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;
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 legacy_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 /* CALL_DUMMY is an array of words (DEPRECATED_REGISTER_SIZE), but
229 each word is in host byte order. Before calling
230 DEPRECATED_FIX_CALL_DUMMY, we byteswap it and remove any extra
231 bytes which might exist because ULONGEST is bigger than
232 DEPRECATED_REGISTER_SIZE. */
233 /* NOTE: This is pretty wierd, as the call dummy is actually a
234 sequence of instructions. But CISC machines will have to pack
235 the instructions into DEPRECATED_REGISTER_SIZE units (and so will
236 RISC machines for which INSTRUCTION_SIZE is not
237 DEPRECATED_REGISTER_SIZE). */
238 /* NOTE: This is pretty stupid. CALL_DUMMY should be in strict
239 target byte order. */
241 ULONGEST *dummy = alloca (DEPRECATED_SIZEOF_CALL_DUMMY_WORDS);
242 int sizeof_dummy1 = (DEPRECATED_REGISTER_SIZE
243 * DEPRECATED_SIZEOF_CALL_DUMMY_WORDS
244 / sizeof (ULONGEST));
245 char *dummy1 = alloca (sizeof_dummy1);
246 memcpy (dummy, DEPRECATED_CALL_DUMMY_WORDS,
247 DEPRECATED_SIZEOF_CALL_DUMMY_WORDS);
248 if (INNER_THAN (1, 2))
250 /* Stack grows down */
260 /* NOTE: cagney/2002-09-10: Don't bother re-adjusting the stack
261 after allocating space for the call dummy. A target can specify
262 a SIZEOF_DUMMY1 (via DEPRECATED_SIZEOF_CALL_DUMMY_WORDS) such
263 that all local alignment requirements are met. */
264 /* Create a call sequence customized for this function and the
265 number of arguments for it. */
268 for (i = 0; i < (int) (DEPRECATED_SIZEOF_CALL_DUMMY_WORDS / sizeof (dummy[0]));
270 store_unsigned_integer (&dummy1[i * DEPRECATED_REGISTER_SIZE],
271 DEPRECATED_REGISTER_SIZE,
272 (ULONGEST) dummy[i]);
274 /* NOTE: cagney/2003-04-22: This computation of REAL_PC, BP_ADDR and
275 DUMMY_ADDR is pretty messed up. It comes from constant tinkering
276 with the values. Instead a DEPRECATED_FIX_CALL_DUMMY replacement
277 (PUSH_DUMMY_BREAKPOINT?) should just do everything. */
278 if (!gdbarch_push_dummy_call_p (current_gdbarch))
280 if (DEPRECATED_FIX_CALL_DUMMY_P ())
282 /* gdb_assert (CALL_DUMMY_LOCATION == ON_STACK) true? */
283 DEPRECATED_FIX_CALL_DUMMY (dummy1, start_sp, funaddr, nargs, args,
284 value_type, using_gcc);
286 (*real_pc) = start_sp;
288 /* Yes, the offset is applied to the real_pc and not the dummy addr.
