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879b9398 GN |
1 | /* Target-dependent code for the Matsushita MN10200 for GDB, the GNU debugger. |
2 | Copyright 1997 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 | ||
a698d0d0 JL |
31 | /* The main purpose of this file is dealing with prologues to extract |
32 | information about stack frames and saved registers. | |
33 | ||
34 | For reference here's how prologues look on the mn10200: | |
35 | ||
36 | With frame pointer: | |
37 | mov fp,a0 | |
38 | mov sp,fp | |
39 | add <size>,sp | |
fe380dcc | 40 | Register saves for d2, d3, a1, a2 as needed. Saves start |
a698d0d0 JL |
41 | at fp - <size> and work towards higher addresses. Note |
42 | that the saves are actually done off the stack pointer | |
43 | in the prologue! This makes for smaller code and easier | |
44 | prologue scanning as the displacement fields will never | |
45 | be more than 8 bits! | |
46 | ||
47 | Without frame pointer: | |
48 | add <size>,sp | |
fe380dcc | 49 | Register saves for d2, d3, a1, a2 as needed. Saves start |
a698d0d0 JL |
50 | at sp and work towards higher addresses. |
51 | ||
52 | ||
53 | One day we might keep the stack pointer constant, that won't | |
54 | change the code for prologues, but it will make the frame | |
55 | pointerless case much more common. */ | |
56 | ||
57 | /* Analyze the prologue to determine where registers are saved, | |
58 | the end of the prologue, etc etc. Return the end of the prologue | |
59 | scanned. | |
60 | ||
61 | We store into FI (if non-null) several tidbits of information: | |
62 | ||
63 | * stack_size -- size of this stack frame. Note that if we stop in | |
64 | certain parts of the prologue/epilogue we may claim the size of the | |
65 | current frame is zero. This happens when the current frame has | |
66 | not been allocated yet or has already been deallocated. | |
67 | ||
68 | * fsr -- Addresses of registers saved in the stack by this frame. | |
69 | ||
70 | * status -- A (relatively) generic status indicator. It's a bitmask | |
71 | with the following bits: | |
72 | ||
73 | MY_FRAME_IN_SP: The base of the current frame is actually in | |
74 | the stack pointer. This can happen for frame pointerless | |
75 | functions, or cases where we're stopped in the prologue/epilogue | |
76 | itself. For these cases mn10200_analyze_prologue will need up | |
77 | update fi->frame before returning or analyzing the register | |
78 | save instructions. | |
79 | ||
80 | MY_FRAME_IN_FP: The base of the current frame is in the | |
81 | frame pointer register ($a2). | |
82 | ||
83 | CALLER_A2_IN_A0: $a2 from the caller's frame is temporarily | |
84 | in $a0. This can happen if we're stopped in the prologue. | |
85 | ||
86 | NO_MORE_FRAMES: Set this if the current frame is "start" or | |
87 | if the first instruction looks like mov <imm>,sp. This tells | |
88 | frame chain to not bother trying to unwind past this frame. */ | |
89 | ||
90 | #define MY_FRAME_IN_SP 0x1 | |
91 | #define MY_FRAME_IN_FP 0x2 | |
92 | #define CALLER_A2_IN_A0 0x4 | |
93 | #define NO_MORE_FRAMES 0x8 | |
94 | ||
95 | static CORE_ADDR | |
96 | mn10200_analyze_prologue (fi, pc) | |
97 | struct frame_info *fi; | |
