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
;
255 /* Initialize it just to avoid a GCC false warning. */
256 CORE_ADDR funaddr
= 0;
258 /* If it's a member function, just look at the function
261 /* Determine address to call. */
262 if (TYPE_CODE (ftype
) == TYPE_CODE_FUNC
263 || TYPE_CODE (ftype
) == TYPE_CODE_METHOD
)
264 funaddr
= value_address (function
);
265 else if (TYPE_CODE (ftype
) == TYPE_CODE_PTR
)
267 funaddr
= value_as_address (function
);
268 ftype
= check_typedef (TYPE_TARGET_TYPE (ftype
));
269 if (TYPE_CODE (ftype
) == TYPE_CODE_FUNC
270 || TYPE_CODE (ftype
) == TYPE_CODE_METHOD
)
271 funaddr
= gdbarch_convert_from_func_ptr_addr (gdbarch
, funaddr
,
274 if (TYPE_CODE (ftype
) == TYPE_CODE_FUNC
275 || TYPE_CODE (ftype
) == TYPE_CODE_METHOD
)
277 value_type
= TYPE_TARGET_TYPE (ftype
);
279 if (TYPE_GNU_IFUNC (ftype
))
281 funaddr
= gnu_ifunc_resolve_addr (gdbarch
, funaddr
);
283 /* Skip querying the function symbol if no RETVAL_TYPE has been
286 value_type
= find_function_return_type (funaddr
);
289 else if (TYPE_CODE (ftype
) == TYPE_CODE_INT
)
291 /* Handle the case of functions lacking debugging info.
292 Their values are characters since their addresses are char. */
293 if (TYPE_LENGTH (ftype
) == 1)
294 funaddr
= value_as_address (value_addr (function
));
297 /* Handle function descriptors lacking debug info. */
298 int found_descriptor
= 0;
300 funaddr
= 0; /* pacify "gcc -Werror" */
301 if (VALUE_LVAL (function
) == lval_memory
)
305 funaddr
= value_as_address (value_addr (function
));
307 funaddr
= gdbarch_convert_from_func_ptr_addr (gdbarch
, funaddr
,
309 if (funaddr
!= nfunaddr
)
310 found_descriptor
= 1;
312 if (!found_descriptor
)
313 /* Handle integer used as address of a function. */
314 funaddr
= (CORE_ADDR
) value_as_long (function
);
318 error (_("Invalid data type for function to be called."));
320 if (retval_type
!= NULL
)
321 *retval_type
= value_type
;
322 return funaddr
+ gdbarch_deprecated_function_start_offset (gdbarch
);
325 /* For CALL_DUMMY_ON_STACK, push a breakpoint sequence that the called
326 function returns to. */
329 push_dummy_code (struct gdbarch
*gdbarch
,
330 CORE_ADDR sp
, CORE_ADDR funaddr
,
331 struct value
**args
, int nargs
,
332 struct type
*value_type
,
333 CORE_ADDR
*real_pc
, CORE_ADDR
*bp_addr
,
334 struct regcache
*regcache
)
336 gdb_assert (gdbarch_push_dummy_code_p (gdbarch
));
338 return gdbarch_push_dummy_code (gdbarch
, sp
, funaddr
,
339 args
, nargs
, value_type
, real_pc
, bp_addr
,
343 /* Fetch the name of the function at FUNADDR.
344 This is used in printing an error message for call_function_by_hand.
345 BUF is used to print FUNADDR in hex if the function name cannot be
346 determined. It must be large enough to hold formatted result of
347 RAW_FUNCTION_ADDRESS_FORMAT. */
350 get_function_name (CORE_ADDR funaddr
, char *buf
, int buf_size
)
353 struct symbol
*symbol
= find_pc_function (funaddr
);
356 return SYMBOL_PRINT_NAME (symbol
);
360 /* Try the minimal symbols. */
361 struct minimal_symbol
*msymbol
= lookup_minimal_symbol_by_pc (funaddr
);
364 return SYMBOL_PRINT_NAME (msymbol
);
368 char *tmp
= xstrprintf (_(RAW_FUNCTION_ADDRESS_FORMAT
),
369 hex_string (funaddr
));
371 gdb_assert (strlen (tmp
) + 1 <= buf_size
);
378 /* Subroutine of call_function_by_hand to simplify it.
379 Start up the inferior and wait for it to stop.
380 Return the exception if there's an error, or an exception with
381 reason >= 0 if there's no error.
