Remove a cleanup from call_function_by_hand_dummy
[deliverable/binutils-gdb.git] / gdb / infcall.c
1 /* Perform an inferior function call, for GDB, the GNU debugger.
2
3 Copyright (C) 1986-2018 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 "gdbthread.h"
37 #include "event-top.h"
38 #include "observer.h"
39 #include "top.h"
40 #include "interps.h"
41 #include "thread-fsm.h"
42 #include <algorithm>
43
44 /* If we can't find a function's name from its address,
45 we print this instead. */
46 #define RAW_FUNCTION_ADDRESS_FORMAT "at 0x%s"
47 #define RAW_FUNCTION_ADDRESS_SIZE (sizeof (RAW_FUNCTION_ADDRESS_FORMAT) \
48 + 2 * sizeof (CORE_ADDR))
49
50 /* NOTE: cagney/2003-04-16: What's the future of this code?
51
52 GDB needs an asynchronous expression evaluator, that means an
53 asynchronous inferior function call implementation, and that in
54 turn means restructuring the code so that it is event driven. */
55
56 /* How you should pass arguments to a function depends on whether it
57 was defined in K&R style or prototype style. If you define a
58 function using the K&R syntax that takes a `float' argument, then
59 callers must pass that argument as a `double'. If you define the
60 function using the prototype syntax, then you must pass the
61 argument as a `float', with no promotion.
62
63 Unfortunately, on certain older platforms, the debug info doesn't
64 indicate reliably how each function was defined. A function type's
65 TYPE_PROTOTYPED flag may be clear, even if the function was defined
66 in prototype style. When calling a function whose TYPE_PROTOTYPED
67 flag is clear, GDB consults this flag to decide what to do.
68
69 For modern targets, it is proper to assume that, if the prototype
70 flag is clear, that can be trusted: `float' arguments should be
71 promoted to `double'. For some older targets, if the prototype
72 flag is clear, that doesn't tell us anything. The default is to
73 trust the debug information; the user can override this behavior
74 with "set coerce-float-to-double 0". */
75
76 static int coerce_float_to_double_p = 1;
77 static void
78 show_coerce_float_to_double_p (struct ui_file *file, int from_tty,
79 struct cmd_list_element *c, const char *value)
80 {
81 fprintf_filtered (file,
82 _("Coercion of floats to doubles "
83 "when calling functions is %s.\n"),
84 value);
85 }
86
87 /* This boolean tells what gdb should do if a signal is received while
88 in a function called from gdb (call dummy). If set, gdb unwinds
89 the stack and restore the context to what as it was before the
90 call.
91
92 The default is to stop in the frame where the signal was received. */
93
94 static int unwind_on_signal_p = 0;
95 static void
96 show_unwind_on_signal_p (struct ui_file *file, int from_tty,
97 struct cmd_list_element *c, const char *value)
98 {
99 fprintf_filtered (file,
100 _("Unwinding of stack if a signal is "
101 "received while in a call dummy is %s.\n"),
102 value);
103 }
104
105 /* This boolean tells what gdb should do if a std::terminate call is
106 made while in a function called from gdb (call dummy).
107 As the confines of a single dummy stack prohibit out-of-frame
108 handlers from handling a raised exception, and as out-of-frame
109 handlers are common in C++, this can lead to no handler being found
110 by the unwinder, and a std::terminate call. This is a false positive.
111 If set, gdb unwinds the stack and restores the context to what it
112 was before the call.
113
114 The default is to unwind the frame if a std::terminate call is
115 made. */
116
117 static int unwind_on_terminating_exception_p = 1;
118
119 static void
120 show_unwind_on_terminating_exception_p (struct ui_file *file, int from_tty,
121 struct cmd_list_element *c,
122 const char *value)
123
124 {
125 fprintf_filtered (file,
126 _("Unwind stack if a C++ exception is "
127 "unhandled while in a call dummy is %s.\n"),
128 value);
129 }
130
131 /* Perform the standard coercions that are specified
132 for arguments to be passed to C or Ada functions.
133
134 If PARAM_TYPE is non-NULL, it is the expected parameter type.
135 IS_PROTOTYPED is non-zero if the function declaration is prototyped.
136 SP is the stack pointer were additional data can be pushed (updating
137 its value as needed). */
138
139 static struct value *
140 value_arg_coerce (struct gdbarch *gdbarch, struct value *arg,
141 struct type *param_type, int is_prototyped, CORE_ADDR *sp)
142 {
143 const struct builtin_type *builtin = builtin_type (gdbarch);
144 struct type *arg_type = check_typedef (value_type (arg));
145 struct type *type
146 = param_type ? check_typedef (param_type) : arg_type;
147
148 /* Perform any Ada-specific coercion first. */
149 if (current_language->la_language == language_ada)
150 arg = ada_convert_actual (arg, type);
151
152 /* Force the value to the target if we will need its address. At
153 this point, we could allocate arguments on the stack instead of
154 calling malloc if we knew that their addresses would not be
155 saved by the called function. */
156 arg = value_coerce_to_target (arg);
157
158 switch (TYPE_CODE (type))
159 {
160 case TYPE_CODE_REF:
161 case TYPE_CODE_RVALUE_REF:
162 {
163 struct value *new_value;
164
165 if (TYPE_IS_REFERENCE (arg_type))
166 return value_cast_pointers (type, arg, 0);
167
168 /* Cast the value to the reference's target type, and then
169 convert it back to a reference. This will issue an error
170 if the value was not previously in memory - in some cases
171 we should clearly be allowing this, but how? */
172 new_value = value_cast (TYPE_TARGET_TYPE (type), arg);
173 new_value = value_ref (new_value, TYPE_CODE (type));
174 return new_value;
175 }
176 case TYPE_CODE_INT:
177 case TYPE_CODE_CHAR:
178 case TYPE_CODE_BOOL:
179 case TYPE_CODE_ENUM:
180 /* If we don't have a prototype, coerce to integer type if necessary. */
181 if (!is_prototyped)
182 {
183 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_int))
184 type = builtin->builtin_int;
185 }
186 /* Currently all target ABIs require at least the width of an integer
187 type for an argument. We may have to conditionalize the following
188 type coercion for future targets. */
189 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_int))
190 type = builtin->builtin_int;
191 break;
192 case TYPE_CODE_FLT:
193 if (!is_prototyped && coerce_float_to_double_p)
194 {
195 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_double))
196 type = builtin->builtin_double;
197 else if (TYPE_LENGTH (type) > TYPE_LENGTH (builtin->builtin_double))
198 type = builtin->builtin_long_double;
199 }
200 break;
201 case TYPE_CODE_FUNC:
202 type = lookup_pointer_type (type);
203 break;
204 case TYPE_CODE_ARRAY:
205 /* Arrays are coerced to pointers to their first element, unless
206 they are vectors, in which case we want to leave them alone,
207 because they are passed by value. */
208 if (current_language->c_style_arrays)
209 if (!TYPE_VECTOR (type))
210 type = lookup_pointer_type (TYPE_TARGET_TYPE (type));
211 break;
212 case TYPE_CODE_UNDEF:
213 case TYPE_CODE_PTR:
214 case TYPE_CODE_STRUCT:
215 case TYPE_CODE_UNION:
216 case TYPE_CODE_VOID:
217 case TYPE_CODE_SET:
218 case TYPE_CODE_RANGE:
219 case TYPE_CODE_STRING:
220 case TYPE_CODE_ERROR:
221 case TYPE_CODE_MEMBERPTR:
222 case TYPE_CODE_METHODPTR:
223 case TYPE_CODE_METHOD:
224 case TYPE_CODE_COMPLEX:
225 default:
226 break;
227 }
228
229 return value_cast (type, arg);
230 }
231
232 /* Return the return type of a function with its first instruction exactly at
233 the PC address. Return NULL otherwise. */
234
235 static struct type *
236 find_function_return_type (CORE_ADDR pc)
237 {
238 struct symbol *sym = find_pc_function (pc);
239
240 if (sym != NULL && BLOCK_START (SYMBOL_BLOCK_VALUE (sym)) == pc
241 && SYMBOL_TYPE (sym) != NULL)
242 return TYPE_TARGET_TYPE (SYMBOL_TYPE (sym));
243
244 return NULL;
245 }
246
247 /* Determine a function's address and its return type from its value.
