+++ /dev/null
-/* -*-c-*-
- *
- * 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.
- */
-
-/*----- Header files ------------------------------------------------------*/
-
-#include "config.h"
-
-#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 -------------------------------------------------*/
~mdw / mLib / blobdiff