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 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 2 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, write to the Free Software
21 Foundation, Inc., 51 Franklin Street, Fifth Floor,
22 Boston, MA 02110-1301, USA. */
25 #include "breakpoint.h"
29 #include "gdb_assert.h"
36 #include "gdb_string.h"
38 #include "dummy-frame.h"
40 /* NOTE: cagney/2003-04-16: What's the future of this code?
42 GDB needs an asynchronous expression evaluator, that means an
43 asynchronous inferior function call implementation, and that in
44 turn means restructuring the code so that it is event driven. */
46 /* How you should pass arguments to a function depends on whether it
47 was defined in K&R style or prototype style. If you define a
48 function using the K&R syntax that takes a `float' argument, then
49 callers must pass that argument as a `double'. If you define the
50 function using the prototype syntax, then you must pass the
51 argument as a `float', with no promotion.
53 Unfortunately, on certain older platforms, the debug info doesn't
54 indicate reliably how each function was defined. A function type's
55 TYPE_FLAG_PROTOTYPED flag may be clear, even if the function was
56 defined in prototype style. When calling a function whose
57 TYPE_FLAG_PROTOTYPED flag is clear, GDB consults this flag to
60 For modern targets, it is proper to assume that, if the prototype
61 flag is clear, that can be trusted: `float' arguments should be
62 promoted to `double'. For some older targets, if the prototype
63 flag is clear, that doesn't tell us anything. The default is to
64 trust the debug information; the user can override this behavior
65 with "set coerce-float-to-double 0". */
67 static int coerce_float_to_double_p
= 1;
69 show_coerce_float_to_double_p (struct ui_file
*file
, int from_tty
,
70 struct cmd_list_element
*c
, const char *value
)
72 fprintf_filtered (file
, _("\
73 Coercion of floats to doubles when calling functions is %s.\n"),
77 /* This boolean tells what gdb should do if a signal is received while
78 in a function called from gdb (call dummy). If set, gdb unwinds
79 the stack and restore the context to what as it was before the
82 The default is to stop in the frame where the signal was received. */
84 int unwind_on_signal_p
= 0;
86 show_unwind_on_signal_p (struct ui_file
*file
, int from_tty
,
87 struct cmd_list_element
*c
, const char *value
)
89 fprintf_filtered (file
, _("\
90 Unwinding of stack if a signal is received while in a call dummy is %s.\n"),
95 /* Perform the standard coercions that are specified
96 for arguments to be passed to C functions.
98 If PARAM_TYPE is non-NULL, it is the expected parameter type.
99 IS_PROTOTYPED is non-zero if the function declaration is prototyped. */
101 static struct value
*
102 value_arg_coerce (struct value
*arg
, struct type
*param_type
,
105 struct type
*arg_type
= check_typedef (value_type (arg
));
107 = param_type
? check_typedef (param_type
) : arg_type
;
109 switch (TYPE_CODE (type
))
113 struct value
*new_value
;
115 if (TYPE_CODE (arg_type
) == TYPE_CODE_REF
)
116 return value_cast_pointers (type
, arg
);
118 /* Cast the value to the reference's target type, and then
119 convert it back to a reference. This will issue an error
120 if the value was not previously in memory - in some cases
121 we should clearly be allowing this, but how? */
122 new_value
= value_cast (TYPE_TARGET_TYPE (type
), arg
);
123 new_value
= value_ref (new_value
);
130 /* If we don't have a prototype, coerce to integer type if necessary. */
133 if (TYPE_LENGTH (type
) < TYPE_LENGTH (builtin_type_int
))
134 type
= builtin_type_int
;
136 /* Currently all target ABIs require at least the width of an integer
137 type for an argument. We may have to conditionalize the following
138 type coercion for future targets. */
139 if (TYPE_LENGTH (type
) < TYPE_LENGTH (builtin_type_int
))
140 type
= builtin_type_int
;
143 if (!is_prototyped
&& coerce_float_to_double_p
)
145 if (TYPE_LENGTH (type
) < TYPE_LENGTH (builtin_type_double
))
146 type
= builtin_type_double
;
147 else if (TYPE_LENGTH (type
) > TYPE_LENGTH (builtin_type_double
))
148 type
= builtin_type_long_double
;
152 type
= lookup_pointer_type (type
);
154 case TYPE_CODE_ARRAY
:
155 /* Arrays are coerced to pointers to their first element, unless
156 they are vectors, in which case we want to leave them alone,
157 because they are passed by value. */
158 if (current_language
->c_style_arrays
)
159 if (!TYPE_VECTOR (type
))
160 type
= lookup_pointer_type (TYPE_TARGET_TYPE (type
));
162 case TYPE_CODE_UNDEF
:
164 case TYPE_CODE_STRUCT
:
165 case TYPE_CODE_UNION
:
168 case TYPE_CODE_RANGE
:
169 case TYPE_CODE_STRING
:
170 case TYPE_CODE_BITSTRING
:
171 case TYPE_CODE_ERROR
:
172 case TYPE_CODE_MEMBERPTR
:
173 case TYPE_CODE_METHODPTR
:
174 case TYPE_CODE_METHOD
:
175 case TYPE_CODE_COMPLEX
:
180 return value_cast (type
, arg
);
183 /* Determine a function's address and its return type from its value.
