source: trunk/texinfo/intl/vasnprintf.c@ 2658

Last change on this file since 2658 was 2617, checked in by bird, 20 years ago

GNU Texinfo 4.8
File size: 21.5 KB
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1/* vsprintf with automatic memory allocation.
2 Copyright (C) 1999, 2002-2003 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
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#ifdef HAVE_CONFIG_H
27# include <config.h>
28#endif
29#ifndef IN_LIBINTL
30# include <alloca.h>
31#endif
32
33/* Specification. */
34#if WIDE_CHAR_VERSION
35# include "vasnwprintf.h"
36#else
37# include "vasnprintf.h"
38#endif
39
40#include <stdio.h> /* snprintf(), sprintf() */
41#include <stdlib.h> /* abort(), malloc(), realloc(), free() */
42#include <string.h> /* memcpy(), strlen() */
43#include <errno.h> /* errno */
44#include <limits.h> /* CHAR_BIT */
45#include <float.h> /* DBL_MAX_EXP, LDBL_MAX_EXP */
46#if WIDE_CHAR_VERSION
47# include "wprintf-parse.h"
48#else
49# include "printf-parse.h"
50#endif
51
52/* Checked size_t computations. */
53#include "xsize.h"
54
55#ifdef HAVE_WCHAR_T
56# ifdef HAVE_WCSLEN
57# define local_wcslen wcslen
58# else
59 /* Solaris 2.5.1 has wcslen() in a separate library libw.so. To avoid
60 a dependency towards this library, here is a local substitute.
61 Define this substitute only once, even if this file is included
62 twice in the same compilation unit. */
63# ifndef local_wcslen_defined
64# define local_wcslen_defined 1
65static size_t
66local_wcslen (const wchar_t *s)
67{
68 const wchar_t *ptr;
69
70 for (ptr = s; *ptr != (wchar_t) 0; ptr++)
71 ;
72 return ptr - s;
73}
74# endif
75# endif
76#endif
77
78#if WIDE_CHAR_VERSION
79# define VASNPRINTF vasnwprintf
80# define CHAR_T wchar_t
81# define DIRECTIVE wchar_t_directive
82# define DIRECTIVES wchar_t_directives
83# define PRINTF_PARSE wprintf_parse
84# define USE_SNPRINTF 1
85# if HAVE_DECL__SNWPRINTF
86 /* On Windows, the function swprintf() has a different signature than
87 on Unix; we use the _snwprintf() function instead. */
88# define SNPRINTF _snwprintf
89# else
90 /* Unix. */
91# define SNPRINTF swprintf
92# endif
93#else
94# define VASNPRINTF vasnprintf
95# define CHAR_T char
96# define DIRECTIVE char_directive
97# define DIRECTIVES char_directives
98# define PRINTF_PARSE printf_parse
99# define USE_SNPRINTF (HAVE_DECL__SNPRINTF || HAVE_SNPRINTF)
100# if HAVE_DECL__SNPRINTF
101 /* Windows. */
102# define SNPRINTF _snprintf
103# else
104 /* Unix. */
105# define SNPRINTF snprintf
106# endif
107#endif
108
109CHAR_T *
110VASNPRINTF (CHAR_T *resultbuf, size_t *lengthp, const CHAR_T *format, va_list args)
111{
112 DIRECTIVES d;
113 arguments a;
114
115 if (PRINTF_PARSE (format, &d, &a) < 0)
116 {
117 errno = EINVAL;
118 return NULL;
119 }
120
121#define CLEANUP() \
122 free (d.dir); \
123 if (a.arg) \
124 free (a.arg);
125
126 if (printf_fetchargs (args, &a) < 0)
127 {
128 CLEANUP ();
129 errno = EINVAL;
130 return NULL;
131 }
132
133 {
