1 /* Perform an inferior function call, for GDB, the GNU debugger.
3 Copyright (C) 1986-2015 Free Software Foundation, Inc.
5 This file is part of GDB.
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.
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.
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/>. */
21 #include "breakpoint.h"
22 #include "tracepoint.h"
34 #include "dummy-frame.h"
36 #include "gdbthread.h"
37 #include "event-top.h"
42 /* If we can't find a function's name from its address,
43 we print this instead. */
44 #define RAW_FUNCTION_ADDRESS_FORMAT "at 0x%s"
45 #define RAW_FUNCTION_ADDRESS_SIZE (sizeof (RAW_FUNCTION_ADDRESS_FORMAT) \
46 + 2 * sizeof (CORE_ADDR))
48 /* NOTE: cagney/2003-04-16: What's the future of this code?
50 GDB needs an asynchronous expression evaluator, that means an
51 asynchronous inferior function call implementation, and that in
52 turn means restructuring the code so that it is event driven. */
54 /* How you should pass arguments to a function depends on whether it
55 was defined in K&R style or prototype style. If you define a
56 function using the K&R syntax that takes a `float' argument, then
57 callers must pass that argument as a `double'. If you define the
58 function using the prototype syntax, then you must pass the
59 argument as a `float', with no promotion.
61 Unfortunately, on certain older platforms, the debug info doesn't
62 indicate reliably how each function was defined. A function type's
63 TYPE_FLAG_PROTOTYPED flag may be clear, even if the function was
64 defined in prototype style. When calling a function whose
65 TYPE_FLAG_PROTOTYPED flag is clear, GDB consults this flag to
68 For modern targets, it is proper to assume that, if the prototype
69 flag is clear, that can be trusted: `float' arguments should be
70 promoted to `double'. For some older targets, if the prototype
71 flag is clear, that doesn't tell us anything. The default is to
72 trust the debug information; the user can override this behavior
73 with "set coerce-float-to-double 0". */
75 static int coerce_float_to_double_p
= 1;
77 show_coerce_float_to_double_p (struct ui_file
*file
, int from_tty
,
78 struct cmd_list_element
*c
, const char *value
)
80 fprintf_filtered (file
,
81 _("Coercion of floats to doubles "
82 "when calling functions is %s.\n"),
86 /* This boolean tells what gdb should do if a signal is received while
87 in a function called from gdb (call dummy). If set, gdb unwinds
88 the stack and restore the context to what as it was before the
91 The default is to stop in the frame where the signal was received. */
93 static int unwind_on_signal_p
= 0;
95 show_unwind_on_signal_p (struct ui_file
*file
, int from_tty
,
96 struct cmd_list_element
*c
, const char *value
)
98 fprintf_filtered (file
,
99 _("Unwinding of stack if a signal is "
100 "received while in a call dummy is %s.\n"),
104 /* This boolean tells what gdb should do if a std::terminate call is
105 made while in a function called from gdb (call dummy).
106 As the confines of a single dummy stack prohibit out-of-frame
107 handlers from handling a raised exception, and as out-of-frame
108 handlers are common in C++, this can lead to no handler being found
109 by the unwinder, and a std::terminate call. This is a false positive.
110 If set, gdb unwinds the stack and restores the context to what it
113 The default is to unwind the frame if a std::terminate call is
116 static int unwind_on_terminating_exception_p
= 1;
119 show_unwind_on_terminating_exception_p (struct ui_file
*file
, int from_tty
,
120 struct cmd_list_element
*c
,
124 fprintf_filtered (file
,
125 _("Unwind stack if a C++ exception is "
126 "unhandled while in a call dummy is %s.\n"),
130 /* Perform the standard coercions that are specified
131 for arguments to be passed to C or Ada functions.
133 If PARAM_TYPE is non-NULL, it is the expected parameter type.
134 IS_PROTOTYPED is non-zero if the function declaration is prototyped.
135 SP is the stack pointer were additional data can be pushed (updating
136 its value as needed). */
138 static struct value
*
139 value_arg_coerce (struct gdbarch
*gdbarch
, struct value
*arg
,
140 struct type
*param_type
, int is_prototyped
, CORE_ADDR
*sp
)
142 const struct builtin_type
*builtin
= builtin_type (gdbarch
);
143 struct type
*arg_type
= check_typedef (value_type (arg
));
145 = param_type
? check_typedef (param_type
) : arg_type
;
147 /* Perform any Ada-specific coercion first. */
148 if (current_language
->la_language
== language_ada
)
149 arg
= ada_convert_actual (arg
, type
);
151 /* Force the value to the target if we will need its address. At
152 this point, we could allocate arguments on the stack instead of
153 calling malloc if we knew that their addresses would not be
154 saved by the called function. */
155 arg
= value_coerce_to_target (arg
);
157 switch (TYPE_CODE (type
))
161 struct value
*new_value
;
163 if (TYPE_CODE (arg_type
) == TYPE_CODE_REF
)
164 return value_cast_pointers (type
, arg
, 0);
