1 /* Target-dependent code for GDB, the GNU debugger.
2 Copyright 1986, 1987, 1989, 1991, 1992, 1993, 1994, 1995
3 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
30 #include "xcoffsolib.h"
34 extern struct obstack frame_cache_obstack
;
38 /* Nonzero if we just simulated a single step break. */
41 /* Breakpoint shadows for the single step instructions will be kept here. */
43 static struct sstep_breaks
{
44 /* Address, or 0 if this is not in use. */
46 /* Shadow contents. */
50 /* Static function prototypes */
53 find_toc_address
PARAMS ((CORE_ADDR pc
));
56 branch_dest
PARAMS ((int opcode
, int instr
, CORE_ADDR pc
, CORE_ADDR safety
));
59 frame_get_cache_fsr
PARAMS ((struct frame_info
*fi
,
60 struct rs6000_framedata
*fdatap
));
63 * Calculate the destination of a branch/jump. Return -1 if not a branch.
66 branch_dest (opcode
, instr
, pc
, safety
)
78 absolute
= (int) ((instr
>> 1) & 1);
82 immediate
= ((instr
& ~3) << 6) >> 6; /* br unconditional */
86 dest
= pc
+ immediate
;
90 immediate
= ((instr
& ~3) << 16) >> 16; /* br conditional */
94 dest
= pc
+ immediate
;
98 ext_op
= (instr
>>1) & 0x3ff;
100 if (ext_op
== 16) /* br conditional register */
101 dest
= read_register (LR_REGNUM
) & ~3;
103 else if (ext_op
== 528) /* br cond to count reg */
105 dest
= read_register (CTR_REGNUM
) & ~3;
107 /* If we are about to execute a system call, dest is something
108 like 0x22fc or 0x3b00. Upon completion the system call
109 will return to the address in the link register. */
110 if (dest
< TEXT_SEGMENT_BASE
)
111 dest
= read_register (LR_REGNUM
) & ~3;
118 return (dest
< TEXT_SEGMENT_BASE
) ? safety
: dest
;
123 /* AIX does not support PT_STEP. Simulate it. */
129 #define INSNLEN(OPCODE) 4
131 static char le_breakp
[] = LITTLE_BREAKPOINT
;
132 static char be_breakp
[] = BIG_BREAKPOINT
;
133 char *breakp
= TARGET_BYTE_ORDER
== BIG_ENDIAN
? be_breakp
: le_breakp
;
142 insn
= read_memory_integer (loc
, 4);
144 breaks
[0] = loc
+ INSNLEN(insn
);
146 breaks
[1] = branch_dest (opcode
, insn
, loc
, breaks
[0]);
148 /* Don't put two breakpoints on the same address. */
149 if (breaks
[1] == breaks
[0])
152 stepBreaks
[1].address
= 0;
154 for (ii
=0; ii
< 2; ++ii
) {
156 /* ignore invalid breakpoint. */
157 if ( breaks
[ii
] == -1)
160 read_memory (breaks
[ii
], stepBreaks
[ii
].data
, 4);
162 write_memory (breaks
[ii
], breakp
, 4);
163 stepBreaks
[ii
].address
= breaks
[ii
];
169 /* remove step breakpoints. */
170 for (ii
=0; ii
< 2; ++ii
)
171 if (stepBreaks
[ii
].address
!= 0)
173 (stepBreaks
[ii
].address
, stepBreaks
[ii
].data
, 4);
177 errno
= 0; /* FIXME, don't ignore errors! */
178 /* What errors? {read,write}_memory call error(). */
182 /* return pc value after skipping a function prologue and also return
183 information about a function frame.
185 in struct rs6000_frameinfo fdata:
186 - frameless is TRUE, if function does not have a frame.
187 - nosavedpc is TRUE, if function does not save %pc value in its frame.
188 - offset is the number of bytes used in the frame to save registers.
189 - saved_gpr is the number of the first saved gpr.
190 - saved_fpr is the number of the first saved fpr.
191 - alloca_reg is the number of the register used for alloca() handling.
