| 1 | /* Perform an inferior function call, for GDB, the GNU debugger. |
| 2 | |
| 3 | Copyright (C) 1986-2015 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 3 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, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | #include "infcall.h" |
| 22 | #include "breakpoint.h" |
| 23 | #include "tracepoint.h" |
| 24 | #include "target.h" |
| 25 | #include "regcache.h" |
| 26 | #include "inferior.h" |
| 27 | #include "infrun.h" |
| 28 | #include "block.h" |
| 29 | #include "gdbcore.h" |
| 30 | #include "language.h" |
| 31 | #include "objfiles.h" |
| 32 | #include "gdbcmd.h" |
| 33 | #include "command.h" |
| 34 | #include "dummy-frame.h" |
| 35 | #include "ada-lang.h" |
| 36 | #include "gdbthread.h" |
| 37 | #include "event-top.h" |
| 38 | #include "observer.h" |
| 39 | #include "top.h" |
| 40 | #include "interps.h" |
| 41 | #include "thread-fsm.h" |
| 42 | |
| 43 | /* If we can't find a function's name from its address, |
| 44 | we print this instead. */ |
| 45 | #define RAW_FUNCTION_ADDRESS_FORMAT "at 0x%s" |
| 46 | #define RAW_FUNCTION_ADDRESS_SIZE (sizeof (RAW_FUNCTION_ADDRESS_FORMAT) \ |
| 47 | + 2 * sizeof (CORE_ADDR)) |
| 48 | |
| 49 | /* NOTE: cagney/2003-04-16: What's the future of this code? |
| 50 | |
| 51 | GDB needs an asynchronous expression evaluator, that means an |
| 52 | asynchronous inferior function call implementation, and that in |
| 53 | turn means restructuring the code so that it is event driven. */ |
| 54 | |
| 55 | /* How you should pass arguments to a function depends on whether it |
| 56 | was defined in K&R style or prototype style. If you define a |
| 57 | function using the K&R syntax that takes a `float' argument, then |
| 58 | callers must pass that argument as a `double'. If you define the |
| 59 | function using the prototype syntax, then you must pass the |
| 60 | argument as a `float', with no promotion. |
| 61 | |
| 62 | Unfortunately, on certain older platforms, the debug info doesn't |
| 63 | indicate reliably how each function was defined. A function type's |
| 64 | TYPE_FLAG_PROTOTYPED flag may be clear, even if the function was |
| 65 | defined in prototype style. When calling a function whose |
| 66 | TYPE_FLAG_PROTOTYPED flag is clear, GDB consults this flag to |
| 67 | decide what to do. |
| 68 | |
| 69 | For modern targets, it is proper to assume that, if the prototype |
| 70 | flag is clear, that can be trusted: `float' arguments should be |
| 71 | promoted to `double'. For some older targets, if the prototype |
| 72 | flag is clear, that doesn't tell us anything. The default is to |
| 73 | trust the debug information; the user can override this behavior |
| 74 | with "set coerce-float-to-double 0". */ |
| 75 | |
| 76 | static int coerce_float_to_double_p = 1; |
| 77 | static void |
| 78 | show_coerce_float_to_double_p (struct ui_file *file, int from_tty, |
| 79 | struct cmd_list_element *c, const char *value) |
| 80 | { |
| 81 | fprintf_filtered (file, |
| 82 | _("Coercion of floats to doubles " |
| 83 | "when calling functions is %s.\n"), |
| 84 | value); |
| 85 | } |
| 86 | |
| 87 | /* This boolean tells what gdb should do if a signal is received while |
| 88 | in a function called from gdb (call dummy). If set, gdb unwinds |
| 89 | the stack and restore the context to what as it was before the |
| 90 | call. |
| 91 | |
| 92 | The default is to stop in the frame where the signal was received. */ |
| 93 | |
| 94 | static int unwind_on_signal_p = 0; |
| 95 | static void |
| 96 | show_unwind_on_signal_p (struct ui_file *file, int from_tty, |
| 97 | struct cmd_list_element *c, const char *value) |
| 98 | { |
| 99 | fprintf_filtered (file, |
| 100 | _("Unwinding of stack if a signal is " |
| 101 | "received while in a call dummy is %s.\n"), |
| 102 | value); |
| 103 | } |
| 104 | |
| 105 | /* This boolean tells what gdb should do if a std::terminate call is |
| 106 | made while in a function called from gdb (call dummy). |
| 107 | As the confines of a single dummy stack prohibit out-of-frame |
| 108 | handlers from handling a raised exception, and as out-of-frame |
| 109 | handlers are common in C++, this can lead to no handler being found |
| 110 | by the unwinder, and a std::terminate call. This is a false positive. |
| 111 | If set, gdb unwinds the stack and restores the context to what it |
| 112 | was before the call. |
| 113 | |
| 114 | The default is to unwind the frame if a std::terminate call is |
| 115 | made. */ |
| 116 | |
| 117 | static int unwind_on_terminating_exception_p = 1; |
| 118 | |
| 119 | static void |
| 120 | show_unwind_on_terminating_exception_p (struct ui_file *file, int from_tty, |
| 121 | struct cmd_list_element *c, |
| 122 | const char *value) |
| 123 | |
| 124 | { |
| 125 | fprintf_filtered (file, |
| 126 | _("Unwind stack if a C++ exception is " |
| 127 | "unhandled while in a call dummy is %s.\n"), |
| 128 | value); |
| 129 | } |
| 130 | |
| 131 | /* Perform the standard coercions that are specified |
| 132 | for arguments to be passed to C or Ada functions. |
| 133 | |
| 134 | If PARAM_TYPE is non-NULL, it is the expected parameter type. |
| 135 | IS_PROTOTYPED is non-zero if the function declaration is prototyped. |
| 136 | SP is the stack pointer were additional data can be pushed (updating |
| 137 | its value as needed). */ |
| 138 | |
| 139 | static struct value * |
| 140 | value_arg_coerce (struct gdbarch *gdbarch, struct value *arg, |
| 141 | struct type *param_type, int is_prototyped, CORE_ADDR *sp) |
| 142 | { |
| 143 | const struct builtin_type *builtin = builtin_type (gdbarch); |
| 144 | struct type *arg_type = check_typedef (value_type (arg)); |
| 145 | struct type *type |
| 146 | = param_type ? check_typedef (param_type) : arg_type; |
| 147 | |
| 148 | /* Perform any Ada-specific coercion first. */ |
| 149 | if (current_language->la_language == language_ada) |
| 150 | arg = ada_convert_actual (arg, type); |
| 151 | |
| 152 | /* Force the value to the target if we will need its address. At |
| 153 | this point, we could allocate arguments on the stack instead of |
| 154 | calling malloc if we knew that their addresses would not be |
| 155 | saved by the called function. */ |
| 156 | arg = value_coerce_to_target (arg); |
| 157 | |
| 158 | switch (TYPE_CODE (type)) |
| 159 | { |
| 160 | case TYPE_CODE_REF: |
| 161 | { |
| 162 | struct value *new_value; |
| 163 | |
| 164 | if (TYPE_CODE (arg_type) == TYPE_CODE_REF) |
| 165 | return value_cast_pointers (type, arg, 0); |
| 166 | |
| 167 | /* Cast the value to the reference's target type, and then |
| 168 | convert it back to a reference. This will issue an error |
| 169 | if the value was not previously in memory - in some cases |
| 170 | we should clearly be allowing this, but how? */ |
| 171 | new_value = value_cast (TYPE_TARGET_TYPE (type), arg); |
| 172 | new_value = value_ref (new_value); |
| 173 | return new_value; |
| 174 | } |
| 175 | case TYPE_CODE_INT: |
| 176 | case TYPE_CODE_CHAR: |
| 177 | case TYPE_CODE_BOOL: |
