| 1 | /* Target-dependent code for GDB, the GNU debugger. |
| 2 | Copyright 1986, 1987, 1989, 1991, 1992 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 | |
| 20 | #include "defs.h" |
| 21 | #include "frame.h" |
| 22 | #include "inferior.h" |
| 23 | #include "symtab.h" |
| 24 | #include "target.h" |
| 25 | #include "gdbcore.h" |
| 26 | |
| 27 | #include "xcoffsolib.h" |
| 28 | |
| 29 | #include <sys/param.h> |
| 30 | #include <sys/dir.h> |
| 31 | #include <sys/user.h> |
| 32 | #include <signal.h> |
| 33 | #include <sys/ioctl.h> |
| 34 | #include <fcntl.h> |
| 35 | |
| 36 | #include <a.out.h> |
| 37 | #include <sys/file.h> |
| 38 | #include <sys/stat.h> |
| 39 | #include <sys/core.h> |
| 40 | #include <sys/ldr.h> |
| 41 | |
| 42 | |
| 43 | extern struct obstack frame_cache_obstack; |
| 44 | |
| 45 | extern int errno; |
| 46 | |
| 47 | /* Nonzero if we just simulated a single step break. */ |
| 48 | int one_stepped; |
| 49 | |
| 50 | /* Breakpoint shadows for the single step instructions will be kept here. */ |
| 51 | |
| 52 | static struct sstep_breaks { |
| 53 | /* Address, or 0 if this is not in use. */ |
| 54 | CORE_ADDR address; |
| 55 | /* Shadow contents. */ |
| 56 | char data[4]; |
| 57 | } stepBreaks[2]; |
| 58 | |
| 59 | /* Static function prototypes */ |
| 60 | |
| 61 | static CORE_ADDR |
| 62 | find_toc_address PARAMS ((CORE_ADDR pc)); |
| 63 | |
| 64 | static CORE_ADDR |
| 65 | branch_dest PARAMS ((int opcode, int instr, CORE_ADDR pc, CORE_ADDR safety)); |
| 66 | |
| 67 | static void |
| 68 | frame_get_cache_fsr PARAMS ((struct frame_info *fi, |
| 69 | struct aix_framedata *fdatap)); |
| 70 | |
| 71 | /* |
| 72 | * Calculate the destination of a branch/jump. Return -1 if not a branch. |
| 73 | */ |
| 74 | static CORE_ADDR |
| 75 | branch_dest (opcode, instr, pc, safety) |
| 76 | int opcode; |
| 77 | int instr; |
| 78 | CORE_ADDR pc; |
| 79 | CORE_ADDR safety; |
| 80 | { |
| 81 | register long offset; |
| 82 | CORE_ADDR dest; |
| 83 | int immediate; |
| 84 | int absolute; |
| 85 | int ext_op; |
| 86 | |
| 87 | absolute = (int) ((instr >> 1) & 1); |
| 88 | |
| 89 | switch (opcode) { |
| 90 | case 18 : |
| 91 | immediate = ((instr & ~3) << 6) >> 6; /* br unconditional */ |
| 92 | |
| 93 | case 16 : |
| 94 | if (opcode != 18) /* br conditional */ |
| 95 | immediate = ((instr & ~3) << 16) >> 16; |
| 96 | if (absolute) |
| 97 | dest = immediate; |
| 98 | else |
| 99 | dest = pc + immediate; |
| 100 | break; |
| 101 | |
| 102 | case 19 : |
| 103 | ext_op = (instr>>1) & 0x3ff; |
| 104 | |
| 105 | if (ext_op == 16) /* br conditional register */ |
| 106 | dest = read_register (LR_REGNUM) & ~3; |
| 107 | |
| 108 | else if (ext_op == 528) /* br cond to count reg */ |
| 109 | { |
| 110 | dest = read_register (CTR_REGNUM) & ~3; |
| 111 | |
| 112 | /* If we are about to execute a system call, dest is something |
| 113 | like 0x22fc or 0x3b00. Upon completion the system call |
| 114 | will return to the address in the link register. */ |
| 115 | if (dest < TEXT_SEGMENT_BASE) |
| 116 | dest = read_register (LR_REGNUM) & ~3; |
| 117 | } |
| 118 | else return -1; |
| 119 | break; |
| 120 | |
| 121 | default: return -1; |
| 122 | } |
| 123 | return (dest < TEXT_SEGMENT_BASE) ? safety : dest; |
| 124 | } |
| 125 | |
| 126 | |
| 127 | |
| 128 | /* AIX does not support PT_STEP. Simulate it. */ |
| 129 | |
| 130 | void |
| 131 | single_step (signal) |
| 132 | int signal; |
| 133 | { |
| 134 | #define INSNLEN(OPCODE) 4 |
| 135 | |
| 136 | static char breakp[] = BREAKPOINT; |
| 137 | int ii, insn; |
| 138 | CORE_ADDR loc; |
| 139 | CORE_ADDR breaks[2]; |
| 140 | int opcode; |
| 141 | |
| 142 | if (!one_stepped) { |
| 143 | loc = read_pc (); |
| 144 | |
| 145 | read_memory (loc, (char *) &insn, 4); |
| 146 | |
| 147 | breaks[0] = loc + INSNLEN(insn); |
| 148 | opcode = insn >> 26; |
| 149 | breaks[1] = branch_dest (opcode, insn, loc, breaks[0]); |
| 150 | |
| 151 | /* Don't put two breakpoints on the same address. */ |
| 152 | if (breaks[1] == breaks[0]) |
| 153 | breaks[1] = -1; |
| 154 | |
| 155 | stepBreaks[1].address = 0; |
| 156 | |
| 157 | for (ii=0; ii < 2; ++ii) { |
| 158 | |
| 159 | /* ignore invalid breakpoint. */ |
| 160 | if ( breaks[ii] == -1) |
| 161 | continue; |
| 162 | |
| 163 | read_memory (breaks[ii], stepBreaks[ii].data, 4); |
| 164 | |
| 165 | write_memory (breaks[ii], breakp, 4); |
| 166 | stepBreaks[ii].address = breaks[ii]; |
| 167 | } |
| 168 | |
| 169 | one_stepped = 1; |
| 170 | } else { |
| 171 | |
| 172 | /* remove step breakpoints. */ |
| 173 | for (ii=0; ii < 2; ++ii) |
| 174 | if (stepBreaks[ii].address != 0) |
| 175 | write_memory |
| 176 | (stepBreaks[ii].address, stepBreaks[ii].data, 4); |
| 177 | |
| 178 | one_stepped = 0; |
| 179 | } |
| 180 | errno = 0; /* FIXME, don't ignore errors! */ |
| 181 | /* What errors? {read,write}_memory call error(). */ |
| 182 | } |
| 183 | |
| 184 | |
| 185 | /* return pc value after skipping a function prologue. */ |
| 186 | |
| 187 | skip_prologue (pc) |
| 188 | CORE_ADDR pc; |
| 189 | { |
| 190 | char buf[4]; |
| 191 | unsigned int tmp; |
| 192 | unsigned long op; |
| 193 | |
| 194 | if (target_read_memory (pc, buf, 4)) |
| 195 | return pc; /* Can't access it -- assume no prologue. */ |
| 196 | op = extract_unsigned_integer (buf, 4); |
| 197 | |
| 198 | /* Assume that subsequent fetches can fail with low probability. */ |
| 199 | |
| 200 | if (op == 0x7c0802a6) { /* mflr r0 */ |
| 201 | pc += 4; |
| 202 | op = read_memory_integer (pc, 4); |
| 203 | } |
| 204 | |
