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 FRAME fr
= get_current_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 (fr
->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
;
569 fdata
->saved_gpr
= fdata
->saved_fpr
= fdata
->alloca_reg
= -1;
570 fdata
->frameless
= 1;
572 op
= read_memory_integer (pc
, 4);
573 if (op
== 0x7c0802a6) { /* mflr r0 */
575 op
= read_memory_integer (pc
, 4);
576 fdata
->nosavedpc
= 0;
577 fdata
->frameless
= 0;
579 else /* else, pc is not saved */
580 fdata
->nosavedpc
= 1;
582 if ((op
& 0xfc00003e) == 0x7c000026) { /* mfcr Rx */
584 op
= read_memory_integer (pc
, 4);
585 fdata
->frameless
= 0;
588 if ((op
& 0xfc000000) == 0x48000000) { /* bl foo, to save fprs??? */
590 op
= read_memory_integer (pc
, 4);
591 /* At this point, make sure this is not a trampoline function
592 (a function that simply calls another functions, and nothing else).
593 If the next is not a nop, this branch was part of the function
596 if (op
== 0x4def7b82 || /* crorc 15, 15, 15 */
598 return; /* prologue is over */
599 fdata
->frameless
= 0;
602 if ((op
& 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */
603 pc
+= 4; /* store floating register double */
604 op
= read_memory_integer (pc
, 4);
605 fdata
->frameless
= 0;
608 if ((op
& 0xfc1f0000) == 0xbc010000) { /* stm Rx, NUM(r1) */
610 fdata
->saved_gpr
= (op
>> 21) & 0x1f;
613 tmp2
= (~0 &~ 0xffff) | tmp2
;
617 fdata
->saved_fpr
= (tmp2
- ((32 - fdata
->saved_gpr
) * 4)) / 8;
618 if ( fdata
->saved_fpr
> 0)
619 fdata
->saved_fpr
= 32 - fdata
->saved_fpr
;
621 fdata
->saved_fpr
= -1;
623 fdata
->offset
= tmp2
;
625 op
= read_memory_integer (pc
, 4);
626 fdata
->frameless
= 0;
629 while (((tmp
= op
>> 16) == 0x9001) || /* st r0, NUM(r1) */
630 (tmp
== 0x9421) || /* stu r1, NUM(r1) */
631 (tmp
== 0x93e1)) /* st r31, NUM(r1) */
635 /* gcc takes a short cut and uses this instruction to save r31 only. */
639 /* fatal ("Unrecognized prolog."); */
640 printf_unfiltered ("Unrecognized prolog!\n");
642 fdata
->saved_gpr
= 31;
645 tmp2
= - ((~0 &~ 0xffff) | tmp2
);
646 fdata
->saved_fpr
= (tmp2
- ((32 - 31) * 4)) / 8;
647 if ( fdata
->saved_fpr
> 0)
648 fdata
->saved_fpr
= 32 - fdata
->saved_fpr
;
650 fdata
->saved_fpr
= -1;
652 fdata
->offset
= tmp2
;
655 op
= read_memory_integer (pc
, 4);
656 fdata
->frameless
= 0;
659 while ((tmp
= (op
>> 22)) == 0x20f) { /* l r31, ... or */
660 pc
+= 4; /* l r30, ... */
661 op
= read_memory_integer (pc
, 4);
662 fdata
->frameless
= 0;
665 /* store parameters into stack */
667 (op
& 0xfc1f0000) == 0xd8010000 || /* stfd Rx,NUM(r1) */
668 (op
& 0xfc1f0000) == 0x90010000 || /* st r?, NUM(r1) */
669 (op
& 0xfc000000) == 0xfc000000 || /* frsp, fp?, .. */
670 (op
& 0xd0000000) == 0xd0000000) /* stfs, fp?, .. */
672 pc
+= 4; /* store fpr double */
673 op
= read_memory_integer (pc
, 4);
674 fdata
->frameless
= 0;
677 if (op
== 0x603f0000 /* oril r31, r1, 0x0 */
678 || op
== 0x7c3f0b78) /* mr r31, r1 */
680 fdata
->alloca_reg
= 31;
681 fdata
->frameless
= 0;
686 /* Pass the arguments in either registers, or in the stack. In RS6000, the first
687 eight words of the argument list (that might be less than eight parameters if
688 some parameters occupy more than one word) are passed in r3..r11 registers.