| 178 | case TYPE_CODE_ENUM: |
| 179 | /* If we don't have a prototype, coerce to integer type if necessary. */ |
| 180 | if (!is_prototyped) |
| 181 | { |
| 182 | if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_int)) |
| 183 | type = builtin->builtin_int; |
| 184 | } |
| 185 | /* Currently all target ABIs require at least the width of an integer |
| 186 | type for an argument. We may have to conditionalize the following |
| 187 | type coercion for future targets. */ |
| 188 | if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_int)) |
| 189 | type = builtin->builtin_int; |
| 190 | break; |
| 191 | case TYPE_CODE_FLT: |
| 192 | if (!is_prototyped && coerce_float_to_double_p) |
| 193 | { |
| 194 | if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_double)) |
| 195 | type = builtin->builtin_double; |
| 196 | else if (TYPE_LENGTH (type) > TYPE_LENGTH (builtin->builtin_double)) |
| 197 | type = builtin->builtin_long_double; |
| 198 | } |
| 199 | break; |
| 200 | case TYPE_CODE_FUNC: |
| 201 | type = lookup_pointer_type (type); |
| 202 | break; |
| 203 | case TYPE_CODE_ARRAY: |
| 204 | /* Arrays are coerced to pointers to their first element, unless |
| 205 | they are vectors, in which case we want to leave them alone, |
| 206 | because they are passed by value. */ |
| 207 | if (current_language->c_style_arrays) |
| 208 | if (!TYPE_VECTOR (type)) |
| 209 | type = lookup_pointer_type (TYPE_TARGET_TYPE (type)); |
| 210 | break; |
| 211 | case TYPE_CODE_UNDEF: |
| 212 | case TYPE_CODE_PTR: |
| 213 | case TYPE_CODE_STRUCT: |
| 214 | case TYPE_CODE_UNION: |
| 215 | case TYPE_CODE_VOID: |
| 216 | case TYPE_CODE_SET: |
| 217 | case TYPE_CODE_RANGE: |
| 218 | case TYPE_CODE_STRING: |
| 219 | case TYPE_CODE_ERROR: |
| 220 | case TYPE_CODE_MEMBERPTR: |
| 221 | case TYPE_CODE_METHODPTR: |
| 222 | case TYPE_CODE_METHOD: |
| 223 | case TYPE_CODE_COMPLEX: |
| 224 | default: |
| 225 | break; |
| 226 | } |
| 227 | |
| 228 | return value_cast (type, arg); |
| 229 | } |
| 230 | |
| 231 | /* Return the return type of a function with its first instruction exactly at |
| 232 | the PC address. Return NULL otherwise. */ |
| 233 | |
| 234 | static struct type * |
| 235 | find_function_return_type (CORE_ADDR pc) |
| 236 | { |
| 237 | struct symbol *sym = find_pc_function (pc); |
| 238 | |
| 239 | if (sym != NULL && BLOCK_START (SYMBOL_BLOCK_VALUE (sym)) == pc |
| 240 | && SYMBOL_TYPE (sym) != NULL) |
| 241 | return TYPE_TARGET_TYPE (SYMBOL_TYPE (sym)); |
| 242 | |
| 243 | return NULL; |
| 244 | } |
| 245 | |
| 246 | /* Determine a function's address and its return type from its value. |
| 247 | Calls error() if the function is not valid for calling. */ |
| 248 | |
| 249 | CORE_ADDR |
| 250 | find_function_addr (struct value *function, struct type **retval_type) |
| 251 | { |
| 252 | struct type *ftype = check_typedef (value_type (function)); |
| 253 | struct gdbarch *gdbarch = get_type_arch (ftype); |
| 254 | struct type *value_type = NULL; |
| 255 | /* Initialize it just to avoid a GCC false warning. */ |
| 256 | CORE_ADDR funaddr = 0; |
| 257 | |
| 258 | /* If it's a member function, just look at the function |
| 259 | part of it. */ |
| 260 | |
| 261 | /* Determine address to call. */ |
| 262 | if (TYPE_CODE (ftype) == TYPE_CODE_FUNC |
| 263 | || TYPE_CODE (ftype) == TYPE_CODE_METHOD) |
| 264 | funaddr = value_address (function); |
| 265 | else if (TYPE_CODE (ftype) == TYPE_CODE_PTR) |
| 266 | { |
| 267 | funaddr = value_as_address (function); |
| 268 | ftype = check_typedef (TYPE_TARGET_TYPE (ftype)); |
| 269 | if (TYPE_CODE (ftype) == TYPE_CODE_FUNC |
| 270 | || TYPE_CODE (ftype) == TYPE_CODE_METHOD) |
| 271 | funaddr = gdbarch_convert_from_func_ptr_addr (gdbarch, funaddr, |
| 272 | ¤t_target); |
| 273 | } |
| 274 | if (TYPE_CODE (ftype) == TYPE_CODE_FUNC |
| 275 | || TYPE_CODE (ftype) == TYPE_CODE_METHOD) |
| 276 | { |
| 277 | value_type = TYPE_TARGET_TYPE (ftype); |
| 278 | |
| 279 | if (TYPE_GNU_IFUNC (ftype)) |
| 280 | { |
| 281 | funaddr = gnu_ifunc_resolve_addr (gdbarch, funaddr); |
| 282 | |
| 283 | /* Skip querying the function symbol if no RETVAL_TYPE has been |
| 284 | asked for. */ |
| 285 | if (retval_type) |
| 286 | value_type = find_function_return_type (funaddr); |
| 287 | } |
| 288 | } |
| 289 | else if (TYPE_CODE (ftype) == TYPE_CODE_INT) |
| 290 | { |
| 291 | /* Handle the case of functions lacking debugging info. |
| 292 | Their values are characters since their addresses are char. */ |
| 293 | if (TYPE_LENGTH (ftype) == 1) |
| 294 | funaddr = value_as_address (value_addr (function)); |
| 295 | else |
| 296 | { |
| 297 | /* Handle function descriptors lacking debug info. */ |
| 298 | int found_descriptor = 0; |
| 299 | |
| 300 | funaddr = 0; /* pacify "gcc -Werror" */ |
| 301 | if (VALUE_LVAL (function) == lval_memory) |
| 302 | { |
| 303 | CORE_ADDR nfunaddr; |
| 304 | |
| 305 | funaddr = value_as_address (value_addr (function)); |
| 306 | nfunaddr = funaddr; |
| 307 | funaddr = gdbarch_convert_from_func_ptr_addr (gdbarch, funaddr, |
| 308 | ¤t_target); |
| 309 | if (funaddr != nfunaddr) |
| 310 | found_descriptor = 1; |
| 311 | } |
| 312 | if (!found_descriptor) |
| 313 | /* Handle integer used as address of a function. */ |
| 314 | funaddr = (CORE_ADDR) value_as_long (function); |
| 315 | } |
| 316 | } |
| 317 | else |
| 318 | error (_("Invalid data type for function to be called.")); |
| 319 | |
| 320 | if (retval_type != NULL) |
| 321 | *retval_type = value_type; |
| 322 | return funaddr + gdbarch_deprecated_function_start_offset (gdbarch); |
| 323 | } |
| 324 | |
| 325 | /* For CALL_DUMMY_ON_STACK, push a breakpoint sequence that the called |
| 326 | function returns to. */ |
| 327 | |
| 328 | static CORE_ADDR |
| 329 | push_dummy_code (struct gdbarch *gdbarch, |
| 330 | CORE_ADDR sp, CORE_ADDR funaddr, |
| 331 | struct value **args, int nargs, |
| 332 | struct type *value_type, |
| 333 | CORE_ADDR *real_pc, CORE_ADDR *bp_addr, |
| 334 | struct regcache *regcache) |
| 335 | { |
| 336 | gdb_assert (gdbarch_push_dummy_code_p (gdbarch)); |
| 337 | |
| 338 | return gdbarch_push_dummy_code (gdbarch, sp, funaddr, |
| 339 | args, nargs, value_type, real_pc, bp_addr, |
| 340 | regcache); |
| 341 | } |
| 342 | |
| 343 | /* Fetch the name of the function at FUNADDR. |
| 344 | This is used in printing an error message for call_function_by_hand. |
| 345 | BUF is used to print FUNADDR in hex if the function name cannot be |
| 346 | determined. It must be large enough to hold formatted result of |
| 347 | RAW_FUNCTION_ADDRESS_FORMAT. */ |
| 348 | |
| 349 | static const char * |
| 350 | get_function_name (CORE_ADDR funaddr, char *buf, int buf_size) |
| 351 | { |
| 352 | { |
| 353 | struct symbol *symbol = find_pc_function (funaddr); |
| 354 | |
| 355 | if (symbol) |
| 356 | return SYMBOL_PRINT_NAME (symbol); |
| 357 | } |
| 358 | |
| 359 | { |
| 360 | /* Try the minimal symbols. */ |
| 361 | struct bound_minimal_symbol msymbol = lookup_minimal_symbol_by_pc (funaddr); |
| 362 | |