| 205 | if ((op & 0xfc00003e) == 0x7c000026) { /* mfcr Rx */ |
| 206 | pc += 4; |
| 207 | op = read_memory_integer (pc, 4); |
| 208 | } |
| 209 | |
| 210 | if ((op & 0xfc000000) == 0x48000000) { /* bl foo, to save fprs??? */ |
| 211 | pc += 4; |
| 212 | op = read_memory_integer (pc, 4); |
| 213 | |
| 214 | /* At this point, make sure this is not a trampoline function |
| 215 | (a function that simply calls another functions, and nothing else). |
| 216 | If the next is not a nop, this branch was part of the function |
| 217 | prologue. */ |
| 218 | |
| 219 | if (op == 0x4def7b82 || /* crorc 15, 15, 15 */ |
| 220 | op == 0x0) |
| 221 | return pc - 4; /* don't skip over this branch */ |
| 222 | } |
| 223 | |
| 224 | if ((op & 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */ |
| 225 | pc += 4; /* store floating register double */ |
| 226 | op = read_memory_integer (pc, 4); |
| 227 | } |
| 228 | |
| 229 | if ((op & 0xfc1f0000) == 0xbc010000) { /* stm Rx, NUM(r1) */ |
| 230 | pc += 4; |
| 231 | op = read_memory_integer (pc, 4); |
| 232 | } |
| 233 | |
| 234 | while (((tmp = op >> 16) == 0x9001) || /* st r0, NUM(r1) */ |
| 235 | (tmp == 0x9421) || /* stu r1, NUM(r1) */ |
| 236 | (tmp == 0x93e1)) /* st r31,NUM(r1) */ |
| 237 | { |
| 238 | pc += 4; |
| 239 | op = read_memory_integer (pc, 4); |
| 240 | } |
| 241 | |
| 242 | while ((tmp = (op >> 22)) == 0x20f) { /* l r31, ... or */ |
| 243 | pc += 4; /* l r30, ... */ |
| 244 | op = read_memory_integer (pc, 4); |
| 245 | } |
| 246 | |
| 247 | /* store parameters into stack */ |
| 248 | while( |
| 249 | (op & 0xfc1f0000) == 0xd8010000 || /* stfd Rx,NUM(r1) */ |
| 250 | (op & 0xfc1f0000) == 0x90010000 || /* st r?, NUM(r1) */ |
| 251 | (op & 0xfc000000) == 0xfc000000 || /* frsp, fp?, .. */ |
| 252 | (op & 0xd0000000) == 0xd0000000) /* stfs, fp?, .. */ |
| 253 | { |
| 254 | pc += 4; /* store fpr double */ |
| 255 | op = read_memory_integer (pc, 4); |
| 256 | } |
| 257 | |
| 258 | if (op == 0x603f0000) { /* oril r31, r1, 0x0 */ |
| 259 | pc += 4; /* this happens if r31 is used as */ |
| 260 | op = read_memory_integer (pc, 4); /* frame ptr. (gcc does that) */ |
| 261 | |
| 262 | tmp = 0; |
| 263 | while ((op >> 16) == (0x907f + tmp)) { /* st r3, NUM(r31) */ |
| 264 | pc += 4; /* st r4, NUM(r31), ... */ |
| 265 | op = read_memory_integer (pc, 4); |
| 266 | tmp += 0x20; |
| 267 | } |
| 268 | } |
| 269 | #if 0 |
| 270 | /* I have problems with skipping over __main() that I need to address |
| 271 | * sometime. Previously, I used to use misc_function_vector which |
| 272 | * didn't work as well as I wanted to be. -MGO */ |
| 273 | |
| 274 | /* If the first thing after skipping a prolog is a branch to a function, |
| 275 | this might be a call to an initializer in main(), introduced by gcc2. |
| 276 | We'd like to skip over it as well. Fortunately, xlc does some extra |
| 277 | work before calling a function right after a prologue, thus we can |
| 278 | single out such gcc2 behaviour. */ |
| 279 | |
| 280 | |
| 281 | if ((op & 0xfc000001) == 0x48000001) { /* bl foo, an initializer function? */ |
| 282 | op = read_memory_integer (pc+4, 4); |
| 283 | |
| 284 | if (op == 0x4def7b82) { /* cror 0xf, 0xf, 0xf (nop) */ |
| 285 | |
| 286 | /* check and see if we are in main. If so, skip over this initializer |
| 287 | function as well. */ |
| 288 | |
| 289 | tmp = find_pc_misc_function (pc); |
| 290 | if (tmp >= 0 && STREQ (misc_function_vector [tmp].name, "main")) |
| 291 | return pc + 8; |
| 292 | } |
| 293 | } |
| 294 | #endif /* 0 */ |
| 295 | |
| 296 | return pc; |
| 297 | } |
| 298 | |
| 299 | |
| 300 | /************************************************************************* |
| 301 | Support for creating pushind a dummy frame into the stack, and popping |
| 302 | frames, etc. |
| 303 | *************************************************************************/ |
| 304 | |
| 305 | /* The total size of dummy frame is 436, which is; |
| 306 | |
| 307 | 32 gpr's - 128 bytes |
| 308 | 32 fpr's - 256 " |
| 309 | 7 the rest - 28 " |
| 310 | and 24 extra bytes for the callee's link area. The last 24 bytes |
| 311 | for the link area might not be necessary, since it will be taken |
| 312 | care of by push_arguments(). */ |
| 313 | |
| 314 | #define DUMMY_FRAME_SIZE 436 |
| 315 | |
| 316 | #define DUMMY_FRAME_ADDR_SIZE 10 |
| 317 | |
| 318 | /* Make sure you initialize these in somewhere, in case gdb gives up what it |
| 319 | was debugging and starts debugging something else. FIXMEibm */ |
| 320 | |
| 321 | static int dummy_frame_count = 0; |
| 322 | static int dummy_frame_size = 0; |
| 323 | static CORE_ADDR *dummy_frame_addr = 0; |
| 324 | |
| 325 | extern int stop_stack_dummy; |
| 326 | |
| 327 | /* push a dummy frame into stack, save all register. Currently we are saving |
| 328 | only gpr's and fpr's, which is not good enough! FIXMEmgo */ |
| 329 | |
| 330 | void |
| 331 | push_dummy_frame () |
| 332 | { |
| 333 | /* stack pointer. */ |
| 334 | CORE_ADDR sp; |
| 335 | |
| 336 | /* link register. */ |
| 337 | CORE_ADDR pc; |
| 338 | /* Same thing, target byte order. */ |
| 339 | char pc_targ[4]; |
| 340 | |
| 341 | int ii; |
| 342 | |
| 343 | target_fetch_registers (-1); |
| 344 | |
| 345 | if (dummy_frame_count >= dummy_frame_size) { |
| 346 | dummy_frame_size += DUMMY_FRAME_ADDR_SIZE; |
| 347 | if (dummy_frame_addr) |
| 348 | dummy_frame_addr = (CORE_ADDR*) xrealloc |
| 349 | (dummy_frame_addr, sizeof(CORE_ADDR) * (dummy_frame_size)); |
| 350 | else |
| 351 | dummy_frame_addr = (CORE_ADDR*) |
