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force use of pandoc version >= 3.1.12.2

Browse Source 
The `bin/pandoc-wrapper.sh` tool will verify that the ssytem
has a recent enough version of `pandoc(1)`.

We explain why we insist on `pandoc(1)`. version >= 3.1.12.2
in comments where the $PANDOC_MIN_VERSION is set.

Added `--wrap=preserve` as a default argument to `pandoc(1)`.
While this change will impact every HTML file generated,
we believe this will improve the ability of someone to look
at the generated HTML and correlate with the original markdown.

Changed `bin/pandoc-wrapper.sh` VERSION from "1.4.2 2024-03-17"
to "1.4.3 2024-03-18".

Performed `make www` to achieve all of the above and to generate
HTML using the new  `--wrap=preserve` `pandoc(1)` mode.
This commit is contained in:
Landon Curt Noll committed 2024-03-18 01:26:39 -07:00
1 parent 9eb7a54e9f
commit b0b212acb1
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+37061 -55132
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1998/schweikh1/index.html
+128 -173
View File
@@ -129,9 +129,9 @@
<h2 id="author"><a name="author"></a>Author:</h2>
<ul>
<li>Name: <a href="../../authors.html#Jens_Schweikhardt">Jens
Schweikhardt</a><br> Location: <a href="../../location.html#DE">DE</a> -
<em>Federal Republic of Germany</em> (<em>Germany</em>) <br><br></li>
<li>Name: <a href="../../authors.html#Jens_Schweikhardt">Jens Schweikhardt</a><br>
Location: <a href="../../location.html#DE">DE</a> - <em>Federal Republic of Germany</em> (<em>Germany</em>)
<br><br></li>
</ul>
<!-- END: next line ends content generated by: bin/output-index-author.sh -->
@@ -141,58 +141,55 @@ Schweikhardt</a><br> Location: <a href="../../location.html#DE">DE</a> -
<h2 id="to-build">To build:</h2>
<div class="sourceCode" id="cb1"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="fu">make</span> all</span></code></pre></div>
<p>There is an alternate version of this entry that will work with
macOS. See the <a href="#alternate-code">Alternate code</a> section
below. We recommend you look at it even if you don’t have a Mac, unless
you want to figure it out yourself, as it includes some interesting
details about the entry.</p>
<p>There is an alternate version of this entry that will work with macOS. See the
<a href="#alternate-code">Alternate code</a> section below. We recommend you look at it
even if you don’t have a Mac, unless you want to figure it out yourself, as it
includes some interesting details about the entry.</p>
<h2 id="to-use">To use:</h2>
<div class="sourceCode" id="cb2"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" aria-hidden="true" tabindex="-1"></a><span class="ex">./schweikh1</span></span></code></pre></div>
<h2 id="alternate-code">Alternate code:</h2>
<p>As noted above this entry will not work as it stands for macOS and
there are some important notes as well as a description of how the fixed
version works (the details of which are relevant to the original entry
that no longer works as well as the fixed version but are described in
the context of the macOS adjustments). For details of what had to
change, see <a href="macos.html">macos.html</a>. Unless you wish to
figure it out yourself, we recommend that you read this even if you
don’t have a Mac as it has some interesting details about the entry.</p>
<p>As noted above this entry will not work as it stands for macOS and there are
some important notes as well as a description of how the fixed version works
(the details of which are relevant to the original entry that no longer works as
well as the fixed version but are described in the context of the macOS
adjustments). For details of what had to change, see <a href="macos.html">macos.html</a>.
Unless you wish to figure it out yourself, we recommend that you read this even
if you don’t have a Mac as it has some interesting details about the entry.</p>
<h3 id="alternate-build">Alternate build:</h3>
<div class="sourceCode" id="cb3"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="fu">make</span> alt</span></code></pre></div>
<h3 id="alternate-build-1">Alternate build:</h3>
<p>Use <code>schweikh1.alt</code> as you would <code>schweikh1</code>
above.</p>
<p>Use <code>schweikh1.alt</code> as you would <code>schweikh1</code> above.</p>
<h3 id="alternate-try">Alternate try:</h3>
<p>Bonus exercise: modify the code to provide a different compiler.</p>
<h2 id="judges-remarks">Judges’ remarks:</h2>
<p>What does it do? It seems to print a list of system headers, perhaps
with words after them. Curiously, if you look at the list of words
defined in a given standard header, they are never printed directly
after that header’s name. Aha! It’s a conformance test for the standard
headers.</p>
after that header’s name. Aha! It’s a conformance test for the
standard headers.</p>
<p>This code is a wonder; it’s a wonder that it compiles. I wonder
whether or not it should. The innovative realization that you can use
special characters, such as <code>'\n'</code>, in <code>#file</code>
directives alone merits some recognition.</p>
whether or not it should. The innovative realization that you can
use special characters, such as <code>'\n'</code>, in <code>#file</code> directives alone
merits some recognition.</p>
<p>I’ve included most of the author’s remarks; they’re fairly thorough.
