1 /* Perform an inferior function call, for GDB, the GNU debugger.
3 Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
4 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
5 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23 #include "breakpoint.h"
24 #include "tracepoint.h"
28 #include "gdb_assert.h"
35 #include "gdb_string.h"
37 #include "dummy-frame.h"
39 #include "gdbthread.h"
40 #include "exceptions.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 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
);
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_BITSTRING
:
219 case TYPE_CODE_ERROR
:
220 case TYPE_CODE_MEMBERPTR
:
221 case TYPE_CODE_METHODPTR
:
222 case TYPE_CODE_METHOD
:
223 case TYPE_CODE_COMPLEX
:
228 return value_cast (type
, arg
);
231 /* Return the return type of a function with its first instruction exactly at
232 the PC address. Return NULL otherwise. */
235 find_function_return_type (CORE_ADDR pc
)
237 struct symbol
*sym
= find_pc_function (pc
);
239 if (sym
!= NULL
&& BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)) == pc
240 && SYMBOL_TYPE (sym
) != NULL
)
241 return TYPE_TARGET_TYPE (SYMBOL_TYPE (sym
));
246 /* Determine a function's address and its return type from its value.
247 Calls error() if the function is not valid for calling. */
250 find_function_addr (struct value
*function
, struct type
**retval_type
)
252 struct type
*ftype
= check_typedef (value_type (function
));
253 struct gdbarch
*gdbarch
= get_type_arch (ftype
);
254 struct type
*value_type
= NULL
;
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 minimal_symbol
*msymbol
= lookup_minimal_symbol_by_pc (funaddr
);
363 return SYMBOL_PRINT_NAME (msymbol
);
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 volatile struct gdb_exception e
;
390 int saved_in_infcall
= call_thread
->control
.in_infcall
;
391 ptid_t call_thread_ptid
= call_thread
->ptid
;
392 char *saved_target_shortname
= xstrdup (target_shortname
);
394 call_thread
->control
.in_infcall
= 1;
396 clear_proceed_status ();
398 disable_watchpoints_before_interactive_call_start ();
400 /* We want stop_registers, please... */
401 call_thread
->control
.proceed_to_finish
= 1;
403 if (target_can_async_p ())
404 saved_async
= target_async_mask (0);
406 TRY_CATCH (e
, RETURN_MASK_ALL
)
407 proceed (real_pc
, TARGET_SIGNAL_0
, 0);
409 /* At this point the current thread may have changed. Refresh
410 CALL_THREAD as it could be invalid if its thread has exited. */
411 call_thread
= find_thread_ptid (call_thread_ptid
);
413 /* Don't restore the async mask if the target has changed,
414 saved_async is for the original target. */
416 && strcmp (saved_target_shortname
, target_shortname
) == 0)
417 target_async_mask (saved_async
);
419 enable_watchpoints_after_interactive_call_stop ();
421 /* Call breakpoint_auto_delete on the current contents of the bpstat
422 of inferior call thread.
423 If all error()s out of proceed ended up calling normal_stop
424 (and perhaps they should; it already does in the special case
425 of error out of resume()), then we wouldn't need this. */
428 if (call_thread
!= NULL
)
429 breakpoint_auto_delete (call_thread
->control
.stop_bpstat
);
432 if (call_thread
!= NULL
)
433 call_thread
->control
.in_infcall
= saved_in_infcall
;
435 xfree (saved_target_shortname
);
440 /* A cleanup function that calls delete_std_terminate_breakpoint. */
442 cleanup_delete_std_terminate_breakpoint (void *ignore
)
444 delete_std_terminate_breakpoint ();
447 /* All this stuff with a dummy frame may seem unnecessarily complicated
448 (why not just save registers in GDB?). The purpose of pushing a dummy
449 frame which looks just like a real frame is so that if you call a
450 function and then hit a breakpoint (get a signal, etc), "backtrace"
451 will look right. Whether the backtrace needs to actually show the
452 stack at the time the inferior function was called is debatable, but
453 it certainly needs to not display garbage. So if you are contemplating
454 making dummy frames be different from normal frames, consider that. */
456 /* Perform a function call in the inferior.
