lib/roken/snprintf.c

   1 /*
   2  * Copyright (c) 1995-2003 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #ifdef HAVE_CONFIG_H
  35 #include <config.h>
  36 RCSID("$Id$");
  37 #endif
  38 #if defined(TEST_SNPRINTF)
  39 #include "snprintf-test.h"
  40 #endif /* TEST_SNPRINTF */
  41 #include <stdio.h>
  42 #include <stdarg.h>
  43 #include <stdlib.h>
  44 #include <string.h>
  45 #include <ctype.h>
  46 #include "roken.h"
  47 #include <assert.h>
  48
  49 enum format_flags {
  50     minus_flag     =  1,
  51     plus_flag      =  2,
  52     space_flag     =  4,
  53     alternate_flag =  8,
  54     zero_flag      = 16
  55 };
  56
  57 /*
  58  * Common state
  59  */
  60
  61 struct snprintf_state {
  62     unsigned char *str;
  63     unsigned char *s;
  64     unsigned char *theend;
  65     size_t sz;
  66     size_t max_sz;
  67     void (*append_char)(struct snprintf_state *, unsigned char);
  68     /* XXX - methods */
  69 };
  70
  71 #if !defined(HAVE_VSNPRINTF) || defined(TEST_SNPRINTF)
  72 static int
  73 sn_reserve (struct snprintf_state *state, size_t n)
  74 {
  75     return state->s + n > state->theend;
  76 }
  77
  78 static void
  79 sn_append_char (struct snprintf_state *state, unsigned char c)
  80 {
  81     if (!sn_reserve (state, 1))
  82         *state->s++ = c;
  83 }
  84 #endif
  85
  86 static int
  87 as_reserve (struct snprintf_state *state, size_t n)
  88 {
  89     if (state->s + n > state->theend) {
  90         int off = state->s - state->str;
  91         unsigned char *tmp;
  92
  93         if (state->max_sz && state->sz >= state->max_sz)
  94             return 1;
  95
  96         state->sz = max(state->sz * 2, state->sz + n);
  97         if (state->max_sz)
  98             state->sz = min(state->sz, state->max_sz);
  99         tmp = realloc (state->str, state->sz);
 100         if (tmp == NULL)
 101             return 1;
 102         state->str = tmp;
 103         state->s = state->str + off;
 104         state->theend = state->str + state->sz - 1;
 105     }
 106     return 0;
 107 }
 108
 109 static void
 110 as_append_char (struct snprintf_state *state, unsigned char c)
 111 {
 112     if(!as_reserve (state, 1))
 113         *state->s++ = c;
 114 }
 115
 116 /* longest integer types */
 117
 118 #ifdef HAVE_LONG_LONG
 119 typedef unsigned long long u_longest;
 120 typedef long long longest;
 121 #else
 122 typedef unsigned long u_longest;
 123 typedef long longest;
 124 #endif
 125
 126
 127
 128 static int
 129 pad(struct snprintf_state *state, int width, char c)
 130 {
 131     int len = 0;
 132     while(width-- > 0){
 133         (*state->append_char)(state,  c);
 134         ++len;
 135     }
 136     return len;
 137 }
 138
 139 /* return true if we should use alternatve hex form */
 140 static int
 141 use_alternative (int flags, u_longest num, unsigned base)
 142 {
 143     return (flags & alternate_flag) && base == 16 && num != 0;
 144 }
 145
 146 static int
 147 append_number(struct snprintf_state *state,
 148               u_longest num, unsigned base, const char *rep,
 149               int width, int prec, int flags, int minusp)
 150 {
 151     int len = 0;
 152     u_longest n = num;
 153     char nstr[64]; /* enough for <192 bit octal integers */
 154     int nstart, nlen;
 155     char signchar;
 156
 157     /* given precision, ignore zero flag */
 158     if(prec != -1)
 159         flags &= ~zero_flag;
 160     else
 161         prec = 1;
 162
 163     /* format number as string */
 164     nstart = sizeof(nstr);
 165     nlen = 0;
 166     nstr[--nstart] = '\0';
 167     do {
 168         assert(nstart > 0);
 169         nstr[--nstart] = rep[n % base];
 170         ++nlen;
 171         n /= base;
 172     } while(n);
 173
 174     /* zero value with zero precision should produce no digits */
 175     if(prec == 0 && num == 0) {
 176         nlen--;
 177         nstart++;
 178     }
 179
 180     /* figure out what char to use for sign */
 181     if(minusp)
 182         signchar = '-';
 183     else if((flags & plus_flag))
