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. */
448 /* Needed to figure out where to save the dummy link area.
449 FIXME: There should be an easier way to do this, no? tiemann 9/9/95. */
450 struct rs6000_framedata fdata
;
454 target_fetch_registers (-1);
456 if (dummy_frame_count
>= dummy_frame_size
) {
457 dummy_frame_size
+= DUMMY_FRAME_ADDR_SIZE
;
458 if (dummy_frame_addr
)
459 dummy_frame_addr
= (CORE_ADDR
*) xrealloc
460 (dummy_frame_addr
, sizeof(CORE_ADDR
) * (dummy_frame_size
));
462 dummy_frame_addr
= (CORE_ADDR
*)
463 xmalloc (sizeof(CORE_ADDR
) * (dummy_frame_size
));
466 sp
= read_register(SP_REGNUM
);
467 pc
= read_register(PC_REGNUM
);
468 store_address (pc_targ
, 4, pc
);
470 (void) skip_prologue (get_pc_function_start (pc
) + FUNCTION_START_OFFSET
, &fdata
);
472 dummy_frame_addr
[dummy_frame_count
++] = sp
;
474 /* Be careful! If the stack pointer is not decremented first, then kernel
475 thinks he is free to use the space underneath it. And kernel actually
476 uses that area for IPC purposes when executing ptrace(2) calls. So
477 before writing register values into the new frame, decrement and update
478 %sp first in order to secure your frame. */
480 /* FIXME: We don't check if the stack really has this much space.
481 This is a problem on the ppc simulator (which only grants one page
482 (4096 bytes) by default. */
484 write_register (SP_REGNUM
, sp
-DUMMY_FRAME_SIZE
);
486 /* gdb relies on the state of current_frame. We'd better update it,
487 otherwise things like do_registers_info() wouldn't work properly! */
489 flush_cached_frames ();
491 /* save program counter in link register's space. */
492 write_memory (sp
+fdata
.lr_offset
, pc_targ
, 4);
494 /* save all floating point and general purpose registers here. */
497 for (ii
= 0; ii
< 32; ++ii
)
498 write_memory (sp
-8-(ii
*8), ®isters
[REGISTER_BYTE (31-ii
+FP0_REGNUM
)], 8);
501 for (ii
=1; ii
<=32; ++ii
)
502 write_memory (sp
-256-(ii
*4), ®isters
[REGISTER_BYTE (32-ii
)], 4);
504 /* so far, 32*2 + 32 words = 384 bytes have been written.
505 7 extra registers in our register set: pc, ps, cnd, lr, cnt, xer, mq */
507 for (ii
=1; ii
<= (LAST_SP_REGNUM
-FIRST_SP_REGNUM
+1); ++ii
) {
508 write_memory (sp
-384-(ii
*4),
509 ®isters
[REGISTER_BYTE (FPLAST_REGNUM
+ ii
)], 4);
512 /* Save sp or so called back chain right here. */
513 store_address (sp_targ
, 4, sp
);
514 write_memory (sp
-DUMMY_FRAME_SIZE
, sp_targ
, 4);
515 sp
-= DUMMY_FRAME_SIZE
;
517 /* And finally, this is the back chain. */
518 write_memory (sp
+8, pc_targ
, 4);
522 /* Pop a dummy frame.
524 In rs6000 when we push a dummy frame, we save all of the registers. This
525 is usually done before user calls a function explicitly.
527 After a dummy frame is pushed, some instructions are copied into stack,
528 and stack pointer is decremented even more. Since we don't have a frame
529 pointer to get back to the parent frame of the dummy, we start having
530 trouble poping it. Therefore, we keep a dummy frame stack, keeping
531 addresses of dummy frames as such. When poping happens and when we
532 detect that was a dummy frame, we pop it back to its parent by using
533 dummy frame stack (`dummy_frame_addr' array).
