| 1 | /* Print VAX instructions for GDB, the GNU debugger. |
| 2 | Copyright 1986, 1989, 1991, 1992, 1995, 1996, 1998, 1999, 2000, 2002, 2003 |
| 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., 59 Temple Place - Suite 330, |
| 20 | Boston, MA 02111-1307, USA. */ |
| 21 | |
| 22 | #include "defs.h" |
| 23 | #include "symtab.h" |
| 24 | #include "opcode/vax.h" |
| 25 | #include "gdbcore.h" |
| 26 | #include "inferior.h" |
| 27 | #include "regcache.h" |
| 28 | #include "frame.h" |
| 29 | #include "value.h" |
| 30 | #include "arch-utils.h" |
| 31 | #include "gdb_string.h" |
| 32 | #include "osabi.h" |
| 33 | |
| 34 | #include "vax-tdep.h" |
| 35 | |
| 36 | static gdbarch_register_name_ftype vax_register_name; |
| 37 | static gdbarch_register_byte_ftype vax_register_byte; |
| 38 | static gdbarch_register_raw_size_ftype vax_register_raw_size; |
| 39 | static gdbarch_register_virtual_size_ftype vax_register_virtual_size; |
| 40 | static gdbarch_register_virtual_type_ftype vax_register_virtual_type; |
| 41 | |
| 42 | static gdbarch_skip_prologue_ftype vax_skip_prologue; |
| 43 | static gdbarch_frame_num_args_ftype vax_frame_num_args; |
| 44 | static gdbarch_deprecated_frame_chain_ftype vax_frame_chain; |
| 45 | static gdbarch_frame_args_address_ftype vax_frame_args_address; |
| 46 | static gdbarch_frame_locals_address_ftype vax_frame_locals_address; |
| 47 | |
| 48 | static gdbarch_deprecated_extract_return_value_ftype vax_extract_return_value; |
| 49 | static gdbarch_deprecated_extract_struct_value_address_ftype |
| 50 | vax_extract_struct_value_address; |
| 51 | |
| 52 | static gdbarch_deprecated_push_dummy_frame_ftype vax_push_dummy_frame; |
| 53 | \f |
| 54 | static const char * |
| 55 | vax_register_name (int regno) |
| 56 | { |
| 57 | static char *register_names[] = |
| 58 | { |
| 59 | "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", |
| 60 | "r8", "r9", "r10", "r11", "ap", "fp", "sp", "pc", |
| 61 | "ps", |
| 62 | }; |
| 63 | |
| 64 | if (regno < 0) |
| 65 | return (NULL); |
| 66 | if (regno >= (sizeof(register_names) / sizeof(*register_names))) |
| 67 | return (NULL); |
| 68 | return (register_names[regno]); |
| 69 | } |
| 70 | |
| 71 | static int |
| 72 | vax_register_byte (int regno) |
| 73 | { |
| 74 | return (regno * 4); |
| 75 | } |
| 76 | |
| 77 | static int |
| 78 | vax_register_raw_size (int regno) |
| 79 | { |
| 80 | return (4); |
| 81 | } |
| 82 | |
| 83 | static int |
| 84 | vax_register_virtual_size (int regno) |
| 85 | { |
| 86 | return (4); |
| 87 | } |
| 88 | |
| 89 | static struct type * |
| 90 | vax_register_virtual_type (int regno) |
| 91 | { |
| 92 | return (builtin_type_int); |
| 93 | } |
| 94 | \f |
| 95 | static void |
| 96 | vax_frame_init_saved_regs (struct frame_info *frame) |
| 97 | { |
| 98 | int regnum, regmask; |
| 99 | CORE_ADDR next_addr; |
| 100 | |
| 101 | if (get_frame_saved_regs (frame)) |
| 102 | return; |
| 103 | |
| 104 | frame_saved_regs_zalloc (frame); |
| 105 | |
