Commit | Line | Data |
---|---|---|
41abdfbd JG |
1 | /* Target-dependent code for GDB, the GNU debugger. |
2 | Copyright (C) 1986, 1987, 1989, 1991 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
19 | ||
41abdfbd | 20 | #include "defs.h" |
41abdfbd JG |
21 | #include "frame.h" |
22 | #include "inferior.h" | |
23 | #include "symtab.h" | |
24 | #include "target.h" | |
25 | ||
26 | #include <sys/param.h> | |
27 | #include <sys/dir.h> | |
28 | #include <sys/user.h> | |
29 | #include <signal.h> | |
30 | #include <sys/ioctl.h> | |
31 | #include <fcntl.h> | |
32 | ||
33 | #include <sys/ptrace.h> | |
34 | #include <sys/reg.h> | |
35 | ||
36 | #include <a.out.h> | |
37 | #include <sys/file.h> | |
38 | #include <sys/stat.h> | |
39 | #include <sys/core.h> | |
40 | ||
41 | extern int errno; | |
42 | extern int attach_flag; | |
43 | ||
44 | /* Nonzero if we just simulated a single step break. */ | |
45 | int one_stepped; | |
46 | ||
507e4004 | 47 | |
41abdfbd JG |
48 | /* Breakpoint shadows for the single step instructions will be kept here. */ |
49 | ||
50 | static struct sstep_breaks { | |
51 | int address; | |
52 | int data; | |
53 | } stepBreaks[2]; | |
54 | ||
55 | ||
56 | /* | |
57 | * Calculate the destination of a branch/jump. Return -1 if not a branch. | |
58 | */ | |
59 | static int | |
60 | branch_dest (opcode, instr, pc, safety) | |
61 | int opcode, instr, pc, safety; | |
62 | { | |
63 | register long offset; | |
64 | unsigned dest; | |
65 | int immediate; | |
66 | int absolute; | |
67 | int ext_op; | |
68 | ||
69 | absolute = (int) ((instr >> 1) & 1); | |
70 | ||
71 | switch (opcode) { | |
72 | case 18 : | |
73 | immediate = ((instr & ~3) << 6) >> 6; /* br unconditionl */ | |
74 | ||
75 | case 16 : | |
76 | if (opcode != 18) /* br conditional */ | |
77 | immediate = ((instr & ~3) << 16) >> 16; | |
78 | if (absolute) | |
79 | dest = immediate; | |
80 | else | |
81 | dest = pc + immediate; | |
82 | break; | |
83 | ||
84 | case 19 : | |
85 | ext_op = (instr>>1) & 0x3ff; | |
86 | ||
87 | if (ext_op == 16) /* br conditional register */ | |
88 | dest = read_register (LR_REGNUM) & ~3; | |
89 | ||
90 | else if (ext_op == 528) /* br cond to count reg */ | |
91 | dest = read_register (CTR_REGNUM) & ~3; | |
92 | ||
93 | else return -1; | |
94 | break; | |
95 | ||
96 | default: return -1; | |
97 | } | |
818de002 | 98 | return (dest < TEXT_SEGMENT_BASE) ? safety : dest; |
41abdfbd JG |
99 | } |
100 | ||
101 | ||
102 | ||
103 | /* AIX does not support PT_STEP. Simulate it. */ | |
104 | ||
105 | int | |
106 | single_step (signal) | |
107 | int signal; | |
108 | { | |
109 | #define INSNLEN(OPCODE) 4 | |
110 | ||
111 | static char breakp[] = BREAKPOINT; | |
112 | int ii, insn, ret, loc; | |
113 | int breaks[2], opcode; | |
114 | ||
115 | if (!one_stepped) { | |
116 | extern CORE_ADDR text_start; | |
117 | loc = read_pc (); | |
118 | ||
119 | ret = read_memory (loc, &insn, sizeof (int)); | |
120 | if (ret) | |
121 | printf ("Error in single_step()!!\n"); | |
122 | ||
123 | breaks[0] = loc + INSNLEN(insn); | |
124 | opcode = insn >> 26; | |
125 | breaks[1] = branch_dest (opcode, insn, loc, breaks[0]); | |
126 | ||
818de002 PB |
127 | /* Don't put two breakpoints on the same address. */ |
128 | if (breaks[1] == breaks[0]) | |
129 | breaks[1] = -1; | |
130 | ||
41abdfbd JG |
131 | stepBreaks[1].address = -1; |
132 | ||
133 | for (ii=0; ii < 2; ++ii) { | |
134 | ||
135 | /* ignore invalid breakpoint. */ | |
136 | if ( breaks[ii] == -1) | |
137 | continue; | |
138 | ||
139 | read_memory (breaks[ii], &(stepBreaks[ii].data), sizeof(int)); | |
140 | ||
141 | ret = write_memory (breaks[ii], breakp, sizeof(int)); | |
142 | stepBreaks[ii].address = breaks[ii]; | |
143 | } | |
144 | ||
145 | one_stepped = 1; | |
818de002 | 146 | ptrace (PT_CONTINUE, inferior_pid, 1, signal, 0); |
41abdfbd JG |
147 | } |
148 | else { | |
149 | ||
150 | /* remove step breakpoints. */ | |
151 | for (ii=0; ii < 2; ++ii) | |