184 Calls error() if the function is not valid for calling. */
187 find_function_addr (struct value
*function
, struct type
**retval_type
)
189 struct type
*ftype
= check_typedef (value_type (function
));
190 enum type_code code
= TYPE_CODE (ftype
);
191 struct type
*value_type
;
194 /* If it's a member function, just look at the function
197 /* Determine address to call. */
198 if (code
== TYPE_CODE_FUNC
|| code
== TYPE_CODE_METHOD
)
200 funaddr
= VALUE_ADDRESS (function
);
201 value_type
= TYPE_TARGET_TYPE (ftype
);
203 else if (code
== TYPE_CODE_PTR
)
205 funaddr
= value_as_address (function
);
206 ftype
= check_typedef (TYPE_TARGET_TYPE (ftype
));
207 if (TYPE_CODE (ftype
) == TYPE_CODE_FUNC
208 || TYPE_CODE (ftype
) == TYPE_CODE_METHOD
)
210 funaddr
= gdbarch_convert_from_func_ptr_addr (current_gdbarch
,
213 value_type
= TYPE_TARGET_TYPE (ftype
);
216 value_type
= builtin_type_int
;
218 else if (code
== TYPE_CODE_INT
)
220 /* Handle the case of functions lacking debugging info.
221 Their values are characters since their addresses are char */
222 if (TYPE_LENGTH (ftype
) == 1)
223 funaddr
= value_as_address (value_addr (function
));
226 /* Handle function descriptors lacking debug info. */
227 int found_descriptor
= 0;
228 if (VALUE_LVAL (function
) == lval_memory
)
231 funaddr
= value_as_address (value_addr (function
));
233 funaddr
= gdbarch_convert_from_func_ptr_addr (current_gdbarch
,
236 if (funaddr
!= nfunaddr
)
237 found_descriptor
= 1;
239 if (!found_descriptor
)
240 /* Handle integer used as address of a function. */
241 funaddr
= (CORE_ADDR
) value_as_long (function
);
244 value_type
= builtin_type_int
;
247 error (_("Invalid data type for function to be called."));
249 if (retval_type
!= NULL
)
250 *retval_type
= value_type
;
251 return funaddr
+ gdbarch_deprecated_function_start_offset (current_gdbarch
);
254 /* Call breakpoint_auto_delete on the current contents of the bpstat
255 pointed to by arg (which is really a bpstat *). */
258 breakpoint_auto_delete_contents (void *arg
)
260 breakpoint_auto_delete (*(bpstat
*) arg
);
264 generic_push_dummy_code (struct gdbarch
*gdbarch
,
265 CORE_ADDR sp
, CORE_ADDR funaddr
, int using_gcc
,
266 struct value
**args
, int nargs
,
267 struct type
*value_type
,
268 CORE_ADDR
*real_pc
, CORE_ADDR
*bp_addr
,
269 struct regcache
*regcache
)
271 /* Something here to findout the size of a breakpoint and then
272 allocate space for it on the stack. */
274 /* This code assumes frame align. */
275 gdb_assert (gdbarch_frame_align_p (gdbarch
));
276 /* Force the stack's alignment. The intent is to ensure that the SP
277 is aligned to at least a breakpoint instruction's boundary. */
278 sp
= gdbarch_frame_align (gdbarch
, sp
);
279 /* Allocate space for, and then position the breakpoint on the
281 if (gdbarch_inner_than (gdbarch
, 1, 2))
284 gdbarch_breakpoint_from_pc (gdbarch
, &bppc
, &bplen
);
285 sp
= gdbarch_frame_align (gdbarch
, sp
- bplen
);
287 /* Should the breakpoint size/location be re-computed here? */
292 gdbarch_breakpoint_from_pc (gdbarch