| 106 | regmask = read_memory_integer (get_frame_base (frame) + 4, 4) >> 16; |
| 107 | |
| 108 | next_addr = get_frame_base (frame) + 16; |
| 109 | |
| 110 | /* regmask's low bit is for register 0, which is the first one |
| 111 | what would be pushed. */ |
| 112 | for (regnum = 0; regnum < VAX_AP_REGNUM; regnum++) |
| 113 | { |
| 114 | if (regmask & (1 << regnum)) |
| 115 | get_frame_saved_regs (frame)[regnum] = next_addr += 4; |
| 116 | } |
| 117 | |
| 118 | get_frame_saved_regs (frame)[SP_REGNUM] = next_addr + 4; |
| 119 | if (regmask & (1 << DEPRECATED_FP_REGNUM)) |
| 120 | get_frame_saved_regs (frame)[SP_REGNUM] += |
| 121 | 4 + (4 * read_memory_integer (next_addr + 4, 4)); |
| 122 | |
| 123 | get_frame_saved_regs (frame)[PC_REGNUM] = get_frame_base (frame) + 16; |
| 124 | get_frame_saved_regs (frame)[DEPRECATED_FP_REGNUM] = get_frame_base (frame) + 12; |
| 125 | get_frame_saved_regs (frame)[VAX_AP_REGNUM] = get_frame_base (frame) + 8; |
| 126 | get_frame_saved_regs (frame)[PS_REGNUM] = get_frame_base (frame) + 4; |
| 127 | } |
| 128 | |
| 129 | /* Get saved user PC for sigtramp from sigcontext for BSD style sigtramp. */ |
| 130 | |
| 131 | static CORE_ADDR |
| 132 | vax_sigtramp_saved_pc (struct frame_info *frame) |
| 133 | { |
| 134 | CORE_ADDR sigcontext_addr; |
| 135 | char *buf; |
| 136 | int ptrbytes = TYPE_LENGTH (builtin_type_void_func_ptr); |
| 137 | int sigcontext_offs = (2 * TARGET_INT_BIT) / TARGET_CHAR_BIT; |
| 138 | |
| 139 | buf = alloca (ptrbytes); |
| 140 | /* Get sigcontext address, it is the third parameter on the stack. */ |
| 141 | if (get_next_frame (frame)) |
| 142 | sigcontext_addr = read_memory_typed_address |
| 143 | (FRAME_ARGS_ADDRESS (get_next_frame (frame)) |
| 144 | + FRAME_ARGS_SKIP + sigcontext_offs, |
| 145 | builtin_type_void_data_ptr); |
| 146 | else |
| 147 | sigcontext_addr = read_memory_typed_address |
| 148 | (read_register (SP_REGNUM) + sigcontext_offs, builtin_type_void_data_ptr); |
| 149 | |
| 150 | /* Don't cause a memory_error when accessing sigcontext in case the stack |
| 151 | layout has changed or the stack is corrupt. */ |
| 152 | target_read_memory (sigcontext_addr + SIGCONTEXT_PC_OFFSET, buf, ptrbytes); |
| 153 | return extract_typed_address (buf, builtin_type_void_func_ptr); |
| 154 | } |
| 155 | |
| 156 | static CORE_ADDR |
| 157 | vax_frame_saved_pc (struct frame_info *frame) |
| 158 | { |
| 159 | if ((get_frame_type (frame) == SIGTRAMP_FRAME)) |
| 160 | return (vax_sigtramp_saved_pc (frame)); /* XXXJRT */ |
| 161 | |
| 162 | return (read_memory_integer (get_frame_base (frame) + 16, 4)); |
| 163 | } |
| 164 | |
| 165 | CORE_ADDR |
| 166 | vax_frame_args_address_correct (struct frame_info *frame) |
| 167 | { |
| 168 | /* Cannot find the AP register value directly from the FP value. Must |
| 169 | find it saved in the frame called by this one, or in the AP register |
| 170 | for the innermost frame. However, there is no way to tell the |
