Commit | Line | Data |
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c906108c SS |
1 | /* Target-dependent code for the Fujitsu FR30. |
2 | Copyright 1999, 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 | ||
392a587b JM |
32 | /* An expression that tells us whether the function invocation represented |
33 | by FI does not have a frame on the stack associated with it. */ | |
34 | int | |
fba45db2 | 35 | fr30_frameless_function_invocation (struct frame_info *fi) |
392a587b JM |
36 | { |
37 | int frameless; | |
38 | CORE_ADDR func_start, after_prologue; | |
39 | func_start = (get_pc_function_start ((fi)->pc) + | |
40 | FUNCTION_START_OFFSET); | |
41 | after_prologue = func_start; | |
42 | after_prologue = SKIP_PROLOGUE (after_prologue); | |
43 | frameless = (after_prologue == func_start); | |
44 | return frameless; | |
45 | } | |
46 | ||
c906108c SS |
47 | /* Function: pop_frame |
48 | This routine gets called when either the user uses the `return' | |
49 | command, or the call dummy breakpoint gets hit. */ | |
50 | ||
51 | void | |
fba45db2 | 52 | fr30_pop_frame (void) |
c906108c | 53 | { |
c5aa993b | 54 | struct frame_info *frame = get_current_frame (); |
c906108c | 55 | int regnum; |
c5aa993b | 56 | CORE_ADDR sp = read_register (SP_REGNUM); |
c906108c | 57 | |
c5aa993b | 58 | if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame)) |
c906108c SS |
59 | generic_pop_dummy_frame (); |
60 | else | |
61 | { | |
62 | write_register (PC_REGNUM, FRAME_SAVED_PC (frame)); | |
63 | ||
64 | for (regnum = 0; regnum < NUM_REGS; regnum++) | |
c5aa993b JM |
65 | if (frame->fsr.regs[regnum] != 0) |
66 | { | |
67 | write_register (regnum, | |
68 | read_memory_unsigned_integer (frame->fsr.regs[regnum], | |
69 | REGISTER_RAW_SIZE (regnum))); | |
70 | } | |
c906108c SS |
71 | write_register (SP_REGNUM, sp + frame->framesize); |
72 | } | |
73 | flush_cached_frames (); | |
74 | } | |
75 | ||
7a292a7a SS |
76 | |
77 | /* Function: fr30_store_return_value | |
78 | Put a value where a caller expects to see it. Used by the 'return' | |
79 | command. */ | |
80 | void | |
81 | fr30_store_return_value (struct type *type, | |
82 | char *valbuf) | |
83 | { | |
84 | /* Here's how the FR30 returns values (gleaned from gcc/config/ | |
85 | fr30/fr30.h): | |
86 | ||
87 | If the return value is 32 bits long or less, it goes in r4. | |
88 | ||
89 | If the return value is 64 bits long or less, it goes in r4 (most | |
90 | significant word) and r5 (least significant word. | |
91 | ||
92 | If the function returns a structure, of any size, the caller | |
93 | passes the function an invisible first argument where the callee | |
94 | should store the value. But GDB doesn't let you do that anyway. | |
95 | ||
96 | If you're returning a value smaller than a word, it's not really | |
97 | necessary to zero the upper bytes of the register; the caller is | |
98 | supposed to ignore them. However, the FR30 typically keeps its | |
99 | values extended to the full register width, so we should emulate | |
100 | that. */ | |
101 | ||
102 | /* The FR30 is big-endian, so if we return a small value (like a | |
103 | short or a char), we need to position it correctly within the | |
104 | register. We round the size up to a register boundary, and then | |
105 | adjust the offset so as to place the value at the right end. */ | |
