| 1 | /* Target-dependent code for GDB, the GNU debugger. |
| 2 | Copyright 1986, 1987, 1989, 1991, 1992, 1993, 1994, 1995 |
| 3 | Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 2 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program; if not, write to the Free Software |
| 19 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| 20 | |
| 21 | #include "defs.h" |
| 22 | #include "frame.h" |
| 23 | #include "inferior.h" |
| 24 | #include "symtab.h" |
| 25 | #include "target.h" |
| 26 | #include "gdbcore.h" |
| 27 | |
| 28 | #include "xcoffsolib.h" |
| 29 | |
| 30 | #include <a.out.h> |
| 31 | |
| 32 | extern struct obstack frame_cache_obstack; |
| 33 | |
| 34 | extern int errno; |
| 35 | |
| 36 | /* Nonzero if we just simulated a single step break. */ |
| 37 | int one_stepped; |
| 38 | |
| 39 | /* Breakpoint shadows for the single step instructions will be kept here. */ |
| 40 | |
| 41 | static struct sstep_breaks { |
| 42 | /* Address, or 0 if this is not in use. */ |
| 43 | CORE_ADDR address; |
| 44 | /* Shadow contents. */ |
| 45 | char data[4]; |
| 46 | } stepBreaks[2]; |
| 47 | |
| 48 | /* Static function prototypes */ |
| 49 | |
| 50 | static CORE_ADDR |
| 51 | find_toc_address PARAMS ((CORE_ADDR pc)); |
| 52 | |
| 53 | static CORE_ADDR |
| 54 | branch_dest PARAMS ((int opcode, int instr, CORE_ADDR pc, CORE_ADDR safety)); |
| 55 | |
| 56 | static void |
| 57 | frame_get_cache_fsr PARAMS ((struct frame_info *fi, |
| 58 | struct aix_framedata *fdatap)); |
| 59 | |
| 60 | /* |
| 61 | * Calculate the destination of a branch/jump. Return -1 if not a branch. |
| 62 | */ |
| 63 | static CORE_ADDR |
| 64 | branch_dest (opcode, instr, pc, safety) |
| 65 | int opcode; |
| 66 | int instr; |
| 67 | CORE_ADDR pc; |
| 68 | CORE_ADDR safety; |
| 69 | { |
| 70 | register long offset; |
| 71 | CORE_ADDR dest; |
| 72 | int immediate; |
| 73 | int absolute; |
| 74 | int ext_op; |
| 75 | |
| 76 | absolute = (int) ((instr >> 1) & 1); |
| 77 | |
| 78 | switch (opcode) { |
| 79 | case 18 : |
| 80 | immediate = ((instr & ~3) << 6) >> 6; /* br unconditional */ |
| 81 | if (absolute) |
| 82 | dest = immediate; |
| 83 | else |
| 84 | dest = pc + immediate; |
| 85 | break; |
| 86 | |
| 87 | case 16 : |
| 88 | immediate = ((instr & ~3) << 16) >> 16; /* br conditional */ |
| 89 | if (absolute) |
| 90 | dest = immediate; |
| 91 | else |
| 92 | dest = pc + immediate; |
| 93 | break; |
| 94 | |
| 95 | case 19 : |
| 96 | ext_op = (instr>>1) & 0x3ff; |
| 97 | |
| 98 | if (ext_op == 16) /* br conditional register */ |
| 99 | dest = read_register (LR_REGNUM) & ~3; |
| 100 | |
| 101 | else if (ext_op == 528) /* br cond to count reg */ |
| 102 | { |
| 103 | dest = read_register (CTR_REGNUM) & ~3; |
| 104 | |
| 105 | /* If we are about to execute a system call, dest is something |
| 106 | like 0x22fc or 0x3b00. Upon completion the system call |
| 107 | will return to the address in the link register. */ |
| 108 | if (dest < TEXT_SEGMENT_BASE) |
| 109 | dest = read_register (LR_REGNUM) & ~3; |
| 110 | } |
| 111 | else return -1; |
| 112 | break; |
| 113 | |
| 114 | default: return -1; |
| 115 | } |
| 116 | return (dest < TEXT_SEGMENT_BASE) ? safety : dest; |
| 117 | } |
| 118 | |
| 119 | |
| 120 | |
| 121 | /* AIX does not support PT_STEP. Simulate it. */ |
| 122 | |
| 123 | void |
| 124 | single_step (signal) |
| 125 | int signal; |
| 126 | { |
| 127 | #define INSNLEN(OPCODE) 4 |
| 128 | |
| 129 | static char breakp[] = BREAKPOINT; |
| 130 | int ii, insn; |
| 131 | CORE_ADDR loc; |
| 132 | CORE_ADDR breaks[2]; |
| 133 | int opcode; |
| 134 | |
| 135 | if (!one_stepped) { |
| 136 | loc = read_pc (); |
| 137 | |
| 138 | insn = read_memory_integer (loc, 4); |
| 139 | |
| 140 | breaks[0] = loc + INSNLEN(insn); |
| 141 | opcode = insn >> 26; |
| 142 | breaks[1] = branch_dest (opcode, insn, loc, breaks[0]); |
| 143 | |
| 144 | /* Don't put two breakpoints on the same address. */ |
| 145 | if (breaks[1] == breaks[0]) |
| 146 | breaks[1] = -1; |
| 147 | |
| 148 | stepBreaks[1].address = 0; |
| 149 | |
| 150 | for (ii=0; ii < 2; ++ii) { |
| 151 | |
| 152 | /* ignore invalid breakpoint. */ |
| 153 | if ( breaks[ii] == -1) |
| 154 | continue; |
| 155 | |
| 156 | read_memory (breaks[ii], stepBreaks[ii].data, 4); |
| 157 | |
| 158 | write_memory (breaks[ii], breakp, 4); |
| 159 | stepBreaks[ii].address = breaks[ii]; |
| 160 | } |
| 161 | |
| 162 | one_stepped = 1; |
| 163 | } else { |
| 164 | |
| 165 | /* remove step breakpoints. */ |
| 166 | for (ii=0; ii < 2; ++ii) |
| 167 | if (stepBreaks[ii].address != 0) |
| 168 | write_memory |
| 169 | (stepBreaks[ii].address, stepBreaks[ii].data, 4); |
| 170 | |
| 171 | one_stepped = 0; |
| 172 | } |
| 173 | errno = 0; /* FIXME, don't ignore errors! */ |
| 174 | /* What errors? {read,write}_memory call error(). */ |
| 175 | } |
| 176 | |
| 177 | |
| 178 | /* return pc value after skipping a function prologue. */ |
| 179 | |
| 180 | skip_prologue (pc) |
| 181 | CORE_ADDR pc; |
| 182 | { |
| 183 | char buf[4]; |
| 184 | unsigned int tmp; |
| 185 | unsigned long op; |
| 186 | |
| 187 | if (target_read_memory (pc, buf, 4)) |
| 188 | return pc; /* Can't access it -- assume no prologue. */ |
| 189 | op = extract_unsigned_integer (buf, 4); |
| 190 | |
| 191 | /* Assume that subsequent fetches can fail with low probability. */ |
| 192 | |
| 193 | if (op == 0x7c0802a6) { /* mflr r0 */ |
| 194 | pc += 4; |
| 195 | op = read_memory_integer (pc, 4); |
| 196 | } |
| 197 | |
