Commit | Line | Data |
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c906108c | 1 | /* Target-dependent code for the Mitsubishi m32r for GDB, the GNU debugger. |
b6ba6518 | 2 | Copyright 1996, 1998, 1999, 2000, 2001 Free Software Foundation, Inc. |
c906108c | 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" | |
4e052eda | 31 | #include "regcache.h" |
c906108c SS |
32 | |
33 | /* Function: m32r_use_struct_convention | |
34 | Return nonzero if call_function should allocate stack space for a | |
35 | struct return? */ | |
36 | int | |
fba45db2 | 37 | m32r_use_struct_convention (int gcc_p, struct type *type) |
c906108c SS |
38 | { |
39 | return (TYPE_LENGTH (type) > 8); | |
40 | } | |
41 | ||
42 | /* Function: frame_find_saved_regs | |
43 | Return the frame_saved_regs structure for the frame. | |
44 | Doesn't really work for dummy frames, but it does pass back | |
45 | an empty frame_saved_regs, so I guess that's better than total failure */ | |
46 | ||
c5aa993b | 47 | void |
fba45db2 KB |
48 | m32r_frame_find_saved_regs (struct frame_info *fi, |
49 | struct frame_saved_regs *regaddr) | |
c906108c | 50 | { |
c5aa993b | 51 | memcpy (regaddr, &fi->fsr, sizeof (struct frame_saved_regs)); |
c906108c SS |
52 | } |
53 | ||
54 | /* Turn this on if you want to see just how much instruction decoding | |
55 | if being done, its quite a lot | |
c5aa993b | 56 | */ |
c906108c | 57 | #if 0 |
c5aa993b JM |
58 | static void |
59 | dump_insn (char *commnt, CORE_ADDR pc, int insn) | |
c906108c | 60 | { |
c5aa993b JM |
61 | printf_filtered (" %s %08x %08x ", |
62 | commnt, (unsigned int) pc, (unsigned int) insn); | |
63 | (*tm_print_insn) (pc, &tm_print_insn_info); | |
64 | printf_filtered ("\n"); | |
c906108c SS |
65 | } |
66 | #define insn_debug(args) { printf_filtered args; } | |
67 | #else | |
68 | #define dump_insn(a,b,c) {} | |
69 | #define insn_debug(args) {} | |
70 | #endif | |
71 | ||
c5aa993b | 72 | #define DEFAULT_SEARCH_LIMIT 44 |
c906108c SS |
73 | |
74 | /* Function: scan_prologue | |
75 | This function decodes the target function prologue to determine | |
76 | 1) the size of the stack frame, and 2) which registers are saved on it. | |
77 | It saves the offsets of saved regs in the frame_saved_regs argument, | |
78 | and returns the frame size. */ | |
79 | ||
80 | /* | |
c5aa993b JM |
81 | The sequence it currently generates is: |
82 | ||
83 | if (varargs function) { ddi sp,#n } | |
84 | push registers | |
85 | if (additional stack <= 256) { addi sp,#-stack } | |
86 | else if (additional stack < 65k) { add3 sp,sp,#-stack | |
87 | ||
88 | } else if (additional stack) { | |
89 | seth sp,#(stack & 0xffff0000) | |
90 | or3 sp,sp,#(stack & 0x0000ffff) | |
91 | sub sp,r4 | |
92 | } | |
93 | if (frame pointer) { | |
94 | mv sp,fp | |
95 | } | |
c906108c | 96 | |
c5aa993b JM |
97 | These instructions are scheduled like everything else, so you should stop at |
98 | the first branch instruction. | |
99 | ||
100 | */ | |
c906108c SS |
101 | |
102 | /* This is required by skip prologue and by m32r_init_extra_frame_info. | |
103 | The results of decoding a prologue should be cached because this | |
104 | thrashing is getting nuts. | |
105 | I am thinking of making a container class with two indexes, name and | |
106 | address. It may be better to extend the symbol table. | |
c5aa993b | 107 | */ |
c906108c | 108 | |
c5aa993b | 109 | static void |
fba45db2 KB |
110 | decode_prologue (CORE_ADDR start_pc, CORE_ADDR scan_limit, CORE_ADDR *pl_endptr, /* var parameter */ |