 184         signchar = '+';
 185     else if((flags & space_flag))
 186         signchar = ' ';
 187     else
 188         signchar = '\0';
 189
 190     if((flags & alternate_flag) && base == 8) {
 191         /* if necessary, increase the precision to
 192            make first digit a zero */
 193
 194         /* XXX C99 claims (regarding # and %o) that "if the value and
 195            precision are both 0, a single 0 is printed", but there is
 196            no such wording for %x. This would mean that %#.o would
 197            output "0", but %#.x "". This does not make sense, and is
 198            also not what other printf implementations are doing. */
 199
 200         if(prec <= nlen && nstr[nstart] != '0' && nstr[nstart] != '\0')
 201             prec = nlen + 1;
 202     }
 203
 204     /* possible formats:
 205        pad | sign | alt | zero | digits
 206        sign | alt | zero | digits | pad   minus_flag
 207        sign | alt | zero | digits zero_flag */
 208
 209     /* if not right justifying or padding with zeros, we need to
 210        compute the length of the rest of the string, and then pad with
 211        spaces */
 212     if(!(flags & (minus_flag | zero_flag))) {
 213         if(prec > nlen)
 214             width -= prec;
 215         else
 216             width -= nlen;
 217
 218         if(use_alternative(flags, num, base))
 219             width -= 2;
 220
 221         if(signchar != '\0')
 222             width--;
 223
 224         /* pad to width */
 225         len += pad(state, width, ' ');
 226     }
 227     if(signchar != '\0') {
 228         (*state->append_char)(state, signchar);
 229         ++len;
 230     }
 231     if(use_alternative(flags, num, base)) {
 232         (*state->append_char)(state, '0');
 233         (*state->append_char)(state, rep[10] + 23); /* XXX */
 234         len += 2;
 235     }
 236     if(flags & zero_flag) {
 237         /* pad to width with zeros */
 238         if(prec - nlen > width - len - nlen)
 239             len += pad(state, prec - nlen, '0');
 240         else
 241             len += pad(state, width - len - nlen, '0');
 242     } else
 243         /* pad to prec with zeros */
 244         len += pad(state, prec - nlen, '0');
 245
 246     while(nstr[nstart] != '\0') {
 247         (*state->append_char)(state, nstr[nstart++]);
 248         ++len;
 249     }
 250
 251     if(flags & minus_flag)
 252         len += pad(state, width - len, ' ');
 253
 254     return len;
 255 }
 256
 257 /*
 258  * return length
 259  */
 260
 261 static int
 262 append_string (struct snprintf_state *state,
 263                const unsigned char *arg,
 264                int width,
 265                int prec,
 266                int flags)
 267 {
 268     int len = 0;
 269
 270     if(arg == NULL)
 271         arg = (const unsigned char*)"(null)";
 272
 273     if(prec != -1)
 274         width -= prec;
 275     else
 276         width -= strlen((const char *)arg);
 277     if(!(flags & minus_flag))
 278         len += pad(state, width, ' ');
 279
 280     if (prec != -1) {
 281         while (*arg && prec--) {
 282             (*state->append_char) (state, *arg++);
 283             ++len;
 284         }
 285     } else {
 286         while (*arg) {
 287             (*state->append_char) (state, *arg++);
 288             ++len;
 289         }
 290     }
 291     if(flags & minus_flag)
 292         len += pad(state, width, ' ');
 293     return len;
 294 }
 295
 296 static int
 297 append_char(struct snprintf_state *state,
 298             unsigned char arg,
 299             int width,
 300             int flags)
 301 {
 302     int len = 0;
 303
 304     while(!(flags & minus_flag) && --width > 0) {
 305         (*state->append_char) (state, ' ')    ;
 306         ++len;
 307     }
 308     (*state->append_char) (state, arg);
 309     ++len;
 310     while((flags & minus_flag) && --width > 0) {
 311         (*state->append_char) (state, ' ');
 312         ++len;
 313     }
 314     return 0;
 315 }
 316
 317 /*
 318  * This can't be made into a function...
