1 /* Interface between gdb and its extension languages. 2 3 Copyright (C) 2014-2021 Free Software Foundation, Inc. 4 5 This file is part of GDB. 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 19 20 #ifndef EXTENSION_H 21 #define EXTENSION_H 22 23 #include "mi/mi-cmds.h" /* For PRINT_NO_VALUES, etc. */ 24 #include "gdbsupport/array-view.h" 25 #include "gdbsupport/gdb_optional.h" 26 27 struct breakpoint; 28 struct command_line; 29 struct frame_info; 30 struct language_defn; 31 struct objfile; 32 struct extension_language_defn; 33 struct type; 34 struct ui_file; 35 struct ui_out; 36 struct value; 37 struct value_print_options; 38 39 /* A function to load and process a script file. 40 The file has been opened and is ready to be read from the beginning. 41 Any exceptions are not caught, and are passed to the caller. */ 42 typedef void script_sourcer_func (const struct extension_language_defn *, 43 FILE *stream, const char *filename); 44 45 /* A function to load and process a script for an objfile. 46 The file has been opened and is ready to be read from the beginning. 47 Any exceptions are not caught, and are passed to the caller. */ 48 typedef void objfile_script_sourcer_func 49 (const struct extension_language_defn *, 50 struct objfile *, FILE *stream, const char *filename); 51 52 /* A function to execute a script for an objfile. 53 Any exceptions are not caught, and are passed to the caller. */ 54 typedef void objfile_script_executor_func 55 (const struct extension_language_defn *, 56 struct objfile *, const char *name, const char *script); 57 58 /* Enum of each extension(/scripting) language. */ 59 60 enum extension_language 61 { 62 EXT_LANG_NONE, 63 EXT_LANG_GDB, 64 EXT_LANG_PYTHON, 65 EXT_LANG_GUILE 66 }; 67 68 /* Extension language frame-filter status return values. */ 69 70 enum ext_lang_bt_status 71 { 72 /* Return when an error has occurred in processing frame filters, 73 or when printing the stack. */ 74 EXT_LANG_BT_ERROR = -1, 75 76 /* Return from internal routines to indicate that the function 77 succeeded. */ 78 EXT_LANG_BT_OK = 1, 79 80 /* Return when the frame filter process is complete, but there 81 were no filter registered and enabled to process. */ 82 EXT_LANG_BT_NO_FILTERS = 2 83 }; 84 85 /* Flags to pass to apply_extlang_frame_filter. */ 86 87 enum frame_filter_flag 88 { 89 /* Set this flag if frame level is to be printed. */ 90 PRINT_LEVEL = 1 << 0, 91 92 /* Set this flag if frame information is to be printed. */ 93 PRINT_FRAME_INFO = 1 << 1, 94 95 /* Set this flag if frame arguments are to be printed. */ 96 PRINT_ARGS = 1 << 2, 97 98 /* Set this flag if frame locals are to be printed. */ 99 PRINT_LOCALS = 1 << 3, 100 101 /* Set this flag if a "More frames" message is to be printed. */ 102 PRINT_MORE_FRAMES = 1 << 4, 103 104 /* Set this flag if elided frames should not be printed. */ 105 PRINT_HIDE = 1 << 5, 106 }; 107 108 DEF_ENUM_FLAGS_TYPE (enum frame_filter_flag, frame_filter_flags); 109 110 /* A choice of the different frame argument printing strategies that 111 can occur in different cases of frame filter instantiation. */ 112 113 enum ext_lang_frame_args 114 { 115 /* Print no values for arguments when invoked from the MI. */ 116 NO_VALUES = PRINT_NO_VALUES, 117 118 MI_PRINT_ALL_VALUES = PRINT_ALL_VALUES, 119 120 /* Print only simple values (what MI defines as "simple") for 121 arguments when invoked from the MI. */ 122 MI_PRINT_SIMPLE_VALUES = PRINT_SIMPLE_VALUES, 123 124 /* Print only scalar values for arguments when invoked from the CLI. */ 125 CLI_SCALAR_VALUES, 126 127 /* Print all values for arguments when invoked from the CLI. */ 128 CLI_ALL_VALUES, 129 130 /* Only indicate the presence of arguments when invoked from the CLI. */ 131 CLI_PRESENCE 132 }; 133 134 /* The possible results of 135 extension_language_ops.breakpoint_cond_says_stop. */ 136 137 enum ext_lang_bp_stop 138 { 139 /* No "stop" condition is set. */ 140 EXT_LANG_BP_STOP_UNSET, 141 142 /* A "stop" condition is set, and it says "don't stop". */ 143 EXT_LANG_BP_STOP_NO, 144 145 /* A "stop" condition is set, and it says "stop". */ 146 EXT_LANG_BP_STOP_YES 147 }; 148 149 /* Table of type printers associated with the global typedef table. */ 150 151 struct ext_lang_type_printers 152 { 153 ext_lang_type_printers (); 154 ~ext_lang_type_printers (); 155 156 DISABLE_COPY_AND_ASSIGN (ext_lang_type_printers); 157 158 /* Type-printers from Python. */ 159 void *py_type_printers = nullptr; 160 }; 161 162 /* The return code for some API calls. */ 163 164 enum ext_lang_rc 165 { 166 /* The operation completed successfully. */ 167 EXT_LANG_RC_OK, 168 169 /* The operation was not performed (e.g., no pretty-printer). */ 170 EXT_LANG_RC_NOP, 171 172 /* There was an error (e.g., Python error while printing a value). 173 When an error occurs no further extension languages are tried. 174 This is to preserve existing behaviour, and because it's convenient 175 for Python developers. 176 Note: This is different than encountering a memory error trying to read 177 a value for pretty-printing. Here we're referring to, e.g., programming 178 errors that trigger an exception in the extension language. */ 179 EXT_LANG_RC_ERROR 180 }; 181 182 /* A type which holds its extension language specific xmethod worker data. */ 183 184 struct xmethod_worker 185 { xmethod_workerxmethod_worker186 xmethod_worker (const extension_language_defn *extlang) 187 : m_extlang (extlang) 188 {} 189 190 virtual ~xmethod_worker () = default; 191 192 /* Invoke the xmethod encapsulated in this worker and return the result. 