[mLib] / crc-mktab.c

/* -*-c-*-
 *
 * $Id: crc-mktab.c,v 1.2 2000/10/08 11:07:21 mdw Exp $
 *
 * Build CRC tables
 *
 * (c) 2000 Straylight/Edgeware
 */

/*----- Licensing notice --------------------------------------------------* 
 *
 * This file is part of the mLib utilities library.
 *
 * mLib is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 * 
 * mLib is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Library General Public License for more details.
 * 
 * You should have received a copy of the GNU Library General Public
 * License along with mLib; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA 02111-1307, USA.
 */

/*----- Revision history --------------------------------------------------* 
 *
 * $Log: crc-mktab.c,v $
 * Revision 1.2  2000/10/08 11:07:21  mdw
 * With no arguments, give an error rather than spewing a big table at the
 * user.
 *
 * Revision 1.1  2000/07/21 19:01:33  mdw
 * Generate the CRC table rather than hardcoding it.
 *
 */

/*----- Header files ------------------------------------------------------*/

#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "mdwopt.h"
#include "quis.h"
#include "report.h"

/*----- Static variables --------------------------------------------------*/

static unsigned long poly = 0;
static const char *guard = 0;
static unsigned bits = 0;
static unsigned chunk = 8;
static const char *file = 0;
static unsigned flags = 0;
static const char *sym = 0;
static const char *type = 0;
static const char *inc = 0;
static FILE *fp;

enum {
  f_bogus = 1,
  f_ctab = 2,
  f_reverse = 4
};

#define BSCOL 72

/*----- Main code ---------------------------------------------------------*/

static unsigned long getint(const char *p, unsigned long max,
			    const char *what)
{
  char *pp;
  unsigned long x = strtoul(p, &pp, 0);
  if (*pp || (max && x > max))
    die(EXIT_FAILURE, "bad %s `%s'", what, p);
  return (x);
}

static void version(FILE *fp)
{
  pquis(fp, "$, mLib version " VERSION "\n");
}

static void usage(FILE *fp)
{
  pquis(fp, "Usage: $ [-cr] [-g guard] [-o file] [-b bits] [-p poly]\n");
}

static void help(FILE *fp)
{
  version(fp);
  putc('\n', stdout);
  usage(fp);
  fputs("\n\
Emits a table containing precomuted values for CRC algorithms.  A number\n\
of options are provided:\n\
\n\
-h, --help		Show this help text.\n\
-v, --version		Show the program's version number.\n\
-u, --usage		Show a terse usage message.\n\
\n\
-c, --c-source		Emit a C source file rather than a header.\n\
-b, --bits=BITS		Emit a table for a BITS bits-wide CRC.\n\
-B, --bit-chunk=BITS	Emit a table to process BITS bits at a time.\n\
-p, --polynomial=POLY	Use the POLY as the dividing polynomial.\n\
-r, --reverse		Create a `reversed' CRC table.\n\
-g, --guard=GUARD	Use GUARD as a multiple-inclusion guard constant.\n\
-s, --symbol=SYM	Name the generated table SYM\n\
-t, --type=TYPE		Give the table entries type TYPE in C source.\n\
-o, --output=FILE	Write the output to FILE.\n\
", stdout);
}

unsigned long reflect(unsigned long x, unsigned b)
{
  unsigned long y = 0;
  unsigned long xm, ym;
  unsigned i;
  if (!(flags & f_reverse))
    return (x);
  xm = 1;
  ym = 1 << (b - 1);
  for (i = 0; i < b; i++) {
    if (x & xm)
      y |= ym;
    xm <<= 1;
    ym >>= 1;
  }
  return (y);
}

int main(int argc, char *argv[])
{
  unsigned n, t, nw;
  unsigned max, i;
  unsigned long mask;

  ego(argv[0]);

  for (;;) {
    static struct option opts[] = {
      { "help",		0,		0,	'h' },
      { "version",	0,		0,	'v' },
      { "usage",	0,		0,	'u' },

      { "output",	OPTF_ARGREQ,	0,	'o' },
      { "c-source",	0,		0,	'c' },
      { "symbol",	OPTF_ARGREQ,	0,	's' },
      { "type",		OPTF_ARGREQ,	0,	't' },
      { "include",	OPTF_ARGREQ,	0,	'i' },
      { "guard",	OPTF_ARGREQ,	0,	'g' },

