Commit | Line | Data |
---|---|---|
c906108c SS |
1 | /* Target-dependent code for the Fujitsu FR30. |
2 | Copyright 1999, Free Software Foundation, Inc. | |
3 | ||
4 | This file is part of GDB. | |
5 | ||
6 | This program is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2 of the License, or | |
9 | (at your option) any later version. | |
10 | ||
11 | This program is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with this program; if not, write to the Free Software | |
18 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ | |
19 | ||
20 | #include "defs.h" | |
21 | #include "frame.h" | |
22 | #include "inferior.h" | |
23 | #include "obstack.h" | |
24 | #include "target.h" | |
25 | #include "value.h" | |
26 | #include "bfd.h" | |
27 | #include "gdb_string.h" | |
28 | #include "gdbcore.h" | |
29 | #include "symfile.h" | |
30 | ||
31 | /* Function: pop_frame | |
32 | This routine gets called when either the user uses the `return' | |
33 | command, or the call dummy breakpoint gets hit. */ | |
34 | ||
35 | void | |
36 | fr30_pop_frame () | |
37 | { | |
38 | struct frame_info *frame = get_current_frame(); | |
39 | int regnum; | |
40 | CORE_ADDR sp = read_register(SP_REGNUM); | |
41 | ||
42 | if (PC_IN_CALL_DUMMY(frame->pc, frame->frame, frame->frame)) | |
43 | generic_pop_dummy_frame (); | |
44 | else | |
45 | { | |
46 | write_register (PC_REGNUM, FRAME_SAVED_PC (frame)); | |
47 | ||
48 | for (regnum = 0; regnum < NUM_REGS; regnum++) | |
49 | if (frame->fsr.regs[regnum] != 0) { | |
50 | write_register (regnum, | |
51 | read_memory_unsigned_integer (frame->fsr.regs[regnum], | |
52 | REGISTER_RAW_SIZE(regnum))); | |
53 | } | |
54 | write_register (SP_REGNUM, sp + frame->framesize); | |
55 | } | |
56 | flush_cached_frames (); | |
57 | } | |
58 | ||
59 | /* Function: skip_prologue | |
60 | Return the address of the first code past the prologue of the function. */ | |
61 | ||
62 | CORE_ADDR | |
63 | fr30_skip_prologue(CORE_ADDR pc) | |
64 | { | |
65 | CORE_ADDR func_addr, func_end; | |
66 | ||
67 | /* See what the symbol table says */ | |
68 | ||
69 | if (find_pc_partial_function (pc, NULL, &func_addr, &func_end)) | |
70 | { | |
71 | struct symtab_and_line sal; | |
72 | ||
73 | sal = find_pc_line (func_addr, 0); | |
74 | ||
75 | if (sal.line != 0 && sal.end < func_end) { | |
76 | return sal.end; | |
77 | } | |
78 | } | |
79 | ||
80 | /* Either we didn't find the start of this function (nothing we can do), | |
81 | or there's no line info, or the line after the prologue is after | |
82 | the end of the function (there probably isn't a prologue). */ | |
83 | ||
84 | return pc; | |
85 | } | |
86 | ||
87 | ||
88 | /* Function: push_arguments | |
89 | Setup arguments and RP for a call to the target. First four args | |
90 | go in FIRST_ARGREG -> LAST_ARGREG, subsequent args go on stack... | |
91 | Structs are passed by reference. XXX not right now Z.R. | |
92 | 64 bit quantities (doubles and long longs) may be split between | |
93 | the regs and the stack. | |
94 | When calling a function that returns a struct, a pointer to the struct | |
95 | is passed in as a secret first argument (always in FIRST_ARGREG). | |
96 | ||
97 | Stack space for the args has NOT been allocated: that job is up to us. | |
98 | */ | |
99 | ||
100 | CORE_ADDR | |
101 | fr30_push_arguments(nargs, args, sp, struct_return, struct_addr) | |
