gdb/amd-dbgapi-target: Use inf param in detach
[binutils-gdb.git] / gdb / infcall.c
1 /* Perform an inferior function call, for GDB, the GNU debugger.
2
3 Copyright (C) 1986-2023 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 "ui.h"
42 #include "interps.h"
43 #include "thread-fsm.h"
44 #include <algorithm>
45 #include "gdbsupport/scope-exit.h"
46 #include <list>
47
48 /* True if we are debugging inferior calls. */
49
50 static bool debug_infcall = false;
51
52 /* Print an "infcall" debug statement. */
53
54 #define infcall_debug_printf(fmt, ...) \
55 debug_prefixed_printf_cond (debug_infcall, "infcall", fmt, ##__VA_ARGS__)
56
57 /* Print "infcall" enter/exit debug statements. */
58
59 #define INFCALL_SCOPED_DEBUG_ENTER_EXIT \
60 scoped_debug_enter_exit (debug_infcall, "infcall")
61
62 /* Print "infcall" start/end debug statements. */
63
64 #define INFCALL_SCOPED_DEBUG_START_END(fmt, ...) \
65 scoped_debug_start_end (debug_infrun, "infcall", fmt, ##__VA_ARGS__)
66
67 /* Implement 'show debug infcall'. */
68
69 static void
70 show_debug_infcall (struct ui_file *file, int from_tty,
71 struct cmd_list_element *c, const char *value)
72 {
73 gdb_printf (file, _("Inferior call debugging is %s.\n"), value);
74 }
75
76 /* If we can't find a function's name from its address,
77 we print this instead. */
78 #define RAW_FUNCTION_ADDRESS_FORMAT "at 0x%s"
79 #define RAW_FUNCTION_ADDRESS_SIZE (sizeof (RAW_FUNCTION_ADDRESS_FORMAT) \
80 + 2 * sizeof (CORE_ADDR))
81
82 /* NOTE: cagney/2003-04-16: What's the future of this code?
83
84 GDB needs an asynchronous expression evaluator, that means an
85 asynchronous inferior function call implementation, and that in
86 turn means restructuring the code so that it is event driven. */
87
88 static bool may_call_functions_p = true;
89 static void
90 show_may_call_functions_p (struct ui_file *file, int from_tty,
91 struct cmd_list_element *c,
92 const char *value)
93 {
94 gdb_printf (file,
95 _("Permission to call functions in the program is %s.\n"),
96 value);
97 }
98
99 /* How you should pass arguments to a function depends on whether it
100 was defined in K&R style or prototype style. If you define a
101 function using the K&R syntax that takes a `float' argument, then
102 callers must pass that argument as a `double'. If you define the
103 function using the prototype syntax, then you must pass the
104 argument as a `float', with no promotion.
105
106 Unfortunately, on certain older platforms, the debug info doesn't
107 indicate reliably how each function was defined. A function type's
108 TYPE_PROTOTYPED flag may be clear, even if the function was defined
109 in prototype style. When calling a function whose TYPE_PROTOTYPED
110 flag is clear, GDB consults this flag to decide what to do.
111
112 For modern targets, it is proper to assume that, if the prototype
113 flag is clear, that can be trusted: `float' arguments should be
114 promoted to `double'. For some older targets, if the prototype
115 flag is clear, that doesn't tell us anything. The default is to
116 trust the debug information; the user can override this behavior
117 with "set coerce-float-to-double 0". */
118
119 static bool coerce_float_to_double_p = true;
120 static void
121 show_coerce_float_to_double_p (struct ui_file *file, int from_tty,
122 struct cmd_list_element *c, const char *value)
123 {
124 gdb_printf (file,
125 _("Coercion of floats to doubles "
126 "when calling functions is %s.\n"),
127 value);
128 }
129
130 /* This boolean tells what gdb should do if a signal is received while
131 in a function called from gdb (call dummy). If set, gdb unwinds
132 the stack and restore the context to what as it was before the
133 call.
134
135 The default is to stop in the frame where the signal was received. */
136
137 static bool unwind_on_signal_p = false;
138 static void
139 show_unwind_on_signal_p (struct ui_file *file, int from_tty,
140 struct cmd_list_element *c, const char *value)
141 {
142 gdb_printf (file,
143 _("Unwinding of stack if a signal is "
144 "received while in a call dummy is %s.\n"),
145 value);
146 }
147
148 /* This boolean tells what gdb should do if a std::terminate call is
149 made while in a function called from gdb (call dummy).
150 As the confines of a single dummy stack prohibit out-of-frame
151 handlers from handling a raised exception, and as out-of-frame
152 handlers are common in C++, this can lead to no handler being found
153 by the unwinder, and a std::terminate call. This is a false positive.
154 If set, gdb unwinds the stack and restores the context to what it
155 was before the call.
156
157 The default is to unwind the frame if a std::terminate call is
158 made. */
159
160 static bool unwind_on_terminating_exception_p = true;
161
162 static void
163 show_unwind_on_terminating_exception_p (struct ui_file *file, int from_tty,
164 struct cmd_list_element *c,
165 const char *value)
166
167 {
168 gdb_printf (file,
169 _("Unwind stack if a C++ exception is "
170 "unhandled while in a call dummy is %s.\n"),
171 value);
172 }
173
174 /* Perform the standard coercions that are specified
175 for arguments to be passed to C, Ada or Fortran functions.
