1 /* Target-dependent code for GDB, the GNU debugger.
2 Copyright 1986, 1987, 1989, 1991, 1992, 1993, 1994
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 */
83 if (opcode
!= 18) /* br conditional */
84 immediate
= ((instr
& ~3) << 16) >> 16;
88 dest
= pc
+ immediate
;
92 ext_op
= (instr
>>1) & 0x3ff;
94 if (ext_op
== 16) /* br conditional register */
95 dest
= read_register (LR_REGNUM
) & ~3;
97 else if (ext_op
== 528) /* br cond to count reg */
99 dest
= read_register (CTR_REGNUM
) & ~3;
101 /* If we are about to execute a system call, dest is something
102 like 0x22fc or 0x3b00. Upon completion the system call
103 will return to the address in the link register. */
104 if (dest
< TEXT_SEGMENT_BASE
)
105 dest
= read_register (LR_REGNUM
) & ~3;
112 return (dest
< TEXT_SEGMENT_BASE
) ? safety
: dest
;
117 /* AIX does not support PT_STEP. Simulate it. */
123 #define INSNLEN(OPCODE) 4
125 static char breakp
[] = BREAKPOINT
;
134 read_memory (loc
, (char *) &insn
, 4);
136 breaks
[0] = loc
+ INSNLEN(insn
);
138 breaks
[1] = branch_dest (opcode
, insn
, loc
, breaks
[0]);
140 /* Don't put two breakpoints on the same address. */
141 if (breaks
[1] == breaks
[0])
144 stepBreaks
[1].address
= 0;
146 for (ii
=0; ii
< 2; ++ii
) {
148 /* ignore invalid breakpoint. */
149 if ( breaks
[ii
] == -1)
152 read_memory (breaks
[ii
], stepBreaks
[ii
].data
, 4);
154 write_memory (breaks
[ii
], breakp
, 4);
155 stepBreaks
[ii
].address
= breaks
[ii
];
161 /* remove step breakpoints. */
162 for (ii
=0; ii
< 2; ++ii
)
163 if (stepBreaks
[ii
].address
!= 0)
165 (stepBreaks
[ii
].address
, stepBreaks
[ii
].data
, 4);
169 errno
= 0; /* FIXME, don't ignore errors! */
170 /* What errors? {read,write}_memory call error(). */
174 /* return pc value after skipping a function prologue. */
183 if (target_read_memory (pc
, buf
, 4))
184 return pc
; /* Can't access it -- assume no prologue. */
185 op
= extract_unsigned_integer (buf
, 4);
187 /* Assume that subsequent fetches can fail with low probability. */
189 if (op
== 0x7c0802a6) { /* mflr r0 */
191 op
= read_memory_integer (pc
, 4);
194 if ((op
& 0xfc00003e) == 0x7c000026) { /* mfcr Rx */
196 op
= read_memory_integer (pc
, 4);
199 if ((op
& 0xfc000000) == 0x48000000) { /* bl foo, to save fprs??? */
201 op
= read_memory_integer (pc
, 4);
203 /* At this point, make sure this is not a trampoline function
204 (a function that simply calls another functions, and nothing else).
205 If the next is not a nop, this branch was part of the function
208 if (op
== 0x4def7b82 || /* crorc 15, 15, 15 */
210 return pc
- 4; /* don't skip over this branch */
213 if ((op
& 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */
214 pc
+= 4; /* store floating register double */
215 op
= read_memory_integer (pc
, 4);
218 if ((op
& 0xfc1f0000) == 0xbc010000) { /* stm Rx, NUM(r1) */
220 op
= read_memory_integer (pc
, 4);
223 while (((tmp
= op
>> 16) == 0x9001) || /* st r0, NUM(r1) */
224 (tmp
== 0x9421) || /* stu r1, NUM(r1) */
225 (tmp
== 0x93e1)) /* st r31,NUM(r1) */
228 op
= read_memory_integer (pc
, 4);
231 while ((tmp
= (op
>> 22)) == 0x20f) { /* l r31, ... or */
232 pc
+= 4; /* l r30, ... */
233 op
= read_memory_integer (pc
, 4);
236 /* store parameters into stack */
238 (op
& 0xfc1f0000) == 0xd8010000 || /* stfd Rx,NUM(r1) */
239 (op
& 0xfc1f0000) == 0x90010000 || /* st r?, NUM(r1) */
240 (op
& 0xfc000000) == 0xfc000000 || /* frsp, fp?, .. */
241 (op
& 0xd0000000) == 0xd0000000) /* stfs, fp?, .. */
243 pc
+= 4; /* store fpr double */
244 op
= read_memory_integer (pc
, 4);
247 if (op
== 0x603f0000 /* oril r31, r1, 0x0 */
248 || op
== 0x7c3f0b78) { /* mr r31, r1 */
249 pc
+= 4; /* this happens if r31 is used as */
250 op
= read_memory_integer (pc
, 4); /* frame ptr. (gcc does that) */
253 while ((op
>> 16) == (0x907f + tmp
)) { /* st r3, NUM(r31) */
254 pc
+= 4; /* st r4, NUM(r31), ... */
255 op
= read_memory_integer (pc
, 4);
260 /* I have problems with skipping over __main() that I need to address
261 * sometime. Previously, I used to use misc_function_vector which
262 * didn't work as well as I wanted to be. -MGO */
264 /* If the first thing after skipping a prolog is a branch to a function,
265 this might be a call to an initializer in main(), introduced by gcc2.
