1 /* vsprintf with automatic memory allocation.
2 Copyright (C) 1999, 2002-2005 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 #ifdef HAVE_CONFIG_H
26 # include <config.h>
27 #endif
28 #ifndef IN_LIBINTL
29 # include <alloca.h>
30 #endif
31
32 /* Specification. */
33 #if WIDE_CHAR_VERSION
34 # include "vasnwprintf.h"
35 #else
36 # include "vasnprintf.h"
37 #endif
38
39 #include <stdio.h> /* snprintf(), sprintf() */
40 #include <stdlib.h> /* abort(), malloc(), realloc(), free() */
41 #include <string.h> /* memcpy(), strlen() */
42 #include <errno.h> /* errno */
43 #include <limits.h> /* CHAR_BIT, INT_MAX */
44 #include <float.h> /* DBL_MAX_EXP, LDBL_MAX_EXP */
45 #if WIDE_CHAR_VERSION
46 # include "wprintf-parse.h"
47 #else
48 # include "printf-parse.h"
49 #endif
50
51 /* Checked size_t computations. */
52 #include "xsize.h"
53
54 /* Some systems, like OSF/1 4.0 and Woe32, don't have EOVERFLOW. */
55 #ifndef EOVERFLOW
56 # define EOVERFLOW E2BIG
57 #endif
58
59 #ifdef HAVE_WCHAR_T
60 # ifdef HAVE_WCSLEN
61 # define local_wcslen wcslen
62 # else
63 /* Solaris 2.5.1 has wcslen() in a separate library libw.so. To avoid
64 a dependency towards this library, here is a local substitute.
65 Define this substitute only once, even if this file is included
66 twice in the same compilation unit. */
67 # ifndef local_wcslen_defined
68 # define local_wcslen_defined 1
69 static size_t
local_wcslen(const wchar_t * s)70 local_wcslen (const wchar_t *s)
71 {
72 const wchar_t *ptr;
73
74 for (ptr = s; *ptr != (wchar_t) 0; ptr++)
75 ;
76 return ptr - s;
77 }
78 # endif
79 # endif
80 #endif
81
82 #if WIDE_CHAR_VERSION
83 # define VASNPRINTF vasnwprintf
84 # define CHAR_T wchar_t
85 # define DIRECTIVE wchar_t_directive
86 # define DIRECTIVES wchar_t_directives
87 # define PRINTF_PARSE wprintf_parse
88 # define USE_SNPRINTF 1
89 # if HAVE_DECL__SNWPRINTF
90 /* On Windows, the function swprintf() has a different signature than
91 on Unix; we use the _snwprintf() function instead. */
92 # define SNPRINTF _snwprintf
93 # else
94 /* Unix. */
95 # define SNPRINTF swprintf
96 # endif
97 #else
98 # define VASNPRINTF vasnprintf
99 # define CHAR_T char
100 # define DIRECTIVE char_directive
101 # define DIRECTIVES char_directives
102 # define PRINTF_PARSE printf_parse
103 # define USE_SNPRINTF (HAVE_DECL__SNPRINTF || HAVE_SNPRINTF)
104 # if HAVE_DECL__SNPRINTF
105 /* Windows. */
106 # define SNPRINTF _snprintf
107 # else
108 /* Unix. */
109 # define SNPRINTF snprintf
110 # endif
111 #endif
112
113 CHAR_T *
VASNPRINTF(CHAR_T * resultbuf,size_t * lengthp,const CHAR_T * format,va_list args)114 VASNPRINTF (CHAR_T *resultbuf, size_t *lengthp, const CHAR_T *format, va_list args)
115 {
116 DIRECTIVES d;
117 arguments a;
118
119 if (PRINTF_PARSE (format, &d, &a) < 0)
120 {
121 errno = EINVAL;
122 return NULL;
123 }
124
125 #define CLEANUP() \
126 free (d.dir); \
127 if (a.arg) \
128 free (a.arg);
129
130 if (printf_fetchargs (args, &a) < 0)
131 {
132 CLEANUP ();
133 errno = EINVAL;
134 return NULL;
135 }
136
137 {
