1 /* Target-dependent code for GDB, the GNU debugger.
2 Copyright 1986, 1987, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997
3 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
29 #include "xcoffsolib.h"
31 extern struct obstack frame_cache_obstack
;
35 /* Nonzero if we just simulated a single step break. */
38 /* Breakpoint shadows for the single step instructions will be kept here. */
40 static struct sstep_breaks
{
41 /* Address, or 0 if this is not in use. */
43 /* Shadow contents. */
47 /* Hook for determining the TOC address when calling functions in the
48 inferior under AIX. The initialization code in rs6000-nat.c sets
49 this hook to point to find_toc_address. */
51 CORE_ADDR (*find_toc_address_hook
) PARAMS ((CORE_ADDR
)) = NULL
;
53 /* Static function prototypes */
55 static CORE_ADDR branch_dest
PARAMS ((int opcode
, int instr
, CORE_ADDR pc
,
58 static void frame_get_cache_fsr
PARAMS ((struct frame_info
*fi
,
59 struct rs6000_framedata
*fdatap
));
61 static void pop_dummy_frame
PARAMS ((void));
63 /* Calculate the destination of a branch/jump. Return -1 if not a branch. */
66 branch_dest (opcode
, instr
, pc
, safety
)
77 absolute
= (int) ((instr
>> 1) & 1);
81 immediate
= ((instr
& ~3) << 6) >> 6; /* br unconditional */
85 dest
= pc
+ immediate
;
89 immediate
= ((instr
& ~3) << 16) >> 16; /* br conditional */
93 dest
= pc
+ immediate
;
97 ext_op
= (instr
>>1) & 0x3ff;
99 if (ext_op
== 16) /* br conditional register */
101 dest
= read_register (LR_REGNUM
) & ~3;
103 /* If we are about to return from a signal handler, dest is
104 something like 0x3c90. The current frame is a signal handler
105 caller frame, upon completion of the sigreturn system call
106 execution will return to the saved PC in the frame. */
107 if (dest
< TEXT_SEGMENT_BASE
)
109 struct frame_info
*fi
;
111 fi
= get_current_frame ();
113 dest
= read_memory_integer (fi
->frame
+ SIG_FRAME_PC_OFFSET
,
118 else if (ext_op
== 528) /* br cond to count reg */
120 dest
= read_register (CTR_REGNUM
) & ~3;
122 /* If we are about to execute a system call, dest is something
123 like 0x22fc or 0x3b00. Upon completion the system call
124 will return to the address in the link register. */
125 if (dest
< TEXT_SEGMENT_BASE
)
126 dest
= read_register (LR_REGNUM
) & ~3;
133 return (dest
< TEXT_SEGMENT_BASE
) ? safety
: dest
;
138 /* AIX does not support PT_STEP. Simulate it. */
142 enum target_signal signal
;
144 #define INSNLEN(OPCODE) 4
146 static char le_breakp
[] = LITTLE_BREAKPOINT
;
147 static char be_breakp
[] = BIG_BREAKPOINT
;
148 char *breakp
= TARGET_BYTE_ORDER
== BIG_ENDIAN
? be_breakp
: le_breakp
;
157 insn
= read_memory_integer (loc
, 4);
159 breaks
[0] = loc
+ INSNLEN(insn
);
161 breaks
[1] = branch_dest (opcode
, insn
, loc
, breaks
[0]);
163 /* Don't put two breakpoints on the same address. */
164 if (breaks
[1] == breaks
[0])
167 stepBreaks
[1].address
= 0;
169 for (ii
=0; ii
< 2; ++ii
) {
171 /* ignore invalid breakpoint. */
172 if ( breaks
[ii
] == -1)
175 read_memory (breaks
[ii
], stepBreaks
[ii
].data
, 4);
177 write_memory (breaks
[ii
], breakp
, 4);
178 stepBreaks
[ii
].address
= breaks
[ii
];
184 /* remove step breakpoints. */
185 for (ii
=0; ii
< 2; ++ii
)
186 if (stepBreaks
[ii
].address
!= 0)
188 (stepBreaks
[ii
].address
, stepBreaks
[ii
].data
, 4);
192 errno
= 0; /* FIXME, don't ignore errors! */
193 /* What errors? {read,write}_memory call error(). */
197 /* return pc value after skipping a function prologue and also return
198 information about a function frame.
200 in struct rs6000_frameinfo fdata:
201 - frameless is TRUE, if function does not have a frame.
202 - nosavedpc is TRUE, if function does not save %pc value in its frame.
203 - offset is the number of bytes used in the frame to save registers.
204 - saved_gpr is the number of the first saved gpr.
205 - saved_fpr is the number of the first saved fpr.
206 - alloca_reg is the number of the register used for alloca() handling.