248 Calls error() if the function is not valid for calling. */
249
250 CORE_ADDR
251 find_function_addr (struct value *function, struct type **retval_type)
252 {
253 struct type *ftype = check_typedef (value_type (function));
254 struct gdbarch *gdbarch = get_type_arch (ftype);
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 (TYPE_CODE (ftype) == TYPE_CODE_FUNC
264 || TYPE_CODE (ftype) == TYPE_CODE_METHOD)
265 funaddr = value_address (function);
266 else if (TYPE_CODE (ftype) == TYPE_CODE_PTR)
267 {
268 funaddr = value_as_address (function);
269 ftype = check_typedef (TYPE_TARGET_TYPE (ftype));
270 if (TYPE_CODE (ftype) == TYPE_CODE_FUNC
271 || TYPE_CODE (ftype) == TYPE_CODE_METHOD)
272 funaddr = gdbarch_convert_from_func_ptr_addr (gdbarch, funaddr,
273 &current_target);
274 }
275 if (TYPE_CODE (ftype) == TYPE_CODE_FUNC
276 || TYPE_CODE (ftype) == TYPE_CODE_METHOD)
277 {
278 value_type = TYPE_TARGET_TYPE (ftype);
279
280 if (TYPE_GNU_IFUNC (ftype))
281 {
282 funaddr = gnu_ifunc_resolve_addr (gdbarch, funaddr);
283
284 /* Skip querying the function symbol if no RETVAL_TYPE has been
285 asked for. */
286 if (retval_type)
287 value_type = find_function_return_type (funaddr);
288 }
289 }
290 else if (TYPE_CODE (ftype) == TYPE_CODE_INT)
291 {
292 /* Handle the case of functions lacking debugging info.
293 Their values are characters since their addresses are char. */
294 if (TYPE_LENGTH (ftype) == 1)
295 funaddr = value_as_address (value_addr (function));
296 else
297 {
298 /* Handle function descriptors lacking debug info. */
299 int found_descriptor = 0;
300
301 funaddr = 0; /* pacify "gcc -Werror" */
302 if (VALUE_LVAL (function) == lval_memory)
303 {
304 CORE_ADDR nfunaddr;
305
306 funaddr = value_as_address (value_addr (function));
307 nfunaddr = funaddr;
308 funaddr = gdbarch_convert_from_func_ptr_addr (gdbarch, funaddr,
309 &current_target);
310 if (funaddr != nfunaddr)
311 found_descriptor = 1;
312 }
313 if (!found_descriptor)
314 /* Handle integer used as address of a function. */
315 funaddr = (CORE_ADDR) value_as_long (function);
316 }
317 }
318 else
319 error (_("Invalid data type for function to be called."));
320
321 if (retval_type != NULL)
322 *retval_type = value_type;
323 return funaddr + gdbarch_deprecated_function_start_offset (gdbarch);
324 }
325
326 /* For CALL_DUMMY_ON_STACK, push a breakpoint sequence that the called
327 function returns to. */
328
329 static CORE_ADDR
330 push_dummy_code (struct gdbarch *gdbarch,
331 CORE_ADDR sp, CORE_ADDR funaddr,
332 struct value **args, int nargs,
333 struct type *value_type,
334 CORE_ADDR *real_pc, CORE_ADDR *bp_addr,
335 struct regcache *regcache)
336 {
337 gdb_assert (gdbarch_push_dummy_code_p (gdbarch));
338
339 return gdbarch_push_dummy_code (gdbarch, sp, funaddr,
340 args, nargs, value_type, real_pc, bp_addr,
341 regcache);
342 }
343
344 /* See infcall.h. */
345
346 void
347 error_call_unknown_return_type (const char *func_name)
348 {
349 if (func_name != NULL)
350 error (_("'%s' has unknown return type; "
351 "cast the call to its declared return type"),
352 func_name);
353 else
354 error (_("function has unknown return type; "
355 "cast the call to its declared return type"));
356 }
357
358 /* Fetch the name of the function at FUNADDR.
