Fix search in TUI
[deliverable/binutils-gdb.git] / gdb / infcall.c
CommitLineData
04714b91
AC
1/* Perform an inferior function call, for GDB, the GNU debugger.
2
b811d2c2 3 Copyright (C) 1986-2020 Free Software Foundation, Inc.
04714b91
AC
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
a9762ec7 9 the Free Software Foundation; either version 3 of the License, or
04714b91
AC
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
a9762ec7 18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
04714b91
AC
19
20#include "defs.h"
0700e23e 21#include "infcall.h"
04714b91 22#include "breakpoint.h"
573cda03 23#include "tracepoint.h"
04714b91
AC
24#include "target.h"
25#include "regcache.h"
26#include "inferior.h"
45741a9c 27#include "infrun.h"
04714b91
AC
28#include "block.h"
29#include "gdbcore.h"
30#include "language.h"
9ab9195f 31#include "objfiles.h"
04714b91
AC
32#include "gdbcmd.h"
33#include "command.h"
96860204 34#include "dummy-frame.h"
a93c0eb6 35#include "ada-lang.h"
aa3cfbda 36#include "f-lang.h"
347bddb7 37#include "gdbthread.h"
beb460e8 38#include "event-top.h"
76727919 39#include "observable.h"
0b333c5e
PA
40#include "top.h"
41#include "interps.h"
388a7084 42#include "thread-fsm.h"
6ccb583f 43#include <algorithm>
268a13a5 44#include "gdbsupport/scope-exit.h"
099a6354 45#include <list>
b89667eb
DE
46
47/* If we can't find a function's name from its address,
48 we print this instead. */
49#define RAW_FUNCTION_ADDRESS_FORMAT "at 0x%s"
50#define RAW_FUNCTION_ADDRESS_SIZE (sizeof (RAW_FUNCTION_ADDRESS_FORMAT) \
51 + 2 * sizeof (CORE_ADDR))
04714b91
AC
52
53/* NOTE: cagney/2003-04-16: What's the future of this code?
54
55 GDB needs an asynchronous expression evaluator, that means an
56 asynchronous inferior function call implementation, and that in
57 turn means restructuring the code so that it is event driven. */
58
491144b5 59static bool may_call_functions_p = true;
136afab8
PW
60static void
61show_may_call_functions_p (struct ui_file *file, int from_tty,
62 struct cmd_list_element *c,
63 const char *value)
64{
65 fprintf_filtered (file,
66 _("Permission to call functions in the program is %s.\n"),
67 value);
68}
69
04714b91
AC
70/* How you should pass arguments to a function depends on whether it
71 was defined in K&R style or prototype style. If you define a
72 function using the K&R syntax that takes a `float' argument, then
73 callers must pass that argument as a `double'. If you define the
74 function using the prototype syntax, then you must pass the
75 argument as a `float', with no promotion.
76
77 Unfortunately, on certain older platforms, the debug info doesn't
78 indicate reliably how each function was defined. A function type's
a9ff5f12
UW
79 TYPE_PROTOTYPED flag may be clear, even if the function was defined
80 in prototype style. When calling a function whose TYPE_PROTOTYPED
81 flag is clear, GDB consults this flag to decide what to do.
04714b91
AC
82
83 For modern targets, it is proper to assume that, if the prototype
84 flag is clear, that can be trusted: `float' arguments should be
85 promoted to `double'. For some older targets, if the prototype
86 flag is clear, that doesn't tell us anything. The default is to
87 trust the debug information; the user can override this behavior
88 with "set coerce-float-to-double 0". */
89
491144b5 90static bool coerce_float_to_double_p = true;
920d2a44
AC
91static void
92show_coerce_float_to_double_p (struct ui_file *file, int from_tty,
93 struct cmd_list_element *c, const char *value)
94{
3e43a32a
MS
95 fprintf_filtered (file,
96 _("Coercion of floats to doubles "
97 "when calling functions is %s.\n"),
920d2a44
AC
98 value);
99}
04714b91
AC
100
101/* This boolean tells what gdb should do if a signal is received while
102 in a function called from gdb (call dummy). If set, gdb unwinds
103 the stack and restore the context to what as it was before the
104 call.
105
1777feb0 106 The default is to stop in the frame where the signal was received. */
04714b91 107
491144b5 108static bool unwind_on_signal_p = false;
920d2a44
AC
109static void
110show_unwind_on_signal_p (struct ui_file *file, int from_tty,
111 struct cmd_list_element *c, const char *value)
112{
3e43a32a
MS
113 fprintf_filtered (file,
114 _("Unwinding of stack if a signal is "
115 "received while in a call dummy is %s.\n"),
920d2a44
AC
116 value);
117}
118
7cd1089b
PM
119/* This boolean tells what gdb should do if a std::terminate call is
120 made while in a function called from gdb (call dummy).
121 As the confines of a single dummy stack prohibit out-of-frame
122 handlers from handling a raised exception, and as out-of-frame
123 handlers are common in C++, this can lead to no handler being found
124 by the unwinder, and a std::terminate call. This is a false positive.
125 If set, gdb unwinds the stack and restores the context to what it
126 was before the call.
127
128 The default is to unwind the frame if a std::terminate call is
129 made. */
130
491144b5 131static bool unwind_on_terminating_exception_p = true;
7cd1089b
PM
132
133static void
134show_unwind_on_terminating_exception_p (struct ui_file *file, int from_tty,
135 struct cmd_list_element *c,
136 const char *value)
137
138{
3e43a32a
MS
139 fprintf_filtered (file,
140 _("Unwind stack if a C++ exception is "
141 "unhandled while in a call dummy is %s.\n"),
7cd1089b
PM
142 value);
143}
04714b91
AC
144
145/* Perform the standard coercions that are specified
aa3cfbda 146 for arguments to be passed to C, Ada or Fortran functions.
04714b91
AC
147
148 If PARAM_TYPE is non-NULL, it is the expected parameter type.
37055cad 149 IS_PROTOTYPED is non-zero if the function declaration is prototyped. */
04714b91
AC
150
151static struct value *
7788af6d 152value_arg_coerce (struct gdbarch *gdbarch, struct value *arg,
37055cad 153 struct type *param_type, int is_prototyped)
04714b91 154{
7788af6d 155 const struct builtin_type *builtin = builtin_type (gdbarch);
df407dfe 156 struct type *arg_type = check_typedef (value_type (arg));
52f0bd74 157 struct type *type
04714b91
AC
158 = param_type ? check_typedef (param_type) : arg_type;
159
aa3cfbda 160 /* Perform any Ada- and Fortran-specific coercion first. */
a93c0eb6 161 if (current_language->la_language == language_ada)
40bc484c 162 arg = ada_convert_actual (arg, type);
aa3cfbda
RB
163 else if (current_language->la_language == language_fortran)
164 type = fortran_preserve_arg_pointer (arg, type);
a93c0eb6 165
63092375
DJ
166 /* Force the value to the target if we will need its address. At
167 this point, we could allocate arguments on the stack instead of
168 calling malloc if we knew that their addresses would not be
169 saved by the called function. */
170 arg = value_coerce_to_target (arg);
171
04714b91
AC
172 switch (TYPE_CODE (type))
173 {
174 case TYPE_CODE_REF:
aa006118 175 case TYPE_CODE_RVALUE_REF:
fb933624
DJ
176 {
177 struct value *new_value;
