1 /* Target-dependent code for GDB, the GNU debugger.
2 Copyright 1986, 1987, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997
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. */
29 #include "xcoffsolib.h"
31 extern struct obstack frame_cache_obstack
;
35 /* Breakpoint shadows for the single step instructions will be kept here. */
37 static struct sstep_breaks
{
38 /* Address, or 0 if this is not in use. */
40 /* Shadow contents. */
44 /* Hook for determining the TOC address when calling functions in the
45 inferior under AIX. The initialization code in rs6000-nat.c sets
46 this hook to point to find_toc_address. */
48 CORE_ADDR (*find_toc_address_hook
) PARAMS ((CORE_ADDR
)) = NULL
;
50 /* Static function prototypes */
52 static CORE_ADDR branch_dest
PARAMS ((int opcode
, int instr
, CORE_ADDR pc
,
55 static void frame_get_cache_fsr
PARAMS ((struct frame_info
*fi
,
56 struct rs6000_framedata
*fdatap
));
58 static void pop_dummy_frame
PARAMS ((void));
60 /* Calculate the destination of a branch/jump. Return -1 if not a branch. */
63 branch_dest (opcode
, instr
, pc
, safety
)
74 absolute
= (int) ((instr
>> 1) & 1);
78 immediate
= ((instr
& ~3) << 6) >> 6; /* br unconditional */
82 dest
= pc
+ immediate
;
86 immediate
= ((instr
& ~3) << 16) >> 16; /* br conditional */
90 dest
= pc
+ immediate
;
94 ext_op
= (instr
>>1) & 0x3ff;
96 if (ext_op
== 16) /* br conditional register */
98 dest
= read_register (LR_REGNUM
) & ~3;
100 /* If we are about to return from a signal handler, dest is
101 something like 0x3c90. The current frame is a signal handler
102 caller frame, upon completion of the sigreturn system call
103 execution will return to the saved PC in the frame. */
104 if (dest
< TEXT_SEGMENT_BASE
)
106 struct frame_info
*fi
;
108 fi
= get_current_frame ();
110 dest
= read_memory_integer (fi
->frame
+ SIG_FRAME_PC_OFFSET
,
115 else if (ext_op
== 528) /* br cond to count reg */
117 dest
= read_register (CTR_REGNUM
) & ~3;
119 /* If we are about to execute a system call, dest is something
120 like 0x22fc or 0x3b00. Upon completion the system call
121 will return to the address in the link register. */
122 if (dest
< TEXT_SEGMENT_BASE
)
123 dest
= read_register (LR_REGNUM
) & ~3;
130 return (dest
< TEXT_SEGMENT_BASE
) ? safety
: dest
;
134 /* Sequence of bytes for breakpoint instruction. */
136 #define BIG_BREAKPOINT { 0x7d, 0x82, 0x10, 0x08 }
137 #define LITTLE_BREAKPOINT { 0x08, 0x10, 0x82, 0x7d }
140 rs6000_breakpoint_from_pc (bp_addr
, bp_size
)
144 static unsigned char big_breakpoint
[] = BIG_BREAKPOINT
;
145 static unsigned char little_breakpoint
[] = LITTLE_BREAKPOINT
;
147 if (TARGET_BYTE_ORDER
== BIG_ENDIAN
)
148 return big_breakpoint
;
150 return little_breakpoint
;
154 /* AIX does not support PT_STEP. Simulate it. */
157 rs6000_software_single_step (signal
, insert_breakpoints_p
)
158 enum target_signal signal
;
159 int insert_breakpoints_p
;
161 #define INSNLEN(OPCODE) 4
163 static char le_breakp
[] = LITTLE_BREAKPOINT
;
164 static char be_breakp
[] = BIG_BREAKPOINT
;
165 char *breakp
= TARGET_BYTE_ORDER
== BIG_ENDIAN
? be_breakp
: le_breakp
;
171 if (insert_breakpoints_p
) {
175 insn
= read_memory_integer (loc
, 4);
177 breaks
[0] = loc
+ INSNLEN(insn
);
179 breaks
[1] = branch_dest (opcode
, insn
, loc
, breaks
[0]);
181 /* Don't put two breakpoints on the same address. */
182 if (breaks
[1] == breaks
[0])
185 stepBreaks
[1].address
= 0;
187 for (ii
=0; ii
< 2; ++ii
) {
189 /* ignore invalid breakpoint. */
190 if ( breaks
[ii
] == -1)
193 read_memory (breaks
[ii
], stepBreaks
[ii
].data
, 4);
195 write_memory (breaks
[ii
], breakp
, 4);
196 stepBreaks
[ii
].address
= breaks
[ii
];
201 /* remove step breakpoints. */
202 for (ii
=0; ii
< 2; ++ii
)
203 if (stepBreaks
[ii
].address
!= 0)
205 (stepBreaks
[ii
].address
, stepBreaks
[ii
].data
, 4);
208 errno
= 0; /* FIXME, don't ignore errors! */
209 /* What errors? {read,write}_memory call error(). */
213 /* return pc value after skipping a function prologue and also return
214 information about a function frame.
216 in struct rs6000_framedata fdata:
217 - frameless is TRUE, if function does not have a frame.
218 - nosavedpc is TRUE, if function does not save %pc value in its frame.
219 - offset is the initial size of this stack frame --- the amount by
220 which we decrement the sp to allocate the frame.
221 - saved_gpr is the number of the first saved gpr.