      { "bits",		OPTF_ARGREQ,	0,	'b' },
      { "bit-chunk",	OPTF_ARGREQ,	0,	'B' },
      { "polynomial",	OPTF_ARGREQ,	0,	'p' },
      { "reverse",	0,		0,	'r' },

      { 0,		0,		0,	0 }
    };
    int i = mdwopt(argc, argv, "hvu o:cs:t:i:g: b:B:p:r", opts, 0, 0, 0);

    if (i < 0)
      break;
    switch (i) {
      case 'h':
	help(stdout);
	exit(0);
      case 'v':
	version(stdout);
	exit(0);
      case 'u':
	usage(stdout);
	exit(0);

      case 'o':
	file = optarg;
	break;
      case 'c':
	flags |= f_ctab;
	break;
      case 's':
	sym = optarg;
	break;
      case 't':
	type = optarg;
	break;
      case 'i':
	inc = optarg;
	break;
      case 'g':
	guard = optarg;
	break;

      case 'b':
	bits = getint(optarg, 32, "CRC width");
	break;
      case 'B':
	chunk = getint(optarg, 32, "chunk size");
	break;
      case 'p':
	poly = getint(optarg, 0xffffffff, "CRC poly");
	break;
      case 'r':
	flags |= f_reverse;
	break;

      default:
	flags |= f_bogus;
	break;
    }
  }
  if ((flags & f_bogus) || optind != argc) {
    usage(stderr);
    exit(EXIT_FAILURE);
  }

  /* --- Sort out the various parameters --- */

  if (!poly) {
    switch (bits) {
      case 16:
	if (flags & f_reverse)
	  poly = 0x8408;
	else
	  poly = 0x1021;
	break;
      case 32:
	poly = 0x04c11db7;
	flags |= f_reverse;
	bits = 32;
	break;
      case 0:
	die(EXIT_FAILURE, "no polynomial or bit width set");
	break;
      default:
	die(EXIT_FAILURE, "no standard polynomials for %u bits", bits);
	break;
    }
  }

  if (!bits) {
    unsigned long x = poly;
    while (x > 1) {
      x >>= 8;
      bits += 8;
    }
  }
  nw = bits/4;

  if ((flags & f_ctab) && !type)
    type = bits > 16 ? "unsigned long" : "unsigned short";

  /* --- Start output --- */

  if (!file)
    fp = stdout;
  else {
    if (!(flags & f_ctab) && !guard) {
      char *p;
      const char *q;
      if ((p = malloc(strlen(file) + 1)) == 0)
	die(EXIT_FAILURE, "not enough memory");
      guard = p;
      for (q = file; *q; p++, q++) {
	if (isalnum((unsigned char)*q))
	  *p = *q;
	else
	  *p = '_';
      }
      *p++ = 0;
    }
    if ((fp = fopen(file, "w")) == 0)
      die(EXIT_FAILURE, "couldn't write `%s': %s", file, strerror(errno));
  }

  if (!sym)
    sym = (flags & f_ctab) ? "crctab" : "CRC_TAB";

  /* --- Dump out the first chunk of the file --- */

  fprintf(fp, "\
/* -*-c-*-\n\
 *\n\
 * CRC table (poly = %0*lx%s) [generated]\n\
 */\n\
\n",
	  nw, poly, flags & f_reverse ? "; reversed" : "");

  if (flags & f_ctab) {
    if (inc)
      fprintf(fp, "#include \"%s\"\n\n", inc);
    fprintf(fp, "%s %s[] = {\n", type, sym);
  } else {
    int n;
    if (guard)
      fprintf(fp, "#ifndef %s\n#define %s\n\n", guard, guard);
    n = fprintf(fp, "#define %s {", sym);
    while (n < BSCOL) {
      fputc('\t', fp);
      n = (n + 8) & ~7;
    }
    fputc('\n', fp);
  }

  /* --- Sort out the line width --- */

  n = 1;
  while (2 + n * (nw + 4) < BSCOL)
    n <<= 1;
  n >>= 1;
  t = 0;
  while (((1 + n * (nw + 4)) & ~7) + 8 * t < BSCOL)
    t++;