689 float and double parameters are passed in fpr's, in addition to that. Rest of
690 the parameters if any are passed in user stack. There might be cases in which
691 half of the parameter is copied into registers, the other half is pushed into
694 If the function is returning a structure, then the return address is passed
695 in r3, then the first 7 words of the parametes can be passed in registers,
699 push_arguments (nargs
, args
, sp
, struct_return
, struct_addr
)
704 CORE_ADDR struct_addr
;
707 int argno
; /* current argument number */
708 int argbytes
; /* current argument byte */
709 char tmp_buffer
[50];
711 int f_argno
= 0; /* current floating point argno */
713 CORE_ADDR saved_sp
, pc
;
715 if ( dummy_frame_count
<= 0)
716 printf_unfiltered ("FATAL ERROR -push_arguments()! frame not found!!\n");
718 /* The first eight words of ther arguments are passed in registers. Copy
721 If the function is returning a `struct', then the first word (which
722 will be passed in r3) is used for struct return address. In that
723 case we should advance one word and start from r4 register to copy
726 ii
= struct_return
? 1 : 0;
728 for (argno
=0, argbytes
=0; argno
< nargs
&& ii
<8; ++ii
) {
730 arg
= value_arg_coerce (args
[argno
]);
731 len
= TYPE_LENGTH (VALUE_TYPE (arg
));
733 if (TYPE_CODE (VALUE_TYPE (arg
)) == TYPE_CODE_FLT
) {
735 /* floating point arguments are passed in fpr's, as well as gpr's.
736 There are 13 fpr's reserved for passing parameters. At this point
737 there is no way we would run out of them. */
741 "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno
);
743 memcpy (®isters
[REGISTER_BYTE(FP0_REGNUM
+ 1 + f_argno
)], VALUE_CONTENTS (arg
),
750 /* Argument takes more than one register. */
751 while (argbytes
< len
) {
753 *(int*)®isters
[REGISTER_BYTE(ii
+3)] = 0;
754 memcpy (®isters
[REGISTER_BYTE(ii
+3)],
755 ((char*)VALUE_CONTENTS (arg
))+argbytes
,
756 (len
- argbytes
) > 4 ? 4 : len
- argbytes
);
760 goto ran_out_of_registers_for_arguments
;
765 else { /* Argument can fit in one register. No problem. */
766 *(int*)®isters
[REGISTER_BYTE(ii
+3)] = 0;
767 memcpy (®isters
[REGISTER_BYTE(ii
+3)], VALUE_CONTENTS (arg
), len
);
772 ran_out_of_registers_for_arguments
:
774 /* location for 8 parameters are always reserved. */
777 /* another six words for back chain, TOC register, link register, etc. */
780 /* if there are more arguments, allocate space for them in
781 the stack, then push them starting from the ninth one. */
783 if ((argno
< nargs
) || argbytes
) {
788 space
+= ((len
- argbytes
+ 3) & -4);
794 for (; jj
< nargs
; ++jj
) {
795 val
= value_arg_coerce (args
[jj
]);
796 space
+= ((TYPE_LENGTH (VALUE_TYPE (val
))) + 3) & -4;
799 /* add location required for the rest of the parameters */
800 space
= (space
+ 7) & -8;
803 /* This is another instance we need to be concerned about securing our
804 stack space. If we write anything underneath %sp (r1), we might conflict
805 with the kernel who thinks he is free to use this area. So, update %sp
806 first before doing anything else. */
808 write_register (SP_REGNUM
, sp
);
810 /* if the last argument copied into the registers didn't fit there
811 completely, push the rest of it into stack. */
815 sp
+24+(ii
*4), ((char*)VALUE_CONTENTS (arg
))+argbytes
, len
- argbytes
);
