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 it
5 under the terms of the GNU Library General Public License as published
6 by 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 GNU
12 Library General Public License for more details.
14 You should have received a copy of the GNU Library General Public
15 License along with this program; if not, write to the Free Software
16 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
19 /* Tell glibc's <stdio.h> to provide a prototype for snprintf().
20 This must come before <config.h> because <config.h> may include
21 <features.h>, and once <features.h> has been included, it's too late. */
23 # define _GNU_SOURCE 1
32 #include "vasnprintf.h"
34 #include <stdio.h> /* snprintf(), sprintf() */
35 #include <stdlib.h> /* abort(), malloc(), realloc(), free() */
36 #include <string.h> /* memcpy(), strlen() */
37 #include <errno.h> /* errno */
38 #include <limits.h> /* CHAR_BIT */
39 #include <float.h> /* DBL_MAX_EXP, LDBL_MAX_EXP */
40 #include "printf-parse.h"
42 /* For those losing systems which don't have 'alloca' we have to add
43 some additional code emulating it. */
45 # define freea(p) /* nothing */
47 # define alloca(n) malloc (n)
48 # define freea(p) free (p)
52 vasnprintf (char *resultbuf, size_t *lengthp, const char *format, va_list args)
57 if (printf_parse (format, &d, &a) < 0)
68 if (printf_fetchargs (args, &a) < 0)
77 (char *) alloca (7 + d.max_width_length + d.max_precision_length + 6);
81 /* Output string accumulator. */
86 if (resultbuf != NULL)
98 result is either == resultbuf or == NULL or malloc-allocated.
99 If length > 0, then result != NULL. */
101 #define ENSURE_ALLOCATION(needed) \
102 if ((needed) > allocated) \
106 allocated = (allocated > 0 ? 2 * allocated : 12); \
107 if ((needed) > allocated) \
108 allocated = (needed); \
109 if (result == resultbuf || result == NULL) \
110 memory = (char *) malloc (allocated); \
112 memory = (char *) realloc (result, allocated); \
114 if (memory == NULL) \
116 if (!(result == resultbuf || result == NULL)) \
123 if (result == resultbuf && length > 0) \
124 memcpy (memory, result, length); \
128 for (cp = format, i = 0, dp = &d.dir[0]; ; cp = dp->dir_end, i++, dp++)
130 if (cp != dp->dir_start)
132 size_t n = dp->dir_start - cp;
134 ENSURE_ALLOCATION (length + n);
135 memcpy (result + length, cp, n);
141 /* Execute a single directive. */
142 if (dp->conversion == '%')
144 if (!(dp->arg_index < 0))
146 ENSURE_ALLOCATION (length + 1);
147 result[length] = '%';
152 if (!(dp->arg_index >= 0))
155 if (dp->conversion == 'n')
157 switch (a.arg[dp->arg_index].type)
159 case TYPE_COUNT_SCHAR_POINTER:
160 *a.arg[dp->arg_index].a.a_count_schar_pointer = length;
162 case TYPE_COUNT_SHORT_POINTER:
163 *a.arg[dp->arg_index].a.a_count_short_pointer = length;
165 case TYPE_COUNT_INT_POINTER:
166 *a.arg[dp->arg_index].a.a_count_int_pointer = length;
168 case TYPE_COUNT_LONGINT_POINTER:
169 *a.arg[dp->arg_index].a.a_count_longint_pointer = length;
171 #ifdef HAVE_LONG_LONG
172 case TYPE_COUNT_LONGLONGINT_POINTER:
173 *a.arg[dp->arg_index].a.a_count_longlongint_pointer = length;
182 arg_type type = a.arg[dp->arg_index].type;
184 unsigned int prefix_count;
187 unsigned int tmp_length;
191 /* Allocate a temporary buffer of sufficient size for calling
195 unsigned int precision;
198 if (dp->width_start != dp->width_end)
200 if (dp->width_arg_index >= 0)
204 if (!(a.arg[dp->width_arg_index].type == TYPE_INT))
206 arg = a.arg[dp->width_arg_index].a.a_int;
207 width = (arg < 0 ? -arg : arg);
211 const char *digitp = dp->width_start;
214 width = width * 10 + (*digitp++ - '0');
215 while (digitp != dp->width_end);
220 if (dp->precision_start != dp->precision_end)
222 if (dp->precision_arg_index >= 0)
226 if (!(a.arg[dp->precision_arg_index].type == TYPE_INT))
