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6dddc817 DE |
1 | /* Interface between gdb and its extension languages. |
2 | ||
4f8fcb74 | 3 | Copyright (C) 2014 Free Software Foundation, Inc. |
6dddc817 DE |
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 | /* Note: With few exceptions, external functions and variables in this file | |
21 | have "ext_lang" in the name, and no other symbol in gdb does. */ | |
22 | ||
23 | #include "defs.h" | |
24 | #include <signal.h> | |
25 | #include "auto-load.h" | |
26 | #include "breakpoint.h" | |
27 | #include "event-top.h" | |
28 | #include "extension.h" | |
29 | #include "extension-priv.h" | |
30 | #include "observer.h" | |
31 | #include "cli/cli-script.h" | |
32 | #include "python/python.h" | |
ed3ef339 | 33 | #include "guile/guile.h" |
6dddc817 DE |
34 | |
35 | /* Iterate over all external extension languages, regardless of whether the | |
36 | support has been compiled in or not. | |
37 | This does not include GDB's own scripting language. */ | |
38 | ||
39 | #define ALL_EXTENSION_LANGUAGES(i, extlang) \ | |
40 | for (/*int*/ i = 0, extlang = extension_languages[0]; \ | |
41 | extlang != NULL; \ | |
42 | extlang = extension_languages[++i]) | |
43 | ||
44 | /* Iterate over all external extension languages that are supported. | |
45 | This does not include GDB's own scripting language. */ | |
46 | ||
47 | #define ALL_ENABLED_EXTENSION_LANGUAGES(i, extlang) \ | |
48 | for (/*int*/ i = 0, extlang = extension_languages[0]; \ | |
49 | extlang != NULL; \ | |
50 | extlang = extension_languages[++i]) \ | |
51 | if (extlang->ops != NULL) | |
52 | ||
53 | static script_sourcer_func source_gdb_script; | |
54 | static objfile_script_sourcer_func source_gdb_objfile_script; | |
55 | ||
56 | /* GDB's own scripting language. | |
57 | This exists, in part, to support auto-loading ${prog}-gdb.gdb scripts. */ | |
58 | ||
59 | static const struct extension_language_script_ops | |
60 | extension_language_gdb_script_ops = | |
61 | { | |
62 | source_gdb_script, | |
63 | source_gdb_objfile_script, | |
64 | auto_load_gdb_scripts_enabled | |
65 | }; | |
66 | ||
67 | const struct extension_language_defn extension_language_gdb = | |
68 | { | |
69 | EXT_LANG_GDB, | |
70 | "gdb", | |
71 | "GDB", | |
72 | ||
73 | /* We fall back to interpreting a script as a GDB script if it doesn't | |
74 | match the other scripting languages, but for consistency's sake | |
75 | give it a formal suffix. */ | |
76 | ".gdb", | |
77 | "-gdb.gdb", | |
78 | ||
79 | /* cli_control_type: This is never used: GDB's own scripting language | |
80 | has a variety of control types (if, while, etc.). */ | |
81 | commands_control, | |
82 | ||
83 | &extension_language_gdb_script_ops, | |
84 | ||
85 | /* The rest of the extension language interface isn't supported by GDB's own | |
86 | extension/scripting language. */ | |
87 | NULL | |
88 | }; | |
89 | ||
90 | /* NULL-terminated table of all external (non-native) extension languages. | |
91 | ||
92 | The order of appearance in the table is important. | |
93 | When multiple extension languages provide the same feature, for example | |
94 | a pretty-printer for a particular type, which one gets used? | |
95 | The algorithm employed here is "the first one wins". For example, in | |
96 | the case of pretty-printers this means the first one to provide a | |
97 | pretty-printed value is the one that is used. This algorithm is employed | |
98 | throughout. */ | |
99 | ||
100 | static const struct extension_language_defn * const extension_languages[] = | |
101 | { | |
102 | /* To preserve existing behaviour, python should always appear first. */ | |
103 | &extension_language_python, | |
ed3ef339 | 104 | &extension_language_guile, |
6dddc817 DE |
105 | NULL |
106 | }; | |
107 | ||
108 | /* Return a pointer to the struct extension_language_defn object of | |
109 | extension language LANG. | |
110 | This always returns a non-NULL pointer, even if support for the language | |
111 | is not compiled into this copy of GDB. */ | |
112 | ||
113 | const struct extension_language_defn * | |