457 ARGS is a vector of values of arguments (NARGS of them).
458 FUNCTION is a value, the function to be called.
459 Returns a value representing what the function returned.
460 May fail to return, if a breakpoint or signal is hit
461 during the execution of the function.
463 ARGS is modified to contain coerced values. */
466 call_function_by_hand (struct value
*function
, int nargs
, struct value
**args
)
469 struct type
*values_type
, *target_values_type
;
470 unsigned char struct_return
= 0, lang_struct_return
= 0;
471 CORE_ADDR struct_addr
= 0;
472 struct infcall_control_state
*inf_status
;
473 struct cleanup
*inf_status_cleanup
;
474 struct infcall_suspend_state
*caller_state
;
477 struct type
*ftype
= check_typedef (value_type (function
));
479 struct frame_id dummy_id
;
480 struct cleanup
*args_cleanup
;
481 struct frame_info
*frame
;
482 struct gdbarch
*gdbarch
;
483 struct cleanup
*terminate_bp_cleanup
;
484 ptid_t call_thread_ptid
;
485 struct gdb_exception e
;
486 char name_buf
[RAW_FUNCTION_ADDRESS_SIZE
];
488 if (TYPE_CODE (ftype
) == TYPE_CODE_PTR
)
489 ftype
= check_typedef (TYPE_TARGET_TYPE (ftype
));
491 if (!target_has_execution
)
494 if (get_traceframe_number () >= 0)
495 error (_("May not call functions while looking at trace frames."));
497 frame
= get_current_frame ();
498 gdbarch
= get_frame_arch (frame
);
500 if (!gdbarch_push_dummy_call_p (gdbarch
))
501 error (_("This target does not support function calls."));
503 /* A cleanup for the inferior status.
504 This is only needed while we're preparing the inferior function call. */
505 inf_status
= save_infcall_control_state ();
507 = make_cleanup_restore_infcall_control_state (inf_status
);
509 /* Save the caller's registers and other state associated with the
510 inferior itself so that they can be restored once the
511 callee returns. To allow nested calls the registers are (further
512 down) pushed onto a dummy frame stack. Include a cleanup (which
513 is tossed once the regcache has been pushed). */
514 caller_state
= save_infcall_suspend_state ();
515 make_cleanup_restore_infcall_suspend_state (caller_state
);
517 /* Ensure that the initial SP is correctly aligned. */
519 CORE_ADDR old_sp
= get_frame_sp (frame
);
521 if (gdbarch_frame_align_p (gdbarch
))
523 sp
= gdbarch_frame_align (gdbarch
, old_sp
);
524 /* NOTE: cagney/2003-08-13: Skip the "red zone". For some
525 ABIs, a function can use memory beyond the inner most stack
526 address. AMD64 called that region the "red zone". Skip at
527 least the "red zone" size before allocating any space on
529 if (gdbarch_inner_than (gdbarch
, 1, 2))
530 sp
-= gdbarch_frame_red_zone_size (gdbarch
);
532 sp
+= gdbarch_frame_red_zone_size (gdbarch
);
534 gdb_assert (sp
== gdbarch_frame_align (gdbarch
, sp
));
535 /* NOTE: cagney/2002-09-18:
537 On a RISC architecture, a void parameterless generic dummy
538 frame (i.e., no parameters, no result) typically does not
539 need to push anything the stack and hence can leave SP and
540 FP. Similarly, a frameless (possibly leaf) function does
541 not push anything on the stack and, hence, that too can
542 leave FP and SP unchanged. As a consequence, a sequence of
543 void parameterless generic dummy frame calls to frameless
544 functions will create a sequence of effectively identical
545 frames (SP, FP and TOS and PC the same). This, not
546 suprisingly, results in what appears to be a stack in an
547 infinite loop --- when GDB tries to find a generic dummy
548 frame on the internal dummy frame stack, it will always
551 To avoid this problem, the code below always grows the
552 stack. That way, two dummy frames can never be identical.