266 We'd like to skip over it as well. Fortunately, xlc does some extra
267 work before calling a function right after a prologue, thus we can
268 single out such gcc2 behaviour. */
271 if ((op
& 0xfc000001) == 0x48000001) { /* bl foo, an initializer function? */
272 op
= read_memory_integer (pc
+4, 4);
274 if (op
== 0x4def7b82) { /* cror 0xf, 0xf, 0xf (nop) */
276 /* check and see if we are in main. If so, skip over this initializer
279 tmp
= find_pc_misc_function (pc
);
280 if (tmp
>= 0 && STREQ (misc_function_vector
[tmp
].name
, "main"))
290 /*************************************************************************
291 Support for creating pushind a dummy frame into the stack, and popping
293 *************************************************************************/
295 /* The total size of dummy frame is 436, which is;
300 and 24 extra bytes for the callee's link area. The last 24 bytes
301 for the link area might not be necessary, since it will be taken
302 care of by push_arguments(). */
304 #define DUMMY_FRAME_SIZE 436
306 #define DUMMY_FRAME_ADDR_SIZE 10
308 /* Make sure you initialize these in somewhere, in case gdb gives up what it
309 was debugging and starts debugging something else. FIXMEibm */
311 static int dummy_frame_count
= 0;
312 static int dummy_frame_size
= 0;
313 static CORE_ADDR
*dummy_frame_addr
= 0;
315 extern int stop_stack_dummy
;
317 /* push a dummy frame into stack, save all register. Currently we are saving
318 only gpr's and fpr's, which is not good enough! FIXMEmgo */
328 /* Same thing, target byte order. */
333 target_fetch_registers (-1);
335 if (dummy_frame_count
>= dummy_frame_size
) {
336 dummy_frame_size
+= DUMMY_FRAME_ADDR_SIZE
;
337 if (dummy_frame_addr
)
338 dummy_frame_addr
= (CORE_ADDR
*) xrealloc
339 (dummy_frame_addr
, sizeof(CORE_ADDR
) * (dummy_frame_size
));
341 dummy_frame_addr
= (CORE_ADDR
*)
342 xmalloc (sizeof(CORE_ADDR
) * (dummy_frame_size
));
345 sp
= read_register(SP_REGNUM
);
346 pc
= read_register(PC_REGNUM
);
347 memcpy (pc_targ
, (char *) &pc
, 4);
349 dummy_frame_addr
[dummy_frame_count
++] = sp
;
351 /* Be careful! If the stack pointer is not decremented first, then kernel
352 thinks he is free to use the space underneath it. And kernel actually
353 uses that area for IPC purposes when executing ptrace(2) calls. So
354 before writing register values into the new frame, decrement and update
355 %sp first in order to secure your frame. */
357 write_register (SP_REGNUM
, sp
-DUMMY_FRAME_SIZE
);
359 /* gdb relies on the state of current_frame. We'd better update it,
360 otherwise things like do_registers_info() wouldn't work properly! */
362 flush_cached_frames ();
364 /* save program counter in link register's space. */
365 write_memory (sp
+8, pc_targ
, 4);
367 /* save all floating point and general purpose registers here. */
370 for (ii
= 0; ii
< 32; ++ii
)
371 write_memory (sp
-8-(ii
*8), ®isters
[REGISTER_BYTE (31-ii
+FP0_REGNUM
)], 8);
374 for (ii
=1; ii
<=32; ++ii
)
375 write_memory (sp
-256-(ii
*4), ®isters
[REGISTER_BYTE (32-ii
)], 4);
377 /* so far, 32*2 + 32 words = 384 bytes have been written.
