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) == 0x9001 && /* st rx,NUM(r1), rx >= r13 */
228 (op
& 0x03e00000) >= 0x01a00000) {
230 op
= read_memory_integer (pc
, 4);
233 if ((op
& 0xfc1f0000) == 0x94210000) { /* stu r1,NUM(r1) */
235 op
= read_memory_integer (pc
, 4);
238 while ((tmp
= (op
>> 22)) == 0x20f) { /* l r31, ... or */
239 pc
+= 4; /* l r30, ... */
240 op
= read_memory_integer (pc
, 4);
243 /* store parameters into stack */
245 (op
& 0xfc1f0000) == 0xd8010000 || /* stfd Rx,NUM(r1) */
246 (op
& 0xfc1f0000) == 0x90010000 || /* st r?, NUM(r1) */
247 (op
& 0xfc000000) == 0xfc000000 || /* frsp, fp?, .. */
248 (op
& 0xd0000000) == 0xd0000000) /* stfs, fp?, .. */
250 pc
+= 4; /* store fpr double */
251 op
= read_memory_integer (pc
, 4);
254 if (op
== 0x603f0000 /* oril r31, r1, 0x0 */
255 || op
== 0x7c3f0b78) { /* mr r31, r1 */
256 pc
+= 4; /* this happens if r31 is used as */
257 op
= read_memory_integer (pc
, 4); /* frame ptr. (gcc does that) */
260 while ((op
>> 16) == (0x907f + tmp
)) { /* st r3, NUM(r31) */
261 pc
+= 4; /* st r4, NUM(r31), ... */
262 op
= read_memory_integer (pc
, 4);
267 /* I have problems with skipping over __main() that I need to address
268 * sometime. Previously, I used to use misc_function_vector which
269 * didn't work as well as I wanted to be. -MGO */
271 /* If the first thing after skipping a prolog is a branch to a function,
272 this might be a call to an initializer in main(), introduced by gcc2.
273 We'd like to skip over it as well. Fortunately, xlc does some extra
274 work before calling a function right after a prologue, thus we can
275 single out such gcc2 behaviour. */
278 if ((op
& 0xfc000001) == 0x48000001) { /* bl foo, an initializer function? */
279 op
= read_memory_integer (pc
+4, 4);
281 if (op
== 0x4def7b82) { /* cror 0xf, 0xf, 0xf (nop) */
283 /* check and see if we are in main. If so, skip over this initializer
286 tmp
= find_pc_misc_function (pc
);
287 if (tmp
>= 0 && STREQ (misc_function_vector
[tmp
].name
, "main"))
297 /*************************************************************************
298 Support for creating pushind a dummy frame into the stack, and popping
300 *************************************************************************/
302 /* The total size of dummy frame is 436, which is;
307 and 24 extra bytes for the callee's link area. The last 24 bytes
308 for the link area might not be necessary, since it will be taken
309 care of by push_arguments(). */
311 #define DUMMY_FRAME_SIZE 436
313 #define DUMMY_FRAME_ADDR_SIZE 10
315 /* Make sure you initialize these in somewhere, in case gdb gives up what it
316 was debugging and starts debugging something else. FIXMEibm */
318 static int dummy_frame_count
= 0;
319 static int dummy_frame_size
= 0;
320 static CORE_ADDR
*dummy_frame_addr
= 0;
322 extern int stop_stack_dummy
;
324 /* push a dummy frame into stack, save all register. Currently we are saving
325 only gpr's and fpr's, which is not good enough! FIXMEmgo */
332 /* Same thing, target byte order. */
337 /* Same thing, target byte order. */
342 target_fetch_registers (-1);
344 if (dummy_frame_count
>= dummy_frame_size
) {
345 dummy_frame_size
+= DUMMY_FRAME_ADDR_SIZE
;
346 if (dummy_frame_addr
)
347 dummy_frame_addr
= (CORE_ADDR
*) xrealloc
348 (dummy_frame_addr
, sizeof(CORE_ADDR
) * (dummy_frame_size
));
350 dummy_frame_addr
= (CORE_ADDR