111 | unsigned long *framelength, struct frame_info *fi, | |
112 | struct frame_saved_regs *fsr) | |
c906108c SS |
113 | { |
114 | unsigned long framesize; | |
115 | int insn; | |
116 | int op1; | |
117 | int maybe_one_more = 0; | |
118 | CORE_ADDR after_prologue = 0; | |
119 | CORE_ADDR after_stack_adjust = 0; | |
120 | CORE_ADDR current_pc; | |
121 | ||
122 | ||
123 | framesize = 0; | |
124 | after_prologue = 0; | |
c5aa993b | 125 | insn_debug (("rd prolog l(%d)\n", scan_limit - current_pc)); |
c906108c SS |
126 | |
127 | for (current_pc = start_pc; current_pc < scan_limit; current_pc += 2) | |
128 | { | |
129 | ||
130 | insn = read_memory_unsigned_integer (current_pc, 2); | |
c5aa993b JM |
131 | dump_insn ("insn-1", current_pc, insn); /* MTZ */ |
132 | ||
133 | /* If this is a 32 bit instruction, we dont want to examine its | |
134 | immediate data as though it were an instruction */ | |
c906108c | 135 | if (current_pc & 0x02) |
c5aa993b | 136 | { /* Clear the parallel execution bit from 16 bit instruction */ |
c906108c | 137 | if (maybe_one_more) |
c5aa993b JM |
138 | { /* The last instruction was a branch, usually terminates |
139 | the series, but if this is a parallel instruction, | |
140 | it may be a stack framing instruction */ | |
141 | if (!(insn & 0x8000)) | |
142 | { | |
143 | insn_debug (("Really done")); | |
144 | break; /* nope, we are really done */ | |
c906108c SS |
145 | } |
146 | } | |
c5aa993b | 147 | insn &= 0x7fff; /* decode this instruction further */ |
c906108c SS |
148 | } |
149 | else | |
150 | { | |
c5aa993b JM |
151 | if (maybe_one_more) |
152 | break; /* This isnt the one more */ | |
c906108c SS |
153 | if (insn & 0x8000) |
154 | { | |
c5aa993b | 155 | insn_debug (("32 bit insn\n")); |
c906108c | 156 | if (current_pc == scan_limit) |
c5aa993b JM |
157 | scan_limit += 2; /* extend the search */ |
158 | current_pc += 2; /* skip the immediate data */ | |
159 | if (insn == 0x8faf) /* add3 sp, sp, xxxx */ | |
c906108c | 160 | /* add 16 bit sign-extended offset */ |
c5aa993b JM |
161 | { |
162 | insn_debug (("stack increment\n")); | |
163 | framesize += -((short) read_memory_unsigned_integer (current_pc, 2)); | |
c906108c SS |
164 | } |
165 | else | |
166 | { | |
c5aa993b JM |
167 | if (((insn >> 8) == 0xe4) && /* ld24 r4, xxxxxx; sub sp, r4 */ |
168 | read_memory_unsigned_integer (current_pc + 2, 2) == 0x0f24) | |
169 | { /* subtract 24 bit sign-extended negative-offset */ | |
170 | dump_insn ("insn-2", current_pc + 2, insn); | |
c906108c | 171 | insn = read_memory_unsigned_integer (current_pc - 2, 4); |
c5aa993b | 172 | dump_insn ("insn-3(l4)", current_pc - 2, insn); |
c906108c | 173 | if (insn & 0x00800000) /* sign extend */ |
c5aa993b | 174 | insn |= 0xff000000; /* negative */ |
c906108c | 175 | else |
c5aa993b | 176 | insn &= 0x00ffffff; /* positive */ |
c906108c SS |
177 | framesize += insn; |
178 | } | |
179 | } | |
180 | after_prologue = current_pc; | |
181 | continue; | |
182 | } | |
183 | } | |
c5aa993b JM |
184 | op1 = insn & 0xf000; /* isolate just the first nibble */ |
185 | ||
c906108c | 186 | if ((insn & 0xf0ff) == 0x207f) |
c5aa993b | 187 | { /* st reg, @-sp */ |
c906108c | 188 | int regno; |
c5aa993b JM |
189 | insn_debug (("push\n")); |
190 | #if 0 /* No, PUSH FP is not an indication that we will use a frame pointer. */ | |
191 | if (((insn & 0xffff) == 0x2d7f) && fi) | |
c906108c SS |
192 | fi->using_frame_pointer = 1; |