166 /* Cast the value to the reference's target type, and then
167 convert it back to a reference. This will issue an error
168 if the value was not previously in memory - in some cases
169 we should clearly be allowing this, but how? */
170 new_value
= value_cast (TYPE_TARGET_TYPE (type
), arg
);
171 new_value
= value_ref (new_value
);
178 /* If we don't have a prototype, coerce to integer type if necessary. */
181 if (TYPE_LENGTH (type
) < TYPE_LENGTH (builtin
->builtin_int
))
182 type
= builtin
->builtin_int
;
184 /* Currently all target ABIs require at least the width of an integer
185 type for an argument. We may have to conditionalize the following
186 type coercion for future targets. */
187 if (TYPE_LENGTH (type
) < TYPE_LENGTH (builtin
->builtin_int
))
188 type
= builtin
->builtin_int
;
191 if (!is_prototyped
&& coerce_float_to_double_p
)
193 if (TYPE_LENGTH (type
) < TYPE_LENGTH (builtin
->builtin_double
))
194 type
= builtin
->builtin_double
;
195 else if (TYPE_LENGTH (type
) > TYPE_LENGTH (builtin
->builtin_double
))
196 type
= builtin
->builtin_long_double
;
200 type
= lookup_pointer_type (type
);
202 case TYPE_CODE_ARRAY
:
203 /* Arrays are coerced to pointers to their first element, unless
204 they are vectors, in which case we want to leave them alone,
205 because they are passed by value. */
206 if (current_language
->c_style_arrays
)
207 if (!TYPE_VECTOR (type
))
208 type
= lookup_pointer_type (TYPE_TARGET_TYPE (type
));
210 case TYPE_CODE_UNDEF
:
212 case TYPE_CODE_STRUCT
:
213 case TYPE_CODE_UNION
:
216 case TYPE_CODE_RANGE
:
217 case TYPE_CODE_STRING
:
218 case TYPE_CODE_ERROR
:
219 case TYPE_CODE_MEMBERPTR
:
220 case TYPE_CODE_METHODPTR
:
221 case TYPE_CODE_METHOD
:
222 case TYPE_CODE_COMPLEX
:
227 return value_cast (type
, arg
);
230 /* Return the return type of a function with its first instruction exactly at
231 the PC address. Return NULL otherwise. */
234 find_function_return_type (CORE_ADDR pc
)
236 struct symbol
*sym
= find_pc_function (pc
);
238 if (sym
!= NULL
&& BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)) == pc
239 && SYMBOL_TYPE (sym
) != NULL
)
240 return TYPE_TARGET_TYPE (SYMBOL_TYPE (sym
));
245 /* Determine a function's address and its return type from its value.
246 Calls error() if the function is not valid for calling. */
249 find_function_addr (struct value
*function
, struct type
**retval_type
)
251 struct type
*ftype
= check_typedef (value_type (function
));
252 struct gdbarch
*gdbarch
= get_type_arch (ftype
);
253 struct type
*value_type
= NULL
;
254 /* Initialize it just to avoid a GCC false warning. */
255 CORE_ADDR funaddr
= 0;
257 /* If it's a member function, just look at the function
260 /* Determine address to call. */
261 if (TYPE_CODE (ftype
) == TYPE_CODE_FUNC
262 || TYPE_CODE (ftype
) == TYPE_CODE_METHOD
)
263 funaddr
= value_address (function
);
264 else if (TYPE_CODE (ftype
) == TYPE_CODE_PTR
)
266 funaddr
= value_as_address (function
);
267 ftype
= check_typedef (TYPE_TARGET_TYPE (ftype
));
268 if (TYPE_CODE (ftype
) == TYPE_CODE_FUNC
269 || TYPE_CODE (ftype
) == TYPE_CODE_METHOD
)
270 funaddr
= gdbarch_convert_from_func_ptr_addr (gdbarch
, funaddr
,
273 if (TYPE_CODE (ftype
) == TYPE_CODE_FUNC
274 || TYPE_CODE (ftype
) == TYPE_CODE_METHOD
)
276 value_type
= TYPE_TARGET_TYPE (ftype
);
278 if (TYPE_GNU_IFUNC (ftype
))
280 funaddr
= gnu_ifunc_resolve_addr (gdbarch
, funaddr
);
282 /* Skip querying the function symbol if no RETVAL_TYPE has been
285 value_type
= find_function_return_type (funaddr
);
288 else if (TYPE_CODE (ftype
) == TYPE_CODE_INT
)
290 /* Handle the case of functions lacking debugging info.
291 Their values are characters since their addresses are char. */
292 if (TYPE_LENGTH (ftype
) == 1)
293 funaddr
= value_as_address (value_addr (function
));
296 /* Handle function descriptors lacking debug info. */
297 int found_descriptor
= 0;
299 funaddr
= 0; /* pacify "gcc -Werror" */
300 if (VALUE_LVAL (function
) == lval_memory
)
304 funaddr
= value_as_address (value_addr (function
));
306 funaddr
= gdbarch_convert_from_func_ptr_addr (gdbarch
, funaddr
,
308 if (funaddr
!= nfunaddr
)
309 found_descriptor
= 1;
311 if (!found_descriptor
)
312 /* Handle integer used as address of a function. */
313 funaddr
= (CORE_ADDR
) value_as_long (function
);
317 error (_("Invalid data type for function to be called."));
319 if (retval_type
!= NULL
)
320 *retval_type
= value_type
;
321 return funaddr
+ gdbarch_deprecated_function_start_offset (gdbarch
);
324 /* For CALL_DUMMY_ON_STACK, push a breakpoint sequence that the called
325 function returns to. */
328 push_dummy_code (struct gdbarch
*gdbarch
,
329 CORE_ADDR sp
, CORE_ADDR funaddr
,
330 struct value
**args
, int nargs
,
331 struct type
*value_type
,
332 CORE_ADDR
*real_pc
, CORE_ADDR
*bp_addr
,
333 struct regcache
*regcache
)
335 gdb_assert (gdbarch_push_dummy_code_p (gdbarch
));
337 return gdbarch_push_dummy_code (gdbarch
, sp
, funaddr
,
338 args
, nargs
, value_type
, real_pc
, bp_addr
,
342 /* Fetch the name of the function at FUNADDR.