378 7 extra registers in our register set: pc, ps, cnd, lr, cnt, xer, mq */
380 for (ii
=1; ii
<= (LAST_SP_REGNUM
-FIRST_SP_REGNUM
+1); ++ii
) {
381 write_memory (sp
-384-(ii
*4),
382 ®isters
[REGISTER_BYTE (FPLAST_REGNUM
+ ii
)], 4);
385 /* Save sp or so called back chain right here. */
386 write_memory (sp
-DUMMY_FRAME_SIZE
, &sp
, 4);
387 sp
-= DUMMY_FRAME_SIZE
;
389 /* And finally, this is the back chain. */
390 write_memory (sp
+8, pc_targ
, 4);
394 /* Pop a dummy frame.
396 In rs6000 when we push a dummy frame, we save all of the registers. This
397 is usually done before user calls a function explicitly.
399 After a dummy frame is pushed, some instructions are copied into stack,
400 and stack pointer is decremented even more. Since we don't have a frame
401 pointer to get back to the parent frame of the dummy, we start having
402 trouble poping it. Therefore, we keep a dummy frame stack, keeping
403 addresses of dummy frames as such. When poping happens and when we
404 detect that was a dummy frame, we pop it back to its parent by using
405 dummy frame stack (`dummy_frame_addr' array).
407 FIXME: This whole concept is broken. You should be able to detect
408 a dummy stack frame *on the user's stack itself*. When you do,
409 then you know the format of that stack frame -- including its
410 saved SP register! There should *not* be a separate stack in the
411 GDB process that keeps track of these dummy frames! -- gnu@cygnus.com Aug92
418 sp
= dummy_frame_addr
[--dummy_frame_count
];
420 /* restore all fpr's. */
421 for (ii
= 1; ii
<= 32; ++ii
)
422 read_memory (sp
-(ii
*8), ®isters
[REGISTER_BYTE (32-ii
+FP0_REGNUM
)], 8);
424 /* restore all gpr's */
425 for (ii
=1; ii
<= 32; ++ii
) {
426 read_memory (sp
-256-(ii
*4), ®isters
[REGISTER_BYTE (32-ii
)], 4);
429 /* restore the rest of the registers. */
430 for (ii
=1; ii
<=(LAST_SP_REGNUM
-FIRST_SP_REGNUM
+1); ++ii
)
431 read_memory (sp
-384-(ii
*4),
432 ®isters
[REGISTER_BYTE (FPLAST_REGNUM
+ ii
)], 4);
434 read_memory (sp
-(DUMMY_FRAME_SIZE
-8),
435 ®isters
[REGISTER_BYTE(PC_REGNUM
)], 4);
437 /* when a dummy frame was being pushed, we had to decrement %sp first, in
438 order to secure astack space. Thus, saved %sp (or %r1) value, is not the
439 one we should restore. Change it with the one we need. */
441 *(int*)®isters
[REGISTER_BYTE(FP_REGNUM
)] = sp
;
443 /* Now we can restore all registers. */
445 target_store_registers (-1);
447 flush_cached_frames ();
451 /* pop the innermost frame, go back to the caller. */
456 CORE_ADDR pc
, lr
, sp
, prev_sp
; /* %pc, %lr, %sp */
457 struct aix_framedata fdata
;
458 struct frame_info
*frame
= get_current_frame ();
462 sp
= FRAME_FP (frame
);
464 if (stop_stack_dummy
&& dummy_frame_count
) {
469 /* Make sure that all registers are valid. */
470 read_register_bytes (0, NULL
, REGISTER_BYTES
);
472 /* figure out previous %pc value. If the function is frameless, it is
473 still in the link register, otherwise walk the frames and retrieve the
474 saved %pc value in the previous frame. */
476 addr
= get_pc_function_start (frame
->pc
) + FUNCTION_START_OFFSET
;
477 function_frame_info (addr
, &fdata
);
482 prev_sp
= read_memory_integer (sp
, 4);
484 lr
= read_register (LR_REGNUM
);
486 lr
= read_memory_integer (prev_sp
+8, 4);
488 /* reset %pc value. */
489 write_register (PC_REGNUM
, lr
);
491 /* reset register values if any was saved earlier. */
492 addr
= prev_sp
- fdata
.offset
;
494 if (fdata
.saved_gpr
!= -1)
495 for (ii
= fdata
.saved_gpr
; ii
<= 31; ++ii
) {
496 read_memory (addr
, ®isters
[REGISTER_BYTE (ii
)], 4);
500 if (fdata
.saved_fpr
!= -1)
501 for (ii
= fdata
.saved_fpr
; ii
<= 31; ++ii
) {
502 read_memory (addr
, ®isters
[REGISTER_BYTE (ii
+FP0_REGNUM
)], 8);
506 write_register (SP_REGNUM
, prev_sp
);
507 target_store_registers (-1);
508 flush_cached_frames ();
511 /* fixup the call sequence of a dummy function, with the real function address.
