source: trunk/essentials/app-arch/cpio/lib/vasnprintf.c

Last change on this file was 3332, checked in by bird, 18 years ago

cpio 2.7
File size: 21.8 KB
Line 
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
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)
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
12 GNU General Public License for more details.
13
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
17
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. */
21#ifndef _GNU_SOURCE
22# define _GNU_SOURCE 1
23#endif
24
25#include <config.h>
26#ifndef IN_LIBINTL
27# include <alloca.h>
28#endif
29
30/* Specification. */
31#if WIDE_CHAR_VERSION
32# include "vasnwprintf.h"
33#else
34# include "vasnprintf.h"
35#endif
36
37#include <stdio.h> /* snprintf(), sprintf() */
38#include <stdlib.h> /* abort(), malloc(), realloc(), free() */
39#include <string.h> /* memcpy(), strlen() */
40#include <errno.h> /* errno */
41#include <limits.h> /* CHAR_BIT */
42#include <float.h> /* DBL_MAX_EXP, LDBL_MAX_EXP */
43#if WIDE_CHAR_VERSION
44# include "wprintf-parse.h"
45#else
46# include "printf-parse.h"
47#endif
48
49/* Checked size_t computations. */
50#include "xsize.h"
51
52#ifdef HAVE_WCHAR_T
53# ifdef HAVE_WCSLEN
54# define local_wcslen wcslen
55# else
56 /* Solaris 2.5.1 has wcslen() in a separate library libw.so. To avoid
57 a dependency towards this library, here is a local substitute.
58 Define this substitute only once, even if this file is included
59 twice in the same compilation unit. */
60# ifndef local_wcslen_defined
61# define local_wcslen_defined 1
62static size_t
63local_wcslen (const wchar_t *s)
64{
65 const wchar_t *ptr;
66
67 for (ptr = s; *ptr != (wchar_t) 0; ptr++)
68 ;
69 return ptr - s;
70}
71# endif
72# endif
73#endif
74
75#if WIDE_CHAR_VERSION
76# define VASNPRINTF vasnwprintf
77# define CHAR_T wchar_t
78# define DIRECTIVE wchar_t_directive
79# define DIRECTIVES wchar_t_directives
80# define PRINTF_PARSE wprintf_parse
81# define USE_SNPRINTF 1
82# if HAVE_DECL__SNWPRINTF
83 /* On Windows, the function swprintf() has a different signature than
84 on Unix; we use the _snwprintf() function instead. */
85# define SNPRINTF _snwprintf
86# else
87 /* Unix. */
88# define SNPRINTF swprintf
89# endif
90#else
91# define VASNPRINTF vasnprintf
92# define CHAR_T char
93# define DIRECTIVE char_directive
94# define DIRECTIVES char_directives
95# define PRINTF_PARSE printf_parse
96# define USE_SNPRINTF (HAVE_DECL__SNPRINTF || HAVE_SNPRINTF)
97# if HAVE_DECL__SNPRINTF
98 /* Windows. */
99# define SNPRINTF _snprintf
100# else
101 /* Unix. */
102# define SNPRINTF snprintf
103# endif
104#endif
105
106CHAR_T *
107VASNPRINTF (CHAR_T *resultbuf, size_t *lengthp, const CHAR_T *format, va_list args)
108{
109 DIRECTIVES d;
110 arguments a;
111
112 if (PRINTF_PARSE (format, &d, &a) < 0)
113 {
114 errno = EINVAL;
115 return NULL;
116 }
117
118#define CLEANUP() \
119 free (d.dir); \
120 if (a.arg) \
121 free (a.arg);
122
123 if (printf_fetchargs (args, &a) < 0)
124 {
125 CLEANUP ();