359 This is used in printing an error message for call_function_by_hand.
360 BUF is used to print FUNADDR in hex if the function name cannot be
361 determined. It must be large enough to hold formatted result of
362 RAW_FUNCTION_ADDRESS_FORMAT. */
363
364 static const char *
365 get_function_name (CORE_ADDR funaddr, char *buf, int buf_size)
366 {
367 {
368 struct symbol *symbol = find_pc_function (funaddr);
369
370 if (symbol)
371 return SYMBOL_PRINT_NAME (symbol);
372 }
373
374 {
375 /* Try the minimal symbols. */
376 struct bound_minimal_symbol msymbol = lookup_minimal_symbol_by_pc (funaddr);
377
378 if (msymbol.minsym)
379 return MSYMBOL_PRINT_NAME (msymbol.minsym);
380 }
381
382 {
383 char *tmp = xstrprintf (_(RAW_FUNCTION_ADDRESS_FORMAT),
384 hex_string (funaddr));
385
386 gdb_assert (strlen (tmp) + 1 <= buf_size);
387 strcpy (buf, tmp);
388 xfree (tmp);
389 return buf;
390 }
391 }
392
393 /* All the meta data necessary to extract the call's return value. */
394
395 struct call_return_meta_info
396 {
397 /* The caller frame's architecture. */
398 struct gdbarch *gdbarch;
399
400 /* The called function. */
401 struct value *function;
402
403 /* The return value's type. */
404 struct type *value_type;
405
406 /* Are we returning a value using a structure return or a normal
407 value return? */
408 int struct_return_p;
409
410 /* If using a structure return, this is the structure's address. */
411 CORE_ADDR struct_addr;
412
413 /* Whether stack temporaries are enabled. */
414 int stack_temporaries_enabled;
415 };
416
417 /* Extract the called function's return value. */
418
419 static struct value *
420 get_call_return_value (struct call_return_meta_info *ri)
421 {
422 struct value *retval = NULL;
423 int stack_temporaries = thread_stack_temporaries_enabled_p (inferior_ptid);
424
425 if (TYPE_CODE (ri->value_type) == TYPE_CODE_VOID)
426 retval = allocate_value (ri->value_type);
427 else if (ri->struct_return_p)
428 {
429 if (stack_temporaries)
430 {
431 retval = value_from_contents_and_address (ri->value_type, NULL,
432 ri->struct_addr);
433 push_thread_stack_temporary (inferior_ptid, retval);
434 }
435 else
436 {
437 retval = allocate_value (ri->value_type);
438 read_value_memory (retval, 0, 1, ri->struct_addr,
439 value_contents_raw (retval),
440 TYPE_LENGTH (ri->value_type));
441 }
442 }
443 else
444 {
445 retval = allocate_value (ri->value_type);
446 gdbarch_return_value (ri->gdbarch, ri->function, ri->value_type,
447 get_current_regcache (),
448 value_contents_raw (retval), NULL);
449 if (stack_temporaries && class_or_union_p (ri->value_type))
450 {
451 /* Values of class type returned in registers are copied onto
452 the stack and their lval_type set to lval_memory. This is
453 required because further evaluation of the expression
454 could potentially invoke methods on the return value
455 requiring GDB to evaluate the "this" pointer. To evaluate
456 the this pointer, GDB needs the memory address of the
457 value. */
458 value_force_lval (retval, ri->struct_addr);
459 push_thread_stack_temporary (inferior_ptid, retval);
460 }
461 }
462
463 gdb_assert (retval != NULL);
464 return retval;
465 }
466
467 /* Data for the FSM that manages an infcall. It's main job is to
468 record the called function's return value. */
469
470 struct call_thread_fsm
471 {
472 /* The base class. */
473 struct thread_fsm thread_fsm;
474
475 /* All the info necessary to be able to extract the return
476 value. */
477 struct call_return_meta_info return_meta_info;
478
479 /* The called function's return value. This is extracted from the
480 target before the dummy frame is popped. */
481 struct value *return_value;
482
483 /* The top level that started the infcall (and is synchronously
484 waiting for it to end). */
485 struct ui *waiting_ui;
486 };
487
488 static int call_thread_fsm_should_stop (struct thread_fsm *self,
489 struct thread_info *thread);
490 static int call_thread_fsm_should_notify_stop (struct thread_fsm *self);
491
492 /* call_thread_fsm's vtable. */
493
494 static struct thread_fsm_ops call_thread_fsm_ops =
495 {
496 NULL, /*dtor */
497 NULL, /* clean_up */
498 call_thread_fsm_should_stop,
499 NULL, /* return_value */
500 NULL, /* async_reply_reason*/
501 call_thread_fsm_should_notify_stop,
502 };
503
504 /* Allocate a new call_thread_fsm object. */
505
506 static struct call_thread_fsm *
507 new_call_thread_fsm (struct ui *waiting_ui, struct interp *cmd_interp,
508 struct gdbarch *gdbarch, struct value *function,
509 struct type *value_type,
510 int struct_return_p, CORE_ADDR struct_addr)
511 {
512 struct call_thread_fsm *sm;
513
514 sm = XCNEW (struct call_thread_fsm);
515 thread_fsm_ctor (&sm->thread_fsm, &call_thread_fsm_ops, cmd_interp);
516
517 sm->return_meta_info.gdbarch = gdbarch;
518 sm->return_meta_info.function = function;
519 sm->return_meta_info.value_type = value_type;
520 sm->return_meta_info.struct_return_p = struct_return_p;
521 sm->return_meta_info.struct_addr = struct_addr;
522
523 sm->waiting_ui = waiting_ui;
524
525 return sm;
526 }
527
528 /* Implementation of should_stop method for infcalls. */
529
530 static int
531 call_thread_fsm_should_stop (struct thread_fsm *self,
532 struct thread_info *thread)
533 {
534 struct call_thread_fsm *f = (struct call_thread_fsm *) self;
535
536 if (stop_stack_dummy == STOP_STACK_DUMMY)
537 {
538 /* Done. */
539 thread_fsm_set_finished (self);
540
541 /* Stash the return value before the dummy frame is popped and
542 registers are restored to what they were before the
543 call.. */
544 f->return_value = get_call_return_value (&f->return_meta_info);
545
546 /* Break out of wait_sync_command_done. */
547 scoped_restore save_ui = make_scoped_restore (&current_ui, f->waiting_ui);
548 target_terminal::ours ();
549 f->waiting_ui->prompt_state = PROMPT_NEEDED;
550 }
551
552 return 1;
553 }
554
555 /* Implementation of should_notify_stop method for infcalls. */
556
557 static int
558 call_thread_fsm_should_notify_stop (struct thread_fsm *self)
559 {
560 if (thread_fsm_finished_p (self))
561 {
562 /* Infcall succeeded. Be silent and proceed with evaluating the
563 expression. */
564 return 0;
565 }
566
567 /* Something wrong happened. E.g., an unexpected breakpoint
568 triggered, or a signal was intercepted. Notify the stop. */
569 return 1;
570 }
571
572 /* Subroutine of call_function_by_hand to simplify it.
573 Start up the inferior and wait for it to stop.
574 Return the exception if there's an error, or an exception with
575 reason >= 0 if there's no error.
