1 /* Perform an inferior function call, for GDB, the GNU debugger.
3 Copyright (C) 1986-2014 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"
26 #include "gdb_assert.h"
35 #include "dummy-frame.h"
37 #include "gdbthread.h"
38 #include "exceptions.h"
39 #include "event-top.h"
41 /* If we can't find a function's name from its address,
42 we print this instead. */
43 #define RAW_FUNCTION_ADDRESS_FORMAT "at 0x%s"
44 #define RAW_FUNCTION_ADDRESS_SIZE (sizeof (RAW_FUNCTION_ADDRESS_FORMAT) \
45 + 2 * sizeof (CORE_ADDR))
47 /* NOTE: cagney/2003-04-16: What's the future of this code?
49 GDB needs an asynchronous expression evaluator, that means an
50 asynchronous inferior function call implementation, and that in
51 turn means restructuring the code so that it is event driven. */
53 /* How you should pass arguments to a function depends on whether it
54 was defined in K&R style or prototype style. If you define a
55 function using the K&R syntax that takes a `float' argument, then
56 callers must pass that argument as a `double'. If you define the
57 function using the prototype syntax, then you must pass the
58 argument as a `float', with no promotion.
60 Unfortunately, on certain older platforms, the debug info doesn't
61 indicate reliably how each function was defined. A function type's
62 TYPE_FLAG_PROTOTYPED flag may be clear, even if the function was
63 defined in prototype style. When calling a function whose
64 TYPE_FLAG_PROTOTYPED flag is clear, GDB consults this flag to
67 For modern targets, it is proper to assume that, if the prototype
68 flag is clear, that can be trusted: `float' arguments should be
69 promoted to `double'. For some older targets, if the prototype
70 flag is clear, that doesn't tell us anything. The default is to
71 trust the debug information; the user can override this behavior
72 with "set coerce-float-to-double 0". */
74 static int coerce_float_to_double_p
= 1;
76 show_coerce_float_to_double_p (struct ui_file
*file
, int from_tty
,
77 struct cmd_list_element
*c
, const char *value
)
79 fprintf_filtered (file
,
80 _("Coercion of floats to doubles "
81 "when calling functions is %s.\n"),
85 /* This boolean tells what gdb should do if a signal is received while
86 in a function called from gdb (call dummy). If set, gdb unwinds
87 the stack and restore the context to what as it was before the
90 The default is to stop in the frame where the signal was received. */
92 static int unwind_on_signal_p
= 0;
94 show_unwind_on_signal_p (struct ui_file
*file
, int from_tty
,
95 struct cmd_list_element
*c
, const char *value
)
97 fprintf_filtered (file
,
98 _("Unwinding of stack if a signal is "
99 "received while in a call dummy is %s.\n"),
103 /* This boolean tells what gdb should do if a std::terminate call is
104 made while in a function called from gdb (call dummy).
105 As the confines of a single dummy stack prohibit out-of-frame
106 handlers from handling a raised exception, and as out-of-frame
107 handlers are common in C++, this can lead to no handler being found
108 by the unwinder, and a std::terminate call. This is a false positive.
109 If set, gdb unwinds the stack and restores the context to what it
112 The default is to unwind the frame if a std::terminate call is
115 static int unwind_on_terminating_exception_p
= 1;
118 show_unwind_on_terminating_exception_p (struct ui_file
*file
, int from_tty
,
119 struct cmd_list_element
*c
,
123 fprintf_filtered (file
,
124 _("Unwind stack if a C++ exception is "
125 "unhandled while in a call dummy is %s.\n"),
129 /* Perform the standard coercions that are specified
130 for arguments to be passed to C or Ada functions.