222 - saved_fpr is the number of the first saved fpr.
223 - alloca_reg is the number of the register used for alloca() handling.
225 - gpr_offset is the offset of the first saved gpr from the previous frame.
226 - fpr_offset is the offset of the first saved fpr from the previous frame.
227 - lr_offset is the offset of the saved lr
228 - cr_offset is the offset of the saved cr
231 #define SIGNED_SHORT(x) \
232 ((sizeof (short) == 2) \
233 ? ((int)(short)(x)) \
234 : ((int)((((x) & 0xffff) ^ 0x8000) - 0x8000)))
236 #define GET_SRC_REG(x) (((x) >> 21) & 0x1f)
239 skip_prologue (pc
, fdata
)
241 struct rs6000_framedata
*fdata
;
243 CORE_ADDR orig_pc
= pc
;
251 int minimal_toc_loaded
= 0;
252 static struct rs6000_framedata zero_frame
;
255 fdata
->saved_gpr
= -1;
256 fdata
->saved_fpr
= -1;
257 fdata
->alloca_reg
= -1;
258 fdata
->frameless
= 1;
259 fdata
->nosavedpc
= 1;
261 if (target_read_memory (pc
, buf
, 4))
262 return pc
; /* Can't access it -- assume no prologue. */
264 /* Assume that subsequent fetches can fail with low probability. */
269 op
= read_memory_integer (pc
, 4);
271 if ((op
& 0xfc1fffff) == 0x7c0802a6) { /* mflr Rx */
272 lr_reg
= (op
& 0x03e00000) | 0x90010000;
275 } else if ((op
& 0xfc1fffff) == 0x7c000026) { /* mfcr Rx */
276 cr_reg
= (op
& 0x03e00000) | 0x90010000;
279 } else if ((op
& 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */
280 reg
= GET_SRC_REG (op
);
281 if (fdata
->saved_fpr
== -1 || fdata
->saved_fpr
> reg
) {
282 fdata
->saved_fpr
= reg
;
283 fdata
->fpr_offset
= SIGNED_SHORT (op
) + offset
;
287 } else if (((op
& 0xfc1f0000) == 0xbc010000) || /* stm Rx, NUM(r1) */
288 ((op
& 0xfc1f0000) == 0x90010000 && /* st rx,NUM(r1),
290 (op
& 0x03e00000) >= 0x01a00000)) {
292 reg
= GET_SRC_REG (op
);
293 if (fdata
->saved_gpr
== -1 || fdata
->saved_gpr
> reg
) {
294 fdata
->saved_gpr
= reg
;
295 fdata
->gpr_offset
= SIGNED_SHORT (op
) + offset
;
299 } else if ((op
& 0xffff0000) == 0x3c000000) { /* addis 0,0,NUM, used
301 fdata
->offset
= (op
& 0x0000ffff) << 16;
302 fdata
->frameless
= 0;
305 } else if ((op
& 0xffff0000) == 0x60000000) { /* ori 0,0,NUM, 2nd ha
306 lf of >= 32k frames */
307 fdata
->offset
|= (op
& 0x0000ffff);
308 fdata
->frameless
= 0;
311 } else if ((op
& 0xffff0000) == lr_reg
) { /* st Rx,NUM(r1)
313 fdata
->lr_offset
= SIGNED_SHORT (op
) + offset
;
314 fdata
->nosavedpc
= 0;
318 } else if ((op
& 0xffff0000) == cr_reg
) { /* st Rx,NUM(r1)
320 fdata
->cr_offset
= SIGNED_SHORT (op
) + offset
;
324 } else if (op
== 0x48000005) { /* bl .+4 used in
328 } else if (op
== 0x48000004) { /* b .+4 (xlc) */
331 } else if (((op
& 0xffff0000) == 0x801e0000 || /* lwz 0,NUM(r30), used
332 in V.4 -mrelocatable */
333 op
== 0x7fc0f214) && /* add r30,r0,r30, used
334 in V.4 -mrelocatable */
335 lr_reg
== 0x901e0000) {
338 } else if ((op
& 0xffff0000) == 0x3fc00000 || /* addis 30,0,foo@ha, used
339 in V.4 -mminimal-toc */
340 (op
& 0xffff0000) == 0x3bde0000) { /* addi 30,30,foo@l */
343 } else if ((op
& 0xfc000000) == 0x48000000) { /* bl foo,
346 fdata
->frameless
= 0;
347 /* Don't skip over the subroutine call if it is not within the first
348 three instructions of the prologue. */
349 if ((pc
- orig_pc
) > 8)
352 op
= read_memory_integer (pc
+4, 4);
354 /* At this point, make sure this is not a trampoline function
355 (a function that simply calls another functions, and nothing else).
