| 1 | /* Machine-dependent code which would otherwise be in inflow.c and core.c, |
| 2 | for GDB, the GNU debugger. This code is for the HP PA-RISC cpu. |
| 3 | Copyright 1986, 1987, 1989, 1990, 1991, 1992, 1993 Free Software Foundation, Inc. |
| 4 | |
| 5 | Contributed by the Center for Software Science at the |
| 6 | University of Utah (pa-gdb-bugs@cs.utah.edu). |
| 7 | |
| 8 | This file is part of GDB. |
| 9 | |
| 10 | This program is free software; you can redistribute it and/or modify |
| 11 | it under the terms of the GNU General Public License as published by |
| 12 | the Free Software Foundation; either version 2 of the License, or |
| 13 | (at your option) any later version. |
| 14 | |
| 15 | This program is distributed in the hope that it will be useful, |
| 16 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 18 | GNU General Public License for more details. |
| 19 | |
| 20 | You should have received a copy of the GNU General Public License |
| 21 | along with this program; if not, write to the Free Software |
| 22 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| 23 | |
| 24 | #include "defs.h" |
| 25 | #include "frame.h" |
| 26 | #include "inferior.h" |
| 27 | #include "value.h" |
| 28 | |
| 29 | /* For argument passing to the inferior */ |
| 30 | #include "symtab.h" |
| 31 | |
| 32 | #ifdef USG |
| 33 | #include <sys/types.h> |
| 34 | #endif |
| 35 | |
| 36 | #include <sys/param.h> |
| 37 | #include <sys/dir.h> |
| 38 | #include <signal.h> |
| 39 | #include <sys/ioctl.h> |
| 40 | |
| 41 | #ifdef COFF_ENCAPSULATE |
| 42 | #include "a.out.encap.h" |
| 43 | #else |
| 44 | #include <a.out.h> |
| 45 | #endif |
| 46 | #ifndef N_SET_MAGIC |
| 47 | #define N_SET_MAGIC(exec, val) ((exec).a_magic = (val)) |
| 48 | #endif |
| 49 | |
| 50 | /*#include <sys/user.h> After a.out.h */ |
| 51 | #include <sys/file.h> |
| 52 | #include <sys/stat.h> |
| 53 | #include <machine/psl.h> |
| 54 | #include "wait.h" |
| 55 | |
| 56 | #include "gdbcore.h" |
| 57 | #include "gdbcmd.h" |
| 58 | #include "target.h" |
| 59 | #include "symfile.h" |
| 60 | #include "objfiles.h" |
| 61 | |
| 62 | static int restore_pc_queue PARAMS ((struct frame_saved_regs *fsr)); |
| 63 | static int hppa_alignof PARAMS ((struct type *arg)); |
| 64 | CORE_ADDR frame_saved_pc PARAMS ((FRAME frame)); |
| 65 | static int prologue_inst_adjust_sp PARAMS ((unsigned long)); |
| 66 | static int is_branch PARAMS ((unsigned long)); |
| 67 | static int inst_saves_gr PARAMS ((unsigned long)); |
| 68 | static int inst_saves_fr PARAMS ((unsigned long)); |
| 69 | |
| 70 | \f |
| 71 | /* Routines to extract various sized constants out of hppa |
| 72 | instructions. */ |
| 73 | |
| 74 | /* This assumes that no garbage lies outside of the lower bits of |
| 75 | value. */ |
| 76 | |
| 77 | int |
| 78 | sign_extend (val, bits) |
| 79 | unsigned val, bits; |
| 80 | { |
| 81 | return (int)(val >> bits - 1 ? (-1 << bits) | val : val); |
| 82 | } |
| 83 | |
| 84 | /* For many immediate values the sign bit is the low bit! */ |
| 85 | |
| 86 | int |
| 87 | low_sign_extend (val, bits) |
| 88 | unsigned val, bits; |
| 89 | { |
| 90 | return (int)((val & 0x1 ? (-1 << (bits - 1)) : 0) | val >> 1); |
| 91 | } |
| 92 | /* extract the immediate field from a ld{bhw}s instruction */ |
| 93 | |
| 94 | unsigned |
| 95 | get_field (val, from, to) |
| 96 | unsigned val, from, to; |
| 97 | { |
| 98 | val = val >> 31 - to; |
| 99 | return val & ((1 << 32 - from) - 1); |
| 100 | } |
| 101 | |
| 102 | unsigned |
| 103 | set_field (val, from, to, new_val) |
| 104 | unsigned *val, from, to; |
| 105 | { |
| 106 | unsigned mask = ~((1 << (to - from + 1)) << (31 - from)); |
| 107 | return *val = *val & mask | (new_val << (31 - from)); |
| 108 | } |
| 109 | |
| 110 | /* extract a 3-bit space register number from a be, ble, mtsp or mfsp */ |
| 111 | |
| 112 | extract_3 (word) |
| 113 | unsigned word; |
| 114 | { |
| 115 | return GET_FIELD (word, 18, 18) << 2 | GET_FIELD (word, 16, 17); |
| 116 | } |
| 117 | |
| 118 | extract_5_load (word) |
| 119 | unsigned word; |
| 120 | { |
| 121 | return low_sign_extend (word >> 16 & MASK_5, 5); |
| 122 | } |
| 123 | |
| 124 | /* extract the immediate field from a st{bhw}s instruction */ |
| 125 | |
| 126 | int |
| 127 | extract_5_store (word) |
| 128 | unsigned word; |
| 129 | { |
| 130 | return low_sign_extend (word & MASK_5, 5); |
| 131 | } |
| 132 | |
| 133 | /* extract the immediate field from a break instruction */ |
| 134 | |
| 135 | unsigned |
| 136 | extract_5r_store (word) |
| 137 | unsigned word; |
| 138 | { |
| 139 | return (word & MASK_5); |
| 140 | } |
| 141 | |
| 142 | /* extract the immediate field from a {sr}sm instruction */ |
| 143 | |
| 144 | unsigned |
| 145 | extract_5R_store (word) |
| 146 | unsigned word; |
| 147 | { |
| 148 | return (word >> 16 & MASK_5); |
| 149 | } |
| 150 | |
| 151 | /* extract an 11 bit immediate field */ |
| 152 | |
| 153 | int |
| 154 | extract_11 (word) |
| 155 | unsigned word; |
| 156 | { |
| 157 | return low_sign_extend (word & MASK_11, 11); |
| 158 | } |
| 159 | |
| 160 | /* extract a 14 bit immediate field */ |
| 161 | |
| 162 | int |
| 163 | extract_14 (word) |
| 164 | unsigned word; |
| 165 | { |
| 166 | return low_sign_extend (word & MASK_14, 14); |
| 167 | } |
| 168 | |
| 169 | /* deposit a 14 bit constant in a word */ |
| 170 | |
| 171 | unsigned |
| 172 | deposit_14 (opnd, word) |
| 173 | int opnd; |
| 174 | unsigned word; |
| 175 | { |
| 176 | unsigned sign = (opnd < 0 ? 1 : 0); |
| 177 | |
| 178 | return word | ((unsigned)opnd << 1 & MASK_14) | sign; |
| 179 | } |
| 180 | |
| 181 | /* extract a 21 bit constant */ |
| 182 | |
| 183 | int |
| 184 | extract_21 (word) |
| 185 | unsigned word; |
| 186 | { |
| 187 | int val; |
| 188 | |
| 189 | word &= MASK_21; |
| 190 | word <<= 11; |
| 191 | val = GET_FIELD (word, 20, 20); |
| 192 | val <<= 11; |
| 193 | val |= GET_FIELD (word, 9, 19); |
| 194 | val <<= 2; |
| 195 | val |= GET_FIELD (word, 5, 6); |
| 196 | val <<= 5; |
| 197 | val |= GET_FIELD (word, 0, 4); |
| 198 | val <<= 2; |
| 199 | val |= GET_FIELD (word, 7, 8); |
| 200 | return sign_extend (val, 21) << 11; |
| 201 | } |
| 202 | |
| 203 | /* deposit a 21 bit constant in a word. Although 21 bit constants are |
| 204 | usually the top 21 bits of a 32 bit constant, we assume that only |
| 205 | the low 21 bits of opnd are relevant */ |
| 206 | |
| 207 | unsigned |
| 208 | deposit_21 (opnd, word) |
| 209 | unsigned opnd, word; |
| 210 | { |
| 211 | unsigned val = 0; |
| 212 | |
| 213 | val |= GET_FIELD (opnd, 11 + 14, 11 + 18); |
| 214 | val <<= 2; |
| 215 | val |= GET_FIELD (opnd, 11 + 12, 11 + 13); |
| 216 | val <<= 2; |
| 217 | val |= GET_FIELD (opnd, 11 + 19, 11 + 20); |
| 218 | val <<= 11; |
| 219 | val |= GET_FIELD (opnd, 11 + 1, 11 + 11); |
| 220 | val <<= 1; |
| 221 | val |= GET_FIELD (opnd, 11 + 0, 11 + 0); |