134 size_t buf_neededlength;
135 CHAR_T *buf;
136 CHAR_T *buf_malloced;
137 const CHAR_T *cp;
138 size_t i;
139 DIRECTIVE *dp;
140 /* Output string accumulator. */
141 CHAR_T *result;
142 size_t allocated;
143 size_t length;
144
145 /* Allocate a small buffer that will hold a directive passed to
146 sprintf or snprintf. */
147 buf_neededlength =
148 xsum4 (7, d.max_width_length, d.max_precision_length, 6);
149#if HAVE_ALLOCA
150 if (buf_neededlength < 4000 / sizeof (CHAR_T))
151 {
152 buf = (CHAR_T *) alloca (buf_neededlength * sizeof (CHAR_T));
153 buf_malloced = NULL;
154 }
155 else
156#endif
157 {
158 size_t buf_memsize = xtimes (buf_neededlength, sizeof (CHAR_T));
159 if (size_overflow_p (buf_memsize))
160 goto out_of_memory_1;
161 buf = (CHAR_T *) malloc (buf_memsize);
162 if (buf == NULL)
163 goto out_of_memory_1;
164 buf_malloced = buf;
165 }
166
167 if (resultbuf != NULL)
168 {
169 result = resultbuf;
170 allocated = *lengthp;
171 }
172 else
173 {
174 result = NULL;
175 allocated = 0;
176 }
177 length = 0;
178 /* Invariants:
179 result is either == resultbuf or == NULL or malloc-allocated.
180 If length > 0, then result != NULL. */
181
182 /* Ensures that allocated >= needed. Aborts through a jump to
183 out_of_memory if needed is SIZE_MAX or otherwise too big. */
184#define ENSURE_ALLOCATION(needed) \
185 if ((needed) > allocated) \
186 { \
187 size_t memory_size; \
188 CHAR_T *memory; \
189 \
190 allocated = (allocated > 0 ? xtimes (allocated, 2) : 12); \
191 if ((needed) > allocated) \
192 allocated = (needed); \
193 memory_size = xtimes (allocated, sizeof (CHAR_T)); \
194 if (size_overflow_p (memory_size)) \
195 goto out_of_memory; \
196 if (result == resultbuf || result == NULL) \
197 memory = (CHAR_T *) malloc (memory_size); \
198 else \
199 memory = (CHAR_T *) realloc (result, memory_size); \
200 if (memory == NULL) \
201 goto out_of_memory; \
202 if (result == resultbuf && length > 0) \
203 memcpy (memory, result, length * sizeof (CHAR_T)); \
204 result = memory; \
205 }
206
207 for (cp = format, i = 0, dp = &d.dir[0]; ; cp = dp->dir_end, i++, dp++)
208 {
209 if (cp != dp->dir_start)
210 {
211 size_t n = dp->dir_start - cp;
212 size_t augmented_length = xsum (length, n);
213
214 ENSURE_ALLOCATION (augmented_length);
215 memcpy (result + length, cp, n * sizeof (CHAR_T));
216 length = augmented_length;
217 }
218 if (i == d.count)
219 break;
220
221 /* Execute a single directive. */
222 if (dp->conversion == '%')
223 {
224 size_t augmented_length;
225
226 if (!(dp->arg_index == ARG_NONE))
227 abort ();
228 augmented_length = xsum (length, 1);
229 ENSURE_ALLOCATION (augmented_length);
230 result[length] = '%';
231 length = augmented_length;
232 }
233 else
234 {
235 if (!(dp->arg_index != ARG_NONE))
236 abort ();
237
238 if (dp->conversion == 'n')
239 {
240 switch (a.arg[dp->arg_index].type)
241 {
242 case TYPE_COUNT_SCHAR_POINTER:
243 *a.arg[dp->arg_index].a.a_count_schar_pointer = length;
244 break;
245 case TYPE_COUNT_SHORT_POINTER:
246 *a.arg[dp->arg_index].a.a_count_short_pointer = length;
247 break;
248 case TYPE_COUNT_INT_POINTER:
249 *a.arg[dp->arg_index].a.a_count_int_pointer = length;
250 break;
251 case TYPE_COUNT_LONGINT_POINTER:
252 *a.arg[dp->arg_index].a.a_count_longint_pointer = length;
253 break;
254#ifdef HAVE_LONG_LONG
255 case TYPE_COUNT_LONGLONGINT_POINTER:
256 *a.arg[dp->arg_index].a.a_count_longlongint_pointer = length;
257 break;
258#endif
259 default:
260 abort ();
261 }
262 }
263 else
264 {
265 arg_type type = a.arg[dp->arg_index].type;
266 CHAR_T *p;
267 unsigned int prefix_count;
268 int prefixes[2];
269#if !USE_SNPRINTF
270 size_t tmp_length;
271 CHAR_T tmpbuf[700];
272 CHAR_T *tmp;
273
274 /* Allocate a temporary buffer of sufficient size for calling
275 sprintf. */
276 {
277 size_t width;
278 size_t precision;
279
280 width = 0;
281 if (dp->width_start != dp->width_end)
282 {
283 if (dp->width_arg_index != ARG_NONE)
284 {
285 int arg;
286
287 if (!(a.arg[dp->width_arg_index].type == TYPE_INT))
288 abort ();
289 arg = a.arg[dp->width_arg_index].a.a_int;
290 width = (arg < 0 ? (unsigned int) (-arg) : arg);
291 }
292 else
293 {
294 const CHAR_T *digitp = dp->width_start;
295
296 do
297 width = xsum (xtimes (width, 10), *digitp++ - '0');
298 while (digitp != dp->width_end);
299 }
300 }
301
302 precision = 6;
303 if (dp->precision_start != dp->precision_end)
304 {
305 if (dp->precision_arg_index != ARG_NONE)
306 {
307 int arg;
308
309 if (!(a.arg[dp->precision_arg_index].type == TYPE_INT))
310 abort ();
311 arg = a.arg[dp->precision_arg_index].a.a_int;
312 precision = (arg < 0 ? 0 : arg);
313 }
314 else
315 {
316 const CHAR_T *digitp = dp->precision_start + 1;
317
318 precision = 0;
319 do
320 precision = xsum (xtimes (precision, 10), *digitp++ - '0');
321 while (digitp != dp->precision_end);
322 }
323 }
324
325 switch (dp->conversion)
326 {
327
328 case 'd': case 'i': case 'u':
329# ifdef HAVE_LONG_LONG
330 if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
331 tmp_length =
332 (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
333 * 0.30103 /* binary -> decimal */
334 * 2 /* estimate for FLAG_GROUP */
335 )
336 + 1 /* turn floor into ceil */
337 + 1; /* account for leading sign */
338 else
339# endif
340 if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
341 tmp_length =
342 (unsigned int) (sizeof (unsigned long) * CHAR_BIT
343 * 0.30103 /* binary -> decimal */
344 * 2 /* estimate for FLAG_GROUP */
345 )
346 + 1 /* turn floor into ceil */
347 + 1; /* account for leading sign */
348 else
349 tmp_length =
350 (unsigned int) (sizeof (unsigned int) * CHAR_BIT
351 * 0.30103 /* binary -> decimal */
352 * 2 /* estimate for FLAG_GROUP */
353 )
354 + 1 /* turn floor into ceil */
355 + 1; /* account for leading sign */
356 break;
357
358 case 'o':
359# ifdef HAVE_LONG_LONG
360 if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
361 tmp_length =
362 (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
363 * 0.333334 /* binary -> octal */
