stdio-common/printf-parse.h

   1 /* Internal header for parsing printf format strings.
   2    Copyright (C) 1995-1999, 2000 Free Software Foundation, Inc.
   3    This file is part of th GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <ctype.h>
  21 #include <limits.h>
  22 #include <printf.h>
  23 #include <stdint.h>
  24 #include <stddef.h>
  25 #include <string.h>
  26
  27 #define NDEBUG 1
  28 #include <assert.h>
  29
  30
  31 struct printf_spec
  32   {
  33     /* Information parsed from the format spec.  */
  34     struct printf_info info;
  35
  36     /* Pointers into the format string for the end of this format
  37        spec and the next (or to the end of the string if no more).  */
  38     const UCHAR_T *end_of_fmt, *next_fmt;
  39
  40     /* Position of arguments for precision and width, or -1 if `info' has
  41        the constant value.  */
  42     int prec_arg, width_arg;
  43
  44     int data_arg;               /* Position of data argument.  */
  45     int data_arg_type;          /* Type of first argument.  */
  46     /* Number of arguments consumed by this format specifier.  */
  47     size_t ndata_args;
  48   };
  49
  50
  51 /* The various kinds off arguments that can be passed to printf.  */
  52 union printf_arg
  53   {
  54     unsigned char pa_char;
  55     wchar_t pa_wchar;
  56     short int pa_short_int;
  57     int pa_int;
  58     long int pa_long_int;
  59     long long int pa_long_long_int;
  60     unsigned short int pa_u_short_int;
  61     unsigned int pa_u_int;
  62     unsigned long int pa_u_long_int;
  63     unsigned long long int pa_u_long_long_int;
  64     float pa_float;
  65     double pa_double;
  66     long double pa_long_double;
  67     const char *pa_string;
  68     const wchar_t *pa_wstring;
  69     void *pa_pointer;
  70   };
  71
  72
  73 /* Read a simple integer from a string and update the string pointer.
  74    It is assumed that the first character is a digit.  */
  75 static inline unsigned int
  76 read_int (const UCHAR_T * *pstr)
  77 {
  78   unsigned int retval = **pstr - L_('0');
  79
  80   while (ISDIGIT (*++(*pstr)))
  81     {
  82       retval *= 10;
  83       retval += **pstr - L_('0');
  84     }
  85
  86   return retval;
  87 }
  88
  89
  90
  91 /* Find the next spec in FORMAT, or the end of the string.  Returns
  92    a pointer into FORMAT, to a '%' or a '\0'.  */
  93 static inline const UCHAR_T *
  94 #ifdef COMPILE_WPRINTF
  95 find_spec (const UCHAR_T *format)
  96 #else
  97 find_spec (const UCHAR_T *format, mbstate_t *ps)
  98 #endif
  99 {
 100 #ifdef COMPILE_WPRINTF
 101   return (const UCHAR_T *) __wcschrnul ((const CHAR_T *) format, L'%');
 102 #else
 103   while (*format != L_('\0') && *format != L_('%'))
 104     {
 105       int len;
 106
 107       /* Remove any hints of a wrong encoding.  */
 108       ps->__count = 0;
 109       if (! isascii (*format) && (len = __mbrlen (format, MB_CUR_MAX, ps)) > 0)
 110         format += len;
 111       else
 112         ++format;
 113     }
 114   return format;
 115 #endif
 116 }
 117
 118
 119 /* These are defined in reg-printf.c.  */
 120 extern printf_arginfo_function *__printf_arginfo_table[];
 121 extern printf_function **__printf_function_table;
 122
 123
 124 /* FORMAT must point to a '%' at the beginning of a spec.  Fills in *SPEC
 125    with the parsed details.  POSN is the number of arguments already
 126    consumed.  At most MAXTYPES - POSN types are filled in TYPES.  Return
 127    the number of args consumed by this spec; *MAX_REF_ARG is updated so it
 128    remains the highest argument index used.  */
 129 static inline size_t
 130 #ifdef COMPILE_WPRINTF
 131 parse_one_spec (const UCHAR_T *format, size_t posn, struct printf_spec *spec,
 132                 size_t *max_ref_arg)
 133 #else
 134 parse_one_spec (const UCHAR_T *format, size_t posn, struct printf_spec *spec,
 135                 size_t *max_ref_arg, mbstate_t *ps)
 136 #endif
 137 {
 138   unsigned int n;
 139   size_t nargs = 0;
 140
 141   /* Skip the '%'.  */
 142   ++format;
 143
 144   /* Clear information structure.  */
 145   spec->data_arg = -1;
 146   spec->info.alt = 0;
 147   spec->info.space = 0;
 148   spec->info.left = 0;
 149   spec->info.showsign = 0;
 150   spec->info.group = 0;
 151   spec->info.i18n = 0;
 152   spec->info.pad = ' ';
 153   spec->info.wide = sizeof (UCHAR_T) > 1;
 154
 155   /* Test for positional argument.  */
 156   if (ISDIGIT (*format))
 157     {
 158       const UCHAR_T *begin = format;
 159
 160       n = read_int (&format);
 161
 162       if (n > 0 && *format == L_('$'))
 163         /* Is positional parameter.  */
 164         {
 165           ++format;             /* Skip the '$'.  */
 166           spec->data_arg = n - 1;
 167           *max_ref_arg = MAX (*max_ref_arg, n);
 168         }
 169       else
 170         /* Oops; that was actually the width and/or 0 padding flag.