343 This is used in printing an error message for call_function_by_hand.
344 BUF is used to print FUNADDR in hex if the function name cannot be
345 determined. It must be large enough to hold formatted result of
346 RAW_FUNCTION_ADDRESS_FORMAT. */
349 get_function_name (CORE_ADDR funaddr
, char *buf
, int buf_size
)
352 struct symbol
*symbol
= find_pc_function (funaddr
);
355 return SYMBOL_PRINT_NAME (symbol
);
359 /* Try the minimal symbols. */
360 struct bound_minimal_symbol msymbol
= lookup_minimal_symbol_by_pc (funaddr
);
363 return MSYMBOL_PRINT_NAME (msymbol
.minsym
);
367 char *tmp
= xstrprintf (_(RAW_FUNCTION_ADDRESS_FORMAT
),
368 hex_string (funaddr
));
370 gdb_assert (strlen (tmp
) + 1 <= buf_size
);
377 /* Subroutine of call_function_by_hand to simplify it.
378 Start up the inferior and wait for it to stop.
379 Return the exception if there's an error, or an exception with
380 reason >= 0 if there's no error.
382 This is done inside a TRY_CATCH so the caller needn't worry about
383 thrown errors. The caller should rethrow if there's an error. */
385 static struct gdb_exception
386 run_inferior_call (struct thread_info
*call_thread
, CORE_ADDR real_pc
)
388 struct gdb_exception caught_error
= exception_none
;
389 int saved_in_infcall
= call_thread
->control
.in_infcall
;
390 ptid_t call_thread_ptid
= call_thread
->ptid
;
391 int saved_sync_execution
= sync_execution
;
392 int was_running
= call_thread
->state
== THREAD_RUNNING
;
393 int saved_interpreter_async
= interpreter_async
;
395 /* Infcalls run synchronously, in the foreground. */
397 /* So that we don't print the prompt prematurely in
398 fetch_inferior_event. */
399 interpreter_async
= 0;
401 call_thread
->control
.in_infcall
= 1;
403 clear_proceed_status (0);
405 disable_watchpoints_before_interactive_call_start ();
407 /* We want to print return value, please... */
408 call_thread
->control
.proceed_to_finish
= 1;
412 proceed (real_pc
, GDB_SIGNAL_0
);
414 /* Inferior function calls are always synchronous, even if the
415 target supports asynchronous execution. */
416 wait_sync_command_done ();
418 CATCH (e
, RETURN_MASK_ALL
)
424 /* If GDB was previously in sync execution mode, then ensure that it
425 remains so. normal_stop calls async_enable_stdin, so reset it
426 again here. In other cases, stdin will be re-enabled by
427 inferior_event_handler, when an exception is thrown. */
428 sync_execution
= saved_sync_execution
;
429 interpreter_async
= saved_interpreter_async
;
431 /* At this point the current thread may have changed. Refresh
432 CALL_THREAD as it could be invalid if its thread has exited. */
433 call_thread
= find_thread_ptid (call_thread_ptid
);
435 /* If the infcall does NOT succeed, normal_stop will have already
436 finished the thread states. However, on success, normal_stop
437 defers here, so that we can set back the thread states to what
438 they were before the call. Note that we must also finish the
439 state of new threads that might have spawned while the call was
440 running. The main cases to handle are:
442 - "(gdb) print foo ()", or any other command that evaluates an
443 expression at the prompt. (The thread was marked stopped before.)
445 - "(gdb) break foo if return_false()" or similar cases where we
446 do an infcall while handling an event (while the thread is still
447 marked running). In this example, whether the condition
448 evaluates true and thus we'll present a user-visible stop is
449 decided elsewhere. */
451 && ptid_equal (call_thread_ptid
, inferior_ptid
)
452 && stop_stack_dummy
== STOP_STACK_DUMMY
)
453 finish_thread_state (user_visible_resume_ptid (0));
455 enable_watchpoints_after_interactive_call_stop ();
457 /* Call breakpoint_auto_delete on the current contents of the bpstat
458 of inferior call thread.
459 If all error()s out of proceed ended up calling normal_stop
460 (and perhaps they should; it already does in the special case
461 of error out of resume()), then we wouldn't need this. */
462 if (caught_error
.reason
< 0)
464 if (call_thread
!= NULL
)
465 breakpoint_auto_delete (call_thread
->control
.stop_bpstat
);
468 if (call_thread
!= NULL
)
469 call_thread
->control
.in_infcall
= saved_in_infcall
;
474 /* A cleanup function that calls delete_std_terminate_breakpoint. */
476 cleanup_delete_std_terminate_breakpoint (void *ignore
)
478 delete_std_terminate_breakpoint ();
484 call_function_by_hand (struct value
*function
, int nargs
, struct value
**args
)
486 return call_function_by_hand_dummy (function
, nargs
, args
, NULL
, NULL
);
489 /* Data for dummy_frame_context_saver. Structure can be freed only
490 after both dummy_frame_context_saver_dtor and
491 dummy_frame_context_saver_drop have been called for it. */
493 struct dummy_frame_context_saver
495 /* Inferior registers fetched before associated dummy_frame got freed
496 and before any other destructors of associated dummy_frame got called.
497 It is initialized to NULL. */
498 struct regcache
*retbuf
;
500 /* It is 1 if this dummy_frame_context_saver_drop has been already
505 /* Free struct dummy_frame_context_saver. */
508 dummy_frame_context_saver_free (struct dummy_frame_context_saver
*saver
)
510 regcache_xfree (saver
->retbuf
);
514 /* Destructor for associated dummy_frame. */
517 dummy_frame_context_saver_dtor (void *data_voidp
, int registers_valid
)
519 struct dummy_frame_context_saver
*data
= data_voidp
;
521 gdb_assert (data
->retbuf
== NULL
);
524 dummy_frame_context_saver_free (data
);
525 else if (registers_valid
)
526 data
->retbuf
= regcache_dup (get_current_regcache ());
529 /* Caller is no longer interested in this
530 struct dummy_frame_context_saver. After its associated dummy_frame
531 gets freed struct dummy_frame_context_saver can be also freed. */
534 dummy_frame_context_saver_drop (struct dummy_frame_context_saver
*saver
)
536 saver
->drop_done
= 1;
538 if (!find_dummy_frame_dtor (dummy_frame_context_saver_dtor
, saver
))
539 dummy_frame_context_saver_free (saver
);
542 /* Stub dummy_frame_context_saver_drop compatible with make_cleanup. */
545 dummy_frame_context_saver_cleanup (void *data
)
547 struct dummy_frame_context_saver
*saver
= data
;
549 dummy_frame_context_saver_drop (saver
);
552 /* Fetch RETBUF field of possibly opaque DTOR_DATA.
