gdb/charset.h

   1 /* Character set conversion support for GDB.
   2    Copyright (C) 2001-2015 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef CHARSET_H
  20 #define CHARSET_H
  21
  22 /* If the target program uses a different character set than the host,
  23    GDB has some support for translating between the two; GDB converts
  24    characters and strings to the host character set before displaying
  25    them, and converts characters and strings appearing in expressions
  26    entered by the user to the target character set.
  27
  28    GDB's code pretty much assumes that the host character set is some
  29    superset of ASCII; there are plenty if ('0' + n) expressions and
  30    the like.  */
  31
  32 /* Return the name of the current host/target character set.  The
  33    result is owned by the charset module; the caller should not free
  34    it.  */
  35 const char *host_charset (void);
  36 const char *target_charset (struct gdbarch *gdbarch);
  37 const char *target_wide_charset (struct gdbarch *gdbarch);
  38
  39 /* These values are used to specify the type of transliteration done
  40    by convert_between_encodings.  */
  41 enum transliterations
  42   {
  43     /* Error on failure to convert.  */
  44     translit_none,
  45     /* Transliterate to host char.  */
  46     translit_char
  47   };
  48
  49 /* Convert between two encodings.
  50
  51    FROM is the name of the source encoding.
  52    TO is the name of the target encoding.
  53    BYTES holds the bytes to convert; this is assumed to be characters
  54    in the target encoding.
  55    NUM_BYTES is the number of bytes.
  56    WIDTH is the width of a character from the FROM charset, in bytes.
  57    For a variable width encoding, WIDTH should be the size of a "base
  58    character".
  59    OUTPUT is an obstack where the converted data is written.  The
  60    caller is responsible for initializing the obstack, and for
  61    destroying the obstack should an error occur.
  62    TRANSLIT specifies how invalid conversions should be handled.  */
  63
  64 void convert_between_encodings (const char *from, const char *to,
  65                                 const gdb_byte *bytes,
  66                                 unsigned int num_bytes,
  67                                 int width, struct obstack *output,
  68                                 enum transliterations translit);
  69
  70
  71 /* These values are used by wchar_iterate to report errors.  */
  72 enum wchar_iterate_result
  73   {
  74     /* Ordinary return.  */
  75     wchar_iterate_ok,
  76     /* Invalid input sequence.  */
  77     wchar_iterate_invalid,
  78     /* Incomplete input sequence at the end of the input.  */
  79     wchar_iterate_incomplete,
  80     /* EOF.  */
  81     wchar_iterate_eof
  82   };
  83
  84 /* Declaration of the opaque wchar iterator type.  */
  85 struct wchar_iterator;
  86
  87 /* Create a new character iterator which returns wchar_t's.  INPUT is
  88    the input buffer.  BYTES is the number of bytes in the input
  89    buffer.  CHARSET is the name of the character set in which INPUT is
  90    encoded.  WIDTH is the number of bytes in a base character of
  91    CHARSET.
  92
  93    This function either returns a new character set iterator, or calls
  94    error.  The result can be freed using a cleanup; see
  95    make_cleanup_wchar_iterator.  */
  96 struct wchar_iterator *make_wchar_iterator (const gdb_byte *input,
  97                                             size_t bytes,
  98                                             const char *charset,
  99                                             size_t width);
 100
 101 /* Return a new cleanup suitable for destroying the wchar iterator
 102    ITER.  */
 103 struct cleanup *make_cleanup_wchar_iterator (struct wchar_iterator *iter);
 104
 105 /* Perform a single iteration of a wchar_t iterator.
 106
 107    Returns the number of characters converted.  A negative result
 108    means that EOF has been reached.  A positive result indicates the
 109    number of valid wchar_ts in the result; *OUT_CHARS is updated to
 110    point to the first valid character.
 111
 112    In all cases aside from EOF, *PTR is set to point to the first
 113    converted target byte.  *LEN is set to the number of bytes
 114    converted.
 115
 116    A zero result means one of several unusual results.  *OUT_RESULT is
 117    set to indicate the type of un-ordinary return.
 118
 119    wchar_iterate_invalid means that an invalid input character was
 120    seen.  The iterator is advanced by WIDTH (the argument to
 121    make_wchar_iterator) bytes.
 122
 123    wchar_iterate_incomplete means that an incomplete character was
 124    seen at the end of the input sequence.
 125
 126    wchar_iterate_eof means that all bytes were successfully
 127    converted.  The other output arguments are not set.  */
 128 int wchar_iterate (struct wchar_iterator *iter,
 129                    enum wchar_iterate_result *out_result,
 130                    gdb_wchar_t **out_chars,
 131                    const gdb_byte **ptr, size_t *len);
 132
 133 \f
 134
 135 /* GDB needs to know a few details of its execution character set.
 136    This knowledge is isolated here and in charset.c.  */
 137
 138 /* The escape character.  */
 139 #define HOST_ESCAPE_CHAR 27
 140
 141 /* Convert a letter, like 'c', to its corresponding control
 142    character.  */
 143 char host_letter_to_control_character (char c);
 144
 145 /* Convert a hex digit character to its numeric value.  E.g., 'f' is
 146    converted to 15.  This function assumes that C is a valid hex
 147    digit.  Both upper- and lower-case letters are recognized.  */
 148 int host_hex_value (char c);
 149
 150 #endif /* CHARSET_H */