[mLib] / crc-mktab.c

/* -*-c-*-
 *
 * $Id: crc-mktab.c,v 1.5 2003/12/15 20:53:47 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 1.5  2003/12/15 20:53:47  mdw
 * Add global unihash table; use universal hashing instead of CRC.
 *
 * 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] [-o FILE] [-g GUARD] [-s SYM] [-i HEADER]\n\
 	[-t TYPE] [-b BITS] [-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\
-i, --include=HEADER	Include HEADER at top of C source file.\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	*
6f444bda	3	* $Id: crc-mktab.c,v 1.5 2003/12/15 20:53:47 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 $
6f444bda	33	* Revision 1.5 2003/12/15 20:53:47 mdw
	34	* Add global unihash table; use universal hashing instead of CRC.
	35	*
0521f473	36	* Revision 1.4 2001/03/10 10:59:21 mdw
	37	* Fix generating tables where the chunk size is longer than the
	38	* polynomial. Also fix output formatting when there aren't enough entries
	39	* to fill a line.
	40	*
393cf1d9	41	* Revision 1.3 2001/01/20 12:06:01 mdw
	42	* Define flags with macros, to ensure unsignedness.
	43	*
000ba0de	44	* Revision 1.2 2000/10/08 11:07:21 mdw
	45	* With no arguments, give an error rather than spewing a big table at the
	46	* user.
	47	*
b7580524	48	* Revision 1.1 2000/07/21 19:01:33 mdw
	49	* Generate the CRC table rather than hardcoding it.
	50	*
	51	*/
	52
	53	/----- Header files ------------------------------------------------------/
	54
	55	#include <ctype.h>
	56	#include <errno.h>
	57	#include <limits.h>
	58	#include <stdarg.h>
	59	#include <stdio.h>
	60	#include <stdlib.h>
	61	#include <string.h>
	62
	63	#include "mdwopt.h"
	64	#include "quis.h"
	65	#include "report.h"
	66
	67	/----- Static variables --------------------------------------------------/
	68
	69	static unsigned long poly = 0;
	70	static const char *guard = 0;
	71	static unsigned bits = 0;
	72	static unsigned chunk = 8;
	73	static const char *file = 0;
	74	static unsigned flags = 0;
	75	static const char *sym = 0;
	76	static const char *type = 0;
	77	static const char *inc = 0;
	78	static FILE *fp;
	79
393cf1d9	80	#define f_bogus 1u
	81	#define f_ctab 2u
	82	#define f_reverse 4u
b7580524	83
	84	#define BSCOL 72
	85
	86	/----- Main code ---------------------------------------------------------/
	87
	88	static unsigned long getint(const char *p, unsigned long max,
	89	const char *what)
	90	{
	91	char *pp;
	92	unsigned long x = strtoul(p, &pp, 0);
	93	if (*pp \|\| (max && x > max))
	94	die(EXIT_FAILURE, "bad %s `%s'", what, p);
	95	return (x);
	96	}
	97
	98	static void version(FILE *fp)
	99	{
	100	pquis(fp, "$, mLib version " VERSION "\n");
	101	}
	102
	103	static void usage(FILE *fp)
	104	{
6f444bda	105	pquis(fp, "Usage: $ [-cr] [-o FILE] [-g GUARD] [-s SYM] [-i HEADER]\n\
6f444bda	106	[-t TYPE] [-b BITS] [-B BITS] [-p POLY]\n");
b7580524	107	}
	108
	109	static void help(FILE *fp)
	110	{
	111	version(fp);
	112	putc('\n', stdout);
	113	usage(fp);
	114	fputs("\n\
	115	Emits a table containing precomuted values for CRC algorithms. A number\n\
	116	of options are provided:\n\
	117	\n\
	118	-h, --help Show this help text.\n\
	119	-v, --version Show the program's version number.\n\