178
aa006118 179 if (TYPE_IS_REFERENCE (arg_type))
b1af9e97 180 return value_cast_pointers (type, arg, 0);
fb933624
DJ
181
182 /* Cast the value to the reference's target type, and then
183 convert it back to a reference. This will issue an error
184 if the value was not previously in memory - in some cases
185 we should clearly be allowing this, but how? */
186 new_value = value_cast (TYPE_TARGET_TYPE (type), arg);
a65cfae5 187 new_value = value_ref (new_value, TYPE_CODE (type));
fb933624
DJ
188 return new_value;
189 }
04714b91
AC
190 case TYPE_CODE_INT:
191 case TYPE_CODE_CHAR:
192 case TYPE_CODE_BOOL:
193 case TYPE_CODE_ENUM:
194 /* If we don't have a prototype, coerce to integer type if necessary. */
195 if (!is_prototyped)
196 {
7788af6d
UW
197 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_int))
198 type = builtin->builtin_int;
04714b91
AC
199 }
200 /* Currently all target ABIs require at least the width of an integer
201 type for an argument. We may have to conditionalize the following
202 type coercion for future targets. */
7788af6d
UW
203 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_int))
204 type = builtin->builtin_int;
04714b91
AC
205 break;
206 case TYPE_CODE_FLT:
207 if (!is_prototyped && coerce_float_to_double_p)
208 {
7788af6d
UW
209 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_double))
210 type = builtin->builtin_double;
211 else if (TYPE_LENGTH (type) > TYPE_LENGTH (builtin->builtin_double))
212 type = builtin->builtin_long_double;
04714b91
AC
213 }
214 break;
215 case TYPE_CODE_FUNC:
216 type = lookup_pointer_type (type);
217 break;
218 case TYPE_CODE_ARRAY:
219 /* Arrays are coerced to pointers to their first element, unless
220 they are vectors, in which case we want to leave them alone,
221 because they are passed by value. */
222 if (current_language->c_style_arrays)
223 if (!TYPE_VECTOR (type))
224 type = lookup_pointer_type (TYPE_TARGET_TYPE (type));
225 break;
226 case TYPE_CODE_UNDEF:
227 case TYPE_CODE_PTR:
228 case TYPE_CODE_STRUCT:
229 case TYPE_CODE_UNION:
230 case TYPE_CODE_VOID:
231 case TYPE_CODE_SET:
232 case TYPE_CODE_RANGE:
233 case TYPE_CODE_STRING:
04714b91 234 case TYPE_CODE_ERROR:
0d5de010
DJ
235 case TYPE_CODE_MEMBERPTR:
236 case TYPE_CODE_METHODPTR:
04714b91
AC
237 case TYPE_CODE_METHOD:
238 case TYPE_CODE_COMPLEX:
239 default:
240 break;
241 }
242
243 return value_cast (type, arg);
244}
245
8388016d 246/* See infcall.h. */
04714b91 247
a9fa03de 248CORE_ADDR
8388016d
PA
249find_function_addr (struct value *function,
250 struct type **retval_type,
251 struct type **function_type)
04714b91 252{
df407dfe 253 struct type *ftype = check_typedef (value_type (function));
50810684 254 struct gdbarch *gdbarch = get_type_arch (ftype);
7788af6d 255 struct type *value_type = NULL;
09b58708
JK
256 /* Initialize it just to avoid a GCC false warning. */
257 CORE_ADDR funaddr = 0;
04714b91
AC
258
259 /* If it's a member function, just look at the function
260 part of it. */
261
262 /* Determine address to call. */
300f8e10
JK
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)
04714b91
AC
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)
300f8e10 272 funaddr = gdbarch_convert_from_func_ptr_addr (gdbarch, funaddr,
8b88a78e 273 current_top_target ());
04714b91 274 }
300f8e10
JK
275 if (TYPE_CODE (ftype) == TYPE_CODE_FUNC
276 || TYPE_CODE (ftype) == TYPE_CODE_METHOD)
07be84bf 277 {
07be84bf
JK
278 if (TYPE_GNU_IFUNC (ftype))
279 {
8388016d 280 CORE_ADDR resolver_addr = funaddr;
07be84bf 281
8388016d
PA
282 /* Resolve the ifunc. Note this may call the resolver
283 function in the inferior. */
284 funaddr = gnu_ifunc_resolve_addr (gdbarch, resolver_addr);
285
286 /* Skip querying the function symbol if no RETVAL_TYPE or
287 FUNCTION_TYPE have been asked for. */
288 if (retval_type != NULL || function_type != NULL)
289 {
290 type *target_ftype = find_function_type (funaddr);
291 /* If we don't have debug info for the target function,
292 see if we can instead extract the target function's
293 type from the type that the resolver returns. */
294 if (target_ftype == NULL)
295 target_ftype = find_gnu_ifunc_target_type (resolver_addr);
296 if (target_ftype != NULL)
297 {
298 value_type = TYPE_TARGET_TYPE (check_typedef (target_ftype));
299 ftype = target_ftype;
300 }
301 }
07be84bf 302 }
8388016d
PA
303 else
304 value_type = TYPE_TARGET_TYPE (ftype);
07be84bf 305 }
300f8e10 306 else if (TYPE_CODE (ftype) == TYPE_CODE_INT)
04714b91
AC
307 {
308 /* Handle the case of functions lacking debugging info.
1777feb0 309 Their values are characters since their addresses are char. */
04714b91
AC
310 if (TYPE_LENGTH (ftype) == 1)
311 funaddr = value_as_address (value_addr (function));
312 else
2bbe3cc1
DJ
313 {
314 /* Handle function descriptors lacking debug info. */
315 int found_descriptor = 0;
abbb1732 316
87bc73ea 317 funaddr = 0; /* pacify "gcc -Werror" */
2bbe3cc1
DJ
318 if (VALUE_LVAL (function) == lval_memory)
319 {
320 CORE_ADDR nfunaddr;
abbb1732 321
2bbe3cc1
DJ
322 funaddr = value_as_address (value_addr (function));
323 nfunaddr = funaddr;
8b88a78e
PA
324 funaddr
325 = gdbarch_convert_from_func_ptr_addr (gdbarch, funaddr,
326 current_top_target ());
2bbe3cc1
DJ
327 if (funaddr != nfunaddr)
328 found_descriptor = 1;
329 }
330 if (!found_descriptor)
331 /* Handle integer used as address of a function. */
332 funaddr = (CORE_ADDR) value_as_long (function);
333 }
04714b91
AC
334 }
335 else
8a3fe4f8 336 error (_("Invalid data type for function to be called."));
04714b91 337
7d9b040b
RC
338 if (retval_type != NULL)
339 *retval_type = value_type;
8388016d
PA
340 if (function_type != NULL)
341 *function_type = ftype;
50810684 342 return funaddr + gdbarch_deprecated_function_start_offset (gdbarch);
04714b91
AC
343}
344
d3712828
AC
345/* For CALL_DUMMY_ON_STACK, push a breakpoint sequence that the called
346 function returns to. */
7043d8dc
AC
347
348static CORE_ADDR
349push_dummy_code (struct gdbarch *gdbarch,
82585c72 350 CORE_ADDR sp, CORE_ADDR funaddr,
e71585ff 351 gdb::array_view<value *> args,
7043d8dc 352 struct type *value_type,
e4fd649a
UW
353 CORE_ADDR *real_pc, CORE_ADDR *bp_addr,
354 struct regcache *regcache)
7043d8dc 355{
50a834af
MK
356 gdb_assert (gdbarch_push_dummy_code_p (gdbarch));
357
358 return gdbarch_push_dummy_code (gdbarch, sp, funaddr,
e71585ff
PA
359 args.data (), args.size (),
360 value_type, real_pc, bp_addr,
50a834af 361 regcache);
7043d8dc
AC
362}
363
7022349d
PA
364/* See infcall.h. */
365
366void
367error_call_unknown_return_type (const char *func_name)
368{
369 if (func_name != NULL)
370 error (_("'%s' has unknown return type; "
371 "cast the call to its declared return type"),
372 func_name);
373 else
374 error (_("function has unknown return type; "
375 "cast the call to its declared return type"));
376}
377
b89667eb
DE
378/* Fetch the name of the function at FUNADDR.
