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1 | /* Perform an inferior function call, for GDB, the GNU debugger. | |
2 | ||
3 | Copyright (C) 1986-2022 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 | #include "defs.h" | |
21 | #include "infcall.h" | |
22 | #include "breakpoint.h" | |
23 | #include "tracepoint.h" | |
24 | #include "target.h" | |
25 | #include "regcache.h" | |
26 | #include "inferior.h" | |
27 | #include "infrun.h" | |
28 | #include "block.h" | |
29 | #include "gdbcore.h" | |
30 | #include "language.h" | |
31 | #include "objfiles.h" | |
32 | #include "gdbcmd.h" | |
33 | #include "command.h" | |
34 | #include "dummy-frame.h" | |
35 | #include "ada-lang.h" | |
36 | #include "f-lang.h" | |
37 | #include "gdbthread.h" | |
38 | #include "event-top.h" | |
39 | #include "observable.h" | |
40 | #include "top.h" | |
41 | #include "interps.h" | |
42 | #include "thread-fsm.h" | |
43 | #include <algorithm> | |
44 | #include "gdbsupport/scope-exit.h" | |
45 | #include <list> | |
46 | ||
47 | /* If we can't find a function's name from its address, | |
48 | we print this instead. */ | |
49 | #define RAW_FUNCTION_ADDRESS_FORMAT "at 0x%s" | |
50 | #define RAW_FUNCTION_ADDRESS_SIZE (sizeof (RAW_FUNCTION_ADDRESS_FORMAT) \ | |
51 | + 2 * sizeof (CORE_ADDR)) | |
52 | ||
53 | /* NOTE: cagney/2003-04-16: What's the future of this code? | |
54 | ||
55 | GDB needs an asynchronous expression evaluator, that means an | |
56 | asynchronous inferior function call implementation, and that in | |
57 | turn means restructuring the code so that it is event driven. */ | |
58 | ||
59 | static bool may_call_functions_p = true; | |
60 | static void | |
61 | show_may_call_functions_p (struct ui_file *file, int from_tty, | |
62 | struct cmd_list_element *c, | |
63 | const char *value) | |
64 | { | |
65 | gdb_printf (file, | |
66 | _("Permission to call functions in the program is %s.\n"), | |
67 | value); | |
68 | } | |
69 | ||
70 | /* How you should pass arguments to a function depends on whether it | |
71 | was defined in K&R style or prototype style. If you define a | |
72 | function using the K&R syntax that takes a `float' argument, then | |
73 | callers must pass that argument as a `double'. If you define the | |
74 | function using the prototype syntax, then you must pass the | |
75 | argument as a `float', with no promotion. | |
76 | ||
77 | Unfortunately, on certain older platforms, the debug info doesn't | |
78 | indicate reliably how each function was defined. A function type's | |
79 | TYPE_PROTOTYPED flag may be clear, even if the function was defined | |
80 | in prototype style. When calling a function whose TYPE_PROTOTYPED | |
81 | flag is clear, GDB consults this flag to decide what to do. | |
82 | ||
83 | For modern targets, it is proper to assume that, if the prototype | |
84 | flag is clear, that can be trusted: `float' arguments should be | |
85 | promoted to `double'. For some older targets, if the prototype | |
86 | flag is clear, that doesn't tell us anything. The default is to | |
87 | trust the debug information; the user can override this behavior | |
88 | with "set coerce-float-to-double 0". */ | |
89 | ||
90 | static bool coerce_float_to_double_p = true; | |
91 | static void | |
92 | show_coerce_float_to_double_p (struct ui_file *file, int from_tty, | |
93 | struct cmd_list_element *c, const char *value) | |
94 | { | |
95 | gdb_printf (file, | |
96 | _("Coercion of floats to doubles " | |
97 | "when calling functions is %s.\n"), | |
98 | value); | |
99 | } | |
100 | ||
101 | /* This boolean tells what gdb should do if a signal is received while | |
102 | in a function called from gdb (call dummy). If set, gdb unwinds | |
103 | the stack and restore the context to what as it was before the | |
104 | call. | |
105 | ||
106 | The default is to stop in the frame where the signal was received. */ | |
107 | ||
108 | static bool unwind_on_signal_p = false; | |
109 | static void | |
110 | show_unwind_on_signal_p (struct ui_file *file, int from_tty, | |
111 | struct cmd_list_element *c, const char *value) | |
112 | { | |
113 | gdb_printf (file, | |
114 | _("Unwinding of stack if a signal is " | |
115 | "received while in a call dummy is %s.\n"), | |
116 | value); | |
117 | } | |
118 | ||
119 | /* This boolean tells what gdb should do if a std::terminate call is | |
120 | made while in a function called from gdb (call dummy). | |
121 | As the confines of a single dummy stack prohibit out-of-frame | |
122 | handlers from handling a raised exception, and as out-of-frame | |
123 | handlers are common in C++, this can lead to no handler being found | |
124 | by the unwinder, and a std::terminate call. This is a false positive. | |
125 | If set, gdb unwinds the stack and restores the context to what it | |
126 | was before the call. | |
127 | ||
128 | The default is to unwind the frame if a std::terminate call is | |
129 | made. */ | |
130 | ||
131 | static bool unwind_on_terminating_exception_p = true; | |
132 | ||
133 | static void | |
134 | show_unwind_on_terminating_exception_p (struct ui_file *file, int from_tty, | |
135 | struct cmd_list_element *c, | |
136 | const char *value) | |
137 | ||
138 | { | |
139 | gdb_printf (file, | |
140 | _("Unwind stack if a C++ exception is " | |
141 | "unhandled while in a call dummy is %s.\n"), | |
142 | value); | |
143 | } | |
144 | ||
145 | /* Perform the standard coercions that are specified | |
146 | for arguments to be passed to C, Ada or Fortran functions. | |
147 | ||
148 | If PARAM_TYPE is non-NULL, it is the expected parameter type. | |
149 | IS_PROTOTYPED is non-zero if the function declaration is prototyped. */ | |
150 | ||
151 | static struct value * | |
152 | value_arg_coerce (struct gdbarch *gdbarch, struct value *arg, | |
153 | struct type *param_type, int is_prototyped) | |
154 | { | |
155 | const struct builtin_type *builtin = builtin_type (gdbarch); | |
156 | struct type *arg_type = check_typedef (value_type (arg)); | |
157 | struct type *type | |
158 | = param_type ? check_typedef (param_type) : arg_type; | |
159 | ||
160 | /* Perform any Ada- and Fortran-specific coercion first. */ | |
161 | if (current_language->la_language == language_ada) | |
162 | arg = ada_convert_actual (arg, type); | |
163 | else if (current_language->la_language == language_fortran) | |
164 | type = fortran_preserve_arg_pointer (arg, type); | |
165 | ||
166 | /* Force the value to the target if we will need its address. At | |
167 | this point, we could allocate arguments on the stack instead of | |
168 | calling malloc if we knew that their addresses would not be | |
169 | saved by the called function. */ | |
170 | arg = value_coerce_to_target (arg); | |
171 | ||
172 | switch (type->code ()) | |
173 | { | |
174 | case TYPE_CODE_REF: | |
175 | case TYPE_CODE_RVALUE_REF: | |
176 | { | |
177 | struct value *new_value; | |
178 | ||
179 | if (TYPE_IS_REFERENCE (arg_type)) | |
180 | return value_cast_pointers (type, arg, 0); | |
181 | ||
182 | /* Cast the value to the reference's target type, and then | |
183 | convert it back to a reference. This will issue an error | |
184 | if the value was not previously in memory - in some cases | |
185 | we should clearly be allowing this, but how? */ | |
186 | new_value = value_cast (TYPE_TARGET_TYPE (type), arg); | |
187 | new_value = value_ref (new_value, type->code ()); | |
188 | return new_value; | |
189 | } | |
190 | case TYPE_CODE_INT: | |
191 | case TYPE_CODE_CHAR: | |
192 | case TYPE_CODE_BOOL: | |
193 | case TYPE_CODE_ENUM: | |
194 | /* If we don't have a prototype, coerce to integer type if necessary. */ | |
195 | if (!is_prototyped) | |
196 | { | |
197 | if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_int)) | |
198 | type = builtin->builtin_int; | |
199 | } | |
200 | /* Currently all target ABIs require at least the width of an integer | |
201 | type for an argument. We may have to conditionalize the following | |
202 | type coercion for future targets. */ | |
203 | if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_int)) | |