289 Ulgh! Blame the HP/UX target. */
290 (*bp_addr) = (*real_pc) + DEPRECATED_CALL_DUMMY_BREAKPOINT_OFFSET;
291 /* Yes, the offset is applied to the real_pc and not the
292 dummy_addr. Ulgh! Blame the HP/UX target. */
293 (*real_pc) += DEPRECATED_CALL_DUMMY_START_OFFSET;
294 write_memory (start_sp, (char *) dummy1, sizeof_dummy1);
295 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES)
296 generic_save_call_dummy_addr (start_sp, start_sp + sizeof_dummy1);
301 generic_push_dummy_code (struct gdbarch *gdbarch,
302 CORE_ADDR sp, CORE_ADDR funaddr, int using_gcc,
303 struct value **args, int nargs,
304 struct type *value_type,
305 CORE_ADDR *real_pc, CORE_ADDR *bp_addr)
307 /* Something here to findout the size of a breakpoint and then
308 allocate space for it on the stack. */
310 /* This code assumes frame align. */
311 gdb_assert (gdbarch_frame_align_p (gdbarch));
312 /* Force the stack's alignment. The intent is to ensure that the SP
313 is aligned to at least a breakpoint instruction's boundary. */
314 sp = gdbarch_frame_align (gdbarch, sp);
315 /* Allocate space for, and then position the breakpoint on the
317 if (gdbarch_inner_than (gdbarch, 1, 2))
320 gdbarch_breakpoint_from_pc (gdbarch, &bppc, &bplen);
321 sp = gdbarch_frame_align (gdbarch, sp - bplen);
323 /* Should the breakpoint size/location be re-computed here? */
328 gdbarch_breakpoint_from_pc (gdbarch, bp_addr, &bplen);
329 sp = gdbarch_frame_align (gdbarch, sp + bplen);
331 /* Inferior resumes at the function entry point. */
332 (*real_pc) = funaddr;
336 /* Provide backward compatibility. Once DEPRECATED_FIX_CALL_DUMMY is
337 eliminated, this can be simplified. */
340 push_dummy_code (struct gdbarch *gdbarch,
341 CORE_ADDR sp, CORE_ADDR funaddr, int using_gcc,
342 struct value **args, int nargs,
343 struct type *value_type,
344 CORE_ADDR *real_pc, CORE_ADDR *bp_addr)
346 if (gdbarch_push_dummy_code_p (gdbarch))
347 return gdbarch_push_dummy_code (gdbarch, sp, funaddr, using_gcc,
348 args, nargs, value_type, real_pc, bp_addr);
349 else if (DEPRECATED_FIX_CALL_DUMMY_P ()
350 && !gdbarch_push_dummy_call_p (gdbarch))
351 return legacy_push_dummy_code (gdbarch, sp, funaddr, using_gcc,
352 args, nargs, value_type, real_pc, bp_addr);
354 return generic_push_dummy_code (gdbarch, sp, funaddr, using_gcc,
355 args, nargs, value_type, real_pc, bp_addr);
358 /* All this stuff with a dummy frame may seem unnecessarily complicated
359 (why not just save registers in GDB?). The purpose of pushing a dummy
360 frame which looks just like a real frame is so that if you call a
361 function and then hit a breakpoint (get a signal, etc), "backtrace"
362 will look right. Whether the backtrace needs to actually show the
363 stack at the time the inferior function was called is debatable, but
364 it certainly needs to not display garbage. So if you are contemplating
365 making dummy frames be different from normal frames, consider that. */
367 /* Perform a function call in the inferior.
368 ARGS is a vector of values of arguments (NARGS of them).
369 FUNCTION is a value, the function to be called.
370 Returns a value representing what the function returned.
371 May fail to return, if a breakpoint or signal is hit
372 during the execution of the function.
374 ARGS is modified to contain coerced values. */
377 call_function_by_hand (struct value *function, int nargs, struct value **args)
380 CORE_ADDR dummy_addr;
381 struct type *value_type;
382 unsigned char struct_return;
383 CORE_ADDR struct_addr = 0;
384 struct regcache *retbuf;
385 struct cleanup *retbuf_cleanup;
386 struct inferior_status *inf_status;
387 struct cleanup *inf_status_cleanup;
389 int using_gcc; /* Set to version of gcc in use, or zero if not gcc */
391 struct type *ftype = check_typedef (SYMBOL_TYPE (function));
394 if (!target_has_execution)
397 /* Create a cleanup chain that contains the retbuf (buffer
398 containing the register values). This chain is create BEFORE the
399 inf_status chain so that the inferior status can cleaned up
400 (restored or discarded) without having the retbuf freed. */
401 retbuf = regcache_xmalloc (current_gdbarch);
402 retbuf_cleanup = make_cleanup_regcache_xfree (retbuf);
404 /* A cleanup for the inferior status. Create this AFTER the retbuf
405 so that this can be discarded or applied without interfering with
407 inf_status = save_inferior_status (1);
408 inf_status_cleanup = make_cleanup_restore_inferior_status (inf_status);
410 if (DEPRECATED_PUSH_DUMMY_FRAME_P ())
412 /* DEPRECATED_PUSH_DUMMY_FRAME is responsible for saving the
413 inferior registers (and frame_pop() for restoring them). (At
414 least on most machines) they are saved on the stack in the
416 DEPRECATED_PUSH_DUMMY_FRAME;
420 /* FIXME: cagney/2003-02-26: Step zero of this little tinker is
421 to extract the generic dummy frame code from the architecture
422 vector. Hence this direct call.
