1 /* Target-dependent code for GDB, the GNU debugger.
2 Copyright 1986, 1987, 1989, 1991, 1992, 1993, 1994, 1995
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., 675 Mass Ave, Cambridge, MA 02139, USA. */
28 #include "xcoffsolib.h"
32 extern struct obstack frame_cache_obstack
;
36 /* Nonzero if we just simulated a single step break. */
39 /* Breakpoint shadows for the single step instructions will be kept here. */
41 static struct sstep_breaks
{
42 /* Address, or 0 if this is not in use. */
44 /* Shadow contents. */
48 /* Static function prototypes */
51 find_toc_address
PARAMS ((CORE_ADDR pc
));
54 branch_dest
PARAMS ((int opcode
, int instr
, CORE_ADDR pc
, CORE_ADDR safety
));
57 frame_get_cache_fsr
PARAMS ((struct frame_info
*fi
,
58 struct aix_framedata
*fdatap
));
61 * Calculate the destination of a branch/jump. Return -1 if not a branch.
64 branch_dest (opcode
, instr
, pc
, safety
)
76 absolute
= (int) ((instr
>> 1) & 1);
80 immediate
= ((instr
& ~3) << 6) >> 6; /* br unconditional */
84 dest
= pc
+ immediate
;
88 immediate
= ((instr
& ~3) << 16) >> 16; /* br conditional */
92 dest
= pc
+ immediate
;
96 ext_op
= (instr
>>1) & 0x3ff;
98 if (ext_op
== 16) /* br conditional register */
99 dest
= read_register (LR_REGNUM
) & ~3;
101 else if (ext_op
== 528) /* br cond to count reg */
103 dest
= read_register (CTR_REGNUM
) & ~3;
105 /* If we are about to execute a system call, dest is something
106 like 0x22fc or 0x3b00. Upon completion the system call
107 will return to the address in the link register. */
108 if (dest
< TEXT_SEGMENT_BASE
)
109 dest
= read_register (LR_REGNUM
) & ~3;
116 return (dest
< TEXT_SEGMENT_BASE
) ? safety
: dest
;
121 /* AIX does not support PT_STEP. Simulate it. */
127 #define INSNLEN(OPCODE) 4
129 static char breakp
[] = BREAKPOINT
;
138 insn
= read_memory_integer (loc
, 4);
140 breaks
[0] = loc
+ INSNLEN(insn
);
142 breaks
[1] = branch_dest (opcode
, insn
, loc
, breaks
[0]);
144 /* Don't put two breakpoints on the same address. */
145 if (breaks
[1] == breaks
[0])
148 stepBreaks
[1].address
= 0;
150 for (ii
=0; ii
< 2; ++ii
) {
152 /* ignore invalid breakpoint. */
153 if ( breaks
[ii
] == -1)
156 read_memory (breaks
[ii
], stepBreaks
[ii
].data
, 4);
158 write_memory (breaks
[ii
], breakp
, 4);
159 stepBreaks
[ii
].address
= breaks
[ii
];
165 /* remove step breakpoints. */
166 for (ii
=0; ii
< 2; ++ii
)
167 if (stepBreaks
[ii
].address
!= 0)
169 (stepBreaks
[ii
].address
, stepBreaks
[ii
].data
, 4);
173 errno
= 0; /* FIXME, don't ignore errors! */
174 /* What errors? {read,write}_memory call error(). */
178 /* return pc value after skipping a function prologue. */
187 if (target_read_memory (pc
, buf
, 4))
188 return pc
; /* Can't access it -- assume no prologue. */
189 op
= extract_unsigned_integer (buf
, 4);
191 /* Assume that subsequent fetches can fail with low probability. */
193 if (op
== 0x7c0802a6) { /* mflr r0 */
195 op
= read_memory_integer (pc
, 4);
198 if ((op
& 0xfc00003e) == 0x7c000026) { /* mfcr Rx */
200 op
= read_memory_integer (pc
, 4);
203 if ((op
& 0xfc000000) == 0x48000000) { /* bl foo, to save fprs??? */
205 op
= read_memory_integer (pc
, 4);
207 /* At this point, make sure this is not a trampoline function
208 (a function that simply calls another functions, and nothing else).
