gdb/demangle.c

   1 /* Basic C++ demangling support for GDB.
   2
   3    Copyright (C) 1991-2015 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 /* 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 /* See documentation in gdb-demangle.h.  */
  44 int demangle = 1;
  45
  46 static void
  47 show_demangle (struct ui_file *file, int from_tty,
  48                struct cmd_list_element *c, const char *value)
  49 {
  50   fprintf_filtered (file,
  51                     _("Demangling of encoded C++/ObjC names "
  52                       "when displaying symbols is %s.\n"),
  53                     value);
  54 }
  55
  56 /* See documentation in gdb-demangle.h.  */
  57 int asm_demangle = 0;
  58
  59 static void
  60 show_asm_demangle (struct ui_file *file, int from_tty,
  61                    struct cmd_list_element *c, const char *value)
  62 {
  63   fprintf_filtered (file,
  64                     _("Demangling of C++/ObjC names in "
  65                       "disassembly listings is %s.\n"),
  66                     value);
  67 }
  68
  69 /* String name for the current demangling style.  Set by the
  70    "set demangle-style" command, printed as part of the output by the
  71    "show demangle-style" command.  */
  72
  73 static const char *current_demangling_style_string;
  74
  75 /* The array of names of the known demanglyng styles.  Generated by
  76    _initialize_demangler from libiberty_demanglers[] array.  */
  77
  78 static const char **demangling_style_names;
  79 static void
  80 show_demangling_style_names(struct ui_file *file, int from_tty,
  81                             struct cmd_list_element *c, const char *value)
  82 {
  83   fprintf_filtered (file, _("The current C++ demangling style is \"%s\".\n"),
  84                     value);
  85 }
  86
  87 /* Set current demangling style.  Called by the "set demangle-style"
  88    command after it has updated the current_demangling_style_string to
  89    match what the user has entered.
  90
  91    If the user has entered a string that matches a known demangling style
  92    name in the demanglers[] array then just leave the string alone and update
  93    the current_demangling_style enum value to match.
  94
  95    If the user has entered a string that doesn't match, including an empty
  96    string, then print a list of the currently known styles and restore
  97    the current_demangling_style_string to match the current_demangling_style
  98    enum value.
  99
 100    Note:  Assumes that current_demangling_style_string always points to
 101    a malloc'd string, even if it is a null-string.  */
 102
 103 static void
 104 set_demangling_command (char *ignore, int from_tty, struct cmd_list_element *c)
 105 {
 106   const struct demangler_engine *dem;
 107   int i;
 108
 109   /*  First just try to match whatever style name the user supplied with
 110      one of the known ones.  Don't bother special casing for an empty
 111      name, we just treat it as any other style name that doesn't match.
 112      If we match, update the current demangling style enum.  */
 113
 114   for (dem = libiberty_demanglers, i = 0;
 115        dem->demangling_style != unknown_demangling;
 116        dem++)
 117     {
 118       if (strcmp (current_demangling_style_string,
 119                   dem->demangling_style_name) == 0)
 120         {
 121           current_demangling_style = dem->demangling_style;
 122           current_demangling_style_string = demangling_style_names[i];
 123           break;
 124         }
 125       i++;
 126     }
 127
 128   /* We should have found a match, given we only add known styles to
 129      the enumeration list.  */
 130   gdb_assert (dem->demangling_style != unknown_demangling);
 131 }
 132
 133 /* G++ uses a special character to indicate certain internal names.  Which
 134    character it is depends on the platform:
 135    - Usually '$' on systems where the assembler will accept that
 136    - Usually '.' otherwise (this includes most sysv4-like systems and most
 137      ELF targets)
 138    - Occasionally '_' if neither of the above is usable
 139
 140    We check '$' first because it is the safest, and '.' often has another
 141    meaning.  We don't currently try to handle '_' because the precise forms
 142    of the names are different on those targets.  */
 143
 144 static char cplus_markers[] = {'$', '.', '\0'};
 145
 146 /* See documentation in gdb-demangle.h.  */
 147
 148 int
 149 is_cplus_marker (int c)
 150 {
 151   return c && strchr (cplus_markers, c) != NULL;
 152 }
 153
 154 extern initialize_file_ftype _initialize_demangler; /* -Wmissing-prototypes */
 155
 156 void
 157 _initialize_demangler (void)
 158 {
 159   int i, ndems;
 160
 161   /* Fill the demangling_style_names[] array, and set the default
 162      demangling style chosen at compilation time.  */
 163   for (ndems = 0;
 164        libiberty_demanglers[ndems].demangling_style != unknown_demangling;
 165        ndems++)
 166     ;
 167   demangling_style_names = xcalloc (ndems + 1, sizeof (char *));
 168   for (i = 0;
 169        libiberty_demanglers[i].demangling_style != unknown_demangling;
 170        i++)
 171     {
 172       demangling_style_names[i]
 173         = xstrdup (libiberty_demanglers[i].demangling_style_name);
 174
 175       if (current_demangling_style_string == NULL
 176           && strcmp (DEFAULT_DEMANGLING_STYLE, demangling_style_names[i]) == 0)
 177         current_demangling_style_string = demangling_style_names[i];
 178     }
 179
 180   add_setshow_boolean_cmd ("demangle", class_support, &demangle, _("\
 181 Set demangling of encoded C++/ObjC names when displaying symbols."), _("\
 182 Show demangling of encoded C++/ObjC names when displaying symbols."), NULL,
 183                            NULL,
 184                            show_demangle,
 185                            &setprintlist, &showprintlist);
 186
 187   add_setshow_boolean_cmd ("asm-demangle", class_support, &asm_demangle, _("\
 188 Set demangling of C++/ObjC names in disassembly listings."), _("\
 189 Show demangling of C++/ObjC names in disassembly listings."), NULL,
 190                            NULL,
 191                            show_asm_demangle,
 192                            &setprintlist, &showprintlist);
 193
 194   add_setshow_enum_cmd ("demangle-style", class_support,
 195                         demangling_style_names,
 196                         &current_demangling_style_string, _("\
 197 Set the current C++ demangling style."), _("\
 198 Show the current C++ demangling style."), _("\
 199 Use `set demangle-style' without arguments for a list of demangling styles."),
 200                         set_demangling_command,
 201                         show_demangling_style_names,
 202                         &setlist, &showlist);
 203 }