204 | type = builtin->builtin_int; | |
205 | break; | |
206 | case TYPE_CODE_FLT: | |
207 | if (!is_prototyped && coerce_float_to_double_p) | |
208 | { | |
209 | if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_double)) | |
210 | type = builtin->builtin_double; | |
211 | else if (TYPE_LENGTH (type) > TYPE_LENGTH (builtin->builtin_double)) | |
212 | type = builtin->builtin_long_double; | |
213 | } | |
214 | break; | |
215 | case TYPE_CODE_FUNC: | |
216 | type = lookup_pointer_type (type); | |
217 | break; | |
218 | case TYPE_CODE_ARRAY: | |
219 | /* Arrays are coerced to pointers to their first element, unless | |
220 | they are vectors, in which case we want to leave them alone, | |
221 | because they are passed by value. */ | |
222 | if (current_language->c_style_arrays_p ()) | |
223 | if (!type->is_vector ()) | |
224 | type = lookup_pointer_type (TYPE_TARGET_TYPE (type)); | |
225 | break; | |
226 | case TYPE_CODE_UNDEF: | |
227 | case TYPE_CODE_PTR: | |
228 | case TYPE_CODE_STRUCT: | |
229 | case TYPE_CODE_UNION: | |
230 | case TYPE_CODE_VOID: | |
231 | case TYPE_CODE_SET: | |
232 | case TYPE_CODE_RANGE: | |
233 | case TYPE_CODE_STRING: | |
234 | case TYPE_CODE_ERROR: | |
235 | case TYPE_CODE_MEMBERPTR: | |
236 | case TYPE_CODE_METHODPTR: | |
237 | case TYPE_CODE_METHOD: | |
238 | case TYPE_CODE_COMPLEX: | |
239 | default: | |
240 | break; | |
241 | } | |
242 | ||
243 | return value_cast (type, arg); | |
244 | } | |
245 | ||
246 | /* See infcall.h. */ | |
247 | ||
248 | CORE_ADDR | |
249 | find_function_addr (struct value *function, | |
250 | struct type **retval_type, | |
251 | struct type **function_type) | |
252 | { | |
253 | struct type *ftype = check_typedef (value_type (function)); | |
254 | struct gdbarch *gdbarch = ftype->arch (); | |
255 | struct type *value_type = NULL; | |
256 | /* Initialize it just to avoid a GCC false warning. */ | |
257 | CORE_ADDR funaddr = 0; | |
258 | ||
259 | /* If it's a member function, just look at the function | |
260 | part of it. */ | |
261 | ||
262 | /* Determine address to call. */ | |
263 | if (ftype->code () == TYPE_CODE_FUNC | |
264 | || ftype->code () == TYPE_CODE_METHOD) | |
265 | funaddr = value_address (function); | |
266 | else if (ftype->code () == TYPE_CODE_PTR) | |
267 | { | |
268 | funaddr = value_as_address (function); | |
269 | ftype = check_typedef (TYPE_TARGET_TYPE (ftype)); | |
270 | if (ftype->code () == TYPE_CODE_FUNC | |
271 | || ftype->code () == TYPE_CODE_METHOD) | |
272 | funaddr = gdbarch_convert_from_func_ptr_addr | |
273 | (gdbarch, funaddr, current_inferior ()->top_target()); | |
274 | } | |
275 | if (ftype->code () == TYPE_CODE_FUNC | |
276 | || ftype->code () == TYPE_CODE_METHOD) | |
277 | { | |
278 | if (ftype->is_gnu_ifunc ()) | |
279 | { | |
280 | CORE_ADDR resolver_addr = funaddr; | |
281 | ||
282 | /* Resolve the ifunc. Note this may call the resolver | |
283 | function in the inferior. */ | |
284 | funaddr = gnu_ifunc_resolve_addr (gdbarch, resolver_addr); | |
285 | ||
286 | /* Skip querying the function symbol if no RETVAL_TYPE or | |
287 | FUNCTION_TYPE have been asked for. */ | |
288 | if (retval_type != NULL || function_type != NULL) | |
289 | { | |
290 | type *target_ftype = find_function_type (funaddr); | |
291 | /* If we don't have debug info for the target function, | |
292 | see if we can instead extract the target function's | |
293 | type from the type that the resolver returns. */ | |
294 | if (target_ftype == NULL) | |
295 | target_ftype = find_gnu_ifunc_target_type (resolver_addr); | |
296 | if (target_ftype != NULL) | |
297 | { | |
298 | value_type = TYPE_TARGET_TYPE (check_typedef (target_ftype)); | |
299 | ftype = target_ftype; | |
300 | } | |
301 | } | |
302 | } | |
303 | else | |
304 | value_type = TYPE_TARGET_TYPE (ftype); | |
305 | } | |
306 | else if (ftype->code () == TYPE_CODE_INT) | |
307 | { | |
308 | /* Handle the case of functions lacking debugging info. | |
309 | Their values are characters since their addresses are char. */ | |
310 | if (TYPE_LENGTH (ftype) == 1) | |
311 | funaddr = value_as_address (value_addr (function)); | |
312 | else | |
313 | { | |
314 | /* Handle function descriptors lacking debug info. */ | |
315 | int found_descriptor = 0; | |
316 | ||
317 | funaddr = 0; /* pacify "gcc -Werror" */ | |
318 | if (VALUE_LVAL (function) == lval_memory) | |
319 | { | |
320 | CORE_ADDR nfunaddr; | |
321 | ||
322 | funaddr = value_as_address (value_addr (function)); | |
323 | nfunaddr = funaddr; | |
324 | funaddr = gdbarch_convert_from_func_ptr_addr | |
325 | (gdbarch, funaddr, current_inferior ()->top_target ()); | |
326 | if (funaddr != nfunaddr) | |
327 | found_descriptor = 1; | |
328 | } | |
329 | if (!found_descriptor) | |
330 | /* Handle integer used as address of a function. */ | |
331 | funaddr = (CORE_ADDR) value_as_long (function); | |
332 | } | |
333 | } | |
334 | else | |
335 | error (_("Invalid data type for function to be called.")); | |
336 | ||
337 | if (retval_type != NULL) | |
338 | *retval_type = value_type; | |
339 | if (function_type != NULL) | |
340 | *function_type = ftype; | |
341 | return funaddr + gdbarch_deprecated_function_start_offset (gdbarch); | |
342 | } | |
343 | ||
344 | /* For CALL_DUMMY_ON_STACK, push a breakpoint sequence that the called | |
345 | function returns to. */ | |
346 | ||
347 | static CORE_ADDR | |
348 | push_dummy_code (struct gdbarch *gdbarch, | |
349 | CORE_ADDR sp, CORE_ADDR funaddr, | |
350 | gdb::array_view<value *> args, | |
351 | struct type *value_type, | |
352 | CORE_ADDR *real_pc, CORE_ADDR *bp_addr, | |
353 | struct regcache *regcache) | |
354 | { | |
355 | gdb_assert (gdbarch_push_dummy_code_p (gdbarch)); | |
356 | ||
357 | return gdbarch_push_dummy_code (gdbarch, sp, funaddr, | |
358 | args.data (), args.size (), | |
359 | value_type, real_pc, bp_addr, | |
360 | regcache); | |
361 | } | |
362 | ||
363 | /* See infcall.h. */ | |
364 | ||
365 | void | |
366 | error_call_unknown_return_type (const char *func_name) | |
367 | { | |
368 | if (func_name != NULL) | |
369 | error (_("'%s' has unknown return type; " | |
370 | "cast the call to its declared return type"), | |
371 | func_name); | |
372 | else | |
373 | error (_("function has unknown return type; " | |
374 | "cast the call to its declared return type")); | |
375 | } | |
376 | ||
377 | /* Fetch the name of the function at FUNADDR. | |
378 | This is used in printing an error message for call_function_by_hand. | |
379 | BUF is used to print FUNADDR in hex if the function name cannot be | |
380 | determined. It must be large enough to hold formatted result of | |
381 | RAW_FUNCTION_ADDRESS_FORMAT. */ | |
382 | ||
383 | static const char * | |
384 | get_function_name (CORE_ADDR funaddr, char *buf, int buf_size) | |
385 | { | |
386 | { | |
387 | struct symbol *symbol = find_pc_function (funaddr); | |
388 | ||
389 | if (symbol) | |
390 | return symbol->print_name (); | |
391 | } | |
392 | ||
393 | { | |
394 | /* Try the minimal symbols. */ | |
395 | struct bound_minimal_symbol msymbol = lookup_minimal_symbol_by_pc (funaddr); | |
396 | ||
397 | if (msymbol.minsym) | |
398 | return msymbol.minsym->print_name (); | |
399 | } | |
400 | ||
401 | { | |
402 | std::string tmp = string_printf (_(RAW_FUNCTION_ADDRESS_FORMAT), | |
403 | hex_string (funaddr)); | |
404 | ||
405 | gdb_assert (tmp.length () + 1 <= buf_size); | |
406 | return strcpy (buf, tmp.c_str ()); | |
407 | } | |
408 | } | |
409 | ||
410 | /* All the meta data necessary to extract the call's return value. */ | |
411 | ||
412 | struct call_return_meta_info | |
413 | { | |
414 | /* The caller frame's architecture. */ | |
415 | struct gdbarch *gdbarch; | |
416 | ||
417 | /* The called function. */ | |
418 | struct value *function; | |
419 | ||
420 | /* The return value's type. */ | |
421 | struct type *value_type; | |
422 | ||
423 | /* Are we returning a value using a structure return or a normal | |
424 | value return? */ | |
425 | int struct_return_p; | |
426 | ||
427 | /* If using a structure return, this is the structure's address. */ | |