*)
351 xmalloc (sizeof(CORE_ADDR
) * (dummy_frame_size
));
354 sp
= read_register(SP_REGNUM
);
355 pc
= read_register(PC_REGNUM
);
356 store_address (pc_targ
, 4, pc
);
358 dummy_frame_addr
[dummy_frame_count
++] = sp
;
360 /* Be careful! If the stack pointer is not decremented first, then kernel
361 thinks he is free to use the space underneath it. And kernel actually
362 uses that area for IPC purposes when executing ptrace(2) calls. So
363 before writing register values into the new frame, decrement and update
364 %sp first in order to secure your frame. */
366 write_register (SP_REGNUM
, sp
-DUMMY_FRAME_SIZE
);
368 /* gdb relies on the state of current_frame. We'd better update it,
369 otherwise things like do_registers_info() wouldn't work properly! */
371 flush_cached_frames ();
373 /* save program counter in link register's space. */
374 write_memory (sp
+8, pc_targ
, 4);
376 /* save all floating point and general purpose registers here. */
379 for (ii
= 0; ii
< 32; ++ii
)
380 write_memory (sp
-8-(ii
*8), ®isters
[REGISTER_BYTE (31-ii
+FP0_REGNUM
)], 8);
383 for (ii
=1; ii
<=32; ++ii
)
384 write_memory (sp
-256-(ii
*4), ®isters
[REGISTER_BYTE (32-ii
)], 4);
386 /* so far, 32*2 + 32 words = 384 bytes have been written.
387 7 extra registers in our register set: pc, ps, cnd, lr, cnt, xer, mq */
389 for (ii
=1; ii
<= (LAST_SP_REGNUM
-FIRST_SP_REGNUM
+1); ++ii
) {
390 write_memory (sp
-384-(ii
*4),
391 ®isters
[REGISTER_BYTE (FPLAST_REGNUM
+ ii
)], 4);
394 /* Save sp or so called back chain right here. */
395 store_address (sp_targ
, 4, sp
);
396 write_memory (sp
-DUMMY_FRAME_SIZE
, sp_targ
, 4);
397 sp
-= DUMMY_FRAME_SIZE
;
399 /* And finally, this is the back chain. */
400 write_memory (sp
+8, pc_targ
, 4);
404 /* Pop a dummy frame.
406 In rs6000 when we push a dummy frame, we save all of the registers. This
407 is usually done before user calls a function explicitly.
409 After a dummy frame is pushed, some instructions are copied into stack,
410 and stack pointer is decremented even more. Since we don't have a frame
411 pointer to get back to the parent frame of the dummy, we start having
412 trouble poping it. Therefore, we keep a dummy frame stack, keeping
413 addresses of dummy frames as such. When poping happens and when we
414 detect that was a dummy frame, we pop it back to its parent by using
415 dummy frame stack (`dummy_frame_addr' array).
417 FIXME: This whole concept is broken. You should be able to detect
418 a dummy stack frame *on the user's stack itself*. When you do,
419 then you know the format of that stack frame -- including its
420 saved SP register! There should *not* be a separate stack in the
421 GDB process that keeps track of these dummy frames! -- gnu@cygnus.com Aug92
428 sp
= dummy_frame_addr
[--dummy_frame_count
];
430 /* restore all fpr's. */
431 for (ii
= 1; ii
<= 32; ++ii
)
432 read_memory (sp
-(ii
*8), ®isters
[REGISTER_BYTE (32-ii
+FP0_REGNUM
)], 8);
434 /* restore all gpr's */
435 for (ii
=1; ii
<= 32; ++ii
) {
436 read_memory (sp
-256-(ii
*4), ®isters
[REGISTER_BYTE (32-ii
)], 4);
439 /* restore the rest of the registers. */
440 for (ii
=1; ii
<=(LAST_SP_REGNUM
-FIRST_SP_REGNUM
+1); ++ii
)
441 read_memory (sp
-384-(ii
*4),
442 ®isters
[REGISTER_BYTE (FPLAST_REGNUM
+ ii
)], 4);
444 read_memory (sp
-(DUMMY_FRAME_SIZE
-8),
445 ®isters
[REGISTER_BYTE(PC_REGNUM
)], 4);
