1 /* Parameters for target execution on an RS6000, for GDB, the GNU debugger.
2 Copyright 1986, 1987, 1989, 1991, 1992, 1993, 1994, 1997
3 Free Software Foundation, Inc.
4 Contributed by IBM Corporation.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
23 /* Forward decls for prototypes */
28 /* Minimum possible text address in AIX */
30 #define TEXT_SEGMENT_BASE 0x10000000
32 /* Load segment of a given pc value. */
34 #define PC_LOAD_SEGMENT(PC) pc_load_segment_name(PC)
35 extern char *pc_load_segment_name (CORE_ADDR
);
37 /* AIX cc seems to get this right. */
39 #define BELIEVE_PCC_PROMOTION 1
41 /* return true if a given `pc' value is in `call dummy' function. */
42 /* FIXME: This just checks for the end of the stack, which is broken
43 for things like stepping through gcc nested function stubs. */
44 #define PC_IN_CALL_DUMMY(STOP_PC, STOP_SP, STOP_FRAME_ADDR) \
45 (STOP_SP < STOP_PC && STOP_PC < STACK_END_ADDR)
48 extern unsigned int text_start
, data_start
;
49 extern char *corefile
;
51 extern int inferior_pid
;
53 /* We are missing register descriptions in the system header files. Sigh! */
57 int gregs
[32]; /* general purpose registers */
58 int pc
; /* program conter */
59 int ps
; /* processor status, or machine state */
64 double fpregs
[32]; /* floating GP registers */
68 /* To be used by skip_prologue. */
70 struct rs6000_framedata
72 int offset
; /* total size of frame --- the distance
73 by which we decrement sp to allocate
75 int saved_gpr
; /* smallest # of saved gpr */
76 int saved_fpr
; /* smallest # of saved fpr */
77 int alloca_reg
; /* alloca register number (frame ptr) */
78 char frameless
; /* true if frameless functions. */
79 char nosavedpc
; /* true if pc not saved. */
80 int gpr_offset
; /* offset of saved gprs from prev sp */
81 int fpr_offset
; /* offset of saved fprs from prev sp */
82 int lr_offset
; /* offset of saved lr */
83 int cr_offset
; /* offset of saved cr */
86 /* Define the byte order of the machine. */
88 #define TARGET_BYTE_ORDER_DEFAULT BIG_ENDIAN
90 /* AIX's assembler doesn't grok dollar signs in identifiers.
91 So we use dots instead. This item must be coordinated with G++. */
93 #define CPLUS_MARKER '.'
95 /* Offset from address of function to start of its code.
96 Zero on most machines. */
98 #define FUNCTION_START_OFFSET 0
100 /* Advance PC across any function entry prologue instructions
101 to reach some "real" code. */
103 extern CORE_ADDR
rs6000_skip_prologue (CORE_ADDR
);
104 #define SKIP_PROLOGUE(pc) (rs6000_skip_prologue (pc))
106 extern CORE_ADDR
skip_prologue (CORE_ADDR
, struct rs6000_framedata
*);
109 /* If PC is in some function-call trampoline code, return the PC
110 where the function itself actually starts. If not, return NULL. */
112 #define SKIP_TRAMPOLINE_CODE(pc) skip_trampoline_code (pc)
113 extern CORE_ADDR
skip_trampoline_code (CORE_ADDR
);
115 /* Number of trap signals we need to skip over, once the inferior process
118 #define START_INFERIOR_TRAPS_EXPECTED 2
120 /* AIX has a couple of strange returns from wait(). */
122 #define CHILD_SPECIAL_WAITSTATUS(ourstatus, hoststatus) ( \
123 /* "stop after load" status. */ \
124 (hoststatus) == 0x57c ? (ourstatus)->kind = TARGET_WAITKIND_LOADED, 1 : \
126 /* signal 0. I have no idea why wait(2) returns with this status word. */ \
127 /* It looks harmless. */ \
128 (hoststatus) == 0x7f ? (ourstatus)->kind = TARGET_WAITKIND_SPURIOUS, 1 : \
130 /* A normal waitstatus. Let the usual macros deal with it. */ \
133 /* In xcoff, we cannot process line numbers when we see them. This is
134 mainly because we don't know the boundaries of the include files. So,
135 we postpone that, and then enter and sort(?) the whole line table at
136 once, when we are closing the current symbol table in end_symtab(). */
138 #define PROCESS_LINENUMBER_HOOK() aix_process_linenos ()
139 extern void aix_process_linenos (void);
141 /* Immediately after a function call, return the saved pc.