 319  */
 320
 321 #ifdef HAVE_LONG_LONG
 322
 323 #define PARSE_INT_FORMAT(res, arg, unsig) \
 324 if (long_long_flag) \
 325      res = (unsig long long)va_arg(arg, unsig long long); \
 326 else if (long_flag) \
 327      res = (unsig long)va_arg(arg, unsig long); \
 328 else if (size_t_flag) \
 329      res = (unsig long)va_arg(arg, size_t); \
 330 else if (short_flag) \
 331      res = (unsig short)va_arg(arg, unsig int); \
 332 else \
 333      res = (unsig int)va_arg(arg, unsig int)
 334
 335 #else
 336
 337 #define PARSE_INT_FORMAT(res, arg, unsig) \
 338 if (long_flag) \
 339      res = (unsig long)va_arg(arg, unsig long); \
 340 else if (size_t_flag) \
 341      res = (unsig long)va_arg(arg, size_t); \
 342 else if (short_flag) \
 343      res = (unsig short)va_arg(arg, unsig int); \
 344 else \
 345      res = (unsig int)va_arg(arg, unsig int)
 346
 347 #endif
 348
 349 /*
 350  * zyxprintf - return length, as snprintf
 351  */
 352
 353 static int
 354 xyzprintf (struct snprintf_state *state, const char *char_format, va_list ap)
 355 {
 356     const unsigned char *format = (const unsigned char *)char_format;
 357     unsigned char c;
 358     int len = 0;
 359
 360     while((c = *format++)) {
 361         if (c == '%') {
 362             int flags          = 0;
 363             int width          = 0;
 364             int prec           = -1;
 365             int size_t_flag    = 0;
 366             int long_long_flag = 0;
 367             int long_flag      = 0;
 368             int short_flag     = 0;
 369
 370             /* flags */
 371             while((c = *format++)){
 372                 if(c == '-')
 373                     flags |= minus_flag;
 374                 else if(c == '+')
 375                     flags |= plus_flag;
 376                 else if(c == ' ')
 377                     flags |= space_flag;
 378                 else if(c == '#')
 379                     flags |= alternate_flag;
 380                 else if(c == '0')
 381                     flags |= zero_flag;
 382                 else if(c == '\'')
 383                     ; /* just ignore */
 384                 else
 385                     break;
 386             }
 387
 388             if((flags & space_flag) && (flags & plus_flag))
 389                 flags ^= space_flag;
 390
 391             if((flags & minus_flag) && (flags & zero_flag))
 392                 flags ^= zero_flag;
 393
 394             /* width */
 395             if (isdigit(c))
 396                 do {
 397                     width = width * 10 + c - '0';
 398                     c = *format++;
 399                 } while(isdigit(c));
 400             else if(c == '*') {
 401                 width = va_arg(ap, int);
 402                 c = *format++;
 403             }
 404
 405             /* precision */
 406             if (c == '.') {
 407                 prec = 0;
 408                 c = *format++;
 409                 if (isdigit(c))
 410                     do {
 411                         prec = prec * 10 + c - '0';
 412                         c = *format++;
 413                     } while(isdigit(c));
 414                 else if (c == '*') {
 415                     prec = va_arg(ap, int);
 416                     c = *format++;
 417                 }
 418             }
 419
 420             /* size */
 421
 422             if (c == 'h') {
 423                 short_flag = 1;
 424                 c = *format++;
 425             } else if (c == 'z') {
 426                 size_t_flag = 1;
 427                 c = *format++;
 428             } else if (c == 'l') {
 429                 long_flag = 1;
 430                 c = *format++;
 431                 if (c == 'l') {
 432                     long_long_flag = 1;
 433                     c = *format++;
 434                 }
 435             }
 436
 437             if(c != 'd' && c != 'i')
 438                 flags &= ~(plus_flag | space_flag);
 439
 440             switch (c) {
 441             case 'c' :
 442                 append_char(state, va_arg(ap, int), width, flags);
 443                 ++len;
 444                 break;
 445             case 's' :