176
177 If PARAM_TYPE is non-NULL, it is the expected parameter type.
178 IS_PROTOTYPED is non-zero if the function declaration is prototyped. */
179
180 static struct value *
181 value_arg_coerce (struct gdbarch *gdbarch, struct value *arg,
182 struct type *param_type, int is_prototyped)
183 {
184 const struct builtin_type *builtin = builtin_type (gdbarch);
185 struct type *arg_type = check_typedef (arg->type ());
186 struct type *type
187 = param_type ? check_typedef (param_type) : arg_type;
188
189 /* Perform any Ada- and Fortran-specific coercion first. */
190 if (current_language->la_language == language_ada)
191 arg = ada_convert_actual (arg, type);
192 else if (current_language->la_language == language_fortran)
193 type = fortran_preserve_arg_pointer (arg, type);
194
195 /* Force the value to the target if we will need its address. At
196 this point, we could allocate arguments on the stack instead of
197 calling malloc if we knew that their addresses would not be
198 saved by the called function. */
199 arg = value_coerce_to_target (arg);
200
201 switch (type->code ())
202 {
203 case TYPE_CODE_REF:
204 case TYPE_CODE_RVALUE_REF:
205 {
206 struct value *new_value;
207
208 if (TYPE_IS_REFERENCE (arg_type))
209 return value_cast_pointers (type, arg, 0);
210
211 /* Cast the value to the reference's target type, and then
212 convert it back to a reference. This will issue an error
213 if the value was not previously in memory - in some cases
214 we should clearly be allowing this, but how? */
215 new_value = value_cast (type->target_type (), arg);
216 new_value = value_ref (new_value, type->code ());
217 return new_value;
218 }
219 case TYPE_CODE_INT:
220 case TYPE_CODE_CHAR:
221 case TYPE_CODE_BOOL:
222 case TYPE_CODE_ENUM:
223 /* If we don't have a prototype, coerce to integer type if necessary. */
224 if (!is_prototyped)
225 {
226 if (type->length () < builtin->builtin_int->length ())
227 type = builtin->builtin_int;
228 }
229 /* Currently all target ABIs require at least the width of an integer
230 type for an argument. We may have to conditionalize the following
231 type coercion for future targets. */
232 if (type->length () < builtin->builtin_int->length ())
233 type = builtin->builtin_int;
234 break;
235 case TYPE_CODE_FLT:
236 if (!is_prototyped && coerce_float_to_double_p)
237 {
238 if (type->length () < builtin->builtin_double->length ())
239 type = builtin->builtin_double;
240 else if (type->length () > builtin->builtin_double->length ())
241 type = builtin->builtin_long_double;
242 }
243 break;
244 case TYPE_CODE_FUNC:
245 type = lookup_pointer_type (type);
246 break;
247 case TYPE_CODE_ARRAY:
248 /* Arrays are coerced to pointers to their first element, unless
249 they are vectors, in which case we want to leave them alone,
250 because they are passed by value. */
251 if (current_language->c_style_arrays_p ())
252 if (!type->is_vector ())
253 type = lookup_pointer_type (type->target_type ());
254 break;
255 case TYPE_CODE_UNDEF:
256 case TYPE_CODE_PTR:
257 case TYPE_CODE_STRUCT:
258 case TYPE_CODE_UNION:
259 case TYPE_CODE_VOID:
260 case TYPE_CODE_SET:
261 case TYPE_CODE_RANGE:
262 case TYPE_CODE_STRING:
263 case TYPE_CODE_ERROR:
264 case TYPE_CODE_MEMBERPTR:
265 case TYPE_CODE_METHODPTR:
266 case TYPE_CODE_METHOD:
267 case TYPE_CODE_COMPLEX:
268 default:
269 break;
270 }
271
272 return value_cast (type, arg);
273 }
274
275 /* See infcall.h. */
276
277 CORE_ADDR
278 find_function_addr (struct value *function,
279 struct type **retval_type,
280 struct type **function_type)
281 {
282 struct type *ftype = check_typedef (function->type ());
283 struct gdbarch *gdbarch = ftype->arch ();
284 struct type *value_type = NULL;
285 /* Initialize it just to avoid a GCC false warning. */
286 CORE_ADDR funaddr = 0;
287
288 /* If it's a member function, just look at the function
289 part of it. */
290
291 /* Determine address to call. */
292 if (ftype->code () == TYPE_CODE_FUNC
293 || ftype->code () == TYPE_CODE_METHOD)
294 funaddr = function->address ();
295 else if (ftype->code () == TYPE_CODE_PTR)
296 {
297 funaddr = value_as_address (function);
298 ftype = check_typedef (ftype->target_type ());
299 if (ftype->code () == TYPE_CODE_FUNC
300 || ftype->code () == TYPE_CODE_METHOD)
301 funaddr = gdbarch_convert_from_func_ptr_addr
302 (gdbarch, funaddr, current_inferior ()->top_target());
303 }
304 if (ftype->code () == TYPE_CODE_FUNC
305 || ftype->code () == TYPE_CODE_METHOD)
306 {
307 if (ftype->is_gnu_ifunc ())
308 {
309 CORE_ADDR resolver_addr = funaddr;
310
311 /* Resolve the ifunc. Note this may call the resolver
312 function in the inferior. */
313 funaddr = gnu_ifunc_resolve_addr (gdbarch, resolver_addr);
314
315 /* Skip querying the function symbol if no RETVAL_TYPE or
316 FUNCTION_TYPE have been asked for. */
317 if (retval_type != NULL || function_type != NULL)
318 {
319 type *target_ftype = find_function_type (funaddr);
320 /* If we don't have debug info for the target function,
321 see if we can instead extract the target function's
322 type from the type that the resolver returns. */
323 if (target_ftype == NULL)
324 target_ftype = find_gnu_ifunc_target_type (resolver_addr);
325 if (target_ftype != NULL)
326 {
327 value_type = check_typedef (target_ftype)->target_type ();
328 ftype = target_ftype;
329 }
330 }
331 }
332 else
333 value_type = ftype->target_type ();
334 }
335 else if (ftype->code () == TYPE_CODE_INT)
336 {
337 /* Handle the case of functions lacking debugging info.
338 Their values are characters since their addresses are char. */
339 if (ftype->length () == 1)
340 funaddr = value_as_address (value_addr (function));
341 else
342 {
343 /* Handle function descriptors lacking debug info. */
344 int found_descriptor = 0;
345
346 funaddr = 0; /* pacify "gcc -Werror" */
347 if (function->lval () == lval_memory)
348 {
349 CORE_ADDR nfunaddr;
350
351 funaddr = value_as_address (value_addr (function));
352 nfunaddr = funaddr;
353 funaddr = gdbarch_convert_from_func_ptr_addr
354 (gdbarch, funaddr, current_inferior ()->top_target ());
355 if (funaddr != nfunaddr)
356 found_descriptor = 1;
357 }
358 if (!found_descriptor)
359 /* Handle integer used as address of a function. */
360 funaddr = (CORE_ADDR) value_as_long (function);
361 }
362 }
363 else
364 error (_("Invalid data type for function to be called."));
365
366 if (retval_type != NULL)
367 *retval_type = value_type;
368 if (function_type != NULL)
369 *function_type = ftype;
370 return funaddr + gdbarch_deprecated_function_start_offset (gdbarch);
371 }
372
373 /* For CALL_DUMMY_ON_STACK, push a breakpoint sequence that the called
374 function returns to. */
375
376 static CORE_ADDR
377 push_dummy_code (struct gdbarch *gdbarch,
378 CORE_ADDR sp, CORE_ADDR funaddr,
379 gdb::array_view<value *> args,
380 struct type *value_type,
381 CORE_ADDR *real_pc, CORE_ADDR *bp_addr,
382 struct regcache *regcache)
383 {
384 gdb_assert (gdbarch_push_dummy_code_p (gdbarch));
385
386 return gdbarch_push_dummy_code (gdbarch, sp, funaddr,
387 args.data (), args.size (),
388 value_type, real_pc, bp_addr,
389 regcache);
390 }
391
392 /* See infcall.h. */
393
394 void
395 error_call_unknown_return_type (const char *func_name)
396 {
397 if (func_name != NULL)
398 error (_("'%s' has unknown return type; "
399 "cast the call to its declared return type"),
400 func_name);
401 else
402 error (_("function has unknown return type; "
403 "cast the call to its declared return type"));
404 }
405
406 /* Fetch the name of the function at FUNADDR.