106 | int value_size = TYPE_LENGTH (type); | |
107 | int returned_size = (value_size + FR30_REGSIZE - 1) & ~(FR30_REGSIZE - 1); | |
108 | int offset = (REGISTER_BYTE (RETVAL_REG) | |
109 | + (returned_size - value_size)); | |
110 | char *zeros = alloca (returned_size); | |
111 | memset (zeros, 0, returned_size); | |
112 | ||
113 | write_register_bytes (REGISTER_BYTE (RETVAL_REG), zeros, returned_size); | |
114 | write_register_bytes (offset, valbuf, value_size); | |
115 | } | |
116 | ||
117 | ||
c906108c SS |
118 | /* Function: skip_prologue |
119 | Return the address of the first code past the prologue of the function. */ | |
120 | ||
121 | CORE_ADDR | |
c5aa993b | 122 | fr30_skip_prologue (CORE_ADDR pc) |
c906108c SS |
123 | { |
124 | CORE_ADDR func_addr, func_end; | |
125 | ||
126 | /* See what the symbol table says */ | |
127 | ||
128 | if (find_pc_partial_function (pc, NULL, &func_addr, &func_end)) | |
129 | { | |
130 | struct symtab_and_line sal; | |
131 | ||
132 | sal = find_pc_line (func_addr, 0); | |
133 | ||
c5aa993b JM |
134 | if (sal.line != 0 && sal.end < func_end) |
135 | { | |
136 | return sal.end; | |
c906108c SS |
137 | } |
138 | } | |
139 | ||
140 | /* Either we didn't find the start of this function (nothing we can do), | |
141 | or there's no line info, or the line after the prologue is after | |
142 | the end of the function (there probably isn't a prologue). */ | |
143 | ||
144 | return pc; | |
145 | } | |
146 | ||
147 | ||
148 | /* Function: push_arguments | |
149 | Setup arguments and RP for a call to the target. First four args | |
150 | go in FIRST_ARGREG -> LAST_ARGREG, subsequent args go on stack... | |
151 | Structs are passed by reference. XXX not right now Z.R. | |
152 | 64 bit quantities (doubles and long longs) may be split between | |
153 | the regs and the stack. | |
154 | When calling a function that returns a struct, a pointer to the struct | |
155 | is passed in as a secret first argument (always in FIRST_ARGREG). | |
156 | ||
157 | Stack space for the args has NOT been allocated: that job is up to us. | |
c5aa993b | 158 | */ |
c906108c SS |
159 | |
160 | CORE_ADDR | |
fba45db2 KB |
161 | fr30_push_arguments (int nargs, value_ptr *args, CORE_ADDR sp, |
162 | int struct_return, CORE_ADDR struct_addr) | |
c906108c SS |
163 | { |
164 | int argreg; | |
165 | int argnum; | |
166 | int stack_offset; | |
c5aa993b JM |
167 | struct stack_arg |
168 | { | |
c906108c SS |
169 | char *val; |
170 | int len; | |
171 | int offset; | |
172 | }; | |
173 | struct stack_arg *stack_args = | |
c5aa993b | 174 | (struct stack_arg *) alloca (nargs * sizeof (struct stack_arg)); |
c906108c SS |
175 | int nstack_args = 0; |
176 | ||
177 | argreg = FIRST_ARGREG; | |
178 | ||
179 | /* the struct_return pointer occupies the first parameter-passing reg */ | |
180 | if (struct_return) | |
c5aa993b | 181 | write_register (argreg++, struct_addr); |
c906108c SS |
182 | |
183 | stack_offset = 0; | |
184 | ||
185 | /* Process args from left to right. Store as many as allowed in | |
c5aa993b JM |
186 | registers, save the rest to be pushed on the stack */ |
187 | for (argnum = 0; argnum < nargs; argnum++) | |
c906108c | 188 | { |
c5aa993b JM |
189 | char *val; |
190 | value_ptr arg = args[argnum]; | |
191 | struct type *arg_type = check_typedef (VALUE_TYPE (arg)); | |
192 | struct type *target_type = TYPE_TARGET_TYPE (arg_type); | |
