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., 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 rs6000_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 */
84 dest
= pc
+ immediate
;
88 immediate
= ((instr
& ~3) << 16) >> 16; /* br conditional */
92 dest
= pc
+ immediate
;
96 ext_op
= (instr
>>1) & 0x3ff;
98 if (ext_op
== 16) /* br conditional register */
99 dest
= read_register (LR_REGNUM
) & ~3;
101 else if (ext_op
== 528) /* br cond to count reg */
103 dest
= read_register (CTR_REGNUM
) & ~3;
105 /* If we are about to execute a system call, dest is something
106 like 0x22fc or 0x3b00. Upon completion the system call
107 will return to the address in the link register. */
108 if (dest
< TEXT_SEGMENT_BASE
)
109 dest
= read_register (LR_REGNUM
) & ~3;
116 return (dest
< TEXT_SEGMENT_BASE
) ? safety
: dest
;
121 /* AIX does not support PT_STEP. Simulate it. */
127 #define INSNLEN(OPCODE) 4
129 static char le_breakp
[] = LITTLE_BREAKPOINT
;
130 static char be_breakp
[] = BIG_BREAKPOINT
;
131 char *breakp
= TARGET_BYTE_ORDER
== BIG_ENDIAN
? be_breakp
: le_breakp
;
140 insn
= read_memory_integer (loc
, 4);
142 breaks
[0] = loc
+ INSNLEN(insn
);
144 breaks
[1] = branch_dest (opcode
, insn
, loc
, breaks
[0]);
146 /* Don't put two breakpoints on the same address. */
147 if (breaks
[1] == breaks
[0])
150 stepBreaks
[1].address
= 0;
152 for (ii
=0; ii
< 2; ++ii
) {
154 /* ignore invalid breakpoint. */
155 if ( breaks
[ii
] == -1)
158 read_memory (breaks
[ii
], stepBreaks
[ii
].data
, 4);
160 write_memory (breaks
[ii
], breakp
, 4);
161 stepBreaks
[ii
].address
= breaks
[ii
];
167 /* remove step breakpoints. */
168 for (ii
=0; ii
< 2; ++ii
)
169 if (stepBreaks
[ii
].address
!= 0)
171 (stepBreaks
[ii
].address
, stepBreaks
[ii
].data
, 4);
175 errno
= 0; /* FIXME, don't ignore errors! */
176 /* What errors? {read,write}_memory call error(). */
180 /* return pc value after skipping a function prologue and also return
181 information about a function frame.
183 in struct rs6000_frameinfo fdata:
184 - frameless is TRUE, if function does not have a frame.
185 - nosavedpc is TRUE, if function does not save %pc value in its frame.
186 - offset is the number of bytes used in the frame to save registers.
187 - saved_gpr is the number of the first saved gpr.
188 - saved_fpr is the number of the first saved fpr.
189 - alloca_reg is the number of the register used for alloca() handling.
191 - gpr_offset is the offset of the saved gprs
192 - fpr_offset is the offset of the saved fprs
193 - lr_offset is the offset of the saved lr
194 - cr_offset is the offset of the saved cr
197 #define SIGNED_SHORT(x) \
198 ((sizeof (short) == 2) \
199 ? ((int)(short)(x)) \
200 : ((int)((((x) & 0xffff) ^ 0x8000) - 0x8000)))
202 #define GET_SRC_REG(x) (((x) >> 21) & 0x1f)
205 skip_prologue (pc
, fdata
)
207 struct rs6000_framedata
*fdata
;
209 CORE_ADDR orig_pc
= pc
;
217 static struct rs6000_framedata zero_frame
;
220 fdata
->saved_gpr
= -1;
221 fdata
->saved_fpr
= -1;
222 fdata
->alloca_reg
= -1;
223 fdata
->frameless
= 1;
224 fdata
->nosavedpc
= 1;
226 if (target_read_memory (pc
, buf
, 4))
227 return pc
; /* Can't access it -- assume no prologue. */
229 /* Assume that subsequent fetches can fail with low probability. */
234 op
= read_memory_integer (pc
, 4);
236 if ((op
& 0xfc1fffff) == 0x7c0802a6) { /* mflr Rx */
237 lr_reg
= (op
& 0x03e00000) | 0x90010000;
240 } else if ((op
& 0xfc1fffff) == 0x7c000026) { /* mfcr Rx */
241 cr_reg
= (op
& 0x03e00000) | 0x90010000;
244 } else if ((op