132 If PARAM_TYPE is non-NULL, it is the expected parameter type.
133 IS_PROTOTYPED is non-zero if the function declaration is prototyped.
134 SP is the stack pointer were additional data can be pushed (updating
135 its value as needed). */
137 static struct value
*
138 value_arg_coerce (struct gdbarch
*gdbarch
, struct value
*arg
,
139 struct type
*param_type
, int is_prototyped
, CORE_ADDR
*sp
)
141 const struct builtin_type
*builtin
= builtin_type (gdbarch
);
142 struct type
*arg_type
= check_typedef (value_type (arg
));
144 = param_type
? check_typedef (param_type
) : arg_type
;
146 /* Perform any Ada-specific coercion first. */
147 if (current_language
->la_language
== language_ada
)
148 arg
= ada_convert_actual (arg
, type
);
150 /* Force the value to the target if we will need its address. At
151 this point, we could allocate arguments on the stack instead of
152 calling malloc if we knew that their addresses would not be
153 saved by the called function. */
154 arg
= value_coerce_to_target (arg
);
156 switch (TYPE_CODE (type
))
160 struct value
*new_value
;
162 if (TYPE_CODE (arg_type
) == TYPE_CODE_REF
)
163 return value_cast_pointers (type
, arg
, 0);
165 /* Cast the value to the reference's target type, and then
166 convert it back to a reference. This will issue an error
167 if the value was not previously in memory - in some cases
168 we should clearly be allowing this, but how? */
169 new_value
= value_cast (TYPE_TARGET_TYPE (type
), arg
);
170 new_value
= value_ref (new_value
);
177 /* If we don't have a prototype, coerce to integer type if necessary. */
180 if (TYPE_LENGTH (type
) < TYPE_LENGTH (builtin
->builtin_int
))
181 type
= builtin
->builtin_int
;
183 /* Currently all target ABIs require at least the width of an integer
184 type for an argument. We may have to conditionalize the following
185 type coercion for future targets. */
186 if (TYPE_LENGTH (type
) < TYPE_LENGTH (builtin
->builtin_int
))
187 type
= builtin
->builtin_int
;
190 if (!is_prototyped
&& coerce_float_to_double_p
)
192 if (TYPE_LENGTH (type
) < TYPE_LENGTH (builtin
->builtin_double
))
193 type
= builtin
->builtin_double
;
194 else if (TYPE_LENGTH (type
) > TYPE_LENGTH (builtin
->builtin_double
))
195 type
= builtin
->builtin_long_double
;
199 type
= lookup_pointer_type (type
);
201 case TYPE_CODE_ARRAY
:
202 /* Arrays are coerced to pointers to their first element, unless
203 they are vectors, in which case we want to leave them alone,
204 because they are passed by value. */
205 if (current_language
->c_style_arrays
)
206 if (!TYPE_VECTOR (type
))
207 type
= lookup_pointer_type (TYPE_TARGET_TYPE (type
));
209 case TYPE_CODE_UNDEF
:
211 case TYPE_CODE_STRUCT
:
212 case TYPE_CODE_UNION
:
215 case TYPE_CODE_RANGE
:
216 case TYPE_CODE_STRING
:
217 case TYPE_CODE_ERROR
:
218 case TYPE_CODE_MEMBERPTR
:
219 case TYPE_CODE_METHODPTR
:
220 case TYPE_CODE_METHOD
:
221 case TYPE_CODE_COMPLEX
:
226 return value_cast (type
, arg
);
229 /* Return the return type of a function with its first instruction exactly at
230 the PC address. Return NULL otherwise. */
233 find_function_return_type (CORE_ADDR pc
)
235 struct symbol
*sym
= find_pc_function (pc
);
237 if (sym
!= NULL
&& BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)) == pc
238 && SYMBOL_TYPE (sym
) != NULL
)
239 return TYPE_TARGET_TYPE (SYMBOL_TYPE (sym
));
244 /* Determine a function's address and its return type from its value.
245 Calls error() if the function is not valid for calling. */
248 find_function_addr (struct value
*function
, struct type
**retval_type
)
250 struct type
*ftype
= check_typedef (value_type (function
));
251 struct gdbarch
*gdbarch
= get_type_arch (ftype
);
252 struct type
*value_type
= NULL
;
253 /* Initialize it just to avoid a GCC false warning. */
254 CORE_ADDR funaddr
= 0;
256 /* If it's a member function, just look at the function
259 /* Determine address to call. */
260 if (TYPE_CODE (ftype
) == TYPE_CODE_FUNC
261 || TYPE_CODE (ftype
) == TYPE_CODE_METHOD
)
262 funaddr
= value_address (function
);
263 else if (TYPE_CODE (ftype
) == TYPE_CODE_PTR
)
265 funaddr
= value_as_address (function
);
266 ftype
= check_typedef (TYPE_TARGET_TYPE (ftype
));
267 if (TYPE_CODE (ftype
) == TYPE_CODE_FUNC
268 || TYPE_CODE (ftype
) == TYPE_CODE_METHOD
)
269 funaddr
= gdbarch_convert_from_func_ptr_addr (gdbarch
, funaddr
,
272 if (TYPE_CODE (ftype
) == TYPE_CODE_FUNC
273 || TYPE_CODE (ftype
) == TYPE_CODE_METHOD
)
275 value_type
= TYPE_TARGET_TYPE (ftype
);
277 if (TYPE_GNU_IFUNC (ftype
))
279 funaddr
= gnu_ifunc_resolve_addr (gdbarch
, funaddr
);
281 /* Skip querying the function symbol if no RETVAL_TYPE has been
284 value_type
= find_function_return_type (funaddr
);
287 else if (TYPE_CODE (ftype
) == TYPE_CODE_INT
)
289 /* Handle the case of functions lacking debugging info.