356 If the next is not a nop, this branch was part of the function
359 if (op
== 0x4def7b82 || op
== 0) /* crorc 15, 15, 15 */
360 break; /* don't skip over
364 /* update stack pointer */
365 } else if ((op
& 0xffff0000) == 0x94210000) { /* stu r1,NUM(r1) */
366 fdata
->frameless
= 0;
367 fdata
->offset
= SIGNED_SHORT (op
);
368 offset
= fdata
->offset
;
371 } else if (op
== 0x7c21016e) { /* stwux 1,1,0 */
372 fdata
->frameless
= 0;
373 offset
= fdata
->offset
;
376 /* Load up minimal toc pointer */
377 } else if ((op
>> 22) == 0x20f
378 && ! minimal_toc_loaded
) { /* l r31,... or l r30,... */
379 minimal_toc_loaded
= 1;
382 /* store parameters in stack */
383 } else if ((op
& 0xfc1f0000) == 0x90010000 || /* st rx,NUM(r1) */
384 (op
& 0xfc1f0000) == 0xd8010000 || /* stfd Rx,NUM(r1) */
385 (op
& 0xfc1f0000) == 0xfc010000) { /* frsp, fp?,NUM(r1) */
388 /* store parameters in stack via frame pointer */
390 ((op
& 0xfc1f0000) == 0x901f0000 || /* st rx,NUM(r1) */
391 (op
& 0xfc1f0000) == 0xd81f0000 || /* stfd Rx,NUM(r1) */
392 (op
& 0xfc1f0000) == 0xfc1f0000)) { /* frsp, fp?,NUM(r1) */
395 /* Set up frame pointer */
396 } else if (op
== 0x603f0000 /* oril r31, r1, 0x0 */
397 || op
== 0x7c3f0b78) { /* mr r31, r1 */
398 fdata
->frameless
= 0;
400 fdata
->alloca_reg
= 31;
403 /* Another way to set up the frame pointer. */
404 } else if ((op
& 0xfc1fffff) == 0x38010000) { /* addi rX, r1, 0x0 */
405 fdata
->frameless
= 0;
407 fdata
->alloca_reg
= (op
& ~0x38010000) >> 21;
416 /* I have problems with skipping over __main() that I need to address
417 * sometime. Previously, I used to use misc_function_vector which
418 * didn't work as well as I wanted to be. -MGO */
420 /* If the first thing after skipping a prolog is a branch to a function,
421 this might be a call to an initializer in main(), introduced by gcc2.
422 We'd like to skip over it as well. Fortunately, xlc does some extra
423 work before calling a function right after a prologue, thus we can
424 single out such gcc2 behaviour. */
427 if ((op
& 0xfc000001) == 0x48000001) { /* bl foo, an initializer function? */
428 op
= read_memory_integer (pc
+4, 4);
430 if (op
== 0x4def7b82) { /* cror 0xf, 0xf, 0xf (nop) */
432 /* check and see if we are in main. If so, skip over this initializer
435 tmp
= find_pc_misc_function (pc
);
436 if (tmp
>= 0 && STREQ (misc_function_vector
[tmp
].name
, "main"))
442 fdata
->offset
= - fdata
->offset
;
447 /*************************************************************************
448 Support for creating pushind a dummy frame into the stack, and popping
450 *************************************************************************/
452 /* The total size of dummy frame is 436, which is;
457 and 24 extra bytes for the callee's link area. The last 24 bytes
458 for the link area might not be necessary, since it will be taken
459 care of by push_arguments(). */
461 #define DUMMY_FRAME_SIZE 436
463 #define DUMMY_FRAME_ADDR_SIZE 10
465 /* Make sure you initialize these in somewhere, in case gdb gives up what it
466 was debugging and starts debugging something else. FIXMEibm */
468 static int dummy_frame_count
= 0;
469 static int dummy_frame_size
= 0;
470 static CORE_ADDR
*dummy_frame_addr
= 0;
472 extern int stop_stack_dummy
;
474 /* push a dummy frame into stack, save all register. Currently we are saving
475 only gpr's and fpr's, which is not good enough! FIXMEmgo */
482 /* Same thing, target byte order. */
487 /* Same thing, target byte order. */
490 /* Needed to figure out where to save the dummy link area.
491 FIXME: There should be an easier way to do this, no? tiemann 9/9/95. */
492 struct rs6000_framedata fdata
;
496 target_fetch_registers (-1);
498 if (dummy_frame_count
>= dummy_frame_size
) {
499 dummy_frame_size
+= DUMMY_FRAME_ADDR_SIZE
;
500 if (dummy_frame_addr
)
501 dummy_frame_addr
= (CORE_ADDR
*) xrealloc
502 (dummy_frame_addr
, sizeof(CORE_ADDR
) * (dummy_frame_size
));
504 dummy_frame_addr
= (CORE_ADDR
*)
505 xmalloc (sizeof(CORE_ADDR
) * (dummy_frame_size
));
508 sp
= read_register(SP_REGNUM
);
509 pc
= read_register(PC_REGNUM
);
510 store_address (pc_targ
, 4, pc
);
512 skip_prologue (get_pc_function_start (pc
) + FUNCTION_START_OFFSET
, &fdata
);
514 dummy_frame_addr
[dummy_frame_count
++] = sp
;
516 /* Be careful! If the stack pointer is not decremented first, then kernel
517 thinks he is free to use the space underneath it. And kernel actually
518 uses that area for IPC purposes when executing ptrace(2) calls. So
519 before writing register values into the new frame, decrement and update
520 %sp first in order to secure your frame. */
522 /* FIXME: We don't check if the stack really has this much space.