Do not read them if you want to figure this out yourself. “Amendment
One” refers to “NA1”, the add-on to C89 which added some fairly crufty
internationalization support.</p>
One” refers to “NA1”, the add-on to C89 which added some fairly
crufty internationalization support.</p>
<h4 id="historical-note">Historical note:</h4>
<p>Some non-gcc compilers that were not fully ANSI standard did not
compile this entry correctly. Using cc by default was not helpful most
of the time on this entry, because the program had a hardcoded gcc
invocation anyway. Anyone who uses egcs and has no plain gcc will need
to frob the source anyway and can be expected to do the right thing with
<code>${CC}</code>. This limitation was removed in 2023 but in the past
compile this entry correctly. Using cc by default was not helpful
most of the time on this entry, because the program had a hardcoded
gcc invocation anyway. Anyone who uses egcs and has no plain gcc
will need to frob the source anyway and can be expected to do the
right thing with <code>${CC}</code>. This limitation was removed in 2023 but in the past
one should have used gcc.</p>
<h2 id="authors-remarks">Author’s remarks:</h2>
<p>Important! This program, if it compiles at all, is mis-compiled by
many compilers due to compiler bugs. It could be the “least likely to
compile and execute” in conjunction with preprocessor abuse. When run,
it is likely to uncover bugs in your system headers.</p>
<p>The program is run without arguments. If your compiler is buggy, the
most likely result is no output and/or an exit status of 1.</p>
<p>Important! This program, if it compiles at all, is mis-compiled by many
compilers due to compiler bugs. It could be the “least likely
to compile and execute” in conjunction with preprocessor abuse.
When run, it is likely to uncover bugs in your system headers.</p>
<p>The program is run without arguments. If your compiler is buggy,
the most likely result is no output and/or an exit status of 1.</p>
<p>If Amendment One headers are missing you will see something like:</p>
<pre><code>&lt;iso646.h&gt;:
gcc: /usr/include/iso646.h: No such file or directory
@@ -204,27 +201,24 @@ gcc: No input files specified
gcc: /usr/include/wchar.h: No such file or directory
gcc: No input files specified</code></pre>
<p>Bug your vendor for an upgrade.</p>
<p>The format of the info file is straightforward and described in the
file itself. Just load it in your favorite editor.</p>
<p>The format of the info file is straightforward and described in the file
itself. Just load it in your favorite editor.</p>
<h3 id="requirements">Requirements</h3>
<p><code>gcc</code> (the GNU C compiler) must be available at runtime.
It is assumed that your C implementation keeps headers as files in the
<code>/usr/include</code> directory. The <a href="info">info</a> file
must be readable and reside in the current working directory. The
current working directory must be writable in order to create a
temporary file (which is removed upon program termination). In case you
don’t have gcc at runtime, not all is lost if your compiler or
preprocessor can produce a list of defined macros in the format output
by <code>gcc -dM</code>, i.e. lines of the form
<p><code>gcc</code> (the GNU C compiler) must be available at runtime. It is assumed that your
C implementation keeps headers as files in the <code>/usr/include</code> directory. The
<a href="info">info</a> file must be readable and reside in the current working directory.
