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c906108c SS |
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. | |
5 | ||
c5aa993b | 6 | This file is part of GDB. |
c906108c | 7 | |
c5aa993b JM |
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. | |
c906108c | 12 | |
c5aa993b JM |
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. | |
c906108c | 17 | |
c5aa993b JM |
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. */ | |
c906108c | 22 | |
c5aa993b | 23 | #ifdef __STDC__ /* Forward decls for prototypes */ |
c906108c SS |
24 | struct frame_info; |
25 | struct type; | |
26 | struct value; | |
27 | #endif | |
28 | ||
29 | /* Minimum possible text address in AIX */ | |
30 | ||
31 | #define TEXT_SEGMENT_BASE 0x10000000 | |
32 | ||
33 | /* Load segment of a given pc value. */ | |
34 | ||
35 | #define PC_LOAD_SEGMENT(PC) pc_load_segment_name(PC) | |
36 | extern char *pc_load_segment_name PARAMS ((CORE_ADDR)); | |
37 | ||
38 | /* AIX cc seems to get this right. */ | |
39 | ||
40 | #define BELIEVE_PCC_PROMOTION 1 | |
41 | ||
42 | /* return true if a given `pc' value is in `call dummy' function. */ | |
43 | /* FIXME: This just checks for the end of the stack, which is broken | |
44 | for things like stepping through gcc nested function stubs. */ | |
45 | #define PC_IN_CALL_DUMMY(STOP_PC, STOP_SP, STOP_FRAME_ADDR) \ | |
46 | (STOP_SP < STOP_PC && STOP_PC < STACK_END_ADDR) | |
47 | ||
48 | #if 0 | |
49 | extern unsigned int text_start, data_start; | |
50 | extern char *corefile; | |
51 | #endif | |
52 | extern int inferior_pid; | |
53 | ||
54 | /* We are missing register descriptions in the system header files. Sigh! */ | |
55 | ||
c5aa993b JM |
56 | struct regs |
57 | { | |
58 | int gregs[32]; /* general purpose registers */ | |
59 | int pc; /* program conter */ | |
60 | int ps; /* processor status, or machine state */ | |
61 | }; | |
c906108c | 62 | |
c5aa993b JM |
63 | struct fp_status |
64 | { | |
65 | double fpregs[32]; /* floating GP registers */ | |
66 | }; | |
c906108c SS |
67 | |
68 | ||
69 | /* To be used by skip_prologue. */ | |
70 | ||
c5aa993b JM |
71 | struct rs6000_framedata |
72 | { | |
73 | int offset; /* total size of frame --- the distance | |
74 | by which we decrement sp to allocate | |
75 | the frame */ | |
76 | int saved_gpr; /* smallest # of saved gpr */ | |
77 | int saved_fpr; /* smallest # of saved fpr */ | |
78 | int alloca_reg; /* alloca register number (frame ptr) */ | |
79 | char frameless; /* true if frameless functions. */ | |
80 | char nosavedpc; /* true if pc not saved. */ | |
81 | int gpr_offset; /* offset of saved gprs from prev sp */ | |
82 | int fpr_offset; /* offset of saved fprs from prev sp */ | |
83 | int lr_offset; /* offset of saved lr */ | |
84 | int cr_offset; /* offset of saved cr */ | |
85 | }; | |
c906108c SS |
86 | |
87 | /* Define the byte order of the machine. */ | |
88 | ||
89 | #define TARGET_BYTE_ORDER_DEFAULT BIG_ENDIAN | |
90 | ||
91 | /* AIX's assembler doesn't grok dollar signs in identifiers. | |
92 | So we use dots instead. This item must be coordinated with G++. */ | |
93 | #undef CPLUS_MARKER | |
94 | #define CPLUS_MARKER '.' | |
95 | ||
96 | /* Offset from address of function to start of its code. | |
97 | Zero on most machines. */ | |
98 | ||
99 | #define FUNCTION_START_OFFSET 0 | |
100 | ||
101 | /* Advance PC across any function entry prologue instructions | |
102 | to reach some "real" code. */ | |
103 | ||
b83266a0 SS |
104 | extern CORE_ADDR rs6000_skip_prologue PARAMS ((CORE_ADDR)); |
105 | #define SKIP_PROLOGUE(pc) (rs6000_skip_prologue (pc)) | |
c906108c | 106 | |
c5aa993b | 107 | extern CORE_ADDR skip_prologue PARAMS ((CORE_ADDR, struct rs6000_framedata *)); |
c906108c SS |