407 This is used in printing an error message for call_function_by_hand.
408 BUF is used to print FUNADDR in hex if the function name cannot be
409 determined. It must be large enough to hold formatted result of
410 RAW_FUNCTION_ADDRESS_FORMAT. */
411
412 static const char *
413 get_function_name (CORE_ADDR funaddr, char *buf, int buf_size)
414 {
415 {
416 struct symbol *symbol = find_pc_function (funaddr);
417
418 if (symbol)
419 return symbol->print_name ();
420 }
421
422 {
423 /* Try the minimal symbols. */
424 struct bound_minimal_symbol msymbol = lookup_minimal_symbol_by_pc (funaddr);
425
426 if (msymbol.minsym)
427 return msymbol.minsym->print_name ();
428 }
429
430 {
431 std::string tmp = string_printf (_(RAW_FUNCTION_ADDRESS_FORMAT),
432 hex_string (funaddr));
433
434 gdb_assert (tmp.length () + 1 <= buf_size);
435 return strcpy (buf, tmp.c_str ());
436 }
437 }
438
439 /* All the meta data necessary to extract the call's return value. */
440
441 struct call_return_meta_info
442 {
443 /* The caller frame's architecture. */
444 struct gdbarch *gdbarch;
445
446 /* The called function. */
447 struct value *function;
448
449 /* The return value's type. */
450 struct type *value_type;
451
452 /* Are we returning a value using a structure return or a normal
453 value return? */
454 int struct_return_p;
455
456 /* If using a structure return, this is the structure's address. */
457 CORE_ADDR struct_addr;
458 };
459
460 /* Extract the called function's return value. */
461
462 static struct value *
463 get_call_return_value (struct call_return_meta_info *ri)
464 {
465 struct value *retval = NULL;
466 thread_info *thr = inferior_thread ();
467 bool stack_temporaries = thread_stack_temporaries_enabled_p (thr);
468
469 if (ri->value_type->code () == TYPE_CODE_VOID)
470 retval = value::allocate (ri->value_type);
471 else if (ri->struct_return_p)
472 {
473 if (stack_temporaries)
474 {
475 retval = value_from_contents_and_address (ri->value_type, NULL,
476 ri->struct_addr);
477 push_thread_stack_temporary (thr, retval);
478 }
479 else
480 retval = value_at_non_lval (ri->value_type, ri->struct_addr);
481 }
482 else
483 {
484 gdbarch_return_value_as_value (ri->gdbarch, ri->function, ri->value_type,
485 get_current_regcache (),
486 &retval, NULL);
487 if (stack_temporaries && class_or_union_p (ri->value_type))
488 {
489 /* Values of class type returned in registers are copied onto
490 the stack and their lval_type set to lval_memory. This is
491 required because further evaluation of the expression
492 could potentially invoke methods on the return value
493 requiring GDB to evaluate the "this" pointer. To evaluate
494 the this pointer, GDB needs the memory address of the
495 value. */
496 retval->force_lval (ri->struct_addr);
497 push_thread_stack_temporary (thr, retval);
498 }
499 }
500
501 gdb_assert (retval != NULL);
502 return retval;
503 }
504
505 /* Data for the FSM that manages an infcall. It's main job is to
506 record the called function's return value. */
507
508 struct call_thread_fsm : public thread_fsm
509 {
510 /* All the info necessary to be able to extract the return
511 value. */
512 struct call_return_meta_info return_meta_info;
513
514 /* The called function's return value. This is extracted from the
515 target before the dummy frame is popped. */
516 struct value *return_value = nullptr;
517
518 /* The top level that started the infcall (and is synchronously
519 waiting for it to end). */
520 struct ui *waiting_ui;
521
522 call_thread_fsm (struct ui *waiting_ui, struct interp *cmd_interp,
523 struct gdbarch *gdbarch, struct value *function,
524 struct type *value_type,
525 int struct_return_p, CORE_ADDR struct_addr);
526
527 bool should_stop (struct thread_info *thread) override;
528
529 bool should_notify_stop () override;
530 };
531
532 /* Allocate a new call_thread_fsm object. */
533
534 call_thread_fsm::call_thread_fsm (struct ui *waiting_ui,
535 struct interp *cmd_interp,
536 struct gdbarch *gdbarch,
537 struct value *function,
538 struct type *value_type,
539 int struct_return_p, CORE_ADDR struct_addr)
540 : thread_fsm (cmd_interp),
541 waiting_ui (waiting_ui)
542 {
543 return_meta_info.gdbarch = gdbarch;
544 return_meta_info.function = function;
545 return_meta_info.value_type = value_type;
546 return_meta_info.struct_return_p = struct_return_p;
547 return_meta_info.struct_addr = struct_addr;
548 }
549
550 /* Implementation of should_stop method for infcalls. */
551
552 bool
553 call_thread_fsm::should_stop (struct thread_info *thread)
554 {
555 INFCALL_SCOPED_DEBUG_ENTER_EXIT;
556
557 if (stop_stack_dummy == STOP_STACK_DUMMY)
558 {
559 /* Done. */
560 set_finished ();
561
562 /* Stash the return value before the dummy frame is popped and
563 registers are restored to what they were before the
564 call.. */
565 return_value = get_call_return_value (&return_meta_info);
566
567 /* Break out of wait_sync_command_done. */
568 scoped_restore save_ui = make_scoped_restore (&current_ui, waiting_ui);
569 target_terminal::ours ();
570 waiting_ui->prompt_state = PROMPT_NEEDED;
571 }
572
573 return true;
574 }
575
576 /* Implementation of should_notify_stop method for infcalls. */
577
578 bool
579 call_thread_fsm::should_notify_stop ()
580 {
581 if (finished_p ())
582 {
583 /* Infcall succeeded. Be silent and proceed with evaluating the
584 expression. */
585 return false;
586 }
587
588 /* Something wrong happened. E.g., an unexpected breakpoint
589 triggered, or a signal was intercepted. Notify the stop. */
590 return true;
591 }
592
593 /* Subroutine of call_function_by_hand to simplify it.
594 Start up the inferior and wait for it to stop.
595 Return the exception if there's an error, or an exception with
596 reason >= 0 if there's no error.
597
598 This is done inside a TRY_CATCH so the caller needn't worry about
599 thrown errors. The caller should rethrow if there's an error. */
600
601 static struct gdb_exception
602 run_inferior_call (std::unique_ptr<call_thread_fsm> sm,
603 struct thread_info *call_thread, CORE_ADDR real_pc)
604 {
605 INFCALL_SCOPED_DEBUG_ENTER_EXIT;
606
607 struct gdb_exception caught_error;
608 ptid_t call_thread_ptid = call_thread->ptid;
609 int was_running = call_thread->state == THREAD_RUNNING;
610
611 infcall_debug_printf ("call function at %s in thread %s, was_running = %d",
612 core_addr_to_string (real_pc),
613 call_thread_ptid.to_string ().c_str (),
614 was_running);
615
616 current_ui->unregister_file_handler ();
617
618 scoped_restore restore_in_infcall
619 = make_scoped_restore (&call_thread->control.in_infcall, 1);
620
621 clear_proceed_status (0);
622
623 /* Associate the FSM with the thread after clear_proceed_status
624 (otherwise it'd clear this FSM). */
625 call_thread->set_thread_fsm (std::move (sm));
626
627 disable_watchpoints_before_interactive_call_start ();
628
629 /* We want to print return value, please... */
630 call_thread->control.proceed_to_finish = 1;
631
632 try
633 {
634 /* Infcalls run synchronously, in the foreground. */
635 scoped_restore restore_prompt_state
636 = make_scoped_restore (&current_ui->prompt_state, PROMPT_BLOCKED);
637
638 /* So that we don't print the prompt prematurely in
639 fetch_inferior_event. */
640 scoped_restore restore_ui_async
641 = make_scoped_restore (&current_ui->async, 0);
642
643 proceed (real_pc, GDB_SIGNAL_0);
644
645 infrun_debug_show_threads ("non-exited threads after proceed for inferior-call",
646 all_non_exited_threads ());
647
648 /* Inferior function calls are always synchronous, even if the
649 target supports asynchronous execution. */
650 wait_sync_command_done ();
651
652 infcall_debug_printf ("inferior call completed successfully");
653 }
654 catch (gdb_exception &e)
655 {
656 infcall_debug_printf ("exception while making inferior call (%d): %s",
657 e.reason, e.what ());
658 caught_error = std::move (e);
659 }
660
661 infcall_debug_printf ("thread is now: %s",
662 inferior_ptid.to_string ().c_str ());
663
664 /* If GDB has the prompt blocked before, then ensure that it remains
665 so. normal_stop calls async_enable_stdin, so reset the prompt
666 state again here. In other cases, stdin will be re-enabled by
667 inferior_event_handler, when an exception is thrown. */
668 if (current_ui->prompt_state == PROMPT_BLOCKED)
669 current_ui->unregister_file_handler ();
670 else
671 current_ui->register_file_handler ();
672
673 /* If the infcall does NOT succeed, normal_stop will have already
674 finished the thread states. However, on success, normal_stop
675 defers here, so that we can set back the thread states to what
676 they were before the call. Note that we must also finish the
677 state of new threads that might have spawned while the call was
678 running. The main cases to handle are:
679
680 - "(gdb) print foo ()", or any other command that evaluates an
681 expression at the prompt. (The thread was marked stopped before.)