| 352 | xmalloc (sizeof(CORE_ADDR) * (dummy_frame_size)); |
| 353 | } |
| 354 | |
| 355 | sp = read_register(SP_REGNUM); |
| 356 | pc = read_register(PC_REGNUM); |
| 357 | memcpy (pc_targ, (char *) &pc, 4); |
| 358 | |
| 359 | dummy_frame_addr [dummy_frame_count++] = sp; |
| 360 | |
| 361 | /* Be careful! If the stack pointer is not decremented first, then kernel |
| 362 | thinks he is free to use the space underneath it. And kernel actually |
| 363 | uses that area for IPC purposes when executing ptrace(2) calls. So |
| 364 | before writing register values into the new frame, decrement and update |
| 365 | %sp first in order to secure your frame. */ |
| 366 | |
| 367 | write_register (SP_REGNUM, sp-DUMMY_FRAME_SIZE); |
| 368 | |
| 369 | /* gdb relies on the state of current_frame. We'd better update it, |
| 370 | otherwise things like do_registers_info() wouldn't work properly! */ |
| 371 | |
| 372 | flush_cached_frames (); |
| 373 | set_current_frame (create_new_frame (sp-DUMMY_FRAME_SIZE, pc)); |
| 374 | |
| 375 | /* save program counter in link register's space. */ |
| 376 | write_memory (sp+8, pc_targ, 4); |
| 377 | |
| 378 | /* save all floating point and general purpose registers here. */ |
| 379 | |
| 380 | /* fpr's, f0..f31 */ |
| 381 | for (ii = 0; ii < 32; ++ii) |
| 382 | write_memory (sp-8-(ii*8), ®isters[REGISTER_BYTE (31-ii+FP0_REGNUM)], 8); |
| 383 | |
| 384 | /* gpr's r0..r31 */ |
| 385 | for (ii=1; ii <=32; ++ii) |
| 386 | write_memory (sp-256-(ii*4), ®isters[REGISTER_BYTE (32-ii)], 4); |
| 387 | |
| 388 | /* so far, 32*2 + 32 words = 384 bytes have been written. |
| 389 | 7 extra registers in our register set: pc, ps, cnd, lr, cnt, xer, mq */ |
| 390 | |
| 391 | for (ii=1; ii <= (LAST_SP_REGNUM-FIRST_SP_REGNUM+1); ++ii) { |
| 392 | write_memory (sp-384-(ii*4), |
| 393 | ®isters[REGISTER_BYTE (FPLAST_REGNUM + ii)], 4); |
| 394 | } |
| 395 | |
| 396 | /* Save sp or so called back chain right here. */ |
| 397 | write_memory (sp-DUMMY_FRAME_SIZE, &sp, 4); |
| 398 | sp -= DUMMY_FRAME_SIZE; |
| 399 | |
| 400 | /* And finally, this is the back chain. */ |
| 401 | write_memory (sp+8, pc_targ, 4); |
| 402 | } |
| 403 | |
| 404 | |
| 405 | /* Pop a dummy frame. |
| 406 | |
| 407 | In rs6000 when we push a dummy frame, we save all of the registers. This |
| 408 | is usually done before user calls a function explicitly. |
| 409 | |
| 410 | After a dummy frame is pushed, some instructions are copied into stack, |
| 411 | and stack pointer is decremented even more. Since we don't have a frame |
| 412 | pointer to get back to the parent frame of the dummy, we start having |
| 413 | trouble poping it. Therefore, we keep a dummy frame stack, keeping |
| 414 | addresses of dummy frames as such. When poping happens and when we |
| 415 | detect that was a dummy frame, we pop it back to its parent by using |
| 416 | dummy frame stack (`dummy_frame_addr' array). |
| 417 | |
| 418 | FIXME: This whole concept is broken. You should be able to detect |
| 419 | a dummy stack frame *on the user's stack itself*. When you do, |
| 420 | then you know the format of that stack frame -- including its |
| 421 | saved SP register! There should *not* be a separate stack in the |
| 422 | GDB process that keeps track of these dummy frames! -- gnu@cygnus.com Aug92 |
| 423 | */ |
| 424 | |
| 425 | pop_dummy_frame () |
| 426 | { |
| 427 | CORE_ADDR sp, pc; |
| 428 | int ii; |
| 429 | sp = dummy_frame_addr [--dummy_frame_count]; |
| 430 | |
| 431 | /* restore all fpr's. */ |
| 432 | for (ii = 1; ii <= 32; ++ii) |
| 433 | read_memory (sp-(ii*8), ®isters[REGISTER_BYTE (32-ii+FP0_REGNUM)], 8); |
| 434 | |
| 435 | /* restore all gpr's */ |
| 436 | for (ii=1; ii <= 32; ++ii) { |
| 437 | read_memory (sp-256-(ii*4), ®isters[REGISTER_BYTE (32-ii)], 4); |
| 438 | } |
| 439 | |
| 440 | /* restore the rest of the registers. */ |
| 441 | for (ii=1; ii <=(LAST_SP_REGNUM-FIRST_SP_REGNUM+1); ++ii) |
| 442 | read_memory (sp-384-(ii*4), |
| 443 | ®isters[REGISTER_BYTE (FPLAST_REGNUM + ii)], 4); |
| 444 | |
| 445 | read_memory (sp-(DUMMY_FRAME_SIZE-8), |
| 446 | ®isters [REGISTER_BYTE(PC_REGNUM)], 4); |
| 447 | |
| 448 | /* when a dummy frame was being pushed, we had to decrement %sp first, in |
| 449 | order to secure astack space. Thus, saved %sp (or %r1) value, is not the |
| 450 | one we should restore. Change it with the one we need. */ |
| 451 | |
| 452 | *(int*)®isters [REGISTER_BYTE(FP_REGNUM)] = sp; |
| 453 | |
| 454 | /* Now we can restore all registers. */ |
| 455 | |
| 456 | target_store_registers (-1); |
| 457 | pc = read_pc (); |
| 458 | flush_cached_frames (); |
| 459 | set_current_frame (create_new_frame (sp, pc)); |
| 460 | } |
| 461 | |
| 462 | |
| 463 | /* pop the innermost frame, go back to the caller. */ |
| 464 | |
| 465 | void |
| 466 | pop_frame () |
| 467 | { |
| 468 | CORE_ADDR pc, lr, sp, prev_sp; /* %pc, %lr, %sp */ |
| 469 | struct aix_framedata fdata; |
| 470 | FRAME fr = get_current_frame (); |
| 471 | int addr, ii; |
| 472 | |
| 473 | pc = read_pc (); |
| 474 | sp = FRAME_FP (fr); |
| 475 | |
| 476 | if (stop_stack_dummy && dummy_frame_count) { |
| 477 | pop_dummy_frame (); |
| 478 | return; |
| 479 | } |
| 480 | |
| 481 | /* figure out previous %pc value. If the function is frameless, it is |
| 482 | still in the link register, otherwise walk the frames and retrieve the |
| 483 | saved %pc value in the previous frame. */ |
| 484 | |
| 485 | addr = get_pc_function_start (fr->pc) + FUNCTION_START_OFFSET; |
| 486 | function_frame_info (addr, &fdata); |