138 size_t buf_neededlength;
139 CHAR_T *buf;
140 CHAR_T *buf_malloced;
141 const CHAR_T *cp;
142 size_t i;
143 DIRECTIVE *dp;
144 /* Output string accumulator. */
145 CHAR_T *result;
146 size_t allocated;
147 size_t length;
148
149 /* Allocate a small buffer that will hold a directive passed to
150 sprintf or snprintf. */
151 buf_neededlength =
152 xsum4 (7, d.max_width_length, d.max_precision_length, 6);
153 #if HAVE_ALLOCA
154 if (buf_neededlength < 4000 / sizeof (CHAR_T))
155 {
156 buf = (CHAR_T *) alloca (buf_neededlength * sizeof (CHAR_T));
157 buf_malloced = NULL;
158 }
159 else
160 #endif
161 {
162 size_t buf_memsize = xtimes (buf_neededlength, sizeof (CHAR_T));
163 if (size_overflow_p (buf_memsize))
164 goto out_of_memory_1;
165 buf = (CHAR_T *) malloc (buf_memsize);
166 if (buf == NULL)
167 goto out_of_memory_1;
168 buf_malloced = buf;
169 }
170
171 if (resultbuf != NULL)
172 {
173 result = resultbuf;
174 allocated = *lengthp;
175 }
176 else
177 {
178 result = NULL;
179 allocated = 0;
180 }
181 length = 0;
182 /* Invariants:
183 result is either == resultbuf or == NULL or malloc-allocated.
184 If length > 0, then result != NULL. */
185
186 /* Ensures that allocated >= needed. Aborts through a jump to
187 out_of_memory if needed is SIZE_MAX or otherwise too big. */
188 #define ENSURE_ALLOCATION(needed) \
189 if ((needed) > allocated) \
190 { \
191 size_t memory_size; \
192 CHAR_T *memory; \
193 \
194 allocated = (allocated > 0 ? xtimes (allocated, 2) : 12); \
195 if ((needed) > allocated) \
196 allocated = (needed); \
197 memory_size = xtimes (allocated, sizeof (CHAR_T)); \
198 if (size_overflow_p (memory_size)) \
199 goto out_of_memory; \
200 if (result == resultbuf || result == NULL) \
201 memory = (CHAR_T *) malloc (memory_size); \
202 else \
203 memory = (CHAR_T *) realloc (result, memory_size); \
204 if (memory == NULL) \
205 goto out_of_memory; \
206 if (result == resultbuf && length > 0) \
207 memcpy (memory, result, length * sizeof (CHAR_T)); \
208 result = memory; \
209 }
210
211 for (cp = format, i = 0, dp = &d.dir[0]; ; cp = dp->dir_end, i++, dp++)
212 {
213 if (cp != dp->dir_start)
214 {
215 size_t n = dp->dir_start - cp;
216 size_t augmented_length = xsum (length, n);
217
218 ENSURE_ALLOCATION (augmented_length);
219 memcpy (result + length, cp, n * sizeof (CHAR_T));
220 length = augmented_length;
221 }
222 if (i == d.count)
223 break;
224
225 /* Execute a single directive. */
226 if (dp->conversion == '%')
227 {
228 size_t augmented_length;
229
230 if (!(dp->arg_index == ARG_NONE))
231 abort ();
232 augmented_length = xsum (length, 1);
233 ENSURE_ALLOCATION (augmented_length);
234 result[length] = '%';
235 length = augmented_length;
236 }
237 else
238 {
239 if (!(dp->arg_index != ARG_NONE))
240 abort ();
241
242 if (dp->conversion == 'n')
243 {
244 switch (a.arg[dp->arg_index].type)
245 {
246 case TYPE_COUNT_SCHAR_POINTER:
247 *a.arg[dp->arg_index].a.a_count_schar_pointer = length;
248 break;
249 case TYPE_COUNT_SHORT_POINTER:
250 *a.arg[dp->arg_index].a.a_count_short_pointer = length;