193 | int len = TYPE_LENGTH (arg_type); | |
c906108c | 194 | enum type_code typecode = TYPE_CODE (arg_type); |
c5aa993b | 195 | CORE_ADDR regval; |
c906108c SS |
196 | int newarg; |
197 | ||
198 | val = (char *) VALUE_CONTENTS (arg); | |
199 | ||
c906108c | 200 | { |
c5aa993b JM |
201 | /* Copy the argument to general registers or the stack in |
202 | register-sized pieces. Large arguments are split between | |
203 | registers and stack. */ | |
204 | while (len > 0) | |
205 | { | |
206 | if (argreg <= LAST_ARGREG) | |
207 | { | |
208 | int partial_len = len < REGISTER_SIZE ? len : REGISTER_SIZE; | |
209 | regval = extract_address (val, partial_len); | |
210 | ||
211 | /* It's a simple argument being passed in a general | |
212 | register. */ | |
213 | write_register (argreg, regval); | |
214 | argreg++; | |
215 | len -= partial_len; | |
216 | val += partial_len; | |
217 | } | |
218 | else | |
219 | { | |
220 | /* keep for later pushing */ | |
221 | stack_args[nstack_args].val = val; | |
222 | stack_args[nstack_args++].len = len; | |
223 | break; | |
224 | } | |
225 | } | |
c906108c | 226 | } |
c5aa993b JM |
227 | } |
228 | /* now do the real stack pushing, process args right to left */ | |
229 | while (nstack_args--) | |
230 | { | |
231 | sp -= stack_args[nstack_args].len; | |
232 | write_memory (sp, stack_args[nstack_args].val, | |
233 | stack_args[nstack_args].len); | |
234 | } | |
c906108c SS |
235 | |
236 | /* Return adjusted stack pointer. */ | |
237 | return sp; | |
238 | } | |
239 | ||
a14ed312 | 240 | void _initialize_fr30_tdep (void); |
c906108c | 241 | |
7a292a7a | 242 | void |
fba45db2 | 243 | _initialize_fr30_tdep (void) |
7a292a7a | 244 | { |
c5aa993b | 245 | extern int print_insn_fr30 (bfd_vma, disassemble_info *); |
7a292a7a | 246 | tm_print_insn = print_insn_fr30; |
c906108c SS |
247 | } |
248 | ||
249 | /* Function: check_prologue_cache | |
250 | Check if prologue for this frame's PC has already been scanned. | |
251 | If it has, copy the relevant information about that prologue and | |
252 | return non-zero. Otherwise do not copy anything and return zero. | |
253 | ||
254 | The information saved in the cache includes: | |
c5aa993b JM |
255 | * the frame register number; |
256 | * the size of the stack frame; | |
257 | * the offsets of saved regs (relative to the old SP); and | |
258 | * the offset from the stack pointer to the frame pointer | |
c906108c SS |
259 | |
260 | The cache contains only one entry, since this is adequate | |
261 | for the typical sequence of prologue scan requests we get. | |
262 | When performing a backtrace, GDB will usually ask to scan | |
263 | the same function twice in a row (once to get the frame chain, | |
264 | and once to fill in the extra frame information). | |
c5aa993b | 265 | */ |
c906108c SS |
266 | |
267 | static struct frame_info prologue_cache; | |
268 | ||
269 | static int | |
fba45db2 | 270 | check_prologue_cache (struct frame_info *fi) |
c906108c SS |
271 | { |
272 | int i; | |
273 | ||
274 | if (fi->pc == prologue_cache.pc) | |
275 | { | |
276 | fi->framereg = prologue_cache.framereg; | |
277 | fi->framesize = prologue_cache.framesize; | |
278 | fi->frameoffset = prologue_cache.frameoffset; | |
279 | for (i = 0; i <= NUM_REGS; i++) | |
280 | fi->fsr.regs[i] = prologue_cache.fsr.regs[i]; | |
281 | return 1; | |
282 | } | |