126 errno = EINVAL;
127 return NULL;
128 }
129
130 {
131 size_t buf_neededlength;
132 CHAR_T *buf;
133 CHAR_T *buf_malloced;
134 const CHAR_T *cp;
135 size_t i;
136 DIRECTIVE *dp;
137 /* Output string accumulator. */
138 CHAR_T *result;
139 size_t allocated;
140 size_t length;
141
142 /* Allocate a small buffer that will hold a directive passed to
143 sprintf or snprintf. */
144 buf_neededlength =
145 xsum4 (7, d.max_width_length, d.max_precision_length, 6);
146#if HAVE_ALLOCA
147 if (buf_neededlength < 4000 / sizeof (CHAR_T))
148 {
149 buf = (CHAR_T *) alloca (buf_neededlength * sizeof (CHAR_T));
150 buf_malloced = NULL;
151 }
152 else
153#endif
154 {
155 size_t buf_memsize = xtimes (buf_neededlength, sizeof (CHAR_T));
156 if (size_overflow_p (buf_memsize))
157 goto out_of_memory_1;
158 buf = (CHAR_T *) malloc (buf_memsize);
159 if (buf == NULL)
160 goto out_of_memory_1;
161 buf_malloced = buf;
162 }
163
164 if (resultbuf != NULL)
165 {
166 result = resultbuf;
167 allocated = *lengthp;
168 }
169 else
170 {
171 result = NULL;
172 allocated = 0;
173 }
174 length = 0;
175 /* Invariants:
176 result is either == resultbuf or == NULL or malloc-allocated.
177 If length > 0, then result != NULL. */
178
179 /* Ensures that allocated >= needed. Aborts through a jump to
180 out_of_memory if needed is SIZE_MAX or otherwise too big. */
181#define ENSURE_ALLOCATION(needed) \
182 if ((needed) > allocated) \
183 { \
184 size_t memory_size; \
185 CHAR_T *memory; \
186 \
187 allocated = (allocated > 0 ? xtimes (allocated, 2) : 12); \
188 if ((needed) > allocated) \
189 allocated = (needed); \
190 memory_size = xtimes (allocated, sizeof (CHAR_T)); \
191 if (size_overflow_p (memory_size)) \
192 goto out_of_memory; \
193 if (result == resultbuf || result == NULL) \
194 memory = (CHAR_T *) malloc (memory_size); \
195 else \
196 memory = (CHAR_T *) realloc (result, memory_size); \
197 if (memory == NULL) \
198 goto out_of_memory; \
199 if (result == resultbuf && length > 0) \
200 memcpy (memory, result, length * sizeof (CHAR_T)); \
201 result = memory; \
202 }
203
204 for (cp = format, i = 0, dp = &d.dir[0]; ; cp = dp->dir_end, i++, dp++)
205 {
206 if (cp != dp->dir_start)
207 {
208 size_t n = dp->dir_start - cp;
209 size_t augmented_length = xsum (length, n);
210
211 ENSURE_ALLOCATION (augmented_length);
212 memcpy (result + length, cp, n * sizeof (CHAR_T));
213 length = augmented_length;
214 }
215 if (i == d.count)
216 break;
217
218 /* Execute a single directive. */
219 if (dp->conversion == '%')
220 {
221 size_t augmented_length;
222
223 if (!(dp->arg_index == ARG_NONE))
224 abort ();
225 augmented_length = xsum (length, 1);
226 ENSURE_ALLOCATION (augmented_length);
227 result[length] = '%';
228 length = augmented_length;
229 }
230 else
231 {
232 if (!(dp->arg_index != ARG_NONE))
233 abort ();
234
235 if (dp->conversion == 'n')
236 {
237 switch (a.arg[dp->arg_index].type)
238 {
239 case TYPE_COUNT_SCHAR_POINTER:
240 *a.arg[dp->arg_index].a.a_count_schar_pointer = length;
241 break;
242 case TYPE_COUNT_SHORT_POINTER:
243 *a.arg[dp->arg_index].a.a_count_short_pointer = length;
244 break;
245 case TYPE_COUNT_INT_POINTER:
246 *a.arg[dp->arg_index].a.a_count_int_pointer = length;
247 break;
248 case TYPE_COUNT_LONGINT_POINTER:
249 *a.arg[dp->arg_index].a.a_count_longint_pointer = length;
250 break;
251#ifdef HAVE_LONG_LONG
252 case TYPE_COUNT_LONGLONGINT_POINTER:
253 *a.arg[dp->arg_index].a.a_count_longlongint_pointer = length;
254 break;
255#endif
256 default:
257 abort ();
258 }
259 }
260 else
261 {
262 arg_type type = a.arg[dp->arg_index].type;
263 CHAR_T *p;
264 unsigned int prefix_count;
265 int prefixes[2];
266#if !USE_SNPRINTF
267 size_t tmp_length;
268 CHAR_T tmpbuf[700];
269 CHAR_T *tmp;
270
271 /* Allocate a temporary buffer of sufficient size for calling
272 sprintf. */
273 {
274 size_t width;
275 size_t precision;
276
277 width = 0;
278 if (dp->width_start != dp->width_end)
279 {
280 if (dp->width_arg_index != ARG_NONE)
281 {
282 int arg;
283
284 if (!(a.arg[dp->width_arg_index].type == TYPE_INT))
285 abort ();
286 arg = a.arg[dp->width_arg_index].a.a_int;
287 width = (arg < 0 ? (unsigned int) (-arg) : arg);
288 }
289 else
290 {
291 const CHAR_T *digitp = dp->width_start;
292
293 do
294 width = xsum (xtimes (width, 10), *digitp++ - '0');
295 while (digitp != dp->width_end);
296 }
297 }
298
299 precision = 6;
300 if (dp->precision_start != dp->precision_end)
301 {
302 if (dp->precision_arg_index != ARG_NONE)
303 {
304 int arg;
305
306 if (!(a.arg[dp->precision_arg_index].type == TYPE_INT))
307 abort ();
308 arg = a.arg[dp->precision_arg_index].a.a_int;
309 precision = (arg < 0 ? 0 : arg);
310 }
311 else
312 {
313 const CHAR_T *digitp = dp->precision_start + 1;
314
315 precision = 0;
316 while (digitp != dp->precision_end)
317 precision = xsum (xtimes (precision, 10), *digitp++ - '0');
318 }
319 }
320
321 switch (dp->conversion)
322 {
323
324 case 'd': case 'i': case 'u':
325# ifdef HAVE_LONG_LONG
326 if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
327 tmp_length =
328 (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
329 * 0.30103 /* binary -> decimal */
330 )
331 + 1; /* turn floor into ceil */
332 else
333# endif
334 if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
335 tmp_length =
336 (unsigned int) (sizeof (unsigned long) * CHAR_BIT
337 * 0.30103 /* binary -> decimal */
338 )
339 + 1; /* turn floor into ceil */
340 else
341 tmp_length =
342 (unsigned int) (sizeof (unsigned int) * CHAR_BIT
343 * 0.30103 /* binary -> decimal */
344 )
345 + 1; /* turn floor into ceil */
346 if (tmp_length < precision)
347 tmp_length = precision;
348 /* Multiply by 2, as an estimate for FLAG_GROUP. */
349 tmp_length = xsum (tmp_length, tmp_length);
350 /* Add 1, to account for a leading sign. */
351 tmp_length = xsum (tmp_length, 1);
352 break;
353
354 case 'o':
355# ifdef HAVE_LONG_LONG
356 if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
357 tmp_length =
358 (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
359 * 0.333334 /* binary -> octal */
360 )
361 + 1; /* turn floor into ceil */