102 | int nargs; | |
103 | value_ptr * args; | |
104 | CORE_ADDR sp; | |
105 | int struct_return; | |
106 | CORE_ADDR struct_addr; | |
107 | { | |
108 | int argreg; | |
109 | int argnum; | |
110 | int stack_offset; | |
111 | struct stack_arg { | |
112 | char *val; | |
113 | int len; | |
114 | int offset; | |
115 | }; | |
116 | struct stack_arg *stack_args = | |
117 | (struct stack_arg*)alloca (nargs * sizeof (struct stack_arg)); | |
118 | int nstack_args = 0; | |
119 | ||
120 | argreg = FIRST_ARGREG; | |
121 | ||
122 | /* the struct_return pointer occupies the first parameter-passing reg */ | |
123 | if (struct_return) | |
124 | write_register (argreg++, struct_addr); | |
125 | ||
126 | stack_offset = 0; | |
127 | ||
128 | /* Process args from left to right. Store as many as allowed in | |
129 | registers, save the rest to be pushed on the stack */ | |
130 | for(argnum = 0; argnum < nargs; argnum++) | |
131 | { | |
132 | char * val; | |
133 | value_ptr arg = args[argnum]; | |
134 | struct type * arg_type = check_typedef (VALUE_TYPE (arg)); | |
135 | struct type * target_type = TYPE_TARGET_TYPE (arg_type); | |
136 | int len = TYPE_LENGTH (arg_type); | |
137 | enum type_code typecode = TYPE_CODE (arg_type); | |
138 | CORE_ADDR regval; | |
139 | int newarg; | |
140 | ||
141 | val = (char *) VALUE_CONTENTS (arg); | |
142 | ||
143 | { | |
144 | /* Copy the argument to general registers or the stack in | |
145 | register-sized pieces. Large arguments are split between | |
146 | registers and stack. */ | |
147 | while (len > 0) | |
148 | { | |
149 | if (argreg <= LAST_ARGREG) | |
150 | { | |
151 | int partial_len = len < REGISTER_SIZE ? len : REGISTER_SIZE; | |
152 | regval = extract_address (val, partial_len); | |
153 | ||
154 | /* It's a simple argument being passed in a general | |
155 | register. */ | |
156 | write_register (argreg, regval); | |
157 | argreg++; | |
158 | len -= partial_len; | |
159 | val += partial_len; | |
160 | } | |
161 | else | |
162 | { | |
163 | /* keep for later pushing */ | |
164 | stack_args[nstack_args].val = val; | |
165 | stack_args[nstack_args++].len = len; | |
166 | break; | |
167 | } | |
168 | } | |
169 | } | |
170 | } | |
171 | /* now do the real stack pushing, process args right to left */ | |
172 | while(nstack_args--) | |
173 | { | |
174 | sp -= stack_args[nstack_args].len; | |
175 | write_memory(sp, stack_args[nstack_args].val, | |
176 | stack_args[nstack_args].len); | |
177 | } | |
178 | ||
179 | /* Return adjusted stack pointer. */ | |
180 | return sp; | |
181 | } | |
182 | ||
183 | _initialize_fr30_tdep() | |
184 | { | |
185 | extern int print_insn_fr30(bfd_vma, disassemble_info *); | |
186 | ||
187 | tm_print_insn = print_insn_fr30; | |
188 | } | |
189 | ||
190 | /* Function: check_prologue_cache | |
191 | Check if prologue for this frame's PC has already been scanned. | |
192 | If it has, copy the relevant information about that prologue and | |
193 | return non-zero. Otherwise do not copy anything and return zero. | |
194 | ||
195 | The information saved in the cache includes: | |
196 | * the frame register number; | |
197 | * the size of the stack frame; | |
198 | * the offsets of saved regs (relative to the old SP); and | |
199 | * the offset from the stack pointer to the frame pointer | |
200 | ||
201 | The cache contains only one entry, since this is adequate | |
