gcc/testsuite/c-c++-common/analyzer/coreutils-cksum-pr108664.c

   1 /* { dg-require-effective-target int32plus } */
   2 /* { dg-require-effective-target size24plus } */
   3
   4 /* Reduced from coreutils's cksum.c: cksum_slice8 */
   5
   6 typedef long unsigned int size_t;
   7 typedef unsigned int __uint32_t;
   8 typedef unsigned long int __uintmax_t;
   9 typedef struct _IO_FILE FILE;
  10
  11 #ifndef __cplusplus
  12   typedef _Bool bool;
  13 #endif
  14
  15 extern size_t
  16 fread_unlocked(void* __restrict __ptr,
  17                size_t __size,
  18                size_t __n,
  19                FILE* __restrict __stream);
  20 extern int
  21 feof_unlocked(FILE* __stream) __attribute__((__nothrow__, __leaf__));
  22 extern int
  23 ferror_unlocked(FILE* __stream) __attribute__((__nothrow__, __leaf__));
  24 static __inline __uint32_t
  25 __bswap_32(__uint32_t __bsx)
  26 {
  27
  28   return __builtin_bswap32(__bsx);
  29 }
  30 typedef __uint32_t uint32_t;
  31 typedef unsigned long int uint_fast32_t;
  32 typedef __uintmax_t uintmax_t;
  33 extern int*
  34 __errno_location(void) __attribute__((__nothrow__, __leaf__))
  35 __attribute__((__const__));
  36 extern uint_fast32_t const crctab[8][256];
  37
  38 static bool
  39 cksum_slice8(FILE* fp, uint_fast32_t* crc_out, uintmax_t* length_out)
  40 {
  41   uint32_t buf[(1 << 16) / sizeof(uint32_t)];
  42   uint_fast32_t crc = 0;
  43   uintmax_t length = 0;
  44   size_t bytes_read;
  45
  46   if (!fp || !crc_out || !length_out)
  47     return 0;
  48
  49   while ((bytes_read = fread_unlocked(buf, 1, (1 << 16), fp)) > 0) {
  50     uint32_t* datap;
  51
  52     if (length + bytes_read < length) {
  53
  54       (*__errno_location()) = 75;
  55       return 0;
  56     }
  57     length += bytes_read;
  58
  59     if (bytes_read == 0) {
  60       if (ferror_unlocked(fp))
  61         return 0;
  62     }
  63
  64     datap = (uint32_t*)buf;
  65     while (bytes_read >= 8) {
  66       uint32_t first = *datap++, second = *datap++; /* { dg-bogus "use of uninitialized value" "PR analyzer/108664" } */
  67       crc ^= __bswap_32(first);
  68       second = __bswap_32(second);
  69       crc =
  70         (crctab[7][(crc >> 24) & 0xFF] ^ crctab[6][(crc >> 16) & 0xFF] ^
  71          crctab[5][(crc >> 8) & 0xFF] ^ crctab[4][(crc)&0xFF] ^
  72          crctab[3][(second >> 24) & 0xFF] ^ crctab[2][(second >> 16) & 0xFF] ^
  73          crctab[1][(second >> 8) & 0xFF] ^ crctab[0][(second)&0xFF]);
  74       bytes_read -= 8;
  75     }
  76
  77     unsigned char* cp = (unsigned char*)datap;
  78     while (bytes_read--)
  79       crc = (crc << 8) ^ crctab[0][((crc >> 24) ^ *cp++) & 0xFF];
  80     if (feof_unlocked(fp))
  81       break;
  82   }
  83
  84   *crc_out = crc;
  85   *length_out = length;
  86
  87   return 1;
  88 }