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
 121
 122 static size_t
 123 pad(struct snprintf_state *state, int width, char c)
 124 {
 125     size_t len = 0;
 126     while(width-- > 0){
 127         (*state->append_char)(state,  c);
 128         ++len;
 129     }
 130     return len;
 131 }
 132
 133 /* return true if we should use alternatve hex form */
 134 static int
 135 use_alternative (int flags, u_longest num, unsigned base)
 136 {
 137     return (flags & alternate_flag) && base == 16 && num != 0;
 138 }
 139
 140 static int
 141 append_number(struct snprintf_state *state,
 142               u_longest num, unsigned base, const char *rep,
 143               int width, int prec, int flags, int minusp)
 144 {
 145     int len = 0;
 146     u_longest n = num;
 147     char nstr[64]; /* enough for <192 bit octal integers */
 148     int nstart, nlen;
 149     char signchar;
 150
 151     /* given precision, ignore zero flag */
 152     if(prec != -1)
 153         flags &= ~zero_flag;
 154     else
 155         prec = 1;
 156
 157     /* format number as string */
 158     nstart = sizeof(nstr);
 159     nlen = 0;
 160     nstr[--nstart] = '\0';
 161     do {
 162         assert(nstart > 0);
 163         nstr[--nstart] = rep[n % base];
 164         ++nlen;
 165         n /= base;
 166     } while(n);
 167
 168     /* zero value with zero precision should produce no digits */
 169     if(prec == 0 && num == 0) {
 170         nlen--;
 171         nstart++;
 172     }
 173
 174     /* figure out what char to use for sign */
 175     if(minusp)
 176         signchar = '-';
 177     else if((flags & plus_flag))
 178         signchar = '+';
 179     else if((flags & space_flag))
 180         signchar = ' ';
 181     else
 182         signchar = '\0';
 183
 184     if((flags & alternate_flag) && base == 8) {
 185         /* if necessary, increase the precision to
 186            make first digit a zero */
 187
 188         /* XXX C99 claims (regarding # and %o) that "if the value and
 189            precision are both 0, a single 0 is printed", but there is
 190            no such wording for %x. This would mean that %#.o would
 191            output "0", but %#.x "". This does not make sense, and is
 192            also not what other printf implementations are doing. */
 193
 194         if(prec <= nlen && nstr[nstart] != '0' && nstr[nstart] != '\0')
 195             prec = nlen + 1;
 196     }
 197
 198     /* possible formats:
 199        pad | sign | alt | zero | digits
 200        sign | alt | zero | digits | pad   minus_flag
 201        sign | alt | zero | digits zero_flag */
 202
 203     /* if not right justifying or padding with zeros, we need to
 204        compute the length of the rest of the string, and then pad with
 205        spaces */
 206     if(!(flags & (minus_flag | zero_flag))) {
 207         if(prec > nlen)
 208             width -= prec;
 209         else
 210             width -= nlen;
 211
 212         if(use_alternative(flags, num, base))
 213             width -= 2;
 214
 215         if(signchar != '\0')
 216             width--;
 217
 218         /* pad to width */
 219         len += pad(state, width, ' ');
 220     }
 221     if(signchar != '\0') {
 222         (*state->append_char)(state, signchar);
 223         ++len;
 224     }
 225     if(use_alternative(flags, num, base)) {
 226         (*state->append_char)(state, '0');
 227         (*state->append_char)(state, rep[10] + 23); /* XXX */
 228         len += 2;
 229     }
 230     if(flags & zero_flag) {
 231         /* pad to width with zeros */
 232         if(prec - nlen > width - len - nlen)
 233             len += pad(state, prec - nlen, '0');
 234         else
 235             len += pad(state, width - len - nlen, '0');
 236     } else
 237         /* pad to prec with zeros */
 238         len += pad(state, prec - nlen, '0');
 239
 240     while(nstr[nstart] != '\0') {
 241         (*state->append_char)(state, nstr[nstart++]);
 242         ++len;
 243     }
 244
 245     if(flags & minus_flag)
 246         len += pad(state, width - len, ' ');
 247
 248     return len;
 249 }
 250
 251 /*
 252  * return length
 253  */
 254
 255 static size_t
 256 append_string (struct snprintf_state *state,
 257                const unsigned char *arg,
 258                int width,
 259                int prec,
 260                int flags)
 261 {
 262     size_t len = 0;
 263
 264     if(arg == NULL)
