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1 | /* Private implementation details of interface between gdb and its |
2 | extension languages. | |
3 | ||
61baf725 | 4 | Copyright (C) 2014-2017 Free Software Foundation, Inc. |
6dddc817 DE |
5 | |
6 | This file is part of GDB. | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 3 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
20 | ||
21 | #ifndef EXTENSION_PRIV_H | |
22 | #define EXTENSION_PRIV_H | |
23 | ||
24 | #include "extension.h" | |
a40805d4 | 25 | #include <signal.h> |
6b66338c | 26 | #include "cli/cli-script.h" |
6dddc817 DE |
27 | |
28 | /* The return code for some API calls. */ | |
29 | ||
30 | enum ext_lang_rc | |
31 | { | |
32 | /* The operation completed successfully. */ | |
33 | EXT_LANG_RC_OK, | |
34 | ||
35 | /* The operation was not performed (e.g., no pretty-printer). */ | |
36 | EXT_LANG_RC_NOP, | |
37 | ||
38 | /* There was an error (e.g., Python error while printing a value). | |
39 | When an error occurs no further extension languages are tried. | |
40 | This is to preserve existing behaviour, and because it's convenient | |
41 | for Python developers. | |
42 | Note: This is different than encountering a memory error trying to read | |
43 | a value for pretty-printing. Here we're referring to, e.g., programming | |
44 | errors that trigger an exception in the extension language. */ | |
45 | EXT_LANG_RC_ERROR | |
46 | }; | |
47 | ||
48 | /* High level description of an extension/scripting language. | |
49 | An entry for each is compiled into GDB regardless of whether the support | |
50 | is present. This is done so that we can issue meaningful errors if the | |
51 | support is not compiled in. */ | |
52 | ||
53 | struct extension_language_defn | |
54 | { | |
55 | /* Enum of the extension language. */ | |
56 | enum extension_language language; | |
57 | ||
58 | /* The name of the extension language, lowercase. E.g., python. */ | |
59 | const char *name; | |
60 | ||
61 | /* The capitalized name of the extension language. | |
62 | For python this is "Python". For gdb this is "GDB". */ | |
63 | const char *capitalized_name; | |
64 | ||
65 | /* The file suffix of this extension language. E.g., ".py". */ | |
66 | const char *suffix; | |
67 | ||
68 | /* The suffix of per-objfile scripts to auto-load. | |
69 | E.g., When the program loads libfoo.so, look for libfoo.so-gdb.py. */ | |
70 | const char *auto_load_suffix; | |
71 | ||
72 | /* We support embedding external extension language code in GDB's own | |
73 | scripting language. We do this by having a special command that begins | |
74 | the extension language snippet, and terminate it with "end". | |
75 | This specifies the control type used to implement this. */ | |
76 | enum command_control_type cli_control_type; | |
77 | ||
78 | /* A pointer to the "methods" to load scripts in this language, | |
79 | or NULL if the support is not compiled into GDB. */ | |
80 | const struct extension_language_script_ops *script_ops; | |
81 | ||
82 | /* Either a pointer to the "methods" of the extension language interface | |
83 | or NULL if the support is not compiled into GDB. | |
84 | This is also NULL for GDB's own scripting language which is relatively | |
85 | primitive, and doesn't provide these features. */ | |
86 | const struct extension_language_ops *ops; | |
87 | }; | |
88 | ||
89 | /* The interface for loading scripts from external extension languages, | |
90 | as well as GDB's own scripting language. | |
1a860409 DE |
91 | All of these methods are required to be implemented. |
92 | ||
93 | By convention all of these functions take a pseudo-this parameter | |
94 | as the first argument. */ | |
6dddc817 DE |
95 | |
96 | struct extension_language_script_ops | |
97 | { | |
98 | /* Load a script. This is called, e.g., via the "source" command. | |
99 | If there's an error while processing the script this function may, | |
100 | but is not required to, throw an error. */ | |
101 | script_sourcer_func *script_sourcer; | |
102 | ||
103 | /* Load a script attached to an objfile. | |
104 | If there's an error while processing the script this function may, | |
105 | but is not required to, throw an error. */ | |
106 | objfile_script_sourcer_func *objfile_script_sourcer; | |
