diff options
Diffstat (limited to 'sysdeps/posix/tempname.c')
| -rw-r--r-- | sysdeps/posix/tempname.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/sysdeps/posix/tempname.c b/sysdeps/posix/tempname.c index ae22f10df9..088da95758 100644 --- a/sysdeps/posix/tempname.c +++ b/sysdeps/posix/tempname.c @@ -107,6 +107,15 @@ # define __secure_getenv getenv #endif +/* Use the widest available unsigned type if uint64_t is not + available. The algorithm below extracts a number less than 62**6 + (approximately 2**35.725) from uint64_t, so ancient hosts where + uintmax_t is only 32 bits lose about 3.725 bits of randomness, + which is better than not having mkstemp at all. */ +#if !defined UINT64_MAX && !defined uint64_t +# define uint64_t uintmax_t +#endif + /* Return nonzero if DIR is an existent directory. */ static int direxists (const char *dir) @@ -218,14 +227,18 @@ __gen_tempname (char *tmpl, int kind) XXXXXX = &tmpl[len - 6]; /* Get some more or less random data. */ -#if HAVE_GETTIMEOFDAY || _LIBC +#ifdef RANDOM_BITS + RANDOM_BITS (random_time_bits); +#else +# if HAVE_GETTIMEOFDAY || _LIBC { struct timeval tv; __gettimeofday (&tv, NULL); random_time_bits = ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec; } -#else +# else random_time_bits = time (NULL); +# endif #endif value += random_time_bits ^ __getpid (); |