290 Their values are characters since their addresses are char. */
291 if (TYPE_LENGTH (ftype
) == 1)
292 funaddr
= value_as_address (value_addr (function
));
295 /* Handle function descriptors lacking debug info. */
296 int found_descriptor
= 0;
298 funaddr
= 0; /* pacify "gcc -Werror" */
299 if (VALUE_LVAL (function
) == lval_memory
)
303 funaddr
= value_as_address (value_addr (function
));
305 funaddr
= gdbarch_convert_from_func_ptr_addr (gdbarch
, funaddr
,
307 if (funaddr
!= nfunaddr
)
308 found_descriptor
= 1;
310 if (!found_descriptor
)
311 /* Handle integer used as address of a function. */
312 funaddr
= (CORE_ADDR
) value_as_long (function
);
316 error (_("Invalid data type for function to be called."));
318 if (retval_type
!= NULL
)
319 *retval_type
= value_type
;
320 return funaddr
+ gdbarch_deprecated_function_start_offset (gdbarch
);
323 /* For CALL_DUMMY_ON_STACK, push a breakpoint sequence that the called
324 function returns to. */
327 push_dummy_code (struct gdbarch
*gdbarch
,
328 CORE_ADDR sp
, CORE_ADDR funaddr
,
329 struct value
**args
, int nargs
,
330 struct type
*value_type
,
331 CORE_ADDR
*real_pc
, CORE_ADDR
*bp_addr
,
332 struct regcache
*regcache
)
334 gdb_assert (gdbarch_push_dummy_code_p (gdbarch
));
336 return gdbarch_push_dummy_code (gdbarch
, sp
, funaddr
,
337 args
, nargs
, value_type
, real_pc
, bp_addr
,
341 /* Fetch the name of the function at FUNADDR.
342 This is used in printing an error message for call_function_by_hand.
343 BUF is used to print FUNADDR in hex if the function name cannot be
344 determined. It must be large enough to hold formatted result of
345 RAW_FUNCTION_ADDRESS_FORMAT. */
348 get_function_name (CORE_ADDR funaddr
, char *buf
, int buf_size
)
351 struct symbol
*symbol
= find_pc_function (funaddr
);
354 return SYMBOL_PRINT_NAME (symbol
);
358 /* Try the minimal symbols. */
359 struct bound_minimal_symbol msymbol
= lookup_minimal_symbol_by_pc (funaddr
);
362 return MSYMBOL_PRINT_NAME (msymbol
.minsym
);
366 char *tmp
= xstrprintf (_(RAW_FUNCTION_ADDRESS_FORMAT
),
367 hex_string (funaddr
));
369 gdb_assert (strlen (tmp
) + 1 <= buf_size
);
376 /* Subroutine of call_function_by_hand to simplify it.
377 Start up the inferior and wait for it to stop.
378 Return the exception if there's an error, or an exception with
379 reason >= 0 if there's no error.
381 This is done inside a TRY_CATCH so the caller needn't worry about
382 thrown errors. The caller should rethrow if there's an error. */
384 static struct gdb_exception
385 run_inferior_call (struct thread_info
*call_thread
, CORE_ADDR real_pc
)
387 volatile struct gdb_exception e
;
388 int saved_in_infcall
= call_thread
->control
.in_infcall
;
389 ptid_t call_thread_ptid
= call_thread
->ptid
;
391 call_thread
->control
.in_infcall
= 1;
393 clear_proceed_status ();
395 disable_watchpoints_before_interactive_call_start ();
397 /* We want stop_registers, please... */
398 call_thread
->control
.proceed_to_finish
= 1;
400 TRY_CATCH (e
, RETURN_MASK_ALL
)
402 int was_sync
= sync_execution
;
404 proceed (real_pc
, GDB_SIGNAL_0
, 0);
406 /* Inferior function calls are always synchronous, even if the
407 target supports asynchronous execution. Do here what
408 `proceed' itself does in sync mode. */
409 if (target_can_async_p () && is_running (inferior_ptid
))
411 wait_for_inferior ();
413 /* If GDB was previously in sync execution mode, then ensure
414 that it remains so. normal_stop calls
415 async_enable_stdin, so reset it again here. In other
416 cases, stdin will be re-enabled by
417 inferior_event_handler, when an exception is thrown. */
419 async_disable_stdin ();
423 /* At this point the current thread may have changed. Refresh
424 CALL_THREAD as it could be invalid if its thread has exited. */
425 call_thread
= find_thread_ptid (call_thread_ptid
);
427 enable_watchpoints_after_interactive_call_stop ();
429 /* Call breakpoint_auto_delete on the current contents of the bpstat
430 of inferior call thread.
431 If all error()s out of proceed ended up calling normal_stop
432 (and perhaps they should; it already does in the special case
433 of error out of resume()), then we wouldn't need this. */
436 if (call_thread
!= NULL
)
437 breakpoint_auto_delete (call_thread
->control
.stop_bpstat
);
440 if (call_thread
!= NULL
)
441 call_thread
->control
.in_infcall
= saved_in_infcall
;
446 /* A cleanup function that calls delete_std_terminate_breakpoint. */
448 cleanup_delete_std_terminate_breakpoint (void *ignore
)
450 delete_std_terminate_breakpoint ();
453 /* All this stuff with a dummy frame may seem unnecessarily complicated
454 (why not just save registers in GDB?). The purpose of pushing a dummy
455 frame which looks just like a real frame is so that if you call a
456 function and then hit a breakpoint (get a signal, etc), "backtrace"
457 will look right. Whether the backtrace needs to actually show the
458 stack at the time the inferior function was called is debatable, but
459 it certainly needs to not display garbage. So if you are contemplating
460 making dummy frames be different from normal frames, consider that. */
462 /* Perform a function call in the inferior.