193 | #endif | |
c5aa993b JM |
194 | framesize += 4; |
195 | #if 0 | |
c906108c SS |
196 | /* Why should we increase the scan limit, just because we did a push? |
197 | And if there is a reason, surely we would only want to do it if we | |
198 | had already reached the scan limit... */ | |
199 | if (current_pc == scan_limit) | |
200 | scan_limit += 2; | |
201 | #endif | |
202 | regno = ((insn >> 8) & 0xf); | |
c5aa993b | 203 | if (fsr) /* save_regs offset */ |
c906108c SS |
204 | fsr->regs[regno] = framesize; |
205 | after_prologue = 0; | |
c5aa993b | 206 | continue; |
c906108c | 207 | } |
c5aa993b | 208 | if ((insn >> 8) == 0x4f) /* addi sp, xx */ |
c906108c SS |
209 | /* add 8 bit sign-extended offset */ |
210 | { | |
211 | int stack_adjust = (char) (insn & 0xff); | |
212 | ||
213 | /* there are probably two of these stack adjustments: | |
214 | 1) A negative one in the prologue, and | |
215 | 2) A positive one in the epilogue. | |
216 | We are only interested in the first one. */ | |
217 | ||
218 | if (stack_adjust < 0) | |
219 | { | |
220 | framesize -= stack_adjust; | |
221 | after_prologue = 0; | |
222 | /* A frameless function may have no "mv fp, sp". | |
c5aa993b | 223 | In that case, this is the end of the prologue. */ |
c906108c SS |
224 | after_stack_adjust = current_pc + 2; |
225 | } | |
226 | continue; | |
227 | } | |
c5aa993b JM |
228 | if (insn == 0x1d8f) |
229 | { /* mv fp, sp */ | |
230 | if (fi) | |
231 | fi->using_frame_pointer = 1; /* fp is now valid */ | |
232 | insn_debug (("done fp found\n")); | |
233 | after_prologue = current_pc + 2; | |
234 | break; /* end of stack adjustments */ | |
235 | } | |
236 | if (insn == 0x7000) /* Nop looks like a branch, continue explicitly */ | |
237 | { | |
238 | insn_debug (("nop\n")); | |
239 | after_prologue = current_pc + 2; | |
240 | continue; /* nop occurs between pushes */ | |
c906108c SS |
241 | } |
242 | /* End of prolog if any of these are branch instructions */ | |
243 | if ((op1 == 0x7000) | |
c5aa993b | 244 | || (op1 == 0xb000) |
cff3e48b | 245 | || (op1 == 0xf000)) |
c906108c SS |
246 | { |
247 | after_prologue = current_pc; | |
c5aa993b | 248 | insn_debug (("Done: branch\n")); |
c906108c SS |
249 | maybe_one_more = 1; |
250 | continue; | |
251 | } | |
252 | /* Some of the branch instructions are mixed with other types */ | |
253 | if (op1 == 0x1000) | |
c5aa993b JM |
254 | { |
255 | int subop = insn & 0x0ff0; | |
c906108c | 256 | if ((subop == 0x0ec0) || (subop == 0x0fc0)) |
c5aa993b JM |
257 | { |
258 | insn_debug (("done: jmp\n")); | |
c906108c SS |
259 | after_prologue = current_pc; |
260 | maybe_one_more = 1; | |
c5aa993b | 261 | continue; /* jmp , jl */ |
c906108c SS |
262 | } |
263 | } | |
264 | } | |
265 | ||
266 | if (current_pc >= scan_limit) | |
267 | { | |
c5aa993b | 268 | if (pl_endptr) |
7a292a7a | 269 | { |
c906108c | 270 | #if 1 |
7a292a7a SS |
271 | if (after_stack_adjust != 0) |
272 | /* We did not find a "mv fp,sp", but we DID find | |
273 | a stack_adjust. Is it safe to use that as the | |
274 | end of the prologue? I just don't know. */ | |
275 | { | |
276 | *pl_endptr = after_stack_adjust; | |
277 | if (framelength) | |
278 | *framelength = framesize; | |
279 | } | |
280 | else | |
c906108c | 281 | #endif |
7a292a7a SS |
282 | /* We reached the end of the loop without finding the end |
283 | of the prologue. No way to win -- we should report failure. | |
284 | The way we do that is to return the original start_pc. | |