817 ii
+= ((len
- argbytes
+ 3) & -4) / 4;
820 /* push the rest of the arguments into stack. */
821 for (; argno
< nargs
; ++argno
) {
823 arg
= value_arg_coerce (args
[argno
]);
824 len
= TYPE_LENGTH (VALUE_TYPE (arg
));
827 /* float types should be passed in fpr's, as well as in the stack. */
828 if (TYPE_CODE (VALUE_TYPE (arg
)) == TYPE_CODE_FLT
&& f_argno
< 13) {
832 "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno
);
834 memcpy (®isters
[REGISTER_BYTE(FP0_REGNUM
+ 1 + f_argno
)], VALUE_CONTENTS (arg
),
839 write_memory (sp
+24+(ii
*4), (char *) VALUE_CONTENTS (arg
), len
);
840 ii
+= ((len
+ 3) & -4) / 4;
844 /* Secure stack areas first, before doing anything else. */
845 write_register (SP_REGNUM
, sp
);
847 saved_sp
= dummy_frame_addr
[dummy_frame_count
- 1];
848 read_memory (saved_sp
, tmp_buffer
, 24);
849 write_memory (sp
, tmp_buffer
, 24);
851 write_memory (sp
, &saved_sp
, 4); /* set back chain properly */
853 target_store_registers (-1);
857 /* a given return value in `regbuf' with a type `valtype', extract and copy its
858 value into `valbuf' */
861 extract_return_value (valtype
, regbuf
, valbuf
)
862 struct type
*valtype
;
863 char regbuf
[REGISTER_BYTES
];
867 if (TYPE_CODE (valtype
) == TYPE_CODE_FLT
) {
870 /* floats and doubles are returned in fpr1. fpr's have a size of 8 bytes.
871 We need to truncate the return value into float size (4 byte) if
874 if (TYPE_LENGTH (valtype
) > 4) /* this is a double */
875 memcpy (valbuf
, ®buf
[REGISTER_BYTE (FP0_REGNUM
+ 1)],
876 TYPE_LENGTH (valtype
));
878 memcpy (&dd
, ®buf
[REGISTER_BYTE (FP0_REGNUM
+ 1)], 8);
880 memcpy (valbuf
, &ff
, sizeof(float));
884 /* return value is copied starting from r3. */
885 memcpy (valbuf
, ®buf
[REGISTER_BYTE (3)], TYPE_LENGTH (valtype
));
889 /* keep structure return address in this variable.
890 FIXME: This is a horrid kludge which should not be allowed to continue
891 living. This only allows a single nested call to a structure-returning
892 function. Come on, guys! -- gnu@cygnus.com, Aug 92 */
894 CORE_ADDR rs6000_struct_return_address
;
897 /* Indirect function calls use a piece of trampoline code to do context
898 switching, i.e. to set the new TOC table. Skip such code if we are on
899 its first instruction (as when we have single-stepped to here).
900 Also skip shared library trampoline code (which is different from
901 indirect function call trampolines).
902 Result is desired PC to step until, or NULL if we are not in
906 skip_trampoline_code (pc
)
909 register unsigned int ii
, op
;
910 CORE_ADDR solib_target_pc
;
912 static unsigned trampoline_code
[] = {
913 0x800b0000, /* l r0,0x0(r11) */
914 0x90410014, /* st r2,0x14(r1) */
915 0x7c0903a6, /* mtctr r0 */
916 0x804b0004, /* l r2,0x4(r11) */
917 0x816b0008, /* l r11,0x8(r11) */
918 0x4e800420, /* bctr */
923 /* If pc is in a shared library trampoline, return its target. */
924 solib_target_pc
= find_solib_trampoline_target (pc
);
926 return solib_target_pc
;
928 for (ii
=0; trampoline_code
[ii
]; ++ii
) {
929 op
= read_memory_integer (pc
+ (ii
*4), 4);
930 if (op
!= trampoline_code
[ii
])
933 ii
= read_register (11); /* r11 holds destination addr */
934 pc
= read_memory_integer (ii
, 4); /* (r11) value */
939 /* Determines whether the function FI has a frame on the stack or not.