114 | get_ext_lang_defn (enum extension_language lang) | |
115 | { | |
116 | int i; | |
117 | const struct extension_language_defn *extlang; | |
118 | ||
119 | gdb_assert (lang != EXT_LANG_NONE); | |
120 | ||
121 | if (lang == EXT_LANG_GDB) | |
122 | return &extension_language_gdb; | |
123 | ||
124 | ALL_EXTENSION_LANGUAGES (i, extlang) | |
125 | { | |
126 | if (extlang->language == lang) | |
127 | return extlang; | |
128 | } | |
129 | ||
130 | gdb_assert_not_reached ("unable to find extension_language_defn"); | |
131 | } | |
132 | ||
133 | /* Return TRUE if FILE has extension EXTENSION. */ | |
134 | ||
135 | static int | |
136 | has_extension (const char *file, const char *extension) | |
137 | { | |
138 | int file_len = strlen (file); | |
139 | int extension_len = strlen (extension); | |
140 | ||
141 | return (file_len > extension_len | |
142 | && strcmp (&file[file_len - extension_len], extension) == 0); | |
143 | } | |
144 | ||
145 | /* Return the extension language of FILE, or NULL if | |
146 | the extension language of FILE is not recognized. | |
147 | This is done by looking at the file's suffix. */ | |
148 | ||
149 | const struct extension_language_defn * | |
150 | get_ext_lang_of_file (const char *file) | |
151 | { | |
152 | int i; | |
153 | const struct extension_language_defn *extlang; | |
154 | ||
155 | ALL_EXTENSION_LANGUAGES (i, extlang) | |
156 | { | |
157 | if (has_extension (file, extlang->suffix)) | |
158 | return extlang; | |
159 | } | |
160 | ||
161 | return NULL; | |
162 | } | |
163 | ||
164 | /* Return non-zero if support for the specified extension language | |
165 | is compiled in. */ | |
166 | ||
167 | int | |
168 | ext_lang_present_p (const struct extension_language_defn *extlang) | |
169 | { | |
170 | return extlang->script_ops != NULL; | |
171 | } | |
172 | ||
173 | /* Return non-zero if the specified extension language has successfully | |
174 | initialized. */ | |
175 | ||
176 | int | |
177 | ext_lang_initialized_p (const struct extension_language_defn *extlang) | |
178 | { | |
179 | if (extlang->ops != NULL) | |
180 | { | |
181 | /* This method is required. */ | |
182 | gdb_assert (extlang->ops->initialized != NULL); | |
183 | return extlang->ops->initialized (extlang); | |
184 | } | |
185 | ||
186 | return 0; | |
187 | } | |
188 | ||
189 | /* Throw an error indicating EXTLANG is not supported in this copy of GDB. */ | |
190 | ||
191 | void | |
192 | throw_ext_lang_unsupported (const struct extension_language_defn *extlang) | |
193 | { | |
194 | error (_("Scripting in the \"%s\" language is not supported" | |
195 | " in this copy of GDB."), | |
196 | ext_lang_capitalized_name (extlang)); | |
197 | } | |
198 | \f | |
199 | /* Methods for GDB's own extension/scripting language. */ | |
200 | ||
201 | /* The extension_language_script_ops.script_sourcer "method". */ | |
202 | ||
203 | static void | |
204 | source_gdb_script (const struct extension_language_defn *extlang, | |
205 | FILE *stream, const char *file) | |
206 | { | |
207 | script_from_file (stream, file); | |
208 | } | |
209 | ||
210 | /* The extension_language_script_ops.objfile_script_sourcer "method". */ | |
211 | ||
212 | static void | |
213 | source_gdb_objfile_script (const struct extension_language_defn *extlang, | |
214 | struct objfile *objfile, | |
215 | FILE *stream, const char *file) | |
216 | { | |
217 | script_from_file (stream, file); | |
218 | } | |
219 | \f | |
220 | /* Accessors for "public" attributes of struct extension_language. */ | |
221 | ||
222 | /* Return the "name" field of EXTLANG. */ | |
223 | ||
224 | const char * | |
225 | ext_lang_name (const struct extension_language_defn *extlang) | |
226 | { | |
227 | return extlang->name; | |
228 | } | |
229 | ||
230 | /* Return the "capitalized_name" field of EXTLANG. */ | |
231 | ||
232 | const char * | |
233 | ext_lang_capitalized_name (const struct extension_language_defn *extlang) | |
234 | { | |
235 | return extlang->capitalized_name; | |
236 | } | |
237 | ||
238 | /* Return the "suffix" field of EXTLANG. */ | |
239 | ||
240 | const char * | |
241 | ext_lang_suffix (const struct extension_language_defn *extlang) | |