& 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */
245 reg
= GET_SRC_REG (op
);
246 if (fdata
->saved_fpr
== -1 || fdata
->saved_fpr
> reg
) {
247 fdata
->saved_fpr
= reg
;
248 fdata
->fpr_offset
= SIGNED_SHORT (op
) + offset
;
252 } else if (((op
& 0xfc1f0000) == 0xbc010000) || /* stm Rx, NUM(r1) */
253 ((op
& 0xfc1f0000) == 0x90010000 && /* st rx,NUM(r1), rx >= r13 */
254 (op
& 0x03e00000) >= 0x01a00000)) {
256 reg
= GET_SRC_REG (op
);
257 if (fdata
->saved_gpr
== -1 || fdata
->saved_gpr
> reg
) {
258 fdata
->saved_gpr
= reg
;
259 fdata
->gpr_offset
= SIGNED_SHORT (op
) + offset
;
263 } else if ((op
& 0xffff0000) == 0x3c000000) { /* addis 0,0,NUM, used for >= 32k frames */
264 fdata
->offset
= (op
& 0x0000ffff) << 16;
267 } else if ((op
& 0xffff0000) == 0x60000000) { /* ori 0,0,NUM, 2nd half of >= 32k frames */
268 fdata
->offset
|= (op
& 0x0000ffff);
271 } else if ((op
& 0xffff0000) == lr_reg
) { /* st Rx,NUM(r1) where Rx == lr */
272 fdata
->lr_offset
= SIGNED_SHORT (op
) + offset
;
273 fdata
->nosavedpc
= 0;
277 } else if ((op
& 0xffff0000) == cr_reg
) { /* st Rx,NUM(r1) where Rx == cr */
278 fdata
->cr_offset
= SIGNED_SHORT (op
) + offset
;
282 } else if (op
== 0x48000005) { /* bl .+4 used in -mrelocatable */
285 } else if (((op
& 0xffff0000) == 0x801e0000 || /* lwz 0,NUM(r30), used in V.4 -mrelocatable */
286 op
== 0x7fc0f214) && /* add r30,r0,r30, used in V.4 -mrelocatable */
287 lr_reg
== 0x901e0000) {
290 } else if ((op
& 0xffff0000) == 0x3fc00000 || /* addis 30,0,foo@ha, used in V.4 -mminimal-toc */
291 (op
& 0xffff0000) == 0x3bde0000) { /* addi 30,30,foo@l */
294 } else if ((op
& 0xfc000000) == 0x48000000) { /* bl foo, to save fprs??? */
296 /* Don't skip over the subroutine call if it is not within the first
297 three instructions of the prologue. */
298 if ((pc
- orig_pc
) > 8)
301 op
= read_memory_integer (pc
+4, 4);
303 /* At this point, make sure this is not a trampoline function
304 (a function that simply calls another functions, and nothing else).
305 If the next is not a nop, this branch was part of the function
308 if (op
== 0x4def7b82 || op
== 0) /* crorc 15, 15, 15 */
309 break; /* don't skip over this branch */
313 /* update stack pointer */
314 } else if ((op
& 0xffff0000) == 0x94210000) { /* stu r1,NUM(r1) */
315 fdata
->offset
= SIGNED_SHORT (op
);
316 offset
= fdata
->offset
;
319 } else if (op
== 0x7c21016e) { /* stwux 1,1,0 */
320 offset
= fdata
->offset
;
323 /* Load up minimal toc pointer */
324 } else if ((op
>> 22) == 0x20f) { /* l r31,... or l r30,... */
327 /* store parameters in stack */
328 } else if ((op
& 0xfc1f0000) == 0x90010000 || /* st rx,NUM(r1) */
329 (op
& 0xfc1f0000) == 0xd8010000 || /* stfd Rx,NUM(r1) */
330 (op
& 0xfc1f0000) == 0xfc010000) { /* frsp, fp?,NUM(r1) */
333 /* store parameters in stack via frame pointer */
335 (op
& 0xfc1f0000) == 0x901f0000 || /* st rx,NUM(r1) */
336 (op
& 0xfc1f0000) == 0xd81f0000 || /* stfd Rx,NUM(r1) */
337 (op
& 0xfc1f0000) == 0xfc1f0000) { /* frsp, fp?,NUM(r1) */
340 /* Set up frame pointer */
341 } else if (op
== 0x603f0000 /* oril r31, r1, 0x0 */
342 || op
== 0x7c3f0b78) { /* mr r31, r1 */
344 fdata
->alloca_reg
= 31;
353 /* I have problems with skipping over __main() that I need to address
354 * sometime. Previously, I used to use misc_function_vector which
355 * didn't work as well as I wanted to be. -MGO */
357 /* If the first thing after skipping a prolog is a branch to a function,
358 this might be a call to an initializer in main(), introduced by gcc2.
