1 /* Perform an inferior function call, for GDB, the GNU debugger.
3 Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
4 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
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., 59 Temple Place - Suite 330,
22 Boston, MA 02111-1307, USA. */
25 #include "breakpoint.h"
29 #include "gdb_assert.h"
36 #include "gdb_string.h"
39 /* NOTE: cagney/2003-04-16: What's the future of this code?
41 GDB needs an asynchronous expression evaluator, that means an
42 asynchronous inferior function call implementation, and that in
43 turn means restructuring the code so that it is event driven. */
45 /* How you should pass arguments to a function depends on whether it
46 was defined in K&R style or prototype style. If you define a
47 function using the K&R syntax that takes a `float' argument, then
48 callers must pass that argument as a `double'. If you define the
49 function using the prototype syntax, then you must pass the
50 argument as a `float', with no promotion.
52 Unfortunately, on certain older platforms, the debug info doesn't
53 indicate reliably how each function was defined. A function type's
54 TYPE_FLAG_PROTOTYPED flag may be clear, even if the function was
55 defined in prototype style. When calling a function whose
56 TYPE_FLAG_PROTOTYPED flag is clear, GDB consults this flag to
59 For modern targets, it is proper to assume that, if the prototype
60 flag is clear, that can be trusted: `float' arguments should be
61 promoted to `double'. For some older targets, if the prototype
62 flag is clear, that doesn't tell us anything. The default is to
63 trust the debug information; the user can override this behavior
64 with "set coerce-float-to-double 0". */
66 static int coerce_float_to_double_p = 1;
68 /* This boolean tells what gdb should do if a signal is received while
69 in a function called from gdb (call dummy). If set, gdb unwinds
70 the stack and restore the context to what as it was before the
73 The default is to stop in the frame where the signal was received. */
75 int unwind_on_signal_p = 0;
77 /* Perform the standard coercions that are specified
78 for arguments to be passed to C functions.
80 If PARAM_TYPE is non-NULL, it is the expected parameter type.
81 IS_PROTOTYPED is non-zero if the function declaration is prototyped. */
84 value_arg_coerce (struct value *arg, struct type *param_type,
87 struct type *arg_type = check_typedef (VALUE_TYPE (arg));
89 = param_type ? check_typedef (param_type) : arg_type;
91 switch (TYPE_CODE (type))
94 if (TYPE_CODE (arg_type) != TYPE_CODE_REF
95 && TYPE_CODE (arg_type) != TYPE_CODE_PTR)
97 arg = value_addr (arg);
98 VALUE_TYPE (arg) = param_type;
106 /* If we don't have a prototype, coerce to integer type if necessary. */
109 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_int))
110 type = builtin_type_int;
112 /* Currently all target ABIs require at least the width of an integer
113 type for an argument. We may have to conditionalize the following
114 type coercion for future targets. */
115 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_int))
116 type = builtin_type_int;
119 if (!is_prototyped && coerce_float_to_double_p)
121 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_double))
122 type = builtin_type_double;
123 else if (TYPE_LENGTH (type) > TYPE_LENGTH (builtin_type_double))
124 type = builtin_type_long_double;
128 type = lookup_pointer_type (type);
130 case TYPE_CODE_ARRAY:
131 /* Arrays are coerced to pointers to their first element, unless
132 they are vectors, in which case we want to leave them alone,
133 because they are passed by value. */
134 if (current_language->c_style_arrays)
135 if (!TYPE_VECTOR (type))
136 type = lookup_pointer_type (TYPE_TARGET_TYPE (type));
138 case TYPE_CODE_UNDEF:
140 case TYPE_CODE_STRUCT:
141 case TYPE_CODE_UNION:
144 case TYPE_CODE_RANGE:
145 case TYPE_CODE_STRING:
146 case TYPE_CODE_BITSTRING:
147 case TYPE_CODE_ERROR:
148 case TYPE_CODE_MEMBER:
149 case TYPE_CODE_METHOD:
150 case TYPE_CODE_COMPLEX:
155 return value_cast (type, arg);
158 /* Determine a function's address and its return type from its value.