228 arg = a.arg[dp->precision_arg_index].a.a_int;
229 precision = (arg < 0 ? 0 : arg);
233 const char *digitp = dp->precision_start + 1;
237 precision = precision * 10 + (*digitp++ - '0');
238 while (digitp != dp->precision_end);
242 switch (dp->conversion)
245 case 'd': case 'i': case 'u':
246 # ifdef HAVE_LONG_LONG
247 if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
249 (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
250 * 0.30103 /* binary -> decimal */
251 * 2 /* estimate for FLAG_GROUP */
253 + 1 /* turn floor into ceil */
254 + 1; /* account for leading sign */
257 if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
259 (unsigned int) (sizeof (unsigned long) * CHAR_BIT
260 * 0.30103 /* binary -> decimal */
261 * 2 /* estimate for FLAG_GROUP */
263 + 1 /* turn floor into ceil */
264 + 1; /* account for leading sign */
267 (unsigned int) (sizeof (unsigned int) * CHAR_BIT
268 * 0.30103 /* binary -> decimal */
269 * 2 /* estimate for FLAG_GROUP */
271 + 1 /* turn floor into ceil */
272 + 1; /* account for leading sign */
276 # ifdef HAVE_LONG_LONG
277 if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
279 (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
280 * 0.333334 /* binary -> octal */
282 + 1 /* turn floor into ceil */
283 + 1; /* account for leading sign */
286 if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
288 (unsigned int) (sizeof (unsigned long) * CHAR_BIT
289 * 0.333334 /* binary -> octal */
291 + 1 /* turn floor into ceil */
292 + 1; /* account for leading sign */
295 (unsigned int) (sizeof (unsigned int) * CHAR_BIT
296 * 0.333334 /* binary -> octal */
298 + 1 /* turn floor into ceil */
299 + 1; /* account for leading sign */
303 # ifdef HAVE_LONG_LONG
304 if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
306 (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
307 * 0.25 /* binary -> hexadecimal */
309 + 1 /* turn floor into ceil */
310 + 2; /* account for leading sign or alternate form */
313 if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
315 (unsigned int) (sizeof (unsigned long) * CHAR_BIT
316 * 0.25 /* binary -> hexadecimal */
318 + 1 /* turn floor into ceil */
319 + 2; /* account for leading sign or alternate form */
322 (unsigned int) (sizeof (unsigned int) * CHAR_BIT
323 * 0.25 /* binary -> hexadecimal */
325 + 1 /* turn floor into ceil */
326 + 2; /* account for leading sign or alternate form */
330 # ifdef HAVE_LONG_DOUBLE
331 if (type == TYPE_LONGDOUBLE)
333 (unsigned int) (LDBL_MAX_EXP
334 * 0.30103 /* binary -> decimal */
335 * 2 /* estimate for FLAG_GROUP */
337 + 1 /* turn floor into ceil */
339 + 10; /* sign, decimal point etc. */
343 (unsigned int) (DBL_MAX_EXP
344 * 0.30103 /* binary -> decimal */
345 * 2 /* estimate for FLAG_GROUP */
347 + 1 /* turn floor into ceil */
349 + 10; /* sign, decimal point etc. */
352 case 'e': case 'E': case 'g': case 'G':
356 + 12; /* sign, decimal point, exponent etc. */
361 if (type == TYPE_WIDE_CHAR)
362 tmp_length = MB_CUR_MAX;
370 if (type == TYPE_WIDE_STRING)
372 wcslen (a.arg[dp->arg_index].a.a_wide_string)
376 tmp_length = strlen (a.arg[dp->arg_index].a.a_string);
381 (unsigned int) (sizeof (void *) * CHAR_BIT
382 * 0.25 /* binary -> hexadecimal */
384 + 1 /* turn floor into ceil */
385 + 2; /* account for leading 0x */
392 if (tmp_length < width)
395 tmp_length++; /* account for trailing NUL */
398 if (tmp_length <= sizeof (tmpbuf))
402 tmp = (char *) malloc (tmp_length);
406 if (!(result == resultbuf || result == NULL))
416 /* Construct the format string for calling snprintf or
420 if (dp->flags & FLAG_GROUP)
422 if (dp->flags & FLAG_LEFT)
424 if (dp->flags & FLAG_SHOWSIGN)
426 if (dp->flags & FLAG_SPACE)
428 if (dp->flags & FLAG_ALT)
430 if (dp->flags & FLAG_ZERO)
432 if (dp->width_start != dp->width_end)