576
577 This is done inside a TRY_CATCH so the caller needn't worry about
578 thrown errors. The caller should rethrow if there's an error. */
579
580 static struct gdb_exception
581 run_inferior_call (struct call_thread_fsm *sm,
582 struct thread_info *call_thread, CORE_ADDR real_pc)
583 {
584 struct gdb_exception caught_error = exception_none;
585 int saved_in_infcall = call_thread->control.in_infcall;
586 ptid_t call_thread_ptid = call_thread->ptid;
587 enum prompt_state saved_prompt_state = current_ui->prompt_state;
588 int was_running = call_thread->state == THREAD_RUNNING;
589 int saved_ui_async = current_ui->async;
590
591 /* Infcalls run synchronously, in the foreground. */
592 current_ui->prompt_state = PROMPT_BLOCKED;
593 /* So that we don't print the prompt prematurely in
594 fetch_inferior_event. */
595 current_ui->async = 0;
596
597 delete_file_handler (current_ui->input_fd);
598
599 call_thread->control.in_infcall = 1;
600
601 clear_proceed_status (0);
602
603 /* Associate the FSM with the thread after clear_proceed_status
604 (otherwise it'd clear this FSM), and before anything throws, so
605 we don't leak it (and any resources it manages). */
606 call_thread->thread_fsm = &sm->thread_fsm;
607
608 disable_watchpoints_before_interactive_call_start ();
609
610 /* We want to print return value, please... */
611 call_thread->control.proceed_to_finish = 1;
612
613 TRY
614 {
615 proceed (real_pc, GDB_SIGNAL_0);
616
617 /* Inferior function calls are always synchronous, even if the
618 target supports asynchronous execution. */
619 wait_sync_command_done ();
620 }
621 CATCH (e, RETURN_MASK_ALL)
622 {
623 caught_error = e;
624 }
625 END_CATCH
626
627 /* If GDB has the prompt blocked before, then ensure that it remains
628 so. normal_stop calls async_enable_stdin, so reset the prompt
629 state again here. In other cases, stdin will be re-enabled by
630 inferior_event_handler, when an exception is thrown. */
631 current_ui->prompt_state = saved_prompt_state;
632 if (current_ui->prompt_state == PROMPT_BLOCKED)
633 delete_file_handler (current_ui->input_fd);
634 else
635 ui_register_input_event_handler (current_ui);
636 current_ui->async = saved_ui_async;
637
638 /* At this point the current thread may have changed. Refresh
639 CALL_THREAD as it could be invalid if its thread has exited. */
640 call_thread = find_thread_ptid (call_thread_ptid);
641
642 /* If the infcall does NOT succeed, normal_stop will have already
643 finished the thread states. However, on success, normal_stop
644 defers here, so that we can set back the thread states to what
645 they were before the call. Note that we must also finish the
646 state of new threads that might have spawned while the call was
647 running. The main cases to handle are:
648
649 - "(gdb) print foo ()", or any other command that evaluates an
650 expression at the prompt. (The thread was marked stopped before.)
651
652 - "(gdb) break foo if return_false()" or similar cases where we
653 do an infcall while handling an event (while the thread is still
654 marked running). In this example, whether the condition
655 evaluates true and thus we'll present a user-visible stop is
656 decided elsewhere. */
657 if (!was_running
658 && ptid_equal (call_thread_ptid, inferior_ptid)
659 && stop_stack_dummy == STOP_STACK_DUMMY)
660 finish_thread_state (user_visible_resume_ptid (0));
661
662 enable_watchpoints_after_interactive_call_stop ();
663
664 /* Call breakpoint_auto_delete on the current contents of the bpstat
665 of inferior call thread.
666 If all error()s out of proceed ended up calling normal_stop
667 (and perhaps they should; it already does in the special case
668 of error out of resume()), then we wouldn't need this. */
669 if (caught_error.reason < 0)
670 {
671 if (call_thread != NULL)
672 breakpoint_auto_delete (call_thread->control.stop_bpstat);
673 }
674
675 if (call_thread != NULL)
676 call_thread->control.in_infcall = saved_in_infcall;
677
678 return caught_error;
679 }
680
681 /* A cleanup function that calls delete_std_terminate_breakpoint. */
682 static void
683 cleanup_delete_std_terminate_breakpoint (void *ignore)
684 {
685 delete_std_terminate_breakpoint ();
686 }
687
688 /* See infcall.h. */
689
690 struct value *
691 call_function_by_hand (struct value *function,
692 type *default_return_type,
693 int nargs, struct value **args)
694 {
695 return call_function_by_hand_dummy (function, default_return_type,
696 nargs, args, NULL, NULL);
697 }
698
699 /* All this stuff with a dummy frame may seem unnecessarily complicated
700 (why not just save registers in GDB?). The purpose of pushing a dummy
701 frame which looks just like a real frame is so that if you call a
702 function and then hit a breakpoint (get a signal, etc), "backtrace"
703 will look right. Whether the backtrace needs to actually show the
704 stack at the time the inferior function was called is debatable, but
705 it certainly needs to not display garbage. So if you are contemplating
706 making dummy frames be different from normal frames, consider that. */
707
708 /* Perform a function call in the inferior.
709 ARGS is a vector of values of arguments (NARGS of them).
710 FUNCTION is a value, the function to be called.
711 Returns a value representing what the function returned.
712 May fail to return, if a breakpoint or signal is hit
713 during the execution of the function.
714
715 ARGS is modified to contain coerced values. */
716
717 struct value *
718 call_function_by_hand_dummy (struct value *function,
719 type *default_return_type,
720 int nargs, struct value **args,
721 dummy_frame_dtor_ftype *dummy_dtor,
722 void *dummy_dtor_data)
723 {
724 CORE_ADDR sp;
725 struct type *values_type, *target_values_type;
726 unsigned char struct_return = 0, hidden_first_param_p = 0;
727 CORE_ADDR struct_addr = 0;
728 struct infcall_control_state *inf_status;
729 struct cleanup *inf_status_cleanup;
730 struct infcall_suspend_state *caller_state;
731 CORE_ADDR funaddr;
732 CORE_ADDR real_pc;
733 struct type *ftype = check_typedef (value_type (function));
734 CORE_ADDR bp_addr;
735 struct frame_id dummy_id;
736 struct frame_info *frame;
737 struct gdbarch *gdbarch;
738 struct cleanup *terminate_bp_cleanup;
739 ptid_t call_thread_ptid;
740 struct gdb_exception e;
741 char name_buf[RAW_FUNCTION_ADDRESS_SIZE];
742 int stack_temporaries = thread_stack_temporaries_enabled_p (inferior_ptid);
743
744 if (TYPE_CODE (ftype) == TYPE_CODE_PTR)
745 ftype = check_typedef (TYPE_TARGET_TYPE (ftype));
746
747 if (!target_has_execution)
748 noprocess ();
749
750 if (get_traceframe_number () >= 0)
751 error (_("May not call functions while looking at trace frames."));
752
753 if (execution_direction == EXEC_REVERSE)
754 error (_("Cannot call functions in reverse mode."));
755
756 frame = get_current_frame ();
757 gdbarch = get_frame_arch (frame);
758
759 if (!gdbarch_push_dummy_call_p (gdbarch))
760 error (_("This target does not support function calls."));
761
762 /* A cleanup for the inferior status.
