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
));
225 /* Handle integer used as address of a function. */
226 funaddr
= (CORE_ADDR
) value_as_long (function
);
228 value_type
= builtin_type_int
;
231 error (_("Invalid data type for function to be called."));
233 if (retval_type
!= NULL
)
234 *retval_type
= value_type
;
235 return funaddr
+ gdbarch_deprecated_function_start_offset (current_gdbarch
);
238 /* Call breakpoint_auto_delete on the current contents of the bpstat
239 pointed to by arg (which is really a bpstat *). */
242 breakpoint_auto_delete_contents (void *arg
)
244 breakpoint_auto_delete (*(bpstat
*) arg
);
248 generic_push_dummy_code (struct gdbarch
*gdbarch
,
249 CORE_ADDR sp
, CORE_ADDR funaddr
, int using_gcc
,
250 struct value
**args
, int nargs
,
251 struct type
*value_type
,
252 CORE_ADDR
*real_pc
, CORE_ADDR
*bp_addr
,
253 struct regcache
*regcache
)
255 /* Something here to findout the size of a breakpoint and then
256 allocate space for it on the stack. */
258 /* This code assumes frame align. */
259 gdb_assert (gdbarch_frame_align_p (gdbarch
));
260 /* Force the stack's alignment. The intent is to ensure that the SP
261 is aligned to at least a breakpoint instruction's boundary. */
262 sp
= gdbarch_frame_align (gdbarch
, sp
);
263 /* Allocate space for, and then position the breakpoint on the
265 if (gdbarch_inner_than (gdbarch
, 1, 2))
268 gdbarch_breakpoint_from_pc (gdbarch
, &bppc
, &bplen
);
269 sp
= gdbarch_frame_align (gdbarch
, sp
- bplen
);
271 /* Should the breakpoint size/location be re-computed here? */
276 gdbarch_breakpoint_from_pc (gdbarch
, bp_addr
, &bplen
);
277 sp
= gdbarch_frame_align (gdbarch
, sp
+ bplen
);
279 /* Inferior resumes at the function entry point. */
280 (*real_pc
) = funaddr
;
284 /* For CALL_DUMMY_ON_STACK, push a breakpoint sequence that the called
285 function returns to. */
288 push_dummy_code (struct gdbarch
*gdbarch
,
289 CORE_ADDR sp
, CORE_ADDR funaddr
, int using_gcc
,
290 struct value
**args
, int nargs
,
291 struct type
*value_type
,
292 CORE_ADDR
*real_pc
, CORE_ADDR
*bp_addr
,
293 struct regcache
*regcache
)
295 if (gdbarch_push_dummy_code_p (gdbarch
))
296 return gdbarch_push_dummy_code (gdbarch
, sp
, funaddr
, using_gcc
,
297 args
, nargs
, value_type
, real_pc
, bp_addr
,
300 return generic_push_dummy_code (gdbarch
, sp
, funaddr
, using_gcc
,
301 args
, nargs
, value_type
, real_pc
, bp_addr
,
305 /* All this stuff with a dummy frame may seem unnecessarily complicated
306 (why not just save registers in GDB?). The purpose of pushing a dummy
307 frame which looks just like a real frame is so that if you call a
308 function and then hit a breakpoint (get a signal, etc), "backtrace"
309 will look right. Whether the backtrace needs to actually show the
310 stack at the time the inferior function was called is debatable, but
311 it certainly needs to not display garbage. So if you are contemplating
312 making dummy frames be different from normal frames, consider that. */
314 /* Perform a function call in the inferior.
315 ARGS is a vector of values of arguments (NARGS of them).
316 FUNCTION is a value, the function to be called.
317 Returns a value representing what the function returned.
318 May fail to return, if a breakpoint or signal is hit
319 during the execution of the function.