553 It does burn a few bytes of stack but that is a small price
557 if (gdbarch_inner_than (gdbarch
, 1, 2))
558 /* Stack grows down. */
559 sp
= gdbarch_frame_align (gdbarch
, old_sp
- 1);
561 /* Stack grows up. */
562 sp
= gdbarch_frame_align (gdbarch
, old_sp
+ 1);
564 /* SP may have underflown address zero here from OLD_SP. Memory access
565 functions will probably fail in such case but that is a target's
569 /* FIXME: cagney/2002-09-18: Hey, you loose!
571 Who knows how badly aligned the SP is!
573 If the generic dummy frame ends up empty (because nothing is
574 pushed) GDB won't be able to correctly perform back traces.
575 If a target is having trouble with backtraces, first thing to
576 do is add FRAME_ALIGN() to the architecture vector. If that
577 fails, try dummy_id().
579 If the ABI specifies a "Red Zone" (see the doco) the code
580 below will quietly trash it. */
584 funaddr
= find_function_addr (function
, &values_type
);
586 values_type
= builtin_type (gdbarch
)->builtin_int
;
588 CHECK_TYPEDEF (values_type
);
590 /* Are we returning a value using a structure return (passing a
591 hidden argument pointing to storage) or a normal value return?
592 There are two cases: language-mandated structure return and
593 target ABI structure return. The variable STRUCT_RETURN only
594 describes the latter. The language version is handled by passing
595 the return location as the first parameter to the function,
596 even preceding "this". This is different from the target
597 ABI version, which is target-specific; for instance, on ia64
598 the first argument is passed in out0 but the hidden structure
599 return pointer would normally be passed in r8. */
601 if (language_pass_by_reference (values_type
))
603 lang_struct_return
= 1;
605 /* Tell the target specific argument pushing routine not to
607 target_values_type
= builtin_type (gdbarch
)->builtin_void
;
611 struct_return
= using_struct_return (gdbarch
,
612 value_type (function
), values_type
);
613 target_values_type
= values_type
;
616 /* Determine the location of the breakpoint (and possibly other
617 stuff) that the called function will return to. The SPARC, for a
618 function returning a structure or union, needs to make space for
619 not just the breakpoint but also an extra word containing the
620 size (?) of the structure being passed. */
622 /* The actual breakpoint (at BP_ADDR) is inserted separatly so there
623 is no need to write that out. */
625 switch (gdbarch_call_dummy_location (gdbarch
))
628 sp
= push_dummy_code (gdbarch
, sp
, funaddr
,
629 args
, nargs
, target_values_type
,
630 &real_pc
, &bp_addr
, get_current_regcache ());
634 CORE_ADDR dummy_addr
;
637 dummy_addr
= entry_point_address ();
638 /* A call dummy always consists of just a single breakpoint, so
639 its address is the same as the address of the dummy. */
640 bp_addr
= dummy_addr
;
644 /* Some executables define a symbol __CALL_DUMMY_ADDRESS whose
645 address is the location where the breakpoint should be
646 placed. Once all targets are using the overhauled frame code
647 this can be deleted - ON_STACK is a better option. */
649 struct minimal_symbol
*sym
;
650 CORE_ADDR dummy_addr
;
652 sym
= lookup_minimal_symbol ("__CALL_DUMMY_ADDRESS", NULL
, NULL
);
656 dummy_addr
= SYMBOL_VALUE_ADDRESS (sym
);
657 /* Make certain that the address points at real code, and not
658 a function descriptor. */
659 dummy_addr
= gdbarch_convert_from_func_ptr_addr (gdbarch
,
664 dummy_addr
= entry_point_address ();