424 A follow-on change is to modify this interface so that it takes
425 thread OR frame OR ptid as a parameter, and returns a dummy
426 frame handle. The handle can then be used further down as a
427 parameter to generic_save_dummy_frame_tos(). Hmm, thinking
428 about it, since everything is ment to be using generic dummy
429 frames, why not even use some of the dummy frame code to here -
430 do a regcache dup and then pass the duped regcache, along with
431 all the other stuff, at one single point.
433 In fact, you can even save the structure's return address in the
434 dummy frame and fix one of those nasty lost struct return edge
436 generic_push_dummy_frame ();
439 /* Ensure that the initial SP is correctly aligned. */
441 CORE_ADDR old_sp = read_sp ();
442 if (gdbarch_frame_align_p (current_gdbarch))
444 sp = gdbarch_frame_align (current_gdbarch, old_sp);
445 /* NOTE: cagney/2003-08-13: Skip the "red zone". For some
446 ABIs, a function can use memory beyond the inner most stack
447 address. AMD64 called that region the "red zone". Skip at
448 least the "red zone" size before allocating any space on
450 if (INNER_THAN (1, 2))
451 sp -= gdbarch_frame_red_zone_size (current_gdbarch);
453 sp += gdbarch_frame_red_zone_size (current_gdbarch);
455 gdb_assert (sp == gdbarch_frame_align (current_gdbarch, sp));
456 /* NOTE: cagney/2002-09-18:
458 On a RISC architecture, a void parameterless generic dummy
459 frame (i.e., no parameters, no result) typically does not
460 need to push anything the stack and hence can leave SP and
461 FP. Similarly, a frameless (possibly leaf) function does
462 not push anything on the stack and, hence, that too can
463 leave FP and SP unchanged. As a consequence, a sequence of
464 void parameterless generic dummy frame calls to frameless
465 functions will create a sequence of effectively identical
466 frames (SP, FP and TOS and PC the same). This, not
467 suprisingly, results in what appears to be a stack in an
468 infinite loop --- when GDB tries to find a generic dummy
469 frame on the internal dummy frame stack, it will always
472 To avoid this problem, the code below always grows the
473 stack. That way, two dummy frames can never be identical.
474 It does burn a few bytes of stack but that is a small price
478 if (INNER_THAN (1, 2))
479 /* Stack grows down. */
480 sp = gdbarch_frame_align (current_gdbarch, old_sp - 1);
482 /* Stack grows up. */
483 sp = gdbarch_frame_align (current_gdbarch, old_sp + 1);
485 gdb_assert ((INNER_THAN (1, 2) && sp <= old_sp)
486 || (INNER_THAN (2, 1) && sp >= old_sp));
489 /* FIXME: cagney/2002-09-18: Hey, you loose!
491 Who knows how badly aligned the SP is!
493 If the generic dummy frame ends up empty (because nothing is
494 pushed) GDB won't be able to correctly perform back traces.
495 If a target is having trouble with backtraces, first thing to
496 do is add FRAME_ALIGN() to the architecture vector. If that
497 fails, try unwind_dummy_id().