| 198 | if ((op & 0xfc00003e) == 0x7c000026) { /* mfcr Rx */ |
| 199 | pc += 4; |
| 200 | op = read_memory_integer (pc, 4); |
| 201 | } |
| 202 | |
| 203 | if ((op & 0xfc000000) == 0x48000000) { /* bl foo, to save fprs??? */ |
| 204 | pc += 4; |
| 205 | op = read_memory_integer (pc, 4); |
| 206 | |
| 207 | /* At this point, make sure this is not a trampoline function |
| 208 | (a function that simply calls another functions, and nothing else). |
| 209 | If the next is not a nop, this branch was part of the function |
| 210 | prologue. */ |
| 211 | |
| 212 | if (op == 0x4def7b82 || /* crorc 15, 15, 15 */ |
| 213 | op == 0x0) |
| 214 | return pc - 4; /* don't skip over this branch */ |
| 215 | } |
| 216 | |
| 217 | if ((op & 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */ |
| 218 | pc += 4; /* store floating register double */ |
| 219 | op = read_memory_integer (pc, 4); |
| 220 | } |
| 221 | |
| 222 | if ((op & 0xfc1f0000) == 0xbc010000) { /* stm Rx, NUM(r1) */ |
| 223 | pc += 4; |
| 224 | op = read_memory_integer (pc, 4); |
| 225 | } |
| 226 | |
| 227 | while ((op & 0xfc1f0000) == 0x90010000 && /* st rx,NUM(r1), rx >= r13 */ |
| 228 | (op & 0x03e00000) >= 0x01a00000) { |
| 229 | pc += 4; |
| 230 | op = read_memory_integer (pc, 4); |
| 231 | } |
| 232 | |
| 233 | if (op == 0x90010008) { /* st r0,8(r1) */ |
| 234 | pc += 4; |
| 235 | op = read_memory_integer (pc, 4); |
| 236 | } |
| 237 | |
| 238 | if (op == 0x91810004) { /* st r12,4(r1) */ |
| 239 | pc += 4; |
| 240 | op = read_memory_integer (pc, 4); |
| 241 | } |
| 242 | |
| 243 | if ((op & 0xffff0000) == 0x94210000) { /* stu r1,NUM(r1) */ |
| 244 | pc += 4; |
| 245 | op = read_memory_integer (pc, 4); |
| 246 | } |
| 247 | |
| 248 | while ((tmp = (op >> 22)) == 0x20f) { /* l r31, ... or */ |
| 249 | pc += 4; /* l r30, ... */ |
| 250 | op = read_memory_integer (pc, 4); |
| 251 | } |
| 252 | |
| 253 | /* store parameters into stack */ |
| 254 | while( |
| 255 | (op & 0xfc1f0000) == 0xd8010000 || /* stfd Rx,NUM(r1) */ |
| 256 | (op & 0xfc1f0000) == 0x90010000 || /* st r?, NUM(r1) */ |
| 257 | (op & 0xfc000000) == 0xfc000000 || /* frsp, fp?, .. */ |
| 258 | (op & 0xd0000000) == 0xd0000000) /* stfs, fp?, .. */ |
| 259 | { |
| 260 | pc += 4; /* store fpr double */ |
| 261 | op = read_memory_integer (pc, 4); |
| 262 | } |
| 263 | |
| 264 | if (op == 0x603f0000 /* oril r31, r1, 0x0 */ |
| 265 | || op == 0x7c3f0b78) { /* mr r31, r1 */ |
| 266 | pc += 4; /* this happens if r31 is used as */ |
| 267 | op = read_memory_integer (pc, 4); /* frame ptr. (gcc does that) */ |
| 268 | |
| 269 | tmp = 0; |
| 270 | while ((op >> 16) == (0x907f + tmp)) { /* st r3, NUM(r31) */ |
| 271 | pc += 4; /* st r4, NUM(r31), ... */ |
| 272 | op = read_memory_integer (pc, 4); |
| 273 | tmp += 0x20; |
| 274 | } |
| 275 | } |
| 276 | #if 0 |
| 277 | /* I have problems with skipping over __main() that I need to address |
| 278 | * sometime. Previously, I used to use misc_function_vector which |
| 279 | * didn't work as well as I wanted to be. -MGO */ |
| 280 | |
| 281 | /* If the first thing after skipping a prolog is a branch to a function, |
| 282 | this might be a call to an initializer in main(), introduced by gcc2. |
| 283 | We'd like to skip over it as well. Fortunately, xlc does some extra |
| 284 | work before calling a function right after a prologue, thus we can |
| 285 | single out such gcc2 behaviour. */ |
| 286 | |
| 287 | |
| 288 | if ((op & 0xfc000001) == 0x48000001) { /* bl foo, an initializer function? */ |
| 289 | op = read_memory_integer (pc+4, 4); |
| 290 | |
| 291 | if (op == 0x4def7b82) { /* cror 0xf, 0xf, 0xf (nop) */ |
| 292 | |
| 293 | /* check and see if we are in main. If so, skip over this initializer |
| 294 | function as well. */ |
| 295 | |
| 296 | tmp = find_pc_misc_function (pc); |
| 297 | if (tmp >= 0 && STREQ (misc_function_vector [tmp].name, "main")) |
| 298 | return pc + 8; |
| 299 | } |
| 300 | } |
| 301 | #endif /* 0 */ |
| 302 | |
| 303 | return pc; |
| 304 | } |
| 305 | |
| 306 | |
| 307 | /************************************************************************* |
| 308 | Support for creating pushind a dummy frame into the stack, and popping |
| 309 | frames, etc. |
| 310 | *************************************************************************/ |
| 311 | |
| 312 | /* The total size of dummy frame is 436, which is; |
| 313 | |
| 314 | 32 gpr's - 128 bytes |
| 315 | 32 fpr's - 256 " |
| 316 | 7 the rest - 28 " |
| 317 | and 24 extra bytes for the callee's link area. The last 24 bytes |
| 318 | for the link area might not be necessary, since it will be taken |
| 319 | care of by push_arguments(). */ |
| 320 | |
| 321 | #define DUMMY_FRAME_SIZE 436 |
| 322 | |
| 323 | #define DUMMY_FRAME_ADDR_SIZE 10 |
| 324 | |
| 325 | /* Make sure you initialize these in somewhere, in case gdb gives up what it |
| 326 | was debugging and starts debugging something else. FIXMEibm */ |
| 327 | |
| 328 | static int dummy_frame_count = 0; |
| 329 | static int dummy_frame_size = 0; |
| 330 | static CORE_ADDR *dummy_frame_addr = 0; |
| 331 | |
| 332 | extern int stop_stack_dummy; |
| 333 | |
| 334 | /* push a dummy frame into stack, save all register. Currently we are saving |
| 335 | only gpr's and fpr's, which is not good enough! FIXMEmgo */ |
| 336 | |
| 337 | void |
| 338 | push_dummy_frame () |
| 339 | { |
| 340 | /* stack pointer. */ |
| 341 | CORE_ADDR sp; |
| 342 | /* Same thing, target byte order. */ |