209 If the next is not a nop, this branch was part of the function
212 if (op
== 0x4def7b82 || /* crorc 15, 15, 15 */
214 return pc
- 4; /* don't skip over this branch */
217 if ((op
& 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */
218 pc
+= 4; /* store floating register double */
219 op
= read_memory_integer (pc
, 4);
222 if ((op
& 0xfc1f0000) == 0xbc010000) { /* stm Rx, NUM(r1) */
224 op
= read_memory_integer (pc
, 4);
227 while ((op
& 0xfc1f0000) == 0x90010000 && /* st rx,NUM(r1), rx >= r13 */
228 (op
& 0x03e00000) >= 0x01a00000) {
230 op
= read_memory_integer (pc
, 4);
233 if (op
== 0x90010008) { /* st r0,8(r1) */
235 op
= read_memory_integer (pc
, 4);
238 if (op
== 0x91810004) { /* st r12,4(r1) */
240 op
= read_memory_integer (pc
, 4);
243 if ((op
& 0xffff0000) == 0x94210000) { /* stu r1,NUM(r1) */
245 op
= read_memory_integer (pc
, 4);
248 while ((tmp
= (op
>> 22)) == 0x20f) { /* l r31, ... or */
249 pc
+= 4; /* l r30, ... */
250 op
= read_memory_integer (pc
, 4);
253 /* store parameters into stack */
255 (op
& 0xfc1f0000) == 0xd8010000 || /* stfd Rx,NUM(r1) */
256 (op
& 0xfc1f0000) == 0x90010000 || /* st r?, NUM(r1) */
257 (op
& 0xfc000000) == 0xfc000000 || /* frsp, fp?, .. */
258 (op
& 0xd0000000) == 0xd0000000) /* stfs, fp?, .. */
260 pc
+= 4; /* store fpr double */
261 op
= read_memory_integer (pc
, 4);
264 if (op
== 0x603f0000 /* oril r31, r1, 0x0 */
265 || op
== 0x7c3f0b78) { /* mr r31, r1 */
266 pc
+= 4; /* this happens if r31 is used as */
267 op
= read_memory_integer (pc
, 4); /* frame ptr. (gcc does that) */
270 while ((op
>> 16) == (0x907f + tmp
)) { /* st r3, NUM(r31) */
271 pc
+= 4; /* st r4, NUM(r31), ... */
272 op
= read_memory_integer (pc
, 4);
277 /* I have problems with skipping over __main() that I need to address
278 * sometime. Previously, I used to use misc_function_vector which
279 * didn't work as well as I wanted to be. -MGO */
281 /* If the first thing after skipping a prolog is a branch to a function,
282 this might be a call to an initializer in main(), introduced by gcc2.
283 We'd like to skip over it as well. Fortunately, xlc does some extra
284 work before calling a function right after a prologue, thus we can
285 single out such gcc2 behaviour. */
288 if ((op
& 0xfc000001) == 0x48000001) { /* bl foo, an initializer function? */
289 op
= read_memory_integer (pc
+4, 4);
291 if (op
== 0x4def7b82) { /* cror 0xf, 0xf, 0xf (nop) */
293 /* check and see if we are in main. If so, skip over this initializer
296 tmp
= find_pc_misc_function (pc
);
297 if (tmp
>= 0 && STREQ (misc_function_vector
[tmp
].name
, "main"))
307 /*************************************************************************
308 Support for creating pushind a dummy frame into the stack, and popping
310 *************************************************************************/
312 /* The total size of dummy frame is 436, which is;
317 and 24 extra bytes for the callee's link area. The last 24 bytes
318 for the link area might not be necessary, since it will be taken
319 care of by push_arguments(). */
321 #define DUMMY_FRAME_SIZE 436
323 #define DUMMY_FRAME_ADDR_SIZE 10
325 /* Make sure you initialize these in somewhere, in case gdb gives up what it
326 was debugging and starts debugging something else. FIXMEibm */
328 static int dummy_frame_count
= 0;
329 static int dummy_frame_size
= 0;
330 static CORE_ADDR
*dummy_frame_addr
= 0;
332 extern int stop_stack_dummy
;
334 /* push a dummy frame into stack, save all register. Currently we are saving
335 only gpr's and fpr's, which is not good enough! FIXMEmgo */
342 /* Same thing, target byte order. */
347 /* Same thing, target byte order. */
352 target_fetch_registers (-1);
354 if (dummy_frame_count
>= dummy_frame_size
) {
355 dummy_frame_size
+= DUMMY_FRAME_ADDR_SIZE
;
356 if (dummy_frame_addr
)
357 dummy_frame_addr
= (CORE_ADDR
*) xrealloc
358 (dummy_frame_addr
, sizeof(CORE_ADDR
) * (dummy_frame_size
));
360 dummy_frame_addr
= (CORE_ADDR
*)
361 xmalloc (sizeof(CORE_ADDR
) * (dummy_frame_size
));
364 sp
= read_register(SP_REGNUM
);
365 pc
= read_register(PC_REGNUM
);
366 store_address (pc_targ
, 4, pc
);
368 dummy_frame_addr
[dummy_frame_count
++] = sp
;
370 /* Be careful! If the stack pointer is not decremented first, then kernel
371 thinks he is free to use the space underneath it. And kernel actually
372 uses that area for IPC purposes when executing ptrace(2) calls. So
373 before writing register values into the new frame, decrement and update
374 %sp first in order to secure your frame. */
376 write_register (SP_REGNUM
, sp
-DUMMY_FRAME_SIZE
);
378 /* gdb relies on the state of current_frame. We'd better update it,
379 otherwise things like do_registers_info() wouldn't work properly! */
381 flush_cached_frames ();
383 /* save program counter in link register's space. */
384 write_memory (sp
+8, pc_targ
, 4);
386 /* save all floating point and general purpose registers here. */
389 for (ii
= 0; ii
< 32; ++ii
)
390 write_memory (sp
-8-(ii
*8), ®isters
[REGISTER_BYTE (31-ii
+FP0_REGNUM
)], 8);
393 for (ii
=1; ii
<=32; ++ii
)
394 write_memory (sp
-256-(ii
*4), ®isters
[REGISTER_BYTE (32-ii
)], 4);
396 /* so far, 32*2 + 32 words = 384 bytes have been written.