208 - gpr_offset is the offset of the saved gprs
209 - fpr_offset is the offset of the saved fprs
210 - lr_offset is the offset of the saved lr
211 - cr_offset is the offset of the saved cr
214 #define SIGNED_SHORT(x) \
215 ((sizeof (short) == 2) \
216 ? ((int)(short)(x)) \
217 : ((int)((((x) & 0xffff) ^ 0x8000) - 0x8000)))
219 #define GET_SRC_REG(x) (((x) >> 21) & 0x1f)
222 skip_prologue (pc
, fdata
)
224 struct rs6000_framedata
*fdata
;
226 CORE_ADDR orig_pc
= pc
;
234 int minimal_toc_loaded
= 0;
235 static struct rs6000_framedata zero_frame
;
238 fdata
->saved_gpr
= -1;
239 fdata
->saved_fpr
= -1;
240 fdata
->alloca_reg
= -1;
241 fdata
->frameless
= 1;
242 fdata
->nosavedpc
= 1;
244 if (target_read_memory (pc
, buf
, 4))
245 return pc
; /* Can't access it -- assume no prologue. */
247 /* Assume that subsequent fetches can fail with low probability. */
252 op
= read_memory_integer (pc
, 4);
254 if ((op
& 0xfc1fffff) == 0x7c0802a6) { /* mflr Rx */
255 lr_reg
= (op
& 0x03e00000) | 0x90010000;
258 } else if ((op
& 0xfc1fffff) == 0x7c000026) { /* mfcr Rx */
259 cr_reg
= (op
& 0x03e00000) | 0x90010000;
262 } else if ((op
& 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */
263 reg
= GET_SRC_REG (op
);
264 if (fdata
->saved_fpr
== -1 || fdata
->saved_fpr
> reg
) {
265 fdata
->saved_fpr
= reg
;
266 fdata
->fpr_offset
= SIGNED_SHORT (op
) + offset
;
270 } else if (((op
& 0xfc1f0000) == 0xbc010000) || /* stm Rx, NUM(r1) */
271 ((op
& 0xfc1f0000) == 0x90010000 && /* st rx,NUM(r1),
273 (op
& 0x03e00000) >= 0x01a00000)) {
275 reg
= GET_SRC_REG (op
);
276 if (fdata
->saved_gpr
== -1 || fdata
->saved_gpr
> reg
) {
277 fdata
->saved_gpr
= reg
;
278 fdata
->gpr_offset
= SIGNED_SHORT (op
) + offset
;
282 } else if ((op
& 0xffff0000) == 0x3c000000) { /* addis 0,0,NUM, used
284 fdata
->offset
= (op
& 0x0000ffff) << 16;
285 fdata
->frameless
= 0;
288 } else if ((op
& 0xffff0000) == 0x60000000) { /* ori 0,0,NUM, 2nd ha
289 lf of >= 32k frames */
290 fdata
->offset
|= (op
& 0x0000ffff);
291 fdata
->frameless
= 0;
294 } else if ((op
& 0xffff0000) == lr_reg
) { /* st Rx,NUM(r1)
296 fdata
->lr_offset
= SIGNED_SHORT (op
) + offset
;
297 fdata
->nosavedpc
= 0;
301 } else if ((op
& 0xffff0000) == cr_reg
) { /* st Rx,NUM(r1)
303 fdata
->cr_offset
= SIGNED_SHORT (op
) + offset
;
307 } else if (op
== 0x48000005) { /* bl .+4 used in
311 } else if (op
== 0x48000004) { /* b .+4 (xlc) */
314 } else if (((op
& 0xffff0000) == 0x801e0000 || /* lwz 0,NUM(r30), used
315 in V.4 -mrelocatable */
316 op
== 0x7fc0f214) && /* add r30,r0,r30, used
317 in V.4 -mrelocatable */
318 lr_reg
== 0x901e0000) {
321 } else if ((op
& 0xffff0000) == 0x3fc00000 || /* addis 30,0,foo@ha, used
322 in V.4 -mminimal-toc */
323 (op
& 0xffff0000) == 0x3bde0000) { /* addi 30,30,foo@l */
326 } else if ((op
& 0xfc000000) == 0x48000000) { /* bl foo,
329 fdata
->frameless
= 0;
330 /* Don't skip over the subroutine call if it is not within the first
331 three instructions of the prologue. */
332 if ((pc
- orig_pc
) > 8)
335 op
= read_memory_integer (pc
+4, 4);
337 /* At this point, make sure this is not a trampoline function
338 (a function that simply calls another functions, and nothing else).