499 If the ABI specifies a "Red Zone" (see the doco) the code
500 below will quietly trash it. */
504 funaddr = find_function_addr (function, &value_type);
505 CHECK_TYPEDEF (value_type);
508 struct block *b = block_for_pc (funaddr);
509 /* If compiled without -g, assume GCC 2. */
510 using_gcc = (b == NULL ? 2 : BLOCK_GCC_COMPILED (b));
513 /* Are we returning a value using a structure return or a normal
516 struct_return = using_struct_return (value_type, using_gcc);
518 /* Determine the location of the breakpoint (and possibly other
519 stuff) that the called function will return to. The SPARC, for a
520 function returning a structure or union, needs to make space for
521 not just the breakpoint but also an extra word containing the
522 size (?) of the structure being passed. */
524 /* The actual breakpoint (at BP_ADDR) is inserted separatly so there
525 is no need to write that out. */
527 switch (CALL_DUMMY_LOCATION)
530 /* "dummy_addr" is here just to keep old targets happy. New
531 targets return that same information via "sp" and "bp_addr". */
532 if (INNER_THAN (1, 2))
534 sp = push_dummy_code (current_gdbarch, sp, funaddr,
535 using_gcc, args, nargs, value_type,
542 sp = push_dummy_code (current_gdbarch, sp, funaddr,
543 using_gcc, args, nargs, value_type,
548 if (DEPRECATED_FIX_CALL_DUMMY_P ()
549 && !gdbarch_push_dummy_call_p (current_gdbarch))
551 /* Sigh. Some targets use DEPRECATED_FIX_CALL_DUMMY to
552 shove extra stuff onto the stack or into registers. That
553 code should be in PUSH_DUMMY_CALL, however, in the mean
555 /* If the target is manipulating DUMMY1, it looses big time. */
557 DEPRECATED_FIX_CALL_DUMMY (dummy1, sp, funaddr, nargs, args,
558 value_type, using_gcc);
561 dummy_addr = entry_point_address ();
562 /* Make certain that the address points at real code, and not a
563 function descriptor. */
564 dummy_addr = gdbarch_convert_from_func_ptr_addr (current_gdbarch,
567 /* A call dummy always consists of just a single breakpoint, so
568 it's address is the same as the address of the dummy. */
569 bp_addr = dummy_addr;
572 /* Some executables define a symbol __CALL_DUMMY_ADDRESS whose
573 address is the location where the breakpoint should be
574 placed. Once all targets are using the overhauled frame code
575 this can be deleted - ON_STACK is a better option. */
577 struct minimal_symbol *sym;
579 sym = lookup_minimal_symbol ("__CALL_DUMMY_ADDRESS", NULL, NULL);
582 dummy_addr = SYMBOL_VALUE_ADDRESS (sym);
584 dummy_addr = entry_point_address ();
585 /* Make certain that the address points at real code, and not
586 a function descriptor. */
587 dummy_addr = gdbarch_convert_from_func_ptr_addr (current_gdbarch,
590 /* A call dummy always consists of just a single breakpoint,
591 so it's address is the same as the address of the dummy. */
592 bp_addr = dummy_addr;
596 internal_error (__FILE__, __LINE__, "bad switch");
599 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES)
600 /* Save where the breakpoint is going to be inserted so that the
601 dummy-frame code is later able to re-identify it. */
602 generic_save_call_dummy_addr (bp_addr, bp_addr + 1);
604 if (nargs < TYPE_NFIELDS (ftype))
605 error ("too few arguments in function call");
609 for (i = nargs - 1; i >= 0; i--)
612 struct type *param_type;
614 /* FIXME drow/2002-05-31: Should just always mark methods as
615 prototyped. Can we respect TYPE_VARARGS? Probably not. */
616 if (TYPE_CODE (ftype) == TYPE_CODE_METHOD)
618 else if (i < TYPE_NFIELDS (ftype))
619 prototyped = TYPE_PROTOTYPED (ftype);
623 if (i < TYPE_NFIELDS (ftype))
624 param_type = TYPE_FIELD_TYPE (ftype, i);
628 args[i] = value_arg_coerce (args[i], param_type, prototyped);
630 /* elz: this code is to handle the case in which the function
631 to be called has a pointer to function as parameter and the
632 corresponding actual argument is the address of a function
633 and not a pointer to function variable. In aCC compiled
634 code, the calls through pointers to functions (in the body
635 of the function called by hand) are made via
636 $$dyncall_external which requires some registers setting,
637 this is taken care of if we call via a function pointer
638 variable, but not via a function address. In cc this is
643 if (param_type != NULL && TYPE_CODE (ftype) != TYPE_CODE_METHOD)
645 /* if this parameter is a pointer to function. */