428 | CORE_ADDR struct_addr; | |
429 | }; | |
430 | ||
431 | /* Extract the called function's return value. */ | |
432 | ||
433 | static struct value * | |
434 | get_call_return_value (struct call_return_meta_info *ri) | |
435 | { | |
436 | struct value *retval = NULL; | |
437 | thread_info *thr = inferior_thread (); | |
438 | bool stack_temporaries = thread_stack_temporaries_enabled_p (thr); | |
439 | ||
440 | if (ri->value_type->code () == TYPE_CODE_VOID) | |
441 | retval = allocate_value (ri->value_type); | |
442 | else if (ri->struct_return_p) | |
443 | { | |
444 | if (stack_temporaries) | |
445 | { | |
446 | retval = value_from_contents_and_address (ri->value_type, NULL, | |
447 | ri->struct_addr); | |
448 | push_thread_stack_temporary (thr, retval); | |
449 | } | |
450 | else | |
451 | { | |
452 | retval = allocate_value (ri->value_type); | |
453 | read_value_memory (retval, 0, 1, ri->struct_addr, | |
454 | value_contents_raw (retval).data (), | |
455 | TYPE_LENGTH (ri->value_type)); | |
456 | } | |
457 | } | |
458 | else | |
459 | { | |
460 | retval = allocate_value (ri->value_type); | |
461 | gdbarch_return_value (ri->gdbarch, ri->function, ri->value_type, | |
462 | get_current_regcache (), | |
463 | value_contents_raw (retval).data (), NULL); | |
464 | if (stack_temporaries && class_or_union_p (ri->value_type)) | |
465 | { | |
466 | /* Values of class type returned in registers are copied onto | |
467 | the stack and their lval_type set to lval_memory. This is | |
468 | required because further evaluation of the expression | |
469 | could potentially invoke methods on the return value | |
470 | requiring GDB to evaluate the "this" pointer. To evaluate | |
471 | the this pointer, GDB needs the memory address of the | |
472 | value. */ | |
473 | value_force_lval (retval, ri->struct_addr); | |
474 | push_thread_stack_temporary (thr, retval); | |
475 | } | |
476 | } | |
477 | ||
478 | gdb_assert (retval != NULL); | |
479 | return retval; | |
480 | } | |
481 | ||
482 | /* Data for the FSM that manages an infcall. It's main job is to | |
483 | record the called function's return value. */ | |
484 | ||
485 | struct call_thread_fsm : public thread_fsm | |
486 | { | |
487 | /* All the info necessary to be able to extract the return | |
488 | value. */ | |
489 | struct call_return_meta_info return_meta_info; | |
490 | ||
491 | /* The called function's return value. This is extracted from the | |
492 | target before the dummy frame is popped. */ | |
493 | struct value *return_value = nullptr; | |
494 | ||
495 | /* The top level that started the infcall (and is synchronously | |
496 | waiting for it to end). */ | |
497 | struct ui *waiting_ui; | |
498 | ||
499 | call_thread_fsm (struct ui *waiting_ui, struct interp *cmd_interp, | |
500 | struct gdbarch *gdbarch, struct value *function, | |
501 | struct type *value_type, | |
502 | int struct_return_p, CORE_ADDR struct_addr); | |
503 | ||
504 | bool should_stop (struct thread_info *thread) override; | |
505 | ||
506 | bool should_notify_stop () override; | |
507 | }; | |
508 | ||
509 | /* Allocate a new call_thread_fsm object. */ | |
510 | ||
511 | call_thread_fsm::call_thread_fsm (struct ui *waiting_ui, | |
512 | struct interp *cmd_interp, | |
513 | struct gdbarch *gdbarch, | |
514 | struct value *function, | |
515 | struct type *value_type, | |
516 | int struct_return_p, CORE_ADDR struct_addr) | |
517 | : thread_fsm (cmd_interp), | |
518 | waiting_ui (waiting_ui) | |
519 | { | |
520 | return_meta_info.gdbarch = gdbarch; | |
521 | return_meta_info.function = function; | |
522 | return_meta_info.value_type = value_type; | |
523 | return_meta_info.struct_return_p = struct_return_p; | |
524 | return_meta_info.struct_addr = struct_addr; | |
525 | } | |
526 | ||
527 | /* Implementation of should_stop method for infcalls. */ | |
528 | ||
529 | bool | |
530 | call_thread_fsm::should_stop (struct thread_info *thread) | |
531 | { | |
532 | if (stop_stack_dummy == STOP_STACK_DUMMY) | |
533 | { | |
534 | /* Done. */ | |
535 | set_finished (); | |
536 | ||
537 | /* Stash the return value before the dummy frame is popped and | |
538 | registers are restored to what they were before the | |
539 | call.. */ | |
540 | return_value = get_call_return_value (&return_meta_info); | |
541 | ||
542 | /* Break out of wait_sync_command_done. */ | |
543 | scoped_restore save_ui = make_scoped_restore (¤t_ui, waiting_ui); | |
544 | target_terminal::ours (); | |
545 | waiting_ui->prompt_state = PROMPT_NEEDED; | |
546 | } | |
547 | ||
548 | return true; | |
549 | } | |
550 | ||
551 | /* Implementation of should_notify_stop method for infcalls. */ | |
552 | ||
553 | bool | |
554 | call_thread_fsm::should_notify_stop () | |
555 | { | |
556 | if (finished_p ()) | |
557 | { | |
558 | /* Infcall succeeded. Be silent and proceed with evaluating the | |
559 | expression. */ | |
560 | return false; | |
561 | } | |
562 | ||
563 | /* Something wrong happened. E.g., an unexpected breakpoint | |
564 | triggered, or a signal was intercepted. Notify the stop. */ | |
565 | return true; | |
566 | } | |
567 | ||
568 | /* Subroutine of call_function_by_hand to simplify it. | |
569 | Start up the inferior and wait for it to stop. | |
570 | Return the exception if there's an error, or an exception with | |
571 | reason >= 0 if there's no error. | |
572 | ||
573 | This is done inside a TRY_CATCH so the caller needn't worry about | |
574 | thrown errors. The caller should rethrow if there's an error. */ | |
575 | ||
576 | static struct gdb_exception | |
577 | run_inferior_call (std::unique_ptr<call_thread_fsm> sm, | |
578 | struct thread_info *call_thread, CORE_ADDR real_pc) | |
579 | { | |
580 | struct gdb_exception caught_error; | |
581 | ptid_t call_thread_ptid = call_thread->ptid; | |
582 | int was_running = call_thread->state == THREAD_RUNNING; | |
583 | ||
584 | current_ui->unregister_file_handler (); | |
585 | ||
586 | scoped_restore restore_in_infcall | |
587 | = make_scoped_restore (&call_thread->control.in_infcall, 1); | |
588 | ||
589 | clear_proceed_status (0); | |
590 | ||
591 | /* Associate the FSM with the thread after clear_proceed_status | |
592 | (otherwise it'd clear this FSM). */ | |
593 | call_thread->set_thread_fsm (std::move (sm)); | |
594 | ||
595 | disable_watchpoints_before_interactive_call_start (); | |
596 | ||
597 | /* We want to print return value, please... */ | |
598 | call_thread->control.proceed_to_finish = 1; | |
599 | ||
600 | try | |
601 | { | |
602 | /* Infcalls run synchronously, in the foreground. */ | |
603 | scoped_restore restore_prompt_state | |
604 | = make_scoped_restore (¤t_ui->prompt_state, PROMPT_BLOCKED); | |
605 | ||
606 | /* So that we don't print the prompt prematurely in | |
607 | fetch_inferior_event. */ | |
608 | scoped_restore restore_ui_async | |
609 | = make_scoped_restore (¤t_ui->async, 0); | |
610 | ||
611 | proceed (real_pc, GDB_SIGNAL_0); | |
612 | ||
613 | /* Inferior function calls are always synchronous, even if the | |
614 | target supports asynchronous execution. */ | |
615 | wait_sync_command_done (); | |
616 | } | |
617 | catch (gdb_exception &e) | |
618 | { | |
619 | caught_error = std::move (e); | |
620 | } | |
621 | ||
622 | /* If GDB has the prompt blocked before, then ensure that it remains | |
623 | so. normal_stop calls async_enable_stdin, so reset the prompt | |
624 | state again here. In other cases, stdin will be re-enabled by | |
625 | inferior_event_handler, when an exception is thrown. */ | |
626 | if (current_ui->prompt_state == PROMPT_BLOCKED) | |
627 | current_ui->unregister_file_handler (); | |
628 | else | |
629 | current_ui->register_file_handler (); | |
630 | ||
631 | /* If the infcall does NOT succeed, normal_stop will have already | |
632 | finished the thread states. However, on success, normal_stop | |
633 | defers here, so that we can set back the thread states to what | |
634 | they were before the call. Note that we must also finish the | |
635 | state of new threads that might have spawned while the call was | |