553 RETBUF must not be NULL. */
556 dummy_frame_context_saver_get_regs (struct dummy_frame_context_saver
*saver
)
558 gdb_assert (saver
->retbuf
!= NULL
);
559 return saver
->retbuf
;
562 /* Register provider of inferior registers at the time DUMMY_ID frame of
563 PTID gets freed (before inferior registers get restored to those
564 before dummy_frame). */
566 struct dummy_frame_context_saver
*
567 dummy_frame_context_saver_setup (struct frame_id dummy_id
, ptid_t ptid
)
569 struct dummy_frame_context_saver
*saver
=
570 XNEW (struct dummy_frame_context_saver
);
572 saver
->retbuf
= NULL
;
573 saver
->drop_done
= 0;
574 register_dummy_frame_dtor (dummy_id
, inferior_ptid
,
575 dummy_frame_context_saver_dtor
, saver
);
579 /* All this stuff with a dummy frame may seem unnecessarily complicated
580 (why not just save registers in GDB?). The purpose of pushing a dummy
581 frame which looks just like a real frame is so that if you call a
582 function and then hit a breakpoint (get a signal, etc), "backtrace"
583 will look right. Whether the backtrace needs to actually show the
584 stack at the time the inferior function was called is debatable, but
585 it certainly needs to not display garbage. So if you are contemplating
586 making dummy frames be different from normal frames, consider that. */
588 /* Perform a function call in the inferior.
589 ARGS is a vector of values of arguments (NARGS of them).
590 FUNCTION is a value, the function to be called.
591 Returns a value representing what the function returned.
592 May fail to return, if a breakpoint or signal is hit
593 during the execution of the function.
595 ARGS is modified to contain coerced values. */
598 call_function_by_hand_dummy (struct value
*function
,
599 int nargs
, struct value
**args
,
600 dummy_frame_dtor_ftype
*dummy_dtor
,
601 void *dummy_dtor_data
)
604 struct type
*values_type
, *target_values_type
;
605 unsigned char struct_return
= 0, hidden_first_param_p
= 0;
606 CORE_ADDR struct_addr
= 0;
607 struct infcall_control_state
*inf_status
;
608 struct cleanup
*inf_status_cleanup
;
609 struct infcall_suspend_state
*caller_state
;
612 struct type
*ftype
= check_typedef (value_type (function
));
614 struct frame_id dummy_id
;
615 struct cleanup
*args_cleanup
;
616 struct frame_info
*frame
;
617 struct gdbarch
*gdbarch
;
618 struct cleanup
*terminate_bp_cleanup
;
619 ptid_t call_thread_ptid
;
620 struct gdb_exception e
;
621 char name_buf
[RAW_FUNCTION_ADDRESS_SIZE
];
622 int stack_temporaries
= thread_stack_temporaries_enabled_p (inferior_ptid
);
623 struct dummy_frame_context_saver
*context_saver
;
624 struct cleanup
*context_saver_cleanup
;
626 if (TYPE_CODE (ftype
) == TYPE_CODE_PTR
)
627 ftype
= check_typedef (TYPE_TARGET_TYPE (ftype
));
629 if (!target_has_execution
)
632 if (get_traceframe_number () >= 0)
633 error (_("May not call functions while looking at trace frames."));
635 if (execution_direction
== EXEC_REVERSE
)
636 error (_("Cannot call functions in reverse mode."));
638 frame
= get_current_frame ();
639 gdbarch
= get_frame_arch (frame
);
641 if (!gdbarch_push_dummy_call_p (gdbarch
))
642 error (_("This target does not support function calls."));
644 /* A cleanup for the inferior status.
645 This is only needed while we're preparing the inferior function call. */
646 inf_status
= save_infcall_control_state ();
648 = make_cleanup_restore_infcall_control_state (inf_status
);
650 /* Save the caller's registers and other state associated with the
651 inferior itself so that they can be restored once the
652 callee returns. To allow nested calls the registers are (further
653 down) pushed onto a dummy frame stack. Include a cleanup (which
654 is tossed once the regcache has been pushed). */
655 caller_state
= save_infcall_suspend_state ();
656 make_cleanup_restore_infcall_suspend_state (caller_state
);
658 /* Ensure that the initial SP is correctly aligned. */
660 CORE_ADDR old_sp
= get_frame_sp (frame
);
662 if (gdbarch_frame_align_p (gdbarch
))
664 sp
= gdbarch_frame_align (gdbarch
, old_sp
);
665 /* NOTE: cagney/2003-08-13: Skip the "red zone". For some
666 ABIs, a function can use memory beyond the inner most stack
667 address. AMD64 called that region the "red zone". Skip at
668 least the "red zone" size before allocating any space on
670 if (gdbarch_inner_than (gdbarch
, 1, 2))
671 sp
-= gdbarch_frame_red_zone_size (gdbarch
);
673 sp
+= gdbarch_frame_red_zone_size (gdbarch
);
675 gdb_assert (sp
== gdbarch_frame_align (gdbarch
, sp
));
676 /* NOTE: cagney/2002-09-18:
678 On a RISC architecture, a void parameterless generic dummy
679 frame (i.e., no parameters, no result) typically does not
680 need to push anything the stack and hence can leave SP and
681 FP. Similarly, a frameless (possibly leaf) function does
682 not push anything on the stack and, hence, that too can
683 leave FP and SP unchanged. As a consequence, a sequence of
684 void parameterless generic dummy frame calls to frameless
685 functions will create a sequence of effectively identical
686 frames (SP, FP and TOS and PC the same). This, not
687 suprisingly, results in what appears to be a stack in an
688 infinite loop --- when GDB tries to find a generic dummy
689 frame on the internal dummy frame stack, it will always
692 To avoid this problem, the code below always grows the
693 stack. That way, two dummy frames can never be identical.