| 343 | char sp_targ[4]; |
| 344 | |
| 345 | /* link register. */ |
| 346 | CORE_ADDR pc; |
| 347 | /* Same thing, target byte order. */ |
| 348 | char pc_targ[4]; |
| 349 | |
| 350 | int ii; |
| 351 | |
| 352 | target_fetch_registers (-1); |
| 353 | |
| 354 | if (dummy_frame_count >= dummy_frame_size) { |
| 355 | dummy_frame_size += DUMMY_FRAME_ADDR_SIZE; |
| 356 | if (dummy_frame_addr) |
| 357 | dummy_frame_addr = (CORE_ADDR*) xrealloc |
| 358 | (dummy_frame_addr, sizeof(CORE_ADDR) * (dummy_frame_size)); |
| 359 | else |
| 360 | dummy_frame_addr = (CORE_ADDR*) |
| 361 | xmalloc (sizeof(CORE_ADDR) * (dummy_frame_size)); |
| 362 | } |
| 363 | |
| 364 | sp = read_register(SP_REGNUM); |
| 365 | pc = read_register(PC_REGNUM); |
| 366 | store_address (pc_targ, 4, pc); |
| 367 | |
| 368 | dummy_frame_addr [dummy_frame_count++] = sp; |
| 369 | |
| 370 | /* Be careful! If the stack pointer is not decremented first, then kernel |
| 371 | thinks he is free to use the space underneath it. And kernel actually |
| 372 | uses that area for IPC purposes when executing ptrace(2) calls. So |
| 373 | before writing register values into the new frame, decrement and update |
| 374 | %sp first in order to secure your frame. */ |
| 375 | |
| 376 | write_register (SP_REGNUM, sp-DUMMY_FRAME_SIZE); |
| 377 | |
| 378 | /* gdb relies on the state of current_frame. We'd better update it, |
| 379 | otherwise things like do_registers_info() wouldn't work properly! */ |
| 380 | |
| 381 | flush_cached_frames (); |
| 382 | |
| 383 | /* save program counter in link register's space. */ |
| 384 | write_memory (sp+8, pc_targ, 4); |
| 385 | |
| 386 | /* save all floating point and general purpose registers here. */ |
| 387 | |
| 388 | /* fpr's, f0..f31 */ |
| 389 | for (ii = 0; ii < 32; ++ii) |
| 390 | write_memory (sp-8-(ii*8), ®isters[REGISTER_BYTE (31-ii+FP0_REGNUM)], 8); |
| 391 | |
| 392 | /* gpr's r0..r31 */ |
| 393 | for (ii=1; ii <=32; ++ii) |
| 394 | write_memory (sp-256-(ii*4), ®isters[REGISTER_BYTE (32-ii)], 4); |
| 395 | |
| 396 | /* so far, 32*2 + 32 words = 384 bytes have been written. |
| 397 | 7 extra registers in our register set: pc, ps, cnd, lr, cnt, xer, mq */ |
| 398 | |
| 399 | for (ii=1; ii <= (LAST_SP_REGNUM-FIRST_SP_REGNUM+1); ++ii) { |
| 400 | write_memory (sp-384-(ii*4), |
| 401 | ®isters[REGISTER_BYTE (FPLAST_REGNUM + ii)], 4); |
| 402 | } |
| 403 | |
| 404 | /* Save sp or so called back chain right here. */ |
| 405 | store_address (sp_targ, 4, sp); |
| 406 | write_memory (sp-DUMMY_FRAME_SIZE, sp_targ, 4); |
| 407 | sp -= DUMMY_FRAME_SIZE; |
| 408 | |
| 409 | /* And finally, this is the back chain. */ |
| 410 | write_memory (sp+8, pc_targ, 4); |
| 411 | } |
| 412 | |
| 413 | |
| 414 | /* Pop a dummy frame. |
| 415 | |
| 416 | In rs6000 when we push a dummy frame, we save all of the registers. This |
| 417 | is usually done before user calls a function explicitly. |
| 418 | |
| 419 | After a dummy frame is pushed, some instructions are copied into stack, |
| 420 | and stack pointer is decremented even more. Since we don't have a frame |
| 421 | pointer to get back to the parent frame of the dummy, we start having |
| 422 | trouble poping it. Therefore, we keep a dummy frame stack, keeping |
| 423 | addresses of dummy frames as such. When poping happens and when we |
| 424 | detect that was a dummy frame, we pop it back to its parent by using |
| 425 | dummy frame stack (`dummy_frame_addr' array). |
| 426 | |
| 427 | FIXME: This whole concept is broken. You should be able to detect |
| 428 | a dummy stack frame *on the user's stack itself*. When you do, |
| 429 | then you know the format of that stack frame -- including its |
| 430 | saved SP register! There should *not* be a separate stack in the |
| 431 | GDB process that keeps track of these dummy frames! -- gnu@cygnus.com Aug92 |
| 432 | */ |
| 433 | |
| 434 | pop_dummy_frame () |
| 435 | { |
| 436 | CORE_ADDR sp, pc; |
| 437 | int ii; |
| 438 | sp = dummy_frame_addr [--dummy_frame_count]; |
| 439 | |
| 440 | /* restore all fpr's. */ |
| 441 | for (ii = 1; ii <= 32; ++ii) |
| 442 | read_memory (sp-(ii*8), ®isters[REGISTER_BYTE (32-ii+FP0_REGNUM)], 8); |
| 443 | |
| 444 | /* restore all gpr's */ |
| 445 | for (ii=1; ii <= 32; ++ii) { |
| 446 | read_memory (sp-256-(ii*4), ®isters[REGISTER_BYTE (32-ii)], 4); |
| 447 | } |
| 448 | |
| 449 | /* restore the rest of the registers. */ |
| 450 | for (ii=1; ii <=(LAST_SP_REGNUM-FIRST_SP_REGNUM+1); ++ii) |
| 451 | read_memory (sp-384-(ii*4), |
| 452 | ®isters[REGISTER_BYTE (FPLAST_REGNUM + ii)], 4); |
| 453 | |
| 454 | read_memory (sp-(DUMMY_FRAME_SIZE-8), |
| 455 | ®isters [REGISTER_BYTE(PC_REGNUM)], 4); |
| 456 | |
| 457 | /* when a dummy frame was being pushed, we had to decrement %sp first, in |
| 458 | order to secure astack space. Thus, saved %sp (or %r1) value, is not the |
| 459 | one we should restore. Change it with the one we need. */ |
| 460 | |
| 461 | *(int*)®isters [REGISTER_BYTE(FP_REGNUM)] = sp; |
| 462 | |
| 463 | /* Now we can restore all registers. */ |
| 464 | |
| 465 | target_store_registers (-1); |
| 466 | pc = read_pc (); |
| 467 | flush_cached_frames (); |
| 468 | } |
| 469 | |
| 470 | |
| 471 | /* pop the innermost frame, go back to the caller. */ |
| 472 | |
| 473 | void |
| 474 | pop_frame () |
| 475 | { |
| 476 | CORE_ADDR pc, lr, sp, prev_sp; /* %pc, %lr, %sp */ |
| 477 | struct aix_framedata fdata; |
| 478 | struct frame_info *frame = get_current_frame (); |