682
683 - "(gdb) break foo if return_false()" or similar cases where we
684 do an infcall while handling an event (while the thread is still
685 marked running). In this example, whether the condition
686 evaluates true and thus we'll present a user-visible stop is
687 decided elsewhere. */
688 if (!was_running
689 && call_thread_ptid == inferior_ptid
690 && stop_stack_dummy == STOP_STACK_DUMMY)
691 finish_thread_state (call_thread->inf->process_target (),
692 user_visible_resume_ptid (0));
693
694 enable_watchpoints_after_interactive_call_stop ();
695
696 /* Call breakpoint_auto_delete on the current contents of the bpstat
697 of inferior call thread.
698 If all error()s out of proceed ended up calling normal_stop
699 (and perhaps they should; it already does in the special case
700 of error out of resume()), then we wouldn't need this. */
701 if (caught_error.reason < 0)
702 {
703 if (call_thread->state != THREAD_EXITED)
704 breakpoint_auto_delete (call_thread->control.stop_bpstat);
705 }
706
707 return caught_error;
708 }
709
710 /* Reserve space on the stack for a value of the given type.
711 Return the address of the allocated space.
712 Make certain that the value is correctly aligned.
713 The SP argument is modified. */
714
715 static CORE_ADDR
716 reserve_stack_space (const type *values_type, CORE_ADDR &sp)
717 {
718 frame_info_ptr frame = get_current_frame ();
719 struct gdbarch *gdbarch = get_frame_arch (frame);
720 CORE_ADDR addr = 0;
721
722 if (gdbarch_inner_than (gdbarch, 1, 2))
723 {
724 /* Stack grows downward. Align STRUCT_ADDR and SP after
725 making space. */
726 sp -= values_type->length ();
727 if (gdbarch_frame_align_p (gdbarch))
728 sp = gdbarch_frame_align (gdbarch, sp);
729 addr = sp;
730 }
731 else
732 {
733 /* Stack grows upward. Align the frame, allocate space, and
734 then again, re-align the frame??? */
735 if (gdbarch_frame_align_p (gdbarch))
736 sp = gdbarch_frame_align (gdbarch, sp);
737 addr = sp;
738 sp += values_type->length ();
739 if (gdbarch_frame_align_p (gdbarch))
740 sp = gdbarch_frame_align (gdbarch, sp);
741 }
742
743 return addr;
744 }
745
746 /* The data structure which keeps a destructor function and
747 its implicit 'this' parameter. */
748
749 struct destructor_info
750 {
751 destructor_info (struct value *function, struct value *self)
752 : function (function), self (self) { }
753
754 struct value *function;
755 struct value *self;
756 };
757
758
759 /* Auxiliary function that takes a list of destructor functions
760 with their 'this' parameters, and invokes the functions. */
761
762 static void
763 call_destructors (const std::list<destructor_info> &dtors_to_invoke,
764 struct type *default_return_type)
765 {
766 for (auto vals : dtors_to_invoke)
767 {
768 call_function_by_hand (vals.function, default_return_type,
769 gdb::make_array_view (&(vals.self), 1));
770 }
771 }
772
773 /* See infcall.h. */
774
775 struct value *
776 call_function_by_hand (struct value *function,
777 type *default_return_type,
778 gdb::array_view<value *> args)
779 {
780 return call_function_by_hand_dummy (function, default_return_type,
781 args, NULL, NULL);
782 }
783
784 /* All this stuff with a dummy frame may seem unnecessarily complicated
785 (why not just save registers in GDB?). The purpose of pushing a dummy
786 frame which looks just like a real frame is so that if you call a
787 function and then hit a breakpoint (get a signal, etc), "backtrace"
788 will look right. Whether the backtrace needs to actually show the
789 stack at the time the inferior function was called is debatable, but
790 it certainly needs to not display garbage. So if you are contemplating
791 making dummy frames be different from normal frames, consider that. */
792
793 /* Perform a function call in the inferior.
794 ARGS is a vector of values of arguments.
795 FUNCTION is a value, the function to be called.
796 Returns a value representing what the function returned.
797 May fail to return, if a breakpoint or signal is hit
798 during the execution of the function.
799
800 ARGS is modified to contain coerced values. */
801
802 struct value *
803 call_function_by_hand_dummy (struct value *function,
804 type *default_return_type,
805 gdb::array_view<value *> args,
806 dummy_frame_dtor_ftype *dummy_dtor,
807 void *dummy_dtor_data)
808 {
809 INFCALL_SCOPED_DEBUG_ENTER_EXIT;
810
811 CORE_ADDR sp;
812 struct type *target_values_type;
813 function_call_return_method return_method = return_method_normal;
814 CORE_ADDR struct_addr = 0;
815 CORE_ADDR real_pc;
816 CORE_ADDR bp_addr;
817 struct frame_id dummy_id;
818 frame_info_ptr frame;
819 struct gdbarch *gdbarch;
820 ptid_t call_thread_ptid;
821 struct gdb_exception e;
822 char name_buf[RAW_FUNCTION_ADDRESS_SIZE];
823
824 if (!may_call_functions_p)
825 error (_("Cannot call functions in the program: "
826 "may-call-functions is off."));
827
828 if (!target_has_execution ())
829 noprocess ();
830
831 if (get_traceframe_number () >= 0)
832 error (_("May not call functions while looking at trace frames."));
833
834 if (execution_direction == EXEC_REVERSE)
835 error (_("Cannot call functions in reverse mode."));
836
837 /* We're going to run the target, and inspect the thread's state
838 afterwards. Hold a strong reference so that the pointer remains
839 valid even if the thread exits. */
840 thread_info_ref call_thread
841 = thread_info_ref::new_reference (inferior_thread ());
842
843 bool stack_temporaries = thread_stack_temporaries_enabled_p (call_thread.get ());
844
845 frame = get_current_frame ();
846 gdbarch = get_frame_arch (frame);
847
848 if (!gdbarch_push_dummy_call_p (gdbarch))
849 error (_("This target does not support function calls."));
850
851 /* Find the function type and do a sanity check. */
852 type *ftype;
853 type *values_type;
854 CORE_ADDR funaddr = find_function_addr (function, &values_type, &ftype);
855
856 if (is_nocall_function (ftype))
857 error (_("Cannot call the function '%s' which does not follow the "
858 "target calling convention."),
859 get_function_name (funaddr, name_buf, sizeof (name_buf)));
860
861 if (values_type == NULL || values_type->is_stub ())
862 values_type = default_return_type;
863 if (values_type == NULL)
864 {
865 const char *name = get_function_name (funaddr,
866 name_buf, sizeof (name_buf));
867 error (_("'%s' has unknown return type; "
868 "cast the call to its declared return type"),
869 name);
870 }
871
872 values_type = check_typedef (values_type);
873
874 if (args.size () < ftype->num_fields ())
875 error (_("Too few arguments in function call."));
876
877 infcall_debug_printf ("calling %s", get_function_name (funaddr, name_buf,
878 sizeof (name_buf)));
879
880 /* A holder for the inferior status.
