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c906108c SS |
1 | /* Target-dependent code for the Matsushita MN10300 for GDB, the GNU debugger. |
2 | Copyright 1996, 1997, 1998 Free Software Foundation, Inc. | |
3 | ||
c5aa993b | 4 | This file is part of GDB. |
c906108c | 5 | |
c5aa993b JM |
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. | |
c906108c | 10 | |
c5aa993b JM |
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. | |
c906108c | 15 | |
c5aa993b JM |
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, | |
19 | Boston, MA 02111-1307, USA. */ | |
c906108c SS |
20 | |
21 | #include "defs.h" | |
22 | #include "frame.h" | |
23 | #include "inferior.h" | |
24 | #include "obstack.h" | |
25 | #include "target.h" | |
26 | #include "value.h" | |
27 | #include "bfd.h" | |
28 | #include "gdb_string.h" | |
29 | #include "gdbcore.h" | |
30 | #include "symfile.h" | |
31 | ||
c5aa993b JM |
32 | static CORE_ADDR mn10300_analyze_prologue PARAMS ((struct frame_info * fi, |
33 | CORE_ADDR pc)); | |
c906108c SS |
34 | |
35 | /* Additional info used by the frame */ | |
36 | ||
37 | struct frame_extra_info | |
c5aa993b JM |
38 | { |
39 | int status; | |
40 | int stack_size; | |
41 | }; | |
c906108c | 42 | |
0f71a2f6 | 43 | |
c5aa993b JM |
44 | static char *mn10300_generic_register_names[] = |
45 | {"d0", "d1", "d2", "d3", "a0", "a1", "a2", "a3", | |
46 | "sp", "pc", "mdr", "psw", "lir", "lar", "", "", | |
47 | "", "", "", "", "", "", "", "", | |
48 | "", "", "", "", "", "", "", "fp"}; | |
0f71a2f6 JM |
49 | |
50 | static char **mn10300_register_names = mn10300_generic_register_names; | |
51 | ||
52 | char * | |
53 | mn10300_register_name (i) | |
54 | int i; | |
55 | { | |
56 | return mn10300_register_names[i]; | |
57 | } | |
58 | ||
59 | CORE_ADDR | |
60 | mn10300_saved_pc_after_call (fi) | |
61 | struct frame_info *fi; | |
62 | { | |
63 | return read_memory_integer (read_register (SP_REGNUM), 4); | |
64 | } | |
65 | ||
66 | void | |
67 | mn10300_extract_return_value (type, regbuf, valbuf) | |
68 | struct type *type; | |
69 | char *regbuf; | |
70 | char *valbuf; | |
71 | { | |
72 | if (TYPE_CODE (type) == TYPE_CODE_PTR) | |
73 | memcpy (valbuf, regbuf + REGISTER_BYTE (4), TYPE_LENGTH (type)); | |
74 | else | |
75 | memcpy (valbuf, regbuf + REGISTER_BYTE (0), TYPE_LENGTH (type)); | |
76 | } | |
77 | ||
78 | CORE_ADDR | |
79 | mn10300_extract_struct_value_address (regbuf) | |
80 | char *regbuf; | |
81 | { | |
82 | return extract_address (regbuf + REGISTER_BYTE (4), | |
83 | REGISTER_RAW_SIZE (4)); | |
84 | } | |
85 | ||
86 | void | |
87 | mn10300_store_return_value (type, valbuf) | |
88 | struct type *type; | |
89 | char *valbuf; | |
90 | { | |
91 | if (TYPE_CODE (type) == TYPE_CODE_PTR) | |
92 | write_register_bytes (REGISTER_BYTE (4), valbuf, TYPE_LENGTH (type)); | |
93 | else | |
94 | write_register_bytes (REGISTER_BYTE (0), valbuf, TYPE_LENGTH (type)); | |
95 | } | |
96 | ||
c906108c SS |
97 | static struct frame_info *analyze_dummy_frame PARAMS ((CORE_ADDR, CORE_ADDR)); |
98 | static struct frame_info * | |
99 | analyze_dummy_frame (pc, frame) | |
100 | CORE_ADDR pc; | |
101 | CORE_ADDR frame; | |
102 | { | |
103 | static struct frame_info *dummy = NULL; | |
104 | if (dummy == NULL) | |
105 | { | |
106 | dummy = xmalloc (sizeof (struct frame_info)); | |
107 | dummy->saved_regs = xmalloc (SIZEOF_FRAME_SAVED_REGS); | |
108 | dummy->extra_info = xmalloc (sizeof (struct frame_extra_info)); | |
109 | } | |
110 | dummy->next = NULL; | |
111 | dummy->prev = NULL; | |
112 | dummy->pc = pc; | |
113 | dummy->frame = frame; | |
114 | dummy->extra_info->status = 0; | |