142 Can't go through the frames for this because on some machines
143 the new frame is not set up until the new function executes
144 some instructions. */
146 #define SAVED_PC_AFTER_CALL(frame) read_register (LR_REGNUM)
148 /* Address of end of stack space. */
150 #define STACK_END_ADDR 0x2ff80000
152 /* Stack grows downward. */
154 #define INNER_THAN(lhs,rhs) ((lhs) < (rhs))
156 /* This is how arguments pushed onto stack or passed in registers.
157 Stack must be aligned on 64-bit boundaries when synthesizing
158 function calls. We don't need STACK_ALIGN, PUSH_ARGUMENTS will
161 #define PUSH_ARGUMENTS(nargs, args, sp, struct_return, struct_addr) \
162 (rs6000_push_arguments((nargs), (args), (sp), (struct_return), (struct_addr)))
163 extern CORE_ADDR
rs6000_push_arguments (int, struct value
**, CORE_ADDR
, int,
166 /* BREAKPOINT_FROM_PC uses the program counter value to determine the
167 breakpoint that should be used */
168 extern breakpoint_from_pc_fn rs6000_breakpoint_from_pc
;
169 #define BREAKPOINT_FROM_PC(pcptr, lenptr) rs6000_breakpoint_from_pc (pcptr, lenptr)
171 /* Amount PC must be decremented by after a breakpoint.
172 This is often the number of bytes in BREAKPOINT
175 #define DECR_PC_AFTER_BREAK 0
177 /* Say how long (ordinary) registers are. This is a piece of bogosity
178 used in push_word and a few other places; REGISTER_RAW_SIZE is the
179 real way to know how big a register is. */
180 #define REGISTER_SIZE 4
183 /* Return the name of register number REG. This may return "" to
184 indicate a register number that's not used on this variant.
185 (Register numbers may be sparse for consistency between variants.) */
186 #define REGISTER_NAME(reg) (rs6000_register_name(reg))
187 extern char *rs6000_register_name (int reg
);
189 /* Number of machine registers */
192 /* Register numbers of various important registers.
193 Note that some of these values are "real" register numbers,
194 and correspond to the general registers of the machine,
195 and some are "phony" register numbers which are too large
196 to be actual register numbers as far as the user is concerned
197 but do serve to get the desired values when passed to read_register. */
199 #define FP_REGNUM 1 /* Contains address of executing stack frame */
200 #define SP_REGNUM 1 /* Contains address of top of stack */
201 #define TOC_REGNUM 2 /* TOC register */
202 #define FP0_REGNUM 32 /* Floating point register 0 */
203 #define GP0_REGNUM 0 /* GPR register 0 */
204 #define FP0_REGNUM 32 /* FPR (Floating point) register 0 */
205 #define FPLAST_REGNUM 63 /* Last floating point register */
207 /* Special purpose registers... */
208 /* P.S. keep these in the same order as in /usr/mstsave.h `mstsave'
209 structure, for easier processing */
211 #define PC_REGNUM 64 /* Program counter (instruction address %iar) */
212 #define PS_REGNUM 65 /* Processor (or machine) status (%msr) */
213 #define CR_REGNUM 66 /* Condition register */
214 #define LR_REGNUM 67 /* Link register */
215 #define CTR_REGNUM 68 /* Count register */
216 #define XER_REGNUM 69 /* Fixed point exception registers */
217 #define MQ_REGNUM 70 /* Multiply/quotient register */
219 /* These #defines are used to parse core files and talk to ptrace, so they
220 must remain fixed. */
221 #define FIRST_UISA_SP_REGNUM 64 /* first special register number */
222 #define LAST_UISA_SP_REGNUM 70 /* last special register number */
224 /* This is the offset in REG_NAMES at which the `set processor'
225 command starts plugging in its names. */
226 #define FIRST_VARIANT_REGISTER 66
228 /* Total amount of space needed to store our copies of the machine's
229 register state, the array `registers'.
232 7 4-byte UISA special purpose registers,
233 16 4-byte segment registers,
234 32 4-byte standard OEA special-purpose registers,
235 and up to 64 4-byte non-standard OEA special purpose regs.