523 This is a problem on the ppc simulator (which only grants one page
524 (4096 bytes) by default. */
526 write_register (SP_REGNUM
, sp
-DUMMY_FRAME_SIZE
);
528 /* gdb relies on the state of current_frame. We'd better update it,
529 otherwise things like do_registers_info() wouldn't work properly! */
531 flush_cached_frames ();
533 /* save program counter in link register's space. */
534 write_memory (sp
+ (fdata
.lr_offset
? fdata
.lr_offset
: DEFAULT_LR_SAVE
),
537 /* save all floating point and general purpose registers here. */
540 for (ii
= 0; ii
< 32; ++ii
)
541 write_memory (sp
-8-(ii
*8), ®isters
[REGISTER_BYTE (31-ii
+FP0_REGNUM
)], 8);
544 for (ii
=1; ii
<=32; ++ii
)
545 write_memory (sp
-256-(ii
*4), ®isters
[REGISTER_BYTE (32-ii
)], 4);
547 /* so far, 32*2 + 32 words = 384 bytes have been written.
548 7 extra registers in our register set: pc, ps, cnd, lr, cnt, xer, mq */
550 for (ii
=1; ii
<= (LAST_SP_REGNUM
-FIRST_SP_REGNUM
+1); ++ii
) {
551 write_memory (sp
-384-(ii
*4),
552 ®isters
[REGISTER_BYTE (FPLAST_REGNUM
+ ii
)], 4);
555 /* Save sp or so called back chain right here. */
556 store_address (sp_targ
, 4, sp
);
557 write_memory (sp
-DUMMY_FRAME_SIZE
, sp_targ
, 4);
558 sp
-= DUMMY_FRAME_SIZE
;
560 /* And finally, this is the back chain. */
561 write_memory (sp
+8, pc_targ
, 4);
565 /* Pop a dummy frame.
567 In rs6000 when we push a dummy frame, we save all of the registers. This
568 is usually done before user calls a function explicitly.
570 After a dummy frame is pushed, some instructions are copied into stack,
571 and stack pointer is decremented even more. Since we don't have a frame
572 pointer to get back to the parent frame of the dummy, we start having
573 trouble poping it. Therefore, we keep a dummy frame stack, keeping
574 addresses of dummy frames as such. When poping happens and when we
575 detect that was a dummy frame, we pop it back to its parent by using
576 dummy frame stack (`dummy_frame_addr' array).
578 FIXME: This whole concept is broken. You should be able to detect
579 a dummy stack frame *on the user's stack itself*. When you do,
580 then you know the format of that stack frame -- including its
581 saved SP register! There should *not* be a separate stack in the
582 GDB process that keeps track of these dummy frames! -- gnu@cygnus.com Aug92
590 sp
= dummy_frame_addr
[--dummy_frame_count
];
592 /* restore all fpr's. */
593 for (ii
= 1; ii
<= 32; ++ii
)
594 read_memory (sp
-(ii
*8), ®isters
[REGISTER_BYTE (32-ii
+FP0_REGNUM
)], 8);
596 /* restore all gpr's */
597 for (ii
=1; ii
<= 32; ++ii
) {
598 read_memory (sp
-256-(ii
*4), ®isters
[REGISTER_BYTE (32-ii
)], 4);
601 /* restore the rest of the registers. */
602 for (ii
=1; ii
<=(LAST_SP_REGNUM
-FIRST_SP_REGNUM
+1); ++ii
)
603 read_memory (sp
-384-(ii
*4),
604 ®isters
[REGISTER_BYTE (FPLAST_REGNUM
+ ii
)], 4);
606 read_memory (sp
-(DUMMY_FRAME_SIZE
-8),
607 ®isters
[REGISTER_BYTE(PC_REGNUM
)], 4);
609 /* when a dummy frame was being pushed, we had to decrement %sp first, in
610 order to secure astack space. Thus, saved %sp (or %r1) value, is not the
611 one we should restore. Change it with the one we need. */
613 memcpy (®isters
[REGISTER_BYTE(FP_REGNUM
)], (char *) &sp
, sizeof (int));
615 /* Now we can restore all registers. */
617 target_store_registers (-1);
619 flush_cached_frames ();
623 /* pop the innermost frame, go back to the caller. */
628 CORE_ADDR pc
, lr
, sp
, prev_sp
; /* %pc, %lr, %sp */
629 struct rs6000_framedata fdata
;
630 struct frame_info
*frame
= get_current_frame ();
634 sp
= FRAME_FP (frame
);
636 if (stop_stack_dummy
)
638 #ifdef USE_GENERIC_DUMMY_FRAMES
639 generic_pop_dummy_frame ();
640 flush_cached_frames ();
643 if (dummy_frame_count
)
649 /* Make sure that all registers are valid. */
650 read_register_bytes (0, NULL
, REGISTER_BYTES
);
652 /* figure out previous %pc value. If the function is frameless, it is
653 still in the link register, otherwise walk the frames and retrieve the
654 saved %pc value in the previous frame. */
656 addr
= get_pc_function_start (frame
->pc
) + FUNCTION_START_OFFSET
;
657 (void) skip_prologue (addr
, &fdata
);
662 prev_sp
= read_memory_integer (sp
, 4);
663 if (fdata
.lr_offset
== 0)
664 lr
= read_register (LR_REGNUM
);
666 lr
= read_memory_integer (prev_sp
+ fdata
.lr_offset
, 4);
668 /* reset %pc value. */
669 write_register (PC_REGNUM
, lr
);
671 /* reset register values if any was saved earlier. */
673 if (fdata
.saved_gpr
!= -1)
675 addr
= prev_sp
+ fdata
.gpr_offset
;
676 for (ii
= fdata
.saved_gpr
; ii
<= 31; ++ii
) {
677 read_memory (addr
, ®isters
[REGISTER_BYTE (ii
)], 4);
682 if (fdata
.saved_fpr
!= -1)
684 addr
= prev_sp
+ fdata
.fpr_offset
;
685 for (ii
= fdata
.saved_fpr
; ii
<= 31; ++ii
) {
686 read_memory (addr
, ®isters
[REGISTER_BYTE (ii
+FP0_REGNUM
)], 8);
691 write_register (SP_REGNUM
, prev_sp
);
692 target_store_registers (-1);
693 flush_cached_frames ();
696 /* fixup the call sequence of a dummy function, with the real function address.
