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 pc
+= 4; /* this happens if r31 is used as */
249 op
= read_memory_integer (pc
, 4); /* frame ptr. (gcc does that) */
252 while ((op
>> 16) == (0x907f + tmp
)) { /* st r3, NUM(r31) */
253 pc
+= 4; /* st r4, NUM(r31), ... */
254 op
= read_memory_integer (pc
, 4);
259 /* I have problems with skipping over __main() that I need to address
260 * sometime. Previously, I used to use misc_function_vector which
261 * didn't work as well as I wanted to be. -MGO */
263 /* If the first thing after skipping a prolog is a branch to a function,
264 this might be a call to an initializer in main(), introduced by gcc2.
265 We'd like to skip over it as well. Fortunately, xlc does some extra
266 work before calling a function right after a prologue, thus we can
267 single out such gcc2 behaviour. */
270 if ((op
& 0xfc000001) == 0x48000001) { /* bl foo, an initializer function? */
271 op
= read_memory_integer (pc
+4, 4);
273 if (op
== 0x4def7b82) { /* cror 0xf, 0xf, 0xf (nop) */
275 /* check and see if we are in main. If so, skip over this initializer
278 tmp
= find_pc_misc_function (pc
);
279 if (tmp
>= 0 && STREQ (misc_function_vector
[tmp
].name
, "main"))
289 /*************************************************************************
290 Support for creating pushind a dummy frame into the stack, and popping
292 *************************************************************************/
294 /* The total size of dummy frame is 436, which is;
299 and 24 extra bytes for the callee's link area. The last 24 bytes
300 for the link area might not be necessary, since it will be taken
301 care of by push_arguments(). */
303 #define DUMMY_FRAME_SIZE 436
305 #define DUMMY_FRAME_ADDR_SIZE 10
307 /* Make sure you initialize these in somewhere, in case gdb gives up what it
308 was debugging and starts debugging something else. FIXMEibm */
310 static int dummy_frame_count
= 0;
311 static int dummy_frame_size
= 0;
312 static CORE_ADDR
*dummy_frame_addr
= 0;
314 extern int stop_stack_dummy
;
316 /* push a dummy frame into stack, save all register. Currently we are saving
317 only gpr's and fpr's, which is not good enough! FIXMEmgo */
327 /* Same thing, target byte order. */
332 target_fetch_registers (-1);
334 if (dummy_frame_count
>= dummy_frame_size
) {
335 dummy_frame_size
+= DUMMY_FRAME_ADDR_SIZE
;
336 if (dummy_frame_addr
)
337 dummy_frame_addr
= (CORE_ADDR
*) xrealloc
338 (dummy_frame_addr
, sizeof(CORE_ADDR
) * (dummy_frame_size
));
340 dummy_frame_addr
= (CORE_ADDR
*)
341 xmalloc (sizeof(CORE_ADDR
) * (dummy_frame_size
));
344 sp
= read_register(SP_REGNUM
);
345 pc
= read_register(PC_REGNUM
);
346 memcpy (pc_targ
, (char *) &pc
, 4);
348 dummy_frame_addr
[dummy_frame_count
++] = sp
;
350 /* Be careful! If the stack pointer is not decremented first, then kernel
351 thinks he is free to use the space underneath it. And kernel actually
352 uses that area for IPC purposes when executing ptrace(2) calls. So
353 before writing register values into the new frame, decrement and update
354 %sp first in order to secure your frame. */
356 write_register (SP_REGNUM
, sp
-DUMMY_FRAME_SIZE
);
358 /* gdb relies on the state of current_frame. We'd better update it,
359 otherwise things like do_registers_info() wouldn't work properly! */
361 flush_cached_frames ();
363 /* save program counter in link register's space. */
364 write_memory (sp
+8, pc_targ
, 4);
366 /* save all floating point and general purpose registers here. */
369 for (ii
= 0; ii
< 32; ++ii
)
370 write_memory (sp
-8-(ii
*8), ®isters
[REGISTER_BYTE (31-ii
+FP0_REGNUM
)], 8);
373 for (ii
=1; ii
<=32; ++ii
)
374 write_memory (sp
-256-(ii
*4), ®isters
[REGISTER_BYTE (32-ii
)], 4);
376 /* so far, 32*2 + 32 words = 384 bytes have been written.
