1 /* vsprintf with automatic memory allocation.
2 Copyright (C) 1999, 2002-2003 Free Software Foundation, Inc.
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2, or (at your option)
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License along
15 with this program; if not, write to the Free Software Foundation,
16 Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
18 /* Tell glibc's <stdio.h> to provide a prototype for snprintf().
19 This must come before <config.h> because <config.h> may include
20 <features.h>, and once <features.h> has been included, it's too late. */
22 # define _GNU_SOURCE 1
31 #include "vasnprintf.h"
33 #include <stdio.h> /* snprintf(), sprintf() */
34 #include <stdlib.h> /* abort(), malloc(), realloc(), free() */
35 #include <string.h> /* memcpy(), strlen() */
36 #include <errno.h> /* errno */
37 #include <limits.h> /* CHAR_BIT */
38 #include <float.h> /* DBL_MAX_EXP, LDBL_MAX_EXP */
39 #include "printf-parse.h"
41 /* For those losing systems which don't have 'alloca' we have to add
42 some additional code emulating it. */
44 # define freea(p) /* nothing */
46 # define alloca(n) malloc (n)
47 # define freea(p) free (p)
52 # define local_wcslen wcslen
54 /* Solaris 2.5.1 has wcslen() in a separate library libw.so. To avoid
55 a dependency towards this library, here is a local substitute. */
57 local_wcslen (const wchar_t *s)
61 for (ptr = s; *ptr != (wchar_t) 0; ptr++)
69 vasnprintf (char *resultbuf, size_t *lengthp, const char *format, va_list args)
74 if (printf_parse (format, &d, &a) < 0)
85 if (printf_fetchargs (args, &a) < 0)
94 (char *) alloca (7 + d.max_width_length + d.max_precision_length + 6);
98 /* Output string accumulator. */
103 if (resultbuf != NULL)
106 allocated = *lengthp;
115 result is either == resultbuf or == NULL or malloc-allocated.
116 If length > 0, then result != NULL. */
118 #define ENSURE_ALLOCATION(needed) \
119 if ((needed) > allocated) \
123 allocated = (allocated > 0 ? 2 * allocated : 12); \
124 if ((needed) > allocated) \
125 allocated = (needed); \
126 if (result == resultbuf || result == NULL) \
127 memory = (char *) malloc (allocated); \
129 memory = (char *) realloc (result, allocated); \
131 if (memory == NULL) \
133 if (!(result == resultbuf || result == NULL)) \
140 if (result == resultbuf && length > 0) \
141 memcpy (memory, result, length); \
145 for (cp = format, i = 0, dp = &d.dir[0]; ; cp = dp->dir_end, i++, dp++)
147 if (cp != dp->dir_start)
149 size_t n = dp->dir_start - cp;
151 ENSURE_ALLOCATION (length + n);
152 memcpy (result + length, cp, n);
158 /* Execute a single directive. */
159 if (dp->conversion == '%')
161 if (!(dp->arg_index < 0))
163 ENSURE_ALLOCATION (length + 1);
164 result[length] = '%';
169 if (!(dp->arg_index >= 0))
172 if (dp->conversion == 'n')
174 switch (a.arg[dp->arg_index].type)
176 case TYPE_COUNT_SCHAR_POINTER:
177 *a.arg[dp->arg_index].a.a_count_schar_pointer = length;
179 case TYPE_COUNT_SHORT_POINTER:
180 *a.arg[dp->arg_index].a.a_count_short_pointer = length;
182 case TYPE_COUNT_INT_POINTER:
183 *a.arg[dp->arg_index].a.a_count_int_pointer = length;
185 case TYPE_COUNT_LONGINT_POINTER:
186 *a.arg[dp->arg_index].a.a_count_longint_pointer = length;
188 #ifdef HAVE_LONG_LONG
189 case TYPE_COUNT_LONGLONGINT_POINTER:
190 *a.arg[dp->arg_index].a.a_count_longlongint_pointer = length;
199 arg_type type = a.arg[dp->arg_index].type;
201 unsigned int prefix_count;
204 unsigned int tmp_length;
208 /* Allocate a temporary buffer of sufficient size for calling
212 unsigned int precision;
215 if (dp->width_start != dp->width_end)
217 if (dp->width_arg_index >= 0)
221 if (!(a.arg[dp->width_arg_index].type == TYPE_INT))
223 arg = a.arg[dp->width_arg_index].a.a_int;
224 width = (arg < 0 ? -arg : arg);
228 const char *digitp = dp->width_start;
231 width = width * 10 + (*digitp++ - '0');
232 while (digitp != dp->width_end);