665 /* A call dummy always consists of just a single breakpoint,
666 so it's address is the same as the address of the dummy. */
667 bp_addr
= dummy_addr
;
671 internal_error (__FILE__
, __LINE__
, _("bad switch"));
674 if (nargs
< TYPE_NFIELDS (ftype
))
675 error (_("Too few arguments in function call."));
680 for (i
= nargs
- 1; i
>= 0; i
--)
683 struct type
*param_type
;
685 /* FIXME drow/2002-05-31: Should just always mark methods as
686 prototyped. Can we respect TYPE_VARARGS? Probably not. */
687 if (TYPE_CODE (ftype
) == TYPE_CODE_METHOD
)
689 else if (i
< TYPE_NFIELDS (ftype
))
690 prototyped
= TYPE_PROTOTYPED (ftype
);
694 if (i
< TYPE_NFIELDS (ftype
))
695 param_type
= TYPE_FIELD_TYPE (ftype
, i
);
699 args
[i
] = value_arg_coerce (gdbarch
, args
[i
],
700 param_type
, prototyped
, &sp
);
702 if (param_type
!= NULL
&& language_pass_by_reference (param_type
))
703 args
[i
] = value_addr (args
[i
]);
707 /* Reserve space for the return structure to be written on the
708 stack, if necessary. Make certain that the value is correctly
711 if (struct_return
|| lang_struct_return
)
713 int len
= TYPE_LENGTH (values_type
);
715 if (gdbarch_inner_than (gdbarch
, 1, 2))
717 /* Stack grows downward. Align STRUCT_ADDR and SP after
718 making space for the return value. */
720 if (gdbarch_frame_align_p (gdbarch
))
721 sp
= gdbarch_frame_align (gdbarch
, sp
);
726 /* Stack grows upward. Align the frame, allocate space, and
727 then again, re-align the frame??? */
728 if (gdbarch_frame_align_p (gdbarch
))
729 sp
= gdbarch_frame_align (gdbarch
, sp
);
732 if (gdbarch_frame_align_p (gdbarch
))
733 sp
= gdbarch_frame_align (gdbarch
, sp
);
737 if (lang_struct_return
)
739 struct value
**new_args
;
741 /* Add the new argument to the front of the argument list. */
742 new_args
= xmalloc (sizeof (struct value
*) * (nargs
+ 1));
743 new_args
[0] = value_from_pointer (lookup_pointer_type (values_type
),
745 memcpy (&new_args
[1], &args
[0], sizeof (struct value
*) * nargs
);
748 args_cleanup
= make_cleanup (xfree
, args
);
751 args_cleanup
= make_cleanup (null_cleanup
, NULL
);
753 /* Create the dummy stack frame. Pass in the call dummy address as,
754 presumably, the ABI code knows where, in the call dummy, the
755 return address should be pointed. */
756 sp
= gdbarch_push_dummy_call (gdbarch
, function
, get_current_regcache (),
757 bp_addr
, nargs
, args
,
758 sp
, struct_return
, struct_addr
);
760 do_cleanups (args_cleanup
);
762 /* Set up a frame ID for the dummy frame so we can pass it to
763 set_momentary_breakpoint. We need to give the breakpoint a frame
764 ID so that the breakpoint code can correctly re-identify the
766 /* Sanity. The exact same SP value is returned by PUSH_DUMMY_CALL,
767 saved as the dummy-frame TOS, and used by dummy_id to form
768 the frame ID's stack address. */
769 dummy_id
= frame_id_build (sp
, bp_addr
);
771 /* Create a momentary breakpoint at the return address of the
772 inferior. That way it breaks when it returns. */
775 struct breakpoint
*bpt
;
776 struct symtab_and_line sal
;
778 init_sal (&sal
); /* initialize to zeroes */
779 sal
.pspace
= current_program_space
;
781 sal
.section
= find_pc_overlay (sal
.pc
);
782 /* Sanity. The exact same SP value is returned by
783 PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by
784 dummy_id to form the frame ID's stack address. */
785 bpt
= set_momentary_breakpoint (gdbarch
, sal
, dummy_id
, bp_call_dummy
);
786 bpt
->disposition
= disp_del
;
789 /* Create a breakpoint in std::terminate.
