gdb/gdb_wchar.h

   1 /* Wide characters for gdb
   2    Copyright (C) 2009, 2010 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 GDB_WCHAR_H
  20 #define GDB_WCHAR_H
  21
  22 /* We handle three different modes here.
  23
  24    Capable systems have the full suite: wchar_t support and iconv
  25    (perhaps via GNU libiconv).  On these machines, full functionality
  26    is available.  Note that full functionality is dependent on us
  27    being able to convert from an arbitrary encoding to wchar_t.  In
  28    practice this means we look for __STDC_ISO_10646__ (where we know
  29    the name of the wchar_t encoding) or GNU libiconv, where we can use
  30    "wchar_t".
  31
  32    DJGPP is known to have libiconv but not wchar_t support.  On
  33    systems like this, we use the narrow character functions.  The full
  34    functionality is available to the user, but many characters (those
  35    outside the narrow range) will be displayed as escapes.
  36
  37    Finally, some systems do not have iconv, or are really broken
  38    (e.g., Solaris, which almost has all of this working, but where
  39    just enough is broken to make it too hard to use).  Here we provide
  40    a phony iconv which only handles a single character set, and we
  41    provide wrappers for the wchar_t functionality we use.  */
  42
  43
  44 #if defined (HAVE_ICONV)
  45 #include <iconv.h>
  46 #else
  47 /* This define is used elsewhere so we don't need to duplicate the
  48    same checking logic in multiple places.  */
  49 #define PHONY_ICONV
  50 #endif
  51
  52 /* We use "btowc" as a sentinel to detect functioning wchar_t support.
  53    We check for either __STDC_ISO_10646__ or a new-enough libiconv in
  54    order to ensure we can convert to and from wchar_t.  We choose
  55    libiconv version 0x10D because it was reported that earlier
  56    versions do not always accept "wchar_t" as an encoding
  57    argument.  */
  58 #if defined (HAVE_ICONV) && defined (HAVE_WCHAR_H) && defined (HAVE_BTOWC) \
  59   && (defined (__STDC_ISO_10646__) \
  60       || (defined (_LIBICONV_VERSION) && _LIBICONV_VERSION >= 0x10D))
  61
  62 #include <wchar.h>
  63 #include <wctype.h>
  64
  65 typedef wchar_t gdb_wchar_t;
  66 typedef wint_t gdb_wint_t;
  67
  68 #define gdb_wcslen wcslen
  69 #define gdb_iswprint iswprint
  70 #define gdb_iswdigit iswdigit
  71 #define gdb_btowc btowc
  72 #define gdb_WEOF WEOF
  73
  74 #define LCST(X) L ## X
  75
  76 /* If __STDC_ISO_10646__ is defined, then the host wchar_t is UCS-4.
  77    We exploit this fact in the hope that there are hosts that define
  78    this but which do not support "wchar_t" as an encoding argument to
  79    iconv_open.  We put the endianness into the encoding name to avoid
  80    hosts that emit a BOM when the unadorned name is used.  */
  81 #if defined (__STDC_ISO_10646__)
  82 #if WORDS_BIGENDIAN
  83 #define INTERMEDIATE_ENCODING "UCS-4BE"
  84 #else
  85 #define INTERMEDIATE_ENCODING "UCS-4LE"
  86 #endif
  87 #elif defined (_LIBICONV_VERSION) && _LIBICONV_VERSION >= 0x10D
  88 #define INTERMEDIATE_ENCODING "wchar_t"
  89 #else
  90 /* This shouldn't happen, because the earlier #if should have filtered
  91    out this case.  */
  92 #error "Neither __STDC_ISO_10646__ nor _LIBICONV_VERSION defined"
  93 #endif
  94
  95 #else
  96
  97 /* If we got here and have wchar_t support, we might be on a system
  98    with some problem.  So, we just disable everything.  */
  99 #if defined (HAVE_WCHAR_H) && defined (HAVE_BTOWC)
 100 #define PHONY_ICONV
 101 #endif
 102
 103 typedef char gdb_wchar_t;
 104 typedef int gdb_wint_t;
 105
 106 #define gdb_wcslen strlen
 107 #define gdb_iswprint isprint
 108 #define gdb_iswdigit isdigit
 109 #define gdb_btowc /* empty */
 110 #define gdb_WEOF EOF
 111
 112 #define LCST(X) X
 113
 114 /* If we are using the narrow character set, we want to use the host
 115    narrow encoding as our intermediate encoding.  However, if we are
 116    also providing a phony iconv, we might as well just stick with
 117    "wchar_t".  */
 118 #ifdef PHONY_ICONV
 119 #define INTERMEDIATE_ENCODING "wchar_t"
 120 #else
 121 #define INTERMEDIATE_ENCODING host_charset ()
 122 #endif
 123
 124 #endif
 125
 126 #endif /* GDB_WCHAR_H */