364 )
365 + 1 /* turn floor into ceil */
366 + 1; /* account for leading sign */
367 else
368# endif
369 if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
370 tmp_length =
371 (unsigned int) (sizeof (unsigned long) * CHAR_BIT
372 * 0.333334 /* binary -> octal */
373 )
374 + 1 /* turn floor into ceil */
375 + 1; /* account for leading sign */
376 else
377 tmp_length =
378 (unsigned int) (sizeof (unsigned int) * CHAR_BIT
379 * 0.333334 /* binary -> octal */
380 )
381 + 1 /* turn floor into ceil */
382 + 1; /* account for leading sign */
383 break;
384
385 case 'x': case 'X':
386# ifdef HAVE_LONG_LONG
387 if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
388 tmp_length =
389 (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
390 * 0.25 /* binary -> hexadecimal */
391 )
392 + 1 /* turn floor into ceil */
393 + 2; /* account for leading sign or alternate form */
394 else
395# endif
396 if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
397 tmp_length =
398 (unsigned int) (sizeof (unsigned long) * CHAR_BIT
399 * 0.25 /* binary -> hexadecimal */
400 )
401 + 1 /* turn floor into ceil */
402 + 2; /* account for leading sign or alternate form */
403 else
404 tmp_length =
405 (unsigned int) (sizeof (unsigned int) * CHAR_BIT
406 * 0.25 /* binary -> hexadecimal */
407 )
408 + 1 /* turn floor into ceil */
409 + 2; /* account for leading sign or alternate form */
410 break;
411
412 case 'f': case 'F':
413# ifdef HAVE_LONG_DOUBLE
414 if (type == TYPE_LONGDOUBLE)
415 tmp_length =
416 (unsigned int) (LDBL_MAX_EXP
417 * 0.30103 /* binary -> decimal */
418 * 2 /* estimate for FLAG_GROUP */
419 )
420 + 1 /* turn floor into ceil */
421 + 10; /* sign, decimal point etc. */
422 else
423# endif
424 tmp_length =
425 (unsigned int) (DBL_MAX_EXP
426 * 0.30103 /* binary -> decimal */
427 * 2 /* estimate for FLAG_GROUP */
428 )
429 + 1 /* turn floor into ceil */
430 + 10; /* sign, decimal point etc. */
431 tmp_length = xsum (tmp_length, precision);
432 break;
433
434 case 'e': case 'E': case 'g': case 'G':
435 case 'a': case 'A':
436 tmp_length =
437 12; /* sign, decimal point, exponent etc. */
438 tmp_length = xsum (tmp_length, precision);
439 break;
440
441 case 'c':
442# if defined HAVE_WINT_T && !WIDE_CHAR_VERSION
443 if (type == TYPE_WIDE_CHAR)
444 tmp_length = MB_CUR_MAX;
445 else
446# endif
447 tmp_length = 1;
448 break;
449
450 case 's':
451# ifdef HAVE_WCHAR_T
452 if (type == TYPE_WIDE_STRING)
453 {
454 tmp_length =
455 local_wcslen (a.arg[dp->arg_index].a.a_wide_string);
456
457# if !WIDE_CHAR_VERSION
458 tmp_length = xtimes (tmp_length, MB_CUR_MAX);
459# endif
460 }
461 else
462# endif
463 tmp_length = strlen (a.arg[dp->arg_index].a.a_string);
464 break;
465
466 case 'p':
467 tmp_length =
468 (unsigned int) (sizeof (void *) * CHAR_BIT
469 * 0.25 /* binary -> hexadecimal */
470 )
471 + 1 /* turn floor into ceil */
472 + 2; /* account for leading 0x */
473 break;
474
475 default:
476 abort ();
477 }
478
479 if (tmp_length < width)