377 7 extra registers in our register set: pc, ps, cnd, lr, cnt, xer, mq */
379 for (ii
=1; ii
<= (LAST_SP_REGNUM
-FIRST_SP_REGNUM
+1); ++ii
) {
380 write_memory (sp
-384-(ii
*4),
381 ®isters
[REGISTER_BYTE (FPLAST_REGNUM
+ ii
)], 4);
384 /* Save sp or so called back chain right here. */
385 write_memory (sp
-DUMMY_FRAME_SIZE
, &sp
, 4);
386 sp
-= DUMMY_FRAME_SIZE
;
388 /* And finally, this is the back chain. */
389 write_memory (sp
+8, pc_targ
, 4);
393 /* Pop a dummy frame.
395 In rs6000 when we push a dummy frame, we save all of the registers. This
396 is usually done before user calls a function explicitly.
398 After a dummy frame is pushed, some instructions are copied into stack,
399 and stack pointer is decremented even more. Since we don't have a frame
400 pointer to get back to the parent frame of the dummy, we start having
401 trouble poping it. Therefore, we keep a dummy frame stack, keeping
402 addresses of dummy frames as such. When poping happens and when we
403 detect that was a dummy frame, we pop it back to its parent by using
404 dummy frame stack (`dummy_frame_addr' array).
406 FIXME: This whole concept is broken. You should be able to detect
407 a dummy stack frame *on the user's stack itself*. When you do,
408 then you know the format of that stack frame -- including its
409 saved SP register! There should *not* be a separate stack in the
410 GDB process that keeps track of these dummy frames! -- gnu@cygnus.com Aug92
417 sp
= dummy_frame_addr
[--dummy_frame_count
];
419 /* restore all fpr's. */
420 for (ii
= 1; ii
<= 32; ++ii
)
421 read_memory (sp
-(ii
*8), ®isters
[REGISTER_BYTE (32-ii
+FP0_REGNUM
)], 8);
423 /* restore all gpr's */
424 for (ii
=1; ii
<= 32; ++ii
) {
425 read_memory (sp
-256-(ii
*4), ®isters
[REGISTER_BYTE (32-ii
)], 4);
428 /* restore the rest of the registers. */
429 for (ii
=1; ii
<=(LAST_SP_REGNUM
-FIRST_SP_REGNUM
+1); ++ii
)
430 read_memory (sp
-384-(ii
*4),
431 ®isters
[REGISTER_BYTE (FPLAST_REGNUM
+ ii
)], 4);
433 read_memory (sp
-(DUMMY_FRAME_SIZE
-8),
434 ®isters
[REGISTER_BYTE(PC_REGNUM
)], 4);
436 /* when a dummy frame was being pushed, we had to decrement %sp first, in
437 order to secure astack space. Thus, saved %sp (or %r1) value, is not the
438 one we should restore. Change it with the one we need. */
440 *(int*)®isters
[REGISTER_BYTE(FP_REGNUM
)] = sp
;
442 /* Now we can restore all registers. */
444 target_store_registers (-1);
446 flush_cached_frames ();
450 /* pop the innermost frame, go back to the caller. */
455 CORE_ADDR pc
, lr
, sp
, prev_sp
; /* %pc, %lr, %sp */
456 struct aix_framedata fdata
;
457 FRAME fr
= get_current_frame ();
463 if (stop_stack_dummy
&& dummy_frame_count
) {
468 /* Make sure that all registers are valid. */
469 read_register_bytes (0, NULL
, REGISTER_BYTES
);
471 /* figure out previous %pc value. If the function is frameless, it is
472 still in the link register, otherwise walk the frames and retrieve the
473 saved %pc value in the previous frame. */
475 addr
= get_pc_function_start (fr
->pc
) + FUNCTION_START_OFFSET
;
476 function_frame_info (addr
, &fdata
);
481 prev_sp