283 | else | |
284 | return 0; | |
285 | } | |
286 | ||
287 | ||
288 | /* Function: save_prologue_cache | |
289 | Copy the prologue information from fi to the prologue cache. | |
c5aa993b | 290 | */ |
c906108c SS |
291 | |
292 | static void | |
fba45db2 | 293 | save_prologue_cache (struct frame_info *fi) |
c906108c SS |
294 | { |
295 | int i; | |
296 | ||
c5aa993b JM |
297 | prologue_cache.pc = fi->pc; |
298 | prologue_cache.framereg = fi->framereg; | |
299 | prologue_cache.framesize = fi->framesize; | |
c906108c | 300 | prologue_cache.frameoffset = fi->frameoffset; |
c5aa993b JM |
301 | |
302 | for (i = 0; i <= NUM_REGS; i++) | |
303 | { | |
304 | prologue_cache.fsr.regs[i] = fi->fsr.regs[i]; | |
305 | } | |
c906108c SS |
306 | } |
307 | ||
308 | ||
309 | /* Function: scan_prologue | |
310 | Scan the prologue of the function that contains PC, and record what | |
311 | we find in PI. PI->fsr must be zeroed by the called. Returns the | |
312 | pc after the prologue. Note that the addresses saved in pi->fsr | |
313 | are actually just frame relative (negative offsets from the frame | |
314 | pointer). This is because we don't know the actual value of the | |
315 | frame pointer yet. In some circumstances, the frame pointer can't | |
316 | be determined till after we have scanned the prologue. */ | |
317 | ||
318 | static void | |
fba45db2 | 319 | fr30_scan_prologue (struct frame_info *fi) |
c906108c SS |
320 | { |
321 | int sp_offset, fp_offset; | |
322 | CORE_ADDR prologue_start, prologue_end, current_pc; | |
323 | ||
324 | /* Check if this function is already in the cache of frame information. */ | |
325 | if (check_prologue_cache (fi)) | |
326 | return; | |
327 | ||
328 | /* Assume there is no frame until proven otherwise. */ | |
c5aa993b JM |
329 | fi->framereg = SP_REGNUM; |
330 | fi->framesize = 0; | |
c906108c SS |
331 | fi->frameoffset = 0; |
332 | ||
333 | /* Find the function prologue. If we can't find the function in | |
334 | the symbol table, peek in the stack frame to find the PC. */ | |
335 | if (find_pc_partial_function (fi->pc, NULL, &prologue_start, &prologue_end)) | |
336 | { | |
337 | /* Assume the prologue is everything between the first instruction | |
338 | in the function and the first source line. */ | |
339 | struct symtab_and_line sal = find_pc_line (prologue_start, 0); | |
340 | ||
c5aa993b | 341 | if (sal.line == 0) /* no line info, use current PC */ |
c906108c SS |
342 | prologue_end = fi->pc; |
343 | else if (sal.end < prologue_end) /* next line begins after fn end */ | |
c5aa993b | 344 | prologue_end = sal.end; /* (probably means no prologue) */ |
c906108c SS |
345 | } |
346 | else | |
347 | { | |
348 | /* XXX Z.R. What now??? The following is entirely bogus */ | |
349 | prologue_start = (read_memory_integer (fi->frame, 4) & 0x03fffffc) - 12; | |
350 | prologue_end = prologue_start + 40; | |
351 | } | |
352 | ||
353 | /* Now search the prologue looking for instructions that set up the | |
354 | frame pointer, adjust the stack pointer, and save registers. */ | |
355 | ||
356 | sp_offset = fp_offset = 0; | |
357 | for (current_pc = prologue_start; current_pc < prologue_end; current_pc += 2) | |
358 | { | |
359 | unsigned int insn; | |
360 | ||
361 | insn = read_memory_unsigned_integer (current_pc, 2); | |
362 | ||
c5aa993b | 363 | if ((insn & 0xfe00) == 0x8e00) /* stm0 or stm1 */ |