379 This is used in printing an error message for call_function_by_hand.
380 BUF is used to print FUNADDR in hex if the function name cannot be
381 determined. It must be large enough to hold formatted result of
382 RAW_FUNCTION_ADDRESS_FORMAT. */
383
384static const char *
385get_function_name (CORE_ADDR funaddr, char *buf, int buf_size)
386{
387 {
388 struct symbol *symbol = find_pc_function (funaddr);
abbb1732 389
b89667eb 390 if (symbol)
987012b8 391 return symbol->print_name ();
b89667eb
DE
392 }
393
394 {
395 /* Try the minimal symbols. */
7cbd4a93 396 struct bound_minimal_symbol msymbol = lookup_minimal_symbol_by_pc (funaddr);
abbb1732 397
7cbd4a93 398 if (msymbol.minsym)
c9d95fa3 399 return msymbol.minsym->print_name ();
b89667eb
DE
400 }
401
402 {
528e1572
SM
403 std::string tmp = string_printf (_(RAW_FUNCTION_ADDRESS_FORMAT),
404 hex_string (funaddr));
abbb1732 405
528e1572
SM
406 gdb_assert (tmp.length () + 1 <= buf_size);
407 return strcpy (buf, tmp.c_str ());
b89667eb
DE
408 }
409}
410
388a7084
PA
411/* All the meta data necessary to extract the call's return value. */
412
413struct call_return_meta_info
414{
415 /* The caller frame's architecture. */
416 struct gdbarch *gdbarch;
417
418 /* The called function. */
419 struct value *function;
420
421 /* The return value's type. */
422 struct type *value_type;
423
424 /* Are we returning a value using a structure return or a normal
425 value return? */
426 int struct_return_p;
427
428 /* If using a structure return, this is the structure's address. */
429 CORE_ADDR struct_addr;
388a7084
PA
430};
431
432/* Extract the called function's return value. */
433
434static struct value *
435get_call_return_value (struct call_return_meta_info *ri)
436{
437 struct value *retval = NULL;
00431a78
PA
438 thread_info *thr = inferior_thread ();
439 bool stack_temporaries = thread_stack_temporaries_enabled_p (thr);
388a7084
PA
440
441 if (TYPE_CODE (ri->value_type) == TYPE_CODE_VOID)
442 retval = allocate_value (ri->value_type);
443 else if (ri->struct_return_p)
444 {
445 if (stack_temporaries)
446 {
447 retval = value_from_contents_and_address (ri->value_type, NULL,
448 ri->struct_addr);
00431a78 449 push_thread_stack_temporary (thr, retval);
388a7084
PA
450 }
451 else
452 {
453 retval = allocate_value (ri->value_type);
454 read_value_memory (retval, 0, 1, ri->struct_addr,
455 value_contents_raw (retval),
456 TYPE_LENGTH (ri->value_type));
457 }
458 }
459 else
460 {
461 retval = allocate_value (ri->value_type);
462 gdbarch_return_value (ri->gdbarch, ri->function, ri->value_type,
463 get_current_regcache (),
464 value_contents_raw (retval), NULL);
465 if (stack_temporaries && class_or_union_p (ri->value_type))
466 {
467 /* Values of class type returned in registers are copied onto
468 the stack and their lval_type set to lval_memory. This is
469 required because further evaluation of the expression
470 could potentially invoke methods on the return value
471 requiring GDB to evaluate the "this" pointer. To evaluate
472 the this pointer, GDB needs the memory address of the
473 value. */
474 value_force_lval (retval, ri->struct_addr);
00431a78 475 push_thread_stack_temporary (thr, retval);
388a7084
PA
476 }
477 }
478
479 gdb_assert (retval != NULL);
480 return retval;
481}
482
483/* Data for the FSM that manages an infcall. It's main job is to
484 record the called function's return value. */
485
46e3ed7f 486struct call_thread_fsm : public thread_fsm
388a7084 487{
388a7084
PA
488 /* All the info necessary to be able to extract the return
489 value. */
490 struct call_return_meta_info return_meta_info;
491
492 /* The called function's return value. This is extracted from the
493 target before the dummy frame is popped. */
46e3ed7f 494 struct value *return_value = nullptr;
3b12939d
PA
495
496 /* The top level that started the infcall (and is synchronously
497 waiting for it to end). */
498 struct ui *waiting_ui;
388a7084 499
46e3ed7f
TT
500 call_thread_fsm (struct ui *waiting_ui, struct interp *cmd_interp,
501 struct gdbarch *gdbarch, struct value *function,
502 struct type *value_type,
503 int struct_return_p, CORE_ADDR struct_addr);
388a7084 504
46e3ed7f 505 bool should_stop (struct thread_info *thread) override;
388a7084 506
46e3ed7f 507 bool should_notify_stop () override;
388a7084
PA
508};
509
510/* Allocate a new call_thread_fsm object. */
511
46e3ed7f
TT
512call_thread_fsm::call_thread_fsm (struct ui *waiting_ui,
513 struct interp *cmd_interp,
514 struct gdbarch *gdbarch,
515 struct value *function,
516 struct type *value_type,
517 int struct_return_p, CORE_ADDR struct_addr)
518 : thread_fsm (cmd_interp),
519 waiting_ui (waiting_ui)
388a7084 520{
46e3ed7f
TT
521 return_meta_info.gdbarch = gdbarch;
522 return_meta_info.function = function;
523 return_meta_info.value_type = value_type;
524 return_meta_info.struct_return_p = struct_return_p;
525 return_meta_info.struct_addr = struct_addr;
388a7084
PA
526}
527
528/* Implementation of should_stop method for infcalls. */
529
46e3ed7f
TT
530bool
531call_thread_fsm::should_stop (struct thread_info *thread)
388a7084 532{
388a7084
PA
533 if (stop_stack_dummy == STOP_STACK_DUMMY)
534 {
535 /* Done. */
46e3ed7f 536 set_finished ();
388a7084
PA
537
538 /* Stash the return value before the dummy frame is popped and
539 registers are restored to what they were before the
540 call.. */
46e3ed7f 541 return_value = get_call_return_value (&return_meta_info);
388a7084
PA
542
543 /* Break out of wait_sync_command_done. */
46e3ed7f 544 scoped_restore save_ui = make_scoped_restore (&current_ui, waiting_ui);
223ffa71 545 target_terminal::ours ();
46e3ed7f 546 waiting_ui->prompt_state = PROMPT_NEEDED;
388a7084
PA
547 }
548
46e3ed7f 549 return true;
388a7084
PA
550}
551
552/* Implementation of should_notify_stop method for infcalls. */
553
46e3ed7f
TT
554bool
555call_thread_fsm::should_notify_stop ()
388a7084 556{
46e3ed7f 557 if (finished_p ())
388a7084
PA
558 {
559 /* Infcall succeeded. Be silent and proceed with evaluating the
560 expression. */
46e3ed7f 561 return false;
388a7084
PA
562 }
563
564 /* Something wrong happened. E.g., an unexpected breakpoint
565 triggered, or a signal was intercepted. Notify the stop. */
46e3ed7f 566 return true;
388a7084
PA
567}
568
b89667eb
DE
569/* Subroutine of call_function_by_hand to simplify it.
570 Start up the inferior and wait for it to stop.
571 Return the exception if there's an error, or an exception with
572 reason >= 0 if there's no error.
573
574 This is done inside a TRY_CATCH so the caller needn't worry about
575 thrown errors. The caller should rethrow if there's an error. */
576
577static struct gdb_exception
388a7084
PA
578run_inferior_call (struct call_thread_fsm *sm,
579 struct thread_info *call_thread, CORE_ADDR real_pc)
b89667eb 580{
cc06b668 581 struct gdb_exception caught_error;
16c381f0 582 int saved_in_infcall = call_thread->control.in_infcall;
b89667eb 583 ptid_t call_thread_ptid = call_thread->ptid;
3b12939d 584 enum prompt_state saved_prompt_state = current_ui->prompt_state;
28bf096c 585 int was_running = call_thread->state == THREAD_RUNNING;
cb814510 586 int saved_ui_async = current_ui->async;
c933f875
PA
587
588 /* Infcalls run synchronously, in the foreground. */
3b12939d 589 current_ui->prompt_state = PROMPT_BLOCKED;
0b333c5e
PA
590 /* So that we don't print the prompt prematurely in
591 fetch_inferior_event. */
cb814510 592 current_ui->async = 0;
b89667eb 593
6d61dee5
PA
594 delete_file_handler (current_ui->input_fd);
595
16c381f0 596 call_thread->control.in_infcall = 1;
c5a4d20b 597
70509625 598 clear_proceed_status (0);
b89667eb 599
388a7084
PA
600 /* Associate the FSM with the thread after clear_proceed_status
601 (otherwise it'd clear this FSM), and before anything throws, so
602 we don't leak it (and any resources it manages). */
46e3ed7f 603 call_thread->thread_fsm = sm;
388a7084 604
b89667eb 605 disable_watchpoints_before_interactive_call_start ();
16c381f0 606
46c03469 607 /* We want to print return value, please... */
16c381f0 608 call_thread->control.proceed_to_finish = 1;
b89667eb 609
a70b8144 610 try
3dd5b83d 611 {
64ce06e4 612 proceed (real_pc, GDB_SIGNAL_0);
3dd5b83d
PA
613
614 /* Inferior function calls are always synchronous, even if the
0b333c5e
PA
615 target supports asynchronous execution. */
616 wait_sync_command_done ();
3dd5b83d 617 }
94aeb44b 618 catch (gdb_exception &e)
492d29ea 619 {
94aeb44b 620 caught_error = std::move (e);
492d29ea 621 }
b89667eb 622
3b12939d
PA
623 /* If GDB has the prompt blocked before, then ensure that it remains
624 so. normal_stop calls async_enable_stdin, so reset the prompt
625 state again here. In other cases, stdin will be re-enabled by
0b333c5e 626 inferior_event_handler, when an exception is thrown. */
3b12939d 627 current_ui->prompt_state = saved_prompt_state;
6d61dee5
PA
628 if (current_ui->prompt_state == PROMPT_BLOCKED)
629 delete_file_handler (current_ui->input_fd);
630 else
631 ui_register_input_event_handler (current_ui);
cb814510 632 current_ui->async = saved_ui_async;
0b333c5e 633
28bf096c
PA
634 /* If the infcall does NOT succeed, normal_stop will have already
635 finished the thread states. However, on success, normal_stop
636 defers here, so that we can set back the thread states to what
637 they were before the call. Note that we must also finish the
638 state of new threads that might have spawned while the call was
639 running. The main cases to handle are:
640
641 - "(gdb) print foo ()", or any other command that evaluates an
642 expression at the prompt. (The thread was marked stopped before.)