98 | CORE_ADDR pc; | |
879b9398 | 99 | { |
a698d0d0 JL |
100 | CORE_ADDR func_addr, func_end, addr, stop; |
101 | CORE_ADDR stack_size; | |
102 | unsigned char buf[4]; | |
103 | int status; | |
104 | char *name; | |
105 | ||
106 | /* Use the PC in the frame if it's provided to look up the | |
107 | start of this function. */ | |
108 | pc = (fi ? fi->pc : pc); | |
109 | ||
110 | /* Find the start of this function. */ | |
111 | status = find_pc_partial_function (pc, &name, &func_addr, &func_end); | |
112 | ||
113 | /* Do nothing if we couldn't find the start of this function or if we're | |
114 | stopped at the first instruction in the prologue. */ | |
115 | if (status == 0) | |
116 | return pc; | |
117 | ||
118 | /* If we're in start, then give up. */ | |
119 | if (strcmp (name, "start") == 0) | |
120 | { | |
121 | fi->status = NO_MORE_FRAMES; | |
122 | return pc; | |
123 | } | |
879b9398 | 124 | |
a698d0d0 JL |
125 | /* At the start of a function our frame is in the stack pointer. */ |
126 | if (fi) | |
127 | fi->status = MY_FRAME_IN_SP; | |
879b9398 | 128 | |
a698d0d0 JL |
129 | /* If we're physically on an RTS instruction, then our frame has already |
130 | been deallocated. | |
879b9398 | 131 | |
a698d0d0 JL |
132 | fi->frame is bogus, we need to fix it. */ |
133 | if (fi && fi->pc + 1 == func_end) | |
134 | { | |
135 | status = target_read_memory (fi->pc, buf, 1); | |
136 | if (status != 0) | |
137 | { | |
05f9155f JL |
138 | if (fi->next == NULL) |
139 | fi->frame = read_sp (); | |
a698d0d0 JL |
140 | return fi->pc; |
141 | } | |
879b9398 | 142 | |
a698d0d0 JL |
143 | if (buf[0] == 0xfe) |
144 | { | |
05f9155f JL |
145 | if (fi->next == NULL) |
146 | fi->frame = read_sp (); | |
a698d0d0 JL |
147 | return fi->pc; |
148 | } | |
149 | } | |
879b9398 | 150 | |
a698d0d0 JL |
151 | /* Similarly if we're stopped on the first insn of a prologue as our |
152 | frame hasn't been allocated yet. */ | |
153 | if (fi && fi->pc == func_addr) | |
154 | { | |
05f9155f JL |
155 | if (fi->next == NULL) |
156 | fi->frame = read_sp (); | |
a698d0d0 JL |
157 | return fi->pc; |
158 | } | |
159 | ||
160 | /* Figure out where to stop scanning. */ | |
161 | stop = fi ? fi->pc : func_end; | |
162 | ||
163 | /* Don't walk off the end of the function. */ | |
164 | stop = stop > func_end ? func_end : stop; | |
165 | ||
166 | /* Start scanning on the first instruction of this function. */ | |
167 | addr = func_addr; | |
168 | ||
169 | status = target_read_memory (addr, buf, 2); | |
170 | if (status != 0) | |
879b9398 | 171 | { |
05f9155f | 172 | if (fi && fi->next == NULL && fi->status & MY_FRAME_IN_SP) |
a698d0d0 JL |
173 | fi->frame = read_sp (); |
174 | return addr; | |
879b9398 GN |
175 | } |
176 | ||
a698d0d0 JL |
177 | /* First see if this insn sets the stack pointer; if so, it's something |
178 | we won't understand, so quit now. */ | |
179 | if (buf[0] == 0xdf | |
180 | || (buf[0] == 0xf4 && buf[1] == 0x77)) | |
181 | { | |
182 | if (fi) | |
183 | fi->status = NO_MORE_FRAMES; | |
184 | return addr; | |
185 | } | |
186 | ||
187 | /* Now see if we have a frame pointer. | |
188 | ||
189 | Search for mov a2,a0 (0xf278) | |
190 | then mov a3,a2 (0xf27e). */ | |
191 | ||