447 /* when a dummy frame was being pushed, we had to decrement %sp first, in
448 order to secure astack space. Thus, saved %sp (or %r1) value, is not the
449 one we should restore. Change it with the one we need. */
451 *(int*)®isters
[REGISTER_BYTE(FP_REGNUM
)] = sp
;
453 /* Now we can restore all registers. */
455 target_store_registers (-1);
457 flush_cached_frames ();
461 /* pop the innermost frame, go back to the caller. */
466 CORE_ADDR pc
, lr
, sp
, prev_sp
; /* %pc, %lr, %sp */
467 struct aix_framedata fdata
;
468 struct frame_info
*frame
= get_current_frame ();
472 sp
= FRAME_FP (frame
);
474 if (stop_stack_dummy
&& dummy_frame_count
) {
479 /* Make sure that all registers are valid. */
480 read_register_bytes (0, NULL
, REGISTER_BYTES
);
482 /* figure out previous %pc value. If the function is frameless, it is
483 still in the link register, otherwise walk the frames and retrieve the
484 saved %pc value in the previous frame. */
486 addr
= get_pc_function_start (frame
->pc
) + FUNCTION_START_OFFSET
;
487 function_frame_info (addr
, &fdata
);
492 prev_sp
= read_memory_integer (sp
, 4);
494 lr
= read_register (LR_REGNUM
);
496 lr
= read_memory_integer (prev_sp
+8, 4);
498 /* reset %pc value. */
499 write_register (PC_REGNUM
, lr
);
501 /* reset register values if any was saved earlier. */
502 addr
= prev_sp
- fdata
.offset
;
504 if (fdata
.saved_gpr
!= -1)
505 for (ii
= fdata
.saved_gpr
; ii
<= 31; ++ii
) {
506 read_memory (addr
, ®isters
[REGISTER_BYTE (ii
)], 4);
510 if (fdata
.saved_fpr
!= -1)
511 for (ii
= fdata
.saved_fpr
; ii
<= 31; ++ii
) {
512 read_memory (addr
, ®isters
[REGISTER_BYTE (ii
+FP0_REGNUM
)], 8);
516 write_register (SP_REGNUM
, prev_sp
);
517 target_store_registers (-1);
518 flush_cached_frames ();
521 /* fixup the call sequence of a dummy function, with the real function address.
522 its argumets will be passed by gdb. */
525 fix_call_dummy(dummyname
, pc
, fun
, nargs
, type
)
529 int nargs
; /* not used */
530 int type
; /* not used */
532 #define TOC_ADDR_OFFSET 20
533 #define TARGET_ADDR_OFFSET 28
536 CORE_ADDR target_addr
;
540 tocvalue
= find_toc_address (target_addr
);
542 ii
= *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
);
543 ii
= (ii
& 0xffff0000) | (tocvalue
>> 16);
544 *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
) = ii
;
546 ii
= *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
+4);
547 ii
= (ii
& 0xffff0000) | (tocvalue
& 0x0000ffff);
548 *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
+4) = ii
;
550 ii
= *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
);
551 ii
= (ii
& 0xffff0000) | (target_addr
>> 16);
552 *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
) = ii
;
554 ii
= *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
+4);
555 ii
= (ii
& 0xffff0000) | (target_addr
& 0x0000ffff);
556 *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
+4) = ii
;
560 /* return information about a function frame.
561 in struct aix_frameinfo fdata:
562 - frameless is TRUE, if function does not have a frame.
563 - nosavedpc is TRUE, if function does not save %pc value in its frame.
564 - offset is the number of bytes used in the frame to save registers.
565 - saved_gpr is the number of the first saved gpr.
566 - saved_fpr is the number of the first saved fpr.
567 - alloca_reg is the number of the register used for alloca() handling.
