[mLib] / crc-mktab.c

/* -*-c-*-
 *
 * $Id: crc-mktab.c,v 1.4 2001/03/10 10:59:21 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 1.4  2001/03/10 10:59:21  mdw
 * Fix generating tables where the chunk size is longer than the
 * polynomial.  Also fix output formatting when there aren't enough entries
 * to fill a line.
 *
 * Revision 1.3  2001/01/20 12:06:01  mdw
 * Define flags with macros, to ensure unsignedness.
 *
 * 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;

#define f_bogus 1u
#define f_ctab 2u
#define f_reverse 4u

#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 + 3)/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 = toupper((unsigned char)*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;
  max = 1 << chunk;
  if (n > max)
    n = max;
  t = 0;
  while (((1 + n * (nw + 4)) & ~7) + 8 * t < BSCOL)
    t++;

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

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

    x = reflect(i, chunk);
    y = 0;
    nn = chunk;
    while (nn) {
      ni = bits;
      if (ni > nn)
	ni = nn;
      z = (x >> (nn - ni)) & (0xffffffff >> (32 - ni));
      y ^= z << (bits - ni);
      for (j = 0; j < ni; j++)
	y = ((y << 1) ^ (y & (1 << (bits - 1)) ? poly : 0)) & mask;
      nn -= ni;
    }
    x = reflect(y, 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	*
0521f473	3	* $Id: crc-mktab.c,v 1.4 2001/03/10 10:59:21 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 $
0521f473	33	* Revision 1.4 2001/03/10 10:59:21 mdw
	34	* Fix generating tables where the chunk size is longer than the
	35	* polynomial. Also fix output formatting when there aren't enough entries
	36	* to fill a line.
	37	*
393cf1d9	38	* Revision 1.3 2001/01/20 12:06:01 mdw
	39	* Define flags with macros, to ensure unsignedness.
	40	*
000ba0de	41	* Revision 1.2 2000/10/08 11:07:21 mdw
	42	* With no arguments, give an error rather than spewing a big table at the
	43	* user.
	44	*
b7580524	45	* Revision 1.1 2000/07/21 19:01:33 mdw
	46	* Generate the CRC table rather than hardcoding it.
	47	*
	48	*/
	49
	50	/----- Header files ------------------------------------------------------/
	51
	52	#include <ctype.h>
	53	#include <errno.h>
	54	#include <limits.h>
	55	#include <stdarg.h>
	56	#include <stdio.h>
	57	#include <stdlib.h>
	58	#include <string.h>
	59
	60	#include "mdwopt.h"
	61	#include "quis.h"
	62	#include "report.h"
	63
	64	/----- Static variables --------------------------------------------------/
	65
	66	static unsigned long poly = 0;
	67	static const char *guard = 0;
	68	static unsigned bits = 0;
	69	static unsigned chunk = 8;
	70	static const char *file = 0;
	71	static unsigned flags = 0;
	72	static const char *sym = 0;
	73	static const char *type = 0;
	74	static const char *inc = 0;
	75	static FILE *fp;
	76
393cf1d9	77	#define f_bogus 1u
	78	#define f_ctab 2u
	79	#define f_reverse 4u
b7580524	80
	81	#define BSCOL 72
	82
	83	/----- Main code ---------------------------------------------------------/
	84
	85	static unsigned long getint(const char *p, unsigned long max,
	86	const char *what)
	87	{
	88	char *pp;
	89	unsigned long x = strtoul(p, &pp, 0);
	90	if (*pp \|\| (max && x > max))
	91	die(EXIT_FAILURE, "bad %s `%s'", what, p);
	92	return (x);
	93	}
	94
	95	static void version(FILE *fp)
	96	{
	97	pquis(fp, "$, mLib version " VERSION "\n");
	98	}