107 | ||
9f050062 DE |
108 | /* Execute a script attached to an objfile. |
109 | If there's an error while processing the script this function may, | |
110 | but is not required to, throw an error. */ | |
111 | objfile_script_executor_func *objfile_script_executor; | |
112 | ||
6dddc817 DE |
113 | /* Return non-zero if auto-loading scripts in this extension language |
114 | is enabled. */ | |
115 | int (*auto_load_enabled) (const struct extension_language_defn *); | |
116 | }; | |
117 | ||
118 | /* The interface for making calls from GDB to an external extension | |
119 | language. This is for non-script-loading related functionality, like | |
120 | pretty-printing, etc. The reason these are separated out is GDB's own | |
121 | scripting language makes use of extension_language_script_opts, but it | |
122 | makes no use of these. There is no (current) intention to split | |
123 | extension_language_ops up any further. | |
124 | All of these methods are optional and may be NULL, except where | |
1a860409 DE |
125 | otherwise indicated. |
126 | ||
127 | By convention all of these functions take a pseudo-this parameter | |
128 | as the first argument. */ | |
6dddc817 DE |
129 | |
130 | struct extension_language_ops | |
131 | { | |
132 | /* Called at the end of gdb initialization to give the extension language | |
133 | an opportunity to finish up. This is useful for things like adding | |
134 | new commands where one has to wait until gdb itself is initialized. */ | |
135 | void (*finish_initialization) (const struct extension_language_defn *); | |
136 | ||
137 | /* Return non-zero if the extension language successfully initialized. | |
138 | This method is required. */ | |
139 | int (*initialized) (const struct extension_language_defn *); | |
140 | ||
141 | /* Process a sequence of commands embedded in GDB's own scripting language. | |
142 | E.g., | |
143 | python | |
144 | print 42 | |
145 | end */ | |
146 | void (*eval_from_control_command) (const struct extension_language_defn *, | |
147 | struct command_line *); | |
148 | ||
149 | /* Type-printing support: | |
150 | start_type_printers, apply_type_printers, free_type_printers. | |
151 | These methods are optional and may be NULL, but if one of them is | |
152 | implemented then they all must be. */ | |
153 | ||
154 | /* Called before printing a type. */ | |
155 | void (*start_type_printers) (const struct extension_language_defn *, | |
156 | struct ext_lang_type_printers *); | |
157 | ||
158 | /* Try to pretty-print TYPE. If successful the pretty-printed type is | |
159 | stored in *PRETTIED_TYPE, and the caller must free it. | |
160 | Returns EXT_LANG_RC_OK upon success, EXT_LANG_RC_NOP if the type | |
161 | is not recognized, and EXT_LANG_RC_ERROR if an error was encountered. | |
162 | This function has a bit of a funny name, since it actually applies | |
163 | recognizers, but this seemed clearer given the start_type_printers | |
164 | and free_type_printers functions. */ | |
165 | enum ext_lang_rc (*apply_type_printers) | |
166 | (const struct extension_language_defn *, | |
167 | const struct ext_lang_type_printers *, | |
168 | struct type *, char **prettied_type); | |
169 | ||
170 | /* Called after a type has been printed to give the type pretty-printer | |
171 | mechanism an opportunity to clean up. */ | |
172 | void (*free_type_printers) (const struct extension_language_defn *, | |
173 | struct ext_lang_type_printers *); | |
174 | ||
668e1674 YQ |
175 | /* Try to pretty-print a value of type TYPE located at VAL's contents |
176 | buffer + EMBEDDED_OFFSET, which came from the inferior at address | |
177 | ADDRESS + EMBEDDED_OFFSET, onto stdio stream STREAM according to | |
178 | OPTIONS. | |
179 | VAL is the whole object that came from ADDRESS. | |
6dddc817 DE |
180 | Returns EXT_LANG_RC_OK upon success, EXT_LANG_RC_NOP if the value |
181 | is not recognized, and EXT_LANG_RC_ERROR if an error was encountered. */ | |
182 | enum ext_lang_rc (*apply_val_pretty_printer) | |
183 | (const struct extension_language_defn *, | |
668e1674 | 184 | struct type *type, |
6b850546 | 185 | LONGEST embedded_offset, CORE_ADDR address, |
6dddc817 | 186 | struct ui_file *stream, int recurse, |
668e1674 | 187 | struct value *val, const struct value_print_options *options, |