339 If the next is not a nop, this branch was part of the function
342 if (op
== 0x4def7b82 || op
== 0) /* crorc 15, 15, 15 */
343 break; /* don't skip over
347 /* update stack pointer */
348 } else if ((op
& 0xffff0000) == 0x94210000) { /* stu r1,NUM(r1) */
349 fdata
->frameless
= 0;
350 fdata
->offset
= SIGNED_SHORT (op
);
351 offset
= fdata
->offset
;
354 } else if (op
== 0x7c21016e) { /* stwux 1,1,0 */
355 fdata
->frameless
= 0;
356 offset
= fdata
->offset
;
359 /* Load up minimal toc pointer */
360 } else if ((op
>> 22) == 0x20f
361 && ! minimal_toc_loaded
) { /* l r31,... or l r30,... */
362 minimal_toc_loaded
= 1;
365 /* store parameters in stack */
366 } else if ((op
& 0xfc1f0000) == 0x90010000 || /* st rx,NUM(r1) */
367 (op
& 0xfc1f0000) == 0xd8010000 || /* stfd Rx,NUM(r1) */
368 (op
& 0xfc1f0000) == 0xfc010000) { /* frsp, fp?,NUM(r1) */
371 /* store parameters in stack via frame pointer */
373 ((op
& 0xfc1f0000) == 0x901f0000 || /* st rx,NUM(r1) */
374 (op
& 0xfc1f0000) == 0xd81f0000 || /* stfd Rx,NUM(r1) */
375 (op
& 0xfc1f0000) == 0xfc1f0000)) { /* frsp, fp?,NUM(r1) */
378 /* Set up frame pointer */
379 } else if (op
== 0x603f0000 /* oril r31, r1, 0x0 */
380 || op
== 0x7c3f0b78) { /* mr r31, r1 */
381 fdata
->frameless
= 0;
383 fdata
->alloca_reg
= 31;
386 /* Another way to set up the frame pointer. */
387 } else if ((op
& 0xfc1fffff) == 0x38010000) { /* addi rX, r1, 0x0 */
388 fdata
->frameless
= 0;
390 fdata
->alloca_reg
= (op
& ~0x38010000) >> 21;
399 /* I have problems with skipping over __main() that I need to address
400 * sometime. Previously, I used to use misc_function_vector which
401 * didn't work as well as I wanted to be. -MGO */
403 /* If the first thing after skipping a prolog is a branch to a function,
404 this might be a call to an initializer in main(), introduced by gcc2.
405 We'd like to skip over it as well. Fortunately, xlc does some extra
406 work before calling a function right after a prologue, thus we can
407 single out such gcc2 behaviour. */
410 if ((op
& 0xfc000001) == 0x48000001) { /* bl foo, an initializer function? */
411 op
= read_memory_integer (pc
+4, 4);
413 if (op
== 0x4def7b82) { /* cror 0xf, 0xf, 0xf (nop) */
415 /* check and see if we are in main. If so, skip over this initializer
418 tmp
= find_pc_misc_function (pc
);
419 if (tmp
>= 0 && STREQ (misc_function_vector
[tmp
].name
, "main"))
425 fdata
->offset
= - fdata
->offset
;
430 /*************************************************************************
431 Support for creating pushind a dummy frame into the stack, and popping
433 *************************************************************************/
435 /* The total size of dummy frame is 436, which is;
440 and 24 extra bytes for the callee's link area. The last 24 bytes
441 for the link area might not be necessary, since it will be taken
442 care of by push_arguments(). */
444 #define DUMMY_FRAME_SIZE 436
446 #define DUMMY_FRAME_ADDR_SIZE 10
448 /* Make sure you initialize these in somewhere, in case gdb gives up what it
449 was debugging and starts debugging something else. FIXMEibm */
451 static int dummy_frame_count
= 0;
452 static int dummy_frame_size
= 0;
453 static CORE_ADDR
*dummy_frame_addr
= 0;
455 extern int stop_stack_dummy
;
457 /* push a dummy frame into stack, save all register. Currently we are saving
458 only gpr's and fpr's, which is not good enough! FIXMEmgo */
465 /* Same thing, target byte order. */
470 /* Same thing, target byte order. */
473 /* Needed to figure out where to save the dummy link area.
474 FIXME: There should be an easier way to do this, no? tiemann 9/9/95. */
475 struct rs6000_framedata fdata
;
479 target_fetch_registers (-1);
481 if (dummy_frame_count
>= dummy_frame_size
) {
482 dummy_frame_size
+= DUMMY_FRAME_ADDR_SIZE
;
483 if (dummy_frame_addr
)
484 dummy_frame_addr
= (CORE_ADDR
*) xrealloc
485 (dummy_frame_addr
, sizeof(CORE_ADDR
) * (dummy_frame_size
));
487 dummy_frame_addr
= (CORE_ADDR
*)
488 xmalloc (sizeof(CORE_ADDR
) * (dummy_frame_size
));
491 sp
= read_register(SP_REGNUM
);
492 pc
= read_register(PC_REGNUM
);
493 store_address (pc_targ
, 4, pc
);
495 skip_prologue (get_pc_function_start (pc
) + FUNCTION_START_OFFSET
, &fdata
);
497 dummy_frame_addr
[dummy_frame_count
++] = sp
;
499 /* Be careful! If the stack pointer is not decremented first, then kernel
500 thinks he is free to use the space underneath it. And kernel actually
501 uses that area for IPC purposes when executing ptrace(2) calls. So
502 before writing register values into the new frame, decrement and update
503 %sp first in order to secure your frame. */
505 /* FIXME: We don't check if the stack really has this much space.
