1 /* vsprintf with automatic memory allocation.
2 Copyright (C) 1999, 2002-2006 Free Software Foundation, Inc.
3
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)
7 any later version.
8
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.
13
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
17 USA. */
18
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. */
22 #ifndef _GNU_SOURCE
23 # define _GNU_SOURCE 1
24 #endif
25
26 #include <config.h>
27 #ifndef IN_LIBINTL
28 # include <alloca.h>
29 #endif
30
31 /* Specification. */
32 #if WIDE_CHAR_VERSION
33 # include "vasnwprintf.h"
34 #else
35 # include "vasnprintf.h"
36 #endif
37
38 #include <stdio.h> /* snprintf(), sprintf() */
39 #include <stdlib.h> /* abort(), malloc(), realloc(), free() */
40 #include <string.h> /* memcpy(), strlen() */
41 #include <errno.h> /* errno */
42 #include <limits.h> /* CHAR_BIT */
43 #include <float.h> /* DBL_MAX_EXP, LDBL_MAX_EXP */
44 #if WIDE_CHAR_VERSION
45 # include "wprintf-parse.h"
46 #else
47 # include "printf-parse.h"
48 #endif
49
50 /* Checked size_t computations. */
51 #include "xsize.h"
52
53 #ifdef HAVE_WCHAR_T
54 # ifdef HAVE_WCSLEN
55 # define local_wcslen wcslen
56 # else
57 /* Solaris 2.5.1 has wcslen() in a separate library libw.so. To avoid
58 a dependency towards this library, here is a local substitute.
59 Define this substitute only once, even if this file is included
60 twice in the same compilation unit. */
61 # ifndef local_wcslen_defined
62 # define local_wcslen_defined 1
63 static size_t
local_wcslen(const wchar_t * s)64 local_wcslen (const wchar_t *s)
65 {
66 const wchar_t *ptr;
67
68 for (ptr = s; *ptr != (wchar_t) 0; ptr++)
69 ;
70 return ptr - s;
71 }
72 # endif
73 # endif
74 #endif
75
76 #if WIDE_CHAR_VERSION
77 # define VASNPRINTF vasnwprintf
78 # define CHAR_T wchar_t
79 # define DIRECTIVE wchar_t_directive
80 # define DIRECTIVES wchar_t_directives
81 # define PRINTF_PARSE wprintf_parse
82 # define USE_SNPRINTF 1
83 # if HAVE_DECL__SNWPRINTF
84 /* On Windows, the function swprintf() has a different signature than
85 on Unix; we use the _snwprintf() function instead. */
86 # define SNPRINTF _snwprintf
87 # else
88 /* Unix. */
89 # define SNPRINTF swprintf
90 # endif
91 #else
92 # define VASNPRINTF vasnprintf
93 # define CHAR_T char
94 # define DIRECTIVE char_directive
95 # define DIRECTIVES char_directives
96 # define PRINTF_PARSE printf_parse
97 # define USE_SNPRINTF (HAVE_DECL__SNPRINTF || HAVE_SNPRINTF)
98 # if HAVE_DECL__SNPRINTF
99 /* Windows. */
100 # define SNPRINTF _snprintf
101 # else
102 /* Unix. */
103 # define SNPRINTF snprintf
104 # endif
105 #endif
106
107 CHAR_T *
VASNPRINTF(CHAR_T * resultbuf,size_t * lengthp,const CHAR_T * format,va_list args)108 VASNPRINTF (CHAR_T *resultbuf, size_t *lengthp, const CHAR_T *format, va_list args)
109 {
110 DIRECTIVES d;
111 arguments a;
112
113 if (PRINTF_PARSE (format, &d, &a) < 0)
114 {
115 errno = EINVAL;
116 return NULL;
117 }
118
119 #define CLEANUP() \
120 free (d.dir); \
121 if (a.arg) \
122 free (a.arg);
123