202 | for the typical sequence of prologue scan requests we get. | |
203 | When performing a backtrace, GDB will usually ask to scan | |
204 | the same function twice in a row (once to get the frame chain, | |
205 | and once to fill in the extra frame information). | |
206 | */ | |
207 | ||
208 | static struct frame_info prologue_cache; | |
209 | ||
210 | static int | |
211 | check_prologue_cache (fi) | |
212 | struct frame_info * fi; | |
213 | { | |
214 | int i; | |
215 | ||
216 | if (fi->pc == prologue_cache.pc) | |
217 | { | |
218 | fi->framereg = prologue_cache.framereg; | |
219 | fi->framesize = prologue_cache.framesize; | |
220 | fi->frameoffset = prologue_cache.frameoffset; | |
221 | for (i = 0; i <= NUM_REGS; i++) | |
222 | fi->fsr.regs[i] = prologue_cache.fsr.regs[i]; | |
223 | return 1; | |
224 | } | |
225 | else | |
226 | return 0; | |
227 | } | |
228 | ||
229 | ||
230 | /* Function: save_prologue_cache | |
231 | Copy the prologue information from fi to the prologue cache. | |
232 | */ | |
233 | ||
234 | static void | |
235 | save_prologue_cache (fi) | |
236 | struct frame_info * fi; | |
237 | { | |
238 | int i; | |
239 | ||
240 | prologue_cache.pc = fi->pc; | |
241 | prologue_cache.framereg = fi->framereg; | |
242 | prologue_cache.framesize = fi->framesize; | |
243 | prologue_cache.frameoffset = fi->frameoffset; | |
244 | ||
245 | for (i = 0; i <= NUM_REGS; i++) { | |
246 | prologue_cache.fsr.regs[i] = fi->fsr.regs[i]; | |
247 | } | |
248 | } | |
249 | ||
250 | ||
251 | /* Function: scan_prologue | |
252 | Scan the prologue of the function that contains PC, and record what | |
253 | we find in PI. PI->fsr must be zeroed by the called. Returns the | |
254 | pc after the prologue. Note that the addresses saved in pi->fsr | |
255 | are actually just frame relative (negative offsets from the frame | |
256 | pointer). This is because we don't know the actual value of the | |
257 | frame pointer yet. In some circumstances, the frame pointer can't | |
258 | be determined till after we have scanned the prologue. */ | |
259 | ||
260 | static void | |
261 | fr30_scan_prologue (fi) | |
262 | struct frame_info * fi; | |
263 | { | |
264 | int sp_offset, fp_offset; | |
265 | CORE_ADDR prologue_start, prologue_end, current_pc; | |
266 | ||
267 | /* Check if this function is already in the cache of frame information. */ | |
268 | if (check_prologue_cache (fi)) | |
269 | return; | |
270 | ||
271 | /* Assume there is no frame until proven otherwise. */ | |
272 | fi->framereg = SP_REGNUM; | |
273 | fi->framesize = 0; | |
274 | fi->frameoffset = 0; | |
275 | ||
276 | /* Find the function prologue. If we can't find the function in | |
277 | the symbol table, peek in the stack frame to find the PC. */ | |
278 | if (find_pc_partial_function (fi->pc, NULL, &prologue_start, &prologue_end)) | |
279 | { | |
280 | /* Assume the prologue is everything between the first instruction | |
281 | in the function and the first source line. */ | |
282 | struct symtab_and_line sal = find_pc_line (prologue_start, 0); | |
283 | ||
284 | if (sal.line == 0) /* no line info, use current PC */ | |
285 | prologue_end = fi->pc; | |
286 | else if (sal.end < prologue_end) /* next line begins after fn end */ | |
287 | prologue_end = sal.end; /* (probably means no prologue) */ | |
288 | } | |
289 | else | |
290 | { | |
291 | /* XXX Z.R. What now??? The following is entirely bogus */ | |