| 487 | |
| 488 | prev_sp = read_memory_integer (sp, 4); |
| 489 | if (fdata.frameless) |
| 490 | lr = read_register (LR_REGNUM); |
| 491 | else |
| 492 | lr = read_memory_integer (prev_sp+8, 4); |
| 493 | |
| 494 | /* reset %pc value. */ |
| 495 | write_register (PC_REGNUM, lr); |
| 496 | |
| 497 | /* reset register values if any was saved earlier. */ |
| 498 | addr = prev_sp - fdata.offset; |
| 499 | |
| 500 | if (fdata.saved_gpr != -1) |
| 501 | for (ii=fdata.saved_gpr; ii <= 31; ++ii) { |
| 502 | read_memory (addr, ®isters [REGISTER_BYTE (ii)], 4); |
| 503 | addr += 4; |
| 504 | } |
| 505 | |
| 506 | if (fdata.saved_fpr != -1) |
| 507 | for (ii=fdata.saved_fpr; ii <= 31; ++ii) { |
| 508 | read_memory (addr, ®isters [REGISTER_BYTE (ii+FP0_REGNUM)], 8); |
| 509 | addr += 8; |
| 510 | } |
| 511 | |
| 512 | write_register (SP_REGNUM, prev_sp); |
| 513 | target_store_registers (-1); |
| 514 | flush_cached_frames (); |
| 515 | set_current_frame (create_new_frame (prev_sp, lr)); |
| 516 | } |
| 517 | |
| 518 | |
| 519 | /* fixup the call sequence of a dummy function, with the real function address. |
| 520 | its argumets will be passed by gdb. */ |
| 521 | |
| 522 | void |
| 523 | fix_call_dummy(dummyname, pc, fun, nargs, type) |
| 524 | char *dummyname; |
| 525 | CORE_ADDR pc; |
| 526 | CORE_ADDR fun; |
| 527 | int nargs; /* not used */ |
| 528 | int type; /* not used */ |
| 529 | { |
| 530 | #define TOC_ADDR_OFFSET 20 |
| 531 | #define TARGET_ADDR_OFFSET 28 |
| 532 | |
| 533 | int ii; |
| 534 | CORE_ADDR target_addr; |
| 535 | CORE_ADDR tocvalue; |
| 536 | |
| 537 | target_addr = fun; |
| 538 | tocvalue = find_toc_address (target_addr); |
| 539 | |
| 540 | ii = *(int*)((char*)dummyname + TOC_ADDR_OFFSET); |
| 541 | ii = (ii & 0xffff0000) | (tocvalue >> 16); |
| 542 | *(int*)((char*)dummyname + TOC_ADDR_OFFSET) = ii; |
| 543 | |
| 544 | ii = *(int*)((char*)dummyname + TOC_ADDR_OFFSET+4); |
| 545 | ii = (ii & 0xffff0000) | (tocvalue & 0x0000ffff); |
| 546 | *(int*)((char*)dummyname + TOC_ADDR_OFFSET+4) = ii; |
| 547 | |
| 548 | ii = *(int*)((char*)dummyname + TARGET_ADDR_OFFSET); |
| 549 | ii = (ii & 0xffff0000) | (target_addr >> 16); |
| 550 | *(int*)((char*)dummyname + TARGET_ADDR_OFFSET) = ii; |
| 551 | |
| 552 | ii = *(int*)((char*)dummyname + TARGET_ADDR_OFFSET+4); |
| 553 | ii = (ii & 0xffff0000) | (target_addr & 0x0000ffff); |
| 554 | *(int*)((char*)dummyname + TARGET_ADDR_OFFSET+4) = ii; |
| 555 | } |
| 556 | |
| 557 | |
| 558 | /* return information about a function frame. |
| 559 | in struct aix_frameinfo fdata: |
| 560 | - frameless is TRUE, if function does not have a frame. |
| 561 | - nosavedpc is TRUE, if function does not save %pc value in its frame. |
| 562 | - offset is the number of bytes used in the frame to save registers. |
| 563 | - saved_gpr is the number of the first saved gpr. |
| 564 | - saved_fpr is the number of the first saved fpr. |
| 565 | - alloca_reg is the number of the register used for alloca() handling. |
| 566 | Otherwise -1. |
| 567 | */ |
| 568 | void |
| 569 | function_frame_info (pc, fdata) |
| 570 | CORE_ADDR pc; |
| 571 | struct aix_framedata *fdata; |
| 572 | { |
| 573 | unsigned int tmp; |
| 574 | register unsigned int op; |
| 575 | |
| 576 | fdata->offset = 0; |
| 577 | fdata->saved_gpr = fdata->saved_fpr = fdata->alloca_reg = -1; |
| 578 | fdata->frameless = 1; |
| 579 | |
| 580 | op = read_memory_integer (pc, 4); |
| 581 | if (op == 0x7c0802a6) { /* mflr r0 */ |
| 582 | pc += 4; |
| 583 | op = read_memory_integer (pc, 4); |
| 584 | fdata->nosavedpc = 0; |
| 585 | fdata->frameless = 0; |
| 586 | } |
| 587 | else /* else, pc is not saved */ |
| 588 | fdata->nosavedpc = 1; |
| 589 | |
| 590 | if ((op & 0xfc00003e) == 0x7c000026) { /* mfcr Rx */ |
| 591 | pc += 4; |
| 592 | op = read_memory_integer (pc, 4); |
| 593 | fdata->frameless = 0; |
| 594 | } |
| 595 | |
| 596 | if ((op & 0xfc000000) == 0x48000000) { /* bl foo, to save fprs??? */ |
| 597 | pc += 4; |
| 598 | op = read_memory_integer (pc, 4); |
| 599 | /* At this point, make sure this is not a trampoline function |
| 600 | (a function that simply calls another functions, and nothing else). |
| 601 | If the next is not a nop, this branch was part of the function |
| 602 | prologue. */ |
| 603 | |
| 604 | if (op == 0x4def7b82 || /* crorc 15, 15, 15 */ |
| 605 | op == 0x0) |
| 606 | return; /* prologue is over */ |
| 607 | fdata->frameless = 0; |
| 608 | } |
| 609 | |
| 610 | if ((op & 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */ |
| 611 | pc += 4; /* store floating register double */ |
| 612 | op = read_memory_integer (pc, 4); |
| 613 | fdata->frameless = 0; |
| 614 | } |
| 615 | |
| 616 | if ((op & 0xfc1f0000) == 0xbc010000) { /* stm Rx, NUM(r1) */ |
| 617 | int tmp2; |
| 618 | fdata->saved_gpr = (op >> 21) & 0x1f; |
| 619 | tmp2 = op & 0xffff; |
| 620 | if (tmp2 > 0x7fff) |
| 621 | tmp2 = (~0 &~ 0xffff) | tmp2; |
| 622 | |
| 623 | if (tmp2 < 0) { |
| 624 | tmp2 = tmp2 * -1; |
| 625 | fdata->saved_fpr = (tmp2 - ((32 - fdata->saved_gpr) * 4)) / 8; |
| 626 | if ( fdata->saved_fpr > 0) |
| 627 | fdata->saved_fpr = 32 - fdata->saved_fpr; |
| 628 | else |
| 629 | fdata->saved_fpr = -1; |
| 630 | } |
| 631 | fdata->offset = tmp2; |
| 632 | pc += 4; |
| 633 | op = read_memory_integer (pc, 4); |
| 634 | fdata->frameless = 0; |
| 635 | } |
| 636 | |
| 637 | while (((tmp = op >> 16) == 0x9001) || /* st r0, NUM(r1) */ |
| 638 | (tmp == 0x9421) || /* stu r1, NUM(r1) */ |
| 639 | (tmp == 0x93e1)) /* st r31, NUM(r1) */ |