124 if (printf_fetchargs (args, &a) < 0)
125 {
126 CLEANUP ();
127 errno = EINVAL;
128 return NULL;
129 }
130
131 {
132 size_t buf_neededlength;
133 CHAR_T *buf;
134 CHAR_T *buf_malloced;
135 const CHAR_T *cp;
136 size_t i;
137 DIRECTIVE *dp;
138 /* Output string accumulator. */
139 CHAR_T *result;
140 size_t allocated;
141 size_t length;
142
143 /* Allocate a small buffer that will hold a directive passed to
144 sprintf or snprintf. */
145 buf_neededlength =
146 xsum4 (7, d.max_width_length, d.max_precision_length, 6);
147 #if HAVE_ALLOCA
148 if (buf_neededlength < 4000 / sizeof (CHAR_T))
149 {
150 buf = (CHAR_T *) alloca (buf_neededlength * sizeof (CHAR_T));
151 buf_malloced = NULL;
152 }
153 else
154 #endif
155 {
156 size_t buf_memsize = xtimes (buf_neededlength, sizeof (CHAR_T));
157 if (size_overflow_p (buf_memsize))
158 goto out_of_memory_1;
159 buf = (CHAR_T *) malloc (buf_memsize);
160 if (buf == NULL)
161 goto out_of_memory_1;
162 buf_malloced = buf;
163 }
164
165 if (resultbuf != NULL)
166 {
167 result = resultbuf;
168 allocated = *lengthp;
169 }
170 else
171 {
172 result = NULL;
173 allocated = 0;
174 }
175 length = 0;
176 /* Invariants:
177 result is either == resultbuf or == NULL or malloc-allocated.
178 If length > 0, then result != NULL. */
179
180 /* Ensures that allocated >= needed. Aborts through a jump to
181 out_of_memory if needed is SIZE_MAX or otherwise too big. */
182 #define ENSURE_ALLOCATION(needed) \
183 if ((needed) > allocated) \
184 { \
185 size_t memory_size; \
186 CHAR_T *memory; \
187 \
188 allocated = (allocated > 0 ? xtimes (allocated, 2) : 12); \
189 if ((needed) > allocated) \
190 allocated = (needed); \
191 memory_size = xtimes (allocated, sizeof (CHAR_T)); \
192 if (size_overflow_p (memory_size)) \
193 goto out_of_memory; \
194 if (result == resultbuf || result == NULL) \
195 memory = (CHAR_T *) malloc (memory_size); \
196 else \
197 memory = (CHAR_T *) realloc (result, memory_size); \
198 if (memory == NULL) \
199 goto out_of_memory; \
200 if (result == resultbuf && length > 0) \
201 memcpy (memory, result, length * sizeof (CHAR_T)); \
202 result = memory; \
203 }
204
205 for (cp = format, i = 0, dp = &d.dir[0]; ; cp = dp->dir_end, i++, dp++)
206 {
207 if (cp != dp->dir_start)
208 {
209 size_t n = dp->dir_start - cp;
210 size_t augmented_length = xsum (length, n);
211
212 ENSURE_ALLOCATION (augmented_length);
213 memcpy (result + length, cp, n * sizeof (CHAR_T));
214 length = augmented_length;
215 }
216 if (i == d.count)
217 break;
218
219 /* Execute a single directive. */
220 if (dp->conversion == '%')
221 {
222 size_t augmented_length;
223
224 if (!(dp->arg_index == ARG_NONE))
225 abort ();
226 augmented_length = xsum (length, 1);
227 ENSURE_ALLOCATION (augmented_length);
228 result[length] = '%';
229 length = augmented_length;
230 }
231 else
232 {
233 if (!(dp->arg_index != ARG_NONE))
234 abort ();
235
236 if (dp->conversion == 'n')
237 {
238 switch (a.arg[dp->arg_index].type)
239 {
240 case TYPE_COUNT_SCHAR_POINTER:
241 *a.arg[dp->arg_index].a.a_count_schar_pointer = length;