  /* --- Start grinding --- */

  max = 1 << chunk;
  mask = 0xffffffff >> (32 - bits);
  fputc(' ', fp);
  for (i = 0; i < max; i++) {
    unsigned long x;
    unsigned j;

    x = reflect(i, chunk) << (bits - chunk);
    for (j = 0; j < chunk; j++)
      x = ((x << 1) ^ (x & (1 << (bits - 1)) ? poly : 0)) & mask;
    x = reflect(x, bits);

    fprintf(fp, " 0x%0*lx", nw, x);
    if (i == max - 1) {
      if (!(flags & f_ctab) && ((2 + n * (nw + 4)) & ~7) + 8 * t < BSCOL)
	fputc('\t', fp);
    } else
      fputc(',', fp);
    if (i + 1 == max || (i + 1)%n == 0) {
      if (!(flags & f_ctab)) {
	for (j = 0; j < t; j++)
	  fputc('\t', fp);
	fputc('\\', fp);
      }
      fputc('\n', fp);
      if (i + 1 != max)
	fputc(' ', fp);
    }
  }

  /* --- Done --- */

  fputs(flags & f_ctab ? "};\n" : "}\n", fp);
  if (!(flags & f_ctab) && guard)
    fputs("\n#endif\n", fp);

  return (0);
}

/*----- That's all, folks -------------------------------------------------*/
Commit	Line	Data
b7580524	1	/* --c--
b7580524	2	*
000ba0de	3	* $Id: crc-mktab.c,v 1.2 2000/10/08 11:07:21 mdw Exp $
b7580524	4	*
	5	* Build CRC tables
	6	*
	7	* (c) 2000 Straylight/Edgeware
	8	*/
	9
	10	/----- Licensing notice --------------------------------------------------
	11	*
	12	* This file is part of the mLib utilities library.
	13	*
	14	* mLib is free software; you can redistribute it and/or modify
	15	* it under the terms of the GNU Library General Public License as
	16	* published by the Free Software Foundation; either version 2 of the
	17	* License, or (at your option) any later version.
	18	*
	19	* mLib is distributed in the hope that it will be useful,
	20	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	21	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	22	* GNU Library General Public License for more details.
	23	*
	24	* You should have received a copy of the GNU Library General Public
	25	* License along with mLib; if not, write to the Free
	26	* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
	27	* MA 02111-1307, USA.
	28	*/
	29
	30	/----- Revision history --------------------------------------------------
	31	*
	32	* $Log: crc-mktab.c,v $
000ba0de	33	* Revision 1.2 2000/10/08 11:07:21 mdw
	34	* With no arguments, give an error rather than spewing a big table at the
	35	* user.
	36	*
b7580524	37	* Revision 1.1 2000/07/21 19:01:33 mdw
	38	* Generate the CRC table rather than hardcoding it.
	39	*
	40	*/
	41
	42	/----- Header files ------------------------------------------------------/
	43
	44	#include <ctype.h>
	45	#include <errno.h>
	46	#include <limits.h>
	47	#include <stdarg.h>
	48	#include <stdio.h>
	49	#include <stdlib.h>
	50	#include <string.h>
	51
	52	#include "mdwopt.h"
	53	#include "quis.h"
	54	#include "report.h"
	55
	56	/----- Static variables --------------------------------------------------/
	57
	58	static unsigned long poly = 0;
	59	static const char *guard = 0;
	60	static unsigned bits = 0;
	61	static unsigned chunk = 8;
	62	static const char *file = 0;
	63	static unsigned flags = 0;
	64	static const char *sym = 0;
	65	static const char *type = 0;
	66	static const char *inc = 0;
	67	static FILE *fp;
	68
	69	enum {
	70	f_bogus = 1,
	71	f_ctab = 2,
	72	f_reverse = 4
	73	};
	74
	75	#define BSCOL 72
	76
	77	/----- Main code ---------------------------------------------------------/