193 - gpr_offset is the offset of the saved gprs
194 - fpr_offset is the offset of the saved fprs
195 - lr_offset is the offset of the saved lr
196 - cr_offset is the offset of the saved cr
199 #define SIGNED_SHORT(x) \
200 ((sizeof (short) == 2) \
201 ? ((int)(short)(x)) \
202 : ((int)((((x) & 0xffff) ^ 0x8000) - 0x8000)))
204 #define GET_SRC_REG(x) (((x) >> 21) & 0x1f)
207 skip_prologue (pc
, fdata
)
209 struct rs6000_framedata
*fdata
;
211 CORE_ADDR orig_pc
= pc
;
219 int minimal_toc_loaded
= 0;
220 static struct rs6000_framedata zero_frame
;
223 fdata
->saved_gpr
= -1;
224 fdata
->saved_fpr
= -1;
225 fdata
->alloca_reg
= -1;
226 fdata
->frameless
= 1;
227 fdata
->nosavedpc
= 1;
229 if (target_read_memory (pc
, buf
, 4))
230 return pc
; /* Can't access it -- assume no prologue. */
232 /* Assume that subsequent fetches can fail with low probability. */
237 op
= read_memory_integer (pc
, 4);
239 if ((op
& 0xfc1fffff) == 0x7c0802a6) { /* mflr Rx */
240 lr_reg
= (op
& 0x03e00000) | 0x90010000;
243 } else if ((op
& 0xfc1fffff) == 0x7c000026) { /* mfcr Rx */
244 cr_reg
= (op
& 0x03e00000) | 0x90010000;
247 } else if ((op
& 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */
248 reg
= GET_SRC_REG (op
);
249 if (fdata
->saved_fpr
== -1 || fdata
->saved_fpr
> reg
) {
250 fdata
->saved_fpr
= reg
;
251 fdata
->fpr_offset
= SIGNED_SHORT (op
) + offset
;
255 } else if (((op
& 0xfc1f0000) == 0xbc010000) || /* stm Rx, NUM(r1) */
256 ((op
& 0xfc1f0000) == 0x90010000 && /* st rx,NUM(r1), rx >= r13 */
257 (op
& 0x03e00000) >= 0x01a00000)) {
259 reg
= GET_SRC_REG (op
);
260 if (fdata
->saved_gpr
== -1 || fdata
->saved_gpr
> reg
) {
261 fdata
->saved_gpr
= reg
;
262 fdata
->gpr_offset
= SIGNED_SHORT (op
) + offset
;
266 } else if ((op
& 0xffff0000) == 0x3c000000) { /* addis 0,0,NUM, used for >= 32k frames */
267 fdata
->offset
= (op
& 0x0000ffff) << 16;
268 fdata
->frameless
= 0;
271 } else if ((op
& 0xffff0000) == 0x60000000) { /* ori 0,0,NUM, 2nd half of >= 32k frames */
272 fdata
->offset
|= (op
& 0x0000ffff);
273 fdata
->frameless
= 0;
276 } else if ((op
& 0xffff0000) == lr_reg
) { /* st Rx,NUM(r1) where Rx == lr */
277 fdata
->lr_offset
= SIGNED_SHORT (op
) + offset
;
278 fdata
->nosavedpc
= 0;
282 } else if ((op
& 0xffff0000) == cr_reg
) { /* st Rx,NUM(r1) where Rx == cr */
283 fdata
->cr_offset
= SIGNED_SHORT (op
) + offset
;
287 } else if (op
== 0x48000005) { /* bl .+4 used in -mrelocatable */
290 } else if (op
== 0x48000004) { /* b .+4 (xlc) */
293 } else if (((op
& 0xffff0000) == 0x801e0000 || /* lwz 0,NUM(r30), used in V.4 -mrelocatable */
294 op
== 0x7fc0f214) && /* add r30,r0,r30, used in V.4 -mrelocatable */
295 lr_reg
== 0x901e0000) {
298 } else if ((op
& 0xffff0000) == 0x3fc00000 || /* addis 30,0,foo@ha, used in V.4 -mminimal-toc */
299 (op
& 0xffff0000) == 0x3bde0000) { /* addi 30,30,foo@l */
302 } else if ((op
& 0xfc000000) == 0x48000000) { /* bl foo, to save fprs??? */
304 fdata
->frameless
= 0;
305 /* Don't skip over the subroutine call if it is not within the first
306 three instructions of the prologue. */
307 if ((pc
- orig_pc
) > 8)
310 op
= read_memory_integer (pc
+4, 4);
312 /* At this point, make sure this is not a trampoline function
313 (a function that simply calls another functions, and nothing else).
314 If the next is not a nop, this branch was part of the function
317 if (op
== 0x4def7b82 || op
== 0) /* crorc 15, 15, 15 */
318 break; /* don't skip over this branch */
322 /* update stack pointer */
323 } else if ((op
& 0xffff0000) == 0x94210000) { /* stu r1,NUM(r1) */
324 fdata
->frameless
= 0;
325 fdata
->offset
= SIGNED_SHORT (op
);
326 offset
= fdata
->offset
;
329 } else if (op
== 0x7c21016e) { /* stwux 1,1,0 */
330 fdata
->frameless
= 0;
331 offset
= fdata
->offset
;
334 /* Load up minimal toc pointer */
335 } else if ((op
>> 22) == 0x20f
336 && ! minimal_toc_loaded
) { /* l r31,... or l r30,... */
337 minimal_toc_loaded
= 1;
340 /* store parameters in stack */
341 } else if ((op
& 0xfc1f0000) == 0x90010000 || /* st rx,NUM(r1) */
342 (op
& 0xfc1f0000) == 0xd8010000 || /* stfd Rx,NUM(r1) */
343 (op
& 0xfc1f0000) == 0xfc010000) { /* frsp, fp?,NUM(r1) */
346 /* store parameters in stack via frame pointer */
348 (op
& 0xfc1f0000) == 0x901f0000 || /* st rx,NUM(r1) */
349 (op
& 0xfc1f0000) == 0xd81f0000 || /* stfd Rx,NUM(r1) */
350 (op
& 0xfc1f0000) == 0xfc1f0000) { /* frsp, fp?,NUM(r1) */
353 /* Set up frame pointer */
354 } else if (op
== 0x603f0000 /* oril r31, r1, 0x0 */
355 || op
== 0x7c3f0b78) { /* mr r31, r1 */
356 fdata
->frameless
= 0;
358 fdata
->alloca_reg
= 31;
361 /* Another way to set up the frame pointer. */
362 } else if ((op
& 0xfc1fffff) == 0x38010000) { /* addi rX, r1, 0x0 */
363 fdata
->frameless
= 0;
365 fdata
->alloca_reg
= (op
& ~0x38010000) >> 21;
374 /* I have problems with skipping over __main() that I need to address
375 * sometime. Previously, I used to use misc_function_vector which
376 * didn't work as well as I wanted to be. -MGO */
378 /* If the first thing after skipping a prolog is a branch to a function,
379 this might be a call to an initializer in main(), introduced by gcc2.