159 Calls error() if the function is not valid for calling. */
162 find_function_addr (struct value *function, struct type **retval_type)
164 struct type *ftype = check_typedef (VALUE_TYPE (function));
165 enum type_code code = TYPE_CODE (ftype);
166 struct type *value_type;
169 /* If it's a member function, just look at the function
172 /* Determine address to call. */
173 if (code == TYPE_CODE_FUNC || code == TYPE_CODE_METHOD)
175 funaddr = VALUE_ADDRESS (function);
176 value_type = TYPE_TARGET_TYPE (ftype);
178 else if (code == TYPE_CODE_PTR)
180 funaddr = value_as_address (function);
181 ftype = check_typedef (TYPE_TARGET_TYPE (ftype));
182 if (TYPE_CODE (ftype) == TYPE_CODE_FUNC
183 || TYPE_CODE (ftype) == TYPE_CODE_METHOD)
185 funaddr = gdbarch_convert_from_func_ptr_addr (current_gdbarch,
188 value_type = TYPE_TARGET_TYPE (ftype);
191 value_type = builtin_type_int;
193 else if (code == TYPE_CODE_INT)
195 /* Handle the case of functions lacking debugging info.
196 Their values are characters since their addresses are char */
197 if (TYPE_LENGTH (ftype) == 1)
198 funaddr = value_as_address (value_addr (function));
200 /* Handle integer used as address of a function. */
201 funaddr = (CORE_ADDR) value_as_long (function);
203 value_type = builtin_type_int;
206 error ("Invalid data type for function to be called.");
208 *retval_type = value_type;
209 return funaddr + FUNCTION_START_OFFSET;
212 /* Call breakpoint_auto_delete on the current contents of the bpstat
213 pointed to by arg (which is really a bpstat *). */
216 breakpoint_auto_delete_contents (void *arg)
218 breakpoint_auto_delete (*(bpstat *) arg);
222 generic_push_dummy_code (struct gdbarch *gdbarch,
223 CORE_ADDR sp, CORE_ADDR funaddr, int using_gcc,
224 struct value **args, int nargs,
225 struct type *value_type,
226 CORE_ADDR *real_pc, CORE_ADDR *bp_addr)
228 /* Something here to findout the size of a breakpoint and then
229 allocate space for it on the stack. */
231 /* This code assumes frame align. */
232 gdb_assert (gdbarch_frame_align_p (gdbarch));
233 /* Force the stack's alignment. The intent is to ensure that the SP
234 is aligned to at least a breakpoint instruction's boundary. */
235 sp = gdbarch_frame_align (gdbarch, sp);
236 /* Allocate space for, and then position the breakpoint on the
238 if (gdbarch_inner_than (gdbarch, 1, 2))
241 gdbarch_breakpoint_from_pc (gdbarch, &bppc, &bplen);
242 sp = gdbarch_frame_align (gdbarch, sp - bplen);
244 /* Should the breakpoint size/location be re-computed here? */
249 gdbarch_breakpoint_from_pc (gdbarch, bp_addr, &bplen);
250 sp = gdbarch_frame_align (gdbarch, sp + bplen);
252 /* Inferior resumes at the function entry point. */
253 (*real_pc) = funaddr;
257 /* For CALL_DUMMY_ON_STACK, push a breakpoint sequence that the called
258 function returns to. */
261 push_dummy_code (struct gdbarch *gdbarch,
262 CORE_ADDR sp, CORE_ADDR funaddr, int using_gcc,
263 struct value **args, int nargs,
264 struct type *value_type,
265 CORE_ADDR *real_pc, CORE_ADDR *bp_addr)
267 if (gdbarch_push_dummy_code_p (gdbarch))
268 return gdbarch_push_dummy_code (gdbarch, sp, funaddr, using_gcc,
269 args, nargs, value_type, real_pc, bp_addr);
271 return generic_push_dummy_code (gdbarch, sp, funaddr, using_gcc,
272 args, nargs, value_type, real_pc, bp_addr);
275 /* All this stuff with a dummy frame may seem unnecessarily complicated
276 (why not just save registers in GDB?). The purpose of pushing a dummy
277 frame which looks just like a real frame is so that if you call a
278 function and then hit a breakpoint (get a signal, etc), "backtrace"
279 will look right. Whether the backtrace needs to actually show the
280 stack at the time the inferior function was called is debatable, but
281 it certainly needs to not display garbage. So if you are contemplating
282 making dummy frames be different from normal frames, consider that. */
284 /* Perform a function call in the inferior.
285 ARGS is a vector of values of arguments (NARGS of them).
286 FUNCTION is a value, the function to be called.
287 Returns a value representing what the function returned.
288 May fail to return, if a breakpoint or signal is hit
289 during the execution of the function.