	78
	79	static unsigned long getint(const char *p, unsigned long max,
	80	const char *what)
	81	{
	82	char *pp;
	83	unsigned long x = strtoul(p, &pp, 0);
	84	if (*pp \|\| (max && x > max))
	85	die(EXIT_FAILURE, "bad %s `%s'", what, p);
	86	return (x);
	87	}
	88
	89	static void version(FILE *fp)
	90	{
	91	pquis(fp, "$, mLib version " VERSION "\n");
	92	}
	93
	94	static void usage(FILE *fp)
	95	{
	96	pquis(fp, "Usage: $ [-cr] [-g guard] [-o file] [-b bits] [-p poly]\n");
	97	}
	98
	99	static void help(FILE *fp)
	100	{
101	version(fp);
102	putc('\n', stdout);
103	usage(fp);
104	fputs("\n\
105	Emits a table containing precomuted values for CRC algorithms. A number\n\
106	of options are provided:\n\
107	\n\
108	-h, --help Show this help text.\n\
109	-v, --version Show the program's version number.\n\
110	-u, --usage Show a terse usage message.\n\
111	\n\
112	-c, --c-source Emit a C source file rather than a header.\n\
113	-b, --bits=BITS Emit a table for a BITS bits-wide CRC.\n\
114	-B, --bit-chunk=BITS Emit a table to process BITS bits at a time.\n\
115	-p, --polynomial=POLY Use the POLY as the dividing polynomial.\n\
116	-r, --reverse Create a `reversed' CRC table.\n\
117	-g, --guard=GUARD Use GUARD as a multiple-inclusion guard constant.\n\
118	-s, --symbol=SYM Name the generated table SYM\n\
119	-t, --type=TYPE Give the table entries type TYPE in C source.\n\
120	-o, --output=FILE Write the output to FILE.\n\
121	", stdout);
122	}
123
124	unsigned long reflect(unsigned long x, unsigned b)
125	{
126	unsigned long y = 0;
127	unsigned long xm, ym;
128	unsigned i;
129	if (!(flags & f_reverse))
130	return (x);
131	xm = 1;
132	ym = 1 << (b - 1);
133	for (i = 0; i < b; i++) {
134	if (x & xm)
135	y \|= ym;
136	xm <<= 1;
137	ym >>= 1;
138	}
139	return (y);
140	}
141
142	int main(int argc, char *argv[])
143	{
144	unsigned n, t, nw;
145	unsigned max, i;
146	unsigned long mask;
147
148	ego(argv[0]);
149
150	for (;;) {
151	static struct option opts[] = {
152	{ "help", 0, 0, 'h' },
153	{ "version", 0, 0, 'v' },
154	{ "usage", 0, 0, 'u' },
155
156	{ "output", OPTF_ARGREQ, 0, 'o' },
157	{ "c-source", 0, 0, 'c' },
158	{ "symbol", OPTF_ARGREQ, 0, 's' },
159	{ "type", OPTF_ARGREQ, 0, 't' },
160	{ "include", OPTF_ARGREQ, 0, 'i' },
161	{ "guard", OPTF_ARGREQ, 0, 'g' },
162
163	{ "bits", OPTF_ARGREQ, 0, 'b' },
164	{ "bit-chunk", OPTF_ARGREQ, 0, 'B' },
165	{ "polynomial", OPTF_ARGREQ, 0, 'p' },
166	{ "reverse", 0, 0, 'r' },
167
168	{ 0, 0, 0, 0 }
169	};
170	int i = mdwopt(argc, argv, "hvu o:cs:t:i:g: b:B:p:r", opts, 0, 0, 0);
171
172	if (i < 0)
173	break;
174	switch (i) {
175	case 'h':
176	help(stdout);
177	exit(0);
178	case 'v':
179	version(stdout);
180	exit(0);
181	case 'u':
182	usage(stdout);
183	exit(0);
184
185	case 'o':
186	file = optarg;
187	break;
188	case 'c':
189	flags \|= f_ctab;
190	break;
191	case 's':
192	sym = optarg;
193	break;
194	case 't':
195	type = optarg;
196	break;
197	case 'i':
198	inc = optarg;
199	break;
200	case 'g':
201	guard = optarg;
202	break;
203
204	case 'b':
205	bits = getint(optarg, 32, "CRC width");
206	break;
207	case 'B':
208	chunk = getint(optarg, 32, "chunk size");
209	break;
210	case 'p':
211	poly = getint(optarg, 0xffffffff, "CRC poly");
212	break;
213	case 'r':
214	flags \|= f_reverse;
215	break;
216
217	default:
218	flags \|= f_bogus;
219	break;
220	}
221	}
222	if ((flags & f_bogus) \|\| optind != argc) {
223	usage(stderr);
224	exit(EXIT_FAILURE);
225	}
226
227	/* --- Sort out the various parameters --- */
228
229	if (!poly) {
230	switch (bits) {
231	case 16:
232	if (flags & f_reverse)
233	poly = 0x8408;
234	else
235	poly = 0x1021;
236	break;
237	case 32:
b7580524	238	poly = 0x04c11db7;
	239	flags \|= f_reverse;
	240	bits = 32;
	241	break;
000ba0de	242	case 0:
	243	die(EXIT_FAILURE, "no polynomial or bit width set");
	244	break;
b7580524	245	default:
	246	die(EXIT_FAILURE, "no standard polynomials for %u bits", bits);
	247	break;
	248	}
	249	}
	250
	251	if (!bits) {
	252	unsigned long x = poly;
	253	while (x > 1) {
	254	x >>= 8;
	255	bits += 8;
	256	}
	257	}
	258	nw = bits/4;
	259
	260	if ((flags & f_ctab) && !type)
	261	type = bits > 16 ? "unsigned long" : "unsigned short";
	262
	263	/* --- Start output --- */
	264
	265	if (!file)
	266	fp = stdout;
	267	else {
	268	if (!(flags & f_ctab) && !guard) {
	269	char *p;
	270	const char *q;
	271	if ((p = malloc(strlen(file) + 1)) == 0)
	272	die(EXIT_FAILURE, "not enough memory");
	273	guard = p;
	274	for (q = file; *q; p++, q++) {
	275	if (isalnum((unsigned char)*q))
	276	p = q;
	277	else
	278	*p = '_';
	279	}
	280	*p++ = 0;
	281	}
	282	if ((fp = fopen(file, "w")) == 0)
	283	die(EXIT_FAILURE, "couldn't write `%s': %s", file, strerror(errno));
	284	}
	285
	286	if (!sym)
	287	sym = (flags & f_ctab) ? "crctab" : "CRC_TAB";
	288
	289	/* --- Dump out the first chunk of the file --- */
	290
	291	fprintf(fp, "\
	292	/* --c--\n\
	293	*\n\
	294	* CRC table (poly = %0*lx%s) [generated]\n\
	295	*/\n\
	296	\n",
	297	nw, poly, flags & f_reverse ? "; reversed" : "");
	298
	299	if (flags & f_ctab) {
	300	if (inc)
	301	fprintf(fp, "#include \"%s\"\n\n", inc);
	302	fprintf(fp, "%s %s[] = {\n", type, sym);
	303	} else {
	304	int n;
	305	if (guard)
	306	fprintf(fp, "#ifndef %s\n#define %s\n\n", guard, guard);
	307	n = fprintf(fp, "#define %s {", sym);
	308	while (n < BSCOL) {
309	fputc('\t', fp);
310	n = (n + 8) & ~7;
311	}
312	fputc('\n', fp);
313	}
314
315	/* --- Sort out the line width --- */
316
317	n = 1;
318	while (2 + n * (nw + 4) < BSCOL)
319	n <<= 1;
320	n >>= 1;
321	t = 0;
322	while (((1 + n * (nw + 4)) & ~7) + 8 * t < BSCOL)
323	t++;
324
325	/* --- Start grinding --- */
326
327	max = 1 << chunk;
328	mask = 0xffffffff >> (32 - bits);
329	fputc(' ', fp);
330	for (i = 0; i < max; i++) {
331	unsigned long x;
332	unsigned j;
333
334	x = reflect(i, chunk) << (bits - chunk);
335	for (j = 0; j < chunk; j++)
336	x = ((x << 1) ^ (x & (1 << (bits - 1)) ? poly : 0)) & mask;
337	x = reflect(x, bits);
338
339	fprintf(fp, " 0x%0*lx", nw, x);
340	if (i == max - 1) {
341	if (!(flags & f_ctab) && ((2 + n * (nw + 4)) & ~7) + 8 * t < BSCOL)
342	fputc('\t', fp);
343	} else
344	fputc(',', fp);
345	if (i + 1 == max \|\| (i + 1)%n == 0) {
346	if (!(flags & f_ctab)) {
347	for (j = 0; j < t; j++)
348	fputc('\t', fp);
349	fputc('\\', fp);
350	}
351	fputc('\n', fp);
352	if (i + 1 != max)
353	fputc(' ', fp);
354	}
355	}
356
357	/* --- Done --- */
358
359	fputs(flags & f_ctab ? "};\n" : "}\n", fp);
360	if (!(flags & f_ctab) && guard)
361	fputs("\n#endif\n", fp);
362
363	return (0);
364	}
365
366	/----- That's all, folks -------------------------------------------------/