321 ARGS is modified to contain coerced values. */
324 call_function_by_hand (struct value
*function
, int nargs
, struct value
**args
)
327 CORE_ADDR dummy_addr
;
328 struct type
*values_type
;
329 unsigned char struct_return
;
330 CORE_ADDR struct_addr
= 0;
331 struct regcache
*retbuf
;
332 struct cleanup
*retbuf_cleanup
;
333 struct inferior_status
*inf_status
;
334 struct cleanup
*inf_status_cleanup
;
336 int using_gcc
; /* Set to version of gcc in use, or zero if not gcc */
338 struct type
*ftype
= check_typedef (value_type (function
));
340 struct regcache
*caller_regcache
;
341 struct cleanup
*caller_regcache_cleanup
;
342 struct frame_id dummy_id
;
344 if (TYPE_CODE (ftype
) == TYPE_CODE_PTR
)
345 ftype
= check_typedef (TYPE_TARGET_TYPE (ftype
));
347 if (!target_has_execution
)
350 if (!gdbarch_push_dummy_call_p (current_gdbarch
))
351 error (_("This target does not support function calls"));
353 /* Create a cleanup chain that contains the retbuf (buffer
354 containing the register values). This chain is create BEFORE the
355 inf_status chain so that the inferior status can cleaned up
356 (restored or discarded) without having the retbuf freed. */
357 retbuf
= regcache_xmalloc (current_gdbarch
);
358 retbuf_cleanup
= make_cleanup_regcache_xfree (retbuf
);
360 /* A cleanup for the inferior status. Create this AFTER the retbuf
361 so that this can be discarded or applied without interfering with
363 inf_status
= save_inferior_status (1);
364 inf_status_cleanup
= make_cleanup_restore_inferior_status (inf_status
);
366 /* Save the caller's registers so that they can be restored once the
367 callee returns. To allow nested calls the registers are (further
368 down) pushed onto a dummy frame stack. Include a cleanup (which
369 is tossed once the regcache has been pushed). */
370 caller_regcache
= frame_save_as_regcache (get_current_frame ());
371 caller_regcache_cleanup
= make_cleanup_regcache_xfree (caller_regcache
);
373 /* Ensure that the initial SP is correctly aligned. */
375 CORE_ADDR old_sp
= get_frame_sp (get_current_frame ());
376 if (gdbarch_frame_align_p (current_gdbarch
))
378 sp
= gdbarch_frame_align (current_gdbarch
, old_sp
);
379 /* NOTE: cagney/2003-08-13: Skip the "red zone". For some
380 ABIs, a function can use memory beyond the inner most stack
381 address. AMD64 called that region the "red zone". Skip at
382 least the "red zone" size before allocating any space on
384 if (gdbarch_inner_than (current_gdbarch
, 1, 2))
385 sp
-= gdbarch_frame_red_zone_size (current_gdbarch
);
387 sp
+= gdbarch_frame_red_zone_size (current_gdbarch
);
389 gdb_assert (sp
== gdbarch_frame_align (current_gdbarch
, sp
));
390 /* NOTE: cagney/2002-09-18:
392 On a RISC architecture, a void parameterless generic dummy
393 frame (i.e., no parameters, no result) typically does not
394 need to push anything the stack and hence can leave SP and
395 FP. Similarly, a frameless (possibly leaf) function does
396 not push anything on the stack and, hence, that too can
397 leave FP and SP unchanged. As a consequence, a sequence of
398 void parameterless generic dummy frame calls to frameless
399 functions will create a sequence of effectively identical
400 frames (SP, FP and TOS and PC the same). This, not
401 suprisingly, results in what appears to be a stack in an
402 infinite loop --- when GDB tries to find a generic dummy
403 frame on the internal dummy frame stack, it will always
406 To avoid this problem, the code below always grows the
407 stack. That way, two dummy frames can never be identical.
408 It does burn a few bytes of stack but that is a small price
412 if (gdbarch_inner_than (current_gdbarch
, 1, 2))
413 /* Stack grows down. */
414 sp
= gdbarch_frame_align (current_gdbarch
, old_sp
- 1);
416 /* Stack grows up. */
417 sp
= gdbarch_frame_align (current_gdbarch
, old_sp
+ 1);
419 gdb_assert ((gdbarch_inner_than (current_gdbarch
, 1, 2)
421 || (gdbarch_inner_than (current_gdbarch
, 2, 1)
425 /* FIXME: cagney/2002-09-18: Hey, you loose!
427 Who knows how badly aligned the SP is!
429 If the generic dummy frame ends up empty (because nothing is
430 pushed) GDB won't be able to correctly perform back traces.
431 If a target is having trouble with backtraces, first thing to
432 do is add FRAME_ALIGN() to the architecture vector. If that
433 fails, try unwind_dummy_id().