 265         arg = (const unsigned char*)"(null)";
 266
 267     if(prec != -1)
 268         width -= prec;
 269     else
 270         width -= strlen((const char *)arg);
 271     if(!(flags & minus_flag))
 272         len += pad(state, width, ' ');
 273
 274     if (prec != -1) {
 275         while (*arg && prec--) {
 276             (*state->append_char) (state, *arg++);
 277             ++len;
 278         }
 279     } else {
 280         while (*arg) {
 281             (*state->append_char) (state, *arg++);
 282             ++len;
 283         }
 284     }
 285     if(flags & minus_flag)
 286         len += pad(state, width, ' ');
 287     return len;
 288 }
 289
 290 static int
 291 append_char(struct snprintf_state *state,
 292             unsigned char arg,
 293             int width,
 294             int flags)
 295 {
 296     int len = 0;
 297
 298     while(!(flags & minus_flag) && --width > 0) {
 299         (*state->append_char) (state, ' ')    ;
 300         ++len;
 301     }
 302     (*state->append_char) (state, arg);
 303     ++len;
 304     while((flags & minus_flag) && --width > 0) {
 305         (*state->append_char) (state, ' ');
 306         ++len;
 307     }
 308     return 0;
 309 }
 310
 311 /*
 312  * This can't be made into a function...
 313  */
 314
 315 #ifdef HAVE_LONG_LONG
 316
 317 #define PARSE_INT_FORMAT(res, arg, unsig) \
 318 if (long_long_flag) \
 319      res = (unsig long long)va_arg(arg, unsig long long); \
 320 else if (long_flag) \
 321      res = (unsig long)va_arg(arg, unsig long); \
 322 else if (size_t_flag) \
 323      res = (unsig long)va_arg(arg, size_t); \
 324 else if (short_flag) \
 325      res = (unsig short)va_arg(arg, unsig int); \
 326 else \
 327      res = (unsig int)va_arg(arg, unsig int)
 328
 329 #else
 330
 331 #define PARSE_INT_FORMAT(res, arg, unsig) \
 332 if (long_flag) \
 333      res = (unsig long)va_arg(arg, unsig long); \
 334 else if (size_t_flag) \
 335      res = (unsig long)va_arg(arg, size_t); \
 336 else if (short_flag) \
 337      res = (unsig short)va_arg(arg, unsig int); \
 338 else \
 339      res = (unsig int)va_arg(arg, unsig int)
 340
 341 #endif
 342
 343 /*
 344  * zyxprintf - return length, as snprintf
 345  */
 346
 347 static size_t
 348 xyzprintf (struct snprintf_state *state, const char *char_format, va_list ap)
 349 {
 350     const unsigned char *format = (const unsigned char *)char_format;
 351     unsigned char c;
 352     size_t len = 0;
 353
 354     while((c = *format++)) {
 355         if (c == '%') {
 356             int flags          = 0;
 357             int width          = 0;
 358             int prec           = -1;
 359             int size_t_flag    = 0;
 360             int long_long_flag = 0;
 361             int long_flag      = 0;
 362             int short_flag     = 0;
 363
 364             /* flags */
 365             while((c = *format++)){
 366                 if(c == '-')
 367                     flags |= minus_flag;
 368                 else if(c == '+')
 369                     flags |= plus_flag;
 370                 else if(c == ' ')
 371                     flags |= space_flag;
 372                 else if(c == '#')
 373                     flags |= alternate_flag;
 374                 else if(c == '0')
 375                     flags |= zero_flag;
 376                 else if(c == '\'')
 377                     ; /* just ignore */
 378                 else
 379                     break;
 380             }
 381
 382             if((flags & space_flag) && (flags & plus_flag))
 383                 flags ^= space_flag;
 384
 385             if((flags & minus_flag) && (flags & zero_flag))
 386                 flags ^= zero_flag;
 387
 388             /* width */
 389             if (isdigit(c))
 390                 do {
 391                     width = width * 10 + c - '0';
 392                     c = *format++;
 393                 } while(isdigit(c));
 394             else if(c == '*') {
 395                 width = va_arg(ap, int);
 396                 c = *format++;
 397             }
 398
 399             /* precision */
 400             if (c == '.') {
 401                 prec = 0;
 402                 c = *format++;
 403                 if (isdigit(c))
 404                     do {
 405                         prec = prec * 10 + c - '0';
 406                         c = *format++;
 407                     } while(isdigit(c));
 408                 else if (c == '*') {
