source: trunk/third/gettext/lib/printf-parse.h @ 16931

/* Internal header for parsing printf format strings.
   Copyright (C) 1995, 1996, 1998, 2000 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

/* We use some extension so define this here.  */
#define _GNU_SOURCE     1

#include <ctype.h>
#include <printf.h>
#if HAVE_STDDEF_H
# include <stddef.h>
#endif
#if HAVE_INTTYPES_H
# include <inttypes.h>
#endif

#if HAVE_STRING_H
# include <string.h>
#else
# include <strings.h>
#endif

#if __GNUC__ >= 2
# define long_double long double
#else
# define long_double double
#endif

#if HAVE_UNSIGNED_LONG_LONG
# define long_long_int long long int
#else
# define long_long_int long int
#endif

#if !HAVE_PTRDIFF_T
# define ptrdiff_t long int
#endif

#define NDEBUG 1
#include <assert.h>

#ifndef MAX
# if defined __GNU__ && __GNUC__ >= 2
#  define MAX(a,b)      ({typeof(a) _a = (a); typeof(b) _b = (b);             \
                          _a > _b ? _a : _b; })
# else
#  define MAX(a,b)      ((a) > (b) ? (a) : (b))
# endif
#endif
#ifndef MIN
# if defined __GNU__ && __GNUC__ >= 2
#  define MIN(a,b)      ({typeof(a) _a = (a); typeof(b) _b = (b);             \
                          _a < _b ? _a : _b; })
# else
#  define MIN(a,b)      ((a) < (b) ? (a) : (b))
# endif
#endif

struct printf_spec
  {
    /* Information parsed from the format spec.  */
    struct printf_info info;

    /* Pointers into the format string for the end of this format
       spec and the next (or to the end of the string if no more).  */
    const char *end_of_fmt, *next_fmt;

    /* Position of arguments for precision and width, or -1 if `info' has
       the constant value.  */
    int prec_arg, width_arg;

    int data_arg;               /* Position of data argument.  */
    int data_arg_type;          /* Type of first argument.  */
    /* Number of arguments consumed by this format specifier.  */
    size_t ndata_args;
  };


/* The various kinds off arguments that can be passed to printf.  */
union printf_arg
  {
    unsigned char pa_char;
    short int pa_short_int;
    int pa_int;
    long int pa_long_int;
    long_long_int pa_long_long_int;
    unsigned short int pa_u_short_int;
    unsigned int pa_u_int;
    unsigned long int pa_u_long_int;
    unsigned long_long_int pa_u_long_long_int;
    float pa_float;
    double pa_double;
    long_double pa_long_double;
    const char *pa_string;
    void *pa_pointer;
  };


/* Prototype for local function.  */
static unsigned int read_int PARAMS ((const char **pstr));
static const char *find_spec PARAMS ((const char *format));
static inline size_t parse_one_spec PARAMS ((const char *format,
                                             size_t posn,
                                             struct printf_spec *spec,
                                             size_t *max_ref_arg));


/* Read a simple integer from a string and update the string pointer.
   It is assumed that the first character is a digit.  */
static inline unsigned int
read_int (pstr)
     const char **pstr;
{
  unsigned int retval = **pstr - '0';

  while (isdigit (*++(*pstr)))
    {
      retval *= 10;
      retval += **pstr - '0';
    }

  return retval;
}



/* Find the next spec in FORMAT, or the end of the string.  Returns
   a pointer into FORMAT, to a '%' or a '\0'.  */
static inline const char *
find_spec (format)
     const char *format;
{
  while (*format != '\0' && *format != '%')
    ++format;
  return format;
}


/* FORMAT must point to a '%' at the beginning of a spec.  Fills in *SPEC
   with the parsed details.  POSN is the number of arguments already
   consumed.  At most MAXTYPES - POSN types are filled in TYPES.  Return
   the number of args consumed by this spec; *MAX_REF_ARG is updated so it
   remains the highest argument index used.  */
static inline size_t
parse_one_spec (format, posn, spec, max_ref_arg)
     const char *format;
     size_t posn;
     struct printf_spec *spec;
     size_t *max_ref_arg;
{
  unsigned int n;
  size_t nargs = 0;