506 This is a problem on the ppc simulator (which only grants one page
507 (4096 bytes) by default. */
509 write_register (SP_REGNUM
, sp
-DUMMY_FRAME_SIZE
);
511 /* gdb relies on the state of current_frame. We'd better update it,
512 otherwise things like do_registers_info() wouldn't work properly! */
514 flush_cached_frames ();
516 /* save program counter in link register's space. */
517 write_memory (sp
+ (fdata
.lr_offset
? fdata
.lr_offset
: DEFAULT_LR_SAVE
),
520 /* save all floating point and general purpose registers here. */
523 for (ii
= 0; ii
< 32; ++ii
)
524 write_memory (sp
-8-(ii
*8), ®isters
[REGISTER_BYTE (31-ii
+FP0_REGNUM
)], 8);
527 for (ii
=1; ii
<=32; ++ii
)
528 write_memory (sp
-256-(ii
*4), ®isters
[REGISTER_BYTE (32-ii
)], 4);
530 /* so far, 32*2 + 32 words = 384 bytes have been written.
531 7 extra registers in our register set: pc, ps, cnd, lr, cnt, xer, mq */
533 for (ii
=1; ii
<= (LAST_SP_REGNUM
-FIRST_SP_REGNUM
+1); ++ii
) {
534 write_memory (sp
-384-(ii
*4),
535 ®isters
[REGISTER_BYTE (FPLAST_REGNUM
+ ii
)], 4);
538 /* Save sp or so called back chain right here. */
539 store_address (sp_targ
, 4, sp
);
540 write_memory (sp
-DUMMY_FRAME_SIZE
, sp_targ
, 4);
541 sp
-= DUMMY_FRAME_SIZE
;
543 /* And finally, this is the back chain. */
544 write_memory (sp
+8, pc_targ
, 4);
548 /* Pop a dummy frame.
550 In rs6000 when we push a dummy frame, we save all of the registers. This
551 is usually done before user calls a function explicitly.
553 After a dummy frame is pushed, some instructions are copied into stack,
554 and stack pointer is decremented even more. Since we don't have a frame
555 pointer to get back to the parent frame of the dummy, we start having
556 trouble poping it. Therefore, we keep a dummy frame stack, keeping
557 addresses of dummy frames as such. When poping happens and when we
558 detect that was a dummy frame, we pop it back to its parent by using
559 dummy frame stack (`dummy_frame_addr' array).
561 FIXME: This whole concept is broken. You should be able to detect
562 a dummy stack frame *on the user's stack itself*. When you do,
563 then you know the format of that stack frame -- including its
564 saved SP register! There should *not* be a separate stack in the
565 GDB process that keeps track of these dummy frames! -- gnu@cygnus.com Aug92
573 sp
= dummy_frame_addr
[--dummy_frame_count
];
575 /* restore all fpr's. */
576 for (ii
= 1; ii
<= 32; ++ii
)
577 read_memory (sp
-(ii
*8), ®isters
[REGISTER_BYTE (32-ii
+FP0_REGNUM
)], 8);
579 /* restore all gpr's */
580 for (ii
=1; ii
<= 32; ++ii
) {
581 read_memory (sp
-256-(ii
*4), ®isters
[REGISTER_BYTE (32-ii
)], 4);
584 /* restore the rest of the registers. */
585 for (ii
=1; ii
<=(LAST_SP_REGNUM
-FIRST_SP_REGNUM
+1); ++ii
)
586 read_memory (sp
-384-(ii
*4),
587 ®isters
[REGISTER_BYTE (FPLAST_REGNUM
+ ii
)], 4);
589 read_memory (sp
-(DUMMY_FRAME_SIZE
-8),
590 ®isters
[REGISTER_BYTE(PC_REGNUM
)], 4);
592 /* when a dummy frame was being pushed, we had to decrement %sp first, in
593 order to secure astack space. Thus, saved %sp (or %r1) value, is not the
594 one we should restore. Change it with the one we need. */
596 memcpy (®isters
[REGISTER_BYTE(FP_REGNUM
)], (char *) &sp
, sizeof (int));
598 /* Now we can restore all registers. */
600 target_store_registers (-1);
602 flush_cached_frames ();
606 /* pop the innermost frame, go back to the caller. */
611 CORE_ADDR pc
, lr
, sp
, prev_sp
; /* %pc, %lr, %sp */
612 struct rs6000_framedata fdata
;
613 struct frame_info
*frame
= get_current_frame ();
617 sp
= FRAME_FP (frame
);
619 if (stop_stack_dummy
&& dummy_frame_count
) {
624 /* Make sure that all registers are valid. */
625 read_register_bytes (0, NULL
, REGISTER_BYTES
);
627 /* figure out previous %pc value. If the function is frameless, it is