	99
	100	static void usage(FILE *fp)
	101	{
	102	pquis(fp, "Usage: $ [-cr] [-g guard] [-o file] [-b bits] [-p poly]\n");
	103	}
	104
	105	static void help(FILE *fp)
	106	{
	107	version(fp);
	108	putc('\n', stdout);
	109	usage(fp);
	110	fputs("\n\
	111	Emits a table containing precomuted values for CRC algorithms. A number\n\
	112	of options are provided:\n\
	113	\n\
	114	-h, --help Show this help text.\n\
	115	-v, --version Show the program's version number.\n\
	116	-u, --usage Show a terse usage message.\n\
	117	\n\
	118	-c, --c-source Emit a C source file rather than a header.\n\
	119	-b, --bits=BITS Emit a table for a BITS bits-wide CRC.\n\
	120	-B, --bit-chunk=BITS Emit a table to process BITS bits at a time.\n\
	121	-p, --polynomial=POLY Use the POLY as the dividing polynomial.\n\
	122	-r, --reverse Create a `reversed' CRC table.\n\
	123	-g, --guard=GUARD Use GUARD as a multiple-inclusion guard constant.\n\
	124	-s, --symbol=SYM Name the generated table SYM\n\
	125	-t, --type=TYPE Give the table entries type TYPE in C source.\n\
	126	-o, --output=FILE Write the output to FILE.\n\
	127	", stdout);
	128	}
	129
	130	unsigned long reflect(unsigned long x, unsigned b)
	131	{
	132	unsigned long y = 0;
	133	unsigned long xm, ym;
	134	unsigned i;
	135	if (!(flags & f_reverse))
	136	return (x);
	137	xm = 1;
	138	ym = 1 << (b - 1);
	139	for (i = 0; i < b; i++) {
	140	if (x & xm)
	141	y \|= ym;
	142	xm <<= 1;
	143	ym >>= 1;
144	}
145	return (y);
146	}
147
148	int main(int argc, char *argv[])
149	{
150	unsigned n, t, nw;
151	unsigned max, i;
152	unsigned long mask;
153
154	ego(argv[0]);
155
156	for (;;) {
157	static struct option opts[] = {
158	{ "help", 0, 0, 'h' },
159	{ "version", 0, 0, 'v' },
160	{ "usage", 0, 0, 'u' },
161
162	{ "output", OPTF_ARGREQ, 0, 'o' },
163	{ "c-source", 0, 0, 'c' },
164	{ "symbol", OPTF_ARGREQ, 0, 's' },
165	{ "type", OPTF_ARGREQ, 0, 't' },
166	{ "include", OPTF_ARGREQ, 0, 'i' },
167	{ "guard", OPTF_ARGREQ, 0, 'g' },
168
169	{ "bits", OPTF_ARGREQ, 0, 'b' },
170	{ "bit-chunk", OPTF_ARGREQ, 0, 'B' },
171	{ "polynomial", OPTF_ARGREQ, 0, 'p' },
172	{ "reverse", 0, 0, 'r' },
173
174	{ 0, 0, 0, 0 }
175	};
176	int i = mdwopt(argc, argv, "hvu o:cs:t:i:g: b:B:p:r", opts, 0, 0, 0);
177
178	if (i < 0)
179	break;
180	switch (i) {
181	case 'h':
182	help(stdout);
183	exit(0);
184	case 'v':
185	version(stdout);
186	exit(0);
187	case 'u':
188	usage(stdout);
189	exit(0);
190
191	case 'o':
192	file = optarg;
193	break;
194	case 'c':
195	flags \|= f_ctab;
196	break;
197	case 's':
198	sym = optarg;
199	break;
200	case 't':
201	type = optarg;
202	break;
203	case 'i':
204	inc = optarg;
205	break;
206	case 'g':
207	guard = optarg;
208	break;
209
210	case 'b':
211	bits = getint(optarg, 32, "CRC width");
212	break;
213	case 'B':
214	chunk = getint(optarg, 32, "chunk size");
215	break;
216	case 'p':
217	poly = getint(optarg, 0xffffffff, "CRC poly");
218	break;
219	case 'r':
220	flags \|= f_reverse;
221	break;
222
223	default:
224	flags \|= f_bogus;
225	break;
226	}
227	}
228	if ((flags & f_bogus) \|\| optind != argc) {
229	usage(stderr);
230	exit(EXIT_FAILURE);
231	}
232
233	/* --- Sort out the various parameters --- */
234
235	if (!poly) {
236	switch (bits) {
237	case 16:
238	if (flags & f_reverse)
239	poly = 0x8408;
240	else
241	poly = 0x1021;
242	break;
243	case 32:
b7580524	244	poly = 0x04c11db7;