242 break;
243 case TYPE_COUNT_SHORT_POINTER:
244 *a.arg[dp->arg_index].a.a_count_short_pointer = length;
245 break;
246 case TYPE_COUNT_INT_POINTER:
247 *a.arg[dp->arg_index].a.a_count_int_pointer = length;
248 break;
249 case TYPE_COUNT_LONGINT_POINTER:
250 *a.arg[dp->arg_index].a.a_count_longint_pointer = length;
251 break;
252 #ifdef HAVE_LONG_LONG_INT
253 case TYPE_COUNT_LONGLONGINT_POINTER:
254 *a.arg[dp->arg_index].a.a_count_longlongint_pointer = length;
255 break;
256 #endif
257 default:
258 abort ();
259 }
260 }
261 else
262 {
263 arg_type type = a.arg[dp->arg_index].type;
264 CHAR_T *p;
265 unsigned int prefix_count;
266 int prefixes[2];
267 #if !USE_SNPRINTF
268 size_t tmp_length;
269 CHAR_T tmpbuf[700];
270 CHAR_T *tmp;
271
272 /* Allocate a temporary buffer of sufficient size for calling
273 sprintf. */
274 {
275 size_t width;
276 size_t precision;
277
278 width = 0;
279 if (dp->width_start != dp->width_end)
280 {
281 if (dp->width_arg_index != ARG_NONE)
282 {
283 int arg;
284
285 if (!(a.arg[dp->width_arg_index].type == TYPE_INT))
286 abort ();
287 arg = a.arg[dp->width_arg_index].a.a_int;
288 width = (arg < 0 ? (unsigned int) (-arg) : arg);
289 }
290 else
291 {
292 const CHAR_T *digitp = dp->width_start;
293
294 do
295 width = xsum (xtimes (width, 10), *digitp++ - '0');
296 while (digitp != dp->width_end);
297 }
298 }
299
300 precision = 6;
301 if (dp->precision_start != dp->precision_end)
302 {
303 if (dp->precision_arg_index != ARG_NONE)
304 {
305 int arg;
306
307 if (!(a.arg[dp->precision_arg_index].type == TYPE_INT))
308 abort ();
309 arg = a.arg[dp->precision_arg_index].a.a_int;
310 precision = (arg < 0 ? 0 : arg);
311 }
312 else
313 {
314 const CHAR_T *digitp = dp->precision_start + 1;
315
316 precision = 0;
317 while (digitp != dp->precision_end)
318 precision = xsum (xtimes (precision, 10), *digitp++ - '0');
319 }
320 }
321
322 switch (dp->conversion)
323 {
324
325 case 'd': case 'i': case 'u':
326 # ifdef HAVE_LONG_LONG_INT
327 if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
328 tmp_length =
329 (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
330 * 0.30103 /* binary -> decimal */
331 )
332 + 1; /* turn floor into ceil */
333 else
334 # endif
335 if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
336 tmp_length =
337 (unsigned int) (sizeof (unsigned long) * CHAR_BIT
338 * 0.30103 /* binary -> decimal */
339 )
340 + 1; /* turn floor into ceil */
341 else
342 tmp_length =
343 (unsigned int) (sizeof (unsigned int) * CHAR_BIT
344 * 0.30103 /* binary -> decimal */
345 )
346 + 1; /* turn floor into ceil */
347 if (tmp_length < precision)
348 tmp_length = precision;
349 /* Multiply by 2, as an estimate for FLAG_GROUP. */
350 tmp_length = xsum (tmp_length, tmp_length);
351 /* Add 1, to account for a leading sign. */
352 tmp_length = xsum (tmp_length, 1);
353 break;
354
355 case 'o':
356 # ifdef HAVE_LONG_LONG_INT
357 if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
358 tmp_length =
359 (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
360 * 0.333334 /* binary -> octal */