790 If a C++ exception is raised in the dummy-frame, and the
791 exception handler is (normally, and expected to be) out-of-frame,
792 the default C++ handler will (wrongly) be called in an inferior
793 function call. This is wrong, as an exception can be normally
794 and legally handled out-of-frame. The confines of the dummy frame
795 prevent the unwinder from finding the correct handler (or any
796 handler, unless it is in-frame). The default handler calls
797 std::terminate. This will kill the inferior. Assert that
798 terminate should never be called in an inferior function
799 call. Place a momentary breakpoint in the std::terminate function
800 and if triggered in the call, rewind. */
801 if (unwind_on_terminating_exception_p
)
802 set_std_terminate_breakpoint ();
804 /* Everything's ready, push all the info needed to restore the
805 caller (and identify the dummy-frame) onto the dummy-frame
807 dummy_frame_push (caller_state
, &dummy_id
);
809 /* Discard both inf_status and caller_state cleanups.
810 From this point on we explicitly restore the associated state
812 discard_cleanups (inf_status_cleanup
);
814 /* Register a clean-up for unwind_on_terminating_exception_breakpoint. */
815 terminate_bp_cleanup
= make_cleanup (cleanup_delete_std_terminate_breakpoint
,
818 /* - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP -
819 If you're looking to implement asynchronous dummy-frames, then
820 just below is the place to chop this function in two.. */
822 /* TP is invalid after run_inferior_call returns, so enclose this
823 in a block so that it's only in scope during the time it's valid. */
825 struct thread_info
*tp
= inferior_thread ();
827 /* Save this thread's ptid, we need it later but the thread
829 call_thread_ptid
= tp
->ptid
;
831 /* Run the inferior until it stops. */
833 e
= run_inferior_call (tp
, real_pc
);
836 /* Rethrow an error if we got one trying to run the inferior. */
840 const char *name
= get_function_name (funaddr
,
841 name_buf
, sizeof (name_buf
));
843 discard_infcall_control_state (inf_status
);
845 /* We could discard the dummy frame here if the program exited,
846 but it will get garbage collected the next time the program is
852 throw_error (e
.error
, _("%s\n\
853 An error occurred while in a function called from GDB.\n\
854 Evaluation of the expression containing the function\n\
855 (%s) will be abandoned.\n\
856 When the function is done executing, GDB will silently stop."),
864 /* If the program has exited, or we stopped at a different thread,
865 exit and inform the user. */
867 if (! target_has_execution
)
869 const char *name
= get_function_name (funaddr
,
870 name_buf
, sizeof (name_buf
));
872 /* If we try to restore the inferior status,
873 we'll crash as the inferior is no longer running. */
874 discard_infcall_control_state (inf_status
);
876 /* We could discard the dummy frame here given that the program exited,
877 but it will get garbage collected the next time the program is
880 error (_("The program being debugged exited while in a function "
882 "Evaluation of the expression containing the function\n"
883 "(%s) will be abandoned."),
887 if (! ptid_equal (call_thread_ptid
, inferior_ptid
))
889 const char *name
= get_function_name (funaddr
,
890 name_buf
, sizeof (name_buf
));
892 /* We've switched threads. This can happen if another thread gets a
893 signal or breakpoint while our thread was running.