512 its argumets will be passed by gdb. */
515 fix_call_dummy(dummyname
, pc
, fun
, nargs
, type
)
519 int nargs
; /* not used */
520 int type
; /* not used */
522 #define TOC_ADDR_OFFSET 20
523 #define TARGET_ADDR_OFFSET 28
526 CORE_ADDR target_addr
;
530 tocvalue
= find_toc_address (target_addr
);
532 ii
= *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
);
533 ii
= (ii
& 0xffff0000) | (tocvalue
>> 16);
534 *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
) = ii
;
536 ii
= *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
+4);
537 ii
= (ii
& 0xffff0000) | (tocvalue
& 0x0000ffff);
538 *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
+4) = ii
;
540 ii
= *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
);
541 ii
= (ii
& 0xffff0000) | (target_addr
>> 16);
542 *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
) = ii
;
544 ii
= *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
+4);
545 ii
= (ii
& 0xffff0000) | (target_addr
& 0x0000ffff);
546 *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
+4) = ii
;
550 /* return information about a function frame.
551 in struct aix_frameinfo fdata:
552 - frameless is TRUE, if function does not have a frame.
553 - nosavedpc is TRUE, if function does not save %pc value in its frame.
554 - offset is the number of bytes used in the frame to save registers.
555 - saved_gpr is the number of the first saved gpr.
556 - saved_fpr is the number of the first saved fpr.
557 - alloca_reg is the number of the register used for alloca() handling.
561 function_frame_info (pc
, fdata
)
563 struct aix_framedata
*fdata
;
566 register unsigned int op
;
570 fdata
->saved_gpr
= fdata
->saved_fpr
= fdata
->alloca_reg
= -1;
571 fdata
->frameless
= 1;
573 /* Do not error out if we can't access the instructions. */
574 if (target_read_memory (pc
, buf
, 4))
576 op
= extract_unsigned_integer (buf
, 4);
577 if (op
== 0x7c0802a6) { /* mflr r0 */
579 op
= read_memory_integer (pc
, 4);
580 fdata
->nosavedpc
= 0;
581 fdata
->frameless
= 0;
583 else /* else, pc is not saved */
584 fdata
->nosavedpc
= 1;
586 if ((op
& 0xfc00003e) == 0x7c000026) { /* mfcr Rx */
588 op
= read_memory_integer (pc
, 4);
589 fdata
->frameless
= 0;
592 if ((op
& 0xfc000000) == 0x48000000) { /* bl foo, to save fprs??? */
594 op
= read_memory_integer (pc
, 4);
595 /* At this point, make sure this is not a trampoline function
596 (a function that simply calls another functions, and nothing else).
597 If the next is not a nop, this branch was part of the function
600 if (op
== 0x4def7b82 || /* crorc 15, 15, 15 */
602 return; /* prologue is over */
603 fdata
->frameless
= 0;
606 if ((op
& 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */
607 pc
+= 4; /* store floating register double */
608 op
= read_memory_integer (pc
, 4);
609 fdata
->frameless
= 0;
612 if ((op
& 0xfc1f0000) == 0xbc010000) { /* stm Rx, NUM(r1) */
614 fdata
->saved_gpr
= (op
>> 21) & 0x1f;
617 tmp2
= (~0 &~ 0xffff) | tmp2
;
621 fdata
->saved_fpr
= (tmp2
- ((32 - fdata
->saved_gpr
) * 4)) / 8;
622 if ( fdata
->saved_fpr
> 0)
623 fdata
->saved_fpr
= 32 - fdata
->saved_fpr
;
