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 #include <config.h>
  35 #include <stdio.h>
  36 #include <stdarg.h>
  37 #include <stdlib.h>
  38 #include <string.h>
  39 #include <ctype.h>
  40 #include "roken.h"
  41 #include <assert.h>
  42
  43 enum format_flags {
  44     minus_flag     =  1,
  45     plus_flag      =  2,
  46     space_flag     =  4,
  47     alternate_flag =  8,
  48     zero_flag      = 16
  49 };
  50
  51 /*
  52  * Common state
  53  */
  54
  55 struct snprintf_state {
  56     unsigned char *str;
  57     unsigned char *s;
  58     unsigned char *theend;
  59     size_t sz;
  60     size_t max_sz;
  61     void (*append_char)(struct snprintf_state *, unsigned char);
  62     /* XXX - methods */
  63 };
  64
  65 #if !defined(HAVE_VSNPRINTF) || defined(TEST_SNPRINTF)
  66 static int
  67 sn_reserve (struct snprintf_state *state, size_t n)
  68 {
  69     return state->s + n > state->theend;
  70 }
  71
  72 static void
  73 sn_append_char (struct snprintf_state *state, unsigned char c)
  74 {
  75     if (!sn_reserve (state, 1))
  76         *state->s++ = c;
  77 }
  78 #endif
  79
  80 static int
  81 as_reserve (struct snprintf_state *state, size_t n)
  82 {
  83     if (state->s + n > state->theend) {
  84         int off = state->s - state->str;
  85         unsigned char *tmp;
  86
  87         if (state->max_sz && state->sz >= state->max_sz)
  88             return 1;
  89
  90         state->sz = max(state->sz * 2, state->sz + n);
  91         if (state->max_sz)
  92             state->sz = min(state->sz, state->max_sz);
  93         tmp = realloc (state->str, state->sz);
  94         if (tmp == NULL)
  95             return 1;
  96         state->str = tmp;
  97         state->s = state->str + off;
  98         state->theend = state->str + state->sz - 1;
  99     }
 100     return 0;
 101 }
 102
 103 static void
 104 as_append_char (struct snprintf_state *state, unsigned char c)
 105 {
 106     if(!as_reserve (state, 1))
 107         *state->s++ = c;
 108 }
 109
 110 /* longest integer types */
 111
 112 #ifdef HAVE_LONG_LONG
 113 typedef unsigned long long u_longest;
 114 typedef long long longest;
 115 #else
 116 typedef unsigned long u_longest;
 117 typedef long longest;
 118 #endif
 119
 120 #ifndef HAVE_UINTPTR_T
 121 typedef u_longest uintptr_t;
 122 #endif
 123
 124
 125
 126 static size_t
 127 pad(struct snprintf_state *state, int width, char c)
 128 {
 129     size_t len = 0;
 130     while(width-- > 0){
 131         (*state->append_char)(state,  c);
 132         ++len;
 133     }
 134     return len;
 135 }
 136
 137 /* return true if we should use alternatve hex form */
 138 static int
 139 use_alternative (int flags, u_longest num, unsigned base)
 140 {
 141     return (flags & alternate_flag) && base == 16 && num != 0;
 142 }
 143
 144 static int
 145 append_number(struct snprintf_state *state,
 146               u_longest num, unsigned base, const char *rep,
 147               int width, int prec, int flags, int minusp)
 148 {
 149     int len = 0;
 150     u_longest n = num;
 151     char nstr[64]; /* enough for <192 bit octal integers */
 152     int nstart, nlen;
 153     char signchar;
 154
 155     /* given precision, ignore zero flag */
 156     if(prec != -1)
 157         flags &= ~zero_flag;
 158     else
 159         prec = 1;
 160
 161     /* format number as string */
 162     nstart = sizeof(nstr);
 163     nlen = 0;
 164     nstr[--nstart] = '\0';
 165     do {
 166         assert(nstart > 0);
 167         nstr[--nstart] = rep[n % base];
 168         ++nlen;
 169         n /= base;
 170     } while(n);
 171
 172     /* zero value with zero precision should produce no digits */
 173     if(prec == 0 && num == 0) {
 174         nlen--;
 175         nstart++;
 176     }
 177
 178     /* figure out what char to use for sign */
 179     if(minusp)
 180         signchar = '-';
 181     else if((flags & plus_flag))
 182         signchar = '+';
 183     else if((flags & space_flag))
