Commit | Line | Data |
---|---|---|
c906108c SS |
1 | /* Target-dependent code for the Mitsubishi m32r for GDB, the GNU debugger. |
2 | Copyright 1996, 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 | ||
32 | /* Function: m32r_use_struct_convention | |
33 | Return nonzero if call_function should allocate stack space for a | |
34 | struct return? */ | |
35 | int | |
36 | m32r_use_struct_convention (gcc_p, type) | |
37 | int gcc_p; | |
38 | struct type *type; | |
39 | { | |
40 | return (TYPE_LENGTH (type) > 8); | |
41 | } | |
42 | ||
43 | /* Function: frame_find_saved_regs | |
44 | Return the frame_saved_regs structure for the frame. | |
45 | Doesn't really work for dummy frames, but it does pass back | |
46 | an empty frame_saved_regs, so I guess that's better than total failure */ | |
47 | ||
c5aa993b | 48 | void |
c906108c SS |
49 | m32r_frame_find_saved_regs (fi, regaddr) |
50 | struct frame_info *fi; | |
51 | struct frame_saved_regs *regaddr; | |
52 | { | |
c5aa993b | 53 | memcpy (regaddr, &fi->fsr, sizeof (struct frame_saved_regs)); |
c906108c SS |
54 | } |
55 | ||
56 | /* Turn this on if you want to see just how much instruction decoding | |
57 | if being done, its quite a lot | |
c5aa993b | 58 | */ |
c906108c | 59 | #if 0 |
c5aa993b JM |
60 | static void |
61 | dump_insn (char *commnt, CORE_ADDR pc, int insn) | |
c906108c | 62 | { |
c5aa993b JM |
63 | printf_filtered (" %s %08x %08x ", |
64 | commnt, (unsigned int) pc, (unsigned int) insn); | |
65 | (*tm_print_insn) (pc, &tm_print_insn_info); | |
66 | printf_filtered ("\n"); | |
c906108c SS |
67 | } |
68 | #define insn_debug(args) { printf_filtered args; } | |
69 | #else | |
70 | #define dump_insn(a,b,c) {} | |
71 | #define insn_debug(args) {} | |
72 | #endif | |
73 | ||
c5aa993b | 74 | #define DEFAULT_SEARCH_LIMIT 44 |
c906108c SS |
75 | |
76 | /* Function: scan_prologue | |
77 | This function decodes the target function prologue to determine | |
78 | 1) the size of the stack frame, and 2) which registers are saved on it. | |
79 | It saves the offsets of saved regs in the frame_saved_regs argument, | |
80 | and returns the frame size. */ | |
81 | ||
82 | /* | |
c5aa993b JM |
83 | The sequence it currently generates is: |
84 | ||
85 | if (varargs function) { ddi sp,#n } | |
86 | push registers | |
87 | if (additional stack <= 256) { addi sp,#-stack } | |
88 | else if (additional stack < 65k) { add3 sp,sp,#-stack | |
89 | ||
90 | } else if (additional stack) { | |
91 | seth sp,#(stack & 0xffff0000) | |
92 | or3 sp,sp,#(stack & 0x0000ffff) | |
93 | sub sp,r4 | |
94 | } | |
95 | if (frame pointer) { | |
96 | mv sp,fp | |
97 | } | |
c906108c | 98 | |
c5aa993b JM |
99 | These instructions are scheduled like everything else, so you should stop at |
100 | the first branch instruction. | |
101 | ||
102 | */ | |
c906108c SS |
103 | |
104 | /* This is required by skip prologue and by m32r_init_extra_frame_info. | |
105 | The results of decoding a prologue should be cached because this | |
106 | thrashing is getting nuts. | |
107 | I am thinking of making a container class with two indexes, name and | |
108 | address. It may be better to extend the symbol table. | |
c5aa993b | 109 | */ |
c906108c | 110 | |
c5aa993b JM |
111 | static void |
112 | decode_prologue (start_pc, scan_limit, | |
113 | pl_endptr, framelength, | |
114 | fi, fsr) | |
c906108c SS |
115 | CORE_ADDR start_pc; |
116 | CORE_ADDR scan_limit; | |
c5aa993b JM |
117 | CORE_ADDR *pl_endptr; /* var parameter */ |