383 This is done inside a TRY_CATCH so the caller needn't worry about
384 thrown errors. The caller should rethrow if there's an error. */
386 static struct gdb_exception
387 run_inferior_call (struct thread_info
*call_thread
, CORE_ADDR real_pc
)
389 volatile struct gdb_exception e
;
391 int saved_in_infcall
= call_thread
->control
.in_infcall
;
392 ptid_t call_thread_ptid
= call_thread
->ptid
;
393 char *saved_target_shortname
= xstrdup (target_shortname
);
395 call_thread
->control
.in_infcall
= 1;
397 clear_proceed_status ();
399 disable_watchpoints_before_interactive_call_start ();
401 /* We want stop_registers, please... */
402 call_thread
->control
.proceed_to_finish
= 1;
404 if (target_can_async_p ())
405 saved_async
= target_async_mask (0);
407 TRY_CATCH (e
, RETURN_MASK_ALL
)
408 proceed (real_pc
, TARGET_SIGNAL_0
, 0);
410 /* At this point the current thread may have changed. Refresh
411 CALL_THREAD as it could be invalid if its thread has exited. */
412 call_thread
= find_thread_ptid (call_thread_ptid
);
414 /* Don't restore the async mask if the target has changed,
415 saved_async is for the original target. */
417 && strcmp (saved_target_shortname
, target_shortname
) == 0)
418 target_async_mask (saved_async
);
420 enable_watchpoints_after_interactive_call_stop ();
422 /* Call breakpoint_auto_delete on the current contents of the bpstat
423 of inferior call thread.
424 If all error()s out of proceed ended up calling normal_stop
425 (and perhaps they should; it already does in the special case
426 of error out of resume()), then we wouldn't need this. */
429 if (call_thread
!= NULL
)
430 breakpoint_auto_delete (call_thread
->control
.stop_bpstat
);
433 if (call_thread
!= NULL
)
434 call_thread
->control
.in_infcall
= saved_in_infcall
;
436 xfree (saved_target_shortname
);
441 /* A cleanup function that calls delete_std_terminate_breakpoint. */
443 cleanup_delete_std_terminate_breakpoint (void *ignore
)
445 delete_std_terminate_breakpoint ();
448 /* All this stuff with a dummy frame may seem unnecessarily complicated
449 (why not just save registers in GDB?). The purpose of pushing a dummy
450 frame which looks just like a real frame is so that if you call a
451 function and then hit a breakpoint (get a signal, etc), "backtrace"
452 will look right. Whether the backtrace needs to actually show the
453 stack at the time the inferior function was called is debatable, but
454 it certainly needs to not display garbage. So if you are contemplating
455 making dummy frames be different from normal frames, consider that. */
457 /* Perform a function call in the inferior.
458 ARGS is a vector of values of arguments (NARGS of them).
459 FUNCTION is a value, the function to be called.
460 Returns a value representing what the function returned.
461 May fail to return, if a breakpoint or signal is hit
462 during the execution of the function.
464 ARGS is modified to contain coerced values. */
467 call_function_by_hand (struct value
*function
, int nargs
, struct value
**args
)
470 struct type
*values_type
, *target_values_type
;
471 unsigned char struct_return
= 0, lang_struct_return
= 0;
472 CORE_ADDR struct_addr
= 0;
473 struct infcall_control_state
*inf_status
;
474 struct cleanup
*inf_status_cleanup
;
475 struct infcall_suspend_state
*caller_state
;
478 struct type
*ftype
= check_typedef (value_type (function
));
480 struct frame_id dummy_id
;
481 struct cleanup
*args_cleanup
;
482 struct frame_info
*frame
;
483 struct gdbarch
*gdbarch
;
484 struct cleanup
*terminate_bp_cleanup
;
485 ptid_t call_thread_ptid
;
486 struct gdb_exception e
;
487 char name_buf
[RAW_FUNCTION_ADDRESS_SIZE
];
489 if (TYPE_CODE (ftype
) == TYPE_CODE_PTR
)
490 ftype
= check_typedef (TYPE_TARGET_TYPE (ftype
));
492 if (!target_has_execution
)
495 if (get_traceframe_number () >= 0)
496 error (_("May not call functions while looking at trace frames."));
498 if (execution_direction
== EXEC_REVERSE
)
499 error (_("May not call functions in reverse."));
501 frame
= get_current_frame ();
502 gdbarch
= get_frame_arch (frame
);
504 if (!gdbarch_push_dummy_call_p (gdbarch
))
505 error (_("This target does not support function calls."));
507 /* A cleanup for the inferior status.