359 We'd like to skip over it as well. Fortunately, xlc does some extra
360 work before calling a function right after a prologue, thus we can
361 single out such gcc2 behaviour. */
364 if ((op
& 0xfc000001) == 0x48000001) { /* bl foo, an initializer function? */
365 op
= read_memory_integer (pc
+4, 4);
367 if (op
== 0x4def7b82) { /* cror 0xf, 0xf, 0xf (nop) */
369 /* check and see if we are in main. If so, skip over this initializer
372 tmp
= find_pc_misc_function (pc
);
373 if (tmp
>= 0 && STREQ (misc_function_vector
[tmp
].name
, "main"))
379 fdata
->frameless
= (pc
== orig_pc
);
380 fdata
->offset
= - fdata
->offset
;
385 /*************************************************************************
386 Support for creating pushind a dummy frame into the stack, and popping
388 *************************************************************************/
390 /* The total size of dummy frame is 436, which is;
395 and 24 extra bytes for the callee's link area. The last 24 bytes
396 for the link area might not be necessary, since it will be taken
397 care of by push_arguments(). */
399 #define DUMMY_FRAME_SIZE 436
401 #define DUMMY_FRAME_ADDR_SIZE 10
403 /* Make sure you initialize these in somewhere, in case gdb gives up what it
404 was debugging and starts debugging something else. FIXMEibm */
406 static int dummy_frame_count
= 0;
407 static int dummy_frame_size
= 0;
408 static CORE_ADDR
*dummy_frame_addr
= 0;
410 extern int stop_stack_dummy
;
412 /* push a dummy frame into stack, save all register. Currently we are saving
413 only gpr's and fpr's, which is not good enough! FIXMEmgo */
420 /* Same thing, target byte order. */
425 /* Same thing, target byte order. */
430 target_fetch_registers (-1);
432 if (dummy_frame_count
>= dummy_frame_size
) {
433 dummy_frame_size
+= DUMMY_FRAME_ADDR_SIZE
;
434 if (dummy_frame_addr
)
435 dummy_frame_addr
= (CORE_ADDR
*) xrealloc
436 (dummy_frame_addr
, sizeof(CORE_ADDR
) * (dummy_frame_size
));
438 dummy_frame_addr
= (CORE_ADDR
*)
439 xmalloc (sizeof(CORE_ADDR
) * (dummy_frame_size
));
442 sp
= read_register(SP_REGNUM
);
443 pc
= read_register(PC_REGNUM
);
444 store_address (pc_targ
, 4, pc
);
446 dummy_frame_addr
[dummy_frame_count
++] = sp
;
448 /* Be careful! If the stack pointer is not decremented first, then kernel
449 thinks he is free to use the space underneath it. And kernel actually
450 uses that area for IPC purposes when executing ptrace(2) calls. So
451 before writing register values into the new frame, decrement and update
452 %sp first in order to secure your frame. */
454 write_register (SP_REGNUM
, sp
-DUMMY_FRAME_SIZE
);
456 /* gdb relies on the state of current_frame. We'd better update it,
457 otherwise things like do_registers_info() wouldn't work properly! */
459 flush_cached_frames ();
461 /* save program counter in link register's space. */
462 write_memory (sp
+8, pc_targ
, 4);
464 /* save all floating point and general purpose registers here. */
467 for (ii
= 0; ii
< 32; ++ii
)
468 write_memory (sp
-8-(ii
*8), ®isters
[REGISTER_BYTE (31-ii
+FP0_REGNUM
)], 8);
471 for (ii
=1; ii
<=32; ++ii
)
472 write_memory (sp
-256-(ii
*4), ®isters
[REGISTER_BYTE (32-ii
)], 4);
474 /* so far, 32*2 + 32 words = 384 bytes have been written.
475 7 extra registers in our register set: pc, ps, cnd, lr, cnt, xer, mq */
477 for (ii
=1; ii
<= (LAST_SP_REGNUM
-FIRST_SP_REGNUM
+1); ++ii
) {
478 write_memory (sp
-384-(ii
*4),
479 ®isters
[REGISTER_BYTE (FPLAST_REGNUM
+ ii
)], 4);
482 /* Save sp or so called back chain right here. */
483 store_address (sp_targ
, 4, sp
);
484 write_memory (sp
-DUMMY_FRAME_SIZE
, sp_targ
, 4);
485 sp
-= DUMMY_FRAME_SIZE
;
487 /* And finally, this is the back chain. */
488 write_memory (sp
+8, pc_targ
, 4);
492 /* Pop a dummy frame.
494 In rs6000 when we push a dummy frame, we save all of the registers. This
495 is usually done before user calls a function explicitly.