463 ARGS is a vector of values of arguments (NARGS of them).
464 FUNCTION is a value, the function to be called.
465 Returns a value representing what the function returned.
466 May fail to return, if a breakpoint or signal is hit
467 during the execution of the function.
469 ARGS is modified to contain coerced values. */
472 call_function_by_hand (struct value
*function
, int nargs
, struct value
**args
)
475 struct type
*values_type
, *target_values_type
;
476 unsigned char struct_return
= 0, hidden_first_param_p
= 0;
477 CORE_ADDR struct_addr
= 0;
478 struct infcall_control_state
*inf_status
;
479 struct cleanup
*inf_status_cleanup
;
480 struct infcall_suspend_state
*caller_state
;
483 struct type
*ftype
= check_typedef (value_type (function
));
485 struct frame_id dummy_id
;
486 struct cleanup
*args_cleanup
;
487 struct frame_info
*frame
;
488 struct gdbarch
*gdbarch
;
489 struct cleanup
*terminate_bp_cleanup
;
490 ptid_t call_thread_ptid
;
491 struct gdb_exception e
;
492 char name_buf
[RAW_FUNCTION_ADDRESS_SIZE
];
494 if (TYPE_CODE (ftype
) == TYPE_CODE_PTR
)
495 ftype
= check_typedef (TYPE_TARGET_TYPE (ftype
));
497 if (!target_has_execution
)
500 if (get_traceframe_number () >= 0)
501 error (_("May not call functions while looking at trace frames."));
503 if (execution_direction
== EXEC_REVERSE
)
504 error (_("Cannot call functions in reverse mode."));
506 frame
= get_current_frame ();
507 gdbarch
= get_frame_arch (frame
);
509 if (!gdbarch_push_dummy_call_p (gdbarch
))
510 error (_("This target does not support function calls."));
512 /* A cleanup for the inferior status.
513 This is only needed while we're preparing the inferior function call. */
514 inf_status
= save_infcall_control_state ();
516 = make_cleanup_restore_infcall_control_state (inf_status
);
518 /* Save the caller's registers and other state associated with the
519 inferior itself so that they can be restored once the
520 callee returns. To allow nested calls the registers are (further
521 down) pushed onto a dummy frame stack. Include a cleanup (which
522 is tossed once the regcache has been pushed). */
523 caller_state
= save_infcall_suspend_state ();
524 make_cleanup_restore_infcall_suspend_state (caller_state
);
526 /* Ensure that the initial SP is correctly aligned. */
528 CORE_ADDR old_sp
= get_frame_sp (frame
);
530 if (gdbarch_frame_align_p (gdbarch
))
532 sp
= gdbarch_frame_align (gdbarch
, old_sp
);
533 /* NOTE: cagney/2003-08-13: Skip the "red zone". For some
534 ABIs, a function can use memory beyond the inner most stack
535 address. AMD64 called that region the "red zone". Skip at
536 least the "red zone" size before allocating any space on
538 if (gdbarch_inner_than (gdbarch
, 1, 2))
539 sp
-= gdbarch_frame_red_zone_size (gdbarch
);
541 sp
+= gdbarch_frame_red_zone_size (gdbarch
);
543 gdb_assert (sp
== gdbarch_frame_align (gdbarch
, sp
));
544 /* NOTE: cagney/2002-09-18:
546 On a RISC architecture, a void parameterless generic dummy
547 frame (i.e., no parameters, no result) typically does not
548 need to push anything the stack and hence can leave SP and
549 FP. Similarly, a frameless (possibly leaf) function does
550 not push anything on the stack and, hence, that too can
551 leave FP and SP unchanged. As a consequence, a sequence of
552 void parameterless generic dummy frame calls to frameless
553 functions will create a sequence of effectively identical
554 frames (SP, FP and TOS and PC the same). This, not
555 suprisingly, results in what appears to be a stack in an
556 infinite loop --- when GDB tries to find a generic dummy
557 frame on the internal dummy frame stack, it will always
560 To avoid this problem, the code below always grows the
561 stack. That way, two dummy frames can never be identical.
562 It does burn a few bytes of stack but that is a small price
566 if (gdbarch_inner_than (gdbarch
, 1, 2))
567 /* Stack grows down. */
568 sp
= gdbarch_frame_align (gdbarch
, old_sp
- 1);
570 /* Stack grows up. */
571 sp
= gdbarch_frame_align (gdbarch
, old_sp
+ 1);
573 /* SP may have underflown address zero here from OLD_SP. Memory access
574 functions will probably fail in such case but that is a target's
578 /* FIXME: cagney/2002-09-18: Hey, you loose!