285 | GDB will set a breakpoint at the start of the function (etc.) */ | |
286 | *pl_endptr = start_pc; | |
c5aa993b | 287 | } |
c906108c SS |
288 | return; |
289 | } | |
c5aa993b | 290 | if (after_prologue == 0) |
c906108c SS |
291 | after_prologue = current_pc; |
292 | ||
c5aa993b JM |
293 | insn_debug ((" framesize %d, firstline %08x\n", framesize, after_prologue)); |
294 | if (framelength) | |
c906108c | 295 | *framelength = framesize; |
c5aa993b | 296 | if (pl_endptr) |
c906108c | 297 | *pl_endptr = after_prologue; |
c5aa993b | 298 | } /* decode_prologue */ |
c906108c SS |
299 | |
300 | /* Function: skip_prologue | |
301 | Find end of function prologue */ | |
302 | ||
303 | CORE_ADDR | |
fba45db2 | 304 | m32r_skip_prologue (CORE_ADDR pc) |
c906108c SS |
305 | { |
306 | CORE_ADDR func_addr, func_end; | |
307 | struct symtab_and_line sal; | |
308 | ||
309 | /* See what the symbol table says */ | |
310 | ||
311 | if (find_pc_partial_function (pc, NULL, &func_addr, &func_end)) | |
312 | { | |
313 | sal = find_pc_line (func_addr, 0); | |
314 | ||
315 | if (sal.line != 0 && sal.end <= func_end) | |
316 | { | |
c5aa993b JM |
317 | |
318 | insn_debug (("BP after prologue %08x\n", sal.end)); | |
c906108c SS |
319 | func_end = sal.end; |
320 | } | |
321 | else | |
322 | /* Either there's no line info, or the line after the prologue is after | |
323 | the end of the function. In this case, there probably isn't a | |
324 | prologue. */ | |
325 | { | |
c5aa993b JM |
326 | insn_debug (("No line info, line(%x) sal_end(%x) funcend(%x)\n", |
327 | sal.line, sal.end, func_end)); | |
328 | func_end = min (func_end, func_addr + DEFAULT_SEARCH_LIMIT); | |
c906108c SS |
329 | } |
330 | } | |
c5aa993b | 331 | else |
c906108c SS |
332 | func_end = pc + DEFAULT_SEARCH_LIMIT; |
333 | decode_prologue (pc, func_end, &sal.end, 0, 0, 0); | |
334 | return sal.end; | |
335 | } | |
336 | ||
337 | static unsigned long | |
fba45db2 | 338 | m32r_scan_prologue (struct frame_info *fi, struct frame_saved_regs *fsr) |
c906108c SS |
339 | { |
340 | struct symtab_and_line sal; | |
341 | CORE_ADDR prologue_start, prologue_end, current_pc; | |
cff3e48b | 342 | unsigned long framesize = 0; |
c906108c SS |
343 | |
344 | /* this code essentially duplicates skip_prologue, | |
345 | but we need the start address below. */ | |
346 | ||
347 | if (find_pc_partial_function (fi->pc, NULL, &prologue_start, &prologue_end)) | |
348 | { | |
349 | sal = find_pc_line (prologue_start, 0); | |
350 | ||
c5aa993b | 351 | if (sal.line == 0) /* no line info, use current PC */ |
c906108c SS |
352 | if (prologue_start == entry_point_address ()) |
353 | return 0; | |
354 | } | |
355 | else | |
356 | { | |
357 | prologue_start = fi->pc; | |
c5aa993b JM |
358 | prologue_end = prologue_start + 48; /* We're in the boondocks: |
359 | allow for 16 pushes, an add, | |
360 | and "mv fp,sp" */ | |
c906108c SS |
361 | } |
362 | #if 0 | |
363 | prologue_end = min (prologue_end, fi->pc); | |
364 | #endif | |
c5aa993b JM |
365 | insn_debug (("fipc(%08x) start(%08x) end(%08x)\n", |
366 | fi->pc, prologue_start, prologue_end)); | |
367 | prologue_end = min (prologue_end, prologue_start + DEFAULT_SEARCH_LIMIT); | |
368 | decode_prologue (prologue_start, prologue_end, &prologue_end, &framesize, | |
369 | fi, fsr); | |
c906108c SS |
370 | return framesize; |
371 | } | |
372 | ||
373 | /* Function: init_extra_frame_info | |
374 | This function actually figures out the frame address for a given pc and | |