292 | prologue_start = (read_memory_integer (fi->frame, 4) & 0x03fffffc) - 12; | |
293 | prologue_end = prologue_start + 40; | |
294 | } | |
295 | ||
296 | /* Now search the prologue looking for instructions that set up the | |
297 | frame pointer, adjust the stack pointer, and save registers. */ | |
298 | ||
299 | sp_offset = fp_offset = 0; | |
300 | for (current_pc = prologue_start; current_pc < prologue_end; current_pc += 2) | |
301 | { | |
302 | unsigned int insn; | |
303 | ||
304 | insn = read_memory_unsigned_integer (current_pc, 2); | |
305 | ||
306 | if ((insn & 0xfe00) == 0x8e00) /* stm0 or stm1 */ | |
307 | { | |
308 | int reg, mask = insn & 0xff; | |
309 | ||
310 | /* scan in one sweep - create virtual 16-bit mask from either insn's mask */ | |
311 | if((insn & 0x0100) == 0) | |
312 | { | |
313 | mask <<= 8; /* stm0 - move to upper byte in virtual mask */ | |
314 | } | |
315 | ||
316 | /* Calculate offsets of saved registers (to be turned later into addresses). */ | |
317 | for (reg = R4_REGNUM; reg <= R11_REGNUM; reg++) | |
318 | if (mask & (1 << (15 - reg))) | |
319 | { | |
320 | sp_offset -= 4; | |
321 | fi->fsr.regs[reg] = sp_offset; | |
322 | } | |
323 | } | |
324 | else if((insn & 0xfff0) == 0x1700) /* st rx,@-r15 */ | |
325 | { | |
326 | int reg = insn & 0xf; | |
327 | ||
328 | sp_offset -= 4; | |
329 | fi->fsr.regs[reg] = sp_offset; | |
330 | } | |
331 | else if((insn & 0xff00) == 0x0f00) /* enter */ | |
332 | { | |
333 | fp_offset = fi->fsr.regs[FP_REGNUM] = sp_offset - 4; | |
334 | sp_offset -= 4 * (insn & 0xff); | |
335 | fi->framereg = FP_REGNUM; | |
336 | } | |
337 | else if(insn == 0x1781) /* st rp,@-sp */ | |
338 | { | |
339 | sp_offset -= 4; | |
340 | fi->fsr.regs[RP_REGNUM] = sp_offset; | |
341 | } | |
342 | else if(insn == 0x170e) /* st fp,@-sp */ | |
343 | { | |
344 | sp_offset -= 4; | |
345 | fi->fsr.regs[FP_REGNUM] = sp_offset; | |
346 | } | |
347 | else if(insn == 0x8bfe) /* mov sp,fp */ | |
348 | { | |
349 | fi->framereg = FP_REGNUM; | |
350 | } | |
351 | else if((insn & 0xff00) == 0xa300) /* addsp xx */ | |
352 | { | |
353 | sp_offset += 4 * (signed char)(insn & 0xff); | |
354 | } | |
355 | else if((insn & 0xff0f) == 0x9b00 && /* ldi:20 xx,r0 */ | |
356 | read_memory_unsigned_integer(current_pc+4, 2) | |
357 | == 0xac0f) /* sub r0,sp */ | |
358 | { | |
359 | /* large stack adjustment */ | |
360 | sp_offset -= (((insn & 0xf0) << 12) | read_memory_unsigned_integer(current_pc+2, 2)); | |
361 | current_pc += 4; | |
362 | } | |
363 | else if(insn == 0x9f80 && /* ldi:32 xx,r0 */ | |
364 | read_memory_unsigned_integer(current_pc+6, 2) | |
365 | == 0xac0f) /* sub r0,sp */ | |
366 | { | |
367 | /* large stack adjustment */ | |
368 | sp_offset -= | |
369 | (read_memory_unsigned_integer(current_pc+2, 2) << 16 | | |
370 | read_memory_unsigned_integer(current_pc+4, 2)); | |
371 | current_pc += 6; | |
372 | } | |
373 | } | |
374 | ||
375 | /* The frame size is just the negative of the offset (from the original SP) | |
376 | of the last thing thing we pushed on the stack. The frame offset is | |
377 | [new FP] - [new SP]. */ | |
378 | fi->framesize = -sp_offset; | |
379 | fi->frameoffset = fp_offset - sp_offset; | |
380 | ||
381 | save_prologue_cache (fi); | |
382 | } | |
383 | ||
384 | /* Function: init_extra_frame_info | |
385 | Setup the frame's frame pointer, pc, and frame addresses for saved | |