508 This is only needed while we're preparing the inferior function call. */
509 inf_status
= save_infcall_control_state ();
511 = make_cleanup_restore_infcall_control_state (inf_status
);
513 /* Save the caller's registers and other state associated with the
514 inferior itself so that they can be restored once the
515 callee returns. To allow nested calls the registers are (further
516 down) pushed onto a dummy frame stack. Include a cleanup (which
517 is tossed once the regcache has been pushed). */
518 caller_state
= save_infcall_suspend_state ();
519 make_cleanup_restore_infcall_suspend_state (caller_state
);
521 /* Ensure that the initial SP is correctly aligned. */
523 CORE_ADDR old_sp
= get_frame_sp (frame
);
525 if (gdbarch_frame_align_p (gdbarch
))
527 sp
= gdbarch_frame_align (gdbarch
, old_sp
);
528 /* NOTE: cagney/2003-08-13: Skip the "red zone". For some
529 ABIs, a function can use memory beyond the inner most stack
530 address. AMD64 called that region the "red zone". Skip at
531 least the "red zone" size before allocating any space on
533 if (gdbarch_inner_than (gdbarch
, 1, 2))
534 sp
-= gdbarch_frame_red_zone_size (gdbarch
);
536 sp
+= gdbarch_frame_red_zone_size (gdbarch
);
538 gdb_assert (sp
== gdbarch_frame_align (gdbarch
, sp
));
539 /* NOTE: cagney/2002-09-18:
541 On a RISC architecture, a void parameterless generic dummy
542 frame (i.e., no parameters, no result) typically does not
543 need to push anything the stack and hence can leave SP and
544 FP. Similarly, a frameless (possibly leaf) function does
545 not push anything on the stack and, hence, that too can
546 leave FP and SP unchanged. As a consequence, a sequence of
547 void parameterless generic dummy frame calls to frameless
548 functions will create a sequence of effectively identical
549 frames (SP, FP and TOS and PC the same). This, not
550 suprisingly, results in what appears to be a stack in an
551 infinite loop --- when GDB tries to find a generic dummy
552 frame on the internal dummy frame stack, it will always
555 To avoid this problem, the code below always grows the
556 stack. That way, two dummy frames can never be identical.
557 It does burn a few bytes of stack but that is a small price
561 if (gdbarch_inner_than (gdbarch
, 1, 2))
562 /* Stack grows down. */
563 sp
= gdbarch_frame_align (gdbarch
, old_sp
- 1);
565 /* Stack grows up. */
566 sp
= gdbarch_frame_align (gdbarch
, old_sp
+ 1);
568 /* SP may have underflown address zero here from OLD_SP. Memory access
569 functions will probably fail in such case but that is a target's
573 /* FIXME: cagney/2002-09-18: Hey, you loose!
575 Who knows how badly aligned the SP is!
577 If the generic dummy frame ends up empty (because nothing is
578 pushed) GDB won't be able to correctly perform back traces.
579 If a target is having trouble with backtraces, first thing to
580 do is add FRAME_ALIGN() to the architecture vector. If that
581 fails, try dummy_id().
583 If the ABI specifies a "Red Zone" (see the doco) the code
584 below will quietly trash it. */
588 funaddr
= find_function_addr (function
, &values_type
);
590 values_type
= builtin_type (gdbarch
)->builtin_int
;
592 CHECK_TYPEDEF (values_type
);
594 /* Are we returning a value using a structure return (passing a
595 hidden argument pointing to storage) or a normal value return?