571 function_frame_info (pc
, fdata
)
573 struct aix_framedata
*fdata
;
576 register unsigned int op
;
580 fdata
->saved_gpr
= fdata
->saved_fpr
= fdata
->alloca_reg
= -1;
581 fdata
->frameless
= 1;
583 /* Do not error out if we can't access the instructions. */
584 if (target_read_memory (pc
, buf
, 4))
586 op
= extract_unsigned_integer (buf
, 4);
587 if (op
== 0x7c0802a6) { /* mflr r0 */
589 op
= read_memory_integer (pc
, 4);
590 fdata
->nosavedpc
= 0;
591 fdata
->frameless
= 0;
593 else /* else, pc is not saved */
594 fdata
->nosavedpc
= 1;
596 if ((op
& 0xfc00003e) == 0x7c000026) { /* mfcr Rx */
598 op
= read_memory_integer (pc
, 4);
599 fdata
->frameless
= 0;
602 if ((op
& 0xfc000000) == 0x48000000) { /* bl foo, to save fprs??? */
604 op
= read_memory_integer (pc
, 4);
605 /* At this point, make sure this is not a trampoline function
606 (a function that simply calls another functions, and nothing else).
607 If the next is not a nop, this branch was part of the function
610 if (op
== 0x4def7b82 || /* crorc 15, 15, 15 */
612 return; /* prologue is over */
613 fdata
->frameless
= 0;
616 if ((op
& 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */
617 pc
+= 4; /* store floating register double */
618 op
= read_memory_integer (pc
, 4);
619 fdata
->frameless
= 0;
622 if ((op
& 0xfc1f0000) == 0xbc010000) { /* stm Rx, NUM(r1) */
624 fdata
->saved_gpr
= (op
>> 21) & 0x1f;
627 tmp2
= (~0 &~ 0xffff) | tmp2
;
631 fdata
->saved_fpr
= (tmp2
- ((32 - fdata
->saved_gpr
) * 4)) / 8;
632 if ( fdata
->saved_fpr
> 0)
633 fdata
->saved_fpr
= 32 - fdata
->saved_fpr
;
635 fdata
->saved_fpr
= -1;
637 fdata
->offset
= tmp2
;
639 op
= read_memory_integer (pc
, 4);
640 fdata
->frameless
= 0;
643 while (((tmp
= op
>> 16) == 0x9001) || /* st r0, NUM(r1) */
644 (tmp
== 0x9421) || /* stu r1, NUM(r1) */
645 (tmp
== 0x93e1)) /* st r31, NUM(r1) */
649 /* gcc takes a short cut and uses this instruction to save r31 only. */
653 /* fatal ("Unrecognized prolog."); */
654 printf_unfiltered ("Unrecognized prolog!\n");
656 fdata
->saved_gpr
= 31;
659 tmp2
= - ((~0 &~ 0xffff) | tmp2
);
660 fdata
->saved_fpr
= (tmp2
- ((32 - 31) * 4)) / 8;
661 if ( fdata
->saved_fpr
> 0)
662 fdata
->saved_fpr
= 32 - fdata
->saved_fpr
;
664 fdata
->saved_fpr
= -1;
666 fdata
->offset
= tmp2
;
669 op
= read_memory_integer (pc
, 4);
670 fdata
->frameless
= 0;
673 while ((tmp
= (op
>> 22)) == 0x20f) { /* l r31, ... or */
674 pc
+= 4; /* l r30, ... */
675 op
= read_memory_integer (pc
, 4);
676 fdata
->frameless
= 0;
679 /* store parameters into stack */
681 (op
& 0xfc1f0000) == 0xd8010000 || /* stfd Rx,NUM(r1) */
682 (op
& 0xfc1f0000) == 0x90010000 || /* st r?, NUM(r1) */
683 (op
& 0xfc000000) == 0xfc000000 || /* frsp, fp?, .. */
684 (op
& 0xd0000000) == 0xd0000000) /* stfs, fp?, .. */
686 pc
+= 4; /* store fpr double */
687 op
= read_memory_integer (pc
, 4);
688 fdata
->frameless
= 0;
691 if (op
== 0x603f0000 /* oril r31, r1, 0x0 */
692 || op
== 0x7c3f0b78) /* mr r31, r1 */
694 fdata
->alloca_reg
= 31;
695 fdata
->frameless
= 0;
700 /* Pass the arguments in either registers, or in the stack. In RS6000, the first
701 eight words of the argument list (that might be less than eight parameters if
702 some parameters occupy more than one word) are passed in r3..r11 registers.