940 Called from the FRAMELESS_FUNCTION_INVOCATION macro in tm.h with a
941 second argument of 0, and from the FRAME_SAVED_PC macro with a
942 second argument of 1. */
945 frameless_function_invocation (fi
, pcsaved
)
946 struct frame_info
*fi
;
949 CORE_ADDR func_start
;
950 struct aix_framedata fdata
;
952 if (fi
->next
!= NULL
)
953 /* Don't even think about framelessness except on the innermost frame. */
954 /* FIXME: Can also be frameless if fi->next->signal_handler_caller (if
955 a signal happens while executing in a frameless function). */
958 func_start
= get_pc_function_start (fi
->pc
) + FUNCTION_START_OFFSET
;
960 /* If we failed to find the start of the function, it is a mistake
961 to inspect the instructions. */
966 function_frame_info (func_start
, &fdata
);
967 return pcsaved
? fdata
.nosavedpc
: fdata
.frameless
;
971 /* If saved registers of frame FI are not known yet, read and cache them.
972 &FDATAP contains aix_framedata; TDATAP can be NULL,
973 in which case the framedata are read. */
976 frame_get_cache_fsr (fi
, fdatap
)
977 struct frame_info
*fi
;
978 struct aix_framedata
*fdatap
;
981 CORE_ADDR frame_addr
;
982 struct aix_framedata work_fdata
;
987 if (fdatap
== NULL
) {
988 fdatap
= &work_fdata
;
989 function_frame_info (get_pc_function_start (fi
->pc
), fdatap
);
992 fi
->cache_fsr
= (struct frame_saved_regs
*)
993 obstack_alloc (&frame_cache_obstack
, sizeof (struct frame_saved_regs
));
994 memset (fi
->cache_fsr
, '\0', sizeof (struct frame_saved_regs
));
996 if (fi
->prev
&& fi
->prev
->frame
)
997 frame_addr
= fi
->prev
->frame
;
999 frame_addr
= read_memory_integer (fi
->frame
, 4);
1001 /* if != -1, fdatap->saved_fpr is the smallest number of saved_fpr.
1002 All fpr's from saved_fpr to fp31 are saved right underneath caller
1003 stack pointer, starting from fp31 first. */
1005 if (fdatap
->saved_fpr
>= 0) {
1006 for (ii
=31; ii
>= fdatap
->saved_fpr
; --ii
)
1007 fi
->cache_fsr
->regs
[FP0_REGNUM
+ ii
] = frame_addr
- ((32 - ii
) * 8);
1008 frame_addr
-= (32 - fdatap
->saved_fpr
) * 8;
1011 /* if != -1, fdatap->saved_gpr is the smallest number of saved_gpr.
1012 All gpr's from saved_gpr to gpr31 are saved right under saved fprs,
1013 starting from r31 first. */
1015 if (fdatap
->saved_gpr
>= 0)
1016 for (ii
=31; ii
>= fdatap
->saved_gpr
; --ii
)
1017 fi
->cache_fsr
->regs
[ii
] = frame_addr
- ((32 - ii
) * 4);
1020 /* Return the address of a frame. This is the inital %sp value when the frame
1021 was first allocated. For functions calling alloca(), it might be saved in
1022 an alloca register. */
1025 frame_initial_stack_address (fi
)
1026 struct frame_info
*fi
;
1029 struct aix_framedata fdata
;
1030 struct frame_info
*callee_fi
;
1032 /* if the initial stack pointer (frame address) of this frame is known,
1036 return fi
->initial_sp
;
1038 /* find out if this function is using an alloca register.. */
1040 function_frame_info (get_pc_function_start (fi
->pc
), &fdata
);
1042 /* if saved registers of this frame are not known yet, read and cache them. */
1045 frame_get_cache_fsr (fi
, &fdata
);
1047 /* If no alloca register used, then fi->frame is the value of the %sp for
1048 this frame, and it is good enough. */
1050 if (fdata
.alloca_reg
< 0) {
1051 fi
->initial_sp
= fi
->frame
;
1052 return fi
->initial_sp
;
1055 /* This function has an alloca register. If this is the top-most frame
1056 (with the lowest address), the value in alloca register is good. */
1059 return fi
->initial_sp
= read_register (fdata
.alloca_reg
);
1061 /* Otherwise, this is a caller frame. Callee has usually already saved