 184         signchar = ' ';
 185     else
 186         signchar = '\0';
 187
 188     if((flags & alternate_flag) && base == 8) {
 189         /* if necessary, increase the precision to
 190            make first digit a zero */
 191
 192         /* XXX C99 claims (regarding # and %o) that "if the value and
 193            precision are both 0, a single 0 is printed", but there is
 194            no such wording for %x. This would mean that %#.o would
 195            output "0", but %#.x "". This does not make sense, and is
 196            also not what other printf implementations are doing. */
 197
 198         if(prec <= nlen && nstr[nstart] != '0' && nstr[nstart] != '\0')
 199             prec = nlen + 1;
 200     }
 201
 202     /* possible formats:
 203        pad | sign | alt | zero | digits
 204        sign | alt | zero | digits | pad   minus_flag
 205        sign | alt | zero | digits zero_flag */
 206
 207     /* if not right justifying or padding with zeros, we need to
 208        compute the length of the rest of the string, and then pad with
 209        spaces */
 210     if(!(flags & (minus_flag | zero_flag))) {
 211         if(prec > nlen)
 212             width -= prec;
 213         else
 214             width -= nlen;
 215
 216         if(use_alternative(flags, num, base))
 217             width -= 2;
 218
 219         if(signchar != '\0')
 220             width--;
 221
 222         /* pad to width */
 223         len += pad(state, width, ' ');
 224     }
 225     if(signchar != '\0') {
 226         (*state->append_char)(state, signchar);
 227         ++len;
 228     }
 229     if(use_alternative(flags, num, base)) {
 230         (*state->append_char)(state, '0');
 231         (*state->append_char)(state, rep[10] + 23); /* XXX */
 232         len += 2;
 233     }
 234     if(flags & zero_flag) {
 235         /* pad to width with zeros */
 236         if(prec - nlen > width - len - nlen)
 237             len += pad(state, prec - nlen, '0');
 238         else
 239             len += pad(state, width - len - nlen, '0');
 240     } else
 241         /* pad to prec with zeros */
 242         len += pad(state, prec - nlen, '0');
 243
 244     while(nstr[nstart] != '\0') {
 245         (*state->append_char)(state, nstr[nstart++]);
 246         ++len;
 247     }
 248
 249     if(flags & minus_flag)
 250         len += pad(state, width - len, ' ');
 251
 252     return len;
 253 }
 254
 255 /*
 256  * return length
 257  */
 258
 259 static size_t
 260 append_string (struct snprintf_state *state,
 261                const unsigned char *arg,
 262                int width,
 263                int prec,
 264                int flags)
 265 {
 266     size_t len = 0;
 267
 268     if(arg == NULL)
 269         arg = (const unsigned char*)"(null)";
 270
 271     if(prec != -1)
 272         width -= prec;
 273     else
 274         width -= strlen((const char *)arg);
 275     if(!(flags & minus_flag))
 276         len += pad(state, width, ' ');
 277
 278     if (prec != -1) {
 279         while (prec-- && *arg) {
 280             (*state->append_char) (state, *arg++);
 281             ++len;
 282         }
 283     } else {
 284         while (*arg) {
 285             (*state->append_char) (state, *arg++);
 286             ++len;
 287         }
 288     }
 289     if(flags & minus_flag)
 290         len += pad(state, width, ' ');
 291     return len;
 292 }
 293
 294 static int
 295 append_char(struct snprintf_state *state,
 296             unsigned char arg,
 297             int width,
 298             int flags)
 299 {
 300     int len = 0;
 301
 302     while(!(flags & minus_flag) && --width > 0) {
 303         (*state->append_char) (state, ' ')    ;
 304         ++len;
 305     }
 306     (*state->append_char) (state, arg);
 307     ++len;
 308     while((flags & minus_flag) && --width > 0) {
 309         (*state->append_char) (state, ' ');
 310         ++len;
 311     }
 312     return len;
 313 }
 314
 315 /*
 316  * This can't be made into a function...