| 171 | difference between the innermost frame and a frame for which we |
| 172 | just don't know the frame that it called (e.g. "info frame 0x7ffec789"). |
| 173 | For the sake of argument, suppose that the stack is somewhat trashed |
| 174 | (which is one reason that "info frame" exists). So, return 0 (indicating |
| 175 | we don't know the address of the arglist) if we don't know what frame |
| 176 | this frame calls. */ |
| 177 | if (get_next_frame (frame)) |
| 178 | return (read_memory_integer (get_frame_base (get_next_frame (frame)) + 8, 4)); |
| 179 | |
| 180 | return (0); |
| 181 | } |
| 182 | |
| 183 | static CORE_ADDR |
| 184 | vax_frame_args_address (struct frame_info *frame) |
| 185 | { |
| 186 | /* In most of GDB, getting the args address is too important to |
| 187 | just say "I don't know". This is sometimes wrong for functions |
| 188 | that aren't on top of the stack, but c'est la vie. */ |
| 189 | if (get_next_frame (frame)) |
| 190 | return (read_memory_integer (get_frame_base (get_next_frame (frame)) + 8, 4)); |
| 191 | |
| 192 | return (read_register (VAX_AP_REGNUM)); |
| 193 | } |
| 194 | |
| 195 | static CORE_ADDR |
| 196 | vax_frame_locals_address (struct frame_info *frame) |
| 197 | { |
| 198 | return (get_frame_base (frame)); |
| 199 | } |
| 200 | |
| 201 | static int |
| 202 | vax_frame_num_args (struct frame_info *fi) |
| 203 | { |
| 204 | return (0xff & read_memory_integer (FRAME_ARGS_ADDRESS (fi), 1)); |
| 205 | } |
| 206 | |
| 207 | static CORE_ADDR |
| 208 | vax_frame_chain (struct frame_info *frame) |
| 209 | { |
| 210 | /* In the case of the VAX, the frame's nominal address is the FP value, |
| 211 | and 12 bytes later comes the saved previous FP value as a 4-byte word. */ |
| 212 | if (inside_entry_file (get_frame_pc (frame))) |
| 213 | return (0); |
| 214 | |
| 215 | return (read_memory_integer (get_frame_base (frame) + 12, 4)); |
| 216 | } |
| 217 | \f |
| 218 | static void |
| 219 | vax_push_dummy_frame (void) |
| 220 | { |
| 221 | CORE_ADDR sp = read_register (SP_REGNUM); |
| 222 | int regnum; |
| 223 | |
| 224 | sp = push_word (sp, 0); /* arglist */ |
| 225 | for (regnum = 11; regnum >= 0; regnum--) |
| 226 | sp = push_word (sp, read_register (regnum)); |
| 227 | sp = push_word (sp, read_register (PC_REGNUM)); |
| 228 | sp = push_word (sp, read_register (DEPRECATED_FP_REGNUM)); |
| 229 | sp = push_word (sp, read_register (VAX_AP_REGNUM)); |
| 230 | sp = push_word (sp, (read_register (PS_REGNUM) & 0xffef) + 0x2fff0000); |
| 231 | sp = push_word (sp, 0); |
| 232 | write_register (SP_REGNUM, sp); |
| 233 | write_register (DEPRECATED_FP_REGNUM, sp); |
| 234 | write_register (VAX_AP_REGNUM, sp + (17 * 4)); |
| 235 | } |
| 236 | |
| 237 | static void |
| 238 | vax_pop_frame (void) |
| 239 | { |
| 240 | CORE_ADDR fp = read_register (DEPRECATED_FP_REGNUM); |
| 241 | int regnum; |
| 242 | int regmask = read_memory_integer (fp + 4, 4); |
| 243 | |
| 244 | write_register (PS_REGNUM, |
| 245 | (regmask & 0xffff) |