397 7 extra registers in our register set: pc, ps, cnd, lr, cnt, xer, mq */
399 for (ii
=1; ii
<= (LAST_SP_REGNUM
-FIRST_SP_REGNUM
+1); ++ii
) {
400 write_memory (sp
-384-(ii
*4),
401 ®isters
[REGISTER_BYTE (FPLAST_REGNUM
+ ii
)], 4);
404 /* Save sp or so called back chain right here. */
405 store_address (sp_targ
, 4, sp
);
406 write_memory (sp
-DUMMY_FRAME_SIZE
, sp_targ
, 4);
407 sp
-= DUMMY_FRAME_SIZE
;
409 /* And finally, this is the back chain. */
410 write_memory (sp
+8, pc_targ
, 4);
414 /* Pop a dummy frame.
416 In rs6000 when we push a dummy frame, we save all of the registers. This
417 is usually done before user calls a function explicitly.
419 After a dummy frame is pushed, some instructions are copied into stack,
420 and stack pointer is decremented even more. Since we don't have a frame
421 pointer to get back to the parent frame of the dummy, we start having
422 trouble poping it. Therefore, we keep a dummy frame stack, keeping
423 addresses of dummy frames as such. When poping happens and when we
424 detect that was a dummy frame, we pop it back to its parent by using
425 dummy frame stack (`dummy_frame_addr' array).
427 FIXME: This whole concept is broken. You should be able to detect
428 a dummy stack frame *on the user's stack itself*. When you do,
429 then you know the format of that stack frame -- including its
430 saved SP register! There should *not* be a separate stack in the
431 GDB process that keeps track of these dummy frames! -- gnu@cygnus.com Aug92
438 sp
= dummy_frame_addr
[--dummy_frame_count
];
440 /* restore all fpr's. */
441 for (ii
= 1; ii
<= 32; ++ii
)
442 read_memory (sp
-(ii
*8), ®isters
[REGISTER_BYTE (32-ii
+FP0_REGNUM
)], 8);
444 /* restore all gpr's */
445 for (ii
=1; ii
<= 32; ++ii
) {
446 read_memory (sp
-256-(ii
*4), ®isters
[REGISTER_BYTE (32-ii
)], 4);
449 /* restore the rest of the registers. */
450 for (ii
=1; ii
<=(LAST_SP_REGNUM
-FIRST_SP_REGNUM
+1); ++ii
)
451 read_memory (sp
-384-(ii
*4),
452 ®isters
[REGISTER_BYTE (FPLAST_REGNUM
+ ii
)], 4);
454 read_memory (sp
-(DUMMY_FRAME_SIZE
-8),
455 ®isters
[REGISTER_BYTE(PC_REGNUM
)], 4);
457 /* when a dummy frame was being pushed, we had to decrement %sp first, in
458 order to secure astack space. Thus, saved %sp (or %r1) value, is not the
459 one we should restore. Change it with the one we need. */
461 *(int*)®isters
[REGISTER_BYTE(FP_REGNUM
)] = sp
;
463 /* Now we can restore all registers. */
465 target_store_registers (-1);
467 flush_cached_frames ();
471 /* pop the innermost frame, go back to the caller. */
476 CORE_ADDR pc
, lr
, sp
, prev_sp
; /* %pc, %lr, %sp */
477 struct aix_framedata fdata
;
478 struct frame_info
*frame
= get_current_frame ();
482 sp
= FRAME_FP (frame
);
484 if (stop_stack_dummy
&& dummy_frame_count
) {
489 /* Make sure that all registers are valid. */
490 read_register_bytes (0, NULL
, REGISTER_BYTES
);
492 /* figure out previous %pc value. If the function is frameless, it is
493 still in the link register, otherwise walk the frames and retrieve the
494 saved %pc value in the previous frame. */
496 addr
= get_pc_function_start (frame
->pc
) + FUNCTION_START_OFFSET
;
497 function_frame_info (addr
, &fdata
);
502 prev_sp
= read_memory_integer (sp
, 4);
504 lr
= read_register (LR_REGNUM
);
506 lr
= read_memory_integer (prev_sp
+8, 4);
508 /* reset %pc value. */
509 write_register (PC_REGNUM
, lr
);
511 /* reset register values if any was saved earlier. */
512 addr
= prev_sp
- fdata
.offset
;
514 if (fdata
.saved_gpr
!= -1)
515 for (ii
= fdata
.saved_gpr
; ii
<= 31; ++ii
) {
516 read_memory (addr
, ®isters
[REGISTER_BYTE (ii
)], 4);
520 if (fdata
.saved_fpr
!= -1)
521 for (ii
= fdata
.saved_fpr
; ii
<= 31; ++ii
) {
522 read_memory (addr
, ®isters
[REGISTER_BYTE (ii
+FP0_REGNUM
)], 8);
526 write_register (SP_REGNUM
, prev_sp
);
527 target_store_registers (-1);
528 flush_cached_frames ();
531 /* fixup the call sequence of a dummy function, with the real function address.