| 640 | { |
| 641 | int tmp2; |
| 642 | |
| 643 | /* gcc takes a short cut and uses this instruction to save r31 only. */ |
| 644 | |
| 645 | if (tmp == 0x93e1) { |
| 646 | if (fdata->offset) |
| 647 | /* fatal ("Unrecognized prolog."); */ |
| 648 | printf ("Unrecognized prolog!\n"); |
| 649 | |
| 650 | fdata->saved_gpr = 31; |
| 651 | tmp2 = op & 0xffff; |
| 652 | if (tmp2 > 0x7fff) { |
| 653 | tmp2 = - ((~0 &~ 0xffff) | tmp2); |
| 654 | fdata->saved_fpr = (tmp2 - ((32 - 31) * 4)) / 8; |
| 655 | if ( fdata->saved_fpr > 0) |
| 656 | fdata->saved_fpr = 32 - fdata->saved_fpr; |
| 657 | else |
| 658 | fdata->saved_fpr = -1; |
| 659 | } |
| 660 | fdata->offset = tmp2; |
| 661 | } |
| 662 | pc += 4; |
| 663 | op = read_memory_integer (pc, 4); |
| 664 | fdata->frameless = 0; |
| 665 | } |
| 666 | |
| 667 | while ((tmp = (op >> 22)) == 0x20f) { /* l r31, ... or */ |
| 668 | pc += 4; /* l r30, ... */ |
| 669 | op = read_memory_integer (pc, 4); |
| 670 | fdata->frameless = 0; |
| 671 | } |
| 672 | |
| 673 | /* store parameters into stack */ |
| 674 | while( |
| 675 | (op & 0xfc1f0000) == 0xd8010000 || /* stfd Rx,NUM(r1) */ |
| 676 | (op & 0xfc1f0000) == 0x90010000 || /* st r?, NUM(r1) */ |
| 677 | (op & 0xfc000000) == 0xfc000000 || /* frsp, fp?, .. */ |
| 678 | (op & 0xd0000000) == 0xd0000000) /* stfs, fp?, .. */ |
| 679 | { |
| 680 | pc += 4; /* store fpr double */ |
| 681 | op = read_memory_integer (pc, 4); |
| 682 | fdata->frameless = 0; |
| 683 | } |
| 684 | |
| 685 | if (op == 0x603f0000) { /* oril r31, r1, 0x0 */ |
| 686 | fdata->alloca_reg = 31; |
| 687 | fdata->frameless = 0; |
| 688 | } |
| 689 | } |
| 690 | |
| 691 | |
| 692 | /* Pass the arguments in either registers, or in the stack. In RS6000, the first |
| 693 | eight words of the argument list (that might be less than eight parameters if |
| 694 | some parameters occupy more than one word) are passed in r3..r11 registers. |
| 695 | float and double parameters are passed in fpr's, in addition to that. Rest of |
| 696 | the parameters if any are passed in user stack. There might be cases in which |
| 697 | half of the parameter is copied into registers, the other half is pushed into |
| 698 | stack. |
| 699 | |
| 700 | If the function is returning a structure, then the return address is passed |
| 701 | in r3, then the first 7 words of the parametes can be passed in registers, |
| 702 | starting from r4. */ |
| 703 | |
| 704 | CORE_ADDR |
| 705 | push_arguments (nargs, args, sp, struct_return, struct_addr) |
| 706 | int nargs; |
| 707 | value *args; |
| 708 | CORE_ADDR sp; |
| 709 | int struct_return; |
| 710 | CORE_ADDR struct_addr; |
| 711 | { |
| 712 | int ii, len; |
| 713 | int argno; /* current argument number */ |
| 714 | int argbytes; /* current argument byte */ |
| 715 | char tmp_buffer [50]; |
| 716 | value arg; |
| 717 | int f_argno = 0; /* current floating point argno */ |
| 718 | |
| 719 | CORE_ADDR saved_sp, pc; |
| 720 | |
| 721 | if ( dummy_frame_count <= 0) |
| 722 | printf ("FATAL ERROR -push_arguments()! frame not found!!\n"); |
| 723 | |
| 724 | /* The first eight words of ther arguments are passed in registers. Copy |
| 725 | them appropriately. |
| 726 | |
| 727 | If the function is returning a `struct', then the first word (which |
| 728 | will be passed in r3) is used for struct return address. In that |
| 729 | case we should advance one word and start from r4 register to copy |
| 730 | parameters. */ |
| 731 | |
| 732 | ii = struct_return ? 1 : 0; |
| 733 | |
| 734 | for (argno=0, argbytes=0; argno < nargs && ii<8; ++ii) { |
| 735 | |
| 736 | arg = value_arg_coerce (args[argno]); |
| 737 | len = TYPE_LENGTH (VALUE_TYPE (arg)); |
| 738 | |
| 739 | if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_FLT) { |
| 740 | |
| 741 | /* floating point arguments are passed in fpr's, as well as gpr's. |
| 742 | There are 13 fpr's reserved for passing parameters. At this point |
| 743 | there is no way we would run out of them. */ |
| 744 | |
| 745 | if (len > 8) |
| 746 | printf ( |
| 747 | "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno); |
| 748 | |
| 749 | memcpy (®isters[REGISTER_BYTE(FP0_REGNUM + 1 + f_argno)], VALUE_CONTENTS (arg), |
| 750 | len); |
| 751 | ++f_argno; |
| 752 | } |
| 753 | |
| 754 | if (len > 4) { |
| 755 | |
| 756 | /* Argument takes more than one register. */ |
| 757 | while (argbytes < len) { |
| 758 | |
| 759 | *(int*)®isters[REGISTER_BYTE(ii+3)] = 0; |
| 760 | memcpy (®isters[REGISTER_BYTE(ii+3)], |
| 761 | ((char*)VALUE_CONTENTS (arg))+argbytes, |
| 762 | (len - argbytes) > 4 ? 4 : len - argbytes); |
| 763 | ++ii, argbytes += 4; |
| 764 | |
| 765 | if (ii >= 8) |
| 766 | goto ran_out_of_registers_for_arguments; |
| 767 | } |
| 768 | argbytes = 0; |
| 769 | --ii; |
| 770 | } |
| 771 | else { /* Argument can fit in one register. No problem. */ |
| 772 | *(int*)®isters[REGISTER_BYTE(ii+3)] = 0; |
| 773 | memcpy (®isters[REGISTER_BYTE(ii+3)], VALUE_CONTENTS (arg), len); |
| 774 | } |
| 775 | ++argno; |
| 776 | } |
| 777 | |
| 778 | ran_out_of_registers_for_arguments: |
| 779 | |
| 780 | /* location for 8 parameters are always reserved. */ |
| 781 | sp -= 4 * 8; |
| 782 | |
| 783 | /* another six words for back chain, TOC register, link register, etc. */ |
| 784 | sp -= 24; |
| 785 | |
| 786 | /* if there are more arguments, allocate space for them in |
| 787 | the stack, then push them starting from the ninth one. */ |
| 788 | |
| 789 | if ((argno < nargs) || argbytes) { |
| 790 | int space = 0, jj; |
| 791 | value val; |