c906108c SS |
364 | { |
365 | int reg, mask = insn & 0xff; | |
366 | ||
367 | /* scan in one sweep - create virtual 16-bit mask from either insn's mask */ | |
c5aa993b | 368 | if ((insn & 0x0100) == 0) |
c906108c | 369 | { |
c5aa993b | 370 | mask <<= 8; /* stm0 - move to upper byte in virtual mask */ |
c906108c SS |
371 | } |
372 | ||
373 | /* Calculate offsets of saved registers (to be turned later into addresses). */ | |
374 | for (reg = R4_REGNUM; reg <= R11_REGNUM; reg++) | |
375 | if (mask & (1 << (15 - reg))) | |
376 | { | |
377 | sp_offset -= 4; | |
378 | fi->fsr.regs[reg] = sp_offset; | |
379 | } | |
380 | } | |
c5aa993b JM |
381 | else if ((insn & 0xfff0) == 0x1700) /* st rx,@-r15 */ |
382 | { | |
c906108c SS |
383 | int reg = insn & 0xf; |
384 | ||
385 | sp_offset -= 4; | |
386 | fi->fsr.regs[reg] = sp_offset; | |
387 | } | |
c5aa993b JM |
388 | else if ((insn & 0xff00) == 0x0f00) /* enter */ |
389 | { | |
c906108c SS |
390 | fp_offset = fi->fsr.regs[FP_REGNUM] = sp_offset - 4; |
391 | sp_offset -= 4 * (insn & 0xff); | |
392 | fi->framereg = FP_REGNUM; | |
393 | } | |
c5aa993b | 394 | else if (insn == 0x1781) /* st rp,@-sp */ |
c906108c | 395 | { |
c5aa993b JM |
396 | sp_offset -= 4; |
397 | fi->fsr.regs[RP_REGNUM] = sp_offset; | |
c906108c | 398 | } |
c5aa993b | 399 | else if (insn == 0x170e) /* st fp,@-sp */ |
c906108c | 400 | { |
c5aa993b JM |
401 | sp_offset -= 4; |
402 | fi->fsr.regs[FP_REGNUM] = sp_offset; | |
c906108c | 403 | } |
c5aa993b | 404 | else if (insn == 0x8bfe) /* mov sp,fp */ |
c906108c SS |
405 | { |
406 | fi->framereg = FP_REGNUM; | |
407 | } | |
c5aa993b | 408 | else if ((insn & 0xff00) == 0xa300) /* addsp xx */ |
c906108c | 409 | { |
c5aa993b | 410 | sp_offset += 4 * (signed char) (insn & 0xff); |
c906108c | 411 | } |
c5aa993b JM |
412 | else if ((insn & 0xff0f) == 0x9b00 && /* ldi:20 xx,r0 */ |
413 | read_memory_unsigned_integer (current_pc + 4, 2) | |
414 | == 0xac0f) /* sub r0,sp */ | |
c906108c SS |
415 | { |
416 | /* large stack adjustment */ | |
c5aa993b | 417 | sp_offset -= (((insn & 0xf0) << 12) | read_memory_unsigned_integer (current_pc + 2, 2)); |
c906108c SS |
418 | current_pc += 4; |
419 | } | |
c5aa993b JM |
420 | else if (insn == 0x9f80 && /* ldi:32 xx,r0 */ |
421 | read_memory_unsigned_integer (current_pc + 6, 2) | |
422 | == 0xac0f) /* sub r0,sp */ | |
c906108c SS |
423 | { |
424 | /* large stack adjustment */ | |
425 | sp_offset -= | |
c5aa993b JM |
426 | (read_memory_unsigned_integer (current_pc + 2, 2) << 16 | |
427 | read_memory_unsigned_integer (current_pc + 4, 2)); | |
c906108c SS |
428 | current_pc += 6; |
429 | } | |
430 | } | |
431 | ||
432 | /* The frame size is just the negative of the offset (from the original SP) | |
433 | of the last thing thing we pushed on the stack. The frame offset is | |
434 | [new FP] - [new SP]. */ | |
435 | fi->framesize = -sp_offset; | |
436 | fi->frameoffset = fp_offset - sp_offset; | |
c5aa993b | 437 | |
c906108c SS |
438 | save_prologue_cache (fi); |
439 | } | |
440 | ||
441 | /* Function: init_extra_frame_info | |
442 | Setup the frame's frame pointer, pc, and frame addresses for saved | |
443 | registers. Most of the work is done in scan_prologue(). | |
444 | ||
445 | Note that when we are called for the last frame (currently active frame), | |
446 | that fi->pc and fi->frame will already be setup. However, fi->frame will | |