152 | if (stepBreaks[ii].address != -1) | |
153 | write_memory | |
154 | (stepBreaks[ii].address, &(stepBreaks[ii].data), sizeof(int)); | |
155 | ||
156 | one_stepped = 0; | |
157 | } | |
818de002 | 158 | errno = 0; |
41abdfbd JG |
159 | return 1; |
160 | } | |
41abdfbd JG |
161 | |
162 | ||
163 | /* return pc value after skipping a function prologue. */ | |
164 | ||
165 | skip_prologue (pc) | |
166 | int pc; | |
167 | { | |
168 | unsigned int tmp; | |
169 | unsigned int op; | |
170 | ||
171 | if (target_read_memory (pc, (char *)&op, sizeof (op))) | |
172 | return pc; /* Can't access it -- assume no prologue. */ | |
173 | SWAP_TARGET_AND_HOST (&op, sizeof (op)); | |
174 | ||
175 | /* Assume that subsequent fetches can fail with low probability. */ | |
176 | ||
177 | if (op == 0x7c0802a6) { /* mflr r0 */ | |
178 | pc += 4; | |
179 | op = read_memory_integer (pc, 4); | |
180 | } | |
41abdfbd JG |
181 | |
182 | if ((op & 0xfc00003e) == 0x7c000026) { /* mfcr Rx */ | |
183 | pc += 4; | |
184 | op = read_memory_integer (pc, 4); | |
185 | } | |
186 | ||
187 | if ((op & 0xfc000000) == 0x48000000) { /* bl foo, to save fprs??? */ | |
188 | pc += 4; | |
189 | op = read_memory_integer (pc, 4); | |
1eeba686 PB |
190 | |
191 | /* At this point, make sure this is not a trampoline function | |
192 | (a function that simply calls another functions, and nothing else). | |
193 | If the next is not a nop, this branch was part of the function | |
194 | prologue. */ | |
195 | ||
196 | if (op == 0x4def7b82 || /* crorc 15, 15, 15 */ | |
197 | op == 0x0) | |
198 | return pc - 4; /* don't skip over this branch */ | |
41abdfbd JG |
199 | } |
200 | ||
41abdfbd JG |
201 | if ((op & 0xfc1f0000) == 0xbc010000) { /* stm Rx, NUM(r1) */ |
202 | pc += 4; | |
203 | op = read_memory_integer (pc, 4); | |
204 | } | |
205 | ||
206 | while (((tmp = op >> 16) == 0x9001) || /* st r0, NUM(r1) */ | |
207 | (tmp == 0x9421) || /* stu r1, NUM(r1) */ | |
208 | (op == 0x93e1fffc)) /* st r31,-4(r1) */ | |
209 | { | |
210 | pc += 4; | |
211 | op = read_memory_integer (pc, 4); | |
212 | } | |
213 | ||
214 | while ((tmp = (op >> 22)) == 0x20f) { /* l r31, ... or */ | |
215 | pc += 4; /* l r30, ... */ | |
216 | op = read_memory_integer (pc, 4); | |
217 | } | |
218 | ||
507e4004 | 219 | /* store parameters into stack */ |
818de002 PB |
220 | while( |
221 | (op & 0xfc1f0000) == 0xd8010000 || /* stfd Rx,NUM(r1) */ | |
222 | (op & 0xfc1f0000) == 0x90010000 || /* st r?, NUM(r1) */ | |
223 | (op & 0xfc000000) == 0xfc000000 || /* frsp, fp?, .. */ | |
224 | (op & 0xd0000000) == 0xd0000000) /* stfs, fp?, .. */ | |
225 | { | |
226 | pc += 4; /* store fpr double */ | |
227 | op = read_memory_integer (pc, 4); | |
228 | } | |
41abdfbd JG |
229 | |
230 | if (op == 0x603f0000) { /* oril r31, r1, 0x0 */ | |
231 | pc += 4; /* this happens if r31 is used as */ | |
232 | op = read_memory_integer (pc, 4); /* frame ptr. (gcc does that) */ | |
233 | ||
818de002 PB |
234 | tmp = 0; |
235 | while ((op >> 16) == (0x907f + tmp)) { /* st r3, NUM(r31) */ | |
236 | pc += 4; /* st r4, NUM(r31), ... */ | |
41abdfbd | 237 | op = read_memory_integer (pc, 4); |
818de002 | 238 | tmp += 0x20; |
41abdfbd JG |
239 | } |
240 | } | |
507e4004 PB |
241 | #if 0 |
242 | /* I have problems with skipping over __main() that I need to address | |
243 | * sometime. Previously, I used to use misc_function_vector which | |
244 | * didn't work as well as I wanted to be. -MGO */ | |
245 | ||
246 | /* If the first thing after skipping a prolog is a branch to a function, | |
247 | this might be a call to an initializer in main(), introduced by gcc2. | |
248 | We'd like to skip over it as well. Fortunately, xlc does some extra | |
249 | work before calling a function right after a prologue, thus we can | |
250 | single out such gcc2 behaviour. */ | |
251 | ||
252 | ||
253 | if ((op & 0xfc000001) == 0x48000001) { /* bl foo, an initializer function? */ | |
254 | op = read_memory_integer (pc+4, 4); | |