532 its argumets will be passed by gdb. */
535 fix_call_dummy(dummyname
, pc
, fun
, nargs
, type
)
539 int nargs
; /* not used */
540 int type
; /* not used */
542 #define TOC_ADDR_OFFSET 20
543 #define TARGET_ADDR_OFFSET 28
546 CORE_ADDR target_addr
;
550 tocvalue
= find_toc_address (target_addr
);
552 ii
= *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
);
553 ii
= (ii
& 0xffff0000) | (tocvalue
>> 16);
554 *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
) = ii
;
556 ii
= *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
+4);
557 ii
= (ii
& 0xffff0000) | (tocvalue
& 0x0000ffff);
558 *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
+4) = ii
;
560 ii
= *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
);
561 ii
= (ii
& 0xffff0000) | (target_addr
>> 16);
562 *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
) = ii
;
564 ii
= *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
+4);
565 ii
= (ii
& 0xffff0000) | (target_addr
& 0x0000ffff);
566 *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
+4) = ii
;
570 /* return information about a function frame.
571 in struct aix_frameinfo fdata:
572 - frameless is TRUE, if function does not have a frame.
573 - nosavedpc is TRUE, if function does not save %pc value in its frame.
574 - offset is the number of bytes used in the frame to save registers.
575 - saved_gpr is the number of the first saved gpr.
576 - saved_fpr is the number of the first saved fpr.
577 - alloca_reg is the number of the register used for alloca() handling.
581 function_frame_info (pc
, fdata
)
583 struct aix_framedata
*fdata
;
586 register unsigned int op
;
590 fdata
->saved_gpr
= fdata
->saved_fpr
= fdata
->alloca_reg
= -1;
591 fdata
->frameless
= 1;
593 /* Do not error out if we can't access the instructions. */
594 if (target_read_memory (pc
, buf
, 4))
596 op
= extract_unsigned_integer (buf
, 4);
597 if (op
== 0x7c0802a6) { /* mflr r0 */
599 op
= read_memory_integer (pc
, 4);
600 fdata
->nosavedpc
= 0;
601 fdata
->frameless
= 0;
603 else /* else, pc is not saved */
604 fdata
->nosavedpc
= 1;
606 if ((op
& 0xfc00003e) == 0x7c000026) { /* mfcr Rx */
608 op
= read_memory_integer (pc
, 4);
609 fdata
->frameless
= 0;
612 if ((op
& 0xfc000000) == 0x48000000) { /* bl foo, to save fprs??? */
614 op
= read_memory_integer (pc
, 4);
615 /* At this point, make sure this is not a trampoline function
616 (a function that simply calls another functions, and nothing else).