697 its argumets will be passed by gdb. */
700 rs6000_fix_call_dummy (dummyname
, pc
, fun
, nargs
, args
, type
, gcc_p
)
709 #define TOC_ADDR_OFFSET 20
710 #define TARGET_ADDR_OFFSET 28
713 CORE_ADDR target_addr
;
715 if (find_toc_address_hook
!= NULL
)
719 tocvalue
= (*find_toc_address_hook
) (fun
);
720 ii
= *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
);
721 ii
= (ii
& 0xffff0000) | (tocvalue
>> 16);
722 *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
) = ii
;
724 ii
= *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
+4);
725 ii
= (ii
& 0xffff0000) | (tocvalue
& 0x0000ffff);
726 *(int*)((char*)dummyname
+ TOC_ADDR_OFFSET
+4) = ii
;
730 ii
= *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
);
731 ii
= (ii
& 0xffff0000) | (target_addr
>> 16);
732 *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
) = ii
;
734 ii
= *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
+4);
735 ii
= (ii
& 0xffff0000) | (target_addr
& 0x0000ffff);
736 *(int*)((char*)dummyname
+ TARGET_ADDR_OFFSET
+4) = ii
;
739 /* Pass the arguments in either registers, or in the stack. In RS6000,
740 the first eight words of the argument list (that might be less than
741 eight parameters if some parameters occupy more than one word) are
742 passed in r3..r11 registers. float and double parameters are
743 passed in fpr's, in addition to that. Rest of the parameters if any
744 are passed in user stack. There might be cases in which half of the
745 parameter is copied into registers, the other half is pushed into
748 If the function is returning a structure, then the return address is passed
749 in r3, then the first 7 words of the parameters can be passed in registers,
753 push_arguments (nargs
, args
, sp
, struct_return
, struct_addr
)
758 CORE_ADDR struct_addr
;
762 int argno
; /* current argument number */
763 int argbytes
; /* current argument byte */
764 char tmp_buffer
[50];
765 int f_argno
= 0; /* current floating point argno */
772 #ifndef USE_GENERIC_DUMMY_FRAMES
773 if ( dummy_frame_count
<= 0)
774 printf_unfiltered ("FATAL ERROR -push_arguments()! frame not found!!\n");
775 #endif /* GENERIC_DUMMY_FRAMES */
777 /* The first eight words of ther arguments are passed in registers. Copy
780 If the function is returning a `struct', then the first word (which
781 will be passed in r3) is used for struct return address. In that
782 case we should advance one word and start from r4 register to copy
785 ii
= struct_return
? 1 : 0;
788 effectively indirect call... gcc does...
790 return_val example( float, int);
793 float in fp0, int in r3
794 offset of stack on overflow 8/16
795 for varargs, must go by type.
797 float in r3&r4, int in r5
798 offset of stack on overflow different
800 return in r3 or f0. If no float, must study how gcc emulates floats;
801 pay attention to arg promotion.
802 User may have to cast\args to handle promotion correctly
803 since gdb won't know if prototype supplied or not.
806 for (argno
=0, argbytes
=0; argno
< nargs
&& ii
<8; ++ii
) {
809 type
= check_typedef (VALUE_TYPE (arg
));
810 len
= TYPE_LENGTH (type
);
812 if (TYPE_CODE (type
) == TYPE_CODE_FLT
) {
814 /* floating point arguments are passed in fpr's, as well as gpr's.
