gdb/demangle.c

   1 /* Basic C++ demangling support for GDB.
   2
   3    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001,
   4    2003, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
   5
   6    Written by Fred Fish at Cygnus Support.
   7
   8    This file is part of GDB.
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  22
  23
  24 /*  This file contains support code for C++ demangling that is common
  25    to a styles of demangling, and GDB specific.  */
  26
  27 #include "defs.h"
  28 #include "command.h"
  29 #include "gdbcmd.h"
  30 #include "demangle.h"
  31 #include "gdb-demangle.h"
  32 #include "gdb_string.h"
  33
  34 /* Select the default C++ demangling style to use.  The default is "auto",
  35    which allows gdb to attempt to pick an appropriate demangling style for
  36    the executable it has loaded.  It can be set to a specific style ("gnu",
  37    "lucid", "arm", "hp", etc.) in which case gdb will never attempt to do auto
  38    selection of the style unless you do an explicit "set demangle auto".
  39    To select one of these as the default, set DEFAULT_DEMANGLING_STYLE in
  40    the appropriate target configuration file.  */
  41
  42 #ifndef DEFAULT_DEMANGLING_STYLE
  43 #define DEFAULT_DEMANGLING_STYLE AUTO_DEMANGLING_STYLE_STRING
  44 #endif
  45
  46 /* See documentation in gdb-demangle.h.  */
  47 int demangle = 1;
  48
  49 static void
  50 show_demangle (struct ui_file *file, int from_tty,
  51                struct cmd_list_element *c, const char *value)
  52 {
  53   fprintf_filtered (file,
  54                     _("Demangling of encoded C++/ObjC names "
  55                       "when displaying symbols is %s.\n"),
  56                     value);
  57 }
  58
  59 /* See documentation in gdb-demangle.h.  */
  60 int asm_demangle = 0;
  61
  62 static void
  63 show_asm_demangle (struct ui_file *file, int from_tty,
  64                    struct cmd_list_element *c, const char *value)
  65 {
  66   fprintf_filtered (file,
  67                     _("Demangling of C++/ObjC names in "
  68                       "disassembly listings is %s.\n"),
  69                     value);
  70 }
  71
  72 /* String name for the current demangling style.  Set by the
  73    "set demangle-style" command, printed as part of the output by the
  74    "show demangle-style" command.  */
  75
  76 static char *current_demangling_style_string;
  77
  78 /* The array of names of the known demanglyng styles.  Generated by
  79    _initialize_demangler from libiberty_demanglers[] array.  */
  80
  81 static const char **demangling_style_names;
  82 static void
  83 show_demangling_style_names(struct ui_file *file, int from_tty,
  84                             struct cmd_list_element *c, const char *value)
  85 {
  86   fprintf_filtered (file, _("The current C++ demangling style is \"%s\".\n"),
  87                     value);
  88 }
  89
  90 /* Set current demangling style.  Called by the "set demangle-style"
  91    command after it has updated the current_demangling_style_string to
  92    match what the user has entered.
  93
  94    If the user has entered a string that matches a known demangling style
  95    name in the demanglers[] array then just leave the string alone and update
  96    the current_demangling_style enum value to match.
  97
  98    If the user has entered a string that doesn't match, including an empty
  99    string, then print a list of the currently known styles and restore
 100    the current_demangling_style_string to match the current_demangling_style
 101    enum value.
