Merge pull request #162 from xexyl/1998-schweikh1

1998/schweikh1/.gitignore

@@ -1 +1,2 @@
 schweikh1
+schweikh1.alt

1998/schweikh1/Makefile

@@ -142,8 +142,8 @@ OBJ= ${PROG}.o
 DATA= info
 TARGET= ${PROG}
 #
-ALT_OBJ=
+ALT_OBJ= ${PROG}.alt.o
-ALT_TARGET=
+ALT_TARGET= ${PROG}.alt
 
 
 #################

1998/schweikh1/README.md

@@ -12,11 +12,67 @@
 
         make all
 
-### To run
+[Cody Boone Ferguson](/winners.html#Cody_Boone_Ferguson) fixed this for modern
+systems (it did not work at all). He also made it so that if a file fails to
+open it does not return but rather skips the reading of the file.
+
+What was
+wrong? The call to `freopen()` was incorrect with the second arg (the mode)
+being instead `5+__FILE__`. It now is `"r"`. There was also a call to `fopen()`
+that was wrong where the mode was instead `44+__FILE__`. Interestingly enough
+though this did not seem to be an issue though I cannot explain why. He notes
+that it works fine with `clang` as well as `gcc` (which is what is used but in
+macOS - see below for alternative code - `gcc` is clang).
+
+Additionally Cody provided an alternative version for macOS. See below for the
+alternative version. Thank you Cody for your assistance!
+
+### Alternative code:
+
+As noted above [Cody Boone Ferguson](/winners.html#Cody_Boone_Ferguson) made an
+alternative version that works with macOS but there are some important notes as
+well as a description of how it works (spoilers for the original version as
+well).
+
+Cody said that at least with his MacBook Pro Max with the M1 chip some header
+files report an unsupported architecture and unsupported compiler (error,
+warning). However the defines are still found okay.
+
+For this alternative version you will need the command line tools which you can
+install like:
+
+```sh
+sudo xcode-select --install
+```
+
+Finally as far as how this works if you look at line 55 you see a funny command.
+This goes for both versions. Now the key are two magic numbers, one on a
+different line shortly below the string. In the original the numbers are,
+respectively, 44 and 46.  But how does this work? Well the string is:
+
+	"0gcc -ansi -E -dM -undef %s /usr/include/%s>r\0 ("
+
+The first number means: the length starting from 0 up through the `>`. The
+second number is the same starting point but up through the `\0` which is why
+it's +2. Somehow it was basic intuition that made me figure out these two
+numbers and a quick test confirmed it. But what happens if only the first number
+is updated? Most of the output will be just `#define` 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.
+
+This allows for opening the right files. The problem with the macOS is
+`/usr/include` does not exist: instead it's
+`/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include` which is why
+the different command line and the different numbers.
+
+To use this version use `schweikh1.alt` instead.
+
+
+### To run:
 
 	./schweikh1
 
-## Judges' comments
+## Judges' comments:
 
 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
@@ -88,7 +144,7 @@
 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: suppose
-    <stdio.h> defines PIPE_BUF, then the conforming
+`<stdio.h>` defines `PIPE_BUF`, then the conforming
 
     #include <assert.h>
     #include <stdio.h>    /*  <- or where the bogus macro is defined */
@@ -193,6 +249,7 @@
 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...
+
 	#!/usr/bin/perl -w
 	$/ = "\0";
 	$_ = <>;