1062 registers, but there are exceptions (such as when the callee
1063 has no parameters). Find the address in which caller's alloca
1064 register is saved. */
1066 for (callee_fi
= fi
->next
; callee_fi
; callee_fi
= callee_fi
->next
) {
1068 if (!callee_fi
->cache_fsr
)
1069 frame_get_cache_fsr (callee_fi
, NULL
);
1071 /* this is the address in which alloca register is saved. */
1073 tmpaddr
= callee_fi
->cache_fsr
->regs
[fdata
.alloca_reg
];
1075 fi
->initial_sp
= read_memory_integer (tmpaddr
, 4);
1076 return fi
->initial_sp
;
1079 /* Go look into deeper levels of the frame chain to see if any one of
1080 the callees has saved alloca register. */
1083 /* If alloca register was not saved, by the callee (or any of its callees)
1084 then the value in the register is still good. */
1086 return fi
->initial_sp
= read_register (fdata
.alloca_reg
);
1090 rs6000_frame_chain (thisframe
)
1091 struct frame_info
*thisframe
;
1094 if (inside_entry_file ((thisframe
)->pc
))
1096 if (thisframe
->signal_handler_caller
)
1098 /* This was determined by experimentation on AIX 3.2. Perhaps
1099 it corresponds to some offset in /usr/include/sys/user.h or
1100 something like that. Using some system include file would
1101 have the advantage of probably being more robust in the face
1102 of OS upgrades, but the disadvantage of being wrong for
1105 #define SIG_FRAME_FP_OFFSET 284
1106 fp
= read_memory_integer (thisframe
->frame
+ SIG_FRAME_FP_OFFSET
, 4);
1109 fp
= read_memory_integer ((thisframe
)->frame
, 4);
1114 /* Keep an array of load segment information and their TOC table addresses.
1115 This info will be useful when calling a shared library function by hand. */
1118 CORE_ADDR textorg
, dataorg
;
1119 unsigned long toc_offset
;
1122 #define LOADINFOLEN 10
1124 static struct loadinfo
*loadinfo
= NULL
;
1125 static int loadinfolen
= 0;
1126 static int loadinfotocindex
= 0;
1127 static int loadinfotextindex
= 0;
1131 xcoff_init_loadinfo ()
1133 loadinfotocindex
= 0;
1134 loadinfotextindex
= 0;
1136 if (loadinfolen
== 0) {
1137 loadinfo
= (struct loadinfo
*)
1138 xmalloc (sizeof (struct loadinfo
) * LOADINFOLEN
);
1139 loadinfolen
= LOADINFOLEN
;
1144 /* FIXME -- this is never called! */
1152 loadinfotocindex
= 0;
1153 loadinfotextindex
= 0;
1156 /* this is called from xcoffread.c */
1159 xcoff_add_toc_to_loadinfo (unsigned long tocoff
)
1161 while (loadinfotocindex
>= loadinfolen
) {
1162 loadinfolen
+= LOADINFOLEN
;
1163 loadinfo
= (struct loadinfo
*)
1164 xrealloc (loadinfo
, sizeof(struct loadinfo
) * loadinfolen
);
1166 loadinfo
[loadinfotocindex
++].toc_offset
= tocoff
;
1170 add_text_to_loadinfo (textaddr
, dataaddr
)
1174 while (loadinfotextindex
>= loadinfolen
) {
1175 loadinfolen
+= LOADINFOLEN
;
1176 loadinfo
= (struct loadinfo
*)
1177 xrealloc (loadinfo
, sizeof(struct loadinfo
) * loadinfolen
);
1179 loadinfo
[loadinfotextindex
].textorg
= textaddr
;
1180 loadinfo
[loadinfotextindex
].dataorg
= dataaddr
;
1181 ++loadinfotextindex
;
1185 /* FIXME: This assumes that the "textorg" and "dataorg" elements
1186 of a member of this array are correlated with the "toc_offset"
1187 element of the same member. But they are sequentially assigned in wildly
1188 different places, and probably there is no correlation. FIXME! */
1191 find_toc_address (pc
)
1194 int ii
, toc_entry
, tocbase
= 0;
1196 for (ii
=0; ii
< loadinfotextindex
; ++ii
)
1197 if (pc
> loadinfo
[ii
].textorg
&& loadinfo
[ii
].textorg
> tocbase
) {
1199 tocbase
= loadinfo
[ii
].textorg
;
1202 return loadinfo
[toc_entry
].dataorg
+ loadinfo
[toc_entry
].toc_offset
;