 171            Step back and read it again.  */
 172         format = begin;
 173     }
 174
 175   /* Check for spec modifiers.  */
 176   do
 177     {
 178       switch (*format)
 179         {
 180         case L_(' '):
 181           /* Output a space in place of a sign, when there is no sign.  */
 182           spec->info.space = 1;
 183           continue;
 184         case L_('+'):
 185           /* Always output + or - for numbers.  */
 186           spec->info.showsign = 1;
 187           continue;
 188         case L_('-'):
 189           /* Left-justify things.  */
 190           spec->info.left = 1;
 191           continue;
 192         case L_('#'):
 193           /* Use the "alternate form":
 194              Hex has 0x or 0X, FP always has a decimal point.  */
 195           spec->info.alt = 1;
 196           continue;
 197         case L_('0'):
 198           /* Pad with 0s.  */
 199           spec->info.pad = '0';
 200           continue;
 201         case L_('\''):
 202           /* Show grouping in numbers if the locale information
 203              indicates any.  */
 204           spec->info.group = 1;
 205           continue;
 206         case L_('I'):
 207           /* Use the internationalized form of the output.  Currently
 208              means to use the `outdigits' of the current locale.  */
 209           spec->info.i18n = 1;
 210           continue;
 211         default:
 212           break;
 213         }
 214       break;
 215     }
 216   while (*++format);
 217
 218   if (spec->info.left)
 219     spec->info.pad = ' ';
 220
 221   /* Get the field width.  */
 222   spec->width_arg = -1;
 223   spec->info.width = 0;
 224   if (*format == L_('*'))
 225     {
 226       /* The field width is given in an argument.
 227          A negative field width indicates left justification.  */
 228       const UCHAR_T *begin = ++format;
 229
 230       if (ISDIGIT (*format))
 231         {
 232           /* The width argument might be found in a positional parameter.  */
 233           n = read_int (&format);
 234
 235           if (n > 0 && *format == L_('$'))
 236             {
 237               spec->width_arg = n - 1;
 238               *max_ref_arg = MAX (*max_ref_arg, n);
 239               ++format;         /* Skip '$'.  */
 240             }
 241         }
 242
 243       if (spec->width_arg < 0)
 244         {
 245           /* Not in a positional parameter.  Consume one argument.  */
 246           spec->width_arg = posn++;
 247           ++nargs;
 248           format = begin;       /* Step back and reread.  */
 249         }
 250     }
 251   else if (ISDIGIT (*format))
 252     /* Constant width specification.  */
 253     spec->info.width = read_int (&format);
 254
 255   /* Get the precision.  */
 256   spec->prec_arg = -1;
 257   /* -1 means none given; 0 means explicit 0.  */
 258   spec->info.prec = -1;
 259   if (*format == L_('.'))
 260     {
 261       ++format;
 262       if (*format == L_('*'))
 263         {
 264           /* The precision is given in an argument.  */
 265           const UCHAR_T *begin = ++format;
 266
 267           if (ISDIGIT (*format))
 268             {
 269               n = read_int (&format);
 270
 271               if (n > 0 && *format == L_('$'))
 272                 {
 273                   spec->prec_arg = n - 1;
 274                   *max_ref_arg = MAX (*max_ref_arg, n);
 275                   ++format;
 276                 }
 277             }
 278
 279           if (spec->prec_arg < 0)
 280             {
 281               /* Not in a positional parameter.  */
 282               spec->prec_arg = posn++;
 283               ++nargs;
 284               format = begin;
 285             }
 286         }
 287       else if (ISDIGIT (*format))
 288         spec->info.prec = read_int (&format);
 289       else
 290         /* "%.?" is treated like "%.0?".  */
 291         spec->info.prec = 0;
 292     }
 293
 294   /* Check for type modifiers.  */
 295   spec->info.is_long_double = 0;
 296   spec->info.is_short = 0;
 297   spec->info.is_long = 0;
 298   spec->info.is_char = 0;
 299
 300   switch (*format++)
 301     {
 302     case L_('h'):
 303       /* ints are short ints or chars.  */
 304       if (*format != L_('h'))
 305         spec->info.is_short = 1;
 306       else
 307         {
 308           ++format;
 309           spec->info.is_char = 1;
 310         }
 311       break;
 312     case L_('l'):
 313       /* ints are long ints.  */
 314       spec->info.is_long = 1;
 315       if (*format != L_('l'))
 316         break;
 317       ++format;
 318       /* FALLTHROUGH */
 319     case L_('L'):