646 if (TYPE_CODE (param_type) == TYPE_CODE_PTR)
647 if (TYPE_CODE (TYPE_TARGET_TYPE (param_type)) == TYPE_CODE_FUNC)
648 /* elz: FIXME here should go the test about the
649 compiler used to compile the target. We want to
650 issue the error message only if the compiler
651 used was HP's aCC. If we used HP's cc, then
652 there is no problem and no need to return at
654 /* Go see if the actual parameter is a variable of
655 type pointer to function or just a function. */
656 if (args[i]->lval == not_lval)
659 if (find_pc_partial_function ((CORE_ADDR) args[i]->aligner.contents[0], &arg_name, NULL, NULL))
661 You cannot use function <%s> as argument. \n\
662 You must use a pointer to function type variable. Command ignored.", arg_name);
669 if (DEPRECATED_REG_STRUCT_HAS_ADDR_P ())
672 /* This is a machine like the sparc, where we may need to pass a
673 pointer to the structure, not the structure itself. */
674 for (i = nargs - 1; i >= 0; i--)
676 struct type *arg_type = check_typedef (VALUE_TYPE (args[i]));
677 if ((TYPE_CODE (arg_type) == TYPE_CODE_STRUCT
678 || TYPE_CODE (arg_type) == TYPE_CODE_UNION
679 || TYPE_CODE (arg_type) == TYPE_CODE_ARRAY
680 || TYPE_CODE (arg_type) == TYPE_CODE_STRING
681 || TYPE_CODE (arg_type) == TYPE_CODE_BITSTRING
682 || TYPE_CODE (arg_type) == TYPE_CODE_SET
683 || (TYPE_CODE (arg_type) == TYPE_CODE_FLT
684 && TYPE_LENGTH (arg_type) > 8)
686 && DEPRECATED_REG_STRUCT_HAS_ADDR (using_gcc, arg_type))
689 int len; /* = TYPE_LENGTH (arg_type); */
691 arg_type = check_typedef (VALUE_ENCLOSING_TYPE (args[i]));
692 len = TYPE_LENGTH (arg_type);
694 if (DEPRECATED_STACK_ALIGN_P ())
695 /* MVS 11/22/96: I think at least some of this
696 stack_align code is really broken. Better to let
697 PUSH_ARGUMENTS adjust the stack in a target-defined
699 aligned_len = DEPRECATED_STACK_ALIGN (len);
702 if (INNER_THAN (1, 2))
704 /* stack grows downward */
706 /* ... so the address of the thing we push is the
707 stack pointer after we push it. */
712 /* The stack grows up, so the address of the thing
713 we push is the stack pointer before we push it. */
717 /* Push the structure. */
718 write_memory (addr, VALUE_CONTENTS_ALL (args[i]), len);
719 /* The value we're going to pass is the address of the
720 thing we just pushed. */
721 /*args[i] = value_from_longest (lookup_pointer_type (value_type),
723 args[i] = value_from_pointer (lookup_pointer_type (arg_type),
730 /* Reserve space for the return structure to be written on the
731 stack, if necessary. Make certain that the value is correctly
736 int len = TYPE_LENGTH (value_type);
737 if (DEPRECATED_STACK_ALIGN_P ())
738 /* NOTE: cagney/2003-03-22: Should rely on frame align, rather
739 than stack align to force the alignment of the stack. */
740 len = DEPRECATED_STACK_ALIGN (len);
741 if (INNER_THAN (1, 2))
743 /* Stack grows downward. Align STRUCT_ADDR and SP after
744 making space for the return value. */
746 if (gdbarch_frame_align_p (current_gdbarch))
747 sp = gdbarch_frame_align (current_gdbarch, sp);
752 /* Stack grows upward. Align the frame, allocate space, and
753 then again, re-align the frame??? */
754 if (gdbarch_frame_align_p (current_gdbarch))
755 sp = gdbarch_frame_align (current_gdbarch, sp);
758 if (gdbarch_frame_align_p (current_gdbarch))
759 sp = gdbarch_frame_align (current_gdbarch, sp);
763 /* Create the dummy stack frame. Pass in the call dummy address as,
764 presumably, the ABI code knows where, in the call dummy, the
765 return address should be pointed. */
766 if (gdbarch_push_dummy_call_p (current_gdbarch))
767 /* When there is no push_dummy_call method, should this code
768 simply error out. That would the implementation of this method
769 for all ABIs (which is probably a good thing). */
770 sp = gdbarch_push_dummy_call (current_gdbarch, funaddr, current_regcache,
771 bp_addr, nargs, args, sp, struct_return,
773 else if (DEPRECATED_PUSH_ARGUMENTS_P ())
774 /* Keep old targets working. */
775 sp = DEPRECATED_PUSH_ARGUMENTS (nargs, args, sp, struct_return,
778 sp = legacy_push_arguments (nargs, args, sp, struct_return, struct_addr);
780 if (DEPRECATED_PUSH_RETURN_ADDRESS_P ())
781 /* for targets that use no CALL_DUMMY */
782 /* There are a number of targets now which actually don't write
783 any CALL_DUMMY instructions into the target, but instead just
784 save the machine state, push the arguments, and jump directly