= read_memory_integer (sp
, 4);
483 lr
= read_register (LR_REGNUM
);
485 lr
= read_memory_integer (prev_sp
+8, 4);
487 /* reset %pc value. */
488 write_register (PC_REGNUM
, lr
);
490 /* reset register values if any was saved earlier. */
491 addr
= prev_sp
- fdata
.offset
;
493 if (fdata
.saved_gpr
!= -1)
494 for (ii
=fdata
.saved_gpr
; ii
<= 31; ++ii
) {
495 read_memory (addr
, ®isters
[REGISTER_BYTE (ii
)], 4);
499 if (fdata
.saved_fpr
!= -1)
500 for (ii
=fdata
.saved_fpr
; ii
<= 31; ++ii
) {
501 read_memory (addr
, ®isters
[REGISTER_BYTE (ii
+FP0_REGNUM
)], 8);
505 write_register (SP_REGNUM
, prev_sp
);
506 target_store_registers (-1);
507 flush_cached_frames ();
510 /* fixup the call sequence of a dummy function, with the real function address.
511 its argumets will be passed by gdb. */
514 fix_call_dummy(dummyname
, pc
, fun
, nargs
, type
)
518 int nargs
; /* not used */
519 int type
; /* not used */
521 #define TOC_ADDR_OFFSET 20
522 #define TARGET_ADDR_OFFSET 28
525 CORE_ADDR target_addr
;
529 tocvalue
= find_toc_address (target_addr
);
531 ii
= *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
);
532 ii
= (ii
& 0xffff0000) | (tocvalue
>> 16);
533 *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
) = ii
;
535 ii
= *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
+4);
536 ii
= (ii
& 0xffff0000) | (tocvalue
& 0x0000ffff);
537 *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
+4) = ii
;
539 ii
= *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
);
540 ii
= (ii
& 0xffff0000) | (target_addr
>> 16);
541 *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
) = ii
;
543 ii
= *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
+4);
544 ii
= (ii
& 0xffff0000) | (target_addr
& 0x0000ffff);
545 *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
+4) = ii
;
549 /* return information about a function frame.
550 in struct aix_frameinfo fdata:
551 - frameless is TRUE, if function does not have a frame.
552 - nosavedpc is TRUE, if function does not save %pc value in its frame.
553 - offset is the number of bytes used in the frame to save registers.
554 - saved_gpr is the number of the first saved gpr.
555 - saved_fpr is the number of the first saved fpr.
556 - alloca_reg is the number of the register used for alloca() handling.
560 function_frame_info (pc
, fdata
)
562 struct aix_framedata
*fdata
;
565 register unsigned int op
;
568 fdata
->saved_gpr
= fdata
->saved_fpr
= fdata
->alloca_reg
= -1;
569 fdata
->frameless
= 1;
571 op
= read_memory_integer (pc
, 4);
572 if (op
== 0x7c0802a6) { /* mflr r0 */
574 op
= read_memory_integer (pc
, 4);
575 fdata
->nosavedpc
= 0;
576 fdata
->frameless
= 0;
578 else /* else, pc is not saved */
579 fdata
->nosavedpc
= 1;
581 if ((op
& 0xfc00003e) == 0x7c000026) { /* mfcr Rx */
583 op
= read_memory_integer (pc
, 4);
584 fdata
->frameless
= 0;
587 if ((op
& 0xfc000000) == 0x48000000) { /* bl foo, to save fprs??? */
589 op
= read_memory_integer (pc
, 4);
590 /* At this point, make sure this is not a trampoline function
591 (a function that simply calls another functions, and nothing else).