| 222 | return word | val; |
| 223 | } |
| 224 | |
| 225 | /* extract a 12 bit constant from branch instructions */ |
| 226 | |
| 227 | int |
| 228 | extract_12 (word) |
| 229 | unsigned word; |
| 230 | { |
| 231 | return sign_extend (GET_FIELD (word, 19, 28) | |
| 232 | GET_FIELD (word, 29, 29) << 10 | |
| 233 | (word & 0x1) << 11, 12) << 2; |
| 234 | } |
| 235 | |
| 236 | /* extract a 17 bit constant from branch instructions, returning the |
| 237 | 19 bit signed value. */ |
| 238 | |
| 239 | int |
| 240 | extract_17 (word) |
| 241 | unsigned word; |
| 242 | { |
| 243 | return sign_extend (GET_FIELD (word, 19, 28) | |
| 244 | GET_FIELD (word, 29, 29) << 10 | |
| 245 | GET_FIELD (word, 11, 15) << 11 | |
| 246 | (word & 0x1) << 16, 17) << 2; |
| 247 | } |
| 248 | \f |
| 249 | /* Lookup the unwind (stack backtrace) info for the given PC. We search all |
| 250 | of the objfiles seeking the unwind table entry for this PC. Each objfile |
| 251 | contains a sorted list of struct unwind_table_entry. Since we do a binary |
| 252 | search of the unwind tables, we depend upon them to be sorted. */ |
| 253 | |
| 254 | static struct unwind_table_entry * |
| 255 | find_unwind_entry(pc) |
| 256 | CORE_ADDR pc; |
| 257 | { |
| 258 | int first, middle, last; |
| 259 | struct objfile *objfile; |
| 260 | |
| 261 | ALL_OBJFILES (objfile) |
| 262 | { |
| 263 | struct obj_unwind_info *ui; |
| 264 | |
| 265 | ui = OBJ_UNWIND_INFO (objfile); |
| 266 | |
| 267 | if (!ui) |
| 268 | continue; |
| 269 | |
| 270 | /* First, check the cache */ |
| 271 | |
| 272 | if (ui->cache |
| 273 | && pc >= ui->cache->region_start |
| 274 | && pc <= ui->cache->region_end) |
| 275 | return ui->cache; |
| 276 | |
| 277 | /* Not in the cache, do a binary search */ |
| 278 | |
| 279 | first = 0; |
| 280 | last = ui->last; |
| 281 | |
| 282 | while (first <= last) |
| 283 | { |
| 284 | middle = (first + last) / 2; |
| 285 | if (pc >= ui->table[middle].region_start |
| 286 | && pc <= ui->table[middle].region_end) |
| 287 | { |
| 288 | ui->cache = &ui->table[middle]; |
| 289 | return &ui->table[middle]; |
| 290 | } |
| 291 | |
| 292 | if (pc < ui->table[middle].region_start) |
| 293 | last = middle - 1; |
| 294 | else |
| 295 | first = middle + 1; |
| 296 | } |
| 297 | } /* ALL_OBJFILES() */ |
| 298 | return NULL; |
| 299 | } |
| 300 | |
| 301 | /* Called when no unwind descriptor was found for PC. Returns 1 if it |
| 302 | appears that PC is in a linker stub. */ |
| 303 | static int pc_in_linker_stub PARAMS ((CORE_ADDR)); |
| 304 | |
| 305 | static int |
| 306 | pc_in_linker_stub (pc) |
| 307 | CORE_ADDR pc; |
| 308 | { |
| 309 | int found_magic_instruction = 0; |
| 310 | int i; |
| 311 | char buf[4]; |
| 312 | |
| 313 | /* If unable to read memory, assume pc is not in a linker stub. */ |
| 314 | if (target_read_memory (pc, buf, 4) != 0) |
| 315 | return 0; |
| 316 | |
| 317 | /* We are looking for something like |
| 318 | |
| 319 | ; $$dyncall jams RP into this special spot in the frame (RP') |
| 320 | ; before calling the "call stub" |
| 321 | ldw -18(sp),rp |
| 322 | |
| 323 | ldsid (rp),r1 ; Get space associated with RP into r1 |
| 324 | mtsp r1,sp ; Move it into space register 0 |
| 325 | be,n 0(sr0),rp) ; back to your regularly scheduled program |
| 326 | */ |
| 327 | |
| 328 | /* Maximum known linker stub size is 4 instructions. Search forward |
| 329 | from the given PC, then backward. */ |
| 330 | for (i = 0; i < 4; i++) |
| 331 | { |
| 332 | /* If we hit something with an unwind, stop searching this direction. */ |
| 333 | |
| 334 | if (find_unwind_entry (pc + i * 4) != 0) |
| 335 | break; |
| 336 | |
| 337 | /* Check for ldsid (rp),r1 which is the magic instruction for a |
| 338 | return from a cross-space function call. */ |
| 339 | if (read_memory_integer (pc + i * 4, 4) == 0x004010a1) |
| 340 | { |
| 341 | found_magic_instruction = 1; |
| 342 | break; |
| 343 | } |
| 344 | /* Add code to handle long call/branch and argument relocation stubs |
| 345 | here. */ |
| 346 | } |
| 347 | |
| 348 | if (found_magic_instruction != 0) |
| 349 | return 1; |
| 350 | |
| 351 | /* Now look backward. */ |
| 352 | for (i = 0; i < 4; i++) |
| 353 | { |
| 354 | /* If we hit something with an unwind, stop searching this direction. */ |
| 355 | |
| 356 | if (find_unwind_entry (pc - i * 4) != 0) |
| 357 | break; |
| 358 | |
| 359 | /* Check for ldsid (rp),r1 which is the magic instruction for a |
| 360 | return from a cross-space function call. */ |
| 361 | if (read_memory_integer (pc - i * 4, 4) == 0x004010a1) |
| 362 | { |
| 363 | found_magic_instruction = 1; |
| 364 | break; |
| 365 | } |
| 366 | /* Add code to handle long call/branch and argument relocation stubs |
| 367 | here. */ |
| 368 | } |
| 369 | return found_magic_instruction; |
| 370 | } |
| 371 | |
| 372 | static int |
| 373 | find_return_regnum(pc) |
| 374 | CORE_ADDR pc; |
| 375 | { |
| 376 | struct unwind_table_entry *u; |
| 377 | |
| 378 | u = find_unwind_entry (pc); |
| 379 | |
| 380 | if (!u) |
| 381 | return RP_REGNUM; |
| 382 | |
| 383 | if (u->Millicode) |
| 384 | return 31; |
| 385 | |
| 386 | return RP_REGNUM; |
| 387 | } |
| 388 | |
| 389 | /* Return size of frame, or -1 if we should use a frame pointer. */ |
| 390 | int |
| 391 | find_proc_framesize(pc) |
| 392 | CORE_ADDR pc; |
| 393 | { |
| 394 | struct unwind_table_entry *u; |
| 395 | |
| 396 | u = find_unwind_entry (pc); |
| 397 | |
| 398 | if (!u) |
| 399 | { |
| 400 | if (pc_in_linker_stub (pc)) |
| 401 | /* Linker stubs have a zero size frame. */ |
| 402 | return 0; |
| 403 | else |
| 404 | return -1; |
| 405 | } |
| 406 | |
| 407 | if (u->Save_SP) |
| 408 | /* If this bit is set, it means there is a frame pointer and we should |
| 409 | use it. */ |
| 410 | return -1; |
| 411 | |
| 412 | return u->Total_frame_size << 3; |
| 413 | } |
| 414 | |
| 415 | /* Return offset from sp at which rp is saved, or 0 if not saved. */ |
| 416 | static int rp_saved PARAMS ((CORE_ADDR)); |
| 417 | |
| 418 | static int |
| 419 | rp_saved (pc) |
| 420 | CORE_ADDR pc; |
| 421 | { |
| 422 | struct unwind_table_entry *u; |
| 423 | |
| 424 | u = find_unwind_entry (pc); |
| 425 | |
| 426 | if (!u) |
| 427 | { |
| 428 | if (pc_in_linker_stub (pc)) |
| 429 | /* This is the so-called RP'. */ |
| 430 | return -24; |
| 431 | else |
| 432 | return 0; |
| 433 | } |
| 434 | |
| 435 | if (u->Save_RP) |
| 436 | return -20; |
| 437 | else if (u->stub_type != 0) |
| 438 | { |
| 439 | switch (u->stub_type) |
| 440 | { |
| 441 | case EXPORT: |
| 442 | return -24; |
| 443 | case PARAMETER_RELOCATION: |
| 444 | return -8; |
| 445 | default: |
| 446 | return 0; |
| 447 | } |
| 448 | } |
| 449 | else |
| 450 | return 0; |
| 451 | } |
| 452 | \f |
| 453 | int |
| 454 | frameless_function_invocation (frame) |
| 455 | FRAME frame; |
| 456 | { |
| 457 | struct unwind_table_entry *u; |