703 float and double parameters are passed in fpr's, in addition to that. Rest of
704 the parameters if any are passed in user stack. There might be cases in which
705 half of the parameter is copied into registers, the other half is pushed into
708 If the function is returning a structure, then the return address is passed
709 in r3, then the first 7 words of the parametes can be passed in registers,
713 push_arguments (nargs
, args
, sp
, struct_return
, struct_addr
)
718 CORE_ADDR struct_addr
;
721 int argno
; /* current argument number */
722 int argbytes
; /* current argument byte */
723 char tmp_buffer
[50];
725 int f_argno
= 0; /* current floating point argno */
727 CORE_ADDR saved_sp
, pc
;
729 if ( dummy_frame_count
<= 0)
730 printf_unfiltered ("FATAL ERROR -push_arguments()! frame not found!!\n");
732 /* The first eight words of ther arguments are passed in registers. Copy
735 If the function is returning a `struct', then the first word (which
736 will be passed in r3) is used for struct return address. In that
737 case we should advance one word and start from r4 register to copy
740 ii
= struct_return
? 1 : 0;
742 for (argno
=0, argbytes
=0; argno
< nargs
&& ii
<8; ++ii
) {
745 len
= TYPE_LENGTH (VALUE_TYPE (arg
));
747 if (TYPE_CODE (VALUE_TYPE (arg
)) == TYPE_CODE_FLT
) {
749 /* floating point arguments are passed in fpr's, as well as gpr's.
750 There are 13 fpr's reserved for passing parameters. At this point
751 there is no way we would run out of them. */
755 "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno
);
757 memcpy (®isters
[REGISTER_BYTE(FP0_REGNUM
+ 1 + f_argno
)], VALUE_CONTENTS (arg
),
764 /* Argument takes more than one register. */
765 while (argbytes
< len
) {
767 *(int*)®isters
[REGISTER_BYTE(ii
+3)] = 0;
768 memcpy (®isters
[REGISTER_BYTE(ii
+3)],
769 ((char*)VALUE_CONTENTS (arg
))+argbytes
,
770 (len
- argbytes
) > 4 ? 4 : len
- argbytes
);
774 goto ran_out_of_registers_for_arguments
;
779 else { /* Argument can fit in one register. No problem. */
780 *(int*)®isters
[REGISTER_BYTE(ii
+3)] = 0;
781 memcpy (®isters
[REGISTER_BYTE(ii
+3)], VALUE_CONTENTS (arg
), len
);
786 ran_out_of_registers_for_arguments
:
788 /* location for 8 parameters are always reserved. */
791 /* another six words for back chain, TOC register, link register, etc. */
794 /* if there are more arguments, allocate space for them in
795 the stack, then push them starting from the ninth one. */
797 if ((argno
< nargs
) || argbytes
) {
802 space
+= ((len
- argbytes
+ 3) & -4);
808 for (; jj
< nargs
; ++jj
) {
810 space
+= ((TYPE_LENGTH (VALUE_TYPE (val
))) + 3) & -4;
813 /* add location required for the rest of the parameters */
814 space
= (space
+ 7) & -8;
817 /* This is another instance we need to be concerned about securing our
818 stack space. If we write anything underneath %sp (r1), we might conflict
819 with the kernel who thinks he is free to use this area. So, update %sp
820 first before doing anything else. */
822 write_register (SP_REGNUM
, sp
);
824 /* if the last argument copied into the registers didn't fit there
825 completely, push the rest of it into stack. */
829 sp
+24+(ii
*4), ((char*)VALUE_CONTENTS (arg
))+argbytes
, len
- argbytes
);
831 ii
+= ((len
- argbytes
+ 3) & -4) / 4;
834 /* push the rest of the arguments into stack. */
835 for (; argno
< nargs
; ++argno
) {
838 len
= TYPE_LENGTH (VALUE_TYPE (arg
));
841 /* float types should be passed in fpr's, as well as in the stack. */
842 if (TYPE_CODE (VALUE_TYPE (arg
)) == TYPE_CODE_FLT
&& f_argno
< 13) {
846 "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno
);
848 memcpy (®isters
[REGISTER_BYTE(FP0_REGNUM
+ 1 + f_argno
)], VALUE_CONTENTS (arg
),
853 write_memory (sp
+24+(ii
*4), (char *) VALUE_CONTENTS (arg
), len
);
854 ii
+= ((len
+ 3) & -4) / 4;
858 /* Secure stack areas first, before doing anything else. */
859 write_register (SP_REGNUM
, sp
);
861 saved_sp
= dummy_frame_addr
[dummy_frame_count
- 1];
862 read_memory (saved_sp
, tmp_buffer
, 24);
863 write_memory (sp
, tmp_buffer
, 24);
865 /* set back chain properly */
866 store_address (tmp_buffer
, 4, saved_sp
);
867 write_memory (sp
, tmp_buffer
, 4);
869 target_store_registers (-1);
873 /* a given return value in `regbuf' with a type `valtype', extract and copy its
874 value into `valbuf' */
877 extract_return_value (valtype
, regbuf
, valbuf
)
878 struct type
*valtype
;
879 char regbuf
[REGISTER_BYTES
];
883 if (TYPE_CODE (valtype
) == TYPE_CODE_FLT
) {
886 /* floats and doubles are returned in fpr1. fpr's have a size of 8 bytes.