643
644 - "(gdb) break foo if return_false()" or similar cases where we
645 do an infcall while handling an event (while the thread is still
646 marked running). In this example, whether the condition
647 evaluates true and thus we'll present a user-visible stop is
648 decided elsewhere. */
649 if (!was_running
00431a78 650 && call_thread_ptid == inferior_ptid
28bf096c
PA
651 && stop_stack_dummy == STOP_STACK_DUMMY)
652 finish_thread_state (user_visible_resume_ptid (0));
653
b89667eb
DE
654 enable_watchpoints_after_interactive_call_stop ();
655
656 /* Call breakpoint_auto_delete on the current contents of the bpstat
657 of inferior call thread.
658 If all error()s out of proceed ended up calling normal_stop
659 (and perhaps they should; it already does in the special case
660 of error out of resume()), then we wouldn't need this. */
492d29ea 661 if (caught_error.reason < 0)
b89667eb 662 {
00431a78 663 if (call_thread->state != THREAD_EXITED)
16c381f0 664 breakpoint_auto_delete (call_thread->control.stop_bpstat);
b89667eb
DE
665 }
666
00431a78 667 call_thread->control.in_infcall = saved_in_infcall;
c5a4d20b 668
492d29ea 669 return caught_error;
b89667eb
DE
670}
671
12e7c35e
TBA
672/* Reserve space on the stack for a value of the given type.
673 Return the address of the allocated space.
674 Make certain that the value is correctly aligned.
675 The SP argument is modified. */
676
677static CORE_ADDR
678reserve_stack_space (const type *values_type, CORE_ADDR &sp)
679{
680 struct frame_info *frame = get_current_frame ();
681 struct gdbarch *gdbarch = get_frame_arch (frame);
682 CORE_ADDR addr = 0;
683
684 if (gdbarch_inner_than (gdbarch, 1, 2))
685 {
686 /* Stack grows downward. Align STRUCT_ADDR and SP after
687 making space. */
688 sp -= TYPE_LENGTH (values_type);
689 if (gdbarch_frame_align_p (gdbarch))
690 sp = gdbarch_frame_align (gdbarch, sp);
691 addr = sp;
692 }
693 else
694 {
695 /* Stack grows upward. Align the frame, allocate space, and
696 then again, re-align the frame??? */
697 if (gdbarch_frame_align_p (gdbarch))
698 sp = gdbarch_frame_align (gdbarch, sp);
699 addr = sp;
700 sp += TYPE_LENGTH (values_type);
701 if (gdbarch_frame_align_p (gdbarch))
702 sp = gdbarch_frame_align (gdbarch, sp);
703 }
704
705 return addr;
706}
707
099a6354
TBA
708/* The data structure which keeps a destructor function and
709 its implicit 'this' parameter. */
710
711struct destructor_info
712{
713 destructor_info (struct value *function, struct value *self)
714 : function (function), self (self) { }
715
716 struct value *function;
717 struct value *self;
718};
719
720
721/* Auxiliary function that takes a list of destructor functions
722 with their 'this' parameters, and invokes the functions. */
723
724static void
725call_destructors (const std::list<destructor_info> &dtors_to_invoke,
726 struct type *default_return_type)
727{
728 for (auto vals : dtors_to_invoke)
729 {
730 call_function_by_hand (vals.function, default_return_type,
731 gdb::make_array_view (&(vals.self), 1));
732 }
733}
734
ed12ef62
JK
735/* See infcall.h. */
736
737struct value *
7022349d
PA
738call_function_by_hand (struct value *function,
739 type *default_return_type,
e71585ff 740 gdb::array_view<value *> args)
ed12ef62 741{
7022349d 742 return call_function_by_hand_dummy (function, default_return_type,
e71585ff 743 args, NULL, NULL);
ed12ef62
JK
744}
745
04714b91
AC
746/* All this stuff with a dummy frame may seem unnecessarily complicated
747 (why not just save registers in GDB?). The purpose of pushing a dummy
748 frame which looks just like a real frame is so that if you call a
749 function and then hit a breakpoint (get a signal, etc), "backtrace"
750 will look right. Whether the backtrace needs to actually show the
751 stack at the time the inferior function was called is debatable, but
752 it certainly needs to not display garbage. So if you are contemplating
753 making dummy frames be different from normal frames, consider that. */
754
755/* Perform a function call in the inferior.
12e7c35e 756 ARGS is a vector of values of arguments.
04714b91
AC
757 FUNCTION is a value, the function to be called.
758 Returns a value representing what the function returned.
759 May fail to return, if a breakpoint or signal is hit
760 during the execution of the function.
761
1777feb0 762 ARGS is modified to contain coerced values. */
04714b91
AC
763
764struct value *
ed12ef62 765call_function_by_hand_dummy (struct value *function,
7022349d 766 type *default_return_type,
e71585ff 767 gdb::array_view<value *> args,
558e5469 768 dummy_frame_dtor_ftype *dummy_dtor,
ed12ef62 769 void *dummy_dtor_data)
04714b91 770{
52f0bd74 771 CORE_ADDR sp;
8388016d 772 struct type *target_values_type;
c5ac5cbb 773 function_call_return_method return_method = return_method_normal;
04714b91 774 CORE_ADDR struct_addr = 0;
04714b91 775 CORE_ADDR real_pc;
d585e13a 776 CORE_ADDR bp_addr;
96860204 777 struct frame_id dummy_id;
0b9dfe2b
MD
778 struct frame_info *frame;
779 struct gdbarch *gdbarch;
b89667eb
DE
780 ptid_t call_thread_ptid;
781 struct gdb_exception e;
b89667eb 782 char name_buf[RAW_FUNCTION_ADDRESS_SIZE];
04714b91 783
136afab8
PW
784 if (!may_call_functions_p)
785 error (_("Cannot call functions in the program: "
786 "may-call-functions is off."));
787
04714b91
AC
788 if (!target_has_execution)
789 noprocess ();
790
573cda03
SS
791 if (get_traceframe_number () >= 0)
792 error (_("May not call functions while looking at trace frames."));
793
949dc678 794 if (execution_direction == EXEC_REVERSE)
c2949be0 795 error (_("Cannot call functions in reverse mode."));
949dc678 796
00431a78
PA
797 /* We're going to run the target, and inspect the thread's state
798 afterwards. Hold a strong reference so that the pointer remains
799 valid even if the thread exits. */
800 thread_info_ref call_thread
801 = thread_info_ref::new_reference (inferior_thread ());
802
803 bool stack_temporaries = thread_stack_temporaries_enabled_p (call_thread.get ());
804
0b9dfe2b
MD
805 frame = get_current_frame ();
806 gdbarch = get_frame_arch (frame);
807
808 if (!gdbarch_push_dummy_call_p (gdbarch))
2e74121d 809 error (_("This target does not support function calls."));
a86c5fc9 810
39bcc47c
TBA
811 /* Find the function type and do a sanity check. */
812 type *ftype;
813 type *values_type;
814 CORE_ADDR funaddr = find_function_addr (function, &values_type, &ftype);
815
816 if (values_type == NULL)
817 values_type = default_return_type;
818 if (values_type == NULL)
819 {
820 const char *name = get_function_name (funaddr,
821 name_buf, sizeof (name_buf));
822 error (_("'%s' has unknown return type; "
823 "cast the call to its declared return type"),
824 name);
825 }
826
827 values_type = check_typedef (values_type);
828
829 if (args.size () < TYPE_NFIELDS (ftype))
830 error (_("Too few arguments in function call."));
831
c7c4d3fa 832 /* A holder for the inferior status.