| 458 | |
| 459 | u = find_unwind_entry (frame->pc); |
| 460 | |
| 461 | if (u == 0) |
| 462 | return frameless_look_for_prologue (frame); |
| 463 | |
| 464 | return (u->Total_frame_size == 0 && u->stub_type == 0); |
| 465 | } |
| 466 | |
| 467 | CORE_ADDR |
| 468 | saved_pc_after_call (frame) |
| 469 | FRAME frame; |
| 470 | { |
| 471 | int ret_regnum; |
| 472 | |
| 473 | ret_regnum = find_return_regnum (get_frame_pc (frame)); |
| 474 | |
| 475 | return read_register (ret_regnum) & ~0x3; |
| 476 | } |
| 477 | \f |
| 478 | CORE_ADDR |
| 479 | frame_saved_pc (frame) |
| 480 | FRAME frame; |
| 481 | { |
| 482 | CORE_ADDR pc = get_frame_pc (frame); |
| 483 | |
| 484 | if (frameless_function_invocation (frame)) |
| 485 | { |
| 486 | int ret_regnum; |
| 487 | |
| 488 | ret_regnum = find_return_regnum (pc); |
| 489 | |
| 490 | return read_register (ret_regnum) & ~0x3; |
| 491 | } |
| 492 | else |
| 493 | { |
| 494 | int rp_offset = rp_saved (pc); |
| 495 | |
| 496 | if (rp_offset == 0) |
| 497 | return read_register (RP_REGNUM) & ~0x3; |
| 498 | else |
| 499 | return read_memory_integer (frame->frame + rp_offset, 4) & ~0x3; |
| 500 | } |
| 501 | } |
| 502 | \f |
| 503 | /* We need to correct the PC and the FP for the outermost frame when we are |
| 504 | in a system call. */ |
| 505 | |
| 506 | void |
| 507 | init_extra_frame_info (fromleaf, frame) |
| 508 | int fromleaf; |
| 509 | struct frame_info *frame; |
| 510 | { |
| 511 | int flags; |
| 512 | int framesize; |
| 513 | |
| 514 | if (frame->next && !fromleaf) |
| 515 | return; |
| 516 | |
| 517 | /* If the next frame represents a frameless function invocation |
| 518 | then we have to do some adjustments that are normally done by |
| 519 | FRAME_CHAIN. (FRAME_CHAIN is not called in this case.) */ |
| 520 | if (fromleaf) |
| 521 | { |
| 522 | /* Find the framesize of *this* frame without peeking at the PC |
| 523 | in the current frame structure (it isn't set yet). */ |
| 524 | framesize = find_proc_framesize (FRAME_SAVED_PC (get_next_frame (frame))); |
| 525 | |
| 526 | /* Now adjust our base frame accordingly. If we have a frame pointer |
| 527 | use it, else subtract the size of this frame from the current |
| 528 | frame. (we always want frame->frame to point at the lowest address |
| 529 | in the frame). */ |
| 530 | if (framesize == -1) |
| 531 | frame->frame = read_register (FP_REGNUM); |
| 532 | else |
| 533 | frame->frame -= framesize; |
| 534 | return; |
| 535 | } |
| 536 | |
| 537 | flags = read_register (FLAGS_REGNUM); |
| 538 | if (flags & 2) /* In system call? */ |
| 539 | frame->pc = read_register (31) & ~0x3; |
| 540 | |
| 541 | /* The outermost frame is always derived from PC-framesize |
| 542 | |
| 543 | One might think frameless innermost frames should have |
| 544 | a frame->frame that is the same as the parent's frame->frame. |
| 545 | That is wrong; frame->frame in that case should be the *high* |
| 546 | address of the parent's frame. It's complicated as hell to |
| 547 | explain, but the parent *always* creates some stack space for |
| 548 | the child. So the child actually does have a frame of some |
| 549 | sorts, and its base is the high address in its parent's frame. */ |
| 550 | framesize = find_proc_framesize(frame->pc); |
| 551 | if (framesize == -1) |
| 552 | frame->frame = read_register (FP_REGNUM); |
| 553 | else |
| 554 | frame->frame = read_register (SP_REGNUM) - framesize; |
| 555 | } |
| 556 | \f |
| 557 | /* Given a GDB frame, determine the address of the calling function's frame. |
| 558 | This will be used to create a new GDB frame struct, and then |
| 559 | INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame. |
| 560 | |
| 561 | This may involve searching through prologues for several functions |
| 562 | at boundaries where GCC calls HP C code, or where code which has |
| 563 | a frame pointer calls code without a frame pointer. */ |
| 564 | |
| 565 | |
| 566 | FRAME_ADDR |
| 567 | frame_chain (frame) |
| 568 | struct frame_info *frame; |
| 569 | { |
| 570 | int my_framesize, caller_framesize; |
| 571 | struct unwind_table_entry *u; |
| 572 | |
| 573 | /* Get frame sizes for the current frame and the frame of the |
| 574 | caller. */ |
| 575 | my_framesize = find_proc_framesize (frame->pc); |
| 576 | caller_framesize = find_proc_framesize (FRAME_SAVED_PC(frame)); |
| 577 | |
| 578 | /* If caller does not have a frame pointer, then its frame |
| 579 | can be found at current_frame - caller_framesize. */ |
| 580 | if (caller_framesize != -1) |
| 581 | return frame->frame - caller_framesize; |
| 582 | |
| 583 | /* Both caller and callee have frame pointers and are GCC compiled |
| 584 | (SAVE_SP bit in unwind descriptor is on for both functions. |
| 585 | The previous frame pointer is found at the top of the current frame. */ |
| 586 | if (caller_framesize == -1 && my_framesize == -1) |
| 587 | return read_memory_integer (frame->frame, 4); |
| 588 | |
| 589 | /* Caller has a frame pointer, but callee does not. This is a little |
| 590 | more difficult as GCC and HP C lay out locals and callee register save |
| 591 | areas very differently. |
| 592 | |
| 593 | The previous frame pointer could be in a register, or in one of |
| 594 | several areas on the stack. |
| 595 | |
| 596 | Walk from the current frame to the innermost frame examining |
| 597 | unwind descriptors to determine if %r3 ever gets saved into the |
| 598 | stack. If so return whatever value got saved into the stack. |
| 599 | If it was never saved in the stack, then the value in %r3 is still |
| 600 | valid, so use it. |
| 601 | |
| 602 | We use information from unwind descriptors to determine if %r3 |
| 603 | is saved into the stack (Entry_GR field has this information). */ |
| 604 | |
| 605 | while (frame) |
| 606 | { |
| 607 | u = find_unwind_entry (frame->pc); |
| 608 | |
| 609 | if (!u) |
| 610 | { |
| 611 | /* We could find this information by examining prologues. I don't |
| 612 | think anyone has actually written any tools (not even "strip") |
| 613 | which leave them out of an executable, so maybe this is a moot |
| 614 | point. */ |
| 615 | warning ("Unable to find unwind for PC 0x%x -- Help!", frame->pc); |
| 616 | return 0; |
| 617 | } |
| 618 | |
| 619 | /* Entry_GR specifies the number of callee-saved general registers |
| 620 | saved in the stack. It starts at %r3, so %r3 would be 1. */ |
| 621 | if (u->Entry_GR >= 1 || u->Save_SP) |
| 622 | break; |
| 623 | else |
| 624 | frame = frame->next; |
| 625 | } |
| 626 | |
| 627 | if (frame) |
| 628 | { |
| 629 | /* We may have walked down the chain into a function with a frame |
| 630 | pointer. */ |
| 631 | if (u->Save_SP) |
| 632 | return read_memory_integer (frame->frame, 4); |
| 633 | /* %r3 was saved somewhere in the stack. Dig it out. */ |
| 634 | else |
| 635 | { |