	245	flags \|= f_reverse;
	246	bits = 32;
	247	break;
000ba0de	248	case 0:
	249	die(EXIT_FAILURE, "no polynomial or bit width set");
	250	break;
b7580524	251	default:
	252	die(EXIT_FAILURE, "no standard polynomials for %u bits", bits);
	253	break;
	254	}
	255	}
	256
	257	if (!bits) {
	258	unsigned long x = poly;
	259	while (x > 1) {
	260	x >>= 8;
	261	bits += 8;
	262	}
	263	}
0521f473	264	nw = (bits + 3)/4;
b7580524	265
	266	if ((flags & f_ctab) && !type)
	267	type = bits > 16 ? "unsigned long" : "unsigned short";
	268
	269	/* --- Start output --- */
	270
	271	if (!file)
	272	fp = stdout;
	273	else {
	274	if (!(flags & f_ctab) && !guard) {
	275	char *p;
	276	const char *q;
	277	if ((p = malloc(strlen(file) + 1)) == 0)
	278	die(EXIT_FAILURE, "not enough memory");
	279	guard = p;
	280	for (q = file; *q; p++, q++) {
	281	if (isalnum((unsigned char)*q))
0521f473	282	p = toupper((unsigned char)q);
b7580524	283	else
	284	*p = '_';
	285	}
	286	*p++ = 0;
	287	}
	288	if ((fp = fopen(file, "w")) == 0)
	289	die(EXIT_FAILURE, "couldn't write `%s': %s", file, strerror(errno));
	290	}
	291
	292	if (!sym)
	293	sym = (flags & f_ctab) ? "crctab" : "CRC_TAB";
	294
	295	/* --- Dump out the first chunk of the file --- */
	296
	297	fprintf(fp, "\
	298	/* --c--\n\
	299	*\n\
	300	* CRC table (poly = %0*lx%s) [generated]\n\
	301	*/\n\
	302	\n",
	303	nw, poly, flags & f_reverse ? "; reversed" : "");
	304
	305	if (flags & f_ctab) {
	306	if (inc)
	307	fprintf(fp, "#include \"%s\"\n\n", inc);
	308	fprintf(fp, "%s %s[] = {\n", type, sym);
	309	} else {
	310	int n;
	311	if (guard)
	312	fprintf(fp, "#ifndef %s\n#define %s\n\n", guard, guard);
	313	n = fprintf(fp, "#define %s {", sym);
	314	while (n < BSCOL) {
	315	fputc('\t', fp);
	316	n = (n + 8) & ~7;
	317	}
	318	fputc('\n', fp);
	319	}
	320
	321	/* --- Sort out the line width --- */
	322
	323	n = 1;
	324	while (2 + n * (nw + 4) < BSCOL)
	325	n <<= 1;
	326	n >>= 1;
0521f473	327	max = 1 << chunk;
	328	if (n > max)
	329	n = max;
b7580524	330	t = 0;
	331	while (((1 + n * (nw + 4)) & ~7) + 8 * t < BSCOL)
	332	t++;
	333
	334	/* --- Start grinding --- */
	335
b7580524	336	mask = 0xffffffff >> (32 - bits);
	337	fputc(' ', fp);
	338	for (i = 0; i < max; i++) {
0521f473	339	unsigned long x, y, z;
b7580524	340	unsigned j;
0521f473	341	unsigned ni, nn;
	342
	343	x = reflect(i, chunk);
	344	y = 0;
	345	nn = chunk;
	346	while (nn) {
	347	ni = bits;
	348	if (ni > nn)
	349	ni = nn;
	350	z = (x >> (nn - ni)) & (0xffffffff >> (32 - ni));
	351	y ^= z << (bits - ni);
	352	for (j = 0; j < ni; j++)
	353	y = ((y << 1) ^ (y & (1 << (bits - 1)) ? poly : 0)) & mask;
	354	nn -= ni;
	355	}
	356	x = reflect(y, bits);
b7580524	357
	358	fprintf(fp, " 0x%0*lx", nw, x);
	359	if (i == max - 1) {
	360	if (!(flags & f_ctab) && ((2 + n * (nw + 4)) & ~7) + 8 * t < BSCOL)
	361	fputc('\t', fp);
	362	} else
	363	fputc(',', fp);
	364	if (i + 1 == max \|\| (i + 1)%n == 0) {
	365	if (!(flags & f_ctab)) {
	366	for (j = 0; j < t; j++)
	367	fputc('\t', fp);
	368	fputc('\\', fp);
	369	}
	370	fputc('\n', fp);
	371	if (i + 1 != max)
	372	fputc(' ', fp);
	373	}
	374	}
	375
	376	/* --- Done --- */
	377
	378	fputs(flags & f_ctab ? "};\n" : "}\n", fp);
	379	if (!(flags & f_ctab) && guard)
	380	fputs("\n#endif\n", fp);
	381
	382	return (0);
	383	}
	384
	385	/----- That's all, folks -------------------------------------------------/