362 else
363# endif
364 if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
365 tmp_length =
366 (unsigned int) (sizeof (unsigned long) * CHAR_BIT
367 * 0.333334 /* binary -> octal */
368 )
369 + 1; /* turn floor into ceil */
370 else
371 tmp_length =
372 (unsigned int) (sizeof (unsigned int) * CHAR_BIT
373 * 0.333334 /* binary -> octal */
374 )
375 + 1; /* turn floor into ceil */
376 if (tmp_length < precision)
377 tmp_length = precision;
378 /* Add 1, to account for a leading sign. */
379 tmp_length = xsum (tmp_length, 1);
380 break;
381
382 case 'x': case 'X':
383# ifdef HAVE_LONG_LONG
384 if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
385 tmp_length =
386 (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
387 * 0.25 /* binary -> hexadecimal */
388 )
389 + 1; /* turn floor into ceil */
390 else
391# endif
392 if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
393 tmp_length =
394 (unsigned int) (sizeof (unsigned long) * CHAR_BIT
395 * 0.25 /* binary -> hexadecimal */
396 )
397 + 1; /* turn floor into ceil */
398 else
399 tmp_length =
400 (unsigned int) (sizeof (unsigned int) * CHAR_BIT
401 * 0.25 /* binary -> hexadecimal */
402 )
403 + 1; /* turn floor into ceil */
404 if (tmp_length < precision)
405 tmp_length = precision;
406 /* Add 2, to account for a leading sign or alternate form. */
407 tmp_length = xsum (tmp_length, 2);
408 break;
409
410 case 'f': case 'F':
411# ifdef HAVE_LONG_DOUBLE
412 if (type == TYPE_LONGDOUBLE)
413 tmp_length =
414 (unsigned int) (LDBL_MAX_EXP
415 * 0.30103 /* binary -> decimal */
416 * 2 /* estimate for FLAG_GROUP */
417 )
418 + 1 /* turn floor into ceil */
419 + 10; /* sign, decimal point etc. */
420 else
421# endif
422 tmp_length =
423 (unsigned int) (DBL_MAX_EXP
424 * 0.30103 /* binary -> decimal */
425 * 2 /* estimate for FLAG_GROUP */
426 )
427 + 1 /* turn floor into ceil */
428 + 10; /* sign, decimal point etc. */
429 tmp_length = xsum (tmp_length, precision);
430 break;
431
432 case 'e': case 'E': case 'g': case 'G':
433 case 'a': case 'A':
434 tmp_length =
435 12; /* sign, decimal point, exponent etc. */
436 tmp_length = xsum (tmp_length, precision);
437 break;
438
439 case 'c':
440# if defined HAVE_WINT_T && !WIDE_CHAR_VERSION
441 if (type == TYPE_WIDE_CHAR)
442 tmp_length = MB_CUR_MAX;
443 else
444# endif
445 tmp_length = 1;
446 break;
447
448 case 's':
449# ifdef HAVE_WCHAR_T
450 if (type == TYPE_WIDE_STRING)
451 {
452 tmp_length =
453 local_wcslen (a.arg[dp->arg_index].a.a_wide_string);
454
455# if !WIDE_CHAR_VERSION
456 tmp_length = xtimes (tmp_length, MB_CUR_MAX);
457# endif
458 }
459 else
460# endif
461 tmp_length = strlen (a.arg[dp->arg_index].a.a_string);
462 break;
463
464 case 'p':
465 tmp_length =
466 (unsigned int) (sizeof (void *) * CHAR_BIT
467 * 0.25 /* binary -> hexadecimal */
468 )
469 + 1 /* turn floor into ceil */
470 + 2; /* account for leading 0x */
471 break;
472
473 default:
474 abort ();
475 }
476
477 if (tmp_length < width)
478 tmp_length = width;
479
480 tmp_length = xsum (tmp_length, 1); /* account for trailing NUL */