, bp_addr
, &bplen
);
293 sp
= gdbarch_frame_align (gdbarch
, sp
+ bplen
);
295 /* Inferior resumes at the function entry point. */
296 (*real_pc
) = funaddr
;
300 /* For CALL_DUMMY_ON_STACK, push a breakpoint sequence that the called
301 function returns to. */
304 push_dummy_code (struct gdbarch
*gdbarch
,
305 CORE_ADDR sp
, CORE_ADDR funaddr
, int using_gcc
,
306 struct value
**args
, int nargs
,
307 struct type
*value_type
,
308 CORE_ADDR
*real_pc
, CORE_ADDR
*bp_addr
,
309 struct regcache
*regcache
)
311 if (gdbarch_push_dummy_code_p (gdbarch
))
312 return gdbarch_push_dummy_code (gdbarch
, sp
, funaddr
, using_gcc
,
313 args
, nargs
, value_type
, real_pc
, bp_addr
,
316 return generic_push_dummy_code (gdbarch
, sp
, funaddr
, using_gcc
,
317 args
, nargs
, value_type
, real_pc
, bp_addr
,
321 /* All this stuff with a dummy frame may seem unnecessarily complicated
322 (why not just save registers in GDB?). The purpose of pushing a dummy
323 frame which looks just like a real frame is so that if you call a
324 function and then hit a breakpoint (get a signal, etc), "backtrace"
325 will look right. Whether the backtrace needs to actually show the
326 stack at the time the inferior function was called is debatable, but
327 it certainly needs to not display garbage. So if you are contemplating
328 making dummy frames be different from normal frames, consider that. */
330 /* Perform a function call in the inferior.
331 ARGS is a vector of values of arguments (NARGS of them).
332 FUNCTION is a value, the function to be called.
333 Returns a value representing what the function returned.
334 May fail to return, if a breakpoint or signal is hit
335 during the execution of the function.
337 ARGS is modified to contain coerced values. */
340 call_function_by_hand (struct value
*function
, int nargs
, struct value
**args
)
343 CORE_ADDR dummy_addr
;
344 struct type
*values_type
;
345 unsigned char struct_return
;
346 CORE_ADDR struct_addr
= 0;
347 struct regcache
*retbuf
;
348 struct cleanup
*retbuf_cleanup
;
349 struct inferior_status
*inf_status
;
350 struct cleanup
*inf_status_cleanup
;
352 int using_gcc
; /* Set to version of gcc in use, or zero if not gcc */
354 struct type
*ftype
= check_typedef (value_type (function
));
356 struct regcache
*caller_regcache
;
357 struct cleanup
*caller_regcache_cleanup
;
358 struct frame_id dummy_id
;
360 if (TYPE_CODE (ftype
) == TYPE_CODE_PTR
)
361 ftype
= check_typedef (TYPE_TARGET_TYPE (ftype
));
363 if (!target_has_execution
)
366 if (!gdbarch_push_dummy_call_p (current_gdbarch
))
367 error (_("This target does not support function calls"));
369 /* Create a cleanup chain that contains the retbuf (buffer
370 containing the register values). This chain is create BEFORE the
371 inf_status chain so that the inferior status can cleaned up
372 (restored or discarded) without having the retbuf freed. */
373 retbuf
= regcache_xmalloc (current_gdbarch
);
374 retbuf_cleanup
= make_cleanup_regcache_xfree (retbuf
);