236 total: (+ (* 32 4) (* 32 8) (* 7 4) (* 16 4) (* 32 4) (* 64 4)) 860 bytes
237 Keep some extra space for now, in case to add more. */
238 #define REGISTER_BYTES 880
241 /* Index within `registers' of the first byte of the space for
244 #define REGISTER_BYTE(N) \
246 ((N) > FPLAST_REGNUM) ? ((((N) - FPLAST_REGNUM -1) * 4) + 384)\
247 :((N) >= FP0_REGNUM) ? ((((N) - FP0_REGNUM) * 8) + 128) \
250 /* Number of bytes of storage in the actual machine representation
252 /* Note that the unsigned cast here forces the result of the
253 subtraction to very high positive values if N < FP0_REGNUM */
255 #define REGISTER_RAW_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 32 ? 8 : 4)
257 /* Number of bytes of storage in the program's representation
258 for register N. On the RS6000, all regs are 4 bytes
259 except the floating point regs which are 8-byte doubles. */
261 #define REGISTER_VIRTUAL_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 32 ? 8 : 4)
263 /* Largest value REGISTER_RAW_SIZE can have. */
265 #define MAX_REGISTER_RAW_SIZE 8
267 /* Largest value REGISTER_VIRTUAL_SIZE can have. */
269 #define MAX_REGISTER_VIRTUAL_SIZE 8
271 /* convert a dbx stab register number (from `r' declaration) to a gdb REGNUM */
273 #define STAB_REG_TO_REGNUM(value) (value)
275 /* Nonzero if register N requires conversion
276 from raw format to virtual format.
277 The register format for rs6000 floating point registers is always
278 double, we need a conversion if the memory format is float. */
280 #define REGISTER_CONVERTIBLE(N) ((N) >= FP0_REGNUM && (N) <= FPLAST_REGNUM)
282 /* Convert data from raw format for register REGNUM in buffer FROM
283 to virtual format with type TYPE in buffer TO. */
285 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,TYPE,FROM,TO) \
287 if (TYPE_LENGTH (TYPE) != REGISTER_RAW_SIZE (REGNUM)) \
289 double val = extract_floating ((FROM), REGISTER_RAW_SIZE (REGNUM)); \
290 store_floating ((TO), TYPE_LENGTH (TYPE), val); \
293 memcpy ((TO), (FROM), REGISTER_RAW_SIZE (REGNUM)); \
296 /* Convert data from virtual format with type TYPE in buffer FROM
297 to raw format for register REGNUM in buffer TO. */
299 #define REGISTER_CONVERT_TO_RAW(TYPE,REGNUM,FROM,TO) \
301 if (TYPE_LENGTH (TYPE) != REGISTER_RAW_SIZE (REGNUM)) \
303 double val = extract_floating ((FROM), TYPE_LENGTH (TYPE)); \
304 store_floating ((TO), REGISTER_RAW_SIZE (REGNUM), val); \
307 memcpy ((TO), (FROM), REGISTER_RAW_SIZE (REGNUM)); \
310 /* Return the GDB type object for the "standard" data type
311 of data in register N. */
313 #define REGISTER_VIRTUAL_TYPE(N) \
314 (((unsigned)(N) - FP0_REGNUM) < 32 ? builtin_type_double : builtin_type_int)
316 /* Store the address of the place in which to copy the structure the
317 subroutine will return. This is called from call_function. */
318 /* in RS6000, struct return addresses are passed as an extra parameter in r3.
319 In function return, callee is not responsible of returning this address back.
320 Since gdb needs to find it, we will store in a designated variable
321 `rs6000_struct_return_address'. */
323 extern CORE_ADDR rs6000_struct_return_address
;
325 #define STORE_STRUCT_RETURN(ADDR, SP) \
326 { write_register (3, (ADDR)); \
327 rs6000_struct_return_address = (ADDR); }
329 /* Extract from an array REGBUF containing the (raw) register state
330 a function return value of type TYPE, and copy that, in virtual format,
333 /* #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
334 memcpy (VALBUF, REGBUF, TYPE_LENGTH (TYPE)) */
336 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
337 extract_return_value(TYPE,REGBUF,VALBUF)
338 extern void extract_return_value (struct type
*, char[], char *);
340 /* Write into appropriate registers a function return value
341 of type TYPE, given in virtual format. */
343 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
345 if (TYPE_CODE (TYPE) == TYPE_CODE_FLT) \
347 /* Floating point values are returned starting from FPR1 and up. \
348 Say a double_double_double type could be returned in \
349 FPR1/FPR2/FPR3 triple. */ \
351 write_register_bytes (REGISTER_BYTE (FP0_REGNUM+1), (VALBUF), \
352 TYPE_LENGTH (TYPE)); \
354 /* Everything else is returned in GPR3 and up. */ \
355 write_register_bytes (REGISTER_BYTE (GP0_REGNUM+3), (VALBUF), \
356 TYPE_LENGTH (TYPE)); \
360 /* Extract from an array REGBUF containing the (raw) register state