481 }
482
483 if (tmp_length <= sizeof (tmpbuf) / sizeof (CHAR_T))
484 tmp = tmpbuf;
485 else
486 {
487 size_t tmp_memsize = xtimes (tmp_length, sizeof (CHAR_T));
488
489 if (size_overflow_p (tmp_memsize))
490 /* Overflow, would lead to out of memory. */
491 goto out_of_memory;
492 tmp = (CHAR_T *) malloc (tmp_memsize);
493 if (tmp == NULL)
494 /* Out of memory. */
495 goto out_of_memory;
496 }
497#endif
498
499 /* Construct the format string for calling snprintf or
500 sprintf. */
501 p = buf;
502 *p++ = '%';
503 if (dp->flags & FLAG_GROUP)
504 *p++ = '\'';
505 if (dp->flags & FLAG_LEFT)
506 *p++ = '-';
507 if (dp->flags & FLAG_SHOWSIGN)
508 *p++ = '+';
509 if (dp->flags & FLAG_SPACE)
510 *p++ = ' ';
511 if (dp->flags & FLAG_ALT)
512 *p++ = '#';
513 if (dp->flags & FLAG_ZERO)
514 *p++ = '0';
515 if (dp->width_start != dp->width_end)
516 {
517 size_t n = dp->width_end - dp->width_start;
518 memcpy (p, dp->width_start, n * sizeof (CHAR_T));
519 p += n;
520 }
521 if (dp->precision_start != dp->precision_end)
522 {
523 size_t n = dp->precision_end - dp->precision_start;
524 memcpy (p, dp->precision_start, n * sizeof (CHAR_T));
525 p += n;
526 }
527
528 switch (type)
529 {
530#ifdef HAVE_LONG_LONG
531 case TYPE_LONGLONGINT:
532 case TYPE_ULONGLONGINT:
533 *p++ = 'l';
534 /*FALLTHROUGH*/
535#endif
536 case TYPE_LONGINT:
537 case TYPE_ULONGINT:
538#ifdef HAVE_WINT_T
539 case TYPE_WIDE_CHAR:
540#endif
541#ifdef HAVE_WCHAR_T
542 case TYPE_WIDE_STRING:
543#endif
544 *p++ = 'l';
545 break;
546#ifdef HAVE_LONG_DOUBLE
547 case TYPE_LONGDOUBLE:
548 *p++ = 'L';
549 break;
550#endif
551 default:
552 break;
553 }
554 *p = dp->conversion;
555#if USE_SNPRINTF
556 p[1] = '%';
557 p[2] = 'n';
558 p[3] = '\0';
559#else
560 p[1] = '\0';
561#endif
562
563 /* Construct the arguments for calling snprintf or sprintf. */
564 prefix_count = 0;
565 if (dp->width_arg_index != ARG_NONE)
566 {
567 if (!(a.arg[dp->width_arg_index].type == TYPE_INT))
568 abort ();
569 prefixes[prefix_count++] = a.arg[dp->width_arg_index].a.a_int;
570 }
571 if (dp->precision_arg_index != ARG_NONE)
572 {
573 if (!(a.arg[dp->precision_arg_index].type == TYPE_INT))
574 abort ();
575 prefixes[prefix_count++] = a.arg[dp->precision_arg_index].a.a_int;
576 }
577
578#if USE_SNPRINTF
579 /* Prepare checking whether snprintf returns the count
580 via %n. */
581 ENSURE_ALLOCATION (xsum (length, 1));
582 result[length] = '\0';
583#endif
584
585 for (;;)
586 {
587 size_t maxlen;
588 int count;
589 int retcount;
590
591 maxlen = allocated - length;
592 count = -1;
593 retcount = 0;
594
595#if USE_SNPRINTF
596# define SNPRINTF_BUF(arg) \
597 switch (prefix_count) \
598 { \
599 case 0: \
600 retcount = SNPRINTF (result + length, maxlen, buf, \
601 arg, &count); \
602 break; \
603 case 1: \
604 retcount = SNPRINTF (result + length, maxlen, buf, \
605 prefixes[0], arg, &count); \
606 break; \
607 case 2: \
608 retcount = SNPRINTF (result + length, maxlen, buf, \
609 prefixes[0], prefixes[1], arg, \
610 &count); \
611 break; \
612 default: \