617 If the next is not a nop, this branch was part of the function
620 if (op
== 0x4def7b82 || /* crorc 15, 15, 15 */
622 return; /* prologue is over */
623 fdata
->frameless
= 0;
626 if ((op
& 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */
627 pc
+= 4; /* store floating register double */
628 op
= read_memory_integer (pc
, 4);
629 fdata
->frameless
= 0;
632 if ((op
& 0xfc1f0000) == 0xbc010000) { /* stm Rx, NUM(r1) */
634 fdata
->saved_gpr
= (op
>> 21) & 0x1f;
637 tmp2
= (~0 &~ 0xffff) | tmp2
;
641 fdata
->saved_fpr
= (tmp2
- ((32 - fdata
->saved_gpr
) * 4)) / 8;
642 if ( fdata
->saved_fpr
> 0)
643 fdata
->saved_fpr
= 32 - fdata
->saved_fpr
;
645 fdata
->saved_fpr
= -1;
647 fdata
->offset
= tmp2
;
649 op
= read_memory_integer (pc
, 4);
650 fdata
->frameless
= 0;
653 while (((tmp
= op
>> 16) == 0x9001) || /* st r0, NUM(r1) */
654 (tmp
== 0x9421) || /* stu r1, NUM(r1) */
655 (tmp
== 0x93e1)) /* st r31, NUM(r1) */
659 /* gcc takes a short cut and uses this instruction to save r31 only. */
663 /* fatal ("Unrecognized prolog."); */
664 printf_unfiltered ("Unrecognized prolog!\n");
666 fdata
->saved_gpr
= 31;
669 tmp2
= - ((~0 &~ 0xffff) | tmp2
);
670 fdata
->saved_fpr
= (tmp2
- ((32 - 31) * 4)) / 8;
671 if ( fdata
->saved_fpr
> 0)
672 fdata
->saved_fpr
= 32 - fdata
->saved_fpr
;
674 fdata
->saved_fpr
= -1;
676 fdata
->offset
= tmp2
;
679 op
= read_memory_integer (pc
, 4);
680 fdata
->frameless
= 0;
683 while ((tmp
= (op
>> 22)) == 0x20f) { /* l r31, ... or */
684 pc
+= 4; /* l r30, ... */
685 op
= read_memory_integer (pc
, 4);
686 fdata
->frameless
= 0;
689 /* store parameters into stack */
691 (op
& 0xfc1f0000) == 0xd8010000 || /* stfd Rx,NUM(r1) */
692 (op
& 0xfc1f0000) == 0x90010000 || /* st r?, NUM(r1) */
693 (op
& 0xfc000000) == 0xfc000000 || /* frsp, fp?, .. */
694 (op
& 0xd0000000) == 0xd0000000) /* stfs, fp?, .. */
696 pc
+= 4; /* store fpr double */
697 op
= read_memory_integer (pc
, 4);
698 fdata
->frameless
= 0;
701 if (op
== 0x603f0000 /* oril r31, r1, 0x0 */
702 || op
== 0x7c3f0b78) /* mr r31, r1 */
704 fdata
->alloca_reg
= 31;
705 fdata
->frameless
= 0;
710 /* Pass the arguments in either registers, or in the stack. In RS6000, the first
711 eight words of the argument list (that might be less than eight parameters if
712 some parameters occupy more than one word) are passed in r3..r11 registers.
713 float and double parameters are passed in fpr's, in addition to that. Rest of
714 the parameters if any are passed in user stack. There might be cases in which
715 half of the 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 parametes can be passed in registers,
723 push_arguments (nargs
, args
, sp
, struct_return
, struct_addr
)
728 CORE_ADDR struct_addr
;
731 int argno
; /* current argument number */
732 int argbytes
; /* current argument byte */
733 char tmp_buffer
[50];
735 int f_argno
= 0; /* current floating point argno */
737 CORE_ADDR saved_sp
, pc
;
739 if ( dummy_frame_count
<= 0)
740 printf_unfiltered ("FATAL ERROR -push_arguments()! frame not found!!\n");
742 /* The first eight words of ther arguments are passed in registers. Copy
745 If the function is returning a `struct', then the first word (which
746 will be passed in r3) is used for struct return address. In that
747 case we should advance one word and start from r4 register to copy
750 ii
= struct_return
? 1 : 0;
752 for (argno
=0, argbytes
=0; argno
< nargs
&& ii
<8; ++ii
) {
755 len
= TYPE_LENGTH (VALUE_TYPE (arg
));
757 if (TYPE_CODE (VALUE_TYPE (arg
)) == TYPE_CODE_FLT
) {
759 /* floating point arguments are passed in fpr's, as well as gpr's.