1998/schweikh1/schweikh1.alt.c

@@ -0,0 +1,70 @@
+%:define H(x) <st%:%:x##.h>
+/*#include H(dio)*/
+/*#include H(dlib)*/
+/*#include H(ring)*/
+
+#define x ) == 0 ?__LINE__:0){O =__LINE__;break;} }
+#define X(x) __LINE__ x __LINE__
+#define t(a)\
+for (c = 0; c <n##a; ++c) { \
+  if (strchr (a[c], 0[__FILE__])) { if (*a[c] == 0[__FILE__]) { \
+      if (strcmp (a[c]+__LINE__, I + strlen (I) + __LINE__ - strlen (a[c]) x else { \
+      if (strncmp (a[c], I, strlen (a[c])-__LINE__ x \
+  } else { if (strcmp (a[c], I x }
+
+#line 4 "info\0r"
+	int
+main (int C, char **V)
+{
+	FILE *G;
+	int c, ne, nn, S = C < 2 ? 060 : *V[1];
+
+	char f[__LINE__][X(*)], K[(X(*))*4], L[4*X(<<)],
+	e[X(<<)][3*__LINE__], n[X(<<)][3*__LINE__], F[__LINE__];
+
+	if (freopen (__FILE__, "r", stdin) == 0) return __LINE__-13;
+	for (c = 0;;) {
+#line		1 "#\n"
+		if (!fgets (f[c], (int)sizeof *f, stdin)) return __LINE__; if (*f[c] == 0[__FILE__]) continue; if (*f[c] != __LINE__[__FILE__]) { f[c][strlen (f[c]) - __LINE__] = 2[__FILE__];
+			++c;
+		} else
+			break;
+	}
+	for (ne = 0;;) {
+		do {
+#line			1 "#%s%s"
+			if (!fgets (L, (int)sizeof L, stdin)) return __LINE__; } while (*L == 0[__FILE__]); switch (sscanf (L, __LINE__+__FILE__, F, e[ne])) { default: goto O;
+			case __LINE__: switch (strchr (F, S)!=0) case 1: ++ne;
+		}
+	}
+
+O:
+	nn = 0;
+	while ((fgets (L, (int) sizeof L, stdin)) != 0) {
+
+
+		char A[__LINE__], f3; if (*L == 0[__FILE__]) continue;
+#line		1 "%s%s %c"
+		switch (sscanf (L, __FILE__, A, n[nn], &f3)) {
+		case __LINE__: if (strchr (A, S)) ++nn; break;
+		case __LINE__:
+			if (strchr (A, S)) {
+#line				8 "<%s>:\n"
+				char *I = L + __LINE__;
+				int O = printf (__FILE__, n[nn]) +
+#line				2 "0gcc -ansi -E -dM -undef %s /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/%s>r\0 ("
+				sprintf (K, 1+__FILE__, f[S-*__FILE__] + __LINE__, n[nn]);
+				O += system (K);
+				if ((G = fopen (__FILE__+95, "r")))
+				while ((fgets (L, (int)sizeof L, G)) != 0) {
+					I[strcspn (I, 97+__FILE__)] = O = 0;
+#line					1 "*r"
+					t (n) t (e)
+					if (0 == O) O = puts (L);
+				}
+				if (G != NULL) nn = fclose (G);
+			}
+		}
+	}
+	return remove (1+__FILE__);
+}

1998/schweikh1/schweikh1.c

@@ -3,9 +3,9 @@
 /*#include H(dlib)*/
 /*#include H(ring)*/
 
-#define x ) == 0 ?__LINE__:0){O =__LINE__;break;} }
+#define x ) == 0 ?__LINE__:0){O =__LINE__;break;} }
-#define X(x) __LINE__ x __LINE__
+#define X(x) __LINE__ x __LINE__
-#define t(a)\
+#define t(a)\
 for (c = 0; c <n##a; ++c) { \
   if (strchr (a[c], 0[__FILE__])) { if (*a[c] == 0[__FILE__]) { \
       if (strcmp (a[c]+__LINE__, I + strlen (I) + __LINE__ - strlen (a[c]) x else { \
@@ -16,13 +16,13 @@ for (c = 0; c <n##a; ++c) { \
 	int
 main (int C, char **V)
 {
-	FILE *H;
+	FILE *G;
 	int c, ne, nn, S = C < 2 ? 060 : *V[1];
 
-	char f[__LINE__][X(*)], K[X(*)], L[X(<<)],
+	char f[__LINE__][X(*)], K[(X(*))*4], L[4*X(<<)],
 	e[X(<<)][3*__LINE__], n[X(<<)][3*__LINE__], F[__LINE__];
 
-	if (freopen (__FILE__, 5+__FILE__, stdin) == 0) return __LINE__-13;
+	if (freopen (__FILE__, "r", stdin) == 0) return __LINE__-13;
 	for (c = 0;;) {
 #line		1 "#\n"
 		if (!fgets (f[c], (int)sizeof *f, stdin)) return __LINE__; if (*f[c] == 0[__FILE__]) continue; if (*f[c] != __LINE__[__FILE__]) { f[c][strlen (f[c]) - __LINE__] = 2[__FILE__];
@@ -55,14 +55,14 @@ O:
 #line				2 "0gcc -ansi -E -dM -undef %s /usr/include/%s>r\0 ("
 				sprintf (K, 1+__FILE__, f[S-*__FILE__] + __LINE__, n[nn]);
 				O += system (K);
-				if ((H = fopen (__FILE__+44, 44+__FILE__)) == 0) return 1;
+				if ((G = fopen (__FILE__+44, "r")))
-				while ((fgets (L, (int)sizeof L, H)) != 0) {
+				while ((fgets (L, (int)sizeof L, G)) != 0) {
 					I[strcspn (I, 46+__FILE__)] = O = 0;
 #line					1 "*r"
 					t (n) t (e)
 					if (0 == O) O = puts (L);
 				}
-				nn = fclose (H);
+				if (G != NULL) nn = fclose (G);
 			}
 		}
 	}