887 We need to truncate the return value into float size (4 byte) if
890 if (TYPE_LENGTH (valtype
) > 4) /* this is a double */
891 memcpy (valbuf
, ®buf
[REGISTER_BYTE (FP0_REGNUM
+ 1)],
892 TYPE_LENGTH (valtype
));
894 memcpy (&dd
, ®buf
[REGISTER_BYTE (FP0_REGNUM
+ 1)], 8);
896 memcpy (valbuf
, &ff
, sizeof(float));
900 /* return value is copied starting from r3. */
901 memcpy (valbuf
, ®buf
[REGISTER_BYTE (3)], TYPE_LENGTH (valtype
));
905 /* keep structure return address in this variable.
906 FIXME: This is a horrid kludge which should not be allowed to continue
907 living. This only allows a single nested call to a structure-returning
908 function. Come on, guys! -- gnu@cygnus.com, Aug 92 */
910 CORE_ADDR rs6000_struct_return_address
;
913 /* Indirect function calls use a piece of trampoline code to do context
914 switching, i.e. to set the new TOC table. Skip such code if we are on
915 its first instruction (as when we have single-stepped to here).
916 Also skip shared library trampoline code (which is different from
917 indirect function call trampolines).
918 Result is desired PC to step until, or NULL if we are not in
922 skip_trampoline_code (pc
)
925 register unsigned int ii
, op
;
926 CORE_ADDR solib_target_pc
;
928 static unsigned trampoline_code
[] = {
929 0x800b0000, /* l r0,0x0(r11) */
930 0x90410014, /* st r2,0x14(r1) */
931 0x7c0903a6, /* mtctr r0 */
932 0x804b0004, /* l r2,0x4(r11) */
933 0x816b0008, /* l r11,0x8(r11) */
934 0x4e800420, /* bctr */
939 /* If pc is in a shared library trampoline, return its target. */
940 solib_target_pc
= find_solib_trampoline_target (pc
);
942 return solib_target_pc
;
944 for (ii
=0; trampoline_code
[ii
]; ++ii
) {
945 op
= read_memory_integer (pc
+ (ii
*4), 4);
946 if (op
!= trampoline_code
[ii
])
949 ii
= read_register (11); /* r11 holds destination addr */
950 pc
= read_memory_integer (ii
, 4); /* (r11) value */
955 /* Determines whether the function FI has a frame on the stack or not.
956 Called from the FRAMELESS_FUNCTION_INVOCATION macro in tm.h with a
957 second argument of 0, and from the FRAME_SAVED_PC macro with a
958 second argument of 1. */
961 frameless_function_invocation (fi
, pcsaved
)
962 struct frame_info
*fi
;
965 CORE_ADDR func_start
;
966 struct aix_framedata fdata
;
968 if (fi
->next
!= NULL
)
969 /* Don't even think about framelessness except on the innermost frame. */
970 /* FIXME: Can also be frameless if fi->next->signal_handler_caller (if
971 a signal happens while executing in a frameless function). */
974 func_start
= get_pc_function_start (fi
->pc
) + FUNCTION_START_OFFSET
;
976 /* If we failed to find the start of the function, it is a mistake
977 to inspect the instructions. */
982 function_frame_info (func_start
, &fdata
);
983 return pcsaved
? fdata
.nosavedpc
: fdata
.frameless
;
987 /* If saved registers of frame FI are not known yet, read and cache them.