| 246 | | (read_register (PS_REGNUM) & 0xffff0000)); |
| 247 | write_register (PC_REGNUM, read_memory_integer (fp + 16, 4)); |
| 248 | write_register (DEPRECATED_FP_REGNUM, read_memory_integer (fp + 12, 4)); |
| 249 | write_register (VAX_AP_REGNUM, read_memory_integer (fp + 8, 4)); |
| 250 | fp += 16; |
| 251 | for (regnum = 0; regnum < 12; regnum++) |
| 252 | if (regmask & (0x10000 << regnum)) |
| 253 | write_register (regnum, read_memory_integer (fp += 4, 4)); |
| 254 | fp = fp + 4 + ((regmask >> 30) & 3); |
| 255 | if (regmask & 0x20000000) |
| 256 | { |
| 257 | regnum = read_memory_integer (fp, 4); |
| 258 | fp += (regnum + 1) * 4; |
| 259 | } |
| 260 | write_register (SP_REGNUM, fp); |
| 261 | flush_cached_frames (); |
| 262 | } |
| 263 | |
| 264 | /* The VAX call dummy sequence: |
| 265 | |
| 266 | calls #69, @#32323232 |
| 267 | bpt |
| 268 | |
| 269 | It is 8 bytes long. The address and argc are patched by |
| 270 | vax_fix_call_dummy(). */ |
| 271 | static LONGEST vax_call_dummy_words[] = { 0x329f69fb, 0x03323232 }; |
| 272 | static int sizeof_vax_call_dummy_words = sizeof(vax_call_dummy_words); |
| 273 | |
| 274 | static void |
| 275 | vax_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs, |
| 276 | struct value **args, struct type *type, int gcc_p) |
| 277 | { |
| 278 | dummy[1] = nargs; |
| 279 | store_unsigned_integer (dummy + 3, 4, fun); |
| 280 | } |
| 281 | \f |
| 282 | static void |
| 283 | vax_store_struct_return (CORE_ADDR addr, CORE_ADDR sp) |
| 284 | { |
| 285 | write_register (1, addr); |
| 286 | } |
| 287 | |
| 288 | static void |
| 289 | vax_extract_return_value (struct type *valtype, char *regbuf, char *valbuf) |
| 290 | { |
| 291 | memcpy (valbuf, regbuf + REGISTER_BYTE (0), TYPE_LENGTH (valtype)); |
| 292 | } |
| 293 | |
| 294 | static void |
| 295 | vax_store_return_value (struct type *valtype, char *valbuf) |
| 296 | { |
| 297 | deprecated_write_register_bytes (0, valbuf, TYPE_LENGTH (valtype)); |
| 298 | } |
| 299 | |
| 300 | static CORE_ADDR |
| 301 | vax_extract_struct_value_address (char *regbuf) |
| 302 | { |
| 303 | return (extract_address (regbuf + REGISTER_BYTE (0), REGISTER_RAW_SIZE (0))); |
| 304 | } |
| 305 | \f |
| 306 | static const unsigned char * |
| 307 | vax_breakpoint_from_pc (CORE_ADDR *pcptr, int *lenptr) |
| 308 | { |
| 309 | static const unsigned char vax_breakpoint[] = { 3 }; |
| 310 | |
| 311 | *lenptr = sizeof(vax_breakpoint); |
| 312 | return (vax_breakpoint); |
| 313 | } |
| 314 | \f |
| 315 | /* Advance PC across any function entry prologue instructions |
| 316 | to reach some "real" code. */ |
| 317 | |
| 318 | static CORE_ADDR |
| 319 | vax_skip_prologue (CORE_ADDR pc) |
| 320 | { |
| 321 | register int op = (unsigned char) read_memory_integer (pc, 1); |
| 322 | if (op == 0x11) |
| 323 | pc += 2; /* skip brb */ |
| 324 | if (op == 0x31) |
| 325 | pc += 3; /* skip brw */ |
| 326 | if (op == 0xC2 |
| 327 | && ((unsigned char) read_memory_integer (pc + 2, 1)) == 0x5E) |