291 ARGS is modified to contain coerced values. */
294 call_function_by_hand (struct value *function, int nargs, struct value **args)
297 CORE_ADDR dummy_addr;
298 struct type *value_type;
299 unsigned char struct_return;
300 CORE_ADDR struct_addr = 0;
301 struct regcache *retbuf;
302 struct cleanup *retbuf_cleanup;
303 struct inferior_status *inf_status;
304 struct cleanup *inf_status_cleanup;
306 int using_gcc; /* Set to version of gcc in use, or zero if not gcc */
308 struct type *ftype = check_typedef (SYMBOL_TYPE (function));
311 if (!target_has_execution)
314 /* Create a cleanup chain that contains the retbuf (buffer
315 containing the register values). This chain is create BEFORE the
316 inf_status chain so that the inferior status can cleaned up
317 (restored or discarded) without having the retbuf freed. */
318 retbuf = regcache_xmalloc (current_gdbarch);
319 retbuf_cleanup = make_cleanup_regcache_xfree (retbuf);
321 /* A cleanup for the inferior status. Create this AFTER the retbuf
322 so that this can be discarded or applied without interfering with
324 inf_status = save_inferior_status (1);
325 inf_status_cleanup = make_cleanup_restore_inferior_status (inf_status);
327 /* FIXME: cagney/2003-02-26: Step zero of this little tinker is to
328 extract the generic dummy frame code from the architecture
329 vector. Hence this direct call.
331 A follow-on change is to modify this interface so that it takes
332 thread OR frame OR ptid as a parameter, and returns a dummy frame
333 handle. The handle can then be used further down as a parameter
334 to generic_save_dummy_frame_tos(). Hmm, thinking about it, since
335 everything is ment to be using generic dummy frames, why not even
336 use some of the dummy frame code to here - do a regcache dup and
337 then pass the duped regcache, along with all the other stuff, at
340 In fact, you can even save the structure's return address in the
341 dummy frame and fix one of those nasty lost struct return edge
343 generic_push_dummy_frame ();
345 /* Ensure that the initial SP is correctly aligned. */
347 CORE_ADDR old_sp = read_sp ();
348 if (gdbarch_frame_align_p (current_gdbarch))
350 sp = gdbarch_frame_align (current_gdbarch, old_sp);
351 /* NOTE: cagney/2003-08-13: Skip the "red zone". For some
352 ABIs, a function can use memory beyond the inner most stack
353 address. AMD64 called that region the "red zone". Skip at
354 least the "red zone" size before allocating any space on
356 if (INNER_THAN (1, 2))
357 sp -= gdbarch_frame_red_zone_size (current_gdbarch);
359 sp += gdbarch_frame_red_zone_size (current_gdbarch);
361 gdb_assert (sp == gdbarch_frame_align (current_gdbarch, sp));
362 /* NOTE: cagney/2002-09-18:
364 On a RISC architecture, a void parameterless generic dummy
365 frame (i.e., no parameters, no result) typically does not
366 need to push anything the stack and hence can leave SP and
367 FP. Similarly, a frameless (possibly leaf) function does
368 not push anything on the stack and, hence, that too can
369 leave FP and SP unchanged. As a consequence, a sequence of
370 void parameterless generic dummy frame calls to frameless
371 functions will create a sequence of effectively identical
372 frames (SP, FP and TOS and PC the same). This, not
373 suprisingly, results in what appears to be a stack in an
374 infinite loop --- when GDB tries to find a generic dummy
375 frame on the internal dummy frame stack, it will always
378 To avoid this problem, the code below always grows the
379 stack. That way, two dummy frames can never be identical.
380 It does burn a few bytes of stack but that is a small price
384 if (INNER_THAN (1, 2))
385 /* Stack grows down. */
386 sp = gdbarch_frame_align (current_gdbarch, old_sp - 1);
388 /* Stack grows up. */
389 sp = gdbarch_frame_align (current_gdbarch, old_sp + 1);
391 gdb_assert ((INNER_THAN (1, 2) && sp <= old_sp)
392 || (INNER_THAN (2, 1) && sp >= old_sp));
395 /* FIXME: cagney/2002-09-18: Hey, you loose!
397 Who knows how badly aligned the SP is!
399 If the generic dummy frame ends up empty (because nothing is
400 pushed) GDB won't be able to correctly perform back traces.