613 abort (); \
614 }
615#else
616# define SNPRINTF_BUF(arg) \
617 switch (prefix_count) \
618 { \
619 case 0: \
620 count = sprintf (tmp, buf, arg); \
621 break; \
622 case 1: \
623 count = sprintf (tmp, buf, prefixes[0], arg); \
624 break; \
625 case 2: \
626 count = sprintf (tmp, buf, prefixes[0], prefixes[1],\
627 arg); \
628 break; \
629 default: \
630 abort (); \
631 }
632#endif
633
634 switch (type)
635 {
636 case TYPE_SCHAR:
637 {
638 int arg = a.arg[dp->arg_index].a.a_schar;
639 SNPRINTF_BUF (arg);
640 }
641 break;
642 case TYPE_UCHAR:
643 {
644 unsigned int arg = a.arg[dp->arg_index].a.a_uchar;
645 SNPRINTF_BUF (arg);
646 }
647 break;
648 case TYPE_SHORT:
649 {
650 int arg = a.arg[dp->arg_index].a.a_short;
651 SNPRINTF_BUF (arg);
652 }
653 break;
654 case TYPE_USHORT:
655 {
656 unsigned int arg = a.arg[dp->arg_index].a.a_ushort;
657 SNPRINTF_BUF (arg);
658 }
659 break;
660 case TYPE_INT:
661 {
662 int arg = a.arg[dp->arg_index].a.a_int;
663 SNPRINTF_BUF (arg);
664 }
665 break;
666 case TYPE_UINT:
667 {
668 unsigned int arg = a.arg[dp->arg_index].a.a_uint;
669 SNPRINTF_BUF (arg);
670 }
671 break;
672 case TYPE_LONGINT:
673 {
674 long int arg = a.arg[dp->arg_index].a.a_longint;
675 SNPRINTF_BUF (arg);
676 }
677 break;
678 case TYPE_ULONGINT:
679 {
680 unsigned long int arg = a.arg[dp->arg_index].a.a_ulongint;
681 SNPRINTF_BUF (arg);
682 }
683 break;
684#ifdef HAVE_LONG_LONG
685 case TYPE_LONGLONGINT:
686 {
687 long long int arg = a.arg[dp->arg_index].a.a_longlongint;
688 SNPRINTF_BUF (arg);
689 }
690 break;
691 case TYPE_ULONGLONGINT:
692 {
693 unsigned long long int arg = a.arg[dp->arg_index].a.a_ulonglongint;
694 SNPRINTF_BUF (arg);
695 }
696 break;
697#endif
698 case TYPE_DOUBLE:
699 {
700 double arg = a.arg[dp->arg_index].a.a_double;
701 SNPRINTF_BUF (arg);
702 }
703 break;
704#ifdef HAVE_LONG_DOUBLE
705 case TYPE_LONGDOUBLE:
706 {
707 long double arg = a.arg[dp->arg_index].a.a_longdouble;
708 SNPRINTF_BUF (arg);
709 }
710 break;
711#endif
712 case TYPE_CHAR:
713 {
714 int arg = a.arg[dp->arg_index].a.a_char;
715 SNPRINTF_BUF (arg);
716 }
717 break;
718#ifdef HAVE_WINT_T
719 case TYPE_WIDE_CHAR:
720 {
721 wint_t arg = a.arg[dp->arg_index].a.a_wide_char;
722 SNPRINTF_BUF (arg);
723 }
724 break;
725#endif
726 case TYPE_STRING:
727 {
728 const char *arg = a.arg[dp->arg_index].a.a_string;
729 SNPRINTF_BUF (arg);
730 }
731 break;
732#ifdef HAVE_WCHAR_T
733 case TYPE_WIDE_STRING:
734 {
735 const wchar_t *arg = a.arg[dp->arg_index].a.a_wide_string;
736 SNPRINTF_BUF (arg);
737 }
738 break;
739#endif
740 case TYPE_POINTER:
741 {
742 void *arg = a.arg[dp->arg_index].a.a_pointer;
743 SNPRINTF_BUF (arg);
744 }
745 break;
746 default:
747 abort ();
748 }
749
750#if USE_SNPRINTF
751 /* Portability: Not all implementations of snprintf()
752 are ISO C 99 compliant. Determine the number of
753 bytes that snprintf() has produced or would have
754 produced. */
755 if (count >= 0)
756 {
757 /* Verify that snprintf() has NUL-terminated its
758 result. */
759 if (count < maxlen && result[length + count] != '\0')