625 fdata
->saved_fpr
= -1;
627 fdata
->offset
= tmp2
;
629 op
= read_memory_integer (pc
, 4);
630 fdata
->frameless
= 0;
633 while (((tmp
= op
>> 16) == 0x9001) || /* st r0, NUM(r1) */
634 (tmp
== 0x9421) || /* stu r1, NUM(r1) */
635 (tmp
== 0x93e1)) /* st r31, NUM(r1) */
639 /* gcc takes a short cut and uses this instruction to save r31 only. */
643 /* fatal ("Unrecognized prolog."); */
644 printf_unfiltered ("Unrecognized prolog!\n");
646 fdata
->saved_gpr
= 31;
649 tmp2
= - ((~0 &~ 0xffff) | tmp2
);
650 fdata
->saved_fpr
= (tmp2
- ((32 - 31) * 4)) / 8;
651 if ( fdata
->saved_fpr
> 0)
652 fdata
->saved_fpr
= 32 - fdata
->saved_fpr
;
654 fdata
->saved_fpr
= -1;
656 fdata
->offset
= tmp2
;
659 op
= read_memory_integer (pc
, 4);
660 fdata
->frameless
= 0;
663 while ((tmp
= (op
>> 22)) == 0x20f) { /* l r31, ... or */
664 pc
+= 4; /* l r30, ... */
665 op
= read_memory_integer (pc
, 4);
666 fdata
->frameless
= 0;
669 /* store parameters into stack */
671 (op
& 0xfc1f0000) == 0xd8010000 || /* stfd Rx,NUM(r1) */
672 (op
& 0xfc1f0000) == 0x90010000 || /* st r?, NUM(r1) */
673 (op
& 0xfc000000) == 0xfc000000 || /* frsp, fp?, .. */
674 (op
& 0xd0000000) == 0xd0000000) /* stfs, fp?, .. */
676 pc
+= 4; /* store fpr double */
677 op
= read_memory_integer (pc
, 4);
678 fdata
->frameless
= 0;
681 if (op
== 0x603f0000 /* oril r31, r1, 0x0 */
682 || op
== 0x7c3f0b78) /* mr r31, r1 */
684 fdata
->alloca_reg
= 31;
685 fdata
->frameless
= 0;
690 /* Pass the arguments in either registers, or in the stack. In RS6000, the first
691 eight words of the argument list (that might be less than eight parameters if
692 some parameters occupy more than one word) are passed in r3..r11 registers.
693 float and double parameters are passed in fpr's, in addition to that. Rest of
694 the parameters if any are passed in user stack. There might be cases in which
695 half of the parameter is copied into registers, the other half is pushed into
698 If the function is returning a structure, then the return address is passed
699 in r3, then the first 7 words of the parametes can be passed in registers,
703 push_arguments (nargs
, args
, sp
, struct_return
, struct_addr
)
708 CORE_ADDR struct_addr
;
711 int argno
; /* current argument number */
712 int argbytes
; /* current argument byte */
713 char tmp_buffer
[50];
715 int f_argno
= 0; /* current floating point argno */
717 CORE_ADDR saved_sp
, pc
;
719 if ( dummy_frame_count
<= 0)
720 printf_unfiltered ("FATAL ERROR -push_arguments()! frame not found!!\n");
722 /* The first eight words of ther arguments are passed in registers. Copy
725 If the function is returning a `struct', then the first word (which
726 will be passed in r3) is used for struct return address. In that
727 case we should advance one word and start from r4 register to copy
730 ii
= struct_return
? 1 : 0;
732 for (argno
=0, argbytes
=0; argno
< nargs
&& ii
<8; ++ii
) {
734 arg
= value_arg_coerce (args
[argno
]);
735 len
= TYPE_LENGTH (VALUE_TYPE (arg
));
737 if (TYPE_CODE (VALUE_TYPE (arg
)) == TYPE_CODE_FLT
) {
739 /* floating point arguments are passed in fpr's, as well as gpr's.