| 479 | int addr, ii; |
| 480 | |
| 481 | pc = read_pc (); |
| 482 | sp = FRAME_FP (frame); |
| 483 | |
| 484 | if (stop_stack_dummy && dummy_frame_count) { |
| 485 | pop_dummy_frame (); |
| 486 | return; |
| 487 | } |
| 488 | |
| 489 | /* Make sure that all registers are valid. */ |
| 490 | read_register_bytes (0, NULL, REGISTER_BYTES); |
| 491 | |
| 492 | /* figure out previous %pc value. If the function is frameless, it is |
| 493 | still in the link register, otherwise walk the frames and retrieve the |
| 494 | saved %pc value in the previous frame. */ |
| 495 | |
| 496 | addr = get_pc_function_start (frame->pc) + FUNCTION_START_OFFSET; |
| 497 | function_frame_info (addr, &fdata); |
| 498 | |
| 499 | if (fdata.frameless) |
| 500 | prev_sp = sp; |
| 501 | else |
| 502 | prev_sp = read_memory_integer (sp, 4); |
| 503 | if (fdata.nosavedpc) |
| 504 | lr = read_register (LR_REGNUM); |
| 505 | else |
| 506 | lr = read_memory_integer (prev_sp+8, 4); |
| 507 | |
| 508 | /* reset %pc value. */ |
| 509 | write_register (PC_REGNUM, lr); |
| 510 | |
| 511 | /* reset register values if any was saved earlier. */ |
| 512 | addr = prev_sp - fdata.offset; |
| 513 | |
| 514 | if (fdata.saved_gpr != -1) |
| 515 | for (ii = fdata.saved_gpr; ii <= 31; ++ii) { |
| 516 | read_memory (addr, ®isters [REGISTER_BYTE (ii)], 4); |
| 517 | addr += 4; |
| 518 | } |
| 519 | |
| 520 | if (fdata.saved_fpr != -1) |
| 521 | for (ii = fdata.saved_fpr; ii <= 31; ++ii) { |
| 522 | read_memory (addr, ®isters [REGISTER_BYTE (ii+FP0_REGNUM)], 8); |
| 523 | addr += 8; |
| 524 | } |
| 525 | |
| 526 | write_register (SP_REGNUM, prev_sp); |
| 527 | target_store_registers (-1); |
| 528 | flush_cached_frames (); |
| 529 | } |
| 530 | |
| 531 | /* fixup the call sequence of a dummy function, with the real function address. |
| 532 | its argumets will be passed by gdb. */ |
| 533 | |
| 534 | void |
| 535 | fix_call_dummy(dummyname, pc, fun, nargs, type) |
| 536 | char *dummyname; |
| 537 | CORE_ADDR pc; |
| 538 | CORE_ADDR fun; |
| 539 | int nargs; /* not used */ |
| 540 | int type; /* not used */ |
| 541 | { |
| 542 | #define TOC_ADDR_OFFSET 20 |
| 543 | #define TARGET_ADDR_OFFSET 28 |
| 544 | |
| 545 | int ii; |
| 546 | CORE_ADDR target_addr; |
| 547 | CORE_ADDR tocvalue; |
| 548 | |
| 549 | target_addr = fun; |
| 550 | tocvalue = find_toc_address (target_addr); |
| 551 | |
| 552 | ii = *(int*)((char*)dummyname + TOC_ADDR_OFFSET); |
| 553 | ii = (ii & 0xffff0000) | (tocvalue >> 16); |
| 554 | *(int*)((char*)dummyname + TOC_ADDR_OFFSET) = ii; |
| 555 | |
| 556 | ii = *(int*)((char*)dummyname + TOC_ADDR_OFFSET+4); |
| 557 | ii = (ii & 0xffff0000) | (tocvalue & 0x0000ffff); |
| 558 | *(int*)((char*)dummyname + TOC_ADDR_OFFSET+4) = ii; |
| 559 | |
| 560 | ii = *(int*)((char*)dummyname + TARGET_ADDR_OFFSET); |
| 561 | ii = (ii & 0xffff0000) | (target_addr >> 16); |
| 562 | *(int*)((char*)dummyname + TARGET_ADDR_OFFSET) = ii; |
| 563 | |
| 564 | ii = *(int*)((char*)dummyname + TARGET_ADDR_OFFSET+4); |
| 565 | ii = (ii & 0xffff0000) | (target_addr & 0x0000ffff); |
| 566 | *(int*)((char*)dummyname + TARGET_ADDR_OFFSET+4) = ii; |
| 567 | } |
| 568 | |
| 569 | |
| 570 | /* return information about a function frame. |
| 571 | in struct aix_frameinfo fdata: |
| 572 | - frameless is TRUE, if function does not have a frame. |
| 573 | - nosavedpc is TRUE, if function does not save %pc value in its frame. |
| 574 | - offset is the number of bytes used in the frame to save registers. |
| 575 | - saved_gpr is the number of the first saved gpr. |
| 576 | - saved_fpr is the number of the first saved fpr. |
| 577 | - alloca_reg is the number of the register used for alloca() handling. |
| 578 | Otherwise -1. |
| 579 | */ |
| 580 | void |
| 581 | function_frame_info (pc, fdata) |
| 582 | CORE_ADDR pc; |
| 583 | struct aix_framedata *fdata; |
| 584 | { |
| 585 | unsigned int tmp; |
| 586 | register unsigned int op; |
| 587 | char buf[4]; |
| 588 | |
| 589 | fdata->offset = 0; |
| 590 | fdata->saved_gpr = fdata->saved_fpr = fdata->alloca_reg = -1; |
| 591 | fdata->frameless = 1; |
| 592 | |
| 593 | /* Do not error out if we can't access the instructions. */ |
| 594 | if (target_read_memory (pc, buf, 4)) |
| 595 | return; |
| 596 | op = extract_unsigned_integer (buf, 4); |
| 597 | if (op == 0x7c0802a6) { /* mflr r0 */ |
| 598 | pc += 4; |
| 599 | op = read_memory_integer (pc, 4); |
| 600 | fdata->nosavedpc = 0; |
| 601 | fdata->frameless = 0; |
| 602 | } |
| 603 | else /* else, pc is not saved */ |
| 604 | fdata->nosavedpc = 1; |
| 605 | |
| 606 | if ((op & 0xfc00003e) == 0x7c000026) { /* mfcr Rx */ |
| 607 | pc += 4; |
| 608 | op = read_memory_integer (pc, 4); |
| 609 | fdata->frameless = 0; |
| 610 | } |
| 611 | |
| 612 | if ((op & 0xfc000000) == 0x48000000) { /* bl foo, to save fprs??? */ |
| 613 | pc += 4; |
| 614 | op = read_memory_integer (pc, 4); |
| 615 | /* At this point, make sure this is not a trampoline function |
| 616 | (a function that simply calls another functions, and nothing else). |
| 617 | If the next is not a nop, this branch was part of the function |
| 618 | prologue. */ |
| 619 | |
| 620 | if (op == 0x4def7b82 || /* crorc 15, 15, 15 */ |
| 621 | op == 0x0) |
| 622 | return; /* prologue is over */ |
| 623 | fdata->frameless = 0; |
| 624 | } |
| 625 | |
| 626 | if ((op & 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */ |
| 627 | pc += 4; /* store floating register double */ |
| 628 | op = read_memory_integer (pc, 4); |