596 There are two cases: language-mandated structure return and
597 target ABI structure return. The variable STRUCT_RETURN only
598 describes the latter. The language version is handled by passing
599 the return location as the first parameter to the function,
600 even preceding "this". This is different from the target
601 ABI version, which is target-specific; for instance, on ia64
602 the first argument is passed in out0 but the hidden structure
603 return pointer would normally be passed in r8. */
605 if (language_pass_by_reference (values_type
))
607 lang_struct_return
= 1;
609 /* Tell the target specific argument pushing routine not to
611 target_values_type
= builtin_type (gdbarch
)->builtin_void
;
615 struct_return
= using_struct_return (gdbarch
,
616 value_type (function
), values_type
);
617 target_values_type
= values_type
;
620 /* Determine the location of the breakpoint (and possibly other
621 stuff) that the called function will return to. The SPARC, for a
622 function returning a structure or union, needs to make space for
623 not just the breakpoint but also an extra word containing the
624 size (?) of the structure being passed. */
626 /* The actual breakpoint (at BP_ADDR) is inserted separatly so there
627 is no need to write that out. */
629 switch (gdbarch_call_dummy_location (gdbarch
))
632 sp
= push_dummy_code (gdbarch
, sp
, funaddr
,
633 args
, nargs
, target_values_type
,
634 &real_pc
, &bp_addr
, get_current_regcache ());
638 CORE_ADDR dummy_addr
;
641 dummy_addr
= entry_point_address ();
642 /* A call dummy always consists of just a single breakpoint, so
643 its address is the same as the address of the dummy. */
644 bp_addr
= dummy_addr
;
648 /* Some executables define a symbol __CALL_DUMMY_ADDRESS whose
649 address is the location where the breakpoint should be
650 placed. Once all targets are using the overhauled frame code
651 this can be deleted - ON_STACK is a better option. */
653 struct minimal_symbol
*sym
;
654 CORE_ADDR dummy_addr
;
656 sym
= lookup_minimal_symbol ("__CALL_DUMMY_ADDRESS", NULL
, NULL
);
660 dummy_addr
= SYMBOL_VALUE_ADDRESS (sym
);
661 /* Make certain that the address points at real code, and not
662 a function descriptor. */
663 dummy_addr
= gdbarch_convert_from_func_ptr_addr (gdbarch
,
668 dummy_addr
= entry_point_address ();
669 /* A call dummy always consists of just a single breakpoint,
670 so it's address is the same as the address of the dummy. */
671 bp_addr
= dummy_addr
;
675 internal_error (__FILE__
, __LINE__
, _("bad switch"));
678 if (nargs
< TYPE_NFIELDS (ftype
))
679 error (_("Too few arguments in function call."));
684 for (i
= nargs
- 1; i
>= 0; i
--)
687 struct type
*param_type
;
689 /* FIXME drow/2002-05-31: Should just always mark methods as
690 prototyped. Can we respect TYPE_VARARGS? Probably not. */
691 if (TYPE_CODE (ftype
) == TYPE_CODE_METHOD
)
693 else if (i
< TYPE_NFIELDS (ftype
))
694 prototyped
= TYPE_PROTOTYPED (ftype
);
698 if (i
< TYPE_NFIELDS (ftype
))
699 param_type
= TYPE_FIELD_TYPE (ftype
, i
);
703 args
[i
] = value_arg_coerce (gdbarch
, args
[i
],
704 param_type
, prototyped
, &sp
);
706 if (param_type
!= NULL
&& language_pass_by_reference (param_type
))
707 args
[i
] = value_addr (args
[i
]);
711 /* Reserve space for the return structure to be written on the
712 stack, if necessary. Make certain that the value is correctly
715 if (struct_return
|| lang_struct_return
)
717 int len
= TYPE_LENGTH (values_type
);
719 if (gdbarch_inner_than (gdbarch
, 1, 2))
721 /* Stack grows downward. Align STRUCT_ADDR and SP after
722 making space for the return value. */
724 if (gdbarch_frame_align_p (gdbarch
))
725 sp
= gdbarch_frame_align (gdbarch
, sp
);
730 /* Stack grows upward. Align the frame, allocate space, and
731 then again, re-align the frame??? */
732 if (gdbarch_frame_align_p (gdbarch
))
733 sp
= gdbarch_frame_align (gdbarch
, sp
);
736 if (gdbarch_frame_align_p (gdbarch
))
737 sp
= gdbarch_frame_align (gdbarch
, sp
);
741 if (lang_struct_return
)
743 struct value
**new_args
;
745 /* Add the new argument to the front of the argument list. */
746 new_args
= xmalloc (sizeof (struct value
*) * (nargs
+ 1));
747 new_args
[0] = value_from_pointer (lookup_pointer_type (values_type
),
749 memcpy (&new_args
[1], &args
[0], sizeof (struct value
*) * nargs
);
752 args_cleanup
= make_cleanup (xfree
, args
);
755 args_cleanup
= make_cleanup (null_cleanup
, NULL
);
757 /* Create the dummy stack frame. Pass in the call dummy address as,
758 presumably, the ABI code knows where, in the call dummy, the
759 return address should be pointed. */
760 sp
= gdbarch_push_dummy_call (gdbarch