 409                     prec = va_arg(ap, int);
 410                     c = *format++;
 411                 }
 412             }
 413
 414             /* size */
 415
 416             if (c == 'h') {
 417                 short_flag = 1;
 418                 c = *format++;
 419             } else if (c == 'z') {
 420                 size_t_flag = 1;
 421                 c = *format++;
 422             } else if (c == 'l') {
 423                 long_flag = 1;
 424                 c = *format++;
 425                 if (c == 'l') {
 426                     long_long_flag = 1;
 427                     c = *format++;
 428                 }
 429             }
 430
 431             if(c != 'd' && c != 'i')
 432                 flags &= ~(plus_flag | space_flag);
 433
 434             switch (c) {
 435             case 'c' :
 436                 append_char(state, va_arg(ap, int), width, flags);
 437                 ++len;
 438                 break;
 439             case 's' :
 440                 len += append_string(state,
 441                                      va_arg(ap, unsigned char*),
 442                                      width,
 443                                      prec,
 444                                      flags);
 445                 break;
 446             case 'd' :
 447             case 'i' : {
 448                 longest arg;
 449                 u_longest num;
 450                 int minusp = 0;
 451
 452                 PARSE_INT_FORMAT(arg, ap, signed);
 453
 454                 if (arg < 0) {
 455                     minusp = 1;
 456                     num = -arg;
 457                 } else
 458                     num = arg;
 459
 460                 len += append_number (state, num, 10, "0123456789",
 461                                       width, prec, flags, minusp);
 462                 break;
 463             }
 464             case 'u' : {
 465                 u_longest arg;
 466
 467                 PARSE_INT_FORMAT(arg, ap, unsigned);
 468
 469                 len += append_number (state, arg, 10, "0123456789",
 470                                       width, prec, flags, 0);
 471                 break;
 472             }
 473             case 'o' : {
 474                 u_longest arg;
 475
 476                 PARSE_INT_FORMAT(arg, ap, unsigned);
 477
 478                 len += append_number (state, arg, 010, "01234567",
 479                                       width, prec, flags, 0);
 480                 break;
 481             }
 482             case 'x' : {
 483                 u_longest arg;
 484
 485                 PARSE_INT_FORMAT(arg, ap, unsigned);
 486
 487                 len += append_number (state, arg, 0x10, "0123456789abcdef",
 488                                       width, prec, flags, 0);
 489                 break;
 490             }
 491             case 'X' :{
 492                 u_longest arg;
 493
 494                 PARSE_INT_FORMAT(arg, ap, unsigned);
 495
 496                 len += append_number (state, arg, 0x10, "0123456789ABCDEF",
 497                                       width, prec, flags, 0);
 498                 break;
 499             }
 500             case 'p' : {
 501                 u_longest arg = (u_longest)va_arg(ap, void*);
 502
 503                 len += append_number (state, arg, 0x10, "0123456789ABCDEF",
 504                                       width, prec, flags, 0);
 505                 break;
 506             }
 507             case 'n' : {
 508                 int *arg = va_arg(ap, int*);
 509                 *arg = state->s - state->str;
 510                 break;
 511             }
 512             case '\0' :
 513                 --format;
 514                 /* FALLTHROUGH */
 515             case '%' :
 516                 (*state->append_char)(state, c);
 517                 ++len;
 518                 break;
 519             default :
 520                 (*state->append_char)(state, '%');
 521                 (*state->append_char)(state, c);
 522                 len += 2;
 523                 break;
 524             }
 525         } else {
 526             (*state->append_char) (state, c);
 527             ++len;
 528         }
 529     }
 530     return len;
 531 }
 532
 533 #if !defined(HAVE_SNPRINTF) || defined(TEST_SNPRINTF)
 534 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
 535 rk_snprintf (char *str, size_t sz, const char *format, ...)