192 | if (buf[0] == 0xf2 && buf[1] == 0x78) | |
193 | { | |
194 | /* Our caller's $a2 will be found in $a0 now. Note it for | |
195 | our callers. */ | |
196 | if (fi) | |
197 | fi->status |= CALLER_A2_IN_A0; | |
198 | addr += 2; | |
199 | if (addr >= stop) | |
200 | { | |
201 | /* We still haven't allocated our local stack. Handle this | |
202 | as if we stopped on the first or last insn of a function. */ | |
05f9155f | 203 | if (fi && fi->next == NULL) |
a698d0d0 JL |
204 | fi->frame = read_sp (); |
205 | return addr; | |
206 | } | |
207 | ||
208 | status = target_read_memory (addr, buf, 2); | |
209 | if (status != 0) | |
210 | { | |
05f9155f | 211 | if (fi && fi->next == NULL) |
a698d0d0 JL |
212 | fi->frame = read_sp (); |
213 | return addr; | |
214 | } | |
215 | if (buf[0] == 0xf2 && buf[1] == 0x7e) | |
216 | { | |
217 | addr += 2; | |
218 | ||
219 | /* Our frame pointer is valid now. */ | |
220 | if (fi) | |
221 | { | |
222 | fi->status |= MY_FRAME_IN_FP; | |
223 | fi->status &= ~MY_FRAME_IN_SP; | |
224 | } | |
225 | if (addr >= stop) | |
226 | return addr; | |
227 | } | |
228 | else | |
229 | { | |
05f9155f | 230 | if (fi && fi->next == NULL) |
a698d0d0 JL |
231 | fi->frame = read_sp (); |
232 | return addr; | |
233 | } | |
234 | } | |
235 | ||
236 | /* Next we should allocate the local frame. | |
237 | ||
238 | Search for add imm8,a3 (0xd3XX) | |
239 | or add imm16,a3 (0xf70bXXXX) | |
240 | or add imm24,a3 (0xf467XXXXXX). | |
241 | ||
242 | If none of the above was found, then this prologue has | |
243 | no stack, and therefore can't have any register saves, | |
244 | so quit now. */ | |
245 | status = target_read_memory (addr, buf, 2); | |
246 | if (status != 0) | |
247 | { | |
05f9155f | 248 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
a698d0d0 JL |
249 | fi->frame = read_sp (); |
250 | return addr; | |
251 | } | |
252 | if (buf[0] == 0xd3) | |
253 | { | |
254 | stack_size = extract_signed_integer (&buf[1], 1); | |
255 | if (fi) | |
256 | fi->stack_size = stack_size; | |
257 | addr += 2; | |
258 | if (addr >= stop) | |
259 | { | |
05f9155f JL |
260 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
261 | fi->frame = read_sp () - stack_size; | |
a698d0d0 JL |
262 | return addr; |
263 | } | |
264 | } | |
265 | else if (buf[0] == 0xf7 && buf[1] == 0x0b) | |
266 | { | |
267 | status = target_read_memory (addr + 2, buf, 2); | |
268 | if (status != 0) | |
269 | { | |
05f9155f | 270 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
a698d0d0 JL |
271 | fi->frame = read_sp (); |
272 | return addr; | |
273 | } | |
274 | stack_size = extract_signed_integer (buf, 2); | |
275 | if (fi) | |
276 | fi->stack_size = stack_size; | |
277 | addr += 4; | |
278 | if (addr >= stop) | |
279 | { | |
05f9155f JL |
280 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
281 | fi->frame = read_sp () - stack_size; | |
a698d0d0 JL |
282 | return addr; |
283 | } | |
284 | } | |
285 | else if (buf[0] == 0xf4 && buf[1] == 0x67) | |
286 | { | |
287 | status = target_read_memory (addr + 2, buf, 3); | |
288 | if (status != 0) | |
289 | { | |
05f9155f | 290 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
a698d0d0 JL |
291 | fi->frame = read_sp (); |
292 | return addr; | |