763 This is only needed while we're preparing the inferior function call. */
764 inf_status = save_infcall_control_state ();
765 inf_status_cleanup
766 = make_cleanup_restore_infcall_control_state (inf_status);
767
768 /* Save the caller's registers and other state associated with the
769 inferior itself so that they can be restored once the
770 callee returns. To allow nested calls the registers are (further
771 down) pushed onto a dummy frame stack. Include a cleanup (which
772 is tossed once the regcache has been pushed). */
773 caller_state = save_infcall_suspend_state ();
774 make_cleanup_restore_infcall_suspend_state (caller_state);
775
776 /* Ensure that the initial SP is correctly aligned. */
777 {
778 CORE_ADDR old_sp = get_frame_sp (frame);
779
780 if (gdbarch_frame_align_p (gdbarch))
781 {
782 sp = gdbarch_frame_align (gdbarch, old_sp);
783 /* NOTE: cagney/2003-08-13: Skip the "red zone". For some
784 ABIs, a function can use memory beyond the inner most stack
785 address. AMD64 called that region the "red zone". Skip at
786 least the "red zone" size before allocating any space on
787 the stack. */
788 if (gdbarch_inner_than (gdbarch, 1, 2))
789 sp -= gdbarch_frame_red_zone_size (gdbarch);
790 else
791 sp += gdbarch_frame_red_zone_size (gdbarch);
792 /* Still aligned? */
793 gdb_assert (sp == gdbarch_frame_align (gdbarch, sp));
794 /* NOTE: cagney/2002-09-18:
795
796 On a RISC architecture, a void parameterless generic dummy
797 frame (i.e., no parameters, no result) typically does not
798 need to push anything the stack and hence can leave SP and
799 FP. Similarly, a frameless (possibly leaf) function does
800 not push anything on the stack and, hence, that too can
801 leave FP and SP unchanged. As a consequence, a sequence of
802 void parameterless generic dummy frame calls to frameless
803 functions will create a sequence of effectively identical
804 frames (SP, FP and TOS and PC the same). This, not
805 suprisingly, results in what appears to be a stack in an
806 infinite loop --- when GDB tries to find a generic dummy
807 frame on the internal dummy frame stack, it will always
808 find the first one.
809
810 To avoid this problem, the code below always grows the
811 stack. That way, two dummy frames can never be identical.
812 It does burn a few bytes of stack but that is a small price
813 to pay :-). */
814 if (sp == old_sp)
815 {
816 if (gdbarch_inner_than (gdbarch, 1, 2))
817 /* Stack grows down. */
818 sp = gdbarch_frame_align (gdbarch, old_sp - 1);
819 else
820 /* Stack grows up. */
821 sp = gdbarch_frame_align (gdbarch, old_sp + 1);
822 }
823 /* SP may have underflown address zero here from OLD_SP. Memory access
824 functions will probably fail in such case but that is a target's
825 problem. */
826 }
827 else
828 /* FIXME: cagney/2002-09-18: Hey, you loose!
829
830 Who knows how badly aligned the SP is!
831
832 If the generic dummy frame ends up empty (because nothing is
833 pushed) GDB won't be able to correctly perform back traces.
834 If a target is having trouble with backtraces, first thing to
835 do is add FRAME_ALIGN() to the architecture vector. If that
836 fails, try dummy_id().
837
838 If the ABI specifies a "Red Zone" (see the doco) the code
839 below will quietly trash it. */
840 sp = old_sp;
841
842 /* Skip over the stack temporaries that might have been generated during
843 the evaluation of an expression. */
844 if (stack_temporaries)
845 {
846 struct value *lastval;
847
848 lastval = get_last_thread_stack_temporary (inferior_ptid);
849 if (lastval != NULL)
850 {
851 CORE_ADDR lastval_addr = value_address (lastval);
852
853 if (gdbarch_inner_than (gdbarch, 1, 2))
854 {
855 gdb_assert (sp >= lastval_addr);
856 sp = lastval_addr;
857 }
858 else
859 {
860 gdb_assert (sp <= lastval_addr);
861 sp = lastval_addr + TYPE_LENGTH (value_type (lastval));
862 }
863
864 if (gdbarch_frame_align_p (gdbarch))
865 sp = gdbarch_frame_align (gdbarch, sp);
866 }
867 }
868 }
869
870 funaddr = find_function_addr (function, &values_type);
871 if (values_type == NULL)
872 values_type = default_return_type;
873 if (values_type == NULL)
874 {
875 const char *name = get_function_name (funaddr,
876 name_buf, sizeof (name_buf));
877 error (_("'%s' has unknown return type; "
878 "cast the call to its declared return type"),
879 name);
880 }
881
882 values_type = check_typedef (values_type);
883
884 /* Are we returning a value using a structure return (passing a
885 hidden argument pointing to storage) or a normal value return?
886 There are two cases: language-mandated structure return and
887 target ABI structure return. The variable STRUCT_RETURN only
888 describes the latter. The language version is handled by passing
889 the return location as the first parameter to the function,
890 even preceding "this". This is different from the target
891 ABI version, which is target-specific; for instance, on ia64
892 the first argument is passed in out0 but the hidden structure
893 return pointer would normally be passed in r8. */
894
895 if (gdbarch_return_in_first_hidden_param_p (gdbarch, values_type))
896 {
897 hidden_first_param_p = 1;
898
899 /* Tell the target specific argument pushing routine not to
900 expect a value. */
901 target_values_type = builtin_type (gdbarch)->builtin_void;
902 }
903 else
904 {
905 struct_return = using_struct_return (gdbarch, function, values_type);
906 target_values_type = values_type;
907 }
908
909 observer_notify_inferior_call_pre (inferior_ptid, funaddr);
910
911 /* Determine the location of the breakpoint (and possibly other
912 stuff) that the called function will return to. The SPARC, for a
913 function returning a structure or union, needs to make space for
914 not just the breakpoint but also an extra word containing the
915 size (?) of the structure being passed. */
916
917 switch (gdbarch_call_dummy_location (gdbarch))
918 {
919 case ON_STACK:
920 {
921 const gdb_byte *bp_bytes;
922 CORE_ADDR bp_addr_as_address;
923 int bp_size;
924
925 /* Be careful BP_ADDR is in inferior PC encoding while
926 BP_ADDR_AS_ADDRESS is a plain memory address. */
927
928 sp = push_dummy_code (gdbarch, sp, funaddr, args, nargs,
929 target_values_type, &real_pc, &bp_addr,
930 get_current_regcache ());
931
932 /* Write a legitimate instruction at the point where the infcall
933 breakpoint is going to be inserted. While this instruction
934 is never going to be executed, a user investigating the
935 memory from GDB would see this instruction instead of random
936 uninitialized bytes. We chose the breakpoint instruction
937 as it may look as the most logical one to the user and also
938 valgrind 3.7.0 needs it for proper vgdb inferior calls.