361 )
362 + 1; /* turn floor into ceil */
363 else
364 # endif
365 if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
366 tmp_length =
367 (unsigned int) (sizeof (unsigned long) * CHAR_BIT
368 * 0.333334 /* binary -> octal */
369 )
370 + 1; /* turn floor into ceil */
371 else
372 tmp_length =
373 (unsigned int) (sizeof (unsigned int) * CHAR_BIT
374 * 0.333334 /* binary -> octal */
375 )
376 + 1; /* turn floor into ceil */
377 if (tmp_length < precision)
378 tmp_length = precision;
379 /* Add 1, to account for a leading sign. */
380 tmp_length = xsum (tmp_length, 1);
381 break;
382
383 case 'x': case 'X':
384 # ifdef HAVE_LONG_LONG_INT
385 if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
386 tmp_length =
387 (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
388 * 0.25 /* binary -> hexadecimal */
389 )
390 + 1; /* turn floor into ceil */
391 else
392 # endif
393 if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
394 tmp_length =
395 (unsigned int) (sizeof (unsigned long) * CHAR_BIT
396 * 0.25 /* binary -> hexadecimal */
397 )
398 + 1; /* turn floor into ceil */
399 else
400 tmp_length =
401 (unsigned int) (sizeof (unsigned int) * CHAR_BIT
402 * 0.25 /* binary -> hexadecimal */
403 )
404 + 1; /* turn floor into ceil */
405 if (tmp_length < precision)
406 tmp_length = precision;
407 /* Add 2, to account for a leading sign or alternate form. */
408 tmp_length = xsum (tmp_length, 2);
409 break;
410
411 case 'f': case 'F':
412 # ifdef HAVE_LONG_DOUBLE
413 if (type == TYPE_LONGDOUBLE)
414 tmp_length =
415 (unsigned int) (LDBL_MAX_EXP
416 * 0.30103 /* binary -> decimal */
417 * 2 /* estimate for FLAG_GROUP */
418 )
419 + 1 /* turn floor into ceil */
420 + 10; /* sign, decimal point etc. */
421 else
422 # endif
423 tmp_length =
424 (unsigned int) (DBL_MAX_EXP
425 * 0.30103 /* binary -> decimal */
426 * 2 /* estimate for FLAG_GROUP */
427 )
428 + 1 /* turn floor into ceil */
429 + 10; /* sign, decimal point etc. */
430 tmp_length = xsum (tmp_length, precision);
431 break;
432
433 case 'e': case 'E': case 'g': case 'G':
434 case 'a': case 'A':
435 tmp_length =
436 12; /* sign, decimal point, exponent etc. */
437 tmp_length = xsum (tmp_length, precision);
438 break;
439
440 case 'c':
441 # if defined HAVE_WINT_T && !WIDE_CHAR_VERSION
442 if (type == TYPE_WIDE_CHAR)
443 tmp_length = MB_CUR_MAX;
444 else
445 # endif
446 tmp_length = 1;
447 break;
448
449 case 's':
450 # ifdef HAVE_WCHAR_T
451 if (type == TYPE_WIDE_STRING)
452 {
453 tmp_length =
454 local_wcslen (a.arg[dp->arg_index].a.a_wide_string);
455
456 # if !WIDE_CHAR_VERSION
457 tmp_length = xtimes (tmp_length, MB_CUR_MAX);
458 # endif
459 }
460 else
461 # endif
462 tmp_length = strlen (a.arg[dp->arg_index].a.a_string);
463 break;
464
465 case 'p':
466 tmp_length =
467 (unsigned int) (sizeof (void *) * CHAR_BIT
468 * 0.25 /* binary -> hexadecimal */
469 )
470 + 1 /* turn floor into ceil */
471 + 2; /* account for leading 0x */
472 break;
473
474 default:
475 abort ();
476 }
477
478 if (tmp_length < width)
479 tmp_length = width;
480