 446                 len += append_string(state,
 447                                      va_arg(ap, unsigned char*),
 448                                      width,
 449                                      prec,
 450                                      flags);
 451                 break;
 452             case 'd' :
 453             case 'i' : {
 454                 longest arg;
 455                 u_longest num;
 456                 int minusp = 0;
 457
 458                 PARSE_INT_FORMAT(arg, ap, signed);
 459
 460                 if (arg < 0) {
 461                     minusp = 1;
 462                     num = -arg;
 463                 } else
 464                     num = arg;
 465
 466                 len += append_number (state, num, 10, "0123456789",
 467                                       width, prec, flags, minusp);
 468                 break;
 469             }
 470             case 'u' : {
 471                 u_longest arg;
 472
 473                 PARSE_INT_FORMAT(arg, ap, unsigned);
 474
 475                 len += append_number (state, arg, 10, "0123456789",
 476                                       width, prec, flags, 0);
 477                 break;
 478             }
 479             case 'o' : {
 480                 u_longest arg;
 481
 482                 PARSE_INT_FORMAT(arg, ap, unsigned);
 483
 484                 len += append_number (state, arg, 010, "01234567",
 485                                       width, prec, flags, 0);
 486                 break;
 487             }
 488             case 'x' : {
 489                 u_longest arg;
 490
 491                 PARSE_INT_FORMAT(arg, ap, unsigned);
 492
 493                 len += append_number (state, arg, 0x10, "0123456789abcdef",
 494                                       width, prec, flags, 0);
 495                 break;
 496             }
 497             case 'X' :{
 498                 u_longest arg;
 499
 500                 PARSE_INT_FORMAT(arg, ap, unsigned);
 501
 502                 len += append_number (state, arg, 0x10, "0123456789ABCDEF",
 503                                       width, prec, flags, 0);
 504                 break;
 505             }
 506             case 'p' : {
 507                 unsigned long arg = (unsigned long)va_arg(ap, void*);
 508
 509                 len += append_number (state, arg, 0x10, "0123456789ABCDEF",
 510                                       width, prec, flags, 0);
 511                 break;
 512             }
 513             case 'n' : {
 514                 int *arg = va_arg(ap, int*);
 515                 *arg = state->s - state->str;
 516                 break;
 517             }
 518             case '\0' :
 519                 --format;
 520                 /* FALLTHROUGH */
 521             case '%' :
 522                 (*state->append_char)(state, c);
 523                 ++len;
 524                 break;
 525             default :
 526                 (*state->append_char)(state, '%');
 527                 (*state->append_char)(state, c);
 528                 len += 2;
 529                 break;
 530             }
 531         } else {
 532             (*state->append_char) (state, c);
 533             ++len;
 534         }
 535     }
 536     return len;
 537 }
 538
 539 #if !defined(HAVE_SNPRINTF) || defined(TEST_SNPRINTF)
 540 int ROKEN_LIB_FUNCTION
 541 snprintf (char *str, size_t sz, const char *format, ...)
 542 {
 543     va_list args;
 544     int ret;
 545
 546     va_start(args, format);
 547     ret = vsnprintf (str, sz, format, args);
 548     va_end(args);
 549
 550 #ifdef PARANOIA
 551     {
 552         int ret2;
 553         char *tmp;
 554
 555         tmp = malloc (sz);
 556         if (tmp == NULL)
 557             abort ();
 558
 559         va_start(args, format);
 560         ret2 = vsprintf (tmp, format, args);
 561         va_end(args);
 562         if (ret != ret2 || strcmp(str, tmp))
 563             abort ();
 564         free (tmp);
 565     }
 566 #endif
 567
 568     return ret;
 569 }
 570 #endif
 571
 572 #if !defined(HAVE_ASPRINTF) || defined(TEST_SNPRINTF)
 573 int ROKEN_LIB_FUNCTION
 574 asprintf (char **ret, const char *format, ...)