740 There are 13 fpr's reserved for passing parameters. At this point
741 there is no way we would run out of them. */
745 "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno
);
747 memcpy (®isters
[REGISTER_BYTE(FP0_REGNUM
+ 1 + f_argno
)], VALUE_CONTENTS (arg
),
754 /* Argument takes more than one register. */
755 while (argbytes
< len
) {
757 *(int*)®isters
[REGISTER_BYTE(ii
+3)] = 0;
758 memcpy (®isters
[REGISTER_BYTE(ii
+3)],
759 ((char*)VALUE_CONTENTS (arg
))+argbytes
,
760 (len
- argbytes
) > 4 ? 4 : len
- argbytes
);
764 goto ran_out_of_registers_for_arguments
;
769 else { /* Argument can fit in one register. No problem. */
770 *(int*)®isters
[REGISTER_BYTE(ii
+3)] = 0;
771 memcpy (®isters
[REGISTER_BYTE(ii
+3)], VALUE_CONTENTS (arg
), len
);
776 ran_out_of_registers_for_arguments
:
778 /* location for 8 parameters are always reserved. */
781 /* another six words for back chain, TOC register, link register, etc. */
784 /* if there are more arguments, allocate space for them in
785 the stack, then push them starting from the ninth one. */
787 if ((argno
< nargs
) || argbytes
) {
792 space
+= ((len
- argbytes
+ 3) & -4);
798 for (; jj
< nargs
; ++jj
) {
799 val
= value_arg_coerce (args
[jj
]);
800 space
+= ((TYPE_LENGTH (VALUE_TYPE (val
))) + 3) & -4;
803 /* add location required for the rest of the parameters */
804 space
= (space
+ 7) & -8;
807 /* This is another instance we need to be concerned about securing our
808 stack space. If we write anything underneath %sp (r1), we might conflict
809 with the kernel who thinks he is free to use this area. So, update %sp
810 first before doing anything else. */
812 write_register (SP_REGNUM
, sp
);
814 /* if the last argument copied into the registers didn't fit there
815 completely, push the rest of it into stack. */
819 sp
+24+(ii
*4), ((char*)VALUE_CONTENTS (arg
))+argbytes
, len
- argbytes
);
821 ii
+= ((len
- argbytes
+ 3) & -4) / 4;
824 /* push the rest of the arguments into stack. */
825 for (; argno
< nargs
; ++argno
) {
827 arg
= value_arg_coerce (args
[argno
]);
828 len
= TYPE_LENGTH (VALUE_TYPE (arg
));
831 /* float types should be passed in fpr's, as well as in the stack. */
832 if (TYPE_CODE (VALUE_TYPE (arg
)) == TYPE_CODE_FLT
&& f_argno
< 13) {
836 "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno
);
838 memcpy (®isters
[REGISTER_BYTE(FP0_REGNUM
+ 1 + f_argno
)], VALUE_CONTENTS (arg
),
843 write_memory (sp
+24+(ii
*4), (char *) VALUE_CONTENTS (arg
), len
);
844 ii
+= ((len
+ 3) & -4) / 4;
848 /* Secure stack areas first, before doing anything else. */
849 write_register (SP_REGNUM
, sp
);
851 saved_sp
= dummy_frame_addr
[dummy_frame_count
- 1];
852 read_memory (saved_sp
, tmp_buffer
, 24);
853 write_memory (sp
, tmp_buffer
, 24);
855 write_memory (sp
, &saved_sp
, 4); /* set back chain properly */
857 target_store_registers (-1);
861 /* a given return value in `regbuf' with a type `valtype', extract and copy its
862 value into `valbuf' */
865 extract_return_value (valtype
, regbuf
, valbuf
)
866 struct type
*valtype
;
867 char regbuf
[REGISTER_BYTES
];
871 if (TYPE_CODE (valtype
) == TYPE_CODE_FLT
) {
874 /* floats and doubles are returned in fpr1. fpr's have a size of 8 bytes.
875 We need to truncate the return value into float size (4 byte) if
878 if (TYPE_LENGTH (valtype
) > 4) /* this is a double */
879 memcpy (valbuf
, ®buf
[REGISTER_BYTE (FP0_REGNUM
+ 1)],
880 TYPE_LENGTH (valtype
));
882 memcpy (&dd
, ®buf
[REGISTER_BYTE (FP0_REGNUM
+ 1)], 8);
884 memcpy (valbuf
, &ff
, sizeof(float));
888 /* return value is copied starting from r3. */
889 memcpy (valbuf
, ®buf
[REGISTER_BYTE (3)], TYPE_LENGTH (valtype
));
893 /* keep structure return address in this variable.
894 FIXME: This is a horrid kludge which should not be allowed to continue
895 living. This only allows a single nested call to a structure-returning
896 function. Come on, guys! -- gnu@cygnus.com, Aug 92 */
898 CORE_ADDR rs6000_struct_return_address
;
901 /* Indirect function calls use a piece of trampoline code to do context
902 switching, i.e. to set the new TOC table. Skip such code if we are on
903 its first instruction (as when we have single-stepped to here).
904 Also skip shared library trampoline code (which is different from
905 indirect function call trampolines).