535 FIXME: This whole concept is broken. You should be able to detect
536 a dummy stack frame *on the user's stack itself*. When you do,
537 then you know the format of that stack frame -- including its
538 saved SP register! There should *not* be a separate stack in the
539 GDB process that keeps track of these dummy frames! -- gnu@cygnus.com Aug92
546 sp
= dummy_frame_addr
[--dummy_frame_count
];
548 /* restore all fpr's. */
549 for (ii
= 1; ii
<= 32; ++ii
)
550 read_memory (sp
-(ii
*8), ®isters
[REGISTER_BYTE (32-ii
+FP0_REGNUM
)], 8);
552 /* restore all gpr's */
553 for (ii
=1; ii
<= 32; ++ii
) {
554 read_memory (sp
-256-(ii
*4), ®isters
[REGISTER_BYTE (32-ii
)], 4);
557 /* restore the rest of the registers. */
558 for (ii
=1; ii
<=(LAST_SP_REGNUM
-FIRST_SP_REGNUM
+1); ++ii
)
559 read_memory (sp
-384-(ii
*4),
560 ®isters
[REGISTER_BYTE (FPLAST_REGNUM
+ ii
)], 4);
562 read_memory (sp
-(DUMMY_FRAME_SIZE
-8),
563 ®isters
[REGISTER_BYTE(PC_REGNUM
)], 4);
565 /* when a dummy frame was being pushed, we had to decrement %sp first, in
566 order to secure astack space. Thus, saved %sp (or %r1) value, is not the
567 one we should restore. Change it with the one we need. */
569 *(int*)®isters
[REGISTER_BYTE(FP_REGNUM
)] = sp
;
571 /* Now we can restore all registers. */
573 target_store_registers (-1);
575 flush_cached_frames ();
579 /* pop the innermost frame, go back to the caller. */
584 CORE_ADDR pc
, lr
, sp
, prev_sp
; /* %pc, %lr, %sp */
585 struct rs6000_framedata fdata
;
586 struct frame_info
*frame
= get_current_frame ();
590 sp
= FRAME_FP (frame
);
592 if (stop_stack_dummy
&& dummy_frame_count
) {
597 /* Make sure that all registers are valid. */
598 read_register_bytes (0, NULL
, REGISTER_BYTES
);
600 /* figure out previous %pc value. If the function is frameless, it is
601 still in the link register, otherwise walk the frames and retrieve the
602 saved %pc value in the previous frame. */
604 addr
= get_pc_function_start (frame
->pc
) + FUNCTION_START_OFFSET
;
605 (void) skip_prologue (addr
, &fdata
);
610 prev_sp
= read_memory_integer (sp
, 4);
611 if (fdata
.lr_offset
== 0)
612 lr
= read_register (LR_REGNUM
);
614 lr
= read_memory_integer (prev_sp
+ fdata
.lr_offset
, 4);
616 /* reset %pc value. */
617 write_register (PC_REGNUM
, lr
);
619 /* reset register values if any was saved earlier. */
620 addr
= prev_sp
- fdata
.offset
;
622 if (fdata
.saved_gpr
!= -1)
623 for (ii
= fdata
.saved_gpr
; ii
<= 31; ++ii
) {
624 read_memory (addr
, ®isters
[REGISTER_BYTE (ii
)], 4);
628 if (fdata
.saved_fpr
!= -1)
629 for (ii
= fdata
.saved_fpr
; ii
<= 31; ++ii
) {
630 read_memory (addr
, ®isters
[REGISTER_BYTE (ii
+FP0_REGNUM
)], 8);
634 write_register (SP_REGNUM
, prev_sp
);
635 target_store_registers (-1);
636 flush_cached_frames ();
639 /* fixup the call sequence of a dummy function, with the real function address.
640 its argumets will be passed by gdb. */
643 fix_call_dummy(dummyname
, pc
, fun
, nargs
, type
)
647 int nargs
; /* not used */
648 int type
; /* not used */
650 #define TOC_ADDR_OFFSET 20
651 #define TARGET_ADDR_OFFSET 28
654 CORE_ADDR target_addr
;
658 tocvalue
= find_toc_address (target_addr
);
660 ii
= *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
);
661 ii
= (ii
& 0xffff0000) | (tocvalue
>> 16);
662 *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
) = ii
;
664 ii
= *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
+4);
665 ii
= (ii
& 0xffff0000) | (tocvalue
& 0x0000ffff);
666 *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
+4) = ii
;
668 ii
= *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
);
669 ii
= (ii
& 0xffff0000) | (target_addr
>> 16);
670 *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
) = ii
;
672 ii
= *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
+4);
673 ii
= (ii
& 0xffff0000) | (target_addr
& 0x0000ffff);
674 *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
+4) = ii
;
677 /* Pass the arguments in either registers, or in the stack. In RS6000, the first
678 eight words of the argument list (that might be less than eight parameters if
679 some parameters occupy more than one word) are passed in r3..r11 registers.