118 | unsigned long *framelength; | |
119 | struct frame_info *fi; | |
120 | struct frame_saved_regs *fsr; | |
c906108c SS |
121 | { |
122 | unsigned long framesize; | |
123 | int insn; | |
124 | int op1; | |
125 | int maybe_one_more = 0; | |
126 | CORE_ADDR after_prologue = 0; | |
127 | CORE_ADDR after_stack_adjust = 0; | |
128 | CORE_ADDR current_pc; | |
129 | ||
130 | ||
131 | framesize = 0; | |
132 | after_prologue = 0; | |
c5aa993b | 133 | insn_debug (("rd prolog l(%d)\n", scan_limit - current_pc)); |
c906108c SS |
134 | |
135 | for (current_pc = start_pc; current_pc < scan_limit; current_pc += 2) | |
136 | { | |
137 | ||
138 | insn = read_memory_unsigned_integer (current_pc, 2); | |
c5aa993b JM |
139 | dump_insn ("insn-1", current_pc, insn); /* MTZ */ |
140 | ||
141 | /* If this is a 32 bit instruction, we dont want to examine its | |
142 | immediate data as though it were an instruction */ | |
c906108c | 143 | if (current_pc & 0x02) |
c5aa993b | 144 | { /* Clear the parallel execution bit from 16 bit instruction */ |
c906108c | 145 | if (maybe_one_more) |
c5aa993b JM |
146 | { /* The last instruction was a branch, usually terminates |
147 | the series, but if this is a parallel instruction, | |
148 | it may be a stack framing instruction */ | |
149 | if (!(insn & 0x8000)) | |
150 | { | |
151 | insn_debug (("Really done")); | |
152 | break; /* nope, we are really done */ | |
c906108c SS |
153 | } |
154 | } | |
c5aa993b | 155 | insn &= 0x7fff; /* decode this instruction further */ |
c906108c SS |
156 | } |
157 | else | |
158 | { | |
c5aa993b JM |
159 | if (maybe_one_more) |
160 | break; /* This isnt the one more */ | |
c906108c SS |
161 | if (insn & 0x8000) |
162 | { | |
c5aa993b | 163 | insn_debug (("32 bit insn\n")); |
c906108c | 164 | if (current_pc == scan_limit) |
c5aa993b JM |
165 | scan_limit += 2; /* extend the search */ |
166 | current_pc += 2; /* skip the immediate data */ | |
167 | if (insn == 0x8faf) /* add3 sp, sp, xxxx */ | |
c906108c | 168 | /* add 16 bit sign-extended offset */ |
c5aa993b JM |
169 | { |
170 | insn_debug (("stack increment\n")); | |
171 | framesize += -((short) read_memory_unsigned_integer (current_pc, 2)); | |
c906108c SS |
172 | } |
173 | else | |
174 | { | |
c5aa993b JM |
175 | if (((insn >> 8) == 0xe4) && /* ld24 r4, xxxxxx; sub sp, r4 */ |
176 | read_memory_unsigned_integer (current_pc + 2, 2) == 0x0f24) | |
177 | { /* subtract 24 bit sign-extended negative-offset */ | |
178 | dump_insn ("insn-2", current_pc + 2, insn); | |
c906108c | 179 | insn = read_memory_unsigned_integer (current_pc - 2, 4); |
c5aa993b | 180 | dump_insn ("insn-3(l4)", current_pc - 2, insn); |
c906108c | 181 | if (insn & 0x00800000) /* sign extend */ |
c5aa993b | 182 | insn |= 0xff000000; /* negative */ |
c906108c | 183 | else |
c5aa993b | 184 | insn &= 0x00ffffff; /* positive */ |
c906108c SS |
185 | framesize += insn; |
186 | } | |
187 | } | |
188 | after_prologue = current_pc; | |
189 | continue; | |
190 | } | |
191 | } | |
c5aa993b JM |
192 | op1 = insn & 0xf000; /* isolate just the first nibble */ |
193 | ||
c906108c | 194 | if ((insn & 0xf0ff) == 0x207f) |
c5aa993b | 195 | { /* st reg, @-sp */ |
c906108c | 196 | int regno; |
c5aa993b JM |
197 | insn_debug (("push\n")); |
198 | #if 0 /* No, PUSH FP is not an indication that we will use a frame pointer. */ | |
199 | if (((insn & 0xffff) == 0x2d7f) && fi) | |
c906108c SS |
200 | fi->using_frame_pointer = 1; |
201 | #endif | |
c5aa993b JM |