375 | sp. This is tricky on the m32r because we sometimes don't use an explicit | |
376 | frame pointer, and the previous stack pointer isn't necessarily recorded | |
377 | on the stack. The only reliable way to get this info is to | |
378 | examine the prologue. */ | |
379 | ||
380 | void | |
fba45db2 | 381 | m32r_init_extra_frame_info (struct frame_info *fi) |
c906108c SS |
382 | { |
383 | int reg; | |
384 | ||
385 | if (fi->next) | |
386 | fi->pc = FRAME_SAVED_PC (fi->next); | |
387 | ||
388 | memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs); | |
389 | ||
390 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) | |
391 | { | |
392 | /* We need to setup fi->frame here because run_stack_dummy gets it wrong | |
c5aa993b | 393 | by assuming it's always FP. */ |
c906108c SS |
394 | fi->frame = generic_read_register_dummy (fi->pc, fi->frame, SP_REGNUM); |
395 | fi->framesize = 0; | |
396 | return; | |
397 | } | |
c5aa993b | 398 | else |
c906108c SS |
399 | { |
400 | fi->using_frame_pointer = 0; | |
401 | fi->framesize = m32r_scan_prologue (fi, &fi->fsr); | |
402 | ||
403 | if (!fi->next) | |
404 | if (fi->using_frame_pointer) | |
405 | { | |
406 | fi->frame = read_register (FP_REGNUM); | |
407 | } | |
408 | else | |
409 | fi->frame = read_register (SP_REGNUM); | |
c5aa993b JM |
410 | else |
411 | /* fi->next means this is not the innermost frame */ if (fi->using_frame_pointer) | |
412 | /* we have an FP */ | |
413 | if (fi->next->fsr.regs[FP_REGNUM] != 0) /* caller saved our FP */ | |
414 | fi->frame = read_memory_integer (fi->next->fsr.regs[FP_REGNUM], 4); | |
c906108c SS |
415 | for (reg = 0; reg < NUM_REGS; reg++) |
416 | if (fi->fsr.regs[reg] != 0) | |
417 | fi->fsr.regs[reg] = fi->frame + fi->framesize - fi->fsr.regs[reg]; | |
418 | } | |
419 | } | |
420 | ||
4b33390a | 421 | /* Function: m32r_virtual_frame_pointer |
c906108c SS |
422 | Return the register that the function uses for a frame pointer, |
423 | plus any necessary offset to be applied to the register before | |
424 | any frame pointer offsets. */ | |
425 | ||
426 | void | |
fba45db2 | 427 | m32r_virtual_frame_pointer (CORE_ADDR pc, long *reg, long *offset) |
c906108c SS |
428 | { |
429 | struct frame_info fi; | |
430 | ||
431 | /* Set up a dummy frame_info. */ | |
432 | fi.next = NULL; | |
433 | fi.prev = NULL; | |
434 | fi.frame = 0; | |
435 | fi.pc = pc; | |
436 | ||
437 | /* Analyze the prolog and fill in the extra info. */ | |
438 | m32r_init_extra_frame_info (&fi); | |
439 | ||
440 | ||
441 | /* Results will tell us which type of frame it uses. */ | |
442 | if (fi.using_frame_pointer) | |
443 | { | |
c5aa993b | 444 | *reg = FP_REGNUM; |
c906108c SS |
445 | *offset = 0; |
446 | } | |
447 | else | |
448 | { | |
c5aa993b | 449 | *reg = SP_REGNUM; |
c906108c SS |
450 | *offset = 0; |
451 | } | |
452 | } | |
453 | ||
454 | /* Function: find_callers_reg | |
455 | Find REGNUM on the stack. Otherwise, it's in an active register. One thing | |
456 | we might want to do here is to check REGNUM against the clobber mask, and | |
457 | somehow flag it as invalid if it isn't saved on the stack somewhere. This | |
458 | would provide a graceful failure mode when trying to get the value of | |
459 | caller-saves registers for an inner frame. */ | |
460 | ||
461 | CORE_ADDR | |
fba45db2 | 462 | m32r_find_callers_reg (struct frame_info *fi, int regnum) |
c906108c SS |
463 | { |
464 | for (; fi; fi = fi->next) | |