636 | running. The main cases to handle are: | |
637 | ||
638 | - "(gdb) print foo ()", or any other command that evaluates an | |
639 | expression at the prompt. (The thread was marked stopped before.) | |
640 | ||
641 | - "(gdb) break foo if return_false()" or similar cases where we | |
642 | do an infcall while handling an event (while the thread is still | |
643 | marked running). In this example, whether the condition | |
644 | evaluates true and thus we'll present a user-visible stop is | |
645 | decided elsewhere. */ | |
646 | if (!was_running | |
647 | && call_thread_ptid == inferior_ptid | |
648 | && stop_stack_dummy == STOP_STACK_DUMMY) | |
649 | finish_thread_state (call_thread->inf->process_target (), | |
650 | user_visible_resume_ptid (0)); | |
651 | ||
652 | enable_watchpoints_after_interactive_call_stop (); | |
653 | ||
654 | /* Call breakpoint_auto_delete on the current contents of the bpstat | |
655 | of inferior call thread. | |
656 | If all error()s out of proceed ended up calling normal_stop | |
657 | (and perhaps they should; it already does in the special case | |
658 | of error out of resume()), then we wouldn't need this. */ | |
659 | if (caught_error.reason < 0) | |
660 | { | |
661 | if (call_thread->state != THREAD_EXITED) | |
662 | breakpoint_auto_delete (call_thread->control.stop_bpstat); | |
663 | } | |
664 | ||
665 | return caught_error; | |
666 | } | |
667 | ||
668 | /* Reserve space on the stack for a value of the given type. | |
669 | Return the address of the allocated space. | |
670 | Make certain that the value is correctly aligned. | |
671 | The SP argument is modified. */ | |
672 | ||
673 | static CORE_ADDR | |
674 | reserve_stack_space (const type *values_type, CORE_ADDR &sp) | |
675 | { | |
676 | struct frame_info *frame = get_current_frame (); | |
677 | struct gdbarch *gdbarch = get_frame_arch (frame); | |
678 | CORE_ADDR addr = 0; | |
679 | ||
680 | if (gdbarch_inner_than (gdbarch, 1, 2)) | |
681 | { | |
682 | /* Stack grows downward. Align STRUCT_ADDR and SP after | |
683 | making space. */ | |
684 | sp -= TYPE_LENGTH (values_type); | |
685 | if (gdbarch_frame_align_p (gdbarch)) | |
686 | sp = gdbarch_frame_align (gdbarch, sp); | |
687 | addr = sp; | |
688 | } | |
689 | else | |
690 | { | |
691 | /* Stack grows upward. Align the frame, allocate space, and | |
692 | then again, re-align the frame??? */ | |
693 | if (gdbarch_frame_align_p (gdbarch)) | |
694 | sp = gdbarch_frame_align (gdbarch, sp); | |
695 | addr = sp; | |
696 | sp += TYPE_LENGTH (values_type); | |
697 | if (gdbarch_frame_align_p (gdbarch)) | |
698 | sp = gdbarch_frame_align (gdbarch, sp); | |
699 | } | |
700 | ||
701 | return addr; | |
702 | } | |
703 | ||
704 | /* The data structure which keeps a destructor function and | |
705 | its implicit 'this' parameter. */ | |
706 | ||
707 | struct destructor_info | |
708 | { | |
709 | destructor_info (struct value *function, struct value *self) | |
710 | : function (function), self (self) { } | |
711 | ||
712 | struct value *function; | |
713 | struct value *self; | |
714 | }; | |
715 | ||
716 | ||
717 | /* Auxiliary function that takes a list of destructor functions | |
718 | with their 'this' parameters, and invokes the functions. */ | |
719 | ||
720 | static void | |
721 | call_destructors (const std::list<destructor_info> &dtors_to_invoke, | |
722 | struct type *default_return_type) | |
723 | { | |
724 | for (auto vals : dtors_to_invoke) | |
725 | { | |
726 | call_function_by_hand (vals.function, default_return_type, | |
727 | gdb::make_array_view (&(vals.self), 1)); | |
728 | } | |
729 | } | |
730 | ||
731 | /* See infcall.h. */ | |
732 | ||
733 | struct value * | |
734 | call_function_by_hand (struct value *function, | |
735 | type *default_return_type, | |
736 | gdb::array_view<value *> args) | |
737 | { | |
738 | return call_function_by_hand_dummy (function, default_return_type, | |
739 | args, NULL, NULL); | |
740 | } | |
741 | ||
742 | /* All this stuff with a dummy frame may seem unnecessarily complicated | |
743 | (why not just save registers in GDB?). The purpose of pushing a dummy | |
744 | frame which looks just like a real frame is so that if you call a | |
745 | function and then hit a breakpoint (get a signal, etc), "backtrace" | |
746 | will look right. Whether the backtrace needs to actually show the | |
747 | stack at the time the inferior function was called is debatable, but | |
748 | it certainly needs to not display garbage. So if you are contemplating | |
749 | making dummy frames be different from normal frames, consider that. */ | |
750 | ||
751 | /* Perform a function call in the inferior. | |
752 | ARGS is a vector of values of arguments. | |
753 | FUNCTION is a value, the function to be called. | |
754 | Returns a value representing what the function returned. | |
755 | May fail to return, if a breakpoint or signal is hit | |
756 | during the execution of the function. | |
757 | ||
758 | ARGS is modified to contain coerced values. */ | |
759 | ||
760 | struct value * | |
761 | call_function_by_hand_dummy (struct value *function, | |
762 | type *default_return_type, | |
763 | gdb::array_view<value *> args, | |
764 | dummy_frame_dtor_ftype *dummy_dtor, | |
765 | void *dummy_dtor_data) | |
766 | { | |
767 | CORE_ADDR sp; | |
768 | struct type *target_values_type; | |
769 | function_call_return_method return_method = return_method_normal; | |
770 | CORE_ADDR struct_addr = 0; | |
771 | CORE_ADDR real_pc; | |
772 | CORE_ADDR bp_addr; | |
773 | struct frame_id dummy_id; | |
774 | struct frame_info *frame; | |
775 | struct gdbarch *gdbarch; | |
776 | ptid_t call_thread_ptid; | |
777 | struct gdb_exception e; | |
778 | char name_buf[RAW_FUNCTION_ADDRESS_SIZE]; | |
779 | ||
780 | if (!may_call_functions_p) | |
781 | error (_("Cannot call functions in the program: " | |
782 | "may-call-functions is off.")); | |
783 | ||
784 | if (!target_has_execution ()) | |
785 | noprocess (); | |
786 | ||
787 | if (get_traceframe_number () >= 0) | |
788 | error (_("May not call functions while looking at trace frames.")); | |
789 | ||
790 | if (execution_direction == EXEC_REVERSE) | |
791 | error (_("Cannot call functions in reverse mode.")); | |
792 | ||
793 | /* We're going to run the target, and inspect the thread's state | |
794 | afterwards. Hold a strong reference so that the pointer remains | |
795 | valid even if the thread exits. */ | |
796 | thread_info_ref call_thread | |
797 | = thread_info_ref::new_reference (inferior_thread ()); | |
798 | ||
799 | bool stack_temporaries = thread_stack_temporaries_enabled_p (call_thread.get ()); | |
800 | ||
801 | frame = get_current_frame (); | |
802 | gdbarch = get_frame_arch (frame); | |
803 | ||
804 | if (!gdbarch_push_dummy_call_p (gdbarch)) | |
805 | error (_("This target does not support function calls.")); | |
806 | ||
807 | /* Find the function type and do a sanity check. */ | |
808 | type *ftype; | |
809 | type *values_type; | |
810 | CORE_ADDR funaddr = find_function_addr (function, &values_type, &ftype); | |
811 | ||
812 | if (is_nocall_function (ftype)) | |
813 | error (_("Cannot call the function '%s' which does not follow the " | |
814 | "target calling convention."), | |
815 | get_function_name (funaddr, name_buf, sizeof (name_buf))); | |
816 | ||
817 | if (values_type == NULL) | |
818 | values_type = default_return_type; | |
819 | if (values_type == NULL) | |
820 | { | |
821 | const char *name = get_function_name (funaddr, | |
822 | name_buf, sizeof (name_buf)); | |
823 | error (_("'%s' has unknown return type; " | |
824 | "cast the call to its declared return type"), | |
825 | name); | |
826 | } | |
827 | ||
828 | values_type = check_typedef (values_type); | |
829 | ||
830 | if (args.size () < ftype->num_fields ()) | |
831 | error (_("Too few arguments in function call.")); | |
832 | ||
833 | /* A holder for the inferior status. | |
834 | This is only needed while we're preparing the inferior function call. */ | |
835 | infcall_control_state_up inf_status (save_infcall_control_state ()); | |