401 If a target is having trouble with backtraces, first thing to
402 do is add FRAME_ALIGN() to the architecture vector. If that
403 fails, try unwind_dummy_id().
405 If the ABI specifies a "Red Zone" (see the doco) the code
406 below will quietly trash it. */
410 funaddr = find_function_addr (function, &value_type);
411 CHECK_TYPEDEF (value_type);
414 struct block *b = block_for_pc (funaddr);
415 /* If compiled without -g, assume GCC 2. */
416 using_gcc = (b == NULL ? 2 : BLOCK_GCC_COMPILED (b));
419 /* Are we returning a value using a structure return or a normal
422 struct_return = using_struct_return (value_type, using_gcc);
424 /* Determine the location of the breakpoint (and possibly other
425 stuff) that the called function will return to. The SPARC, for a
426 function returning a structure or union, needs to make space for
427 not just the breakpoint but also an extra word containing the
428 size (?) of the structure being passed. */
430 /* The actual breakpoint (at BP_ADDR) is inserted separatly so there
431 is no need to write that out. */
433 switch (CALL_DUMMY_LOCATION)
436 /* "dummy_addr" is here just to keep old targets happy. New
437 targets return that same information via "sp" and "bp_addr". */
438 if (INNER_THAN (1, 2))
440 sp = push_dummy_code (current_gdbarch, sp, funaddr,
441 using_gcc, args, nargs, value_type,
448 sp = push_dummy_code (current_gdbarch, sp, funaddr,
449 using_gcc, args, nargs, value_type,
454 if (DEPRECATED_FIX_CALL_DUMMY_P ()
455 && !gdbarch_push_dummy_call_p (current_gdbarch))
457 /* Sigh. Some targets use DEPRECATED_FIX_CALL_DUMMY to
458 shove extra stuff onto the stack or into registers. That
459 code should be in PUSH_DUMMY_CALL, however, in the mean
461 /* If the target is manipulating DUMMY1, it looses big time. */
463 DEPRECATED_FIX_CALL_DUMMY (dummy1, sp, funaddr, nargs, args,
464 value_type, using_gcc);
467 dummy_addr = entry_point_address ();
468 /* Make certain that the address points at real code, and not a
469 function descriptor. */
470 dummy_addr = gdbarch_convert_from_func_ptr_addr (current_gdbarch,
473 /* A call dummy always consists of just a single breakpoint, so
474 it's address is the same as the address of the dummy. */
475 bp_addr = dummy_addr;
478 /* Some executables define a symbol __CALL_DUMMY_ADDRESS whose
479 address is the location where the breakpoint should be
480 placed. Once all targets are using the overhauled frame code
481 this can be deleted - ON_STACK is a better option. */
483 struct minimal_symbol *sym;
485 sym = lookup_minimal_symbol ("__CALL_DUMMY_ADDRESS", NULL, NULL);
488 dummy_addr = SYMBOL_VALUE_ADDRESS (sym);
490 dummy_addr = entry_point_address ();
491 /* Make certain that the address points at real code, and not
492 a function descriptor. */
493 dummy_addr = gdbarch_convert_from_func_ptr_addr (current_gdbarch,
496 /* A call dummy always consists of just a single breakpoint,
497 so it's address is the same as the address of the dummy. */
498 bp_addr = dummy_addr;
502 internal_error (__FILE__, __LINE__, "bad switch");
505 /* Save where the breakpoint is going to be inserted so that the
506 dummy-frame code is later able to re-identify it. */
507 generic_save_call_dummy_addr (bp_addr, bp_addr + 1);
509 if (nargs < TYPE_NFIELDS (ftype))
510 error ("too few arguments in function call");
514 for (i = nargs - 1; i >= 0; i--)
517 struct type *param_type;
519 /* FIXME drow/2002-05-31: Should just always mark methods as
520 prototyped. Can we respect TYPE_VARARGS? Probably not. */
521 if (TYPE_CODE (ftype) == TYPE_CODE_METHOD)
523 else if (i < TYPE_NFIELDS (ftype))
524 prototyped = TYPE_PROTOTYPED (ftype);
528 if (i < TYPE_NFIELDS (ftype))
529 param_type = TYPE_FIELD_TYPE (ftype, i);
533 args[i] = value_arg_coerce (args[i], param_type, prototyped);
535 /* elz: this code is to handle the case in which the function
536 to be called has a pointer to function as parameter and the
537 corresponding actual argument is the address of a function
538 and not a pointer to function variable. In aCC compiled
539 code, the calls through pointers to functions (in the body
540 of the function called by hand) are made via
541 $$dyncall_external which requires some registers setting,
542 this is taken care of if we call via a function pointer