465 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) | |
466 | return generic_read_register_dummy (fi->pc, fi->frame, regnum); | |
467 | else if (fi->fsr.regs[regnum] != 0) | |
c5aa993b JM |
468 | return read_memory_integer (fi->fsr.regs[regnum], |
469 | REGISTER_RAW_SIZE (regnum)); | |
c906108c SS |
470 | return read_register (regnum); |
471 | } | |
472 | ||
473 | /* Function: frame_chain | |
474 | Given a GDB frame, determine the address of the calling function's frame. | |
475 | This will be used to create a new GDB frame struct, and then | |
476 | INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame. | |
477 | For m32r, we save the frame size when we initialize the frame_info. */ | |
478 | ||
479 | CORE_ADDR | |
fba45db2 | 480 | m32r_frame_chain (struct frame_info *fi) |
c906108c SS |
481 | { |
482 | CORE_ADDR fn_start, callers_pc, fp; | |
483 | ||
484 | /* is this a dummy frame? */ | |
c5aa993b JM |
485 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) |
486 | return fi->frame; /* dummy frame same as caller's frame */ | |
c906108c SS |
487 | |
488 | /* is caller-of-this a dummy frame? */ | |
c5aa993b | 489 | callers_pc = FRAME_SAVED_PC (fi); /* find out who called us: */ |
c906108c | 490 | fp = m32r_find_callers_reg (fi, FP_REGNUM); |
c5aa993b JM |
491 | if (PC_IN_CALL_DUMMY (callers_pc, fp, fp)) |
492 | return fp; /* dummy frame's frame may bear no relation to ours */ | |
c906108c SS |
493 | |
494 | if (find_pc_partial_function (fi->pc, 0, &fn_start, 0)) | |
495 | if (fn_start == entry_point_address ()) | |
c5aa993b | 496 | return 0; /* in _start fn, don't chain further */ |
c906108c SS |
497 | if (fi->framesize == 0) |
498 | { | |
d4f3574e SS |
499 | printf_filtered ("cannot determine frame size @ %s , pc(%s)\n", |
500 | paddr (fi->frame), | |
501 | paddr (fi->pc)); | |
c906108c SS |
502 | return 0; |
503 | } | |
c5aa993b | 504 | insn_debug (("m32rx frame %08x\n", fi->frame + fi->framesize)); |
c906108c SS |
505 | return fi->frame + fi->framesize; |
506 | } | |
507 | ||
508 | /* Function: push_return_address (pc) | |
509 | Set up the return address for the inferior function call. | |
510 | Necessary for targets that don't actually execute a JSR/BSR instruction | |
511 | (ie. when using an empty CALL_DUMMY) */ | |
512 | ||
513 | CORE_ADDR | |
fba45db2 | 514 | m32r_push_return_address (CORE_ADDR pc, CORE_ADDR sp) |
c906108c SS |
515 | { |
516 | write_register (RP_REGNUM, CALL_DUMMY_ADDRESS ()); | |
517 | return sp; | |
518 | } | |
519 | ||
520 | ||
521 | /* Function: pop_frame | |
522 | Discard from the stack the innermost frame, | |
523 | restoring all saved registers. */ | |
524 | ||
525 | struct frame_info * | |
fba45db2 | 526 | m32r_pop_frame (struct frame_info *frame) |
c906108c SS |
527 | { |
528 | int regnum; | |
529 | ||
530 | if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame)) | |
531 | generic_pop_dummy_frame (); | |
532 | else | |
533 | { | |
534 | for (regnum = 0; regnum < NUM_REGS; regnum++) | |
535 | if (frame->fsr.regs[regnum] != 0) | |
c5aa993b | 536 | write_register (regnum, |
c906108c SS |
537 | read_memory_integer (frame->fsr.regs[regnum], 4)); |
538 | ||
539 | write_register (PC_REGNUM, FRAME_SAVED_PC (frame)); | |
540 | write_register (SP_REGNUM, read_register (FP_REGNUM)); | |
541 | if (read_register (PSW_REGNUM) & 0x80) | |
542 | write_register (SPU_REGNUM, read_register (SP_REGNUM)); | |
543 | else | |
544 | write_register (SPI_REGNUM, read_register (SP_REGNUM)); | |