| 629 | fdata->frameless = 0; |
| 630 | } |
| 631 | |
| 632 | if ((op & 0xfc1f0000) == 0xbc010000) { /* stm Rx, NUM(r1) */ |
| 633 | int tmp2; |
| 634 | fdata->saved_gpr = (op >> 21) & 0x1f; |
| 635 | tmp2 = op & 0xffff; |
| 636 | if (tmp2 > 0x7fff) |
| 637 | tmp2 = (~0 &~ 0xffff) | tmp2; |
| 638 | |
| 639 | if (tmp2 < 0) { |
| 640 | tmp2 = tmp2 * -1; |
| 641 | fdata->saved_fpr = (tmp2 - ((32 - fdata->saved_gpr) * 4)) / 8; |
| 642 | if ( fdata->saved_fpr > 0) |
| 643 | fdata->saved_fpr = 32 - fdata->saved_fpr; |
| 644 | else |
| 645 | fdata->saved_fpr = -1; |
| 646 | } |
| 647 | fdata->offset = tmp2; |
| 648 | pc += 4; |
| 649 | op = read_memory_integer (pc, 4); |
| 650 | fdata->frameless = 0; |
| 651 | } |
| 652 | |
| 653 | while (((tmp = op >> 16) == 0x9001) || /* st r0, NUM(r1) */ |
| 654 | (tmp == 0x9421) || /* stu r1, NUM(r1) */ |
| 655 | (tmp == 0x93e1)) /* st r31, NUM(r1) */ |
| 656 | { |
| 657 | int tmp2; |
| 658 | |
| 659 | /* gcc takes a short cut and uses this instruction to save r31 only. */ |
| 660 | |
| 661 | if (tmp == 0x93e1) { |
| 662 | if (fdata->offset) |
| 663 | /* fatal ("Unrecognized prolog."); */ |
| 664 | printf_unfiltered ("Unrecognized prolog!\n"); |
| 665 | |
| 666 | fdata->saved_gpr = 31; |
| 667 | tmp2 = op & 0xffff; |
| 668 | if (tmp2 > 0x7fff) { |
| 669 | tmp2 = - ((~0 &~ 0xffff) | tmp2); |
| 670 | fdata->saved_fpr = (tmp2 - ((32 - 31) * 4)) / 8; |
| 671 | if ( fdata->saved_fpr > 0) |
| 672 | fdata->saved_fpr = 32 - fdata->saved_fpr; |
| 673 | else |
| 674 | fdata->saved_fpr = -1; |
| 675 | } |
| 676 | fdata->offset = tmp2; |
| 677 | } |
| 678 | pc += 4; |
| 679 | op = read_memory_integer (pc, 4); |
| 680 | fdata->frameless = 0; |
| 681 | } |
| 682 | |
| 683 | while ((tmp = (op >> 22)) == 0x20f) { /* l r31, ... or */ |
| 684 | pc += 4; /* l r30, ... */ |
| 685 | op = read_memory_integer (pc, 4); |
| 686 | fdata->frameless = 0; |
| 687 | } |
| 688 | |
| 689 | /* store parameters into stack */ |
| 690 | while( |
| 691 | (op & 0xfc1f0000) == 0xd8010000 || /* stfd Rx,NUM(r1) */ |
| 692 | (op & 0xfc1f0000) == 0x90010000 || /* st r?, NUM(r1) */ |
| 693 | (op & 0xfc000000) == 0xfc000000 || /* frsp, fp?, .. */ |
| 694 | (op & 0xd0000000) == 0xd0000000) /* stfs, fp?, .. */ |
| 695 | { |
| 696 | pc += 4; /* store fpr double */ |
| 697 | op = read_memory_integer (pc, 4); |
| 698 | fdata->frameless = 0; |
| 699 | } |
| 700 | |
| 701 | if (op == 0x603f0000 /* oril r31, r1, 0x0 */ |
| 702 | || op == 0x7c3f0b78) /* mr r31, r1 */ |
| 703 | { |
| 704 | fdata->alloca_reg = 31; |
| 705 | fdata->frameless = 0; |
| 706 | } |
| 707 | } |
| 708 | |
| 709 | |
| 710 | /* Pass the arguments in either registers, or in the stack. In RS6000, the first |
| 711 | eight words of the argument list (that might be less than eight parameters if |
| 712 | some parameters occupy more than one word) are passed in r3..r11 registers. |
| 713 | float and double parameters are passed in fpr's, in addition to that. Rest of |
| 714 | the parameters if any are passed in user stack. There might be cases in which |
| 715 | half of the parameter is copied into registers, the other half is pushed into |
| 716 | stack. |
| 717 | |
| 718 | If the function is returning a structure, then the return address is passed |
| 719 | in r3, then the first 7 words of the parametes can be passed in registers, |
| 720 | starting from r4. */ |
| 721 | |
| 722 | CORE_ADDR |
| 723 | push_arguments (nargs, args, sp, struct_return, struct_addr) |
| 724 | int nargs; |
| 725 | value_ptr *args; |
| 726 | CORE_ADDR sp; |
| 727 | int struct_return; |
| 728 | CORE_ADDR struct_addr; |
| 729 | { |
| 730 | int ii, len; |
| 731 | int argno; /* current argument number */ |
| 732 | int argbytes; /* current argument byte */ |
| 733 | char tmp_buffer [50]; |
| 734 | value_ptr arg; |
| 735 | int f_argno = 0; /* current floating point argno */ |
| 736 | |
| 737 | CORE_ADDR saved_sp, pc; |
| 738 | |
| 739 | if ( dummy_frame_count <= 0) |
| 740 | printf_unfiltered ("FATAL ERROR -push_arguments()! frame not found!!\n"); |
| 741 | |
| 742 | /* The first eight words of ther arguments are passed in registers. Copy |
| 743 | them appropriately. |
| 744 | |
| 745 | If the function is returning a `struct', then the first word (which |
| 746 | will be passed in r3) is used for struct return address. In that |
| 747 | case we should advance one word and start from r4 register to copy |
| 748 | parameters. */ |
| 749 | |
| 750 | ii = struct_return ? 1 : 0; |
| 751 | |
| 752 | for (argno=0, argbytes=0; argno < nargs && ii<8; ++ii) { |
| 753 | |
| 754 | arg = args[argno]; |
| 755 | len = TYPE_LENGTH (VALUE_TYPE (arg)); |
| 756 | |
| 757 | if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_FLT) { |
| 758 | |
| 759 | /* floating point arguments are passed in fpr's, as well as gpr's. |
| 760 | There are 13 fpr's reserved for passing parameters. At this point |
| 761 | there is no way we would run out of them. */ |
| 762 | |
| 763 | if (len > 8) |
| 764 | printf_unfiltered ( |
| 765 | "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno); |
| 766 | |
| 767 | memcpy (®isters[REGISTER_BYTE(FP0_REGNUM + 1 + f_argno)], VALUE_CONTENTS (arg), |
| 768 | len); |
| 769 | ++f_argno; |
| 770 | } |
| 771 | |
| 772 | if (len > 4) { |
| 773 | |
| 774 | /* Argument takes more than one register. */ |
| 775 | while (argbytes < len) { |
| 776 | |
| 777 | *(int*)®isters[REGISTER_BYTE(ii+3)] = 0; |
| 778 | memcpy (®isters[REGISTER_BYTE(ii+3)], |