255 | ||
256 | if (op == 0x4def7b82) { /* cror 0xf, 0xf, 0xf (nop) */ | |
257 | ||
258 | /* check and see if we are in main. If so, skip over this initializer | |
259 | function as well. */ | |
260 | ||
261 | tmp = find_pc_misc_function (pc); | |
262 | if (tmp >= 0 && !strcmp (misc_function_vector [tmp].name, "main")) | |
263 | return pc + 8; | |
264 | } | |
265 | } | |
266 | #endif /* 0 */ | |
267 | ||
41abdfbd JG |
268 | return pc; |
269 | } | |
270 | ||
818de002 | 271 | |
41abdfbd JG |
272 | /* text start and end addresses in virtual memory. */ |
273 | ||
274 | CORE_ADDR text_start; | |
275 | CORE_ADDR text_end; | |
276 | ||
507e4004 | 277 | |
41abdfbd JG |
278 | /************************************************************************* |
279 | Support for creating pushind a dummy frame into the stack, and popping | |
280 | frames, etc. | |
281 | *************************************************************************/ | |
282 | ||
818de002 PB |
283 | /* The total size of dummy frame is 436, which is; |
284 | ||
285 | 32 gpr's - 128 bytes | |
286 | 32 fpr's - 256 " | |
287 | 7 the rest - 28 " | |
288 | and 24 extra bytes for the callee's link area. The last 24 bytes | |
289 | for the link area might not be necessary, since it will be taken | |
290 | care of by push_arguments(). */ | |
291 | ||
292 | #define DUMMY_FRAME_SIZE 436 | |
293 | ||
41abdfbd JG |
294 | #define DUMMY_FRAME_ADDR_SIZE 10 |
295 | ||
296 | /* Make sure you initialize these in somewhere, in case gdb gives up what it | |
818de002 | 297 | was debugging and starts debugging something else. FIXMEibm */ |
41abdfbd JG |
298 | |
299 | static int dummy_frame_count = 0; | |
300 | static int dummy_frame_size = 0; | |
301 | static CORE_ADDR *dummy_frame_addr = 0; | |
302 | ||
303 | extern int stop_stack_dummy; | |
304 | ||
305 | /* push a dummy frame into stack, save all register. Currently we are saving | |
306 | only gpr's and fpr's, which is not good enough! FIXMEmgo */ | |
307 | ||
308 | push_dummy_frame () | |
309 | { | |
310 | int sp, pc; /* stack pointer and link register */ | |
311 | int ii; | |
312 | ||
6c6afbb9 PB |
313 | fetch_inferior_registers (-1); |
314 | ||
41abdfbd JG |
315 | if (dummy_frame_count >= dummy_frame_size) { |
316 | dummy_frame_size += DUMMY_FRAME_ADDR_SIZE; | |
317 | if (dummy_frame_addr) | |
318 | dummy_frame_addr = (CORE_ADDR*) xrealloc | |
319 | (dummy_frame_addr, sizeof(CORE_ADDR) * (dummy_frame_size)); | |
320 | else | |
321 | dummy_frame_addr = (CORE_ADDR*) | |
322 | xmalloc (sizeof(CORE_ADDR) * (dummy_frame_size)); | |
323 | } | |
324 | ||
325 | sp = read_register(SP_REGNUM); | |
326 | pc = read_register(PC_REGNUM); | |
327 | ||
328 | dummy_frame_addr [dummy_frame_count++] = sp; | |
329 | ||
330 | /* Be careful! If the stack pointer is not decremented first, then kernel | |
6c6afbb9 | 331 | thinks he is free to use the space underneath it. And kernel actually |
41abdfbd JG |
332 | uses that area for IPC purposes when executing ptrace(2) calls. So |
333 | before writing register values into the new frame, decrement and update | |
334 | %sp first in order to secure your frame. */ | |
335 | ||
818de002 | 336 | write_register (SP_REGNUM, sp-DUMMY_FRAME_SIZE); |
41abdfbd | 337 | |
41abdfbd JG |
338 | /* gdb relies on the state of current_frame. We'd better update it, |
339 | otherwise things like do_registers_info() wouldn't work properly! */ | |
340 | ||
341 | flush_cached_frames (); | |
818de002 | 342 | set_current_frame (create_new_frame (sp-DUMMY_FRAME_SIZE, pc)); |
41abdfbd JG |
343 | |
344 | /* save program counter in link register's space. */ | |
345 | write_memory (sp+8, &pc, 4); | |
346 | ||
6c6afbb9 | 347 | /* save all floating point and general purpose registers here. */ |
41abdfbd JG |
348 | |
349 | /* fpr's, f0..f31 */ | |
350 | for (ii = 0; ii < 32; ++ii) | |
351 | write_memory (sp-8-(ii*8), ®isters[REGISTER_BYTE (31-ii+FP0_REGNUM)], 8); | |
352 | ||
353 | /* gpr's r0..r31 */ | |