193 The method is invoked on OBJ with arguments in the ARGS array. */ 194 195 virtual value *invoke (value *obj, gdb::array_view<value *> args) = 0; 196 197 /* Return the arg types of the xmethod encapsulated in this worker. 198 The type of the 'this' object is returned as the first element of 199 the vector. */ 200 201 std::vector<type *> get_arg_types (); 202 203 /* Return the type of the result of the xmethod encapsulated in this worker. 204 OBJECT and ARGS are the same as for invoke. */ 205 206 type *get_result_type (value *object, gdb::array_view<value *> args); 207 208 private: 209 210 /* Return the types of the arguments the method takes. The types 211 are returned in TYPE_ARGS, one per argument. */ 212 213 virtual enum ext_lang_rc do_get_arg_types 214 (std::vector<type *> *type_args) = 0; 215 216 /* Fetch the type of the result of the method implemented by this 217 worker. OBJECT and ARGS are the same as for the invoked method. 218 The result type is stored in *RESULT_TYPE. */ 219 220 virtual enum ext_lang_rc do_get_result_type 221 (struct value *obj, gdb::array_view<value *> args, 222 struct type **result_type_ptr) = 0; 223 224 /* The language the xmethod worker is implemented in. */ 225 226 const extension_language_defn *m_extlang; 227 }; 228 229 typedef std::unique_ptr<xmethod_worker> xmethod_worker_up; 230 231 /* The interface for gdb's own extension(/scripting) language. */ 232 extern const struct extension_language_defn extension_language_gdb; 233 234 extern const struct extension_language_defn *get_ext_lang_defn 235 (enum extension_language lang); 236 237 extern const struct extension_language_defn *get_ext_lang_of_file 238 (const char *file); 239 240 extern int ext_lang_present_p (const struct extension_language_defn *); 241 242 extern int ext_lang_initialized_p (const struct extension_language_defn *); 243 244 extern void throw_ext_lang_unsupported 245 (const struct extension_language_defn *); 246 247 /* Accessors for "public" attributes of the extension language definition. */ 248 249 extern enum extension_language ext_lang_kind 250 (const struct extension_language_defn *); 251 252 extern const char *ext_lang_name (const struct extension_language_defn *); 253 254 extern const char *ext_lang_capitalized_name 255 (const struct extension_language_defn *); 256 257 extern const char *ext_lang_suffix (const struct extension_language_defn *); 258 259 extern const char *ext_lang_auto_load_suffix 260 (const struct extension_language_defn *); 261 262 extern script_sourcer_func *ext_lang_script_sourcer 263 (const struct extension_language_defn *); 264 265 extern objfile_script_sourcer_func *ext_lang_objfile_script_sourcer 266 (const struct extension_language_defn *); 267 268 extern objfile_script_executor_func *ext_lang_objfile_script_executor 269 (const struct extension_language_defn *); 270 271 /* Return true if auto-loading of EXTLANG scripts is enabled. 272 False is returned if support for this language isn't compiled in. */ 273 274 extern bool ext_lang_auto_load_enabled (const struct extension_language_defn *); 275 276 /* Wrappers for each extension language API function that iterate over all 277 extension languages. */ 278 279 extern void ext_lang_initialization (void); 280 281 extern void eval_ext_lang_from_control_command (struct command_line *cmd); 282 283 extern void auto_load_ext_lang_scripts_for_objfile (struct objfile *); 284 285 extern char *apply_ext_lang_type_printers (struct ext_lang_type_printers *, 286 struct type *); 287 288 extern int apply_ext_lang_val_pretty_printer 289 (struct value *value, struct ui_file *stream, int recurse, 290 const struct value_print_options *options, 291 const struct language_defn *language); 292 293 extern enum ext_lang_bt_status apply_ext_lang_frame_filter 294 (struct frame_info *frame, frame_filter_flags flags, 295 enum ext_lang_frame_args args_type, 296 struct ui_out *out, int frame_low, int frame_high); 297 298 extern void preserve_ext_lang_values (struct objfile *, htab_t copied_types); 299 300 extern const struct extension_language_defn *get_breakpoint_cond_ext_lang 301 (struct breakpoint *b, enum extension_language skip_lang); 302 303 extern int breakpoint_ext_lang_cond_says_stop (struct breakpoint *); 304 305 /* If a method with name METHOD_NAME is to be invoked on an object of type 306 TYPE, then all extension languages are searched for implementations of 307 methods with name METHOD_NAME. All matches found are appended to the WORKERS 308 vector. */ 309 310 extern void get_matching_xmethod_workers 311 (struct type *type, const char *method_name, 312 std::vector<xmethod_worker_up> *workers); 313 314 /* Try to colorize some source code. FILENAME is the name of the file 315 holding the code. CONTENTS is the source code itself. This will 316 either a colorized (using ANSI terminal escapes) version of the 317 source code, or an empty value if colorizing could not be done. */ 318 319 extern gdb::optional<std::string> ext_lang_colorize 320 (const std::string &filename, const std::string &contents); 321 322 #endif /* EXTENSION_H */ 323