680 float and double parameters are passed in fpr's, in addition to that. Rest of
681 the parameters if any are passed in user stack. There might be cases in which
682 half of the parameter is copied into registers, the other half is pushed into
685 If the function is returning a structure, then the return address is passed
686 in r3, then the first 7 words of the parametes can be passed in registers,
690 push_arguments (nargs
, args
, sp
, struct_return
, struct_addr
)
695 CORE_ADDR struct_addr
;
698 int argno
; /* current argument number */
699 int argbytes
; /* current argument byte */
700 char tmp_buffer
[50];
702 int f_argno
= 0; /* current floating point argno */
704 CORE_ADDR saved_sp
, pc
;
706 if ( dummy_frame_count
<= 0)
707 printf_unfiltered ("FATAL ERROR -push_arguments()! frame not found!!\n");
709 /* The first eight words of ther arguments are passed in registers. Copy
712 If the function is returning a `struct', then the first word (which
713 will be passed in r3) is used for struct return address. In that
714 case we should advance one word and start from r4 register to copy
717 ii
= struct_return
? 1 : 0;
719 for (argno
=0, argbytes
=0; argno
< nargs
&& ii
<8; ++ii
) {
722 len
= TYPE_LENGTH (VALUE_TYPE (arg
));
724 if (TYPE_CODE (VALUE_TYPE (arg
)) == TYPE_CODE_FLT
) {
726 /* floating point arguments are passed in fpr's, as well as gpr's.
727 There are 13 fpr's reserved for passing parameters. At this point
728 there is no way we would run out of them. */
732 "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno
);
734 memcpy (®isters
[REGISTER_BYTE(FP0_REGNUM
+ 1 + f_argno
)], VALUE_CONTENTS (arg
),
741 /* Argument takes more than one register. */
742 while (argbytes
< len
) {
744 *(int*)®isters
[REGISTER_BYTE(ii
+3)] = 0;
745 memcpy (®isters
[REGISTER_BYTE(ii
+3)],
746 ((char*)VALUE_CONTENTS (arg
))+argbytes
,
747 (len
- argbytes
) > 4 ? 4 : len
- argbytes
);
751 goto ran_out_of_registers_for_arguments
;
756 else { /* Argument can fit in one register. No problem. */
757 *(int*)®isters
[REGISTER_BYTE(ii
+3)] = 0;
758 memcpy (®isters
[REGISTER_BYTE(ii
+3)], VALUE_CONTENTS (arg
), len
);
763 ran_out_of_registers_for_arguments
:
765 /* location for 8 parameters are always reserved. */
768 /* another six words for back chain, TOC register, link register, etc. */
771 /* if there are more arguments, allocate space for them in
772 the stack, then push them starting from the ninth one. */
774 if ((argno
< nargs
) || argbytes
) {
779 space
+= ((len
- argbytes
+ 3) & -4);
785 for (; jj
< nargs
; ++jj
) {
787 space
+= ((TYPE_LENGTH (VALUE_TYPE (val
))) + 3) & -4;
790 /* add location required for the rest of the parameters */
791 space
= (space
+ 7) & -8;
794 /* This is another instance we need to be concerned about securing our
795 stack space. If we write anything underneath %sp (r1), we might conflict
796 with the kernel who thinks he is free to use this area. So, update %sp
797 first before doing anything else. */
799 write_register (SP_REGNUM
, sp
);
801 /* if the last argument copied into the registers didn't fit there
802 completely, push the rest of it into stack. */
806 sp
+24+(ii
*4), ((char*)VALUE_CONTENTS (arg
))+argbytes
, len
- argbytes
);
808 ii
+= ((len
- argbytes
+ 3) & -4) / 4;
811 /* push the rest of the arguments into stack. */
812 for (; argno
< nargs
; ++argno
) {
815 len
= TYPE_LENGTH (VALUE_TYPE (arg
));
818 /* float types should be passed in fpr's, as well as in the stack. */
819 if (TYPE_CODE (VALUE_TYPE (arg
)) == TYPE_CODE_FLT
&& f_argno
< 13) {
823 "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno
);
825 memcpy (®isters
[REGISTER_BYTE(FP0_REGNUM
+ 1 + f_argno
)], VALUE_CONTENTS (arg
),
830 write_memory (sp
+24+(ii
*4), (char *) VALUE_CONTENTS (arg
), len
);
831 ii
+= ((len
+ 3) & -4) / 4;
835 /* Secure stack areas first, before doing anything else. */
836 write_register (SP_REGNUM
, sp
);
838 saved_sp
= dummy_frame_addr
[dummy_frame_count
- 1];
839 read_memory (saved_sp
, tmp_buffer
, 24);
840 write_memory (sp
, tmp_buffer
, 24);
842 /* set back chain properly */
843 store_address (tmp_buffer
, 4, saved_sp
);
844 write_memory (sp
, tmp_buffer
, 4);
846 target_store_registers (-1);
850 /* a given return value in `regbuf' with a type `valtype', extract and copy its
851 value into `valbuf' */
854 extract_return_value (valtype
, regbuf
, valbuf
)
855 struct type
*valtype
;
856 char regbuf
[REGISTER_BYTES
];
861 if (TYPE_CODE (valtype
) == TYPE_CODE_FLT
) {
864 /* floats and doubles are returned in fpr1. fpr's have a size of 8 bytes.