836 | ||
837 | /* Save the caller's registers and other state associated with the | |
838 | inferior itself so that they can be restored once the | |
839 | callee returns. To allow nested calls the registers are (further | |
840 | down) pushed onto a dummy frame stack. This unique pointer | |
841 | is released once the regcache has been pushed). */ | |
842 | infcall_suspend_state_up caller_state (save_infcall_suspend_state ()); | |
843 | ||
844 | /* Ensure that the initial SP is correctly aligned. */ | |
845 | { | |
846 | CORE_ADDR old_sp = get_frame_sp (frame); | |
847 | ||
848 | if (gdbarch_frame_align_p (gdbarch)) | |
849 | { | |
850 | sp = gdbarch_frame_align (gdbarch, old_sp); | |
851 | /* NOTE: cagney/2003-08-13: Skip the "red zone". For some | |
852 | ABIs, a function can use memory beyond the inner most stack | |
853 | address. AMD64 called that region the "red zone". Skip at | |
854 | least the "red zone" size before allocating any space on | |
855 | the stack. */ | |
856 | if (gdbarch_inner_than (gdbarch, 1, 2)) | |
857 | sp -= gdbarch_frame_red_zone_size (gdbarch); | |
858 | else | |
859 | sp += gdbarch_frame_red_zone_size (gdbarch); | |
860 | /* Still aligned? */ | |
861 | gdb_assert (sp == gdbarch_frame_align (gdbarch, sp)); | |
862 | /* NOTE: cagney/2002-09-18: | |
863 | ||
864 | On a RISC architecture, a void parameterless generic dummy | |
865 | frame (i.e., no parameters, no result) typically does not | |
866 | need to push anything the stack and hence can leave SP and | |
867 | FP. Similarly, a frameless (possibly leaf) function does | |
868 | not push anything on the stack and, hence, that too can | |
869 | leave FP and SP unchanged. As a consequence, a sequence of | |
870 | void parameterless generic dummy frame calls to frameless | |
871 | functions will create a sequence of effectively identical | |
872 | frames (SP, FP and TOS and PC the same). This, not | |
873 | surprisingly, results in what appears to be a stack in an | |
874 | infinite loop --- when GDB tries to find a generic dummy | |
875 | frame on the internal dummy frame stack, it will always | |
876 | find the first one. | |
877 | ||
878 | To avoid this problem, the code below always grows the | |
879 | stack. That way, two dummy frames can never be identical. | |
880 | It does burn a few bytes of stack but that is a small price | |
881 | to pay :-). */ | |
882 | if (sp == old_sp) | |
883 | { | |
884 | if (gdbarch_inner_than (gdbarch, 1, 2)) | |
885 | /* Stack grows down. */ | |
886 | sp = gdbarch_frame_align (gdbarch, old_sp - 1); | |
887 | else | |
888 | /* Stack grows up. */ | |
889 | sp = gdbarch_frame_align (gdbarch, old_sp + 1); | |
890 | } | |
891 | /* SP may have underflown address zero here from OLD_SP. Memory access | |
892 | functions will probably fail in such case but that is a target's | |
893 | problem. */ | |
894 | } | |
895 | else | |
896 | /* FIXME: cagney/2002-09-18: Hey, you loose! | |
897 | ||
898 | Who knows how badly aligned the SP is! | |
899 | ||
900 | If the generic dummy frame ends up empty (because nothing is | |
901 | pushed) GDB won't be able to correctly perform back traces. | |
902 | If a target is having trouble with backtraces, first thing to | |
903 | do is add FRAME_ALIGN() to the architecture vector. If that | |
904 | fails, try dummy_id(). | |
905 | ||
906 | If the ABI specifies a "Red Zone" (see the doco) the code | |
907 | below will quietly trash it. */ | |
908 | sp = old_sp; | |
909 | ||
910 | /* Skip over the stack temporaries that might have been generated during | |
911 | the evaluation of an expression. */ | |
912 | if (stack_temporaries) | |
913 | { | |
914 | struct value *lastval; | |
915 | ||
916 | lastval = get_last_thread_stack_temporary (call_thread.get ()); | |
917 | if (lastval != NULL) | |
918 | { | |
919 | CORE_ADDR lastval_addr = value_address (lastval); | |
920 | ||
921 | if (gdbarch_inner_than (gdbarch, 1, 2)) | |
922 | { | |
923 | gdb_assert (sp >= lastval_addr); | |
924 | sp = lastval_addr; | |
925 | } | |
926 | else | |
927 | { | |
928 | gdb_assert (sp <= lastval_addr); | |
929 | sp = lastval_addr + TYPE_LENGTH (value_type (lastval)); | |
930 | } | |
931 | ||
932 | if (gdbarch_frame_align_p (gdbarch)) | |
933 | sp = gdbarch_frame_align (gdbarch, sp); | |
934 | } | |
935 | } | |
936 | } | |
937 | ||
938 | /* Are we returning a value using a structure return? */ | |
939 | ||
940 | if (gdbarch_return_in_first_hidden_param_p (gdbarch, values_type)) | |
941 | { | |
942 | return_method = return_method_hidden_param; | |
943 | ||
944 | /* Tell the target specific argument pushing routine not to | |
945 | expect a value. */ | |
946 | target_values_type = builtin_type (gdbarch)->builtin_void; | |
947 | } | |
948 | else | |
949 | { | |
950 | if (using_struct_return (gdbarch, function, values_type)) | |
951 | return_method = return_method_struct; | |
952 | target_values_type = values_type; | |
953 | } | |
954 | ||
955 | gdb::observers::inferior_call_pre.notify (inferior_ptid, funaddr); | |
956 | ||
957 | /* Determine the location of the breakpoint (and possibly other | |
958 | stuff) that the called function will return to. The SPARC, for a | |
959 | function returning a structure or union, needs to make space for | |
960 | not just the breakpoint but also an extra word containing the | |
961 | size (?) of the structure being passed. */ | |
962 | ||
963 | switch (gdbarch_call_dummy_location (gdbarch)) | |
964 | { | |
965 | case ON_STACK: | |
966 | { | |
967 | const gdb_byte *bp_bytes; | |
968 | CORE_ADDR bp_addr_as_address; | |
969 | int bp_size; | |
970 | ||
971 | /* Be careful BP_ADDR is in inferior PC encoding while | |
972 | BP_ADDR_AS_ADDRESS is a plain memory address. */ | |
973 | ||
974 | sp = push_dummy_code (gdbarch, sp, funaddr, args, | |
975 | target_values_type, &real_pc, &bp_addr, | |
976 | get_current_regcache ()); | |
977 | ||
978 | /* Write a legitimate instruction at the point where the infcall | |
979 | breakpoint is going to be inserted. While this instruction | |
980 | is never going to be executed, a user investigating the | |
981 | memory from GDB would see this instruction instead of random | |
982 | uninitialized bytes. We chose the breakpoint instruction | |
983 | as it may look as the most logical one to the user and also | |
984 | valgrind 3.7.0 needs it for proper vgdb inferior calls. | |
985 | ||
986 | If software breakpoints are unsupported for this target we | |
987 | leave the user visible memory content uninitialized. */ | |
988 | ||
989 | bp_addr_as_address = bp_addr; | |
990 | bp_bytes = gdbarch_breakpoint_from_pc (gdbarch, &bp_addr_as_address, | |
991 | &bp_size); | |
992 | if (bp_bytes != NULL) | |
993 | write_memory (bp_addr_as_address, bp_bytes, bp_size); | |
994 | } | |
995 | break; | |
996 | case AT_ENTRY_POINT: | |
997 | { | |
998 | CORE_ADDR dummy_addr; | |
999 | ||
1000 | real_pc = funaddr; | |
1001 | dummy_addr = entry_point_address (); | |
1002 | ||
1003 | /* A call dummy always consists of just a single breakpoint, so | |
1004 | its address is the same as the address of the dummy. | |
1005 | ||
1006 | The actual breakpoint is inserted separatly so there is no need to | |
1007 | write that out. */ | |
1008 | bp_addr = dummy_addr; | |
1009 | break; | |
1010 | } | |
1011 | default: | |
1012 | internal_error (__FILE__, __LINE__, _("bad switch")); | |
1013 | } | |
1014 | ||
1015 | /* Coerce the arguments and handle pass-by-reference. | |
1016 | We want to remember the destruction required for pass-by-ref values. | |
1017 | For these, store the dtor function and the 'this' argument | |
1018 | in DTORS_TO_INVOKE. */ | |
1019 | std::list<destructor_info> dtors_to_invoke; | |
1020 | ||
1021 | for (int i = args.size () - 1; i >= 0; i--) | |
1022 | { | |
1023 | int prototyped; | |
1024 | struct type *param_type; | |
1025 | ||
1026 | /* FIXME drow/2002-05-31: Should just always mark methods as | |
1027 | prototyped. Can we respect TYPE_VARARGS? Probably not. */ | |
1028 | if (ftype->code () == TYPE_CODE_METHOD) | |