628 still in the link register, otherwise walk the frames and retrieve the
629 saved %pc value in the previous frame. */
631 addr
= get_pc_function_start (frame
->pc
) + FUNCTION_START_OFFSET
;
632 (void) skip_prologue (addr
, &fdata
);
637 prev_sp
= read_memory_integer (sp
, 4);
638 if (fdata
.lr_offset
== 0)
639 lr
= read_register (LR_REGNUM
);
641 lr
= read_memory_integer (prev_sp
+ fdata
.lr_offset
, 4);
643 /* reset %pc value. */
644 write_register (PC_REGNUM
, lr
);
646 /* reset register values if any was saved earlier. */
647 addr
= prev_sp
- fdata
.offset
;
649 if (fdata
.saved_gpr
!= -1)
650 for (ii
= fdata
.saved_gpr
; ii
<= 31; ++ii
) {
651 read_memory (addr
, ®isters
[REGISTER_BYTE (ii
)], 4);
655 if (fdata
.saved_fpr
!= -1)
656 for (ii
= fdata
.saved_fpr
; ii
<= 31; ++ii
) {
657 read_memory (addr
, ®isters
[REGISTER_BYTE (ii
+FP0_REGNUM
)], 8);
661 write_register (SP_REGNUM
, prev_sp
);
662 target_store_registers (-1);
663 flush_cached_frames ();
666 /* fixup the call sequence of a dummy function, with the real function address.
667 its argumets will be passed by gdb. */
670 rs6000_fix_call_dummy (dummyname
, pc
, fun
, nargs
, args
, type
, gcc_p
)
679 #define TOC_ADDR_OFFSET 20
680 #define TARGET_ADDR_OFFSET 28
683 CORE_ADDR target_addr
;
685 if (find_toc_address_hook
!= NULL
)
689 tocvalue
= (*find_toc_address_hook
) (fun
);
690 ii
= *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
);
691 ii
= (ii
& 0xffff0000) | (tocvalue
>> 16);
692 *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
) = ii
;
694 ii
= *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
+4);
695 ii
= (ii
& 0xffff0000) | (tocvalue
& 0x0000ffff);
696 *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
+4) = ii
;
700 ii
= *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
);
701 ii
= (ii
& 0xffff0000) | (target_addr
>> 16);
702 *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
) = ii
;
704 ii
= *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
+4);
705 ii
= (ii
& 0xffff0000) | (target_addr
& 0x0000ffff);
706 *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
+4) = ii
;
709 /* Pass the arguments in either registers, or in the stack. In RS6000,
710 the first eight words of the argument list (that might be less than
711 eight parameters if some parameters occupy more than one word) are
712 passed in r3..r11 registers. float and double parameters are
713 passed in fpr's, in addition to that. Rest of the parameters if any
714 are passed in user stack. There might be cases in which half of the
715 parameter is copied into registers, the other half is pushed into
718 If the function is returning a structure, then the return address is passed
719 in r3, then the first 7 words of the parameters can be passed in registers,
723 push_arguments (nargs
, args
, sp
, struct_return
, struct_addr
)
728 CORE_ADDR struct_addr
;
732 int argno
; /* current argument number */
733 int argbytes
; /* current argument byte */
734 char tmp_buffer
[50];
735 int f_argno
= 0; /* current floating point argno */
741 if ( dummy_frame_count
<= 0)
742 printf_unfiltered ("FATAL ERROR -push_arguments()! frame not found!!\n");
744 /* The first eight words of ther arguments are passed in registers. Copy
747 If the function is returning a `struct', then the first word (which
748 will be passed in r3) is used for struct return address. In that
749 case we should advance one word and start from r4 register to copy
752 ii
= struct_return
? 1 : 0;
754 for (argno
=0, argbytes
=0; argno
< nargs
&& ii
<8; ++ii
) {
757 type
= check_typedef (VALUE_TYPE (arg
));
758 len
= TYPE_LENGTH (type
);
760 if (TYPE_CODE (type
) == TYPE_CODE_FLT
) {
762 /* floating point arguments are passed in fpr's, as well as gpr's.