| 363 | if (msymbol.minsym) |
| 364 | return MSYMBOL_PRINT_NAME (msymbol.minsym); |
| 365 | } |
| 366 | |
| 367 | { |
| 368 | char *tmp = xstrprintf (_(RAW_FUNCTION_ADDRESS_FORMAT), |
| 369 | hex_string (funaddr)); |
| 370 | |
| 371 | gdb_assert (strlen (tmp) + 1 <= buf_size); |
| 372 | strcpy (buf, tmp); |
| 373 | xfree (tmp); |
| 374 | return buf; |
| 375 | } |
| 376 | } |
| 377 | |
| 378 | /* All the meta data necessary to extract the call's return value. */ |
| 379 | |
| 380 | struct call_return_meta_info |
| 381 | { |
| 382 | /* The caller frame's architecture. */ |
| 383 | struct gdbarch *gdbarch; |
| 384 | |
| 385 | /* The called function. */ |
| 386 | struct value *function; |
| 387 | |
| 388 | /* The return value's type. */ |
| 389 | struct type *value_type; |
| 390 | |
| 391 | /* Are we returning a value using a structure return or a normal |
| 392 | value return? */ |
| 393 | int struct_return_p; |
| 394 | |
| 395 | /* If using a structure return, this is the structure's address. */ |
| 396 | CORE_ADDR struct_addr; |
| 397 | |
| 398 | /* Whether stack temporaries are enabled. */ |
| 399 | int stack_temporaries_enabled; |
| 400 | }; |
| 401 | |
| 402 | /* Extract the called function's return value. */ |
| 403 | |
| 404 | static struct value * |
| 405 | get_call_return_value (struct call_return_meta_info *ri) |
| 406 | { |
| 407 | struct value *retval = NULL; |
| 408 | int stack_temporaries = thread_stack_temporaries_enabled_p (inferior_ptid); |
| 409 | |
| 410 | if (TYPE_CODE (ri->value_type) == TYPE_CODE_VOID) |
| 411 | retval = allocate_value (ri->value_type); |
| 412 | else if (ri->struct_return_p) |
| 413 | { |
| 414 | if (stack_temporaries) |
| 415 | { |
| 416 | retval = value_from_contents_and_address (ri->value_type, NULL, |
| 417 | ri->struct_addr); |
| 418 | push_thread_stack_temporary (inferior_ptid, retval); |
| 419 | } |
| 420 | else |
| 421 | { |
| 422 | retval = allocate_value (ri->value_type); |
| 423 | read_value_memory (retval, 0, 1, ri->struct_addr, |
| 424 | value_contents_raw (retval), |
| 425 | TYPE_LENGTH (ri->value_type)); |
| 426 | } |
| 427 | } |
| 428 | else |
| 429 | { |
| 430 | retval = allocate_value (ri->value_type); |
| 431 | gdbarch_return_value (ri->gdbarch, ri->function, ri->value_type, |
| 432 | get_current_regcache (), |
| 433 | value_contents_raw (retval), NULL); |
| 434 | if (stack_temporaries && class_or_union_p (ri->value_type)) |
| 435 | { |
| 436 | /* Values of class type returned in registers are copied onto |
| 437 | the stack and their lval_type set to lval_memory. This is |
| 438 | required because further evaluation of the expression |
| 439 | could potentially invoke methods on the return value |
| 440 | requiring GDB to evaluate the "this" pointer. To evaluate |
| 441 | the this pointer, GDB needs the memory address of the |
| 442 | value. */ |
| 443 | value_force_lval (retval, ri->struct_addr); |
| 444 | push_thread_stack_temporary (inferior_ptid, retval); |
| 445 | } |
| 446 | } |
| 447 | |
| 448 | gdb_assert (retval != NULL); |
| 449 | return retval; |
| 450 | } |
| 451 | |
| 452 | /* Data for the FSM that manages an infcall. It's main job is to |
| 453 | record the called function's return value. */ |
| 454 | |
| 455 | struct call_thread_fsm |
| 456 | { |
| 457 | /* The base class. */ |
| 458 | struct thread_fsm thread_fsm; |
| 459 | |
| 460 | /* All the info necessary to be able to extract the return |
| 461 | value. */ |
| 462 | struct call_return_meta_info return_meta_info; |
| 463 | |
| 464 | /* The called function's return value. This is extracted from the |
| 465 | target before the dummy frame is popped. */ |
| 466 | struct value *return_value; |
| 467 | }; |
| 468 | |
| 469 | static int call_thread_fsm_should_stop (struct thread_fsm *self); |
| 470 | static int call_thread_fsm_should_notify_stop (struct thread_fsm *self); |
| 471 | |
| 472 | /* call_thread_fsm's vtable. */ |
| 473 | |
| 474 | static struct thread_fsm_ops call_thread_fsm_ops = |
| 475 | { |
| 476 | NULL, /*dtor */ |
| 477 | NULL, /* clean_up */ |
| 478 | call_thread_fsm_should_stop, |
| 479 | NULL, /* return_value */ |
| 480 | NULL, /* async_reply_reason*/ |
| 481 | call_thread_fsm_should_notify_stop, |
| 482 | }; |
| 483 | |
| 484 | /* Allocate a new call_thread_fsm object. */ |
| 485 | |
| 486 | static struct call_thread_fsm * |
| 487 | new_call_thread_fsm (struct gdbarch *gdbarch, struct value *function, |
| 488 | struct type *value_type, |
| 489 | int struct_return_p, CORE_ADDR struct_addr) |
| 490 | { |
| 491 | struct call_thread_fsm *sm; |
| 492 | |
| 493 | sm = XCNEW (struct call_thread_fsm); |
| 494 | thread_fsm_ctor (&sm->thread_fsm, &call_thread_fsm_ops); |
| 495 | |
| 496 | sm->return_meta_info.gdbarch = gdbarch; |
| 497 | sm->return_meta_info.function = function; |
| 498 | sm->return_meta_info.value_type = value_type; |
| 499 | sm->return_meta_info.struct_return_p = struct_return_p; |
| 500 | sm->return_meta_info.struct_addr = struct_addr; |
| 501 | |
| 502 | return sm; |
| 503 | } |
| 504 | |
| 505 | /* Implementation of should_stop method for infcalls. */ |
| 506 | |
| 507 | static int |
| 508 | call_thread_fsm_should_stop (struct thread_fsm *self) |
| 509 | { |
| 510 | struct call_thread_fsm *f = (struct call_thread_fsm *) self; |
| 511 | |
| 512 | if (stop_stack_dummy == STOP_STACK_DUMMY) |
| 513 | { |
| 514 | /* Done. */ |
| 515 | thread_fsm_set_finished (self); |
| 516 | |
| 517 | /* Stash the return value before the dummy frame is popped and |
| 518 | registers are restored to what they were before the |
| 519 | call.. */ |
| 520 | f->return_value = get_call_return_value (&f->return_meta_info); |
| 521 | |
| 522 | /* Break out of wait_sync_command_done. */ |
| 523 | async_enable_stdin (); |
| 524 | } |
| 525 | |
| 526 | return 1; |
| 527 | } |
| 528 | |
| 529 | /* Implementation of should_notify_stop method for infcalls. */ |
| 530 | |
| 531 | static int |
| 532 | call_thread_fsm_should_notify_stop (struct thread_fsm *self) |
| 533 | { |
| 534 | if (thread_fsm_finished_p (self)) |
| 535 | { |
| 536 | /* Infcall succeeded. Be silent and proceed with evaluating the |
| 537 | expression. */ |
| 538 | return 0; |
| 539 | } |
| 540 | |
| 541 | /* Something wrong happened. E.g., an unexpected breakpoint |
| 542 | triggered, or a signal was intercepted. Notify the stop. */ |
| 543 | return 1; |
| 544 | } |
| 545 | |
| 546 | /* Subroutine of call_function_by_hand to simplify it. |
| 547 | Start up the inferior and wait for it to stop. |
| 548 | Return the exception if there's an error, or an exception with |
| 549 | reason >= 0 if there's no error. |
| 550 | |
| 551 | This is done inside a TRY_CATCH so the caller needn't worry about |
| 552 | thrown errors. The caller should rethrow if there's an error. */ |
| 553 | |
| 554 | static struct gdb_exception |
| 555 | run_inferior_call (struct call_thread_fsm *sm, |
| 556 | struct thread_info *call_thread, CORE_ADDR real_pc) |
| 557 | { |
| 558 | struct gdb_exception caught_error = exception_none; |