894 There's no point in restoring the inferior status,
895 we're in a different thread. */
896 discard_infcall_control_state (inf_status
);
897 /* Keep the dummy frame record, if the user switches back to the
898 thread with the hand-call, we'll need it. */
899 if (stopped_by_random_signal
)
901 The program received a signal in another thread while\n\
902 making a function call from GDB.\n\
903 Evaluation of the expression containing the function\n\
904 (%s) will be abandoned.\n\
905 When the function is done executing, GDB will silently stop."),
909 The program stopped in another thread while making a function call from GDB.\n\
910 Evaluation of the expression containing the function\n\
911 (%s) will be abandoned.\n\
912 When the function is done executing, GDB will silently stop."),
916 if (stopped_by_random_signal
|| stop_stack_dummy
!= STOP_STACK_DUMMY
)
918 const char *name
= get_function_name (funaddr
,
919 name_buf
, sizeof (name_buf
));
921 if (stopped_by_random_signal
)
923 /* We stopped inside the FUNCTION because of a random
924 signal. Further execution of the FUNCTION is not
927 if (unwind_on_signal_p
)
929 /* The user wants the context restored. */
931 /* We must get back to the frame we were before the
933 dummy_frame_pop (dummy_id
);
935 /* We also need to restore inferior status to that before the
937 restore_infcall_control_state (inf_status
);
939 /* FIXME: Insert a bunch of wrap_here; name can be very
940 long if it's a C++ name with arguments and stuff. */
942 The program being debugged was signaled while in a function called from GDB.\n\
943 GDB has restored the context to what it was before the call.\n\
944 To change this behavior use \"set unwindonsignal off\".\n\
945 Evaluation of the expression containing the function\n\
946 (%s) will be abandoned."),
951 /* The user wants to stay in the frame where we stopped
953 Discard inferior status, we're not at the same point
955 discard_infcall_control_state (inf_status
);
957 /* FIXME: Insert a bunch of wrap_here; name can be very
958 long if it's a C++ name with arguments and stuff. */
960 The program being debugged was signaled while in a function called from GDB.\n\
961 GDB remains in the frame where the signal was received.\n\
962 To change this behavior use \"set unwindonsignal on\".\n\
963 Evaluation of the expression containing the function\n\
964 (%s) will be abandoned.\n\
965 When the function is done executing, GDB will silently stop."),
970 if (stop_stack_dummy
== STOP_STD_TERMINATE
)
972 /* We must get back to the frame we were before the dummy
974 dummy_frame_pop (dummy_id
);
976 /* We also need to restore inferior status to that before
978 restore_infcall_control_state (inf_status
);
981 The program being debugged entered a std::terminate call, most likely\n\
982 caused by an unhandled C++ exception. GDB blocked this call in order\n\
983 to prevent the program from being terminated, and has restored the\n\
984 context to its original state before the call.\n\
985 To change this behaviour use \"set unwind-on-terminating-exception off\".\n\
986 Evaluation of the expression containing the function (%s)\n\
987 will be abandoned."),
990 else if (stop_stack_dummy
== STOP_NONE
)
993 /* We hit a breakpoint inside the FUNCTION.
994 Keep the dummy frame, the user may want to examine its state.
995 Discard inferior status, we're not at the same point
997 discard_infcall_control_state (inf_status
);
999 /* The following error message used to say "The expression
1000 which contained the function call has been discarded."
1001 It is a hard concept to explain in a few words. Ideally,
1002 GDB would be able to resume evaluation of the expression
1003 when the function finally is done executing. Perhaps
1004 someday this will be implemented (it would not be easy). */
1005 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
1006 a C++ name with arguments and stuff. */
1008 The program being debugged stopped while in a function called from GDB.\n\
1009 Evaluation of the expression containing the function\n\
1010 (%s) will be abandoned.\n\
1011 When the function is done executing, GDB will silently stop."),
1015 /* The above code errors out, so ... */
1016 internal_error (__FILE__
, __LINE__
, _("... should not be here"));
1019 do_cleanups (terminate_bp_cleanup
);
1021 /* If we get here the called FUNCTION ran to completion,
1022 and the dummy frame has already been popped. */
1025 struct address_space
*aspace
= get_regcache_aspace (stop_registers
);
1026 struct regcache
*retbuf
= regcache_xmalloc (gdbarch
, aspace
);
1027 struct cleanup
*retbuf_cleanup
= make_cleanup_regcache_xfree (retbuf
);
1028 struct value
*retval
= NULL
;
1030 regcache_cpy_no_passthrough (retbuf
, stop_registers
);
1032 /* Inferior call is successful. Restore the inferior status.