497 After a dummy frame is pushed, some instructions are copied into stack,
498 and stack pointer is decremented even more. Since we don't have a frame
499 pointer to get back to the parent frame of the dummy, we start having
500 trouble poping it. Therefore, we keep a dummy frame stack, keeping
501 addresses of dummy frames as such. When poping happens and when we
502 detect that was a dummy frame, we pop it back to its parent by using
503 dummy frame stack (`dummy_frame_addr' array).
505 FIXME: This whole concept is broken. You should be able to detect
506 a dummy stack frame *on the user's stack itself*. When you do,
507 then you know the format of that stack frame -- including its
508 saved SP register! There should *not* be a separate stack in the
509 GDB process that keeps track of these dummy frames! -- gnu@cygnus.com Aug92
516 sp
= dummy_frame_addr
[--dummy_frame_count
];
518 /* restore all fpr's. */
519 for (ii
= 1; ii
<= 32; ++ii
)
520 read_memory (sp
-(ii
*8), ®isters
[REGISTER_BYTE (32-ii
+FP0_REGNUM
)], 8);
522 /* restore all gpr's */
523 for (ii
=1; ii
<= 32; ++ii
) {
524 read_memory (sp
-256-(ii
*4), ®isters
[REGISTER_BYTE (32-ii
)], 4);
527 /* restore the rest of the registers. */
528 for (ii
=1; ii
<=(LAST_SP_REGNUM
-FIRST_SP_REGNUM
+1); ++ii
)
529 read_memory (sp
-384-(ii
*4),
530 ®isters
[REGISTER_BYTE (FPLAST_REGNUM
+ ii
)], 4);
532 read_memory (sp
-(DUMMY_FRAME_SIZE
-8),
533 ®isters
[REGISTER_BYTE(PC_REGNUM
)], 4);
535 /* when a dummy frame was being pushed, we had to decrement %sp first, in
536 order to secure astack space. Thus, saved %sp (or %r1) value, is not the
537 one we should restore. Change it with the one we need. */
539 *(int*)®isters
[REGISTER_BYTE(FP_REGNUM
)] = sp
;
541 /* Now we can restore all registers. */
543 target_store_registers (-1);
545 flush_cached_frames ();
549 /* pop the innermost frame, go back to the caller. */
554 CORE_ADDR pc
, lr
, sp
, prev_sp
; /* %pc, %lr, %sp */
555 struct rs6000_framedata fdata
;
556 struct frame_info
*frame
= get_current_frame ();
560 sp
= FRAME_FP (frame
);
562 if (stop_stack_dummy
&& dummy_frame_count
) {
567 /* Make sure that all registers are valid. */
568 read_register_bytes (0, NULL
, REGISTER_BYTES
);
570 /* figure out previous %pc value. If the function is frameless, it is
571 still in the link register, otherwise walk the frames and retrieve the
572 saved %pc value in the previous frame. */
574 addr
= get_pc_function_start (frame
->pc
) + FUNCTION_START_OFFSET
;
575 (void) skip_prologue (addr
, &fdata
);
580 prev_sp
= read_memory_integer (sp
, 4);
581 if (fdata
.lr_offset
== 0)
582 lr
= read_register (LR_REGNUM
);
584 lr
= read_memory_integer (prev_sp
+ fdata
.lr_offset
, 4);
586 /* reset %pc value. */
587 write_register (PC_REGNUM
, lr
);
589 /* reset register values if any was saved earlier. */
590 addr
= prev_sp
- fdata
.offset
;
592 if (fdata
.saved_gpr
!= -1)
593 for (ii
= fdata
.saved_gpr
; ii
<= 31; ++ii
) {
594 read_memory (addr
, ®isters
[REGISTER_BYTE (ii
)], 4);
598 if (fdata
.saved_fpr
!= -1)
599 for (ii
= fdata
.saved_fpr
; ii
<= 31; ++ii
) {
600 read_memory (addr
, ®isters
[REGISTER_BYTE (ii
+FP0_REGNUM
)], 8);
604 write_register (SP_REGNUM
, prev_sp
);
605 target_store_registers (-1);
606 flush_cached_frames ();
609 /* fixup the call sequence of a dummy function, with the real function address.
610 its argumets will be passed by gdb. */
613 fix_call_dummy(dummyname
, pc
, fun
, nargs
, type
)
617 int nargs
; /* not used */
618 int type
; /* not used */
620 #define TOC_ADDR_OFFSET 20
621 #define TARGET_ADDR_OFFSET 28
624 CORE_ADDR target_addr
;
628 tocvalue
= find_toc_address (target_addr
);
630 ii
= *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
);
631 ii
= (ii
& 0xffff0000) | (tocvalue
>> 16);
632 *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
) = ii
;
634 ii
= *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
+4);
635 ii
= (ii
& 0xffff0000) | (tocvalue
& 0x0000ffff);
636 *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
+4) = ii
;
638 ii
= *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
);
639 ii
= (ii
& 0xffff0000) | (target_addr
>> 16);
640 *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
) = ii
;
642 ii
= *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
+4);
643 ii
= (ii
& 0xffff0000) | (target_addr
& 0x0000ffff);
644 *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
+4) = ii
;
647 /* Pass the arguments in either registers, or in the stack. In RS6000, the first
648 eight words of the argument list (that might be less than eight parameters if
649 some parameters occupy more than one word) are passed in r3..r11 registers.