237 if (dp->precision_start != dp->precision_end)
239 if (dp->precision_arg_index >= 0)
243 if (!(a.arg[dp->precision_arg_index].type == TYPE_INT))
245 arg = a.arg[dp->precision_arg_index].a.a_int;
246 precision = (arg < 0 ? 0 : arg);
250 const char *digitp = dp->precision_start + 1;
254 precision = precision * 10 + (*digitp++ - '0');
255 while (digitp != dp->precision_end);
259 switch (dp->conversion)
262 case 'd': case 'i': case 'u':
263 # ifdef HAVE_LONG_LONG
264 if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
266 (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
267 * 0.30103 /* binary -> decimal */
268 * 2 /* estimate for FLAG_GROUP */
270 + 1 /* turn floor into ceil */
271 + 1; /* account for leading sign */
274 if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
276 (unsigned int) (sizeof (unsigned long) * CHAR_BIT
277 * 0.30103 /* binary -> decimal */
278 * 2 /* estimate for FLAG_GROUP */
280 + 1 /* turn floor into ceil */
281 + 1; /* account for leading sign */
284 (unsigned int) (sizeof (unsigned int) * CHAR_BIT
285 * 0.30103 /* binary -> decimal */
286 * 2 /* estimate for FLAG_GROUP */
288 + 1 /* turn floor into ceil */
289 + 1; /* account for leading sign */
293 # ifdef HAVE_LONG_LONG
294 if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
296 (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
297 * 0.333334 /* binary -> octal */
299 + 1 /* turn floor into ceil */
300 + 1; /* account for leading sign */
303 if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
305 (unsigned int) (sizeof (unsigned long) * CHAR_BIT
306 * 0.333334 /* binary -> octal */
308 + 1 /* turn floor into ceil */
309 + 1; /* account for leading sign */
312 (unsigned int) (sizeof (unsigned int) * CHAR_BIT
313 * 0.333334 /* binary -> octal */
315 + 1 /* turn floor into ceil */
316 + 1; /* account for leading sign */
320 # ifdef HAVE_LONG_LONG
321 if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
323 (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
324 * 0.25 /* binary -> hexadecimal */
326 + 1 /* turn floor into ceil */
327 + 2; /* account for leading sign or alternate form */
330 if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
332 (unsigned int) (sizeof (unsigned long) * CHAR_BIT
333 * 0.25 /* binary -> hexadecimal */
335 + 1 /* turn floor into ceil */
336 + 2; /* account for leading sign or alternate form */
339 (unsigned int) (sizeof (unsigned int) * CHAR_BIT
340 * 0.25 /* binary -> hexadecimal */
342 + 1 /* turn floor into ceil */
343 + 2; /* account for leading sign or alternate form */
347 # ifdef HAVE_LONG_DOUBLE
348 if (type == TYPE_LONGDOUBLE)
350 (unsigned int) (LDBL_MAX_EXP
351 * 0.30103 /* binary -> decimal */
352 * 2 /* estimate for FLAG_GROUP */
354 + 1 /* turn floor into ceil */
356 + 10; /* sign, decimal point etc. */
360 (unsigned int) (DBL_MAX_EXP
361 * 0.30103 /* binary -> decimal */
362 * 2 /* estimate for FLAG_GROUP */
364 + 1 /* turn floor into ceil */
366 + 10; /* sign, decimal point etc. */
369 case 'e': case 'E': case 'g': case 'G':
373 + 12; /* sign, decimal point, exponent etc. */
378 if (type == TYPE_WIDE_CHAR)
379 tmp_length = MB_CUR_MAX;
387 if (type == TYPE_WIDE_STRING)
389 local_wcslen (a.arg[dp->arg_index].a.a_wide_string)
393 tmp_length = strlen (a.arg[dp->arg_index].a.a_string);
398 (unsigned int) (sizeof (void *) * CHAR_BIT
399 * 0.25 /* binary -> hexadecimal */
401 + 1 /* turn floor into ceil */
402 + 2; /* account for leading 0x */
409 if (tmp_length < width)
412 tmp_length++; /* account for trailing NUL */
415 if (tmp_length <= sizeof (tmpbuf))
419 tmp = (char *) malloc (tmp_length);
423 if (!(result == resultbuf || result == NULL))
433 /* Construct the format string for calling snprintf or
437 if (dp->flags & FLAG_GROUP)
439 if (dp->flags & FLAG_LEFT)
441 if (dp->flags & FLAG_SHOWSIGN)
443 if (dp->flags & FLAG_SPACE)
445 if (dp->flags & FLAG_ALT)