293 | } | |
294 | stack_size = extract_signed_integer (buf, 3); | |
295 | if (fi) | |
296 | fi->stack_size = stack_size; | |
297 | addr += 5; | |
298 | if (addr >= stop) | |
299 | { | |
05f9155f JL |
300 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
301 | fi->frame = read_sp () - stack_size; | |
a698d0d0 JL |
302 | return addr; |
303 | } | |
304 | } | |
305 | else | |
879b9398 | 306 | { |
05f9155f | 307 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
a698d0d0 JL |
308 | fi->frame = read_sp (); |
309 | return addr; | |
879b9398 GN |
310 | } |
311 | ||
a698d0d0 JL |
312 | /* At this point fi->frame needs to be correct. |
313 | ||
05f9155f JL |
314 | If MY_FRAME_IN_SP is set and we're the innermost frame, then we |
315 | need to fix fi->frame so that backtracing, find_frame_saved_regs, | |
316 | etc work correctly. */ | |
317 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP) != 0) | |
a698d0d0 JL |
318 | fi->frame = read_sp () - fi->stack_size; |
319 | ||
320 | /* And last we have the register saves. These are relatively | |
321 | simple because they're physically done off the stack pointer, | |
322 | and thus the number of different instructions we need to | |
323 | check is greatly reduced because we know the displacements | |
324 | will be small. | |
325 | ||
326 | Search for movx d2,(X,a3) (0xf55eXX) | |
327 | then movx d3,(X,a3) (0xf55fXX) | |
fe380dcc | 328 | then mov a1,(X,a3) (0x5dXX) No frame pointer case |
a698d0d0 JL |
329 | then mov a2,(X,a3) (0x5eXX) No frame pointer case |
330 | or mov a0,(X,a3) (0x5cXX) Frame pointer case. */ | |
331 | ||
332 | status = target_read_memory (addr, buf, 2); | |
333 | if (status != 0) | |
334 | return addr; | |
335 | if (buf[0] == 0xf5 && buf[1] == 0x5e) | |
336 | { | |
337 | if (fi) | |
338 | { | |
339 | status = target_read_memory (addr + 2, buf, 1); | |
340 | if (status != 0) | |
341 | return addr; | |
342 | fi->fsr.regs[2] = (fi->frame + stack_size | |
343 | + extract_signed_integer (buf, 1)); | |
344 | } | |
345 | addr += 3; | |
346 | if (addr >= stop) | |
347 | return addr; | |
348 | status = target_read_memory (addr, buf, 2); | |
349 | if (status != 0) | |
350 | return addr; | |
351 | } | |
352 | if (buf[0] == 0xf5 && buf[1] == 0x5f) | |
353 | { | |
354 | if (fi) | |
355 | { | |
356 | status = target_read_memory (addr + 2, buf, 1); | |
357 | if (status != 0) | |
358 | return addr; | |
359 | fi->fsr.regs[3] = (fi->frame + stack_size | |
360 | + extract_signed_integer (buf, 1)); | |
361 | } | |
362 | addr += 3; | |
363 | if (addr >= stop) | |
364 | return addr; | |
365 | status = target_read_memory (addr, buf, 2); | |
366 | if (status != 0) | |
367 | return addr; | |
368 | } | |
fe380dcc JL |
369 | if (buf[0] == 0x5d) |
370 | { | |
371 | if (fi) | |
372 | { | |
373 | status = target_read_memory (addr + 1, buf, 1); | |
374 | if (status != 0) | |
375 | return addr; | |
376 | fi->fsr.regs[5] = (fi->frame + stack_size | |
377 | + extract_signed_integer (buf, 1)); | |
378 | } | |
379 | addr += 2; | |
380 | if (addr >= stop) | |
381 | return addr; | |
382 | status = target_read_memory (addr, buf, 2); | |
383 | if (status != 0) | |
384 | return addr; | |
385 | } | |
a698d0d0 JL |