| 328 | pc += 3; /* skip subl2 */ |
| 329 | if (op == 0x9E |
| 330 | && ((unsigned char) read_memory_integer (pc + 1, 1)) == 0xAE |
| 331 | && ((unsigned char) read_memory_integer (pc + 3, 1)) == 0x5E) |
| 332 | pc += 4; /* skip movab */ |
| 333 | if (op == 0x9E |
| 334 | && ((unsigned char) read_memory_integer (pc + 1, 1)) == 0xCE |
| 335 | && ((unsigned char) read_memory_integer (pc + 4, 1)) == 0x5E) |
| 336 | pc += 5; /* skip movab */ |
| 337 | if (op == 0x9E |
| 338 | && ((unsigned char) read_memory_integer (pc + 1, 1)) == 0xEE |
| 339 | && ((unsigned char) read_memory_integer (pc + 6, 1)) == 0x5E) |
| 340 | pc += 7; /* skip movab */ |
| 341 | return pc; |
| 342 | } |
| 343 | |
| 344 | static CORE_ADDR |
| 345 | vax_saved_pc_after_call (struct frame_info *frame) |
| 346 | { |
| 347 | return (DEPRECATED_FRAME_SAVED_PC(frame)); |
| 348 | } |
| 349 | \f |
| 350 | /* Initialize the current architecture based on INFO. If possible, re-use an |
| 351 | architecture from ARCHES, which is a list of architectures already created |
| 352 | during this debugging session. |
| 353 | |
| 354 | Called e.g. at program startup, when reading a core file, and when reading |
| 355 | a binary file. */ |
| 356 | |
| 357 | static struct gdbarch * |
| 358 | vax_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) |
| 359 | { |
| 360 | struct gdbarch *gdbarch; |
| 361 | |
| 362 | /* If there is already a candidate, use it. */ |
| 363 | arches = gdbarch_list_lookup_by_info (arches, &info); |
| 364 | if (arches != NULL) |
| 365 | return arches->gdbarch; |
| 366 | |
| 367 | gdbarch = gdbarch_alloc (&info, NULL); |
| 368 | |
| 369 | /* NOTE: cagney/2002-12-06: This can be deleted when this arch is |
| 370 | ready to unwind the PC first (see frame.c:get_prev_frame()). */ |
| 371 | set_gdbarch_deprecated_init_frame_pc (gdbarch, init_frame_pc_default); |
| 372 | |
| 373 | /* Register info */ |
| 374 | set_gdbarch_num_regs (gdbarch, VAX_NUM_REGS); |
| 375 | set_gdbarch_sp_regnum (gdbarch, VAX_SP_REGNUM); |
| 376 | set_gdbarch_deprecated_fp_regnum (gdbarch, VAX_FP_REGNUM); |
| 377 | set_gdbarch_pc_regnum (gdbarch, VAX_PC_REGNUM); |
| 378 | set_gdbarch_ps_regnum (gdbarch, VAX_PS_REGNUM); |
| 379 | |
| 380 | set_gdbarch_register_name (gdbarch, vax_register_name); |
| 381 | set_gdbarch_deprecated_register_size (gdbarch, VAX_REGISTER_SIZE); |
| 382 | set_gdbarch_register_bytes (gdbarch, VAX_REGISTER_BYTES); |
| 383 | set_gdbarch_register_byte (gdbarch, vax_register_byte); |
| 384 | set_gdbarch_register_raw_size (gdbarch, vax_register_raw_size); |
| 385 | set_gdbarch_deprecated_max_register_raw_size (gdbarch, VAX_MAX_REGISTER_RAW_SIZE); |
| 386 | set_gdbarch_register_virtual_size (gdbarch, vax_register_virtual_size); |
| 387 | set_gdbarch_deprecated_max_register_virtual_size (gdbarch, |
| 388 | VAX_MAX_REGISTER_VIRTUAL_SIZE); |
| 389 | set_gdbarch_register_virtual_type (gdbarch, vax_register_virtual_type); |
| 390 | |
| 391 | /* Frame and stack info */ |
