gdb/demangle.c

   1 /* Basic C++ demangling support for GDB.
   2    Copyright 1991, 1992, 1996, 1999 Free Software Foundation, Inc.
   3    Written by Fred Fish at Cygnus Support.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 59 Temple Place - Suite 330,
  20    Boston, MA 02111-1307, USA.  */
  21
  22
  23 /*  This file contains support code for C++ demangling that is common
  24    to a styles of demangling, and GDB specific. */
  25
  26 #include "defs.h"
  27 #include "command.h"
  28 #include "gdbcmd.h"
  29 #include "demangle.h"
  30 #include "gdb_string.h"
  31
  32 /* Select the default C++ demangling style to use.  The default is "auto",
  33    which allows gdb to attempt to pick an appropriate demangling style for
  34    the executable it has loaded.  It can be set to a specific style ("gnu",
  35    "lucid", "arm", "hp", etc.) in which case gdb will never attempt to do auto
  36    selection of the style unless you do an explicit "set demangle auto".
  37    To select one of these as the default, set DEFAULT_DEMANGLING_STYLE in
  38    the appropriate target configuration file. */
  39
  40 #ifndef DEFAULT_DEMANGLING_STYLE
  41 #define DEFAULT_DEMANGLING_STYLE AUTO_DEMANGLING_STYLE_STRING
  42 #endif
  43
  44 extern void _initialize_demangler (void);
  45
  46 /* String name for the current demangling style.  Set by the
  47    "set demangle-style" command, printed as part of the output by the
  48    "show demangle-style" command. */
  49
  50 static char *current_demangling_style_string;
  51
  52 static void set_demangling_command (char *, int, struct cmd_list_element *);
  53
  54 /* Set current demangling style.  Called by the "set demangle-style"
  55    command after it has updated the current_demangling_style_string to
  56    match what the user has entered.
  57
  58    If the user has entered a string that matches a known demangling style
  59    name in the demanglers[] array then just leave the string alone and update
  60    the current_demangling_style enum value to match.
  61
  62    If the user has entered a string that doesn't match, including an empty
  63    string, then print a list of the currently known styles and restore
  64    the current_demangling_style_string to match the current_demangling_style
  65    enum value.
  66
  67    Note:  Assumes that current_demangling_style_string always points to
  68    a malloc'd string, even if it is a null-string. */
  69
  70 static void
  71 set_demangling_command (char *ignore, int from_tty, struct cmd_list_element *c)
  72 {
  73   const struct demangler_engine *dem;
  74
  75   /*  First just try to match whatever style name the user supplied with
  76      one of the known ones.  Don't bother special casing for an empty
  77      name, we just treat it as any other style name that doesn't match.
  78      If we match, update the current demangling style enum. */
  79
  80   for (dem = libiberty_demanglers;
  81        dem->demangling_style != unknown_demangling;
  82        dem++)
  83     {
  84       if (STREQ (current_demangling_style_string,
  85                  dem->demangling_style_name))
  86         {
  87           current_demangling_style = dem->demangling_style;
  88           break;
  89         }
  90     }
  91
  92   /* Check to see if we found a match.  If not, gripe about any non-empty
  93      style name and supply a list of valid ones.  FIXME:  This should
  94      probably be done with some sort of completion and with help. */
  95
  96   if (dem->demangling_style == unknown_demangling)
  97     {
  98       if (*current_demangling_style_string != '\0')
  99         {
 100           printf_unfiltered ("Unknown demangling style `%s'.\n",
 101                              current_demangling_style_string);
 102         }
 103       printf_unfiltered ("The currently understood settings are:\n\n");
 104       for (dem = libiberty_demanglers;
 105            dem->demangling_style != unknown_demangling;
 106            dem++)
 107         {
 108           printf_unfiltered ("%-10s %s\n", dem->demangling_style_name,
 109                              dem->demangling_style_doc);
 110           if (dem->demangling_style == current_demangling_style)
 111             {
 112               xfree (current_demangling_style_string);
 113               current_demangling_style_string =
 114                 savestring (dem->demangling_style_name,
 115                             strlen (dem->demangling_style_name));
 116             }
 117         }
 118       if (current_demangling_style == unknown_demangling)
 119         {
 120           /* This can happen during initialization if gdb is compiled with
 121              a DEMANGLING_STYLE value that is unknown, so pick the first
 122              one as the default. */
 123           current_demangling_style = libiberty_demanglers[0].demangling_style;
 124           current_demangling_style_string =
 125             savestring (
 126               libiberty_demanglers[0].demangling_style_name,
 127               strlen (libiberty_demanglers[0].demangling_style_name));
 128           warning ("`%s' style demangling chosen as the default.\n",
 129                    current_demangling_style_string);
 130         }
 131     }
 132 }
 133
 134 /* Fake a "set demangle-style" command. */
 135
 136 void
 137 set_demangling_style (char *style)
 138 {
 139   if (current_demangling_style_string != NULL)
 140     {
 141       xfree (current_demangling_style_string);
 142     }
 143   current_demangling_style_string = savestring (style, strlen (style));
 144   set_demangling_command ((char *) NULL, 0, (struct cmd_list_element *) NULL);
 145 }
 146
 147 /* In order to allow a single demangler executable to demangle strings
 148    using various common values of CPLUS_MARKER, as well as any specific
 149    one set at compile time, we maintain a string containing all the
 150    commonly used ones, and check to see if the marker we are looking for
 151    is in that string.  CPLUS_MARKER is usually '$' on systems where the
 152    assembler can deal with that.  Where the assembler can't, it's usually
 153    '.' (but on many systems '.' is used for other things).  We put the
 154    current defined CPLUS_MARKER first (which defaults to '$'), followed
 155    by the next most common value, followed by an explicit '$' in case
 156    the value of CPLUS_MARKER is not '$'.
 157
 158    We could avoid this if we could just get g++ to tell us what the actual
 159    cplus marker character is as part of the debug information, perhaps by
 160    ensuring that it is the character that terminates the gcc<n>_compiled
 161    marker symbol (FIXME). */
 162
 163 static char cplus_markers[] =
 164 {CPLUS_MARKER, '.', '$', '\0'};
 165
 166 int
 167 is_cplus_marker (int c)
 168 {
 169   return c && strchr (cplus_markers, c) != NULL;
 170 }
 171
 172 void
 173 _initialize_demangler (void)
 174 {
 175   struct cmd_list_element *set, *show;
 176
 177   set = add_set_cmd ("demangle-style", class_support, var_string_noescape,
 178                      (char *) &current_demangling_style_string,
 179                      "Set the current C++ demangling style.\n\
 180 Use `set demangle-style' without arguments for a list of demangling styles.",
 181                      &setlist);
 182   show = add_show_from_set (set, &showlist);
 183   set->function.sfunc = set_demangling_command;
 184
 185   /* Set the default demangling style chosen at compilation time. */
 186   set_demangling_style (DEFAULT_DEMANGLING_STYLE);
 187   set_cplus_marker_for_demangling (CPLUS_MARKER);
 188 }