108 | |
109 | ||
110 | /* If PC is in some function-call trampoline code, return the PC | |
111 | where the function itself actually starts. If not, return NULL. */ | |
112 | ||
113 | #define SKIP_TRAMPOLINE_CODE(pc) skip_trampoline_code (pc) | |
114 | extern CORE_ADDR skip_trampoline_code PARAMS ((CORE_ADDR)); | |
115 | ||
116 | /* Number of trap signals we need to skip over, once the inferior process | |
117 | starts running. */ | |
118 | ||
119 | #define START_INFERIOR_TRAPS_EXPECTED 2 | |
120 | ||
121 | /* AIX has a couple of strange returns from wait(). */ | |
122 | ||
123 | #define CHILD_SPECIAL_WAITSTATUS(ourstatus, hoststatus) ( \ | |
124 | /* "stop after load" status. */ \ | |
125 | (hoststatus) == 0x57c ? (ourstatus)->kind = TARGET_WAITKIND_LOADED, 1 : \ | |
126 | \ | |
127 | /* signal 0. I have no idea why wait(2) returns with this status word. */ \ | |
128 | /* It looks harmless. */ \ | |
129 | (hoststatus) == 0x7f ? (ourstatus)->kind = TARGET_WAITKIND_SPURIOUS, 1 : \ | |
130 | \ | |
131 | /* A normal waitstatus. Let the usual macros deal with it. */ \ | |
132 | 0) | |
133 | ||
134 | /* In xcoff, we cannot process line numbers when we see them. This is | |
135 | mainly because we don't know the boundaries of the include files. So, | |
136 | we postpone that, and then enter and sort(?) the whole line table at | |
137 | once, when we are closing the current symbol table in end_symtab(). */ | |
138 | ||
139 | #define PROCESS_LINENUMBER_HOOK() aix_process_linenos () | |
140 | extern void aix_process_linenos PARAMS ((void)); | |
c5aa993b | 141 | |
c906108c SS |
142 | /* Immediately after a function call, return the saved pc. |
143 | Can't go through the frames for this because on some machines | |
144 | the new frame is not set up until the new function executes | |
145 | some instructions. */ | |
146 | ||
147 | #define SAVED_PC_AFTER_CALL(frame) read_register (LR_REGNUM) | |
148 | ||
149 | /* Address of end of stack space. */ | |
150 | ||
151 | #define STACK_END_ADDR 0x2ff80000 | |
152 | ||
153 | /* Stack grows downward. */ | |
154 | ||
155 | #define INNER_THAN(lhs,rhs) ((lhs) < (rhs)) | |
156 | ||
157 | /* This is how arguments pushed onto stack or passed in registers. | |
158 | Stack must be aligned on 64-bit boundaries when synthesizing | |
159 | function calls. We don't need STACK_ALIGN, PUSH_ARGUMENTS will | |
160 | handle it. */ | |
161 | ||
162 | #define PUSH_ARGUMENTS(nargs, args, sp, struct_return, struct_addr) \ | |
392a587b JM |
163 | (rs6000_push_arguments((nargs), (args), (sp), (struct_return), (struct_addr))) |
164 | extern CORE_ADDR rs6000_push_arguments PARAMS ((int, struct value **, CORE_ADDR, int, CORE_ADDR)); | |
c906108c SS |
165 | |
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) | |
170 | ||
171 | /* Amount PC must be decremented by after a breakpoint. | |
172 | This is often the number of bytes in BREAKPOINT | |
173 | but not always. */ | |
174 | ||
175 | #define DECR_PC_AFTER_BREAK 0 | |
176 | ||
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 | |
181 | ||
182 | ||
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); | |
188 | ||
189 | /* Number of machine registers */ | |
190 | #define NUM_REGS 183 | |
191 | ||
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. */ | |
198 | ||
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 */ | |
c5aa993b | 205 | #define FPLAST_REGNUM 63 /* Last floating point register */ |
c906108c SS |
206 | |
207 | /* Special purpose registers... */ | |
208 | /* P.S. keep these in the same order as in /usr/mstsave.h `mstsave' | |
209 | structure, for easier processing */ | |
210 | ||
c5aa993b | 211 | #define PC_REGNUM 64 /* Program counter (instruction address %iar) */ |
