1 /* Basic C++ demangling support for GDB. 2 3 Copyright (C) 1991-2020 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 "cli/cli-utils.h" /* for skip_to_space */ 28 #include "command.h" 29 #include "gdbcmd.h" 30 #include "demangle.h" 31 #include "gdb-demangle.h" 32 #include "language.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 bool demangle = true; 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 bool asm_demangle = false; 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 const char *current_demangling_style_string; 77 78 /* The array of names of the known demangling 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 (const char *ignore, 108 int from_tty, struct cmd_list_element *c) 109 { 110 const struct demangler_engine *dem; 111 int i; 112 113 /* First just try to match whatever style name the user supplied with 114 one of the known ones. Don't bother special casing for an empty 115 name, we just treat it as any other style name that doesn't match. 116 If we match, update the current demangling style enum. */ 117 118 for (dem = libiberty_demanglers, i = 0; 119 dem->demangling_style != unknown_demangling; 120 dem++) 121 { 122 if (strcmp (current_demangling_style_string, 123 dem->demangling_style_name) == 0) 124 { 125 current_demangling_style = dem->demangling_style; 126 current_demangling_style_string = demangling_style_names[i]; 127 break; 128 } 129 i++; 130 } 131 132 /* We should have found a match, given we only add known styles to 133 the enumeration list. */ 134 gdb_assert (dem->demangling_style != unknown_demangling); 135 } 136 137 /* G++ uses a special character to indicate certain internal names. Which 138 character it is depends on the platform: 139 - Usually '$' on systems where the assembler will accept that 140 - Usually '.' otherwise (this includes most sysv4-like systems and most 141 ELF targets) 142 - Occasionally '_' if neither of the above is usable 143 144 We check '$' first because it is the safest, and '.' often has another 145 meaning. We don't currently try to handle '_' because the precise forms 146 of the names are different on those targets. */ 147 148 static char cplus_markers[] = {'$', '.', '\0'}; 149 150 /* See documentation in gdb-demangle.h. */ 151 152 bool 153 is_cplus_marker (int c) 154 { 155 return c && strchr (cplus_markers, c) != NULL; 156 } 157 158 /* Demangle the given string in the current language. */ 159 160 static void 161 demangle_command (const char *args, int from_tty) 162 { 163 char *demangled; 164 const char *name; 165 const char *arg_start; 166 int processing_args = 1; 167 const struct language_defn *lang; 168 169 std::string arg_buf = args != NULL ? args : ""; 170 arg_start = arg_buf.c_str (); 171 172 std::string lang_name; 173 while (processing_args 174 && *arg_start == '-') 175 { 176 const char *p = skip_to_space (arg_start); 177 178 if (strncmp (arg_start, "-l", p - arg_start) == 0) 179 lang_name = extract_arg (&p); 180 else if (strncmp (arg_start, "--", p - arg_start) == 0) 181 processing_args = 0; 182 else 183 report_unrecognized_option_error ("demangle", arg_start); 184 185 arg_start = skip_spaces (p); 186 } 187 188 name = arg_start; 189 190 if (*name == '\0') 191 error (_("Usage: demangle [-l LANGUAGE] [--] NAME")); 192 193 if (!lang_name.empty ()) 194 { 195 enum language lang_enum; 196 197 lang_enum = language_enum (lang_name.c_str ()); 198 if (lang_enum == language_unknown) 199 error (_("Unknown language \"%s\""), lang_name.c_str ()); 200 lang = language_def (lang_enum); 201 } 202 else 203 lang = current_language; 204 205 demangled = language_demangle (lang, name, DMGL_ANSI | DMGL_PARAMS); 206 if (demangled != NULL) 207 { 208 printf_filtered ("%s\n", demangled); 209 xfree (demangled); 210 } 211 else 212 error (_("Can't demangle \"%s\""), name); 213 } 214 215 void _initialize_gdb_demangle (); 216 void 217 _initialize_gdb_demangle () 218 { 219 int i, ndems; 220 221 /* Fill the demangling_style_names[] array, and set the default 222 demangling style chosen at compilation time. */ 223 for (ndems = 0; 224 libiberty_demanglers[ndems].demangling_style != unknown_demangling; 225 ndems++) 226 ; 227 demangling_style_names = XCNEWVEC (const char *, ndems + 1); 228 for (i = 0; 229 libiberty_demanglers[i].demangling_style != unknown_demangling; 230 i++) 231 { 232 demangling_style_names[i] 233 = xstrdup (libiberty_demanglers[i].demangling_style_name); 234 235 if (current_demangling_style_string == NULL 236 && strcmp (DEFAULT_DEMANGLING_STYLE, demangling_style_names[i]) == 0) 237 current_demangling_style_string = demangling_style_names[i]; 238 } 239 240 add_setshow_boolean_cmd ("demangle", class_support, &demangle, _("\ 241 Set demangling of encoded C++/ObjC names when displaying symbols."), _("\ 242 Show demangling of encoded C++/ObjC names when displaying symbols."), NULL, 243 NULL, 244 show_demangle, 245 &setprintlist, &showprintlist); 246 247 add_setshow_boolean_cmd ("asm-demangle", class_support, &asm_demangle, _("\ 248 Set demangling of C++/ObjC names in disassembly listings."), _("\ 249 Show demangling of C++/ObjC names in disassembly listings."), NULL, 250 NULL, 251 show_asm_demangle, 252 &setprintlist, &showprintlist); 253 254 add_setshow_enum_cmd ("demangle-style", class_support, 255 demangling_style_names, 256 ¤t_demangling_style_string, _("\ 257 Set the current C++ demangling style."), _("\ 258 Show the current C++ demangling style."), _("\ 259 Use `set demangle-style' without arguments for a list of demangling styles."), 260 set_demangling_command, 261 show_demangling_style_names, 262 &setlist, &showlist); 263 264 add_cmd ("demangle", class_support, demangle_command, _("\ 265 Demangle a mangled name.\n\ 266 Usage: demangle [-l LANGUAGE] [--] NAME\n\ 267 If LANGUAGE is not specified, NAME is demangled in the current language."), 268 &cmdlist); 269 } 270