592 If the next is not a nop, this branch was part of the function
595 if (op
== 0x4def7b82 || /* crorc 15, 15, 15 */
597 return; /* prologue is over */
598 fdata
->frameless
= 0;
601 if ((op
& 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */
602 pc
+= 4; /* store floating register double */
603 op
= read_memory_integer (pc
, 4);
604 fdata
->frameless
= 0;
607 if ((op
& 0xfc1f0000) == 0xbc010000) { /* stm Rx, NUM(r1) */
609 fdata
->saved_gpr
= (op
>> 21) & 0x1f;
612 tmp2
= (~0 &~ 0xffff) | tmp2
;
616 fdata
->saved_fpr
= (tmp2
- ((32 - fdata
->saved_gpr
) * 4)) / 8;
617 if ( fdata
->saved_fpr
> 0)
618 fdata
->saved_fpr
= 32 - fdata
->saved_fpr
;
620 fdata
->saved_fpr
= -1;
622 fdata
->offset
= tmp2
;
624 op
= read_memory_integer (pc
, 4);
625 fdata
->frameless
= 0;
628 while (((tmp
= op
>> 16) == 0x9001) || /* st r0, NUM(r1) */
629 (tmp
== 0x9421) || /* stu r1, NUM(r1) */
630 (tmp
== 0x93e1)) /* st r31, NUM(r1) */
634 /* gcc takes a short cut and uses this instruction to save r31 only. */
638 /* fatal ("Unrecognized prolog."); */
639 printf_unfiltered ("Unrecognized prolog!\n");
641 fdata
->saved_gpr
= 31;
644 tmp2
= - ((~0 &~ 0xffff) | tmp2
);
645 fdata
->saved_fpr
= (tmp2
- ((32 - 31) * 4)) / 8;
646 if ( fdata
->saved_fpr
> 0)
647 fdata
->saved_fpr
= 32 - fdata
->saved_fpr
;
649 fdata
->saved_fpr
= -1;
651 fdata
->offset
= tmp2
;
654 op
= read_memory_integer (pc
, 4);
655 fdata
->frameless
= 0;
658 while ((tmp
= (op
>> 22)) == 0x20f) { /* l r31, ... or */
659 pc
+= 4; /* l r30, ... */
660 op
= read_memory_integer (pc
, 4);
661 fdata
->frameless
= 0;
664 /* store parameters into stack */
666 (op
& 0xfc1f0000) == 0xd8010000 || /* stfd Rx,NUM(r1) */
667 (op
& 0xfc1f0000) == 0x90010000 || /* st r?, NUM(r1) */
668 (op
& 0xfc000000) == 0xfc000000 || /* frsp, fp?, .. */
669 (op
& 0xd0000000) == 0xd0000000) /* stfs, fp?, .. */
671 pc
+= 4; /* store fpr double */
672 op
= read_memory_integer (pc
, 4);
673 fdata
->frameless
= 0;
676 if (op
== 0x603f0000 /* oril r31, r1, 0x0 */
677 || op
== 0x7c3f0b78) /* mr r31, r1 */
679 fdata
->alloca_reg
= 31;
680 fdata
->frameless
= 0;
685 /* Pass the arguments in either registers, or in the stack. In RS6000, the first
686 eight words of the argument list (that might be less than eight parameters if
687 some parameters occupy more than one word) are passed in r3..r11 registers.
688 float and double parameters are passed in fpr's, in addition to that. Rest of
689 the parameters if any are passed in user stack. There might be cases in which
690 half of the parameter is copied into registers, the other half is pushed into
693 If the function is returning a structure, then the return address is passed
694 in r3, then the first 7 words of the parametes can be passed in registers,
698 push_arguments (nargs
, args
, sp
, struct_return
, struct_addr
)
703 CORE_ADDR struct_addr
;
706 int argno
; /* current argument number */
707 int argbytes
; /* current argument byte */
708 char tmp_buffer
[50];
710 int f_argno
= 0; /* current floating point argno */
712 CORE_ADDR saved_sp
, pc
;
714 if ( dummy_frame_count
<= 0)
715 printf_unfiltered ("FATAL ERROR -push_arguments()! frame not found!!\n");
717 /* The first eight words of ther arguments are passed in registers. Copy
720 If the function is returning a `struct', then the first word (which
721 will be passed in r3) is used for struct return address. In that
722 case we should advance one word and start from r4 register to copy
725 ii
= struct_return
? 1 : 0;
727 for (argno
=0, argbytes
=0; argno
< nargs
&& ii
<8; ++ii
) {
729 arg
= value_arg_coerce (args
[argno
]);
730 len
= TYPE_LENGTH (VALUE_TYPE (arg
));
732 if (TYPE_CODE (VALUE_TYPE (arg
)) == TYPE_CODE_FLT
) {
734 /* floating point arguments are passed in fpr's, as well as gpr's.