380 We'd like to skip over it as well. Fortunately, xlc does some extra
381 work before calling a function right after a prologue, thus we can
382 single out such gcc2 behaviour. */
385 if ((op
& 0xfc000001) == 0x48000001) { /* bl foo, an initializer function? */
386 op
= read_memory_integer (pc
+4, 4);
388 if (op
== 0x4def7b82) { /* cror 0xf, 0xf, 0xf (nop) */
390 /* check and see if we are in main. If so, skip over this initializer
393 tmp
= find_pc_misc_function (pc
);
394 if (tmp
>= 0 && STREQ (misc_function_vector
[tmp
].name
, "main"))
400 fdata
->offset
= - fdata
->offset
;
405 /*************************************************************************
406 Support for creating pushind a dummy frame into the stack, and popping
408 *************************************************************************/
410 /* The total size of dummy frame is 436, which is;
415 and 24 extra bytes for the callee's link area. The last 24 bytes
416 for the link area might not be necessary, since it will be taken
417 care of by push_arguments(). */
419 #define DUMMY_FRAME_SIZE 436
421 #define DUMMY_FRAME_ADDR_SIZE 10
423 /* Make sure you initialize these in somewhere, in case gdb gives up what it
424 was debugging and starts debugging something else. FIXMEibm */
426 static int dummy_frame_count
= 0;
427 static int dummy_frame_size
= 0;
428 static CORE_ADDR
*dummy_frame_addr
= 0;
430 extern int stop_stack_dummy
;
432 /* push a dummy frame into stack, save all register. Currently we are saving
433 only gpr's and fpr's, which is not good enough! FIXMEmgo */
440 /* Same thing, target byte order. */
445 /* Same thing, target byte order. */
450 target_fetch_registers (-1);
452 if (dummy_frame_count
>= dummy_frame_size
) {
453 dummy_frame_size
+= DUMMY_FRAME_ADDR_SIZE
;
454 if (dummy_frame_addr
)
455 dummy_frame_addr
= (CORE_ADDR
*) xrealloc
456 (dummy_frame_addr
, sizeof(CORE_ADDR
) * (dummy_frame_size
));
458 dummy_frame_addr
= (CORE_ADDR
*)
459 xmalloc (sizeof(CORE_ADDR
) * (dummy_frame_size
));
462 sp
= read_register(SP_REGNUM
);
463 pc
= read_register(PC_REGNUM
);
464 store_address (pc_targ
, 4, pc
);
466 dummy_frame_addr
[dummy_frame_count
++] = sp
;
468 /* Be careful! If the stack pointer is not decremented first, then kernel
469 thinks he is free to use the space underneath it. And kernel actually
470 uses that area for IPC purposes when executing ptrace(2) calls. So
471 before writing register values into the new frame, decrement and update
472 %sp first in order to secure your frame. */
474 write_register (SP_REGNUM
, sp
-DUMMY_FRAME_SIZE
);
476 /* gdb relies on the state of current_frame. We'd better update it,
477 otherwise things like do_registers_info() wouldn't work properly! */
479 flush_cached_frames ();
481 /* save program counter in link register's space. */
482 write_memory (sp
+8, pc_targ
, 4);
484 /* save all floating point and general purpose registers here. */
487 for (ii
= 0; ii
< 32; ++ii
)
488 write_memory (sp
-8-(ii
*8), ®isters
[REGISTER_BYTE (31-ii
+FP0_REGNUM
)], 8);
491 for (ii
=1; ii
<=32; ++ii
)
492 write_memory (sp
-256-(ii
*4), ®isters
[REGISTER_BYTE (32-ii
)], 4);
494 /* so far, 32*2 + 32 words = 384 bytes have been written.