580 Who knows how badly aligned the SP is!
582 If the generic dummy frame ends up empty (because nothing is
583 pushed) GDB won't be able to correctly perform back traces.
584 If a target is having trouble with backtraces, first thing to
585 do is add FRAME_ALIGN() to the architecture vector. If that
586 fails, try dummy_id().
588 If the ABI specifies a "Red Zone" (see the doco) the code
589 below will quietly trash it. */
593 funaddr
= find_function_addr (function
, &values_type
);
595 values_type
= builtin_type (gdbarch
)->builtin_int
;
597 CHECK_TYPEDEF (values_type
);
599 /* Are we returning a value using a structure return (passing a
600 hidden argument pointing to storage) or a normal value return?
601 There are two cases: language-mandated structure return and
602 target ABI structure return. The variable STRUCT_RETURN only
603 describes the latter. The language version is handled by passing
604 the return location as the first parameter to the function,
605 even preceding "this". This is different from the target
606 ABI version, which is target-specific; for instance, on ia64
607 the first argument is passed in out0 but the hidden structure
608 return pointer would normally be passed in r8. */
610 if (gdbarch_return_in_first_hidden_param_p (gdbarch
, values_type
))
612 hidden_first_param_p
= 1;
614 /* Tell the target specific argument pushing routine not to
616 target_values_type
= builtin_type (gdbarch
)->builtin_void
;
620 struct_return
= using_struct_return (gdbarch
, function
, values_type
);
621 target_values_type
= values_type
;
624 /* Determine the location of the breakpoint (and possibly other
625 stuff) that the called function will return to. The SPARC, for a
626 function returning a structure or union, needs to make space for
627 not just the breakpoint but also an extra word containing the
628 size (?) of the structure being passed. */
630 switch (gdbarch_call_dummy_location (gdbarch
))
634 const gdb_byte
*bp_bytes
;
635 CORE_ADDR bp_addr_as_address
;
638 /* Be careful BP_ADDR is in inferior PC encoding while
639 BP_ADDR_AS_ADDRESS is a plain memory address. */
641 sp
= push_dummy_code (gdbarch
, sp
, funaddr
, args
, nargs
,
642 target_values_type
, &real_pc
, &bp_addr
,
643 get_current_regcache ());
645 /* Write a legitimate instruction at the point where the infcall
646 breakpoint is going to be inserted. While this instruction
647 is never going to be executed, a user investigating the
648 memory from GDB would see this instruction instead of random
649 uninitialized bytes. We chose the breakpoint instruction
650 as it may look as the most logical one to the user and also
651 valgrind 3.7.0 needs it for proper vgdb inferior calls.
653 If software breakpoints are unsupported for this target we
654 leave the user visible memory content uninitialized. */
656 bp_addr_as_address
= bp_addr
;
657 bp_bytes
= gdbarch_breakpoint_from_pc (gdbarch
, &bp_addr_as_address
,
659 if (bp_bytes
!= NULL
)
660 write_memory (bp_addr_as_address
, bp_bytes
, bp_size
);
665 CORE_ADDR dummy_addr
;
668 dummy_addr
= entry_point_address ();
670 /* A call dummy always consists of just a single breakpoint, so
671 its address is the same as the address of the dummy.
673 The actual breakpoint is inserted separatly so there is no need to
675 bp_addr
= dummy_addr
;
679 internal_error (__FILE__
, __LINE__
, _("bad switch"));
682 if (nargs
< TYPE_NFIELDS (ftype
))
683 error (_("Too few arguments in function call."));
688 for (i
= nargs
- 1; i
>= 0; i
--)
691 struct type
*param_type
;
693 /* FIXME drow/2002-05-31: Should just always mark methods as
694 prototyped. Can we respect TYPE_VARARGS? Probably not. */
695 if (TYPE_CODE (ftype
) == TYPE_CODE_METHOD
)
697 else if (i
< TYPE_NFIELDS (ftype
))
698 prototyped
= TYPE_PROTOTYPED (ftype
);
702 if (i
< TYPE_NFIELDS (ftype
))
703 param_type
= TYPE_FIELD_TYPE (ftype
, i
);
707 args
[i
] = value_arg_coerce (gdbarch
, args
[i
],
708 param_type
, prototyped
, &sp
);
710 if (param_type
!= NULL
&& language_pass_by_reference (param_type
))
711 args
[i
] = value_addr (args
[i
]);