988 &FDATAP contains aix_framedata; TDATAP can be NULL,
989 in which case the framedata are read. */
992 frame_get_cache_fsr (fi
, fdatap
)
993 struct frame_info
*fi
;
994 struct aix_framedata
*fdatap
;
997 CORE_ADDR frame_addr
;
998 struct aix_framedata work_fdata
;
1003 if (fdatap
== NULL
) {
1004 fdatap
= &work_fdata
;
1005 function_frame_info (get_pc_function_start (fi
->pc
), fdatap
);
1008 fi
->cache_fsr
= (struct frame_saved_regs
*)
1009 obstack_alloc (&frame_cache_obstack
, sizeof (struct frame_saved_regs
));
1010 memset (fi
->cache_fsr
, '\0', sizeof (struct frame_saved_regs
));
1012 if (fi
->prev
&& fi
->prev
->frame
)
1013 frame_addr
= fi
->prev
->frame
;
1015 frame_addr
= read_memory_integer (fi
->frame
, 4);
1017 /* if != -1, fdatap->saved_fpr is the smallest number of saved_fpr.
1018 All fpr's from saved_fpr to fp31 are saved right underneath caller
1019 stack pointer, starting from fp31 first. */
1021 if (fdatap
->saved_fpr
>= 0) {
1022 for (ii
=31; ii
>= fdatap
->saved_fpr
; --ii
)
1023 fi
->cache_fsr
->regs
[FP0_REGNUM
+ ii
] = frame_addr
- ((32 - ii
) * 8);
1024 frame_addr
-= (32 - fdatap
->saved_fpr
) * 8;
1027 /* if != -1, fdatap->saved_gpr is the smallest number of saved_gpr.
1028 All gpr's from saved_gpr to gpr31 are saved right under saved fprs,
1029 starting from r31 first. */
1031 if (fdatap
->saved_gpr
>= 0)
1032 for (ii
=31; ii
>= fdatap
->saved_gpr
; --ii
)
1033 fi
->cache_fsr
->regs
[ii
] = frame_addr
- ((32 - ii
) * 4);
1036 /* Return the address of a frame. This is the inital %sp value when the frame
1037 was first allocated. For functions calling alloca(), it might be saved in
1038 an alloca register. */
1041 frame_initial_stack_address (fi
)
1042 struct frame_info
*fi
;
1045 struct aix_framedata fdata
;
1046 struct frame_info
*callee_fi
;
1048 /* if the initial stack pointer (frame address) of this frame is known,
1052 return fi
->initial_sp
;
1054 /* find out if this function is using an alloca register.. */
1056 function_frame_info (get_pc_function_start (fi
->pc
), &fdata
);
1058 /* if saved registers of this frame are not known yet, read and cache them. */
1061 frame_get_cache_fsr (fi
, &fdata
);
1063 /* If no alloca register used, then fi->frame is the value of the %sp for
1064 this frame, and it is good enough. */
1066 if (fdata
.alloca_reg
< 0) {
1067 fi
->initial_sp
= fi
->frame
;
1068 return fi
->initial_sp
;
1071 /* This function has an alloca register. If this is the top-most frame
1072 (with the lowest address), the value in alloca register is good. */
1075 return fi
->initial_sp
= read_register (fdata
.alloca_reg
);
1077 /* Otherwise, this is a caller frame. Callee has usually already saved
1078 registers, but there are exceptions (such as when the callee
1079 has no parameters). Find the address in which caller's alloca
1080 register is saved. */
1082 for (callee_fi
= fi
->next
; callee_fi
; callee_fi
= callee_fi
->next
) {
1084 if (!callee_fi
->cache_fsr
)
1085 frame_get_cache_fsr (callee_fi
, NULL
);
1087 /* this is the address in which alloca register is saved. */
1089 tmpaddr
= callee_fi
->cache_fsr
->regs
[fdata
.alloca_reg
];
1091 fi
->initial_sp
= read_memory_integer (tmpaddr
, 4);
1092 return fi
->initial_sp
;
1095 /* Go look into deeper levels of the frame chain to see if any one of
1096 the callees has saved alloca register. */
1099 /* If alloca register was not saved, by the callee (or any of its callees)
1100 then the value in the register is still good. */
1102 return fi
->initial_sp
= read_register (fdata
.alloca_reg
);
1106 rs6000_frame_chain (thisframe
)
1107 struct frame_info
*thisframe
;
1110 if (inside_entry_file ((thisframe
)->pc
))
1112 if (thisframe
->signal_handler_caller
)
1113 fp
= read_memory_integer (thisframe
->frame
+ SIG_FRAME_FP_OFFSET
, 4);
1115 fp
= read_memory_integer ((thisframe
)->frame
, 4);
1120 /* Keep an array of load segment information and their TOC table addresses.