251 break;
252 case TYPE_COUNT_INT_POINTER:
253 *a.arg[dp->arg_index].a.a_count_int_pointer = length;
254 break;
255 case TYPE_COUNT_LONGINT_POINTER:
256 *a.arg[dp->arg_index].a.a_count_longint_pointer = length;
257 break;
258 #ifdef HAVE_LONG_LONG
259 case TYPE_COUNT_LONGLONGINT_POINTER:
260 *a.arg[dp->arg_index].a.a_count_longlongint_pointer = length;
261 break;
262 #endif
263 default:
264 abort ();
265 }
266 }
267 else
268 {
269 arg_type type = a.arg[dp->arg_index].type;
270 CHAR_T *p;
271 unsigned int prefix_count;
272 int prefixes[2];
273 #if !USE_SNPRINTF
274 size_t tmp_length;
275 CHAR_T tmpbuf[700];
276 CHAR_T *tmp;
277
278 /* Allocate a temporary buffer of sufficient size for calling
279 sprintf. */
280 {
281 size_t width;
282 size_t precision;
283
284 width = 0;
285 if (dp->width_start != dp->width_end)
286 {
287 if (dp->width_arg_index != ARG_NONE)
288 {
289 int arg;
290
291 if (!(a.arg[dp->width_arg_index].type == TYPE_INT))
292 abort ();
293 arg = a.arg[dp->width_arg_index].a.a_int;
294 width = (arg < 0 ? (unsigned int) (-arg) : arg);
295 }
296 else
297 {
298 const CHAR_T *digitp = dp->width_start;
299
300 do
301 width = xsum (xtimes (width, 10), *digitp++ - '0');
302 while (digitp != dp->width_end);
303 }
304 }
305
306 precision = 6;
307 if (dp->precision_start != dp->precision_end)
308 {
309 if (dp->precision_arg_index != ARG_NONE)
310 {
311 int arg;
312
313 if (!(a.arg[dp->precision_arg_index].type == TYPE_INT))
314 abort ();
315 arg = a.arg[dp->precision_arg_index].a.a_int;
316 precision = (arg < 0 ? 0 : arg);
317 }
318 else
319 {
320 const CHAR_T *digitp = dp->precision_start + 1;
321
322 precision = 0;
323 while (digitp != dp->precision_end)
324 precision = xsum (xtimes (precision, 10), *digitp++ - '0');
325 }
326 }
327
328 switch (dp->conversion)
329 {
330
331 case 'd': case 'i': case 'u':
332 # ifdef HAVE_LONG_LONG
333 if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
334 tmp_length =
335 (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
336 * 0.30103 /* binary -> decimal */
337 * 2 /* estimate for FLAG_GROUP */
338 )
339 + 1 /* turn floor into ceil */
340 + 1; /* account for leading sign */
341 else
342 # endif
343 if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
344 tmp_length =
345 (unsigned int) (sizeof (unsigned long) * CHAR_BIT
346 * 0.30103 /* binary -> decimal */
347 * 2 /* estimate for FLAG_GROUP */
348 )
349 + 1 /* turn floor into ceil */
350 + 1; /* account for leading sign */
351 else
352 tmp_length =
353 (unsigned int) (sizeof (unsigned int) * CHAR_BIT
354 * 0.30103 /* binary -> decimal */
355 * 2 /* estimate for FLAG_GROUP */
356 )
357 + 1 /* turn floor into ceil */
358 + 1; /* account for leading sign */
359 break;
360
361 case 'o':
362 # ifdef HAVE_LONG_LONG
363 if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
364 tmp_length =
365 (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
366 * 0.333334 /* binary -> octal */
367 )
368 + 1 /* turn floor into ceil */
369 + 1; /* account for leading sign */
370 else
371 # endif