480 tmp_length = width;
481
482 tmp_length = xsum (tmp_length, 1); /* account for trailing NUL */
483 }
484
485 if (tmp_length <= sizeof (tmpbuf) / sizeof (CHAR_T))
486 tmp = tmpbuf;
487 else
488 {
489 size_t tmp_memsize = xtimes (tmp_length, sizeof (CHAR_T));
490
491 if (size_overflow_p (tmp_memsize))
492 /* Overflow, would lead to out of memory. */
493 goto out_of_memory;
494 tmp = (CHAR_T *) malloc (tmp_memsize);
495 if (tmp == NULL)
496 /* Out of memory. */
497 goto out_of_memory;
498 }
499#endif
500
501 /* Construct the format string for calling snprintf or
502 sprintf. */
503 p = buf;
504 *p++ = '%';
505 if (dp->flags & FLAG_GROUP)
506 *p++ = '\'';
507 if (dp->flags & FLAG_LEFT)
508 *p++ = '-';
509 if (dp->flags & FLAG_SHOWSIGN)
510 *p++ = '+';
511 if (dp->flags & FLAG_SPACE)
512 *p++ = ' ';
513 if (dp->flags & FLAG_ALT)
514 *p++ = '#';
515 if (dp->flags & FLAG_ZERO)
516 *p++ = '0';
517 if (dp->width_start != dp->width_end)
518 {
519 size_t n = dp->width_end - dp->width_start;
520 memcpy (p, dp->width_start, n * sizeof (CHAR_T));
521 p += n;
522 }
523 if (dp->precision_start != dp->precision_end)
524 {
525 size_t n = dp->precision_end - dp->precision_start;
526 memcpy (p, dp->precision_start, n * sizeof (CHAR_T));
527 p += n;
528 }
529
530 switch (type)
531 {
532#ifdef HAVE_LONG_LONG
533 case TYPE_LONGLONGINT:
534 case TYPE_ULONGLONGINT:
535 *p++ = 'l';
536 /*FALLTHROUGH*/
537#endif
538 case TYPE_LONGINT:
539 case TYPE_ULONGINT:
540#ifdef HAVE_WINT_T
541 case TYPE_WIDE_CHAR:
542#endif
543#ifdef HAVE_WCHAR_T
544 case TYPE_WIDE_STRING:
545#endif
546 *p++ = 'l';
547 break;
548#ifdef HAVE_LONG_DOUBLE
549 case TYPE_LONGDOUBLE:
550 *p++ = 'L';
551 break;
552#endif
553 default:
554 break;
555 }
556 *p = dp->conversion;
557#if USE_SNPRINTF
558 p[1] = '%';
559 p[2] = 'n';
560 p[3] = '\0';
561#else
562 p[1] = '\0';
563#endif
564
565 /* Construct the arguments for calling snprintf or sprintf. */
566 prefix_count = 0;
567 if (dp->width_arg_index != ARG_NONE)
568 {
569 if (!(a.arg[dp->width_arg_index].type == TYPE_INT))
570 abort ();
571 prefixes[prefix_count++] = a.arg[dp->width_arg_index].a.a_int;
572 }
573 if (dp->precision_arg_index != ARG_NONE)
574 {
575 if (!(a.arg[dp->precision_arg_index].type == TYPE_INT))
576 abort ();
577 prefixes[prefix_count++] = a.arg[dp->precision_arg_index].a.a_int;
578 }
579
580#if USE_SNPRINTF
581 /* Prepare checking whether snprintf returns the count
582 via %n. */
583 ENSURE_ALLOCATION (xsum (length, 1));
584 result[length] = '\0';
585#endif
586
587 for (;;)
588 {
589 size_t maxlen;
590 int count;
591 int retcount;
592
593 maxlen = allocated - length;
594 count = -1;
595 retcount = 0;
596
597#if USE_SNPRINTF
598# define SNPRINTF_BUF(arg) \
599 switch (prefix_count) \
600 { \
601 case 0: \
602 retcount = SNPRINTF (result + length, maxlen, buf, \
603 arg, &count); \
604 break; \
605 case 1: \
606 retcount = SNPRINTF (result + length, maxlen, buf, \
607 prefixes[0], arg, &count); \
608 break; \
609 case 2: \