435 If the ABI specifies a "Red Zone" (see the doco) the code
436 below will quietly trash it. */
440 funaddr
= find_function_addr (function
, &values_type
);
441 CHECK_TYPEDEF (values_type
);
444 struct block
*b
= block_for_pc (funaddr
);
445 /* If compiled without -g, assume GCC 2. */
446 using_gcc
= (b
== NULL
? 2 : BLOCK_GCC_COMPILED (b
));
449 /* Are we returning a value using a structure return or a normal
452 struct_return
= using_struct_return (values_type
, using_gcc
);
454 /* Determine the location of the breakpoint (and possibly other
455 stuff) that the called function will return to. The SPARC, for a
456 function returning a structure or union, needs to make space for
457 not just the breakpoint but also an extra word containing the
458 size (?) of the structure being passed. */
460 /* The actual breakpoint (at BP_ADDR) is inserted separatly so there
461 is no need to write that out. */
463 switch (gdbarch_call_dummy_location (current_gdbarch
))
466 /* "dummy_addr" is here just to keep old targets happy. New
467 targets return that same information via "sp" and "bp_addr". */
468 if (gdbarch_inner_than (current_gdbarch
, 1, 2))
470 sp
= push_dummy_code (current_gdbarch
, sp
, funaddr
,
471 using_gcc
, args
, nargs
, values_type
,
472 &real_pc
, &bp_addr
, get_current_regcache ());
478 sp
= push_dummy_code (current_gdbarch
, sp
, funaddr
,
479 using_gcc
, args
, nargs
, values_type
,
480 &real_pc
, &bp_addr
, get_current_regcache ());
485 dummy_addr
= entry_point_address ();
486 /* Make certain that the address points at real code, and not a
487 function descriptor. */
488 dummy_addr
= gdbarch_convert_from_func_ptr_addr (current_gdbarch
,
491 /* A call dummy always consists of just a single breakpoint, so
492 it's address is the same as the address of the dummy. */
493 bp_addr
= dummy_addr
;
496 /* Some executables define a symbol __CALL_DUMMY_ADDRESS whose
497 address is the location where the breakpoint should be
498 placed. Once all targets are using the overhauled frame code
499 this can be deleted - ON_STACK is a better option. */
501 struct minimal_symbol
*sym
;
503 sym
= lookup_minimal_symbol ("__CALL_DUMMY_ADDRESS", NULL
, NULL
);
506 dummy_addr
= SYMBOL_VALUE_ADDRESS (sym
);
508 dummy_addr
= entry_point_address ();
509 /* Make certain that the address points at real code, and not
510 a function descriptor. */
511 dummy_addr
= gdbarch_convert_from_func_ptr_addr (current_gdbarch
,
514 /* A call dummy always consists of just a single breakpoint,
515 so it's address is the same as the address of the dummy. */
516 bp_addr
= dummy_addr
;
520 internal_error (__FILE__
, __LINE__
, _("bad switch"));
523 if (nargs
< TYPE_NFIELDS (ftype
))
524 error (_("too few arguments in function call"));
528 for (i
= nargs
- 1; i
>= 0; i
--)
531 struct type
*param_type
;
533 /* FIXME drow/2002-05-31: Should just always mark methods as
534 prototyped. Can we respect TYPE_VARARGS? Probably not. */
535 if (TYPE_CODE (ftype
) == TYPE_CODE_METHOD
)
537 else if (i
< TYPE_NFIELDS (ftype
))
538 prototyped
= TYPE_PROTOTYPED (ftype
);
542 if (i
< TYPE_NFIELDS (ftype
))
543 param_type
= TYPE_FIELD_TYPE (ftype
, i
);
547 args
[i
] = value_arg_coerce (args
[i
], param_type
, prototyped
);
549 /* elz: this code is to handle the case in which the function
550 to be called has a pointer to function as parameter and the
551 corresponding actual argument is the address of a function
552 and not a pointer to function variable. In aCC compiled
553 code, the calls through pointers to functions (in the body
554 of the function called by hand) are made via
555 $$dyncall_external which requires some registers setting,
556 this is taken care of if we call via a function pointer
557 variable, but not via a function address. In cc this is
562 if (param_type
!= NULL
&& TYPE_CODE (ftype
) != TYPE_CODE_METHOD
)
564 /* if this parameter is a pointer to function. */
565 if (TYPE_CODE (param_type
) == TYPE_CODE_PTR
)
566 if (TYPE_CODE (TYPE_TARGET_TYPE (param_type
)) == TYPE_CODE_FUNC
)
567 /* elz: FIXME here should go the test about the
568 compiler used to compile the target. We want to
569 issue the error message only if the compiler
570 used was HP's aCC. If we used HP's cc, then
571 there is no problem and no need to return at