| 559 | int saved_in_infcall = call_thread->control.in_infcall; |
| 560 | ptid_t call_thread_ptid = call_thread->ptid; |
| 561 | int saved_sync_execution = sync_execution; |
| 562 | int was_running = call_thread->state == THREAD_RUNNING; |
| 563 | int saved_interpreter_async = interpreter_async; |
| 564 | |
| 565 | /* Infcalls run synchronously, in the foreground. */ |
| 566 | sync_execution = 1; |
| 567 | /* So that we don't print the prompt prematurely in |
| 568 | fetch_inferior_event. */ |
| 569 | interpreter_async = 0; |
| 570 | |
| 571 | call_thread->control.in_infcall = 1; |
| 572 | |
| 573 | clear_proceed_status (0); |
| 574 | |
| 575 | /* Associate the FSM with the thread after clear_proceed_status |
| 576 | (otherwise it'd clear this FSM), and before anything throws, so |
| 577 | we don't leak it (and any resources it manages). */ |
| 578 | call_thread->thread_fsm = &sm->thread_fsm; |
| 579 | |
| 580 | disable_watchpoints_before_interactive_call_start (); |
| 581 | |
| 582 | /* We want to print return value, please... */ |
| 583 | call_thread->control.proceed_to_finish = 1; |
| 584 | |
| 585 | TRY |
| 586 | { |
| 587 | proceed (real_pc, GDB_SIGNAL_0); |
| 588 | |
| 589 | /* Inferior function calls are always synchronous, even if the |
| 590 | target supports asynchronous execution. */ |
| 591 | wait_sync_command_done (); |
| 592 | } |
| 593 | CATCH (e, RETURN_MASK_ALL) |
| 594 | { |
| 595 | caught_error = e; |
| 596 | } |
| 597 | END_CATCH |
| 598 | |
| 599 | /* If GDB was previously in sync execution mode, then ensure that it |
| 600 | remains so. normal_stop calls async_enable_stdin, so reset it |
| 601 | again here. In other cases, stdin will be re-enabled by |
| 602 | inferior_event_handler, when an exception is thrown. */ |
| 603 | sync_execution = saved_sync_execution; |
| 604 | interpreter_async = saved_interpreter_async; |
| 605 | |
| 606 | /* At this point the current thread may have changed. Refresh |
| 607 | CALL_THREAD as it could be invalid if its thread has exited. */ |
| 608 | call_thread = find_thread_ptid (call_thread_ptid); |
| 609 | |
| 610 | /* If the infcall does NOT succeed, normal_stop will have already |
| 611 | finished the thread states. However, on success, normal_stop |
| 612 | defers here, so that we can set back the thread states to what |
| 613 | they were before the call. Note that we must also finish the |
| 614 | state of new threads that might have spawned while the call was |
| 615 | running. The main cases to handle are: |
| 616 | |
| 617 | - "(gdb) print foo ()", or any other command that evaluates an |
| 618 | expression at the prompt. (The thread was marked stopped before.) |
| 619 | |
| 620 | - "(gdb) break foo if return_false()" or similar cases where we |
| 621 | do an infcall while handling an event (while the thread is still |
| 622 | marked running). In this example, whether the condition |
| 623 | evaluates true and thus we'll present a user-visible stop is |
| 624 | decided elsewhere. */ |
| 625 | if (!was_running |
| 626 | && ptid_equal (call_thread_ptid, inferior_ptid) |
| 627 | && stop_stack_dummy == STOP_STACK_DUMMY) |
| 628 | finish_thread_state (user_visible_resume_ptid (0)); |
| 629 | |
| 630 | enable_watchpoints_after_interactive_call_stop (); |
| 631 | |
| 632 | /* Call breakpoint_auto_delete on the current contents of the bpstat |
| 633 | of inferior call thread. |
| 634 | If all error()s out of proceed ended up calling normal_stop |
| 635 | (and perhaps they should; it already does in the special case |
| 636 | of error out of resume()), then we wouldn't need this. */ |
| 637 | if (caught_error.reason < 0) |
| 638 | { |
| 639 | if (call_thread != NULL) |
| 640 | breakpoint_auto_delete (call_thread->control.stop_bpstat); |
| 641 | } |
| 642 | |
| 643 | if (call_thread != NULL) |
| 644 | call_thread->control.in_infcall = saved_in_infcall; |
| 645 | |
| 646 | return caught_error; |
| 647 | } |
| 648 | |
| 649 | /* A cleanup function that calls delete_std_terminate_breakpoint. */ |
| 650 | static void |
| 651 | cleanup_delete_std_terminate_breakpoint (void *ignore) |
| 652 | { |
| 653 | delete_std_terminate_breakpoint (); |
| 654 | } |
| 655 | |
| 656 | /* See infcall.h. */ |
| 657 | |
| 658 | struct value * |
| 659 | call_function_by_hand (struct value *function, int nargs, struct value **args) |
| 660 | { |
| 661 | return call_function_by_hand_dummy (function, nargs, args, NULL, NULL); |
| 662 | } |
| 663 | |
| 664 | /* All this stuff with a dummy frame may seem unnecessarily complicated |
| 665 | (why not just save registers in GDB?). The purpose of pushing a dummy |
| 666 | frame which looks just like a real frame is so that if you call a |
| 667 | function and then hit a breakpoint (get a signal, etc), "backtrace" |
| 668 | will look right. Whether the backtrace needs to actually show the |
| 669 | stack at the time the inferior function was called is debatable, but |
| 670 | it certainly needs to not display garbage. So if you are contemplating |
| 671 | making dummy frames be different from normal frames, consider that. */ |
| 672 | |
| 673 | /* Perform a function call in the inferior. |
| 674 | ARGS is a vector of values of arguments (NARGS of them). |
| 675 | FUNCTION is a value, the function to be called. |
| 676 | Returns a value representing what the function returned. |
| 677 | May fail to return, if a breakpoint or signal is hit |
| 678 | during the execution of the function. |
| 679 | |
| 680 | ARGS is modified to contain coerced values. */ |
| 681 | |
| 682 | struct value * |
| 683 | call_function_by_hand_dummy (struct value *function, |
| 684 | int nargs, struct value **args, |
| 685 | dummy_frame_dtor_ftype *dummy_dtor, |
| 686 | void *dummy_dtor_data) |
| 687 | { |
| 688 | CORE_ADDR sp; |
| 689 | struct type *values_type, *target_values_type; |
| 690 | unsigned char struct_return = 0, hidden_first_param_p = 0; |
| 691 | CORE_ADDR struct_addr = 0; |
| 692 | struct infcall_control_state *inf_status; |
| 693 | struct cleanup *inf_status_cleanup; |
| 694 | struct infcall_suspend_state *caller_state; |
| 695 | CORE_ADDR funaddr; |
| 696 | CORE_ADDR real_pc; |
| 697 | struct type *ftype = check_typedef (value_type (function)); |
| 698 | CORE_ADDR bp_addr; |
| 699 | struct frame_id dummy_id; |
| 700 | struct cleanup *args_cleanup; |
| 701 | struct frame_info *frame; |
| 702 | struct gdbarch *gdbarch; |
| 703 | struct cleanup *terminate_bp_cleanup; |
| 704 | ptid_t call_thread_ptid; |
| 705 | struct gdb_exception e; |
| 706 | char name_buf[RAW_FUNCTION_ADDRESS_SIZE]; |
| 707 | int stack_temporaries = thread_stack_temporaries_enabled_p (inferior_ptid); |
| 708 | |
| 709 | if (TYPE_CODE (ftype) == TYPE_CODE_PTR) |
| 710 | ftype = check_typedef (TYPE_TARGET_TYPE (ftype)); |
| 711 | |
| 712 | if (!target_has_execution) |
| 713 | noprocess (); |
| 714 | |
| 715 | if (get_traceframe_number () >= 0) |
| 716 | error (_("May not call functions while looking at trace frames.")); |
| 717 | |
| 718 | if (execution_direction == EXEC_REVERSE) |