 320       /* doubles are long doubles, and ints are long long ints.  */
 321     case L_('q'):
 322       /* 4.4 uses this for long long.  */
 323       spec->info.is_long_double = 1;
 324       break;
 325     case L_('z'):
 326     case L_('Z'):
 327       /* ints are size_ts.  */
 328       assert (sizeof (size_t) <= sizeof (unsigned long long int));
 329 #if LONG_MAX != LONG_LONG_MAX
 330       spec->info.is_long_double = sizeof (size_t) > sizeof (unsigned long int);
 331 #endif
 332       spec->info.is_long = sizeof (size_t) > sizeof (unsigned int);
 333       break;
 334     case L_('t'):
 335       assert (sizeof (ptrdiff_t) <= sizeof (long long int));
 336 #if LONG_MAX != LONG_LONG_MAX
 337       spec->info.is_long_double = (sizeof (ptrdiff_t) > sizeof (long int));
 338 #endif
 339       spec->info.is_long = sizeof (ptrdiff_t) > sizeof (int);
 340       break;
 341     case L_('j'):
 342       assert (sizeof (uintmax_t) <= sizeof (unsigned long long int));
 343 #if LONG_MAX != LONG_LONG_MAX
 344       spec->info.is_long_double = (sizeof (uintmax_t)
 345                                    > sizeof (unsigned long int));
 346 #endif
 347       spec->info.is_long = sizeof (uintmax_t) > sizeof (unsigned int);
 348       break;
 349     default:
 350       /* Not a recognized modifier.  Backup.  */
 351       --format;
 352       break;
 353     }
 354
 355   /* Get the format specification.  */
 356   spec->info.spec = (wchar_t) *format++;
 357   if (__printf_function_table != NULL
 358       && spec->info.spec <= UCHAR_MAX
 359       && __printf_arginfo_table[spec->info.spec] != NULL)
 360     /* We don't try to get the types for all arguments if the format
 361        uses more than one.  The normal case is covered though.  */
 362     spec->ndata_args = (*__printf_arginfo_table[spec->info.spec])
 363       (&spec->info, 1, &spec->data_arg_type);
 364   else
 365     {
 366       /* Find the data argument types of a built-in spec.  */
 367       spec->ndata_args = 1;
 368
 369       switch (spec->info.spec)
 370         {
 371         case L'i':
 372         case L'd':
 373         case L'u':
 374         case L'o':
 375         case L'X':
 376         case L'x':
 377 #if LONG_MAX != LONG_LONG_MAX
 378           if (spec->info.is_long_double)
 379             spec->data_arg_type = PA_INT|PA_FLAG_LONG_LONG;
 380           else
 381 #endif
 382             if (spec->info.is_long)
 383               spec->data_arg_type = PA_INT|PA_FLAG_LONG;
 384             else if (spec->info.is_short)
 385               spec->data_arg_type = PA_INT|PA_FLAG_SHORT;
 386             else if (spec->info.is_char)
 387               spec->data_arg_type = PA_CHAR;
 388             else
 389               spec->data_arg_type = PA_INT;
 390           break;
 391         case L'e':
 392         case L'E':
 393         case L'f':
 394         case L'F':
 395         case L'g':
 396         case L'G':
 397         case L'a':
 398         case L'A':
 399           if (spec->info.is_long_double)
 400             spec->data_arg_type = PA_DOUBLE|PA_FLAG_LONG_DOUBLE;
 401           else
 402             spec->data_arg_type = PA_DOUBLE;
 403           break;
 404         case L'c':
 405           spec->data_arg_type = PA_CHAR;
 406           break;
 407         case L'C':
 408           spec->data_arg_type = PA_WCHAR;
 409           break;
 410         case L's':
 411           spec->data_arg_type = PA_STRING;
 412           break;
 413         case L'S':
 414           spec->data_arg_type = PA_WSTRING;
 415           break;
 416         case L'p':
 417           spec->data_arg_type = PA_POINTER;
 418           break;
 419         case L'n':
 420           spec->data_arg_type = PA_INT|PA_FLAG_PTR;
 421           break;
 422
 423         case L'm':
 424         default:
 425           /* An unknown spec will consume no args.  */
 426           spec->ndata_args = 0;
 427           break;
 428         }
 429     }
 430
 431   if (spec->data_arg == -1 && spec->ndata_args > 0)
 432     {
 433       /* There are args consumed, but no positional spec.  Use the
 434          next sequential arg position.  */
 435       spec->data_arg = posn;
 436       nargs += spec->ndata_args;
 437     }
 438
 439   if (spec->info.spec == L'\0')
 440     /* Format ended before this spec was complete.  */
 441     spec->end_of_fmt = spec->next_fmt = format - 1;
 442   else
 443     {
 444       /* Find the next format spec.  */
 445       spec->end_of_fmt = format;
 446 #ifdef COMPILE_WPRINTF
 447       spec->next_fmt = find_spec (format);
 448 #else
 449       spec->next_fmt = find_spec (format, ps);
 450 #endif
 451     }
 452
 453   return nargs;
 454 }