573 /* Go see if the actual parameter is a variable of
574 type pointer to function or just a function. */
575 if (VALUE_LVAL (args
[i
]) == not_lval
)
578 /* NOTE: cagney/2005-01-02: THIS IS BOGUS. */
579 if (find_pc_partial_function ((CORE_ADDR
) value_contents (args
[i
])[0], &arg_name
, NULL
, NULL
))
581 You cannot use function <%s> as argument. \n\
582 You must use a pointer to function type variable. Command ignored."), arg_name
);
589 if (gdbarch_deprecated_reg_struct_has_addr_p (current_gdbarch
))
592 /* This is a machine like the sparc, where we may need to pass a
593 pointer to the structure, not the structure itself. */
594 for (i
= nargs
- 1; i
>= 0; i
--)
596 struct type
*arg_type
= check_typedef (value_type (args
[i
]));
597 if ((TYPE_CODE (arg_type
) == TYPE_CODE_STRUCT
598 || TYPE_CODE (arg_type
) == TYPE_CODE_UNION
599 || TYPE_CODE (arg_type
) == TYPE_CODE_ARRAY
600 || TYPE_CODE (arg_type
) == TYPE_CODE_STRING
601 || TYPE_CODE (arg_type
) == TYPE_CODE_BITSTRING
602 || TYPE_CODE (arg_type
) == TYPE_CODE_SET
603 || (TYPE_CODE (arg_type
) == TYPE_CODE_FLT
604 && TYPE_LENGTH (arg_type
) > 8)
606 && gdbarch_deprecated_reg_struct_has_addr
607 (current_gdbarch
, using_gcc
, arg_type
))
610 int len
; /* = TYPE_LENGTH (arg_type); */
612 arg_type
= check_typedef (value_enclosing_type (args
[i
]));
613 len
= TYPE_LENGTH (arg_type
);
616 if (gdbarch_inner_than (current_gdbarch
, 1, 2))
618 /* stack grows downward */
620 /* ... so the address of the thing we push is the
621 stack pointer after we push it. */
626 /* The stack grows up, so the address of the thing
627 we push is the stack pointer before we push it. */
631 /* Push the structure. */
632 write_memory (addr
, value_contents_all (args
[i
]), len
);
633 /* The value we're going to pass is the address of the
634 thing we just pushed. */
635 /*args[i] = value_from_longest (lookup_pointer_type (values_type),
637 args
[i
] = value_from_pointer (lookup_pointer_type (arg_type
),
644 /* Reserve space for the return structure to be written on the
645 stack, if necessary. Make certain that the value is correctly
650 int len
= TYPE_LENGTH (values_type
);
651 if (gdbarch_inner_than (current_gdbarch
, 1, 2))
653 /* Stack grows downward. Align STRUCT_ADDR and SP after
654 making space for the return value. */
656 if (gdbarch_frame_align_p (current_gdbarch
))
657 sp
= gdbarch_frame_align (current_gdbarch
, sp
);
662 /* Stack grows upward. Align the frame, allocate space, and
663 then again, re-align the frame??? */
664 if (gdbarch_frame_align_p (current_gdbarch
))
665 sp
= gdbarch_frame_align (current_gdbarch
, sp
);
668 if (gdbarch_frame_align_p (current_gdbarch
))
669 sp
= gdbarch_frame_align (current_gdbarch
, sp
);
673 /* Create the dummy stack frame. Pass in the call dummy address as,
674 presumably, the ABI code knows where, in the call dummy, the
675 return address should be pointed. */
676 sp
= gdbarch_push_dummy_call (current_gdbarch
, function
,
677 get_current_regcache (), bp_addr
, nargs
, args
,
678 sp
, struct_return
, struct_addr
);
680 /* Set up a frame ID for the dummy frame so we can pass it to
681 set_momentary_breakpoint. We need to give the breakpoint a frame
682 ID so that the breakpoint code can correctly re-identify the
684 /* Sanity. The exact same SP value is returned by PUSH_DUMMY_CALL,
685 saved as the dummy-frame TOS, and used by unwind_dummy_id to form
686 the frame ID's stack address. */
687 dummy_id
= frame_id_build (sp
, bp_addr
);
689 /* Create a momentary breakpoint at the return address of the
690 inferior. That way it breaks when it returns. */
693 struct breakpoint
*bpt
;
694 struct symtab_and_line sal
;
695 init_sal (&sal
); /* initialize to zeroes */
697 sal
.section
= find_pc_overlay (sal
.pc
);
698 /* Sanity. The exact same SP value is returned by
699 PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by
700 unwind_dummy_id to form the frame ID's stack address. */
701 bpt
= set_momentary_breakpoint (sal
, dummy_id
, bp_call_dummy
);
702 bpt
->disposition
= disp_del
;
705 /* Everything's ready, push all the info needed to restore the
706 caller (and identify the dummy-frame) onto the dummy-frame
708 dummy_frame_push (caller_regcache
, &dummy_id
);
709 discard_cleanups (caller_regcache_cleanup
);
711 /* - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP -
712 If you're looking to implement asynchronous dummy-frames, then
713 just below is the place to chop this function in two.. */
715 /* Now proceed, having reached the desired place. */
716 clear_proceed_status ();
718 /* Execute a "stack dummy", a piece of code stored in the stack by
719 the debugger to be executed in the inferior.
721 The dummy's frame is automatically popped whenever that break is
722 hit. If that is the first time the program stops,
723 call_function_by_hand returns to its caller with that frame
724 already gone and sets RC to 0.
726 Otherwise, set RC to a non-zero value. If the called function
727 receives a random signal, we do not allow the user to continue
728 executing it as this may not work. The dummy frame is poped and
729 we return 1. If we hit a breakpoint, we leave the frame in place
730 and return 2 (the frame will eventually be popped when we do hit
731 the dummy end breakpoint). */
734 struct cleanup
*old_cleanups
= make_cleanup (null_cleanup
, 0);
737 /* If all error()s out of proceed ended up calling normal_stop
738 (and perhaps they should; it already does in the special case
739 of error out of resume()), then we wouldn't need this. */
740 make_cleanup (breakpoint_auto_delete_contents
, &stop_bpstat
);
742 disable_watchpoints_before_interactive_call_start ();
743 proceed_to_finish
= 1; /* We want stop_registers, please... */
745 if (target_can_async_p ())
746 saved_async
= target_async_mask (0);
748 proceed (real_pc
, TARGET_SIGNAL_0
, 0);
751 target_async_mask (saved_async
);
753 enable_watchpoints_after_interactive_call_stop ();
755 discard_cleanups (old_cleanups
);
758 if (stopped_by_random_signal
|| !stop_stack_dummy
)
760 /* Find the name of the function we're about to complain about. */
761 const char *name
= NULL
;
763 struct symbol
*symbol
= find_pc_function (funaddr
);
765 name
= SYMBOL_PRINT_NAME (symbol
);
768 /* Try the minimal symbols. */
769 struct minimal_symbol
*msymbol
= lookup_minimal_symbol_by_pc (funaddr
);
771 name
= SYMBOL_PRINT_NAME (msymbol
);
775 /* Can't use a cleanup here. It is discarded, instead use
777 char *tmp
= xstrprintf ("at %s", hex_string (funaddr
));
778 char *a
= alloca (strlen (tmp
) + 1);
784 if (stopped_by_random_signal
)
786 /* We stopped inside the FUNCTION because of a random
787 signal. Further execution of the FUNCTION is not
790 if (unwind_on_signal_p
)
792 /* The user wants the context restored. */
794 /* We must get back to the frame we were before the
796 frame_pop (get_current_frame ());
798 /* FIXME: Insert a bunch of wrap_here; name can be very
799 long if it's a C++ name with arguments and stuff. */
801 The program being debugged was signaled while in a function called from GDB.\n\
802 GDB has restored the context to what it was before the call.\n\
803 To change this behavior use \"set unwindonsignal off\"\n\
804 Evaluation of the expression containing the function (%s) will be abandoned."),
809 /* The user wants to stay in the frame where we stopped
811 /* If we restored the inferior status (via the cleanup),
812 we would print a spurious error message (Unable to
813 restore previously selected frame), would write the
814 registers from the inf_status (which is wrong), and
815 would do other wrong things. */
816 discard_cleanups (inf_status_cleanup
);
817 discard_inferior_status (inf_status
);
818 /* FIXME: Insert a bunch of wrap_here; name can be very
819 long if it's a C++ name with arguments and stuff. */
821 The program being debugged was signaled while in a function called from GDB.\n\
822 GDB remains in the frame where the signal was received.\n\
823 To change this behavior use \"set unwindonsignal on\"\n\
824 Evaluation of the expression containing the function (%s) will be abandoned."),
829 if (!stop_stack_dummy
)
831 /* We hit a breakpoint inside the FUNCTION. */
832 /* If we restored the inferior status (via the cleanup), we
833 would print a spurious error message (Unable to restore
834 previously selected frame), would write the registers
835 from the inf_status (which is wrong), and would do other
837 discard_cleanups (inf_status_cleanup
);
838 discard_inferior_status (inf_status
);
839 /* The following error message used to say "The expression
840 which contained the function call has been discarded."