242 | { | |
243 | return extlang->suffix; | |
244 | } | |
245 | ||
246 | /* Return the "auto_load_suffix" field of EXTLANG. */ | |
247 | ||
248 | const char * | |
249 | ext_lang_auto_load_suffix (const struct extension_language_defn *extlang) | |
250 | { | |
251 | return extlang->auto_load_suffix; | |
252 | } | |
253 | \f | |
254 | /* extension_language_script_ops wrappers. */ | |
255 | ||
256 | /* Return the script "sourcer" function for EXTLANG. | |
257 | This is the function that loads and processes a script. | |
258 | If support for this language isn't compiled in, NULL is returned. */ | |
259 | ||
260 | script_sourcer_func * | |
261 | ext_lang_script_sourcer (const struct extension_language_defn *extlang) | |
262 | { | |
263 | if (extlang->script_ops == NULL) | |
264 | return NULL; | |
265 | ||
266 | /* The extension language is required to implement this function. */ | |
267 | gdb_assert (extlang->script_ops->script_sourcer != NULL); | |
268 | ||
269 | return extlang->script_ops->script_sourcer; | |
270 | } | |
271 | ||
272 | /* Return the objfile script "sourcer" function for EXTLANG. | |
273 | This is the function that loads and processes a script for a particular | |
274 | objfile. | |
275 | If support for this language isn't compiled in, NULL is returned. */ | |
276 | ||
277 | objfile_script_sourcer_func * | |
278 | ext_lang_objfile_script_sourcer (const struct extension_language_defn *extlang) | |
279 | { | |
280 | if (extlang->script_ops == NULL) | |
281 | return NULL; | |
282 | ||
283 | /* The extension language is required to implement this function. */ | |
284 | gdb_assert (extlang->script_ops->objfile_script_sourcer != NULL); | |
285 | ||
286 | return extlang->script_ops->objfile_script_sourcer; | |
287 | } | |
288 | ||
289 | /* Return non-zero if auto-loading of EXTLANG scripts is enabled. | |
290 | Zero is returned if support for this language isn't compiled in. */ | |
291 | ||
292 | int | |
293 | ext_lang_auto_load_enabled (const struct extension_language_defn *extlang) | |
294 | { | |
295 | if (extlang->script_ops == NULL) | |
296 | return 0; | |
297 | ||
298 | /* The extension language is required to implement this function. */ | |
299 | gdb_assert (extlang->script_ops->auto_load_enabled != NULL); | |
300 | ||
301 | return extlang->script_ops->auto_load_enabled (extlang); | |
302 | } | |
303 | \f | |
304 | /* Functions that iterate over all extension languages. | |
305 | These only iterate over external extension languages, not including | |
306 | GDB's own extension/scripting language, unless otherwise indicated. */ | |
307 | ||
308 | /* Wrapper to call the extension_language_ops.finish_initialization "method" | |
309 | for each compiled-in extension language. */ | |
310 | ||
311 | void | |
312 | finish_ext_lang_initialization (void) | |
313 | { | |
314 | int i; | |
315 | const struct extension_language_defn *extlang; | |
316 | ||
317 | ALL_ENABLED_EXTENSION_LANGUAGES (i, extlang) | |
318 | { | |
319 | if (extlang->ops->finish_initialization != NULL) | |
320 | extlang->ops->finish_initialization (extlang); | |
321 | } | |
322 | } | |
323 | ||
324 | /* Invoke the appropriate extension_language_ops.eval_from_control_command | |
325 | method to perform CMD, which is a list of commands in an extension language. | |
326 | ||
327 | This function is what implements, for example: | |
328 | ||
329 | python | |
330 | print 42 | |
331 | end | |
332 | ||
333 | in a GDB script. */ | |
334 | ||
335 | void | |
336 | eval_ext_lang_from_control_command (struct command_line *cmd) | |
337 | { | |
338 | int i; | |
339 | const struct extension_language_defn *extlang; | |
340 | ||
341 | ALL_EXTENSION_LANGUAGES (i, extlang) | |
342 | { | |
343 | if (extlang->cli_control_type == cmd->control_type) | |
344 | { | |
345 | if (extlang->ops->eval_from_control_command != NULL) | |
346 | { | |
347 | extlang->ops->eval_from_control_command (extlang, cmd); | |
348 | return; | |
349 | } | |
350 | /* The requested extension language is not supported in this GDB. */ | |
351 | throw_ext_lang_unsupported (extlang); | |
352 | } | |
353 | } | |
