stdio-common/printf-parse.h

   1 /* Internal header for parsing printf format strings.
   2    Copyright (C) 1995-2023 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, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <printf.h>
  20 #include <stdint.h>
  21 #include <stddef.h>
  22 #include <string.h>
  23 #include <wchar.h>
  24
  25
  26 struct printf_spec
  27   {
  28     /* Information parsed from the format spec.  */
  29     struct printf_info info;
  30
  31     /* Pointers into the format string for the end of this format
  32        spec and the next (or to the end of the string if no more).  */
  33     const UCHAR_T *end_of_fmt, *next_fmt;
  34
  35     /* Position of arguments for precision and width, or -1 if `info' has
  36        the constant value.  */
  37     int prec_arg, width_arg;
  38
  39     int data_arg;               /* Position of data argument.  */
  40     int data_arg_type;          /* Type of first argument.  */
  41     /* Number of arguments consumed by this format specifier.  */
  42     size_t ndata_args;
  43     /* Size of the parameter for PA_USER type.  */
  44     int size;
  45   };
  46
  47 #ifndef DONT_NEED_READ_INT
  48 /* Read a simple integer from a string and update the string pointer.
  49    It is assumed that the first character is a digit.  */
  50 static int
  51 read_int (const UCHAR_T * *pstr)
  52 {
  53   int retval = **pstr - L_('0');
  54
  55   while (ISDIGIT (*++(*pstr)))
  56     if (retval >= 0)
  57       {
  58         if (INT_MAX / 10 < retval)
  59           retval = -1;
  60         else
  61           {
  62             int digit = **pstr - L_('0');
  63
  64             retval *= 10;
  65             if (INT_MAX - digit < retval)
  66               retval = -1;
  67             else
  68               retval += digit;
  69           }
  70       }
  71
  72   return retval;
  73 }
  74 #endif
  75
  76
  77 /* Find the next spec in FORMAT, or the end of the string.  Returns
  78    a pointer into FORMAT, to a '%' or a '\0'.  */
  79 __extern_always_inline const unsigned char *
  80 __find_specmb (const unsigned char *format)
  81 {
  82   return (const unsigned char *) __strchrnul ((const char *) format, '%');
  83 }
  84
  85 __extern_always_inline const unsigned int *
  86 __find_specwc (const unsigned int *format)
  87 {
  88   return (const unsigned int *) __wcschrnul ((const wchar_t *) format, L'%');
  89 }
  90
  91
  92 /* FORMAT must point to a '%' at the beginning of a spec.  Fills in *SPEC
  93    with the parsed details.  POSN is the number of arguments already
  94    consumed.  At most MAXTYPES - POSN types are filled in TYPES.  Return
  95    the number of args consumed by this spec; *MAX_REF_ARG is updated so it
  96    remains the highest argument index used.  *FAILED is set to indicate
  97    whether parsing failed and printf should return with an error status.  */
  98 extern size_t __parse_one_specmb (const unsigned char *format, size_t posn,
  99                                   struct printf_spec *spec,
 100                                   size_t *max_ref_arg,
 101                                   bool *failed) attribute_hidden;
 102
 103 extern size_t __parse_one_specwc (const unsigned int *format, size_t posn,
 104                                   struct printf_spec *spec,
 105                                   size_t *max_ref_arg,
 106                                   bool *failed) attribute_hidden;
 107
 108
 109
 110 /* This variable is defined in reg-modifier.c.  */
 111 struct printf_modifier_record;
 112 extern struct printf_modifier_record **__printf_modifier_table
 113      attribute_hidden;
 114
 115 /* Handle registered modifiers.  */
 116 extern int __handle_registered_modifier_mb (const unsigned char **format,
 117                                             struct printf_info *info)
 118      attribute_hidden;
 119 extern int __handle_registered_modifier_wc (const unsigned int **format,
 120                                             struct printf_info *info)
 121      attribute_hidden;