354 | for (ii=1; ii <=32; ++ii) | |
355 | write_memory (sp-256-(ii*4), ®isters[REGISTER_BYTE (32-ii)], 4); | |
356 | ||
818de002 PB |
357 | /* so far, 32*2 + 32 words = 384 bytes have been written. |
358 | 7 extra registers in our register set: pc, ps, cnd, lr, cnt, xer, mq */ | |
359 | ||
360 | for (ii=1; ii <= (LAST_SP_REGNUM-FIRST_SP_REGNUM+1); ++ii) { | |
361 | write_memory (sp-384-(ii*4), | |
362 | ®isters[REGISTER_BYTE (FPLAST_REGNUM + ii)], 4); | |
363 | } | |
364 | ||
365 | /* Save sp or so called back chain right here. */ | |
366 | write_memory (sp-DUMMY_FRAME_SIZE, &sp, 4); | |
367 | sp -= DUMMY_FRAME_SIZE; | |
41abdfbd JG |
368 | |
369 | /* And finally, this is the back chain. */ | |
370 | write_memory (sp+8, &pc, 4); | |
371 | } | |
372 | ||
373 | ||
374 | /* Pop a dummy frame. | |
375 | ||
376 | In rs6000 when we push a dummy frame, we save all of the registers. This | |
377 | is usually done before user calls a function explicitly. | |
378 | ||
818de002 PB |
379 | After a dummy frame is pushed, some instructions are copied into stack, |
380 | and stack pointer is decremented even more. Since we don't have a frame | |
381 | pointer to get back to the parent frame of the dummy, we start having | |
382 | trouble poping it. Therefore, we keep a dummy frame stack, keeping | |
383 | addresses of dummy frames as such. When poping happens and when we | |
384 | detect that was a dummy frame, we pop it back to its parent by using | |
385 | dummy frame stack (`dummy_frame_addr' array). | |
41abdfbd JG |
386 | */ |
387 | ||
388 | pop_dummy_frame () | |
389 | { | |
390 | CORE_ADDR sp, pc; | |
391 | int ii; | |
392 | sp = dummy_frame_addr [--dummy_frame_count]; | |
393 | ||
394 | /* restore all fpr's. */ | |
395 | for (ii = 1; ii <= 32; ++ii) | |
396 | read_memory (sp-(ii*8), ®isters[REGISTER_BYTE (32-ii+FP0_REGNUM)], 8); | |
397 | ||
398 | /* restore all gpr's */ | |
399 | for (ii=1; ii <= 32; ++ii) { | |
400 | read_memory (sp-256-(ii*4), ®isters[REGISTER_BYTE (32-ii)], 4); | |
401 | } | |
402 | ||
818de002 PB |
403 | /* restore the rest of the registers. */ |
404 | for (ii=1; ii <=(LAST_SP_REGNUM-FIRST_SP_REGNUM+1); ++ii) | |
405 | read_memory (sp-384-(ii*4), | |
406 | ®isters[REGISTER_BYTE (FPLAST_REGNUM + ii)], 4); | |
407 | ||
408 | read_memory (sp-(DUMMY_FRAME_SIZE-8), | |
409 | ®isters [REGISTER_BYTE(PC_REGNUM)], 4); | |
41abdfbd JG |
410 | |
411 | /* when a dummy frame was being pushed, we had to decrement %sp first, in | |
412 | order to secure astack space. Thus, saved %sp (or %r1) value, is not the | |
413 | one we should restore. Change it with the one we need. */ | |
414 | ||
415 | *(int*)®isters [REGISTER_BYTE(FP_REGNUM)] = sp; | |
416 | ||
417 | /* Now we can restore all registers. */ | |
418 | ||
419 | store_inferior_registers (-1); | |
420 | pc = read_pc (); | |
421 | flush_cached_frames (); | |
422 | set_current_frame (create_new_frame (sp, pc)); | |
423 | } | |
424 | ||
425 | ||
426 | /* pop the innermost frame, go back to the caller. */ | |
427 | ||
428 | pop_frame () | |
429 | { | |
430 | int pc, lr, sp, prev_sp; /* %pc, %lr, %sp */ | |
6c6afbb9 | 431 | struct aix_framedata fdata; |
41abdfbd | 432 | FRAME fr = get_current_frame (); |
41abdfbd | 433 | int addr, ii; |
41abdfbd JG |
434 | |
435 | pc = read_pc (); | |
436 | sp = FRAME_FP (fr); | |
437 | ||
438 | if (stop_stack_dummy && dummy_frame_count) { | |
439 | pop_dummy_frame (); | |
440 | return; | |
441 | } | |
442 | ||
443 | /* figure out previous %pc value. If the function is frameless, it is | |
444 | still in the link register, otherwise walk the frames and retrieve the | |
445 | saved %pc value in the previous frame. */ | |
446 | ||
447 | addr = get_pc_function_start (fr->pc) + FUNCTION_START_OFFSET; | |
6c6afbb9 | 448 | function_frame_info (addr, &fdata); |
41abdfbd JG |
449 | |
450 | read_memory (sp, &prev_sp, 4); | |
6c6afbb9 | 451 | if (fdata.frameless) |
41abdfbd JG |
452 | lr = read_register (LR_REGNUM); |
