gdb/demangle.c

   1 /* Basic C++ demangling support for GDB.
   2
   3    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001,
   4    2003, 2007 Free Software Foundation, Inc.
   5
   6    Written by Fred Fish at Cygnus Support.
   7
   8    This file is part of GDB.
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 2 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program; if not, write to the Free Software
  22    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  23    Boston, MA 02110-1301, USA.  */
  24
  25
  26 /*  This file contains support code for C++ demangling that is common
  27    to a styles of demangling, and GDB specific. */
  28
  29 #include "defs.h"
  30 #include "command.h"
  31 #include "gdbcmd.h"
  32 #include "demangle.h"
  33 #include "gdb_string.h"
  34
  35 /* Select the default C++ demangling style to use.  The default is "auto",
  36    which allows gdb to attempt to pick an appropriate demangling style for
  37    the executable it has loaded.  It can be set to a specific style ("gnu",
  38    "lucid", "arm", "hp", etc.) in which case gdb will never attempt to do auto
  39    selection of the style unless you do an explicit "set demangle auto".
  40    To select one of these as the default, set DEFAULT_DEMANGLING_STYLE in
  41    the appropriate target configuration file. */
  42
  43 #ifndef DEFAULT_DEMANGLING_STYLE
  44 #define DEFAULT_DEMANGLING_STYLE AUTO_DEMANGLING_STYLE_STRING
  45 #endif
  46
  47 extern void _initialize_demangler (void);
  48
  49 /* String name for the current demangling style.  Set by the
  50    "set demangle-style" command, printed as part of the output by the
  51    "show demangle-style" command. */
  52
  53 static char *current_demangling_style_string;
  54
  55 /* The array of names of the known demanglyng styles.  Generated by
  56    _initialize_demangler from libiberty_demanglers[] array.  */
  57
  58 static const char **demangling_style_names;
  59 static void
  60 show_demangling_style_names(struct ui_file *file, int from_tty,
  61                             struct cmd_list_element *c, const char *value)
  62 {
  63   fprintf_filtered (file, _("The current C++ demangling style is \"%s\".\n"),
  64                     value);
  65 }
  66
  67
  68 static void set_demangling_command (char *, int, struct cmd_list_element *);
  69
  70 /* Set current demangling style.  Called by the "set demangle-style"
  71    command after it has updated the current_demangling_style_string to
  72    match what the user has entered.
  73
  74    If the user has entered a string that matches a known demangling style
  75    name in the demanglers[] array then just leave the string alone and update
  76    the current_demangling_style enum value to match.
  77
  78    If the user has entered a string that doesn't match, including an empty
  79    string, then print a list of the currently known styles and restore
  80    the current_demangling_style_string to match the current_demangling_style
  81    enum value.
  82
  83    Note:  Assumes that current_demangling_style_string always points to
  84    a malloc'd string, even if it is a null-string. */
  85
  86 static void
  87 set_demangling_command (char *ignore, int from_tty, struct cmd_list_element *c)
  88 {
  89   const struct demangler_engine *dem;
  90
  91   /*  First just try to match whatever style name the user supplied with
  92      one of the known ones.  Don't bother special casing for an empty
  93      name, we just treat it as any other style name that doesn't match.