386 | registers. Most of the work is done in scan_prologue(). | |
387 | ||
388 | Note that when we are called for the last frame (currently active frame), | |
389 | that fi->pc and fi->frame will already be setup. However, fi->frame will | |
390 | be valid only if this routine uses FP. For previous frames, fi-frame will | |
391 | always be correct (since that is derived from fr30_frame_chain ()). | |
392 | ||
393 | We can be called with the PC in the call dummy under two circumstances. | |
394 | First, during normal backtracing, second, while figuring out the frame | |
395 | pointer just prior to calling the target function (see run_stack_dummy). */ | |
396 | ||
397 | void | |
398 | fr30_init_extra_frame_info (fi) | |
399 | struct frame_info * fi; | |
400 | { | |
401 | int reg; | |
402 | ||
403 | if (fi->next) | |
404 | fi->pc = FRAME_SAVED_PC (fi->next); | |
405 | ||
406 | memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs); | |
407 | ||
408 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) | |
409 | { | |
410 | /* We need to setup fi->frame here because run_stack_dummy gets it wrong | |
411 | by assuming it's always FP. */ | |
412 | fi->frame = generic_read_register_dummy (fi->pc, fi->frame, SP_REGNUM); | |
413 | fi->framesize = 0; | |
414 | fi->frameoffset = 0; | |
415 | return; | |
416 | } | |
417 | fr30_scan_prologue (fi); | |
418 | ||
419 | if (!fi->next) /* this is the innermost frame? */ | |
420 | fi->frame = read_register (fi->framereg); | |
421 | else /* not the innermost frame */ | |
422 | /* If we have an FP, the callee saved it. */ | |
423 | if (fi->framereg == FP_REGNUM) | |
424 | if (fi->next->fsr.regs[fi->framereg] != 0) | |
425 | fi->frame = read_memory_integer (fi->next->fsr.regs[fi->framereg], | |
426 | 4); | |
427 | /* Calculate actual addresses of saved registers using offsets determined | |
428 | by fr30_scan_prologue. */ | |
429 | for (reg = 0; reg < NUM_REGS; reg++) | |
430 | if (fi->fsr.regs[reg] != 0) { | |
431 | fi->fsr.regs[reg] += fi->frame + fi->framesize - fi->frameoffset; | |
432 | } | |
433 | } | |
434 | ||
435 | /* Function: find_callers_reg | |
436 | Find REGNUM on the stack. Otherwise, it's in an active register. | |
437 | One thing we might want to do here is to check REGNUM against the | |
438 | clobber mask, and somehow flag it as invalid if it isn't saved on | |
439 | the stack somewhere. This would provide a graceful failure mode | |
440 | when trying to get the value of caller-saves registers for an inner | |
441 | frame. */ | |
442 | ||
443 | CORE_ADDR | |
444 | fr30_find_callers_reg (fi, regnum) | |
445 | struct frame_info *fi; | |
446 | int regnum; | |
447 | { | |
448 | for (; fi; fi = fi->next) | |
449 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) | |
450 | return generic_read_register_dummy (fi->pc, fi->frame, regnum); | |
451 | else if (fi->fsr.regs[regnum] != 0) | |
452 | return read_memory_unsigned_integer (fi->fsr.regs[regnum], | |
453 | REGISTER_RAW_SIZE(regnum)); | |
454 | ||
455 | return read_register (regnum); | |
456 | } | |
457 | ||
458 | ||
459 | /* Function: frame_chain | |
460 | Figure out the frame prior to FI. Unfortunately, this involves | |
461 | scanning the prologue of the caller, which will also be done | |
462 | shortly by fr30_init_extra_frame_info. For the dummy frame, we | |