b89667eb 833 This is only needed while we're preparing the inferior function call. */
c7c4d3fa 834 infcall_control_state_up inf_status (save_infcall_control_state ());
04714b91 835
b89667eb
DE
836 /* Save the caller's registers and other state associated with the
837 inferior itself so that they can be restored once the
96860204 838 callee returns. To allow nested calls the registers are (further
c7c4d3fa
TT
839 down) pushed onto a dummy frame stack. This unique pointer
840 is released once the regcache has been pushed). */
841 infcall_suspend_state_up caller_state (save_infcall_suspend_state ());
04714b91 842
04714b91 843 /* Ensure that the initial SP is correctly aligned. */
ebc7896c 844 {
0b9dfe2b 845 CORE_ADDR old_sp = get_frame_sp (frame);
abbb1732 846
0b9dfe2b 847 if (gdbarch_frame_align_p (gdbarch))
ebc7896c 848 {
0b9dfe2b 849 sp = gdbarch_frame_align (gdbarch, old_sp);
8b148df9
AC
850 /* NOTE: cagney/2003-08-13: Skip the "red zone". For some
851 ABIs, a function can use memory beyond the inner most stack
852 address. AMD64 called that region the "red zone". Skip at
853 least the "red zone" size before allocating any space on
854 the stack. */
0b9dfe2b
MD
855 if (gdbarch_inner_than (gdbarch, 1, 2))
856 sp -= gdbarch_frame_red_zone_size (gdbarch);
8b148df9 857 else
0b9dfe2b 858 sp += gdbarch_frame_red_zone_size (gdbarch);
8b148df9 859 /* Still aligned? */
0b9dfe2b 860 gdb_assert (sp == gdbarch_frame_align (gdbarch, sp));
ebc7896c
AC
861 /* NOTE: cagney/2002-09-18:
862
863 On a RISC architecture, a void parameterless generic dummy
864 frame (i.e., no parameters, no result) typically does not
865 need to push anything the stack and hence can leave SP and
c48a845b 866 FP. Similarly, a frameless (possibly leaf) function does
ebc7896c
AC
867 not push anything on the stack and, hence, that too can
868 leave FP and SP unchanged. As a consequence, a sequence of
869 void parameterless generic dummy frame calls to frameless
870 functions will create a sequence of effectively identical
871 frames (SP, FP and TOS and PC the same). This, not
30baf67b 872 surprisingly, results in what appears to be a stack in an
ebc7896c
AC
873 infinite loop --- when GDB tries to find a generic dummy
874 frame on the internal dummy frame stack, it will always
875 find the first one.
876
877 To avoid this problem, the code below always grows the
878 stack. That way, two dummy frames can never be identical.
879 It does burn a few bytes of stack but that is a small price
880 to pay :-). */
ebc7896c
AC
881 if (sp == old_sp)
882 {
0b9dfe2b 883 if (gdbarch_inner_than (gdbarch, 1, 2))
ebc7896c 884 /* Stack grows down. */
0b9dfe2b 885 sp = gdbarch_frame_align (gdbarch, old_sp - 1);
ebc7896c
AC
886 else
887 /* Stack grows up. */
0b9dfe2b 888 sp = gdbarch_frame_align (gdbarch, old_sp + 1);
ebc7896c 889 }
0e095b7e
JK
890 /* SP may have underflown address zero here from OLD_SP. Memory access
891 functions will probably fail in such case but that is a target's
892 problem. */
ebc7896c
AC
893 }
894 else
a59fe496
AC
895 /* FIXME: cagney/2002-09-18: Hey, you loose!
896
8b148df9
AC
897 Who knows how badly aligned the SP is!
898
899 If the generic dummy frame ends up empty (because nothing is
900 pushed) GDB won't be able to correctly perform back traces.
901 If a target is having trouble with backtraces, first thing to
1777feb0 902 do is add FRAME_ALIGN() to the architecture vector. If that
669fac23 903 fails, try dummy_id().
8b148df9
AC
904
905 If the ABI specifies a "Red Zone" (see the doco) the code
906 below will quietly trash it. */
ebc7896c 907 sp = old_sp;
6c659fc2
SC
908
909 /* Skip over the stack temporaries that might have been generated during
910 the evaluation of an expression. */
911 if (stack_temporaries)
912 {
913 struct value *lastval;
914
00431a78 915 lastval = get_last_thread_stack_temporary (call_thread.get ());
6c659fc2
SC
916 if (lastval != NULL)
917 {
918 CORE_ADDR lastval_addr = value_address (lastval);
919
920 if (gdbarch_inner_than (gdbarch, 1, 2))
921 {
922 gdb_assert (sp >= lastval_addr);
923 sp = lastval_addr;
924 }
925 else
926 {
927 gdb_assert (sp <= lastval_addr);
928 sp = lastval_addr + TYPE_LENGTH (value_type (lastval));
929 }
930
931 if (gdbarch_frame_align_p (gdbarch))
932 sp = gdbarch_frame_align (gdbarch, sp);
933 }
934 }
ebc7896c 935 }
04714b91 936
c5ac5cbb 937 /* Are we returning a value using a structure return? */
41f1b697 938
18648a37 939 if (gdbarch_return_in_first_hidden_param_p (gdbarch, values_type))
41f1b697 940 {
c5ac5cbb 941 return_method = return_method_hidden_param;
04714b91 942
41f1b697
DJ
943 /* Tell the target specific argument pushing routine not to
944 expect a value. */
48319d1f 945 target_values_type = builtin_type (gdbarch)->builtin_void;
41f1b697
DJ
946 }
947 else
948 {
c5ac5cbb
AH
949 if (using_struct_return (gdbarch, function, values_type))
950 return_method = return_method_struct;
41f1b697
DJ
951 target_values_type = values_type;
952 }
04714b91 953
76727919 954 gdb::observers::inferior_call_pre.notify (inferior_ptid, funaddr);
162078c8 955
7043d8dc
AC
956 /* Determine the location of the breakpoint (and possibly other
957 stuff) that the called function will return to. The SPARC, for a
958 function returning a structure or union, needs to make space for
959 not just the breakpoint but also an extra word containing the
960 size (?) of the structure being passed. */
961
0b9dfe2b 962 switch (gdbarch_call_dummy_location (gdbarch))
04714b91
AC
963 {
964 case ON_STACK:
a14dd77e
JK
965 {
966 const gdb_byte *bp_bytes;
967 CORE_ADDR bp_addr_as_address;
968 int bp_size;
969
970 /* Be careful BP_ADDR is in inferior PC encoding while
971 BP_ADDR_AS_ADDRESS is a plain memory address. */
972
e71585ff 973 sp = push_dummy_code (gdbarch, sp, funaddr, args,
a14dd77e
JK
974 target_values_type, &real_pc, &bp_addr,
975 get_current_regcache ());
976
977 /* Write a legitimate instruction at the point where the infcall
978 breakpoint is going to be inserted. While this instruction
979 is never going to be executed, a user investigating the
980 memory from GDB would see this instruction instead of random
981 uninitialized bytes. We chose the breakpoint instruction
982 as it may look as the most logical one to the user and also
983 valgrind 3.7.0 needs it for proper vgdb inferior calls.
984
985 If software breakpoints are unsupported for this target we
986 leave the user visible memory content uninitialized. */
987
988 bp_addr_as_address = bp_addr;
989 bp_bytes = gdbarch_breakpoint_from_pc (gdbarch, &bp_addr_as_address,
990 &bp_size);
991 if (bp_bytes != NULL)
992 write_memory (bp_addr_as_address, bp_bytes, bp_size);
993 }
7043d8dc 994 break;
5931a2fa
JK
995 case AT_ENTRY_POINT:
996 {
997 CORE_ADDR dummy_addr;
998
999 real_pc = funaddr;
1000 dummy_addr = entry_point_address ();
a14dd77e 1001
5931a2fa 1002 /* A call dummy always consists of just a single breakpoint, so
a14dd77e
JK
1003 its address is the same as the address of the dummy.
1004
1005 The actual breakpoint is inserted separatly so there is no need to
1006 write that out. */
5931a2fa
JK
1007 bp_addr = dummy_addr;
1008 break;
1009 }
04714b91 1010 default:
e2e0b3e5 1011 internal_error (__FILE__, __LINE__, _("bad switch"));
04714b91
AC
1012 }
1013
099a6354
TBA
1014 /* Coerce the arguments and handle pass-by-reference.