  /* Skip the '%'.  */
  ++format;

  /* Clear information structure.  */
  spec->data_arg = -1;
  spec->info.alt = 0;
  spec->info.space = 0;
  spec->info.left = 0;
  spec->info.showsign = 0;
  spec->info.group = 0;
  spec->info.pad = ' ';

  /* Test for positional argument.  */
  if (isdigit (*format))
    {
      const char *begin = format;

      n = read_int (&format);

      if (n > 0 && *format == '$')
        /* Is positional parameter.  */
        {
          ++format;             /* Skip the '$'.  */
          spec->data_arg = n - 1;
          *max_ref_arg = MAX (*max_ref_arg, n);
        }
      else
        /* Oops; that was actually the width and/or 0 padding flag.
           Step back and read it again.  */
        format = begin;
    }

  /* Check for spec modifiers.  */
  while (*format == ' ' || *format == '+' || *format == '-' ||
         *format == '#' || *format == '0' || *format == '\'')
    switch (*format++)
      {
      case ' ':
        /* Output a space in place of a sign, when there is no sign.  */
        spec->info.space = 1;
        break;
      case '+':
        /* Always output + or - for numbers.  */
        spec->info.showsign = 1;
        break;
      case '-':
        /* Left-justify things.  */
        spec->info.left = 1;
        break;
      case '#':
        /* Use the "alternate form":
           Hex has 0x or 0X, FP always has a decimal point.  */
        spec->info.alt = 1;
        break;
      case '0':
        /* Pad with 0s.  */
        spec->info.pad = '0';
        break;
      case '\'':
        /* Show grouping in numbers if the locale information
           indicates any.  */
        spec->info.group = 1;
        break;
      }
  if (spec->info.left)
    spec->info.pad = ' ';

  /* Get the field width.  */
  spec->width_arg = -1;
  spec->info.width = 0;
  if (*format == '*')
    {
      /* The field width is given in an argument.
         A negative field width indicates left justification.  */
      const char *begin = ++format;

      if (isdigit (*format))
        {
          /* The width argument might be found in a positional parameter.  */
          n = read_int (&format);

          if (n > 0 && *format == '$')
            {
              spec->width_arg = n - 1;
              *max_ref_arg = MAX (*max_ref_arg, n);
              ++format;         /* Skip '$'.  */
            }
        }

      if (spec->width_arg < 0)
        {
          /* Not in a positional parameter.  Consume one argument.  */
          spec->width_arg = posn++;
          ++nargs;
          format = begin;       /* Step back and reread.  */
        }
    }
  else if (isdigit (*format))
    /* Constant width specification.  */
    spec->info.width = read_int (&format);

  /* Get the precision.  */
  spec->prec_arg = -1;
  /* -1 means none given; 0 means explicit 0.  */
  spec->info.prec = -1;
  if (*format == '.')
    {
      ++format;
      if (*format == '*')
        {
          /* The precision is given in an argument.  */
          const char *begin = ++format;

          if (isdigit (*format))
            {
              n = read_int (&format);

              if (n > 0 && *format == '$')
                {
                  spec->prec_arg = n - 1;
                  *max_ref_arg = MAX (*max_ref_arg, n);
                  ++format;
                }
            }

          if (spec->prec_arg < 0)
            {
              /* Not in a positional parameter.  */
              spec->prec_arg = posn++;
              ++nargs;
              format = begin;
            }
        }
      else if (isdigit (*format))
        spec->info.prec = read_int (&format);
      else
        /* "%.?" is treated like "%.0?".  */
        spec->info.prec = 0;
    }