715 /* Reserve space for the return structure to be written on the
716 stack, if necessary. Make certain that the value is correctly
719 if (struct_return
|| hidden_first_param_p
)
721 if (gdbarch_inner_than (gdbarch
, 1, 2))
723 /* Stack grows downward. Align STRUCT_ADDR and SP after
724 making space for the return value. */
725 sp
-= TYPE_LENGTH (values_type
);
726 if (gdbarch_frame_align_p (gdbarch
))
727 sp
= gdbarch_frame_align (gdbarch
, sp
);
732 /* Stack grows upward. Align the frame, allocate space, and
733 then again, re-align the frame??? */
734 if (gdbarch_frame_align_p (gdbarch
))
735 sp
= gdbarch_frame_align (gdbarch
, sp
);
737 sp
+= TYPE_LENGTH (values_type
);
738 if (gdbarch_frame_align_p (gdbarch
))
739 sp
= gdbarch_frame_align (gdbarch
, sp
);
743 if (hidden_first_param_p
)
745 struct value
**new_args
;
747 /* Add the new argument to the front of the argument list. */
748 new_args
= xmalloc (sizeof (struct value
*) * (nargs
+ 1));
749 new_args
[0] = value_from_pointer (lookup_pointer_type (values_type
),
751 memcpy (&new_args
[1], &args
[0], sizeof (struct value
*) * nargs
);
754 args_cleanup
= make_cleanup (xfree
, args
);
757 args_cleanup
= make_cleanup (null_cleanup
, NULL
);
759 /* Create the dummy stack frame. Pass in the call dummy address as,
760 presumably, the ABI code knows where, in the call dummy, the
761 return address should be pointed. */
762 sp
= gdbarch_push_dummy_call (gdbarch
, function
, get_current_regcache (),
763 bp_addr
, nargs
, args
,
764 sp
, struct_return
, struct_addr
);
766 do_cleanups (args_cleanup
);
768 /* Set up a frame ID for the dummy frame so we can pass it to
769 set_momentary_breakpoint. We need to give the breakpoint a frame
770 ID so that the breakpoint code can correctly re-identify the
772 /* Sanity. The exact same SP value is returned by PUSH_DUMMY_CALL,
773 saved as the dummy-frame TOS, and used by dummy_id to form
774 the frame ID's stack address. */
775 dummy_id
= frame_id_build (sp
, bp_addr
);
777 /* Create a momentary breakpoint at the return address of the
778 inferior. That way it breaks when it returns. */
781 struct breakpoint
*bpt
, *longjmp_b
;
782 struct symtab_and_line sal
;
784 init_sal (&sal
); /* initialize to zeroes */
785 sal
.pspace
= current_program_space
;
787 sal
.section
= find_pc_overlay (sal
.pc
);
788 /* Sanity. The exact same SP value is returned by
789 PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by
790 dummy_id to form the frame ID's stack address. */
791 bpt
= set_momentary_breakpoint (gdbarch
, sal
, dummy_id
, bp_call_dummy
);
793 /* set_momentary_breakpoint invalidates FRAME. */
796 bpt
->disposition
= disp_del
;
797 gdb_assert (bpt
->related_breakpoint
== bpt
);
799 longjmp_b
= set_longjmp_breakpoint_for_call_dummy ();
802 /* Link BPT into the chain of LONGJMP_B. */
803 bpt
->related_breakpoint
= longjmp_b
;
804 while (longjmp_b
->related_breakpoint
!= bpt
->related_breakpoint
)
805 longjmp_b
= longjmp_b
->related_breakpoint
;
806 longjmp_b
->related_breakpoint
= bpt
;
810 /* Create a breakpoint in std::terminate.
811 If a C++ exception is raised in the dummy-frame, and the
812 exception handler is (normally, and expected to be) out-of-frame,
813 the default C++ handler will (wrongly) be called in an inferior
814 function call. This is wrong, as an exception can be normally
815 and legally handled out-of-frame. The confines of the dummy frame
816 prevent the unwinder from finding the correct handler (or any
817 handler, unless it is in-frame). The default handler calls
818 std::terminate. This will kill the inferior. Assert that
819 terminate should never be called in an inferior function
820 call. Place a momentary breakpoint in the std::terminate function
821 and if triggered in the call, rewind. */
822 if (unwind_on_terminating_exception_p
)
823 set_std_terminate_breakpoint ();
825 /* Everything's ready, push all the info needed to restore the
826 caller (and identify the dummy-frame) onto the dummy-frame
828 dummy_frame_push (caller_state
, &dummy_id
);
830 /* Discard both inf_status and caller_state cleanups.