The current working directory must be writable in order to create a temporary
file (which is removed upon program termination). In case you don’t have gcc at
runtime, not all is lost if your compiler or preprocessor can produce a list of
defined macros in the format output by <code>gcc -dM</code>, i.e. lines of the form
<code>#define MACRO value</code>.</p>
<p>Edit the source at line 55 in this case.</p>
<h3 id="background">Background</h3>
<p>ISO C has a very strict idea of visibility of identifiers. All
possible macros are explicitly enumerated. In a compliant implementation
no other macros can be defined, because you could write strictly
conforming programs that may fail to compile due to syntax errors:
supposing that <code>&lt;stdio.h&gt;</code> defines
<code>PIPE_BUF</code>, then the conforming</p>
<p>ISO C has a very strict idea of visibility of identifiers. All possible
macros are explicitly enumerated. In a compliant implementation no other
macros can be defined, because you could write strictly conforming
programs that may fail to compile due to syntax errors: supposing that
<code>&lt;stdio.h&gt;</code> defines <code>PIPE_BUF</code>, then the conforming</p>
<div class="sourceCode" id="cb5"><pre class="sourceCode c"><code class="sourceCode c"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="pp">#include </span><span class="im">&lt;assert.h&gt;</span></span>
<span id="cb5-2"><a href="#cb5-2" aria-hidden="true" tabindex="-1"></a><span class="pp">#include </span><span class="im">&lt;stdio.h&gt;</span><span class="pp"> </span><span class="co">/* &lt;- or where the bogus macro is defined */</span></span>
<span id="cb5-3"><a href="#cb5-3" aria-hidden="true" tabindex="-1"></a><span class="pp">#include </span><span class="im">&lt;string.h&gt;</span></span>
@@ -238,38 +232,36 @@ supposing that <code>&lt;stdio.h&gt;</code> defines
<span id="cb5-11"><a href="#cb5-11" aria-hidden="true" tabindex="-1"></a><span class="op">}</span></span></code></pre></div>
<p>is expected to compile and meet the assertion. If it does not, your
compiler compiles some other language than ISO C.</p>
<h3 id="why-i-think-my-program-is-obfuscated">Why I think my program is
obfuscated</h3>
<h3 id="why-i-think-my-program-is-obfuscated">Why I think my program is obfuscated</h3>
<p>Not only is the program’s purpose a thorough standard conformance
test, the source itself is a beast and has uncovered bugs in many C
compilers.</p>
test, the source itself is a beast and has uncovered bugs in many
C compilers.</p>
<ol type="1">
<li>The token sequence after <code>#include</code> can consist of
pp-tokens and “are processed just as in normal text.” [ISO 6.8.2] The
result must resemble one of the canonical forms, <code>"foo.h"</code> or
<code>&lt;bar.h&gt;</code>. This lets us write things like</li>
<li>The token sequence after <code>#include</code> can consist of pp-tokens and
“are processed just as in normal text.” [ISO 6.8.2] The result
must resemble one of the canonical forms, <code>"foo.h"</code> or <code>&lt;bar.h&gt;</code>.
This lets us write things like</li>
</ol>
<div class="sourceCode" id="cb6"><pre class="sourceCode c"><code class="sourceCode c"><span id="cb6-1"><a href="#cb6-1" aria-hidden="true" tabindex="-1"></a><span class="pp">#define HEADER </span><span class="st">&quot;foo.h&quot;</span></span>
<span id="cb6-2"><a href="#cb6-2" aria-hidden="true" tabindex="-1"></a><span class="pp">#include HEADER</span></span></code></pre></div>
<p>I could not find a compiler rejecting this. However, if we’re
torturing the preprocessor a little more, by using token pasting, at
least one compiler falls over.</p>
torturing the preprocessor a little more, by using token pasting,
at least one compiler falls over.</p>
<div class="sourceCode" id="cb7"><pre class="sourceCode c"><code class="sourceCode c"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a><span class="pp">#define H</span><span class="op">(</span><span class="pp">x</span><span class="op">)</span><span class="pp"> </span><span class="op">&lt;</span><span class="pp">st</span><span class="op">##</span><span class="pp">x</span><span class="op">##.</span><span class="pp">h</span><span class="op">&gt;</span></span>
<span id="cb7-2"><a href="#cb7-2" aria-hidden="true" tabindex="-1"></a><span class="pp">#include H(dio) </span><span class="co">/* expands to &lt;stdio.h&gt; */</span></span></code></pre></div>
<p>is rejected by tcc version 4.1.2, the TenDRA compiler:
<code>"t.c", line 3: Error:\ [ISO 6.8.3.3]: Invalid result for '##' operator in macro 'H'.</code></p>
<p>To be honest, I don’t know if the rules for pp-tokens and token
pasting don’t forbid what I do (and thus tcc is correct in rejecting
it). In this case, all other compilers I tried are buggy, or the
Standard itself :-)</p>
pasting don’t forbid what I do (and thus tcc is correct in rejecting it).