481 tmp_length = xsum (tmp_length, 1); /* account for trailing NUL */
482 }
483
484 if (tmp_length <= sizeof (tmpbuf) / sizeof (CHAR_T))
485 tmp = tmpbuf;
486 else
487 {
488 size_t tmp_memsize = xtimes (tmp_length, sizeof (CHAR_T));
489
490 if (size_overflow_p (tmp_memsize))
491 /* Overflow, would lead to out of memory. */
492 goto out_of_memory;
493 tmp = (CHAR_T *) malloc (tmp_memsize);
494 if (tmp == NULL)
495 /* Out of memory. */
496 goto out_of_memory;
497 }
498 #endif
499
500 /* Construct the format string for calling snprintf or
501 sprintf. */
502 p = buf;
503 *p++ = '%';
504 if (dp->flags & FLAG_GROUP)
505 *p++ = '\'';
506 if (dp->flags & FLAG_LEFT)
507 *p++ = '-';
508 if (dp->flags & FLAG_SHOWSIGN)
509 *p++ = '+';
510 if (dp->flags & FLAG_SPACE)
511 *p++ = ' ';
512 if (dp->flags & FLAG_ALT)
513 *p++ = '#';
514 if (dp->flags & FLAG_ZERO)
515 *p++ = '0';
516 if (dp->width_start != dp->width_end)
517 {
518 size_t n = dp->width_end - dp->width_start;
519 memcpy (p, dp->width_start, n * sizeof (CHAR_T));
520 p += n;
521 }
522 if (dp->precision_start != dp->precision_end)
523 {
524 size_t n = dp->precision_end - dp->precision_start;
525 memcpy (p, dp->precision_start, n * sizeof (CHAR_T));
526 p += n;
527 }
528
529 switch (type)
530 {
531 #ifdef HAVE_LONG_LONG_INT
532 case TYPE_LONGLONGINT:
533 case TYPE_ULONGLONGINT:
534 *p++ = 'l';
535 /*FALLTHROUGH*/
536 #endif
537 case TYPE_LONGINT:
538 case TYPE_ULONGINT:
539 #ifdef HAVE_WINT_T
540 case TYPE_WIDE_CHAR:
541 #endif
542 #ifdef HAVE_WCHAR_T
543 case TYPE_WIDE_STRING:
544 #endif
545 *p++ = 'l';
546 break;
547 #ifdef HAVE_LONG_DOUBLE
548 case TYPE_LONGDOUBLE:
549 *p++ = 'L';
550 break;
551 #endif
552 default:
553 break;
554 }
555 *p = dp->conversion;
556 #if USE_SNPRINTF
557 p[1] = '%';
558 p[2] = 'n';
559 p[3] = '\0';
560 #else
561 p[1] = '\0';
562 #endif
563
564 /* Construct the arguments for calling snprintf or sprintf. */
565 prefix_count = 0;
566 if (dp->width_arg_index != ARG_NONE)
567 {
568 if (!(a.arg[dp->width_arg_index].type == TYPE_INT))
569 abort ();
570 prefixes[prefix_count++] = a.arg[dp->width_arg_index].a.a_int;
571 }
572 if (dp->precision_arg_index != ARG_NONE)
573 {
574 if (!(a.arg[dp->precision_arg_index].type == TYPE_INT))
575 abort ();
576 prefixes[prefix_count++] = a.arg[dp->precision_arg_index].a.a_int;
577 }
578
579 #if USE_SNPRINTF
580 /* Prepare checking whether snprintf returns the count
581 via %n. */
582 ENSURE_ALLOCATION (xsum (length, 1));
583 result[length] = '\0';
584 #endif
585
586 for (;;)
587 {
588 size_t maxlen;
589 int count;
590 int retcount;
591
592 maxlen = allocated - length;
593 count = -1;
594 retcount = 0;
595
596 #if USE_SNPRINTF
597 # define SNPRINTF_BUF(arg) \
598 switch (prefix_count) \
599 { \
600 case 0: \
601 retcount = SNPRINTF (result + length, maxlen, buf, \
602 arg, &count); \
603 break; \
604 case 1: \
605 retcount = SNPRINTF (result + length, maxlen, buf, \
606 prefixes[0], arg, &count); \
607 break; \
608 case 2: \
609 retcount = SNPRINTF (result + length, maxlen, buf, \
610 prefixes[0], prefixes[1], arg, \