881 This is only needed while we're preparing the inferior function call. */
882 infcall_control_state_up inf_status (save_infcall_control_state ());
883
884 /* Save the caller's registers and other state associated with the
885 inferior itself so that they can be restored once the
886 callee returns. To allow nested calls the registers are (further
887 down) pushed onto a dummy frame stack. This unique pointer
888 is released once the regcache has been pushed). */
889 infcall_suspend_state_up caller_state (save_infcall_suspend_state ());
890
891 /* Ensure that the initial SP is correctly aligned. */
892 {
893 CORE_ADDR old_sp = get_frame_sp (frame);
894
895 if (gdbarch_frame_align_p (gdbarch))
896 {
897 sp = gdbarch_frame_align (gdbarch, old_sp);
898 /* NOTE: cagney/2003-08-13: Skip the "red zone". For some
899 ABIs, a function can use memory beyond the inner most stack
900 address. AMD64 called that region the "red zone". Skip at
901 least the "red zone" size before allocating any space on
902 the stack. */
903 if (gdbarch_inner_than (gdbarch, 1, 2))
904 sp -= gdbarch_frame_red_zone_size (gdbarch);
905 else
906 sp += gdbarch_frame_red_zone_size (gdbarch);
907 /* Still aligned? */
908 gdb_assert (sp == gdbarch_frame_align (gdbarch, sp));
909 /* NOTE: cagney/2002-09-18:
910
911 On a RISC architecture, a void parameterless generic dummy
912 frame (i.e., no parameters, no result) typically does not
913 need to push anything the stack and hence can leave SP and
914 FP. Similarly, a frameless (possibly leaf) function does
915 not push anything on the stack and, hence, that too can
916 leave FP and SP unchanged. As a consequence, a sequence of
917 void parameterless generic dummy frame calls to frameless
918 functions will create a sequence of effectively identical
919 frames (SP, FP and TOS and PC the same). This, not
920 surprisingly, results in what appears to be a stack in an
921 infinite loop --- when GDB tries to find a generic dummy
922 frame on the internal dummy frame stack, it will always
923 find the first one.
924
925 To avoid this problem, the code below always grows the
926 stack. That way, two dummy frames can never be identical.
927 It does burn a few bytes of stack but that is a small price
928 to pay :-). */
929 if (sp == old_sp)
930 {
931 if (gdbarch_inner_than (gdbarch, 1, 2))
932 /* Stack grows down. */
933 sp = gdbarch_frame_align (gdbarch, old_sp - 1);
934 else
935 /* Stack grows up. */
936 sp = gdbarch_frame_align (gdbarch, old_sp + 1);
937 }
938 /* SP may have underflown address zero here from OLD_SP. Memory access
939 functions will probably fail in such case but that is a target's
940 problem. */
941 }
942 else
943 /* FIXME: cagney/2002-09-18: Hey, you loose!
944
945 Who knows how badly aligned the SP is!
946
947 If the generic dummy frame ends up empty (because nothing is
948 pushed) GDB won't be able to correctly perform back traces.
949 If a target is having trouble with backtraces, first thing to
950 do is add FRAME_ALIGN() to the architecture vector. If that
951 fails, try dummy_id().
952
953 If the ABI specifies a "Red Zone" (see the doco) the code
954 below will quietly trash it. */
955 sp = old_sp;
956
957 /* Skip over the stack temporaries that might have been generated during
958 the evaluation of an expression. */
959 if (stack_temporaries)
960 {
961 struct value *lastval;
962
963 lastval = get_last_thread_stack_temporary (call_thread.get ());
964 if (lastval != NULL)
965 {
966 CORE_ADDR lastval_addr = lastval->address ();
967
968 if (gdbarch_inner_than (gdbarch, 1, 2))
969 {
970 gdb_assert (sp >= lastval_addr);
971 sp = lastval_addr;
972 }
973 else
974 {
975 gdb_assert (sp <= lastval_addr);
976 sp = lastval_addr + lastval->type ()->length ();
977 }
978
979 if (gdbarch_frame_align_p (gdbarch))
980 sp = gdbarch_frame_align (gdbarch, sp);
981 }
982 }
983 }
984
985 /* Are we returning a value using a structure return? */
986
987 if (gdbarch_return_in_first_hidden_param_p (gdbarch, values_type))
988 {
989 return_method = return_method_hidden_param;
990
991 /* Tell the target specific argument pushing routine not to
992 expect a value. */
993 target_values_type = builtin_type (gdbarch)->builtin_void;
994 }
995 else
996 {
997 if (using_struct_return (gdbarch, function, values_type))
998 return_method = return_method_struct;
999 target_values_type = values_type;
1000 }
1001
1002 gdb::observers::inferior_call_pre.notify (inferior_ptid, funaddr);
1003
1004 /* Determine the location of the breakpoint (and possibly other
1005 stuff) that the called function will return to. The SPARC, for a
1006 function returning a structure or union, needs to make space for
1007 not just the breakpoint but also an extra word containing the
1008 size (?) of the structure being passed. */
1009
1010 switch (gdbarch_call_dummy_location (gdbarch))
1011 {
1012 case ON_STACK:
1013 {
1014 const gdb_byte *bp_bytes;
1015 CORE_ADDR bp_addr_as_address;
1016 int bp_size;
1017
1018 /* Be careful BP_ADDR is in inferior PC encoding while
1019 BP_ADDR_AS_ADDRESS is a plain memory address. */
1020
1021 sp = push_dummy_code (gdbarch, sp, funaddr, args,
1022 target_values_type, &real_pc, &bp_addr,
1023 get_current_regcache ());
1024
1025 /* Write a legitimate instruction at the point where the infcall
1026 breakpoint is going to be inserted. While this instruction
1027 is never going to be executed, a user investigating the
1028 memory from GDB would see this instruction instead of random
1029 uninitialized bytes. We chose the breakpoint instruction
1030 as it may look as the most logical one to the user and also
1031 valgrind 3.7.0 needs it for proper vgdb inferior calls.
1032
1033 If software breakpoints are unsupported for this target we
1034 leave the user visible memory content uninitialized. */
1035
1036 bp_addr_as_address = bp_addr;
1037 bp_bytes = gdbarch_breakpoint_from_pc (gdbarch, &bp_addr_as_address,
1038 &bp_size);
1039 if (bp_bytes != NULL)
1040 write_memory (bp_addr_as_address, bp_bytes, bp_size);
1041 }
1042 break;
1043 case AT_ENTRY_POINT:
1044 {
1045 CORE_ADDR dummy_addr;
1046
1047 real_pc = funaddr;
1048 dummy_addr = entry_point_address ();
1049
1050 /* A call dummy always consists of just a single breakpoint, so
1051 its address is the same as the address of the dummy.
1052
1053 The actual breakpoint is inserted separatly so there is no need to
1054 write that out. */
1055 bp_addr = dummy_addr;
1056 break;
1057 }
1058 default:
1059 internal_error (_("bad switch"));
1060 }
1061
1062 /* Coerce the arguments and handle pass-by-reference.
1063 We want to remember the destruction required for pass-by-ref values.
1064 For these, store the dtor function and the 'this' argument
1065 in DTORS_TO_INVOKE. */
1066 std::list<destructor_info> dtors_to_invoke;
1067
1068 for (int i = args.size () - 1; i >= 0; i--)
1069 {
1070 int prototyped;
1071 struct type *param_type;
1072
1073 /* FIXME drow/2002-05-31: Should just always mark methods as
1074 prototyped. Can we respect TYPE_VARARGS? Probably not. */
1075 if (ftype->code () == TYPE_CODE_METHOD)
1076 prototyped = 1;
1077 else if (ftype->target_type () == NULL && ftype->num_fields () == 0
1078 && default_return_type != NULL)
1079 {
1080 /* Calling a no-debug function with the return type
1081 explicitly cast. Assume the function is prototyped,
1082 with a prototype matching the types of the arguments.