In this case, all other compilers I tried are buggy, or the Standard
itself :-)</p>
<ol start="2" type="1">
<li>The <code>#line</code> directive allows to set a line number, and
optionally a file name, i.e. modify <code>__LINE__</code> and
<code>__FILE__</code>. Strange things happen if the file name contains a
NUL byte – which the Standard allows: in <code>#line num "file"</code>
the <code>"file"</code> is an s-char-sequence per ISO 6.8.4. ISO 6.1.4
defines string literals as s-char-sequences, which may include octal
escape sequences. Let’s look at</li>
<li>The <code>#line</code> directive allows to set a line number, and optionally
a file name, i.e. modify <code>__LINE__</code> and <code>__FILE__</code>. Strange things
happen if the file name contains a NUL byte – which the Standard
allows: in <code>#line num "file"</code> the <code>"file"</code> is an s-char-sequence per
ISO 6.8.4. ISO 6.1.4 defines string literals as s-char-sequences,
which may include octal escape sequences. Let’s look at</li>
</ol>
<div class="sourceCode" id="cb8"><pre class="sourceCode c"><code class="sourceCode c"><span id="cb8-1"><a href="#cb8-1" aria-hidden="true" tabindex="-1"></a><span class="pp">#include </span><span class="im">&lt;stdio.h&gt;</span></span>
<span id="cb8-2"><a href="#cb8-2" aria-hidden="true" tabindex="-1"></a><span class="pp">#line 42 &quot;foo\0bar&quot;</span></span>
@@ -277,22 +269,18 @@ escape sequences. Let’s look at</li>
<span id="cb8-4"><a href="#cb8-4" aria-hidden="true" tabindex="-1"></a> printf <span class="op">(</span><span class="st">&quot;</span><span class="sc">%s</span><span class="st"> </span><span class="sc">%d\n</span><span class="st">&quot;</span><span class="op">,</span> __FILE__<span class="op">,</span> <span class="op">(</span><span class="dt">int</span><span class="op">)</span><span class="kw">sizeof</span> __FILE__<span class="op">);</span></span>
<span id="cb8-5"><a href="#cb8-5" aria-hidden="true" tabindex="-1"></a> <span class="cf">return</span> <span class="dv">0</span><span class="op">;</span></span>
<span id="cb8-6"><a href="#cb8-6" aria-hidden="true" tabindex="-1"></a><span class="op">}</span></span></code></pre></div>
<p>This is supposed to output <code>'foo 8'</code>. Here’s what happens
in RL:</p>
<p>This is supposed to output <code>'foo 8'</code>. Here’s what happens in RL:</p>
<pre><code>foo 4 gcc 2.7.2.1, lcc
foo\0bar 9 tcc 4.1.2, Sunsoft cc turn &quot;\0&quot; into &quot;\\0&quot;, ugh!</code></pre>
<p>(I have written a bug report for gcc. Newer versions and egcs are
ok.)</p>
<p>(I have written a bug report for gcc. Newer versions and egcs are ok.)</p>
<ol start="3" type="1">
<li><p>The <code>%:</code> and <code>%:%:</code> digraphs test for
conformance to Amendment One.</p>
<p>Ask your local guru if C allows the same case label in the same
switch statement to appear more than once. Ask him/her to think real
hard. The answer will be “no”. The true guru will cite a constraint in
ISO 6.6.4.2. Then make fun of the guru’s answer by waving
<code>case __LINE__:</code> under his/her nose. Easy money from a bet!
Make sure your guru has no chance to use Standardese weasel words as an
escape: can I have</p></li>
<li><p>The <code>%:</code> and <code>%:%:</code> digraphs test for conformance to Amendment One.</p>
<p>Ask your local guru if C allows the same case label in the same switch
statement to appear more than once. Ask him/her to think real hard.