495 7 extra registers in our register set: pc, ps, cnd, lr, cnt, xer, mq */
497 for (ii
=1; ii
<= (LAST_SP_REGNUM
-FIRST_SP_REGNUM
+1); ++ii
) {
498 write_memory (sp
-384-(ii
*4),
499 ®isters
[REGISTER_BYTE (FPLAST_REGNUM
+ ii
)], 4);
502 /* Save sp or so called back chain right here. */
503 store_address (sp_targ
, 4, sp
);
504 write_memory (sp
-DUMMY_FRAME_SIZE
, sp_targ
, 4);
505 sp
-= DUMMY_FRAME_SIZE
;
507 /* And finally, this is the back chain. */
508 write_memory (sp
+8, pc_targ
, 4);
512 /* Pop a dummy frame.
514 In rs6000 when we push a dummy frame, we save all of the registers. This
515 is usually done before user calls a function explicitly.
517 After a dummy frame is pushed, some instructions are copied into stack,
518 and stack pointer is decremented even more. Since we don't have a frame
519 pointer to get back to the parent frame of the dummy, we start having
520 trouble poping it. Therefore, we keep a dummy frame stack, keeping
521 addresses of dummy frames as such. When poping happens and when we
522 detect that was a dummy frame, we pop it back to its parent by using
523 dummy frame stack (`dummy_frame_addr' array).
525 FIXME: This whole concept is broken. You should be able to detect
526 a dummy stack frame *on the user's stack itself*. When you do,
527 then you know the format of that stack frame -- including its
528 saved SP register! There should *not* be a separate stack in the
529 GDB process that keeps track of these dummy frames! -- gnu@cygnus.com Aug92
536 sp
= dummy_frame_addr
[--dummy_frame_count
];
538 /* restore all fpr's. */
539 for (ii
= 1; ii
<= 32; ++ii
)
540 read_memory (sp
-(ii
*8), ®isters
[REGISTER_BYTE (32-ii
+FP0_REGNUM
)], 8);
542 /* restore all gpr's */
543 for (ii
=1; ii
<= 32; ++ii
) {
544 read_memory (sp
-256-(ii
*4), ®isters
[REGISTER_BYTE (32-ii
)], 4);
547 /* restore the rest of the registers. */
548 for (ii
=1; ii
<=(LAST_SP_REGNUM
-FIRST_SP_REGNUM
+1); ++ii
)
549 read_memory (sp
-384-(ii
*4),
550 ®isters
[REGISTER_BYTE (FPLAST_REGNUM
+ ii
)], 4);
552 read_memory (sp
-(DUMMY_FRAME_SIZE
-8),
553 ®isters
[REGISTER_BYTE(PC_REGNUM
)], 4);
555 /* when a dummy frame was being pushed, we had to decrement %sp first, in
556 order to secure astack space. Thus, saved %sp (or %r1) value, is not the
557 one we should restore. Change it with the one we need. */
559 *(int*)®isters
[REGISTER_BYTE(FP_REGNUM
)] = sp
;
561 /* Now we can restore all registers. */
563 target_store_registers (-1);
565 flush_cached_frames ();
569 /* pop the innermost frame, go back to the caller. */
574 CORE_ADDR pc
, lr
, sp
, prev_sp
; /* %pc, %lr, %sp */
575 struct rs6000_framedata fdata
;
576 struct frame_info
*frame
= get_current_frame ();
580 sp
= FRAME_FP (frame
);
582 if (stop_stack_dummy
&& dummy_frame_count
) {
587 /* Make sure that all registers are valid. */
588 read_register_bytes (0, NULL
, REGISTER_BYTES
);
590 /* figure out previous %pc value. If the function is frameless, it is
591 still in the link register, otherwise walk the frames and retrieve the
592 saved %pc value in the previous frame. */
594 addr
= get_pc_function_start (frame
->pc
) + FUNCTION_START_OFFSET
;
595 (void) skip_prologue (addr
, &fdata
);
600 prev_sp
= read_memory_integer (sp
, 4);
601 if (fdata
.lr_offset
== 0)
602 lr
= read_register (LR_REGNUM
);
604 lr
= read_memory_integer (prev_sp
+ fdata
.lr_offset
, 4);
606 /* reset %pc value. */
607 write_register (PC_REGNUM
, lr
);
609 /* reset register values if any was saved earlier. */
610 addr
= prev_sp
- fdata
.offset
;
612 if (fdata
.saved_gpr
!= -1)
613 for (ii
= fdata
.saved_gpr
; ii
<= 31; ++ii
) {
614 read_memory (addr
, ®isters
[REGISTER_BYTE (ii
)], 4);
618 if (fdata
.saved_fpr
!= -1)
619 for (ii
= fdata
.saved_fpr
; ii
<= 31; ++ii
) {
620 read_memory (addr
, ®isters
[REGISTER_BYTE (ii
+FP0_REGNUM
)], 8);
624 write_register (SP_REGNUM
, prev_sp
);
625 target_store_registers (-1);
626 flush_cached_frames ();
629 /* fixup the call sequence of a dummy function, with the real function address.