, function
, get_current_regcache (),
761 bp_addr
, nargs
, args
,
762 sp
, struct_return
, struct_addr
);
764 do_cleanups (args_cleanup
);
766 /* Set up a frame ID for the dummy frame so we can pass it to
767 set_momentary_breakpoint. We need to give the breakpoint a frame
768 ID so that the breakpoint code can correctly re-identify the
770 /* Sanity. The exact same SP value is returned by PUSH_DUMMY_CALL,
771 saved as the dummy-frame TOS, and used by dummy_id to form
772 the frame ID's stack address. */
773 dummy_id
= frame_id_build (sp
, bp_addr
);
775 /* Create a momentary breakpoint at the return address of the
776 inferior. That way it breaks when it returns. */
779 struct breakpoint
*bpt
;
780 struct symtab_and_line sal
;
782 init_sal (&sal
); /* initialize to zeroes */
783 sal
.pspace
= current_program_space
;
785 sal
.section
= find_pc_overlay (sal
.pc
);
786 /* Sanity. The exact same SP value is returned by
787 PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by
788 dummy_id to form the frame ID's stack address. */
789 bpt
= set_momentary_breakpoint (gdbarch
, sal
, dummy_id
, bp_call_dummy
);
790 bpt
->disposition
= disp_del
;
793 /* Create a breakpoint in std::terminate.
794 If a C++ exception is raised in the dummy-frame, and the
795 exception handler is (normally, and expected to be) out-of-frame,
796 the default C++ handler will (wrongly) be called in an inferior
797 function call. This is wrong, as an exception can be normally
798 and legally handled out-of-frame. The confines of the dummy frame
799 prevent the unwinder from finding the correct handler (or any
800 handler, unless it is in-frame). The default handler calls
801 std::terminate. This will kill the inferior. Assert that
802 terminate should never be called in an inferior function
803 call. Place a momentary breakpoint in the std::terminate function
804 and if triggered in the call, rewind. */
805 if (unwind_on_terminating_exception_p
)
806 set_std_terminate_breakpoint ();
808 /* Everything's ready, push all the info needed to restore the
809 caller (and identify the dummy-frame) onto the dummy-frame
811 dummy_frame_push (caller_state
, &dummy_id
);
813 /* Discard both inf_status and caller_state cleanups.
814 From this point on we explicitly restore the associated state
816 discard_cleanups (inf_status_cleanup
);
818 /* Register a clean-up for unwind_on_terminating_exception_breakpoint. */
819 terminate_bp_cleanup
= make_cleanup (cleanup_delete_std_terminate_breakpoint
,
822 /* - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP -
823 If you're looking to implement asynchronous dummy-frames, then
824 just below is the place to chop this function in two.. */
826 /* TP is invalid after run_inferior_call returns, so enclose this
827 in a block so that it's only in scope during the time it's valid. */
829 struct thread_info
*tp
= inferior_thread ();
831 /* Save this thread's ptid, we need it later but the thread
833 call_thread_ptid
= tp
->ptid
;
835 /* Run the inferior until it stops. */
837 e
= run_inferior_call (tp
, real_pc
);
840 /* Rethrow an error if we got one trying to run the inferior. */
844 const char *name
= get_function_name (funaddr
,
845 name_buf
, sizeof (name_buf
));
847 discard_infcall_control_state (inf_status
);
849 /* We could discard the dummy frame here if the program exited,
850 but it will get garbage collected the next time the program is
856 throw_error (e
.error
, _("%s\n\
857 An error occurred while in a function called from GDB.\n\
858 Evaluation of the expression containing the function\n\
859 (%s) will be abandoned.\n\
860 When the function is done executing, GDB will silently stop."),
868 /* If the program has exited, or we stopped at a different thread,
869 exit and inform the user. */
871 if (! target_has_execution
)
873 const char *name
= get_function_name (funaddr
,
874 name_buf
, sizeof (name_buf
));
876 /* If we try to restore the inferior status,
877 we'll crash as the inferior is no longer running. */
878 discard_infcall_control_state (inf_status
);
880 /* We could discard the dummy frame here given that the program exited,
881 but it will get garbage collected the next time the program is
884 error (_("The program being debugged exited while in a function "
886 "Evaluation of the expression containing the function\n"
887 "(%s) will be abandoned."),
891 if (! ptid_equal (call_thread_ptid
, inferior_ptid
))
893 const char *name
= get_function_name (funaddr
,
894 name_buf
, sizeof (name_buf
));
896 /* We've switched threads. This can happen if another thread gets a
897 signal or breakpoint while our thread was running.