447 | be valid only if this routine uses FP. For previous frames, fi-frame will | |
448 | always be correct (since that is derived from fr30_frame_chain ()). | |
449 | ||
450 | We can be called with the PC in the call dummy under two circumstances. | |
451 | First, during normal backtracing, second, while figuring out the frame | |
452 | pointer just prior to calling the target function (see run_stack_dummy). */ | |
453 | ||
454 | void | |
fba45db2 | 455 | fr30_init_extra_frame_info (struct frame_info *fi) |
c906108c SS |
456 | { |
457 | int reg; | |
458 | ||
459 | if (fi->next) | |
460 | fi->pc = FRAME_SAVED_PC (fi->next); | |
461 | ||
462 | memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs); | |
463 | ||
464 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) | |
465 | { | |
466 | /* We need to setup fi->frame here because run_stack_dummy gets it wrong | |
c5aa993b JM |
467 | by assuming it's always FP. */ |
468 | fi->frame = generic_read_register_dummy (fi->pc, fi->frame, SP_REGNUM); | |
469 | fi->framesize = 0; | |
c906108c SS |
470 | fi->frameoffset = 0; |
471 | return; | |
472 | } | |
c5aa993b JM |
473 | fr30_scan_prologue (fi); |
474 | ||
475 | if (!fi->next) /* this is the innermost frame? */ | |
476 | fi->frame = read_register (fi->framereg); | |
477 | else | |
478 | /* not the innermost frame */ | |
0fb34c3a MS |
479 | /* If we have an FP, the callee saved it. */ |
480 | if (fi->framereg == FP_REGNUM) | |
481 | if (fi->next->fsr.regs[fi->framereg] != 0) | |
482 | fi->frame = read_memory_integer (fi->next->fsr.regs[fi->framereg], 4); | |
483 | ||
c5aa993b JM |
484 | /* Calculate actual addresses of saved registers using offsets determined |
485 | by fr30_scan_prologue. */ | |
486 | for (reg = 0; reg < NUM_REGS; reg++) | |
487 | if (fi->fsr.regs[reg] != 0) | |
488 | { | |
489 | fi->fsr.regs[reg] += fi->frame + fi->framesize - fi->frameoffset; | |
490 | } | |
c906108c SS |
491 | } |
492 | ||
493 | /* Function: find_callers_reg | |
494 | Find REGNUM on the stack. Otherwise, it's in an active register. | |
495 | One thing we might want to do here is to check REGNUM against the | |
496 | clobber mask, and somehow flag it as invalid if it isn't saved on | |
497 | the stack somewhere. This would provide a graceful failure mode | |
498 | when trying to get the value of caller-saves registers for an inner | |
499 | frame. */ | |
500 | ||
501 | CORE_ADDR | |
fba45db2 | 502 | fr30_find_callers_reg (struct frame_info *fi, int regnum) |
c906108c SS |
503 | { |
504 | for (; fi; fi = fi->next) | |
505 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) | |
506 | return generic_read_register_dummy (fi->pc, fi->frame, regnum); | |
507 | else if (fi->fsr.regs[regnum] != 0) | |
c5aa993b JM |
508 | return read_memory_unsigned_integer (fi->fsr.regs[regnum], |
509 | REGISTER_RAW_SIZE (regnum)); | |
c906108c SS |
510 | |
511 | return read_register (regnum); | |
512 | } | |
513 | ||
514 | ||
515 | /* Function: frame_chain | |
516 | Figure out the frame prior to FI. Unfortunately, this involves | |
517 | scanning the prologue of the caller, which will also be done | |
518 | shortly by fr30_init_extra_frame_info. For the dummy frame, we | |
519 | just return the stack pointer that was in use at the time the | |
520 | function call was made. */ | |
521 | ||
522 | ||
523 | CORE_ADDR | |