| 792 | |
| 793 | if (argbytes) { |
| 794 | space += ((len - argbytes + 3) & -4); |
| 795 | jj = argno + 1; |
| 796 | } |
| 797 | else |
| 798 | jj = argno; |
| 799 | |
| 800 | for (; jj < nargs; ++jj) { |
| 801 | val = value_arg_coerce (args[jj]); |
| 802 | space += ((TYPE_LENGTH (VALUE_TYPE (val))) + 3) & -4; |
| 803 | } |
| 804 | |
| 805 | /* add location required for the rest of the parameters */ |
| 806 | space = (space + 7) & -8; |
| 807 | sp -= space; |
| 808 | |
| 809 | /* This is another instance we need to be concerned about securing our |
| 810 | stack space. If we write anything underneath %sp (r1), we might conflict |
| 811 | with the kernel who thinks he is free to use this area. So, update %sp |
| 812 | first before doing anything else. */ |
| 813 | |
| 814 | write_register (SP_REGNUM, sp); |
| 815 | |
| 816 | /* if the last argument copied into the registers didn't fit there |
| 817 | completely, push the rest of it into stack. */ |
| 818 | |
| 819 | if (argbytes) { |
| 820 | write_memory ( |
| 821 | sp+24+(ii*4), ((char*)VALUE_CONTENTS (arg))+argbytes, len - argbytes); |
| 822 | ++argno; |
| 823 | ii += ((len - argbytes + 3) & -4) / 4; |
| 824 | } |
| 825 | |
| 826 | /* push the rest of the arguments into stack. */ |
| 827 | for (; argno < nargs; ++argno) { |
| 828 | |
| 829 | arg = value_arg_coerce (args[argno]); |
| 830 | len = TYPE_LENGTH (VALUE_TYPE (arg)); |
| 831 | |
| 832 | |
| 833 | /* float types should be passed in fpr's, as well as in the stack. */ |
| 834 | if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_FLT && f_argno < 13) { |
| 835 | |
| 836 | if (len > 8) |
| 837 | printf ( |
| 838 | "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno); |
| 839 | |
| 840 | memcpy (®isters[REGISTER_BYTE(FP0_REGNUM + 1 + f_argno)], VALUE_CONTENTS (arg), |
| 841 | len); |
| 842 | ++f_argno; |
| 843 | } |
| 844 | |
| 845 | write_memory (sp+24+(ii*4), (char *) VALUE_CONTENTS (arg), len); |
| 846 | ii += ((len + 3) & -4) / 4; |
| 847 | } |
| 848 | } |
| 849 | else |
| 850 | /* Secure stack areas first, before doing anything else. */ |
| 851 | write_register (SP_REGNUM, sp); |
| 852 | |
| 853 | saved_sp = dummy_frame_addr [dummy_frame_count - 1]; |
| 854 | read_memory (saved_sp, tmp_buffer, 24); |
| 855 | write_memory (sp, tmp_buffer, 24); |
| 856 | |
| 857 | write_memory (sp, &saved_sp, 4); /* set back chain properly */ |
| 858 | |
| 859 | target_store_registers (-1); |
| 860 | return sp; |
| 861 | } |
| 862 | |
| 863 | /* a given return value in `regbuf' with a type `valtype', extract and copy its |
| 864 | value into `valbuf' */ |
| 865 | |
| 866 | void |
| 867 | extract_return_value (valtype, regbuf, valbuf) |
| 868 | struct type *valtype; |
| 869 | char regbuf[REGISTER_BYTES]; |
| 870 | char *valbuf; |
| 871 | { |
| 872 | |
| 873 | if (TYPE_CODE (valtype) == TYPE_CODE_FLT) { |
| 874 | |
| 875 | double dd; float ff; |
| 876 | /* floats and doubles are returned in fpr1. fpr's have a size of 8 bytes. |
| 877 | We need to truncate the return value into float size (4 byte) if |
| 878 | necessary. */ |
| 879 | |
| 880 | if (TYPE_LENGTH (valtype) > 4) /* this is a double */ |
| 881 | memcpy (valbuf, ®buf[REGISTER_BYTE (FP0_REGNUM + 1)], |
| 882 | TYPE_LENGTH (valtype)); |
| 883 | else { /* float */ |
| 884 | memcpy (&dd, ®buf[REGISTER_BYTE (FP0_REGNUM + 1)], 8); |
| 885 | ff = (float)dd; |
| 886 | memcpy (valbuf, &ff, sizeof(float)); |
| 887 | } |
| 888 | } |
| 889 | else |
| 890 | /* return value is copied starting from r3. */ |
| 891 | memcpy (valbuf, ®buf[REGISTER_BYTE (3)], TYPE_LENGTH (valtype)); |
| 892 | } |
| 893 | |
| 894 | |
| 895 | /* keep structure return address in this variable. |
| 896 | FIXME: This is a horrid kludge which should not be allowed to continue |
| 897 | living. This only allows a single nested call to a structure-returning |
| 898 | function. Come on, guys! -- gnu@cygnus.com, Aug 92 */ |
| 899 | |
| 900 | CORE_ADDR rs6000_struct_return_address; |
| 901 | |
| 902 | |
| 903 | /* Indirect function calls use a piece of trampoline code to do context |
| 904 | switching, i.e. to set the new TOC table. Skip such code if we are on |
| 905 | its first instruction (as when we have single-stepped to here). |
| 906 | Result is desired PC to step until, or NULL if we are not in |
| 907 | trampoline code. */ |
| 908 | |
| 909 | CORE_ADDR |
| 910 | skip_trampoline_code (pc) |
| 911 | CORE_ADDR pc; |
| 912 | { |
| 913 | register unsigned int ii, op; |
| 914 | |
| 915 | static unsigned trampoline_code[] = { |
| 916 | 0x800b0000, /* l r0,0x0(r11) */ |
| 917 | 0x90410014, /* st r2,0x14(r1) */ |
| 918 | 0x7c0903a6, /* mtctr r0 */ |
| 919 | 0x804b0004, /* l r2,0x4(r11) */ |
| 920 | 0x816b0008, /* l r11,0x8(r11) */ |
| 921 | 0x4e800420, /* bctr */ |
| 922 | 0x4e800020, /* br */ |
| 923 | 0 |
| 924 | }; |
| 925 | |
| 926 | for (ii=0; trampoline_code[ii]; ++ii) { |
| 927 | op = read_memory_integer (pc + (ii*4), 4); |
| 928 | if (op != trampoline_code [ii]) |
| 929 | return 0; |
| 930 | } |
| 931 | ii = read_register (11); /* r11 holds destination addr */ |
| 932 | pc = read_memory_integer (ii, 4); /* (r11) value */ |
| 933 | return pc; |
| 934 | } |
| 935 | |
| 936 | |
| 937 | /* Determines whether the function FI has a frame on the stack or not. |
| 938 | Called from the FRAMELESS_FUNCTION_INVOCATION macro in tm.h with a |
| 939 | second argument of 0, and from the FRAME_SAVED_PC macro with a |
| 940 | second argument of 1. */ |
| 941 | |
| 942 | int |
| 943 | frameless_function_invocation (fi, pcsaved) |