372 if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
373 tmp_length =
374 (unsigned int) (sizeof (unsigned long) * CHAR_BIT
375 * 0.333334 /* binary -> octal */
376 )
377 + 1 /* turn floor into ceil */
378 + 1; /* account for leading sign */
379 else
380 tmp_length =
381 (unsigned int) (sizeof (unsigned int) * CHAR_BIT
382 * 0.333334 /* binary -> octal */
383 )
384 + 1 /* turn floor into ceil */
385 + 1; /* account for leading sign */
386 break;
387
388 case 'x': case 'X':
389 # ifdef HAVE_LONG_LONG
390 if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
391 tmp_length =
392 (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
393 * 0.25 /* binary -> hexadecimal */
394 )
395 + 1 /* turn floor into ceil */
396 + 2; /* account for leading sign or alternate form */
397 else
398 # endif
399 if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
400 tmp_length =
401 (unsigned int) (sizeof (unsigned long) * CHAR_BIT
402 * 0.25 /* binary -> hexadecimal */
403 )
404 + 1 /* turn floor into ceil */
405 + 2; /* account for leading sign or alternate form */
406 else
407 tmp_length =
408 (unsigned int) (sizeof (unsigned int) * CHAR_BIT
409 * 0.25 /* binary -> hexadecimal */
410 )
411 + 1 /* turn floor into ceil */
412 + 2; /* account for leading sign or alternate form */
413 break;
414
415 case 'f': case 'F':
416 # ifdef HAVE_LONG_DOUBLE
417 if (type == TYPE_LONGDOUBLE)
418 tmp_length =
419 (unsigned int) (LDBL_MAX_EXP
420 * 0.30103 /* binary -> decimal */
421 * 2 /* estimate for FLAG_GROUP */
422 )
423 + 1 /* turn floor into ceil */
424 + 10; /* sign, decimal point etc. */
425 else
426 # endif
427 tmp_length =
428 (unsigned int) (DBL_MAX_EXP
429 * 0.30103 /* binary -> decimal */
430 * 2 /* estimate for FLAG_GROUP */
431 )
432 + 1 /* turn floor into ceil */
433 + 10; /* sign, decimal point etc. */
434 tmp_length = xsum (tmp_length, precision);
435 break;
436
437 case 'e': case 'E': case 'g': case 'G':
438 case 'a': case 'A':
439 tmp_length =
440 12; /* sign, decimal point, exponent etc. */
441 tmp_length = xsum (tmp_length, precision);
442 break;
443
444 case 'c':
445 # if defined HAVE_WINT_T && !WIDE_CHAR_VERSION
446 if (type == TYPE_WIDE_CHAR)
447 tmp_length = MB_CUR_MAX;
448 else
449 # endif
450 tmp_length = 1;
451 break;
452
453 case 's':
454 # ifdef HAVE_WCHAR_T
455 if (type == TYPE_WIDE_STRING)
456 {
457 tmp_length =
458 local_wcslen (a.arg[dp->arg_index].a.a_wide_string);
459
460 # if !WIDE_CHAR_VERSION
461 tmp_length = xtimes (tmp_length, MB_CUR_MAX);
462 # endif
463 }
464 else
465 # endif
466 tmp_length = strlen (a.arg[dp->arg_index].a.a_string);
467 break;
468
469 case 'p':
470 tmp_length =
471 (unsigned int) (sizeof (void *) * CHAR_BIT
472 * 0.25 /* binary -> hexadecimal */
473 )
474 + 1 /* turn floor into ceil */
475 + 2; /* account for leading 0x */
476 break;
477
478 default:
479 abort ();
480 }
481
482 if (tmp_length < width)
483 tmp_length = width;
484
485 tmp_length = xsum (tmp_length, 1); /* account for trailing NUL */
486 }
487
488 if (tmp_length <= sizeof (tmpbuf) / sizeof (CHAR_T))