115 | dummy->extra_info->stack_size = 0; | |
116 | memset (dummy->saved_regs, '\000', SIZEOF_FRAME_SAVED_REGS); | |
117 | mn10300_analyze_prologue (dummy, 0); | |
118 | return dummy; | |
119 | } | |
120 | ||
121 | /* Values for frame_info.status */ | |
122 | ||
123 | #define MY_FRAME_IN_SP 0x1 | |
124 | #define MY_FRAME_IN_FP 0x2 | |
125 | #define NO_MORE_FRAMES 0x4 | |
126 | ||
127 | ||
128 | /* Should call_function allocate stack space for a struct return? */ | |
129 | int | |
130 | mn10300_use_struct_convention (gcc_p, type) | |
131 | int gcc_p; | |
132 | struct type *type; | |
133 | { | |
134 | return (TYPE_NFIELDS (type) > 1 || TYPE_LENGTH (type) > 8); | |
135 | } | |
136 | ||
137 | /* The breakpoint instruction must be the same size as the smallest | |
138 | instruction in the instruction set. | |
139 | ||
140 | The Matsushita mn10x00 processors have single byte instructions | |
141 | so we need a single byte breakpoint. Matsushita hasn't defined | |
142 | one, so we defined it ourselves. */ | |
143 | ||
144 | unsigned char * | |
145 | mn10300_breakpoint_from_pc (bp_addr, bp_size) | |
146 | CORE_ADDR *bp_addr; | |
147 | int *bp_size; | |
148 | { | |
c5aa993b JM |
149 | static char breakpoint[] = |
150 | {0xff}; | |
c906108c SS |
151 | *bp_size = 1; |
152 | return breakpoint; | |
153 | } | |
154 | ||
155 | ||
156 | /* Fix fi->frame if it's bogus at this point. This is a helper | |
157 | function for mn10300_analyze_prologue. */ | |
158 | ||
159 | static void | |
160 | fix_frame_pointer (fi, stack_size) | |
c5aa993b JM |
161 | struct frame_info *fi; |
162 | int stack_size; | |
c906108c SS |
163 | { |
164 | if (fi && fi->next == NULL) | |
165 | { | |
166 | if (fi->extra_info->status & MY_FRAME_IN_SP) | |
167 | fi->frame = read_sp () - stack_size; | |
168 | else if (fi->extra_info->status & MY_FRAME_IN_FP) | |
169 | fi->frame = read_register (A3_REGNUM); | |
170 | } | |
171 | } | |
172 | ||
173 | ||
174 | /* Set offsets of registers saved by movm instruction. | |
175 | This is a helper function for mn10300_analyze_prologue. */ | |
176 | ||
177 | static void | |
178 | set_movm_offsets (fi, movm_args) | |
c5aa993b JM |
179 | struct frame_info *fi; |
180 | int movm_args; | |
c906108c SS |
181 | { |
182 | int offset = 0; | |
183 | ||
184 | if (fi == NULL || movm_args == 0) | |
185 | return; | |
186 | ||
187 | if (movm_args & 0x10) | |
188 | { | |
189 | fi->saved_regs[A3_REGNUM] = fi->frame + offset; | |
190 | offset += 4; | |
191 | } | |
192 | if (movm_args & 0x20) | |
193 | { | |
194 | fi->saved_regs[A2_REGNUM] = fi->frame + offset; | |
195 | offset += 4; | |
196 | } | |
197 | if (movm_args & 0x40) | |
198 | { | |
199 | fi->saved_regs[D3_REGNUM] = fi->frame + offset; | |
200 | offset += 4; | |
201 | } | |
202 | if (movm_args & 0x80) | |
203 | { | |
204 | fi->saved_regs[D2_REGNUM] = fi->frame + offset; | |
205 | offset += 4; | |
206 | } | |
207 | } | |
208 | ||
209 | ||
210 | /* The main purpose of this file is dealing with prologues to extract | |
211 | information about stack frames and saved registers. | |
212 | ||
213 | For reference here's how prologues look on the mn10300: | |
214 | ||
c5aa993b JM |
215 | With frame pointer: |
216 | movm [d2,d3,a2,a3],sp | |
217 | mov sp,a3 | |
218 | add <size>,sp | |
c906108c | 219 | |
c5aa993b JM |
220 | Without frame pointer: |
221 | movm [d2,d3,a2,a3],sp (if needed) | |
222 | add <size>,sp | |
c906108c SS |
223 | |
224 | One day we might keep the stack pointer constant, that won't | |
225 | change the code for prologues, but it will make the frame | |
226 | pointerless case much more common. */ | |