376 /* A cleanup for the inferior status. Create this AFTER the retbuf
377 so that this can be discarded or applied without interfering with
379 inf_status
= save_inferior_status (1);
380 inf_status_cleanup
= make_cleanup_restore_inferior_status (inf_status
);
382 /* Save the caller's registers so that they can be restored once the
383 callee returns. To allow nested calls the registers are (further
384 down) pushed onto a dummy frame stack. Include a cleanup (which
385 is tossed once the regcache has been pushed). */
386 caller_regcache
= frame_save_as_regcache (get_current_frame ());
387 caller_regcache_cleanup
= make_cleanup_regcache_xfree (caller_regcache
);
389 /* Ensure that the initial SP is correctly aligned. */
391 CORE_ADDR old_sp
= get_frame_sp (get_current_frame ());
392 if (gdbarch_frame_align_p (current_gdbarch
))
394 sp
= gdbarch_frame_align (current_gdbarch
, old_sp
);
395 /* NOTE: cagney/2003-08-13: Skip the "red zone". For some
396 ABIs, a function can use memory beyond the inner most stack
397 address. AMD64 called that region the "red zone". Skip at
398 least the "red zone" size before allocating any space on
400 if (gdbarch_inner_than (current_gdbarch
, 1, 2))
401 sp
-= gdbarch_frame_red_zone_size (current_gdbarch
);
403 sp
+= gdbarch_frame_red_zone_size (current_gdbarch
);
405 gdb_assert (sp
== gdbarch_frame_align (current_gdbarch
, sp
));
406 /* NOTE: cagney/2002-09-18:
408 On a RISC architecture, a void parameterless generic dummy
409 frame (i.e., no parameters, no result) typically does not
410 need to push anything the stack and hence can leave SP and
411 FP. Similarly, a frameless (possibly leaf) function does
412 not push anything on the stack and, hence, that too can
413 leave FP and SP unchanged. As a consequence, a sequence of
414 void parameterless generic dummy frame calls to frameless
415 functions will create a sequence of effectively identical
416 frames (SP, FP and TOS and PC the same). This, not
417 suprisingly, results in what appears to be a stack in an
418 infinite loop --- when GDB tries to find a generic dummy
419 frame on the internal dummy frame stack, it will always
422 To avoid this problem, the code below always grows the
423 stack. That way, two dummy frames can never be identical.
424 It does burn a few bytes of stack but that is a small price
428 if (gdbarch_inner_than (current_gdbarch
, 1, 2))
429 /* Stack grows down. */
430 sp
= gdbarch_frame_align (current_gdbarch
, old_sp
- 1);
432 /* Stack grows up. */
433 sp
= gdbarch_frame_align (current_gdbarch
, old_sp
+ 1);
435 gdb_assert ((gdbarch_inner_than (current_gdbarch
, 1, 2)
437 || (gdbarch_inner_than (current_gdbarch
, 2, 1)
441 /* FIXME: cagney/2002-09-18: Hey, you loose!
443 Who knows how badly aligned the SP is!
445 If the generic dummy frame ends up empty (because nothing is
446 pushed) GDB won't be able to correctly perform back traces.
447 If a target is having trouble with backtraces, first thing to
448 do is add FRAME_ALIGN() to the architecture vector. If that
449 fails, try unwind_dummy_id().