785 to the callee function. Since this doesn't actually involve
786 executing a JSR/BSR instruction, the return address must be set
787 up by hand, either by pushing onto the stack or copying into a
788 return-address register as appropriate. Formerly this has been
789 done in PUSH_ARGUMENTS, but that's overloading its
790 functionality a bit, so I'm making it explicit to do it here. */
791 /* NOTE: cagney/2003-04-22: The first parameter ("real_pc") has
792 been replaced with zero, it turns out that no implementation
793 used that parameter. This occured because the value being
794 supplied - the address of the called function's entry point
795 instead of the address of the breakpoint that the called
796 function should return to - wasn't useful. */
797 sp = DEPRECATED_PUSH_RETURN_ADDRESS (0, sp);
799 /* NOTE: cagney/2003-03-23: Diable this code when there is a
800 push_dummy_call() method. Since that method will have already
801 handled any alignment issues, the code below is entirely
803 if (!gdbarch_push_dummy_call_p (current_gdbarch)
804 && DEPRECATED_STACK_ALIGN_P () && !INNER_THAN (1, 2))
806 /* If stack grows up, we must leave a hole at the bottom, note
807 that sp already has been advanced for the arguments! */
808 sp = DEPRECATED_STACK_ALIGN (sp);
811 /* Store the address at which the structure is supposed to be
813 /* NOTE: 2003-03-24: Since PUSH_ARGUMENTS can (and typically does)
814 store the struct return address, this call is entirely redundant. */
815 if (struct_return && DEPRECATED_STORE_STRUCT_RETURN_P ())
816 DEPRECATED_STORE_STRUCT_RETURN (struct_addr, sp);
818 /* Write the stack pointer. This is here because the statements
819 above might fool with it. On SPARC, this write also stores the
820 register window into the right place in the new stack frame,
821 which otherwise wouldn't happen (see store_inferior_registers in
823 /* NOTE: cagney/2003-03-23: Since the architecture method
824 push_dummy_call() should have already stored the stack pointer
825 (as part of creating the fake call frame), and none of the code
826 following that call adjusts the stack-pointer value, the below
827 call is entirely redundant. */
828 if (DEPRECATED_DUMMY_WRITE_SP_P ())
829 DEPRECATED_DUMMY_WRITE_SP (sp);
831 if (gdbarch_unwind_dummy_id_p (current_gdbarch))
833 /* Sanity. The exact same SP value is returned by
834 PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by
835 unwind_dummy_id to form the frame ID's stack address. */
836 gdb_assert (DEPRECATED_USE_GENERIC_DUMMY_FRAMES);
837 generic_save_dummy_frame_tos (sp);
839 else if (DEPRECATED_SAVE_DUMMY_FRAME_TOS_P ())
840 DEPRECATED_SAVE_DUMMY_FRAME_TOS (sp);
842 /* Now proceed, having reached the desired place. */
843 clear_proceed_status ();
845 /* Create a momentary breakpoint at the return address of the
846 inferior. That way it breaks when it returns. */
849 struct breakpoint *bpt;
850 struct symtab_and_line sal;
851 struct frame_id frame;
852 init_sal (&sal); /* initialize to zeroes */
854 sal.section = find_pc_overlay (sal.pc);
855 /* Set up a frame ID for the dummy frame so we can pass it to
856 set_momentary_breakpoint. We need to give the breakpoint a
857 frame ID so that the breakpoint code can correctly re-identify
858 the dummy breakpoint. */
859 if (gdbarch_unwind_dummy_id_p (current_gdbarch))
861 /* Sanity. The exact same SP value is returned by
862 PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by
863 unwind_dummy_id to form the frame ID's stack address. */
864 gdb_assert (DEPRECATED_USE_GENERIC_DUMMY_FRAMES);
865 frame = frame_id_build (sp, sal.pc);
869 /* The assumption here is that push_dummy_call() returned the
870 stack part of the frame ID. Unfortunately, many older
871 architectures were, via a convoluted mess, relying on the
872 poorly defined and greatly overloaded
873 DEPRECATED_TARGET_READ_FP or DEPRECATED_FP_REGNUM to supply
875 if (DEPRECATED_TARGET_READ_FP_P ())
876 frame = frame_id_build (DEPRECATED_TARGET_READ_FP (), sal.pc);
877 else if (DEPRECATED_FP_REGNUM >= 0)
878 frame = frame_id_build (read_register (DEPRECATED_FP_REGNUM), sal.pc);
880 frame = frame_id_build (sp, sal.pc);
882 bpt = set_momentary_breakpoint (sal, frame, bp_call_dummy);
883 bpt->disposition = disp_del;
886 /* Execute a "stack dummy", a piece of code stored in the stack by
887 the debugger to be executed in the inferior.