c5aa993b | 227 | |
c906108c SS |
228 | /* Analyze the prologue to determine where registers are saved, |
229 | the end of the prologue, etc etc. Return the end of the prologue | |
230 | scanned. | |
231 | ||
232 | We store into FI (if non-null) several tidbits of information: | |
233 | ||
c5aa993b JM |
234 | * stack_size -- size of this stack frame. Note that if we stop in |
235 | certain parts of the prologue/epilogue we may claim the size of the | |
236 | current frame is zero. This happens when the current frame has | |
237 | not been allocated yet or has already been deallocated. | |
c906108c | 238 | |
c5aa993b | 239 | * fsr -- Addresses of registers saved in the stack by this frame. |
c906108c | 240 | |
c5aa993b JM |
241 | * status -- A (relatively) generic status indicator. It's a bitmask |
242 | with the following bits: | |
c906108c | 243 | |
c5aa993b JM |
244 | MY_FRAME_IN_SP: The base of the current frame is actually in |
245 | the stack pointer. This can happen for frame pointerless | |
246 | functions, or cases where we're stopped in the prologue/epilogue | |
247 | itself. For these cases mn10300_analyze_prologue will need up | |
248 | update fi->frame before returning or analyzing the register | |
249 | save instructions. | |
c906108c | 250 | |
c5aa993b JM |
251 | MY_FRAME_IN_FP: The base of the current frame is in the |
252 | frame pointer register ($a2). | |
c906108c | 253 | |
c5aa993b JM |
254 | NO_MORE_FRAMES: Set this if the current frame is "start" or |
255 | if the first instruction looks like mov <imm>,sp. This tells | |
256 | frame chain to not bother trying to unwind past this frame. */ | |
c906108c SS |
257 | |
258 | static CORE_ADDR | |
259 | mn10300_analyze_prologue (fi, pc) | |
c5aa993b JM |
260 | struct frame_info *fi; |
261 | CORE_ADDR pc; | |
c906108c SS |
262 | { |
263 | CORE_ADDR func_addr, func_end, addr, stop; | |
264 | CORE_ADDR stack_size; | |
265 | int imm_size; | |
266 | unsigned char buf[4]; | |
267 | int status, movm_args = 0; | |
268 | char *name; | |
269 | ||
270 | /* Use the PC in the frame if it's provided to look up the | |
271 | start of this function. */ | |
272 | pc = (fi ? fi->pc : pc); | |
273 | ||
274 | /* Find the start of this function. */ | |
275 | status = find_pc_partial_function (pc, &name, &func_addr, &func_end); | |
276 | ||
277 | /* Do nothing if we couldn't find the start of this function or if we're | |
278 | stopped at the first instruction in the prologue. */ | |
279 | if (status == 0) | |
43ff13b4 JM |
280 | { |
281 | return pc; | |
282 | } | |
c906108c SS |
283 | |
284 | /* If we're in start, then give up. */ | |
285 | if (strcmp (name, "start") == 0) | |
286 | { | |
287 | if (fi != NULL) | |
288 | fi->extra_info->status = NO_MORE_FRAMES; | |
289 | return pc; | |
290 | } | |
291 | ||
292 | /* At the start of a function our frame is in the stack pointer. */ | |
293 | if (fi) | |
294 | fi->extra_info->status = MY_FRAME_IN_SP; | |
295 | ||
296 | /* Get the next two bytes into buf, we need two because rets is a two | |
297 | byte insn and the first isn't enough to uniquely identify it. */ | |
298 | status = read_memory_nobpt (pc, buf, 2); | |
299 | if (status != 0) | |
300 | return pc; | |
301 | ||
302 | /* If we're physically on an "rets" instruction, then our frame has | |
303 | already been deallocated. Note this can also be true for retf | |
304 | and ret if they specify a size of zero. | |
305 | ||
306 | In this case fi->frame is bogus, we need to fix it. */ | |
307 | if (fi && buf[0] == 0xf0 && buf[1] == 0xfc) | |
308 | { | |
309 | if (fi->next == NULL) | |
310 | fi->frame = read_sp (); | |