815 There are 13 fpr's reserved for passing parameters. At this point
816 there is no way we would run out of them. */
820 "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno
);
822 memcpy (®isters
[REGISTER_BYTE(FP0_REGNUM
+ 1 + f_argno
)],
823 VALUE_CONTENTS (arg
),
830 /* Argument takes more than one register. */
831 while (argbytes
< len
) {
832 memset (®isters
[REGISTER_BYTE(ii
+3)], 0, sizeof(int));
833 memcpy (®isters
[REGISTER_BYTE(ii
+3)],
834 ((char*)VALUE_CONTENTS (arg
))+argbytes
,
835 (len
- argbytes
) > 4 ? 4 : len
- argbytes
);
839 goto ran_out_of_registers_for_arguments
;
844 else { /* Argument can fit in one register. No problem. */
845 memset (®isters
[REGISTER_BYTE(ii
+3)], 0, sizeof(int));
846 memcpy (®isters
[REGISTER_BYTE(ii
+3)], VALUE_CONTENTS (arg
), len
);
851 ran_out_of_registers_for_arguments
:
853 #ifdef USE_GENERIC_DUMMY_FRAMES
854 saved_sp
= read_sp ();
856 /* location for 8 parameters are always reserved. */
859 /* another six words for back chain, TOC register, link register, etc. */
861 #endif /* GENERIC_DUMMY_FRAMES */
862 /* if there are more arguments, allocate space for them in
863 the stack, then push them starting from the ninth one. */
865 if ((argno
< nargs
) || argbytes
) {
869 space
+= ((len
- argbytes
+ 3) & -4);
875 for (; jj
< nargs
; ++jj
) {
876 value_ptr val
= args
[jj
];
877 space
+= ((TYPE_LENGTH (VALUE_TYPE (val
))) + 3) & -4;
880 /* add location required for the rest of the parameters */
881 space
= (space
+ 7) & -8;
884 /* This is another instance we need to be concerned about securing our
885 stack space. If we write anything underneath %sp (r1), we might conflict
886 with the kernel who thinks he is free to use this area. So, update %sp
887 first before doing anything else. */
889 write_register (SP_REGNUM
, sp
);
891 /* if the last argument copied into the registers didn't fit there
892 completely, push the rest of it into stack. */
895 write_memory (sp
+24+(ii
*4),
896 ((char*)VALUE_CONTENTS (arg
))+argbytes
,
899 ii
+= ((len
- argbytes
+ 3) & -4) / 4;
902 /* push the rest of the arguments into stack. */
903 for (; argno
< nargs
; ++argno
) {
906 type
= check_typedef (VALUE_TYPE (arg
));
907 len
= TYPE_LENGTH (type
);
910 /* float types should be passed in fpr's, as well as in the stack. */
911 if (TYPE_CODE (type
) == TYPE_CODE_FLT
&& f_argno
< 13) {
915 "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno
);
917 memcpy (®isters
[REGISTER_BYTE(FP0_REGNUM
+ 1 + f_argno
)],
918 VALUE_CONTENTS (arg
),
923 write_memory (sp
+24+(ii
*4), (char *) VALUE_CONTENTS (arg
), len
);
924 ii
+= ((len
+ 3) & -4) / 4;
928 /* Secure stack areas first, before doing anything else. */
929 write_register (SP_REGNUM
, sp
);
931 #ifndef USE_GENERIC_DUMMY_FRAMES
932 /* we want to copy 24 bytes of target's frame to dummy's frame,
933 then set back chain to point to new frame. */
935 saved_sp
= dummy_frame_addr
[dummy_frame_count
- 1];
936 read_memory (saved_sp
, tmp_buffer
, 24);
937 write_memory (sp
, tmp_buffer
, 24);
938 #endif /* GENERIC_DUMMY_FRAMES */
940 /* set back chain properly */
941 store_address (tmp_buffer
, 4, saved_sp
);
942 write_memory (sp
, tmp_buffer
, 4);
944 target_store_registers (-1);
947 #ifdef ELF_OBJECT_FORMAT
949 /* Function: ppc_push_return_address (pc, sp)
950 Set up the return address for the inferior function call. */
953 ppc_push_return_address (pc
, sp
)
957 write_register (LR_REGNUM
, CALL_DUMMY_ADDRESS ());
963 /* a given return value in `regbuf' with a type `valtype', extract and copy its
964 value into `valbuf' */
967 extract_return_value (valtype
, regbuf
, valbuf
)
968 struct type
*valtype
;
969 char regbuf
[REGISTER_BYTES
];
974 if (TYPE_CODE (valtype
) == TYPE_CODE_FLT
) {
977 /* floats and doubles are returned in fpr1. fpr's have a size of 8 bytes.
978 We need to truncate the return value into float size (4 byte) if
981 if (TYPE_LENGTH (valtype
) > 4) /* this is a double */
983 ®buf
[REGISTER_BYTE (FP0_REGNUM
+ 1)],
984 TYPE_LENGTH (valtype
));
986 memcpy (&dd
, ®buf
[REGISTER_BYTE (FP0_REGNUM
+ 1)], 8);
988 memcpy (valbuf
, &ff
, sizeof(float));
992 /* return value is copied starting from r3. */
993 if (TARGET_BYTE_ORDER
== BIG_ENDIAN
994 && TYPE_LENGTH (valtype
) < REGISTER_RAW_SIZE (3))
995 offset
= REGISTER_RAW_SIZE (3) - TYPE_LENGTH (valtype
);
998 regbuf
+ REGISTER_BYTE (3) + offset
,
999 TYPE_LENGTH (valtype
));
1004 /* keep structure return address in this variable.
1005 FIXME: This is a horrid kludge which should not be allowed to continue
1006 living. This only allows a single nested call to a structure-returning
1007 function. Come on, guys! -- gnu@cygnus.com, Aug 92 */
1009 CORE_ADDR rs6000_struct_return_address
;
1012 /* Indirect function calls use a piece of trampoline code to do context
1013 switching, i.e. to set the new TOC table. Skip such code if we are on
1014 its first instruction (as when we have single-stepped to here).
1015 Also skip shared library trampoline code (which is different from
1016 indirect function call trampolines).