| 779 | ((char*)VALUE_CONTENTS (arg))+argbytes, |
| 780 | (len - argbytes) > 4 ? 4 : len - argbytes); |
| 781 | ++ii, argbytes += 4; |
| 782 | |
| 783 | if (ii >= 8) |
| 784 | goto ran_out_of_registers_for_arguments; |
| 785 | } |
| 786 | argbytes = 0; |
| 787 | --ii; |
| 788 | } |
| 789 | else { /* Argument can fit in one register. No problem. */ |
| 790 | *(int*)®isters[REGISTER_BYTE(ii+3)] = 0; |
| 791 | memcpy (®isters[REGISTER_BYTE(ii+3)], VALUE_CONTENTS (arg), len); |
| 792 | } |
| 793 | ++argno; |
| 794 | } |
| 795 | |
| 796 | ran_out_of_registers_for_arguments: |
| 797 | |
| 798 | /* location for 8 parameters are always reserved. */ |
| 799 | sp -= 4 * 8; |
| 800 | |
| 801 | /* another six words for back chain, TOC register, link register, etc. */ |
| 802 | sp -= 24; |
| 803 | |
| 804 | /* if there are more arguments, allocate space for them in |
| 805 | the stack, then push them starting from the ninth one. */ |
| 806 | |
| 807 | if ((argno < nargs) || argbytes) { |
| 808 | int space = 0, jj; |
| 809 | value_ptr val; |
| 810 | |
| 811 | if (argbytes) { |
| 812 | space += ((len - argbytes + 3) & -4); |
| 813 | jj = argno + 1; |
| 814 | } |
| 815 | else |
| 816 | jj = argno; |
| 817 | |
| 818 | for (; jj < nargs; ++jj) { |
| 819 | val = args[jj]; |
| 820 | space += ((TYPE_LENGTH (VALUE_TYPE (val))) + 3) & -4; |
| 821 | } |
| 822 | |
| 823 | /* add location required for the rest of the parameters */ |
| 824 | space = (space + 7) & -8; |
| 825 | sp -= space; |
| 826 | |
| 827 | /* This is another instance we need to be concerned about securing our |
| 828 | stack space. If we write anything underneath %sp (r1), we might conflict |
| 829 | with the kernel who thinks he is free to use this area. So, update %sp |
| 830 | first before doing anything else. */ |
| 831 | |
| 832 | write_register (SP_REGNUM, sp); |
| 833 | |
| 834 | /* if the last argument copied into the registers didn't fit there |
| 835 | completely, push the rest of it into stack. */ |
| 836 | |
| 837 | if (argbytes) { |
| 838 | write_memory ( |
| 839 | sp+24+(ii*4), ((char*)VALUE_CONTENTS (arg))+argbytes, len - argbytes); |
| 840 | ++argno; |
| 841 | ii += ((len - argbytes + 3) & -4) / 4; |
| 842 | } |
| 843 | |
| 844 | /* push the rest of the arguments into stack. */ |
| 845 | for (; argno < nargs; ++argno) { |
| 846 | |
| 847 | arg = args[argno]; |
| 848 | len = TYPE_LENGTH (VALUE_TYPE (arg)); |
| 849 | |
| 850 | |
| 851 | /* float types should be passed in fpr's, as well as in the stack. */ |
| 852 | if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_FLT && f_argno < 13) { |
| 853 | |
| 854 | if (len > 8) |
| 855 | printf_unfiltered ( |
| 856 | "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno); |
| 857 | |
| 858 | memcpy (®isters[REGISTER_BYTE(FP0_REGNUM + 1 + f_argno)], VALUE_CONTENTS (arg), |
| 859 | len); |
| 860 | ++f_argno; |
| 861 | } |
| 862 | |
| 863 | write_memory (sp+24+(ii*4), (char *) VALUE_CONTENTS (arg), len); |
| 864 | ii += ((len + 3) & -4) / 4; |
| 865 | } |
| 866 | } |
| 867 | else |
| 868 | /* Secure stack areas first, before doing anything else. */ |
| 869 | write_register (SP_REGNUM, sp); |
| 870 | |
| 871 | saved_sp = dummy_frame_addr [dummy_frame_count - 1]; |
| 872 | read_memory (saved_sp, tmp_buffer, 24); |
| 873 | write_memory (sp, tmp_buffer, 24); |
| 874 | |
| 875 | /* set back chain properly */ |
| 876 | store_address (tmp_buffer, 4, saved_sp); |
| 877 | write_memory (sp, tmp_buffer, 4); |
| 878 | |
| 879 | target_store_registers (-1); |
| 880 | return sp; |
| 881 | } |
| 882 | |
| 883 | /* a given return value in `regbuf' with a type `valtype', extract and copy its |
| 884 | value into `valbuf' */ |
| 885 | |
| 886 | void |
| 887 | extract_return_value (valtype, regbuf, valbuf) |
| 888 | struct type *valtype; |
| 889 | char regbuf[REGISTER_BYTES]; |
| 890 | char *valbuf; |
| 891 | { |
| 892 | |
| 893 | if (TYPE_CODE (valtype) == TYPE_CODE_FLT) { |
| 894 | |
| 895 | double dd; float ff; |
| 896 | /* floats and doubles are returned in fpr1. fpr's have a size of 8 bytes. |
| 897 | We need to truncate the return value into float size (4 byte) if |
| 898 | necessary. */ |
| 899 | |
| 900 | if (TYPE_LENGTH (valtype) > 4) /* this is a double */ |
| 901 | memcpy (valbuf, ®buf[REGISTER_BYTE (FP0_REGNUM + 1)], |
| 902 | TYPE_LENGTH (valtype)); |
| 903 | else { /* float */ |
| 904 | memcpy (&dd, ®buf[REGISTER_BYTE (FP0_REGNUM + 1)], 8); |
| 905 | ff = (float)dd; |
| 906 | memcpy (valbuf, &ff, sizeof(float)); |
| 907 | } |
| 908 | } |
| 909 | else |
| 910 | /* return value is copied starting from r3. */ |
| 911 | memcpy (valbuf, ®buf[REGISTER_BYTE (3)], TYPE_LENGTH (valtype)); |
| 912 | } |
| 913 | |
| 914 | |
| 915 | /* keep structure return address in this variable. |
| 916 | FIXME: This is a horrid kludge which should not be allowed to continue |
| 917 | living. This only allows a single nested call to a structure-returning |
| 918 | function. Come on, guys! -- gnu@cygnus.com, Aug 92 */ |
| 919 | |
| 920 | CORE_ADDR rs6000_struct_return_address; |
| 921 | |
| 922 | |
| 923 | /* Indirect function calls use a piece of trampoline code to do context |
| 924 | switching, i.e. to set the new TOC table. Skip such code if we are on |
| 925 | its first instruction (as when we have single-stepped to here). |
| 926 | Also skip shared library trampoline code (which is different from |
| 927 | indirect function call trampolines). |