| 719 | error (_("Cannot call functions in reverse mode.")); |
| 720 | |
| 721 | frame = get_current_frame (); |
| 722 | gdbarch = get_frame_arch (frame); |
| 723 | |
| 724 | if (!gdbarch_push_dummy_call_p (gdbarch)) |
| 725 | error (_("This target does not support function calls.")); |
| 726 | |
| 727 | /* A cleanup for the inferior status. |
| 728 | This is only needed while we're preparing the inferior function call. */ |
| 729 | inf_status = save_infcall_control_state (); |
| 730 | inf_status_cleanup |
| 731 | = make_cleanup_restore_infcall_control_state (inf_status); |
| 732 | |
| 733 | /* Save the caller's registers and other state associated with the |
| 734 | inferior itself so that they can be restored once the |
| 735 | callee returns. To allow nested calls the registers are (further |
| 736 | down) pushed onto a dummy frame stack. Include a cleanup (which |
| 737 | is tossed once the regcache has been pushed). */ |
| 738 | caller_state = save_infcall_suspend_state (); |
| 739 | make_cleanup_restore_infcall_suspend_state (caller_state); |
| 740 | |
| 741 | /* Ensure that the initial SP is correctly aligned. */ |
| 742 | { |
| 743 | CORE_ADDR old_sp = get_frame_sp (frame); |
| 744 | |
| 745 | if (gdbarch_frame_align_p (gdbarch)) |
| 746 | { |
| 747 | sp = gdbarch_frame_align (gdbarch, old_sp); |
| 748 | /* NOTE: cagney/2003-08-13: Skip the "red zone". For some |
| 749 | ABIs, a function can use memory beyond the inner most stack |
| 750 | address. AMD64 called that region the "red zone". Skip at |
| 751 | least the "red zone" size before allocating any space on |
| 752 | the stack. */ |
| 753 | if (gdbarch_inner_than (gdbarch, 1, 2)) |
| 754 | sp -= gdbarch_frame_red_zone_size (gdbarch); |
| 755 | else |
| 756 | sp += gdbarch_frame_red_zone_size (gdbarch); |
| 757 | /* Still aligned? */ |
| 758 | gdb_assert (sp == gdbarch_frame_align (gdbarch, sp)); |
| 759 | /* NOTE: cagney/2002-09-18: |
| 760 | |
| 761 | On a RISC architecture, a void parameterless generic dummy |
| 762 | frame (i.e., no parameters, no result) typically does not |
| 763 | need to push anything the stack and hence can leave SP and |
| 764 | FP. Similarly, a frameless (possibly leaf) function does |
| 765 | not push anything on the stack and, hence, that too can |
| 766 | leave FP and SP unchanged. As a consequence, a sequence of |
| 767 | void parameterless generic dummy frame calls to frameless |
| 768 | functions will create a sequence of effectively identical |
| 769 | frames (SP, FP and TOS and PC the same). This, not |
| 770 | suprisingly, results in what appears to be a stack in an |
| 771 | infinite loop --- when GDB tries to find a generic dummy |
| 772 | frame on the internal dummy frame stack, it will always |
| 773 | find the first one. |
| 774 | |
| 775 | To avoid this problem, the code below always grows the |
| 776 | stack. That way, two dummy frames can never be identical. |
| 777 | It does burn a few bytes of stack but that is a small price |
| 778 | to pay :-). */ |
| 779 | if (sp == old_sp) |
| 780 | { |
| 781 | if (gdbarch_inner_than (gdbarch, 1, 2)) |
| 782 | /* Stack grows down. */ |
| 783 | sp = gdbarch_frame_align (gdbarch, old_sp - 1); |
| 784 | else |
| 785 | /* Stack grows up. */ |
| 786 | sp = gdbarch_frame_align (gdbarch, old_sp + 1); |
| 787 | } |
| 788 | /* SP may have underflown address zero here from OLD_SP. Memory access |
| 789 | functions will probably fail in such case but that is a target's |
| 790 | problem. */ |
| 791 | } |
| 792 | else |
| 793 | /* FIXME: cagney/2002-09-18: Hey, you loose! |
| 794 | |
| 795 | Who knows how badly aligned the SP is! |
| 796 | |
| 797 | If the generic dummy frame ends up empty (because nothing is |
| 798 | pushed) GDB won't be able to correctly perform back traces. |
| 799 | If a target is having trouble with backtraces, first thing to |
| 800 | do is add FRAME_ALIGN() to the architecture vector. If that |
| 801 | fails, try dummy_id(). |
| 802 | |
| 803 | If the ABI specifies a "Red Zone" (see the doco) the code |
| 804 | below will quietly trash it. */ |
| 805 | sp = old_sp; |
| 806 | |
| 807 | /* Skip over the stack temporaries that might have been generated during |
| 808 | the evaluation of an expression. */ |
| 809 | if (stack_temporaries) |
| 810 | { |
| 811 | struct value *lastval; |
| 812 | |
| 813 | lastval = get_last_thread_stack_temporary (inferior_ptid); |
| 814 | if (lastval != NULL) |
| 815 | { |
| 816 | CORE_ADDR lastval_addr = value_address (lastval); |
| 817 | |
| 818 | if (gdbarch_inner_than (gdbarch, 1, 2)) |
| 819 | { |
| 820 | gdb_assert (sp >= lastval_addr); |
| 821 | sp = lastval_addr; |
| 822 | } |
| 823 | else |
| 824 | { |
| 825 | gdb_assert (sp <= lastval_addr); |
| 826 | sp = lastval_addr + TYPE_LENGTH (value_type (lastval)); |
| 827 | } |
| 828 | |
| 829 | if (gdbarch_frame_align_p (gdbarch)) |
| 830 | sp = gdbarch_frame_align (gdbarch, sp); |
| 831 | } |
| 832 | } |
| 833 | } |
| 834 | |
| 835 | funaddr = find_function_addr (function, &values_type); |
| 836 | if (!values_type) |
| 837 | values_type = builtin_type (gdbarch)->builtin_int; |
| 838 | |
| 839 | values_type = check_typedef (values_type); |
| 840 | |
| 841 | /* Are we returning a value using a structure return (passing a |
| 842 | hidden argument pointing to storage) or a normal value return? |
| 843 | There are two cases: language-mandated structure return and |
| 844 | target ABI structure return. The variable STRUCT_RETURN only |
| 845 | describes the latter. The language version is handled by passing |
| 846 | the return location as the first parameter to the function, |
| 847 | even preceding "this". This is different from the target |
| 848 | ABI version, which is target-specific; for instance, on ia64 |
| 849 | the first argument is passed in out0 but the hidden structure |
| 850 | return pointer would normally be passed in r8. */ |
| 851 | |
| 852 | if (gdbarch_return_in_first_hidden_param_p (gdbarch, values_type)) |
| 853 | { |
| 854 | hidden_first_param_p = 1; |
| 855 | |
| 856 | /* Tell the target specific argument pushing routine not to |
| 857 | expect a value. */ |
| 858 | target_values_type = builtin_type (gdbarch)->builtin_void; |
| 859 | } |
| 860 | else |
| 861 | { |
| 862 | struct_return = using_struct_return (gdbarch, function, values_type); |
| 863 | target_values_type = values_type; |
| 864 | } |
| 865 | |
| 866 | observer_notify_inferior_call_pre (inferior_ptid, funaddr); |
| 867 | |
| 868 | /* Determine the location of the breakpoint (and possibly other |
| 869 | stuff) that the called function will return to. The SPARC, for a |
| 870 | function returning a structure or union, needs to make space for |
| 871 | not just the breakpoint but also an extra word containing the |
| 872 | size (?) of the structure being passed. */ |
| 873 | |
| 874 | switch (gdbarch_call_dummy_location (gdbarch)) |
| 875 | { |
| 876 | case ON_STACK: |
| 877 | { |
| 878 | const gdb_byte *bp_bytes; |
| 879 | CORE_ADDR bp_addr_as_address; |
| 880 | int bp_size; |
| 881 | |