| 636 | struct frame_info *fi; |
| 637 | struct frame_saved_regs saved_regs; |
| 638 | |
| 639 | fi = get_frame_info (frame); |
| 640 | get_frame_saved_regs (fi, &saved_regs); |
| 641 | return read_memory_integer (saved_regs.regs[FP_REGNUM], 4); |
| 642 | } |
| 643 | } |
| 644 | else |
| 645 | { |
| 646 | /* The value in %r3 was never saved into the stack (thus %r3 still |
| 647 | holds the value of the previous frame pointer). */ |
| 648 | return read_register (FP_REGNUM); |
| 649 | } |
| 650 | } |
| 651 | |
| 652 | \f |
| 653 | /* To see if a frame chain is valid, see if the caller looks like it |
| 654 | was compiled with gcc. */ |
| 655 | |
| 656 | int |
| 657 | frame_chain_valid (chain, thisframe) |
| 658 | FRAME_ADDR chain; |
| 659 | FRAME thisframe; |
| 660 | { |
| 661 | struct minimal_symbol *msym_us; |
| 662 | struct minimal_symbol *msym_start; |
| 663 | struct unwind_table_entry *u; |
| 664 | |
| 665 | if (!chain) |
| 666 | return 0; |
| 667 | |
| 668 | u = find_unwind_entry (thisframe->pc); |
| 669 | |
| 670 | /* We can't just check that the same of msym_us is "_start", because |
| 671 | someone idiotically decided that they were going to make a Ltext_end |
| 672 | symbol with the same address. This Ltext_end symbol is totally |
| 673 | indistinguishable (as nearly as I can tell) from the symbol for a function |
| 674 | which is (legitimately, since it is in the user's namespace) |
| 675 | named Ltext_end, so we can't just ignore it. */ |
| 676 | msym_us = lookup_minimal_symbol_by_pc (FRAME_SAVED_PC (thisframe)); |
| 677 | msym_start = lookup_minimal_symbol ("_start", NULL); |
| 678 | if (msym_us |
| 679 | && msym_start |
| 680 | && SYMBOL_VALUE_ADDRESS (msym_us) == SYMBOL_VALUE_ADDRESS (msym_start)) |
| 681 | return 0; |
| 682 | |
| 683 | if (u == NULL) |
| 684 | return 1; |
| 685 | |
| 686 | if (u->Save_SP || u->Total_frame_size || u->stub_type != 0) |
| 687 | return 1; |
| 688 | |
| 689 | if (pc_in_linker_stub (thisframe->pc)) |
| 690 | return 1; |
| 691 | |
| 692 | return 0; |
| 693 | } |
| 694 | |
| 695 | /* |
| 696 | * These functions deal with saving and restoring register state |
| 697 | * around a function call in the inferior. They keep the stack |
| 698 | * double-word aligned; eventually, on an hp700, the stack will have |
| 699 | * to be aligned to a 64-byte boundary. |
| 700 | */ |
| 701 | |
| 702 | int |
| 703 | push_dummy_frame () |
| 704 | { |
| 705 | register CORE_ADDR sp; |
| 706 | register int regnum; |
| 707 | int int_buffer; |
| 708 | double freg_buffer; |
| 709 | |
| 710 | /* Space for "arguments"; the RP goes in here. */ |
| 711 | sp = read_register (SP_REGNUM) + 48; |
| 712 | int_buffer = read_register (RP_REGNUM) | 0x3; |
| 713 | write_memory (sp - 20, (char *)&int_buffer, 4); |
| 714 | |
| 715 | int_buffer = read_register (FP_REGNUM); |
| 716 | write_memory (sp, (char *)&int_buffer, 4); |
| 717 | |
| 718 | write_register (FP_REGNUM, sp); |
| 719 | |
| 720 | sp += 8; |
| 721 | |
| 722 | for (regnum = 1; regnum < 32; regnum++) |
| 723 | if (regnum != RP_REGNUM && regnum != FP_REGNUM) |
| 724 | sp = push_word (sp, read_register (regnum)); |
| 725 | |
| 726 | sp += 4; |
| 727 | |
| 728 | for (regnum = FP0_REGNUM; regnum < NUM_REGS; regnum++) |
| 729 | { |
| 730 | read_register_bytes (REGISTER_BYTE (regnum), (char *)&freg_buffer, 8); |
| 731 | sp = push_bytes (sp, (char *)&freg_buffer, 8); |
| 732 | } |
| 733 | sp = push_word (sp, read_register (IPSW_REGNUM)); |
| 734 | sp = push_word (sp, read_register (SAR_REGNUM)); |
| 735 | sp = push_word (sp, read_register (PCOQ_HEAD_REGNUM)); |
| 736 | sp = push_word (sp, read_register (PCSQ_HEAD_REGNUM)); |
| 737 | sp = push_word (sp, read_register (PCOQ_TAIL_REGNUM)); |
| 738 | sp = push_word (sp, read_register (PCSQ_TAIL_REGNUM)); |
| 739 | write_register (SP_REGNUM, sp); |
| 740 | } |
| 741 | |
| 742 | find_dummy_frame_regs (frame, frame_saved_regs) |
| 743 | struct frame_info *frame; |
| 744 | struct frame_saved_regs *frame_saved_regs; |
| 745 | { |
| 746 | CORE_ADDR fp = frame->frame; |
| 747 | int i; |
| 748 | |
| 749 | frame_saved_regs->regs[RP_REGNUM] = fp - 20 & ~0x3; |
| 750 | frame_saved_regs->regs[FP_REGNUM] = fp; |
| 751 | frame_saved_regs->regs[1] = fp + 8; |
| 752 | |
| 753 | for (fp += 12, i = 3; i < 32; i++) |
| 754 | { |
| 755 | if (i != FP_REGNUM) |
| 756 | { |
| 757 | frame_saved_regs->regs[i] = fp; |
| 758 | fp += 4; |
| 759 | } |
| 760 | } |
| 761 | |
| 762 | fp += 4; |
| 763 | for (i = FP0_REGNUM; i < NUM_REGS; i++, fp += 8) |
| 764 | frame_saved_regs->regs[i] = fp; |
| 765 | |
| 766 | frame_saved_regs->regs[IPSW_REGNUM] = fp; |
| 767 | frame_saved_regs->regs[SAR_REGNUM] = fp + 4; |
| 768 | frame_saved_regs->regs[PCOQ_HEAD_REGNUM] = fp + 8; |
| 769 | frame_saved_regs->regs[PCSQ_HEAD_REGNUM] = fp + 12; |
| 770 | frame_saved_regs->regs[PCOQ_TAIL_REGNUM] = fp + 16; |
| 771 | frame_saved_regs->regs[PCSQ_TAIL_REGNUM] = fp + 20; |
| 772 | } |
| 773 | |
| 774 | int |
| 775 | hppa_pop_frame () |
| 776 | { |
| 777 | register FRAME frame = get_current_frame (); |
| 778 | register CORE_ADDR fp; |
| 779 | register int regnum; |
| 780 | struct frame_saved_regs fsr; |
| 781 | struct frame_info *fi; |
| 782 | double freg_buffer; |
| 783 | |
| 784 | fi = get_frame_info (frame); |
| 785 | fp = fi->frame; |
| 786 | get_frame_saved_regs (fi, &fsr); |
| 787 | |
| 788 | if (fsr.regs[IPSW_REGNUM]) /* Restoring a call dummy frame */ |
| 789 | restore_pc_queue (&fsr); |
| 790 | |
| 791 | for (regnum = 31; regnum > 0; regnum--) |
| 792 | if (fsr.regs[regnum]) |
| 793 | write_register (regnum, read_memory_integer (fsr.regs[regnum], 4)); |
| 794 | |
| 795 | for (regnum = NUM_REGS - 1; regnum >= FP0_REGNUM ; regnum--) |
| 796 | if (fsr.regs[regnum]) |
| 797 | { |
| 798 | read_memory (fsr.regs[regnum], (char *)&freg_buffer, 8); |
| 799 | write_register_bytes (REGISTER_BYTE (regnum), (char *)&freg_buffer, 8); |
| 800 | } |
| 801 | |
| 802 | if (fsr.regs[IPSW_REGNUM]) |
| 803 | write_register (IPSW_REGNUM, |
| 804 | read_memory_integer (fsr.regs[IPSW_REGNUM], 4)); |
| 805 | |
| 806 | if (fsr.regs[SAR_REGNUM]) |
| 807 | write_register (SAR_REGNUM, |
| 808 | read_memory_integer (fsr.regs[SAR_REGNUM], 4)); |
| 809 | |
| 810 | /* If the PC was explicitly saved, then just restore it. */ |
| 811 | if (fsr.regs[PCOQ_TAIL_REGNUM]) |
| 812 | write_register (PCOQ_TAIL_REGNUM, |
| 813 | read_memory_integer (fsr.regs[PCOQ_TAIL_REGNUM], 4)); |
| 814 | |
| 815 | /* Else use the value in %rp to set the new PC. */ |
| 816 | else |
| 817 | target_write_pc (read_register (RP_REGNUM)); |
| 818 | |
| 819 | write_register (FP_REGNUM, read_memory_integer (fp, 4)); |
| 820 | |
| 821 | if (fsr.regs[IPSW_REGNUM]) /* call dummy */ |
| 822 | write_register (SP_REGNUM, fp - 48); |
| 823 | else |
| 824 | write_register (SP_REGNUM, fp); |
| 825 | |
| 826 | flush_cached_frames (); |