763 There are 13 fpr's reserved for passing parameters. At this point
764 there is no way we would run out of them. */
768 "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno
);
770 memcpy (®isters
[REGISTER_BYTE(FP0_REGNUM
+ 1 + f_argno
)],
771 VALUE_CONTENTS (arg
),
778 /* Argument takes more than one register. */
779 while (argbytes
< len
) {
780 memset (®isters
[REGISTER_BYTE(ii
+3)], 0, sizeof(int));
781 memcpy (®isters
[REGISTER_BYTE(ii
+3)],
782 ((char*)VALUE_CONTENTS (arg
))+argbytes
,
783 (len
- argbytes
) > 4 ? 4 : len
- argbytes
);
787 goto ran_out_of_registers_for_arguments
;
792 else { /* Argument can fit in one register. No problem. */
793 memset (®isters
[REGISTER_BYTE(ii
+3)], 0, sizeof(int));
794 memcpy (®isters
[REGISTER_BYTE(ii
+3)], VALUE_CONTENTS (arg
), len
);
799 ran_out_of_registers_for_arguments
:
801 /* location for 8 parameters are always reserved. */
804 /* another six words for back chain, TOC register, link register, etc. */
807 /* if there are more arguments, allocate space for them in
808 the stack, then push them starting from the ninth one. */
810 if ((argno
< nargs
) || argbytes
) {
814 space
+= ((len
- argbytes
+ 3) & -4);
820 for (; jj
< nargs
; ++jj
) {
821 value_ptr val
= args
[jj
];
822 space
+= ((TYPE_LENGTH (VALUE_TYPE (val
))) + 3) & -4;
825 /* add location required for the rest of the parameters */
826 space
= (space
+ 7) & -8;
829 /* This is another instance we need to be concerned about securing our
830 stack space. If we write anything underneath %sp (r1), we might conflict
831 with the kernel who thinks he is free to use this area. So, update %sp
832 first before doing anything else. */
834 write_register (SP_REGNUM
, sp
);
836 /* if the last argument copied into the registers didn't fit there
837 completely, push the rest of it into stack. */
840 write_memory (sp
+24+(ii
*4),
841 ((char*)VALUE_CONTENTS (arg
))+argbytes
,
844 ii
+= ((len
- argbytes
+ 3) & -4) / 4;
847 /* push the rest of the arguments into stack. */
848 for (; argno
< nargs
; ++argno
) {
851 type
= check_typedef (VALUE_TYPE (arg
));
852 len
= TYPE_LENGTH (type
);
855 /* float types should be passed in fpr's, as well as in the stack. */
856 if (TYPE_CODE (type
) == TYPE_CODE_FLT
&& f_argno
< 13) {
860 "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno
);
862 memcpy (®isters
[REGISTER_BYTE(FP0_REGNUM
+ 1 + f_argno
)],
863 VALUE_CONTENTS (arg
),
868 write_memory (sp
+24+(ii
*4), (char *) VALUE_CONTENTS (arg
), len
);
869 ii
+= ((len
+ 3) & -4) / 4;
873 /* Secure stack areas first, before doing anything else. */
874 write_register (SP_REGNUM
, sp
);
876 saved_sp
= dummy_frame_addr
[dummy_frame_count
- 1];
877 read_memory (saved_sp
, tmp_buffer
, 24);
878 write_memory (sp
, tmp_buffer
, 24);
880 /* set back chain properly */
881 store_address (tmp_buffer
, 4, saved_sp
);
882 write_memory (sp
, tmp_buffer
, 4);
884 target_store_registers (-1);
888 /* a given return value in `regbuf' with a type `valtype', extract and copy its
889 value into `valbuf' */
892 extract_return_value (valtype
, regbuf
, valbuf
)
893 struct type
*valtype
;
894 char regbuf
[REGISTER_BYTES
];
899 if (TYPE_CODE (valtype
) == TYPE_CODE_FLT
) {
902 /* floats and doubles are returned in fpr1. fpr's have a size of 8 bytes.
903 We need to truncate the return value into float size (4 byte) if
906 if (TYPE_LENGTH (valtype
) > 4) /* this is a double */
908 ®buf
[REGISTER_BYTE (FP0_REGNUM
+ 1)],
909 TYPE_LENGTH (valtype
));
911 memcpy (&dd
, ®buf
[REGISTER_BYTE (FP0_REGNUM
+ 1)], 8);
913 memcpy (valbuf
, &ff
, sizeof(float));
917 /* return value is copied starting from r3. */
918 if (TARGET_BYTE_ORDER
== BIG_ENDIAN
919 && TYPE_LENGTH (valtype
) < REGISTER_RAW_SIZE (3))
920 offset
= REGISTER_RAW_SIZE (3) - TYPE_LENGTH (valtype
);
923 regbuf
+ REGISTER_BYTE (3) + offset
,
924 TYPE_LENGTH (valtype
));
929 /* keep structure return address in this variable.
930 FIXME: This is a horrid kludge which should not be allowed to continue
931 living. This only allows a single nested call to a structure-returning
932 function. Come on, guys! -- gnu@cygnus.com, Aug 92 */
934 CORE_ADDR rs6000_struct_return_address
;
937 /* Indirect function calls use a piece of trampoline code to do context
938 switching, i.e. to set the new TOC table. Skip such code if we are on
939 its first instruction (as when we have single-stepped to here).
940 Also skip shared library trampoline code (which is different from
941 indirect function call trampolines).