760 There are 13 fpr's reserved for passing parameters. At this point
761 there is no way we would run out of them. */
765 "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno
);
767 memcpy (®isters
[REGISTER_BYTE(FP0_REGNUM
+ 1 + f_argno
)], VALUE_CONTENTS (arg
),
774 /* Argument takes more than one register. */
775 while (argbytes
< len
) {
777 *(int*)®isters
[REGISTER_BYTE(ii
+3)] = 0;
778 memcpy (®isters
[REGISTER_BYTE(ii
+3)],
779 ((char*)VALUE_CONTENTS (arg
))+argbytes
,
780 (len
- argbytes
) > 4 ? 4 : len
- argbytes
);
784 goto ran_out_of_registers_for_arguments
;
789 else { /* Argument can fit in one register. No problem. */
790 *(int*)®isters
[REGISTER_BYTE(ii
+3)] = 0;
791 memcpy (®isters
[REGISTER_BYTE(ii
+3)], VALUE_CONTENTS (arg
), len
);
796 ran_out_of_registers_for_arguments
:
798 /* location for 8 parameters are always reserved. */
801 /* another six words for back chain, TOC register, link register, etc. */
804 /* if there are more arguments, allocate space for them in
805 the stack, then push them starting from the ninth one. */
807 if ((argno
< nargs
) || argbytes
) {
812 space
+= ((len
- argbytes
+ 3) & -4);
818 for (; jj
< nargs
; ++jj
) {
820 space
+= ((TYPE_LENGTH (VALUE_TYPE (val
))) + 3) & -4;
823 /* add location required for the rest of the parameters */
824 space
= (space
+ 7) & -8;
827 /* This is another instance we need to be concerned about securing our
828 stack space. If we write anything underneath %sp (r1), we might conflict
829 with the kernel who thinks he is free to use this area. So, update %sp
830 first before doing anything else. */
832 write_register (SP_REGNUM
, sp
);
834 /* if the last argument copied into the registers didn't fit there
835 completely, push the rest of it into stack. */
839 sp
+24+(ii
*4), ((char*)VALUE_CONTENTS (arg
))+argbytes
, len
- argbytes
);
841 ii
+= ((len
- argbytes
+ 3) & -4) / 4;
844 /* push the rest of the arguments into stack. */
845 for (; argno
< nargs
; ++argno
) {
848 len
= TYPE_LENGTH (VALUE_TYPE (arg
));
851 /* float types should be passed in fpr's, as well as in the stack. */
852 if (TYPE_CODE (VALUE_TYPE (arg
)) == TYPE_CODE_FLT
&& f_argno
< 13) {
856 "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno
);
858 memcpy (®isters
[REGISTER_BYTE(FP0_REGNUM
+ 1 + f_argno
)], VALUE_CONTENTS (arg
),
863 write_memory (sp
+24+(ii
*4), (char *) VALUE_CONTENTS (arg
), len
);
864 ii
+= ((len
+ 3) & -4) / 4;
868 /* Secure stack areas first, before doing anything else. */
869 write_register (SP_REGNUM
, sp
);
871 saved_sp
= dummy_frame_addr
[dummy_frame_count
- 1];
872 read_memory (saved_sp
, tmp_buffer
, 24);
873 write_memory (sp
, tmp_buffer
, 24);
875 /* set back chain properly */
876 store_address (tmp_buffer
, 4, saved_sp
);
877 write_memory (sp
, tmp_buffer
, 4);
879 target_store_registers (-1);
883 /* a given return value in `regbuf' with a type `valtype', extract and copy its
884 value into `valbuf' */
887 extract_return_value (valtype
, regbuf
, valbuf
)
888 struct type
*valtype
;
889 char regbuf
[REGISTER_BYTES
];
893 if (TYPE_CODE (valtype
) == TYPE_CODE_FLT
) {
896 /* floats and doubles are returned in fpr1. fpr's have a size of 8 bytes.
897 We need to truncate the return value into float size (4 byte) if
900 if (TYPE_LENGTH (valtype
) > 4) /* this is a double */
901 memcpy (valbuf
, ®buf
[REGISTER_BYTE (FP0_REGNUM
+ 1)],
902 TYPE_LENGTH (valtype
));
904 memcpy (&dd
, ®buf
[REGISTER_BYTE (FP0_REGNUM
+ 1)], 8);
906 memcpy (valbuf
, &ff
, sizeof(float));
910 /* return value is copied starting from r3. */
911 memcpy (valbuf
, ®buf
[REGISTER_BYTE (3)], TYPE_LENGTH (valtype
));
915 /* keep structure return address in this variable.
916 FIXME: This is a horrid kludge which should not be allowed to continue
917 living. This only allows a single nested call to a structure-returning
918 function. Come on, guys! -- gnu@cygnus.com, Aug 92 */
920 CORE_ADDR rs6000_struct_return_address
;
923 /* Indirect function calls use a piece of trampoline code to do context
924 switching, i.e. to set the new TOC table. Skip such code if we are on
925 its first instruction (as when we have single-stepped to here).
926 Also skip shared library trampoline code (which is different from
927 indirect function call trampolines).