| 944 | struct frame_info *fi; |
| 945 | int pcsaved; |
| 946 | { |
| 947 | CORE_ADDR func_start; |
| 948 | struct aix_framedata fdata; |
| 949 | |
| 950 | if (fi->next != NULL) |
| 951 | /* Don't even think about framelessness except on the innermost frame. */ |
| 952 | return 0; |
| 953 | |
| 954 | func_start = get_pc_function_start (fi->pc) + FUNCTION_START_OFFSET; |
| 955 | |
| 956 | /* If we failed to find the start of the function, it is a mistake |
| 957 | to inspect the instructions. */ |
| 958 | |
| 959 | if (!func_start) |
| 960 | return 0; |
| 961 | |
| 962 | function_frame_info (func_start, &fdata); |
| 963 | return pcsaved ? fdata.nosavedpc : fdata.frameless; |
| 964 | } |
| 965 | |
| 966 | |
| 967 | /* If saved registers of frame FI are not known yet, read and cache them. |
| 968 | &FDATAP contains aix_framedata; TDATAP can be NULL, |
| 969 | in which case the framedata are read. */ |
| 970 | |
| 971 | static void |
| 972 | frame_get_cache_fsr (fi, fdatap) |
| 973 | struct frame_info *fi; |
| 974 | struct aix_framedata *fdatap; |
| 975 | { |
| 976 | int ii; |
| 977 | CORE_ADDR frame_addr; |
| 978 | struct aix_framedata work_fdata; |
| 979 | |
| 980 | if (fi->cache_fsr) |
| 981 | return; |
| 982 | |
| 983 | if (fdatap == NULL) { |
| 984 | fdatap = &work_fdata; |
| 985 | function_frame_info (get_pc_function_start (fi->pc), fdatap); |
| 986 | } |
| 987 | |
| 988 | fi->cache_fsr = (struct frame_saved_regs *) |
| 989 | obstack_alloc (&frame_cache_obstack, sizeof (struct frame_saved_regs)); |
| 990 | memset (fi->cache_fsr, '\0', sizeof (struct frame_saved_regs)); |
| 991 | |
| 992 | if (fi->prev && fi->prev->frame) |
| 993 | frame_addr = fi->prev->frame; |
| 994 | else |
| 995 | frame_addr = read_memory_integer (fi->frame, 4); |
| 996 | |
| 997 | /* if != -1, fdatap->saved_fpr is the smallest number of saved_fpr. |
| 998 | All fpr's from saved_fpr to fp31 are saved right underneath caller |
| 999 | stack pointer, starting from fp31 first. */ |
| 1000 | |
| 1001 | if (fdatap->saved_fpr >= 0) { |
| 1002 | for (ii=31; ii >= fdatap->saved_fpr; --ii) |
| 1003 | fi->cache_fsr->regs [FP0_REGNUM + ii] = frame_addr - ((32 - ii) * 8); |
| 1004 | frame_addr -= (32 - fdatap->saved_fpr) * 8; |
| 1005 | } |
| 1006 | |
| 1007 | /* if != -1, fdatap->saved_gpr is the smallest number of saved_gpr. |
| 1008 | All gpr's from saved_gpr to gpr31 are saved right under saved fprs, |
| 1009 | starting from r31 first. */ |
| 1010 | |
| 1011 | if (fdatap->saved_gpr >= 0) |
| 1012 | for (ii=31; ii >= fdatap->saved_gpr; --ii) |
| 1013 | fi->cache_fsr->regs [ii] = frame_addr - ((32 - ii) * 4); |
| 1014 | } |
| 1015 | |
| 1016 | /* Return the address of a frame. This is the inital %sp value when the frame |
| 1017 | was first allocated. For functions calling alloca(), it might be saved in |
| 1018 | an alloca register. */ |
| 1019 | |
| 1020 | CORE_ADDR |
| 1021 | frame_initial_stack_address (fi) |
| 1022 | struct frame_info *fi; |
| 1023 | { |
| 1024 | CORE_ADDR tmpaddr; |
| 1025 | struct aix_framedata fdata; |
| 1026 | struct frame_info *callee_fi; |
| 1027 | |
| 1028 | /* if the initial stack pointer (frame address) of this frame is known, |
| 1029 | just return it. */ |
| 1030 | |
| 1031 | if (fi->initial_sp) |
| 1032 | return fi->initial_sp; |
| 1033 | |
| 1034 | /* find out if this function is using an alloca register.. */ |
| 1035 | |
| 1036 | function_frame_info (get_pc_function_start (fi->pc), &fdata); |
| 1037 | |
| 1038 | /* if saved registers of this frame are not known yet, read and cache them. */ |
| 1039 | |
| 1040 | if (!fi->cache_fsr) |
| 1041 | frame_get_cache_fsr (fi, &fdata); |
| 1042 | |
| 1043 | /* If no alloca register used, then fi->frame is the value of the %sp for |
| 1044 | this frame, and it is good enough. */ |
| 1045 | |
| 1046 | if (fdata.alloca_reg < 0) { |
| 1047 | fi->initial_sp = fi->frame; |
| 1048 | return fi->initial_sp; |
| 1049 | } |
| 1050 | |
| 1051 | /* This function has an alloca register. If this is the top-most frame |
| 1052 | (with the lowest address), the value in alloca register is good. */ |
| 1053 | |
| 1054 | if (!fi->next) |
| 1055 | return fi->initial_sp = read_register (fdata.alloca_reg); |
| 1056 | |
| 1057 | /* Otherwise, this is a caller frame. Callee has usually already saved |
| 1058 | registers, but there are exceptions (such as when the callee |
| 1059 | has no parameters). Find the address in which caller's alloca |
| 1060 | register is saved. */ |
| 1061 | |
| 1062 | for (callee_fi = fi->next; callee_fi; callee_fi = callee_fi->next) { |
| 1063 | |
| 1064 | if (!callee_fi->cache_fsr) |
| 1065 | frame_get_cache_fsr (callee_fi, NULL); |
| 1066 | |
| 1067 | /* this is the address in which alloca register is saved. */ |
| 1068 | |
| 1069 | tmpaddr = callee_fi->cache_fsr->regs [fdata.alloca_reg]; |
| 1070 | if (tmpaddr) { |
| 1071 | fi->initial_sp = read_memory_integer (tmpaddr, 4); |
| 1072 | return fi->initial_sp; |
| 1073 | } |
| 1074 | |
| 1075 | /* Go look into deeper levels of the frame chain to see if any one of |
| 1076 | the callees has saved alloca register. */ |
| 1077 | } |
| 1078 | |
| 1079 | /* If alloca register was not saved, by the callee (or any of its callees) |
| 1080 | then the value in the register is still good. */ |
| 1081 | |
| 1082 | return fi->initial_sp = read_register (fdata.alloca_reg); |
| 1083 | } |
| 1084 | |
| 1085 | FRAME_ADDR |
| 1086 | rs6000_frame_chain (thisframe) |
| 1087 | struct frame_info *thisframe; |
| 1088 | { |
| 1089 | FRAME_ADDR fp; |