The answer will be “no”. The true guru will cite a constraint in
ISO 6.6.4.2. Then make fun of the guru’s answer by waving <code>case __LINE__:</code>
under his/her nose. Easy money from a bet! Make sure your guru has
no chance to use Standardese weasel words as an escape: can I have</p></li>
</ol>
<div class="sourceCode" id="cb10"><pre class="sourceCode c"><code class="sourceCode c"><span id="cb10-1"><a href="#cb10-1" aria-hidden="true" tabindex="-1"></a> <span class="cf">case</span> <span class="op">&lt;</span>some_token<span class="op">&gt;:</span></span>
<span id="cb10-2"><a href="#cb10-2" aria-hidden="true" tabindex="-1"></a> <span class="cf">case</span> <span class="op">&lt;</span>some_token<span class="op">&gt;:</span></span></code></pre></div>
@@ -300,116 +288,83 @@ escape: can I have</p></li>
can generously allow the additional constraint that no `#undef`s or
`#define`s are allowed between the two cases.)</code></pre>
<p>Lots of integer constants and string literals come into the source
via <code>__LINE__</code> and <code>__FILE__</code> which are redefined
at various places. Sometimes the <code>__FILE__</code> contains
<code>\0</code> bytes; different strings or characters are then accessed
with offsets, say <code>10+__FILE__</code> or
<code>__LINE__+__FILE__</code> or <code>2[__FILE__]</code>. One integral
constant in octal. This makes the source and header input depend on
ASCII.</p>
<p>A few old obfuscations, like one character identifiers, not too many
macros, a <code>goto O</code>, “needless” assignments to satisfy lint
with its “function value ignored” warnings. My lint has nothing to
complain about.</p>
<p>There’s more whitespace in the Standard than just space, tab and
newline. In particular, there are vertical tab and form-feed that can be
used in certain places (outside of preprocessing directives, i.e. they
are not allowed from just after the <code>#</code> up to the final
newline. See 6.8 for details.) On many implementations these appear as
<code>^L</code> and <code>^K</code>. My source starts with an extremely
uncommon 32bit word consisting of <code>^L</code>, <code>^K</code>,
<code>%</code> and <code>:</code>. I have grepped old winning entries
for ^K, none of them contains one, so this is something new – after 14
years of IOCCC. Be sure to have enough paper in your printer when you
make a hard copy of the source…</p>
<p>While I’m at it, the rules state that only space, tab and newline are
ignored for the count (plus ‘<code>{</code>’, ‘<code>}</code>’,
‘<code>;</code>’ followed by whitespace). The <a
href="../mkentry.c">mkentry.c</a> program, however, uses
<code>isspace(3)</code> which returns nonzero for <code>\v</code> and
<code>\f</code> and other characters as well. I could have used a lot
more <code>^K</code> and <code>^L</code> probably undetected by your
counter but decided to err on the side of safety. I use a perl script to
compute the character count according to the rules. The advantages of an
independent clean room approach…</p>
<div class="sourceCode" id="cb12"><pre
class="sourceCode perl"><code class="sourceCode perl"><span id="cb12-1"><a href="#cb12-1" aria-hidden="true" tabindex="-1"></a><span class="kw">#!/usr/bin/perl -w</span></span>
via <code>__LINE__</code> and <code>__FILE__</code> which are redefined at various places.
Sometimes the <code>__FILE__</code> contains <code>\0</code> bytes; different strings or
characters are then accessed with offsets, say <code>10+__FILE__</code> or
<code>__LINE__+__FILE__</code> or <code>2[__FILE__]</code>. One integral constant in octal.
This makes the source and header input depend on ASCII.</p>
<p>A few old obfuscations, like one character identifiers, not too
many macros, a <code>goto O</code>, “needless” assignments to satisfy lint
with its “function value ignored” warnings. My lint has nothing
to complain about.</p>
<p>There’s more whitespace in the Standard than just space, tab and newline. In
particular, there are vertical tab and form-feed that can be used in certain
places (outside of preprocessing directives, i.e. they are not allowed from just
after the <code>#</code> up to the final newline. See 6.8 for details.) On many
implementations these appear as <code>^L</code> and <code>^K</code>. My source starts with an
extremely uncommon 32bit word consisting of <code>^L</code>, <code>^K</code>, <code>%</code> and <code>:</code>. I have
grepped old winning entries for ^K, none of them contains one, so this is
something new – after 14 years of IOCCC. Be sure to have enough paper in your
printer when you make a hard copy of the source…</p>
<p>While I’m at it, the rules state that only space, tab and newline
are ignored for the count (plus ‘<code>{</code>’, ‘<code>}</code>’, ‘<code>;</code>’ followed by
whitespace). The <a href="../mkentry.c">mkentry.c</a> program, however, uses <code>isspace(3)</code> which
returns nonzero for <code>\v</code> and <code>\f</code> and other characters as well.
I could have used a lot more <code>^K</code> and <code>^L</code> probably undetected by your
counter but decided to err on the side of safety. I use a perl
script to compute the character count according to the rules.
