqdi3sut0ktTi/642Yop8B6k5vrcg mlAvB2J8boNz5Ad3mLPQUG6dvzJ5mj9K89Q0Z0FOsentyZeGeHovLdBy/tIXjZvTx8Xp ABxwcP/Z7iBWNx359kXKgpMKCDaGGIElUd7L9lCIAgVMjHH0XH2eFGe/IGI7XjJGI+XJ AfERNd60BAIMeNC/9ldciMzqu9N0SjAMUTWsy8nJtv+uJ2VkzdT+4lqp31YgIY0l47zd MR6sED+YGMxqMLG/V4PJR+GRkYJvZKHsAr2fDPc1rseXs/OTlzXhVHLJsgpOQpQ0cYHX 7VZQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1716392270; x=1716997070; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=GUd/Y7LAoteIniJ47Se4mEy+vNqkDZ7Y8U3ISx4St5c=; b=mgG7Dg5CdZ2xnnMT2gKAS5KaooN6udkUeT70hHVvOlEdIHomGhodOZjwzIg86cODjm RbWhG06cjSlbJT3U6InbqXrJQTotm2q4aP32CfiJijPv7BPBt96EoqTNX4PbJ6bDmmvY vTSz+UJQHt3AGo8kbBoyFhuZ2gmfZ2qxeUvQ3WP6tOX1N8hjgFF4q2jUMlOkCB+CJSh/ WXlcMkgZa++zeIwznnVYnjk/LZoUVDlQrVlQWkQRtPKcAMM8SzwnuM3QnATJBI401AEx Q1n+7gM4uiV2u596OUFfyg/Ky7GfmCVuXEE6FtPhENgc+/x4mRI429YZnNzMimHfQQ7l DUHQ== X-Gm-Message-State: AOJu0YxLy8zSLCklbkTZK3Kxu/RdkG+QiKfJMwuFMhB9CZ20nQJTv5CK bCDfuFdbNoZfxC4Gu53g6+2GEi7fbPkfuRiBZ0jXw9uNqndZTBwG0uhWXJdJhbekU95vuNxyZDw NVzZk36L3Ipdks1yQ+/mkoHaDqsma3g== X-Google-Smtp-Source: AGHT+IFZLp+w7JBnN4xBv+fcbN3Y1RFp7G2t5s2V5yKkaEbk0L6MrRbGlik4UvQH5aeCozArSJyp9A7Cg7oXaXTVnXk= X-Received: by 2002:a17:90b:4414:b0:2bd:71ed:ca9e with SMTP id 98e67ed59e1d1-2bd9f460970mr2357422a91.22.1716392269920; Wed, 22 May 2024 08:37:49 -0700 (PDT) MIME-Version: 1.0 References: <51CC9A0D-122C-4A3D-8BAF-C249489FB817@serissa.com> In-Reply-To: From: Paul Winalski Date: Wed, 22 May 2024 11:37:39 -0400 Message-ID: To: Luther Johnson Content-Type: multipart/alternative; boundary="0000000000008b4c3406190cb7d5" Message-ID-Hash: 2NXIUKBCUOJYA66NQH3MHHBQNBC5A2D6 X-Message-ID-Hash: 2NXIUKBCUOJYA66NQH3MHHBQNBC5A2D6 X-MailFrom: paul.winalski@gmail.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: tuhs@tuhs.org X-Mailman-Version: 3.3.6b1 Precedence: list Subject: [TUHS] Re: A fuzzy awk. List-Id: The Unix Heritage Society mailing list Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: --0000000000008b4c3406190cb7d5 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, May 21, 2024 at 2:12=E2=80=AFPM Luther Johnson wrote: > I like this anecdote because it points out the difference between being > able to handle and process bizarre conditions, as if they were something > that should work, which is maybe not that helpful, vs. detecting them and > doing something reasonable, like failiing with a "limit exceeded" message > That is in fact precisely how the DEC compiler handled the 100 nested parentheses condition. > . A silent, insidious failure down the line because a limit was exceeded > is never good. > Amen! One should always do bounds checking when dealing with fixed-size aggregate data structures. One compiler that I worked on got a bug report of bad code being generated. The problem was an illegal optimization that never should have triggered but did due to a corrupted data table. Finding the culprit of the corruption took hours. It finally turned out to be due to overflow of an adjacent data table in use elsewhere in the compiler. The routine to add another entry to that table didn't check for table overflow. -Paul W. --0000000000008b4c3406190cb7d5 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
On Tue, May 21, 2024 at 2:12=E2=80=AFPM L= uther Johnson <luther.johnson@makerlisp.com> wrote:
=

I like this anecdote because it points out the difference between being able to handle and process bizarre conditions, as if they were something that should work, which is maybe not that helpful, vs. detecting them and doing something reasonable, like failiing with a "limit exceeded" message

= That is in fact precisely how the DEC compiler handled the 100 nested paren= theses condition.

. A silent, insidious failure down the line because a limit was exceeded is never good.

Amen!=C2=A0 One should always do bounds check= ing when dealing with fixed-size aggregate data structures.=C2=A0 One compi= ler that I worked on got a bug report of bad code being generated.=C2=A0 Th= e problem was an illegal optimization that never should have triggered but = did due to a corrupted data table.=C2=A0 Finding the culprit of the corrupt= ion took hours.=C2=A0 It finally turned out to be due to overflow of an adj= acent data table in use elsewhere in the compiler.=C2=A0 The routine to add= another entry to that table didn't check for table overflow.

-Paul W.
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