545 | } | |
546 | flush_cached_frames (); | |
547 | return NULL; | |
548 | } | |
549 | ||
550 | /* Function: frame_saved_pc | |
551 | Find the caller of this frame. We do this by seeing if RP_REGNUM is saved | |
552 | in the stack anywhere, otherwise we get it from the registers. */ | |
553 | ||
554 | CORE_ADDR | |
fba45db2 | 555 | m32r_frame_saved_pc (struct frame_info *fi) |
c906108c | 556 | { |
c5aa993b JM |
557 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) |
558 | return generic_read_register_dummy (fi->pc, fi->frame, PC_REGNUM); | |
c906108c SS |
559 | else |
560 | return m32r_find_callers_reg (fi, RP_REGNUM); | |
561 | } | |
562 | ||
563 | /* Function: push_arguments | |
564 | Setup the function arguments for calling a function in the inferior. | |
565 | ||
566 | On the Mitsubishi M32R architecture, there are four registers (R0 to R3) | |
567 | which are dedicated for passing function arguments. Up to the first | |
568 | four arguments (depending on size) may go into these registers. | |
569 | The rest go on the stack. | |
570 | ||
571 | Arguments that are smaller than 4 bytes will still take up a whole | |
572 | register or a whole 32-bit word on the stack, and will be | |
573 | right-justified in the register or the stack word. This includes | |
574 | chars, shorts, and small aggregate types. | |
c5aa993b | 575 | |
c906108c SS |
576 | Arguments of 8 bytes size are split between two registers, if |
577 | available. If only one register is available, the argument will | |
578 | be split between the register and the stack. Otherwise it is | |
579 | passed entirely on the stack. Aggregate types with sizes between | |
580 | 4 and 8 bytes are passed entirely on the stack, and are left-justified | |
581 | within the double-word (as opposed to aggregates smaller than 4 bytes | |
582 | which are right-justified). | |
583 | ||
584 | Aggregates of greater than 8 bytes are first copied onto the stack, | |
585 | and then a pointer to the copy is passed in the place of the normal | |
586 | argument (either in a register if available, or on the stack). | |
587 | ||
588 | Functions that must return an aggregate type can return it in the | |
589 | normal return value registers (R0 and R1) if its size is 8 bytes or | |
590 | less. For larger return values, the caller must allocate space for | |
591 | the callee to copy the return value to. A pointer to this space is | |
592 | passed as an implicit first argument, always in R0. */ | |
593 | ||
594 | CORE_ADDR | |
fba45db2 KB |
595 | m32r_push_arguments (int nargs, value_ptr *args, CORE_ADDR sp, |
596 | unsigned char struct_return, CORE_ADDR struct_addr) | |
c906108c SS |
597 | { |
598 | int stack_offset, stack_alloc; | |
599 | int argreg; | |
600 | int argnum; | |
601 | struct type *type; | |
602 | CORE_ADDR regval; | |
603 | char *val; | |
604 | char valbuf[4]; | |
605 | int len; | |
606 | int odd_sized_struct; | |
607 | ||
608 | /* first force sp to a 4-byte alignment */ | |
609 | sp = sp & ~3; | |
610 | ||
c5aa993b | 611 | argreg = ARG0_REGNUM; |
c906108c SS |
612 | /* The "struct return pointer" pseudo-argument goes in R0 */ |
613 | if (struct_return) | |
c5aa993b JM |
614 | write_register (argreg++, struct_addr); |
615 | ||
c906108c SS |
616 | /* Now make sure there's space on the stack */ |
617 | for (argnum = 0, stack_alloc = 0; | |
618 | argnum < nargs; argnum++) | |
c5aa993b JM |
619 | stack_alloc += ((TYPE_LENGTH (VALUE_TYPE (args[argnum])) + 3) & ~3); |