1017 Result is desired PC to step until, or NULL if we are not in
1021 skip_trampoline_code (pc
)
1024 register unsigned int ii
, op
;
1025 CORE_ADDR solib_target_pc
;
1027 static unsigned trampoline_code
[] = {
1028 0x800b0000, /* l r0,0x0(r11) */
1029 0x90410014, /* st r2,0x14(r1) */
1030 0x7c0903a6, /* mtctr r0 */
1031 0x804b0004, /* l r2,0x4(r11) */
1032 0x816b0008, /* l r11,0x8(r11) */
1033 0x4e800420, /* bctr */
1034 0x4e800020, /* br */
1038 /* If pc is in a shared library trampoline, return its target. */
1039 solib_target_pc
= find_solib_trampoline_target (pc
);
1040 if (solib_target_pc
)
1041 return solib_target_pc
;
1043 for (ii
=0; trampoline_code
[ii
]; ++ii
) {
1044 op
= read_memory_integer (pc
+ (ii
*4), 4);
1045 if (op
!= trampoline_code
[ii
])
1048 ii
= read_register (11); /* r11 holds destination addr */
1049 pc
= read_memory_integer (ii
, 4); /* (r11) value */
1053 /* Determines whether the function FI has a frame on the stack or not. */
1056 frameless_function_invocation (fi
)
1057 struct frame_info
*fi
;
1059 CORE_ADDR func_start
;
1060 struct rs6000_framedata fdata
;
1062 /* Don't even think about framelessness except on the innermost frame
1063 or if the function was interrupted by a signal. */
1064 if (fi
->next
!= NULL
&& !fi
->next
->signal_handler_caller
)
1067 func_start
= get_pc_function_start (fi
->pc
);
1069 /* If we failed to find the start of the function, it is a mistake
1070 to inspect the instructions. */
1074 /* A frame with a zero PC is usually created by dereferencing a NULL
1075 function pointer, normally causing an immediate core dump of the
1076 inferior. Mark function as frameless, as the inferior has no chance
1077 of setting up a stack frame. */
1084 func_start
+= FUNCTION_START_OFFSET
;
1085 (void) skip_prologue (func_start
, &fdata
);
1086 return fdata
.frameless
;
1089 /* Return the PC saved in a frame */
1093 struct frame_info
*fi
;
1095 CORE_ADDR func_start
;
1096 struct rs6000_framedata fdata
;
1098 if (fi
->signal_handler_caller
)
1099 return read_memory_integer (fi
->frame
+ SIG_FRAME_PC_OFFSET
, 4);
1101 #ifdef USE_GENERIC_DUMMY_FRAMES
1102 if (PC_IN_CALL_DUMMY (fi
->pc
, fi
->frame
, fi
->frame
))
1103 return generic_read_register_dummy(fi
->pc
, fi
->frame
, PC_REGNUM
);
1104 #endif /* GENERIC_DUMMY_FRAMES */
1106 func_start
= get_pc_function_start (fi
->pc
) + FUNCTION_START_OFFSET
;
1108 /* If we failed to find the start of the function, it is a mistake
1109 to inspect the instructions. */
1113 (void) skip_prologue (func_start
, &fdata
);
1115 if (fdata
.lr_offset
== 0 && fi
->next
!= NULL
)
1117 if (fi
->next
->signal_handler_caller
)
1118 return read_memory_integer (fi
->next
->frame
+ SIG_FRAME_LR_OFFSET
, 4);
1120 return read_memory_integer (rs6000_frame_chain (fi
) + DEFAULT_LR_SAVE
,
1124 if (fdata
.lr_offset
== 0)
1125 return read_register (LR_REGNUM
);
1127 return read_memory_integer (rs6000_frame_chain (fi
) + fdata
.lr_offset
, 4);
1130 /* If saved registers of frame FI are not known yet, read and cache them.
1131 &FDATAP contains rs6000_framedata; TDATAP can be NULL,
1132 in which case the framedata are read. */
1135 frame_get_cache_fsr (fi
, fdatap
)
1136 struct frame_info
*fi
;
1137 struct rs6000_framedata
*fdatap
;
1140 CORE_ADDR frame_addr
;
1141 struct rs6000_framedata work_fdata
;
1146 if (fdatap
== NULL
) {
1147 fdatap
= &work_fdata
;
1148 (void) skip_prologue (get_pc_function_start (fi
->pc
), fdatap
);
1151 fi
->cache_fsr
= (struct frame_saved_regs
*)
1152 obstack_alloc (&frame_cache_obstack
, sizeof (struct frame_saved_regs
));
1153 memset (fi
->cache_fsr
, '\0', sizeof (struct frame_saved_regs
));
1155 if (fi
->prev
&& fi
->prev
->frame
)
1156 frame_addr
= fi
->prev
->frame
;
1158 frame_addr
= read_memory_integer (fi
->frame
, 4);
1160 /* if != -1, fdatap->saved_fpr is the smallest number of saved_fpr.
1161 All fpr's from saved_fpr to fp31 are saved. */
1163 if (fdatap
->saved_fpr
>= 0) {
1164 int fpr_offset
= frame_addr
+ fdatap
->fpr_offset
;
1165 for (ii
= fdatap
->saved_fpr
; ii
< 32; ii
++) {
1166 fi
->cache_fsr
->regs
[FP0_REGNUM
+ ii
] = fpr_offset
;
1171 /* if != -1, fdatap->saved_gpr is the smallest number of saved_gpr.
