Fix type mismatch between get_crc_table() and crc_table.

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.
author: Mark Adler <madler@alumni.caltech.edu> 2012-04-29 16:18:12 -0700
committer: Mark Adler <madler@alumni.caltech.edu> 2012-04-29 16:18:12 -0700
commit: 6c9bd474aa08312ef2e2e9655a80e18db24a1680 (patch)
tree: 2539e04a1037206dc3853fbdbb33194bb2690aaa /crc32.c
parent: 1be117908397b0ce065c07c60fa2b4ae778ff112 (diff)
download: zlib-6c9bd474aa08312ef2e2e9655a80e18db24a1680.tar.gz
zlib-6c9bd474aa08312ef2e2e9655a80e18db24a1680.tar.bz2
zlib-6c9bd474aa08312ef2e2e9655a80e18db24a1680.zip
1 files changed, 22 insertions, 45 deletions
diff --git a/crc32.c b/crc32.c
index 5cfc8ff..979a719 100644
--- a/crc32.c
+++ b/crc32.c
@@ -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 z_crc_t c;
-    register const u4 FAR *buf4;
+    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 z_crc_t c;
-    register const u4 FAR *buf4;
+    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;
author	Mark Adler <madler@alumni.caltech.edu>	2012-04-29 16:18:12 -0700
committer	Mark Adler <madler@alumni.caltech.edu>	2012-04-29 16:18:12 -0700
commit	6c9bd474aa08312ef2e2e9655a80e18db24a1680 (patch)
tree	2539e04a1037206dc3853fbdbb33194bb2690aaa /crc32.c
parent	1be117908397b0ce065c07c60fa2b4ae778ff112 (diff)
download	zlib-6c9bd474aa08312ef2e2e9655a80e18db24a1680.tar.gz zlib-6c9bd474aa08312ef2e2e9655a80e18db24a1680.tar.bz2 zlib-6c9bd474aa08312ef2e2e9655a80e18db24a1680.zip