1015 We want to remember the destruction required for pass-by-ref values.
1016 For these, store the dtor function and the 'this' argument
1017 in DTORS_TO_INVOKE. */
1018 std::list<destructor_info> dtors_to_invoke;
1019
e71585ff 1020 for (int i = args.size () - 1; i >= 0; i--)
b4b08fa2
TT
1021 {
1022 int prototyped;
1023 struct type *param_type;
e71585ff 1024
b4b08fa2
TT
1025 /* FIXME drow/2002-05-31: Should just always mark methods as
1026 prototyped. Can we respect TYPE_VARARGS? Probably not. */
1027 if (TYPE_CODE (ftype) == TYPE_CODE_METHOD)
1028 prototyped = 1;
1029 if (TYPE_TARGET_TYPE (ftype) == NULL && TYPE_NFIELDS (ftype) == 0
1030 && default_return_type != NULL)
1031 {
1032 /* Calling a no-debug function with the return type
1033 explicitly cast. Assume the function is prototyped,
1034 with a prototype matching the types of the arguments.
1035 E.g., with:
1036 float mult (float v1, float v2) { return v1 * v2; }
1037 This:
1038 (gdb) p (float) mult (2.0f, 3.0f)
1039 Is a simpler alternative to:
1040 (gdb) p ((float (*) (float, float)) mult) (2.0f, 3.0f)
1041 */
ebc7896c 1042 prototyped = 1;
b4b08fa2
TT
1043 }
1044 else if (i < TYPE_NFIELDS (ftype))
1045 prototyped = TYPE_PROTOTYPED (ftype);
1046 else
1047 prototyped = 0;
ebc7896c 1048
b4b08fa2
TT
1049 if (i < TYPE_NFIELDS (ftype))
1050 param_type = TYPE_FIELD_TYPE (ftype, i);
1051 else
1052 param_type = NULL;
41f1b697 1053
099a6354 1054 value *original_arg = args[i];
b4b08fa2 1055 args[i] = value_arg_coerce (gdbarch, args[i],
37055cad 1056 param_type, prototyped);
ebc7896c 1057
099a6354
TBA
1058 if (param_type == NULL)
1059 continue;
1060
1061 auto info = language_pass_by_reference (param_type);
1062 if (!info.copy_constructible)
1063 error (_("expression cannot be evaluated because the type '%s' "
1064 "is not copy constructible"), TYPE_NAME (param_type));
1065
1066 if (!info.destructible)
1067 error (_("expression cannot be evaluated because the type '%s' "
1068 "is not destructible"), TYPE_NAME (param_type));
1069
1070 if (info.trivially_copyable)
1071 continue;
1072
1073 /* Make a copy of the argument on the stack. If the argument is
1074 trivially copy ctor'able, copy bit by bit. Otherwise, call
1075 the copy ctor to initialize the clone. */
1076 CORE_ADDR addr = reserve_stack_space (param_type, sp);
1077 value *clone
1078 = value_from_contents_and_address (param_type, nullptr, addr);
1079 push_thread_stack_temporary (call_thread.get (), clone);
1080 value *clone_ptr
1081 = value_from_pointer (lookup_pointer_type (param_type), addr);
1082
1083 if (info.trivially_copy_constructible)
1084 {
1085 int length = TYPE_LENGTH (param_type);
1086 write_memory (addr, value_contents (args[i]), length);
1087 }
1088 else
1089 {
1090 value *copy_ctor;
1091 value *cctor_args[2] = { clone_ptr, original_arg };
1092 find_overload_match (gdb::make_array_view (cctor_args, 2),
1093 TYPE_NAME (param_type), METHOD,
1094 &clone_ptr, nullptr, &copy_ctor, nullptr,
1095 nullptr, 0, EVAL_NORMAL);
1096
1097 if (copy_ctor == nullptr)
1098 error (_("expression cannot be evaluated because a copy "
1099 "constructor for the type '%s' could not be found "
1100 "(maybe inlined?)"), TYPE_NAME (param_type));
1101
1102 call_function_by_hand (copy_ctor, default_return_type,
1103 gdb::make_array_view (cctor_args, 2));
1104 }
1105
1106 /* If the argument has a destructor, remember it so that we
1107 invoke it after the infcall is complete. */
1108 if (!info.trivially_destructible)
1109 {
1110 /* Looking up the function via overload resolution does not
1111 work because the compiler (in particular, gcc) adds an
1112 artificial int parameter in some cases. So we look up
1113 the function by using the "~" name. This should be OK
1114 because there can be only one dtor definition. */
1115 const char *dtor_name = nullptr;
1116 for (int fieldnum = 0;
1117 fieldnum < TYPE_NFN_FIELDS (param_type);
1118 fieldnum++)
1119 {
1120 fn_field *fn
1121 = TYPE_FN_FIELDLIST1 (param_type, fieldnum);
1122 const char *field_name
1123 = TYPE_FN_FIELDLIST_NAME (param_type, fieldnum);
1124
1125 if (field_name[0] == '~')
1126 dtor_name = TYPE_FN_FIELD_PHYSNAME (fn, 0);
1127 }
1128
1129 if (dtor_name == nullptr)
1130 error (_("expression cannot be evaluated because a destructor "
1131 "for the type '%s' could not be found "
1132 "(maybe inlined?)"), TYPE_NAME (param_type));
1133
1134 value *dtor
1135 = find_function_in_inferior (dtor_name, 0);
1136
1137 /* Insert the dtor to the front of the list to call them
1138 in reverse order later. */
1139 dtors_to_invoke.emplace_front (dtor, clone_ptr);
1140 }
1141
1142 args[i] = clone_ptr;
b4b08fa2 1143 }
04714b91 1144
04714b91 1145 /* Reserve space for the return structure to be written on the
12e7c35e 1146 stack, if necessary.
6c659fc2
SC
1147
1148 While evaluating expressions, we reserve space on the stack for
1149 return values of class type even if the language ABI and the target
1150 ABI do not require that the return value be passed as a hidden first
1151 argument. This is because we want to store the return value as an
1152 on-stack temporary while the expression is being evaluated. This
1153 enables us to have chained function calls in expressions.
04714b91 1154
6c659fc2
SC
1155 Keeping the return values as on-stack temporaries while the expression
1156 is being evaluated is OK because the thread is stopped until the
1157 expression is completely evaluated. */
1158
c5ac5cbb 1159 if (return_method != return_method_normal
6c659fc2 1160 || (stack_temporaries && class_or_union_p (values_type)))
12e7c35e 1161 struct_addr = reserve_stack_space (values_type, sp);
04714b91 1162
6ccb583f 1163 std::vector<struct value *> new_args;
c5ac5cbb 1164 if (return_method == return_method_hidden_param)
41f1b697 1165 {
41f1b697 1166 /* Add the new argument to the front of the argument list. */
e71585ff 1167 new_args.reserve (args.size ());
6ccb583f
TT
1168 new_args.push_back
1169 (value_from_pointer (lookup_pointer_type (values_type), struct_addr));
e71585ff
PA
1170 new_args.insert (new_args.end (), args.begin (), args.end ());
1171 args = new_args;
41f1b697 1172 }
41f1b697 1173
04714b91
AC
1174 /* Create the dummy stack frame. Pass in the call dummy address as,
1175 presumably, the ABI code knows where, in the call dummy, the
1176 return address should be pointed. */
0b9dfe2b 1177 sp = gdbarch_push_dummy_call (gdbarch, function, get_current_regcache (),
e71585ff
PA
1178 bp_addr, args.size (), args.data (),
1179 sp, return_method, struct_addr);
04714b91 1180
96860204
AC
1181 /* Set up a frame ID for the dummy frame so we can pass it to
1182 set_momentary_breakpoint. We need to give the breakpoint a frame
1183 ID so that the breakpoint code can correctly re-identify the
1184 dummy breakpoint. */
8241eaa6 1185 /* Sanity. The exact same SP value is returned by PUSH_DUMMY_CALL,
669fac23 1186 saved as the dummy-frame TOS, and used by dummy_id to form
8241eaa6 1187 the frame ID's stack address. */
96860204 1188 dummy_id = frame_id_build (sp, bp_addr);
04714b91 1189
74cfe982
AC
1190 /* Create a momentary breakpoint at the return address of the
1191 inferior. That way it breaks when it returns. */
04714b91 1192
74cfe982 1193 {
51abb421 1194 symtab_and_line sal;
6c95b8df 1195 sal.pspace = current_program_space;
74cfe982
AC
1196 sal.pc = bp_addr;
1197 sal.section = find_pc_overlay (sal.pc);
51abb421 1198
8241eaa6
AC
1199 /* Sanity. The exact same SP value is returned by
1200 PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by
669fac23 1201 dummy_id to form the frame ID's stack address. */
454dafbd
TT
1202 breakpoint *bpt
1203 = set_momentary_breakpoint (gdbarch, sal,
1204 dummy_id, bp_call_dummy).release ();
c70a6932
JK
1205
1206 /* set_momentary_breakpoint invalidates FRAME. */
1207 frame = NULL;
1208
74cfe982 1209 bpt->disposition = disp_del;
e2e4d78b
JK
1210 gdb_assert (bpt->related_breakpoint == bpt);
1211
51abb421 1212 breakpoint *longjmp_b = set_longjmp_breakpoint_for_call_dummy ();
e2e4d78b
JK
1213 if (longjmp_b)
1214 {
1215 /* Link BPT into the chain of LONGJMP_B. */
1216 bpt->related_breakpoint = longjmp_b;
1217 while (longjmp_b->related_breakpoint != bpt->related_breakpoint)
1218 longjmp_b = longjmp_b->related_breakpoint;
1219 longjmp_b->related_breakpoint = bpt;
1220 }
74cfe982 1221 }
04714b91 1222
7cd1089b
PM
1223 /* Create a breakpoint in std::terminate.
