diff options
Diffstat (limited to 'gmp-6.3.0/printf/snprntffuns.c')
| -rw-r--r-- | gmp-6.3.0/printf/snprntffuns.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/gmp-6.3.0/printf/snprntffuns.c b/gmp-6.3.0/printf/snprntffuns.c new file mode 100644 index 0000000..885c7ab --- /dev/null +++ b/gmp-6.3.0/printf/snprntffuns.c @@ -0,0 +1,157 @@ +/* __gmp_snprintf_funs -- support for gmp_snprintf and gmp_vsnprintf. + + THE FUNCTIONS IN THIS FILE ARE FOR INTERNAL USE ONLY. THEY'RE ALMOST + CERTAIN TO BE SUBJECT TO INCOMPATIBLE CHANGES OR DISAPPEAR COMPLETELY IN + FUTURE GNU MP RELEASES. + +Copyright 2001, 2002, 2018 Free Software Foundation, Inc. + +This file is part of the GNU MP Library. + +The GNU MP Library is free software; you can redistribute it and/or modify +it under the terms of either: + + * the GNU Lesser General Public License as published by the Free + Software Foundation; either version 3 of the License, or (at your + option) any later version. + +or + + * the GNU General Public License as published by the Free Software + Foundation; either version 2 of the License, or (at your option) any + later version. + +or both in parallel, as here. + +The GNU MP Library 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 General Public License +for more details. + +You should have received copies of the GNU General Public License and the +GNU Lesser General Public License along with the GNU MP Library. If not, +see https://www.gnu.org/licenses/. */ + +#include <stdarg.h> +#include <stdio.h> +#include <string.h> + +#include "gmp-impl.h" + + +#if ! HAVE_VSNPRINTF +#define vsnprintf __gmp_replacement_vsnprintf +#endif + + +/* glibc 2.0.x vsnprintf returns either -1 or size-1 for an overflow, with + no indication how big the output would have been. It's necessary to + re-run to determine that size. + + "size-1" would mean success from a C99 vsnprintf, and the re-run is + unnecessary in this case, but we don't bother to try to detect what sort + of vsnprintf we've got. size-1 should occur rarely in normal + circumstances. + + vsnprintf might trash it's given ap (it does for instance in glibc 2.1.3 + on powerpc), so copy it in case we need to use it to probe for the size + output that would have been produced. Note there's no need to preserve + it for our callers, just for ourselves. */ + +static int +gmp_snprintf_format (struct gmp_snprintf_t *d, const char *fmt, + va_list orig_ap) +{ + int ret; + size_t step, alloc, avail; + va_list ap; + char *p; + + ASSERT (d->size >= 0); + + avail = d->size; + if (avail > 1) + { + va_copy (ap, orig_ap); + ret = vsnprintf (d->buf, avail, fmt, ap); + if (ret == -1) + return ret; + + step = MIN (ret, avail-1); + d->size -= step; + d->buf += step; + + if (ret != avail-1) + return ret; + + /* probably glibc 2.0.x truncated output, probe for actual size */ + alloc = MAX (128, ret); + } + else + { + /* no space to write anything, just probe for size */ + alloc = 128; + } + + do + { + alloc *= 2; + p = __GMP_ALLOCATE_FUNC_TYPE (alloc, char); + va_copy (ap, orig_ap); + ret = vsnprintf (p, alloc, fmt, ap); + __GMP_FREE_FUNC_TYPE (p, alloc, char); + } + while (ret == alloc-1); + + return ret; +} + +static int +gmp_snprintf_memory (struct gmp_snprintf_t *d, const char *str, size_t len) +{ + size_t n; + + ASSERT (d->size >= 0); + + if (d->size > 1) + { + n = MIN (d->size-1, len); + memcpy (d->buf, str, n); + d->buf += n; + d->size -= n; + } + return len; +} + +static int +gmp_snprintf_reps (struct gmp_snprintf_t *d, int c, int reps) +{ + size_t n; + + ASSERT (reps >= 0); + ASSERT (d->size >= 0); + + if (d->size > 1) + { + n = MIN (d->size-1, reps); + memset (d->buf, c, n); + d->buf += n; + d->size -= n; + } + return reps; +} + +static int +gmp_snprintf_final (struct gmp_snprintf_t *d) +{ + if (d->size >= 1) + d->buf[0] = '\0'; + return 0; +} + +const struct doprnt_funs_t __gmp_snprintf_funs = { + (doprnt_format_t) gmp_snprintf_format, + (doprnt_memory_t) gmp_snprintf_memory, + (doprnt_reps_t) gmp_snprintf_reps, + (doprnt_final_t) gmp_snprintf_final +}; |