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Fix type mismatch between get_crc_table() and crc_table.

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crc_table is made using a four-byte integer (when that can be
determined).  However get_crc_table() returned a pointer to an
unsigned long, which could be eight bytes.  This fixes that by
creating a new z_crc_t type for the crc_table.

This type is also used for the BYFOUR crc calculations that depend
on a four-byte type.  The four-byte type can now be determined by
./configure, which also solves a problem where ./configure --solo
would never use BYFOUR.  No the Z_U4 #define indicates that four-
byte integer was found either by ./configure or by zconf.h.
This commit is contained in:
Mark Adler
2012-04-29 16:18:12 -07:00
parent 1be1179083
commit 6c9bd474aa
7 changed files with 120 additions and 47 deletions
Download Patch File Download Diff File Expand all files Collapse all files

67
crc32.c
View File

@@ -32,40 +32,17 @@
#define local static
/* Find a four-byte integer type for crc32_little() and crc32_big(). */
#ifdef Z_SOLO
# define NOBYFOUR
#endif
#ifndef NOBYFOUR
# ifdef STDC /* need ANSI C limits.h to determine sizes */
# include <limits.h>
# define BYFOUR
# if (UINT_MAX == 0xffffffffUL)
typedef unsigned int u4;
# else
# if (ULONG_MAX == 0xffffffffUL)
typedef unsigned long u4;
# else
# if (USHRT_MAX == 0xffffffffUL)
typedef unsigned short u4;
# else
# undef BYFOUR /* can't find a four-byte integer type! */
# endif
# endif
# endif
# endif /* STDC */
#endif /* !NOBYFOUR */
/* Definitions for doing the crc four data bytes at a time. */
#if !defined(NOBYFOUR) && defined(Z_U4)
# define BYFOUR
#endif
#ifdef BYFOUR
typedef u4 crc_table_t;
local unsigned long crc32_little OF((unsigned long,
const unsigned char FAR *, unsigned));
local unsigned long crc32_big OF((unsigned long,
const unsigned char FAR *, unsigned));
# define TBLS 8
#else
typedef unsigned long crc_table_t;
# define TBLS 1
#endif /* BYFOUR */
@@ -79,10 +56,10 @@ local uLong crc32_combine_ OF((uLong crc1, uLong crc2, z_off64_t len2));
#ifdef DYNAMIC_CRC_TABLE
local volatile int crc_table_empty = 1;
local crc_table_t FAR crc_table[TBLS][256];
local z_crc_t FAR crc_table[TBLS][256];
local void make_crc_table OF((void));
#ifdef MAKECRCH
local void write_table OF((FILE *, const crc_table_t FAR *));
local void write_table OF((FILE *, const z_crc_t FAR *));
#endif /* MAKECRCH */
/*
Generate tables for a byte-wise 32-bit CRC calculation on the polynomial:
@@ -112,9 +89,9 @@ local void make_crc_table OF((void));
*/
local void make_crc_table()
{
crc_table_t c;
z_crc_t c;
int n, k;
crc_table_t poly; /* polynomial exclusive-or pattern */
z_crc_t poly; /* polynomial exclusive-or pattern */
/* terms of polynomial defining this crc (except x^32): */
static volatile int first = 1; /* flag to limit concurrent making */
static const unsigned char p[] = {0,1,2,4,5,7,8,10,11,12,16,22,23,26};
@@ -128,11 +105,11 @@ local void make_crc_table()
/* make exclusive-or pattern from polynomial (0xedb88320UL) */
poly = 0;
for (n = 0; n < (int)(sizeof(p)/sizeof(unsigned char)); n++)
poly |= (crc_table_t)1 << (31 - p[n]);
poly |= (z_crc_t)1 << (31 - p[n]);
/* generate a crc for every 8-bit value */
for (n = 0; n < 256; n++) {
c = (crc_table_t)n;
c = (z_crc_t)n;
for (k = 0; k < 8; k++)
c = c & 1 ? poly ^ (c >> 1) : c >> 1;
crc_table[0][n] = c;
@@ -169,7 +146,7 @@ local void make_crc_table()
if (out == NULL) return;
fprintf(out, "/* crc32.h -- tables for rapid CRC calculation\n");
fprintf(out, " * Generated automatically by crc32.c\n */\n\n");
fprintf(out, "local const crc_table_t FAR ");
fprintf(out, "local const z_crc_t FAR ");
fprintf(out, "crc_table[TBLS][256] =\n{\n {\n");
write_table(out, crc_table[0]);
# ifdef BYFOUR
@@ -189,7 +166,7 @@ local void make_crc_table()
#ifdef MAKECRCH
local void write_table(out, table)
FILE *out;
const crc_table_t FAR *table;
const z_crc_t FAR *table;
{
int n;
@@ -210,13 +187,13 @@ local void write_table(out, table)
/* =========================================================================
* This function can be used by asm versions of crc32()
*/
const unsigned long FAR * ZEXPORT get_crc_table()
const z_crc_t FAR * ZEXPORT get_crc_table()
{
#ifdef DYNAMIC_CRC_TABLE
if (crc_table_empty)
make_crc_table();
#endif /* DYNAMIC_CRC_TABLE */
return (const unsigned long FAR *)crc_table;
return (const z_crc_t FAR *)crc_table;
}
/* ========================================================================= */
@@ -238,7 +215,7 @@ unsigned long ZEXPORT crc32(crc, buf, len)
#ifdef BYFOUR
if (sizeof(void *) == sizeof(ptrdiff_t)) {
u4 endian;
z_crc_t endian;
endian = 1;
if (*((unsigned char *)(&endian)))
@@ -272,17 +249,17 @@ local unsigned long crc32_little(crc, buf, len)
const unsigned char FAR *buf;
unsigned len;
{
register u4 c;
register const u4 FAR *buf4;
register z_crc_t c;
register const z_crc_t FAR *buf4;
c = (u4)crc;
c = (z_crc_t)crc;
c = ~c;
while (len && ((ptrdiff_t)buf & 3)) {
c = crc_table[0][(c ^ *buf++) & 0xff] ^ (c >> 8);
len--;
}
buf4 = (const u4 FAR *)(const void FAR *)buf;
buf4 = (const z_crc_t FAR *)(const void FAR *)buf;
while (len >= 32) {
DOLIT32;
len -= 32;
@@ -312,17 +289,17 @@ local unsigned long crc32_big(crc, buf, len)
const unsigned char FAR *buf;
unsigned len;
{
register u4 c;
register const u4 FAR *buf4;
register z_crc_t c;
register const z_crc_t FAR *buf4;
c = ZSWAP32((u4)crc);
c = ZSWAP32((z_crc_t)crc);
c = ~c;
while (len && ((ptrdiff_t)buf & 3)) {
c = crc_table[4][(c >> 24) ^ *buf++] ^ (c << 8);
len--;
}
buf4 = (const u4 FAR *)(const void FAR *)buf;
buf4 = (const z_crc_t FAR *)(const void FAR *)buf;
buf4--;
while (len >= 32) {
DOBIG32;