| 827 | set_current_frame (create_new_frame (read_register (FP_REGNUM), |
| 828 | read_pc ())); |
| 829 | } |
| 830 | |
| 831 | /* |
| 832 | * After returning to a dummy on the stack, restore the instruction |
| 833 | * queue space registers. */ |
| 834 | |
| 835 | static int |
| 836 | restore_pc_queue (fsr) |
| 837 | struct frame_saved_regs *fsr; |
| 838 | { |
| 839 | CORE_ADDR pc = read_pc (); |
| 840 | CORE_ADDR new_pc = read_memory_integer (fsr->regs[PCOQ_HEAD_REGNUM], 4); |
| 841 | int pid; |
| 842 | struct target_waitstatus w; |
| 843 | int insn_count; |
| 844 | |
| 845 | /* Advance past break instruction in the call dummy. */ |
| 846 | write_register (PCOQ_HEAD_REGNUM, pc + 4); |
| 847 | write_register (PCOQ_TAIL_REGNUM, pc + 8); |
| 848 | |
| 849 | /* |
| 850 | * HPUX doesn't let us set the space registers or the space |
| 851 | * registers of the PC queue through ptrace. Boo, hiss. |
| 852 | * Conveniently, the call dummy has this sequence of instructions |
| 853 | * after the break: |
| 854 | * mtsp r21, sr0 |
| 855 | * ble,n 0(sr0, r22) |
| 856 | * |
| 857 | * So, load up the registers and single step until we are in the |
| 858 | * right place. |
| 859 | */ |
| 860 | |
| 861 | write_register (21, read_memory_integer (fsr->regs[PCSQ_HEAD_REGNUM], 4)); |
| 862 | write_register (22, new_pc); |
| 863 | |
| 864 | for (insn_count = 0; insn_count < 3; insn_count++) |
| 865 | { |
| 866 | /* FIXME: What if the inferior gets a signal right now? Want to |
| 867 | merge this into wait_for_inferior (as a special kind of |
| 868 | watchpoint? By setting a breakpoint at the end? Is there |
| 869 | any other choice? Is there *any* way to do this stuff with |
| 870 | ptrace() or some equivalent?). */ |
| 871 | resume (1, 0); |
| 872 | target_wait (inferior_pid, &w); |
| 873 | |
| 874 | if (w.kind == TARGET_WAITKIND_SIGNALLED) |
| 875 | { |
| 876 | stop_signal = w.value.sig; |
| 877 | terminal_ours_for_output (); |
| 878 | printf_unfiltered ("\nProgram terminated with signal %s, %s.\n", |
| 879 | target_signal_to_name (stop_signal), |
| 880 | target_signal_to_string (stop_signal)); |
| 881 | gdb_flush (gdb_stdout); |
| 882 | return 0; |
| 883 | } |
| 884 | } |
| 885 | target_terminal_ours (); |
| 886 | fetch_inferior_registers (-1); |
| 887 | return 1; |
| 888 | } |
| 889 | |
| 890 | CORE_ADDR |
| 891 | hppa_push_arguments (nargs, args, sp, struct_return, struct_addr) |
| 892 | int nargs; |
| 893 | value *args; |
| 894 | CORE_ADDR sp; |
| 895 | int struct_return; |
| 896 | CORE_ADDR struct_addr; |
| 897 | { |
| 898 | /* array of arguments' offsets */ |
| 899 | int *offset = (int *)alloca(nargs * sizeof (int)); |
| 900 | int cum = 0; |
| 901 | int i, alignment; |
| 902 | |
| 903 | for (i = 0; i < nargs; i++) |
| 904 | { |
| 905 | /* Coerce chars to int & float to double if necessary */ |
| 906 | args[i] = value_arg_coerce (args[i]); |
| 907 | |
| 908 | cum += TYPE_LENGTH (VALUE_TYPE (args[i])); |
| 909 | |
| 910 | /* value must go at proper alignment. Assume alignment is a |
| 911 | power of two.*/ |
| 912 | alignment = hppa_alignof (VALUE_TYPE (args[i])); |
| 913 | if (cum % alignment) |
| 914 | cum = (cum + alignment) & -alignment; |
| 915 | offset[i] = -cum; |
| 916 | } |
| 917 | sp += max ((cum + 7) & -8, 16); |
| 918 | |
| 919 | for (i = 0; i < nargs; i++) |
| 920 | write_memory (sp + offset[i], VALUE_CONTENTS (args[i]), |
| 921 | TYPE_LENGTH (VALUE_TYPE (args[i]))); |
| 922 | |
| 923 | if (struct_return) |
| 924 | write_register (28, struct_addr); |
| 925 | return sp + 32; |
| 926 | } |
| 927 | |
| 928 | /* |
| 929 | * Insert the specified number of args and function address |
| 930 | * into a call sequence of the above form stored at DUMMYNAME. |
| 931 | * |
| 932 | * On the hppa we need to call the stack dummy through $$dyncall. |
| 933 | * Therefore our version of FIX_CALL_DUMMY takes an extra argument, |
| 934 | * real_pc, which is the location where gdb should start up the |
| 935 | * inferior to do the function call. |
| 936 | */ |
| 937 | |
| 938 | CORE_ADDR |
| 939 | hppa_fix_call_dummy (dummy, pc, fun, nargs, args, type, gcc_p) |
| 940 | char *dummy; |
| 941 | CORE_ADDR pc; |
| 942 | CORE_ADDR fun; |
| 943 | int nargs; |
| 944 | value *args; |
| 945 | struct type *type; |
| 946 | int gcc_p; |
| 947 | { |
| 948 | CORE_ADDR dyncall_addr, sr4export_addr; |
| 949 | struct minimal_symbol *msymbol; |
| 950 | int flags = read_register (FLAGS_REGNUM); |
| 951 | |
| 952 | msymbol = lookup_minimal_symbol ("$$dyncall", (struct objfile *) NULL); |
| 953 | if (msymbol == NULL) |
| 954 | error ("Can't find an address for $$dyncall trampoline"); |
| 955 | |
| 956 | dyncall_addr = SYMBOL_VALUE_ADDRESS (msymbol); |
| 957 | |
| 958 | msymbol = lookup_minimal_symbol ("_sr4export", (struct objfile *) NULL); |
| 959 | if (msymbol == NULL) |
| 960 | error ("Can't find an address for _sr4export trampoline"); |
| 961 | |
| 962 | sr4export_addr = SYMBOL_VALUE_ADDRESS (msymbol); |
| 963 | |
| 964 | store_unsigned_integer |
| 965 | (&dummy[9*REGISTER_SIZE], |
| 966 | REGISTER_SIZE, |
| 967 | deposit_21 (fun >> 11, |
| 968 | extract_unsigned_integer (&dummy[9*REGISTER_SIZE], |
| 969 | REGISTER_SIZE))); |
| 970 | store_unsigned_integer |
| 971 | (&dummy[10*REGISTER_SIZE], |
| 972 | REGISTER_SIZE, |
| 973 | deposit_14 (fun & MASK_11, |
| 974 | extract_unsigned_integer (&dummy[10*REGISTER_SIZE], |
| 975 | REGISTER_SIZE))); |
| 976 | store_unsigned_integer |
| 977 | (&dummy[12*REGISTER_SIZE], |
| 978 | REGISTER_SIZE, |
| 979 | deposit_21 (sr4export_addr >> 11, |
| 980 | extract_unsigned_integer (&dummy[12*REGISTER_SIZE], |
| 981 | REGISTER_SIZE))); |
| 982 | store_unsigned_integer |
| 983 | (&dummy[13*REGISTER_SIZE], |
| 984 | REGISTER_SIZE, |
| 985 | deposit_14 (sr4export_addr & MASK_11, |
| 986 | extract_unsigned_integer (&dummy[13*REGISTER_SIZE], |
| 987 | REGISTER_SIZE))); |
| 988 | |
| 989 | write_register (22, pc); |
| 990 | |
| 991 | /* If we are in a syscall, then we should call the stack dummy |
| 992 | directly. $$dyncall is not needed as the kernel sets up the |
| 993 | space id registers properly based on the value in %r31. In |
| 994 | fact calling $$dyncall will not work because the value in %r22 |
| 995 | will be clobbered on the syscall exit path. */ |
| 996 | if (flags & 2) |
| 997 | return pc; |
| 998 | else |
| 999 | return dyncall_addr; |
| 1000 | |
| 1001 | } |
| 1002 | |
| 1003 | /* Get the PC from %r31 if currently in a syscall. Also mask out privilege |
| 1004 | bits. */ |
| 1005 | CORE_ADDR |
| 1006 | target_read_pc () |
| 1007 | { |
| 1008 | int flags = read_register (FLAGS_REGNUM); |
| 1009 | |
| 1010 | if (flags & 2) |
| 1011 | return read_register (31) & ~0x3; |
| 1012 | return read_register (PC_REGNUM) & ~0x3; |
| 1013 | } |
| 1014 | |
| 1015 | /* Write out the PC. If currently in a syscall, then also write the new |