6dddc817 DE |
188 | const struct language_defn *language); |
189 | ||
190 | /* GDB access to the "frame filter" feature. | |
191 | FRAME is the source frame to start frame-filter invocation. FLAGS is an | |
192 | integer holding the flags for printing. The following elements of | |
193 | the FRAME_FILTER_FLAGS enum denotes the make-up of FLAGS: | |
194 | PRINT_LEVEL is a flag indicating whether to print the frame's | |
195 | relative level in the output. PRINT_FRAME_INFO is a flag that | |
196 | indicates whether this function should print the frame | |
197 | information, PRINT_ARGS is a flag that indicates whether to print | |
198 | frame arguments, and PRINT_LOCALS, likewise, with frame local | |
199 | variables. ARGS_TYPE is an enumerator describing the argument | |
200 | format, OUT is the output stream to print. FRAME_LOW is the | |
201 | beginning of the slice of frames to print, and FRAME_HIGH is the | |
202 | upper limit of the frames to count. Returns SCR_BT_ERROR on error, | |
203 | or SCR_BT_COMPLETED on success. */ | |
204 | enum ext_lang_bt_status (*apply_frame_filter) | |
205 | (const struct extension_language_defn *, | |
206 | struct frame_info *frame, int flags, enum ext_lang_frame_args args_type, | |
207 | struct ui_out *out, int frame_low, int frame_high); | |
208 | ||
209 | /* Update values held by the extension language when OBJFILE is discarded. | |
210 | New global types must be created for every such value, which must then be | |
211 | updated to use the new types. | |
212 | This function typically just iterates over all appropriate values and | |
213 | calls preserve_one_value for each one. | |
214 | COPIED_TYPES is used to prevent cycles / duplicates and is passed to | |
215 | preserve_one_value. */ | |
216 | void (*preserve_values) (const struct extension_language_defn *, | |
217 | struct objfile *objfile, htab_t copied_types); | |
218 | ||
219 | /* Return non-zero if there is a stop condition for the breakpoint. | |
220 | This is used to implement the restriction that a breakpoint may have | |
221 | at most one condition. */ | |
222 | int (*breakpoint_has_cond) (const struct extension_language_defn *, | |
223 | struct breakpoint *); | |
224 | ||
225 | /* Return a value of enum ext_lang_bp_stop indicating if there is a stop | |
226 | condition for the breakpoint, and if so whether the program should | |
227 | stop. This is called when the program has stopped at the specified | |
228 | breakpoint. | |
229 | While breakpoints can have at most one condition, this is called for | |
230 | every extension language, even if another extension language has a | |
231 | "stop" method: other kinds of breakpoints may be implemented using | |
232 | this method, e.g., "finish breakpoints" in Python. */ | |
233 | enum ext_lang_bp_stop (*breakpoint_cond_says_stop) | |
234 | (const struct extension_language_defn *, struct breakpoint *); | |
235 | ||
a149683b | 236 | /* The next two are used to connect GDB's SIGINT handling with the |
6dddc817 DE |
237 | extension language's. |
238 | ||
239 | Terminology: If an extension language can use GDB's SIGINT handling then | |
240 | we say the extension language has "cooperative SIGINT handling". | |
241 | Python is an example of this. | |
242 | ||
243 | These need not be implemented, but if one of them is implemented | |
244 | then they all must be. */ | |
245 | ||
6dddc817 DE |
246 | /* Set the SIGINT indicator. |
247 | This is called by GDB's SIGINT handler and must be async-safe. */ | |
248 | void (*set_quit_flag) (const struct extension_language_defn *); | |
249 | ||
250 | /* Return non-zero if a SIGINT has occurred. | |
251 | This is expected to also clear the indicator. */ | |
252 | int (*check_quit_flag) (const struct extension_language_defn *); | |
253 | ||
254 | /* Called before gdb prints its prompt, giving extension languages an | |
255 | opportunity to change it with set_prompt. | |
256 | Returns EXT_LANG_RC_OK if the prompt was changed, EXT_LANG_RC_NOP if | |
257 | the prompt was not changed, and EXT_LANG_RC_ERROR if an error was | |
258 | encountered. | |
259 | Extension languages are called in order, and once the prompt is | |
260 | changed or an error occurs no further languages are called. */ | |