202 | framesize += 4; |
203 | #if 0 | |
c906108c SS |
204 | /* Why should we increase the scan limit, just because we did a push? |
205 | And if there is a reason, surely we would only want to do it if we | |
206 | had already reached the scan limit... */ | |
207 | if (current_pc == scan_limit) | |
208 | scan_limit += 2; | |
209 | #endif | |
210 | regno = ((insn >> 8) & 0xf); | |
c5aa993b | 211 | if (fsr) /* save_regs offset */ |
c906108c SS |
212 | fsr->regs[regno] = framesize; |
213 | after_prologue = 0; | |
c5aa993b | 214 | continue; |
c906108c | 215 | } |
c5aa993b | 216 | if ((insn >> 8) == 0x4f) /* addi sp, xx */ |
c906108c SS |
217 | /* add 8 bit sign-extended offset */ |
218 | { | |
219 | int stack_adjust = (char) (insn & 0xff); | |
220 | ||
221 | /* there are probably two of these stack adjustments: | |
222 | 1) A negative one in the prologue, and | |
223 | 2) A positive one in the epilogue. | |
224 | We are only interested in the first one. */ | |
225 | ||
226 | if (stack_adjust < 0) | |
227 | { | |
228 | framesize -= stack_adjust; | |
229 | after_prologue = 0; | |
230 | /* A frameless function may have no "mv fp, sp". | |
c5aa993b | 231 | In that case, this is the end of the prologue. */ |
c906108c SS |
232 | after_stack_adjust = current_pc + 2; |
233 | } | |
234 | continue; | |
235 | } | |
c5aa993b JM |
236 | if (insn == 0x1d8f) |
237 | { /* mv fp, sp */ | |
238 | if (fi) | |
239 | fi->using_frame_pointer = 1; /* fp is now valid */ | |
240 | insn_debug (("done fp found\n")); | |
241 | after_prologue = current_pc + 2; | |
242 | break; /* end of stack adjustments */ | |
243 | } | |
244 | if (insn == 0x7000) /* Nop looks like a branch, continue explicitly */ | |
245 | { | |
246 | insn_debug (("nop\n")); | |
247 | after_prologue = current_pc + 2; | |
248 | continue; /* nop occurs between pushes */ | |
c906108c SS |
249 | } |
250 | /* End of prolog if any of these are branch instructions */ | |
251 | if ((op1 == 0x7000) | |
c5aa993b | 252 | || (op1 == 0xb000) |
cff3e48b | 253 | || (op1 == 0xf000)) |
c906108c SS |
254 | { |
255 | after_prologue = current_pc; | |
c5aa993b | 256 | insn_debug (("Done: branch\n")); |
c906108c SS |
257 | maybe_one_more = 1; |
258 | continue; | |
259 | } | |
260 | /* Some of the branch instructions are mixed with other types */ | |
261 | if (op1 == 0x1000) | |
c5aa993b JM |
262 | { |
263 | int subop = insn & 0x0ff0; | |
c906108c | 264 | if ((subop == 0x0ec0) || (subop == 0x0fc0)) |
c5aa993b JM |
265 | { |
266 | insn_debug (("done: jmp\n")); | |
c906108c SS |
267 | after_prologue = current_pc; |
268 | maybe_one_more = 1; | |
c5aa993b | 269 | continue; /* jmp , jl */ |
c906108c SS |
270 | } |
271 | } | |
272 | } | |
273 | ||
274 | if (current_pc >= scan_limit) | |
275 | { | |
c5aa993b | 276 | if (pl_endptr) |
7a292a7a | 277 | { |
c906108c | 278 | #if 1 |
7a292a7a SS |
279 | if (after_stack_adjust != 0) |
280 | /* We did not find a "mv fp,sp", but we DID find | |
281 | a stack_adjust. Is it safe to use that as the | |
282 | end of the prologue? I just don't know. */ | |
283 | { | |
284 | *pl_endptr = after_stack_adjust; | |
285 | if (framelength) | |
286 | *framelength = framesize; | |
287 | } | |
288 | else | |
c906108c | 289 | #endif |
7a292a7a SS |
290 | /* We reached the end of the loop without finding the end |
291 | of the prologue. No way to win -- we should report failure. | |
292 | The way we do that is to return the original start_pc. | |
293 | GDB will set a breakpoint at the start of the function (etc.) */ | |