| 1016 | PC value into %r31. */ |
| 1017 | void |
| 1018 | target_write_pc (v) |
| 1019 | CORE_ADDR v; |
| 1020 | { |
| 1021 | int flags = read_register (FLAGS_REGNUM); |
| 1022 | |
| 1023 | /* If in a syscall, then set %r31. Also make sure to get the |
| 1024 | privilege bits set correctly. */ |
| 1025 | if (flags & 2) |
| 1026 | write_register (31, (long) (v | 0x3)); |
| 1027 | |
| 1028 | write_register (PC_REGNUM, (long) v); |
| 1029 | write_register (NPC_REGNUM, (long) v + 4); |
| 1030 | } |
| 1031 | |
| 1032 | /* return the alignment of a type in bytes. Structures have the maximum |
| 1033 | alignment required by their fields. */ |
| 1034 | |
| 1035 | static int |
| 1036 | hppa_alignof (arg) |
| 1037 | struct type *arg; |
| 1038 | { |
| 1039 | int max_align, align, i; |
| 1040 | switch (TYPE_CODE (arg)) |
| 1041 | { |
| 1042 | case TYPE_CODE_PTR: |
| 1043 | case TYPE_CODE_INT: |
| 1044 | case TYPE_CODE_FLT: |
| 1045 | return TYPE_LENGTH (arg); |
| 1046 | case TYPE_CODE_ARRAY: |
| 1047 | return hppa_alignof (TYPE_FIELD_TYPE (arg, 0)); |
| 1048 | case TYPE_CODE_STRUCT: |
| 1049 | case TYPE_CODE_UNION: |
| 1050 | max_align = 2; |
| 1051 | for (i = 0; i < TYPE_NFIELDS (arg); i++) |
| 1052 | { |
| 1053 | /* Bit fields have no real alignment. */ |
| 1054 | if (!TYPE_FIELD_BITPOS (arg, i)) |
| 1055 | { |
| 1056 | align = hppa_alignof (TYPE_FIELD_TYPE (arg, i)); |
| 1057 | max_align = max (max_align, align); |
| 1058 | } |
| 1059 | } |
| 1060 | return max_align; |
| 1061 | default: |
| 1062 | return 4; |
| 1063 | } |
| 1064 | } |
| 1065 | |
| 1066 | /* Print the register regnum, or all registers if regnum is -1 */ |
| 1067 | |
| 1068 | pa_do_registers_info (regnum, fpregs) |
| 1069 | int regnum; |
| 1070 | int fpregs; |
| 1071 | { |
| 1072 | char raw_regs [REGISTER_BYTES]; |
| 1073 | int i; |
| 1074 | |
| 1075 | for (i = 0; i < NUM_REGS; i++) |
| 1076 | read_relative_register_raw_bytes (i, raw_regs + REGISTER_BYTE (i)); |
| 1077 | if (regnum == -1) |
| 1078 | pa_print_registers (raw_regs, regnum, fpregs); |
| 1079 | else if (regnum < FP0_REGNUM) |
| 1080 | printf_unfiltered ("%s %x\n", reg_names[regnum], *(long *)(raw_regs + |
| 1081 | REGISTER_BYTE (regnum))); |
| 1082 | else |
| 1083 | pa_print_fp_reg (regnum); |
| 1084 | } |
| 1085 | |
| 1086 | pa_print_registers (raw_regs, regnum, fpregs) |
| 1087 | char *raw_regs; |
| 1088 | int regnum; |
| 1089 | int fpregs; |
| 1090 | { |
| 1091 | int i; |
| 1092 | |
| 1093 | for (i = 0; i < 18; i++) |
| 1094 | printf_unfiltered ("%8.8s: %8x %8.8s: %8x %8.8s: %8x %8.8s: %8x\n", |
| 1095 | reg_names[i], |
| 1096 | *(int *)(raw_regs + REGISTER_BYTE (i)), |
| 1097 | reg_names[i + 18], |
| 1098 | *(int *)(raw_regs + REGISTER_BYTE (i + 18)), |
| 1099 | reg_names[i + 36], |
| 1100 | *(int *)(raw_regs + REGISTER_BYTE (i + 36)), |
| 1101 | reg_names[i + 54], |
| 1102 | *(int *)(raw_regs + REGISTER_BYTE (i + 54))); |
| 1103 | |
| 1104 | if (fpregs) |
| 1105 | for (i = 72; i < NUM_REGS; i++) |
| 1106 | pa_print_fp_reg (i); |
| 1107 | } |
| 1108 | |
| 1109 | pa_print_fp_reg (i) |
| 1110 | int i; |
| 1111 | { |
| 1112 | unsigned char raw_buffer[MAX_REGISTER_RAW_SIZE]; |
| 1113 | unsigned char virtual_buffer[MAX_REGISTER_VIRTUAL_SIZE]; |
| 1114 | |
| 1115 | /* Get the data in raw format. */ |
| 1116 | read_relative_register_raw_bytes (i, raw_buffer); |
| 1117 | |
| 1118 | /* Convert raw data to virtual format if necessary. */ |
| 1119 | #ifdef REGISTER_CONVERTIBLE |
| 1120 | if (REGISTER_CONVERTIBLE (i)) |
| 1121 | { |
| 1122 | REGISTER_CONVERT_TO_VIRTUAL (i, REGISTER_VIRTUAL_TYPE (i), |
| 1123 | raw_buffer, virtual_buffer); |
| 1124 | } |
| 1125 | else |
| 1126 | #endif |
| 1127 | memcpy (virtual_buffer, raw_buffer, |
| 1128 | REGISTER_VIRTUAL_SIZE (i)); |
| 1129 | |
| 1130 | fputs_filtered (reg_names[i], gdb_stdout); |
| 1131 | print_spaces_filtered (15 - strlen (reg_names[i]), gdb_stdout); |
| 1132 | |
| 1133 | val_print (REGISTER_VIRTUAL_TYPE (i), virtual_buffer, 0, gdb_stdout, 0, |
| 1134 | 1, 0, Val_pretty_default); |
| 1135 | printf_filtered ("\n"); |
| 1136 | } |
| 1137 | |
| 1138 | /* Function calls that pass into a new compilation unit must pass through a |
| 1139 | small piece of code that does long format (`external' in HPPA parlance) |
| 1140 | jumps. We figure out where the trampoline is going to end up, and return |
| 1141 | the PC of the final destination. If we aren't in a trampoline, we just |
| 1142 | return NULL. |
| 1143 | |
| 1144 | For computed calls, we just extract the new PC from r22. */ |
| 1145 | |
| 1146 | CORE_ADDR |
| 1147 | skip_trampoline_code (pc, name) |
| 1148 | CORE_ADDR pc; |
| 1149 | char *name; |
| 1150 | { |
| 1151 | long inst0, inst1; |
| 1152 | static CORE_ADDR dyncall = 0; |
| 1153 | struct minimal_symbol *msym; |
| 1154 | |
| 1155 | /* FIXME XXX - dyncall must be initialized whenever we get a new exec file */ |
| 1156 | |
| 1157 | if (!dyncall) |
| 1158 | { |
| 1159 | msym = lookup_minimal_symbol ("$$dyncall", NULL); |
| 1160 | if (msym) |
| 1161 | dyncall = SYMBOL_VALUE_ADDRESS (msym); |
| 1162 | else |
| 1163 | dyncall = -1; |
| 1164 | } |
| 1165 | |
| 1166 | if (pc == dyncall) |
| 1167 | return (CORE_ADDR)(read_register (22) & ~0x3); |
| 1168 | |
| 1169 | inst0 = read_memory_integer (pc, 4); |
| 1170 | inst1 = read_memory_integer (pc+4, 4); |
| 1171 | |
| 1172 | if ( (inst0 & 0xffe00000) == 0x20200000 /* ldil xxx, r1 */ |
| 1173 | && (inst1 & 0xffe0e002) == 0xe0202002) /* be,n yyy(sr4, r1) */ |
| 1174 | pc = extract_21 (inst0) + extract_17 (inst1); |
| 1175 | else |
| 1176 | pc = (CORE_ADDR)NULL; |
| 1177 | |
| 1178 | return pc; |
| 1179 | } |
| 1180 | |
| 1181 | /* For the given instruction (INST), return any adjustment it makes |
| 1182 | to the stack pointer or zero for no adjustment. |
| 1183 | |
| 1184 | This only handles instructions commonly found in prologues. */ |
| 1185 | |
| 1186 | static int |
| 1187 | prologue_inst_adjust_sp (inst) |
| 1188 | unsigned long inst; |
| 1189 | { |
| 1190 | /* This must persist across calls. */ |
| 1191 | static int save_high21; |
| 1192 | |
| 1193 | /* The most common way to perform a stack adjustment ldo X(sp),sp */ |
| 1194 | if ((inst & 0xffffc000) == 0x37de0000) |
| 1195 | return extract_14 (inst); |
| 1196 | |
| 1197 | /* stwm X,D(sp) */ |
| 1198 | if ((inst & 0xffe00000) == 0x6fc00000) |
| 1199 | return extract_14 (inst); |
| 1200 | |
| 1201 | /* addil high21,%r1; ldo low11,(%r1),%r30) |
| 1202 | save high bits in save_high21 for later use. */ |
| 1203 | if ((inst & 0xffe00000) == 0x28200000) |
| 1204 | { |
| 1205 | save_high21 = extract_21 (inst); |
| 1206 | return 0; |
| 1207 | } |
| 1208 | |
| 1209 | if ((inst & 0xffff0000) == 0x343e0000) |
| 1210 | return save_high21 + extract_14 (inst); |
| 1211 | |
| 1212 | /* fstws as used by the HP compilers. */ |
| 1213 | if ((inst & 0xffffffe0) == 0x2fd01220) |