735 There are 13 fpr's reserved for passing parameters. At this point
736 there is no way we would run out of them. */
740 "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno
);
742 memcpy (®isters
[REGISTER_BYTE(FP0_REGNUM
+ 1 + f_argno
)], VALUE_CONTENTS (arg
),
749 /* Argument takes more than one register. */
750 while (argbytes
< len
) {
752 *(int*)®isters
[REGISTER_BYTE(ii
+3)] = 0;
753 memcpy (®isters
[REGISTER_BYTE(ii
+3)],
754 ((char*)VALUE_CONTENTS (arg
))+argbytes
,
755 (len
- argbytes
) > 4 ? 4 : len
- argbytes
);
759 goto ran_out_of_registers_for_arguments
;
764 else { /* Argument can fit in one register. No problem. */
765 *(int*)®isters
[REGISTER_BYTE(ii
+3)] = 0;
766 memcpy (®isters
[REGISTER_BYTE(ii
+3)], VALUE_CONTENTS (arg
), len
);
771 ran_out_of_registers_for_arguments
:
773 /* location for 8 parameters are always reserved. */
776 /* another six words for back chain, TOC register, link register, etc. */
779 /* if there are more arguments, allocate space for them in
780 the stack, then push them starting from the ninth one. */
782 if ((argno
< nargs
) || argbytes
) {
787 space
+= ((len
- argbytes
+ 3) & -4);
793 for (; jj
< nargs
; ++jj
) {
794 val
= value_arg_coerce (args
[jj
]);
795 space
+= ((TYPE_LENGTH (VALUE_TYPE (val
))) + 3) & -4;
798 /* add location required for the rest of the parameters */
799 space
= (space
+ 7) & -8;
802 /* This is another instance we need to be concerned about securing our
803 stack space. If we write anything underneath %sp (r1), we might conflict
804 with the kernel who thinks he is free to use this area. So, update %sp
805 first before doing anything else. */
807 write_register (SP_REGNUM
, sp
);
809 /* if the last argument copied into the registers didn't fit there
810 completely, push the rest of it into stack. */
814 sp
+24+(ii
*4), ((char*)VALUE_CONTENTS (arg
))+argbytes
, len
- argbytes
);
816 ii
+= ((len
- argbytes
+ 3) & -4) / 4;
819 /* push the rest of the arguments into stack. */
820 for (; argno
< nargs
; ++argno
) {
822 arg
= value_arg_coerce (args
[argno
]);
823 len
= TYPE_LENGTH (VALUE_TYPE (arg
));
826 /* float types should be passed in fpr's, as well as in the stack. */
827 if (TYPE_CODE (VALUE_TYPE (arg
)) == TYPE_CODE_FLT
&& f_argno
< 13) {
831 "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno
);
833 memcpy (®isters
[REGISTER_BYTE(FP0_REGNUM
+ 1 + f_argno
)], VALUE_CONTENTS (arg
),
838 write_memory (sp
+24+(ii
*4), (char *) VALUE_CONTENTS (arg
), len
);
839 ii
+= ((len
+ 3) & -4) / 4;
843 /* Secure stack areas first, before doing anything else. */
844 write_register (SP_REGNUM
, sp
);
846 saved_sp
= dummy_frame_addr
[dummy_frame_count
- 1];
847 read_memory (saved_sp
, tmp_buffer
, 24);
848 write_memory (sp
, tmp_buffer
, 24);
850 write_memory (sp
, &saved_sp
, 4); /* set back chain properly */
852 target_store_registers (-1);
856 /* a given return value in `regbuf' with a type `valtype', extract and copy its
857 value into `valbuf' */
860 extract_return_value (valtype
, regbuf
, valbuf
)
861 struct type
*valtype
;
862 char regbuf
[REGISTER_BYTES
];
866 if (TYPE_CODE (valtype
) == TYPE_CODE_FLT
) {
869 /* floats and doubles are returned in fpr1. fpr's have a size of 8 bytes.