760 abort ();
761 /* Portability hack. */
762 if (retcount > count)
763 count = retcount;
764 }
765 else
766 {
767 /* snprintf() doesn't understand the '%n'
768 directive. */
769 if (p[1] != '\0')
770 {
771 /* Don't use the '%n' directive; instead, look
772 at the snprintf() return value. */
773 p[1] = '\0';
774 continue;
775 }
776 else
777 {
778 /* Look at the snprintf() return value. */
779 if (retcount < 0)
780 {
781 /* HP-UX 10.20 snprintf() is doubly deficient:
782 It doesn't understand the '%n' directive,
783 *and* it returns -1 (rather than the length
784 that would have been required) when the
785 buffer is too small. */
786 size_t bigger_need =
787 xsum (xtimes (allocated, 2), 12);
788 ENSURE_ALLOCATION (bigger_need);
789 continue;
790 }
791 else
792 count = retcount;
793 }
794 }
795#endif
796
797 /* Attempt to handle failure. */
798 if (count < 0)
799 {
800 if (!(result == resultbuf || result == NULL))
801 free (result);
802 if (buf_malloced != NULL)
803 free (buf_malloced);
804 CLEANUP ();
805 errno = EINVAL;
806 return NULL;
807 }
808
809#if !USE_SNPRINTF
810 if (count >= tmp_length)
811 /* tmp_length was incorrectly calculated - fix the
812 code above! */
813 abort ();
814#endif
815
816 /* Make room for the result. */
817 if (count >= maxlen)
818 {
819 /* Need at least count bytes. But allocate
820 proportionally, to avoid looping eternally if
821 snprintf() reports a too small count. */
822 size_t n =
823 xmax (xsum (length, count), xtimes (allocated, 2));
824
825 ENSURE_ALLOCATION (n);
826#if USE_SNPRINTF
827 continue;
828#endif
829 }
830
831#if USE_SNPRINTF
832 /* The snprintf() result did fit. */
833#else
834 /* Append the sprintf() result. */
835 memcpy (result + length, tmp, count * sizeof (CHAR_T));
836 if (tmp != tmpbuf)
837 free (tmp);
838#endif
839
840 length += count;
841 break;
842 }
843 }
844 }
845 }
846
847 /* Add the final NUL. */
848 ENSURE_ALLOCATION (xsum (length, 1));
849 result[length] = '\0';
850
851 if (result != resultbuf && length + 1 < allocated)
852 {
853 /* Shrink the allocated memory if possible. */
854 CHAR_T *memory;
855
856 memory = (CHAR_T *) realloc (result, (length + 1) * sizeof (CHAR_T));
857 if (memory != NULL)
858 result = memory;
859 }
860
861 if (buf_malloced != NULL)
862 free (buf_malloced);
863 CLEANUP ();
864 *lengthp = length;
865 /* Note that we can produce a big string of a length > INT_MAX. POSIX
866 says that snprintf() fails with errno = EOVERFLOW in this case, but
867 that's only because snprintf() returns an 'int'. This function does
868 not have this limitation. */
869 return result;
870
871 out_of_memory:
872 if (!(result == resultbuf || result == NULL))
873 free (result);
874 if (buf_malloced != NULL)
875 free (buf_malloced);
876 out_of_memory_1:
877 CLEANUP ();
878 errno = ENOMEM;
879 return NULL;
880 }
881}
882
883#undef SNPRINTF
884#undef USE_SNPRINTF
885#undef PRINTF_PARSE
886#undef DIRECTIVES
887#undef DIRECTIVE
888#undef CHAR_T
889#undef VASNPRINTF
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