831 From this point on we explicitly restore the associated state
833 discard_cleanups (inf_status_cleanup
);
835 /* Register a clean-up for unwind_on_terminating_exception_breakpoint. */
836 terminate_bp_cleanup
= make_cleanup (cleanup_delete_std_terminate_breakpoint
,
839 /* - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP -
840 If you're looking to implement asynchronous dummy-frames, then
841 just below is the place to chop this function in two.. */
843 /* TP is invalid after run_inferior_call returns, so enclose this
844 in a block so that it's only in scope during the time it's valid. */
846 struct thread_info
*tp
= inferior_thread ();
848 /* Save this thread's ptid, we need it later but the thread
850 call_thread_ptid
= tp
->ptid
;
852 /* Run the inferior until it stops. */
854 e
= run_inferior_call (tp
, real_pc
);
857 /* Rethrow an error if we got one trying to run the inferior. */
861 const char *name
= get_function_name (funaddr
,
862 name_buf
, sizeof (name_buf
));
864 discard_infcall_control_state (inf_status
);
866 /* We could discard the dummy frame here if the program exited,
867 but it will get garbage collected the next time the program is
873 throw_error (e
.error
, _("%s\n\
874 An error occurred while in a function called from GDB.\n\
875 Evaluation of the expression containing the function\n\
876 (%s) will be abandoned.\n\
877 When the function is done executing, GDB will silently stop."),
885 /* If the program has exited, or we stopped at a different thread,
886 exit and inform the user. */
888 if (! target_has_execution
)
890 const char *name
= get_function_name (funaddr
,
891 name_buf
, sizeof (name_buf
));
893 /* If we try to restore the inferior status,
894 we'll crash as the inferior is no longer running. */
895 discard_infcall_control_state (inf_status
);
897 /* We could discard the dummy frame here given that the program exited,
898 but it will get garbage collected the next time the program is
901 error (_("The program being debugged exited while in a function "
903 "Evaluation of the expression containing the function\n"
904 "(%s) will be abandoned."),
908 if (! ptid_equal (call_thread_ptid
, inferior_ptid
))
910 const char *name
= get_function_name (funaddr
,
911 name_buf
, sizeof (name_buf
));
913 /* We've switched threads. This can happen if another thread gets a
914 signal or breakpoint while our thread was running.
915 There's no point in restoring the inferior status,
916 we're in a different thread. */
917 discard_infcall_control_state (inf_status
);
918 /* Keep the dummy frame record, if the user switches back to the
919 thread with the hand-call, we'll need it. */
920 if (stopped_by_random_signal
)
922 The program received a signal in another thread while\n\
923 making a function call from GDB.\n\
924 Evaluation of the expression containing the function\n\
925 (%s) will be abandoned.\n\
926 When the function is done executing, GDB will silently stop."),
930 The program stopped in another thread while making a function call from GDB.\n\
931 Evaluation of the expression containing the function\n\
932 (%s) will be abandoned.\n\
933 When the function is done executing, GDB will silently stop."),
937 if (stopped_by_random_signal
|| stop_stack_dummy
!= STOP_STACK_DUMMY
)
939 const char *name
= get_function_name (funaddr
,
940 name_buf
, sizeof (name_buf
));
942 if (stopped_by_random_signal
)
944 /* We stopped inside the FUNCTION because of a random
945 signal. Further execution of the FUNCTION is not
948 if (unwind_on_signal_p
)
950 /* The user wants the context restored. */
952 /* We must get back to the frame we were before the
954 dummy_frame_pop (dummy_id
);
956 /* We also need to restore inferior status to that before the
958 restore_infcall_control_state (inf_status
);
960 /* FIXME: Insert a bunch of wrap_here; name can be very
961 long if it's a C++ name with arguments and stuff. */
963 The program being debugged was signaled while in a function called from GDB.\n\
964 GDB has restored the context to what it was before the call.\n\
965 To change this behavior use \"set unwindonsignal off\".\n\
966 Evaluation of the expression containing the function\n\
967 (%s) will be abandoned."),
972 /* The user wants to stay in the frame where we stopped
974 Discard inferior status, we're not at the same point
976 discard_infcall_control_state (inf_status
);
978 /* FIXME: Insert a bunch of wrap_here; name can be very
979 long if it's a C++ name with arguments and stuff. */
981 The program being debugged was signaled while in a function called from GDB.\n\
982 GDB remains in the frame where the signal was received.\n\
983 To change this behavior use \"set unwindonsignal on\".\n\
984 Evaluation of the expression containing the function\n\
985 (%s) will be abandoned.\n\
986 When the function is done executing, GDB will silently stop."),
991 if (stop_stack_dummy
== STOP_STD_TERMINATE
)
993 /* We must get back to the frame we were before the dummy
995 dummy_frame_pop (dummy_id
);
997 /* We also need to restore inferior status to that before
999 restore_infcall_control_state (inf_status
);
1002 The program being debugged entered a std::terminate call, most likely\n\
1003 caused by an unhandled C++ exception. GDB blocked this call in order\n\
1004 to prevent the program from being terminated, and has restored the\n\
1005 context to its original state before the call.\n\
1006 To change this behaviour use \"set unwind-on-terminating-exception off\".\n\
1007 Evaluation of the expression containing the function (%s)\n\
1008 will be abandoned."),
1011 else if (stop_stack_dummy
== STOP_NONE
)
1014 /* We hit a breakpoint inside the FUNCTION.
1015 Keep the dummy frame, the user may want to examine its state.
1016 Discard inferior status, we're not at the same point
1018 discard_infcall_control_state (inf_status
);
1020 /* The following error message used to say "The expression
1021 which contained the function call has been discarded."