942 Result is desired PC to step until, or NULL if we are not in
946 skip_trampoline_code (pc
)
949 register unsigned int ii
, op
;
950 CORE_ADDR solib_target_pc
;
952 static unsigned trampoline_code
[] = {
953 0x800b0000, /* l r0,0x0(r11) */
954 0x90410014, /* st r2,0x14(r1) */
955 0x7c0903a6, /* mtctr r0 */
956 0x804b0004, /* l r2,0x4(r11) */
957 0x816b0008, /* l r11,0x8(r11) */
958 0x4e800420, /* bctr */
963 /* If pc is in a shared library trampoline, return its target. */
964 solib_target_pc
= find_solib_trampoline_target (pc
);
966 return solib_target_pc
;
968 for (ii
=0; trampoline_code
[ii
]; ++ii
) {
969 op
= read_memory_integer (pc
+ (ii
*4), 4);
970 if (op
!= trampoline_code
[ii
])
973 ii
= read_register (11); /* r11 holds destination addr */
974 pc
= read_memory_integer (ii
, 4); /* (r11) value */
978 /* Determines whether the function FI has a frame on the stack or not. */
981 frameless_function_invocation (fi
)
982 struct frame_info
*fi
;
984 CORE_ADDR func_start
;
985 struct rs6000_framedata fdata
;
987 /* Don't even think about framelessness except on the innermost frame
988 or if the function was interrupted by a signal. */
989 if (fi
->next
!= NULL
&& !fi
->next
->signal_handler_caller
)
992 func_start
= get_pc_function_start (fi
->pc
);
994 /* If we failed to find the start of the function, it is a mistake
995 to inspect the instructions. */
999 /* A frame with a zero PC is usually created by dereferencing a NULL
1000 function pointer, normally causing an immediate core dump of the
1001 inferior. Mark function as frameless, as the inferior has no chance
1002 of setting up a stack frame. */
1009 func_start
+= FUNCTION_START_OFFSET
;
1010 (void) skip_prologue (func_start
, &fdata
);
1011 return fdata
.frameless
;
1014 /* Return the PC saved in a frame */
1018 struct frame_info
*fi
;
1020 CORE_ADDR func_start
;
1021 struct rs6000_framedata fdata
;
1023 if (fi
->signal_handler_caller
)
1024 return read_memory_integer (fi
->frame
+ SIG_FRAME_PC_OFFSET
, 4);
1026 func_start
= get_pc_function_start (fi
->pc
) + FUNCTION_START_OFFSET
;
1028 /* If we failed to find the start of the function, it is a mistake
1029 to inspect the instructions. */
1033 (void) skip_prologue (func_start
, &fdata
);
1035 if (fdata
.lr_offset
== 0 && fi
->next
!= NULL
)
1037 if (fi
->next
->signal_handler_caller
)
1038 return read_memory_integer (fi
->next
->frame
+ SIG_FRAME_LR_OFFSET
, 4);
1040 return read_memory_integer (rs6000_frame_chain (fi
) + DEFAULT_LR_SAVE
,
1044 if (fdata
.lr_offset
== 0)
1045 return read_register (LR_REGNUM
);
1047 return read_memory_integer (rs6000_frame_chain (fi
) + fdata
.lr_offset
, 4);
1050 /* If saved registers of frame FI are not known yet, read and cache them.
1051 &FDATAP contains rs6000_framedata; TDATAP can be NULL,
1052 in which case the framedata are read. */
1055 frame_get_cache_fsr (fi
, fdatap
)
1056 struct frame_info
*fi
;
1057 struct rs6000_framedata
*fdatap
;
1060 CORE_ADDR frame_addr
;
1061 struct rs6000_framedata work_fdata
;
1066 if (fdatap
== NULL
) {
1067 fdatap
= &work_fdata
;
1068 (void) skip_prologue (get_pc_function_start (fi
->pc
), fdatap
);
1071 fi
->cache_fsr
= (struct frame_saved_regs
*)
1072 obstack_alloc (&frame_cache_obstack
, sizeof (struct frame_saved_regs
));
1073 memset (fi
->cache_fsr
, '\0', sizeof (struct frame_saved_regs
));
1075 if (fi
->prev
&& fi
->prev
->frame
)
1076 frame_addr
= fi
->prev
->frame
;
1078 frame_addr
= read_memory_integer (fi
->frame
, 4);
1080 /* if != -1, fdatap->saved_fpr is the smallest number of saved_fpr.
1081 All fpr's from saved_fpr to fp31 are saved. */
1083 if (fdatap
->saved_fpr
>= 0) {
1084 int fpr_offset
= frame_addr
+ fdatap
->fpr_offset
;
1085 for (ii
= fdatap
->saved_fpr
; ii
< 32; ii
++) {
1086 fi
->cache_fsr
->regs
[FP0_REGNUM
+ ii
] = fpr_offset
;
1091 /* if != -1, fdatap->saved_gpr is the smallest number of saved_gpr.