| 882 | /* Be careful BP_ADDR is in inferior PC encoding while |
| 883 | BP_ADDR_AS_ADDRESS is a plain memory address. */ |
| 884 | |
| 885 | sp = push_dummy_code (gdbarch, sp, funaddr, args, nargs, |
| 886 | target_values_type, &real_pc, &bp_addr, |
| 887 | get_current_regcache ()); |
| 888 | |
| 889 | /* Write a legitimate instruction at the point where the infcall |
| 890 | breakpoint is going to be inserted. While this instruction |
| 891 | is never going to be executed, a user investigating the |
| 892 | memory from GDB would see this instruction instead of random |
| 893 | uninitialized bytes. We chose the breakpoint instruction |
| 894 | as it may look as the most logical one to the user and also |
| 895 | valgrind 3.7.0 needs it for proper vgdb inferior calls. |
| 896 | |
| 897 | If software breakpoints are unsupported for this target we |
| 898 | leave the user visible memory content uninitialized. */ |
| 899 | |
| 900 | bp_addr_as_address = bp_addr; |
| 901 | bp_bytes = gdbarch_breakpoint_from_pc (gdbarch, &bp_addr_as_address, |
| 902 | &bp_size); |
| 903 | if (bp_bytes != NULL) |
| 904 | write_memory (bp_addr_as_address, bp_bytes, bp_size); |
| 905 | } |
| 906 | break; |
| 907 | case AT_ENTRY_POINT: |
| 908 | { |
| 909 | CORE_ADDR dummy_addr; |
| 910 | |
| 911 | real_pc = funaddr; |
| 912 | dummy_addr = entry_point_address (); |
| 913 | |
| 914 | /* A call dummy always consists of just a single breakpoint, so |
| 915 | its address is the same as the address of the dummy. |
| 916 | |
| 917 | The actual breakpoint is inserted separatly so there is no need to |
| 918 | write that out. */ |
| 919 | bp_addr = dummy_addr; |
| 920 | break; |
| 921 | } |
| 922 | default: |
| 923 | internal_error (__FILE__, __LINE__, _("bad switch")); |
| 924 | } |
| 925 | |
| 926 | if (nargs < TYPE_NFIELDS (ftype)) |
| 927 | error (_("Too few arguments in function call.")); |
| 928 | |
| 929 | { |
| 930 | int i; |
| 931 | |
| 932 | for (i = nargs - 1; i >= 0; i--) |
| 933 | { |
| 934 | int prototyped; |
| 935 | struct type *param_type; |
| 936 | |
| 937 | /* FIXME drow/2002-05-31: Should just always mark methods as |
| 938 | prototyped. Can we respect TYPE_VARARGS? Probably not. */ |
| 939 | if (TYPE_CODE (ftype) == TYPE_CODE_METHOD) |
| 940 | prototyped = 1; |
| 941 | else if (i < TYPE_NFIELDS (ftype)) |
| 942 | prototyped = TYPE_PROTOTYPED (ftype); |
| 943 | else |
| 944 | prototyped = 0; |
| 945 | |
| 946 | if (i < TYPE_NFIELDS (ftype)) |
| 947 | param_type = TYPE_FIELD_TYPE (ftype, i); |
| 948 | else |
| 949 | param_type = NULL; |
| 950 | |
| 951 | args[i] = value_arg_coerce (gdbarch, args[i], |
| 952 | param_type, prototyped, &sp); |
| 953 | |
| 954 | if (param_type != NULL && language_pass_by_reference (param_type)) |
| 955 | args[i] = value_addr (args[i]); |
| 956 | } |
| 957 | } |
| 958 | |
| 959 | /* Reserve space for the return structure to be written on the |
| 960 | stack, if necessary. Make certain that the value is correctly |
| 961 | aligned. |
| 962 | |
| 963 | While evaluating expressions, we reserve space on the stack for |
| 964 | return values of class type even if the language ABI and the target |
| 965 | ABI do not require that the return value be passed as a hidden first |
| 966 | argument. This is because we want to store the return value as an |
| 967 | on-stack temporary while the expression is being evaluated. This |
| 968 | enables us to have chained function calls in expressions. |
| 969 | |
| 970 | Keeping the return values as on-stack temporaries while the expression |
| 971 | is being evaluated is OK because the thread is stopped until the |
| 972 | expression is completely evaluated. */ |
| 973 | |
| 974 | if (struct_return || hidden_first_param_p |
| 975 | || (stack_temporaries && class_or_union_p (values_type))) |
| 976 | { |
| 977 | if (gdbarch_inner_than (gdbarch, 1, 2)) |
| 978 | { |
| 979 | /* Stack grows downward. Align STRUCT_ADDR and SP after |
| 980 | making space for the return value. */ |
| 981 | sp -= TYPE_LENGTH (values_type); |
| 982 | if (gdbarch_frame_align_p (gdbarch)) |
| 983 | sp = gdbarch_frame_align (gdbarch, sp); |
| 984 | struct_addr = sp; |
| 985 | } |
| 986 | else |
| 987 | { |
| 988 | /* Stack grows upward. Align the frame, allocate space, and |
| 989 | then again, re-align the frame??? */ |
| 990 | if (gdbarch_frame_align_p (gdbarch)) |
| 991 | sp = gdbarch_frame_align (gdbarch, sp); |
| 992 | struct_addr = sp; |
| 993 | sp += TYPE_LENGTH (values_type); |
| 994 | if (gdbarch_frame_align_p (gdbarch)) |
| 995 | sp = gdbarch_frame_align (gdbarch, sp); |
| 996 | } |
| 997 | } |
| 998 | |
| 999 | if (hidden_first_param_p) |
| 1000 | { |
| 1001 | struct value **new_args; |
| 1002 | |
| 1003 | /* Add the new argument to the front of the argument list. */ |
| 1004 | new_args = XNEWVEC (struct value *, nargs + 1); |
| 1005 | new_args[0] = value_from_pointer (lookup_pointer_type (values_type), |
| 1006 | struct_addr); |
| 1007 | memcpy (&new_args[1], &args[0], sizeof (struct value *) * nargs); |
| 1008 | args = new_args; |
| 1009 | nargs++; |
| 1010 | args_cleanup = make_cleanup (xfree, args); |
| 1011 | } |
| 1012 | else |
| 1013 | args_cleanup = make_cleanup (null_cleanup, NULL); |
| 1014 | |
| 1015 | /* Create the dummy stack frame. Pass in the call dummy address as, |
| 1016 | presumably, the ABI code knows where, in the call dummy, the |
| 1017 | return address should be pointed. */ |
| 1018 | sp = gdbarch_push_dummy_call (gdbarch, function, get_current_regcache (), |
| 1019 | bp_addr, nargs, args, |
| 1020 | sp, struct_return, struct_addr); |
| 1021 | |
| 1022 | do_cleanups (args_cleanup); |
| 1023 | |
| 1024 | /* Set up a frame ID for the dummy frame so we can pass it to |
| 1025 | set_momentary_breakpoint. We need to give the breakpoint a frame |
| 1026 | ID so that the breakpoint code can correctly re-identify the |
| 1027 | dummy breakpoint. */ |
| 1028 | /* Sanity. The exact same SP value is returned by PUSH_DUMMY_CALL, |
| 1029 | saved as the dummy-frame TOS, and used by dummy_id to form |
| 1030 | the frame ID's stack address. */ |
| 1031 | dummy_id = frame_id_build (sp, bp_addr); |
| 1032 | |
| 1033 | /* Create a momentary breakpoint at the return address of the |
| 1034 | inferior. That way it breaks when it returns. */ |
| 1035 | |
| 1036 | { |
| 1037 | struct breakpoint *bpt, *longjmp_b; |
| 1038 | struct symtab_and_line sal; |
| 1039 | |
| 1040 | init_sal (&sal); /* initialize to zeroes */ |
| 1041 | sal.pspace = current_program_space; |
| 1042 | sal.pc = bp_addr; |
| 1043 | sal.section = find_pc_overlay (sal.pc); |
| 1044 | /* Sanity. The exact same SP value is returned by |
| 1045 | PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by |
| 1046 | dummy_id to form the frame ID's stack address. */ |
| 1047 | bpt = set_momentary_breakpoint (gdbarch, sal, dummy_id, bp_call_dummy); |
| 1048 | |
| 1049 | /* set_momentary_breakpoint invalidates FRAME. */ |
| 1050 | frame = NULL; |
| 1051 | |
| 1052 | bpt->disposition = disp_del; |