1083 E.g., with:
1084 float mult (float v1, float v2) { return v1 * v2; }
1085 This:
1086 (gdb) p (float) mult (2.0f, 3.0f)
1087 Is a simpler alternative to:
1088 (gdb) p ((float (*) (float, float)) mult) (2.0f, 3.0f)
1089 */
1090 prototyped = 1;
1091 }
1092 else if (i < ftype->num_fields ())
1093 prototyped = ftype->is_prototyped ();
1094 else
1095 prototyped = 0;
1096
1097 if (i < ftype->num_fields ())
1098 param_type = ftype->field (i).type ();
1099 else
1100 param_type = NULL;
1101
1102 value *original_arg = args[i];
1103 args[i] = value_arg_coerce (gdbarch, args[i],
1104 param_type, prototyped);
1105
1106 if (param_type == NULL)
1107 continue;
1108
1109 auto info = language_pass_by_reference (param_type);
1110 if (!info.copy_constructible)
1111 error (_("expression cannot be evaluated because the type '%s' "
1112 "is not copy constructible"), param_type->name ());
1113
1114 if (!info.destructible)
1115 error (_("expression cannot be evaluated because the type '%s' "
1116 "is not destructible"), param_type->name ());
1117
1118 if (info.trivially_copyable)
1119 continue;
1120
1121 /* Make a copy of the argument on the stack. If the argument is
1122 trivially copy ctor'able, copy bit by bit. Otherwise, call
1123 the copy ctor to initialize the clone. */
1124 CORE_ADDR addr = reserve_stack_space (param_type, sp);
1125 value *clone
1126 = value_from_contents_and_address (param_type, nullptr, addr);
1127 push_thread_stack_temporary (call_thread.get (), clone);
1128 value *clone_ptr
1129 = value_from_pointer (lookup_pointer_type (param_type), addr);
1130
1131 if (info.trivially_copy_constructible)
1132 {
1133 int length = param_type->length ();
1134 write_memory (addr, args[i]->contents ().data (), length);
1135 }
1136 else
1137 {
1138 value *copy_ctor;
1139 value *cctor_args[2] = { clone_ptr, original_arg };
1140 find_overload_match (gdb::make_array_view (cctor_args, 2),
1141 param_type->name (), METHOD,
1142 &clone_ptr, nullptr, &copy_ctor, nullptr,
1143 nullptr, 0, EVAL_NORMAL);
1144
1145 if (copy_ctor == nullptr)
1146 error (_("expression cannot be evaluated because a copy "
1147 "constructor for the type '%s' could not be found "
1148 "(maybe inlined?)"), param_type->name ());
1149
1150 call_function_by_hand (copy_ctor, default_return_type,
1151 gdb::make_array_view (cctor_args, 2));
1152 }
1153
1154 /* If the argument has a destructor, remember it so that we
1155 invoke it after the infcall is complete. */
1156 if (!info.trivially_destructible)
1157 {
1158 /* Looking up the function via overload resolution does not
1159 work because the compiler (in particular, gcc) adds an
1160 artificial int parameter in some cases. So we look up
1161 the function by using the "~" name. This should be OK
1162 because there can be only one dtor definition. */
1163 const char *dtor_name = nullptr;
1164 for (int fieldnum = 0;
1165 fieldnum < TYPE_NFN_FIELDS (param_type);
1166 fieldnum++)
1167 {
1168 fn_field *fn
1169 = TYPE_FN_FIELDLIST1 (param_type, fieldnum);
1170 const char *field_name
1171 = TYPE_FN_FIELDLIST_NAME (param_type, fieldnum);
1172
1173 if (field_name[0] == '~')
1174 dtor_name = TYPE_FN_FIELD_PHYSNAME (fn, 0);
1175 }
1176
1177 if (dtor_name == nullptr)
1178 error (_("expression cannot be evaluated because a destructor "
1179 "for the type '%s' could not be found "
1180 "(maybe inlined?)"), param_type->name ());
1181
1182 value *dtor
1183 = find_function_in_inferior (dtor_name, 0);
1184
1185 /* Insert the dtor to the front of the list to call them
1186 in reverse order later. */
1187 dtors_to_invoke.emplace_front (dtor, clone_ptr);
1188 }
1189
1190 args[i] = clone_ptr;
1191 }
1192
1193 /* Reserve space for the return structure to be written on the
1194 stack, if necessary.
1195
1196 While evaluating expressions, we reserve space on the stack for
1197 return values of class type even if the language ABI and the target
1198 ABI do not require that the return value be passed as a hidden first
1199 argument. This is because we want to store the return value as an
1200 on-stack temporary while the expression is being evaluated. This
1201 enables us to have chained function calls in expressions.
1202
1203 Keeping the return values as on-stack temporaries while the expression
1204 is being evaluated is OK because the thread is stopped until the
1205 expression is completely evaluated. */
1206
1207 if (return_method != return_method_normal
1208 || (stack_temporaries && class_or_union_p (values_type)))
1209 struct_addr = reserve_stack_space (values_type, sp);
1210
1211 std::vector<struct value *> new_args;
1212 if (return_method == return_method_hidden_param)
1213 {
1214 /* Add the new argument to the front of the argument list. */
1215 new_args.reserve (args.size ());
1216 new_args.push_back
1217 (value_from_pointer (lookup_pointer_type (values_type), struct_addr));
1218 new_args.insert (new_args.end (), args.begin (), args.end ());
1219 args = new_args;
1220 }
1221
1222 /* Create the dummy stack frame. Pass in the call dummy address as,
1223 presumably, the ABI code knows where, in the call dummy, the
1224 return address should be pointed. */
1225 sp = gdbarch_push_dummy_call (gdbarch, function, get_current_regcache (),
1226 bp_addr, args.size (), args.data (),
1227 sp, return_method, struct_addr);
1228
1229 /* Set up a frame ID for the dummy frame so we can pass it to
1230 set_momentary_breakpoint. We need to give the breakpoint a frame
1231 ID so that the breakpoint code can correctly re-identify the
1232 dummy breakpoint. */
1233 /* Sanity. The exact same SP value is returned by PUSH_DUMMY_CALL,
1234 saved as the dummy-frame TOS, and used by dummy_id to form
1235 the frame ID's stack address. */
1236 dummy_id = frame_id_build (sp, bp_addr);
1237
1238 /* Create a momentary breakpoint at the return address of the
1239 inferior. That way it breaks when it returns. */
1240
1241 {
1242 symtab_and_line sal;
1243 sal.pspace = current_program_space;
1244 sal.pc = bp_addr;
1245 sal.section = find_pc_overlay (sal.pc);
1246
1247 /* Sanity. The exact same SP value is returned by
1248 PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by
1249 dummy_id to form the frame ID's stack address. */
1250 breakpoint *bpt
1251 = set_momentary_breakpoint (gdbarch, sal,
1252 dummy_id, bp_call_dummy).release ();
1253
1254 /* set_momentary_breakpoint invalidates FRAME. */
1255 frame = NULL;
1256
1257 bpt->disposition = disp_del;
1258 gdb_assert (bpt->related_breakpoint == bpt);
1259
1260 breakpoint *longjmp_b = set_longjmp_breakpoint_for_call_dummy ();
1261 if (longjmp_b)
1262 {
1263 /* Link BPT into the chain of LONGJMP_B. */
1264 bpt->related_breakpoint = longjmp_b;
1265 while (longjmp_b->related_breakpoint != bpt->related_breakpoint)
1266 longjmp_b = longjmp_b->related_breakpoint;
1267 longjmp_b->related_breakpoint = bpt;
1268 }
1269 }
1270
1271 /* Create a breakpoint in std::terminate.