889 The dummy's frame is automatically popped whenever that break is
890 hit. If that is the first time the program stops,
891 call_function_by_hand returns to its caller with that frame
892 already gone and sets RC to 0.
894 Otherwise, set RC to a non-zero value. If the called function
895 receives a random signal, we do not allow the user to continue
896 executing it as this may not work. The dummy frame is poped and
897 we return 1. If we hit a breakpoint, we leave the frame in place
898 and return 2 (the frame will eventually be popped when we do hit
899 the dummy end breakpoint). */
902 struct cleanup *old_cleanups = make_cleanup (null_cleanup, 0);
905 /* If all error()s out of proceed ended up calling normal_stop
906 (and perhaps they should; it already does in the special case
907 of error out of resume()), then we wouldn't need this. */
908 make_cleanup (breakpoint_auto_delete_contents, &stop_bpstat);
910 disable_watchpoints_before_interactive_call_start ();
911 proceed_to_finish = 1; /* We want stop_registers, please... */
913 if (target_can_async_p ())
914 saved_async = target_async_mask (0);
916 proceed (real_pc, TARGET_SIGNAL_0, 0);
919 target_async_mask (saved_async);
921 enable_watchpoints_after_interactive_call_stop ();
923 discard_cleanups (old_cleanups);
926 if (stopped_by_random_signal || !stop_stack_dummy)
928 /* Find the name of the function we're about to complain about. */
929 const char *name = NULL;
931 struct symbol *symbol = find_pc_function (funaddr);
933 name = SYMBOL_PRINT_NAME (symbol);
936 /* Try the minimal symbols. */
937 struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (funaddr);
939 name = SYMBOL_PRINT_NAME (msymbol);
943 /* Can't use a cleanup here. It is discarded, instead use
945 char *tmp = xstrprintf ("at %s", local_hex_string (funaddr));
946 char *a = alloca (strlen (tmp) + 1);
952 if (stopped_by_random_signal)
954 /* We stopped inside the FUNCTION because of a random
955 signal. Further execution of the FUNCTION is not
958 if (unwind_on_signal_p)
960 /* The user wants the context restored. */
962 /* We must get back to the frame we were before the
964 frame_pop (get_current_frame ());
966 /* FIXME: Insert a bunch of wrap_here; name can be very
967 long if it's a C++ name with arguments and stuff. */
969 The program being debugged was signaled while in a function called from GDB.\n\
970 GDB has restored the context to what it was before the call.\n\
971 To change this behavior use \"set unwindonsignal off\"\n\
972 Evaluation of the expression containing the function (%s) will be abandoned.",
977 /* The user wants to stay in the frame where we stopped
979 /* If we restored the inferior status (via the cleanup),
980 we would print a spurious error message (Unable to
981 restore previously selected frame), would write the
982 registers from the inf_status (which is wrong), and
983 would do other wrong things. */
984 discard_cleanups (inf_status_cleanup);
985 discard_inferior_status (inf_status);
986 /* FIXME: Insert a bunch of wrap_here; name can be very
987 long if it's a C++ name with arguments and stuff. */
989 The program being debugged was signaled while in a function called from GDB.\n\
990 GDB remains in the frame where the signal was received.\n\
991 To change this behavior use \"set unwindonsignal on\"\n\
992 Evaluation of the expression containing the function (%s) will be abandoned.",
997 if (!stop_stack_dummy)
999 /* We hit a breakpoint inside the FUNCTION. */
1000 /* If we restored the inferior status (via the cleanup), we
1001 would print a spurious error message (Unable to restore
1002 previously selected frame), would write the registers
1003 from the inf_status (which is wrong), and would do other
1005 discard_cleanups (inf_status_cleanup);
1006 discard_inferior_status (inf_status);
1007 /* The following error message used to say "The expression
1008 which contained the function call has been discarded."