447 if (dp->flags & FLAG_ZERO)
449 if (dp->width_start != dp->width_end)
451 size_t n = dp->width_end - dp->width_start;
452 memcpy (p, dp->width_start, n);
455 if (dp->precision_start != dp->precision_end)
457 size_t n = dp->precision_end - dp->precision_start;
458 memcpy (p, dp->precision_start, n);
464 #ifdef HAVE_LONG_LONG
465 case TYPE_LONGLONGINT:
466 case TYPE_ULONGLONGINT:
476 case TYPE_WIDE_STRING:
480 #ifdef HAVE_LONG_DOUBLE
481 case TYPE_LONGDOUBLE:
497 /* Construct the arguments for calling snprintf or sprintf. */
499 if (dp->width_arg_index >= 0)
501 if (!(a.arg[dp->width_arg_index].type == TYPE_INT))
503 prefixes[prefix_count++] = a.arg[dp->width_arg_index].a.a_int;
505 if (dp->precision_arg_index >= 0)
507 if (!(a.arg[dp->precision_arg_index].type == TYPE_INT))
509 prefixes[prefix_count++] = a.arg[dp->precision_arg_index].a.a_int;
513 /* Prepare checking whether snprintf returns the count
515 ENSURE_ALLOCATION (length + 1);
516 result[length] = '\0';
525 maxlen = allocated - length;
530 #define SNPRINTF_BUF(arg) \
531 switch (prefix_count) \
534 retcount = snprintf (result + length, maxlen, buf, \
538 retcount = snprintf (result + length, maxlen, buf, \
539 prefixes[0], arg, &count); \
542 retcount = snprintf (result + length, maxlen, buf, \
543 prefixes[0], prefixes[1], arg, \
550 #define SNPRINTF_BUF(arg) \
551 switch (prefix_count) \
554 count = sprintf (tmp, buf, arg); \
557 count = sprintf (tmp, buf, prefixes[0], arg); \
560 count = sprintf (tmp, buf, prefixes[0], prefixes[1],\
572 int arg = a.arg[dp->arg_index].a.a_schar;
578 unsigned int arg = a.arg[dp->arg_index].a.a_uchar;
584 int arg = a.arg[dp->arg_index].a.a_short;
590 unsigned int arg = a.arg[dp->arg_index].a.a_ushort;
596 int arg = a.arg[dp->arg_index].a.a_int;
602 unsigned int arg = a.arg[dp->arg_index].a.a_uint;
608 long int arg = a.arg[dp->arg_index].a.a_longint;
614 unsigned long int arg = a.arg[dp->arg_index].a.a_ulongint;
618 #ifdef HAVE_LONG_LONG
619 case TYPE_LONGLONGINT:
621 long long int arg = a.arg[dp->arg_index].a.a_longlongint;
625 case TYPE_ULONGLONGINT:
627 unsigned long long int arg = a.arg[dp->arg_index].a.a_ulonglongint;
634 double arg = a.arg[dp->arg_index].a.a_double;
638 #ifdef HAVE_LONG_DOUBLE
639 case TYPE_LONGDOUBLE:
641 long double arg = a.arg[dp->arg_index].a.a_longdouble;
648 int arg = a.arg[dp->arg_index].a.a_char;
655 wint_t arg = a.arg[dp->arg_index].a.a_wide_char;
662 const char *arg = a.arg[dp->arg_index].a.a_string;
667 case TYPE_WIDE_STRING:
669 const wchar_t *arg = a.arg[dp->arg_index].a.a_wide_string;
676 void *arg = a.arg[dp->arg_index].a.a_pointer;
685 /* Portability: Not all implementations of snprintf()
686 are ISO C 99 compliant. Determine the number of
687 bytes that snprintf() has produced or would have
691 /* Verify that snprintf() has NUL-terminated its
693 if (count < maxlen && result[length + count] != '\0')
695 /* Portability hack. */
696 if (retcount > count)
701 /* snprintf() doesn't understand the '%n'
705 /* Don't use the '%n' directive; instead, look
706 at the snprintf() return value. */
714 /* Attempt to handle failure. */
717 if (!(result == resultbuf || result == NULL))
726 if (count >= tmp_length)
727 /* tmp_length was incorrectly calculated - fix the
732 /* Make room for the result. */
735 /* Need at least count bytes. But allocate
736 proportionally, to avoid looping eternally if
737 snprintf() reports a too small count. */
738 size_t n = length + count;
740 if (n < 2 * allocated)
743 ENSURE_ALLOCATION (n);
750 /* The snprintf() result did fit. */
752 /* Append the sprintf() result. */
753 memcpy (result + length, tmp, count);
765 /* Add the final NUL. */
766 ENSURE_ALLOCATION (length + 1);
767 result[length] = '\0';
769 if (result != resultbuf && length + 1 < allocated)
771 /* Shrink the allocated memory if possible. */
774 memory = (char *) realloc (result, length + 1);