1272 If a C++ exception is raised in the dummy-frame, and the
1273 exception handler is (normally, and expected to be) out-of-frame,
1274 the default C++ handler will (wrongly) be called in an inferior
1275 function call. This is wrong, as an exception can be normally
1276 and legally handled out-of-frame. The confines of the dummy frame
1277 prevent the unwinder from finding the correct handler (or any
1278 handler, unless it is in-frame). The default handler calls
1279 std::terminate. This will kill the inferior. Assert that
1280 terminate should never be called in an inferior function
1281 call. Place a momentary breakpoint in the std::terminate function
1282 and if triggered in the call, rewind. */
1283 if (unwind_on_terminating_exception_p)
1284 set_std_terminate_breakpoint ();
1285
1286 /* Everything's ready, push all the info needed to restore the
1287 caller (and identify the dummy-frame) onto the dummy-frame
1288 stack. */
1289 dummy_frame_push (caller_state.release (), &dummy_id, call_thread.get ());
1290 if (dummy_dtor != NULL)
1291 register_dummy_frame_dtor (dummy_id, call_thread.get (),
1292 dummy_dtor, dummy_dtor_data);
1293
1294 /* Register a clean-up for unwind_on_terminating_exception_breakpoint. */
1295 SCOPE_EXIT { delete_std_terminate_breakpoint (); };
1296
1297 /* The stopped_by_random_signal variable is global. If we are here
1298 as part of a breakpoint condition check then the global will have
1299 already been setup as part of the original breakpoint stop. By
1300 making the inferior call the global will be changed when GDB
1301 handles the stop after the inferior call. Avoid confusion by
1302 restoring the current value after the inferior call. */
1303 scoped_restore restore_stopped_by_random_signal
1304 = make_scoped_restore (&stopped_by_random_signal, 0);
1305
1306 /* - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP -
1307 If you're looking to implement asynchronous dummy-frames, then
1308 just below is the place to chop this function in two.. */
1309
1310 {
1311 /* Save the current FSM. We'll override it. */
1312 std::unique_ptr<thread_fsm> saved_sm = call_thread->release_thread_fsm ();
1313 struct call_thread_fsm *sm;
1314
1315 /* Save this thread's ptid, we need it later but the thread
1316 may have exited. */
1317 call_thread_ptid = call_thread->ptid;
1318
1319 /* Run the inferior until it stops. */
1320
1321 /* Create the FSM used to manage the infcall. It tells infrun to
1322 not report the stop to the user, and captures the return value
1323 before the dummy frame is popped. run_inferior_call registers
1324 it with the thread ASAP. */
1325 sm = new call_thread_fsm (current_ui, command_interp (),
1326 gdbarch, function,
1327 values_type,
1328 return_method != return_method_normal,
1329 struct_addr);
1330 {
1331 std::unique_ptr<call_thread_fsm> sm_up (sm);
1332 e = run_inferior_call (std::move (sm_up), call_thread.get (), real_pc);
1333 }
1334
1335 if (e.reason < 0)
1336 infcall_debug_printf ("after inferior call, exception (%d): %s",
1337 e.reason, e.what ());
1338 infcall_debug_printf ("after inferior call, thread state is: %s",
1339 thread_state_string (call_thread->state));
1340
1341 gdb::observers::inferior_call_post.notify (call_thread_ptid, funaddr);
1342
1343 if (call_thread->state != THREAD_EXITED)
1344 {
1345 /* The FSM should still be the same. */
1346 gdb_assert (call_thread->thread_fsm () == sm);
1347
1348 if (call_thread->thread_fsm ()->finished_p ())
1349 {
1350 struct value *retval;
1351
1352 infcall_debug_printf ("call completed");
1353
1354 /* The inferior call is successful. Pop the dummy frame,
1355 which runs its destructors and restores the inferior's
1356 suspend state, and restore the inferior control
1357 state. */
1358 dummy_frame_pop (dummy_id, call_thread.get ());
1359 restore_infcall_control_state (inf_status.release ());
1360
1361 /* Get the return value. */
1362 retval = sm->return_value;
1363
1364 /* Restore the original FSM and clean up / destroy the call FSM.
1365 Doing it in this order ensures that if the call to clean_up
1366 throws, the original FSM is properly restored. */
1367 {
1368 std::unique_ptr<thread_fsm> finalizing
1369 = call_thread->release_thread_fsm ();
1370 call_thread->set_thread_fsm (std::move (saved_sm));
1371
1372 finalizing->clean_up (call_thread.get ());
1373 }
1374
1375 maybe_remove_breakpoints ();
1376
1377 gdb_assert (retval != NULL);
1378
1379 /* Destruct the pass-by-ref argument clones. */
1380 call_destructors (dtors_to_invoke, default_return_type);
1381
1382 return retval;
1383 }
1384 else
1385 infcall_debug_printf ("call did not complete");
1386
1387 /* Didn't complete. Clean up / destroy the call FSM, and restore the
1388 previous state machine, and handle the error. */
1389 {
1390 std::unique_ptr<thread_fsm> finalizing
1391 = call_thread->release_thread_fsm ();
1392 call_thread->set_thread_fsm (std::move (saved_sm));
1393
1394 finalizing->clean_up (call_thread.get ());
1395 }
1396 }
1397 }
1398
1399 /* Rethrow an error if we got one trying to run the inferior. */
1400
1401 if (e.reason < 0)
1402 {
1403 const char *name = get_function_name (funaddr,
1404 name_buf, sizeof (name_buf));
1405
1406 discard_infcall_control_state (inf_status.release ());
1407
1408 /* We could discard the dummy frame here if the program exited,
1409 but it will get garbage collected the next time the program is
1410 run anyway. */
1411
1412 switch (e.reason)
1413 {
1414 case RETURN_ERROR:
1415 throw_error (e.error, _("%s\n\
1416 An error occurred while in a function called from GDB.\n\
1417 Evaluation of the expression containing the function\n\
1418 (%s) will be abandoned.\n\
1419 When the function is done executing, GDB will silently stop."),
1420 e.what (), name);
1421 case RETURN_QUIT:
1422 default:
1423 throw_exception (std::move (e));
1424 }
1425 }
1426
1427 /* If the program has exited, or we stopped at a different thread,
1428 exit and inform the user. */
1429
1430 if (! target_has_execution ())
1431 {
1432 const char *name = get_function_name (funaddr,
1433 name_buf, sizeof (name_buf));
1434
1435 /* If we try to restore the inferior status,
1436 we'll crash as the inferior is no longer running. */
1437 discard_infcall_control_state (inf_status.release ());
1438
1439 /* We could discard the dummy frame here given that the program exited,
1440 but it will get garbage collected the next time the program is
1441 run anyway. */
1442
1443 error (_("The program being debugged exited while in a function "
1444 "called from GDB.\n"
1445 "Evaluation of the expression containing the function\n"
1446 "(%s) will be abandoned."),
1447 name);
1448 }
1449
1450 if (call_thread_ptid != inferior_ptid)
1451 {
1452 const char *name = get_function_name (funaddr,
1453 name_buf, sizeof (name_buf));
1454
1455 /* We've switched threads. This can happen if another thread gets a
1456 signal or breakpoint while our thread was running.
