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 /* String name for the current demangling style.  Set by the
  44    "set demangle-style" command, printed as part of the output by the
  45    "show demangle-style" command. */
  46
  47 static char *current_demangling_style_string;
  48
  49 /* List of supported demangling styles.  Contains the name of the style as
  50    seen by the user, and the enum value that corresponds to that style. */
  51
  52 static const struct demangler
  53   {
  54     char *demangling_style_name;
  55     enum demangling_styles demangling_style;
  56     char *demangling_style_doc;
  57   }
  58 demanglers[] =
  59 {
  60   {
  61     AUTO_DEMANGLING_STYLE_STRING,
  62       auto_demangling,
  63       "Automatic selection based on executable"
  64   }
  65   ,
  66   {
  67     GNU_DEMANGLING_STYLE_STRING,
  68       gnu_demangling,
  69       "GNU (g++) style demangling"
  70   }
  71   ,
  72   {
  73     LUCID_DEMANGLING_STYLE_STRING,
  74       lucid_demangling,
  75       "Lucid (lcc) style demangling"
  76   }
  77   ,
  78   {
  79     ARM_DEMANGLING_STYLE_STRING,
  80       arm_demangling,
  81       "ARM style demangling"
  82   }
  83   ,
  84   {
  85     HP_DEMANGLING_STYLE_STRING,
  86       hp_demangling,
  87       "HP (aCC) style demangling"
  88   }
  89   ,
  90   {
  91     EDG_DEMANGLING_STYLE_STRING,
  92       edg_demangling,
  93       "EDG style demangling"
  94   }
  95   ,
  96   {
  97     NULL, unknown_demangling, NULL
  98   }
  99 };
 100
 101 static void
 102 set_demangling_command PARAMS ((char *, int, struct cmd_list_element *));
 103
 104 /* Set current demangling style.  Called by the "set demangle-style"
 105    command after it has updated the current_demangling_style_string to
 106    match what the user has entered.
 107
 108    If the user has entered a string that matches a known demangling style
 109    name in the demanglers[] array then just leave the string alone and update
 110    the current_demangling_style enum value to match.
 111
 112    If the user has entered a string that doesn't match, including an empty
 113    string, then print a list of the currently known styles and restore
 114    the current_demangling_style_string to match the current_demangling_style
 115    enum value.
 116
 117    Note:  Assumes that current_demangling_style_string always points to
 118    a malloc'd string, even if it is a null-string. */
 119
 120 static void
 121 set_demangling_command (ignore, from_tty, c)
 122      char *ignore;
 123      int from_tty;
 124      struct cmd_list_element *c;
 125 {
 126   const struct demangler *dem;
 127
 128   /*  First just try to match whatever style name the user supplied with
 129      one of the known ones.  Don't bother special casing for an empty
 130      name, we just treat it as any other style name that doesn't match.
 131      If we match, update the current demangling style enum. */
 132
 133   for (dem = demanglers; dem->demangling_style_name != NULL; dem++)
 134     {
 135       if (STREQ (current_demangling_style_string,
 136                  dem->demangling_style_name))
 137         {
 138           current_demangling_style = dem->demangling_style;
 139           break;
 140         }
 141     }
 142
 143   /* Check to see if we found a match.  If not, gripe about any non-empty
 144      style name and supply a list of valid ones.  FIXME:  This should
 145      probably be done with some sort of completion and with help. */
 146
 147   if (dem->demangling_style_name == NULL)
 148     {
 149       if (*current_demangling_style_string != '\0')
 150         {
 151           printf_unfiltered ("Unknown demangling style `%s'.\n",
 152                              current_demangling_style_string);
 153         }
 154       printf_unfiltered ("The currently understood settings are:\n\n");
 155       for (dem = demanglers; dem->demangling_style_name != NULL; dem++)
 156         {
 157           printf_unfiltered ("%-10s %s\n", dem->demangling_style_name,
 158                              dem->demangling_style_doc);
 159           if (dem->demangling_style == current_demangling_style)
 160             {
 161               free (current_demangling_style_string);
 162               current_demangling_style_string =
 163                 savestring (dem->demangling_style_name,
 164                             strlen (dem->demangling_style_name));
 165             }
 166         }
 167       if (current_demangling_style == unknown_demangling)
 168         {
 169           /* This can happen during initialization if gdb is compiled with
 170              a DEMANGLING_STYLE value that is unknown, so pick the first
 171              one as the default. */
 172           current_demangling_style = demanglers[0].demangling_style;
 173           current_demangling_style_string =
 174             savestring (demanglers[0].demangling_style_name,
 175                         strlen (demanglers[0].demangling_style_name));
 176           warning ("`%s' style demangling chosen as the default.\n",
 177                    current_demangling_style_string);
 178         }
 179     }
 180 }
 181
 182 /* Fake a "set demangle-style" command. */
 183
 184 void
 185 set_demangling_style (style)
 186      char *style;
 187 {
 188   if (current_demangling_style_string != NULL)
 189     {
 190       free (current_demangling_style_string);
 191     }
 192   current_demangling_style_string = savestring (style, strlen (style));
 193   set_demangling_command ((char *) NULL, 0, (struct cmd_list_element *) NULL);
 194 }
 195
 196 /* In order to allow a single demangler executable to demangle strings
 197    using various common values of CPLUS_MARKER, as well as any specific
 198    one set at compile time, we maintain a string containing all the
 199    commonly used ones, and check to see if the marker we are looking for
 200    is in that string.  CPLUS_MARKER is usually '$' on systems where the
 201    assembler can deal with that.  Where the assembler can't, it's usually
 202    '.' (but on many systems '.' is used for other things).  We put the
 203    current defined CPLUS_MARKER first (which defaults to '$'), followed
 204    by the next most common value, followed by an explicit '$' in case
 205    the value of CPLUS_MARKER is not '$'.
 206
 207    We could avoid this if we could just get g++ to tell us what the actual
 208    cplus marker character is as part of the debug information, perhaps by
 209    ensuring that it is the character that terminates the gcc<n>_compiled
 210    marker symbol (FIXME). */
 211
 212 static char cplus_markers[] = {CPLUS_MARKER, '.', '$', '\0'};
 213
 214 int
 215 is_cplus_marker (c)
 216      int c;
 217 {
 218   return c && strchr (cplus_markers, c) != NULL;
 219 }
 220
 221 void
 222 _initialize_demangler ()
 223 {
 224   struct cmd_list_element *set, *show;
 225
 226   set = add_set_cmd ("demangle-style", class_support, var_string_noescape,
 227                      (char *) &current_demangling_style_string,
 228                      "Set the current C++ demangling style.\n\
 229 Use `set demangle-style' without arguments for a list of demangling styles.",
 230                      &setlist);
 231   show = add_show_from_set (set, &showlist);
 232   set->function.sfunc = set_demangling_command;
 233
 234   /* Set the default demangling style chosen at compilation time. */
 235   set_demangling_style (DEFAULT_DEMANGLING_STYLE);
 236   set_cplus_marker_for_demangling (CPLUS_MARKER);
 237 }