c906108c SS |
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 */ | |
218 | ||
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 */ | |
223 | ||
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 | |
227 | ||
228 | /* Total amount of space needed to store our copies of the machine's | |
229 | register state, the array `registers'. | |
c5aa993b JM |
230 | 32 4-byte gpr's |
231 | 32 8-byte fpr's | |
232 | 7 4-byte UISA special purpose registers, | |
233 | 16 4-byte segment registers, | |
234 | 32 4-byte standard OEA special-purpose registers, | |
c906108c SS |
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 | |
239 | ||
240 | ||
241 | /* Index within `registers' of the first byte of the space for | |
242 | register N. */ | |
243 | ||
244 | #define REGISTER_BYTE(N) \ | |
245 | ( \ | |
246 | ((N) > FPLAST_REGNUM) ? ((((N) - FPLAST_REGNUM -1) * 4) + 384)\ | |
247 | :((N) >= FP0_REGNUM) ? ((((N) - FP0_REGNUM) * 8) + 128) \ | |
248 | :((N) * 4) ) | |
249 | ||
250 | /* Number of bytes of storage in the actual machine representation | |
251 | for register N. */ | |
252 | /* Note that the unsigned cast here forces the result of the | |
253 | subtraction to very high positive values if N < FP0_REGNUM */ | |
254 | ||
255 | #define REGISTER_RAW_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 32 ? 8 : 4) | |
256 | ||
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. */ | |
260 | ||
261 | #define REGISTER_VIRTUAL_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 32 ? 8 : 4) | |
262 | ||
263 | /* Largest value REGISTER_RAW_SIZE can have. */ | |
264 | ||
265 | #define MAX_REGISTER_RAW_SIZE 8 | |
266 | ||
267 | /* Largest value REGISTER_VIRTUAL_SIZE can have. */ | |
268 | ||
269 | #define MAX_REGISTER_VIRTUAL_SIZE 8 | |
270 | ||
271 | /* convert a dbx stab register number (from `r' declaration) to a gdb REGNUM */ | |
272 | ||
273 | #define STAB_REG_TO_REGNUM(value) (value) | |
274 | ||
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. */ | |
279 | ||
280 | #define REGISTER_CONVERTIBLE(N) ((N) >= FP0_REGNUM && (N) <= FPLAST_REGNUM) | |
281 | ||
282 | /* Convert data from raw format for register REGNUM in buffer FROM | |
283 | to virtual format with type TYPE in buffer TO. */ | |
284 | ||
285 | #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,TYPE,FROM,TO) \ | |
286 | { \ | |
287 | if (TYPE_LENGTH (TYPE) != REGISTER_RAW_SIZE (REGNUM)) \ | |
288 | { \ | |
289 | double val = extract_floating ((FROM), REGISTER_RAW_SIZE (REGNUM)); \ | |
290 | store_floating ((TO), TYPE_LENGTH (TYPE), val); \ | |
291 | } \ | |
292 | else \ | |
293 | memcpy ((TO), (FROM), REGISTER_RAW_SIZE (REGNUM)); \ | |
294 | } | |
295 | ||
296 | /* Convert data from virtual format with type TYPE in buffer FROM | |
297 | to raw format for register REGNUM in buffer TO. */ | |
298 | ||
299 | #define REGISTER_CONVERT_TO_RAW(TYPE,REGNUM,FROM,TO) \ | |
300 | { \ | |
301 | if (TYPE_LENGTH (TYPE) != REGISTER_RAW_SIZE (REGNUM)) \ | |
302 | { \ | |
303 | double val = extract_floating ((FROM), TYPE_LENGTH (TYPE)); \ | |
304 | store_floating ((TO), REGISTER_RAW_SIZE (REGNUM), val); \ | |
305 | } \ | |
306 | else \ | |
307 | memcpy ((TO), (FROM), REGISTER_RAW_SIZE (REGNUM)); \ | |
308 | } | |
309 | ||
310 | /* Return the GDB type object for the "standard" data type | |
311 | of data in register N. */ | |
312 | ||
313 | #define REGISTER_VIRTUAL_TYPE(N) \ | |
314 | (((unsigned)(N) - FP0_REGNUM) < 32 ? builtin_type_double : builtin_type_int) | |
315 | ||
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'. */ | |
322 | ||
323 | extern CORE_ADDR rs6000_struct_return_address; | |
324 | ||
325 | #define STORE_STRUCT_RETURN(ADDR, SP) \ | |
326 | { write_register (3, (ADDR)); \ | |