1457 There's no point in restoring the inferior status,
1458 we're in a different thread. */
1459 discard_infcall_control_state (inf_status.release ());
1460 /* Keep the dummy frame record, if the user switches back to the
1461 thread with the hand-call, we'll need it. */
1462 if (stopped_by_random_signal)
1463 error (_("\
1464 The program received a signal in another thread while\n\
1465 making a function call from GDB.\n\
1466 Evaluation of the expression containing the function\n\
1467 (%s) will be abandoned.\n\
1468 When the function is done executing, GDB will silently stop."),
1469 name);
1470 else
1471 error (_("\
1472 The program stopped in another thread while making a function call from GDB.\n\
1473 Evaluation of the expression containing the function\n\
1474 (%s) will be abandoned.\n\
1475 When the function is done executing, GDB will silently stop."),
1476 name);
1477 }
1478
1479 {
1480 /* Make a copy as NAME may be in an objfile freed by dummy_frame_pop. */
1481 std::string name = get_function_name (funaddr, name_buf,
1482 sizeof (name_buf));
1483
1484 if (stopped_by_random_signal)
1485 {
1486 /* We stopped inside the FUNCTION because of a random
1487 signal. Further execution of the FUNCTION is not
1488 allowed. */
1489
1490 if (unwind_on_signal_p)
1491 {
1492 /* The user wants the context restored. */
1493
1494 /* We must get back to the frame we were before the
1495 dummy call. */
1496 dummy_frame_pop (dummy_id, call_thread.get ());
1497
1498 /* We also need to restore inferior status to that before the
1499 dummy call. */
1500 restore_infcall_control_state (inf_status.release ());
1501
1502 /* FIXME: Insert a bunch of wrap_here; name can be very
1503 long if it's a C++ name with arguments and stuff. */
1504 error (_("\
1505 The program being debugged was signaled while in a function called from GDB.\n\
1506 GDB has restored the context to what it was before the call.\n\
1507 To change this behavior use \"set unwindonsignal off\".\n\
1508 Evaluation of the expression containing the function\n\
1509 (%s) will be abandoned."),
1510 name.c_str ());
1511 }
1512 else
1513 {
1514 /* The user wants to stay in the frame where we stopped
1515 (default).
1516 Discard inferior status, we're not at the same point
1517 we started at. */
1518 discard_infcall_control_state (inf_status.release ());
1519
1520 /* FIXME: Insert a bunch of wrap_here; name can be very
1521 long if it's a C++ name with arguments and stuff. */
1522 error (_("\
1523 The program being debugged was signaled while in a function called from GDB.\n\
1524 GDB remains in the frame where the signal was received.\n\
1525 To change this behavior use \"set unwindonsignal on\".\n\
1526 Evaluation of the expression containing the function\n\
1527 (%s) will be abandoned.\n\
1528 When the function is done executing, GDB will silently stop."),
1529 name.c_str ());
1530 }
1531 }
1532
1533 if (stop_stack_dummy == STOP_STD_TERMINATE)
1534 {
1535 /* We must get back to the frame we were before the dummy
1536 call. */
1537 dummy_frame_pop (dummy_id, call_thread.get ());
1538
1539 /* We also need to restore inferior status to that before
1540 the dummy call. */
1541 restore_infcall_control_state (inf_status.release ());
1542
1543 error (_("\
1544 The program being debugged entered a std::terminate call, most likely\n\
1545 caused by an unhandled C++ exception. GDB blocked this call in order\n\
1546 to prevent the program from being terminated, and has restored the\n\
1547 context to its original state before the call.\n\
1548 To change this behaviour use \"set unwind-on-terminating-exception off\".\n\
1549 Evaluation of the expression containing the function (%s)\n\
1550 will be abandoned."),
1551 name.c_str ());
1552 }
1553 else if (stop_stack_dummy == STOP_NONE)
1554 {
1555
1556 /* We hit a breakpoint inside the FUNCTION.
1557 Keep the dummy frame, the user may want to examine its state.
1558 Discard inferior status, we're not at the same point
1559 we started at. */
1560 discard_infcall_control_state (inf_status.release ());
1561
1562 /* The following error message used to say "The expression
1563 which contained the function call has been discarded."
1564 It is a hard concept to explain in a few words. Ideally,
1565 GDB would be able to resume evaluation of the expression
1566 when the function finally is done executing. Perhaps
1567 someday this will be implemented (it would not be easy). */
1568 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
1569 a C++ name with arguments and stuff. */
1570 error (_("\
1571 The program being debugged stopped while in a function called from GDB.\n\
1572 Evaluation of the expression containing the function\n\
1573 (%s) will be abandoned.\n\
1574 When the function is done executing, GDB will silently stop."),
1575 name.c_str ());
1576 }
1577
1578 }
1579
1580 /* The above code errors out, so ... */
1581 gdb_assert_not_reached ("... should not be here");
1582 }
1583
1584 void _initialize_infcall ();
1585 void
1586 _initialize_infcall ()
1587 {
1588 add_setshow_boolean_cmd ("may-call-functions", no_class,
1589 &may_call_functions_p, _("\
1590 Set permission to call functions in the program."), _("\
1591 Show permission to call functions in the program."), _("\
1592 When this permission is on, GDB may call functions in the program.\n\
1593 Otherwise, any sort of attempt to call a function in the program\n\
1594 will result in an error."),
1595 NULL,
1596 show_may_call_functions_p,
1597 &setlist, &showlist);
1598
1599 add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure,
1600 &coerce_float_to_double_p, _("\
1601 Set coercion of floats to doubles when calling functions."), _("\
1602 Show coercion of floats to doubles when calling functions."), _("\
1603 Variables of type float should generally be converted to doubles before\n\
1604 calling an unprototyped function, and left alone when calling a prototyped\n\
1605 function. However, some older debug info formats do not provide enough\n\
1606 information to determine that a function is prototyped. If this flag is\n\
1607 set, GDB will perform the conversion for a function it considers\n\
1608 unprototyped.\n\
1609 The default is to perform the conversion."),
1610 NULL,
1611 show_coerce_float_to_double_p,
1612 &setlist, &showlist);
1613
1614 add_setshow_boolean_cmd ("unwindonsignal", no_class,
1615 &unwind_on_signal_p, _("\
1616 Set unwinding of stack if a signal is received while in a call dummy."), _("\
1617 Show unwinding of stack if a signal is received while in a call dummy."), _("\
1618 The unwindonsignal lets the user determine what gdb should do if a signal\n\
1619 is received while in a function called from gdb (call dummy). If set, gdb\n\
1620 unwinds the stack and restore the context to what as it was before the call.\n\
1621 The default is to stop in the frame where the signal was received."),
1622 NULL,
1623 show_unwind_on_signal_p,
1624 &setlist, &showlist);
1625
1626 add_setshow_boolean_cmd ("unwind-on-terminating-exception", no_class,
1627 &unwind_on_terminating_exception_p, _("\
1628 Set unwinding of stack if std::terminate is called while in call dummy."), _("\
1629 Show unwinding of stack if std::terminate() is called while in a call dummy."),
1630 _("\
1631 The unwind on terminating exception flag lets the user determine\n\
1632 what gdb should do if a std::terminate() call is made from the\n\
1633 default exception handler. If set, gdb unwinds the stack and restores\n\
1634 the context to what it was before the call. If unset, gdb allows the\n\
1635 std::terminate call to proceed.\n\
1636 The default is to unwind the frame."),
1637 NULL,
1638 show_unwind_on_terminating_exception_p,
1639 &setlist, &showlist);
1640
1641 add_setshow_boolean_cmd
1642 ("infcall", class_maintenance, &debug_infcall,
1643 _("Set inferior call debugging."),
1644 _("Show inferior call debugging."),
1645 _("When on, inferior function call specific debugging is enabled."),
1646 NULL, show_debug_infcall, &setdebuglist, &showdebuglist);
1647 }