451 If the ABI specifies a "Red Zone" (see the doco) the code
452 below will quietly trash it. */
456 funaddr
= find_function_addr (function
, &values_type
);
457 CHECK_TYPEDEF (values_type
);
460 struct block
*b
= block_for_pc (funaddr
);
461 /* If compiled without -g, assume GCC 2. */
462 using_gcc
= (b
== NULL
? 2 : BLOCK_GCC_COMPILED (b
));
465 /* Are we returning a value using a structure return or a normal
468 struct_return
= using_struct_return (values_type
, using_gcc
);
470 /* Determine the location of the breakpoint (and possibly other
471 stuff) that the called function will return to. The SPARC, for a
472 function returning a structure or union, needs to make space for
473 not just the breakpoint but also an extra word containing the
474 size (?) of the structure being passed. */
476 /* The actual breakpoint (at BP_ADDR) is inserted separatly so there
477 is no need to write that out. */
479 switch (gdbarch_call_dummy_location (current_gdbarch
))
482 /* "dummy_addr" is here just to keep old targets happy. New
483 targets return that same information via "sp" and "bp_addr". */
484 if (gdbarch_inner_than (current_gdbarch
, 1, 2))
486 sp
= push_dummy_code (current_gdbarch
, sp
, funaddr
,
487 using_gcc
, args
, nargs
, values_type
,
488 &real_pc
, &bp_addr
, get_current_regcache ());
494 sp
= push_dummy_code (current_gdbarch
, sp
, funaddr
,
495 using_gcc
, args
, nargs
, values_type
,
496 &real_pc
, &bp_addr
, get_current_regcache ());
501 dummy_addr
= entry_point_address ();
502 /* Make certain that the address points at real code, and not a
503 function descriptor. */
504 dummy_addr
= gdbarch_convert_from_func_ptr_addr (current_gdbarch
,
507 /* A call dummy always consists of just a single breakpoint, so
508 it's address is the same as the address of the dummy. */
509 bp_addr
= dummy_addr
;
512 /* Some executables define a symbol __CALL_DUMMY_ADDRESS whose
513 address is the location where the breakpoint should be
514 placed. Once all targets are using the overhauled frame code
515 this can be deleted - ON_STACK is a better option. */
517 struct minimal_symbol
*sym
;
519 sym
= lookup_minimal_symbol ("__CALL_DUMMY_ADDRESS", NULL
, NULL
);
522 dummy_addr
= SYMBOL_VALUE_ADDRESS (sym
);
524 dummy_addr
= entry_point_address ();
525 /* Make certain that the address points at real code, and not
526 a function descriptor. */
527 dummy_addr
= gdbarch_convert_from_func_ptr_addr (current_gdbarch
,
530 /* A call dummy always consists of just a single breakpoint,
531 so it's address is the same as the address of the dummy. */
532 bp_addr
= dummy_addr
;
536 internal_error (__FILE__
, __LINE__
, _("bad switch"));
539 if (nargs
< TYPE_NFIELDS (ftype
))
540 error (_("too few arguments in function call"));
544 for (i
= nargs
- 1; i
>= 0; i
--)
547 struct type
*param_type
;
549 /* FIXME drow/2002-05-31: Should just always mark methods as
550 prototyped. Can we respect TYPE_VARARGS? Probably not. */
551 if (TYPE_CODE (ftype
) == TYPE_CODE_METHOD
)
553 else if (i
< TYPE_NFIELDS (ftype
))
554 prototyped
= TYPE_PROTOTYPED (ftype
);
558 if (i
< TYPE_NFIELDS (ftype
))
559 param_type
= TYPE_FIELD_TYPE (ftype
, i
);
563 args
[i
] = value_arg_coerce (args
[i
], param_type
, prototyped
);
565 /* elz: this code is to handle the case in which the function
566 to be called has a pointer to function as parameter and the
567 corresponding actual argument is the address of a function
568 and not a pointer to function variable. In aCC compiled
569 code, the calls through pointers to functions (in the body
570 of the function called by hand) are made via
571 $$dyncall_external which requires some registers setting,
572 this is taken care of if we call via a function pointer
573 variable, but not via a function address. In cc this is
578 if (param_type
!= NULL
&& TYPE_CODE (ftype
) != TYPE_CODE_METHOD
)
580 /* if this parameter is a pointer to function. */
581 if (TYPE_CODE (param_type
) == TYPE_CODE_PTR
)
582 if (TYPE_CODE (TYPE_TARGET_TYPE (param_type
)) == TYPE_CODE_FUNC
)
583 /* elz: FIXME here should go the test about the
584 compiler used to compile the target. We want to
585 issue the error message only if the compiler
586 used was HP's aCC. If we used HP's cc, then
587 there is no problem and no need to return at
589 /* Go see if the actual parameter is a variable of
590 type pointer to function or just a function. */
591 if (VALUE_LVAL (args
[i
]) == not_lval
)
594 /* NOTE: cagney/2005-01-02: THIS IS BOGUS. */