1033 At this stage, leave the RETBUF alone. */
1034 restore_infcall_control_state (inf_status
);
1036 /* Figure out the value returned by the function. */
1037 retval
= allocate_value (values_type
);
1039 if (lang_struct_return
)
1040 read_value_memory (retval
, 0, 1, struct_addr
,
1041 value_contents_raw (retval
),
1042 TYPE_LENGTH (values_type
));
1043 else if (TYPE_CODE (target_values_type
) != TYPE_CODE_VOID
)
1045 /* If the function returns void, don't bother fetching the
1047 switch (gdbarch_return_value (gdbarch
, value_type (function
),
1048 target_values_type
, NULL
, NULL
, NULL
))
1050 case RETURN_VALUE_REGISTER_CONVENTION
:
1051 case RETURN_VALUE_ABI_RETURNS_ADDRESS
:
1052 case RETURN_VALUE_ABI_PRESERVES_ADDRESS
:
1053 gdbarch_return_value (gdbarch
, value_type (function
), values_type
,
1054 retbuf
, value_contents_raw (retval
), NULL
);
1056 case RETURN_VALUE_STRUCT_CONVENTION
:
1057 read_value_memory (retval
, 0, 1, struct_addr
,
1058 value_contents_raw (retval
),
1059 TYPE_LENGTH (values_type
));
1064 do_cleanups (retbuf_cleanup
);
1066 gdb_assert (retval
);
1072 /* Provide a prototype to silence -Wmissing-prototypes. */
1073 void _initialize_infcall (void);
1076 _initialize_infcall (void)
1078 add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure
,
1079 &coerce_float_to_double_p
, _("\
1080 Set coercion of floats to doubles when calling functions."), _("\
1081 Show coercion of floats to doubles when calling functions"), _("\
1082 Variables of type float should generally be converted to doubles before\n\
1083 calling an unprototyped function, and left alone when calling a prototyped\n\
1084 function. However, some older debug info formats do not provide enough\n\
1085 information to determine that a function is prototyped. If this flag is\n\
1086 set, GDB will perform the conversion for a function it considers\n\
1088 The default is to perform the conversion.\n"),
1090 show_coerce_float_to_double_p
,
1091 &setlist
, &showlist
);
1093 add_setshow_boolean_cmd ("unwindonsignal", no_class
,
1094 &unwind_on_signal_p
, _("\
1095 Set unwinding of stack if a signal is received while in a call dummy."), _("\
1096 Show unwinding of stack if a signal is received while in a call dummy."), _("\
1097 The unwindonsignal lets the user determine what gdb should do if a signal\n\
1098 is received while in a function called from gdb (call dummy). If set, gdb\n\
1099 unwinds the stack and restore the context to what as it was before the call.\n\
1100 The default is to stop in the frame where the signal was received."),
1102 show_unwind_on_signal_p
,
1103 &setlist
, &showlist
);
1105 add_setshow_boolean_cmd ("unwind-on-terminating-exception", no_class
,
1106 &unwind_on_terminating_exception_p
, _("\
1107 Set unwinding of stack if std::terminate is called while in call dummy."), _("\
1108 Show unwinding of stack if std::terminate() is called while in a call dummy."),
1110 The unwind on terminating exception flag lets the user determine\n\
1111 what gdb should do if a std::terminate() call is made from the\n\
1112 default exception handler. If set, gdb unwinds the stack and restores\n\
1113 the context to what it was before the call. If unset, gdb allows the\n\
1114 std::terminate call to proceed.\n\
1115 The default is to unwind the frame."),
1117 show_unwind_on_terminating_exception_p
,
1118 &setlist
, &showlist
);