489 tmp = tmpbuf;
490 else
491 {
492 size_t tmp_memsize = xtimes (tmp_length, sizeof (CHAR_T));
493
494 if (size_overflow_p (tmp_memsize))
495 /* Overflow, would lead to out of memory. */
496 goto out_of_memory;
497 tmp = (CHAR_T *) malloc (tmp_memsize);
498 if (tmp == NULL)
499 /* Out of memory. */
500 goto out_of_memory;
501 }
502 #endif
503
504 /* Construct the format string for calling snprintf or
505 sprintf. */
506 p = buf;
507 *p++ = '%';
508 if (dp->flags & FLAG_GROUP)
509 *p++ = '\'';
510 if (dp->flags & FLAG_LEFT)
511 *p++ = '-';
512 if (dp->flags & FLAG_SHOWSIGN)
513 *p++ = '+';
514 if (dp->flags & FLAG_SPACE)
515 *p++ = ' ';
516 if (dp->flags & FLAG_ALT)
517 *p++ = '#';
518 if (dp->flags & FLAG_ZERO)
519 *p++ = '0';
520 if (dp->width_start != dp->width_end)
521 {
522 size_t n = dp->width_end - dp->width_start;
523 memcpy (p, dp->width_start, n * sizeof (CHAR_T));
524 p += n;
525 }
526 if (dp->precision_start != dp->precision_end)
527 {
528 size_t n = dp->precision_end - dp->precision_start;
529 memcpy (p, dp->precision_start, n * sizeof (CHAR_T));
530 p += n;
531 }
532
533 switch (type)
534 {
535 #ifdef HAVE_LONG_LONG
536 case TYPE_LONGLONGINT:
537 case TYPE_ULONGLONGINT:
538 *p++ = 'l';
539 /*FALLTHROUGH*/
540 #endif
541 case TYPE_LONGINT:
542 case TYPE_ULONGINT:
543 #ifdef HAVE_WINT_T
544 case TYPE_WIDE_CHAR:
545 #endif
546 #ifdef HAVE_WCHAR_T
547 case TYPE_WIDE_STRING:
548 #endif
549 *p++ = 'l';
550 break;
551 #ifdef HAVE_LONG_DOUBLE
552 case TYPE_LONGDOUBLE:
553 *p++ = 'L';
554 break;
555 #endif
556 default:
557 break;
558 }
559 *p = dp->conversion;
560 #if USE_SNPRINTF
561 p[1] = '%';
562 p[2] = 'n';
563 p[3] = '\0';
564 #else
565 p[1] = '\0';
566 #endif
567
568 /* Construct the arguments for calling snprintf or sprintf. */
569 prefix_count = 0;
570 if (dp->width_arg_index != ARG_NONE)
571 {
572 if (!(a.arg[dp->width_arg_index].type == TYPE_INT))
573 abort ();
574 prefixes[prefix_count++] = a.arg[dp->width_arg_index].a.a_int;
575 }
576 if (dp->precision_arg_index != ARG_NONE)
577 {
578 if (!(a.arg[dp->precision_arg_index].type == TYPE_INT))
579 abort ();
580 prefixes[prefix_count++] = a.arg[dp->precision_arg_index].a.a_int;
581 }
582
583 #if USE_SNPRINTF
584 /* Prepare checking whether snprintf returns the count
585 via %n. */
586 ENSURE_ALLOCATION (xsum (length, 1));
587 result[length] = '\0';
588 #endif
589
590 for (;;)
591 {
592 size_t maxlen;
593 int count;
594 int retcount;
595
596 maxlen = allocated - length;
597 count = -1;
598 retcount = 0;
599
600 #if USE_SNPRINTF
601 # define SNPRINTF_BUF(arg) \
602 switch (prefix_count) \
603 { \
604 case 0: \
605 retcount = SNPRINTF (result + length, maxlen, buf, \
606 arg, &count); \
607 break; \
608 case 1: \
609 retcount = SNPRINTF (result + length, maxlen, buf, \
610 prefixes[0], arg, &count); \
611 break; \
612 case 2: \
613 retcount = SNPRINTF (result + length, maxlen, buf, \
614 prefixes[0], prefixes[1], arg, \
615 &count); \
616 break; \
617 default: \
618 abort (); \
619 }
620 #else
621 # define SNPRINTF_BUF(arg) \