928 Result is desired PC to step until, or NULL if we are not in
932 skip_trampoline_code (pc
)
935 register unsigned int ii
, op
;
936 CORE_ADDR solib_target_pc
;
938 static unsigned trampoline_code
[] = {
939 0x800b0000, /* l r0,0x0(r11) */
940 0x90410014, /* st r2,0x14(r1) */
941 0x7c0903a6, /* mtctr r0 */
942 0x804b0004, /* l r2,0x4(r11) */
943 0x816b0008, /* l r11,0x8(r11) */
944 0x4e800420, /* bctr */
949 /* If pc is in a shared library trampoline, return its target. */
950 solib_target_pc
= find_solib_trampoline_target (pc
);
952 return solib_target_pc
;
954 for (ii
=0; trampoline_code
[ii
]; ++ii
) {
955 op
= read_memory_integer (pc
+ (ii
*4), 4);
956 if (op
!= trampoline_code
[ii
])
959 ii
= read_register (11); /* r11 holds destination addr */
960 pc
= read_memory_integer (ii
, 4); /* (r11) value */
965 /* Determines whether the function FI has a frame on the stack or not.
966 Called from the FRAMELESS_FUNCTION_INVOCATION macro in tm.h with a
967 second argument of 0, and from the FRAME_SAVED_PC macro with a
968 second argument of 1. */
971 frameless_function_invocation (fi
, pcsaved
)
972 struct frame_info
*fi
;
975 CORE_ADDR func_start
;
976 struct aix_framedata fdata
;
978 if (fi
->next
!= NULL
)
979 /* Don't even think about framelessness except on the innermost frame. */
980 /* FIXME: Can also be frameless if fi->next->signal_handler_caller (if
981 a signal happens while executing in a frameless function). */
984 func_start
= get_pc_function_start (fi
->pc
) + FUNCTION_START_OFFSET
;
986 /* If we failed to find the start of the function, it is a mistake
987 to inspect the instructions. */
992 function_frame_info (func_start
, &fdata
);
993 return pcsaved
? fdata
.nosavedpc
: fdata
.frameless
;
997 /* If saved registers of frame FI are not known yet, read and cache them.
998 &FDATAP contains aix_framedata; TDATAP can be NULL,
999 in which case the framedata are read. */
1002 frame_get_cache_fsr (fi
, fdatap
)
1003 struct frame_info
*fi
;
1004 struct aix_framedata
*fdatap
;
1007 CORE_ADDR frame_addr
;
1008 struct aix_framedata work_fdata
;
1013 if (fdatap
== NULL
) {
1014 fdatap
= &work_fdata
;
1015 function_frame_info (get_pc_function_start (fi
->pc
), fdatap
);
1018 fi
->cache_fsr
= (struct frame_saved_regs
*)
1019 obstack_alloc (&frame_cache_obstack
, sizeof (struct frame_saved_regs
));
1020 memset (fi
->cache_fsr
, '\0', sizeof (struct frame_saved_regs
));
1022 if (fi
->prev
&& fi
->prev
->frame
)
1023 frame_addr
= fi
->prev
->frame
;
1025 frame_addr
= read_memory_integer (fi
->frame
, 4);
1027 /* if != -1, fdatap->saved_fpr is the smallest number of saved_fpr.
1028 All fpr's from saved_fpr to fp31 are saved right underneath caller
1029 stack pointer, starting from fp31 first. */
1031 if (fdatap
->saved_fpr
>= 0) {
1032 for (ii
=31; ii
>= fdatap
->saved_fpr
; --ii
)
1033 fi
->cache_fsr
->regs
[FP0_REGNUM
+ ii
] = frame_addr
- ((32 - ii
) * 8);
1034 frame_addr
-= (32 - fdatap
->saved_fpr
) * 8;
1037 /* if != -1, fdatap->saved_gpr is the smallest number of saved_gpr.