595 if (find_pc_partial_function ((CORE_ADDR
) value_contents (args
[i
])[0], &arg_name
, NULL
, NULL
))
597 You cannot use function <%s> as argument. \n\
598 You must use a pointer to function type variable. Command ignored."), arg_name
);
605 if (gdbarch_deprecated_reg_struct_has_addr_p (current_gdbarch
))
608 /* This is a machine like the sparc, where we may need to pass a
609 pointer to the structure, not the structure itself. */
610 for (i
= nargs
- 1; i
>= 0; i
--)
612 struct type
*arg_type
= check_typedef (value_type (args
[i
]));
613 if ((TYPE_CODE (arg_type
) == TYPE_CODE_STRUCT
614 || TYPE_CODE (arg_type
) == TYPE_CODE_UNION
615 || TYPE_CODE (arg_type
) == TYPE_CODE_ARRAY
616 || TYPE_CODE (arg_type
) == TYPE_CODE_STRING
617 || TYPE_CODE (arg_type
) == TYPE_CODE_BITSTRING
618 || TYPE_CODE (arg_type
) == TYPE_CODE_SET
619 || (TYPE_CODE (arg_type
) == TYPE_CODE_FLT
620 && TYPE_LENGTH (arg_type
) > 8)
622 && gdbarch_deprecated_reg_struct_has_addr
623 (current_gdbarch
, using_gcc
, arg_type
))
626 int len
; /* = TYPE_LENGTH (arg_type); */
628 arg_type
= check_typedef (value_enclosing_type (args
[i
]));
629 len
= TYPE_LENGTH (arg_type
);
632 if (gdbarch_inner_than (current_gdbarch
, 1, 2))
634 /* stack grows downward */
636 /* ... so the address of the thing we push is the
637 stack pointer after we push it. */
642 /* The stack grows up, so the address of the thing
643 we push is the stack pointer before we push it. */
647 /* Push the structure. */
648 write_memory (addr
, value_contents_all (args
[i
]), len
);
649 /* The value we're going to pass is the address of the
650 thing we just pushed. */
651 /*args[i] = value_from_longest (lookup_pointer_type (values_type),
653 args
[i
] = value_from_pointer (lookup_pointer_type (arg_type
),
660 /* Reserve space for the return structure to be written on the
661 stack, if necessary. Make certain that the value is correctly
666 int len
= TYPE_LENGTH (values_type
);
667 if (gdbarch_inner_than (current_gdbarch
, 1, 2))
669 /* Stack grows downward. Align STRUCT_ADDR and SP after
670 making space for the return value. */
672 if (gdbarch_frame_align_p (current_gdbarch
))
673 sp
= gdbarch_frame_align (current_gdbarch
, sp
);
678 /* Stack grows upward. Align the frame, allocate space, and
679 then again, re-align the frame??? */
680 if (gdbarch_frame_align_p (current_gdbarch
))
681 sp
= gdbarch_frame_align (current_gdbarch
, sp
);
684 if (gdbarch_frame_align_p (current_gdbarch
))
685 sp
= gdbarch_frame_align (current_gdbarch
, sp
);
689 /* Create the dummy stack frame. Pass in the call dummy address as,
690 presumably, the ABI code knows where, in the call dummy, the
691 return address should be pointed. */
692 sp
= gdbarch_push_dummy_call (current_gdbarch
, function
,
693 get_current_regcache (), bp_addr
, nargs
, args
,
694 sp
, struct_return
, struct_addr
);
696 /* Set up a frame ID for the dummy frame so we can pass it to
697 set_momentary_breakpoint. We need to give the breakpoint a frame
698 ID so that the breakpoint code can correctly re-identify the
700 /* Sanity. The exact same SP value is returned by PUSH_DUMMY_CALL,
701 saved as the dummy-frame TOS, and used by unwind_dummy_id to form
702 the frame ID's stack address. */
703 dummy_id
= frame_id_build (sp
, bp_addr
);
705 /* Create a momentary breakpoint at the return address of the
706 inferior. That way it breaks when it returns. */
709 struct breakpoint
*bpt
;
710 struct symtab_and_line sal
;
711 init_sal (&sal
); /* initialize to zeroes */
713 sal
.section
= find_pc_overlay (sal
.pc
);
714 /* Sanity. The exact same SP value is returned by
715 PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by
716 unwind_dummy_id to form the frame ID's stack address. */
717 bpt
= set_momentary_breakpoint (sal
, dummy_id
, bp_call_dummy
);
718 bpt
->disposition
= disp_del
;
721 /* Everything's ready, push all the info needed to restore the
722 caller (and identify the dummy-frame) onto the dummy-frame
724 dummy_frame_push (caller_regcache
, &dummy_id
);
725 discard_cleanups (caller_regcache_cleanup
);
727 /* - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP -
728 If you're looking to implement asynchronous dummy-frames, then
729 just below is the place to chop this function in two.. */
731 /* Now proceed, having reached the desired place. */
732 clear_proceed_status ();
734 /* Execute a "stack dummy", a piece of code stored in the stack by
735 the debugger to be executed in the inferior.