294 | *pl_endptr = start_pc; | |
c5aa993b | 295 | } |
c906108c SS |
296 | return; |
297 | } | |
c5aa993b | 298 | if (after_prologue == 0) |
c906108c SS |
299 | after_prologue = current_pc; |
300 | ||
c5aa993b JM |
301 | insn_debug ((" framesize %d, firstline %08x\n", framesize, after_prologue)); |
302 | if (framelength) | |
c906108c | 303 | *framelength = framesize; |
c5aa993b | 304 | if (pl_endptr) |
c906108c | 305 | *pl_endptr = after_prologue; |
c5aa993b | 306 | } /* decode_prologue */ |
c906108c SS |
307 | |
308 | /* Function: skip_prologue | |
309 | Find end of function prologue */ | |
310 | ||
311 | CORE_ADDR | |
312 | m32r_skip_prologue (pc) | |
313 | CORE_ADDR pc; | |
314 | { | |
315 | CORE_ADDR func_addr, func_end; | |
316 | struct symtab_and_line sal; | |
317 | ||
318 | /* See what the symbol table says */ | |
319 | ||
320 | if (find_pc_partial_function (pc, NULL, &func_addr, &func_end)) | |
321 | { | |
322 | sal = find_pc_line (func_addr, 0); | |
323 | ||
324 | if (sal.line != 0 && sal.end <= func_end) | |
325 | { | |
c5aa993b JM |
326 | |
327 | insn_debug (("BP after prologue %08x\n", sal.end)); | |
c906108c SS |
328 | func_end = sal.end; |
329 | } | |
330 | else | |
331 | /* Either there's no line info, or the line after the prologue is after | |
332 | the end of the function. In this case, there probably isn't a | |
333 | prologue. */ | |
334 | { | |
c5aa993b JM |
335 | insn_debug (("No line info, line(%x) sal_end(%x) funcend(%x)\n", |
336 | sal.line, sal.end, func_end)); | |
337 | func_end = min (func_end, func_addr + DEFAULT_SEARCH_LIMIT); | |
c906108c SS |
338 | } |
339 | } | |
c5aa993b | 340 | else |
c906108c SS |
341 | func_end = pc + DEFAULT_SEARCH_LIMIT; |
342 | decode_prologue (pc, func_end, &sal.end, 0, 0, 0); | |
343 | return sal.end; | |
344 | } | |
345 | ||
346 | static unsigned long | |
347 | m32r_scan_prologue (fi, fsr) | |
348 | struct frame_info *fi; | |
349 | struct frame_saved_regs *fsr; | |
350 | { | |
351 | struct symtab_and_line sal; | |
352 | CORE_ADDR prologue_start, prologue_end, current_pc; | |
cff3e48b | 353 | unsigned long framesize = 0; |
c906108c SS |
354 | |
355 | /* this code essentially duplicates skip_prologue, | |
356 | but we need the start address below. */ | |
357 | ||
358 | if (find_pc_partial_function (fi->pc, NULL, &prologue_start, &prologue_end)) | |
359 | { | |
360 | sal = find_pc_line (prologue_start, 0); | |
361 | ||
c5aa993b | 362 | if (sal.line == 0) /* no line info, use current PC */ |
c906108c SS |
363 | if (prologue_start == entry_point_address ()) |
364 | return 0; | |
365 | } | |
366 | else | |
367 | { | |
368 | prologue_start = fi->pc; | |
c5aa993b JM |
369 | prologue_end = prologue_start + 48; /* We're in the boondocks: |
370 | allow for 16 pushes, an add, | |
371 | and "mv fp,sp" */ | |
c906108c SS |
372 | } |
373 | #if 0 | |
374 | prologue_end = min (prologue_end, fi->pc); | |
375 | #endif | |
c5aa993b JM |
376 | insn_debug (("fipc(%08x) start(%08x) end(%08x)\n", |
377 | fi->pc, prologue_start, prologue_end)); | |
378 | prologue_end = min (prologue_end, prologue_start + DEFAULT_SEARCH_LIMIT); | |
379 | decode_prologue (prologue_start, prologue_end, &prologue_end, &framesize, | |
380 | fi, fsr); | |
c906108c SS |
381 | return framesize; |
382 | } | |
383 | ||
384 | /* Function: init_extra_frame_info | |
385 | This function actually figures out the frame address for a given pc and | |
386 | sp. This is tricky on the m32r because we sometimes don't use an explicit | |