1029 | prototyped = 1; | |
1030 | else if (TYPE_TARGET_TYPE (ftype) == NULL && ftype->num_fields () == 0 | |
1031 | && default_return_type != NULL) | |
1032 | { | |
1033 | /* Calling a no-debug function with the return type | |
1034 | explicitly cast. Assume the function is prototyped, | |
1035 | with a prototype matching the types of the arguments. | |
1036 | E.g., with: | |
1037 | float mult (float v1, float v2) { return v1 * v2; } | |
1038 | This: | |
1039 | (gdb) p (float) mult (2.0f, 3.0f) | |
1040 | Is a simpler alternative to: | |
1041 | (gdb) p ((float (*) (float, float)) mult) (2.0f, 3.0f) | |
1042 | */ | |
1043 | prototyped = 1; | |
1044 | } | |
1045 | else if (i < ftype->num_fields ()) | |
1046 | prototyped = ftype->is_prototyped (); | |
1047 | else | |
1048 | prototyped = 0; | |
1049 | ||
1050 | if (i < ftype->num_fields ()) | |
1051 | param_type = ftype->field (i).type (); | |
1052 | else | |
1053 | param_type = NULL; | |
1054 | ||
1055 | value *original_arg = args[i]; | |
1056 | args[i] = value_arg_coerce (gdbarch, args[i], | |
1057 | param_type, prototyped); | |
1058 | ||
1059 | if (param_type == NULL) | |
1060 | continue; | |
1061 | ||
1062 | auto info = language_pass_by_reference (param_type); | |
1063 | if (!info.copy_constructible) | |
1064 | error (_("expression cannot be evaluated because the type '%s' " | |
1065 | "is not copy constructible"), param_type->name ()); | |
1066 | ||
1067 | if (!info.destructible) | |
1068 | error (_("expression cannot be evaluated because the type '%s' " | |
1069 | "is not destructible"), param_type->name ()); | |
1070 | ||
1071 | if (info.trivially_copyable) | |
1072 | continue; | |
1073 | ||
1074 | /* Make a copy of the argument on the stack. If the argument is | |
1075 | trivially copy ctor'able, copy bit by bit. Otherwise, call | |
1076 | the copy ctor to initialize the clone. */ | |
1077 | CORE_ADDR addr = reserve_stack_space (param_type, sp); | |
1078 | value *clone | |
1079 | = value_from_contents_and_address (param_type, nullptr, addr); | |
1080 | push_thread_stack_temporary (call_thread.get (), clone); | |
1081 | value *clone_ptr | |
1082 | = value_from_pointer (lookup_pointer_type (param_type), addr); | |
1083 | ||
1084 | if (info.trivially_copy_constructible) | |
1085 | { | |
1086 | int length = TYPE_LENGTH (param_type); | |
1087 | write_memory (addr, value_contents (args[i]).data (), length); | |
1088 | } | |
1089 | else | |
1090 | { | |
1091 | value *copy_ctor; | |
1092 | value *cctor_args[2] = { clone_ptr, original_arg }; | |
1093 | find_overload_match (gdb::make_array_view (cctor_args, 2), | |
1094 | param_type->name (), METHOD, | |
1095 | &clone_ptr, nullptr, ©_ctor, nullptr, | |
1096 | nullptr, 0, EVAL_NORMAL); | |
1097 | ||
1098 | if (copy_ctor == nullptr) | |
1099 | error (_("expression cannot be evaluated because a copy " | |
1100 | "constructor for the type '%s' could not be found " | |
1101 | "(maybe inlined?)"), param_type->name ()); | |
1102 | ||
1103 | call_function_by_hand (copy_ctor, default_return_type, | |
1104 | gdb::make_array_view (cctor_args, 2)); | |
1105 | } | |
1106 | ||
1107 | /* If the argument has a destructor, remember it so that we | |
1108 | invoke it after the infcall is complete. */ | |
1109 | if (!info.trivially_destructible) | |
1110 | { | |
1111 | /* Looking up the function via overload resolution does not | |
1112 | work because the compiler (in particular, gcc) adds an | |
1113 | artificial int parameter in some cases. So we look up | |
1114 | the function by using the "~" name. This should be OK | |
1115 | because there can be only one dtor definition. */ | |
1116 | const char *dtor_name = nullptr; | |
1117 | for (int fieldnum = 0; | |
1118 | fieldnum < TYPE_NFN_FIELDS (param_type); | |
1119 | fieldnum++) | |
1120 | { | |
1121 | fn_field *fn | |
1122 | = TYPE_FN_FIELDLIST1 (param_type, fieldnum); | |
1123 | const char *field_name | |
1124 | = TYPE_FN_FIELDLIST_NAME (param_type, fieldnum); | |
1125 | ||
1126 | if (field_name[0] == '~') | |
1127 | dtor_name = TYPE_FN_FIELD_PHYSNAME (fn, 0); | |
1128 | } | |
1129 | ||
1130 | if (dtor_name == nullptr) | |
1131 | error (_("expression cannot be evaluated because a destructor " | |
1132 | "for the type '%s' could not be found " | |
1133 | "(maybe inlined?)"), param_type->name ()); | |
1134 | ||
1135 | value *dtor | |
1136 | = find_function_in_inferior (dtor_name, 0); | |
1137 | ||
1138 | /* Insert the dtor to the front of the list to call them | |
1139 | in reverse order later. */ | |
1140 | dtors_to_invoke.emplace_front (dtor, clone_ptr); | |
1141 | } | |
1142 | ||
1143 | args[i] = clone_ptr; | |
1144 | } | |
1145 | ||
1146 | /* Reserve space for the return structure to be written on the | |
1147 | stack, if necessary. | |
1148 | ||
1149 | While evaluating expressions, we reserve space on the stack for | |
1150 | return values of class type even if the language ABI and the target | |
1151 | ABI do not require that the return value be passed as a hidden first | |
1152 | argument. This is because we want to store the return value as an | |
1153 | on-stack temporary while the expression is being evaluated. This | |
1154 | enables us to have chained function calls in expressions. | |
1155 | ||
1156 | Keeping the return values as on-stack temporaries while the expression | |
1157 | is being evaluated is OK because the thread is stopped until the | |
1158 | expression is completely evaluated. */ | |
1159 | ||
1160 | if (return_method != return_method_normal | |
1161 | || (stack_temporaries && class_or_union_p (values_type))) | |
1162 | struct_addr = reserve_stack_space (values_type, sp); | |
1163 | ||
1164 | std::vector<struct value *> new_args; | |
1165 | if (return_method == return_method_hidden_param) | |
1166 | { | |
1167 | /* Add the new argument to the front of the argument list. */ | |
1168 | new_args.reserve (args.size ()); | |
1169 | new_args.push_back | |
1170 | (value_from_pointer (lookup_pointer_type (values_type), struct_addr)); | |
1171 | new_args.insert (new_args.end (), args.begin (), args.end ()); | |
1172 | args = new_args; | |
1173 | } | |
1174 | ||
1175 | /* Create the dummy stack frame. Pass in the call dummy address as, | |
1176 | presumably, the ABI code knows where, in the call dummy, the | |
1177 | return address should be pointed. */ | |
1178 | sp = gdbarch_push_dummy_call (gdbarch, function, get_current_regcache (), | |
1179 | bp_addr, args.size (), args.data (), | |
1180 | sp, return_method, struct_addr); | |
1181 | ||
1182 | /* Set up a frame ID for the dummy frame so we can pass it to | |
1183 | set_momentary_breakpoint. We need to give the breakpoint a frame | |
1184 | ID so that the breakpoint code can correctly re-identify the | |
1185 | dummy breakpoint. */ | |
1186 | /* Sanity. The exact same SP value is returned by PUSH_DUMMY_CALL, | |
1187 | saved as the dummy-frame TOS, and used by dummy_id to form | |
1188 | the frame ID's stack address. */ | |
1189 | dummy_id = frame_id_build (sp, bp_addr); | |
1190 | ||
1191 | /* Create a momentary breakpoint at the return address of the | |
1192 | inferior. That way it breaks when it returns. */ | |
1193 | ||
1194 | { | |
1195 | symtab_and_line sal; | |
1196 | sal.pspace = current_program_space; | |
1197 | sal.pc = bp_addr; | |
1198 | sal.section = find_pc_overlay (sal.pc); | |
1199 | ||
1200 | /* Sanity. The exact same SP value is returned by | |
1201 | PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by | |
1202 | dummy_id to form the frame ID's stack address. */ | |
1203 | breakpoint *bpt | |
1204 | = set_momentary_breakpoint (gdbarch, sal, | |
1205 | dummy_id, bp_call_dummy).release (); | |
1206 | ||
1207 | /* set_momentary_breakpoint invalidates FRAME. */ | |
1208 | frame = NULL; | |
1209 | ||
1210 | bpt->disposition = disp_del; | |
1211 | gdb_assert (bpt->related_breakpoint == bpt); | |
1212 | ||
1213 | breakpoint *longjmp_b = set_longjmp_breakpoint_for_call_dummy (); | |
1214 | if (longjmp_b) | |
1215 | { | |
1216 | /* Link BPT into the chain of LONGJMP_B. */ | |
1217 | bpt->related_breakpoint = longjmp_b; | |