610 retcount = SNPRINTF (result + length, maxlen, buf, \
611 prefixes[0], prefixes[1], arg, \
612 &count); \
613 break; \
614 default: \
615 abort (); \
616 }
617#else
618# define SNPRINTF_BUF(arg) \
619 switch (prefix_count) \
620 { \
621 case 0: \
622 count = sprintf (tmp, buf, arg); \
623 break; \
624 case 1: \
625 count = sprintf (tmp, buf, prefixes[0], arg); \
626 break; \
627 case 2: \
628 count = sprintf (tmp, buf, prefixes[0], prefixes[1],\
629 arg); \
630 break; \
631 default: \
632 abort (); \
633 }
634#endif
635
636 switch (type)
637 {
638 case TYPE_SCHAR:
639 {
640 int arg = a.arg[dp->arg_index].a.a_schar;
641 SNPRINTF_BUF (arg);
642 }
643 break;
644 case TYPE_UCHAR:
645 {
646 unsigned int arg = a.arg[dp->arg_index].a.a_uchar;
647 SNPRINTF_BUF (arg);
648 }
649 break;
650 case TYPE_SHORT:
651 {
652 int arg = a.arg[dp->arg_index].a.a_short;
653 SNPRINTF_BUF (arg);
654 }
655 break;
656 case TYPE_USHORT:
657 {
658 unsigned int arg = a.arg[dp->arg_index].a.a_ushort;
659 SNPRINTF_BUF (arg);
660 }
661 break;
662 case TYPE_INT:
663 {
664 int arg = a.arg[dp->arg_index].a.a_int;
665 SNPRINTF_BUF (arg);
666 }
667 break;
668 case TYPE_UINT:
669 {
670 unsigned int arg = a.arg[dp->arg_index].a.a_uint;
671 SNPRINTF_BUF (arg);
672 }
673 break;
674 case TYPE_LONGINT:
675 {
676 long int arg = a.arg[dp->arg_index].a.a_longint;
677 SNPRINTF_BUF (arg);
678 }
679 break;
680 case TYPE_ULONGINT:
681 {
682 unsigned long int arg = a.arg[dp->arg_index].a.a_ulongint;
683 SNPRINTF_BUF (arg);
684 }
685 break;
686#ifdef HAVE_LONG_LONG
687 case TYPE_LONGLONGINT:
688 {
689 long long int arg = a.arg[dp->arg_index].a.a_longlongint;
690 SNPRINTF_BUF (arg);
691 }
692 break;
693 case TYPE_ULONGLONGINT:
694 {
695 unsigned long long int arg = a.arg[dp->arg_index].a.a_ulonglongint;
696 SNPRINTF_BUF (arg);
697 }
698 break;
699#endif
700 case TYPE_DOUBLE:
701 {
702 double arg = a.arg[dp->arg_index].a.a_double;
703 SNPRINTF_BUF (arg);
704 }
705 break;
706#ifdef HAVE_LONG_DOUBLE
707 case TYPE_LONGDOUBLE:
708 {
709 long double arg = a.arg[dp->arg_index].a.a_longdouble;
710 SNPRINTF_BUF (arg);
711 }
712 break;
713#endif
714 case TYPE_CHAR:
715 {
716 int arg = a.arg[dp->arg_index].a.a_char;
717 SNPRINTF_BUF (arg);
718 }
719 break;
720#ifdef HAVE_WINT_T
721 case TYPE_WIDE_CHAR:
722 {
723 wint_t arg = a.arg[dp->arg_index].a.a_wide_char;
724 SNPRINTF_BUF (arg);
725 }
726 break;
727#endif
728 case TYPE_STRING:
729 {
730 const char *arg = a.arg[dp->arg_index].a.a_string;
731 SNPRINTF_BUF (arg);
732 }
733 break;
734#ifdef HAVE_WCHAR_T
735 case TYPE_WIDE_STRING:
736 {
737 const wchar_t *arg = a.arg[dp->arg_index].a.a_wide_string;
738 SNPRINTF_BUF (arg);
739 }
740 break;
741#endif
742 case TYPE_POINTER:
743 {
744 void *arg = a.arg[dp->arg_index].a.a_pointer;
745 SNPRINTF_BUF (arg);
746 }
747 break;
748 default:
749 abort ();
750 }
751
752#if USE_SNPRINTF
753 /* Portability: Not all implementations of snprintf()
754 are ISO C 99 compliant. Determine the number of