387 | frame pointer, and the previous stack pointer isn't necessarily recorded | |
388 | on the stack. The only reliable way to get this info is to | |
389 | examine the prologue. */ | |
390 | ||
391 | void | |
392 | m32r_init_extra_frame_info (fi) | |
393 | struct frame_info *fi; | |
394 | { | |
395 | int reg; | |
396 | ||
397 | if (fi->next) | |
398 | fi->pc = FRAME_SAVED_PC (fi->next); | |
399 | ||
400 | memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs); | |
401 | ||
402 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) | |
403 | { | |
404 | /* We need to setup fi->frame here because run_stack_dummy gets it wrong | |
c5aa993b | 405 | by assuming it's always FP. */ |
c906108c SS |
406 | fi->frame = generic_read_register_dummy (fi->pc, fi->frame, SP_REGNUM); |
407 | fi->framesize = 0; | |
408 | return; | |
409 | } | |
c5aa993b | 410 | else |
c906108c SS |
411 | { |
412 | fi->using_frame_pointer = 0; | |
413 | fi->framesize = m32r_scan_prologue (fi, &fi->fsr); | |
414 | ||
415 | if (!fi->next) | |
416 | if (fi->using_frame_pointer) | |
417 | { | |
418 | fi->frame = read_register (FP_REGNUM); | |
419 | } | |
420 | else | |
421 | fi->frame = read_register (SP_REGNUM); | |
c5aa993b JM |
422 | else |
423 | /* fi->next means this is not the innermost frame */ if (fi->using_frame_pointer) | |
424 | /* we have an FP */ | |
425 | if (fi->next->fsr.regs[FP_REGNUM] != 0) /* caller saved our FP */ | |
426 | fi->frame = read_memory_integer (fi->next->fsr.regs[FP_REGNUM], 4); | |
c906108c SS |
427 | for (reg = 0; reg < NUM_REGS; reg++) |
428 | if (fi->fsr.regs[reg] != 0) | |
429 | fi->fsr.regs[reg] = fi->frame + fi->framesize - fi->fsr.regs[reg]; | |
430 | } | |
431 | } | |
432 | ||
433 | /* Function: mn10300_virtual_frame_pointer | |
434 | Return the register that the function uses for a frame pointer, | |
435 | plus any necessary offset to be applied to the register before | |
436 | any frame pointer offsets. */ | |
437 | ||
438 | void | |
439 | m32r_virtual_frame_pointer (pc, reg, offset) | |
440 | CORE_ADDR pc; | |
441 | long *reg; | |
442 | long *offset; | |
443 | { | |
444 | struct frame_info fi; | |
445 | ||
446 | /* Set up a dummy frame_info. */ | |
447 | fi.next = NULL; | |
448 | fi.prev = NULL; | |
449 | fi.frame = 0; | |
450 | fi.pc = pc; | |
451 | ||
452 | /* Analyze the prolog and fill in the extra info. */ | |
453 | m32r_init_extra_frame_info (&fi); | |
454 | ||
455 | ||
456 | /* Results will tell us which type of frame it uses. */ | |
457 | if (fi.using_frame_pointer) | |
458 | { | |
c5aa993b | 459 | *reg = FP_REGNUM; |
c906108c SS |
460 | *offset = 0; |
461 | } | |
462 | else | |
463 | { | |
c5aa993b | 464 | *reg = SP_REGNUM; |
c906108c SS |
465 | *offset = 0; |
466 | } | |
467 | } | |
468 | ||
469 | /* Function: find_callers_reg | |
470 | Find REGNUM on the stack. Otherwise, it's in an active register. One thing | |
471 | we might want to do here is to check REGNUM against the clobber mask, and | |
472 | somehow flag it as invalid if it isn't saved on the stack somewhere. This | |
473 | would provide a graceful failure mode when trying to get the value of | |
474 | caller-saves registers for an inner frame. */ | |
475 | ||
476 | CORE_ADDR | |
477 | m32r_find_callers_reg (fi, regnum) | |
478 | struct frame_info *fi; | |
479 | int regnum; | |
480 | { | |
481 | for (; fi; fi = fi->next) | |
482 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) | |