620 | sp -= stack_alloc; /* make room on stack for args */ | |
621 | ||
622 | ||
c906108c SS |
623 | /* Now load as many as possible of the first arguments into |
624 | registers, and push the rest onto the stack. There are 16 bytes | |
625 | in four registers available. Loop thru args from first to last. */ | |
c5aa993b | 626 | |
c906108c SS |
627 | argreg = ARG0_REGNUM; |
628 | for (argnum = 0, stack_offset = 0; argnum < nargs; argnum++) | |
629 | { | |
630 | type = VALUE_TYPE (args[argnum]); | |
c5aa993b JM |
631 | len = TYPE_LENGTH (type); |
632 | memset (valbuf, 0, sizeof (valbuf)); | |
c906108c | 633 | if (len < 4) |
c5aa993b JM |
634 | { /* value gets right-justified in the register or stack word */ |
635 | memcpy (valbuf + (4 - len), | |
636 | (char *) VALUE_CONTENTS (args[argnum]), len); | |
637 | val = valbuf; | |
638 | } | |
c906108c | 639 | else |
c5aa993b JM |
640 | val = (char *) VALUE_CONTENTS (args[argnum]); |
641 | ||
c906108c | 642 | if (len > 4 && (len & 3) != 0) |
c5aa993b | 643 | odd_sized_struct = 1; /* such structs go entirely on stack */ |
c906108c | 644 | else |
c5aa993b | 645 | odd_sized_struct = 0; |
c906108c | 646 | while (len > 0) |
c5aa993b JM |
647 | { |
648 | if (argreg > ARGLAST_REGNUM || odd_sized_struct) | |
649 | { /* must go on the stack */ | |
650 | write_memory (sp + stack_offset, val, 4); | |
651 | stack_offset += 4; | |
652 | } | |
653 | /* NOTE WELL!!!!! This is not an "else if" clause!!! | |
654 | That's because some *&^%$ things get passed on the stack | |
655 | AND in the registers! */ | |
656 | if (argreg <= ARGLAST_REGNUM) | |
657 | { /* there's room in a register */ | |
658 | regval = extract_address (val, REGISTER_RAW_SIZE (argreg)); | |
659 | write_register (argreg++, regval); | |
660 | } | |
661 | /* Store the value 4 bytes at a time. This means that things | |
662 | larger than 4 bytes may go partly in registers and partly | |
663 | on the stack. */ | |
664 | len -= REGISTER_RAW_SIZE (argreg); | |
665 | val += REGISTER_RAW_SIZE (argreg); | |
666 | } | |
c906108c SS |
667 | } |
668 | return sp; | |
669 | } | |
670 | ||
671 | /* Function: fix_call_dummy | |
672 | If there is real CALL_DUMMY code (eg. on the stack), this function | |
673 | has the responsability to insert the address of the actual code that | |
674 | is the target of the target function call. */ | |
675 | ||
676 | void | |
fba45db2 KB |
677 | m32r_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs, |
678 | value_ptr *args, struct type *type, int gcc_p) | |
c906108c SS |
679 | { |
680 | /* ld24 r8, <(imm24) fun> */ | |
681 | *(unsigned long *) (dummy) = (fun & 0x00ffffff) | 0xe8000000; | |
682 | } | |
683 | ||
c906108c SS |
684 | |
685 | /* Function: m32r_write_sp | |
686 | Because SP is really a read-only register that mirrors either SPU or SPI, | |
687 | we must actually write one of those two as well, depending on PSW. */ | |
688 | ||
689 | void | |
fba45db2 | 690 | m32r_write_sp (CORE_ADDR val) |
c906108c SS |
691 | { |
692 | unsigned long psw = read_register (PSW_REGNUM); | |
693 | ||
c5aa993b | 694 | if (psw & 0x80) /* stack mode: user or interrupt */ |
c906108c SS |
695 | write_register (SPU_REGNUM, val); |
696 | else | |
697 | write_register (SPI_REGNUM, val); | |
698 | write_register (SP_REGNUM, val); | |
699 | } | |
700 | ||
701 | void | |
fba45db2 | 702 | _initialize_m32r_tdep (void) |
c906108c SS |
703 | { |
704 | tm_print_insn = print_insn_m32r; | |
705 | } |