glibc/stdio-common/printf-parse.h

/* Internal header for parsing printf format strings.
   Copyright (C) 1995-2024 Free Software Foundation, Inc.
   This file is part of th GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#include <printf.h>
#include <stdint.h>
#include <stddef.h>
#include <string.h>
#include <wchar.h>


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 UCHAR_T *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;
    /* Size of the parameter for PA_USER type.  */
    int size;
  };

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

  while (ISDIGIT (*++(*pstr)))
    if (retval >= 0)
      {
	if (INT_MAX / 10 < retval)
	  retval = -1;
	else
	  {
	    int digit = **pstr - L_('0');

	    retval *= 10;
	    if (INT_MAX - digit < retval)
	      retval = -1;
	    else
	      retval += digit;
	  }
      }

  return retval;
}
#endif


/* Find the next spec in FORMAT, or the end of the string.  Returns
   a pointer into FORMAT, to a '%' or a '\0'.  */
__extern_always_inline const unsigned char *
__find_specmb (const unsigned char *format)
{
  return (const unsigned char *) __strchrnul ((const char *) format, '%');
}

__extern_always_inline const unsigned int *
__find_specwc (const unsigned int *format)
{
  return (const unsigned int *) __wcschrnul ((const wchar_t *) format, L'%');
}


/* 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.  *FAILED is set to indicate
   whether parsing failed and printf should return with an error status.  */
extern size_t __parse_one_specmb (const unsigned char *format, size_t posn,
				  struct printf_spec *spec,
				  size_t *max_ref_arg,
				  bool *failed) attribute_hidden;

extern size_t __parse_one_specwc (const unsigned int *format, size_t posn,
				  struct printf_spec *spec,
				  size_t *max_ref_arg,
				  bool *failed) attribute_hidden;



/* This variable is defined in reg-modifier.c.  */
struct printf_modifier_record;
extern struct printf_modifier_record **__printf_modifier_table
     attribute_hidden;

/* Handle registered modifiers.  */
extern int __handle_registered_modifier_mb (const unsigned char **format,
					    struct printf_info *info)
     attribute_hidden;
extern int __handle_registered_modifier_wc (const unsigned int **format,
					    struct printf_info *info)
     attribute_hidden;