483 | return generic_read_register_dummy (fi->pc, fi->frame, regnum); | |
484 | else if (fi->fsr.regs[regnum] != 0) | |
c5aa993b JM |
485 | return read_memory_integer (fi->fsr.regs[regnum], |
486 | REGISTER_RAW_SIZE (regnum)); | |
c906108c SS |
487 | return read_register (regnum); |
488 | } | |
489 | ||
490 | /* Function: frame_chain | |
491 | Given a GDB frame, determine the address of the calling function's frame. | |
492 | This will be used to create a new GDB frame struct, and then | |
493 | INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame. | |
494 | For m32r, we save the frame size when we initialize the frame_info. */ | |
495 | ||
496 | CORE_ADDR | |
497 | m32r_frame_chain (fi) | |
498 | struct frame_info *fi; | |
499 | { | |
500 | CORE_ADDR fn_start, callers_pc, fp; | |
501 | ||
502 | /* is this a dummy frame? */ | |
c5aa993b JM |
503 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) |
504 | return fi->frame; /* dummy frame same as caller's frame */ | |
c906108c SS |
505 | |
506 | /* is caller-of-this a dummy frame? */ | |
c5aa993b | 507 | callers_pc = FRAME_SAVED_PC (fi); /* find out who called us: */ |
c906108c | 508 | fp = m32r_find_callers_reg (fi, FP_REGNUM); |
c5aa993b JM |
509 | if (PC_IN_CALL_DUMMY (callers_pc, fp, fp)) |
510 | return fp; /* dummy frame's frame may bear no relation to ours */ | |
c906108c SS |
511 | |
512 | if (find_pc_partial_function (fi->pc, 0, &fn_start, 0)) | |
513 | if (fn_start == entry_point_address ()) | |
c5aa993b | 514 | return 0; /* in _start fn, don't chain further */ |
c906108c SS |
515 | if (fi->framesize == 0) |
516 | { | |
d4f3574e SS |
517 | printf_filtered ("cannot determine frame size @ %s , pc(%s)\n", |
518 | paddr (fi->frame), | |
519 | paddr (fi->pc)); | |
c906108c SS |
520 | return 0; |
521 | } | |
c5aa993b | 522 | insn_debug (("m32rx frame %08x\n", fi->frame + fi->framesize)); |
c906108c SS |
523 | return fi->frame + fi->framesize; |
524 | } | |
525 | ||
526 | /* Function: push_return_address (pc) | |
527 | Set up the return address for the inferior function call. | |
528 | Necessary for targets that don't actually execute a JSR/BSR instruction | |
529 | (ie. when using an empty CALL_DUMMY) */ | |
530 | ||
531 | CORE_ADDR | |
532 | m32r_push_return_address (pc, sp) | |
533 | CORE_ADDR pc; | |
534 | CORE_ADDR sp; | |
535 | { | |
536 | write_register (RP_REGNUM, CALL_DUMMY_ADDRESS ()); | |
537 | return sp; | |
538 | } | |
539 | ||
540 | ||
541 | /* Function: pop_frame | |
542 | Discard from the stack the innermost frame, | |
543 | restoring all saved registers. */ | |
544 | ||
545 | struct frame_info * | |
546 | m32r_pop_frame (frame) | |
547 | struct frame_info *frame; | |
548 | { | |
549 | int regnum; | |
550 | ||
551 | if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame)) | |
552 | generic_pop_dummy_frame (); | |
553 | else | |
554 | { | |
555 | for (regnum = 0; regnum < NUM_REGS; regnum++) | |
556 | if (frame->fsr.regs[regnum] != 0) | |
c5aa993b | 557 | write_register (regnum, |
c906108c SS |
558 | read_memory_integer (frame->fsr.regs[regnum], 4)); |
559 | ||
560 | write_register (PC_REGNUM, FRAME_SAVED_PC (frame)); | |
561 | write_register (SP_REGNUM, read_register (FP_REGNUM)); | |
562 | if (read_register (PSW_REGNUM) & 0x80) | |
563 | write_register (SPU_REGNUM, read_register (SP_REGNUM)); | |
564 | else | |
565 | write_register (SPI_REGNUM, read_register (SP_REGNUM)); | |
566 | } | |
567 | flush_cached_frames (); | |
568 | return NULL; | |
569 | } | |