The advantages of an independent clean room approach…</p>
<div class="sourceCode" id="cb12"><pre class="sourceCode perl"><code class="sourceCode perl"><span id="cb12-1"><a href="#cb12-1" aria-hidden="true" tabindex="-1"></a><span class="kw">#!/usr/bin/perl -w</span></span>
<span id="cb12-2"><a href="#cb12-2" aria-hidden="true" tabindex="-1"></a><span class="wa">$/</span> = <span class="ot">&quot;</span><span class="st">\0</span><span class="ot">&quot;</span>;</span>
<span id="cb12-3"><a href="#cb12-3" aria-hidden="true" tabindex="-1"></a><span class="wa">$_</span> = &lt;&gt;;</span>
<span id="cb12-4"><a href="#cb12-4" aria-hidden="true" tabindex="-1"></a><span class="ot">s/</span><span class="ch">[</span><span class="bn">;{}</span><span class="ch">][</span><span class="bn"> \t\n</span><span class="ch">]</span><span class="ot">/</span><span class="ch">\n</span><span class="ot">/g</span>;</span>
<span id="cb12-5"><a href="#cb12-5" aria-hidden="true" tabindex="-1"></a><span class="ot">s/</span><span class="ch">[</span><span class="bn"> \t\n</span><span class="ch">]+</span><span class="ot">//g</span>;</span>
<span id="cb12-6"><a href="#cb12-6" aria-hidden="true" tabindex="-1"></a><span class="fu">print</span> <span class="fu">length</span> (<span class="wa">$_</span>),<span class="ot">&quot;</span><span class="ch">\n</span><span class="ot">&quot;</span>;</span></code></pre></div>
<p>To use, try:</p>
<div class="sourceCode" id="cb13"><pre
class="sourceCode sh"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" aria-hidden="true" tabindex="-1"></a><span class="fu">perl</span> ./charcount.pl schweikh1.c</span></code></pre></div>
<div class="sourceCode" id="cb13"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" aria-hidden="true" tabindex="-1"></a><span class="fu">perl</span> ./charcount.pl schweikh1.c</span></code></pre></div>
<p>I have tried, as suggested in the guidelines, to let the code look
like ordinary C code. Apart from a few long lines I think I left the
indentation like I would in RL. You should however not try to use
<code>indent</code> on the source. The code is extremely fragile because
of the myriads of <code>__LINE__</code> macros – indenting is a sure way
to break the program. Don’t even think of maintaining that beast; I’ve
had my share of core dumps during development :-) A test suite was used
after every minor change to find out if the program still does what it
should.</p>
<p>From the goals: “To stress C compilers with unusual code.” That
describes exactly my modest attempts…</p>
<h2 id="copyright-and-cc-by-sa-4.0-license">Copyright and CC BY-SA 4.0
License:</h2>
<p>This file is Copyright (c) 2023 by Landon Curt Noll. All Rights
Reserved. You are free to share and adapt this file under the terms of
this license:</p>
like ordinary C code. Apart from a few long lines I think I left
the indentation like I would in RL. You should however not try to
use <code>indent</code> on the source. The code is extremely fragile because of the
myriads of <code>__LINE__</code> macros – indenting is a sure way to break
the program. Don’t even think of maintaining that beast; I’ve
had my share of core dumps during development :-) A test suite
was used after every minor change to find out if the program still
does what it should.</p>
<p>From the goals: “To stress C compilers with unusual code.”
That describes exactly my modest attempts…</p>
<h2 id="copyright-and-cc-by-sa-4.0-license">Copyright and CC BY-SA 4.0 License:</h2>
<p>This file is Copyright (c) 2023 by Landon Curt Noll. All Rights Reserved.