543 variable, but not via a function address. In cc this is
548 if (param_type != NULL && TYPE_CODE (ftype) != TYPE_CODE_METHOD)
550 /* if this parameter is a pointer to function. */
551 if (TYPE_CODE (param_type) == TYPE_CODE_PTR)
552 if (TYPE_CODE (TYPE_TARGET_TYPE (param_type)) == TYPE_CODE_FUNC)
553 /* elz: FIXME here should go the test about the
554 compiler used to compile the target. We want to
555 issue the error message only if the compiler
556 used was HP's aCC. If we used HP's cc, then
557 there is no problem and no need to return at
559 /* Go see if the actual parameter is a variable of
560 type pointer to function or just a function. */
561 if (args[i]->lval == not_lval)
564 if (find_pc_partial_function ((CORE_ADDR) args[i]->aligner.contents[0], &arg_name, NULL, NULL))
566 You cannot use function <%s> as argument. \n\
567 You must use a pointer to function type variable. Command ignored.", arg_name);
574 if (DEPRECATED_REG_STRUCT_HAS_ADDR_P ())
577 /* This is a machine like the sparc, where we may need to pass a
578 pointer to the structure, not the structure itself. */
579 for (i = nargs - 1; i >= 0; i--)
581 struct type *arg_type = check_typedef (VALUE_TYPE (args[i]));
582 if ((TYPE_CODE (arg_type) == TYPE_CODE_STRUCT
583 || TYPE_CODE (arg_type) == TYPE_CODE_UNION
584 || TYPE_CODE (arg_type) == TYPE_CODE_ARRAY
585 || TYPE_CODE (arg_type) == TYPE_CODE_STRING
586 || TYPE_CODE (arg_type) == TYPE_CODE_BITSTRING
587 || TYPE_CODE (arg_type) == TYPE_CODE_SET
588 || (TYPE_CODE (arg_type) == TYPE_CODE_FLT
589 && TYPE_LENGTH (arg_type) > 8)
591 && DEPRECATED_REG_STRUCT_HAS_ADDR (using_gcc, arg_type))
594 int len; /* = TYPE_LENGTH (arg_type); */
596 arg_type = check_typedef (VALUE_ENCLOSING_TYPE (args[i]));
597 len = TYPE_LENGTH (arg_type);
599 if (DEPRECATED_STACK_ALIGN_P ())
600 /* MVS 11/22/96: I think at least some of this
601 stack_align code is really broken. Better to let
602 PUSH_ARGUMENTS adjust the stack in a target-defined
604 aligned_len = DEPRECATED_STACK_ALIGN (len);
607 if (INNER_THAN (1, 2))
609 /* stack grows downward */
611 /* ... so the address of the thing we push is the
612 stack pointer after we push it. */
617 /* The stack grows up, so the address of the thing
618 we push is the stack pointer before we push it. */
622 /* Push the structure. */
623 write_memory (addr, VALUE_CONTENTS_ALL (args[i]), len);
624 /* The value we're going to pass is the address of the
625 thing we just pushed. */
626 /*args[i] = value_from_longest (lookup_pointer_type (value_type),
628 args[i] = value_from_pointer (lookup_pointer_type (arg_type),
635 /* Reserve space for the return structure to be written on the
636 stack, if necessary. Make certain that the value is correctly
641 int len = TYPE_LENGTH (value_type);
642 if (DEPRECATED_STACK_ALIGN_P ())
643 /* NOTE: cagney/2003-03-22: Should rely on frame align, rather
644 than stack align to force the alignment of the stack. */
645 len = DEPRECATED_STACK_ALIGN (len);
646 if (INNER_THAN (1, 2))
648 /* Stack grows downward. Align STRUCT_ADDR and SP after
649 making space for the return value. */
651 if (gdbarch_frame_align_p (current_gdbarch))
652 sp = gdbarch_frame_align (current_gdbarch, sp);
657 /* Stack grows upward. Align the frame, allocate space, and
658 then again, re-align the frame??? */
659 if (gdbarch_frame_align_p (current_gdbarch))
660 sp = gdbarch_frame_align (current_gdbarch, sp);
663 if (gdbarch_frame_align_p (current_gdbarch))
664 sp = gdbarch_frame_align (current_gdbarch, sp);
668 /* Create the dummy stack frame. Pass in the call dummy address as,
669 presumably, the ABI code knows where, in the call dummy, the
670 return address should be pointed. */
671 if (gdbarch_push_dummy_call_p (current_gdbarch))
672 /* When there is no push_dummy_call method, should this code
673 simply error out. That would the implementation of this method
674 for all ABIs (which is probably a good thing). */
675 sp = gdbarch_push_dummy_call (current_gdbarch, funaddr, current_regcache,
676 bp_addr, nargs, args, sp, struct_return,
678 else if (DEPRECATED_PUSH_ARGUMENTS_P ())
679 /* Keep old targets working. */
680 sp = DEPRECATED_PUSH_ARGUMENTS (nargs, args, sp, struct_return,