694 It does burn a few bytes of stack but that is a small price
698 if (gdbarch_inner_than (gdbarch
, 1, 2))
699 /* Stack grows down. */
700 sp
= gdbarch_frame_align (gdbarch
, old_sp
- 1);
702 /* Stack grows up. */
703 sp
= gdbarch_frame_align (gdbarch
, old_sp
+ 1);
705 /* SP may have underflown address zero here from OLD_SP. Memory access
706 functions will probably fail in such case but that is a target's
710 /* FIXME: cagney/2002-09-18: Hey, you loose!
712 Who knows how badly aligned the SP is!
714 If the generic dummy frame ends up empty (because nothing is
715 pushed) GDB won't be able to correctly perform back traces.
716 If a target is having trouble with backtraces, first thing to
717 do is add FRAME_ALIGN() to the architecture vector. If that
718 fails, try dummy_id().
720 If the ABI specifies a "Red Zone" (see the doco) the code
721 below will quietly trash it. */
724 /* Skip over the stack temporaries that might have been generated during
725 the evaluation of an expression. */
726 if (stack_temporaries
)
728 struct value
*lastval
;
730 lastval
= get_last_thread_stack_temporary (inferior_ptid
);
733 CORE_ADDR lastval_addr
= value_address (lastval
);
735 if (gdbarch_inner_than (gdbarch
, 1, 2))
737 gdb_assert (sp
>= lastval_addr
);
742 gdb_assert (sp
<= lastval_addr
);
743 sp
= lastval_addr
+ TYPE_LENGTH (value_type (lastval
));
746 if (gdbarch_frame_align_p (gdbarch
))
747 sp
= gdbarch_frame_align (gdbarch
, sp
);
752 funaddr
= find_function_addr (function
, &values_type
);
754 values_type
= builtin_type (gdbarch
)->builtin_int
;
756 values_type
= check_typedef (values_type
);
758 /* Are we returning a value using a structure return (passing a
759 hidden argument pointing to storage) or a normal value return?
760 There are two cases: language-mandated structure return and
761 target ABI structure return. The variable STRUCT_RETURN only
762 describes the latter. The language version is handled by passing
763 the return location as the first parameter to the function,
764 even preceding "this". This is different from the target
765 ABI version, which is target-specific; for instance, on ia64
766 the first argument is passed in out0 but the hidden structure
767 return pointer would normally be passed in r8. */
769 if (gdbarch_return_in_first_hidden_param_p (gdbarch
, values_type
))
771 hidden_first_param_p
= 1;
773 /* Tell the target specific argument pushing routine not to
775 target_values_type
= builtin_type (gdbarch
)->builtin_void
;
779 struct_return
= using_struct_return (gdbarch
, function
, values_type
);
780 target_values_type
= values_type
;
783 observer_notify_inferior_call_pre (inferior_ptid
, funaddr
);
785 /* Determine the location of the breakpoint (and possibly other
786 stuff) that the called function will return to. The SPARC, for a
787 function returning a structure or union, needs to make space for
788 not just the breakpoint but also an extra word containing the
789 size (?) of the structure being passed. */
791 switch (gdbarch_call_dummy_location (gdbarch
))
795 const gdb_byte
*bp_bytes
;
796 CORE_ADDR bp_addr_as_address
;
799 /* Be careful BP_ADDR is in inferior PC encoding while
800 BP_ADDR_AS_ADDRESS is a plain memory address. */
802 sp
= push_dummy_code (gdbarch
, sp
, funaddr
, args
, nargs
,
803 target_values_type
, &real_pc
, &bp_addr
,
804 get_current_regcache ());
806 /* Write a legitimate instruction at the point where the infcall
807 breakpoint is going to be inserted. While this instruction
808 is never going to be executed, a user investigating the
809 memory from GDB would see this instruction instead of random
810 uninitialized bytes. We chose the breakpoint instruction
811 as it may look as the most logical one to the user and also
812 valgrind 3.7.0 needs it for proper vgdb inferior calls.
814 If software breakpoints are unsupported for this target we
815 leave the user visible memory content uninitialized. */
817 bp_addr_as_address
= bp_addr
;
818 bp_bytes
= gdbarch_breakpoint_from_pc (gdbarch
, &bp_addr_as_address
,
820 if (bp_bytes
!= NULL
)
821 write_memory (bp_addr_as_address
, bp_bytes
, bp_size
);
826 CORE_ADDR dummy_addr
;
829 dummy_addr
= entry_point_address ();
831 /* A call dummy always consists of just a single breakpoint, so
832 its address is the same as the address of the dummy.