939
940 If software breakpoints are unsupported for this target we
941 leave the user visible memory content uninitialized. */
942
943 bp_addr_as_address = bp_addr;
944 bp_bytes = gdbarch_breakpoint_from_pc (gdbarch, &bp_addr_as_address,
945 &bp_size);
946 if (bp_bytes != NULL)
947 write_memory (bp_addr_as_address, bp_bytes, bp_size);
948 }
949 break;
950 case AT_ENTRY_POINT:
951 {
952 CORE_ADDR dummy_addr;
953
954 real_pc = funaddr;
955 dummy_addr = entry_point_address ();
956
957 /* A call dummy always consists of just a single breakpoint, so
958 its address is the same as the address of the dummy.
959
960 The actual breakpoint is inserted separatly so there is no need to
961 write that out. */
962 bp_addr = dummy_addr;
963 break;
964 }
965 default:
966 internal_error (__FILE__, __LINE__, _("bad switch"));
967 }
968
969 if (nargs < TYPE_NFIELDS (ftype))
970 error (_("Too few arguments in function call."));
971
972 {
973 int i;
974
975 for (i = nargs - 1; i >= 0; i--)
976 {
977 int prototyped;
978 struct type *param_type;
979
980 /* FIXME drow/2002-05-31: Should just always mark methods as
981 prototyped. Can we respect TYPE_VARARGS? Probably not. */
982 if (TYPE_CODE (ftype) == TYPE_CODE_METHOD)
983 prototyped = 1;
984 if (TYPE_TARGET_TYPE (ftype) == NULL && TYPE_NFIELDS (ftype) == 0
985 && default_return_type != NULL)
986 {
987 /* Calling a no-debug function with the return type
988 explicitly cast. Assume the function is prototyped,
989 with a prototype matching the types of the arguments.
990 E.g., with:
991 float mult (float v1, float v2) { return v1 * v2; }
992 This:
993 (gdb) p (float) mult (2.0f, 3.0f)
994 Is a simpler alternative to:
995 (gdb) p ((float (*) (float, float)) mult) (2.0f, 3.0f)
996 */
997 prototyped = 1;
998 }
999 else if (i < TYPE_NFIELDS (ftype))
1000 prototyped = TYPE_PROTOTYPED (ftype);
1001 else
1002 prototyped = 0;
1003
1004 if (i < TYPE_NFIELDS (ftype))
1005 param_type = TYPE_FIELD_TYPE (ftype, i);
1006 else
1007 param_type = NULL;
1008
1009 args[i] = value_arg_coerce (gdbarch, args[i],
1010 param_type, prototyped, &sp);
1011
1012 if (param_type != NULL && language_pass_by_reference (param_type))
1013 args[i] = value_addr (args[i]);
1014 }
1015 }
1016
1017 /* Reserve space for the return structure to be written on the
1018 stack, if necessary. Make certain that the value is correctly
1019 aligned.
1020
1021 While evaluating expressions, we reserve space on the stack for
1022 return values of class type even if the language ABI and the target
1023 ABI do not require that the return value be passed as a hidden first
1024 argument. This is because we want to store the return value as an
1025 on-stack temporary while the expression is being evaluated. This
1026 enables us to have chained function calls in expressions.
1027
1028 Keeping the return values as on-stack temporaries while the expression
1029 is being evaluated is OK because the thread is stopped until the
1030 expression is completely evaluated. */
1031
1032 if (struct_return || hidden_first_param_p
1033 || (stack_temporaries && class_or_union_p (values_type)))
1034 {
1035 if (gdbarch_inner_than (gdbarch, 1, 2))
1036 {
1037 /* Stack grows downward. Align STRUCT_ADDR and SP after
1038 making space for the return value. */
1039 sp -= TYPE_LENGTH (values_type);
1040 if (gdbarch_frame_align_p (gdbarch))
1041 sp = gdbarch_frame_align (gdbarch, sp);
1042 struct_addr = sp;
1043 }
1044 else
1045 {
1046 /* Stack grows upward. Align the frame, allocate space, and
1047 then again, re-align the frame??? */
1048 if (gdbarch_frame_align_p (gdbarch))
1049 sp = gdbarch_frame_align (gdbarch, sp);
1050 struct_addr = sp;
1051 sp += TYPE_LENGTH (values_type);
1052 if (gdbarch_frame_align_p (gdbarch))
1053 sp = gdbarch_frame_align (gdbarch, sp);
1054 }
1055 }
1056
1057 std::vector<struct value *> new_args;
1058 if (hidden_first_param_p)
1059 {
1060 /* Add the new argument to the front of the argument list. */
1061 new_args.push_back
1062 (value_from_pointer (lookup_pointer_type (values_type), struct_addr));
1063 std::copy (&args[0], &args[nargs], std::back_inserter (new_args));
1064 args = new_args.data ();
1065 nargs++;
1066 }
1067
1068 /* Create the dummy stack frame. Pass in the call dummy address as,
1069 presumably, the ABI code knows where, in the call dummy, the
1070 return address should be pointed. */
1071 sp = gdbarch_push_dummy_call (gdbarch, function, get_current_regcache (),
1072 bp_addr, nargs, args,
1073 sp, struct_return, struct_addr);
1074
1075 /* Set up a frame ID for the dummy frame so we can pass it to
1076 set_momentary_breakpoint. We need to give the breakpoint a frame
1077 ID so that the breakpoint code can correctly re-identify the
1078 dummy breakpoint. */
1079 /* Sanity. The exact same SP value is returned by PUSH_DUMMY_CALL,
1080 saved as the dummy-frame TOS, and used by dummy_id to form
1081 the frame ID's stack address. */
1082 dummy_id = frame_id_build (sp, bp_addr);
1083
1084 /* Create a momentary breakpoint at the return address of the
1085 inferior. That way it breaks when it returns. */
1086
1087 {
1088 symtab_and_line sal;
1089 sal.pspace = current_program_space;
1090 sal.pc = bp_addr;
1091 sal.section = find_pc_overlay (sal.pc);
1092
1093 /* Sanity. The exact same SP value is returned by
1094 PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by
1095 dummy_id to form the frame ID's stack address. */
1096 breakpoint *bpt
1097 = set_momentary_breakpoint (gdbarch, sal,
1098 dummy_id, bp_call_dummy).release ();
1099
1100 /* set_momentary_breakpoint invalidates FRAME. */
1101 frame = NULL;
1102
1103 bpt->disposition = disp_del;
1104 gdb_assert (bpt->related_breakpoint == bpt);
1105
1106 breakpoint *longjmp_b = set_longjmp_breakpoint_for_call_dummy ();
1107 if (longjmp_b)
1108 {
1109 /* Link BPT into the chain of LONGJMP_B. */
1110 bpt->related_breakpoint = longjmp_b;
1111 while (longjmp_b->related_breakpoint != bpt->related_breakpoint)
1112 longjmp_b = longjmp_b->related_breakpoint;
1113 longjmp_b->related_breakpoint = bpt;
1114 }
1115 }
1116
1117 /* Create a breakpoint in std::terminate.