683 sp = legacy_push_arguments (nargs, args, sp, struct_return, struct_addr);
685 if (DEPRECATED_PUSH_RETURN_ADDRESS_P ())
686 /* for targets that use no CALL_DUMMY */
687 /* There are a number of targets now which actually don't write
688 any CALL_DUMMY instructions into the target, but instead just
689 save the machine state, push the arguments, and jump directly
690 to the callee function. Since this doesn't actually involve
691 executing a JSR/BSR instruction, the return address must be set
692 up by hand, either by pushing onto the stack or copying into a
693 return-address register as appropriate. Formerly this has been
694 done in PUSH_ARGUMENTS, but that's overloading its
695 functionality a bit, so I'm making it explicit to do it here. */
696 /* NOTE: cagney/2003-04-22: The first parameter ("real_pc") has
697 been replaced with zero, it turns out that no implementation
698 used that parameter. This occured because the value being
699 supplied - the address of the called function's entry point
700 instead of the address of the breakpoint that the called
701 function should return to - wasn't useful. */
702 sp = DEPRECATED_PUSH_RETURN_ADDRESS (0, sp);
704 /* NOTE: cagney/2003-03-23: Diable this code when there is a
705 push_dummy_call() method. Since that method will have already
706 handled any alignment issues, the code below is entirely
708 if (!gdbarch_push_dummy_call_p (current_gdbarch)
709 && DEPRECATED_STACK_ALIGN_P () && !INNER_THAN (1, 2))
711 /* If stack grows up, we must leave a hole at the bottom, note
712 that sp already has been advanced for the arguments! */
713 sp = DEPRECATED_STACK_ALIGN (sp);
716 /* Store the address at which the structure is supposed to be
718 /* NOTE: 2003-03-24: Since PUSH_ARGUMENTS can (and typically does)
719 store the struct return address, this call is entirely redundant. */
720 if (struct_return && DEPRECATED_STORE_STRUCT_RETURN_P ())
721 DEPRECATED_STORE_STRUCT_RETURN (struct_addr, sp);
723 /* Write the stack pointer. This is here because the statements
724 above might fool with it. On SPARC, this write also stores the
725 register window into the right place in the new stack frame,
726 which otherwise wouldn't happen (see store_inferior_registers in
728 /* NOTE: cagney/2003-03-23: Since the architecture method
729 push_dummy_call() should have already stored the stack pointer
730 (as part of creating the fake call frame), and none of the code
731 following that call adjusts the stack-pointer value, the below
732 call is entirely redundant. */
733 if (DEPRECATED_DUMMY_WRITE_SP_P ())
734 DEPRECATED_DUMMY_WRITE_SP (sp);
736 if (gdbarch_unwind_dummy_id_p (current_gdbarch))
738 /* Sanity. The exact same SP value is returned by
739 PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by
740 unwind_dummy_id to form the frame ID's stack address. */
741 generic_save_dummy_frame_tos (sp);
743 else if (DEPRECATED_SAVE_DUMMY_FRAME_TOS_P ())
744 DEPRECATED_SAVE_DUMMY_FRAME_TOS (sp);
746 /* Now proceed, having reached the desired place. */
747 clear_proceed_status ();
749 /* Create a momentary breakpoint at the return address of the
750 inferior. That way it breaks when it returns. */
753 struct breakpoint *bpt;
754 struct symtab_and_line sal;
755 struct frame_id frame;
756 init_sal (&sal); /* initialize to zeroes */
758 sal.section = find_pc_overlay (sal.pc);
759 /* Set up a frame ID for the dummy frame so we can pass it to
760 set_momentary_breakpoint. We need to give the breakpoint a
761 frame ID so that the breakpoint code can correctly re-identify
762 the dummy breakpoint. */
763 if (gdbarch_unwind_dummy_id_p (current_gdbarch))
765 /* Sanity. The exact same SP value is returned by
766 PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by
767 unwind_dummy_id to form the frame ID's stack address. */
768 frame = frame_id_build (sp, sal.pc);
772 /* The assumption here is that push_dummy_call() returned the
773 stack part of the frame ID. Unfortunately, many older
774 architectures were, via a convoluted mess, relying on the
775 poorly defined and greatly overloaded
776 DEPRECATED_TARGET_READ_FP or DEPRECATED_FP_REGNUM to supply
778 if (DEPRECATED_TARGET_READ_FP_P ())
779 frame = frame_id_build (DEPRECATED_TARGET_READ_FP (), sal.pc);
780 else if (DEPRECATED_FP_REGNUM >= 0)