361 the address in which a function should return its structure value,
362 as a CORE_ADDR (or an expression that can be used as one). */
364 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) rs6000_struct_return_address
366 /* Describe the pointer in each stack frame to the previous stack frame
369 /* FRAME_CHAIN takes a frame's nominal address
370 and produces the frame's chain-pointer. */
372 /* In the case of the RS6000, the frame's nominal address
373 is the address of a 4-byte word containing the calling frame's address. */
375 #define FRAME_CHAIN(thisframe) rs6000_frame_chain (thisframe)
376 CORE_ADDR
rs6000_frame_chain (struct frame_info
*);
378 /* Define other aspects of the stack frame. */
380 /* A macro that tells us whether the function invocation represented
381 by FI does not have a frame on the stack associated with it. If it
382 does not, FRAMELESS is set to 1, else 0. */
384 extern int rs6000_frameless_function_invocation (struct frame_info
*);
385 #define FRAMELESS_FUNCTION_INVOCATION(FI) \
386 (rs6000_frameless_function_invocation (FI))
388 #define INIT_FRAME_PC_FIRST(fromleaf, prev) \
389 prev->pc = (fromleaf ? SAVED_PC_AFTER_CALL (prev->next) : \
390 prev->next ? FRAME_SAVED_PC (prev->next) : read_pc ());
391 #define INIT_FRAME_PC(fromleaf, prev) /* nothing */
392 extern void rs6000_init_extra_frame_info (int fromleaf
, struct frame_info
*);
393 #define INIT_EXTRA_FRAME_INFO(fromleaf, fi) rs6000_init_extra_frame_info (fromleaf, fi)
395 /* If the kernel has to deliver a signal, it pushes a sigcontext
396 structure on the stack and then calls the signal handler, passing
397 the address of the sigcontext in an argument register. Usually
398 the signal handler doesn't save this register, so we have to
399 access the sigcontext structure via an offset from the signal handler
401 The following constants were determined by experimentation on AIX 3.2. */
402 #define SIG_FRAME_PC_OFFSET 96
403 #define SIG_FRAME_LR_OFFSET 108
404 #define SIG_FRAME_FP_OFFSET 284
406 /* Default offset from SP where the LR is stored */
407 #define DEFAULT_LR_SAVE 8
409 /* Return saved PC from a frame */
410 #define FRAME_SAVED_PC(FRAME) rs6000_frame_saved_pc (FRAME)
412 extern unsigned long rs6000_frame_saved_pc (struct frame_info
*);
414 extern CORE_ADDR
rs6000_frame_args_address (struct frame_info
*);
415 #define FRAME_ARGS_ADDRESS(FI) rs6000_frame_args_address (FI)
417 #define FRAME_LOCALS_ADDRESS(FI) FRAME_ARGS_ADDRESS(FI)
420 /* Set VAL to the number of args passed to frame described by FI.
421 Can set VAL to -1, meaning no way to tell. */
423 /* We can't tell how many args there are
424 now that the C compiler delays popping them. */
426 #define FRAME_NUM_ARGS(fi) (-1)
428 /* Return number of bytes at start of arglist that are not really args. */
430 #define FRAME_ARGS_SKIP 8 /* Not sure on this. FIXMEmgo */
432 /* Put here the code to store, into a struct frame_saved_regs,
433 the addresses of the saved registers of frame described by FRAME_INFO.
434 This includes special registers such as pc and fp saved in special
435 ways in the stack frame. sp is even more special:
436 the address we return for it IS the sp for the next frame. */
437 /* In the following implementation for RS6000, we did *not* save sp. I am
438 not sure if it will be needed. The following macro takes care of gpr's
441 extern void rs6000_frame_init_saved_regs (struct frame_info
*);
442 #define FRAME_INIT_SAVED_REGS(FI) rs6000_frame_init_saved_regs (FI)
444 /* Things needed for making the inferior call functions. */
446 /* Push an empty stack frame, to record the current PC, etc. */
447 /* Change these names into rs6k_{push, pop}_frame(). FIXMEmgo. */
449 #define PUSH_DUMMY_FRAME push_dummy_frame ()
450 extern void push_dummy_frame (void);
452 /* Discard from the stack the innermost frame,
453 restoring all saved registers. */
455 #define POP_FRAME pop_frame ()
456 extern void pop_frame (void);
458 /* This sequence of words is the instructions:
460 mflr r0 // 0x7c0802a6
462 stfd r?, num(r1) // 0xd8010000 there should be 32 of this??
464 stm r0, num(r1) // 0xbc010000
465 stu r1, num(r1) // 0x94210000
467 // the function we want to branch might be in a different load
468 // segment. reset the toc register. Note that the actual toc address
469 // will be fix by fix_call_dummy () along with function address.