737 The dummy's frame is automatically popped whenever that break is
738 hit. If that is the first time the program stops,
739 call_function_by_hand returns to its caller with that frame
740 already gone and sets RC to 0.
742 Otherwise, set RC to a non-zero value. If the called function
743 receives a random signal, we do not allow the user to continue
744 executing it as this may not work. The dummy frame is poped and
745 we return 1. If we hit a breakpoint, we leave the frame in place
746 and return 2 (the frame will eventually be popped when we do hit
747 the dummy end breakpoint). */
750 struct cleanup
*old_cleanups
= make_cleanup (null_cleanup
, 0);
753 /* If all error()s out of proceed ended up calling normal_stop
754 (and perhaps they should; it already does in the special case
755 of error out of resume()), then we wouldn't need this. */
756 make_cleanup (breakpoint_auto_delete_contents
, &stop_bpstat
);
758 disable_watchpoints_before_interactive_call_start ();
759 proceed_to_finish
= 1; /* We want stop_registers, please... */
761 if (target_can_async_p ())
762 saved_async
= target_async_mask (0);
764 proceed (real_pc
, TARGET_SIGNAL_0
, 0);
767 target_async_mask (saved_async
);
769 enable_watchpoints_after_interactive_call_stop ();
771 discard_cleanups (old_cleanups
);
774 if (stopped_by_random_signal
|| !stop_stack_dummy
)
776 /* Find the name of the function we're about to complain about. */
777 const char *name
= NULL
;
779 struct symbol
*symbol
= find_pc_function (funaddr
);
781 name
= SYMBOL_PRINT_NAME (symbol
);
784 /* Try the minimal symbols. */
785 struct minimal_symbol
*msymbol
= lookup_minimal_symbol_by_pc (funaddr
);
787 name
= SYMBOL_PRINT_NAME (msymbol
);
791 /* Can't use a cleanup here. It is discarded, instead use
793 char *tmp
= xstrprintf ("at %s", hex_string (funaddr
));
794 char *a
= alloca (strlen (tmp
) + 1);
800 if (stopped_by_random_signal
)
802 /* We stopped inside the FUNCTION because of a random
803 signal. Further execution of the FUNCTION is not
806 if (unwind_on_signal_p
)
808 /* The user wants the context restored. */
810 /* We must get back to the frame we were before the
812 frame_pop (get_current_frame ());
814 /* FIXME: Insert a bunch of wrap_here; name can be very
815 long if it's a C++ name with arguments and stuff. */
817 The program being debugged was signaled while in a function called from GDB.\n\
818 GDB has restored the context to what it was before the call.\n\
819 To change this behavior use \"set unwindonsignal off\"\n\
820 Evaluation of the expression containing the function (%s) will be abandoned."),
825 /* The user wants to stay in the frame where we stopped
827 /* If we restored the inferior status (via the cleanup),
828 we would print a spurious error message (Unable to
829 restore previously selected frame), would write the
830 registers from the inf_status (which is wrong), and
831 would do other wrong things. */
832 discard_cleanups (inf_status_cleanup
);
833 discard_inferior_status (inf_status
);
834 /* FIXME: Insert a bunch of wrap_here; name can be very
835 long if it's a C++ name with arguments and stuff. */
837 The program being debugged was signaled while in a function called from GDB.\n\
838 GDB remains in the frame where the signal was received.\n\
839 To change this behavior use \"set unwindonsignal on\"\n\
840 Evaluation of the expression containing the function (%s) will be abandoned."),
845 if (!stop_stack_dummy
)
847 /* We hit a breakpoint inside the FUNCTION. */
848 /* If we restored the inferior status (via the cleanup), we
849 would print a spurious error message (Unable to restore
850 previously selected frame), would write the registers
851 from the inf_status (which is wrong), and would do other
853 discard_cleanups (inf_status_cleanup
);
854 discard_inferior_status (inf_status
);
855 /* The following error message used to say "The expression
856 which contained the function call has been discarded."