1224 If a C++ exception is raised in the dummy-frame, and the
1225 exception handler is (normally, and expected to be) out-of-frame,
1226 the default C++ handler will (wrongly) be called in an inferior
1227 function call. This is wrong, as an exception can be normally
1228 and legally handled out-of-frame. The confines of the dummy frame
1229 prevent the unwinder from finding the correct handler (or any
1230 handler, unless it is in-frame). The default handler calls
1231 std::terminate. This will kill the inferior. Assert that
1232 terminate should never be called in an inferior function
1233 call. Place a momentary breakpoint in the std::terminate function
1234 and if triggered in the call, rewind. */
1235 if (unwind_on_terminating_exception_p)
aa7d318d 1236 set_std_terminate_breakpoint ();
7cd1089b 1237
96860204
AC
1238 /* Everything's ready, push all the info needed to restore the
1239 caller (and identify the dummy-frame) onto the dummy-frame
1240 stack. */
c7c4d3fa 1241 dummy_frame_push (caller_state.release (), &dummy_id, call_thread.get ());
ed12ef62 1242 if (dummy_dtor != NULL)
00431a78 1243 register_dummy_frame_dtor (dummy_id, call_thread.get (),
ed12ef62 1244 dummy_dtor, dummy_dtor_data);
b89667eb 1245
7cd1089b 1246 /* Register a clean-up for unwind_on_terminating_exception_breakpoint. */
2cc83d1e 1247 SCOPE_EXIT { delete_std_terminate_breakpoint (); };
7cd1089b 1248
96860204
AC
1249 /* - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP -
1250 If you're looking to implement asynchronous dummy-frames, then
1251 just below is the place to chop this function in two.. */
1252
74cfe982 1253 {
388a7084
PA
1254 struct thread_fsm *saved_sm;
1255 struct call_thread_fsm *sm;
1256
1257 /* Save the current FSM. We'll override it. */
00431a78
PA
1258 saved_sm = call_thread->thread_fsm;
1259 call_thread->thread_fsm = NULL;
74cfe982 1260
b89667eb
DE
1261 /* Save this thread's ptid, we need it later but the thread
1262 may have exited. */
00431a78 1263 call_thread_ptid = call_thread->ptid;
74cfe982 1264
b89667eb 1265 /* Run the inferior until it stops. */
f5871ec0 1266
388a7084
PA
1267 /* Create the FSM used to manage the infcall. It tells infrun to
1268 not report the stop to the user, and captures the return value
1269 before the dummy frame is popped. run_inferior_call registers
1270 it with the thread ASAP. */
46e3ed7f 1271 sm = new call_thread_fsm (current_ui, command_interp (),
3b12939d 1272 gdbarch, function,
388a7084 1273 values_type,
c5ac5cbb 1274 return_method != return_method_normal,
388a7084
PA
1275 struct_addr);
1276
00431a78 1277 e = run_inferior_call (sm, call_thread.get (), real_pc);
388a7084 1278
76727919 1279 gdb::observers::inferior_call_post.notify (call_thread_ptid, funaddr);
388a7084 1280
00431a78 1281 if (call_thread->state != THREAD_EXITED)
388a7084
PA
1282 {
1283 /* The FSM should still be the same. */
46e3ed7f 1284 gdb_assert (call_thread->thread_fsm == sm);
388a7084 1285
46e3ed7f 1286 if (call_thread->thread_fsm->finished_p ())
388a7084
PA
1287 {
1288 struct value *retval;
1289
1290 /* The inferior call is successful. Pop the dummy frame,
1291 which runs its destructors and restores the inferior's
1292 suspend state, and restore the inferior control
1293 state. */
00431a78 1294 dummy_frame_pop (dummy_id, call_thread.get ());
c7c4d3fa 1295 restore_infcall_control_state (inf_status.release ());
388a7084
PA
1296
1297 /* Get the return value. */
1298 retval = sm->return_value;
1299
1300 /* Clean up / destroy the call FSM, and restore the
1301 original one. */
46e3ed7f
TT
1302 call_thread->thread_fsm->clean_up (call_thread.get ());
1303 delete call_thread->thread_fsm;
00431a78 1304 call_thread->thread_fsm = saved_sm;
04714b91 1305
388a7084
PA
1306 maybe_remove_breakpoints ();
1307
388a7084 1308 gdb_assert (retval != NULL);
099a6354
TBA
1309
1310 /* Destruct the pass-by-ref argument clones. */
1311 call_destructors (dtors_to_invoke, default_return_type);
1312
388a7084
PA
1313 return retval;
1314 }
1315
e3319240
PW
1316 /* Didn't complete. Clean up / destroy the call FSM, and restore the
1317 previous state machine, and handle the error. */
46e3ed7f
TT
1318 call_thread->thread_fsm->clean_up (call_thread.get ());
1319 delete call_thread->thread_fsm;
00431a78 1320 call_thread->thread_fsm = saved_sm;
388a7084
PA
1321 }
1322 }
162078c8 1323
b89667eb
DE
1324 /* Rethrow an error if we got one trying to run the inferior. */
1325
1326 if (e.reason < 0)
1327 {
1328 const char *name = get_function_name (funaddr,
1329 name_buf, sizeof (name_buf));
1330
c7c4d3fa 1331 discard_infcall_control_state (inf_status.release ());
b89667eb
DE
1332
1333 /* We could discard the dummy frame here if the program exited,
1334 but it will get garbage collected the next time the program is
1335 run anyway. */
1336
1337 switch (e.reason)
1338 {
1339 case RETURN_ERROR:
ac74f770
MS
1340 throw_error (e.error, _("%s\n\
1341An error occurred while in a function called from GDB.\n\
1342Evaluation of the expression containing the function\n\
1343(%s) will be abandoned.\n\
1344When the function is done executing, GDB will silently stop."),
3d6e9d23 1345 e.what (), name);
b89667eb
DE
1346 case RETURN_QUIT:
1347 default:
94aeb44b 1348 throw_exception (std::move (e));
b89667eb
DE
1349 }
1350 }
1351
1352 /* If the program has exited, or we stopped at a different thread,
1353 exit and inform the user. */
1354
de04a248
DE
1355 if (! target_has_execution)
1356 {
b89667eb
DE
1357 const char *name = get_function_name (funaddr,
1358 name_buf, sizeof (name_buf));
1359
1360 /* If we try to restore the inferior status,
de04a248 1361 we'll crash as the inferior is no longer running. */
c7c4d3fa 1362 discard_infcall_control_state (inf_status.release ());
b89667eb
DE
1363
1364 /* We could discard the dummy frame here given that the program exited,
1365 but it will get garbage collected the next time the program is
1366 run anyway. */
1367
3e43a32a
MS
1368 error (_("The program being debugged exited while in a function "
1369 "called from GDB.\n"
1370 "Evaluation of the expression containing the function\n"
1371 "(%s) will be abandoned."),
b89667eb
DE
1372 name);
1373 }
1374
d7e15655 1375 if (call_thread_ptid != inferior_ptid)
b89667eb
DE
1376 {
1377 const char *name = get_function_name (funaddr,
1378 name_buf, sizeof (name_buf));
1379
1380 /* We've switched threads. This can happen if another thread gets a
1381 signal or breakpoint while our thread was running.