327 | rs6000_struct_return_address = (ADDR); } | |
328 | ||
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, | |
331 | into VALBUF. */ | |
332 | ||
333 | /* #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \ | |
c5aa993b | 334 | memcpy (VALBUF, REGBUF, TYPE_LENGTH (TYPE)) */ |
c906108c SS |
335 | |
336 | #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \ | |
337 | extract_return_value(TYPE,REGBUF,VALBUF) | |
c5aa993b | 338 | extern void extract_return_value PARAMS ((struct type *, char[], char *)); |
c906108c SS |
339 | |
340 | /* Write into appropriate registers a function return value | |
341 | of type TYPE, given in virtual format. */ | |
342 | ||
343 | #define STORE_RETURN_VALUE(TYPE,VALBUF) \ | |
344 | { \ | |
345 | if (TYPE_CODE (TYPE) == TYPE_CODE_FLT) \ | |
346 | \ | |
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. */ \ | |
350 | \ | |
351 | write_register_bytes (REGISTER_BYTE (FP0_REGNUM+1), (VALBUF), \ | |
352 | TYPE_LENGTH (TYPE)); \ | |
353 | else \ | |
354 | /* Everything else is returned in GPR3 and up. */ \ | |
355 | write_register_bytes (REGISTER_BYTE (GP0_REGNUM+3), (VALBUF), \ | |
356 | TYPE_LENGTH (TYPE)); \ | |
357 | } | |
358 | ||
359 | ||
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). */ | |
363 | ||
364 | #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) rs6000_struct_return_address | |
365 | \f | |
366 | /* Describe the pointer in each stack frame to the previous stack frame | |
367 | (its caller). */ | |
368 | ||
369 | /* FRAME_CHAIN takes a frame's nominal address | |
370 | and produces the frame's chain-pointer. */ | |
371 | ||
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. */ | |
374 | ||
375 | #define FRAME_CHAIN(thisframe) rs6000_frame_chain (thisframe) | |
376 | CORE_ADDR rs6000_frame_chain PARAMS ((struct frame_info *)); | |
377 | ||
378 | /* Define other aspects of the stack frame. */ | |
379 | ||
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. */ | |
383 | ||
392a587b JM |
384 | #define FRAMELESS_FUNCTION_INVOCATION(FI) \ |
385 | (frameless_function_invocation (FI)) | |
c906108c | 386 | |
c5aa993b | 387 | extern int frameless_function_invocation PARAMS ((struct frame_info *)); |
c906108c SS |
388 | |
389 | #define INIT_FRAME_PC_FIRST(fromleaf, prev) \ | |
390 | prev->pc = (fromleaf ? SAVED_PC_AFTER_CALL (prev->next) : \ | |
391 | prev->next ? FRAME_SAVED_PC (prev->next) : read_pc ()); | |
c5aa993b | 392 | #define INIT_FRAME_PC(fromleaf, prev) /* nothing */ |
c906108c SS |
393 | extern void rs6000_init_extra_frame_info (int fromleaf, struct frame_info *); |
394 | #define INIT_EXTRA_FRAME_INFO(fromleaf, fi) rs6000_init_extra_frame_info (fromleaf, fi) | |
395 | ||
396 | /* If the kernel has to deliver a signal, it pushes a sigcontext | |
397 | structure on the stack and then calls the signal handler, passing | |
398 | the address of the sigcontext in an argument register. Usually | |
399 | the signal handler doesn't save this register, so we have to | |
400 | access the sigcontext structure via an offset from the signal handler | |
401 | frame. | |
402 | The following constants were determined by experimentation on AIX 3.2. */ | |
403 | #define SIG_FRAME_PC_OFFSET 96 | |
404 | #define SIG_FRAME_LR_OFFSET 108 | |
405 | #define SIG_FRAME_FP_OFFSET 284 | |
406 | ||
407 | /* Default offset from SP where the LR is stored */ | |
408 | #define DEFAULT_LR_SAVE 8 | |
409 | ||
410 | /* Return saved PC from a frame */ | |
411 | #define FRAME_SAVED_PC(FRAME) frame_saved_pc (FRAME) | |
412 | ||
413 | extern unsigned long frame_saved_pc PARAMS ((struct frame_info *)); | |
414 | ||
415 | extern CORE_ADDR rs6000_frame_args_address PARAMS ((struct frame_info *)); | |
416 | #define FRAME_ARGS_ADDRESS(FI) rs6000_frame_args_address (FI) | |