1172 All gpr's from saved_gpr to gpr31 are saved. */
1174 if (fdatap
->saved_gpr
>= 0) {
1175 int gpr_offset
= frame_addr
+ fdatap
->gpr_offset
;
1176 for (ii
= fdatap
->saved_gpr
; ii
< 32; ii
++) {
1177 fi
->cache_fsr
->regs
[ii
] = gpr_offset
;
1182 /* If != 0, fdatap->cr_offset is the offset from the frame that holds
1184 if (fdatap
->cr_offset
!= 0)
1185 fi
->cache_fsr
->regs
[CR_REGNUM
] = frame_addr
+ fdatap
->cr_offset
;
1187 /* If != 0, fdatap->lr_offset is the offset from the frame that holds
1189 if (fdatap
->lr_offset
!= 0)
1190 fi
->cache_fsr
->regs
[LR_REGNUM
] = frame_addr
+ fdatap
->lr_offset
;
1193 /* Return the address of a frame. This is the inital %sp value when the frame
1194 was first allocated. For functions calling alloca(), it might be saved in
1195 an alloca register. */
1198 frame_initial_stack_address (fi
)
1199 struct frame_info
*fi
;
1202 struct rs6000_framedata fdata
;
1203 struct frame_info
*callee_fi
;
1205 /* if the initial stack pointer (frame address) of this frame is known,
1209 return fi
->initial_sp
;
1211 /* find out if this function is using an alloca register.. */
1213 (void) skip_prologue (get_pc_function_start (fi
->pc
), &fdata
);
1215 /* if saved registers of this frame are not known yet, read and cache them. */
1218 frame_get_cache_fsr (fi
, &fdata
);
1220 /* If no alloca register used, then fi->frame is the value of the %sp for
1221 this frame, and it is good enough. */
1223 if (fdata
.alloca_reg
< 0) {
1224 fi
->initial_sp
= fi
->frame
;
1225 return fi
->initial_sp
;
1228 /* This function has an alloca register. If this is the top-most frame
1229 (with the lowest address), the value in alloca register is good. */
1232 return fi
->initial_sp
= read_register (fdata
.alloca_reg
);
1234 /* Otherwise, this is a caller frame. Callee has usually already saved
1235 registers, but there are exceptions (such as when the callee
1236 has no parameters). Find the address in which caller's alloca
1237 register is saved. */
1239 for (callee_fi
= fi
->next
; callee_fi
; callee_fi
= callee_fi
->next
) {
1241 if (!callee_fi
->cache_fsr
)
1242 frame_get_cache_fsr (callee_fi
, NULL
);
1244 /* this is the address in which alloca register is saved. */
1246 tmpaddr
= callee_fi
->cache_fsr
->regs
[fdata
.alloca_reg
];
1248 fi
->initial_sp
= read_memory_integer (tmpaddr
, 4);
1249 return fi
->initial_sp
;
1252 /* Go look into deeper levels of the frame chain to see if any one of
1253 the callees has saved alloca register. */
1256 /* If alloca register was not saved, by the callee (or any of its callees)
1257 then the value in the register is still good. */
1259 return fi
->initial_sp
= read_register (fdata
.alloca_reg
);
1263 rs6000_frame_chain (thisframe
)
1264 struct frame_info
*thisframe
;
1268 #ifdef USE_GENERIC_DUMMY_FRAMES
1269 if (PC_IN_CALL_DUMMY (thisframe
->pc
, thisframe
->frame
, thisframe
->frame
))
1270 return thisframe
->frame
; /* dummy frame same as caller's frame */
1271 #endif /* GENERIC_DUMMY_FRAMES */
1273 if (inside_entry_file (thisframe
->pc
) ||
1274 thisframe
->pc
== entry_point_address ())
1277 if (thisframe
->signal_handler_caller
)
1278 fp
= read_memory_integer (thisframe
->frame
+ SIG_FRAME_FP_OFFSET
, 4);
1279 else if (thisframe
->next
!= NULL
1280 && thisframe
->next
->signal_handler_caller
1281 && frameless_function_invocation (thisframe
))
1282 /* A frameless function interrupted by a signal did not change the
1284 fp
= FRAME_FP (thisframe
);
1286 fp
= read_memory_integer ((thisframe
)->frame
, 4);
1288 #ifdef USE_GENERIC_DUMMY_FRAMES
1292 lr
= read_register (LR_REGNUM
);
1293 if (lr
== entry_point_address ())
1294 if (fp
!= 0 && (fpp
= read_memory_integer (fp
, 4)) != 0)
1295 if (PC_IN_CALL_DUMMY (lr
, fpp
, fpp
))
1298 #endif /* GENERIC_DUMMY_FRAMES */
1302 /* Return nonzero if ADDR (a function pointer) is in the data space and
1303 is therefore a special function pointer. */
1306 is_magic_function_pointer (addr
)
1309 struct obj_section
*s
;
1311 s
= find_pc_section (addr
);
1312 if (s
&& s
->the_bfd_section
->flags
& SEC_CODE
)
1318 #ifdef GDB_TARGET_POWERPC
1320 gdb_print_insn_powerpc (memaddr
, info
)
1322 disassemble_info
*info
;
1324 if (TARGET_BYTE_ORDER
== BIG_ENDIAN
)
1325 return print_insn_big_powerpc (memaddr
, info
);
1327 return print_insn_little_powerpc (memaddr
, info
);
1331 /* Function: get_saved_register
1332 Just call the generic_get_saved_register function. */
1334 #ifdef USE_GENERIC_DUMMY_FRAMES
1336 get_saved_register (raw_buffer
, optimized
, addrp
, frame
, regnum
, lval
)
1340 struct frame_info
*frame
;
1342 enum lval_type
*lval
;
1344 generic_get_saved_register (raw_buffer
, optimized
, addrp
,
1345 frame
, regnum
, lval
);
1351 _initialize_rs6000_tdep ()
1353 /* FIXME, this should not be decided via ifdef. */
1354 #ifdef GDB_TARGET_POWERPC
1355 tm_print_insn
= gdb_print_insn_powerpc
;
1357 tm_print_insn
= print_insn_rs6000
;