311 | return fi->pc; | |
312 | } | |
313 | ||
314 | /* Similarly if we're stopped on the first insn of a prologue as our | |
315 | frame hasn't been allocated yet. */ | |
316 | if (fi && fi->pc == func_addr) | |
317 | { | |
318 | if (fi->next == NULL) | |
319 | fi->frame = read_sp (); | |
320 | return fi->pc; | |
321 | } | |
322 | ||
323 | /* Figure out where to stop scanning. */ | |
324 | stop = fi ? fi->pc : func_end; | |
325 | ||
326 | /* Don't walk off the end of the function. */ | |
327 | stop = stop > func_end ? func_end : stop; | |
328 | ||
329 | /* Start scanning on the first instruction of this function. */ | |
330 | addr = func_addr; | |
331 | ||
332 | /* Suck in two bytes. */ | |
333 | status = read_memory_nobpt (addr, buf, 2); | |
334 | if (status != 0) | |
335 | { | |
336 | fix_frame_pointer (fi, 0); | |
337 | return addr; | |
338 | } | |
339 | ||
340 | /* First see if this insn sets the stack pointer; if so, it's something | |
341 | we won't understand, so quit now. */ | |
342 | if (buf[0] == 0xf2 && (buf[1] & 0xf3) == 0xf0) | |
343 | { | |
344 | if (fi) | |
345 | fi->extra_info->status = NO_MORE_FRAMES; | |
346 | return addr; | |
347 | } | |
348 | ||
349 | /* Now look for movm [regs],sp, which saves the callee saved registers. | |
350 | ||
351 | At this time we don't know if fi->frame is valid, so we only note | |
352 | that we encountered a movm instruction. Later, we'll set the entries | |
353 | in fsr.regs as needed. */ | |
354 | if (buf[0] == 0xcf) | |
355 | { | |
356 | /* Extract the register list for the movm instruction. */ | |
357 | status = read_memory_nobpt (addr + 1, buf, 1); | |
358 | movm_args = *buf; | |
359 | ||
360 | addr += 2; | |
361 | ||
362 | /* Quit now if we're beyond the stop point. */ | |
363 | if (addr >= stop) | |
364 | { | |
365 | /* Fix fi->frame since it's bogus at this point. */ | |
366 | if (fi && fi->next == NULL) | |
367 | fi->frame = read_sp (); | |
368 | ||
369 | /* Note if/where callee saved registers were saved. */ | |
370 | set_movm_offsets (fi, movm_args); | |
371 | return addr; | |
372 | } | |
373 | ||
374 | /* Get the next two bytes so the prologue scan can continue. */ | |
375 | status = read_memory_nobpt (addr, buf, 2); | |
376 | if (status != 0) | |
377 | { | |
378 | /* Fix fi->frame since it's bogus at this point. */ | |
379 | if (fi && fi->next == NULL) | |
380 | fi->frame = read_sp (); | |
381 | ||
382 | /* Note if/where callee saved registers were saved. */ | |
383 | set_movm_offsets (fi, movm_args); | |
384 | return addr; | |
385 | } | |
386 | } | |
387 | ||
388 | /* Now see if we set up a frame pointer via "mov sp,a3" */ | |
389 | if (buf[0] == 0x3f) | |
390 | { | |
391 | addr += 1; | |
392 | ||
393 | /* The frame pointer is now valid. */ | |
394 | if (fi) | |
395 | { | |
396 | fi->extra_info->status |= MY_FRAME_IN_FP; | |
397 | fi->extra_info->status &= ~MY_FRAME_IN_SP; | |
398 | } | |
399 | ||
400 | /* Quit now if we're beyond the stop point. */ | |
401 | if (addr >= stop) | |
402 | { | |
403 | /* Fix fi->frame if it's bogus at this point. */ | |
404 | fix_frame_pointer (fi, 0); | |
405 | ||
406 | /* Note if/where callee saved registers were saved. */ | |
407 | set_movm_offsets (fi, movm_args); | |
408 | return addr; | |
409 | } | |
410 | ||
411 | /* Get two more bytes so scanning can continue. */ | |
412 | status = read_memory_nobpt (addr, buf, 2); | |
413 | if (status != 0) | |
414 | { | |
415 | /* Fix fi->frame if it's bogus at this point. */ | |
416 | fix_frame_pointer (fi, 0); | |
417 | ||
418 | /* Note if/where callee saved registers were saved. */ | |
419 | set_movm_offsets (fi, movm_args); | |