| 1053 | gdb_assert (bpt->related_breakpoint == bpt); |
| 1054 | |
| 1055 | longjmp_b = set_longjmp_breakpoint_for_call_dummy (); |
| 1056 | if (longjmp_b) |
| 1057 | { |
| 1058 | /* Link BPT into the chain of LONGJMP_B. */ |
| 1059 | bpt->related_breakpoint = longjmp_b; |
| 1060 | while (longjmp_b->related_breakpoint != bpt->related_breakpoint) |
| 1061 | longjmp_b = longjmp_b->related_breakpoint; |
| 1062 | longjmp_b->related_breakpoint = bpt; |
| 1063 | } |
| 1064 | } |
| 1065 | |
| 1066 | /* Create a breakpoint in std::terminate. |
| 1067 | If a C++ exception is raised in the dummy-frame, and the |
| 1068 | exception handler is (normally, and expected to be) out-of-frame, |
| 1069 | the default C++ handler will (wrongly) be called in an inferior |
| 1070 | function call. This is wrong, as an exception can be normally |
| 1071 | and legally handled out-of-frame. The confines of the dummy frame |
| 1072 | prevent the unwinder from finding the correct handler (or any |
| 1073 | handler, unless it is in-frame). The default handler calls |
| 1074 | std::terminate. This will kill the inferior. Assert that |
| 1075 | terminate should never be called in an inferior function |
| 1076 | call. Place a momentary breakpoint in the std::terminate function |
| 1077 | and if triggered in the call, rewind. */ |
| 1078 | if (unwind_on_terminating_exception_p) |
| 1079 | set_std_terminate_breakpoint (); |
| 1080 | |
| 1081 | /* Discard both inf_status and caller_state cleanups. |
| 1082 | From this point on we explicitly restore the associated state |
| 1083 | or discard it. */ |
| 1084 | discard_cleanups (inf_status_cleanup); |
| 1085 | |
| 1086 | /* Everything's ready, push all the info needed to restore the |
| 1087 | caller (and identify the dummy-frame) onto the dummy-frame |
| 1088 | stack. */ |
| 1089 | dummy_frame_push (caller_state, &dummy_id, inferior_ptid); |
| 1090 | if (dummy_dtor != NULL) |
| 1091 | register_dummy_frame_dtor (dummy_id, inferior_ptid, |
| 1092 | dummy_dtor, dummy_dtor_data); |
| 1093 | |
| 1094 | /* Register a clean-up for unwind_on_terminating_exception_breakpoint. */ |
| 1095 | terminate_bp_cleanup = make_cleanup (cleanup_delete_std_terminate_breakpoint, |
| 1096 | NULL); |
| 1097 | |
| 1098 | /* - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - |
| 1099 | If you're looking to implement asynchronous dummy-frames, then |
| 1100 | just below is the place to chop this function in two.. */ |
| 1101 | |
| 1102 | /* TP is invalid after run_inferior_call returns, so enclose this |
| 1103 | in a block so that it's only in scope during the time it's valid. */ |
| 1104 | { |
| 1105 | struct thread_info *tp = inferior_thread (); |
| 1106 | struct thread_fsm *saved_sm; |
| 1107 | struct call_thread_fsm *sm; |
| 1108 | |
| 1109 | /* Save the current FSM. We'll override it. */ |
| 1110 | saved_sm = tp->thread_fsm; |
| 1111 | tp->thread_fsm = NULL; |
| 1112 | |
| 1113 | /* Save this thread's ptid, we need it later but the thread |
| 1114 | may have exited. */ |
| 1115 | call_thread_ptid = tp->ptid; |
| 1116 | |
| 1117 | /* Run the inferior until it stops. */ |
| 1118 | |
| 1119 | /* Create the FSM used to manage the infcall. It tells infrun to |
| 1120 | not report the stop to the user, and captures the return value |
| 1121 | before the dummy frame is popped. run_inferior_call registers |
| 1122 | it with the thread ASAP. */ |
| 1123 | sm = new_call_thread_fsm (gdbarch, function, |
| 1124 | values_type, |
| 1125 | struct_return || hidden_first_param_p, |
| 1126 | struct_addr); |
| 1127 | |
| 1128 | e = run_inferior_call (sm, tp, real_pc); |
| 1129 | |
| 1130 | observer_notify_inferior_call_post (call_thread_ptid, funaddr); |
| 1131 | |
| 1132 | tp = find_thread_ptid (call_thread_ptid); |
| 1133 | if (tp != NULL) |
| 1134 | { |
| 1135 | /* The FSM should still be the same. */ |
| 1136 | gdb_assert (tp->thread_fsm == &sm->thread_fsm); |
| 1137 | |
| 1138 | if (thread_fsm_finished_p (tp->thread_fsm)) |
| 1139 | { |
| 1140 | struct value *retval; |
| 1141 | |
| 1142 | /* The inferior call is successful. Pop the dummy frame, |
| 1143 | which runs its destructors and restores the inferior's |
| 1144 | suspend state, and restore the inferior control |
| 1145 | state. */ |
| 1146 | dummy_frame_pop (dummy_id, call_thread_ptid); |
| 1147 | restore_infcall_control_state (inf_status); |
| 1148 | |
| 1149 | /* Get the return value. */ |
| 1150 | retval = sm->return_value; |
| 1151 | |
| 1152 | /* Clean up / destroy the call FSM, and restore the |
| 1153 | original one. */ |
| 1154 | thread_fsm_clean_up (tp->thread_fsm); |
| 1155 | thread_fsm_delete (tp->thread_fsm); |
| 1156 | tp->thread_fsm = saved_sm; |
| 1157 | |
| 1158 | maybe_remove_breakpoints (); |
| 1159 | |
| 1160 | do_cleanups (terminate_bp_cleanup); |
| 1161 | gdb_assert (retval != NULL); |
| 1162 | return retval; |
| 1163 | } |
| 1164 | |
| 1165 | /* Didn't complete. Restore previous state machine, and |
| 1166 | handle the error. */ |
| 1167 | tp->thread_fsm = saved_sm; |
| 1168 | } |
| 1169 | } |
| 1170 | |
| 1171 | /* Rethrow an error if we got one trying to run the inferior. */ |
| 1172 | |
| 1173 | if (e.reason < 0) |
| 1174 | { |
| 1175 | const char *name = get_function_name (funaddr, |
| 1176 | name_buf, sizeof (name_buf)); |
| 1177 | |
| 1178 | discard_infcall_control_state (inf_status); |
| 1179 | |
| 1180 | /* We could discard the dummy frame here if the program exited, |
| 1181 | but it will get garbage collected the next time the program is |
| 1182 | run anyway. */ |
| 1183 | |
| 1184 | switch (e.reason) |
| 1185 | { |
| 1186 | case RETURN_ERROR: |
| 1187 | throw_error (e.error, _("%s\n\ |
| 1188 | An error occurred while in a function called from GDB.\n\ |
| 1189 | Evaluation of the expression containing the function\n\ |
| 1190 | (%s) will be abandoned.\n\ |
| 1191 | When the function is done executing, GDB will silently stop."), |
| 1192 | e.message, name); |
| 1193 | case RETURN_QUIT: |
| 1194 | default: |
| 1195 | throw_exception (e); |
| 1196 | } |
| 1197 | } |
| 1198 | |
| 1199 | /* If the program has exited, or we stopped at a different thread, |
| 1200 | exit and inform the user. */ |
| 1201 | |
| 1202 | if (! target_has_execution) |
| 1203 | { |
| 1204 | const char *name = get_function_name (funaddr, |
| 1205 | name_buf, sizeof (name_buf)); |
| 1206 | |
| 1207 | /* If we try to restore the inferior status, |
| 1208 | we'll crash as the inferior is no longer running. */ |
| 1209 | discard_infcall_control_state (inf_status); |
| 1210 | |
| 1211 | /* We could discard the dummy frame here given that the program exited, |
| 1212 | but it will get garbage collected the next time the program is |
| 1213 | run anyway. */ |
| 1214 | |
| 1215 | error (_("The program being debugged exited while in a function " |
| 1216 | "called from GDB.\n" |
| 1217 | "Evaluation of the expression containing the function\n" |
| 1218 | "(%s) will be abandoned."), |
| 1219 | name); |
| 1220 | } |
| 1221 | |
| 1222 | if (! ptid_equal (call_thread_ptid, inferior_ptid)) |