898 There's no point in restoring the inferior status,
899 we're in a different thread. */
900 discard_infcall_control_state (inf_status
);
901 /* Keep the dummy frame record, if the user switches back to the
902 thread with the hand-call, we'll need it. */
903 if (stopped_by_random_signal
)
905 The program received a signal in another thread while\n\
906 making a function call from GDB.\n\
907 Evaluation of the expression containing the function\n\
908 (%s) will be abandoned.\n\
909 When the function is done executing, GDB will silently stop."),
913 The program stopped in another thread while making a function call from GDB.\n\
914 Evaluation of the expression containing the function\n\
915 (%s) will be abandoned.\n\
916 When the function is done executing, GDB will silently stop."),
920 if (stopped_by_random_signal
|| stop_stack_dummy
!= STOP_STACK_DUMMY
)
922 const char *name
= get_function_name (funaddr
,
923 name_buf
, sizeof (name_buf
));
925 if (stopped_by_random_signal
)
927 /* We stopped inside the FUNCTION because of a random
928 signal. Further execution of the FUNCTION is not
931 if (unwind_on_signal_p
)
933 /* The user wants the context restored. */
935 /* We must get back to the frame we were before the
937 dummy_frame_pop (dummy_id
);
939 /* We also need to restore inferior status to that before the
941 restore_infcall_control_state (inf_status
);
943 /* FIXME: Insert a bunch of wrap_here; name can be very
944 long if it's a C++ name with arguments and stuff. */
946 The program being debugged was signaled while in a function called from GDB.\n\
947 GDB has restored the context to what it was before the call.\n\
948 To change this behavior use \"set unwindonsignal off\".\n\
949 Evaluation of the expression containing the function\n\
950 (%s) will be abandoned."),
955 /* The user wants to stay in the frame where we stopped
957 Discard inferior status, we're not at the same point
959 discard_infcall_control_state (inf_status
);
961 /* FIXME: Insert a bunch of wrap_here; name can be very
962 long if it's a C++ name with arguments and stuff. */
964 The program being debugged was signaled while in a function called from GDB.\n\
965 GDB remains in the frame where the signal was received.\n\
966 To change this behavior use \"set unwindonsignal on\".\n\
967 Evaluation of the expression containing the function\n\
968 (%s) will be abandoned.\n\
969 When the function is done executing, GDB will silently stop."),
974 if (stop_stack_dummy
== STOP_STD_TERMINATE
)
976 /* We must get back to the frame we were before the dummy
978 dummy_frame_pop (dummy_id
);
980 /* We also need to restore inferior status to that before
982 restore_infcall_control_state (inf_status
);
985 The program being debugged entered a std::terminate call, most likely\n\
986 caused by an unhandled C++ exception. GDB blocked this call in order\n\
987 to prevent the program from being terminated, and has restored the\n\
988 context to its original state before the call.\n\
989 To change this behaviour use \"set unwind-on-terminating-exception off\".\n\
990 Evaluation of the expression containing the function (%s)\n\
991 will be abandoned."),
994 else if (stop_stack_dummy
== STOP_NONE
)
997 /* We hit a breakpoint inside the FUNCTION.
998 Keep the dummy frame, the user may want to examine its state.
999 Discard inferior status, we're not at the same point
1001 discard_infcall_control_state (inf_status
);
1003 /* The following error message used to say "The expression
1004 which contained the function call has been discarded."