630 its argumets will be passed by gdb. */
633 fix_call_dummy(dummyname
, pc
, fun
, nargs
, type
)
637 int nargs
; /* not used */
638 int type
; /* not used */
640 #define TOC_ADDR_OFFSET 20
641 #define TARGET_ADDR_OFFSET 28
644 CORE_ADDR target_addr
;
648 tocvalue
= find_toc_address (target_addr
);
650 ii
= *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
);
651 ii
= (ii
& 0xffff0000) | (tocvalue
>> 16);
652 *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
) = ii
;
654 ii
= *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
+4);
655 ii
= (ii
& 0xffff0000) | (tocvalue
& 0x0000ffff);
656 *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
+4) = ii
;
658 ii
= *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
);
659 ii
= (ii
& 0xffff0000) | (target_addr
>> 16);
660 *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
) = ii
;
662 ii
= *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
+4);
663 ii
= (ii
& 0xffff0000) | (target_addr
& 0x0000ffff);
664 *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
+4) = ii
;
667 /* Pass the arguments in either registers, or in the stack. In RS6000, the first
668 eight words of the argument list (that might be less than eight parameters if
669 some parameters occupy more than one word) are passed in r3..r11 registers.
670 float and double parameters are passed in fpr's, in addition to that. Rest of
671 the parameters if any are passed in user stack. There might be cases in which
672 half of the parameter is copied into registers, the other half is pushed into
675 If the function is returning a structure, then the return address is passed
676 in r3, then the first 7 words of the parametes can be passed in registers,
680 push_arguments (nargs
, args
, sp
, struct_return
, struct_addr
)
685 CORE_ADDR struct_addr
;
688 int argno
; /* current argument number */
689 int argbytes
; /* current argument byte */
690 char tmp_buffer
[50];
692 int f_argno
= 0; /* current floating point argno */
694 CORE_ADDR saved_sp
, pc
;
696 if ( dummy_frame_count
<= 0)
697 printf_unfiltered ("FATAL ERROR -push_arguments()! frame not found!!\n");
699 /* The first eight words of ther arguments are passed in registers. Copy
702 If the function is returning a `struct', then the first word (which
703 will be passed in r3) is used for struct return address. In that
704 case we should advance one word and start from r4 register to copy
707 ii
= struct_return
? 1 : 0;
709 for (argno
=0, argbytes
=0; argno
< nargs
&& ii
<8; ++ii
) {
712 len
= TYPE_LENGTH (VALUE_TYPE (arg
));
714 if (TYPE_CODE (VALUE_TYPE (arg
)) == TYPE_CODE_FLT
) {
716 /* floating point arguments are passed in fpr's, as well as gpr's.
717 There are 13 fpr's reserved for passing parameters. At this point
718 there is no way we would run out of them. */
722 "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno
);
724 memcpy (®isters
[REGISTER_BYTE(FP0_REGNUM
+ 1 + f_argno
)], VALUE_CONTENTS (arg
),
731 /* Argument takes more than one register. */
732 while (argbytes
< len
) {
734 *(int*)®isters
[REGISTER_BYTE(ii
+3)] = 0;
735 memcpy (®isters
[REGISTER_BYTE(ii
+3)],
736 ((char*)VALUE_CONTENTS (arg
))+argbytes
,
737 (len
- argbytes
) > 4 ? 4 : len
- argbytes
);
741 goto ran_out_of_registers_for_arguments
;
746 else { /* Argument can fit in one register. No problem. */
747 *(int*)®isters
[REGISTER_BYTE(ii
+3)] = 0;
748 memcpy (®isters
[REGISTER_BYTE(ii
+3)], VALUE_CONTENTS (arg
), len
);
753 ran_out_of_registers_for_arguments
:
755 /* location for 8 parameters are always reserved. */
758 /* another six words for back chain, TOC register, link register, etc. */
761 /* if there are more arguments, allocate space for them in
762 the stack, then push them starting from the ninth one. */
764 if ((argno
< nargs
) || argbytes
) {
769 space
+= ((len
- argbytes
+ 3) & -4);
775 for (; jj
< nargs
; ++jj
) {
777 space
+= ((TYPE_LENGTH (VALUE_TYPE (val
))) + 3) & -4;
780 /* add location required for the rest of the parameters */
781 space
= (space
+ 7) & -8;
784 /* This is another instance we need to be concerned about securing our
785 stack space. If we write anything underneath %sp (r1), we might conflict
786 with the kernel who thinks he is free to use this area. So, update %sp
787 first before doing anything else. */
789 write_register (SP_REGNUM
, sp
);
791 /* if the last argument copied into the registers didn't fit there
792 completely, push the rest of it into stack. */
796 sp
+24+(ii
*4), ((char*)VALUE_CONTENTS (arg
))+argbytes
, len
- argbytes
);
798 ii
+= ((len
- argbytes
+ 3) & -4) / 4;
801 /* push the rest of the arguments into stack. */
802 for (; argno
< nargs
; ++argno
) {
805 len
= TYPE_LENGTH (VALUE_TYPE (arg
));
808 /* float types should be passed in fpr's, as well as in the stack. */
809 if (TYPE_CODE (VALUE_TYPE (arg
)) == TYPE_CODE_FLT
&& f_argno
< 13) {
813 "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno
);
815 memcpy (®isters
[REGISTER_BYTE(FP0_REGNUM
+ 1 + f_argno
)], VALUE_CONTENTS (arg
),
820 write_memory (sp
+24+(ii
*4), (char *) VALUE_CONTENTS (arg
), len
);
821 ii
+= ((len
+ 3) & -4) / 4;
825 /* Secure stack areas first, before doing anything else. */
826 write_register (SP_REGNUM
, sp
);
828 saved_sp
= dummy_frame_addr
[dummy_frame_count
- 1];
829 read_memory (saved_sp
, tmp_buffer
, 24);
830 write_memory (sp
, tmp_buffer
, 24);
832 /* set back chain properly */
833 store_address (tmp_buffer
, 4, saved_sp
);
834 write_memory (sp
, tmp_buffer
, 4);
836 target_store_registers (-1);
840 /* a given return value in `regbuf' with a type `valtype', extract and copy its
841 value into `valbuf' */
844 extract_return_value (valtype
, regbuf
, valbuf
)
845 struct type
*valtype
;
846 char regbuf
[REGISTER_BYTES
];
851 if (TYPE_CODE (valtype
) == TYPE_CODE_FLT
) {
854 /* floats and doubles are returned in fpr1. fpr's have a size of 8 bytes.