755 bytes that snprintf() has produced or would have
756 produced. */
757 if (count >= 0)
758 {
759 /* Verify that snprintf() has NUL-terminated its
760 result. */
761 if (count < maxlen && result[length + count] != '\0')
762 abort ();
763 /* Portability hack. */
764 if (retcount > count)
765 count = retcount;
766 }
767 else
768 {
769 /* snprintf() doesn't understand the '%n'
770 directive. */
771 if (p[1] != '\0')
772 {
773 /* Don't use the '%n' directive; instead, look
774 at the snprintf() return value. */
775 p[1] = '\0';
776 continue;
777 }
778 else
779 {
780 /* Look at the snprintf() return value. */
781 if (retcount < 0)
782 {
783 /* HP-UX 10.20 snprintf() is doubly deficient:
784 It doesn't understand the '%n' directive,
785 *and* it returns -1 (rather than the length
786 that would have been required) when the
787 buffer is too small. */
788 size_t bigger_need =
789 xsum (xtimes (allocated, 2), 12);
790 ENSURE_ALLOCATION (bigger_need);
791 continue;
792 }
793 else
794 count = retcount;
795 }
796 }
797#endif
798
799 /* Attempt to handle failure. */
800 if (count < 0)
801 {
802 if (!(result == resultbuf || result == NULL))
803 free (result);
804 if (buf_malloced != NULL)
805 free (buf_malloced);
806 CLEANUP ();
807 errno = EINVAL;
808 return NULL;
809 }
810
811#if !USE_SNPRINTF
812 if (count >= tmp_length)
813 /* tmp_length was incorrectly calculated - fix the
814 code above! */
815 abort ();
816#endif
817
818 /* Make room for the result. */
819 if (count >= maxlen)
820 {
821 /* Need at least count bytes. But allocate
822 proportionally, to avoid looping eternally if
823 snprintf() reports a too small count. */
824 size_t n =
825 xmax (xsum (length, count), xtimes (allocated, 2));
826
827 ENSURE_ALLOCATION (n);
828#if USE_SNPRINTF
829 continue;
830#endif
831 }
832
833#if USE_SNPRINTF
834 /* The snprintf() result did fit. */
835#else
836 /* Append the sprintf() result. */
837 memcpy (result + length, tmp, count * sizeof (CHAR_T));
838 if (tmp != tmpbuf)
839 free (tmp);
840#endif
841
842 length += count;
843 break;
844 }
845 }
846 }
847 }
848
849 /* Add the final NUL. */
850 ENSURE_ALLOCATION (xsum (length, 1));
851 result[length] = '\0';
852
853 if (result != resultbuf && length + 1 < allocated)
854 {
855 /* Shrink the allocated memory if possible. */
856 CHAR_T *memory;
857
858 memory = (CHAR_T *) realloc (result, (length + 1) * sizeof (CHAR_T));
859 if (memory != NULL)
860 result = memory;
861 }
862
863 if (buf_malloced != NULL)
864 free (buf_malloced);
865 CLEANUP ();
866 *lengthp = length;
867 return result;
868
869 out_of_memory:
870 if (!(result == resultbuf || result == NULL))
871 free (result);
872 if (buf_malloced != NULL)
873 free (buf_malloced);
874 out_of_memory_1:
875 CLEANUP ();
876 errno = ENOMEM;
877 return NULL;
878 }
879}
880
881#undef SNPRINTF
882#undef USE_SNPRINTF
883#undef PRINTF_PARSE
884#undef DIRECTIVES
885#undef DIRECTIVE
886#undef CHAR_T
887#undef VASNPRINTF
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