650 float and double parameters are passed in fpr's, in addition to that. Rest of
651 the parameters if any are passed in user stack. There might be cases in which
652 half of the parameter is copied into registers, the other half is pushed into
655 If the function is returning a structure, then the return address is passed
656 in r3, then the first 7 words of the parametes can be passed in registers,
660 push_arguments (nargs
, args
, sp
, struct_return
, struct_addr
)
665 CORE_ADDR struct_addr
;
668 int argno
; /* current argument number */
669 int argbytes
; /* current argument byte */
670 char tmp_buffer
[50];
672 int f_argno
= 0; /* current floating point argno */
674 CORE_ADDR saved_sp
, pc
;
676 if ( dummy_frame_count
<= 0)
677 printf_unfiltered ("FATAL ERROR -push_arguments()! frame not found!!\n");
679 /* The first eight words of ther arguments are passed in registers. Copy
682 If the function is returning a `struct', then the first word (which
683 will be passed in r3) is used for struct return address. In that
684 case we should advance one word and start from r4 register to copy
687 ii
= struct_return
? 1 : 0;
689 for (argno
=0, argbytes
=0; argno
< nargs
&& ii
<8; ++ii
) {
692 len
= TYPE_LENGTH (VALUE_TYPE (arg
));
694 if (TYPE_CODE (VALUE_TYPE (arg
)) == TYPE_CODE_FLT
) {
696 /* floating point arguments are passed in fpr's, as well as gpr's.
697 There are 13 fpr's reserved for passing parameters. At this point
698 there is no way we would run out of them. */
702 "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno
);
704 memcpy (®isters
[REGISTER_BYTE(FP0_REGNUM
+ 1 + f_argno
)], VALUE_CONTENTS (arg
),
711 /* Argument takes more than one register. */
712 while (argbytes
< len
) {
714 *(int*)®isters
[REGISTER_BYTE(ii
+3)] = 0;
715 memcpy (®isters
[REGISTER_BYTE(ii
+3)],
716 ((char*)VALUE_CONTENTS (arg
))+argbytes
,
717 (len
- argbytes
) > 4 ? 4 : len
- argbytes
);
721 goto ran_out_of_registers_for_arguments
;
726 else { /* Argument can fit in one register. No problem. */
727 *(int*)®isters
[REGISTER_BYTE(ii
+3)] = 0;
728 memcpy (®isters
[REGISTER_BYTE(ii
+3)], VALUE_CONTENTS (arg
), len
);
733 ran_out_of_registers_for_arguments
:
735 /* location for 8 parameters are always reserved. */
738 /* another six words for back chain, TOC register, link register, etc. */
741 /* if there are more arguments, allocate space for them in
742 the stack, then push them starting from the ninth one. */
744 if ((argno
< nargs
) || argbytes
) {
749 space
+= ((len
- argbytes
+ 3) & -4);
755 for (; jj
< nargs
; ++jj
) {
757 space
+= ((TYPE_LENGTH (VALUE_TYPE (val
))) + 3) & -4;
760 /* add location required for the rest of the parameters */
761 space
= (space
+ 7) & -8;
764 /* This is another instance we need to be concerned about securing our
765 stack space. If we write anything underneath %sp (r1), we might conflict
766 with the kernel who thinks he is free to use this area. So, update %sp
767 first before doing anything else. */
769 write_register (SP_REGNUM
, sp
);
771 /* if the last argument copied into the registers didn't fit there
772 completely, push the rest of it into stack. */
776 sp
+24+(ii
*4), ((char*)VALUE_CONTENTS (arg
))+argbytes
, len
- argbytes
);
778 ii
+= ((len
- argbytes
+ 3) & -4) / 4;
781 /* push the rest of the arguments into stack. */
782 for (; argno
< nargs
; ++argno
) {
785 len
= TYPE_LENGTH (VALUE_TYPE (arg
));
788 /* float types should be passed in fpr's, as well as in the stack. */
789 if (TYPE_CODE (VALUE_TYPE (arg
)) == TYPE_CODE_FLT
&& f_argno
< 13) {
793 "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno
);
795 memcpy (®isters
[REGISTER_BYTE(FP0_REGNUM
+ 1 + f_argno
)], VALUE_CONTENTS (arg
),
800 write_memory (sp
+24+(ii
*4), (char *) VALUE_CONTENTS (arg
), len
);
801 ii
+= ((len
+ 3) & -4) / 4;
805 /* Secure stack areas first, before doing anything else. */
806 write_register (SP_REGNUM
, sp
);
808 saved_sp
= dummy_frame_addr
[dummy_frame_count
- 1];
809 read_memory (saved_sp
, tmp_buffer
, 24);
810 write_memory (sp
, tmp_buffer
, 24);
812 /* set back chain properly */
813 store_address (tmp_buffer
, 4, saved_sp
);
814 write_memory (sp
, tmp_buffer
, 4);
816 target_store_registers (-1);
820 /* a given return value in `regbuf' with a type `valtype', extract and copy its
821 value into `valbuf' */
824 extract_return_value (valtype
, regbuf
, valbuf
)
825 struct type
*valtype
;
826 char regbuf
[REGISTER_BYTES
];
830 if (TYPE_CODE (valtype
) == TYPE_CODE_FLT
) {
833 /* floats and doubles are returned in fpr1. fpr's have a size of 8 bytes.