834 The actual breakpoint is inserted separatly so there is no need to
836 bp_addr
= dummy_addr
;
840 internal_error (__FILE__
, __LINE__
, _("bad switch"));
843 if (nargs
< TYPE_NFIELDS (ftype
))
844 error (_("Too few arguments in function call."));
849 for (i
= nargs
- 1; i
>= 0; i
--)
852 struct type
*param_type
;
854 /* FIXME drow/2002-05-31: Should just always mark methods as
855 prototyped. Can we respect TYPE_VARARGS? Probably not. */
856 if (TYPE_CODE (ftype
) == TYPE_CODE_METHOD
)
858 else if (i
< TYPE_NFIELDS (ftype
))
859 prototyped
= TYPE_PROTOTYPED (ftype
);
863 if (i
< TYPE_NFIELDS (ftype
))
864 param_type
= TYPE_FIELD_TYPE (ftype
, i
);
868 args
[i
] = value_arg_coerce (gdbarch
, args
[i
],
869 param_type
, prototyped
, &sp
);
871 if (param_type
!= NULL
&& language_pass_by_reference (param_type
))
872 args
[i
] = value_addr (args
[i
]);
876 /* Reserve space for the return structure to be written on the
877 stack, if necessary. Make certain that the value is correctly
880 While evaluating expressions, we reserve space on the stack for
881 return values of class type even if the language ABI and the target
882 ABI do not require that the return value be passed as a hidden first
883 argument. This is because we want to store the return value as an
884 on-stack temporary while the expression is being evaluated. This
885 enables us to have chained function calls in expressions.
887 Keeping the return values as on-stack temporaries while the expression
888 is being evaluated is OK because the thread is stopped until the
889 expression is completely evaluated. */
891 if (struct_return
|| hidden_first_param_p
892 || (stack_temporaries
&& class_or_union_p (values_type
)))
894 if (gdbarch_inner_than (gdbarch
, 1, 2))
896 /* Stack grows downward. Align STRUCT_ADDR and SP after
897 making space for the return value. */
898 sp
-= TYPE_LENGTH (values_type
);
899 if (gdbarch_frame_align_p (gdbarch
))
900 sp
= gdbarch_frame_align (gdbarch
, sp
);
905 /* Stack grows upward. Align the frame, allocate space, and
906 then again, re-align the frame??? */
907 if (gdbarch_frame_align_p (gdbarch
))
908 sp
= gdbarch_frame_align (gdbarch
, sp
);
910 sp
+= TYPE_LENGTH (values_type
);
911 if (gdbarch_frame_align_p (gdbarch
))
912 sp
= gdbarch_frame_align (gdbarch
, sp
);
916 if (hidden_first_param_p
)
918 struct value
**new_args
;
920 /* Add the new argument to the front of the argument list. */
921 new_args
= XNEWVEC (struct value
*, nargs
+ 1);
922 new_args
[0] = value_from_pointer (lookup_pointer_type (values_type
),
924 memcpy (&new_args
[1], &args
[0], sizeof (struct value
*) * nargs
);
927 args_cleanup
= make_cleanup (xfree
, args
);
930 args_cleanup
= make_cleanup (null_cleanup
, NULL
);
932 /* Create the dummy stack frame. Pass in the call dummy address as,
933 presumably, the ABI code knows where, in the call dummy, the
934 return address should be pointed. */
935 sp
= gdbarch_push_dummy_call (gdbarch
, function
, get_current_regcache (),
936 bp_addr
, nargs
, args
,
937 sp
, struct_return
, struct_addr
);
939 do_cleanups (args_cleanup
);
941 /* Set up a frame ID for the dummy frame so we can pass it to
942 set_momentary_breakpoint. We need to give the breakpoint a frame
943 ID so that the breakpoint code can correctly re-identify the
945 /* Sanity. The exact same SP value is returned by PUSH_DUMMY_CALL,
946 saved as the dummy-frame TOS, and used by dummy_id to form
947 the frame ID's stack address. */
948 dummy_id
= frame_id_build (sp
, bp_addr
);
950 /* Create a momentary breakpoint at the return address of the
951 inferior. That way it breaks when it returns. */
954 struct breakpoint
*bpt
, *longjmp_b
;
955 struct symtab_and_line sal
;
957 init_sal (&sal
); /* initialize to zeroes */
958 sal
.pspace
= current_program_space
;
960 sal
.section
= find_pc_overlay (sal
.pc
);
961 /* Sanity. The exact same SP value is returned by
962 PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by
963 dummy_id to form the frame ID's stack address. */
964 bpt
= set_momentary_breakpoint (gdbarch
, sal
, dummy_id
, bp_call_dummy
);
966 /* set_momentary_breakpoint invalidates FRAME. */
969 bpt
->disposition
= disp_del
;
970 gdb_assert (bpt
->related_breakpoint
== bpt
);
972 longjmp_b
= set_longjmp_breakpoint_for_call_dummy ();
975 /* Link BPT into the chain of LONGJMP_B. */
976 bpt
->related_breakpoint
= longjmp_b
;
977 while (longjmp_b
->related_breakpoint
!= bpt
->related_breakpoint
)
978 longjmp_b
= longjmp_b
->related_breakpoint
;
979 longjmp_b
->related_breakpoint
= bpt
;
983 /* Create a breakpoint in std::terminate.
984 If a C++ exception is raised in the dummy-frame, and the
985 exception handler is (normally, and expected to be) out-of-frame,
986 the default C++ handler will (wrongly) be called in an inferior
987 function call. This is wrong, as an exception can be normally
988 and legally handled out-of-frame. The confines of the dummy frame
989 prevent the unwinder from finding the correct handler (or any
990 handler, unless it is in-frame). The default handler calls
991 std::terminate. This will kill the inferior. Assert that
992 terminate should never be called in an inferior function
993 call. Place a momentary breakpoint in the std::terminate function
994 and if triggered in the call, rewind. */
995 if (unwind_on_terminating_exception_p
)
996 set_std_terminate_breakpoint ();
998 /* Discard both inf_status and caller_state cleanups.