870 We need to truncate the return value into float size (4 byte) if
873 if (TYPE_LENGTH (valtype
) > 4) /* this is a double */
874 memcpy (valbuf
, ®buf
[REGISTER_BYTE (FP0_REGNUM
+ 1)],
875 TYPE_LENGTH (valtype
));
877 memcpy (&dd
, ®buf
[REGISTER_BYTE (FP0_REGNUM
+ 1)], 8);
879 memcpy (valbuf
, &ff
, sizeof(float));
883 /* return value is copied starting from r3. */
884 memcpy (valbuf
, ®buf
[REGISTER_BYTE (3)], TYPE_LENGTH (valtype
));
888 /* keep structure return address in this variable.
889 FIXME: This is a horrid kludge which should not be allowed to continue
890 living. This only allows a single nested call to a structure-returning
891 function. Come on, guys! -- gnu@cygnus.com, Aug 92 */
893 CORE_ADDR rs6000_struct_return_address
;
896 /* Indirect function calls use a piece of trampoline code to do context
897 switching, i.e. to set the new TOC table. Skip such code if we are on
898 its first instruction (as when we have single-stepped to here).
899 Also skip shared library trampoline code (which is different from
900 indirect function call trampolines).
901 Result is desired PC to step until, or NULL if we are not in
905 skip_trampoline_code (pc
)
908 register unsigned int ii
, op
;
909 CORE_ADDR solib_target_pc
;
911 static unsigned trampoline_code
[] = {
912 0x800b0000, /* l r0,0x0(r11) */
913 0x90410014, /* st r2,0x14(r1) */
914 0x7c0903a6, /* mtctr r0 */
915 0x804b0004, /* l r2,0x4(r11) */
916 0x816b0008, /* l r11,0x8(r11) */
917 0x4e800420, /* bctr */
922 /* If pc is in a shared library trampoline, return its target. */
923 solib_target_pc
= find_solib_trampoline_target (pc
);
925 return solib_target_pc
;
927 for (ii
=0; trampoline_code
[ii
]; ++ii
) {
928 op
= read_memory_integer (pc
+ (ii
*4), 4);
929 if (op
!= trampoline_code
[ii
])
932 ii
= read_register (11); /* r11 holds destination addr */
933 pc
= read_memory_integer (ii
, 4); /* (r11) value */
938 /* Determines whether the function FI has a frame on the stack or not.
939 Called from the FRAMELESS_FUNCTION_INVOCATION macro in tm.h with a
940 second argument of 0, and from the FRAME_SAVED_PC macro with a
941 second argument of 1. */
944 frameless_function_invocation (fi
, pcsaved
)
945 struct frame_info
*fi
;
948 CORE_ADDR func_start
;
949 struct aix_framedata fdata
;
951 if (fi
->next
!= NULL
)
952 /* Don't even think about framelessness except on the innermost frame. */
953 /* FIXME: Can also be frameless if fi->next->signal_handler_caller (if
954 a signal happens while executing in a frameless function). */
957 func_start
= get_pc_function_start (fi
->pc
) + FUNCTION_START_OFFSET
;
959 /* If we failed to find the start of the function, it is a mistake
960 to inspect the instructions. */
965 function_frame_info (func_start
, &fdata
);
966 return pcsaved
? fdata
.nosavedpc
: fdata
.frameless
;
970 /* If saved registers of frame FI are not known yet, read and cache them.