1218 | while (longjmp_b->related_breakpoint != bpt->related_breakpoint) | |
1219 | longjmp_b = longjmp_b->related_breakpoint; | |
1220 | longjmp_b->related_breakpoint = bpt; | |
1221 | } | |
1222 | } | |
1223 | ||
1224 | /* Create a breakpoint in std::terminate. | |
1225 | If a C++ exception is raised in the dummy-frame, and the | |
1226 | exception handler is (normally, and expected to be) out-of-frame, | |
1227 | the default C++ handler will (wrongly) be called in an inferior | |
1228 | function call. This is wrong, as an exception can be normally | |
1229 | and legally handled out-of-frame. The confines of the dummy frame | |
1230 | prevent the unwinder from finding the correct handler (or any | |
1231 | handler, unless it is in-frame). The default handler calls | |
1232 | std::terminate. This will kill the inferior. Assert that | |
1233 | terminate should never be called in an inferior function | |
1234 | call. Place a momentary breakpoint in the std::terminate function | |
1235 | and if triggered in the call, rewind. */ | |
1236 | if (unwind_on_terminating_exception_p) | |
1237 | set_std_terminate_breakpoint (); | |
1238 | ||
1239 | /* Everything's ready, push all the info needed to restore the | |
1240 | caller (and identify the dummy-frame) onto the dummy-frame | |
1241 | stack. */ | |
1242 | dummy_frame_push (caller_state.release (), &dummy_id, call_thread.get ()); | |
1243 | if (dummy_dtor != NULL) | |
1244 | register_dummy_frame_dtor (dummy_id, call_thread.get (), | |
1245 | dummy_dtor, dummy_dtor_data); | |
1246 | ||
1247 | /* Register a clean-up for unwind_on_terminating_exception_breakpoint. */ | |
1248 | SCOPE_EXIT { delete_std_terminate_breakpoint (); }; | |
1249 | ||
1250 | /* - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - | |
1251 | If you're looking to implement asynchronous dummy-frames, then | |
1252 | just below is the place to chop this function in two.. */ | |
1253 | ||
1254 | { | |
1255 | /* Save the current FSM. We'll override it. */ | |
1256 | std::unique_ptr<thread_fsm> saved_sm = call_thread->release_thread_fsm (); | |
1257 | struct call_thread_fsm *sm; | |
1258 | ||
1259 | /* Save this thread's ptid, we need it later but the thread | |
1260 | may have exited. */ | |
1261 | call_thread_ptid = call_thread->ptid; | |
1262 | ||
1263 | /* Run the inferior until it stops. */ | |
1264 | ||
1265 | /* Create the FSM used to manage the infcall. It tells infrun to | |
1266 | not report the stop to the user, and captures the return value | |
1267 | before the dummy frame is popped. run_inferior_call registers | |
1268 | it with the thread ASAP. */ | |
1269 | sm = new call_thread_fsm (current_ui, command_interp (), | |
1270 | gdbarch, function, | |
1271 | values_type, | |
1272 | return_method != return_method_normal, | |
1273 | struct_addr); | |
1274 | { | |
1275 | std::unique_ptr<call_thread_fsm> sm_up (sm); | |
1276 | e = run_inferior_call (std::move (sm_up), call_thread.get (), real_pc); | |
1277 | } | |
1278 | ||
1279 | gdb::observers::inferior_call_post.notify (call_thread_ptid, funaddr); | |
1280 | ||
1281 | if (call_thread->state != THREAD_EXITED) | |
1282 | { | |
1283 | /* The FSM should still be the same. */ | |
1284 | gdb_assert (call_thread->thread_fsm () == sm); | |
1285 | ||
1286 | if (call_thread->thread_fsm ()->finished_p ()) | |
1287 | { | |
1288 | struct value *retval; | |
1289 | ||
1290 | /* The inferior call is successful. Pop the dummy frame, | |
1291 | which runs its destructors and restores the inferior's | |
1292 | suspend state, and restore the inferior control | |
1293 | state. */ | |
1294 | dummy_frame_pop (dummy_id, call_thread.get ()); | |
1295 | restore_infcall_control_state (inf_status.release ()); | |
1296 | ||
1297 | /* Get the return value. */ | |
1298 | retval = sm->return_value; | |
1299 | ||
1300 | /* Restore the original FSM and clean up / destroh the call FSM. | |
1301 | Doing it in this order ensures that if the call to clean_up | |
1302 | throws, the original FSM is properly restored. */ | |
1303 | { | |
1304 | std::unique_ptr<thread_fsm> finalizing | |
1305 | = call_thread->release_thread_fsm (); | |
1306 | call_thread->set_thread_fsm (std::move (saved_sm)); | |
1307 | ||
1308 | finalizing->clean_up (call_thread.get ()); | |
1309 | } | |
1310 | ||
1311 | maybe_remove_breakpoints (); | |
1312 | ||
1313 | gdb_assert (retval != NULL); | |
1314 | ||
1315 | /* Destruct the pass-by-ref argument clones. */ | |
1316 | call_destructors (dtors_to_invoke, default_return_type); | |
1317 | ||
1318 | return retval; | |
1319 | } | |
1320 | ||
1321 | /* Didn't complete. Clean up / destroy the call FSM, and restore the | |
1322 | previous state machine, and handle the error. */ | |
1323 | { | |
1324 | std::unique_ptr<thread_fsm> finalizing | |
1325 | = call_thread->release_thread_fsm (); | |
1326 | call_thread->set_thread_fsm (std::move (saved_sm)); | |
1327 | ||
1328 | finalizing->clean_up (call_thread.get ()); | |
1329 | } | |
1330 | } | |
1331 | } | |
1332 | ||
1333 | /* Rethrow an error if we got one trying to run the inferior. */ | |
1334 | ||
1335 | if (e.reason < 0) | |
1336 | { | |
1337 | const char *name = get_function_name (funaddr, | |
1338 | name_buf, sizeof (name_buf)); | |
1339 | ||
1340 | discard_infcall_control_state (inf_status.release ()); | |
1341 | ||
1342 | /* We could discard the dummy frame here if the program exited, | |
1343 | but it will get garbage collected the next time the program is | |
1344 | run anyway. */ | |
1345 | ||
1346 | switch (e.reason) | |
1347 | { | |
1348 | case RETURN_ERROR: | |
1349 | throw_error (e.error, _("%s\n\ | |
1350 | An error occurred while in a function called from GDB.\n\ | |
1351 | Evaluation of the expression containing the function\n\ | |
1352 | (%s) will be abandoned.\n\ | |
1353 | When the function is done executing, GDB will silently stop."), | |
1354 | e.what (), name); | |
1355 | case RETURN_QUIT: | |
1356 | default: | |
1357 | throw_exception (std::move (e)); | |
1358 | } | |
1359 | } | |
1360 | ||
1361 | /* If the program has exited, or we stopped at a different thread, | |
1362 | exit and inform the user. */ | |
1363 | ||
1364 | if (! target_has_execution ()) | |
1365 | { | |
1366 | const char *name = get_function_name (funaddr, | |
1367 | name_buf, sizeof (name_buf)); | |
1368 | ||
1369 | /* If we try to restore the inferior status, | |
1370 | we'll crash as the inferior is no longer running. */ | |
1371 | discard_infcall_control_state (inf_status.release ()); | |
1372 | ||
1373 | /* We could discard the dummy frame here given that the program exited, | |
1374 | but it will get garbage collected the next time the program is | |
1375 | run anyway. */ | |
1376 | ||
1377 | error (_("The program being debugged exited while in a function " | |
1378 | "called from GDB.\n" | |
1379 | "Evaluation of the expression containing the function\n" | |
1380 | "(%s) will be abandoned."), | |
1381 | name); | |
1382 | } | |
1383 | ||
1384 | if (call_thread_ptid != inferior_ptid) | |
1385 | { | |
1386 | const char *name = get_function_name (funaddr, | |
1387 | name_buf, sizeof (name_buf)); | |
1388 | ||
1389 | /* We've switched threads. This can happen if another thread gets a | |
1390 | signal or breakpoint while our thread was running. | |
1391 | There's no point in restoring the inferior status, | |
1392 | we're in a different thread. */ | |
1393 | discard_infcall_control_state (inf_status.release ()); | |
1394 | /* Keep the dummy frame record, if the user switches back to the | |
1395 | thread with the hand-call, we'll need it. */ | |
1396 | if (stopped_by_random_signal) | |
1397 | error (_("\ | |
1398 | The program received a signal in another thread while\n\ | |
1399 | making a function call from GDB.\n\ | |
1400 | Evaluation of the expression containing the function\n\ | |
1401 | (%s) will be abandoned.\n\ | |
1402 | When the function is done executing, GDB will silently stop."), | |
1403 | name); | |
1404 | else | |
1405 | error (_("\ | |
1406 | The program stopped in another thread while making a function call from GDB.\n\ | |