1038 All gpr's from saved_gpr to gpr31 are saved right under saved fprs,
1039 starting from r31 first. */
1041 if (fdatap
->saved_gpr
>= 0)
1042 for (ii
=31; ii
>= fdatap
->saved_gpr
; --ii
)
1043 fi
->cache_fsr
->regs
[ii
] = frame_addr
- ((32 - ii
) * 4);
1046 /* Return the address of a frame. This is the inital %sp value when the frame
1047 was first allocated. For functions calling alloca(), it might be saved in
1048 an alloca register. */
1051 frame_initial_stack_address (fi
)
1052 struct frame_info
*fi
;
1055 struct aix_framedata fdata
;
1056 struct frame_info
*callee_fi
;
1058 /* if the initial stack pointer (frame address) of this frame is known,
1062 return fi
->initial_sp
;
1064 /* find out if this function is using an alloca register.. */
1066 function_frame_info (get_pc_function_start (fi
->pc
), &fdata
);
1068 /* if saved registers of this frame are not known yet, read and cache them. */
1071 frame_get_cache_fsr (fi
, &fdata
);
1073 /* If no alloca register used, then fi->frame is the value of the %sp for
1074 this frame, and it is good enough. */
1076 if (fdata
.alloca_reg
< 0) {
1077 fi
->initial_sp
= fi
->frame
;
1078 return fi
->initial_sp
;
1081 /* This function has an alloca register. If this is the top-most frame
1082 (with the lowest address), the value in alloca register is good. */
1085 return fi
->initial_sp
= read_register (fdata
.alloca_reg
);
1087 /* Otherwise, this is a caller frame. Callee has usually already saved
1088 registers, but there are exceptions (such as when the callee
1089 has no parameters). Find the address in which caller's alloca
1090 register is saved. */
1092 for (callee_fi
= fi
->next
; callee_fi
; callee_fi
= callee_fi
->next
) {
1094 if (!callee_fi
->cache_fsr
)
1095 frame_get_cache_fsr (callee_fi
, NULL
);
1097 /* this is the address in which alloca register is saved. */
1099 tmpaddr
= callee_fi
->cache_fsr
->regs
[fdata
.alloca_reg
];
1101 fi
->initial_sp
= read_memory_integer (tmpaddr
, 4);
1102 return fi
->initial_sp
;
1105 /* Go look into deeper levels of the frame chain to see if any one of
1106 the callees has saved alloca register. */
1109 /* If alloca register was not saved, by the callee (or any of its callees)
1110 then the value in the register is still good. */
1112 return fi
->initial_sp
= read_register (fdata
.alloca_reg
);
1116 rs6000_frame_chain (thisframe
)
1117 struct frame_info
*thisframe
;
1120 if (inside_entry_file ((thisframe
)->pc
))
1122 if (thisframe
->signal_handler_caller
)
1123 fp
= read_memory_integer (thisframe
->frame
+ SIG_FRAME_FP_OFFSET
, 4);
1125 fp
= read_memory_integer ((thisframe
)->frame
, 4);
1130 /* Keep an array of load segment information and their TOC table addresses.
1131 This info will be useful when calling a shared library function by hand. */
1134 CORE_ADDR textorg
, dataorg
;
1135 unsigned long toc_offset
;
1138 #define LOADINFOLEN 10
1140 static struct loadinfo
*loadinfo
= NULL
;
1141 static int loadinfolen
= 0;
1142 static int loadinfotocindex
= 0;
1143 static int loadinfotextindex
= 0;
1147 xcoff_init_loadinfo ()
1149 loadinfotocindex
= 0;
1150 loadinfotextindex
= 0;
1152 if (loadinfolen
== 0) {
1153 loadinfo
= (struct loadinfo
*)
1154 xmalloc (sizeof (struct loadinfo
) * LOADINFOLEN
);
1155 loadinfolen
= LOADINFOLEN
;
1160 /* FIXME -- this is never called! */
1168 loadinfotocindex
= 0;
1169 loadinfotextindex
= 0;
1172 /* this is called from xcoffread.c */
1175 xcoff_add_toc_to_loadinfo (tocoff
)
1176 unsigned long tocoff
;
1178 while (loadinfotocindex
>= loadinfolen
) {
1179 loadinfolen
+= LOADINFOLEN
;
1180 loadinfo
= (struct loadinfo
*)
1181 xrealloc (loadinfo
, sizeof(struct loadinfo
) * loadinfolen
);
1183 loadinfo
[loadinfotocindex
++].toc_offset
= tocoff
;
1187 add_text_to_loadinfo (textaddr
, dataaddr
)
1191 while (loadinfotextindex
>= loadinfolen
) {
1192 loadinfolen
+= LOADINFOLEN
;
1193 loadinfo
= (struct loadinfo
*)
1194 xrealloc (loadinfo
, sizeof(struct loadinfo
) * loadinfolen
);
1196 loadinfo
[loadinfotextindex
].textorg
= textaddr
;
1197 loadinfo
[loadinfotextindex
].dataorg
= dataaddr
;
1198 ++loadinfotextindex
;
1202 /* FIXME: This assumes that the "textorg" and "dataorg" elements
1203 of a member of this array are correlated with the "toc_offset"
1204 element of the same member. But they are sequentially assigned in wildly
1205 different places, and probably there is no correlation. FIXME! */
1208 find_toc_address (pc
)
1211 int ii
, toc_entry
, tocbase
= 0;
1213 for (ii
=0; ii
< loadinfotextindex
; ++ii
)
1214 if (pc
> loadinfo
[ii
].textorg
&& loadinfo
[ii
].textorg
> tocbase
) {
1216 tocbase
= loadinfo
[ii
].textorg
;
1219 return loadinfo
[toc_entry
].dataorg
+ loadinfo
[toc_entry
].toc_offset
;
1223 _initialize_rs6000_tdep ()
1225 /* FIXME, this should not be decided via ifdef. */
1226 #ifdef GDB_TARGET_POWERPC
1227 tm_print_insn
= print_insn_big_powerpc
;
1229 tm_print_insn
= print_insn_rs6000
;