1118 If a C++ exception is raised in the dummy-frame, and the
1119 exception handler is (normally, and expected to be) out-of-frame,
1120 the default C++ handler will (wrongly) be called in an inferior
1121 function call. This is wrong, as an exception can be normally
1122 and legally handled out-of-frame. The confines of the dummy frame
1123 prevent the unwinder from finding the correct handler (or any
1124 handler, unless it is in-frame). The default handler calls
1125 std::terminate. This will kill the inferior. Assert that
1126 terminate should never be called in an inferior function
1127 call. Place a momentary breakpoint in the std::terminate function
1128 and if triggered in the call, rewind. */
1129 if (unwind_on_terminating_exception_p)
1130 set_std_terminate_breakpoint ();
1131
1132 /* Discard both inf_status and caller_state cleanups.
1133 From this point on we explicitly restore the associated state
1134 or discard it. */
1135 discard_cleanups (inf_status_cleanup);
1136
1137 /* Everything's ready, push all the info needed to restore the
1138 caller (and identify the dummy-frame) onto the dummy-frame
1139 stack. */
1140 dummy_frame_push (caller_state, &dummy_id, inferior_ptid);
1141 if (dummy_dtor != NULL)
1142 register_dummy_frame_dtor (dummy_id, inferior_ptid,
1143 dummy_dtor, dummy_dtor_data);
1144
1145 /* Register a clean-up for unwind_on_terminating_exception_breakpoint. */
1146 terminate_bp_cleanup = make_cleanup (cleanup_delete_std_terminate_breakpoint,
1147 NULL);
1148
1149 /* - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP -
1150 If you're looking to implement asynchronous dummy-frames, then
1151 just below is the place to chop this function in two.. */
1152
1153 /* TP is invalid after run_inferior_call returns, so enclose this
1154 in a block so that it's only in scope during the time it's valid. */
1155 {
1156 struct thread_info *tp = inferior_thread ();
1157 struct thread_fsm *saved_sm;
1158 struct call_thread_fsm *sm;
1159
1160 /* Save the current FSM. We'll override it. */
1161 saved_sm = tp->thread_fsm;
1162 tp->thread_fsm = NULL;
1163
1164 /* Save this thread's ptid, we need it later but the thread
1165 may have exited. */
1166 call_thread_ptid = tp->ptid;
1167
1168 /* Run the inferior until it stops. */
1169
1170 /* Create the FSM used to manage the infcall. It tells infrun to
1171 not report the stop to the user, and captures the return value
1172 before the dummy frame is popped. run_inferior_call registers
1173 it with the thread ASAP. */
1174 sm = new_call_thread_fsm (current_ui, command_interp (),
1175 gdbarch, function,
1176 values_type,
1177 struct_return || hidden_first_param_p,
1178 struct_addr);
1179
1180 e = run_inferior_call (sm, tp, real_pc);
1181
1182 observer_notify_inferior_call_post (call_thread_ptid, funaddr);
1183
1184 tp = find_thread_ptid (call_thread_ptid);
1185 if (tp != NULL)
1186 {
1187 /* The FSM should still be the same. */
1188 gdb_assert (tp->thread_fsm == &sm->thread_fsm);
1189
1190 if (thread_fsm_finished_p (tp->thread_fsm))
1191 {
1192 struct value *retval;
1193
1194 /* The inferior call is successful. Pop the dummy frame,
1195 which runs its destructors and restores the inferior's
1196 suspend state, and restore the inferior control
1197 state. */
1198 dummy_frame_pop (dummy_id, call_thread_ptid);
1199 restore_infcall_control_state (inf_status);
1200
1201 /* Get the return value. */
1202 retval = sm->return_value;
1203
1204 /* Clean up / destroy the call FSM, and restore the
1205 original one. */
1206 thread_fsm_clean_up (tp->thread_fsm, tp);
1207 thread_fsm_delete (tp->thread_fsm);
1208 tp->thread_fsm = saved_sm;
1209
1210 maybe_remove_breakpoints ();
1211
1212 do_cleanups (terminate_bp_cleanup);
1213 gdb_assert (retval != NULL);
1214 return retval;
1215 }
1216
1217 /* Didn't complete. Restore previous state machine, and
1218 handle the error. */
1219 tp->thread_fsm = saved_sm;
1220 }
1221 }
1222
1223 /* Rethrow an error if we got one trying to run the inferior. */
1224
1225 if (e.reason < 0)
1226 {
1227 const char *name = get_function_name (funaddr,
1228 name_buf, sizeof (name_buf));
1229
1230 discard_infcall_control_state (inf_status);
1231
1232 /* We could discard the dummy frame here if the program exited,
1233 but it will get garbage collected the next time the program is
1234 run anyway. */
1235
1236 switch (e.reason)
1237 {
1238 case RETURN_ERROR:
1239 throw_error (e.error, _("%s\n\
1240 An error occurred while in a function called from GDB.\n\
1241 Evaluation of the expression containing the function\n\
1242 (%s) will be abandoned.\n\
1243 When the function is done executing, GDB will silently stop."),
1244 e.message, name);
1245 case RETURN_QUIT:
1246 default:
1247 throw_exception (e);
1248 }
1249 }
1250
1251 /* If the program has exited, or we stopped at a different thread,
1252 exit and inform the user. */
1253
1254 if (! target_has_execution)
1255 {
1256 const char *name = get_function_name (funaddr,
1257 name_buf, sizeof (name_buf));
1258
1259 /* If we try to restore the inferior status,
1260 we'll crash as the inferior is no longer running. */
1261 discard_infcall_control_state (inf_status);
1262
1263 /* We could discard the dummy frame here given that the program exited,
1264 but it will get garbage collected the next time the program is
1265 run anyway. */
1266
1267 error (_("The program being debugged exited while in a function "
1268 "called from GDB.\n"
1269 "Evaluation of the expression containing the function\n"
1270 "(%s) will be abandoned."),
1271 name);
1272 }
1273
1274 if (! ptid_equal (call_thread_ptid, inferior_ptid))
1275 {
1276 const char *name = get_function_name (funaddr,
1277 name_buf, sizeof (name_buf));
1278
1279 /* We've switched threads. This can happen if another thread gets a
1280 signal or breakpoint while our thread was running.
