gdb/demangle.c

   1 /* Basic C++ demangling support for GDB.
   2
   3    Copyright (C) 1991-2014 Free Software Foundation, Inc.
   4
   5    Written by Fred Fish at Cygnus Support.
   6
   7    This file is part of GDB.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  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-demangle.h"
  31 #include <string.h>
  32
  33 /* Select the default C++ demangling style to use.  The default is "auto",
  34    which allows gdb to attempt to pick an appropriate demangling style for
  35    the executable it has loaded.  It can be set to a specific style ("gnu",
  36    "lucid", "arm", "hp", etc.) in which case gdb will never attempt to do auto
  37    selection of the style unless you do an explicit "set demangle auto".
  38    To select one of these as the default, set DEFAULT_DEMANGLING_STYLE in
  39    the appropriate target configuration file.  */
  40
  41 #ifndef DEFAULT_DEMANGLING_STYLE
  42 #define DEFAULT_DEMANGLING_STYLE AUTO_DEMANGLING_STYLE_STRING
  43 #endif
  44
  45 /* See documentation in gdb-demangle.h.  */
  46 int demangle = 1;
  47
  48 static void
  49 show_demangle (struct ui_file *file, int from_tty,
  50                struct cmd_list_element *c, const char *value)
  51 {
  52   fprintf_filtered (file,
  53                     _("Demangling of encoded C++/ObjC names "
  54                       "when displaying symbols is %s.\n"),
  55                     value);
  56 }
  57
  58 /* See documentation in gdb-demangle.h.  */
  59 int asm_demangle = 0;
  60
  61 static void
  62 show_asm_demangle (struct ui_file *file, int from_tty,
  63                    struct cmd_list_element *c, const char *value)
  64 {
  65   fprintf_filtered (file,
  66                     _("Demangling of C++/ObjC names in "
  67                       "disassembly listings is %s.\n"),
  68                     value);
  69 }
  70
  71 /* String name for the current demangling style.  Set by the
  72    "set demangle-style" command, printed as part of the output by the
  73    "show demangle-style" command.  */
  74
  75 static const char *current_demangling_style_string;
  76
  77 /* The array of names of the known demanglyng styles.  Generated by
  78    _initialize_demangler from libiberty_demanglers[] array.  */
  79
  80 static const char **demangling_style_names;
  81 static void
  82 show_demangling_style_names(struct ui_file *file, int from_tty,
  83                             struct cmd_list_element *c, const char *value)
  84 {
  85   fprintf_filtered (file, _("The current C++ demangling style is \"%s\".\n"),
  86                     value);
  87 }
  88
  89 /* Set current demangling style.  Called by the "set demangle-style"
  90    command after it has updated the current_demangling_style_string to
  91    match what the user has entered.
  92
  93    If the user has entered a string that matches a known demangling style
  94    name in the demanglers[] array then just leave the string alone and update
  95    the current_demangling_style enum value to match.
  96
  97    If the user has entered a string that doesn't match, including an empty
  98    string, then print a list of the currently known styles and restore
  99    the current_demangling_style_string to match the current_demangling_style
 100    enum value.
 101
 102    Note:  Assumes that current_demangling_style_string always points to
 103    a malloc'd string, even if it is a null-string.  */
 104
 105 static void
 106 set_demangling_command (char *ignore, int from_tty, struct cmd_list_element *c)
 107 {
 108   const struct demangler_engine *dem;
 109   int i;
 110
 111   /*  First just try to match whatever style name the user supplied with
 112      one of the known ones.  Don't bother special casing for an empty
 113      name, we just treat it as any other style name that doesn't match.
 114      If we match, update the current demangling style enum.  */
 115
 116   for (dem = libiberty_demanglers, i = 0;
 117        dem->demangling_style != unknown_demangling;
 118        dem++)
 119     {
 120       if (strcmp (current_demangling_style_string,
 121                   dem->demangling_style_name) == 0)
 122         {
 123           current_demangling_style = dem->demangling_style;
 124           current_demangling_style_string = demangling_style_names[i];
 125           break;
 126         }
 127       i++;
 128     }
 129
 130   /* We should have found a match, given we only add known styles to
 131      the enumeration list.  */
 132   gdb_assert (dem->demangling_style != unknown_demangling);
 133 }
 134
 135 /* G++ uses a special character to indicate certain internal names.  Which
 136    character it is depends on the platform:
 137    - Usually '$' on systems where the assembler will accept that
 138    - Usually '.' otherwise (this includes most sysv4-like systems and most
 139      ELF targets)
 140    - Occasionally '_' if neither of the above is usable
 141
 142    We check '$' first because it is the safest, and '.' often has another
 143    meaning.  We don't currently try to handle '_' because the precise forms
 144    of the names are different on those targets.  */
 145
 146 static char cplus_markers[] = {'$', '.', '\0'};
 147
 148 /* See documentation in gdb-demangle.h.  */
 149
 150 int
 151 is_cplus_marker (int c)
 152 {
 153   return c && strchr (cplus_markers, c) != NULL;
 154 }
 155
 156 extern initialize_file_ftype _initialize_demangler; /* -Wmissing-prototypes */
 157
 158 void
 159 _initialize_demangler (void)
 160 {
 161   int i, ndems;
 162
 163   /* Fill the demangling_style_names[] array, and set the default
 164      demangling style chosen at compilation time.  */
 165   for (ndems = 0;
 166        libiberty_demanglers[ndems].demangling_style != unknown_demangling;
 167        ndems++)
 168     ;
 169   demangling_style_names = xcalloc (ndems + 1, sizeof (char *));
 170   for (i = 0;
 171        libiberty_demanglers[i].demangling_style != unknown_demangling;
 172        i++)
 173     {
 174       demangling_style_names[i]
 175         = xstrdup (libiberty_demanglers[i].demangling_style_name);
 176
 177       if (current_demangling_style_string == NULL
 178           && strcmp (DEFAULT_DEMANGLING_STYLE, demangling_style_names[i]) == 0)
 179         current_demangling_style_string = demangling_style_names[i];
 180     }
 181
 182   add_setshow_boolean_cmd ("demangle", class_support, &demangle, _("\
 183 Set demangling of encoded C++/ObjC names when displaying symbols."), _("\
 184 Show demangling of encoded C++/ObjC names when displaying symbols."), NULL,
 185                            NULL,
 186                            show_demangle,
 187                            &setprintlist, &showprintlist);
 188
 189   add_setshow_boolean_cmd ("asm-demangle", class_support, &asm_demangle, _("\
 190 Set demangling of C++/ObjC names in disassembly listings."), _("\
 191 Show demangling of C++/ObjC names in disassembly listings."), NULL,
 192                            NULL,
 193                            show_asm_demangle,
 194                            &setprintlist, &showprintlist);
 195
 196   add_setshow_enum_cmd ("demangle-style", class_support,
 197                         demangling_style_names,
 198                         &current_demangling_style_string, _("\
 199 Set the current C++ demangling style."), _("\
 200 Show the current C++ demangling style."), _("\
 201 Use `set demangle-style' without arguments for a list of demangling styles."),
 202                         set_demangling_command,
 203                         show_demangling_style_names,
 204                         &setlist, &showlist);
 205 }