1009 It is a hard concept to explain in a few words. Ideally,
1010 GDB would be able to resume evaluation of the expression
1011 when the function finally is done executing. Perhaps
1012 someday this will be implemented (it would not be easy). */
1013 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
1014 a C++ name with arguments and stuff. */
1016 The program being debugged stopped while in a function called from GDB.\n\
1017 When the function (%s) is done executing, GDB will silently\n\
1018 stop (instead of continuing to evaluate the expression containing\n\
1019 the function call).", name);
1022 /* The above code errors out, so ... */
1023 internal_error (__FILE__, __LINE__, "... should not be here");
1026 /* If we get here the called FUNCTION run to completion. */
1028 /* On normal return, the stack dummy has been popped already. */
1029 regcache_cpy_no_passthrough (retbuf, stop_registers);
1031 /* Restore the inferior status, via its cleanup. At this stage,
1032 leave the RETBUF alone. */
1033 do_cleanups (inf_status_cleanup);
1035 /* Figure out the value returned by the function. */
1038 /* NOTE: cagney/2003-09-27: This assumes that PUSH_DUMMY_CALL
1039 has correctly stored STRUCT_ADDR in the target. In the past
1040 that hasn't been the case, the old MIPS PUSH_ARGUMENTS
1041 (PUSH_DUMMY_CALL precursor) would silently move the location
1042 of the struct return value making STRUCT_ADDR bogus. If
1043 you're seeing problems with values being returned using the
1044 "struct return convention", check that PUSH_DUMMY_CALL isn't
1046 struct value *retval = value_at (value_type, struct_addr, NULL);
1047 do_cleanups (retbuf_cleanup);
1052 /* The non-register case was handled above. */
1053 struct value *retval = register_value_being_returned (value_type,
1055 do_cleanups (retbuf_cleanup);
1060 void _initialize_infcall (void);
1063 _initialize_infcall (void)
1065 add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure,
1066 &coerce_float_to_double_p, "\
1067 Set coercion of floats to doubles when calling functions\n\
1068 Variables of type float should generally be converted to doubles before\n\
1069 calling an unprototyped function, and left alone when calling a prototyped\n\
1070 function. However, some older debug info formats do not provide enough\n\
1071 information to determine that a function is prototyped. If this flag is\n\
1072 set, GDB will perform the conversion for a function it considers\n\
1074 The default is to perform the conversion.\n", "\
1075 Show coercion of floats to doubles when calling functions\n\
1076 Variables of type float should generally be converted to doubles before\n\
1077 calling an unprototyped function, and left alone when calling a prototyped\n\
1078 function. However, some older debug info formats do not provide enough\n\
1079 information to determine that a function is prototyped. If this flag is\n\
1080 set, GDB will perform the conversion for a function it considers\n\
1082 The default is to perform the conversion.\n",
1083 NULL, NULL, &setlist, &showlist);
1085 add_setshow_boolean_cmd ("unwindonsignal", no_class,
1086 &unwind_on_signal_p, "\
1087 Set unwinding of stack if a signal is received while in a call dummy.\n\
1088 The unwindonsignal lets the user determine what gdb should do if a signal\n\
1089 is received while in a function called from gdb (call dummy). If set, gdb\n\
1090 unwinds the stack and restore the context to what as it was before the call.\n\
1091 The default is to stop in the frame where the signal was received.", "\
1092 Set unwinding of stack if a signal is received while in a call dummy.\n\
1093 The unwindonsignal lets the user determine what gdb should do if a signal\n\
1094 is received while in a function called from gdb (call dummy). If set, gdb\n\
1095 unwinds the stack and restore the context to what as it was before the call.\n\
1096 The default is to stop in the frame where the signal was received.",
1097 NULL, NULL, &setlist, &showlist);