354 | ||
355 | gdb_assert_not_reached ("unknown extension language in command_line"); | |
356 | } | |
357 | ||
358 | /* Search for and load scripts for OBJFILE written in extension languages. | |
359 | This includes GDB's own scripting language. | |
360 | ||
361 | This function is what implements the loading of OBJFILE-gdb.py and | |
362 | OBJFILE-gdb.gdb. */ | |
363 | ||
364 | void | |
365 | auto_load_ext_lang_scripts_for_objfile (struct objfile *objfile) | |
366 | { | |
367 | int i; | |
368 | const struct extension_language_defn *extlang; | |
369 | ||
370 | extlang = &extension_language_gdb; | |
371 | if (ext_lang_auto_load_enabled (extlang)) | |
372 | auto_load_objfile_script (objfile, extlang); | |
373 | ||
374 | ALL_ENABLED_EXTENSION_LANGUAGES (i, extlang) | |
375 | { | |
376 | if (ext_lang_auto_load_enabled (extlang)) | |
377 | auto_load_objfile_script (objfile, extlang); | |
378 | } | |
379 | } | |
380 | \f | |
381 | /* Interface to type pretty-printers implemented in an extension language. */ | |
382 | ||
383 | /* Call this at the start when preparing to pretty-print a type. | |
384 | The result is a pointer to an opaque object (to the caller) to be passed | |
385 | to apply_ext_lang_type_printers and free_ext_lang_type_printers. | |
386 | ||
387 | We don't know in advance which extension language will provide a | |
388 | pretty-printer for the type, so all are initialized. */ | |
389 | ||
390 | struct ext_lang_type_printers * | |
391 | start_ext_lang_type_printers (void) | |
392 | { | |
393 | struct ext_lang_type_printers *printers | |
394 | = XCNEW (struct ext_lang_type_printers); | |
395 | int i; | |
396 | const struct extension_language_defn *extlang; | |
397 | ||
398 | ALL_ENABLED_EXTENSION_LANGUAGES (i, extlang) | |
399 | { | |
400 | if (extlang->ops->start_type_printers != NULL) | |
401 | extlang->ops->start_type_printers (extlang, printers); | |
402 | } | |
403 | ||
404 | return printers; | |
405 | } | |
406 | ||
407 | /* Iteratively try the type pretty-printers specified by PRINTERS | |
408 | according to the standard search order (specified by extension_languages), | |
409 | returning the result of the first one that succeeds. | |
410 | If there was an error, or if no printer succeeds, then NULL is returned. */ | |
411 | ||
412 | char * | |
413 | apply_ext_lang_type_printers (struct ext_lang_type_printers *printers, | |
414 | struct type *type) | |
415 | { | |
416 | int i; | |
417 | const struct extension_language_defn *extlang; | |
418 | ||
419 | ALL_ENABLED_EXTENSION_LANGUAGES (i, extlang) | |
420 | { | |
421 | char *result = NULL; | |
422 | enum ext_lang_rc rc; | |
423 | ||
424 | if (extlang->ops->apply_type_printers == NULL) | |
425 | continue; | |
426 | rc = extlang->ops->apply_type_printers (extlang, printers, type, | |
427 | &result); | |
428 | switch (rc) | |
429 | { | |
430 | case EXT_LANG_RC_OK: | |
431 | gdb_assert (result != NULL); | |
432 | return result; | |
433 | case EXT_LANG_RC_ERROR: | |
434 | return NULL; | |
435 | case EXT_LANG_RC_NOP: | |
436 | break; | |
437 | default: | |
438 | gdb_assert_not_reached ("bad return from apply_type_printers"); | |
439 | } | |
440 | } | |
441 | ||
442 | return NULL; | |
443 | } | |
444 | ||
445 | /* Call this after pretty-printing a type to release all memory held | |
446 | by PRINTERS. */ | |
447 | ||
448 | void | |
449 | free_ext_lang_type_printers (struct ext_lang_type_printers *printers) | |
450 | { | |
451 | int i; | |
452 | const struct extension_language_defn *extlang; | |
453 | ||
454 | ALL_ENABLED_EXTENSION_LANGUAGES (i, extlang) | |
455 | { | |
456 | if (extlang->ops->free_type_printers != NULL) | |
457 | extlang->ops->free_type_printers (extlang, printers); | |
458 | } | |
459 | ||
460 | xfree (printers); | |
461 | } | |
462 | \f | |
463 | /* Try to pretty-print a value of type TYPE located at VALADDR | |
464 | + EMBEDDED_OFFSET, which came from the inferior at address ADDRESS | |
465 | + EMBEDDED_OFFSET, onto stdio stream STREAM according to OPTIONS. | |
466 | VAL is the whole object that came from ADDRESS. VALADDR must point to | |