611 &count); \
612 break; \
613 default: \
614 abort (); \
615 }
616 #else
617 # define SNPRINTF_BUF(arg) \
618 switch (prefix_count) \
619 { \
620 case 0: \
621 count = sprintf (tmp, buf, arg); \
622 break; \
623 case 1: \
624 count = sprintf (tmp, buf, prefixes[0], arg); \
625 break; \
626 case 2: \
627 count = sprintf (tmp, buf, prefixes[0], prefixes[1],\
628 arg); \
629 break; \
630 default: \
631 abort (); \
632 }
633 #endif
634
635 switch (type)
636 {
637 case TYPE_SCHAR:
638 {
639 int arg = a.arg[dp->arg_index].a.a_schar;
640 SNPRINTF_BUF (arg);
641 }
642 break;
643 case TYPE_UCHAR:
644 {
645 unsigned int arg = a.arg[dp->arg_index].a.a_uchar;
646 SNPRINTF_BUF (arg);
647 }
648 break;
649 case TYPE_SHORT:
650 {
651 int arg = a.arg[dp->arg_index].a.a_short;
652 SNPRINTF_BUF (arg);
653 }
654 break;
655 case TYPE_USHORT:
656 {
657 unsigned int arg = a.arg[dp->arg_index].a.a_ushort;
658 SNPRINTF_BUF (arg);
659 }
660 break;
661 case TYPE_INT:
662 {
663 int arg = a.arg[dp->arg_index].a.a_int;
664 SNPRINTF_BUF (arg);
665 }
666 break;
667 case TYPE_UINT:
668 {
669 unsigned int arg = a.arg[dp->arg_index].a.a_uint;
670 SNPRINTF_BUF (arg);
671 }
672 break;
673 case TYPE_LONGINT:
674 {
675 long int arg = a.arg[dp->arg_index].a.a_longint;
676 SNPRINTF_BUF (arg);
677 }
678 break;
679 case TYPE_ULONGINT:
680 {
681 unsigned long int arg = a.arg[dp->arg_index].a.a_ulongint;
682 SNPRINTF_BUF (arg);
683 }
684 break;
685 #ifdef HAVE_LONG_LONG_INT
686 case TYPE_LONGLONGINT:
687 {
688 long long int arg = a.arg[dp->arg_index].a.a_longlongint;
689 SNPRINTF_BUF (arg);
690 }
691 break;
692 case TYPE_ULONGLONGINT:
693 {
694 unsigned long long int arg = a.arg[dp->arg_index].a.a_ulonglongint;
695 SNPRINTF_BUF (arg);
696 }
697 break;
698 #endif
699 case TYPE_DOUBLE:
700 {
701 double arg = a.arg[dp->arg_index].a.a_double;
702 SNPRINTF_BUF (arg);
703 }
704 break;
705 #ifdef HAVE_LONG_DOUBLE
706 case TYPE_LONGDOUBLE:
707 {
708 long double arg = a.arg[dp->arg_index].a.a_longdouble;
709 SNPRINTF_BUF (arg);
710 }
711 break;
712 #endif
713 case TYPE_CHAR:
714 {
715 int arg = a.arg[dp->arg_index].a.a_char;
716 SNPRINTF_BUF (arg);
717 }
718 break;
719 #ifdef HAVE_WINT_T
720 case TYPE_WIDE_CHAR:
721 {
722 wint_t arg = a.arg[dp->arg_index].a.a_wide_char;
723 SNPRINTF_BUF (arg);
724 }
725 break;
726 #endif
727 case TYPE_STRING:
728 {
729 const char *arg = a.arg[dp->arg_index].a.a_string;
730 SNPRINTF_BUF (arg);
731 }
732 break;
733 #ifdef HAVE_WCHAR_T
734 case TYPE_WIDE_STRING:
735 {
736 const wchar_t *arg = a.arg[dp->arg_index].a.a_wide_string;
737 SNPRINTF_BUF (arg);
738 }
739 break;
740 #endif
741 case TYPE_POINTER:
742 {
743 void *arg = a.arg[dp->arg_index].a.a_pointer;
744 SNPRINTF_BUF (arg);
745 }
746 break;
747 default:
748 abort ();
749 }
750
751 #if USE_SNPRINTF
752 /* Portability: Not all implementations of snprintf()
753 are ISO C 99 compliant. Determine the number of
754 bytes that snprintf() has produced or would have
755 produced. */
756 if (count >= 0)
757 {
758 /* Verify that snprintf() has NUL-terminated its