417 | ||
418 | #define FRAME_LOCALS_ADDRESS(FI) FRAME_ARGS_ADDRESS(FI) | |
419 | ||
420 | ||
421 | /* Set VAL to the number of args passed to frame described by FI. | |
422 | Can set VAL to -1, meaning no way to tell. */ | |
423 | ||
424 | /* We can't tell how many args there are | |
425 | now that the C compiler delays popping them. */ | |
426 | ||
392a587b | 427 | #define FRAME_NUM_ARGS(fi) (-1) |
c906108c SS |
428 | |
429 | /* Return number of bytes at start of arglist that are not really args. */ | |
430 | ||
431 | #define FRAME_ARGS_SKIP 8 /* Not sure on this. FIXMEmgo */ | |
432 | ||
433 | /* Put here the code to store, into a struct frame_saved_regs, | |
434 | the addresses of the saved registers of frame described by FRAME_INFO. | |
435 | This includes special registers such as pc and fp saved in special | |
436 | ways in the stack frame. sp is even more special: | |
437 | the address we return for it IS the sp for the next frame. */ | |
438 | /* In the following implementation for RS6000, we did *not* save sp. I am | |
439 | not sure if it will be needed. The following macro takes care of gpr's | |
440 | and fpr's only. */ | |
441 | ||
442 | extern void rs6000_frame_init_saved_regs PARAMS ((struct frame_info *)); | |
443 | #define FRAME_INIT_SAVED_REGS(FI) rs6000_frame_init_saved_regs (FI) | |
444 | ||
445 | /* Things needed for making the inferior call functions. */ | |
446 | ||
447 | /* Push an empty stack frame, to record the current PC, etc. */ | |
448 | /* Change these names into rs6k_{push, pop}_frame(). FIXMEmgo. */ | |
449 | ||
450 | #define PUSH_DUMMY_FRAME push_dummy_frame () | |
451 | extern void push_dummy_frame PARAMS ((void)); | |
452 | ||
453 | /* Discard from the stack the innermost frame, | |
454 | restoring all saved registers. */ | |
455 | ||
456 | #define POP_FRAME pop_frame () | |
457 | extern void pop_frame PARAMS ((void)); | |
458 | ||
459 | /* This sequence of words is the instructions: | |
460 | ||
c5aa993b JM |
461 | mflr r0 // 0x7c0802a6 |
462 | // save fpr's | |
463 | stfd r?, num(r1) // 0xd8010000 there should be 32 of this?? | |
464 | // save gpr's | |
465 | stm r0, num(r1) // 0xbc010000 | |
466 | stu r1, num(r1) // 0x94210000 | |
467 | ||
468 | // the function we want to branch might be in a different load | |
469 | // segment. reset the toc register. Note that the actual toc address | |
470 | // will be fix by fix_call_dummy () along with function address. | |
471 | ||
472 | st r2, 0x14(r1) // 0x90410014 save toc register | |
473 | liu r2, 0x1234 // 0x3c401234 reset a new toc value 0x12345678 | |
474 | oril r2, r2,0x5678 // 0x60425678 | |
475 | ||
476 | // load absolute address 0x12345678 to r0 | |
477 | liu r0, 0x1234 // 0x3c001234 | |
478 | oril r0, r0,0x5678 // 0x60005678 | |
479 | mtctr r0 // 0x7c0903a6 ctr <- r0 | |
480 | bctrl // 0x4e800421 jump subroutine 0x12345678 (%ctr) | |
481 | cror 0xf, 0xf, 0xf // 0x4def7b82 | |
482 | brpt // 0x7d821008, breakpoint | |
483 | cror 0xf, 0xf, 0xf // 0x4def7b82 (for 8 byte alignment) | |
484 | ||
485 | ||
486 | We actually start executing by saving the toc register first, since the pushing | |
487 | of the registers is done by PUSH_DUMMY_FRAME. If this were real code, | |
488 | the arguments for the function called by the `bctrl' would be pushed | |
489 | between the `stu' and the `bctrl', and we could allow it to execute through. | |
490 | But the arguments have to be pushed by GDB after the PUSH_DUMMY_FRAME is done, | |
491 | and we cannot allow to push the registers again. | |
492 | */ | |
493 | ||
c906108c SS |
494 | #define CALL_DUMMY {0x7c0802a6, 0xd8010000, 0xbc010000, 0x94210000, \ |
495 | 0x90410014, 0x3c401234, 0x60425678, \ | |