570 | ||
571 | /* Function: frame_saved_pc | |
572 | Find the caller of this frame. We do this by seeing if RP_REGNUM is saved | |
573 | in the stack anywhere, otherwise we get it from the registers. */ | |
574 | ||
575 | CORE_ADDR | |
576 | m32r_frame_saved_pc (fi) | |
577 | struct frame_info *fi; | |
578 | { | |
c5aa993b JM |
579 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) |
580 | return generic_read_register_dummy (fi->pc, fi->frame, PC_REGNUM); | |
c906108c SS |
581 | else |
582 | return m32r_find_callers_reg (fi, RP_REGNUM); | |
583 | } | |
584 | ||
585 | /* Function: push_arguments | |
586 | Setup the function arguments for calling a function in the inferior. | |
587 | ||
588 | On the Mitsubishi M32R architecture, there are four registers (R0 to R3) | |
589 | which are dedicated for passing function arguments. Up to the first | |
590 | four arguments (depending on size) may go into these registers. | |
591 | The rest go on the stack. | |
592 | ||
593 | Arguments that are smaller than 4 bytes will still take up a whole | |
594 | register or a whole 32-bit word on the stack, and will be | |
595 | right-justified in the register or the stack word. This includes | |
596 | chars, shorts, and small aggregate types. | |
c5aa993b | 597 | |
c906108c SS |
598 | Arguments of 8 bytes size are split between two registers, if |
599 | available. If only one register is available, the argument will | |
600 | be split between the register and the stack. Otherwise it is | |
601 | passed entirely on the stack. Aggregate types with sizes between | |
602 | 4 and 8 bytes are passed entirely on the stack, and are left-justified | |
603 | within the double-word (as opposed to aggregates smaller than 4 bytes | |
604 | which are right-justified). | |
605 | ||
606 | Aggregates of greater than 8 bytes are first copied onto the stack, | |
607 | and then a pointer to the copy is passed in the place of the normal | |
608 | argument (either in a register if available, or on the stack). | |
609 | ||
610 | Functions that must return an aggregate type can return it in the | |
611 | normal return value registers (R0 and R1) if its size is 8 bytes or | |
612 | less. For larger return values, the caller must allocate space for | |
613 | the callee to copy the return value to. A pointer to this space is | |
614 | passed as an implicit first argument, always in R0. */ | |
615 | ||
616 | CORE_ADDR | |
617 | m32r_push_arguments (nargs, args, sp, struct_return, struct_addr) | |
618 | int nargs; | |
619 | value_ptr *args; | |
620 | CORE_ADDR sp; | |
621 | unsigned char struct_return; | |
622 | CORE_ADDR struct_addr; | |
623 | { | |
624 | int stack_offset, stack_alloc; | |
625 | int argreg; | |
626 | int argnum; | |
627 | struct type *type; | |
628 | CORE_ADDR regval; | |
629 | char *val; | |
630 | char valbuf[4]; | |
631 | int len; | |
632 | int odd_sized_struct; | |
633 | ||
634 | /* first force sp to a 4-byte alignment */ | |
635 | sp = sp & ~3; | |
636 | ||
c5aa993b | 637 | argreg = ARG0_REGNUM; |
c906108c SS |
638 | /* The "struct return pointer" pseudo-argument goes in R0 */ |
639 | if (struct_return) | |
c5aa993b JM |
640 | write_register (argreg++, struct_addr); |
641 | ||
c906108c SS |
642 | /* Now make sure there's space on the stack */ |
643 | for (argnum = 0, stack_alloc = 0; | |
644 | argnum < nargs; argnum++) | |
c5aa993b JM |
645 | stack_alloc += ((TYPE_LENGTH (VALUE_TYPE (args[argnum])) + 3) & ~3); |