1382 There's no point in restoring the inferior status,
1383 we're in a different thread. */
c7c4d3fa 1384 discard_infcall_control_state (inf_status.release ());
b89667eb
DE
1385 /* Keep the dummy frame record, if the user switches back to the
1386 thread with the hand-call, we'll need it. */
1387 if (stopped_by_random_signal)
ac74f770
MS
1388 error (_("\
1389The program received a signal in another thread while\n\
1390making a function call from GDB.\n\
1391Evaluation of the expression containing the function\n\
1392(%s) will be abandoned.\n\
1393When the function is done executing, GDB will silently stop."),
b89667eb
DE
1394 name);
1395 else
ac74f770
MS
1396 error (_("\
1397The program stopped in another thread while making a function call from GDB.\n\
1398Evaluation of the expression containing the function\n\
1399(%s) will be abandoned.\n\
1400When the function is done executing, GDB will silently stop."),
b89667eb 1401 name);
de04a248
DE
1402 }
1403
52557533 1404 {
5fe75eec 1405 /* Make a copy as NAME may be in an objfile freed by dummy_frame_pop. */
395423c4
TT
1406 std::string name = get_function_name (funaddr, name_buf,
1407 sizeof (name_buf));
b89667eb 1408
52557533
AC
1409 if (stopped_by_random_signal)
1410 {
1411 /* We stopped inside the FUNCTION because of a random
1412 signal. Further execution of the FUNCTION is not
1777feb0 1413 allowed. */
04714b91 1414
52557533
AC
1415 if (unwind_on_signal_p)
1416 {
1777feb0 1417 /* The user wants the context restored. */
52557533
AC
1418
1419 /* We must get back to the frame we were before the
b89667eb 1420 dummy call. */
00431a78 1421 dummy_frame_pop (dummy_id, call_thread.get ());
b89667eb
DE
1422
1423 /* We also need to restore inferior status to that before the
1424 dummy call. */
c7c4d3fa 1425 restore_infcall_control_state (inf_status.release ());
04714b91 1426
52557533
AC
1427 /* FIXME: Insert a bunch of wrap_here; name can be very
1428 long if it's a C++ name with arguments and stuff. */
ac74f770
MS
1429 error (_("\
1430The program being debugged was signaled while in a function called from GDB.\n\
1431GDB has restored the context to what it was before the call.\n\
1432To change this behavior use \"set unwindonsignal off\".\n\
1433Evaluation of the expression containing the function\n\
1434(%s) will be abandoned."),
395423c4 1435 name.c_str ());
52557533
AC
1436 }
1437 else
1438 {
1439 /* The user wants to stay in the frame where we stopped
b89667eb
DE
1440 (default).
1441 Discard inferior status, we're not at the same point
1442 we started at. */
c7c4d3fa 1443 discard_infcall_control_state (inf_status.release ());
b89667eb 1444
52557533
AC
1445 /* FIXME: Insert a bunch of wrap_here; name can be very
1446 long if it's a C++ name with arguments and stuff. */
ac74f770
MS
1447 error (_("\
1448The program being debugged was signaled while in a function called from GDB.\n\
1449GDB remains in the frame where the signal was received.\n\
1450To change this behavior use \"set unwindonsignal on\".\n\
1451Evaluation of the expression containing the function\n\
1452(%s) will be abandoned.\n\
1453When the function is done executing, GDB will silently stop."),
395423c4 1454 name.c_str ());
52557533
AC
1455 }
1456 }
04714b91 1457
aa7d318d 1458 if (stop_stack_dummy == STOP_STD_TERMINATE)
52557533 1459 {
aa7d318d
TT
1460 /* We must get back to the frame we were before the dummy
1461 call. */
00431a78 1462 dummy_frame_pop (dummy_id, call_thread.get ());
7cd1089b 1463
aa7d318d
TT
1464 /* We also need to restore inferior status to that before
1465 the dummy call. */
c7c4d3fa 1466 restore_infcall_control_state (inf_status.release ());
aa7d318d 1467
ac74f770
MS
1468 error (_("\
1469The program being debugged entered a std::terminate call, most likely\n\
1470caused by an unhandled C++ exception. GDB blocked this call in order\n\
1471to prevent the program from being terminated, and has restored the\n\
1472context to its original state before the call.\n\
1473To change this behaviour use \"set unwind-on-terminating-exception off\".\n\
1474Evaluation of the expression containing the function (%s)\n\
1475will be abandoned."),
395423c4 1476 name.c_str ());
aa7d318d
TT
1477 }
1478 else if (stop_stack_dummy == STOP_NONE)
1479 {
1480
b89667eb
DE
1481 /* We hit a breakpoint inside the FUNCTION.
1482 Keep the dummy frame, the user may want to examine its state.
1483 Discard inferior status, we're not at the same point
1484 we started at. */
c7c4d3fa 1485 discard_infcall_control_state (inf_status.release ());
b89667eb 1486
52557533
AC
1487 /* The following error message used to say "The expression
1488 which contained the function call has been discarded."
1489 It is a hard concept to explain in a few words. Ideally,
1490 GDB would be able to resume evaluation of the expression
1491 when the function finally is done executing. Perhaps
1492 someday this will be implemented (it would not be easy). */
1493 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
1494 a C++ name with arguments and stuff. */
ac74f770
MS
1495 error (_("\
1496The program being debugged stopped while in a function called from GDB.\n\
1497Evaluation of the expression containing the function\n\
1498(%s) will be abandoned.\n\
1499When the function is done executing, GDB will silently stop."),
395423c4 1500 name.c_str ());
52557533
AC
1501 }
1502
52557533 1503 }
04714b91 1504
388a7084
PA
1505 /* The above code errors out, so ... */
1506 gdb_assert_not_reached ("... should not be here");
04714b91 1507}
04714b91
AC
1508
1509void
1510_initialize_infcall (void)
1511{
136afab8
PW
1512 add_setshow_boolean_cmd ("may-call-functions", no_class,
1513 &may_call_functions_p, _("\
1514Set permission to call functions in the program."), _("\
1515Show permission to call functions in the program."), _("\
1516When this permission is on, GDB may call functions in the program.\n\
1517Otherwise, any sort of attempt to call a function in the program\n\
1518will result in an error."),
1519 NULL,
1520 show_may_call_functions_p,
1521 &setlist, &showlist);
1522
04714b91 1523 add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure,
7915a72c
AC
1524 &coerce_float_to_double_p, _("\
1525Set coercion of floats to doubles when calling functions."), _("\
590042fc 1526Show coercion of floats to doubles when calling functions."), _("\
04714b91
AC
1527Variables of type float should generally be converted to doubles before\n\
1528calling an unprototyped function, and left alone when calling a prototyped\n\
1529function. However, some older debug info formats do not provide enough\n\
1530information to determine that a function is prototyped. If this flag is\n\
1531set, GDB will perform the conversion for a function it considers\n\
1532unprototyped.\n\
89549d7f 1533The default is to perform the conversion."),
2c5b56ce 1534 NULL,
920d2a44 1535 show_coerce_float_to_double_p,
2c5b56ce 1536 &setlist, &showlist);
04714b91
AC
1537
1538 add_setshow_boolean_cmd ("unwindonsignal", no_class,
7915a72c
AC
1539 &unwind_on_signal_p, _("\
1540Set unwinding of stack if a signal is received while in a call dummy."), _("\
1541Show unwinding of stack if a signal is received while in a call dummy."), _("\
04714b91
AC
1542The unwindonsignal lets the user determine what gdb should do if a signal\n\
1543is received while in a function called from gdb (call dummy). If set, gdb\n\
1544unwinds the stack and restore the context to what as it was before the call.\n\
7915a72c 1545The default is to stop in the frame where the signal was received."),
2c5b56ce 1546 NULL,
920d2a44 1547 show_unwind_on_signal_p,
2c5b56ce 1548 &setlist, &showlist);
7cd1089b
PM
1549
1550 add_setshow_boolean_cmd ("unwind-on-terminating-exception", no_class,
1551 &unwind_on_terminating_exception_p, _("\
1552Set unwinding of stack if std::terminate is called while in call dummy."), _("\
3e43a32a
MS
1553Show unwinding of stack if std::terminate() is called while in a call dummy."),
1554 _("\
7cd1089b
PM
1555The unwind on terminating exception flag lets the user determine\n\
1556what gdb should do if a std::terminate() call is made from the\n\
1557default exception handler. If set, gdb unwinds the stack and restores\n\
1558the context to what it was before the call. If unset, gdb allows the\n\
1559std::terminate call to proceed.\n\
1560The default is to unwind the frame."),
1561 NULL,
1562 show_unwind_on_terminating_exception_p,
1563 &setlist, &showlist);
1564
04714b91 1565}
This page took 1.548985 seconds and 4 git commands to generate.