fba45db2 | 524 | fr30_frame_chain (struct frame_info *fi) |
c906108c SS |
525 | { |
526 | CORE_ADDR fn_start, callers_pc, fp; | |
527 | struct frame_info caller_fi; | |
528 | int framereg; | |
529 | ||
530 | /* is this a dummy frame? */ | |
531 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) | |
c5aa993b | 532 | return fi->frame; /* dummy frame same as caller's frame */ |
c906108c SS |
533 | |
534 | /* is caller-of-this a dummy frame? */ | |
c5aa993b | 535 | callers_pc = FRAME_SAVED_PC (fi); /* find out who called us: */ |
c906108c | 536 | fp = fr30_find_callers_reg (fi, FP_REGNUM); |
c5aa993b JM |
537 | if (PC_IN_CALL_DUMMY (callers_pc, fp, fp)) |
538 | return fp; /* dummy frame's frame may bear no relation to ours */ | |
c906108c SS |
539 | |
540 | if (find_pc_partial_function (fi->pc, 0, &fn_start, 0)) | |
541 | if (fn_start == entry_point_address ()) | |
c5aa993b | 542 | return 0; /* in _start fn, don't chain further */ |
c906108c SS |
543 | |
544 | framereg = fi->framereg; | |
545 | ||
546 | /* If the caller is the startup code, we're at the end of the chain. */ | |
547 | if (find_pc_partial_function (callers_pc, 0, &fn_start, 0)) | |
548 | if (fn_start == entry_point_address ()) | |
549 | return 0; | |
550 | ||
c5aa993b | 551 | memset (&caller_fi, 0, sizeof (caller_fi)); |
c906108c | 552 | caller_fi.pc = callers_pc; |
c5aa993b | 553 | fr30_scan_prologue (&caller_fi); |
c906108c SS |
554 | framereg = caller_fi.framereg; |
555 | ||
556 | /* If the caller used a frame register, return its value. | |
557 | Otherwise, return the caller's stack pointer. */ | |
558 | if (framereg == FP_REGNUM) | |
559 | return fr30_find_callers_reg (fi, framereg); | |
560 | else | |
561 | return fi->frame + fi->framesize; | |
562 | } | |
563 | ||
564 | /* Function: frame_saved_pc | |
565 | Find the caller of this frame. We do this by seeing if RP_REGNUM | |
566 | is saved in the stack anywhere, otherwise we get it from the | |
567 | registers. If the inner frame is a dummy frame, return its PC | |
568 | instead of RP, because that's where "caller" of the dummy-frame | |
569 | will be found. */ | |
570 | ||
571 | CORE_ADDR | |
fba45db2 | 572 | fr30_frame_saved_pc (struct frame_info *fi) |
c906108c | 573 | { |
c5aa993b JM |
574 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) |
575 | return generic_read_register_dummy (fi->pc, fi->frame, PC_REGNUM); | |
c906108c SS |
576 | else |
577 | return fr30_find_callers_reg (fi, RP_REGNUM); | |
578 | } | |
579 | ||
580 | /* Function: fix_call_dummy | |
581 | Pokes the callee function's address into the CALL_DUMMY assembly stub. | |
582 | Assumes that the CALL_DUMMY looks like this: | |
c5aa993b JM |
583 | jarl <offset24>, r31 |
584 | trap | |
585 | */ | |
c906108c SS |
586 | |
587 | int | |
fba45db2 KB |
588 | fr30_fix_call_dummy (char *dummy, CORE_ADDR sp, CORE_ADDR fun, int nargs, |
589 | value_ptr *args, struct type *type, int gcc_p) | |
c906108c SS |
590 | { |
591 | long offset24; | |
592 | ||
593 | offset24 = (long) fun - (long) entry_point_address (); | |
594 | offset24 &= 0x3fffff; | |
595 | offset24 |= 0xff800000; /* jarl <offset24>, r31 */ | |
596 | ||
c5aa993b JM |
597 | store_unsigned_integer ((unsigned int *) &dummy[2], 2, offset24 & 0xffff); |
598 | store_unsigned_integer ((unsigned int *) &dummy[0], 2, offset24 >> 16); | |
c906108c SS |
599 | return 0; |
600 | } |