471 st r2, 0x14(r1) // 0x90410014 save toc register
472 liu r2, 0x1234 // 0x3c401234 reset a new toc value 0x12345678
473 oril r2, r2,0x5678 // 0x60425678
475 // load absolute address 0x12345678 to r0
476 liu r0, 0x1234 // 0x3c001234
477 oril r0, r0,0x5678 // 0x60005678
478 mtctr r0 // 0x7c0903a6 ctr <- r0
479 bctrl // 0x4e800421 jump subroutine 0x12345678 (%ctr)
480 cror 0xf, 0xf, 0xf // 0x4def7b82
481 brpt // 0x7d821008, breakpoint
482 cror 0xf, 0xf, 0xf // 0x4def7b82 (for 8 byte alignment)
485 We actually start executing by saving the toc register first, since the pushing
486 of the registers is done by PUSH_DUMMY_FRAME. If this were real code,
487 the arguments for the function called by the `bctrl' would be pushed
488 between the `stu' and the `bctrl', and we could allow it to execute through.
489 But the arguments have to be pushed by GDB after the PUSH_DUMMY_FRAME is done,
490 and we cannot allow to push the registers again.
493 #define CALL_DUMMY {0x7c0802a6, 0xd8010000, 0xbc010000, 0x94210000, \
494 0x90410014, 0x3c401234, 0x60425678, \
495 0x3c001234, 0x60005678, 0x7c0903a6, 0x4e800421, \
496 0x4def7b82, 0x7d821008, 0x4def7b82 }
499 /* keep this as multiple of 8 (%sp requires 8 byte alignment) */
500 #define CALL_DUMMY_LENGTH 56
502 #define CALL_DUMMY_START_OFFSET 16
504 /* Insert the specified number of args and function address into a
505 call sequence of the above form stored at DUMMYNAME. */
507 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p) \
508 rs6000_fix_call_dummy (dummyname, pc, fun, nargs, args, type, gcc_p)
509 extern void rs6000_fix_call_dummy (char *, CORE_ADDR
, CORE_ADDR
,
510 int, struct value
**, struct type
*, int);
512 /* Hook in rs6000-tdep.c for determining the TOC address when
513 calling functions in the inferior. */
515 CORE_ADDR (*find_toc_address_hook
) PARAMS ((CORE_ADDR
));
517 /* xcoffread.c provides a function to determine the TOC offset
518 for a given object file.
519 It is used under native AIX configurations for determining the
520 TOC address when calling functions in the inferior. */
523 extern CORE_ADDR
get_toc_offset (struct objfile
*);
525 /* Usually a function pointer's representation is simply the address
526 of the function. On the RS/6000 however, a function pointer is
527 represented by a pointer to a TOC entry. This TOC entry contains
528 three words, the first word is the address of the function, the
529 second word is the TOC pointer (r2), and the third word is the
530 static chain value. Throughout GDB it is currently assumed that a
531 function pointer contains the address of the function, which is not
532 easy to fix. In addition, the conversion of a function address to
533 a function pointer would require allocation of a TOC entry in the
534 inferior's memory space, with all its drawbacks. To be able to
535 call C++ virtual methods in the inferior (which are called via
536 function pointers), find_function_addr uses this macro to get the
537 function address from a function pointer. */
539 #define CONVERT_FROM_FUNC_PTR_ADDR(ADDR) \
540 (is_magic_function_pointer (ADDR) ? read_memory_integer (ADDR, 4) : (ADDR))
541 extern int is_magic_function_pointer (CORE_ADDR
);
543 /* Flag for machine-specific stuff in shared files. FIXME */
544 #define IBM6000_TARGET
546 /* RS6000/AIX does not support PT_STEP. Has to be simulated. */
548 #define SOFTWARE_SINGLE_STEP_P 1
549 extern void rs6000_software_single_step (unsigned int, int);
550 #define SOFTWARE_SINGLE_STEP(sig,bp_p) rs6000_software_single_step (sig, bp_p)
552 /* If the current gcc for for this target does not produce correct debugging
553 information for float parameters, both prototyped and unprototyped, then
554 define this macro. This forces gdb to always assume that floats are
555 passed as doubles and then converted in the callee.
557 For the PowerPC, it appears that the debug info marks the parameters as
558 floats regardless of whether the function is prototyped, but the actual
559 values are always passed in as doubles. Thus by setting this to 1, both
560 types of calls will work. */
562 #define COERCE_FLOAT_TO_DOUBLE(formal, actual) (1)