gdb/demangle.c

   1 /* Basic C++ demangling support for GDB.
   2    Copyright 1991, 1992, 1996 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", 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 "set demangling"
  44    command, printed as part of the output by the "show demangling" command. */
  45
  46 static char *current_demangling_style_string;
  47
  48 /* List of supported demangling styles.  Contains the name of the style as
  49    seen by the user, and the enum value that corresponds to that style. */
  50
  51 static const struct demangler
  52 {
  53   char *demangling_style_name;
  54   enum demangling_styles demangling_style;
  55   char *demangling_style_doc;
  56 } demanglers [] =
  57 {
  58   {AUTO_DEMANGLING_STYLE_STRING,
  59      auto_demangling,
  60      "Automatic selection based on executable"},
  61   {GNU_DEMANGLING_STYLE_STRING,
  62      gnu_demangling,
  63      "GNU (g++) style demangling"},
  64   {LUCID_DEMANGLING_STYLE_STRING,
  65      lucid_demangling,
  66      "Lucid (lcc) style demangling"},
  67   {ARM_DEMANGLING_STYLE_STRING,
  68      arm_demangling,
  69      "ARM style demangling"},
  70   {NULL, unknown_demangling, NULL}
  71 };
  72
  73 static void
  74 set_demangling_command PARAMS ((char *, int, struct cmd_list_element *));
  75
  76 /* set current demangling style.  called by the "set demangling" command
  77    after it has updated the current_demangling_style_string to match
  78    what the user has entered.
  79
  80    if the user has entered a string that matches a known demangling style
  81    name in the demanglers[] array then just leave the string alone and update
  82    the current_demangling_style enum value to match.
  83
  84    if the user has entered a string that doesn't match, including an empty
  85    string, then print a list of the currently known styles and restore
  86    the current_demangling_style_string to match the current_demangling_style
  87    enum value.
  88
  89    Note:  Assumes that current_demangling_style_string always points to
  90    a malloc'd string, even if it is a null-string. */
  91
  92 static void
  93 set_demangling_command (ignore, from_tty, c)
  94      char *ignore;
  95      int from_tty;
  96      struct cmd_list_element *c;
  97 {
  98   const struct demangler *dem;
  99
 100   /*  First just try to match whatever style name the user supplied with
 101       one of the known ones.  Don't bother special casing for an empty
 102       name, we just treat it as any other style name that doesn't match.
 103       If we match, update the current demangling style enum. */
 104
 105   for (dem = demanglers; dem -> demangling_style_name != NULL; dem++)
 106     {
 107       if (STREQ (current_demangling_style_string,
 108                   dem -> demangling_style_name))
 109         {
 110           current_demangling_style = dem -> demangling_style;
 111           break;
 112         }
 113     }
 114
 115   /* Check to see if we found a match.  If not, gripe about any non-empty
 116      style name and supply a list of valid ones.  FIXME:  This should
 117      probably be done with some sort of completion and with help. */
 118
 119   if (dem -> demangling_style_name == NULL)
 120     {
 121       if (*current_demangling_style_string != '\0')
 122         {
 123           printf_unfiltered ("Unknown demangling style `%s'.\n",
 124                   current_demangling_style_string);
 125         }
 126       printf_unfiltered ("The currently understood settings are:\n\n");
 127       for (dem = demanglers; dem -> demangling_style_name != NULL; dem++)
 128         {
 129           printf_unfiltered ("%-10s %s\n", dem -> demangling_style_name,
 130                   dem -> demangling_style_doc);
 131           if (dem -> demangling_style == current_demangling_style)
 132             {
 133               free (current_demangling_style_string);
 134               current_demangling_style_string =
 135                 savestring (dem -> demangling_style_name,
 136                             strlen (dem -> demangling_style_name));
 137             }
 138         }
 139       if (current_demangling_style == unknown_demangling)
 140         {
 141           /* This can happen during initialization if gdb is compiled with
 142              a DEMANGLING_STYLE value that is unknown, so pick the first
 143              one as the default. */
 144           current_demangling_style = demanglers[0].demangling_style;
 145           current_demangling_style_string =
 146             savestring (demanglers[0].demangling_style_name,
 147                         strlen (demanglers[0].demangling_style_name));
 148           warning ("`%s' style demangling chosen as the default.\n",
 149                    current_demangling_style_string);
 150         }
 151     }
 152 }
 153
 154 /* Fake a "set demangling" command. */
 155
 156 void
 157 set_demangling_style (style)
 158      char *style;
 159 {
 160   if (current_demangling_style_string != NULL)
 161     {
 162       free (current_demangling_style_string);
 163     }
 164   current_demangling_style_string = savestring (style, strlen (style));
 165   set_demangling_command ((char *) NULL, 0, (struct cmd_list_element *) NULL);
 166 }
 167
 168 /* In order to allow a single demangler executable to demangle strings
 169    using various common values of CPLUS_MARKER, as well as any specific
 170    one set at compile time, we maintain a string containing all the
 171    commonly used ones, and check to see if the marker we are looking for
 172    is in that string.  CPLUS_MARKER is usually '$' on systems where the
 173    assembler can deal with that.  Where the assembler can't, it's usually
 174    '.' (but on many systems '.' is used for other things).  We put the
 175    current defined CPLUS_MARKER first (which defaults to '$'), followed
 176    by the next most common value, followed by an explicit '$' in case
 177    the value of CPLUS_MARKER is not '$'.
 178
 179    We could avoid this if we could just get g++ to tell us what the actual
 180    cplus marker character is as part of the debug information, perhaps by
 181    ensuring that it is the character that terminates the gcc<n>_compiled
 182    marker symbol (FIXME). */
 183
 184 static char cplus_markers[] = { CPLUS_MARKER, '.', '$', '\0' };
 185
 186 int
 187 is_cplus_marker (c)
 188      int c;
 189 {
 190   return c && strchr (cplus_markers, c) != NULL;
 191 }
 192
 193 void
 194 _initialize_demangler ()
 195 {
 196    struct cmd_list_element *set, *show;
 197
 198    set = add_set_cmd ("demangle-style", class_support, var_string_noescape,
 199                       (char *) &current_demangling_style_string,
 200                       "Set the current C++ demangling style.\n\
 201 Use `set demangle-style' without arguments for a list of demangling styles.",
 202                       &setlist);
 203    show = add_show_from_set (set, &showlist);
 204    set -> function.sfunc = set_demangling_command;
 205
 206    /* Set the default demangling style chosen at compilation time. */
 207    set_demangling_style (DEFAULT_DEMANGLING_STYLE);
 208    set_cplus_marker_for_demangling (CPLUS_MARKER);
 209 }