453 | else | |
454 | read_memory (prev_sp+8, &lr, 4); | |
455 | ||
456 | /* reset %pc value. */ | |
457 | write_register (PC_REGNUM, lr); | |
458 | ||
459 | /* reset register values if any was saved earlier. */ | |
6c6afbb9 | 460 | addr = prev_sp - fdata.offset; |
41abdfbd | 461 | |
6c6afbb9 PB |
462 | if (fdata.saved_gpr != -1) |
463 | for (ii=fdata.saved_gpr; ii <= 31; ++ii) { | |
41abdfbd JG |
464 | read_memory (addr, ®isters [REGISTER_BYTE (ii)], 4); |
465 | addr += sizeof (int); | |
466 | } | |
467 | ||
6c6afbb9 PB |
468 | if (fdata.saved_fpr != -1) |
469 | for (ii=fdata.saved_fpr; ii <= 31; ++ii) { | |
41abdfbd JG |
470 | read_memory (addr, ®isters [REGISTER_BYTE (ii+FP0_REGNUM)], 8); |
471 | addr += 8; | |
472 | } | |
473 | ||
474 | write_register (SP_REGNUM, prev_sp); | |
475 | store_inferior_registers (-1); | |
476 | flush_cached_frames (); | |
477 | set_current_frame (create_new_frame (prev_sp, lr)); | |
478 | } | |
479 | ||
480 | ||
481 | /* fixup the call sequence of a dummy function, with the real function address. | |
482 | its argumets will be passed by gdb. */ | |
483 | ||
484 | fix_call_dummy(dummyname, pc, fun, nargs, type) | |
485 | char *dummyname; | |
486 | int pc; | |
487 | int fun; | |
488 | int nargs; /* not used */ | |
489 | int type; /* not used */ | |
490 | ||
491 | { | |
492 | #define TOC_ADDR_OFFSET 20 | |
493 | #define TARGET_ADDR_OFFSET 28 | |
494 | ||
495 | int ii; | |
496 | unsigned long target_addr; | |
497 | unsigned long tocvalue; | |
498 | ||
499 | target_addr = fun; | |
500 | tocvalue = find_toc_address (target_addr); | |
501 | ||
502 | ii = *(int*)((char*)dummyname + TOC_ADDR_OFFSET); | |
503 | ii = (ii & 0xffff0000) | (tocvalue >> 16); | |
504 | *(int*)((char*)dummyname + TOC_ADDR_OFFSET) = ii; | |
505 | ||
506 | ii = *(int*)((char*)dummyname + TOC_ADDR_OFFSET+4); | |
507 | ii = (ii & 0xffff0000) | (tocvalue & 0x0000ffff); | |
508 | *(int*)((char*)dummyname + TOC_ADDR_OFFSET+4) = ii; | |
509 | ||
510 | ii = *(int*)((char*)dummyname + TARGET_ADDR_OFFSET); | |
511 | ii = (ii & 0xffff0000) | (target_addr >> 16); | |
512 | *(int*)((char*)dummyname + TARGET_ADDR_OFFSET) = ii; | |
513 | ||
514 | ii = *(int*)((char*)dummyname + TARGET_ADDR_OFFSET+4); | |
515 | ii = (ii & 0xffff0000) | (target_addr & 0x0000ffff); | |
516 | *(int*)((char*)dummyname + TARGET_ADDR_OFFSET+4) = ii; | |
517 | } | |
518 | ||
519 | ||
520 | ||
521 | /* return information about a function frame. | |
6c6afbb9 | 522 | in struct aix_frameinfo fdata: |
41abdfbd JG |
523 | - frameless is TRUE, if function does not save %pc value in its frame. |
524 | - offset is the number of bytes used in the frame to save registers. | |
525 | - saved_gpr is the number of the first saved gpr. | |
526 | - saved_fpr is the number of the first saved fpr. | |
6c6afbb9 PB |
527 | - alloca_reg is the number of the register used for alloca() handling. |
528 | Otherwise -1. | |
41abdfbd | 529 | */ |
6c6afbb9 | 530 | function_frame_info (pc, fdata) |
41abdfbd | 531 | int pc; |
6c6afbb9 | 532 | struct aix_framedata *fdata; |
41abdfbd JG |
533 | { |
534 | unsigned int tmp; | |
535 | register unsigned int op; | |
536 | ||
6c6afbb9 PB |
537 | fdata->offset = 0; |
538 | fdata->saved_gpr = fdata->saved_fpr = fdata->alloca_reg = -1; | |
41abdfbd | 539 | |
41abdfbd JG |
540 | op = read_memory_integer (pc, 4); |
541 | if (op == 0x7c0802a6) { /* mflr r0 */ | |
542 | pc += 4; | |
543 | op = read_memory_integer (pc, 4); | |
6c6afbb9 | 544 | fdata->frameless = 0; |
41abdfbd JG |
545 | } |
546 | else /* else, this is a frameless invocation */ | |
6c6afbb9 | 547 | fdata->frameless = 1; |
41abdfbd JG |
548 | |
549 | ||
550 | if ((op & 0xfc00003e) == 0x7c000026) { /* mfcr Rx */ | |
551 | pc += 4; | |
552 | op = read_memory_integer (pc, 4); | |
553 | } | |
554 | ||
555 | if ((op & 0xfc000000) == 0x48000000) { /* bl foo, to save fprs??? */ | |
556 | pc += 4; | |
557 | op = read_memory_integer (pc, 4); | |
1eeba686 PB |