781 frame = frame_id_build (read_register (DEPRECATED_FP_REGNUM), sal.pc);
783 frame = frame_id_build (sp, sal.pc);
785 bpt = set_momentary_breakpoint (sal, frame, bp_call_dummy);
786 bpt->disposition = disp_del;
789 /* Execute a "stack dummy", a piece of code stored in the stack by
790 the debugger to be executed in the inferior.
792 The dummy's frame is automatically popped whenever that break is
793 hit. If that is the first time the program stops,
794 call_function_by_hand returns to its caller with that frame
795 already gone and sets RC to 0.
797 Otherwise, set RC to a non-zero value. If the called function
798 receives a random signal, we do not allow the user to continue
799 executing it as this may not work. The dummy frame is poped and
800 we return 1. If we hit a breakpoint, we leave the frame in place
801 and return 2 (the frame will eventually be popped when we do hit
802 the dummy end breakpoint). */
805 struct cleanup *old_cleanups = make_cleanup (null_cleanup, 0);
808 /* If all error()s out of proceed ended up calling normal_stop
809 (and perhaps they should; it already does in the special case
810 of error out of resume()), then we wouldn't need this. */
811 make_cleanup (breakpoint_auto_delete_contents, &stop_bpstat);
813 disable_watchpoints_before_interactive_call_start ();
814 proceed_to_finish = 1; /* We want stop_registers, please... */
816 if (target_can_async_p ())
817 saved_async = target_async_mask (0);
819 proceed (real_pc, TARGET_SIGNAL_0, 0);
822 target_async_mask (saved_async);
824 enable_watchpoints_after_interactive_call_stop ();
826 discard_cleanups (old_cleanups);
829 if (stopped_by_random_signal || !stop_stack_dummy)
831 /* Find the name of the function we're about to complain about. */
832 const char *name = NULL;
834 struct symbol *symbol = find_pc_function (funaddr);
836 name = SYMBOL_PRINT_NAME (symbol);
839 /* Try the minimal symbols. */
840 struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (funaddr);
842 name = SYMBOL_PRINT_NAME (msymbol);
846 /* Can't use a cleanup here. It is discarded, instead use
848 char *tmp = xstrprintf ("at %s", local_hex_string (funaddr));
849 char *a = alloca (strlen (tmp) + 1);
855 if (stopped_by_random_signal)
857 /* We stopped inside the FUNCTION because of a random
858 signal. Further execution of the FUNCTION is not
861 if (unwind_on_signal_p)
863 /* The user wants the context restored. */
865 /* We must get back to the frame we were before the
867 frame_pop (get_current_frame ());
869 /* FIXME: Insert a bunch of wrap_here; name can be very
870 long if it's a C++ name with arguments and stuff. */
872 The program being debugged was signaled while in a function called from GDB.\n\
873 GDB has restored the context to what it was before the call.\n\
874 To change this behavior use \"set unwindonsignal off\"\n\
875 Evaluation of the expression containing the function (%s) will be abandoned.",
880 /* The user wants to stay in the frame where we stopped
882 /* If we restored the inferior status (via the cleanup),
883 we would print a spurious error message (Unable to
884 restore previously selected frame), would write the
885 registers from the inf_status (which is wrong), and
886 would do other wrong things. */
887 discard_cleanups (inf_status_cleanup);
888 discard_inferior_status (inf_status);
889 /* FIXME: Insert a bunch of wrap_here; name can be very
890 long if it's a C++ name with arguments and stuff. */
892 The program being debugged was signaled while in a function called from GDB.\n\
893 GDB remains in the frame where the signal was received.\n\
894 To change this behavior use \"set unwindonsignal on\"\n\
895 Evaluation of the expression containing the function (%s) will be abandoned.",
900 if (!stop_stack_dummy)
902 /* We hit a breakpoint inside the FUNCTION. */
903 /* If we restored the inferior status (via the cleanup), we
904 would print a spurious error message (Unable to restore
905 previously selected frame), would write the registers
906 from the inf_status (which is wrong), and would do other
908 discard_cleanups (inf_status_cleanup);
909 discard_inferior_status (inf_status);
910 /* The following error message used to say "The expression
911 which contained the function call has been discarded."