| 1214 | return extract_5_load (inst); |
| 1215 | |
| 1216 | /* No adjustment. */ |
| 1217 | return 0; |
| 1218 | } |
| 1219 | |
| 1220 | /* Return nonzero if INST is a branch of some kind, else return zero. */ |
| 1221 | |
| 1222 | static int |
| 1223 | is_branch (inst) |
| 1224 | unsigned long inst; |
| 1225 | { |
| 1226 | switch (inst >> 26) |
| 1227 | { |
| 1228 | case 0x20: |
| 1229 | case 0x21: |
| 1230 | case 0x22: |
| 1231 | case 0x23: |
| 1232 | case 0x28: |
| 1233 | case 0x29: |
| 1234 | case 0x2a: |
| 1235 | case 0x2b: |
| 1236 | case 0x30: |
| 1237 | case 0x31: |
| 1238 | case 0x32: |
| 1239 | case 0x33: |
| 1240 | case 0x38: |
| 1241 | case 0x39: |
| 1242 | case 0x3a: |
| 1243 | return 1; |
| 1244 | |
| 1245 | default: |
| 1246 | return 0; |
| 1247 | } |
| 1248 | } |
| 1249 | |
| 1250 | /* Return the register number for a GR which is saved by INST or |
| 1251 | zero it INST does not save a GR. |
| 1252 | |
| 1253 | Note we only care about full 32bit register stores (that's the only |
| 1254 | kind of stores the prologue will use). */ |
| 1255 | |
| 1256 | static int |
| 1257 | inst_saves_gr (inst) |
| 1258 | unsigned long inst; |
| 1259 | { |
| 1260 | /* Does it look like a stw? */ |
| 1261 | if ((inst >> 26) == 0x1a) |
| 1262 | return extract_5R_store (inst); |
| 1263 | |
| 1264 | /* Does it look like a stwm? */ |
| 1265 | if ((inst >> 26) == 0x1b) |
| 1266 | return extract_5R_store (inst); |
| 1267 | |
| 1268 | return 0; |
| 1269 | } |
| 1270 | |
| 1271 | /* Return the register number for a FR which is saved by INST or |
| 1272 | zero it INST does not save a FR. |
| 1273 | |
| 1274 | Note we only care about full 64bit register stores (that's the only |
| 1275 | kind of stores the prologue will use). */ |
| 1276 | |
| 1277 | static int |
| 1278 | inst_saves_fr (inst) |
| 1279 | unsigned long inst; |
| 1280 | { |
| 1281 | if ((inst & 0xfc1fffe0) == 0x2c101220) |
| 1282 | return extract_5r_store (inst); |
| 1283 | return 0; |
| 1284 | } |
| 1285 | |
| 1286 | /* Advance PC across any function entry prologue instructions |
| 1287 | to reach some "real" code. |
| 1288 | |
| 1289 | Use information in the unwind table to determine what exactly should |
| 1290 | be in the prologue. */ |
| 1291 | |
| 1292 | CORE_ADDR |
| 1293 | skip_prologue(pc) |
| 1294 | CORE_ADDR pc; |
| 1295 | { |
| 1296 | char buf[4]; |
| 1297 | unsigned long inst, stack_remaining, save_gr, save_fr, save_rp, save_sp; |
| 1298 | int status, i; |
| 1299 | struct unwind_table_entry *u; |
| 1300 | |
| 1301 | u = find_unwind_entry (pc); |
| 1302 | if (!u) |
| 1303 | return 0; |
| 1304 | |
| 1305 | /* This is how much of a frame adjustment we need to account for. */ |
| 1306 | stack_remaining = u->Total_frame_size << 3; |
| 1307 | |
| 1308 | /* Magic register saves we want to know about. */ |
| 1309 | save_rp = u->Save_RP; |
| 1310 | save_sp = u->Save_SP; |
| 1311 | |
| 1312 | /* Turn the Entry_GR field into a bitmask. */ |
| 1313 | save_gr = 0; |
| 1314 | for (i = 3; i < u->Entry_GR + 3; i++) |
| 1315 | { |
| 1316 | /* Frame pointer gets saved into a special location. */ |
| 1317 | if (u->Save_SP && i == FP_REGNUM) |
| 1318 | continue; |
| 1319 | |
| 1320 | save_gr |= (1 << i); |
| 1321 | } |
| 1322 | |
| 1323 | /* Turn the Entry_FR field into a bitmask too. */ |
| 1324 | save_fr = 0; |
| 1325 | for (i = 12; i < u->Entry_FR + 12; i++) |
| 1326 | save_fr |= (1 << i); |
| 1327 | |
| 1328 | /* Loop until we find everything of interest or hit a branch. |
| 1329 | |
| 1330 | For unoptimized GCC code and for any HP CC code this will never ever |
| 1331 | examine any user instructions. |
| 1332 | |
| 1333 | For optimzied GCC code we're faced with problems. GCC will schedule |
| 1334 | its prologue and make prologue instructions available for delay slot |
| 1335 | filling. The end result is user code gets mixed in with the prologue |
| 1336 | and a prologue instruction may be in the delay slot of the first branch |
| 1337 | or call. |
| 1338 | |
| 1339 | Some unexpected things are expected with debugging optimized code, so |
| 1340 | we allow this routine to walk past user instructions in optimized |
| 1341 | GCC code. */ |
| 1342 | while (save_gr || save_fr || save_rp || save_sp || stack_remaining > 0) |
| 1343 | { |
| 1344 | status = target_read_memory (pc, buf, 4); |
| 1345 | inst = extract_unsigned_integer (buf, 4); |
| 1346 | |
| 1347 | /* Yow! */ |
| 1348 | if (status != 0) |
| 1349 | return pc; |
| 1350 | |
| 1351 | /* Note the interesting effects of this instruction. */ |
| 1352 | stack_remaining -= prologue_inst_adjust_sp (inst); |
| 1353 | |
| 1354 | /* There is only one instruction used for saving RP into the stack. */ |
| 1355 | if (inst == 0x6bc23fd9) |
| 1356 | save_rp = 0; |
| 1357 | |
| 1358 | /* This is the only way we save SP into the stack. At this time |
| 1359 | the HP compilers never bother to save SP into the stack. */ |
| 1360 | if ((inst & 0xffffc000) == 0x6fc10000) |
| 1361 | save_sp = 0; |
| 1362 | |
| 1363 | /* Account for general and floating-point register saves. */ |
| 1364 | save_gr &= ~(1 << inst_saves_gr (inst)); |
| 1365 | save_fr &= ~(1 << inst_saves_fr (inst)); |
| 1366 | |
| 1367 | /* Quit if we hit any kind of branch. This can happen if a prologue |
| 1368 | instruction is in the delay slot of the first call/branch. */ |
| 1369 | if (is_branch (inst)) |
| 1370 | break; |
| 1371 | |
| 1372 | /* Bump the PC. */ |
| 1373 | pc += 4; |
| 1374 | } |
| 1375 | |
| 1376 | return pc; |
| 1377 | } |
| 1378 | |
| 1379 | /* Put here the code to store, into a struct frame_saved_regs, |
| 1380 | the addresses of the saved registers of frame described by FRAME_INFO. |
| 1381 | This includes special registers such as pc and fp saved in special |
| 1382 | ways in the stack frame. sp is even more special: |
| 1383 | the address we return for it IS the sp for the next frame. */ |
| 1384 | |
| 1385 | void |
| 1386 | hppa_frame_find_saved_regs (frame_info, frame_saved_regs) |
| 1387 | struct frame_info *frame_info; |
| 1388 | struct frame_saved_regs *frame_saved_regs; |
| 1389 | { |
| 1390 | CORE_ADDR pc; |
| 1391 | struct unwind_table_entry *u; |
| 1392 | unsigned long inst, stack_remaining, save_gr, save_fr, save_rp, save_sp; |
| 1393 | int status, i, reg; |
| 1394 | char buf[4]; |
| 1395 | int fp_loc = -1; |
| 1396 | |
| 1397 | /* Zero out everything. */ |
| 1398 | memset (frame_saved_regs, '\0', sizeof (struct frame_saved_regs)); |
| 1399 | |
| 1400 | /* Call dummy frames always look the same, so there's no need to |
| 1401 | examine the dummy code to determine locations of saved registers; |
| 1402 | instead, let find_dummy_frame_regs fill in the correct offsets |
| 1403 | for the saved registers. */ |
| 1404 | if ((frame_info->pc >= frame_info->frame |
| 1405 | && frame_info->pc <= (frame_info->frame + CALL_DUMMY_LENGTH |