865 We need to truncate the return value into float size (4 byte) if
868 if (TYPE_LENGTH (valtype
) > 4) /* this is a double */
869 memcpy (valbuf
, ®buf
[REGISTER_BYTE (FP0_REGNUM
+ 1)],
870 TYPE_LENGTH (valtype
));
872 memcpy (&dd
, ®buf
[REGISTER_BYTE (FP0_REGNUM
+ 1)], 8);
874 memcpy (valbuf
, &ff
, sizeof(float));
878 /* return value is copied starting from r3. */
879 if (TARGET_BYTE_ORDER
== BIG_ENDIAN
880 && TYPE_LENGTH (valtype
) < REGISTER_RAW_SIZE (3))
881 offset
= REGISTER_RAW_SIZE (3) - TYPE_LENGTH (valtype
);
883 memcpy (valbuf
, regbuf
+ REGISTER_BYTE (3) + offset
,
884 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. */
941 frameless_function_invocation (fi
)
942 struct frame_info
*fi
;
944 CORE_ADDR func_start
;
945 struct rs6000_framedata fdata
;
947 if (fi
->next
!= NULL
)
948 /* Don't even think about framelessness except on the innermost frame. */
949 /* FIXME: Can also be frameless if fi->next->signal_handler_caller (if
950 a signal happens while executing in a frameless function). */
953 func_start
= get_pc_function_start (fi
->pc
) + FUNCTION_START_OFFSET
;
955 /* If we failed to find the start of the function, it is a mistake
956 to inspect the instructions. */
961 (void) skip_prologue (func_start
, &fdata
);
962 return fdata
.frameless
;
965 /* Return the PC saved in a frame */
968 struct frame_info
*fi
;
970 CORE_ADDR func_start
;
971 struct rs6000_framedata fdata
;
974 if (fi
->signal_handler_caller
)
975 return read_memory_integer (fi
->frame
+ SIG_FRAME_PC_OFFSET
, 4);
977 func_start
= get_pc_function_start (fi
->pc
) + FUNCTION_START_OFFSET
;
979 /* If we failed to find the start of the function, it is a mistake
980 to inspect the instructions. */
984 (void) skip_prologue (func_start
, &fdata
);
986 if (fdata
.lr_offset
== 0 && fi
->next
!= NULL
)
987 return read_memory_integer (rs6000_frame_chain (fi
) + DEFAULT_LR_SAVE
, 4);
989 if (fdata
.lr_offset
== 0)
990 return read_register (LR_REGNUM
);
992 return read_memory_integer (rs6000_frame_chain (fi
) + fdata
.lr_offset
, 4);
995 /* If saved registers of frame FI are not known yet, read and cache them.
996 &FDATAP contains rs6000_framedata; TDATAP can be NULL,
997 in which case the framedata are read. */
1000 frame_get_cache_fsr (fi
, fdatap
)
1001 struct frame_info
*fi
;
1002 struct rs6000_framedata
*fdatap
;
1005 CORE_ADDR frame_addr
;
1006 struct rs6000_framedata work_fdata
;
1011 if (fdatap
== NULL
) {
1012 fdatap
= &work_fdata
;
1013 (void) skip_prologue (get_pc_function_start (fi
->pc
), fdatap
);
1016 fi
->cache_fsr
= (struct frame_saved_regs
*)
1017 obstack_alloc (&frame_cache_obstack
, sizeof (struct frame_saved_regs
));
1018 memset (fi
->cache_fsr
, '\0', sizeof (struct frame_saved_regs
));
1020 if (fi
->prev
&& fi
->prev
->frame
)
1021 frame_addr
= fi
->prev
->frame
;
1023 frame_addr
= read_memory_integer (fi
->frame
, 4);
1025 /* if != -1, fdatap->saved_fpr is the smallest number of saved_fpr.
