gdb/demangle.c

   1 /* Basic C++ demangling support for GDB.
   2
   3    Copyright (C) 1991-2013 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 "gdb_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 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
 110   /*  First just try to match whatever style name the user supplied with
 111      one of the known ones.  Don't bother special casing for an empty
 112      name, we just treat it as any other style name that doesn't match.
 113      If we match, update the current demangling style enum.  */
 114
 115   for (dem = libiberty_demanglers;
 116        dem->demangling_style != unknown_demangling;
 117        dem++)
 118     {
 119       if (strcmp (current_demangling_style_string,
 120                   dem->demangling_style_name) == 0)
 121         {
 122           current_demangling_style = dem->demangling_style;
 123           break;
 124         }
 125     }
 126
 127   /* Check to see if we found a match.  If not, gripe about any non-empty
 128      style name and supply a list of valid ones.  FIXME: This should
 129      probably be done with some sort of completion and with help.  */
 130
 131   if (dem->demangling_style == unknown_demangling)
 132     {
 133       if (*current_demangling_style_string != '\0')
 134         {
 135           printf_unfiltered (_("Unknown demangling style `%s'.\n"),
 136                              current_demangling_style_string);
 137         }
 138       printf_unfiltered (_("The currently understood settings are:\n\n"));
 139       for (dem = libiberty_demanglers;
 140            dem->demangling_style != unknown_demangling;
 141            dem++)
 142         {
 143           printf_unfiltered ("%-10s %s\n", dem->demangling_style_name,
 144                              dem->demangling_style_doc);
 145           if (dem->demangling_style == current_demangling_style)
 146             {
 147               xfree (current_demangling_style_string);
 148               current_demangling_style_string =
 149                 xstrdup (dem->demangling_style_name);
 150             }
 151         }
 152       if (current_demangling_style == unknown_demangling)
 153         {
 154           /* This can happen during initialization if gdb is compiled with
 155              a DEMANGLING_STYLE value that is unknown, so pick the first
 156              one as the default.  */
 157           current_demangling_style = libiberty_demanglers[0].demangling_style;
 158           current_demangling_style_string =
 159             xstrdup (libiberty_demanglers[0].demangling_style_name);
 160           warning (_("`%s' style demangling chosen as the default."),
 161                    current_demangling_style_string);
 162         }
 163     }
 164 }
 165
 166 /* See documentation in gdb-demangle.h.  */
 167
 168 void
 169 set_demangling_style (char *style)
 170 {
 171   if (current_demangling_style_string != NULL)
 172     {
 173       xfree (current_demangling_style_string);
 174     }
 175   current_demangling_style_string = xstrdup (style);
 176   set_demangling_command ((char *) NULL, 0, (struct cmd_list_element *) NULL);
 177 }
 178
 179 /* G++ uses a special character to indicate certain internal names.  Which
 180    character it is depends on the platform:
 181    - Usually '$' on systems where the assembler will accept that
 182    - Usually '.' otherwise (this includes most sysv4-like systems and most
 183      ELF targets)
 184    - Occasionally '_' if neither of the above is usable
 185
 186    We check '$' first because it is the safest, and '.' often has another
 187    meaning.  We don't currently try to handle '_' because the precise forms
 188    of the names are different on those targets.  */
 189
 190 static char cplus_markers[] = {'$', '.', '\0'};
 191
 192 /* See documentation in gdb-demangle.h.  */
 193
 194 int
 195 is_cplus_marker (int c)
 196 {
 197   return c && strchr (cplus_markers, c) != NULL;
 198 }
 199
 200 extern initialize_file_ftype _initialize_demangler; /* -Wmissing-prototypes */
 201
 202 void
 203 _initialize_demangler (void)
 204 {
 205   int i, ndems;
 206
 207   /* Fill the demangling_style_names[] array.  */
 208   for (ndems = 0;
 209        libiberty_demanglers[ndems].demangling_style != unknown_demangling;
 210        ndems++)
 211     ;
 212   demangling_style_names = xcalloc (ndems + 1, sizeof (char *));
 213   for (i = 0;
 214        libiberty_demanglers[i].demangling_style != unknown_demangling;
 215        i++)
 216     demangling_style_names[i] =
 217       xstrdup (libiberty_demanglers[i].demangling_style_name);
 218
 219   add_setshow_boolean_cmd ("demangle", class_support, &demangle, _("\
 220 Set demangling of encoded C++/ObjC names when displaying symbols."), _("\
 221 Show demangling of encoded C++/ObjC names when displaying symbols."), NULL,
 222                            NULL,
 223                            show_demangle,
 224                            &setprintlist, &showprintlist);
 225
 226   add_setshow_boolean_cmd ("asm-demangle", class_support, &asm_demangle, _("\
 227 Set demangling of C++/ObjC names in disassembly listings."), _("\
 228 Show demangling of C++/ObjC names in disassembly listings."), NULL,
 229                            NULL,
 230                            show_asm_demangle,
 231                            &setprintlist, &showprintlist);
 232
 233   /* FIXME: cagney/2005-02-20: The code implementing this variable are
 234      malloc-ing and free-ing current_demangling_style_string when it
 235      should instead just point to an element of
 236      demangling_style_names.  */
 237   add_setshow_enum_cmd ("demangle-style", class_support,
 238                         demangling_style_names,
 239                         (const char **) &current_demangling_style_string, _("\
 240 Set the current C++ demangling style."), _("\
 241 Show the current C++ demangling style."), _("\
 242 Use `set demangle-style' without arguments for a list of demangling styles."),
 243                         set_demangling_command,
 244                         show_demangling_style_names,
 245                         &setlist, &showlist);
 246
 247   /* Set the default demangling style chosen at compilation time.  */
 248   set_demangling_style (DEFAULT_DEMANGLING_STYLE);
 249 }