386 | if (buf[0] == 0x5e || buf[0] == 0x5c) |
387 | { | |
388 | if (fi) | |
389 | { | |
390 | status = target_read_memory (addr + 1, buf, 1); | |
391 | if (status != 0) | |
392 | return addr; | |
393 | fi->fsr.regs[6] = (fi->frame + stack_size | |
394 | + extract_signed_integer (buf, 1)); | |
395 | fi->status &= ~CALLER_A2_IN_A0; | |
396 | } | |
397 | addr += 2; | |
398 | if (addr >= stop) | |
399 | return addr; | |
400 | return addr; | |
401 | } | |
402 | return addr; | |
879b9398 | 403 | } |
a698d0d0 JL |
404 | |
405 | /* Function: frame_chain | |
406 | Figure out and return the caller's frame pointer given current | |
407 | frame_info struct. | |
879b9398 | 408 | |
a698d0d0 JL |
409 | We don't handle dummy frames yet but we would probably just return the |
410 | stack pointer that was in use at the time the function call was made? */ | |
879b9398 GN |
411 | |
412 | CORE_ADDR | |
a698d0d0 | 413 | mn10200_frame_chain (fi) |
879b9398 | 414 | struct frame_info *fi; |
879b9398 | 415 | { |
a698d0d0 JL |
416 | struct frame_info dummy_frame; |
417 | ||
418 | /* Walk through the prologue to determine the stack size, | |
419 | location of saved registers, end of the prologue, etc. */ | |
420 | if (fi->status == 0) | |
421 | mn10200_analyze_prologue (fi, (CORE_ADDR)0); | |
422 | ||
423 | /* Quit now if mn10200_analyze_prologue set NO_MORE_FRAMES. */ | |
424 | if (fi->status & NO_MORE_FRAMES) | |
425 | return 0; | |
426 | ||
427 | /* Now that we've analyzed our prologue, determine the frame | |
428 | pointer for our caller. | |
429 | ||
430 | If our caller has a frame pointer, then we need to | |
431 | find the entry value of $a2 to our function. | |
432 | ||
433 | If CALLER_A2_IN_A0, then the chain is in $a0. | |
434 | ||
435 | If fsr.regs[6] is nonzero, then it's at the memory | |
436 | location pointed to by fsr.regs[6]. | |
437 | ||
438 | Else it's still in $a2. | |
879b9398 | 439 | |
a698d0d0 | 440 | If our caller does not have a frame pointer, then his |
05f9155f | 441 | frame base is fi->frame + -caller's stack size + 4. */ |
a698d0d0 JL |
442 | |
443 | /* The easiest way to get that info is to analyze our caller's frame. | |
879b9398 | 444 | |
a698d0d0 JL |
445 | So we set up a dummy frame and call mn10200_analyze_prologue to |
446 | find stuff for us. */ | |
447 | dummy_frame.pc = FRAME_SAVED_PC (fi); | |
448 | dummy_frame.frame = fi->frame; | |
449 | memset (dummy_frame.fsr.regs, '\000', sizeof dummy_frame.fsr.regs); | |
450 | dummy_frame.status = 0; | |
451 | dummy_frame.stack_size = 0; | |
452 | mn10200_analyze_prologue (&dummy_frame); | |
453 | ||
454 | if (dummy_frame.status & MY_FRAME_IN_FP) | |
455 | { | |
456 | /* Our caller has a frame pointer. So find the frame in $a2, $a0, | |
457 | or in the stack. */ | |
458 | if (fi->fsr.regs[6]) | |
459 | return (read_memory_integer (fi->fsr.regs[FP_REGNUM], REGISTER_SIZE) | |
460 | & 0xffffff); | |
461 | else if (fi->status & CALLER_A2_IN_A0) | |
462 | return read_register (4); | |
463 | else | |
464 | return read_register (FP_REGNUM); | |
465 | } | |
466 | else | |
467 | { | |
468 | /* Our caller does not have a frame pointer. So his frame starts | |
469 | at the base of our frame (fi->frame) + <his size> + 4 (saved pc). */ | |