971 &FDATAP contains aix_framedata; TDATAP can be NULL,
972 in which case the framedata are read. */
975 frame_get_cache_fsr (fi
, fdatap
)
976 struct frame_info
*fi
;
977 struct aix_framedata
*fdatap
;
980 CORE_ADDR frame_addr
;
981 struct aix_framedata work_fdata
;
986 if (fdatap
== NULL
) {
987 fdatap
= &work_fdata
;
988 function_frame_info (get_pc_function_start (fi
->pc
), fdatap
);
991 fi
->cache_fsr
= (struct frame_saved_regs
*)
992 obstack_alloc (&frame_cache_obstack
, sizeof (struct frame_saved_regs
));
993 memset (fi
->cache_fsr
, '\0', sizeof (struct frame_saved_regs
));
995 if (fi
->prev
&& fi
->prev
->frame
)
996 frame_addr
= fi
->prev
->frame
;
998 frame_addr
= read_memory_integer (fi
->frame
, 4);
1000 /* if != -1, fdatap->saved_fpr is the smallest number of saved_fpr.
1001 All fpr's from saved_fpr to fp31 are saved right underneath caller
1002 stack pointer, starting from fp31 first. */
1004 if (fdatap
->saved_fpr
>= 0) {
1005 for (ii
=31; ii
>= fdatap
->saved_fpr
; --ii
)
1006 fi
->cache_fsr
->regs
[FP0_REGNUM
+ ii
] = frame_addr
- ((32 - ii
) * 8);
1007 frame_addr
-= (32 - fdatap
->saved_fpr
) * 8;
1010 /* if != -1, fdatap->saved_gpr is the smallest number of saved_gpr.
1011 All gpr's from saved_gpr to gpr31 are saved right under saved fprs,
1012 starting from r31 first. */
1014 if (fdatap
->saved_gpr
>= 0)
1015 for (ii
=31; ii
>= fdatap
->saved_gpr
; --ii
)
1016 fi
->cache_fsr
->regs
[ii
] = frame_addr
- ((32 - ii
) * 4);
1019 /* Return the address of a frame. This is the inital %sp value when the frame
1020 was first allocated. For functions calling alloca(), it might be saved in
1021 an alloca register. */
1024 frame_initial_stack_address (fi
)
1025 struct frame_info
*fi
;
1028 struct aix_framedata fdata
;
1029 struct frame_info
*callee_fi
;
1031 /* if the initial stack pointer (frame address) of this frame is known,
1035 return fi
->initial_sp
;
1037 /* find out if this function is using an alloca register.. */
1039 function_frame_info (get_pc_function_start (fi
->pc
), &fdata
);
1041 /* if saved registers of this frame are not known yet, read and cache them. */
1044 frame_get_cache_fsr (fi
, &fdata
);
1046 /* If no alloca register used, then fi->frame is the value of the %sp for
1047 this frame, and it is good enough. */
1049 if (fdata
.alloca_reg
< 0) {
1050 fi
->initial_sp
= fi
->frame
;
1051 return fi
->initial_sp
;
1054 /* This function has an alloca register. If this is the top-most frame
1055 (with the lowest address), the value in alloca register is good. */
1058 return fi
->initial_sp
= read_register (fdata
.alloca_reg
);
1060 /* Otherwise, this is a caller frame. Callee has usually already saved
1061 registers, but there are exceptions (such as when the callee
1062 has no parameters). Find the address in which caller's alloca
1063 register is saved. */
1065 for (callee_fi
= fi
->next
; callee_fi
; callee_fi
= callee_fi
->next
) {
1067 if (!callee_fi
->cache_fsr
)
1068 frame_get_cache_fsr (callee_fi
, NULL
);
1070 /* this is the address in which alloca register is saved. */
1072 tmpaddr
= callee_fi
->cache_fsr
->regs
[fdata
.alloca_reg
];