1121 This info will be useful when calling a shared library function by hand. */
1124 CORE_ADDR textorg
, dataorg
;
1125 unsigned long toc_offset
;
1128 #define LOADINFOLEN 10
1130 static struct loadinfo
*loadinfo
= NULL
;
1131 static int loadinfolen
= 0;
1132 static int loadinfotocindex
= 0;
1133 static int loadinfotextindex
= 0;
1137 xcoff_init_loadinfo ()
1139 loadinfotocindex
= 0;
1140 loadinfotextindex
= 0;
1142 if (loadinfolen
== 0) {
1143 loadinfo
= (struct loadinfo
*)
1144 xmalloc (sizeof (struct loadinfo
) * LOADINFOLEN
);
1145 loadinfolen
= LOADINFOLEN
;
1150 /* FIXME -- this is never called! */
1158 loadinfotocindex
= 0;
1159 loadinfotextindex
= 0;
1162 /* this is called from xcoffread.c */
1165 xcoff_add_toc_to_loadinfo (unsigned long tocoff
)
1167 while (loadinfotocindex
>= loadinfolen
) {
1168 loadinfolen
+= LOADINFOLEN
;
1169 loadinfo
= (struct loadinfo
*)
1170 xrealloc (loadinfo
, sizeof(struct loadinfo
) * loadinfolen
);
1172 loadinfo
[loadinfotocindex
++].toc_offset
= tocoff
;
1176 add_text_to_loadinfo (textaddr
, dataaddr
)
1180 while (loadinfotextindex
>= loadinfolen
) {
1181 loadinfolen
+= LOADINFOLEN
;
1182 loadinfo
= (struct loadinfo
*)
1183 xrealloc (loadinfo
, sizeof(struct loadinfo
) * loadinfolen
);
1185 loadinfo
[loadinfotextindex
].textorg
= textaddr
;
1186 loadinfo
[loadinfotextindex
].dataorg
= dataaddr
;
1187 ++loadinfotextindex
;
1191 /* FIXME: This assumes that the "textorg" and "dataorg" elements
1192 of a member of this array are correlated with the "toc_offset"
1193 element of the same member. But they are sequentially assigned in wildly
1194 different places, and probably there is no correlation. FIXME! */
1197 find_toc_address (pc
)
1200 int ii
, toc_entry
, tocbase
= 0;
1202 for (ii
=0; ii
< loadinfotextindex
; ++ii
)
1203 if (pc
> loadinfo
[ii
].textorg
&& loadinfo
[ii
].textorg
> tocbase
) {
1205 tocbase
= loadinfo
[ii
].textorg
;
1208 return loadinfo
[toc_entry
].dataorg
+ loadinfo
[toc_entry
].toc_offset
;
1212 _initialize_rs6000_tdep ()
1214 /* FIXME, this should not be decided via ifdef. */
1215 #ifdef GDB_TARGET_POWERPC
1216 tm_print_insn
= print_insn_big_powerpc
;
1218 tm_print_insn
= print_insn_rs6000
;