906 Result is desired PC to step until, or NULL if we are not in
910 skip_trampoline_code (pc
)
913 register unsigned int ii
, op
;
914 CORE_ADDR solib_target_pc
;
916 static unsigned trampoline_code
[] = {
917 0x800b0000, /* l r0,0x0(r11) */
918 0x90410014, /* st r2,0x14(r1) */
919 0x7c0903a6, /* mtctr r0 */
920 0x804b0004, /* l r2,0x4(r11) */
921 0x816b0008, /* l r11,0x8(r11) */
922 0x4e800420, /* bctr */
927 /* If pc is in a shared library trampoline, return its target. */
928 solib_target_pc
= find_solib_trampoline_target (pc
);
930 return solib_target_pc
;
932 for (ii
=0; trampoline_code
[ii
]; ++ii
) {
933 op
= read_memory_integer (pc
+ (ii
*4), 4);
934 if (op
!= trampoline_code
[ii
])
937 ii
= read_register (11); /* r11 holds destination addr */
938 pc
= read_memory_integer (ii
, 4); /* (r11) value */
943 /* Determines whether the function FI has a frame on the stack or not.
944 Called from the FRAMELESS_FUNCTION_INVOCATION macro in tm.h with a
945 second argument of 0, and from the FRAME_SAVED_PC macro with a
946 second argument of 1. */
949 frameless_function_invocation (fi
, pcsaved
)
950 struct frame_info
*fi
;
953 CORE_ADDR func_start
;
954 struct aix_framedata fdata
;
956 if (fi
->next
!= NULL
)
957 /* Don't even think about framelessness except on the innermost frame. */
958 /* FIXME: Can also be frameless if fi->next->signal_handler_caller (if
959 a signal happens while executing in a frameless function). */
962 func_start
= get_pc_function_start (fi
->pc
) + FUNCTION_START_OFFSET
;
964 /* If we failed to find the start of the function, it is a mistake
965 to inspect the instructions. */
970 function_frame_info (func_start
, &fdata
);
971 return pcsaved
? fdata
.nosavedpc
: fdata
.frameless
;
975 /* If saved registers of frame FI are not known yet, read and cache them.
976 &FDATAP contains aix_framedata; TDATAP can be NULL,
977 in which case the framedata are read. */
980 frame_get_cache_fsr (fi
, fdatap
)
981 struct frame_info
*fi
;
982 struct aix_framedata
*fdatap
;
985 CORE_ADDR frame_addr
;
986 struct aix_framedata work_fdata
;
991 if (fdatap
== NULL
) {
992 fdatap
= &work_fdata
;
993 function_frame_info (get_pc_function_start (fi
->pc
), fdatap
);
996 fi
->cache_fsr
= (struct frame_saved_regs
*)
997 obstack_alloc (&frame_cache_obstack
, sizeof (struct frame_saved_regs
));
998 memset (fi
->cache_fsr
, '\0', sizeof (struct frame_saved_regs
));
1000 if (fi
->prev
&& fi
->prev
->frame
)
1001 frame_addr
= fi
->prev
->frame
;
1003 frame_addr
= read_memory_integer (fi
->frame
, 4);
1005 /* if != -1, fdatap->saved_fpr is the smallest number of saved_fpr.
1006 All fpr's from saved_fpr to fp31 are saved right underneath caller
1007 stack pointer, starting from fp31 first. */
1009 if (fdatap
->saved_fpr
>= 0) {
1010 for (ii
=31; ii
>= fdatap
->saved_fpr
; --ii
)
1011 fi
->cache_fsr
->regs
[FP0_REGNUM
+ ii
] = frame_addr
- ((32 - ii
) * 8);
1012 frame_addr
-= (32 - fdatap
->saved_fpr
) * 8;
1015 /* if != -1, fdatap->saved_gpr is the smallest number of saved_gpr.