496 | 0x3c001234, 0x60005678, 0x7c0903a6, 0x4e800421, \ | |
497 | 0x4def7b82, 0x7d821008, 0x4def7b82 } | |
498 | ||
499 | ||
500 | /* keep this as multiple of 8 (%sp requires 8 byte alignment) */ | |
501 | #define CALL_DUMMY_LENGTH 56 | |
502 | ||
503 | #define CALL_DUMMY_START_OFFSET 16 | |
504 | ||
505 | /* Insert the specified number of args and function address into a | |
506 | call sequence of the above form stored at DUMMYNAME. */ | |
507 | ||
508 | #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p) \ | |
509 | rs6000_fix_call_dummy (dummyname, pc, fun, nargs, args, type, gcc_p) | |
510 | extern void rs6000_fix_call_dummy PARAMS ((char *, CORE_ADDR, CORE_ADDR, | |
511 | int, struct value **, | |
512 | struct type *, int)); | |
513 | ||
514 | /* Hook in rs6000-tdep.c for determining the TOC address when | |
515 | calling functions in the inferior. */ | |
c5aa993b JM |
516 | extern |
517 | CORE_ADDR (*find_toc_address_hook) PARAMS ((CORE_ADDR)); | |
c906108c SS |
518 | |
519 | /* xcoffread.c provides a function to determine the TOC offset | |
520 | for a given object file. | |
521 | It is used under native AIX configurations for determining the | |
522 | TOC address when calling functions in the inferior. */ | |
523 | #ifdef __STDC__ | |
c5aa993b | 524 | struct objfile; |
c906108c | 525 | #endif |
c5aa993b | 526 | extern CORE_ADDR get_toc_offset PARAMS ((struct objfile *)); |
c906108c SS |
527 | |
528 | /* Usually a function pointer's representation is simply the address | |
529 | of the function. On the RS/6000 however, a function pointer is | |
530 | represented by a pointer to a TOC entry. This TOC entry contains | |
531 | three words, the first word is the address of the function, the | |
532 | second word is the TOC pointer (r2), and the third word is the | |
533 | static chain value. Throughout GDB it is currently assumed that a | |
534 | function pointer contains the address of the function, which is not | |
535 | easy to fix. In addition, the conversion of a function address to | |
536 | a function pointer would require allocation of a TOC entry in the | |
537 | inferior's memory space, with all its drawbacks. To be able to | |
538 | call C++ virtual methods in the inferior (which are called via | |
539 | function pointers), find_function_addr uses this macro to get the | |
540 | function address from a function pointer. */ | |
541 | ||
542 | #define CONVERT_FROM_FUNC_PTR_ADDR(ADDR) \ | |
543 | (is_magic_function_pointer (ADDR) ? read_memory_integer (ADDR, 4) : (ADDR)) | |
c5aa993b | 544 | extern int is_magic_function_pointer PARAMS ((CORE_ADDR)); |
c906108c SS |
545 | |
546 | /* Flag for machine-specific stuff in shared files. FIXME */ | |
547 | #define IBM6000_TARGET | |
548 | ||
549 | /* RS6000/AIX does not support PT_STEP. Has to be simulated. */ | |
550 | ||
551 | #define SOFTWARE_SINGLE_STEP_P 1 | |
c5aa993b | 552 | extern void rs6000_software_single_step PARAMS ((unsigned int, int)); |
c906108c SS |
553 | #define SOFTWARE_SINGLE_STEP(sig,bp_p) rs6000_software_single_step (sig, bp_p) |
554 | ||
555 | /* If the current gcc for for this target does not produce correct debugging | |
556 | information for float parameters, both prototyped and unprototyped, then | |
557 | define this macro. This forces gdb to always assume that floats are | |
558 | passed as doubles and then converted in the callee. | |
559 | ||
560 | For the PowerPC, it appears that the debug info marks the parameters as | |
561 | floats regardless of whether the function is prototyped, but the actual | |
562 | values are always passed in as doubles. Thus by setting this to 1, both | |
563 | types of calls will work. */ | |
564 | ||
565 | #define COERCE_FLOAT_TO_DOUBLE 1 |