463 | just return the stack pointer that was in use at the time the | |
464 | function call was made. */ | |
465 | ||
466 | ||
467 | CORE_ADDR | |
468 | fr30_frame_chain (fi) | |
469 | struct frame_info * fi; | |
470 | { | |
471 | CORE_ADDR fn_start, callers_pc, fp; | |
472 | struct frame_info caller_fi; | |
473 | int framereg; | |
474 | ||
475 | /* is this a dummy frame? */ | |
476 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) | |
477 | return fi->frame; /* dummy frame same as caller's frame */ | |
478 | ||
479 | /* is caller-of-this a dummy frame? */ | |
480 | callers_pc = FRAME_SAVED_PC(fi); /* find out who called us: */ | |
481 | fp = fr30_find_callers_reg (fi, FP_REGNUM); | |
482 | if (PC_IN_CALL_DUMMY (callers_pc, fp, fp)) | |
483 | return fp; /* dummy frame's frame may bear no relation to ours */ | |
484 | ||
485 | if (find_pc_partial_function (fi->pc, 0, &fn_start, 0)) | |
486 | if (fn_start == entry_point_address ()) | |
487 | return 0; /* in _start fn, don't chain further */ | |
488 | ||
489 | framereg = fi->framereg; | |
490 | ||
491 | /* If the caller is the startup code, we're at the end of the chain. */ | |
492 | if (find_pc_partial_function (callers_pc, 0, &fn_start, 0)) | |
493 | if (fn_start == entry_point_address ()) | |
494 | return 0; | |
495 | ||
496 | memset (& caller_fi, 0, sizeof (caller_fi)); | |
497 | caller_fi.pc = callers_pc; | |
498 | fr30_scan_prologue (& caller_fi); | |
499 | framereg = caller_fi.framereg; | |
500 | ||
501 | /* If the caller used a frame register, return its value. | |
502 | Otherwise, return the caller's stack pointer. */ | |
503 | if (framereg == FP_REGNUM) | |
504 | return fr30_find_callers_reg (fi, framereg); | |
505 | else | |
506 | return fi->frame + fi->framesize; | |
507 | } | |
508 | ||
509 | /* Function: frame_saved_pc | |
510 | Find the caller of this frame. We do this by seeing if RP_REGNUM | |
511 | is saved in the stack anywhere, otherwise we get it from the | |
512 | registers. If the inner frame is a dummy frame, return its PC | |
513 | instead of RP, because that's where "caller" of the dummy-frame | |
514 | will be found. */ | |
515 | ||
516 | CORE_ADDR | |
517 | fr30_frame_saved_pc (fi) | |
518 | struct frame_info *fi; | |
519 | { | |
520 | if (PC_IN_CALL_DUMMY(fi->pc, fi->frame, fi->frame)) | |
521 | return generic_read_register_dummy(fi->pc, fi->frame, PC_REGNUM); | |
522 | else | |
523 | return fr30_find_callers_reg (fi, RP_REGNUM); | |
524 | } | |
525 | ||
526 | /* Function: fix_call_dummy | |
527 | Pokes the callee function's address into the CALL_DUMMY assembly stub. | |
528 | Assumes that the CALL_DUMMY looks like this: | |
529 | jarl <offset24>, r31 | |
530 | trap | |
531 | */ | |
532 | ||
533 | int | |
534 | fr30_fix_call_dummy (dummy, sp, fun, nargs, args, type, gcc_p) | |
535 | char *dummy; | |
536 | CORE_ADDR sp; | |
537 | CORE_ADDR fun; | |
538 | int nargs; | |
539 | value_ptr *args; | |
540 | struct type *type; | |
541 | int gcc_p; | |
542 | { | |
543 | long offset24; | |
544 | ||
545 | offset24 = (long) fun - (long) entry_point_address (); | |
546 | offset24 &= 0x3fffff; | |
547 | offset24 |= 0xff800000; /* jarl <offset24>, r31 */ | |
548 | ||
549 | store_unsigned_integer ((unsigned int *)&dummy[2], 2, offset24 & 0xffff); | |
550 | store_unsigned_integer ((unsigned int *)&dummy[0], 2, offset24 >> 16); | |
551 | return 0; | |
552 | } |