| 1090 | if (inside_entry_file ((thisframe)->pc)) |
| 1091 | return 0; |
| 1092 | if (thisframe->signal_handler_caller) |
| 1093 | { |
| 1094 | /* This was determined by experimentation on AIX 3.2. Perhaps |
| 1095 | it corresponds to some offset in /usr/include/sys/user.h or |
| 1096 | something like that. Using some system include file would |
| 1097 | have the advantage of probably being more robust in the face |
| 1098 | of OS upgrades, but the disadvantage of being wrong for |
| 1099 | cross-debugging. */ |
| 1100 | |
| 1101 | #define SIG_FRAME_FP_OFFSET 284 |
| 1102 | fp = read_memory_integer (thisframe->frame + SIG_FRAME_FP_OFFSET, 4); |
| 1103 | } |
| 1104 | else |
| 1105 | fp = read_memory_integer ((thisframe)->frame, 4); |
| 1106 | |
| 1107 | return fp; |
| 1108 | } |
| 1109 | |
| 1110 | \f |
| 1111 | /* xcoff_relocate_symtab - hook for symbol table relocation. |
| 1112 | also reads shared libraries.. */ |
| 1113 | |
| 1114 | xcoff_relocate_symtab (pid) |
| 1115 | unsigned int pid; |
| 1116 | { |
| 1117 | #define MAX_LOAD_SEGS 64 /* maximum number of load segments */ |
| 1118 | |
| 1119 | struct ld_info *ldi; |
| 1120 | int temp; |
| 1121 | |
| 1122 | ldi = (void *) alloca(MAX_LOAD_SEGS * sizeof (*ldi)); |
| 1123 | |
| 1124 | /* According to my humble theory, AIX has some timing problems and |
| 1125 | when the user stack grows, kernel doesn't update stack info in time |
| 1126 | and ptrace calls step on user stack. That is why we sleep here a little, |
| 1127 | and give kernel to update its internals. */ |
| 1128 | |
| 1129 | usleep (36000); |
| 1130 | |
| 1131 | errno = 0; |
| 1132 | ptrace(PT_LDINFO, pid, (PTRACE_ARG3_TYPE) ldi, |
| 1133 | MAX_LOAD_SEGS * sizeof(*ldi), ldi); |
| 1134 | if (errno) { |
| 1135 | perror_with_name ("ptrace ldinfo"); |
| 1136 | return 0; |
| 1137 | } |
| 1138 | |
| 1139 | vmap_ldinfo(ldi); |
| 1140 | |
| 1141 | do { |
| 1142 | /* We are allowed to assume CORE_ADDR == pointer. This code is |
| 1143 | native only. */ |
| 1144 | add_text_to_loadinfo ((CORE_ADDR) ldi->ldinfo_textorg, |
| 1145 | (CORE_ADDR) ldi->ldinfo_dataorg); |
| 1146 | } while (ldi->ldinfo_next |
| 1147 | && (ldi = (void *) (ldi->ldinfo_next + (char *) ldi))); |
| 1148 | |
| 1149 | #if 0 |
| 1150 | /* Now that we've jumbled things around, re-sort them. */ |
| 1151 | sort_minimal_symbols (); |
| 1152 | #endif |
| 1153 | |
| 1154 | /* relocate the exec and core sections as well. */ |
| 1155 | vmap_exec (); |
| 1156 | } |
| 1157 | \f |
| 1158 | /* Keep an array of load segment information and their TOC table addresses. |
| 1159 | This info will be useful when calling a shared library function by hand. */ |
| 1160 | |
| 1161 | struct loadinfo { |
| 1162 | CORE_ADDR textorg, dataorg; |
| 1163 | unsigned long toc_offset; |
| 1164 | }; |
| 1165 | |
| 1166 | #define LOADINFOLEN 10 |
| 1167 | |
| 1168 | static struct loadinfo *loadinfo = NULL; |
| 1169 | static int loadinfolen = 0; |
| 1170 | static int loadinfotocindex = 0; |
| 1171 | static int loadinfotextindex = 0; |
| 1172 | |
| 1173 | |
| 1174 | void |
| 1175 | xcoff_init_loadinfo () |
| 1176 | { |
| 1177 | loadinfotocindex = 0; |
| 1178 | loadinfotextindex = 0; |
| 1179 | |
| 1180 | if (loadinfolen == 0) { |
| 1181 | loadinfo = (struct loadinfo *) |
| 1182 | xmalloc (sizeof (struct loadinfo) * LOADINFOLEN); |
| 1183 | loadinfolen = LOADINFOLEN; |
| 1184 | } |
| 1185 | } |
| 1186 | |
| 1187 | |
| 1188 | /* FIXME -- this is never called! */ |
| 1189 | void |
| 1190 | free_loadinfo () |
| 1191 | { |
| 1192 | if (loadinfo) |
| 1193 | free (loadinfo); |
| 1194 | loadinfo = NULL; |
| 1195 | loadinfolen = 0; |
| 1196 | loadinfotocindex = 0; |
| 1197 | loadinfotextindex = 0; |
| 1198 | } |
| 1199 | |
| 1200 | /* this is called from xcoffread.c */ |
| 1201 | |
| 1202 | void |
| 1203 | xcoff_add_toc_to_loadinfo (unsigned long tocoff) |
| 1204 | { |
| 1205 | while (loadinfotocindex >= loadinfolen) { |
| 1206 | loadinfolen += LOADINFOLEN; |
| 1207 | loadinfo = (struct loadinfo *) |
| 1208 | xrealloc (loadinfo, sizeof(struct loadinfo) * loadinfolen); |
| 1209 | } |
| 1210 | loadinfo [loadinfotocindex++].toc_offset = tocoff; |
| 1211 | } |
| 1212 | |
| 1213 | |
| 1214 | void |
| 1215 | add_text_to_loadinfo (textaddr, dataaddr) |
| 1216 | CORE_ADDR textaddr; |
| 1217 | CORE_ADDR dataaddr; |
| 1218 | { |
| 1219 | while (loadinfotextindex >= loadinfolen) { |
| 1220 | loadinfolen += LOADINFOLEN; |
| 1221 | loadinfo = (struct loadinfo *) |
| 1222 | xrealloc (loadinfo, sizeof(struct loadinfo) * loadinfolen); |
| 1223 | } |
| 1224 | loadinfo [loadinfotextindex].textorg = textaddr; |
| 1225 | loadinfo [loadinfotextindex].dataorg = dataaddr; |
| 1226 | ++loadinfotextindex; |
| 1227 | } |
| 1228 | |
| 1229 | |
| 1230 | /* FIXME: This assumes that the "textorg" and "dataorg" elements |
| 1231 | of a member of this array are correlated with the "toc_offset" |
| 1232 | element of the same member. But they are sequentially assigned in wildly |
| 1233 | different places, and probably there is no correlation. FIXME! */ |
| 1234 | |
| 1235 | static CORE_ADDR |
| 1236 | find_toc_address (pc) |
| 1237 | CORE_ADDR pc; |
| 1238 | { |
| 1239 | int ii, toc_entry, tocbase = 0; |
| 1240 | |
| 1241 | for (ii=0; ii < loadinfotextindex; ++ii) |
| 1242 | if (pc > loadinfo[ii].textorg && loadinfo[ii].textorg > tocbase) { |
| 1243 | toc_entry = ii; |
| 1244 | tocbase = loadinfo[ii].textorg; |
| 1245 | } |
| 1246 | |
| 1247 | return loadinfo[toc_entry].dataorg + loadinfo[toc_entry].toc_offset; |
| 1248 | } |