1022 It is a hard concept to explain in a few words. Ideally,
1023 GDB would be able to resume evaluation of the expression
1024 when the function finally is done executing. Perhaps
1025 someday this will be implemented (it would not be easy). */
1026 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
1027 a C++ name with arguments and stuff. */
1029 The program being debugged stopped while in a function called from GDB.\n\
1030 Evaluation of the expression containing the function\n\
1031 (%s) will be abandoned.\n\
1032 When the function is done executing, GDB will silently stop."),
1036 /* The above code errors out, so ... */
1037 internal_error (__FILE__
, __LINE__
, _("... should not be here"));
1040 do_cleanups (terminate_bp_cleanup
);
1042 /* If we get here the called FUNCTION ran to completion,
1043 and the dummy frame has already been popped. */
1046 struct address_space
*aspace
= get_regcache_aspace (stop_registers
);
1047 struct regcache
*retbuf
= regcache_xmalloc (gdbarch
, aspace
);
1048 struct cleanup
*retbuf_cleanup
= make_cleanup_regcache_xfree (retbuf
);
1049 struct value
*retval
= NULL
;
1051 regcache_cpy_no_passthrough (retbuf
, stop_registers
);
1053 /* Inferior call is successful. Restore the inferior status.
1054 At this stage, leave the RETBUF alone. */
1055 restore_infcall_control_state (inf_status
);
1057 /* Figure out the value returned by the function. */
1058 retval
= allocate_value (values_type
);
1060 if (hidden_first_param_p
)
1061 read_value_memory (retval
, 0, 1, struct_addr
,
1062 value_contents_raw (retval
),
1063 TYPE_LENGTH (values_type
));
1064 else if (TYPE_CODE (target_values_type
) != TYPE_CODE_VOID
)
1066 /* If the function returns void, don't bother fetching the
1068 switch (gdbarch_return_value (gdbarch
, function
, target_values_type
,
1071 case RETURN_VALUE_REGISTER_CONVENTION
:
1072 case RETURN_VALUE_ABI_RETURNS_ADDRESS
:
1073 case RETURN_VALUE_ABI_PRESERVES_ADDRESS
:
1074 gdbarch_return_value (gdbarch
, function
, values_type
,
1075 retbuf
, value_contents_raw (retval
), NULL
);
1077 case RETURN_VALUE_STRUCT_CONVENTION
:
1078 read_value_memory (retval
, 0, 1, struct_addr
,
1079 value_contents_raw (retval
),
1080 TYPE_LENGTH (values_type
));
1085 do_cleanups (retbuf_cleanup
);
1087 gdb_assert (retval
);
1093 /* Provide a prototype to silence -Wmissing-prototypes. */
1094 void _initialize_infcall (void);
1097 _initialize_infcall (void)
1099 add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure
,
1100 &coerce_float_to_double_p
, _("\
1101 Set coercion of floats to doubles when calling functions."), _("\
1102 Show coercion of floats to doubles when calling functions"), _("\
1103 Variables of type float should generally be converted to doubles before\n\
1104 calling an unprototyped function, and left alone when calling a prototyped\n\
1105 function. However, some older debug info formats do not provide enough\n\
1106 information to determine that a function is prototyped. If this flag is\n\
1107 set, GDB will perform the conversion for a function it considers\n\
1109 The default is to perform the conversion.\n"),
1111 show_coerce_float_to_double_p
,
1112 &setlist
, &showlist
);
1114 add_setshow_boolean_cmd ("unwindonsignal", no_class
,
1115 &unwind_on_signal_p
, _("\
1116 Set unwinding of stack if a signal is received while in a call dummy."), _("\
1117 Show unwinding of stack if a signal is received while in a call dummy."), _("\
1118 The unwindonsignal lets the user determine what gdb should do if a signal\n\
1119 is received while in a function called from gdb (call dummy). If set, gdb\n\
1120 unwinds the stack and restore the context to what as it was before the call.\n\
1121 The default is to stop in the frame where the signal was received."),
1123 show_unwind_on_signal_p
,
1124 &setlist
, &showlist
);
1126 add_setshow_boolean_cmd ("unwind-on-terminating-exception", no_class
,
1127 &unwind_on_terminating_exception_p
, _("\
1128 Set unwinding of stack if std::terminate is called while in call dummy."), _("\
1129 Show unwinding of stack if std::terminate() is called while in a call dummy."),
1131 The unwind on terminating exception flag lets the user determine\n\
1132 what gdb should do if a std::terminate() call is made from the\n\
1133 default exception handler. If set, gdb unwinds the stack and restores\n\
1134 the context to what it was before the call. If unset, gdb allows the\n\
1135 std::terminate call to proceed.\n\
1136 The default is to unwind the frame."),
1138 show_unwind_on_terminating_exception_p
,
1139 &setlist
, &showlist
);