420 | return addr; | |
421 | } | |
422 | } | |
c5aa993b | 423 | |
c906108c SS |
424 | /* Next we should allocate the local frame. No more prologue insns |
425 | are found after allocating the local frame. | |
c5aa993b | 426 | |
c906108c | 427 | Search for add imm8,sp (0xf8feXX) |
c5aa993b JM |
428 | or add imm16,sp (0xfafeXXXX) |
429 | or add imm32,sp (0xfcfeXXXXXXXX). | |
430 | ||
c906108c SS |
431 | If none of the above was found, then this prologue has no |
432 | additional stack. */ | |
433 | ||
434 | status = read_memory_nobpt (addr, buf, 2); | |
435 | if (status != 0) | |
436 | { | |
437 | /* Fix fi->frame if it's bogus at this point. */ | |
438 | fix_frame_pointer (fi, 0); | |
439 | ||
440 | /* Note if/where callee saved registers were saved. */ | |
441 | set_movm_offsets (fi, movm_args); | |
442 | return addr; | |
443 | } | |
444 | ||
445 | imm_size = 0; | |
446 | if (buf[0] == 0xf8 && buf[1] == 0xfe) | |
447 | imm_size = 1; | |
448 | else if (buf[0] == 0xfa && buf[1] == 0xfe) | |
449 | imm_size = 2; | |
450 | else if (buf[0] == 0xfc && buf[1] == 0xfe) | |
451 | imm_size = 4; | |
452 | ||
453 | if (imm_size != 0) | |
454 | { | |
455 | /* Suck in imm_size more bytes, they'll hold the size of the | |
456 | current frame. */ | |
457 | status = read_memory_nobpt (addr + 2, buf, imm_size); | |
458 | if (status != 0) | |
459 | { | |
460 | /* Fix fi->frame if it's bogus at this point. */ | |
461 | fix_frame_pointer (fi, 0); | |
462 | ||
463 | /* Note if/where callee saved registers were saved. */ | |
464 | set_movm_offsets (fi, movm_args); | |
465 | return addr; | |
466 | } | |
467 | ||
468 | /* Note the size of the stack in the frame info structure. */ | |
469 | stack_size = extract_signed_integer (buf, imm_size); | |
470 | if (fi) | |
471 | fi->extra_info->stack_size = stack_size; | |
472 | ||
473 | /* We just consumed 2 + imm_size bytes. */ | |
474 | addr += 2 + imm_size; | |
475 | ||
476 | /* No more prologue insns follow, so begin preparation to return. */ | |
477 | /* Fix fi->frame if it's bogus at this point. */ | |
478 | fix_frame_pointer (fi, stack_size); | |
479 | ||
480 | /* Note if/where callee saved registers were saved. */ | |
481 | set_movm_offsets (fi, movm_args); | |
482 | return addr; | |
483 | } | |
484 | ||
485 | /* We never found an insn which allocates local stack space, regardless | |
486 | this is the end of the prologue. */ | |
487 | /* Fix fi->frame if it's bogus at this point. */ | |
488 | fix_frame_pointer (fi, 0); | |
489 | ||
490 | /* Note if/where callee saved registers were saved. */ | |
491 | set_movm_offsets (fi, movm_args); | |
492 | return addr; | |
493 | } | |
c5aa993b | 494 | |
c906108c SS |
495 | /* Function: frame_chain |
496 | Figure out and return the caller's frame pointer given current | |
497 | frame_info struct. | |
498 | ||
499 | We don't handle dummy frames yet but we would probably just return the | |
500 | stack pointer that was in use at the time the function call was made? */ | |
501 | ||
502 | CORE_ADDR | |
503 | mn10300_frame_chain (fi) | |
504 | struct frame_info *fi; | |
505 | { | |
506 | struct frame_info *dummy; | |
507 | /* Walk through the prologue to determine the stack size, | |
508 | location of saved registers, end of the prologue, etc. */ | |
509 | if (fi->extra_info->status == 0) | |
c5aa993b | 510 | mn10300_analyze_prologue (fi, (CORE_ADDR) 0); |
c906108c SS |
511 | |
512 | /* Quit now if mn10300_analyze_prologue set NO_MORE_FRAMES. */ | |
513 | if (fi->extra_info->status & NO_MORE_FRAMES) | |
514 | return 0; | |
515 | ||
516 | /* Now that we've analyzed our prologue, determine the frame | |