622 switch (prefix_count) \
623 { \
624 case 0: \
625 count = sprintf (tmp, buf, arg); \
626 break; \
627 case 1: \
628 count = sprintf (tmp, buf, prefixes[0], arg); \
629 break; \
630 case 2: \
631 count = sprintf (tmp, buf, prefixes[0], prefixes[1],\
632 arg); \
633 break; \
634 default: \
635 abort (); \
636 }
637 #endif
638
639 switch (type)
640 {
641 case TYPE_SCHAR:
642 {
643 int arg = a.arg[dp->arg_index].a.a_schar;
644 SNPRINTF_BUF (arg);
645 }
646 break;
647 case TYPE_UCHAR:
648 {
649 unsigned int arg = a.arg[dp->arg_index].a.a_uchar;
650 SNPRINTF_BUF (arg);
651 }
652 break;
653 case TYPE_SHORT:
654 {
655 int arg = a.arg[dp->arg_index].a.a_short;
656 SNPRINTF_BUF (arg);
657 }
658 break;
659 case TYPE_USHORT:
660 {
661 unsigned int arg = a.arg[dp->arg_index].a.a_ushort;
662 SNPRINTF_BUF (arg);
663 }
664 break;
665 case TYPE_INT:
666 {
667 int arg = a.arg[dp->arg_index].a.a_int;
668 SNPRINTF_BUF (arg);
669 }
670 break;
671 case TYPE_UINT:
672 {
673 unsigned int arg = a.arg[dp->arg_index].a.a_uint;
674 SNPRINTF_BUF (arg);
675 }
676 break;
677 case TYPE_LONGINT:
678 {
679 long int arg = a.arg[dp->arg_index].a.a_longint;
680 SNPRINTF_BUF (arg);
681 }
682 break;
683 case TYPE_ULONGINT:
684 {
685 unsigned long int arg = a.arg[dp->arg_index].a.a_ulongint;
686 SNPRINTF_BUF (arg);
687 }
688 break;
689 #ifdef HAVE_LONG_LONG
690 case TYPE_LONGLONGINT:
691 {
692 long long int arg = a.arg[dp->arg_index].a.a_longlongint;
693 SNPRINTF_BUF (arg);
694 }
695 break;
696 case TYPE_ULONGLONGINT:
697 {
698 unsigned long long int arg = a.arg[dp->arg_index].a.a_ulonglongint;
699 SNPRINTF_BUF (arg);
700 }
701 break;
702 #endif
703 case TYPE_DOUBLE:
704 {
705 double arg = a.arg[dp->arg_index].a.a_double;
706 SNPRINTF_BUF (arg);
707 }
708 break;
709 #ifdef HAVE_LONG_DOUBLE
710 case TYPE_LONGDOUBLE:
711 {
712 long double arg = a.arg[dp->arg_index].a.a_longdouble;
713 SNPRINTF_BUF (arg);
714 }
715 break;
716 #endif
717 case TYPE_CHAR:
718 {
719 int arg = a.arg[dp->arg_index].a.a_char;
720 SNPRINTF_BUF (arg);
721 }
722 break;
723 #ifdef HAVE_WINT_T
724 case TYPE_WIDE_CHAR:
725 {
726 wint_t arg = a.arg[dp->arg_index].a.a_wide_char;
727 SNPRINTF_BUF (arg);
728 }
729 break;
730 #endif
731 case TYPE_STRING:
732 {
733 const char *arg = a.arg[dp->arg_index].a.a_string;
734 SNPRINTF_BUF (arg);
735 }
736 break;
737 #ifdef HAVE_WCHAR_T
738 case TYPE_WIDE_STRING:
739 {
740 const wchar_t *arg = a.arg[dp->arg_index].a.a_wide_string;
741 SNPRINTF_BUF (arg);
742 }
743 break;
744 #endif
745 case TYPE_POINTER:
746 {
747 void *arg = a.arg[dp->arg_index].a.a_pointer;
748 SNPRINTF_BUF (arg);
749 }
750 break;
751 default:
752 abort ();
753 }
754
755 #if USE_SNPRINTF
756 /* Portability: Not all implementations of snprintf()
757 are ISO C 99 compliant. Determine the number of
758 bytes that snprintf() has produced or would have
759 produced. */
760 if (count >= 0)
761 {
762 /* Verify that snprintf() has NUL-terminated its
763 result. */
764 if (count < maxlen && result[length + count] != '\0')
765 abort ();