558 | /* At this point, make sure this is not a trampoline function |
559 | (a function that simply calls another functions, and nothing else). | |
560 | If the next is not a nop, this branch was part of the function | |
561 | prologue. */ | |
562 | ||
563 | if (op == 0x4def7b82 || /* crorc 15, 15, 15 */ | |
564 | op == 0x0) | |
565 | return; /* prologue is over */ | |
41abdfbd JG |
566 | } |
567 | ||
568 | if ((op & 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */ | |
569 | pc += 4; /* store floating register double */ | |
570 | op = read_memory_integer (pc, 4); | |
571 | } | |
572 | ||
573 | if ((op & 0xfc1f0000) == 0xbc010000) { /* stm Rx, NUM(r1) */ | |
574 | int tmp2; | |
6c6afbb9 | 575 | fdata->saved_gpr = (op >> 21) & 0x1f; |
41abdfbd JG |
576 | tmp2 = op & 0xffff; |
577 | if (tmp2 > 0x7fff) | |
578 | tmp2 = 0xffff0000 | tmp2; | |
579 | ||
580 | if (tmp2 < 0) { | |
581 | tmp2 = tmp2 * -1; | |
6c6afbb9 PB |
582 | fdata->saved_fpr = (tmp2 - ((32 - fdata->saved_gpr) * 4)) / 8; |
583 | if ( fdata->saved_fpr > 0) | |
584 | fdata->saved_fpr = 32 - fdata->saved_fpr; | |
41abdfbd | 585 | else |
6c6afbb9 | 586 | fdata->saved_fpr = -1; |
41abdfbd | 587 | } |
6c6afbb9 PB |
588 | fdata->offset = tmp2; |
589 | pc += 4; | |
590 | op = read_memory_integer (pc, 4); | |
41abdfbd | 591 | } |
6c6afbb9 PB |
592 | |
593 | while (((tmp = op >> 16) == 0x9001) || /* st r0, NUM(r1) */ | |
594 | (tmp == 0x9421) || /* stu r1, NUM(r1) */ | |
595 | (op == 0x93e1fffc)) /* st r31,-4(r1) */ | |
596 | { | |
597 | /* gcc takes a short cut and uses this instruction to save r31 only. */ | |
598 | ||
599 | if (op == 0x93e1fffc) { | |
600 | if (fdata->offset) | |
601 | /* fatal ("Unrecognized prolog."); */ | |
602 | printf ("Unrecognized prolog!\n"); | |
603 | ||
604 | fdata->saved_gpr = 31; | |
605 | fdata->offset = 4; | |
606 | } | |
607 | pc += 4; | |
608 | op = read_memory_integer (pc, 4); | |
609 | } | |
610 | ||
611 | while ((tmp = (op >> 22)) == 0x20f) { /* l r31, ... or */ | |
612 | pc += 4; /* l r30, ... */ | |
613 | op = read_memory_integer (pc, 4); | |
614 | } | |
615 | ||
616 | /* store parameters into stack */ | |
617 | while( | |
618 | (op & 0xfc1f0000) == 0xd8010000 || /* stfd Rx,NUM(r1) */ | |
619 | (op & 0xfc1f0000) == 0x90010000 || /* st r?, NUM(r1) */ | |
620 | (op & 0xfc000000) == 0xfc000000 || /* frsp, fp?, .. */ | |
621 | (op & 0xd0000000) == 0xd0000000) /* stfs, fp?, .. */ | |
622 | { | |
623 | pc += 4; /* store fpr double */ | |
624 | op = read_memory_integer (pc, 4); | |
625 | } | |
626 | ||
627 | if (op == 0x603f0000) /* oril r31, r1, 0x0 */ | |
628 | fdata->alloca_reg = 31; | |
41abdfbd JG |
629 | } |
630 | ||
631 | ||
632 | /* Pass the arguments in either registers, or in the stack. In RS6000, the first | |
633 | eight words of the argument list (that might be less than eight parameters if | |
634 | some parameters occupy more than one word) are passed in r3..r11 registers. | |
635 | float and double parameters are passed in fpr's, in addition to that. Rest of | |
636 | the parameters if any are passed in user stack. There might be cases in which | |
637 | half of the parameter is copied into registers, the other half is pushed into | |
638 | stack. | |
639 | ||
640 | If the function is returning a structure, then the return address is passed | |
641 | in r3, then the first 7 words of the parametes can be passed in registers, | |
642 | starting from r4. */ | |
643 | ||
644 | CORE_ADDR | |
645 | push_arguments (nargs, args, sp, struct_return, struct_addr) | |
646 | int nargs; | |
647 | value *args; | |
648 | CORE_ADDR sp; | |
649 | int struct_return; | |
650 | CORE_ADDR struct_addr; | |
651 | { | |
652 | int ii, len; | |
653 | int argno; /* current argument number */ | |
654 | int argbytes; /* current argument byte */ | |
655 | char tmp_buffer [50]; | |
656 | value arg; | |
657 | int f_argno = 0; /* current floating point argno */ | |
658 | ||
659 | CORE_ADDR saved_sp, pc; | |
660 | ||