05f9155f | 470 | return fi->frame + -dummy_frame.stack_size + 4; |
a698d0d0 | 471 | } |
879b9398 GN |
472 | } |
473 | ||
474 | /* Function: skip_prologue | |
a698d0d0 | 475 | Return the address of the first inst past the prologue of the function. */ |
879b9398 GN |
476 | |
477 | CORE_ADDR | |
478 | mn10200_skip_prologue (pc) | |
479 | CORE_ADDR pc; | |
480 | { | |
481 | CORE_ADDR func_addr, func_end; | |
482 | ||
a698d0d0 JL |
483 | /* First check the symbol table. That'll be faster than scanning |
484 | the prologue instructions if we have debug sybmols. */ | |
879b9398 GN |
485 | if (find_pc_partial_function (pc, NULL, &func_addr, &func_end)) |
486 | { | |
487 | struct symtab_and_line sal; | |
488 | ||
489 | sal = find_pc_line (func_addr, 0); | |
490 | ||
491 | if (sal.line != 0 && sal.end < func_end) | |
492 | return sal.end; | |
a698d0d0 JL |
493 | |
494 | return mn10200_analyze_prologue (NULL, pc); | |
879b9398 GN |
495 | } |
496 | ||
a698d0d0 | 497 | /* We couldn't find the start of this function, do nothing. */ |
879b9398 GN |
498 | return pc; |
499 | } | |
500 | ||
501 | /* Function: pop_frame | |
502 | This routine gets called when either the user uses the `return' | |
503 | command, or the call dummy breakpoint gets hit. */ | |
504 | ||
505 | void | |
506 | mn10200_pop_frame (frame) | |
507 | struct frame_info *frame; | |
508 | { | |
509 | int regnum; | |
510 | ||
879b9398 GN |
511 | if (PC_IN_CALL_DUMMY(frame->pc, frame->frame, frame->frame)) |
512 | generic_pop_dummy_frame (); | |
513 | else | |
514 | { | |
515 | write_register (PC_REGNUM, FRAME_SAVED_PC (frame)); | |
516 | ||
a698d0d0 | 517 | /* Restore any saved registers. */ |
879b9398 GN |
518 | for (regnum = 0; regnum < NUM_REGS; regnum++) |
519 | if (frame->fsr.regs[regnum] != 0) | |
a698d0d0 JL |
520 | { |
521 | ULONGEST value; | |
522 | ||
523 | value = read_memory_unsigned_integer (frame->fsr.regs[regnum], | |
524 | REGISTER_RAW_SIZE (regnum)); | |
525 | write_register (regnum, value); | |
526 | } | |
879b9398 | 527 | |
a698d0d0 | 528 | /* Actually cut back the stack. */ |
879b9398 | 529 | write_register (SP_REGNUM, FRAME_FP (frame)); |
a698d0d0 JL |
530 | |
531 | /* Don't we need to set the PC?!? XXX FIXME. */ | |
879b9398 GN |
532 | } |
533 | ||
a698d0d0 | 534 | /* Throw away any cached frame information. */ |
879b9398 | 535 | flush_cached_frames (); |
879b9398 GN |
536 | } |
537 | ||
538 | /* Function: push_arguments | |
539 | Setup arguments for a call to the target. Arguments go in | |
a698d0d0 | 540 | order on the stack. */ |
879b9398 GN |
541 | |
542 | CORE_ADDR | |
543 | mn10200_push_arguments (nargs, args, sp, struct_return, struct_addr) | |
544 | int nargs; | |
545 | value_ptr *args; | |
546 | CORE_ADDR sp; | |
547 | unsigned char struct_return; | |
548 | CORE_ADDR struct_addr; | |
549 | { | |
550 | int argnum = 0; | |
551 | int len = 0; | |
a698d0d0 | 552 | int stack_offset = 0; |
fc5c7595 | 553 | int regsused = struct_return ? 1 : 0; |
879b9398 | 554 | |
a698d0d0 | 555 | /* This should be a nop, but align the stack just in case something |
25de138b JL |
556 | went wrong. Stacks are two byte aligned on the mn10200. */ |
557 | sp &= ~1; | |
879b9398 | 558 | |
a698d0d0 JL |