1026 All fpr's from saved_fpr to fp31 are saved. */
1028 if (fdatap
->saved_fpr
>= 0) {
1029 int fpr_offset
= frame_addr
+ fdatap
->fpr_offset
;
1030 for (ii
= fdatap
->saved_fpr
; ii
< 32; ii
++) {
1031 fi
->cache_fsr
->regs
[FP0_REGNUM
+ ii
] = fpr_offset
;
1036 /* if != -1, fdatap->saved_gpr is the smallest number of saved_gpr.
1037 All gpr's from saved_gpr to gpr31 are saved. */
1039 if (fdatap
->saved_gpr
>= 0) {
1040 int gpr_offset
= frame_addr
+ fdatap
->gpr_offset
;
1041 for (ii
= fdatap
->saved_gpr
; ii
< 32; ii
++) {
1042 fi
->cache_fsr
->regs
[ii
] = gpr_offset
;
1047 /* If != 0, fdatap->cr_offset is the offset from the frame that holds
1049 if (fdatap
->cr_offset
!= 0)
1050 fi
->cache_fsr
->regs
[CR_REGNUM
] = frame_addr
+ fdatap
->cr_offset
;
1052 /* If != 0, fdatap->lr_offset is the offset from the frame that holds
1054 if (fdatap
->lr_offset
!= 0)
1055 fi
->cache_fsr
->regs
[LR_REGNUM
] = frame_addr
+ fdatap
->lr_offset
;
1058 /* Return the address of a frame. This is the inital %sp value when the frame
1059 was first allocated. For functions calling alloca(), it might be saved in
1060 an alloca register. */
1063 frame_initial_stack_address (fi
)
1064 struct frame_info
*fi
;
1067 struct rs6000_framedata fdata
;
1068 struct frame_info
*callee_fi
;
1070 /* if the initial stack pointer (frame address) of this frame is known,
1074 return fi
->initial_sp
;
1076 /* find out if this function is using an alloca register.. */
1078 (void) skip_prologue (get_pc_function_start (fi
->pc
), &fdata
);
1080 /* if saved registers of this frame are not known yet, read and cache them. */
1083 frame_get_cache_fsr (fi
, &fdata
);
1085 /* If no alloca register used, then fi->frame is the value of the %sp for
1086 this frame, and it is good enough. */
1088 if (fdata
.alloca_reg
< 0) {
1089 fi
->initial_sp
= fi
->frame
;
1090 return fi
->initial_sp
;
1093 /* This function has an alloca register. If this is the top-most frame
1094 (with the lowest address), the value in alloca register is good. */
1097 return fi
->initial_sp
= read_register (fdata
.alloca_reg
);
1099 /* Otherwise, this is a caller frame. Callee has usually already saved
1100 registers, but there are exceptions (such as when the callee
1101 has no parameters). Find the address in which caller's alloca
1102 register is saved. */
1104 for (callee_fi
= fi
->next
; callee_fi
; callee_fi
= callee_fi
->next
) {
1106 if (!callee_fi
->cache_fsr
)
1107 frame_get_cache_fsr (callee_fi
, NULL
);
1109 /* this is the address in which alloca register is saved. */
1111 tmpaddr
= callee_fi
->cache_fsr
->regs
[fdata
.alloca_reg
];
1113 fi
->initial_sp
= read_memory_integer (tmpaddr
, 4);
1114 return fi
->initial_sp
;
1117 /* Go look into deeper levels of the frame chain to see if any one of
1118 the callees has saved alloca register. */
1121 /* If alloca register was not saved, by the callee (or any of its callees)
1122 then the value in the register is still good. */
1124 return fi
->initial_sp
= read_register (fdata
.alloca_reg
);
1128 rs6000_frame_chain (thisframe
)
1129 struct frame_info
*thisframe
;
1132 if (inside_entry_file ((thisframe
)->pc
))
1134 if (thisframe
->signal_handler_caller
)
1135 fp
= read_memory_integer (thisframe
->frame
+ SIG_FRAME_FP_OFFSET
, 4);
1137 fp
= read_memory_integer ((thisframe
)->frame
, 4);
1142 /* Keep an array of load segment information and their TOC table addresses.