 317  */
 318
 319 #ifdef HAVE_LONG_LONG
 320
 321 #define PARSE_INT_FORMAT(res, arg, unsig) \
 322 if (long_long_flag) \
 323      res = (unsig long long)va_arg(arg, unsig long long); \
 324 else if (long_flag) \
 325      res = (unsig long)va_arg(arg, unsig long); \
 326 else if (size_t_flag) \
 327      res = (unsig long)va_arg(arg, size_t); \
 328 else if (short_flag) \
 329      res = (unsig short)va_arg(arg, unsig int); \
 330 else \
 331      res = (unsig int)va_arg(arg, unsig int)
 332
 333 #else
 334
 335 #define PARSE_INT_FORMAT(res, arg, unsig) \
 336 if (long_flag) \
 337      res = (unsig long)va_arg(arg, unsig long); \
 338 else if (size_t_flag) \
 339      res = (unsig long)va_arg(arg, size_t); \
 340 else if (short_flag) \
 341      res = (unsig short)va_arg(arg, unsig int); \
 342 else \
 343      res = (unsig int)va_arg(arg, unsig int)
 344
 345 #endif
 346
 347 /*
 348  * zyxprintf - return length, as snprintf
 349  */
 350
 351 static size_t
 352 xyzprintf (struct snprintf_state *state, const char *char_format, va_list ap)
 353 {
 354     const unsigned char *format = (const unsigned char *)char_format;
 355     unsigned char c;
 356     size_t len = 0;
 357
 358     while((c = *format++)) {
 359         if (c == '%') {
 360             int flags          = 0;
 361             int width          = 0;
 362             int prec           = -1;
 363             int size_t_flag    = 0;
 364             int long_long_flag = 0;
 365             int long_flag      = 0;
 366             int short_flag     = 0;
 367
 368             /* flags */
 369             while((c = *format++)){
 370                 if(c == '-')
 371                     flags |= minus_flag;
 372                 else if(c == '+')
 373                     flags |= plus_flag;
 374                 else if(c == ' ')
 375                     flags |= space_flag;
 376                 else if(c == '#')
 377                     flags |= alternate_flag;
 378                 else if(c == '0')
 379                     flags |= zero_flag;
 380                 else if(c == '\'')
 381                     ; /* just ignore */
 382                 else
 383                     break;
 384             }
 385
 386             if((flags & space_flag) && (flags & plus_flag))
 387                 flags ^= space_flag;
 388
 389             if((flags & minus_flag) && (flags & zero_flag))
 390                 flags ^= zero_flag;
 391
 392             /* width */
 393             if (isdigit(c))
 394                 do {
 395                     width = width * 10 + c - '0';
 396                     c = *format++;
 397                 } while(isdigit(c));
 398             else if(c == '*') {
 399                 width = va_arg(ap, int);
 400                 c = *format++;
 401             }
 402
 403             /* precision */
 404             if (c == '.') {
 405                 prec = 0;
 406                 c = *format++;
 407                 if (isdigit(c))
 408                     do {
 409                         prec = prec * 10 + c - '0';
 410                         c = *format++;
 411                     } while(isdigit(c));
 412                 else if (c == '*') {
 413                     prec = va_arg(ap, int);
 414                     c = *format++;
 415                 }
 416             }
 417
 418             /* size */
 419
 420             if (c == 'h') {
 421                 short_flag = 1;
 422                 c = *format++;
 423             } else if (c == 'z') {
 424                 size_t_flag = 1;
 425                 c = *format++;
 426             } else if (c == 'l') {
 427                 long_flag = 1;
 428                 c = *format++;
 429                 if (c == 'l') {
 430                     long_long_flag = 1;
 431                     c = *format++;
 432                 }
 433             }
 434
 435             if(c != 'd' && c != 'i')
 436                 flags &= ~(plus_flag | space_flag);
 437
 438             switch (c) {
 439             case 'c' :
 440                 len += append_char(state, va_arg(ap, int), width, flags);
 441                 break;
 442             case 's' :
 443                 len += append_string(state,
 444                                      va_arg(ap, unsigned char*),
 445                                      width,
 446                                      prec,
 447                                      flags);
 448                 break;
 449             case 'd' :
 450             case 'i' : {
 451                 int64_t arg;
 452                 uint64_t num;
 453                 int minusp = 0;
 454
 455                 PARSE_INT_FORMAT(arg, ap, signed);
 456
 457                 if (arg == INT64_MIN) {
 458                     minusp = 1;
 459                     num = (uint64_t)INT64_MAX + 1;
 460                 } else 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                 uintptr_t arg = (uintptr_t)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                 HEIM_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 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
 541 rk_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) != 0)
 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 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
 574 rk_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) != 0)
 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 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
 606 rk_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) != 0)
 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 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
 636 rk_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 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
 645 rk_vasnprintf (char **ret, size_t max_sz, const char *format, va_list args)
 646 {
 647     size_t 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 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
 684 rk_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
 703
 704 #if !defined(HAVE_EVASPRINTF) || defined(TEST_SNPRINTF)
 705 ROKEN_LIB_FUNCTION char * ROKEN_LIB_CALL
 706 rk_evasprintf(const char *format, va_list args)
 707 {
 708     char *s = NULL;
 709
 710     if (vasprintf(&s, format, args) == -1 || s == NULL)
 711         errx(1, "Out of memory");
 712     return s;
 713 }
 714 #endif
 715
 716 #if !defined(HAVE_EASPRINTF) || defined(TEST_SNPRINTF)
 717 ROKEN_LIB_FUNCTION char * ROKEN_LIB_CALL
 718 rk_easprintf(const char *format, ...)
 719 {
 720     va_list args;
 721     char *s = NULL;
 722
 723     va_start(args, format);
 724     if (vasprintf(&s, format, args) == -1 || s == NULL)
 725         errx(1, "Out of memory");
 726     va_end(args);
 727     return s;
 728 }
 729 #endif