1016 All gpr's from saved_gpr to gpr31 are saved right under saved fprs,
1017 starting from r31 first. */
1019 if (fdatap
->saved_gpr
>= 0)
1020 for (ii
=31; ii
>= fdatap
->saved_gpr
; --ii
)
1021 fi
->cache_fsr
->regs
[ii
] = frame_addr
- ((32 - ii
) * 4);
1024 /* Return the address of a frame. This is the inital %sp value when the frame
1025 was first allocated. For functions calling alloca(), it might be saved in
1026 an alloca register. */
1029 frame_initial_stack_address (fi
)
1030 struct frame_info
*fi
;
1033 struct aix_framedata fdata
;
1034 struct frame_info
*callee_fi
;
1036 /* if the initial stack pointer (frame address) of this frame is known,
1040 return fi
->initial_sp
;
1042 /* find out if this function is using an alloca register.. */
1044 function_frame_info (get_pc_function_start (fi
->pc
), &fdata
);
1046 /* if saved registers of this frame are not known yet, read and cache them. */
1049 frame_get_cache_fsr (fi
, &fdata
);
1051 /* If no alloca register used, then fi->frame is the value of the %sp for
1052 this frame, and it is good enough. */
1054 if (fdata
.alloca_reg
< 0) {
1055 fi
->initial_sp
= fi
->frame
;
1056 return fi
->initial_sp
;
1059 /* This function has an alloca register. If this is the top-most frame
1060 (with the lowest address), the value in alloca register is good. */
1063 return fi
->initial_sp
= read_register (fdata
.alloca_reg
);
1065 /* Otherwise, this is a caller frame. Callee has usually already saved
1066 registers, but there are exceptions (such as when the callee
1067 has no parameters). Find the address in which caller's alloca
1068 register is saved. */
1070 for (callee_fi
= fi
->next
; callee_fi
; callee_fi
= callee_fi
->next
) {
1072 if (!callee_fi
->cache_fsr
)
1073 frame_get_cache_fsr (callee_fi
, NULL
);
1075 /* this is the address in which alloca register is saved. */
1077 tmpaddr
= callee_fi
->cache_fsr
->regs
[fdata
.alloca_reg
];
1079 fi
->initial_sp
= read_memory_integer (tmpaddr
, 4);
1080 return fi
->initial_sp
;
1083 /* Go look into deeper levels of the frame chain to see if any one of
1084 the callees has saved alloca register. */
1087 /* If alloca register was not saved, by the callee (or any of its callees)
1088 then the value in the register is still good. */
1090 return fi
->initial_sp
= read_register (fdata
.alloca_reg
);
1094 rs6000_frame_chain (thisframe
)
1095 struct frame_info
*thisframe
;
1098 if (inside_entry_file ((thisframe
)->pc
))
1100 if (thisframe
->signal_handler_caller
)
1101 fp
= read_memory_integer (thisframe
->frame
+ SIG_FRAME_FP_OFFSET
, 4);
1103 fp
= read_memory_integer ((thisframe
)->frame
, 4);
1108 /* Keep an array of load segment information and their TOC table addresses.
1109 This info will be useful when calling a shared library function by hand. */
1112 CORE_ADDR textorg
, dataorg
;
1113 unsigned long toc_offset
;
1116 #define LOADINFOLEN 10
1118 static struct loadinfo
*loadinfo
= NULL
;
1119 static int loadinfolen
= 0;
1120 static int loadinfotocindex
= 0;
1121 static int loadinfotextindex
= 0;
1125 xcoff_init_loadinfo ()
1127 loadinfotocindex
= 0;
1128 loadinfotextindex
= 0;
1130 if (loadinfolen
== 0) {
1131 loadinfo
= (struct loadinfo
*)
1132 xmalloc (sizeof (struct loadinfo
) * LOADINFOLEN
);
1133 loadinfolen
= LOADINFOLEN
;
1138 /* FIXME -- this is never called! */
1146 loadinfotocindex
= 0;
1147 loadinfotextindex
= 0;
1150 /* this is called from xcoffread.c */
1153 xcoff_add_toc_to_loadinfo (unsigned long tocoff
)
1155 while (loadinfotocindex
>= loadinfolen
) {
1156 loadinfolen
+= LOADINFOLEN
;
1157 loadinfo
= (struct loadinfo
*)
1158 xrealloc (loadinfo
, sizeof(struct loadinfo
) * loadinfolen
);
1160 loadinfo
[loadinfotocindex
++].toc_offset
= tocoff
;
1164 add_text_to_loadinfo (textaddr
, dataaddr
)
1168 while (loadinfotextindex
>= loadinfolen
) {
1169 loadinfolen
+= LOADINFOLEN
;
1170 loadinfo
= (struct loadinfo
*)
1171 xrealloc (loadinfo
, sizeof(struct loadinfo
) * loadinfolen
);
1173 loadinfo
[loadinfotextindex
].textorg
= textaddr
;
1174 loadinfo
[loadinfotextindex
].dataorg
= dataaddr
;
1175 ++loadinfotextindex
;
1179 /* FIXME: This assumes that the "textorg" and "dataorg" elements
1180 of a member of this array are correlated with the "toc_offset"
1181 element of the same member. But they are sequentially assigned in wildly
1182 different places, and probably there is no correlation. FIXME! */
1185 find_toc_address (pc
)
1188 int ii
, toc_entry
, tocbase
= 0;
1190 for (ii
=0; ii
< loadinfotextindex
; ++ii
)
1191 if (pc
> loadinfo
[ii
].textorg
&& loadinfo
[ii
].textorg
> tocbase
) {
1193 tocbase
= loadinfo
[ii
].textorg
;
1196 return loadinfo
[toc_entry
].dataorg
+ loadinfo
[toc_entry
].toc_offset
;