999 From this point on we explicitly restore the associated state
1001 discard_cleanups (inf_status_cleanup
);
1003 /* Everything's ready, push all the info needed to restore the
1004 caller (and identify the dummy-frame) onto the dummy-frame
1006 dummy_frame_push (caller_state
, &dummy_id
, inferior_ptid
);
1007 if (dummy_dtor
!= NULL
)
1008 register_dummy_frame_dtor (dummy_id
, inferior_ptid
,
1009 dummy_dtor
, dummy_dtor_data
);
1011 /* dummy_frame_context_saver_setup must be called last so that its
1012 saving of inferior registers gets called first (before possible
1013 DUMMY_DTOR destructor). */
1014 context_saver
= dummy_frame_context_saver_setup (dummy_id
, inferior_ptid
);
1015 context_saver_cleanup
= make_cleanup (dummy_frame_context_saver_cleanup
,
1018 /* Register a clean-up for unwind_on_terminating_exception_breakpoint. */
1019 terminate_bp_cleanup
= make_cleanup (cleanup_delete_std_terminate_breakpoint
,
1022 /* - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP -
1023 If you're looking to implement asynchronous dummy-frames, then
1024 just below is the place to chop this function in two.. */
1026 /* TP is invalid after run_inferior_call returns, so enclose this
1027 in a block so that it's only in scope during the time it's valid. */
1029 struct thread_info
*tp
= inferior_thread ();
1031 /* Save this thread's ptid, we need it later but the thread
1033 call_thread_ptid
= tp
->ptid
;
1035 /* Run the inferior until it stops. */
1037 e
= run_inferior_call (tp
, real_pc
);
1040 observer_notify_inferior_call_post (call_thread_ptid
, funaddr
);
1042 /* Rethrow an error if we got one trying to run the inferior. */
1046 const char *name
= get_function_name (funaddr
,
1047 name_buf
, sizeof (name_buf
));
1049 discard_infcall_control_state (inf_status
);
1051 /* We could discard the dummy frame here if the program exited,
1052 but it will get garbage collected the next time the program is
1058 throw_error (e
.error
, _("%s\n\
1059 An error occurred while in a function called from GDB.\n\
1060 Evaluation of the expression containing the function\n\
1061 (%s) will be abandoned.\n\
1062 When the function is done executing, GDB will silently stop."),
1066 throw_exception (e
);
1070 /* If the program has exited, or we stopped at a different thread,
1071 exit and inform the user. */
1073 if (! target_has_execution
)
1075 const char *name
= get_function_name (funaddr
,
1076 name_buf
, sizeof (name_buf
));
1078 /* If we try to restore the inferior status,
1079 we'll crash as the inferior is no longer running. */
1080 discard_infcall_control_state (inf_status
);
1082 /* We could discard the dummy frame here given that the program exited,
1083 but it will get garbage collected the next time the program is
1086 error (_("The program being debugged exited while in a function "
1087 "called from GDB.\n"
1088 "Evaluation of the expression containing the function\n"
1089 "(%s) will be abandoned."),
1093 if (! ptid_equal (call_thread_ptid
, inferior_ptid
))
1095 const char *name
= get_function_name (funaddr
,
1096 name_buf
, sizeof (name_buf
));
1098 /* We've switched threads. This can happen if another thread gets a
1099 signal or breakpoint while our thread was running.
1100 There's no point in restoring the inferior status,
1101 we're in a different thread. */
1102 discard_infcall_control_state (inf_status
);
1103 /* Keep the dummy frame record, if the user switches back to the
1104 thread with the hand-call, we'll need it. */
1105 if (stopped_by_random_signal
)
1107 The program received a signal in another thread while\n\
1108 making a function call from GDB.\n\
1109 Evaluation of the expression containing the function\n\
1110 (%s) will be abandoned.\n\
1111 When the function is done executing, GDB will silently stop."),
1115 The program stopped in another thread while making a function call from GDB.\n\
1116 Evaluation of the expression containing the function\n\
1117 (%s) will be abandoned.\n\
1118 When the function is done executing, GDB will silently stop."),
1122 if (stopped_by_random_signal
|| stop_stack_dummy
!= STOP_STACK_DUMMY
)
1124 /* Make a copy as NAME may be in an objfile freed by dummy_frame_pop. */
1125 char *name
= xstrdup (get_function_name (funaddr
,
1126 name_buf
, sizeof (name_buf
)));
1127 make_cleanup (xfree
, name
);
1130 if (stopped_by_random_signal
)
1132 /* We stopped inside the FUNCTION because of a random
1133 signal. Further execution of the FUNCTION is not
1136 if (unwind_on_signal_p
)
1138 /* The user wants the context restored. */
1140 /* We must get back to the frame we were before the
1142 dummy_frame_pop (dummy_id
, call_thread_ptid
);
1144 /* We also need to restore inferior status to that before the
1146 restore_infcall_control_state (inf_status
);
1148 /* FIXME: Insert a bunch of wrap_here; name can be very
1149 long if it's a C++ name with arguments and stuff. */
1151 The program being debugged was signaled while in a function called from GDB.\n\
1152 GDB has restored the context to what it was before the call.\n\
1153 To change this behavior use \"set unwindonsignal off\".\n\
1154 Evaluation of the expression containing the function\n\
1155 (%s) will be abandoned."),
1160 /* The user wants to stay in the frame where we stopped
1162 Discard inferior status, we're not at the same point
1164 discard_infcall_control_state (inf_status
);
1166 /* FIXME: Insert a bunch of wrap_here; name can be very
1167 long if it's a C++ name with arguments and stuff. */
1169 The program being debugged was signaled while in a function called from GDB.\n\
1170 GDB remains in the frame where the signal was received.\n\
1171 To change this behavior use \"set unwindonsignal on\".\n\
1172 Evaluation of the expression containing the function\n\
1173 (%s) will be abandoned.\n\
1174 When the function is done executing, GDB will silently stop."),
1179 if (stop_stack_dummy
== STOP_STD_TERMINATE
)
1181 /* We must get back to the frame we were before the dummy
1183 dummy_frame_pop (dummy_id
, call_thread_ptid
);
1185 /* We also need to restore inferior status to that before
1187 restore_infcall_control_state (inf_status
);
1190 The program being debugged entered a std::terminate call, most likely\n\
1191 caused by an unhandled C++ exception. GDB blocked this call in order\n\
1192 to prevent the program from being terminated, and has restored the\n\
1193 context to its original state before the call.\n\
1194 To change this behaviour use \"set unwind-on-terminating-exception off\".\n\
1195 Evaluation of the expression containing the function (%s)\n\
1196 will be abandoned."),
1199 else if (stop_stack_dummy
== STOP_NONE
)
1202 /* We hit a breakpoint inside the FUNCTION.