759 result. */
760 if (count < maxlen && result[length + count] != '\0')
761 abort ();
762 /* Portability hack. */
763 if (retcount > count)
764 count = retcount;
765 }
766 else
767 {
768 /* snprintf() doesn't understand the '%n'
769 directive. */
770 if (p[1] != '\0')
771 {
772 /* Don't use the '%n' directive; instead, look
773 at the snprintf() return value. */
774 p[1] = '\0';
775 continue;
776 }
777 else
778 {
779 /* Look at the snprintf() return value. */
780 if (retcount < 0)
781 {
782 /* HP-UX 10.20 snprintf() is doubly deficient:
783 It doesn't understand the '%n' directive,
784 *and* it returns -1 (rather than the length
785 that would have been required) when the
786 buffer is too small. */
787 size_t bigger_need =
788 xsum (xtimes (allocated, 2), 12);
789 ENSURE_ALLOCATION (bigger_need);
790 continue;
791 }
792 else
793 count = retcount;
794 }
795 }
796 #endif
797
798 /* Attempt to handle failure. */
799 if (count < 0)
800 {
801 if (!(result == resultbuf || result == NULL))
802 free (result);
803 if (buf_malloced != NULL)
804 free (buf_malloced);
805 CLEANUP ();
806 errno = EINVAL;
807 return NULL;
808 }
809
810 #if !USE_SNPRINTF
811 if (count >= tmp_length)
812 /* tmp_length was incorrectly calculated - fix the
813 code above! */
814 abort ();
815 #endif
816
817 /* Make room for the result. */
818 if (count >= maxlen)
819 {
820 /* Need at least count bytes. But allocate
821 proportionally, to avoid looping eternally if
822 snprintf() reports a too small count. */
823 size_t n =
824 xmax (xsum (length, count), xtimes (allocated, 2));
825
826 ENSURE_ALLOCATION (n);
827 #if USE_SNPRINTF
828 continue;
829 #endif
830 }
831
832 #if USE_SNPRINTF
833 /* The snprintf() result did fit. */
834 #else
835 /* Append the sprintf() result. */
836 memcpy (result + length, tmp, count * sizeof (CHAR_T));
837 if (tmp != tmpbuf)
838 free (tmp);
839 #endif
840
841 length += count;
842 break;
843 }
844 }
845 }
846 }
847
848 /* Add the final NUL. */
849 ENSURE_ALLOCATION (xsum (length, 1));
850 result[length] = '\0';
851
852 if (result != resultbuf && length + 1 < allocated)
853 {
854 /* Shrink the allocated memory if possible. */
855 CHAR_T *memory;
856
857 memory = (CHAR_T *) realloc (result, (length + 1) * sizeof (CHAR_T));
858 if (memory != NULL)
859 result = memory;
860 }
861
862 if (buf_malloced != NULL)
863 free (buf_malloced);
864 CLEANUP ();
865 *lengthp = length;
866 /* Note that we can produce a big string of a length > INT_MAX. POSIX
867 says that snprintf() fails with errno = EOVERFLOW in this case, but
868 that's only because snprintf() returns an 'int'. This function does
869 not have this limitation. */
870 return result;
871
872 out_of_memory:
873 if (!(result == resultbuf || result == NULL))
874 free (result);
875 if (buf_malloced != NULL)
876 free (buf_malloced);
877 out_of_memory_1:
878 CLEANUP ();
879 errno = ENOMEM;
880 return NULL;
881 }
882 }
883
884 #undef SNPRINTF
885 #undef USE_SNPRINTF
886 #undef PRINTF_PARSE
887 #undef DIRECTIVES
888 #undef DIRECTIVE
889 #undef CHAR_T
890 #undef VASNPRINTF
891