467 | the head of VAL's contents buffer. | |
468 | Returns non-zero if the value was successfully pretty-printed. | |
469 | ||
470 | Extension languages are tried in the order specified by | |
471 | extension_languages. The first one to provide a pretty-printed | |
472 | value "wins". | |
473 | ||
474 | If an error is encountered in a pretty-printer, no further extension | |
475 | languages are tried. | |
476 | Note: This is different than encountering a memory error trying to read a | |
477 | value for pretty-printing. Here we're referring to, e.g., programming | |
478 | errors that trigger an exception in the extension language. */ | |
479 | ||
480 | int | |
481 | apply_ext_lang_val_pretty_printer (struct type *type, const gdb_byte *valaddr, | |
482 | int embedded_offset, CORE_ADDR address, | |
483 | struct ui_file *stream, int recurse, | |
484 | const struct value *val, | |
485 | const struct value_print_options *options, | |
486 | const struct language_defn *language) | |
487 | { | |
488 | int i; | |
489 | const struct extension_language_defn *extlang; | |
490 | ||
491 | ALL_ENABLED_EXTENSION_LANGUAGES (i, extlang) | |
492 | { | |
493 | enum ext_lang_rc rc; | |
494 | ||
495 | if (extlang->ops->apply_val_pretty_printer == NULL) | |
496 | continue; | |
497 | rc = extlang->ops->apply_val_pretty_printer (extlang, type, valaddr, | |
498 | embedded_offset, address, | |
499 | stream, recurse, val, | |
500 | options, language); | |
501 | switch (rc) | |
502 | { | |
503 | case EXT_LANG_RC_OK: | |
504 | return 1; | |
505 | case EXT_LANG_RC_ERROR: | |
506 | return 0; | |
507 | case EXT_LANG_RC_NOP: | |
508 | break; | |
509 | default: | |
510 | gdb_assert_not_reached ("bad return from apply_val_pretty_printer"); | |
511 | } | |
512 | } | |
513 | ||
514 | return 0; | |
515 | } | |
516 | ||
517 | /* GDB access to the "frame filter" feature. | |
518 | FRAME is the source frame to start frame-filter invocation. FLAGS is an | |
519 | integer holding the flags for printing. The following elements of | |
520 | the FRAME_FILTER_FLAGS enum denotes the make-up of FLAGS: | |
521 | PRINT_LEVEL is a flag indicating whether to print the frame's | |
522 | relative level in the output. PRINT_FRAME_INFO is a flag that | |
523 | indicates whether this function should print the frame | |
524 | information, PRINT_ARGS is a flag that indicates whether to print | |
525 | frame arguments, and PRINT_LOCALS, likewise, with frame local | |
526 | variables. ARGS_TYPE is an enumerator describing the argument | |
527 | format, OUT is the output stream to print. FRAME_LOW is the | |
528 | beginning of the slice of frames to print, and FRAME_HIGH is the | |
529 | upper limit of the frames to count. Returns EXT_LANG_BT_ERROR on error, | |
530 | or EXT_LANG_BT_COMPLETED on success. | |
531 | ||
532 | Extension languages are tried in the order specified by | |
533 | extension_languages. The first one to provide a filter "wins". | |
534 | If there is an error (EXT_LANG_BT_ERROR) it is reported immediately | |
535 | rather than trying filters in other extension languages. */ | |
536 | ||
537 | enum ext_lang_bt_status | |
538 | apply_ext_lang_frame_filter (struct frame_info *frame, int flags, | |
539 | enum ext_lang_frame_args args_type, | |
540 | struct ui_out *out, | |
541 | int frame_low, int frame_high) | |
542 | { | |
543 | int i; | |
544 | const struct extension_language_defn *extlang; | |
545 | ||
546 | ALL_ENABLED_EXTENSION_LANGUAGES (i, extlang) | |
547 | { | |
548 | enum ext_lang_bt_status status; | |
549 | ||
550 | if (extlang->ops->apply_frame_filter == NULL) | |
551 | continue; | |
552 | status = extlang->ops->apply_frame_filter (extlang, frame, flags, | |
553 | args_type, out, | |
554 | frame_low, frame_high); | |
555 | /* We use the filters from the first extension language that has | |
556 | applicable filters. Also, an error is reported immediately | |
557 | rather than continue trying. */ | |
558 | if (status != EXT_LANG_BT_NO_FILTERS) | |
559 | return status; | |
560 | } | |
561 | ||
562 | return EXT_LANG_BT_NO_FILTERS; | |
563 | } | |
564 | ||