1143 This info will be useful when calling a shared library function by hand. */
1146 CORE_ADDR textorg
, dataorg
;
1147 unsigned long toc_offset
;
1150 #define LOADINFOLEN 10
1152 static struct loadinfo
*loadinfo
= NULL
;
1153 static int loadinfolen
= 0;
1154 static int loadinfotocindex
= 0;
1155 static int loadinfotextindex
= 0;
1159 xcoff_init_loadinfo ()
1161 loadinfotocindex
= 0;
1162 loadinfotextindex
= 0;
1164 if (loadinfolen
== 0) {
1165 loadinfo
= (struct loadinfo
*)
1166 xmalloc (sizeof (struct loadinfo
) * LOADINFOLEN
);
1167 loadinfolen
= LOADINFOLEN
;
1172 /* FIXME -- this is never called! */
1180 loadinfotocindex
= 0;
1181 loadinfotextindex
= 0;
1184 /* this is called from xcoffread.c */
1187 xcoff_add_toc_to_loadinfo (tocoff
)
1188 unsigned long tocoff
;
1190 while (loadinfotocindex
>= loadinfolen
) {
1191 loadinfolen
+= LOADINFOLEN
;
1192 loadinfo
= (struct loadinfo
*)
1193 xrealloc (loadinfo
, sizeof(struct loadinfo
) * loadinfolen
);
1195 loadinfo
[loadinfotocindex
++].toc_offset
= tocoff
;
1199 add_text_to_loadinfo (textaddr
, dataaddr
)
1203 while (loadinfotextindex
>= loadinfolen
) {
1204 loadinfolen
+= LOADINFOLEN
;
1205 loadinfo
= (struct loadinfo
*)
1206 xrealloc (loadinfo
, sizeof(struct loadinfo
) * loadinfolen
);
1208 loadinfo
[loadinfotextindex
].textorg
= textaddr
;
1209 loadinfo
[loadinfotextindex
].dataorg
= dataaddr
;
1210 ++loadinfotextindex
;
1214 /* Note that this assumes that the "textorg" and "dataorg" elements
1215 of a member of this array are correlated with the "toc_offset"
1216 element of the same member. This is taken care of because the loops
1217 which assign the former (in xcoff_relocate_symtab or xcoff_relocate_core)
1218 and the latter (in scan_xcoff_symtab, via vmap_symtab, in vmap_ldinfo
1219 or xcoff_relocate_core) traverse the same objfiles in the same order. */
1222 find_toc_address (pc
)
1225 int ii
, toc_entry
, tocbase
= 0;
1228 for (ii
=0; ii
< loadinfotextindex
; ++ii
)
1229 if (pc
> loadinfo
[ii
].textorg
&& loadinfo
[ii
].textorg
> tocbase
) {
1231 tocbase
= loadinfo
[ii
].textorg
;
1234 if (toc_entry
== -1)
1235 error ("Unable to find TOC entry for pc 0x%x\n", pc
);
1236 return loadinfo
[toc_entry
].dataorg
+ loadinfo
[toc_entry
].toc_offset
;
1239 /* Return nonzero if ADDR (a function pointer) is in the data space and
1240 is therefore a special function pointer. */
1243 is_magic_function_pointer (addr
)
1246 struct obj_section
*s
;
1248 s
= find_pc_section (addr
);
1249 if (s
&& s
->the_bfd_section
->flags
& SEC_CODE
)
1255 #ifdef GDB_TARGET_POWERPC
1257 gdb_print_insn_powerpc (memaddr
, info
)
1259 disassemble_info
*info
;
1261 if (TARGET_BYTE_ORDER
== BIG_ENDIAN
)
1262 return print_insn_big_powerpc (memaddr
, info
);
1264 return print_insn_little_powerpc (memaddr
, info
);
1269 _initialize_rs6000_tdep ()
1271 /* FIXME, this should not be decided via ifdef. */
1272 #ifdef GDB_TARGET_POWERPC
1273 tm_print_insn
= gdb_print_insn_powerpc
;
1275 tm_print_insn
= print_insn_rs6000
;