517 | pointer for our caller. | |
518 | ||
c5aa993b JM |
519 | If our caller has a frame pointer, then we need to |
520 | find the entry value of $a3 to our function. | |
521 | ||
522 | If fsr.regs[A3_REGNUM] is nonzero, then it's at the memory | |
523 | location pointed to by fsr.regs[A3_REGNUM]. | |
c906108c | 524 | |
c5aa993b | 525 | Else it's still in $a3. |
c906108c | 526 | |
c5aa993b JM |
527 | If our caller does not have a frame pointer, then his |
528 | frame base is fi->frame + -caller's stack size. */ | |
c906108c | 529 | |
c906108c SS |
530 | /* The easiest way to get that info is to analyze our caller's frame. |
531 | So we set up a dummy frame and call mn10300_analyze_prologue to | |
532 | find stuff for us. */ | |
533 | dummy = analyze_dummy_frame (FRAME_SAVED_PC (fi), fi->frame); | |
534 | ||
535 | if (dummy->extra_info->status & MY_FRAME_IN_FP) | |
536 | { | |
537 | /* Our caller has a frame pointer. So find the frame in $a3 or | |
538 | in the stack. */ | |
539 | if (fi->saved_regs[A3_REGNUM]) | |
540 | return (read_memory_integer (fi->saved_regs[A3_REGNUM], REGISTER_SIZE)); | |
541 | else | |
542 | return read_register (A3_REGNUM); | |
543 | } | |
544 | else | |
545 | { | |
546 | int adjust = 0; | |
547 | ||
548 | adjust += (fi->saved_regs[D2_REGNUM] ? 4 : 0); | |
549 | adjust += (fi->saved_regs[D3_REGNUM] ? 4 : 0); | |
550 | adjust += (fi->saved_regs[A2_REGNUM] ? 4 : 0); | |
551 | adjust += (fi->saved_regs[A3_REGNUM] ? 4 : 0); | |
552 | ||
553 | /* Our caller does not have a frame pointer. So his frame starts | |
c5aa993b JM |
554 | at the base of our frame (fi->frame) + register save space |
555 | + <his size>. */ | |
c906108c SS |
556 | return fi->frame + adjust + -dummy->extra_info->stack_size; |
557 | } | |
558 | } | |
559 | ||
560 | /* Function: skip_prologue | |
561 | Return the address of the first inst past the prologue of the function. */ | |
562 | ||
563 | CORE_ADDR | |
564 | mn10300_skip_prologue (pc) | |
565 | CORE_ADDR pc; | |
566 | { | |
567 | /* We used to check the debug symbols, but that can lose if | |
568 | we have a null prologue. */ | |
569 | return mn10300_analyze_prologue (NULL, pc); | |
570 | } | |
571 | ||
572 | ||
573 | /* Function: pop_frame | |
574 | This routine gets called when either the user uses the `return' | |
575 | command, or the call dummy breakpoint gets hit. */ | |
576 | ||
577 | void | |
578 | mn10300_pop_frame (frame) | |
579 | struct frame_info *frame; | |
580 | { | |
581 | int regnum; | |
582 | ||
c5aa993b | 583 | if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame)) |
c906108c SS |
584 | generic_pop_dummy_frame (); |
585 | else | |
586 | { | |
587 | write_register (PC_REGNUM, FRAME_SAVED_PC (frame)); | |
588 | ||
589 | /* Restore any saved registers. */ | |
590 | for (regnum = 0; regnum < NUM_REGS; regnum++) | |
591 | if (frame->saved_regs[regnum] != 0) | |
592 | { | |
593 | ULONGEST value; | |
594 | ||
595 | value = read_memory_unsigned_integer (frame->saved_regs[regnum], | |
c5aa993b | 596 | REGISTER_RAW_SIZE (regnum)); |
c906108c SS |
597 | write_register (regnum, value); |
598 | } | |
599 | ||
600 | /* Actually cut back the stack. */ | |
601 | write_register (SP_REGNUM, FRAME_FP (frame)); | |
602 | ||
603 | /* Don't we need to set the PC?!? XXX FIXME. */ | |
604 | } | |
605 | ||
606 | /* Throw away any cached frame information. */ | |
607 | flush_cached_frames (); | |
608 | } | |
609 | ||
610 | /* Function: push_arguments | |
611 | Setup arguments for a call to the target. Arguments go in | |
612 | order on the stack. */ | |
613 | ||
614 | CORE_ADDR | |