855 We need to truncate the return value into float size (4 byte) if
858 if (TYPE_LENGTH (valtype
) > 4) /* this is a double */
859 memcpy (valbuf
, ®buf
[REGISTER_BYTE (FP0_REGNUM
+ 1)],
860 TYPE_LENGTH (valtype
));
862 memcpy (&dd
, ®buf
[REGISTER_BYTE (FP0_REGNUM
+ 1)], 8);
864 memcpy (valbuf
, &ff
, sizeof(float));
868 /* return value is copied starting from r3. */
869 if (TARGET_BYTE_ORDER
== BIG_ENDIAN
870 && TYPE_LENGTH (valtype
) < REGISTER_RAW_SIZE (3))
871 offset
= REGISTER_RAW_SIZE (3) - TYPE_LENGTH (valtype
);
873 memcpy (valbuf
, regbuf
+ REGISTER_BYTE (3) + offset
,
874 TYPE_LENGTH (valtype
));
879 /* keep structure return address in this variable.
880 FIXME: This is a horrid kludge which should not be allowed to continue
881 living. This only allows a single nested call to a structure-returning
882 function. Come on, guys! -- gnu@cygnus.com, Aug 92 */
884 CORE_ADDR rs6000_struct_return_address
;
887 /* Indirect function calls use a piece of trampoline code to do context
888 switching, i.e. to set the new TOC table. Skip such code if we are on
889 its first instruction (as when we have single-stepped to here).
890 Also skip shared library trampoline code (which is different from
891 indirect function call trampolines).
892 Result is desired PC to step until, or NULL if we are not in
896 skip_trampoline_code (pc
)
899 register unsigned int ii
, op
;
900 CORE_ADDR solib_target_pc
;
902 static unsigned trampoline_code
[] = {
903 0x800b0000, /* l r0,0x0(r11) */
904 0x90410014, /* st r2,0x14(r1) */
905 0x7c0903a6, /* mtctr r0 */
906 0x804b0004, /* l r2,0x4(r11) */
907 0x816b0008, /* l r11,0x8(r11) */
908 0x4e800420, /* bctr */
913 /* If pc is in a shared library trampoline, return its target. */
914 solib_target_pc
= find_solib_trampoline_target (pc
);
916 return solib_target_pc
;
918 for (ii
=0; trampoline_code
[ii
]; ++ii
) {
919 op
= read_memory_integer (pc
+ (ii
*4), 4);
920 if (op
!= trampoline_code
[ii
])
923 ii
= read_register (11); /* r11 holds destination addr */
924 pc
= read_memory_integer (ii
, 4); /* (r11) value */
929 /* Determines whether the function FI has a frame on the stack or not. */
931 frameless_function_invocation (fi
)
932 struct frame_info
*fi
;
934 CORE_ADDR func_start
;
935 struct rs6000_framedata fdata
;
937 if (fi
->next
!= NULL
)
938 /* Don't even think about framelessness except on the innermost frame. */
939 /* FIXME: Can also be frameless if fi->next->signal_handler_caller (if
940 a signal happens while executing in a frameless function). */
943 func_start
= get_pc_function_start (fi
->pc
) + FUNCTION_START_OFFSET
;
945 /* If we failed to find the start of the function, it is a mistake
946 to inspect the instructions. */
951 (void) skip_prologue (func_start
, &fdata
);
952 return fdata
.frameless
;
955 /* Return the PC saved in a frame */
958 struct frame_info
*fi
;
960 CORE_ADDR func_start
;
961 struct rs6000_framedata fdata
;
964 if (fi
->signal_handler_caller
)
965 return read_memory_integer (fi
->frame
+ SIG_FRAME_PC_OFFSET
, 4);
967 func_start
= get_pc_function_start (fi
->pc
) + FUNCTION_START_OFFSET
;
969 /* If we failed to find the start of the function, it is a mistake
970 to inspect the instructions. */
974 (void) skip_prologue (func_start
, &fdata
);
976 if (fdata
.lr_offset
== 0 && fi
->next
!= NULL
)
977 return read_memory_integer (rs6000_frame_chain (fi
) + DEFAULT_LR_SAVE
, 4);
979 if (fdata
.lr_offset
== 0)
980 return read_register (LR_REGNUM
);
982 return read_memory_integer (rs6000_frame_chain (fi
) + fdata
.lr_offset
, 4);
985 /* If saved registers of frame FI are not known yet, read and cache them.
