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, Boston, MA 02111-1307, USA.  */
  20
  21
  22 /*  This file contains support code for C++ demangling that is common
  23    to a styles of demangling, and GDB specific. */
  24
  25 #include "defs.h"
  26 #include "command.h"
  27 #include "gdbcmd.h"
  28 #include "demangle.h"
  29 #include "gdb_string.h"
  30
  31 /* Select the default C++ demangling style to use.  The default is "auto",
  32    which allows gdb to attempt to pick an appropriate demangling style for
  33    the executable it has loaded.  It can be set to a specific style ("gnu",
  34    "lucid", "arm", "hp", etc.) in which case gdb will never attempt to do auto
  35    selection of the style unless you do an explicit "set demangle auto".
  36    To select one of these as the default, set DEFAULT_DEMANGLING_STYLE in
  37    the appropriate target configuration file. */
  38
  39 #ifndef DEFAULT_DEMANGLING_STYLE
  40 #define DEFAULT_DEMANGLING_STYLE AUTO_DEMANGLING_STYLE_STRING
  41 #endif
  42
  43 extern void _initialize_demangler PARAMS ((void));
  44
  45 /* String name for the current demangling style.  Set by the
  46    "set demangle-style" command, printed as part of the output by the
  47    "show demangle-style" command. */
  48
  49 static char *current_demangling_style_string;
  50
  51 /* List of supported demangling styles.  Contains the name of the style as
  52    seen by the user, and the enum value that corresponds to that style. */
  53
  54 static const struct demangler
  55   {
  56     char *demangling_style_name;
  57     enum demangling_styles demangling_style;
  58     char *demangling_style_doc;
  59   }
  60 demanglers[] =
  61 {
  62   {
  63     AUTO_DEMANGLING_STYLE_STRING,
  64       auto_demangling,
  65       "Automatic selection based on executable"
  66   }
  67   ,
  68   {
  69     GNU_DEMANGLING_STYLE_STRING,
  70       gnu_demangling,
  71       "GNU (g++) style demangling"
  72   }
  73   ,
  74   {
  75     LUCID_DEMANGLING_STYLE_STRING,
  76       lucid_demangling,
  77       "Lucid (lcc) style demangling"
  78   }
  79   ,
  80   {
  81     ARM_DEMANGLING_STYLE_STRING,
  82       arm_demangling,
  83       "ARM style demangling"
  84   }
  85   ,
  86   {
  87     HP_DEMANGLING_STYLE_STRING,
  88       hp_demangling,
  89       "HP (aCC) style demangling"
  90   }
  91   ,
  92   {
  93     EDG_DEMANGLING_STYLE_STRING,
  94       edg_demangling,
  95       "EDG style demangling"
  96   }
  97   ,
  98   {
  99     NULL, unknown_demangling, NULL
 100   }
 101 };
 102
 103 static void
 104 set_demangling_command PARAMS ((char *, int, struct cmd_list_element *));
 105
 106 /* Set current demangling style.  Called by the "set demangle-style"
 107    command after it has updated the current_demangling_style_string to
 108    match what the user has entered.
 109
 110    If the user has entered a string that matches a known demangling style
 111    name in the demanglers[] array then just leave the string alone and update
 112    the current_demangling_style enum value to match.
 113
 114    If the user has entered a string that doesn't match, including an empty
 115    string, then print a list of the currently known styles and restore
 116    the current_demangling_style_string to match the current_demangling_style
 117    enum value.
 118
 119    Note:  Assumes that current_demangling_style_string always points to
 120    a malloc'd string, even if it is a null-string. */
 121
 122 static void
 123 set_demangling_command (ignore, from_tty, c)
 124      char *ignore;
 125      int from_tty;
 126      struct cmd_list_element *c;
 127 {
 128   const struct demangler *dem;
 129
 130   /*  First just try to match whatever style name the user supplied with
 131      one of the known ones.  Don't bother special casing for an empty
 132      name, we just treat it as any other style name that doesn't match.