646 | sp -= stack_alloc; /* make room on stack for args */ | |
647 | ||
648 | ||
c906108c SS |
649 | /* Now load as many as possible of the first arguments into |
650 | registers, and push the rest onto the stack. There are 16 bytes | |
651 | in four registers available. Loop thru args from first to last. */ | |
c5aa993b | 652 | |
c906108c SS |
653 | argreg = ARG0_REGNUM; |
654 | for (argnum = 0, stack_offset = 0; argnum < nargs; argnum++) | |
655 | { | |
656 | type = VALUE_TYPE (args[argnum]); | |
c5aa993b JM |
657 | len = TYPE_LENGTH (type); |
658 | memset (valbuf, 0, sizeof (valbuf)); | |
c906108c | 659 | if (len < 4) |
c5aa993b JM |
660 | { /* value gets right-justified in the register or stack word */ |
661 | memcpy (valbuf + (4 - len), | |
662 | (char *) VALUE_CONTENTS (args[argnum]), len); | |
663 | val = valbuf; | |
664 | } | |
c906108c | 665 | else |
c5aa993b JM |
666 | val = (char *) VALUE_CONTENTS (args[argnum]); |
667 | ||
c906108c | 668 | if (len > 4 && (len & 3) != 0) |
c5aa993b | 669 | odd_sized_struct = 1; /* such structs go entirely on stack */ |
c906108c | 670 | else |
c5aa993b | 671 | odd_sized_struct = 0; |
c906108c | 672 | while (len > 0) |
c5aa993b JM |
673 | { |
674 | if (argreg > ARGLAST_REGNUM || odd_sized_struct) | |
675 | { /* must go on the stack */ | |
676 | write_memory (sp + stack_offset, val, 4); | |
677 | stack_offset += 4; | |
678 | } | |
679 | /* NOTE WELL!!!!! This is not an "else if" clause!!! | |
680 | That's because some *&^%$ things get passed on the stack | |
681 | AND in the registers! */ | |
682 | if (argreg <= ARGLAST_REGNUM) | |
683 | { /* there's room in a register */ | |
684 | regval = extract_address (val, REGISTER_RAW_SIZE (argreg)); | |
685 | write_register (argreg++, regval); | |
686 | } | |
687 | /* Store the value 4 bytes at a time. This means that things | |
688 | larger than 4 bytes may go partly in registers and partly | |
689 | on the stack. */ | |
690 | len -= REGISTER_RAW_SIZE (argreg); | |
691 | val += REGISTER_RAW_SIZE (argreg); | |
692 | } | |
c906108c SS |
693 | } |
694 | return sp; | |
695 | } | |
696 | ||
697 | /* Function: fix_call_dummy | |
698 | If there is real CALL_DUMMY code (eg. on the stack), this function | |
699 | has the responsability to insert the address of the actual code that | |
700 | is the target of the target function call. */ | |
701 | ||
702 | void | |
703 | m32r_fix_call_dummy (dummy, pc, fun, nargs, args, type, gcc_p) | |
704 | char *dummy; | |
705 | CORE_ADDR pc; | |
706 | CORE_ADDR fun; | |
707 | int nargs; | |
708 | value_ptr *args; | |
709 | struct type *type; | |
710 | int gcc_p; | |
711 | { | |
712 | /* ld24 r8, <(imm24) fun> */ | |
713 | *(unsigned long *) (dummy) = (fun & 0x00ffffff) | 0xe8000000; | |
714 | } | |
715 | ||
c906108c SS |
716 | |
717 | /* Function: m32r_write_sp | |
718 | Because SP is really a read-only register that mirrors either SPU or SPI, | |
719 | we must actually write one of those two as well, depending on PSW. */ | |
720 | ||
721 | void | |
722 | m32r_write_sp (val) | |
723 | CORE_ADDR val; | |
724 | { | |
725 | unsigned long psw = read_register (PSW_REGNUM); | |
726 | ||
c5aa993b | 727 | if (psw & 0x80) /* stack mode: user or interrupt */ |
c906108c SS |
728 | write_register (SPU_REGNUM, val); |
729 | else | |
730 | write_register (SPI_REGNUM, val); | |
731 | write_register (SP_REGNUM, val); | |
732 | } | |
733 | ||
734 | void | |
735 | _initialize_m32r_tdep () | |
736 | { | |
737 | tm_print_insn = print_insn_m32r; | |
738 | } |