| 392 | set_gdbarch_skip_prologue (gdbarch, vax_skip_prologue); |
| 393 | set_gdbarch_deprecated_saved_pc_after_call (gdbarch, vax_saved_pc_after_call); |
| 394 | |
| 395 | set_gdbarch_frame_num_args (gdbarch, vax_frame_num_args); |
| 396 | set_gdbarch_frameless_function_invocation (gdbarch, |
| 397 | generic_frameless_function_invocation_not); |
| 398 | |
| 399 | set_gdbarch_deprecated_frame_chain (gdbarch, vax_frame_chain); |
| 400 | set_gdbarch_deprecated_frame_saved_pc (gdbarch, vax_frame_saved_pc); |
| 401 | |
| 402 | set_gdbarch_frame_args_address (gdbarch, vax_frame_args_address); |
| 403 | set_gdbarch_frame_locals_address (gdbarch, vax_frame_locals_address); |
| 404 | |
| 405 | set_gdbarch_deprecated_frame_init_saved_regs (gdbarch, vax_frame_init_saved_regs); |
| 406 | |
| 407 | set_gdbarch_frame_args_skip (gdbarch, 4); |
| 408 | |
| 409 | set_gdbarch_inner_than (gdbarch, core_addr_lessthan); |
| 410 | |
| 411 | /* Return value info */ |
| 412 | set_gdbarch_deprecated_store_struct_return (gdbarch, vax_store_struct_return); |
| 413 | set_gdbarch_deprecated_extract_return_value (gdbarch, vax_extract_return_value); |
| 414 | set_gdbarch_deprecated_store_return_value (gdbarch, vax_store_return_value); |
| 415 | set_gdbarch_deprecated_extract_struct_value_address (gdbarch, vax_extract_struct_value_address); |
| 416 | |
| 417 | /* Call dummy info */ |
| 418 | set_gdbarch_deprecated_push_dummy_frame (gdbarch, vax_push_dummy_frame); |
| 419 | set_gdbarch_deprecated_pop_frame (gdbarch, vax_pop_frame); |
| 420 | set_gdbarch_call_dummy_location (gdbarch, ON_STACK); |
| 421 | set_gdbarch_deprecated_call_dummy_words (gdbarch, vax_call_dummy_words); |
| 422 | set_gdbarch_deprecated_sizeof_call_dummy_words (gdbarch, sizeof_vax_call_dummy_words); |
| 423 | set_gdbarch_deprecated_fix_call_dummy (gdbarch, vax_fix_call_dummy); |
| 424 | set_gdbarch_deprecated_call_dummy_breakpoint_offset (gdbarch, 7); |
| 425 | set_gdbarch_deprecated_use_generic_dummy_frames (gdbarch, 0); |
| 426 | set_gdbarch_deprecated_pc_in_call_dummy (gdbarch, deprecated_pc_in_call_dummy_on_stack); |
| 427 | |
| 428 | /* Breakpoint info */ |
| 429 | set_gdbarch_breakpoint_from_pc (gdbarch, vax_breakpoint_from_pc); |
| 430 | set_gdbarch_decr_pc_after_break (gdbarch, 0); |
| 431 | |
| 432 | /* Misc info */ |
| 433 | set_gdbarch_function_start_offset (gdbarch, 2); |
| 434 | set_gdbarch_believe_pcc_promotion (gdbarch, 1); |
| 435 | |
| 436 | /* Should be using push_dummy_call. */ |
| 437 | set_gdbarch_deprecated_dummy_write_sp (gdbarch, generic_target_write_sp); |
| 438 | |
| 439 | /* Hook in ABI-specific overrides, if they have been registered. */ |
| 440 | gdbarch_init_osabi (info, gdbarch); |
| 441 | |
| 442 | set_gdbarch_print_insn (gdbarch, print_insn_vax); |
| 443 | |
| 444 | return (gdbarch); |
| 445 | } |
| 446 | |
| 447 | void |
| 448 | _initialize_vax_tdep (void) |
| 449 | { |
| 450 | gdbarch_register (bfd_arch_vax, vax_gdbarch_init, NULL); |
| 451 | } |