 536 {
 537     va_list args;
 538     int ret;
 539
 540     va_start(args, format);
 541     ret = vsnprintf (str, sz, format, args);
 542     va_end(args);
 543
 544 #ifdef PARANOIA
 545     {
 546         int ret2;
 547         char *tmp;
 548
 549         tmp = malloc (sz);
 550         if (tmp == NULL)
 551             abort ();
 552
 553         va_start(args, format);
 554         ret2 = vsprintf (tmp, format, args);
 555         va_end(args);
 556         if (ret != ret2 || strcmp(str, tmp))
 557             abort ();
 558         free (tmp);
 559     }
 560 #endif
 561
 562     return ret;
 563 }
 564 #endif
 565
 566 #if !defined(HAVE_ASPRINTF) || defined(TEST_SNPRINTF)
 567 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
 568 rk_asprintf (char **ret, const char *format, ...)
 569 {
 570     va_list args;
 571     int val;
 572
 573     va_start(args, format);
 574     val = vasprintf (ret, format, args);
 575     va_end(args);
 576
 577 #ifdef PARANOIA
 578     {
 579         int ret2;
 580         char *tmp;
 581         tmp = malloc (val + 1);
 582         if (tmp == NULL)
 583             abort ();
 584
 585         va_start(args, format);
 586         ret2 = vsprintf (tmp, format, args);
 587         va_end(args);
 588         if (val != ret2 || strcmp(*ret, tmp))
 589             abort ();
 590         free (tmp);
 591     }
 592 #endif
 593
 594     return val;
 595 }
 596 #endif
 597
 598 #if !defined(HAVE_ASNPRINTF) || defined(TEST_SNPRINTF)
 599 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
 600 rk_asnprintf (char **ret, size_t max_sz, const char *format, ...)
 601 {
 602     va_list args;
 603     int val;
 604
 605     va_start(args, format);
 606     val = vasnprintf (ret, max_sz, format, args);
 607
 608 #ifdef PARANOIA
 609     {
 610         int ret2;
 611         char *tmp;
 612         tmp = malloc (val + 1);
 613         if (tmp == NULL)
 614             abort ();
 615
 616         ret2 = vsprintf (tmp, format, args);
 617         if (val != ret2 || strcmp(*ret, tmp))
 618             abort ();
 619         free (tmp);
 620     }
 621 #endif
 622
 623     va_end(args);
 624     return val;
 625 }
 626 #endif
 627
 628 #if !defined(HAVE_VASPRINTF) || defined(TEST_SNPRINTF)
 629 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
 630 rk_vasprintf (char **ret, const char *format, va_list args)
 631 {
 632     return vasnprintf (ret, 0, format, args);
 633 }
 634 #endif
 635
 636
 637 #if !defined(HAVE_VASNPRINTF) || defined(TEST_SNPRINTF)
 638 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
 639 rk_vasnprintf (char **ret, size_t max_sz, const char *format, va_list args)
 640 {
 641     size_t st;
 642     struct snprintf_state state;
 643
 644     state.max_sz = max_sz;
 645     state.sz     = 1;
 646     state.str    = malloc(state.sz);
 647     if (state.str == NULL) {
 648         *ret = NULL;
 649         return -1;
 650     }
 651     state.s = state.str;
 652     state.theend = state.s + state.sz - 1;
 653     state.append_char = as_append_char;
 654
 655     st = xyzprintf (&state, format, args);
 656     if (st > state.sz) {
 657         free (state.str);
 658         *ret = NULL;
 659         return -1;
 660     } else {
 661         char *tmp;
 662
 663         *state.s = '\0';
 664         tmp = realloc (state.str, st+1);
 665         if (tmp == NULL) {
 666             free (state.str);
 667             *ret = NULL;
 668             return -1;
 669         }
 670         *ret = tmp;
 671         return st;
 672     }
 673 }
 674 #endif
 675
 676 #if !defined(HAVE_VSNPRINTF) || defined(TEST_SNPRINTF)
 677 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
 678 rk_vsnprintf (char *str, size_t sz, const char *format, va_list args)
 679 {
 680     struct snprintf_state state;
 681     int ret;
 682     unsigned char *ustr = (unsigned char *)str;
 683
 684     state.max_sz = 0;
 685     state.sz     = sz;
 686     state.str    = ustr;
 687     state.s      = ustr;
 688     state.theend = ustr + sz - (sz > 0);
 689     state.append_char = sn_append_char;
 690
 691     ret = xyzprintf (&state, format, args);
 692     if (state.s != NULL && sz != 0)
 693         *state.s = '\0';
 694     return ret;
 695 }
 696 #endif