 575 {
 576     va_list args;
 577     int val;
 578
 579     va_start(args, format);
 580     val = vasprintf (ret, format, args);
 581     va_end(args);
 582
 583 #ifdef PARANOIA
 584     {
 585         int ret2;
 586         char *tmp;
 587         tmp = malloc (val + 1);
 588         if (tmp == NULL)
 589             abort ();
 590
 591         va_start(args, format);
 592         ret2 = vsprintf (tmp, format, args);
 593         va_end(args);
 594         if (val != ret2 || strcmp(*ret, tmp))
 595             abort ();
 596         free (tmp);
 597     }
 598 #endif
 599
 600     return val;
 601 }
 602 #endif
 603
 604 #if !defined(HAVE_ASNPRINTF) || defined(TEST_SNPRINTF)
 605 int ROKEN_LIB_FUNCTION
 606 asnprintf (char **ret, size_t max_sz, const char *format, ...)
 607 {
 608     va_list args;
 609     int val;
 610
 611     va_start(args, format);
 612     val = vasnprintf (ret, max_sz, format, args);
 613
 614 #ifdef PARANOIA
 615     {
 616         int ret2;
 617         char *tmp;
 618         tmp = malloc (val + 1);
 619         if (tmp == NULL)
 620             abort ();
 621
 622         ret2 = vsprintf (tmp, format, args);
 623         if (val != ret2 || strcmp(*ret, tmp))
 624             abort ();
 625         free (tmp);
 626     }
 627 #endif
 628
 629     va_end(args);
 630     return val;
 631 }
 632 #endif
 633
 634 #if !defined(HAVE_VASPRINTF) || defined(TEST_SNPRINTF)
 635 int ROKEN_LIB_FUNCTION
 636 vasprintf (char **ret, const char *format, va_list args)
 637 {
 638     return vasnprintf (ret, 0, format, args);
 639 }
 640 #endif
 641
 642
 643 #if !defined(HAVE_VASNPRINTF) || defined(TEST_SNPRINTF)
 644 int ROKEN_LIB_FUNCTION
 645 vasnprintf (char **ret, size_t max_sz, const char *format, va_list args)
 646 {
 647     int st;
 648     struct snprintf_state state;
 649
 650     state.max_sz = max_sz;
 651     state.sz     = 1;
 652     state.str    = malloc(state.sz);
 653     if (state.str == NULL) {
 654         *ret = NULL;
 655         return -1;
 656     }
 657     state.s = state.str;
 658     state.theend = state.s + state.sz - 1;
 659     state.append_char = as_append_char;
 660
 661     st = xyzprintf (&state, format, args);
 662     if (st > state.sz) {
 663         free (state.str);
 664         *ret = NULL;
 665         return -1;
 666     } else {
 667         char *tmp;
 668
 669         *state.s = '\0';
 670         tmp = realloc (state.str, st+1);
 671         if (tmp == NULL) {
 672             free (state.str);
 673             *ret = NULL;
 674             return -1;
 675         }
 676         *ret = tmp;
 677         return st;
 678     }
 679 }
 680 #endif
 681
 682 #if !defined(HAVE_VSNPRINTF) || defined(TEST_SNPRINTF)
 683 int ROKEN_LIB_FUNCTION
 684 vsnprintf (char *str, size_t sz, const char *format, va_list args)
 685 {
 686     struct snprintf_state state;
 687     int ret;
 688     unsigned char *ustr = (unsigned char *)str;
 689
 690     state.max_sz = 0;
 691     state.sz     = sz;
 692     state.str    = ustr;
 693     state.s      = ustr;
 694     state.theend = ustr + sz - (sz > 0);
 695     state.append_char = sn_append_char;
 696
 697     ret = xyzprintf (&state, format, args);
 698     if (state.s != NULL && sz != 0)
 699         *state.s = '\0';
 700     return ret;
 701 }
 702 #endif