661 | if ( dummy_frame_count <= 0) | |
662 | printf ("FATAL ERROR -push_arguments()! frame not found!!\n"); | |
663 | ||
664 | /* The first eight words of ther arguments are passed in registers. Copy | |
665 | them appropriately. | |
666 | ||
667 | If the function is returning a `struct', then the first word (which | |
668 | will be passed in r3) is used for struct return address. In that | |
669 | case we should advance one word and start from r4 register to copy | |
670 | parameters. */ | |
671 | ||
672 | ii = struct_return ? 1 : 0; | |
673 | ||
674 | for (argno=0, argbytes=0; argno < nargs && ii<8; ++ii) { | |
675 | ||
676 | arg = value_arg_coerce (args[argno]); | |
677 | len = TYPE_LENGTH (VALUE_TYPE (arg)); | |
678 | ||
679 | if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_FLT) { | |
680 | ||
681 | /* floating point arguments are passed in fpr's, as well as gpr's. | |
682 | There are 13 fpr's reserved for passing parameters. At this point | |
683 | there is no way we would run out of them. */ | |
684 | ||
685 | if (len > 8) | |
686 | printf ( | |
687 | "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno); | |
688 | ||
689 | bcopy (VALUE_CONTENTS (arg), | |
690 | ®isters[REGISTER_BYTE(FP0_REGNUM + 1 + f_argno)], len); | |
691 | ++f_argno; | |
692 | } | |
693 | ||
694 | if (len > 4) { | |
695 | ||
696 | /* Argument takes more than one register. */ | |
697 | while (argbytes < len) { | |
698 | ||
699 | *(int*)®isters[REGISTER_BYTE(ii+3)] = 0; | |
700 | bcopy ( ((char*)VALUE_CONTENTS (arg))+argbytes, | |
701 | ®isters[REGISTER_BYTE(ii+3)], | |
702 | (len - argbytes) > 4 ? 4 : len - argbytes); | |
703 | ++ii, argbytes += 4; | |
704 | ||
705 | if (ii >= 8) | |
706 | goto ran_out_of_registers_for_arguments; | |
707 | } | |
708 | argbytes = 0; | |
709 | --ii; | |
710 | } | |
711 | else { /* Argument can fit in one register. No problem. */ | |
712 | *(int*)®isters[REGISTER_BYTE(ii+3)] = 0; | |
713 | bcopy (VALUE_CONTENTS (arg), ®isters[REGISTER_BYTE(ii+3)], len); | |
714 | } | |
715 | ++argno; | |
716 | } | |
717 | ||
718 | ran_out_of_registers_for_arguments: | |
719 | ||
720 | /* location for 8 parameters are always reserved. */ | |
721 | sp -= 4 * 8; | |
722 | ||
723 | /* another six words for back chain, TOC register, link register, etc. */ | |
724 | sp -= 24; | |
725 | ||
726 | /* if there are more arguments, allocate space for them in | |
727 | the stack, then push them starting from the ninth one. */ | |
728 | ||
729 | if ((argno < nargs) || argbytes) { | |
730 | int space = 0, jj; | |
731 | value val; | |
732 | ||
733 | if (argbytes) { | |
734 | space += ((len - argbytes + 3) & -4); | |
735 | jj = argno + 1; | |
736 | } | |
737 | else | |
738 | jj = argno; | |
739 | ||
740 | for (; jj < nargs; ++jj) { | |
741 | val = value_arg_coerce (args[jj]); | |
742 | space += ((TYPE_LENGTH (VALUE_TYPE (val))) + 3) & -4; | |
743 | } | |
744 | ||
745 | /* add location required for the rest of the parameters */ | |
746 | space = (space + 7) & -8; | |
747 | sp -= space; | |
748 | ||
749 | /* This is another instance we need to be concerned about securing our | |
750 | stack space. If we write anything underneath %sp (r1), we might conflict | |
751 | with the kernel who thinks he is free to use this area. So, update %sp | |
752 | first before doing anything else. */ | |
753 | ||
754 | write_register (SP_REGNUM, sp); | |
755 | ||
41abdfbd JG |
756 | /* if the last argument copied into the registers didn't fit there |
757 | completely, push the rest of it into stack. */ | |
758 | ||
759 | if (argbytes) { | |
760 | write_memory ( | |
761 | sp+24+(ii*4), ((char*)VALUE_CONTENTS (arg))+argbytes, len - argbytes); | |
762 | ++argno; | |
763 | ii += ((len - argbytes + 3) & -4) / 4; | |
764 | } | |
765 | ||
766 | /* push the rest of the arguments into stack. */ | |
767 | for (; argno < nargs; ++argno) { | |
768 | ||
769 | arg = value_arg_coerce (args[argno]); | |
770 | len = TYPE_LENGTH (VALUE_TYPE (arg)); | |