| 1406 | + 32 * 4 + (NUM_REGS - FP0_REGNUM) * 8 |
| 1407 | + 6 * 4))) |
| 1408 | find_dummy_frame_regs (frame_info, frame_saved_regs); |
| 1409 | |
| 1410 | /* Get the starting address of the function referred to by the PC |
| 1411 | saved in frame_info. */ |
| 1412 | pc = get_pc_function_start (frame_info->pc); |
| 1413 | |
| 1414 | /* Yow! */ |
| 1415 | u = find_unwind_entry (pc); |
| 1416 | if (!u) |
| 1417 | return; |
| 1418 | |
| 1419 | /* This is how much of a frame adjustment we need to account for. */ |
| 1420 | stack_remaining = u->Total_frame_size << 3; |
| 1421 | |
| 1422 | /* Magic register saves we want to know about. */ |
| 1423 | save_rp = u->Save_RP; |
| 1424 | save_sp = u->Save_SP; |
| 1425 | |
| 1426 | /* Turn the Entry_GR field into a bitmask. */ |
| 1427 | save_gr = 0; |
| 1428 | for (i = 3; i < u->Entry_GR + 3; i++) |
| 1429 | { |
| 1430 | /* Frame pointer gets saved into a special location. */ |
| 1431 | if (u->Save_SP && i == FP_REGNUM) |
| 1432 | continue; |
| 1433 | |
| 1434 | save_gr |= (1 << i); |
| 1435 | } |
| 1436 | |
| 1437 | /* Turn the Entry_FR field into a bitmask too. */ |
| 1438 | save_fr = 0; |
| 1439 | for (i = 12; i < u->Entry_FR + 12; i++) |
| 1440 | save_fr |= (1 << i); |
| 1441 | |
| 1442 | /* Loop until we find everything of interest or hit a branch. |
| 1443 | |
| 1444 | For unoptimized GCC code and for any HP CC code this will never ever |
| 1445 | examine any user instructions. |
| 1446 | |
| 1447 | For optimzied GCC code we're faced with problems. GCC will schedule |
| 1448 | its prologue and make prologue instructions available for delay slot |
| 1449 | filling. The end result is user code gets mixed in with the prologue |
| 1450 | and a prologue instruction may be in the delay slot of the first branch |
| 1451 | or call. |
| 1452 | |
| 1453 | Some unexpected things are expected with debugging optimized code, so |
| 1454 | we allow this routine to walk past user instructions in optimized |
| 1455 | GCC code. */ |
| 1456 | while (save_gr || save_fr || save_rp || save_sp || stack_remaining > 0) |
| 1457 | { |
| 1458 | status = target_read_memory (pc, buf, 4); |
| 1459 | inst = extract_unsigned_integer (buf, 4); |
| 1460 | |
| 1461 | /* Yow! */ |
| 1462 | if (status != 0) |
| 1463 | return; |
| 1464 | |
| 1465 | /* Note the interesting effects of this instruction. */ |
| 1466 | stack_remaining -= prologue_inst_adjust_sp (inst); |
| 1467 | |
| 1468 | /* There is only one instruction used for saving RP into the stack. */ |
| 1469 | if (inst == 0x6bc23fd9) |
| 1470 | { |
| 1471 | save_rp = 0; |
| 1472 | frame_saved_regs->regs[RP_REGNUM] = frame_info->frame - 20; |
| 1473 | } |
| 1474 | |
| 1475 | /* This is the only way we save SP into the stack. At this time |
| 1476 | the HP compilers never bother to save SP into the stack. */ |
| 1477 | if ((inst & 0xffffc000) == 0x6fc10000) |
| 1478 | { |
| 1479 | save_sp = 0; |
| 1480 | frame_saved_regs->regs[SP_REGNUM] = frame_info->frame; |
| 1481 | } |
| 1482 | |
| 1483 | /* Account for general and floating-point register saves. */ |
| 1484 | reg = inst_saves_gr (inst); |
| 1485 | if (reg >= 3 && reg <= 18 |
| 1486 | && (!u->Save_SP || reg != FP_REGNUM)) |
| 1487 | { |
| 1488 | save_gr &= ~(1 << reg); |
| 1489 | |
| 1490 | /* stwm with a positive displacement is a *post modify*. */ |
| 1491 | if ((inst >> 26) == 0x1b |
| 1492 | && extract_14 (inst) >= 0) |
| 1493 | frame_saved_regs->regs[reg] = frame_info->frame; |
| 1494 | else |
| 1495 | { |
| 1496 | /* Handle code with and without frame pointers. */ |
| 1497 | if (u->Save_SP) |
| 1498 | frame_saved_regs->regs[reg] |
| 1499 | = frame_info->frame + extract_14 (inst); |
| 1500 | else |
| 1501 | frame_saved_regs->regs[reg] |
| 1502 | = frame_info->frame + (u->Total_frame_size << 3) |
| 1503 | + extract_14 (inst); |
| 1504 | } |
| 1505 | } |
| 1506 | |
| 1507 | |
| 1508 | /* GCC handles callee saved FP regs a little differently. |
| 1509 | |
| 1510 | It emits an instruction to put the value of the start of |
| 1511 | the FP store area into %r1. It then uses fstds,ma with |
| 1512 | a basereg of %r1 for the stores. |
| 1513 | |
| 1514 | HP CC emits them at the current stack pointer modifying |
| 1515 | the stack pointer as it stores each register. */ |
| 1516 | |
| 1517 | /* ldo X(%r3),%r1 or ldo X(%r30),%r1. */ |
| 1518 | if ((inst & 0xffffc000) == 0x34610000 |
| 1519 | || (inst & 0xffffc000) == 0x37c10000) |
| 1520 | fp_loc = extract_14 (inst); |
| 1521 | |
| 1522 | reg = inst_saves_fr (inst); |
| 1523 | if (reg >= 12 && reg <= 21) |
| 1524 | { |
| 1525 | /* Note +4 braindamage below is necessary because the FP status |
| 1526 | registers are internally 8 registers rather than the expected |
| 1527 | 4 registers. */ |
| 1528 | save_fr &= ~(1 << reg); |
| 1529 | if (fp_loc == -1) |
| 1530 | { |
| 1531 | /* 1st HP CC FP register store. After this instruction |
| 1532 | we've set enough state that the GCC and HPCC code are |
| 1533 | both handled in the same manner. */ |
| 1534 | frame_saved_regs->regs[reg + FP4_REGNUM + 4] = frame_info->frame; |
| 1535 | fp_loc = 8; |
| 1536 | } |
| 1537 | else |
| 1538 | { |
| 1539 | frame_saved_regs->regs[reg + FP0_REGNUM + 4] |
| 1540 | = frame_info->frame + fp_loc; |
| 1541 | fp_loc += 8; |
| 1542 | } |
| 1543 | } |
| 1544 | |
| 1545 | /* Quit if we hit any kind of branch. This can happen if a prologue |
| 1546 | instruction is in the delay slot of the first call/branch. */ |
| 1547 | if (is_branch (inst)) |
| 1548 | break; |
| 1549 | |
| 1550 | /* Bump the PC. */ |
| 1551 | pc += 4; |
| 1552 | } |
| 1553 | } |
| 1554 | |
| 1555 | #ifdef MAINTENANCE_CMDS |
| 1556 | |
| 1557 | static void |
| 1558 | unwind_command (exp, from_tty) |
| 1559 | char *exp; |
| 1560 | int from_tty; |
| 1561 | { |
| 1562 | CORE_ADDR address; |
| 1563 | union |
| 1564 | { |
| 1565 | int *foo; |
| 1566 | struct unwind_table_entry *u; |
| 1567 | } xxx; |
| 1568 | |
| 1569 | /* If we have an expression, evaluate it and use it as the address. */ |
| 1570 | |
| 1571 | if (exp != 0 && *exp != 0) |
| 1572 | address = parse_and_eval_address (exp); |
| 1573 | else |
| 1574 | return; |
| 1575 | |
| 1576 | xxx.u = find_unwind_entry (address); |
| 1577 | |
| 1578 | if (!xxx.u) |
| 1579 | { |
| 1580 | printf_unfiltered ("Can't find unwind table entry for PC 0x%x\n", address); |
| 1581 | return; |
| 1582 | } |
| 1583 | |
| 1584 | printf_unfiltered ("%08x\n%08X\n%08X\n%08X\n", xxx.foo[0], xxx.foo[1], xxx.foo[2], |
| 1585 | xxx.foo[3]); |
| 1586 | } |
| 1587 | #endif /* MAINTENANCE_CMDS */ |
| 1588 | |
| 1589 | void |
| 1590 | _initialize_hppa_tdep () |
| 1591 | { |
| 1592 | #ifdef MAINTENANCE_CMDS |
| 1593 | add_cmd ("unwind", class_maintenance, unwind_command, |
| 1594 | "Print unwind table entry at given address.", |
| 1595 | &maintenanceprintlist); |
| 1596 | #endif /* MAINTENANCE_CMDS */ |
| 1597 | } |