You are free to share and adapt this file under the terms of this license:</p>
<pre><code>Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)</code></pre>
<p>For more information, see:
https://creativecommons.org/licenses/by-sa/4.0/</p>
<p>For more information, see: https://creativecommons.org/licenses/by-sa/4.0/</p>
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<h1 id="inventory-for-1998schweikh1"><a name="inventory"></a>Inventory
for 1998/schweikh1</h1>
<h1 id="inventory-for-1998schweikh1"><a name="inventory"></a>Inventory for 1998/schweikh1</h1>
<p><a href="#top">Jump to top</a></p>
<h2 id="primary-files">Primary files</h2>
<ul>
<li><a
href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1998/schweikh1/schweikh1.c">schweikh1.c</a>
- entry source</li>
<li><a
href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1998/schweikh1/Makefile">Makefile</a>
- entry Makefile</li>
<li><a
href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1998/schweikh1/schweikh1.alt.c">schweikh1.alt.c</a>
- alternative source</li>
<li><a
href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1998/schweikh1/schweikh1.orig.c">schweikh1.orig.c</a>
- original source</li>
<li><a
href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1998/schweikh1/charcount.pl">charcount.pl</a>
- character counter</li>
<li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1998/schweikh1/schweikh1.c">schweikh1.c</a> - entry source</li>
<li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1998/schweikh1/Makefile">Makefile</a> - entry Makefile</li>
<li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1998/schweikh1/schweikh1.alt.c">schweikh1.alt.c</a> - alternative source</li>
<li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1998/schweikh1/schweikh1.orig.c">schweikh1.orig.c</a> - original source</li>
<li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1998/schweikh1/charcount.pl">charcount.pl</a> - character counter</li>
<li><a href="macos.html">macos.html</a> - work with macOS</li>
<li><a
href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1998/schweikh1/info">info</a>
- standards compliance</li>
<li><a href="1998_schweikh1.tar.bz2">1998_schweikh1.tar.bz2</a> -
download entry source</li>
<li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1998/schweikh1/info">info</a> - standards compliance</li>
<li><a href="1998_schweikh1.tar.bz2">1998_schweikh1.tar.bz2</a> - download entry source</li>
</ul>
<h2 id="secondary-files">Secondary files</h2>
<ul>
<li><a href="index.html">index.html</a> - entry home page</li>
<li><a
href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1998/schweikh1/.entry.json">.entry.json</a>
- description of entry in JSON</li>
<li><a
href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1998/schweikh1/.gitignore">.gitignore</a>
- list of files that should not be committed under git</li>
<li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1998/schweikh1/.entry.json">.entry.json</a> - description of entry in JSON</li>
<li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1998/schweikh1/.gitignore">.gitignore</a> - list of files that should not be committed under git</li>
<li><a href=".path">.path</a> - directory path from top directory</li>
<li><a
href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1998/schweikh1/README.md">README.md</a>
- markdown source for index.html</li>
<li><a
href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1998/schweikh1/macos.md">macos.md</a>
- markdown source for marcos.html</li>
<li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1998/schweikh1/README.md">README.md</a> - markdown source for index.html</li>
<li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/1998/schweikh1/macos.md">macos.md</a> - markdown source for marcos.html</li>
</ul>
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1998/schweikh1/macos.html
+37 -47
View File
@@ -120,40 +120,34 @@
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<p>This document describes how this was fixed to work with macOS as well
as some of the magic in the entry. Even if you don’t have a Mac it might
be worth your time reading especially as some of it details some
important fixes and changes in the original entry as well.</p>
<p>This document describes how this was fixed to work with macOS as well as some of
the magic in the entry. Even if you don’t have a Mac it might be worth your time
reading especially as some of it details some important fixes and changes in the
original entry as well.</p>
<h1 id="macos-changes">macOS changes</h1>
<p>As an aside: if you have a Mac with the Apple chip, some of the
header files will report an unsupported architecture and unsupported
compiler (error, warning). This will not make the program abort,
however, but even with an Intel CPU though, the original entry will not
work in macOS as it stands because <code>/usr/include</code> is
hard-coded in the code and macOS does not have it.</p>
<p>Nevertheless, although some of it would not work in other systems
where <code>/usr/include</code> exists, the <code>#define</code>s would
still be found okay, at least until a file was not found (this
limitation was removed in both versions in 2023). see</p>
<p>However, as noted, macOS does <strong>not</strong> have
<code>/usr/include</code> so this would never work for macOS without
some changes, described next. For macOS you will need the command line
tools installed which can be done like:</p>
<p>As an aside: if you have a Mac with the Apple chip, some of the header files
will report an unsupported architecture and unsupported compiler (error,
warning). This will not make the program abort, however, but even with an Intel
CPU though, the original entry will not work in macOS as it stands because