615 | mn10300_push_arguments (nargs, args, sp, struct_return, struct_addr) | |
616 | int nargs; | |
617 | value_ptr *args; | |
618 | CORE_ADDR sp; | |
619 | unsigned char struct_return; | |
620 | CORE_ADDR struct_addr; | |
621 | { | |
622 | int argnum = 0; | |
623 | int len = 0; | |
624 | int stack_offset = 0; | |
625 | int regsused = struct_return ? 1 : 0; | |
626 | ||
627 | /* This should be a nop, but align the stack just in case something | |
628 | went wrong. Stacks are four byte aligned on the mn10300. */ | |
629 | sp &= ~3; | |
630 | ||
631 | /* Now make space on the stack for the args. | |
632 | ||
633 | XXX This doesn't appear to handle pass-by-invisible reference | |
634 | arguments. */ | |
635 | for (argnum = 0; argnum < nargs; argnum++) | |
636 | { | |
637 | int arg_length = (TYPE_LENGTH (VALUE_TYPE (args[argnum])) + 3) & ~3; | |
638 | ||
639 | while (regsused < 2 && arg_length > 0) | |
640 | { | |
641 | regsused++; | |
642 | arg_length -= 4; | |
643 | } | |
644 | len += arg_length; | |
645 | } | |
646 | ||
647 | /* Allocate stack space. */ | |
648 | sp -= len; | |
649 | ||
650 | regsused = struct_return ? 1 : 0; | |
651 | /* Push all arguments onto the stack. */ | |
652 | for (argnum = 0; argnum < nargs; argnum++) | |
653 | { | |
654 | int len; | |
655 | char *val; | |
656 | ||
657 | /* XXX Check this. What about UNIONS? */ | |
658 | if (TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_STRUCT | |
659 | && TYPE_LENGTH (VALUE_TYPE (*args)) > 8) | |
660 | { | |
661 | /* XXX Wrong, we want a pointer to this argument. */ | |
c5aa993b JM |
662 | len = TYPE_LENGTH (VALUE_TYPE (*args)); |
663 | val = (char *) VALUE_CONTENTS (*args); | |
c906108c SS |
664 | } |
665 | else | |
666 | { | |
667 | len = TYPE_LENGTH (VALUE_TYPE (*args)); | |
c5aa993b | 668 | val = (char *) VALUE_CONTENTS (*args); |
c906108c SS |
669 | } |
670 | ||
671 | while (regsused < 2 && len > 0) | |
672 | { | |
673 | write_register (regsused, extract_unsigned_integer (val, 4)); | |
674 | val += 4; | |
675 | len -= 4; | |
676 | regsused++; | |
677 | } | |
678 | ||
679 | while (len > 0) | |
680 | { | |
681 | write_memory (sp + stack_offset, val, 4); | |
682 | len -= 4; | |
683 | val += 4; | |
684 | stack_offset += 4; | |
685 | } | |
686 | ||
687 | args++; | |
688 | } | |
689 | ||
690 | /* Make space for the flushback area. */ | |
691 | sp -= 8; | |
692 | return sp; | |
693 | } | |
694 | ||
695 | /* Function: push_return_address (pc) | |
696 | Set up the return address for the inferior function call. | |
697 | Needed for targets where we don't actually execute a JSR/BSR instruction */ | |
c5aa993b | 698 | |
c906108c SS |
699 | CORE_ADDR |
700 | mn10300_push_return_address (pc, sp) | |
701 | CORE_ADDR pc; | |
702 | CORE_ADDR sp; | |
703 | { | |
704 | unsigned char buf[4]; | |
705 | ||
706 | store_unsigned_integer (buf, 4, CALL_DUMMY_ADDRESS ()); | |
707 | write_memory (sp - 4, buf, 4); | |
708 | return sp - 4; | |
709 | } | |
710 | ||
711 | /* Function: store_struct_return (addr,sp) | |
712 | Store the structure value return address for an inferior function | |
713 | call. */ | |
c5aa993b | 714 | |
c906108c SS |
715 | CORE_ADDR |
716 | mn10300_store_struct_return (addr, sp) | |
717 | CORE_ADDR addr; | |
718 | CORE_ADDR sp; | |
719 | { | |
720 | /* The structure return address is passed as the first argument. */ | |
721 | write_register (0, addr); | |
722 | return sp; | |
723 | } | |
c5aa993b | 724 | |
c906108c SS |
725 | /* Function: frame_saved_pc |
726 | Find the caller of this frame. We do this by seeing if RP_REGNUM | |
727 | is saved in the stack anywhere, otherwise we get it from the | |