986 &FDATAP contains rs6000_framedata; TDATAP can be NULL,
987 in which case the framedata are read. */
990 frame_get_cache_fsr (fi
, fdatap
)
991 struct frame_info
*fi
;
992 struct rs6000_framedata
*fdatap
;
995 CORE_ADDR frame_addr
;
996 struct rs6000_framedata work_fdata
;
1001 if (fdatap
== NULL
) {
1002 fdatap
= &work_fdata
;
1003 (void) skip_prologue (get_pc_function_start (fi
->pc
), fdatap
);
1006 fi
->cache_fsr
= (struct frame_saved_regs
*)
1007 obstack_alloc (&frame_cache_obstack
, sizeof (struct frame_saved_regs
));
1008 memset (fi
->cache_fsr
, '\0', sizeof (struct frame_saved_regs
));
1010 if (fi
->prev
&& fi
->prev
->frame
)
1011 frame_addr
= fi
->prev
->frame
;
1013 frame_addr
= read_memory_integer (fi
->frame
, 4);
1015 /* if != -1, fdatap->saved_fpr is the smallest number of saved_fpr.
1016 All fpr's from saved_fpr to fp31 are saved. */
1018 if (fdatap
->saved_fpr
>= 0) {
1019 int fpr_offset
= frame_addr
+ fdatap
->fpr_offset
;
1020 for (ii
= fdatap
->saved_fpr
; ii
< 32; ii
++) {
1021 fi
->cache_fsr
->regs
[FP0_REGNUM
+ ii
] = fpr_offset
;
1026 /* if != -1, fdatap->saved_gpr is the smallest number of saved_gpr.
1027 All gpr's from saved_gpr to gpr31 are saved. */
1029 if (fdatap
->saved_gpr
>= 0) {
1030 int gpr_offset
= frame_addr
+ fdatap
->gpr_offset
;
1031 for (ii
= fdatap
->saved_gpr
; ii
< 32; ii
++) {
1032 fi
->cache_fsr
->regs
[ii
] = gpr_offset
;
1037 /* If != 0, fdatap->cr_offset is the offset from the frame that holds
1039 if (fdatap
->cr_offset
!= 0)
1040 fi
->cache_fsr
->regs
[CR_REGNUM
] = frame_addr
+ fdatap
->cr_offset
;
1042 /* If != 0, fdatap->lr_offset is the offset from the frame that holds
1044 if (fdatap
->lr_offset
!= 0)
1045 fi
->cache_fsr
->regs
[LR_REGNUM
] = frame_addr
+ fdatap
->lr_offset
;
1048 /* Return the address of a frame. This is the inital %sp value when the frame
1049 was first allocated. For functions calling alloca(), it might be saved in
1050 an alloca register. */
1053 frame_initial_stack_address (fi
)
1054 struct frame_info
*fi
;
1057 struct rs6000_framedata fdata
;
1058 struct frame_info
*callee_fi
;
1060 /* if the initial stack pointer (frame address) of this frame is known,
1064 return fi
->initial_sp
;
1066 /* find out if this function is using an alloca register.. */
1068 (void) skip_prologue (get_pc_function_start (fi
->pc
), &fdata
);
1070 /* if saved registers of this frame are not known yet, read and cache them. */
1073 frame_get_cache_fsr (fi
, &fdata
);
1075 /* If no alloca register used, then fi->frame is the value of the %sp for
1076 this frame, and it is good enough. */
1078 if (fdata
.alloca_reg
< 0) {
1079 fi
->initial_sp
= fi
->frame
;
1080 return fi
->initial_sp
;
1083 /* This function has an alloca register. If this is the top-most frame
1084 (with the lowest address), the value in alloca register is good. */
1087 return fi
->initial_sp
= read_register (fdata
.alloca_reg
);
1089 /* Otherwise, this is a caller frame. Callee has usually already saved
1090 registers, but there are exceptions (such as when the callee
1091 has no parameters). Find the address in which caller's alloca
1092 register is saved. */
1094 for (callee_fi
= fi
->next
; callee_fi
; callee_fi
= callee_fi
->next
) {
1096 if (!callee_fi
->cache_fsr
)
1097 frame_get_cache_fsr (callee_fi
, NULL
);
1099 /* this is the address in which alloca register is saved. */
1101 tmpaddr
= callee_fi
->cache_fsr
->regs
[fdata
.alloca_reg
];
1103 fi
->initial_sp
= read_memory_integer (tmpaddr
, 4);
1104 return fi
->initial_sp
;
1107 /* Go look into deeper levels of the frame chain to see if any one of
1108 the callees has saved alloca register. */
1111 /* If alloca register was not saved, by the callee (or any of its callees)
1112 then the value in the register is still good. */
1114 return fi
->initial_sp
= read_register (fdata
.alloca_reg
);
1118 rs6000_frame_chain (thisframe
)
1119 struct frame_info
*thisframe
;
1122 if (inside_entry_file ((thisframe
)->pc
))
1124 if (thisframe
->signal_handler_caller
)
1125 fp
= read_memory_integer (thisframe
->frame
+ SIG_FRAME_FP_OFFSET
, 4);
1127 fp
= read_memory_integer ((thisframe
)->frame
, 4);
1132 /* Keep an array of load segment information and their TOC table addresses.