1281 There's no point in restoring the inferior status,
1282 we're in a different thread. */
1283 discard_infcall_control_state (inf_status);
1284 /* Keep the dummy frame record, if the user switches back to the
1285 thread with the hand-call, we'll need it. */
1286 if (stopped_by_random_signal)
1287 error (_("\
1288 The program received a signal in another thread while\n\
1289 making a function call from GDB.\n\
1290 Evaluation of the expression containing the function\n\
1291 (%s) will be abandoned.\n\
1292 When the function is done executing, GDB will silently stop."),
1293 name);
1294 else
1295 error (_("\
1296 The program stopped in another thread while making a function call from GDB.\n\
1297 Evaluation of the expression containing the function\n\
1298 (%s) will be abandoned.\n\
1299 When the function is done executing, GDB will silently stop."),
1300 name);
1301 }
1302
1303 {
1304 /* Make a copy as NAME may be in an objfile freed by dummy_frame_pop. */
1305 std::string name = get_function_name (funaddr, name_buf,
1306 sizeof (name_buf));
1307
1308 if (stopped_by_random_signal)
1309 {
1310 /* We stopped inside the FUNCTION because of a random
1311 signal. Further execution of the FUNCTION is not
1312 allowed. */
1313
1314 if (unwind_on_signal_p)
1315 {
1316 /* The user wants the context restored. */
1317
1318 /* We must get back to the frame we were before the
1319 dummy call. */
1320 dummy_frame_pop (dummy_id, call_thread_ptid);
1321
1322 /* We also need to restore inferior status to that before the
1323 dummy call. */
1324 restore_infcall_control_state (inf_status);
1325
1326 /* FIXME: Insert a bunch of wrap_here; name can be very
1327 long if it's a C++ name with arguments and stuff. */
1328 error (_("\
1329 The program being debugged was signaled while in a function called from GDB.\n\
1330 GDB has restored the context to what it was before the call.\n\
1331 To change this behavior use \"set unwindonsignal off\".\n\
1332 Evaluation of the expression containing the function\n\
1333 (%s) will be abandoned."),
1334 name.c_str ());
1335 }
1336 else
1337 {
1338 /* The user wants to stay in the frame where we stopped
1339 (default).
1340 Discard inferior status, we're not at the same point
1341 we started at. */
1342 discard_infcall_control_state (inf_status);
1343
1344 /* FIXME: Insert a bunch of wrap_here; name can be very
1345 long if it's a C++ name with arguments and stuff. */
1346 error (_("\
1347 The program being debugged was signaled while in a function called from GDB.\n\
1348 GDB remains in the frame where the signal was received.\n\
1349 To change this behavior use \"set unwindonsignal on\".\n\
1350 Evaluation of the expression containing the function\n\
1351 (%s) will be abandoned.\n\
1352 When the function is done executing, GDB will silently stop."),
1353 name.c_str ());
1354 }
1355 }
1356
1357 if (stop_stack_dummy == STOP_STD_TERMINATE)
1358 {
1359 /* We must get back to the frame we were before the dummy
1360 call. */
1361 dummy_frame_pop (dummy_id, call_thread_ptid);
1362
1363 /* We also need to restore inferior status to that before
1364 the dummy call. */
1365 restore_infcall_control_state (inf_status);
1366
1367 error (_("\
1368 The program being debugged entered a std::terminate call, most likely\n\
1369 caused by an unhandled C++ exception. GDB blocked this call in order\n\
1370 to prevent the program from being terminated, and has restored the\n\
1371 context to its original state before the call.\n\
1372 To change this behaviour use \"set unwind-on-terminating-exception off\".\n\
1373 Evaluation of the expression containing the function (%s)\n\
1374 will be abandoned."),
1375 name.c_str ());
1376 }
1377 else if (stop_stack_dummy == STOP_NONE)
1378 {
1379
1380 /* We hit a breakpoint inside the FUNCTION.
1381 Keep the dummy frame, the user may want to examine its state.
1382 Discard inferior status, we're not at the same point
1383 we started at. */
1384 discard_infcall_control_state (inf_status);
1385
1386 /* The following error message used to say "The expression
1387 which contained the function call has been discarded."
1388 It is a hard concept to explain in a few words. Ideally,
1389 GDB would be able to resume evaluation of the expression
1390 when the function finally is done executing. Perhaps
1391 someday this will be implemented (it would not be easy). */
1392 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
1393 a C++ name with arguments and stuff. */
1394 error (_("\
1395 The program being debugged stopped while in a function called from GDB.\n\
1396 Evaluation of the expression containing the function\n\
1397 (%s) will be abandoned.\n\
1398 When the function is done executing, GDB will silently stop."),
1399 name.c_str ());
1400 }
1401
1402 }
1403
1404 /* The above code errors out, so ... */
1405 gdb_assert_not_reached ("... should not be here");
1406 }
1407
1408 void
1409 _initialize_infcall (void)
1410 {
1411 add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure,
1412 &coerce_float_to_double_p, _("\
1413 Set coercion of floats to doubles when calling functions."), _("\
1414 Show coercion of floats to doubles when calling functions"), _("\
1415 Variables of type float should generally be converted to doubles before\n\
1416 calling an unprototyped function, and left alone when calling a prototyped\n\
1417 function. However, some older debug info formats do not provide enough\n\
1418 information to determine that a function is prototyped. If this flag is\n\
1419 set, GDB will perform the conversion for a function it considers\n\
1420 unprototyped.\n\
1421 The default is to perform the conversion.\n"),
1422 NULL,
1423 show_coerce_float_to_double_p,
1424 &setlist, &showlist);
1425
1426 add_setshow_boolean_cmd ("unwindonsignal", no_class,
1427 &unwind_on_signal_p, _("\
1428 Set unwinding of stack if a signal is received while in a call dummy."), _("\
1429 Show unwinding of stack if a signal is received while in a call dummy."), _("\
1430 The unwindonsignal lets the user determine what gdb should do if a signal\n\
1431 is received while in a function called from gdb (call dummy). If set, gdb\n\
1432 unwinds the stack and restore the context to what as it was before the call.\n\
1433 The default is to stop in the frame where the signal was received."),
1434 NULL,
1435 show_unwind_on_signal_p,
1436 &setlist, &showlist);
1437
1438 add_setshow_boolean_cmd ("unwind-on-terminating-exception", no_class,
1439 &unwind_on_terminating_exception_p, _("\
1440 Set unwinding of stack if std::terminate is called while in call dummy."), _("\
1441 Show unwinding of stack if std::terminate() is called while in a call dummy."),
1442 _("\
1443 The unwind on terminating exception flag lets the user determine\n\
1444 what gdb should do if a std::terminate() call is made from the\n\
1445 default exception handler. If set, gdb unwinds the stack and restores\n\
1446 the context to what it was before the call. If unset, gdb allows the\n\
1447 std::terminate call to proceed.\n\
1448 The default is to unwind the frame."),
1449 NULL,
1450 show_unwind_on_terminating_exception_p,
1451 &setlist, &showlist);
1452
1453 }
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