565 | /* Update values held by the extension language when OBJFILE is discarded. | |
566 | New global types must be created for every such value, which must then be | |
567 | updated to use the new types. | |
568 | The function typically just iterates over all appropriate values and | |
569 | calls preserve_one_value for each one. | |
570 | COPIED_TYPES is used to prevent cycles / duplicates and is passed to | |
571 | preserve_one_value. */ | |
572 | ||
573 | void | |
574 | preserve_ext_lang_values (struct objfile *objfile, htab_t copied_types) | |
575 | { | |
576 | int i; | |
577 | const struct extension_language_defn *extlang; | |
578 | ||
579 | ALL_ENABLED_EXTENSION_LANGUAGES (i, extlang) | |
580 | { | |
581 | if (extlang->ops->preserve_values != NULL) | |
582 | extlang->ops->preserve_values (extlang, objfile, copied_types); | |
583 | } | |
584 | } | |
585 | ||
586 | /* If there is a stop condition implemented in an extension language for | |
587 | breakpoint B, return a pointer to the extension language's definition. | |
588 | Otherwise return NULL. | |
589 | If SKIP_LANG is not EXT_LANG_NONE, skip checking this language. | |
590 | This is for the case where we're setting a new condition: Only one | |
591 | condition is allowed, so when setting a condition for any particular | |
592 | extension language, we need to check if any other extension language | |
593 | already has a condition set. */ | |
594 | ||
595 | const struct extension_language_defn * | |
596 | get_breakpoint_cond_ext_lang (struct breakpoint *b, | |
597 | enum extension_language skip_lang) | |
598 | { | |
599 | int i; | |
600 | const struct extension_language_defn *extlang; | |
601 | ||
602 | ALL_ENABLED_EXTENSION_LANGUAGES (i, extlang) | |
603 | { | |
604 | if (extlang->language != skip_lang | |
605 | && extlang->ops->breakpoint_has_cond != NULL | |
606 | && extlang->ops->breakpoint_has_cond (extlang, b)) | |
607 | return extlang; | |
608 | } | |
609 | ||
610 | return NULL; | |
611 | } | |
612 | ||
613 | /* Return whether a stop condition for breakpoint B says to stop. | |
614 | True is also returned if there is no stop condition for B. */ | |
615 | ||
616 | int | |
617 | breakpoint_ext_lang_cond_says_stop (struct breakpoint *b) | |
618 | { | |
619 | int i; | |
620 | const struct extension_language_defn *extlang; | |
621 | enum ext_lang_bp_stop stop = EXT_LANG_BP_STOP_UNSET; | |
622 | ||
623 | ALL_ENABLED_EXTENSION_LANGUAGES (i, extlang) | |
624 | { | |
625 | /* There is a rule that a breakpoint can have at most one of any of a | |
626 | CLI or extension language condition. However, Python hacks in "finish | |
627 | breakpoints" on top of the "stop" check, so we have to call this for | |
628 | every language, even if we could first determine whether a "stop" | |
629 | method exists. */ | |
630 | if (extlang->ops->breakpoint_cond_says_stop != NULL) | |
631 | { | |
632 | enum ext_lang_bp_stop this_stop | |
633 | = extlang->ops->breakpoint_cond_says_stop (extlang, b); | |
634 | ||
635 | if (this_stop != EXT_LANG_BP_STOP_UNSET) | |
636 | { | |
637 | /* Even though we have to check every extension language, only | |
638 | one of them can return yes/no (because only one of them | |
639 | can have a "stop" condition). */ | |
640 | gdb_assert (stop == EXT_LANG_BP_STOP_UNSET); | |
641 | stop = this_stop; | |
642 | } | |
643 | } | |
644 | } | |
645 | ||
646 | return stop == EXT_LANG_BP_STOP_NO ? 0 : 1; | |
647 | } | |
648 | \f | |
649 | /* ^C/SIGINT support. | |
650 | This requires cooperation with the extension languages so the support | |
651 | is defined here. */ | |
652 | ||
653 | /* This flag tracks quit requests when we haven't called out to an | |
654 | extension language. it also holds quit requests when we transition to | |
655 | an extension language that doesn't have cooperative SIGINT handling. */ | |
656 | static int quit_flag; | |
657 | ||
658 | /* The current extension language we've called out to, or | |
659 | extension_language_gdb if there isn't one. | |
660 | This must be set everytime we call out to an extension language, and reset | |
661 | to the previous value when it returns. Note that the previous value may | |