  94      If we match, update the current demangling style enum. */
  95
  96   for (dem = libiberty_demanglers;
  97        dem->demangling_style != unknown_demangling;
  98        dem++)
  99     {
 100       if (strcmp (current_demangling_style_string,
 101                   dem->demangling_style_name) == 0)
 102         {
 103           current_demangling_style = dem->demangling_style;
 104           break;
 105         }
 106     }
 107
 108   /* Check to see if we found a match.  If not, gripe about any non-empty
 109      style name and supply a list of valid ones.  FIXME:  This should
 110      probably be done with some sort of completion and with help. */
 111
 112   if (dem->demangling_style == unknown_demangling)
 113     {
 114       if (*current_demangling_style_string != '\0')
 115         {
 116           printf_unfiltered (_("Unknown demangling style `%s'.\n"),
 117                              current_demangling_style_string);
 118         }
 119       printf_unfiltered (_("The currently understood settings are:\n\n"));
 120       for (dem = libiberty_demanglers;
 121            dem->demangling_style != unknown_demangling;
 122            dem++)
 123         {
 124           printf_unfiltered ("%-10s %s\n", dem->demangling_style_name,
 125                              dem->demangling_style_doc);
 126           if (dem->demangling_style == current_demangling_style)
 127             {
 128               xfree (current_demangling_style_string);
 129               current_demangling_style_string =
 130                 savestring (dem->demangling_style_name,
 131                             strlen (dem->demangling_style_name));
 132             }
 133         }
 134       if (current_demangling_style == unknown_demangling)
 135         {
 136           /* This can happen during initialization if gdb is compiled with
 137              a DEMANGLING_STYLE value that is unknown, so pick the first
 138              one as the default. */
 139           current_demangling_style = libiberty_demanglers[0].demangling_style;
 140           current_demangling_style_string =
 141             savestring (
 142               libiberty_demanglers[0].demangling_style_name,
 143               strlen (libiberty_demanglers[0].demangling_style_name));
 144           warning (_("`%s' style demangling chosen as the default."),
 145                    current_demangling_style_string);
 146         }
 147     }
 148 }
 149
 150 /* Fake a "set demangle-style" command. */
 151
 152 void
 153 set_demangling_style (char *style)
 154 {
 155   if (current_demangling_style_string != NULL)
 156     {
 157       xfree (current_demangling_style_string);
 158     }
 159   current_demangling_style_string = savestring (style, strlen (style));
 160   set_demangling_command ((char *) NULL, 0, (struct cmd_list_element *) NULL);
 161 }
 162
 163 /* G++ uses a special character to indicate certain internal names.  Which
 164    character it is depends on the platform:
 165    - Usually '$' on systems where the assembler will accept that
 166    - Usually '.' otherwise (this includes most sysv4-like systems and most
 167      ELF targets)
 168    - Occasionally '_' if neither of the above is usable
 169
 170    We check '$' first because it is the safest, and '.' often has another
 171    meaning.  We don't currently try to handle '_' because the precise forms
 172    of the names are different on those targets.  */
 173
 174 static char cplus_markers[] = {'$', '.', '\0'};
 175
 176 int
 177 is_cplus_marker (int c)
 178 {
 179   return c && strchr (cplus_markers, c) != NULL;
 180 }
 181
 182 void
 183 _initialize_demangler (void)
 184 {
 185   struct cmd_list_element *set, *show;
 186   int i, ndems;
 187
 188   /* Fill the demangling_style_names[] array.  */
 189   for (ndems = 0;
 190        libiberty_demanglers[ndems].demangling_style != unknown_demangling;
 191        ndems++)
 192     ;
 193   demangling_style_names = xcalloc (ndems + 1, sizeof (char *));
 194   for (i = 0;
 195        libiberty_demanglers[i].demangling_style != unknown_demangling;
 196        i++)
 197     demangling_style_names[i] =
 198       xstrdup (libiberty_demanglers[i].demangling_style_name);
 199
 200   /* FIXME: cagney/2005-02-20: The code implementing this variable are
 201      malloc-ing and free-ing current_demangling_style_string when it
 202      should instead just point to an element of
 203      demangling_style_names.  */
 204   add_setshow_enum_cmd ("demangle-style", class_support,
 205                         demangling_style_names,
 206                         (const char **) &current_demangling_style_string, _("\
 207 Set the current C++ demangling style."), _("\
 208 Show the current C++ demangling style."), _("\
 209 Use `set demangle-style' without arguments for a list of demangling styles."),
 210                         set_demangling_command,
 211                         show_demangling_style_names,
 212                         &setlist, &showlist);
 213
 214   /* Set the default demangling style chosen at compilation time. */
 215   set_demangling_style (DEFAULT_DEMANGLING_STYLE);
 216 }