834 We need to truncate the return value into float size (4 byte) if
837 if (TYPE_LENGTH (valtype
) > 4) /* this is a double */
838 memcpy (valbuf
, ®buf
[REGISTER_BYTE (FP0_REGNUM
+ 1)],
839 TYPE_LENGTH (valtype
));
841 memcpy (&dd
, ®buf
[REGISTER_BYTE (FP0_REGNUM
+ 1)], 8);
843 memcpy (valbuf
, &ff
, sizeof(float));
847 /* return value is copied starting from r3. */
848 memcpy (valbuf
, ®buf
[REGISTER_BYTE (3)], TYPE_LENGTH (valtype
));
852 /* keep structure return address in this variable.
853 FIXME: This is a horrid kludge which should not be allowed to continue
854 living. This only allows a single nested call to a structure-returning
855 function. Come on, guys! -- gnu@cygnus.com, Aug 92 */
857 CORE_ADDR rs6000_struct_return_address
;
860 /* Indirect function calls use a piece of trampoline code to do context
861 switching, i.e. to set the new TOC table. Skip such code if we are on
862 its first instruction (as when we have single-stepped to here).
863 Also skip shared library trampoline code (which is different from
864 indirect function call trampolines).
865 Result is desired PC to step until, or NULL if we are not in
869 skip_trampoline_code (pc
)
872 register unsigned int ii
, op
;
873 CORE_ADDR solib_target_pc
;
875 static unsigned trampoline_code
[] = {
876 0x800b0000, /* l r0,0x0(r11) */
877 0x90410014, /* st r2,0x14(r1) */
878 0x7c0903a6, /* mtctr r0 */
879 0x804b0004, /* l r2,0x4(r11) */
880 0x816b0008, /* l r11,0x8(r11) */
881 0x4e800420, /* bctr */
886 /* If pc is in a shared library trampoline, return its target. */
887 solib_target_pc
= find_solib_trampoline_target (pc
);
889 return solib_target_pc
;
891 for (ii
=0; trampoline_code
[ii
]; ++ii
) {
892 op
= read_memory_integer (pc
+ (ii
*4), 4);
893 if (op
!= trampoline_code
[ii
])
896 ii
= read_register (11); /* r11 holds destination addr */
897 pc
= read_memory_integer (ii
, 4); /* (r11) value */
902 /* Determines whether the function FI has a frame on the stack or not. */
904 frameless_function_invocation (fi
)
905 struct frame_info
*fi
;
907 CORE_ADDR func_start
;
908 struct rs6000_framedata fdata
;
910 if (fi
->next
!= NULL
)
911 /* Don't even think about framelessness except on the innermost frame. */
912 /* FIXME: Can also be frameless if fi->next->signal_handler_caller (if
913 a signal happens while executing in a frameless function). */
916 func_start
= get_pc_function_start (fi
->pc
) + FUNCTION_START_OFFSET
;
918 /* If we failed to find the start of the function, it is a mistake
919 to inspect the instructions. */
924 (void) skip_prologue (func_start
, &fdata
);
925 return fdata
.frameless
;
928 /* Return the PC saved in a frame */
931 struct frame_info
*fi
;
933 CORE_ADDR func_start
;
934 struct rs6000_framedata fdata
;
937 if (fi
->signal_handler_caller
)
938 return read_memory_integer (fi
->frame
+ SIG_FRAME_PC_OFFSET
, 4);
940 func_start
= get_pc_function_start (fi
->pc
) + FUNCTION_START_OFFSET
;
942 /* If we failed to find the start of the function, it is a mistake
943 to inspect the instructions. */
947 (void) skip_prologue (func_start
, &fdata
);
949 if (fdata
.lr_offset
== 0 && fi
->next
!= NULL
)
950 return read_memory_integer (rs6000_frame_chain (fi
) + DEFAULT_LR_SAVE
, 4);
952 if (fdata
.lr_offset
== 0)
953 return read_register (LR_REGNUM
);
955 return read_memory_integer (rs6000_frame_chain (fi
) + fdata
.lr_offset
, 4);
958 /* If saved registers of frame FI are not known yet, read and cache them.