261 | enum ext_lang_rc (*before_prompt) (const struct extension_language_defn *, | |
262 | const char *current_gdb_prompt); | |
e81e7f5e SC |
263 | |
264 | /* xmethod support: | |
265 | clone_xmethod_worker_data, free_xmethod_worker_data, | |
266 | get_matching_xmethod_workers, get_xmethod_arg_types, | |
2ce1cdbf | 267 | get_xmethod_return_type, invoke_xmethod. |
e81e7f5e SC |
268 | These methods are optional and may be NULL, but if one of them is |
269 | implemented then they all must be. */ | |
270 | ||
271 | /* Clone DATA and return a new but identical xmethod worker data | |
272 | object for this extension language. */ | |
273 | void * (*clone_xmethod_worker_data) | |
274 | (const struct extension_language_defn *extlang, void *data); | |
275 | ||
276 | /* Free the DATA object of this extension language. */ | |
277 | void (*free_xmethod_worker_data) | |
278 | (const struct extension_language_defn *extlang, void *data); | |
279 | ||
280 | /* Return a vector of matching xmethod workers defined in this | |
281 | extension language. The workers service methods with name | |
282 | METHOD_NAME on objects of type OBJ_TYPE. The vector is returned | |
283 | in DM_VEC. */ | |
284 | enum ext_lang_rc (*get_matching_xmethod_workers) | |
285 | (const struct extension_language_defn *extlang, | |
286 | struct type *obj_type, | |
287 | const char *method_name, | |
288 | xmethod_worker_vec **dm_vec); | |
289 | ||
290 | /* Given a WORKER servicing a particular method, return the types | |
291 | of the arguments the method takes. The number of arguments is | |
292 | returned in NARGS, and their types are returned in the array | |
293 | ARGTYPES. */ | |
294 | enum ext_lang_rc (*get_xmethod_arg_types) | |
295 | (const struct extension_language_defn *extlang, | |
296 | struct xmethod_worker *worker, | |
297 | int *nargs, | |
298 | struct type ***arg_types); | |
299 | ||
2ce1cdbf DE |
300 | /* Given a WORKER servicing a particular method, fetch the type of the |
301 | result of the method. OBJECT, ARGS, NARGS are the same as for | |
302 | invoke_xmethod. The result type is stored in *RESULT_TYPE. | |
303 | For backward compatibility with 7.9, which did not support getting the | |
304 | result type, if the get_result_type operation is not provided by WORKER | |
305 | then EXT_LANG_RC_OK is returned and NULL is returned in *RESULT_TYPE. */ | |
306 | enum ext_lang_rc (*get_xmethod_result_type) | |
307 | (const struct extension_language_defn *extlang, | |
308 | struct xmethod_worker *worker, | |
309 | struct value *object, struct value **args, int nargs, | |
310 | struct type **result_type); | |
311 | ||
e81e7f5e SC |
312 | /* Invoke the xmethod serviced by WORKER. The xmethod is invoked |
313 | on OBJECT with arguments in the array ARGS. NARGS is the length of | |
314 | this array. Returns the value returned by the xmethod. */ | |
315 | struct value * (*invoke_xmethod) | |
316 | (const struct extension_language_defn *extlang, | |
317 | struct xmethod_worker *worker, | |
318 | struct value *object, | |
319 | struct value **args, | |
320 | int nargs); | |
6dddc817 DE |
321 | }; |
322 | ||
323 | /* State necessary to restore a signal handler to its previous value. */ | |
324 | ||
325 | struct signal_handler | |
326 | { | |
327 | /* Non-zero if "handler" has been set. */ | |
328 | int handler_saved; | |
329 | ||
330 | /* The signal handler. */ | |
a40805d4 | 331 | sighandler_t handler; |
6dddc817 DE |
332 | }; |
333 | ||
334 | /* State necessary to restore the currently active extension language | |
1a860409 | 335 | to its previous value. */ |
6dddc817 DE |
336 | |
337 | struct active_ext_lang_state | |
338 | { | |
339 | /* The previously active extension language. */ | |
340 | const struct extension_language_defn *ext_lang; | |
341 | ||
342 | /* Its SIGINT handler. */ | |
343 | struct signal_handler sigint_handler; | |
344 | }; | |
345 | ||
346 | extern const struct extension_language_defn *get_active_ext_lang (void); | |
347 | ||
348 | extern struct active_ext_lang_state *set_active_ext_lang | |
349 | (const struct extension_language_defn *); | |
350 | ||
351 | extern void restore_active_ext_lang (struct active_ext_lang_state *previous); | |
352 | ||
353 | #endif /* EXTENSION_PRIV_H */ |