| 928 | Result is desired PC to step until, or NULL if we are not in |
| 929 | trampoline code. */ |
| 930 | |
| 931 | CORE_ADDR |
| 932 | skip_trampoline_code (pc) |
| 933 | CORE_ADDR pc; |
| 934 | { |
| 935 | register unsigned int ii, op; |
| 936 | CORE_ADDR solib_target_pc; |
| 937 | |
| 938 | static unsigned trampoline_code[] = { |
| 939 | 0x800b0000, /* l r0,0x0(r11) */ |
| 940 | 0x90410014, /* st r2,0x14(r1) */ |
| 941 | 0x7c0903a6, /* mtctr r0 */ |
| 942 | 0x804b0004, /* l r2,0x4(r11) */ |
| 943 | 0x816b0008, /* l r11,0x8(r11) */ |
| 944 | 0x4e800420, /* bctr */ |
| 945 | 0x4e800020, /* br */ |
| 946 | 0 |
| 947 | }; |
| 948 | |
| 949 | /* If pc is in a shared library trampoline, return its target. */ |
| 950 | solib_target_pc = find_solib_trampoline_target (pc); |
| 951 | if (solib_target_pc) |
| 952 | return solib_target_pc; |
| 953 | |
| 954 | for (ii=0; trampoline_code[ii]; ++ii) { |
| 955 | op = read_memory_integer (pc + (ii*4), 4); |
| 956 | if (op != trampoline_code [ii]) |
| 957 | return 0; |
| 958 | } |
| 959 | ii = read_register (11); /* r11 holds destination addr */ |
| 960 | pc = read_memory_integer (ii, 4); /* (r11) value */ |
| 961 | return pc; |
| 962 | } |
| 963 | |
| 964 | |
| 965 | /* Determines whether the function FI has a frame on the stack or not. |
| 966 | Called from the FRAMELESS_FUNCTION_INVOCATION macro in tm.h with a |
| 967 | second argument of 0, and from the FRAME_SAVED_PC macro with a |
| 968 | second argument of 1. */ |
| 969 | |
| 970 | int |
| 971 | frameless_function_invocation (fi, pcsaved) |
| 972 | struct frame_info *fi; |
| 973 | int pcsaved; |
| 974 | { |
| 975 | CORE_ADDR func_start; |
| 976 | struct aix_framedata fdata; |
| 977 | |
| 978 | if (fi->next != NULL) |
| 979 | /* Don't even think about framelessness except on the innermost frame. */ |
| 980 | /* FIXME: Can also be frameless if fi->next->signal_handler_caller (if |
| 981 | a signal happens while executing in a frameless function). */ |
| 982 | return 0; |
| 983 | |
| 984 | func_start = get_pc_function_start (fi->pc) + FUNCTION_START_OFFSET; |
| 985 | |
| 986 | /* If we failed to find the start of the function, it is a mistake |
| 987 | to inspect the instructions. */ |
| 988 | |
| 989 | if (!func_start) |
| 990 | return 0; |
| 991 | |
| 992 | function_frame_info (func_start, &fdata); |
| 993 | return pcsaved ? fdata.nosavedpc : fdata.frameless; |
| 994 | } |
| 995 | |
| 996 | |
| 997 | /* If saved registers of frame FI are not known yet, read and cache them. |
| 998 | &FDATAP contains aix_framedata; TDATAP can be NULL, |
| 999 | in which case the framedata are read. */ |
| 1000 | |
| 1001 | static void |
| 1002 | frame_get_cache_fsr (fi, fdatap) |
| 1003 | struct frame_info *fi; |
| 1004 | struct aix_framedata *fdatap; |
| 1005 | { |
| 1006 | int ii; |
| 1007 | CORE_ADDR frame_addr; |
| 1008 | struct aix_framedata work_fdata; |
| 1009 | |
| 1010 | if (fi->cache_fsr) |
| 1011 | return; |
| 1012 | |
| 1013 | if (fdatap == NULL) { |
| 1014 | fdatap = &work_fdata; |
| 1015 | function_frame_info (get_pc_function_start (fi->pc), fdatap); |
| 1016 | } |
| 1017 | |
| 1018 | fi->cache_fsr = (struct frame_saved_regs *) |
| 1019 | obstack_alloc (&frame_cache_obstack, sizeof (struct frame_saved_regs)); |
| 1020 | memset (fi->cache_fsr, '\0', sizeof (struct frame_saved_regs)); |
| 1021 | |
| 1022 | if (fi->prev && fi->prev->frame) |
| 1023 | frame_addr = fi->prev->frame; |
| 1024 | else |
| 1025 | frame_addr = read_memory_integer (fi->frame, 4); |
| 1026 | |
| 1027 | /* if != -1, fdatap->saved_fpr is the smallest number of saved_fpr. |
| 1028 | All fpr's from saved_fpr to fp31 are saved right underneath caller |
| 1029 | stack pointer, starting from fp31 first. */ |
| 1030 | |
| 1031 | if (fdatap->saved_fpr >= 0) { |
| 1032 | for (ii=31; ii >= fdatap->saved_fpr; --ii) |
| 1033 | fi->cache_fsr->regs [FP0_REGNUM + ii] = frame_addr - ((32 - ii) * 8); |
| 1034 | frame_addr -= (32 - fdatap->saved_fpr) * 8; |
| 1035 | } |
| 1036 | |
| 1037 | /* if != -1, fdatap->saved_gpr is the smallest number of saved_gpr. |
| 1038 | All gpr's from saved_gpr to gpr31 are saved right under saved fprs, |
| 1039 | starting from r31 first. */ |
| 1040 | |
| 1041 | if (fdatap->saved_gpr >= 0) |
| 1042 | for (ii=31; ii >= fdatap->saved_gpr; --ii) |
| 1043 | fi->cache_fsr->regs [ii] = frame_addr - ((32 - ii) * 4); |
| 1044 | } |
| 1045 | |
| 1046 | /* Return the address of a frame. This is the inital %sp value when the frame |
| 1047 | was first allocated. For functions calling alloca(), it might be saved in |
| 1048 | an alloca register. */ |
| 1049 | |
| 1050 | CORE_ADDR |
| 1051 | frame_initial_stack_address (fi) |
| 1052 | struct frame_info *fi; |
| 1053 | { |
| 1054 | CORE_ADDR tmpaddr; |
| 1055 | struct aix_framedata fdata; |
| 1056 | struct frame_info *callee_fi; |
| 1057 | |
| 1058 | /* if the initial stack pointer (frame address) of this frame is known, |
| 1059 | just return it. */ |
| 1060 | |
| 1061 | if (fi->initial_sp) |
| 1062 | return fi->initial_sp; |
| 1063 | |
| 1064 | /* find out if this function is using an alloca register.. */ |
| 1065 | |
| 1066 | function_frame_info (get_pc_function_start (fi->pc), &fdata); |
| 1067 | |
| 1068 | /* if saved registers of this frame are not known yet, read and cache them. */ |
| 1069 | |
| 1070 | if (!fi->cache_fsr) |
| 1071 | frame_get_cache_fsr (fi, &fdata); |
| 1072 | |
| 1073 | /* If no alloca register used, then fi->frame is the value of the %sp for |