1092 All gpr's from saved_gpr to gpr31 are saved. */
1094 if (fdatap
->saved_gpr
>= 0) {
1095 int gpr_offset
= frame_addr
+ fdatap
->gpr_offset
;
1096 for (ii
= fdatap
->saved_gpr
; ii
< 32; ii
++) {
1097 fi
->cache_fsr
->regs
[ii
] = gpr_offset
;
1102 /* If != 0, fdatap->cr_offset is the offset from the frame that holds
1104 if (fdatap
->cr_offset
!= 0)
1105 fi
->cache_fsr
->regs
[CR_REGNUM
] = frame_addr
+ fdatap
->cr_offset
;
1107 /* If != 0, fdatap->lr_offset is the offset from the frame that holds
1109 if (fdatap
->lr_offset
!= 0)
1110 fi
->cache_fsr
->regs
[LR_REGNUM
] = frame_addr
+ fdatap
->lr_offset
;
1113 /* Return the address of a frame. This is the inital %sp value when the frame
1114 was first allocated. For functions calling alloca(), it might be saved in
1115 an alloca register. */
1118 frame_initial_stack_address (fi
)
1119 struct frame_info
*fi
;
1122 struct rs6000_framedata fdata
;
1123 struct frame_info
*callee_fi
;
1125 /* if the initial stack pointer (frame address) of this frame is known,
1129 return fi
->initial_sp
;
1131 /* find out if this function is using an alloca register.. */
1133 (void) skip_prologue (get_pc_function_start (fi
->pc
), &fdata
);
1135 /* if saved registers of this frame are not known yet, read and cache them. */
1138 frame_get_cache_fsr (fi
, &fdata
);
1140 /* If no alloca register used, then fi->frame is the value of the %sp for
1141 this frame, and it is good enough. */
1143 if (fdata
.alloca_reg
< 0) {
1144 fi
->initial_sp
= fi
->frame
;
1145 return fi
->initial_sp
;
1148 /* This function has an alloca register. If this is the top-most frame
1149 (with the lowest address), the value in alloca register is good. */
1152 return fi
->initial_sp
= read_register (fdata
.alloca_reg
);
1154 /* Otherwise, this is a caller frame. Callee has usually already saved
1155 registers, but there are exceptions (such as when the callee
1156 has no parameters). Find the address in which caller's alloca
1157 register is saved. */
1159 for (callee_fi
= fi
->next
; callee_fi
; callee_fi
= callee_fi
->next
) {
1161 if (!callee_fi
->cache_fsr
)
1162 frame_get_cache_fsr (callee_fi
, NULL
);
1164 /* this is the address in which alloca register is saved. */
1166 tmpaddr
= callee_fi
->cache_fsr
->regs
[fdata
.alloca_reg
];
1168 fi
->initial_sp
= read_memory_integer (tmpaddr
, 4);
1169 return fi
->initial_sp
;
1172 /* Go look into deeper levels of the frame chain to see if any one of
1173 the callees has saved alloca register. */
1176 /* If alloca register was not saved, by the callee (or any of its callees)
1177 then the value in the register is still good. */
1179 return fi
->initial_sp
= read_register (fdata
.alloca_reg
);
1183 rs6000_frame_chain (thisframe
)
1184 struct frame_info
*thisframe
;
1187 if (inside_entry_file ((thisframe
)->pc
))
1189 if (thisframe
->signal_handler_caller
)
1190 fp
= read_memory_integer (thisframe
->frame
+ SIG_FRAME_FP_OFFSET
, 4);
1191 else if (thisframe
->next
!= NULL
1192 && thisframe
->next
->signal_handler_caller
1193 && frameless_function_invocation (thisframe
))
1194 /* A frameless function interrupted by a signal did not change the
1196 fp
= FRAME_FP (thisframe
);
1198 fp
= read_memory_integer ((thisframe
)->frame
, 4);
1203 /* Return nonzero if ADDR (a function pointer) is in the data space and
1204 is therefore a special function pointer. */
1207 is_magic_function_pointer (addr
)
1210 struct obj_section
*s
;
1212 s
= find_pc_section (addr
);
1213 if (s
&& s
->the_bfd_section
->flags
& SEC_CODE
)
1219 #ifdef GDB_TARGET_POWERPC
1221 gdb_print_insn_powerpc (memaddr
, info
)
1223 disassemble_info
*info
;
1225 if (TARGET_BYTE_ORDER
== BIG_ENDIAN
)
1226 return print_insn_big_powerpc (memaddr
, info
);
1228 return print_insn_little_powerpc (memaddr
, info
);
1233 _initialize_rs6000_tdep ()
1235 /* FIXME, this should not be decided via ifdef. */
1236 #ifdef GDB_TARGET_POWERPC
1237 tm_print_insn
= gdb_print_insn_powerpc
;
1239 tm_print_insn
= print_insn_rs6000
;