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 PARAMS ((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 /* List of supported demangling styles.  Contains the name of the style as
  53    seen by the user, and the enum value that corresponds to that style. */
  54
  55 static const struct demangler
  56   {
  57     char *demangling_style_name;
  58     enum demangling_styles demangling_style;
  59     char *demangling_style_doc;
  60   }
  61 demanglers[] =
  62 {
  63   {
  64     AUTO_DEMANGLING_STYLE_STRING,
  65       auto_demangling,
  66       "Automatic selection based on executable"
  67   }
  68   ,
  69   {
  70     GNU_DEMANGLING_STYLE_STRING,
  71       gnu_demangling,
  72       "GNU (g++) style demangling"
  73   }
  74   ,
  75   {
  76     LUCID_DEMANGLING_STYLE_STRING,
  77       lucid_demangling,
  78       "Lucid (lcc) style demangling"
  79   }
  80   ,
  81   {
  82     ARM_DEMANGLING_STYLE_STRING,
  83       arm_demangling,
  84       "ARM style demangling"
  85   }
  86   ,
  87   {
  88     HP_DEMANGLING_STYLE_STRING,
  89       hp_demangling,
  90       "HP (aCC) style demangling"
  91   }
  92   ,
  93   {
  94     EDG_DEMANGLING_STYLE_STRING,
  95       edg_demangling,
  96       "EDG style demangling"
  97   }
  98   ,
  99   {
 100     NULL, unknown_demangling, NULL
 101   }
 102 };
 103
 104 static void
 105 set_demangling_command PARAMS ((char *, int, struct cmd_list_element *));
 106
 107 /* Set current demangling style.  Called by the "set demangle-style"
 108    command after it has updated the current_demangling_style_string to
 109    match what the user has entered.
 110
 111    If the user has entered a string that matches a known demangling style
 112    name in the demanglers[] array then just leave the string alone and update
 113    the current_demangling_style enum value to match.
 114
 115    If the user has entered a string that doesn't match, including an empty
 116    string, then print a list of the currently known styles and restore
 117    the current_demangling_style_string to match the current_demangling_style
 118    enum value.
 119
 120    Note:  Assumes that current_demangling_style_string always points to
 121    a malloc'd string, even if it is a null-string. */
 122
 123 static void
 124 set_demangling_command (ignore, from_tty, c)
 125      char *ignore;
 126      int from_tty;
 127      struct cmd_list_element *c;
 128 {
 129   const struct demangler *dem;
 130
 131   /*  First just try to match whatever style name the user supplied with
 132      one of the known ones.  Don't bother special casing for an empty
 133      name, we just treat it as any other style name that doesn't match.
 134      If we match, update the current demangling style enum. */
 135
 136   for (dem = demanglers; dem->demangling_style_name != NULL; dem++)
 137     {
 138       if (STREQ (current_demangling_style_string,
 139                  dem->demangling_style_name))
 140         {
 141           current_demangling_style = dem->demangling_style;
 142           break;
 143         }
 144     }
 145
 146   /* Check to see if we found a match.  If not, gripe about any non-empty
 147      style name and supply a list of valid ones.  FIXME:  This should
 148      probably be done with some sort of completion and with help. */
 149
 150   if (dem->demangling_style_name == NULL)
 151     {
 152       if (*current_demangling_style_string != '\0')
 153         {
 154           printf_unfiltered ("Unknown demangling style `%s'.\n",
 155                              current_demangling_style_string);
 156         }
 157       printf_unfiltered ("The currently understood settings are:\n\n");
 158       for (dem = demanglers; dem->demangling_style_name != NULL; dem++)
 159         {
 160           printf_unfiltered ("%-10s %s\n", dem->demangling_style_name,
 161                              dem->demangling_style_doc);
 162           if (dem->demangling_style == current_demangling_style)
 163             {
 164               free (current_demangling_style_string);
 165               current_demangling_style_string =
 166                 savestring (dem->demangling_style_name,
 167                             strlen (dem->demangling_style_name));
 168             }
 169         }
 170       if (current_demangling_style == unknown_demangling)
 171         {
 172           /* This can happen during initialization if gdb is compiled with
 173              a DEMANGLING_STYLE value that is unknown, so pick the first
 174              one as the default. */
 175           current_demangling_style = demanglers[0].demangling_style;
 176           current_demangling_style_string =
 177             savestring (demanglers[0].demangling_style_name,
 178                         strlen (demanglers[0].demangling_style_name));
 179           warning ("`%s' style demangling chosen as the default.\n",
 180                    current_demangling_style_string);
 181         }
 182     }
 183 }
 184
 185 /* Fake a "set demangle-style" command. */
 186
 187 void
 188 set_demangling_style (style)
 189      char *style;
 190 {
 191   if (current_demangling_style_string != NULL)
 192     {
 193       free (current_demangling_style_string);
 194     }
 195   current_demangling_style_string = savestring (style, strlen (style));
 196   set_demangling_command ((char *) NULL, 0, (struct cmd_list_element *) NULL);
 197 }
 198
 199 /* In order to allow a single demangler executable to demangle strings
 200    using various common values of CPLUS_MARKER, as well as any specific
 201    one set at compile time, we maintain a string containing all the
 202    commonly used ones, and check to see if the marker we are looking for
 203    is in that string.  CPLUS_MARKER is usually '$' on systems where the
 204    assembler can deal with that.  Where the assembler can't, it's usually
 205    '.' (but on many systems '.' is used for other things).  We put the
 206    current defined CPLUS_MARKER first (which defaults to '$'), followed
 207    by the next most common value, followed by an explicit '$' in case
 208    the value of CPLUS_MARKER is not '$'.
 209
 210    We could avoid this if we could just get g++ to tell us what the actual
 211    cplus marker character is as part of the debug information, perhaps by
 212    ensuring that it is the character that terminates the gcc<n>_compiled
 213    marker symbol (FIXME). */
 214
 215 static char cplus_markers[] =
 216 {CPLUS_MARKER, '.', '$', '\0'};
 217
 218 int
 219 is_cplus_marker (c)
 220      int c;
 221 {
 222   return c && strchr (cplus_markers, c) != NULL;
 223 }
 224
 225 void
 226 _initialize_demangler ()
 227 {
 228   struct cmd_list_element *set, *show;
 229
 230   set = add_set_cmd ("demangle-style", class_support, var_string_noescape,
 231                      (char *) &current_demangling_style_string,
 232                      "Set the current C++ demangling style.\n\
 233 Use `set demangle-style' without arguments for a list of demangling styles.",
 234                      &setlist);
 235   show = add_show_from_set (set, &showlist);
 236   set->function.sfunc = set_demangling_command;
 237
 238   /* Set the default demangling style chosen at compilation time. */
 239   set_demangling_style (DEFAULT_DEMANGLING_STYLE);
 240   set_cplus_marker_for_demangling (CPLUS_MARKER);
 241 }