1074 fi
->initial_sp
= read_memory_integer (tmpaddr
, 4);
1075 return fi
->initial_sp
;
1078 /* Go look into deeper levels of the frame chain to see if any one of
1079 the callees has saved alloca register. */
1082 /* If alloca register was not saved, by the callee (or any of its callees)
1083 then the value in the register is still good. */
1085 return fi
->initial_sp
= read_register (fdata
.alloca_reg
);
1089 rs6000_frame_chain (thisframe
)
1090 struct frame_info
*thisframe
;
1093 if (inside_entry_file ((thisframe
)->pc
))
1095 if (thisframe
->signal_handler_caller
)
1097 /* This was determined by experimentation on AIX 3.2. Perhaps
1098 it corresponds to some offset in /usr/include/sys/user.h or
1099 something like that. Using some system include file would
1100 have the advantage of probably being more robust in the face
1101 of OS upgrades, but the disadvantage of being wrong for
1104 #define SIG_FRAME_FP_OFFSET 284
1105 fp
= read_memory_integer (thisframe
->frame
+ SIG_FRAME_FP_OFFSET
, 4);
1108 fp
= read_memory_integer ((thisframe
)->frame
, 4);
1113 /* Keep an array of load segment information and their TOC table addresses.
1114 This info will be useful when calling a shared library function by hand. */
1117 CORE_ADDR textorg
, dataorg
;
1118 unsigned long toc_offset
;
1121 #define LOADINFOLEN 10
1123 static struct loadinfo
*loadinfo
= NULL
;
1124 static int loadinfolen
= 0;
1125 static int loadinfotocindex
= 0;
1126 static int loadinfotextindex
= 0;
1130 xcoff_init_loadinfo ()
1132 loadinfotocindex
= 0;
1133 loadinfotextindex
= 0;
1135 if (loadinfolen
== 0) {
1136 loadinfo
= (struct loadinfo
*)
1137 xmalloc (sizeof (struct loadinfo
) * LOADINFOLEN
);
1138 loadinfolen
= LOADINFOLEN
;
1143 /* FIXME -- this is never called! */
1151 loadinfotocindex
= 0;
1152 loadinfotextindex
= 0;
1155 /* this is called from xcoffread.c */
1158 xcoff_add_toc_to_loadinfo (unsigned long tocoff
)
1160 while (loadinfotocindex
>= loadinfolen
) {
1161 loadinfolen
+= LOADINFOLEN
;
1162 loadinfo
= (struct loadinfo
*)
1163 xrealloc (loadinfo
, sizeof(struct loadinfo
) * loadinfolen
);
1165 loadinfo
[loadinfotocindex
++].toc_offset
= tocoff
;
1169 add_text_to_loadinfo (textaddr
, dataaddr
)
1173 while (loadinfotextindex
>= loadinfolen
) {
1174 loadinfolen
+= LOADINFOLEN
;
1175 loadinfo
= (struct loadinfo
*)
1176 xrealloc (loadinfo
, sizeof(struct loadinfo
) * loadinfolen
);
1178 loadinfo
[loadinfotextindex
].textorg
= textaddr
;
1179 loadinfo
[loadinfotextindex
].dataorg
= dataaddr
;
1180 ++loadinfotextindex
;
1184 /* FIXME: This assumes that the "textorg" and "dataorg" elements
1185 of a member of this array are correlated with the "toc_offset"
1186 element of the same member. But they are sequentially assigned in wildly
1187 different places, and probably there is no correlation. FIXME! */
1190 find_toc_address (pc
)
1193 int ii
, toc_entry
, tocbase
= 0;
1195 for (ii
=0; ii
< loadinfotextindex
; ++ii
)
1196 if (pc
> loadinfo
[ii
].textorg
&& loadinfo
[ii
].textorg
> tocbase
) {
1198 tocbase
= loadinfo
[ii
].textorg
;
1201 return loadinfo
[toc_entry
].dataorg
+ loadinfo
[toc_entry
].toc_offset
;