662 | be a different (or the same) extension language. */ | |
663 | static const struct extension_language_defn *active_ext_lang | |
664 | = &extension_language_gdb; | |
665 | ||
666 | /* Return the currently active extension language. */ | |
667 | ||
668 | const struct extension_language_defn * | |
669 | get_active_ext_lang (void) | |
670 | { | |
671 | return active_ext_lang; | |
672 | } | |
673 | ||
674 | /* Install a SIGINT handler. */ | |
675 | ||
676 | static void | |
677 | install_sigint_handler (const struct signal_handler *handler_state) | |
678 | { | |
679 | gdb_assert (handler_state->handler_saved); | |
680 | ||
681 | signal (SIGINT, handler_state->handler); | |
682 | } | |
683 | ||
684 | /* Install GDB's SIGINT handler, storing the previous version in *PREVIOUS. | |
685 | As a simple optimization, if the previous version was GDB's SIGINT handler | |
686 | then mark the previous handler as not having been saved, and thus it won't | |
687 | be restored. */ | |
688 | ||
689 | static void | |
690 | install_gdb_sigint_handler (struct signal_handler *previous) | |
691 | { | |
692 | /* Save here to simplify comparison. */ | |
693 | RETSIGTYPE (*handle_sigint_for_compare) () = handle_sigint; | |
694 | ||
695 | previous->handler = signal (SIGINT, handle_sigint); | |
696 | if (previous->handler != handle_sigint_for_compare) | |
697 | previous->handler_saved = 1; | |
698 | else | |
699 | previous->handler_saved = 0; | |
700 | } | |
701 | ||
702 | /* Set the currently active extension language to NOW_ACTIVE. | |
703 | The result is a pointer to a malloc'd block of memory to pass to | |
704 | restore_active_ext_lang. | |
705 | ||
706 | N.B. This function must be called every time we call out to an extension | |
707 | language, and the result must be passed to restore_active_ext_lang | |
708 | afterwards. | |
709 | ||
710 | If there is a pending SIGINT it is "moved" to the now active extension | |
711 | language, if it supports cooperative SIGINT handling (i.e., it provides | |
712 | {clear,set,check}_quit_flag methods). If the extension language does not | |
713 | support cooperative SIGINT handling, then the SIGINT is left queued and | |
714 | we require the non-cooperative extension language to call check_quit_flag | |
715 | at appropriate times. | |
716 | It is important for the extension language to call check_quit_flag if it | |
717 | installs its own SIGINT handler to prevent the situation where a SIGINT | |
718 | is queued on entry, extension language code runs for a "long" time possibly | |
719 | serving one or more SIGINTs, and then returns. Upon return, if | |
720 | check_quit_flag is not called, the original SIGINT will be thrown. | |
721 | Non-cooperative extension languages are free to install their own SIGINT | |
722 | handler but the original must be restored upon return, either itself | |
723 | or via restore_active_ext_lang. */ | |
724 | ||
725 | struct active_ext_lang_state * | |
726 | set_active_ext_lang (const struct extension_language_defn *now_active) | |
727 | { | |
728 | struct active_ext_lang_state *previous | |
729 | = XCNEW (struct active_ext_lang_state); | |
730 | ||
731 | previous->ext_lang = active_ext_lang; | |
732 | active_ext_lang = now_active; | |
733 | ||
734 | /* If the newly active extension language uses cooperative SIGINT handling | |
735 | then ensure GDB's SIGINT handler is installed. */ | |
736 | if (now_active->language == EXT_LANG_GDB | |
737 | || now_active->ops->check_quit_flag != NULL) | |
738 | install_gdb_sigint_handler (&previous->sigint_handler); | |
739 | ||
740 | /* If there's a SIGINT recorded in the cooperative extension languages, | |
741 | move it to the new language, or save it in GDB's global flag if the newly | |
742 | active extension language doesn't use cooperative SIGINT handling. */ | |
743 | if (check_quit_flag ()) | |
744 | set_quit_flag (); | |
745 | ||
746 | return previous; | |
747 | } | |
748 | ||
749 | /* Restore active extension language from PREVIOUS. */ | |
750 | ||
751 | void | |
752 | restore_active_ext_lang (struct active_ext_lang_state *previous) | |