434 size_t n = dp->width_end - dp->width_start;
435 memcpy (p, dp->width_start, n);
438 if (dp->precision_start != dp->precision_end)
440 size_t n = dp->precision_end - dp->precision_start;
441 memcpy (p, dp->precision_start, n);
447 #ifdef HAVE_LONG_LONG
448 case TYPE_LONGLONGINT:
449 case TYPE_ULONGLONGINT:
459 case TYPE_WIDE_STRING:
463 #ifdef HAVE_LONG_DOUBLE
464 case TYPE_LONGDOUBLE:
480 /* Construct the arguments for calling snprintf or sprintf. */
482 if (dp->width_arg_index >= 0)
484 if (!(a.arg[dp->width_arg_index].type == TYPE_INT))
486 prefixes[prefix_count++] = a.arg[dp->width_arg_index].a.a_int;
488 if (dp->precision_arg_index >= 0)
490 if (!(a.arg[dp->precision_arg_index].type == TYPE_INT))
492 prefixes[prefix_count++] = a.arg[dp->precision_arg_index].a.a_int;
496 /* Prepare checking whether snprintf returns the count
498 ENSURE_ALLOCATION (length + 1);
499 result[length] = '\0';
508 maxlen = allocated - length;
513 #define SNPRINTF_BUF(arg) \
514 switch (prefix_count) \
517 retcount = snprintf (result + length, maxlen, buf, \
521 retcount = snprintf (result + length, maxlen, buf, \
522 prefixes[0], arg, &count); \
525 retcount = snprintf (result + length, maxlen, buf, \
526 prefixes[0], prefixes[1], arg, \
533 #define SNPRINTF_BUF(arg) \
534 switch (prefix_count) \
537 count = sprintf (tmp, buf, arg); \
540 count = sprintf (tmp, buf, prefixes[0], arg); \
543 count = sprintf (tmp, buf, prefixes[0], prefixes[1],\
555 int arg = a.arg[dp->arg_index].a.a_schar;
561 unsigned int arg = a.arg[dp->arg_index].a.a_uchar;
567 int arg = a.arg[dp->arg_index].a.a_short;
573 unsigned int arg = a.arg[dp->arg_index].a.a_ushort;
579 int arg = a.arg[dp->arg_index].a.a_int;
585 unsigned int arg = a.arg[dp->arg_index].a.a_uint;
591 long int arg = a.arg[dp->arg_index].a.a_longint;
597 unsigned long int arg = a.arg[dp->arg_index].a.a_ulongint;
601 #ifdef HAVE_LONG_LONG
602 case TYPE_LONGLONGINT:
604 long long int arg = a.arg[dp->arg_index].a.a_longlongint;
608 case TYPE_ULONGLONGINT:
610 unsigned long long int arg = a.arg[dp->arg_index].a.a_ulonglongint;
617 double arg = a.arg[dp->arg_index].a.a_double;
621 #ifdef HAVE_LONG_DOUBLE
622 case TYPE_LONGDOUBLE:
624 long double arg = a.arg[dp->arg_index].a.a_longdouble;
631 int arg = a.arg[dp->arg_index].a.a_char;
638 wint_t arg = a.arg[dp->arg_index].a.a_wide_char;
645 const char *arg = a.arg[dp->arg_index].a.a_string;
650 case TYPE_WIDE_STRING:
652 const wchar_t *arg = a.arg[dp->arg_index].a.a_wide_string;
659 void *arg = a.arg[dp->arg_index].a.a_pointer;
668 /* Portability: Not all implementations of snprintf()
669 are ISO C 99 compliant. Determine the number of
670 bytes that snprintf() has produced or would have
674 /* Verify that snprintf() has NUL-terminated its
676 if (count < maxlen && result[length + count] != '\0')
678 /* Portability hack. */
679 if (retcount > count)
684 /* snprintf() doesn't understand the '%n'
688 /* Don't use the '%n' directive; instead, look
689 at the snprintf() return value. */
697 /* Attempt to handle failure. */
700 if (!(result == resultbuf || result == NULL))
709 if (count >= tmp_length)
710 /* tmp_length was incorrectly calculated - fix the
715 /* Make room for the result. */
718 /* Need at least count bytes. But allocate
719 proportionally, to avoid looping eternally if
720 snprintf() reports a too small count. */
721 size_t n = length + count;
723 if (n < 2 * allocated)
726 ENSURE_ALLOCATION (n);
733 /* The snprintf() result did fit. */
735 /* Append the sprintf() result. */
736 memcpy (result + length, tmp, count);
748 /* Add the final NUL. */
749 ENSURE_ALLOCATION (length + 1);
750 result[length] = '\0';
752 if (result != resultbuf && length + 1 < allocated)
754 /* Shrink the allocated memory if possible. */
757 memory = (char *) realloc (result, length + 1);