766 /* Portability hack. */
767 if (retcount > count)
768 count = retcount;
769 }
770 else
771 {
772 /* snprintf() doesn't understand the '%n'
773 directive. */
774 if (p[1] != '\0')
775 {
776 /* Don't use the '%n' directive; instead, look
777 at the snprintf() return value. */
778 p[1] = '\0';
779 continue;
780 }
781 else
782 {
783 /* Look at the snprintf() return value. */
784 if (retcount < 0)
785 {
786 /* HP-UX 10.20 snprintf() is doubly deficient:
787 It doesn't understand the '%n' directive,
788 *and* it returns -1 (rather than the length
789 that would have been required) when the
790 buffer is too small. */
791 size_t bigger_need =
792 xsum (xtimes (allocated, 2), 12);
793 ENSURE_ALLOCATION (bigger_need);
794 continue;
795 }
796 else
797 count = retcount;
798 }
799 }
800 #endif
801
802 /* Attempt to handle failure. */
803 if (count < 0)
804 {
805 if (!(result == resultbuf || result == NULL))
806 free (result);
807 if (buf_malloced != NULL)
808 free (buf_malloced);
809 CLEANUP ();
810 errno = EINVAL;
811 return NULL;
812 }
813
814 #if !USE_SNPRINTF
815 if (count >= tmp_length)
816 /* tmp_length was incorrectly calculated - fix the
817 code above! */
818 abort ();
819 #endif
820
821 /* Make room for the result. */
822 if (count >= maxlen)
823 {
824 /* Need at least count bytes. But allocate
825 proportionally, to avoid looping eternally if
826 snprintf() reports a too small count. */
827 size_t n =
828 xmax (xsum (length, count), xtimes (allocated, 2));
829
830 ENSURE_ALLOCATION (n);
831 #if USE_SNPRINTF
832 continue;
833 #endif
834 }
835
836 #if USE_SNPRINTF
837 /* The snprintf() result did fit. */
838 #else
839 /* Append the sprintf() result. */
840 memcpy (result + length, tmp, count * sizeof (CHAR_T));
841 if (tmp != tmpbuf)
842 free (tmp);
843 #endif
844
845 length += count;
846 break;
847 }
848 }
849 }
850 }
851
852 /* Add the final NUL. */
853 ENSURE_ALLOCATION (xsum (length, 1));
854 result[length] = '\0';
855
856 if (result != resultbuf && length + 1 < allocated)
857 {
858 /* Shrink the allocated memory if possible. */
859 CHAR_T *memory;
860
861 memory = (CHAR_T *) realloc (result, (length + 1) * sizeof (CHAR_T));
862 if (memory != NULL)
863 result = memory;
864 }
865
866 if (buf_malloced != NULL)
867 free (buf_malloced);
868 CLEANUP ();
869 *lengthp = length;
870 if (length > INT_MAX)
871 goto length_overflow;
872 return result;
873
874 length_overflow:
875 /* We could produce such a big string, but its length doesn't fit into
876 an 'int'. POSIX says that snprintf() fails with errno = EOVERFLOW in
877 this case. */
878 if (result != resultbuf)
879 free (result);
880 errno = EOVERFLOW;
881 return NULL;
882
883 out_of_memory:
884 if (!(result == resultbuf || result == NULL))
885 free (result);
886 if (buf_malloced != NULL)
887 free (buf_malloced);
888 out_of_memory_1:
889 CLEANUP ();
890 errno = ENOMEM;
891 return NULL;
892 }
893 }
894
895 #undef SNPRINTF
896 #undef USE_SNPRINTF
897 #undef PRINTF_PARSE
898 #undef DIRECTIVES
899 #undef DIRECTIVE
900 #undef CHAR_T
901 #undef VASNPRINTF
902