1133 This info will be useful when calling a shared library function by hand. */
1136 CORE_ADDR textorg
, dataorg
;
1137 unsigned long toc_offset
;
1140 #define LOADINFOLEN 10
1142 static struct loadinfo
*loadinfo
= NULL
;
1143 static int loadinfolen
= 0;
1144 static int loadinfotocindex
= 0;
1145 static int loadinfotextindex
= 0;
1149 xcoff_init_loadinfo ()
1151 loadinfotocindex
= 0;
1152 loadinfotextindex
= 0;
1154 if (loadinfolen
== 0) {
1155 loadinfo
= (struct loadinfo
*)
1156 xmalloc (sizeof (struct loadinfo
) * LOADINFOLEN
);
1157 loadinfolen
= LOADINFOLEN
;
1162 /* FIXME -- this is never called! */
1170 loadinfotocindex
= 0;
1171 loadinfotextindex
= 0;
1174 /* this is called from xcoffread.c */
1177 xcoff_add_toc_to_loadinfo (tocoff
)
1178 unsigned long tocoff
;
1180 while (loadinfotocindex
>= loadinfolen
) {
1181 loadinfolen
+= LOADINFOLEN
;
1182 loadinfo
= (struct loadinfo
*)
1183 xrealloc (loadinfo
, sizeof(struct loadinfo
) * loadinfolen
);
1185 loadinfo
[loadinfotocindex
++].toc_offset
= tocoff
;
1189 add_text_to_loadinfo (textaddr
, dataaddr
)
1193 while (loadinfotextindex
>= loadinfolen
) {
1194 loadinfolen
+= LOADINFOLEN
;
1195 loadinfo
= (struct loadinfo
*)
1196 xrealloc (loadinfo
, sizeof(struct loadinfo
) * loadinfolen
);
1198 loadinfo
[loadinfotextindex
].textorg
= textaddr
;
1199 loadinfo
[loadinfotextindex
].dataorg
= dataaddr
;
1200 ++loadinfotextindex
;
1204 /* Note that this assumes that the "textorg" and "dataorg" elements
1205 of a member of this array are correlated with the "toc_offset"
1206 element of the same member. This is taken care of because the loops
1207 which assign the former (in xcoff_relocate_symtab or xcoff_relocate_core)
1208 and the latter (in scan_xcoff_symtab, via vmap_symtab, in vmap_ldinfo
1209 or xcoff_relocate_core) traverse the same objfiles in the same order. */
1212 find_toc_address (pc
)
1215 int ii
, toc_entry
, tocbase
= 0;
1218 for (ii
=0; ii
< loadinfotextindex
; ++ii
)
1219 if (pc
> loadinfo
[ii
].textorg
&& loadinfo
[ii
].textorg
> tocbase
) {
1221 tocbase
= loadinfo
[ii
].textorg
;
1224 if (toc_entry
== -1)
1225 error ("Unable to find TOC entry for pc 0x%x\n", pc
);
1226 return loadinfo
[toc_entry
].dataorg
+ loadinfo
[toc_entry
].toc_offset
;
1229 /* Return nonzero if ADDR (a function pointer) is in the data space and
1230 is therefore a special function pointer. */
1233 is_magic_function_pointer (addr
)
1236 struct obj_section
*s
;
1238 s
= find_pc_section (addr
);
1239 if (s
&& s
->the_bfd_section
->flags
& SEC_CODE
)
1245 #ifdef GDB_TARGET_POWERPC
1247 gdb_print_insn_powerpc (memaddr
, info
)
1249 disassemble_info
*info
;
1251 if (TARGET_BYTE_ORDER
== BIG_ENDIAN
)
1252 return print_insn_big_powerpc (memaddr
, info
);
1254 return print_insn_little_powerpc (memaddr
, info
);
1259 _initialize_rs6000_tdep ()
1261 /* FIXME, this should not be decided via ifdef. */
1262 #ifdef GDB_TARGET_POWERPC
1263 tm_print_insn
= gdb_print_insn_powerpc
;
1265 tm_print_insn
= print_insn_rs6000
;