  /* Check for type modifiers.  */
  spec->info.is_long_double = 0;
  spec->info.is_short = 0;
  spec->info.is_char = 0;
  spec->info.is_long = 0;
  spec->info.is_longlong = 0;

  while (*format == 'h' || *format == 'l' || *format == 'L' ||
         *format == 'Z' || *format == 'q')
    switch (*format++)
      {
      case 'h':
        if (spec->info.is_short)
          /* int's are char's.  */
          spec->info.is_char = 1;
        else
          /* int's are short int's.  */
          spec->info.is_short = 1;
        break;
      case 'l':
        if (spec->info.is_long)
          /* A double `l' is equivalent to an `L'.  */
          spec->info.is_longlong = spec->info.is_long_double = 1;
        else
          /* int's are long int's.  */
          spec->info.is_long = 1;
        break;
      case 'L':
        /* double's are long double's, and int's are long long int's.  */
        spec->info.is_long_double = spec->info.is_longlong = 1;
        break;
      case 'j':
        /* int's are intmax_t's.  */
        assert (sizeof(uintmax_t) <= sizeof(unsigned long_long_int));
        spec->info.is_longlong = sizeof(uintmax_t) > sizeof(unsigned long int);
        spec->info.is_long = sizeof(uintmax_t) > sizeof(unsigned int);
        break;
      case 't':
        /* int's are ptrdiff_t's.  */
        assert (sizeof(ptrdiff_t) <= sizeof(unsigned long_long_int));
        spec->info.is_longlong = sizeof(ptrdiff_t) > sizeof(unsigned long int);
        spec->info.is_long = sizeof(ptrdiff_t) > sizeof(unsigned int);
        break;
      case 'z':
      case 'Z':
        /* int's are size_t's.  */
        assert (sizeof(size_t) <= sizeof(unsigned long_long_int));
        spec->info.is_longlong = sizeof(size_t) > sizeof(unsigned long int);
        spec->info.is_long = sizeof(size_t) > sizeof(unsigned int);
        break;
      case 'q':
        /* 4.4 uses this for long long.  */
        spec->info.is_longlong = 1;
        break;
      }

  /* Get the format specification.  */
  spec->info.spec = *format++;
  /* Find the data argument types of a built-in spec.  */
  spec->ndata_args = 1;

  switch (spec->info.spec)
    {
    case 'i':
    case 'd':
    case 'u':
    case 'o':
    case 'X':
    case 'x':
      if (spec->info.is_longlong)
        spec->data_arg_type = PA_INT|PA_FLAG_LONG_LONG;
      else if (spec->info.is_long)
        spec->data_arg_type = PA_INT|PA_FLAG_LONG;
      else if (spec->info.is_char)
        spec->data_arg_type = PA_INT|PA_FLAG_CHAR;
      else if (spec->info.is_short)
        spec->data_arg_type = PA_INT|PA_FLAG_SHORT;
      else
        spec->data_arg_type = PA_INT;
      break;
    case 'e':
    case 'E':
    case 'f':
    case 'g':
    case 'G':
      if (spec->info.is_long_double)
        spec->data_arg_type = PA_DOUBLE|PA_FLAG_LONG_DOUBLE;
      else
        spec->data_arg_type = PA_DOUBLE;
      break;
    case 'c':
      spec->data_arg_type = PA_CHAR;
      break;
    case 's':
      spec->data_arg_type = PA_STRING;
      break;
    case 'p':
      spec->data_arg_type = PA_POINTER|PA_FLAG_PTR;
      break;
    case 'n':
      spec->data_arg_type = PA_INT|PA_FLAG_PTR;
      break;

    case 'm':
    default:
      /* An unknown spec will consume no args.  */
      spec->ndata_args = 0;
      break;
    }

  if (spec->data_arg == -1 && spec->ndata_args > 0)
    {
      /* There are args consumed, but no positional spec.
         Use the next sequential arg position.  */
      spec->data_arg = posn;
      posn += spec->ndata_args;
      nargs += spec->ndata_args;
    }

  if (spec->info.spec == '\0')
    /* Format ended before this spec was complete.  */
    spec->end_of_fmt = spec->next_fmt = format - 1;
  else
    {
      /* Find the next format spec.  */
      spec->end_of_fmt = format;
      spec->next_fmt = find_spec (format);
    }

  return nargs;
}