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