1005 It is a hard concept to explain in a few words. Ideally,
1006 GDB would be able to resume evaluation of the expression
1007 when the function finally is done executing. Perhaps
1008 someday this will be implemented (it would not be easy). */
1009 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
1010 a C++ name with arguments and stuff. */
1012 The program being debugged stopped while in a function called from GDB.\n\
1013 Evaluation of the expression containing the function\n\
1014 (%s) will be abandoned.\n\
1015 When the function is done executing, GDB will silently stop."),
1019 /* The above code errors out, so ... */
1020 internal_error (__FILE__
, __LINE__
, _("... should not be here"));
1023 do_cleanups (terminate_bp_cleanup
);
1025 /* If we get here the called FUNCTION ran to completion,
1026 and the dummy frame has already been popped. */
1029 struct address_space
*aspace
= get_regcache_aspace (stop_registers
);
1030 struct regcache
*retbuf
= regcache_xmalloc (gdbarch
, aspace
);
1031 struct cleanup
*retbuf_cleanup
= make_cleanup_regcache_xfree (retbuf
);
1032 struct value
*retval
= NULL
;
1034 regcache_cpy_no_passthrough (retbuf
, stop_registers
);
1036 /* Inferior call is successful. Restore the inferior status.
1037 At this stage, leave the RETBUF alone. */
1038 restore_infcall_control_state (inf_status
);
1040 /* Figure out the value returned by the function. */
1041 retval
= allocate_value (values_type
);
1043 if (lang_struct_return
)
1044 read_value_memory (retval
, 0, 1, struct_addr
,
1045 value_contents_raw (retval
),
1046 TYPE_LENGTH (values_type
));
1047 else if (TYPE_CODE (target_values_type
) != TYPE_CODE_VOID
)
1049 /* If the function returns void, don't bother fetching the
1051 switch (gdbarch_return_value (gdbarch
, value_type (function
),
1052 target_values_type
, NULL
, NULL
, NULL
))
1054 case RETURN_VALUE_REGISTER_CONVENTION
:
1055 case RETURN_VALUE_ABI_RETURNS_ADDRESS
:
1056 case RETURN_VALUE_ABI_PRESERVES_ADDRESS
:
1057 gdbarch_return_value (gdbarch
, value_type (function
), values_type
,
1058 retbuf
, value_contents_raw (retval
), NULL
);
1060 case RETURN_VALUE_STRUCT_CONVENTION
:
1061 read_value_memory (retval
, 0, 1, struct_addr
,
1062 value_contents_raw (retval
),
1063 TYPE_LENGTH (values_type
));
1068 do_cleanups (retbuf_cleanup
);
1070 gdb_assert (retval
);
1076 /* Provide a prototype to silence -Wmissing-prototypes. */
1077 void _initialize_infcall (void);
1080 _initialize_infcall (void)
1082 add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure
,
1083 &coerce_float_to_double_p
, _("\
1084 Set coercion of floats to doubles when calling functions."), _("\
1085 Show coercion of floats to doubles when calling functions"), _("\
1086 Variables of type float should generally be converted to doubles before\n\
1087 calling an unprototyped function, and left alone when calling a prototyped\n\
1088 function. However, some older debug info formats do not provide enough\n\
1089 information to determine that a function is prototyped. If this flag is\n\
1090 set, GDB will perform the conversion for a function it considers\n\
1092 The default is to perform the conversion.\n"),
1094 show_coerce_float_to_double_p
,
1095 &setlist
, &showlist
);
1097 add_setshow_boolean_cmd ("unwindonsignal", no_class
,
1098 &unwind_on_signal_p
, _("\
1099 Set unwinding of stack if a signal is received while in a call dummy."), _("\
1100 Show unwinding of stack if a signal is received while in a call dummy."), _("\
1101 The unwindonsignal lets the user determine what gdb should do if a signal\n\
1102 is received while in a function called from gdb (call dummy). If set, gdb\n\
1103 unwinds the stack and restore the context to what as it was before the call.\n\
1104 The default is to stop in the frame where the signal was received."),
1106 show_unwind_on_signal_p
,
1107 &setlist
, &showlist
);
1109 add_setshow_boolean_cmd ("unwind-on-terminating-exception", no_class
,
1110 &unwind_on_terminating_exception_p
, _("\
1111 Set unwinding of stack if std::terminate is called while in call dummy."), _("\
1112 Show unwinding of stack if std::terminate() is called while in a call dummy."),
1114 The unwind on terminating exception flag lets the user determine\n\
1115 what gdb should do if a std::terminate() call is made from the\n\
1116 default exception handler. If set, gdb unwinds the stack and restores\n\
1117 the context to what it was before the call. If unset, gdb allows the\n\
1118 std::terminate call to proceed.\n\
1119 The default is to unwind the frame."),
1121 show_unwind_on_terminating_exception_p
,
1122 &setlist
, &showlist
);