1203 Keep the dummy frame, the user may want to examine its state.
1204 Discard inferior status, we're not at the same point
1206 discard_infcall_control_state (inf_status
);
1208 /* The following error message used to say "The expression
1209 which contained the function call has been discarded."
1210 It is a hard concept to explain in a few words. Ideally,
1211 GDB would be able to resume evaluation of the expression
1212 when the function finally is done executing. Perhaps
1213 someday this will be implemented (it would not be easy). */
1214 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
1215 a C++ name with arguments and stuff. */
1217 The program being debugged stopped while in a function called from GDB.\n\
1218 Evaluation of the expression containing the function\n\
1219 (%s) will be abandoned.\n\
1220 When the function is done executing, GDB will silently stop."),
1224 /* The above code errors out, so ... */
1225 internal_error (__FILE__
, __LINE__
, _("... should not be here"));
1228 do_cleanups (terminate_bp_cleanup
);
1230 /* If we get here the called FUNCTION ran to completion,
1231 and the dummy frame has already been popped. */
1234 struct value
*retval
= NULL
;
1236 /* Inferior call is successful. Restore the inferior status.
1237 At this stage, leave the RETBUF alone. */
1238 restore_infcall_control_state (inf_status
);
1240 if (TYPE_CODE (values_type
) == TYPE_CODE_VOID
)
1241 retval
= allocate_value (values_type
);
1242 else if (struct_return
|| hidden_first_param_p
)
1244 if (stack_temporaries
)
1246 retval
= value_from_contents_and_address (values_type
, NULL
,
1248 push_thread_stack_temporary (inferior_ptid
, retval
);
1252 retval
= allocate_value (values_type
);
1253 read_value_memory (retval
, 0, 1, struct_addr
,
1254 value_contents_raw (retval
),
1255 TYPE_LENGTH (values_type
));
1260 retval
= allocate_value (values_type
);
1261 gdbarch_return_value (gdbarch
, function
, values_type
,
1262 dummy_frame_context_saver_get_regs (context_saver
),
1263 value_contents_raw (retval
), NULL
);
1264 if (stack_temporaries
&& class_or_union_p (values_type
))
1266 /* Values of class type returned in registers are copied onto
1267 the stack and their lval_type set to lval_memory. This is
1268 required because further evaluation of the expression
1269 could potentially invoke methods on the return value
1270 requiring GDB to evaluate the "this" pointer. To evaluate
1271 the this pointer, GDB needs the memory address of the
1273 value_force_lval (retval
, struct_addr
);
1274 push_thread_stack_temporary (inferior_ptid
, retval
);
1278 do_cleanups (context_saver_cleanup
);
1280 gdb_assert (retval
);
1286 /* Provide a prototype to silence -Wmissing-prototypes. */
1287 void _initialize_infcall (void);
1290 _initialize_infcall (void)
1292 add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure
,
1293 &coerce_float_to_double_p
, _("\
1294 Set coercion of floats to doubles when calling functions."), _("\
1295 Show coercion of floats to doubles when calling functions"), _("\
1296 Variables of type float should generally be converted to doubles before\n\
1297 calling an unprototyped function, and left alone when calling a prototyped\n\
1298 function. However, some older debug info formats do not provide enough\n\
1299 information to determine that a function is prototyped. If this flag is\n\
1300 set, GDB will perform the conversion for a function it considers\n\
1302 The default is to perform the conversion.\n"),
1304 show_coerce_float_to_double_p
,
1305 &setlist
, &showlist
);
1307 add_setshow_boolean_cmd ("unwindonsignal", no_class
,
1308 &unwind_on_signal_p
, _("\
1309 Set unwinding of stack if a signal is received while in a call dummy."), _("\
1310 Show unwinding of stack if a signal is received while in a call dummy."), _("\
1311 The unwindonsignal lets the user determine what gdb should do if a signal\n\
1312 is received while in a function called from gdb (call dummy). If set, gdb\n\
1313 unwinds the stack and restore the context to what as it was before the call.\n\
1314 The default is to stop in the frame where the signal was received."),
1316 show_unwind_on_signal_p
,
1317 &setlist
, &showlist
);
1319 add_setshow_boolean_cmd ("unwind-on-terminating-exception", no_class
,
1320 &unwind_on_terminating_exception_p
, _("\
1321 Set unwinding of stack if std::terminate is called while in call dummy."), _("\
1322 Show unwinding of stack if std::terminate() is called while in a call dummy."),
1324 The unwind on terminating exception flag lets the user determine\n\
1325 what gdb should do if a std::terminate() call is made from the\n\
1326 default exception handler. If set, gdb unwinds the stack and restores\n\
1327 the context to what it was before the call. If unset, gdb allows the\n\
1328 std::terminate call to proceed.\n\
1329 The default is to unwind the frame."),
1331 show_unwind_on_terminating_exception_p
,
1332 &setlist
, &showlist
);