 133      If we match, update the current demangling style enum. */
 134
 135   for (dem = demanglers; dem->demangling_style_name != NULL; dem++)
 136     {
 137       if (STREQ (current_demangling_style_string,
 138                  dem->demangling_style_name))
 139         {
 140           current_demangling_style = dem->demangling_style;
 141           break;
 142         }
 143     }
 144
 145   /* Check to see if we found a match.  If not, gripe about any non-empty
 146      style name and supply a list of valid ones.  FIXME:  This should
 147      probably be done with some sort of completion and with help. */
 148
 149   if (dem->demangling_style_name == NULL)
 150     {
 151       if (*current_demangling_style_string != '\0')
 152         {
 153           printf_unfiltered ("Unknown demangling style `%s'.\n",
 154                              current_demangling_style_string);
 155         }
 156       printf_unfiltered ("The currently understood settings are:\n\n");
 157       for (dem = demanglers; dem->demangling_style_name != NULL; dem++)
 158         {
 159           printf_unfiltered ("%-10s %s\n", dem->demangling_style_name,
 160                              dem->demangling_style_doc);
 161           if (dem->demangling_style == current_demangling_style)
 162             {
 163               free (current_demangling_style_string);
 164               current_demangling_style_string =
 165                 savestring (dem->demangling_style_name,
 166                             strlen (dem->demangling_style_name));
 167             }
 168         }
 169       if (current_demangling_style == unknown_demangling)
 170         {
 171           /* This can happen during initialization if gdb is compiled with
 172              a DEMANGLING_STYLE value that is unknown, so pick the first
 173              one as the default. */
 174           current_demangling_style = demanglers[0].demangling_style;
 175           current_demangling_style_string =
 176             savestring (demanglers[0].demangling_style_name,
 177                         strlen (demanglers[0].demangling_style_name));
 178           warning ("`%s' style demangling chosen as the default.\n",
 179                    current_demangling_style_string);
 180         }
 181     }
 182 }
 183
 184 /* Fake a "set demangle-style" command. */
 185
 186 void
 187 set_demangling_style (style)
 188      char *style;
 189 {
 190   if (current_demangling_style_string != NULL)
 191     {
 192       free (current_demangling_style_string);
 193     }
 194   current_demangling_style_string = savestring (style, strlen (style));
 195   set_demangling_command ((char *) NULL, 0, (struct cmd_list_element *) NULL);
 196 }
 197
 198 /* In order to allow a single demangler executable to demangle strings
 199    using various common values of CPLUS_MARKER, as well as any specific
 200    one set at compile time, we maintain a string containing all the
 201    commonly used ones, and check to see if the marker we are looking for
 202    is in that string.  CPLUS_MARKER is usually '$' on systems where the
 203    assembler can deal with that.  Where the assembler can't, it's usually
 204    '.' (but on many systems '.' is used for other things).  We put the
 205    current defined CPLUS_MARKER first (which defaults to '$'), followed
 206    by the next most common value, followed by an explicit '$' in case
 207    the value of CPLUS_MARKER is not '$'.
 208
 209    We could avoid this if we could just get g++ to tell us what the actual
 210    cplus marker character is as part of the debug information, perhaps by
 211    ensuring that it is the character that terminates the gcc<n>_compiled
 212    marker symbol (FIXME). */
 213
 214 static char cplus_markers[] = {CPLUS_MARKER, '.', '$', '\0'};
 215
 216 int
 217 is_cplus_marker (c)
 218      int c;
 219 {
 220   return c && strchr (cplus_markers, c) != NULL;
 221 }
 222
 223 void
 224 _initialize_demangler ()
 225 {
 226   struct cmd_list_element *set, *show;
 227
 228   set = add_set_cmd ("demangle-style", class_support, var_string_noescape,
 229                      (char *) &current_demangling_style_string,
 230                      "Set the current C++ demangling style.\n\
 231 Use `set demangle-style' without arguments for a list of demangling styles.",
 232                      &setlist);
 233   show = add_show_from_set (set, &showlist);
 234   set->function.sfunc = set_demangling_command;
 235
 236   /* Set the default demangling style chosen at compilation time. */
 237   set_demangling_style (DEFAULT_DEMANGLING_STYLE);
 238   set_cplus_marker_for_demangling (CPLUS_MARKER);
 239 }