	120	-u, --usage Show a terse usage message.\n\
	121	\n\
	122	-c, --c-source Emit a C source file rather than a header.\n\
	123	-b, --bits=BITS Emit a table for a BITS bits-wide CRC.\n\
	124	-B, --bit-chunk=BITS Emit a table to process BITS bits at a time.\n\
	125	-p, --polynomial=POLY Use the POLY as the dividing polynomial.\n\
	126	-r, --reverse Create a `reversed' CRC table.\n\
	127	-g, --guard=GUARD Use GUARD as a multiple-inclusion guard constant.\n\
6f444bda	128	-i, --include=HEADER Include HEADER at top of C source file.\n\
6f444bda	129	-s, --symbol=SYM Name the generated table SYM.\n\
b7580524	130	-t, --type=TYPE Give the table entries type TYPE in C source.\n\
	131	-o, --output=FILE Write the output to FILE.\n\
	132	", stdout);
	133	}
	134
	135	unsigned long reflect(unsigned long x, unsigned b)
	136	{
	137	unsigned long y = 0;
	138	unsigned long xm, ym;
	139	unsigned i;
	140	if (!(flags & f_reverse))
	141	return (x);
	142	xm = 1;
	143	ym = 1 << (b - 1);
	144	for (i = 0; i < b; i++) {
	145	if (x & xm)
	146	y \|= ym;
	147	xm <<= 1;
	148	ym >>= 1;
	149	}
	150	return (y);
	151	}
	152
	153	int main(int argc, char *argv[])
	154	{
	155	unsigned n, t, nw;
	156	unsigned max, i;
	157	unsigned long mask;
	158
	159	ego(argv[0]);
	160
	161	for (;;) {
	162	static struct option opts[] = {
	163	{ "help", 0, 0, 'h' },
	164	{ "version", 0, 0, 'v' },
	165	{ "usage", 0, 0, 'u' },
	166
	167	{ "output", OPTF_ARGREQ, 0, 'o' },
	168	{ "c-source", 0, 0, 'c' },
	169	{ "symbol", OPTF_ARGREQ, 0, 's' },
	170	{ "type", OPTF_ARGREQ, 0, 't' },
	171	{ "include", OPTF_ARGREQ, 0, 'i' },
	172	{ "guard", OPTF_ARGREQ, 0, 'g' },
	173
	174	{ "bits", OPTF_ARGREQ, 0, 'b' },
	175	{ "bit-chunk", OPTF_ARGREQ, 0, 'B' },
	176	{ "polynomial", OPTF_ARGREQ, 0, 'p' },
	177	{ "reverse", 0, 0, 'r' },
	178
	179	{ 0, 0, 0, 0 }
	180	};
	181	int i = mdwopt(argc, argv, "hvu o:cs:t:i:g: b:B:p:r", opts, 0, 0, 0);
	182
	183	if (i < 0)
	184	break;
	185	switch (i) {
	186	case 'h':
	187	help(stdout);
	188	exit(0);
	189	case 'v':
	190	version(stdout);
	191	exit(0);
	192	case 'u':
	193	usage(stdout);
194	exit(0);
195
196	case 'o':
197	file = optarg;
198	break;
199	case 'c':
200	flags \|= f_ctab;
201	break;
202	case 's':
203	sym = optarg;
204	break;
205	case 't':
206	type = optarg;
207	break;
208	case 'i':
209	inc = optarg;
210	break;
211	case 'g':
212	guard = optarg;
213	break;
214
215	case 'b':
216	bits = getint(optarg, 32, "CRC width");
217	break;
218	case 'B':
219	chunk = getint(optarg, 32, "chunk size");
220	break;
221	case 'p':
222	poly = getint(optarg, 0xffffffff, "CRC poly");
223	break;
224	case 'r':
225	flags \|= f_reverse;
226	break;
227
228	default:
229	flags \|= f_bogus;
230	break;
231	}
232	}
233	if ((flags & f_bogus) \|\| optind != argc) {
234	usage(stderr);
235	exit(EXIT_FAILURE);
236	}
237
238	/* --- Sort out the various parameters --- */
239
240	if (!poly) {
241	switch (bits) {
242	case 16:
243	if (flags & f_reverse)
244	poly = 0x8408;
245	else
246	poly = 0x1021;
247	break;
248	case 32:
b7580524	249	poly = 0x04c11db7;
	250	flags \|= f_reverse;
	251	bits = 32;
	252	break;
000ba0de	253	case 0:
	254	die(EXIT_FAILURE, "no polynomial or bit width set");
	255	break;
b7580524	256	default:
	257	die(EXIT_FAILURE, "no standard polynomials for %u bits", bits);
	258	break;
	259	}
	260	}
	261
	262	if (!bits) {
	263	unsigned long x = poly;
	264	while (x > 1) {
	265	x >>= 8;
	266	bits += 8;
	267	}
	268	}
0521f473	269	nw = (bits + 3)/4;
b7580524	270
	271	if ((flags & f_ctab) && !type)
	272	type = bits > 16 ? "unsigned long" : "unsigned short";
	273
	274	/* --- Start output --- */
	275
	276	if (!file)
	277	fp = stdout;
	278	else {
	279	if (!(flags & f_ctab) && !guard) {
	280	char *p;
	281	const char *q;
	282	if ((p = malloc(strlen(file) + 1)) == 0)
	283	die(EXIT_FAILURE, "not enough memory");
	284	guard = p;
	285	for (q = file; *q; p++, q++) {
	286	if (isalnum((unsigned char)*q))
0521f473	287	p = toupper((unsigned char)q);
b7580524	288	else
	289	*p = '_';
	290	}
	291	*p++ = 0;
	292	}
	293	if ((fp = fopen(file, "w")) == 0)
	294	die(EXIT_FAILURE, "couldn't write `%s': %s", file, strerror(errno));
	295	}
	296
	297	if (!sym)
	298	sym = (flags & f_ctab) ? "crctab" : "CRC_TAB";
	299
	300	/* --- Dump out the first chunk of the file --- */
	301
	302	fprintf(fp, "\
	303	/* --c--\n\
	304	*\n\
	305	* CRC table (poly = %0*lx%s) [generated]\n\
	306	*/\n\
	307	\n",
	308	nw, poly, flags & f_reverse ? "; reversed" : "");
	309
	310	if (flags & f_ctab) {
	311	if (inc)
	312	fprintf(fp, "#include \"%s\"\n\n", inc);
	313	fprintf(fp, "%s %s[] = {\n", type, sym);
	314	} else {
	315	int n;
	316	if (guard)
	317	fprintf(fp, "#ifndef %s\n#define %s\n\n", guard, guard);
	318	n = fprintf(fp, "#define %s {", sym);
	319	while (n < BSCOL) {
	320	fputc('\t', fp);
	321	n = (n + 8) & ~7;
	322	}
	323	fputc('\n', fp);
	324	}
	325
	326	/* --- Sort out the line width --- */
	327
	328	n = 1;
	329	while (2 + n * (nw + 4) < BSCOL)
	330	n <<= 1;
	331	n >>= 1;
0521f473	332	max = 1 << chunk;
	333	if (n > max)
	334	n = max;
b7580524	335	t = 0;
	336	while (((1 + n * (nw + 4)) & ~7) + 8 * t < BSCOL)
	337	t++;
	338
	339	/* --- Start grinding --- */
	340
b7580524	341	mask = 0xffffffff >> (32 - bits);
	342	fputc(' ', fp);
	343	for (i = 0; i < max; i++) {
0521f473	344	unsigned long x, y, z;
b7580524	345	unsigned j;
0521f473	346	unsigned ni, nn;
	347
	348	x = reflect(i, chunk);
	349	y = 0;
	350	nn = chunk;
	351	while (nn) {
	352	ni = bits;
	353	if (ni > nn)
	354	ni = nn;
	355	z = (x >> (nn - ni)) & (0xffffffff >> (32 - ni));
	356	y ^= z << (bits - ni);
	357	for (j = 0; j < ni; j++)
	358	y = ((y << 1) ^ (y & (1 << (bits - 1)) ? poly : 0)) & mask;
	359	nn -= ni;
	360	}
	361	x = reflect(y, bits);
b7580524	362
	363	fprintf(fp, " 0x%0*lx", nw, x);
	364	if (i == max - 1) {
	365	if (!(flags & f_ctab) && ((2 + n * (nw + 4)) & ~7) + 8 * t < BSCOL)
	366	fputc('\t', fp);
	367	} else
	368	fputc(',', fp);
	369	if (i + 1 == max \|\| (i + 1)%n == 0) {
	370	if (!(flags & f_ctab)) {
	371	for (j = 0; j < t; j++)
	372	fputc('\t', fp);
	373	fputc('\\', fp);
	374	}
	375	fputc('\n', fp);
	376	if (i + 1 != max)
	377	fputc(' ', fp);
	378	}
	379	}
	380
	381	/* --- Done --- */
	382
	383	fputs(flags & f_ctab ? "};\n" : "}\n", fp);
	384	if (!(flags & f_ctab) && guard)
	385	fputs("\n#endif\n", fp);
	386
	387	return (0);
	388	}
	389
	390	/----- That's all, folks -------------------------------------------------/