 102
 103    Note:  Assumes that current_demangling_style_string always points to
 104    a malloc'd string, even if it is a null-string.  */
 105
 106 static void
 107 set_demangling_command (char *ignore, int from_tty, struct cmd_list_element *c)
 108 {
 109   const struct demangler_engine *dem;
 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;
 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           break;
 125         }
 126     }
 127
 128   /* Check to see if we found a match.  If not, gripe about any non-empty
 129      style name and supply a list of valid ones.  FIXME: This should
 130      probably be done with some sort of completion and with help.  */
 131
 132   if (dem->demangling_style == unknown_demangling)
 133     {
 134       if (*current_demangling_style_string != '\0')
 135         {
 136           printf_unfiltered (_("Unknown demangling style `%s'.\n"),
 137                              current_demangling_style_string);
 138         }
 139       printf_unfiltered (_("The currently understood settings are:\n\n"));
 140       for (dem = libiberty_demanglers;
 141            dem->demangling_style != unknown_demangling;
 142            dem++)
 143         {
 144           printf_unfiltered ("%-10s %s\n", dem->demangling_style_name,
 145                              dem->demangling_style_doc);
 146           if (dem->demangling_style == current_demangling_style)
 147             {
 148               xfree (current_demangling_style_string);
 149               current_demangling_style_string =
 150                 xstrdup (dem->demangling_style_name);
 151             }
 152         }
 153       if (current_demangling_style == unknown_demangling)
 154         {
 155           /* This can happen during initialization if gdb is compiled with
 156              a DEMANGLING_STYLE value that is unknown, so pick the first
 157              one as the default.  */
 158           current_demangling_style = libiberty_demanglers[0].demangling_style;
 159           current_demangling_style_string =
 160             xstrdup (libiberty_demanglers[0].demangling_style_name);
 161           warning (_("`%s' style demangling chosen as the default."),
 162                    current_demangling_style_string);
 163         }
 164     }
 165 }
 166
 167 /* See documentation in gdb-demangle.h.  */
 168
 169 void
 170 set_demangling_style (char *style)
 171 {
 172   if (current_demangling_style_string != NULL)
 173     {
 174       xfree (current_demangling_style_string);
 175     }
 176   current_demangling_style_string = xstrdup (style);
 177   set_demangling_command ((char *) NULL, 0, (struct cmd_list_element *) NULL);
 178 }
 179
 180 /* G++ uses a special character to indicate certain internal names.  Which
 181    character it is depends on the platform:
 182    - Usually '$' on systems where the assembler will accept that
 183    - Usually '.' otherwise (this includes most sysv4-like systems and most
 184      ELF targets)
 185    - Occasionally '_' if neither of the above is usable
 186
 187    We check '$' first because it is the safest, and '.' often has another
 188    meaning.  We don't currently try to handle '_' because the precise forms
 189    of the names are different on those targets.  */
 190
 191 static char cplus_markers[] = {'$', '.', '\0'};
 192
 193 /* See documentation in gdb-demangle.h.  */
 194
 195 int
 196 is_cplus_marker (int c)
 197 {
 198   return c && strchr (cplus_markers, c) != NULL;
 199 }
 200
 201 extern initialize_file_ftype _initialize_demangler; /* -Wmissing-prototypes */
 202
 203 void
 204 _initialize_demangler (void)
 205 {
 206   int i, ndems;
 207
 208   /* Fill the demangling_style_names[] array.  */
 209   for (ndems = 0;
 210        libiberty_demanglers[ndems].demangling_style != unknown_demangling;
 211        ndems++)
 212     ;
 213   demangling_style_names = xcalloc (ndems + 1, sizeof (char *));
 214   for (i = 0;
 215        libiberty_demanglers[i].demangling_style != unknown_demangling;
 216        i++)
 217     demangling_style_names[i] =
 218       xstrdup (libiberty_demanglers[i].demangling_style_name);
 219
 220   add_setshow_boolean_cmd ("demangle", class_support, &demangle, _("\
 221 Set demangling of encoded C++/ObjC names when displaying symbols."), _("\
 222 Show demangling of encoded C++/ObjC names when displaying symbols."), NULL,
 223                            NULL,
 224                            show_demangle,
 225                            &setprintlist, &showprintlist);
 226
 227   add_setshow_boolean_cmd ("asm-demangle", class_support, &asm_demangle, _("\
 228 Set demangling of C++/ObjC names in disassembly listings."), _("\
 229 Show demangling of C++/ObjC names in disassembly listings."), NULL,
 230                            NULL,
 231                            show_asm_demangle,
 232                            &setprintlist, &showprintlist);
 233
 234   /* FIXME: cagney/2005-02-20: The code implementing this variable are
 235      malloc-ing and free-ing current_demangling_style_string when it
 236      should instead just point to an element of
 237      demangling_style_names.  */
 238   add_setshow_enum_cmd ("demangle-style", class_support,
 239                         demangling_style_names,
 240                         (const char **) &current_demangling_style_string, _("\
 241 Set the current C++ demangling style."), _("\
 242 Show the current C++ demangling style."), _("\
 243 Use `set demangle-style' without arguments for a list of demangling styles."),
 244                         set_demangling_command,
 245                         show_demangling_style_names,
 246                         &setlist, &showlist);
 247
 248   /* Set the default demangling style chosen at compilation time.  */
 249   set_demangling_style (DEFAULT_DEMANGLING_STYLE);
 250 }