841 It is a hard concept to explain in a few words. Ideally,
842 GDB would be able to resume evaluation of the expression
843 when the function finally is done executing. Perhaps
844 someday this will be implemented (it would not be easy). */
845 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
846 a C++ name with arguments and stuff. */
848 The program being debugged stopped while in a function called from GDB.\n\
849 When the function (%s) is done executing, GDB will silently\n\
850 stop (instead of continuing to evaluate the expression containing\n\
851 the function call)."), name
);
854 /* The above code errors out, so ... */
855 internal_error (__FILE__
, __LINE__
, _("... should not be here"));
858 /* If we get here the called FUNCTION run to completion. */
860 /* On normal return, the stack dummy has been popped already. */
861 regcache_cpy_no_passthrough (retbuf
, stop_registers
);
863 /* Restore the inferior status, via its cleanup. At this stage,
864 leave the RETBUF alone. */
865 do_cleanups (inf_status_cleanup
);
867 /* Figure out the value returned by the function. */
869 struct value
*retval
= NULL
;
871 if (TYPE_CODE (values_type
) == TYPE_CODE_VOID
)
873 /* If the function returns void, don't bother fetching the
875 retval
= allocate_value (values_type
);
879 struct gdbarch
*arch
= current_gdbarch
;
881 switch (gdbarch_return_value (arch
, values_type
, NULL
, NULL
, NULL
))
883 case RETURN_VALUE_REGISTER_CONVENTION
:
884 case RETURN_VALUE_ABI_RETURNS_ADDRESS
:
885 case RETURN_VALUE_ABI_PRESERVES_ADDRESS
:
886 retval
= allocate_value (values_type
);
887 gdbarch_return_value (current_gdbarch
, values_type
, retbuf
,
888 value_contents_raw (retval
), NULL
);
890 case RETURN_VALUE_STRUCT_CONVENTION
:
891 retval
= value_at (values_type
, struct_addr
);
896 do_cleanups (retbuf_cleanup
);
904 /* Provide a prototype to silence -Wmissing-prototypes. */
905 void _initialize_infcall (void);
908 _initialize_infcall (void)
910 add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure
,
911 &coerce_float_to_double_p
, _("\
912 Set coercion of floats to doubles when calling functions."), _("\
913 Show coercion of floats to doubles when calling functions"), _("\
914 Variables of type float should generally be converted to doubles before\n\
915 calling an unprototyped function, and left alone when calling a prototyped\n\
916 function. However, some older debug info formats do not provide enough\n\
917 information to determine that a function is prototyped. If this flag is\n\
918 set, GDB will perform the conversion for a function it considers\n\
920 The default is to perform the conversion.\n"),
922 show_coerce_float_to_double_p
,
923 &setlist
, &showlist
);
925 add_setshow_boolean_cmd ("unwindonsignal", no_class
,
926 &unwind_on_signal_p
, _("\
927 Set unwinding of stack if a signal is received while in a call dummy."), _("\
928 Show unwinding of stack if a signal is received while in a call dummy."), _("\
929 The unwindonsignal lets the user determine what gdb should do if a signal\n\
930 is received while in a function called from gdb (call dummy). If set, gdb\n\
931 unwinds the stack and restore the context to what as it was before the call.\n\
932 The default is to stop in the frame where the signal was received."),
934 show_unwind_on_signal_p
,
935 &setlist
, &showlist
);