559 | /* Now make space on the stack for the args. |
560 | ||
561 | XXX This doesn't appear to handle pass-by-invisible reference | |
562 | arguments. */ | |
879b9398 | 563 | for (argnum = 0; argnum < nargs; argnum++) |
fc5c7595 JL |
564 | { |
565 | int arg_length = (TYPE_LENGTH (VALUE_TYPE (args[argnum])) + 1) & ~1; | |
566 | ||
567 | /* If we've used all argument registers, then this argument is | |
568 | pushed. */ | |
569 | if (regsused >= 2 || arg_length > 4) | |
570 | { | |
571 | regsused = 2; | |
572 | len += arg_length; | |
573 | } | |
574 | /* We know we've got some arg register space left. If this argument | |
575 | will fit entirely in regs, then put it there. */ | |
576 | else if (arg_length <= 2 | |
577 | || TYPE_CODE (VALUE_TYPE (args[argnum])) == TYPE_CODE_PTR) | |
578 | { | |
579 | regsused++; | |
580 | } | |
581 | else if (regsused == 0) | |
582 | { | |
583 | regsused = 2; | |
584 | } | |
585 | else | |
586 | { | |
587 | regsused = 2; | |
588 | len += arg_length; | |
589 | } | |
590 | } | |
879b9398 | 591 | |
a698d0d0 | 592 | /* Allocate stack space. */ |
879b9398 GN |
593 | sp -= len; |
594 | ||
fc5c7595 | 595 | regsused = struct_return ? 1 : 0; |
879b9398 GN |
596 | /* Push all arguments onto the stack. */ |
597 | for (argnum = 0; argnum < nargs; argnum++) | |
598 | { | |
599 | int len; | |
600 | char *val; | |
601 | ||
fc5c7595 | 602 | /* XXX Check this. What about UNIONS? */ |
879b9398 GN |
603 | if (TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_STRUCT |
604 | && TYPE_LENGTH (VALUE_TYPE (*args)) > 8) | |
605 | { | |
a698d0d0 | 606 | /* XXX Wrong, we want a pointer to this argument. */ |
879b9398 GN |
607 | len = TYPE_LENGTH (VALUE_TYPE (*args)); |
608 | val = (char *)VALUE_CONTENTS (*args); | |
609 | } | |
610 | else | |
611 | { | |
612 | len = TYPE_LENGTH (VALUE_TYPE (*args)); | |
613 | val = (char *)VALUE_CONTENTS (*args); | |
614 | } | |
615 | ||
fc5c7595 JL |
616 | if (regsused < 2 |
617 | && (len <= 2 | |
618 | || TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_PTR)) | |
879b9398 | 619 | { |
fc5c7595 JL |
620 | write_register (regsused, extract_unsigned_integer (val, 4)); |
621 | regsused++; | |
622 | } | |
623 | else if (regsused == 0 && len == 4) | |
624 | { | |
625 | write_register (regsused, extract_unsigned_integer (val, 2)); | |
626 | write_register (regsused + 1, extract_unsigned_integer (val + 2, 2)); | |
627 | regsused = 2; | |
628 | } | |
629 | else | |
630 | { | |
631 | regsused = 2; | |
632 | while (len > 0) | |
633 | { | |
634 | write_memory (sp + stack_offset, val, 2); | |
879b9398 | 635 | |
fc5c7595 JL |
636 | len -= 2; |
637 | val += 2; | |
638 | stack_offset += 2; | |
639 | } | |
879b9398 GN |
640 | } |
641 | args++; | |
642 | } | |
643 | ||
879b9398 GN |
644 | return sp; |
645 | } | |
646 | ||
647 | /* Function: push_return_address (pc) | |
648 | Set up the return address for the inferior function call. | |
649 | Needed for targets where we don't actually execute a JSR/BSR instruction */ | |
650 | ||
651 | CORE_ADDR | |
652 | mn10200_push_return_address (pc, sp) | |
653 | CORE_ADDR pc; | |
654 | CORE_ADDR sp; | |
655 | { | |
25de138b | 656 | unsigned char buf[4]; |
879b9398 | 657 | |
25de138b JL |