857 It is a hard concept to explain in a few words. Ideally,
858 GDB would be able to resume evaluation of the expression
859 when the function finally is done executing. Perhaps
860 someday this will be implemented (it would not be easy). */
861 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
862 a C++ name with arguments and stuff. */
864 The program being debugged stopped while in a function called from GDB.\n\
865 When the function (%s) is done executing, GDB will silently\n\
866 stop (instead of continuing to evaluate the expression containing\n\
867 the function call)."), name
);
870 /* The above code errors out, so ... */
871 internal_error (__FILE__
, __LINE__
, _("... should not be here"));
874 /* If we get here the called FUNCTION run to completion. */
876 /* On normal return, the stack dummy has been popped already. */
877 regcache_cpy_no_passthrough (retbuf
, stop_registers
);
879 /* Restore the inferior status, via its cleanup. At this stage,
880 leave the RETBUF alone. */
881 do_cleanups (inf_status_cleanup
);
883 /* Figure out the value returned by the function. */
885 struct value
*retval
= NULL
;
887 if (TYPE_CODE (values_type
) == TYPE_CODE_VOID
)
889 /* If the function returns void, don't bother fetching the
891 retval
= allocate_value (values_type
);
895 struct gdbarch
*arch
= current_gdbarch
;
897 switch (gdbarch_return_value (arch
, values_type
, NULL
, NULL
, NULL
))
899 case RETURN_VALUE_REGISTER_CONVENTION
:
900 case RETURN_VALUE_ABI_RETURNS_ADDRESS
:
901 case RETURN_VALUE_ABI_PRESERVES_ADDRESS
:
902 retval
= allocate_value (values_type
);
903 gdbarch_return_value (current_gdbarch
, values_type
, retbuf
,
904 value_contents_raw (retval
), NULL
);
906 case RETURN_VALUE_STRUCT_CONVENTION
:
907 retval
= value_at (values_type
, struct_addr
);
912 do_cleanups (retbuf_cleanup
);
920 /* Provide a prototype to silence -Wmissing-prototypes. */
921 void _initialize_infcall (void);
924 _initialize_infcall (void)
926 add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure
,
927 &coerce_float_to_double_p
, _("\
928 Set coercion of floats to doubles when calling functions."), _("\
929 Show coercion of floats to doubles when calling functions"), _("\
930 Variables of type float should generally be converted to doubles before\n\
931 calling an unprototyped function, and left alone when calling a prototyped\n\
932 function. However, some older debug info formats do not provide enough\n\
933 information to determine that a function is prototyped. If this flag is\n\
934 set, GDB will perform the conversion for a function it considers\n\
936 The default is to perform the conversion.\n"),
938 show_coerce_float_to_double_p
,
939 &setlist
, &showlist
);
941 add_setshow_boolean_cmd ("unwindonsignal", no_class
,
942 &unwind_on_signal_p
, _("\
943 Set unwinding of stack if a signal is received while in a call dummy."), _("\
944 Show unwinding of stack if a signal is received while in a call dummy."), _("\
945 The unwindonsignal lets the user determine what gdb should do if a signal\n\
946 is received while in a function called from gdb (call dummy). If set, gdb\n\
947 unwinds the stack and restore the context to what as it was before the call.\n\
948 The default is to stop in the frame where the signal was received."),
950 show_unwind_on_signal_p
,
951 &setlist
, &showlist
);