753 | { | |
754 | const struct extension_language_defn *current = active_ext_lang; | |
755 | ||
756 | active_ext_lang = previous->ext_lang; | |
757 | ||
758 | /* Restore the previous SIGINT handler if one was saved. */ | |
759 | if (previous->sigint_handler.handler_saved) | |
760 | install_sigint_handler (&previous->sigint_handler); | |
761 | ||
762 | /* If there's a SIGINT recorded in the cooperative extension languages, | |
763 | move it to the new language, or save it in GDB's global flag if the newly | |
764 | active extension language doesn't use cooperative SIGINT handling. */ | |
765 | if (check_quit_flag ()) | |
766 | set_quit_flag (); | |
767 | ||
768 | xfree (previous); | |
769 | } | |
770 | ||
771 | /* Clear the quit flag. | |
772 | The flag is cleared in all extension languages, | |
773 | not just the currently active one. */ | |
774 | ||
775 | void | |
776 | clear_quit_flag (void) | |
777 | { | |
778 | int i; | |
779 | const struct extension_language_defn *extlang; | |
780 | ||
781 | ALL_ENABLED_EXTENSION_LANGUAGES (i, extlang) | |
782 | { | |
783 | if (extlang->ops->clear_quit_flag != NULL) | |
784 | extlang->ops->clear_quit_flag (extlang); | |
785 | } | |
786 | ||
787 | quit_flag = 0; | |
788 | } | |
789 | ||
790 | /* Set the quit flag. | |
791 | This only sets the flag in the currently active extension language. | |
792 | If the currently active extension language does not have cooperative | |
793 | SIGINT handling, then GDB's global flag is set, and it is up to the | |
794 | extension language to call check_quit_flag. The extension language | |
795 | is free to install its own SIGINT handler, but we still need to handle | |
796 | the transition. */ | |
797 | ||
798 | void | |
799 | set_quit_flag (void) | |
800 | { | |
801 | if (active_ext_lang->ops != NULL | |
802 | && active_ext_lang->ops->set_quit_flag != NULL) | |
803 | active_ext_lang->ops->set_quit_flag (active_ext_lang); | |
804 | else | |
805 | quit_flag = 1; | |
806 | } | |
807 | ||
808 | /* Return true if the quit flag has been set, false otherwise. | |
809 | Note: The flag is cleared as a side-effect. | |
810 | The flag is checked in all extension languages that support cooperative | |
811 | SIGINT handling, not just the current one. This simplifies transitions. */ | |
812 | ||
813 | int | |
814 | check_quit_flag (void) | |
815 | { | |
816 | int i, result = 0; | |
817 | const struct extension_language_defn *extlang; | |
818 | ||
819 | ALL_ENABLED_EXTENSION_LANGUAGES (i, extlang) | |
820 | { | |
821 | if (extlang->ops->check_quit_flag != NULL) | |
822 | if (extlang->ops->check_quit_flag (extlang) != 0) | |
823 | result = 1; | |
824 | } | |
825 | ||
826 | /* This is written in a particular way to avoid races. */ | |
827 | if (quit_flag) | |
828 | { | |
829 | quit_flag = 0; | |
830 | result = 1; | |
831 | } | |
832 | ||
833 | return result; | |
834 | } | |
835 | \f | |
836 | /* Called via an observer before gdb prints its prompt. | |
837 | Iterate over the extension languages giving them a chance to | |
838 | change the prompt. The first one to change the prompt wins, | |
839 | and no further languages are tried. */ | |
840 | ||
841 | static void | |
842 | ext_lang_before_prompt (const char *current_gdb_prompt) | |
843 | { | |
844 | int i; | |
845 | const struct extension_language_defn *extlang; | |
846 | ||
847 | ALL_ENABLED_EXTENSION_LANGUAGES (i, extlang) | |
848 | { | |
849 | enum ext_lang_rc rc; | |
850 | ||
851 | if (extlang->ops->before_prompt == NULL) | |
852 | continue; | |
853 | rc = extlang->ops->before_prompt (extlang, current_gdb_prompt); | |
854 | switch (rc) | |
855 | { | |
856 | case EXT_LANG_RC_OK: | |
857 | case EXT_LANG_RC_ERROR: | |
858 | return; | |
859 | case EXT_LANG_RC_NOP: | |
860 | break; | |
861 | default: | |
862 | gdb_assert_not_reached ("bad return from before_prompt"); | |
863 | } | |
864 | } | |
865 | } | |
866 | ||
867 | extern initialize_file_ftype _initialize_extension; | |
868 | ||
869 | void | |
870 | _initialize_extension (void) | |
871 | { | |
872 | observer_attach_before_prompt (ext_lang_before_prompt); | |
873 | } |