658 | store_unsigned_integer (buf, 4, CALL_DUMMY_ADDRESS ()); |
659 | write_memory (sp - 4, buf, 4); | |
660 | return sp - 4; | |
879b9398 | 661 | } |
d601a41f JL |
662 | |
663 | /* Function: store_struct_return (addr,sp) | |
664 | Store the structure value return address for an inferior function | |
665 | call. */ | |
666 | ||
667 | CORE_ADDR | |
668 | mn10200_store_struct_return (addr, sp) | |
669 | CORE_ADDR addr; | |
670 | CORE_ADDR sp; | |
671 | { | |
fc5c7595 JL |
672 | /* The structure return address is passed as the first argument. */ |
673 | write_register (0, addr); | |
674 | return sp; | |
d601a41f | 675 | } |
879b9398 GN |
676 | |
677 | /* Function: frame_saved_pc | |
678 | Find the caller of this frame. We do this by seeing if RP_REGNUM | |
679 | is saved in the stack anywhere, otherwise we get it from the | |
680 | registers. If the inner frame is a dummy frame, return its PC | |
681 | instead of RP, because that's where "caller" of the dummy-frame | |
682 | will be found. */ | |
683 | ||
684 | CORE_ADDR | |
685 | mn10200_frame_saved_pc (fi) | |
686 | struct frame_info *fi; | |
687 | { | |
a698d0d0 JL |
688 | /* The saved PC will always be at the base of the current frame. */ |
689 | return (read_memory_integer (fi->frame, REGISTER_SIZE) & 0xffffff); | |
879b9398 GN |
690 | } |
691 | ||
692 | void | |
693 | get_saved_register (raw_buffer, optimized, addrp, frame, regnum, lval) | |
694 | char *raw_buffer; | |
695 | int *optimized; | |
696 | CORE_ADDR *addrp; | |
697 | struct frame_info *frame; | |
698 | int regnum; | |
699 | enum lval_type *lval; | |
700 | { | |
879b9398 GN |
701 | generic_get_saved_register (raw_buffer, optimized, addrp, |
702 | frame, regnum, lval); | |
703 | } | |
704 | ||
705 | /* Function: init_extra_frame_info | |
706 | Setup the frame's frame pointer, pc, and frame addresses for saved | |
a698d0d0 | 707 | registers. Most of the work is done in mn10200_analyze_prologue(). |
879b9398 GN |
708 | |
709 | Note that when we are called for the last frame (currently active frame), | |
710 | that fi->pc and fi->frame will already be setup. However, fi->frame will | |
711 | be valid only if this routine uses FP. For previous frames, fi-frame will | |
a698d0d0 JL |
712 | always be correct. mn10200_analyze_prologue will fix fi->frame if |
713 | it's not valid. | |
879b9398 GN |
714 | |
715 | We can be called with the PC in the call dummy under two circumstances. | |
716 | First, during normal backtracing, second, while figuring out the frame | |
a698d0d0 | 717 | pointer just prior to calling the target function (see run_stack_dummy). */ |
879b9398 GN |
718 | |
719 | void | |
720 | mn10200_init_extra_frame_info (fi) | |
721 | struct frame_info *fi; | |
722 | { | |
879b9398 GN |
723 | if (fi->next) |
724 | fi->pc = FRAME_SAVED_PC (fi->next); | |
725 | ||
726 | memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs); | |
a698d0d0 JL |
727 | fi->status = 0; |
728 | fi->stack_size = 0; | |
879b9398 | 729 | |
a698d0d0 | 730 | mn10200_analyze_prologue (fi, 0); |
879b9398 GN |
731 | } |
732 | ||
733 | void | |
734 | _initialize_mn10200_tdep () | |
735 | { | |
879b9398 GN |
736 | tm_print_insn = print_insn_mn10200; |
737 | } | |
738 |