| 1074 | this frame, and it is good enough. */ |
| 1075 | |
| 1076 | if (fdata.alloca_reg < 0) { |
| 1077 | fi->initial_sp = fi->frame; |
| 1078 | return fi->initial_sp; |
| 1079 | } |
| 1080 | |
| 1081 | /* This function has an alloca register. If this is the top-most frame |
| 1082 | (with the lowest address), the value in alloca register is good. */ |
| 1083 | |
| 1084 | if (!fi->next) |
| 1085 | return fi->initial_sp = read_register (fdata.alloca_reg); |
| 1086 | |
| 1087 | /* Otherwise, this is a caller frame. Callee has usually already saved |
| 1088 | registers, but there are exceptions (such as when the callee |
| 1089 | has no parameters). Find the address in which caller's alloca |
| 1090 | register is saved. */ |
| 1091 | |
| 1092 | for (callee_fi = fi->next; callee_fi; callee_fi = callee_fi->next) { |
| 1093 | |
| 1094 | if (!callee_fi->cache_fsr) |
| 1095 | frame_get_cache_fsr (callee_fi, NULL); |
| 1096 | |
| 1097 | /* this is the address in which alloca register is saved. */ |
| 1098 | |
| 1099 | tmpaddr = callee_fi->cache_fsr->regs [fdata.alloca_reg]; |
| 1100 | if (tmpaddr) { |
| 1101 | fi->initial_sp = read_memory_integer (tmpaddr, 4); |
| 1102 | return fi->initial_sp; |
| 1103 | } |
| 1104 | |
| 1105 | /* Go look into deeper levels of the frame chain to see if any one of |
| 1106 | the callees has saved alloca register. */ |
| 1107 | } |
| 1108 | |
| 1109 | /* If alloca register was not saved, by the callee (or any of its callees) |
| 1110 | then the value in the register is still good. */ |
| 1111 | |
| 1112 | return fi->initial_sp = read_register (fdata.alloca_reg); |
| 1113 | } |
| 1114 | |
| 1115 | CORE_ADDR |
| 1116 | rs6000_frame_chain (thisframe) |
| 1117 | struct frame_info *thisframe; |
| 1118 | { |
| 1119 | CORE_ADDR fp; |
| 1120 | if (inside_entry_file ((thisframe)->pc)) |
| 1121 | return 0; |
| 1122 | if (thisframe->signal_handler_caller) |
| 1123 | fp = read_memory_integer (thisframe->frame + SIG_FRAME_FP_OFFSET, 4); |
| 1124 | else |
| 1125 | fp = read_memory_integer ((thisframe)->frame, 4); |
| 1126 | |
| 1127 | return fp; |
| 1128 | } |
| 1129 | \f |
| 1130 | /* Keep an array of load segment information and their TOC table addresses. |
| 1131 | This info will be useful when calling a shared library function by hand. */ |
| 1132 | |
| 1133 | struct loadinfo { |
| 1134 | CORE_ADDR textorg, dataorg; |
| 1135 | unsigned long toc_offset; |
| 1136 | }; |
| 1137 | |
| 1138 | #define LOADINFOLEN 10 |
| 1139 | |
| 1140 | static struct loadinfo *loadinfo = NULL; |
| 1141 | static int loadinfolen = 0; |
| 1142 | static int loadinfotocindex = 0; |
| 1143 | static int loadinfotextindex = 0; |
| 1144 | |
| 1145 | |
| 1146 | void |
| 1147 | xcoff_init_loadinfo () |
| 1148 | { |
| 1149 | loadinfotocindex = 0; |
| 1150 | loadinfotextindex = 0; |
| 1151 | |
| 1152 | if (loadinfolen == 0) { |
| 1153 | loadinfo = (struct loadinfo *) |
| 1154 | xmalloc (sizeof (struct loadinfo) * LOADINFOLEN); |
| 1155 | loadinfolen = LOADINFOLEN; |
| 1156 | } |
| 1157 | } |
| 1158 | |
| 1159 | |
| 1160 | /* FIXME -- this is never called! */ |
| 1161 | void |
| 1162 | free_loadinfo () |
| 1163 | { |
| 1164 | if (loadinfo) |
| 1165 | free (loadinfo); |
| 1166 | loadinfo = NULL; |
| 1167 | loadinfolen = 0; |
| 1168 | loadinfotocindex = 0; |
| 1169 | loadinfotextindex = 0; |
| 1170 | } |
| 1171 | |
| 1172 | /* this is called from xcoffread.c */ |
| 1173 | |
| 1174 | void |
| 1175 | xcoff_add_toc_to_loadinfo (unsigned long tocoff) |
| 1176 | { |
| 1177 | while (loadinfotocindex >= loadinfolen) { |
| 1178 | loadinfolen += LOADINFOLEN; |
| 1179 | loadinfo = (struct loadinfo *) |
| 1180 | xrealloc (loadinfo, sizeof(struct loadinfo) * loadinfolen); |
| 1181 | } |
| 1182 | loadinfo [loadinfotocindex++].toc_offset = tocoff; |
| 1183 | } |
| 1184 | |
| 1185 | void |
| 1186 | add_text_to_loadinfo (textaddr, dataaddr) |
| 1187 | CORE_ADDR textaddr; |
| 1188 | CORE_ADDR dataaddr; |
| 1189 | { |
| 1190 | while (loadinfotextindex >= loadinfolen) { |
| 1191 | loadinfolen += LOADINFOLEN; |
| 1192 | loadinfo = (struct loadinfo *) |
| 1193 | xrealloc (loadinfo, sizeof(struct loadinfo) * loadinfolen); |
| 1194 | } |
| 1195 | loadinfo [loadinfotextindex].textorg = textaddr; |
| 1196 | loadinfo [loadinfotextindex].dataorg = dataaddr; |
| 1197 | ++loadinfotextindex; |
| 1198 | } |
| 1199 | |
| 1200 | |
| 1201 | /* FIXME: This assumes that the "textorg" and "dataorg" elements |
| 1202 | of a member of this array are correlated with the "toc_offset" |
| 1203 | element of the same member. But they are sequentially assigned in wildly |
| 1204 | different places, and probably there is no correlation. FIXME! */ |
| 1205 | |
| 1206 | static CORE_ADDR |
| 1207 | find_toc_address (pc) |
| 1208 | CORE_ADDR pc; |
| 1209 | { |
| 1210 | int ii, toc_entry, tocbase = 0; |
| 1211 | |
| 1212 | for (ii=0; ii < loadinfotextindex; ++ii) |
| 1213 | if (pc > loadinfo[ii].textorg && loadinfo[ii].textorg > tocbase) { |
| 1214 | toc_entry = ii; |
| 1215 | tocbase = loadinfo[ii].textorg; |
| 1216 | } |
| 1217 | |
| 1218 | return loadinfo[toc_entry].dataorg + loadinfo[toc_entry].toc_offset; |
| 1219 | } |
| 1220 | |
| 1221 | void |
| 1222 | _initialize_rs6000_tdep () |
| 1223 | { |
| 1224 | /* FIXME, this should not be decided via ifdef. */ |
| 1225 | #ifdef GDB_TARGET_POWERPC |
| 1226 | tm_print_insn = print_insn_big_powerpc; |
| 1227 | #else |
| 1228 | tm_print_insn = print_insn_rs6000; |
| 1229 | #endif |
| 1230 | } |