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 /* The array of names of the known demanglyng styles.  Generated by
  53    _initialize_demangler from libiberty_demanglers[] array.  */
  54
  55 static const char **demangling_style_names;
  56
  57 static void set_demangling_command (char *, int, struct cmd_list_element *);
  58
  59 /* Set current demangling style.  Called by the "set demangle-style"
  60    command after it has updated the current_demangling_style_string to
  61    match what the user has entered.
  62
  63    If the user has entered a string that matches a known demangling style
  64    name in the demanglers[] array then just leave the string alone and update
  65    the current_demangling_style enum value to match.
  66
  67    If the user has entered a string that doesn't match, including an empty
  68    string, then print a list of the currently known styles and restore
  69    the current_demangling_style_string to match the current_demangling_style
  70    enum value.
  71
  72    Note:  Assumes that current_demangling_style_string always points to
  73    a malloc'd string, even if it is a null-string. */
  74
  75 static void
  76 set_demangling_command (char *ignore, int from_tty, struct cmd_list_element *c)
  77 {
  78   const struct demangler_engine *dem;
  79
  80   /*  First just try to match whatever style name the user supplied with
  81      one of the known ones.  Don't bother special casing for an empty
  82      name, we just treat it as any other style name that doesn't match.
  83      If we match, update the current demangling style enum. */
  84
  85   for (dem = libiberty_demanglers;
  86        dem->demangling_style != unknown_demangling;
  87        dem++)
  88     {
  89       if (STREQ (current_demangling_style_string,
  90                  dem->demangling_style_name))
  91         {
  92           current_demangling_style = dem->demangling_style;
  93           break;
  94         }
  95     }
  96
  97   /* Check to see if we found a match.  If not, gripe about any non-empty
  98      style name and supply a list of valid ones.  FIXME:  This should
  99      probably be done with some sort of completion and with help. */
 100
 101   if (dem->demangling_style == unknown_demangling)
 102     {
 103       if (*current_demangling_style_string != '\0')
 104         {
 105           printf_unfiltered ("Unknown demangling style `%s'.\n",
 106                              current_demangling_style_string);
 107         }
 108       printf_unfiltered ("The currently understood settings are:\n\n");
 109       for (dem = libiberty_demanglers;
 110            dem->demangling_style != unknown_demangling;
 111            dem++)
 112         {
 113           printf_unfiltered ("%-10s %s\n", dem->demangling_style_name,
 114                              dem->demangling_style_doc);
 115           if (dem->demangling_style == current_demangling_style)
 116             {
 117               xfree (current_demangling_style_string);
 118               current_demangling_style_string =
 119                 savestring (dem->demangling_style_name,
 120                             strlen (dem->demangling_style_name));
 121             }
 122         }
 123       if (current_demangling_style == unknown_demangling)
 124         {
 125           /* This can happen during initialization if gdb is compiled with
 126              a DEMANGLING_STYLE value that is unknown, so pick the first
 127              one as the default. */
 128           current_demangling_style = libiberty_demanglers[0].demangling_style;
 129           current_demangling_style_string =
 130             savestring (
 131               libiberty_demanglers[0].demangling_style_name,
 132               strlen (libiberty_demanglers[0].demangling_style_name));
 133           warning ("`%s' style demangling chosen as the default.\n",
 134                    current_demangling_style_string);
 135         }
 136     }
 137 }
 138
 139 /* Fake a "set demangle-style" command. */
 140
 141 void
 142 set_demangling_style (char *style)
 143 {
 144   if (current_demangling_style_string != NULL)
 145     {
 146       xfree (current_demangling_style_string);
 147     }
 148   current_demangling_style_string = savestring (style, strlen (style));
 149   set_demangling_command ((char *) NULL, 0, (struct cmd_list_element *) NULL);
 150 }
 151
 152 /* In order to allow a single demangler executable to demangle strings
 153    using various common values of CPLUS_MARKER, as well as any specific
 154    one set at compile time, we maintain a string containing all the
 155    commonly used ones, and check to see if the marker we are looking for
 156    is in that string.  CPLUS_MARKER is usually '$' on systems where the
 157    assembler can deal with that.  Where the assembler can't, it's usually
 158    '.' (but on many systems '.' is used for other things).  We put the
 159    current defined CPLUS_MARKER first (which defaults to '$'), followed
 160    by the next most common value, followed by an explicit '$' in case
 161    the value of CPLUS_MARKER is not '$'.
 162
 163    We could avoid this if we could just get g++ to tell us what the actual
 164    cplus marker character is as part of the debug information, perhaps by
 165    ensuring that it is the character that terminates the gcc<n>_compiled
 166    marker symbol (FIXME). */
 167
 168 static char cplus_markers[] =
 169 {CPLUS_MARKER, '.', '$', '\0'};
 170
 171 int
 172 is_cplus_marker (int c)
 173 {
 174   return c && strchr (cplus_markers, c) != NULL;
 175 }
 176
 177 void
 178 _initialize_demangler (void)
 179 {
 180   struct cmd_list_element *set, *show;
 181   int i, ndems;
 182
 183   /* Fill the demangling_style_names[] array.  */
 184   for (ndems = 0;
 185        libiberty_demanglers[ndems].demangling_style != unknown_demangling;
 186        ndems++)
 187     ;
 188   demangling_style_names = xmalloc (ndems * sizeof (char *));
 189   for (i = 0;
 190        libiberty_demanglers[i].demangling_style != unknown_demangling;
 191        i++)
 192     demangling_style_names[i] =
 193       xstrdup (libiberty_demanglers[i].demangling_style_name);
 194
 195   set = add_set_enum_cmd ("demangle-style", class_support,
 196                           demangling_style_names,
 197                           (const char **) &current_demangling_style_string,
 198                           "Set the current C++ demangling style.\n\
 199 Use `set demangle-style' without arguments for a list of demangling styles.",
 200                           &setlist);
 201   show = add_show_from_set (set, &showlist);
 202   set->function.sfunc = set_demangling_command;
 203
 204   /* Set the default demangling style chosen at compilation time. */
 205   set_demangling_style (DEFAULT_DEMANGLING_STYLE);
 206   set_cplus_marker_for_demangling (CPLUS_MARKER);
 207 }