1407 | Evaluation of the expression containing the function\n\ | |
1408 | (%s) will be abandoned.\n\ | |
1409 | When the function is done executing, GDB will silently stop."), | |
1410 | name); | |
1411 | } | |
1412 | ||
1413 | { | |
1414 | /* Make a copy as NAME may be in an objfile freed by dummy_frame_pop. */ | |
1415 | std::string name = get_function_name (funaddr, name_buf, | |
1416 | sizeof (name_buf)); | |
1417 | ||
1418 | if (stopped_by_random_signal) | |
1419 | { | |
1420 | /* We stopped inside the FUNCTION because of a random | |
1421 | signal. Further execution of the FUNCTION is not | |
1422 | allowed. */ | |
1423 | ||
1424 | if (unwind_on_signal_p) | |
1425 | { | |
1426 | /* The user wants the context restored. */ | |
1427 | ||
1428 | /* We must get back to the frame we were before the | |
1429 | dummy call. */ | |
1430 | dummy_frame_pop (dummy_id, call_thread.get ()); | |
1431 | ||
1432 | /* We also need to restore inferior status to that before the | |
1433 | dummy call. */ | |
1434 | restore_infcall_control_state (inf_status.release ()); | |
1435 | ||
1436 | /* FIXME: Insert a bunch of wrap_here; name can be very | |
1437 | long if it's a C++ name with arguments and stuff. */ | |
1438 | error (_("\ | |
1439 | The program being debugged was signaled while in a function called from GDB.\n\ | |
1440 | GDB has restored the context to what it was before the call.\n\ | |
1441 | To change this behavior use \"set unwindonsignal off\".\n\ | |
1442 | Evaluation of the expression containing the function\n\ | |
1443 | (%s) will be abandoned."), | |
1444 | name.c_str ()); | |
1445 | } | |
1446 | else | |
1447 | { | |
1448 | /* The user wants to stay in the frame where we stopped | |
1449 | (default). | |
1450 | Discard inferior status, we're not at the same point | |
1451 | we started at. */ | |
1452 | discard_infcall_control_state (inf_status.release ()); | |
1453 | ||
1454 | /* FIXME: Insert a bunch of wrap_here; name can be very | |
1455 | long if it's a C++ name with arguments and stuff. */ | |
1456 | error (_("\ | |
1457 | The program being debugged was signaled while in a function called from GDB.\n\ | |
1458 | GDB remains in the frame where the signal was received.\n\ | |
1459 | To change this behavior use \"set unwindonsignal on\".\n\ | |
1460 | Evaluation of the expression containing the function\n\ | |
1461 | (%s) will be abandoned.\n\ | |
1462 | When the function is done executing, GDB will silently stop."), | |
1463 | name.c_str ()); | |
1464 | } | |
1465 | } | |
1466 | ||
1467 | if (stop_stack_dummy == STOP_STD_TERMINATE) | |
1468 | { | |
1469 | /* We must get back to the frame we were before the dummy | |
1470 | call. */ | |
1471 | dummy_frame_pop (dummy_id, call_thread.get ()); | |
1472 | ||
1473 | /* We also need to restore inferior status to that before | |
1474 | the dummy call. */ | |
1475 | restore_infcall_control_state (inf_status.release ()); | |
1476 | ||
1477 | error (_("\ | |
1478 | The program being debugged entered a std::terminate call, most likely\n\ | |
1479 | caused by an unhandled C++ exception. GDB blocked this call in order\n\ | |
1480 | to prevent the program from being terminated, and has restored the\n\ | |
1481 | context to its original state before the call.\n\ | |
1482 | To change this behaviour use \"set unwind-on-terminating-exception off\".\n\ | |
1483 | Evaluation of the expression containing the function (%s)\n\ | |
1484 | will be abandoned."), | |
1485 | name.c_str ()); | |
1486 | } | |
1487 | else if (stop_stack_dummy == STOP_NONE) | |
1488 | { | |
1489 | ||
1490 | /* We hit a breakpoint inside the FUNCTION. | |
1491 | Keep the dummy frame, the user may want to examine its state. | |
1492 | Discard inferior status, we're not at the same point | |
1493 | we started at. */ | |
1494 | discard_infcall_control_state (inf_status.release ()); | |
1495 | ||
1496 | /* The following error message used to say "The expression | |
1497 | which contained the function call has been discarded." | |
1498 | It is a hard concept to explain in a few words. Ideally, | |
1499 | GDB would be able to resume evaluation of the expression | |
1500 | when the function finally is done executing. Perhaps | |
1501 | someday this will be implemented (it would not be easy). */ | |
1502 | /* FIXME: Insert a bunch of wrap_here; name can be very long if it's | |
1503 | a C++ name with arguments and stuff. */ | |
1504 | error (_("\ | |
1505 | The program being debugged stopped while in a function called from GDB.\n\ | |
1506 | Evaluation of the expression containing the function\n\ | |
1507 | (%s) will be abandoned.\n\ | |
1508 | When the function is done executing, GDB will silently stop."), | |
1509 | name.c_str ()); | |
1510 | } | |
1511 | ||
1512 | } | |
1513 | ||
1514 | /* The above code errors out, so ... */ | |
1515 | gdb_assert_not_reached ("... should not be here"); | |
1516 | } | |
1517 | ||
1518 | void _initialize_infcall (); | |
1519 | void | |
1520 | _initialize_infcall () | |
1521 | { | |
1522 | add_setshow_boolean_cmd ("may-call-functions", no_class, | |
1523 | &may_call_functions_p, _("\ | |
1524 | Set permission to call functions in the program."), _("\ | |
1525 | Show permission to call functions in the program."), _("\ | |
1526 | When this permission is on, GDB may call functions in the program.\n\ | |
1527 | Otherwise, any sort of attempt to call a function in the program\n\ | |
1528 | will result in an error."), | |
1529 | NULL, | |
1530 | show_may_call_functions_p, | |
1531 | &setlist, &showlist); | |
1532 | ||
1533 | add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure, | |
1534 | &coerce_float_to_double_p, _("\ | |
1535 | Set coercion of floats to doubles when calling functions."), _("\ | |
1536 | Show coercion of floats to doubles when calling functions."), _("\ | |
1537 | Variables of type float should generally be converted to doubles before\n\ | |
1538 | calling an unprototyped function, and left alone when calling a prototyped\n\ | |
1539 | function. However, some older debug info formats do not provide enough\n\ | |
1540 | information to determine that a function is prototyped. If this flag is\n\ | |
1541 | set, GDB will perform the conversion for a function it considers\n\ | |
1542 | unprototyped.\n\ | |
1543 | The default is to perform the conversion."), | |
1544 | NULL, | |
1545 | show_coerce_float_to_double_p, | |
1546 | &setlist, &showlist); | |
1547 | ||
1548 | add_setshow_boolean_cmd ("unwindonsignal", no_class, | |
1549 | &unwind_on_signal_p, _("\ | |
1550 | Set unwinding of stack if a signal is received while in a call dummy."), _("\ | |
1551 | Show unwinding of stack if a signal is received while in a call dummy."), _("\ | |
1552 | The unwindonsignal lets the user determine what gdb should do if a signal\n\ | |
1553 | is received while in a function called from gdb (call dummy). If set, gdb\n\ | |
1554 | unwinds the stack and restore the context to what as it was before the call.\n\ | |
1555 | The default is to stop in the frame where the signal was received."), | |
1556 | NULL, | |
1557 | show_unwind_on_signal_p, | |
1558 | &setlist, &showlist); | |
1559 | ||
1560 | add_setshow_boolean_cmd ("unwind-on-terminating-exception", no_class, | |
1561 | &unwind_on_terminating_exception_p, _("\ | |
1562 | Set unwinding of stack if std::terminate is called while in call dummy."), _("\ | |
1563 | Show unwinding of stack if std::terminate() is called while in a call dummy."), | |
1564 | _("\ | |
1565 | The unwind on terminating exception flag lets the user determine\n\ | |
1566 | what gdb should do if a std::terminate() call is made from the\n\ | |
1567 | default exception handler. If set, gdb unwinds the stack and restores\n\ | |
1568 | the context to what it was before the call. If unset, gdb allows the\n\ | |
1569 | std::terminate call to proceed.\n\ | |
1570 | The default is to unwind the frame."), | |
1571 | NULL, | |
1572 | show_unwind_on_terminating_exception_p, | |
1573 | &setlist, &showlist); | |
1574 | ||
1575 | } |