912 It is a hard concept to explain in a few words. Ideally,
913 GDB would be able to resume evaluation of the expression
914 when the function finally is done executing. Perhaps
915 someday this will be implemented (it would not be easy). */
916 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
917 a C++ name with arguments and stuff. */
919 The program being debugged stopped while in a function called from GDB.\n\
920 When the function (%s) is done executing, GDB will silently\n\
921 stop (instead of continuing to evaluate the expression containing\n\
922 the function call).", name);
925 /* The above code errors out, so ... */
926 internal_error (__FILE__, __LINE__, "... should not be here");
929 /* If we get here the called FUNCTION run to completion. */
931 /* On normal return, the stack dummy has been popped already. */
932 regcache_cpy_no_passthrough (retbuf, stop_registers);
934 /* Restore the inferior status, via its cleanup. At this stage,
935 leave the RETBUF alone. */
936 do_cleanups (inf_status_cleanup);
938 /* Figure out the value returned by the function. */
941 /* NOTE: cagney/2003-09-27: This assumes that PUSH_DUMMY_CALL
942 has correctly stored STRUCT_ADDR in the target. In the past
943 that hasn't been the case, the old MIPS PUSH_ARGUMENTS
944 (PUSH_DUMMY_CALL precursor) would silently move the location
945 of the struct return value making STRUCT_ADDR bogus. If
946 you're seeing problems with values being returned using the
947 "struct return convention", check that PUSH_DUMMY_CALL isn't
949 struct value *retval = value_at (value_type, struct_addr, NULL);
950 do_cleanups (retbuf_cleanup);
955 /* The non-register case was handled above. */
956 struct value *retval = register_value_being_returned (value_type,
958 do_cleanups (retbuf_cleanup);
963 void _initialize_infcall (void);
966 _initialize_infcall (void)
968 add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure,
969 &coerce_float_to_double_p, "\
970 Set coercion of floats to doubles when calling functions\n\
971 Variables of type float should generally be converted to doubles before\n\
972 calling an unprototyped function, and left alone when calling a prototyped\n\
973 function. However, some older debug info formats do not provide enough\n\
974 information to determine that a function is prototyped. If this flag is\n\
975 set, GDB will perform the conversion for a function it considers\n\
977 The default is to perform the conversion.\n", "\
978 Show coercion of floats to doubles when calling functions\n\
979 Variables of type float should generally be converted to doubles before\n\
980 calling an unprototyped function, and left alone when calling a prototyped\n\
981 function. However, some older debug info formats do not provide enough\n\
982 information to determine that a function is prototyped. If this flag is\n\
983 set, GDB will perform the conversion for a function it considers\n\
985 The default is to perform the conversion.\n",
986 NULL, NULL, &setlist, &showlist);
988 add_setshow_boolean_cmd ("unwindonsignal", no_class,
989 &unwind_on_signal_p, "\
990 Set unwinding of stack if a signal is received while in a call dummy.\n\
991 The unwindonsignal lets the user determine what gdb should do if a signal\n\
992 is received while in a function called from gdb (call dummy). If set, gdb\n\
993 unwinds the stack and restore the context to what as it was before the call.\n\
994 The default is to stop in the frame where the signal was received.", "\
995 Show unwinding of stack if a signal is received while in a call dummy.\n\
996 The unwindonsignal lets the user determine what gdb should do if a signal\n\
997 is received while in a function called from gdb (call dummy). If set, gdb\n\
998 unwinds the stack and restore the context to what as it was before the call.\n\
999 The default is to stop in the frame where the signal was received.",
1000 NULL, NULL, &setlist, &showlist);