<code>/usr/include</code> is hard-coded in the code and macOS does not have it.</p>
<p>Nevertheless, although some of it would not work in other systems where
<code>/usr/include</code> exists, the <code>#define</code>s would still be found okay, at least until
a file was not found (this limitation was removed in both versions in 2023). see</p>
<p>However, as noted, macOS does <strong>not</strong> have <code>/usr/include</code> so this would never
work for macOS without some changes, described next. For macOS you will need the
command line tools installed which can be done like:</p>
<div class="sourceCode" id="cb1"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="fu">sudo</span> xcode-select <span class="at">--install</span></span></code></pre></div>
<p>An important point is that the original version hard-coded
<code>gcc</code> but just like the entry, the alternate version has also
removed this limitation despite <code>gcc</code> existing (though it’s
<code>clang</code>) in macOS.</p>
<p>Now as far as how this works if you look at the code of <a
href="schweikh1.c">schweikh1.c</a>, on line 55 you’ll see a funny
command (this goes for the alternate version as well but a bit
different).</p>
<p>Now the key is two magic numbers, one (two times) on a different line
shortly below the string and the other a couple lines further below.</p>
<p>In the original the numbers are, respectively, <code>44</code> and
<code>46</code>, but with the gcc limitation removed the numbers now are
<code>43</code> and <code>45</code>. But how does this work? Well the
command is:</p>
<p>An important point is that the original version hard-coded <code>gcc</code> but just like
the entry, the alternate version has also removed this limitation despite <code>gcc</code>
existing (though it’s <code>clang</code>) in macOS.</p>
<p>Now as far as how this works if you look at the code of
<a href="schweikh1.c">schweikh1.c</a>, on line 55 you’ll see a funny command (this goes for
the alternate version as well but a bit different).</p>
<p>Now the key is two magic numbers, one (two times) on a different line shortly below the
string and the other a couple lines further below.</p>
<p>In the original the numbers are, respectively, <code>44</code> and <code>46</code>, but with the gcc
limitation removed the numbers now are <code>43</code> and <code>45</code>. But how does this work? Well
the command is:</p>
<pre><code>&quot;0gcc -ansi -E -dM -undef %s /usr/include/%s&gt;r\0 (&quot;</code></pre>
<p>which has been changed to be:</p>
<pre><code>&quot;0cc -ansi -E -dM -undef %s /usr/include/%s&gt;r\0 (&quot;</code></pre>
@@ -161,21 +155,17 @@ command is:</p>
<div class="sourceCode" id="cb4"><pre class="sourceCode c"><code class="sourceCode c"><span id="cb4-1"><a href="#cb4-1" aria-hidden="true" tabindex="-1"></a><span class="cf">if</span> <span class="op">((</span>H <span class="op">=</span> fopen <span class="op">(</span>__FILE__<span class="op">+</span><span class="dv">43</span><span class="op">,</span> <span class="dv">43</span><span class="op">+</span>__FILE__<span class="op">)))</span></span>
<span id="cb4-2"><a href="#cb4-2" aria-hidden="true" tabindex="-1"></a><span class="cf">while</span> <span class="op">((</span>fgets <span class="op">(</span>L<span class="op">,</span> <span class="op">(</span><span class="dt">int</span><span class="op">)</span><span class="kw">sizeof</span> L<span class="op">,</span> H<span class="op">))</span> <span class="op">!=</span> <span class="dv">0</span><span class="op">)</span> <span class="op">{</span></span>
<span id="cb4-3"><a href="#cb4-3" aria-hidden="true" tabindex="-1"></a> I<span class="op">[</span>strcspn <span class="op">(</span>I<span class="op">,</span> <span class="dv">45</span><span class="op">+</span>__FILE__<span class="op">)]</span> <span class="op">=</span> O <span class="op">=</span> <span class="dv">0</span><span class="op">;</span></span></code></pre></div>
<p>The first number in the above C means the length starting from 0 up
through the <code>&gt;</code>. The second number is the same starting
point but up through the <code>\0</code> which is why it’s
<code>+2</code>. But what happens if only the first number is updated
(from the original)? Most of the output will be just
<code>#define</code> by itself; in the cases where there was text after
that it was macros that certainly were not defined. There might have
been other errors as well.</p>
<p>Changing this for macOS allows for opening the right files; the
problem with macOS is <code>/usr/include</code> does not exist: instead
it’s
<code>/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include</code>
which is why the different command line and the different numbers. The
change of the numbers can be found in the alternate code and the
explanation is the same.</p>
<p>The first number in the above C means the length starting from 0 up through the
<code>&gt;</code>. The second number is the same starting point but up through the <code>\0</code> which
is why it’s <code>+2</code>. But what happens if only the first number is updated (from the
original)? Most of the output will be just <code>#define</code> by itself; in the cases
where there was text after that it was macros that certainly were not defined.
There might have been other errors as well.</p>
<p>Changing this for macOS allows for opening the right files; the problem with
macOS is <code>/usr/include</code> does not exist: instead it’s
<code>/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include</code> which is why
the different command line and the different numbers. The change of the numbers
can be found in the alternate code and the explanation is the same.</p>
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