959 &FDATAP contains rs6000_framedata; TDATAP can be NULL,
960 in which case the framedata are read. */
963 frame_get_cache_fsr (fi
, fdatap
)
964 struct frame_info
*fi
;
965 struct rs6000_framedata
*fdatap
;
968 CORE_ADDR frame_addr
;
969 struct rs6000_framedata work_fdata
;
974 if (fdatap
== NULL
) {
975 fdatap
= &work_fdata
;
976 (void) skip_prologue (get_pc_function_start (fi
->pc
), fdatap
);
979 fi
->cache_fsr
= (struct frame_saved_regs
*)
980 obstack_alloc (&frame_cache_obstack
, sizeof (struct frame_saved_regs
));
981 memset (fi
->cache_fsr
, '\0', sizeof (struct frame_saved_regs
));
983 if (fi
->prev
&& fi
->prev
->frame
)
984 frame_addr
= fi
->prev
->frame
;
986 frame_addr
= read_memory_integer (fi
->frame
, 4);
988 /* if != -1, fdatap->saved_fpr is the smallest number of saved_fpr.
989 All fpr's from saved_fpr to fp31 are saved. */
991 if (fdatap
->saved_fpr
>= 0) {
992 int fpr_offset
= frame_addr
+ fdatap
->fpr_offset
;
993 for (ii
= fdatap
->saved_fpr
; ii
< 32; ii
++) {
994 fi
->cache_fsr
->regs
[FP0_REGNUM
+ ii
] = fpr_offset
;
999 /* if != -1, fdatap->saved_gpr is the smallest number of saved_gpr.
1000 All gpr's from saved_gpr to gpr31 are saved. */
1002 if (fdatap
->saved_gpr
>= 0) {
1003 int gpr_offset
= frame_addr
+ fdatap
->gpr_offset
;
1004 for (ii
= fdatap
->saved_gpr
; ii
< 32; ii
++) {
1005 fi
->cache_fsr
->regs
[ii
] = gpr_offset
;
1010 /* If != 0, fdatap->cr_offset is the offset from the frame that holds
1012 if (fdatap
->cr_offset
!= 0)
1013 fi
->cache_fsr
->regs
[CR_REGNUM
] = frame_addr
+ fdatap
->cr_offset
;
1015 /* If != 0, fdatap->lr_offset is the offset from the frame that holds
1017 if (fdatap
->lr_offset
!= 0)
1018 fi
->cache_fsr
->regs
[LR_REGNUM
] = frame_addr
+ fdatap
->lr_offset
;
1021 /* Return the address of a frame. This is the inital %sp value when the frame
1022 was first allocated. For functions calling alloca(), it might be saved in
1023 an alloca register. */
1026 frame_initial_stack_address (fi
)
1027 struct frame_info
*fi
;
1030 struct rs6000_framedata fdata
;
1031 struct frame_info
*callee_fi
;
1033 /* if the initial stack pointer (frame address) of this frame is known,
1037 return fi
->initial_sp
;
1039 /* find out if this function is using an alloca register.. */
1041 (void) skip_prologue (get_pc_function_start (fi
->pc
), &fdata
);
1043 /* if saved registers of this frame are not known yet, read and cache them. */
1046 frame_get_cache_fsr (fi
, &fdata
);
1048 /* If no alloca register used, then fi->frame is the value of the %sp for
1049 this frame, and it is good enough. */
1051 if (fdata
.alloca_reg
< 0) {
1052 fi
->initial_sp
= fi
->frame
;
1053 return fi
->initial_sp
;
1056 /* This function has an alloca register. If this is the top-most frame
1057 (with the lowest address), the value in alloca register is good. */
1060 return fi
->initial_sp
= read_register (fdata
.alloca_reg
);
1062 /* Otherwise, this is a caller frame. Callee has usually already saved
1063 registers, but there are exceptions (such as when the callee
1064 has no parameters). Find the address in which caller's alloca
1065 register is saved. */
1067 for (callee_fi
= fi
->next
; callee_fi
; callee_fi
= callee_fi
->next
) {
1069 if (!callee_fi
->cache_fsr
)
1070 frame_get_cache_fsr (callee_fi
, NULL
);
1072 /* this is the address in which alloca register is saved. */
1074 tmpaddr
= callee_fi
->cache_fsr
->regs
[fdata
.alloca_reg
];
1076 fi
->initial_sp
= read_memory_integer (tmpaddr
, 4);
1077 return fi
->initial_sp
;
1080 /* Go look into deeper levels of the frame chain to see if any one of
1081 the callees has saved alloca register. */
1084 /* If alloca register was not saved, by the callee (or any of its callees)
1085 then the value in the register is still good. */
1087 return fi
->initial_sp
= read_register (fdata
.alloca_reg
);
1091 rs6000_frame_chain (thisframe
)
1092 struct frame_info
*thisframe
;
1095 if (inside_entry_file ((thisframe
)->pc
))
1097 if (thisframe
->signal_handler_caller
)
1098 fp
= read_memory_integer (thisframe
->frame
+ SIG_FRAME_FP_OFFSET
, 4);
1100 fp
= read_memory_integer ((thisframe
)->frame
, 4);
1105 /* Keep an array of load segment information and their TOC table addresses.