728 | registers. If the inner frame is a dummy frame, return its PC | |
729 | instead of RP, because that's where "caller" of the dummy-frame | |
730 | will be found. */ | |
731 | ||
732 | CORE_ADDR | |
733 | mn10300_frame_saved_pc (fi) | |
734 | struct frame_info *fi; | |
735 | { | |
736 | int adjust = 0; | |
737 | ||
738 | adjust += (fi->saved_regs[D2_REGNUM] ? 4 : 0); | |
739 | adjust += (fi->saved_regs[D3_REGNUM] ? 4 : 0); | |
740 | adjust += (fi->saved_regs[A2_REGNUM] ? 4 : 0); | |
741 | adjust += (fi->saved_regs[A3_REGNUM] ? 4 : 0); | |
742 | ||
743 | return (read_memory_integer (fi->frame + adjust, REGISTER_SIZE)); | |
744 | } | |
745 | ||
c906108c SS |
746 | /* Function: mn10300_init_extra_frame_info |
747 | Setup the frame's frame pointer, pc, and frame addresses for saved | |
748 | registers. Most of the work is done in mn10300_analyze_prologue(). | |
749 | ||
750 | Note that when we are called for the last frame (currently active frame), | |
751 | that fi->pc and fi->frame will already be setup. However, fi->frame will | |
752 | be valid only if this routine uses FP. For previous frames, fi-frame will | |
753 | always be correct. mn10300_analyze_prologue will fix fi->frame if | |
754 | it's not valid. | |
755 | ||
756 | We can be called with the PC in the call dummy under two circumstances. | |
757 | First, during normal backtracing, second, while figuring out the frame | |
758 | pointer just prior to calling the target function (see run_stack_dummy). */ | |
759 | ||
760 | void | |
761 | mn10300_init_extra_frame_info (fi) | |
762 | struct frame_info *fi; | |
763 | { | |
764 | if (fi->next) | |
765 | fi->pc = FRAME_SAVED_PC (fi->next); | |
766 | ||
767 | frame_saved_regs_zalloc (fi); | |
768 | fi->extra_info = (struct frame_extra_info *) | |
769 | frame_obstack_alloc (sizeof (struct frame_extra_info)); | |
770 | ||
771 | fi->extra_info->status = 0; | |
772 | fi->extra_info->stack_size = 0; | |
773 | ||
774 | mn10300_analyze_prologue (fi, 0); | |
775 | } | |
776 | ||
777 | /* Function: mn10300_virtual_frame_pointer | |
778 | Return the register that the function uses for a frame pointer, | |
779 | plus any necessary offset to be applied to the register before | |
780 | any frame pointer offsets. */ | |
781 | ||
782 | void | |
783 | mn10300_virtual_frame_pointer (pc, reg, offset) | |
784 | CORE_ADDR pc; | |
785 | long *reg; | |
786 | long *offset; | |
787 | { | |
788 | struct frame_info *dummy = analyze_dummy_frame (pc, 0); | |
789 | /* Set up a dummy frame_info, Analyze the prolog and fill in the | |
790 | extra info. */ | |
791 | /* Results will tell us which type of frame it uses. */ | |
792 | if (dummy->extra_info->status & MY_FRAME_IN_SP) | |
793 | { | |
c5aa993b | 794 | *reg = SP_REGNUM; |
c906108c SS |
795 | *offset = -(dummy->extra_info->stack_size); |
796 | } | |
797 | else | |
798 | { | |
c5aa993b | 799 | *reg = A3_REGNUM; |
c906108c SS |
800 | *offset = 0; |
801 | } | |
802 | } | |
c5aa993b | 803 | |
c906108c SS |
804 | /* This can be made more generic later. */ |
805 | static void | |
806 | set_machine_hook (filename) | |
807 | char *filename; | |
808 | { | |
809 | int i; | |
810 | ||
811 | if (bfd_get_mach (exec_bfd) == bfd_mach_mn10300 | |
812 | || bfd_get_mach (exec_bfd) == 0) | |
813 | { | |
814 | mn10300_register_names = mn10300_generic_register_names; | |
815 | } | |
816 | ||
817 | } | |
818 | ||
819 | void | |
820 | _initialize_mn10300_tdep () | |
821 | { | |
822 | /* printf("_initialize_mn10300_tdep\n"); */ | |
823 | ||
824 | tm_print_insn = print_insn_mn10300; | |
825 | ||
826 | specify_exec_file_hook (set_machine_hook); | |
827 | } |