771 | ||
772 | ||
773 | /* float types should be passed in fpr's, as well as in the stack. */ | |
774 | if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_FLT && f_argno < 13) { | |
775 | ||
776 | if (len > 8) | |
777 | printf ( | |
778 | "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno); | |
779 | ||
780 | bcopy (VALUE_CONTENTS (arg), | |
781 | ®isters[REGISTER_BYTE(FP0_REGNUM + 1 + f_argno)], len); | |
782 | ++f_argno; | |
783 | } | |
784 | ||
785 | write_memory (sp+24+(ii*4), VALUE_CONTENTS (arg), len); | |
786 | ii += ((len + 3) & -4) / 4; | |
787 | } | |
788 | } | |
6c6afbb9 | 789 | else |
41abdfbd JG |
790 | /* Secure stack areas first, before doing anything else. */ |
791 | write_register (SP_REGNUM, sp); | |
792 | ||
41abdfbd JG |
793 | saved_sp = dummy_frame_addr [dummy_frame_count - 1]; |
794 | read_memory (saved_sp, tmp_buffer, 24); | |
795 | write_memory (sp, tmp_buffer, 24); | |
796 | ||
797 | write_memory (sp, &saved_sp, 4); /* set back chain properly */ | |
798 | ||
799 | store_inferior_registers (-1); | |
800 | return sp; | |
801 | } | |
802 | ||
803 | /* a given return value in `regbuf' with a type `valtype', extract and copy its | |
804 | value into `valbuf' */ | |
805 | ||
806 | extract_return_value (valtype, regbuf, valbuf) | |
807 | struct type *valtype; | |
808 | char regbuf[REGISTER_BYTES]; | |
809 | char *valbuf; | |
810 | { | |
811 | ||
812 | if (TYPE_CODE (valtype) == TYPE_CODE_FLT) { | |
813 | ||
814 | double dd; float ff; | |
815 | /* floats and doubles are returned in fpr1. fpr's have a size of 8 bytes. | |
816 | We need to truncate the return value into float size (4 byte) if | |
817 | necessary. */ | |
818 | ||
819 | if (TYPE_LENGTH (valtype) > 4) /* this is a double */ | |
820 | bcopy (®buf[REGISTER_BYTE (FP0_REGNUM + 1)], valbuf, | |
821 | TYPE_LENGTH (valtype)); | |
822 | else { /* float */ | |
823 | bcopy (®buf[REGISTER_BYTE (FP0_REGNUM + 1)], &dd, 8); | |
824 | ff = (float)dd; | |
825 | bcopy (&ff, valbuf, sizeof(float)); | |
826 | } | |
827 | } | |
828 | else | |
829 | /* return value is copied starting from r3. */ | |
830 | bcopy (®buf[REGISTER_BYTE (3)], valbuf, TYPE_LENGTH (valtype)); | |
831 | } | |
832 | ||
833 | ||
834 | /* keep keep structure return address in this variable. */ | |
835 | ||
836 | CORE_ADDR rs6000_struct_return_address; | |
837 | ||
838 | ||
839 | /* Throw away this debugging code. FIXMEmgo. */ | |
840 | print_frame(fram) | |
841 | int fram; | |
842 | { | |
843 | int ii, val; | |
844 | for (ii=0; ii<40; ++ii) { | |
845 | if ((ii % 4) == 0) | |
846 | printf ("\n"); | |
847 | val = read_memory_integer (fram + ii * 4, 4); | |
848 | printf ("0x%08x\t", val); | |
849 | } | |
850 | printf ("\n"); | |
851 | } | |
852 | ||
853 | ||
854 | ||
c2e4669f JG |
855 | /* Indirect function calls use a piece of trampoline code to do context |
856 | switching, i.e. to set the new TOC table. Skip such code if we are on | |
857 | its first instruction (as when we have single-stepped to here). | |
858 | Result is desired PC to step until, or NULL if we are not in | |
859 | trampoline code. */ | |
41abdfbd JG |
860 | |
861 | skip_trampoline_code (pc) | |
862 | int pc; | |
863 | { | |
864 | register unsigned int ii, op; | |
865 | ||
866 | static unsigned trampoline_code[] = { | |
867 | 0x800b0000, /* l r0,0x0(r11) */ | |
868 | 0x90410014, /* st r2,0x14(r1) */ | |
869 | 0x7c0903a6, /* mtctr r0 */ | |
870 | 0x804b0004, /* l r2,0x4(r11) */ | |
871 | 0x816b0008, /* l r11,0x8(r11) */ | |
872 | 0x4e800420, /* bctr */ | |
873 | 0x4e800020, /* br */ | |
874 | 0 | |
875 | }; | |
876 | ||
877 | for (ii=0; trampoline_code[ii]; ++ii) { | |
878 | op = read_memory_integer (pc + (ii*4), 4); | |
879 | if (op != trampoline_code [ii]) | |
880 | return NULL; | |
881 | } | |
882 | ii = read_register (11); /* r11 holds destination addr */ | |
883 | pc = read_memory_integer (ii, 4); /* (r11) value */ | |
884 | return pc; | |
885 | } | |
886 |