1106 This info will be useful when calling a shared library function by hand. */
1109 CORE_ADDR textorg
, dataorg
;
1110 unsigned long toc_offset
;
1113 #define LOADINFOLEN 10
1115 static struct loadinfo
*loadinfo
= NULL
;
1116 static int loadinfolen
= 0;
1117 static int loadinfotocindex
= 0;
1118 static int loadinfotextindex
= 0;
1122 xcoff_init_loadinfo ()
1124 loadinfotocindex
= 0;
1125 loadinfotextindex
= 0;
1127 if (loadinfolen
== 0) {
1128 loadinfo
= (struct loadinfo
*)
1129 xmalloc (sizeof (struct loadinfo
) * LOADINFOLEN
);
1130 loadinfolen
= LOADINFOLEN
;
1135 /* FIXME -- this is never called! */
1143 loadinfotocindex
= 0;
1144 loadinfotextindex
= 0;
1147 /* this is called from xcoffread.c */
1150 xcoff_add_toc_to_loadinfo (tocoff
)
1151 unsigned long tocoff
;
1153 while (loadinfotocindex
>= loadinfolen
) {
1154 loadinfolen
+= LOADINFOLEN
;
1155 loadinfo
= (struct loadinfo
*)
1156 xrealloc (loadinfo
, sizeof(struct loadinfo
) * loadinfolen
);
1158 loadinfo
[loadinfotocindex
++].toc_offset
= tocoff
;
1162 add_text_to_loadinfo (textaddr
, dataaddr
)
1166 while (loadinfotextindex
>= loadinfolen
) {
1167 loadinfolen
+= LOADINFOLEN
;
1168 loadinfo
= (struct loadinfo
*)
1169 xrealloc (loadinfo
, sizeof(struct loadinfo
) * loadinfolen
);
1171 loadinfo
[loadinfotextindex
].textorg
= textaddr
;
1172 loadinfo
[loadinfotextindex
].dataorg
= dataaddr
;
1173 ++loadinfotextindex
;
1177 /* Note that this assumes that the "textorg" and "dataorg" elements
1178 of a member of this array are correlated with the "toc_offset"
1179 element of the same member. This is taken care of because the loops
1180 which assign the former (in xcoff_relocate_symtab or xcoff_relocate_core)
1181 and the latter (in scan_xcoff_symtab, via vmap_symtab, in vmap_ldinfo
1182 or xcoff_relocate_core) traverse the same objfiles in the same order. */
1185 find_toc_address (pc
)
1188 int ii
, toc_entry
, tocbase
= 0;
1190 for (ii
=0; ii
< loadinfotextindex
; ++ii
)
1191 if (pc
> loadinfo
[ii
].textorg
&& loadinfo
[ii
].textorg
> tocbase
) {
1193 tocbase
= loadinfo
[ii
].textorg
;
1196 return loadinfo
[toc_entry
].dataorg
+ loadinfo
[toc_entry
].toc_offset
;
1199 #ifdef GDB_TARGET_POWERPC
1201 gdb_print_insn_powerpc (memaddr
, info
)
1203 disassemble_info
*info
;
1205 if (TARGET_BYTE_ORDER
== BIG_ENDIAN
)
1206 return print_insn_big_powerpc (memaddr
, info
);
1208 return print_insn_little_powerpc (memaddr
, info
);
1213 _initialize_rs6000_tdep ()
1215 /* FIXME, this should not be decided via ifdef. */
1216 #ifdef GDB_TARGET_POWERPC
1217 tm_print_insn
= gdb_print_insn_powerpc
;
1219 tm_print_insn
= print_insn_rs6000
;