| 1223 | { |
| 1224 | const char *name = get_function_name (funaddr, |
| 1225 | name_buf, sizeof (name_buf)); |
| 1226 | |
| 1227 | /* We've switched threads. This can happen if another thread gets a |
| 1228 | signal or breakpoint while our thread was running. |
| 1229 | There's no point in restoring the inferior status, |
| 1230 | we're in a different thread. */ |
| 1231 | discard_infcall_control_state (inf_status); |
| 1232 | /* Keep the dummy frame record, if the user switches back to the |
| 1233 | thread with the hand-call, we'll need it. */ |
| 1234 | if (stopped_by_random_signal) |
| 1235 | error (_("\ |
| 1236 | The program received a signal in another thread while\n\ |
| 1237 | making a function call from GDB.\n\ |
| 1238 | Evaluation of the expression containing the function\n\ |
| 1239 | (%s) will be abandoned.\n\ |
| 1240 | When the function is done executing, GDB will silently stop."), |
| 1241 | name); |
| 1242 | else |
| 1243 | error (_("\ |
| 1244 | The program stopped in another thread while making a function call from GDB.\n\ |
| 1245 | Evaluation of the expression containing the function\n\ |
| 1246 | (%s) will be abandoned.\n\ |
| 1247 | When the function is done executing, GDB will silently stop."), |
| 1248 | name); |
| 1249 | } |
| 1250 | |
| 1251 | { |
| 1252 | /* Make a copy as NAME may be in an objfile freed by dummy_frame_pop. */ |
| 1253 | char *name = xstrdup (get_function_name (funaddr, |
| 1254 | name_buf, sizeof (name_buf))); |
| 1255 | make_cleanup (xfree, name); |
| 1256 | |
| 1257 | |
| 1258 | if (stopped_by_random_signal) |
| 1259 | { |
| 1260 | /* We stopped inside the FUNCTION because of a random |
| 1261 | signal. Further execution of the FUNCTION is not |
| 1262 | allowed. */ |
| 1263 | |
| 1264 | if (unwind_on_signal_p) |
| 1265 | { |
| 1266 | /* The user wants the context restored. */ |
| 1267 | |
| 1268 | /* We must get back to the frame we were before the |
| 1269 | dummy call. */ |
| 1270 | dummy_frame_pop (dummy_id, call_thread_ptid); |
| 1271 | |
| 1272 | /* We also need to restore inferior status to that before the |
| 1273 | dummy call. */ |
| 1274 | restore_infcall_control_state (inf_status); |
| 1275 | |
| 1276 | /* FIXME: Insert a bunch of wrap_here; name can be very |
| 1277 | long if it's a C++ name with arguments and stuff. */ |
| 1278 | error (_("\ |
| 1279 | The program being debugged was signaled while in a function called from GDB.\n\ |
| 1280 | GDB has restored the context to what it was before the call.\n\ |
| 1281 | To change this behavior use \"set unwindonsignal off\".\n\ |
| 1282 | Evaluation of the expression containing the function\n\ |
| 1283 | (%s) will be abandoned."), |
| 1284 | name); |
| 1285 | } |
| 1286 | else |
| 1287 | { |
| 1288 | /* The user wants to stay in the frame where we stopped |
| 1289 | (default). |
| 1290 | Discard inferior status, we're not at the same point |
| 1291 | we started at. */ |
| 1292 | discard_infcall_control_state (inf_status); |
| 1293 | |
| 1294 | /* FIXME: Insert a bunch of wrap_here; name can be very |
| 1295 | long if it's a C++ name with arguments and stuff. */ |
| 1296 | error (_("\ |
| 1297 | The program being debugged was signaled while in a function called from GDB.\n\ |
| 1298 | GDB remains in the frame where the signal was received.\n\ |
| 1299 | To change this behavior use \"set unwindonsignal on\".\n\ |
| 1300 | Evaluation of the expression containing the function\n\ |
| 1301 | (%s) will be abandoned.\n\ |
| 1302 | When the function is done executing, GDB will silently stop."), |
| 1303 | name); |
| 1304 | } |
| 1305 | } |
| 1306 | |
| 1307 | if (stop_stack_dummy == STOP_STD_TERMINATE) |
| 1308 | { |
| 1309 | /* We must get back to the frame we were before the dummy |
| 1310 | call. */ |
| 1311 | dummy_frame_pop (dummy_id, call_thread_ptid); |
| 1312 | |
| 1313 | /* We also need to restore inferior status to that before |
| 1314 | the dummy call. */ |
| 1315 | restore_infcall_control_state (inf_status); |
| 1316 | |
| 1317 | error (_("\ |
| 1318 | The program being debugged entered a std::terminate call, most likely\n\ |
| 1319 | caused by an unhandled C++ exception. GDB blocked this call in order\n\ |
| 1320 | to prevent the program from being terminated, and has restored the\n\ |
| 1321 | context to its original state before the call.\n\ |
| 1322 | To change this behaviour use \"set unwind-on-terminating-exception off\".\n\ |
| 1323 | Evaluation of the expression containing the function (%s)\n\ |
| 1324 | will be abandoned."), |
| 1325 | name); |
| 1326 | } |
| 1327 | else if (stop_stack_dummy == STOP_NONE) |
| 1328 | { |
| 1329 | |
| 1330 | /* We hit a breakpoint inside the FUNCTION. |
| 1331 | Keep the dummy frame, the user may want to examine its state. |
| 1332 | Discard inferior status, we're not at the same point |
| 1333 | we started at. */ |
| 1334 | discard_infcall_control_state (inf_status); |
| 1335 | |
| 1336 | /* The following error message used to say "The expression |
| 1337 | which contained the function call has been discarded." |
| 1338 | It is a hard concept to explain in a few words. Ideally, |
| 1339 | GDB would be able to resume evaluation of the expression |
| 1340 | when the function finally is done executing. Perhaps |
| 1341 | someday this will be implemented (it would not be easy). */ |
| 1342 | /* FIXME: Insert a bunch of wrap_here; name can be very long if it's |
| 1343 | a C++ name with arguments and stuff. */ |
| 1344 | error (_("\ |
| 1345 | The program being debugged stopped while in a function called from GDB.\n\ |
| 1346 | Evaluation of the expression containing the function\n\ |
| 1347 | (%s) will be abandoned.\n\ |
| 1348 | When the function is done executing, GDB will silently stop."), |
| 1349 | name); |
| 1350 | } |
| 1351 | |
| 1352 | } |
| 1353 | |
| 1354 | /* The above code errors out, so ... */ |
| 1355 | gdb_assert_not_reached ("... should not be here"); |
| 1356 | } |
| 1357 | \f |
| 1358 | |
| 1359 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
| 1360 | void _initialize_infcall (void); |
| 1361 | |
| 1362 | void |
| 1363 | _initialize_infcall (void) |
| 1364 | { |
| 1365 | add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure, |
| 1366 | &coerce_float_to_double_p, _("\ |
| 1367 | Set coercion of floats to doubles when calling functions."), _("\ |
| 1368 | Show coercion of floats to doubles when calling functions"), _("\ |
| 1369 | Variables of type float should generally be converted to doubles before\n\ |
| 1370 | calling an unprototyped function, and left alone when calling a prototyped\n\ |
| 1371 | function. However, some older debug info formats do not provide enough\n\ |
| 1372 | information to determine that a function is prototyped. If this flag is\n\ |
| 1373 | set, GDB will perform the conversion for a function it considers\n\ |
| 1374 | unprototyped.\n\ |
| 1375 | The default is to perform the conversion.\n"), |
| 1376 | NULL, |
| 1377 | show_coerce_float_to_double_p, |
| 1378 | &setlist, &showlist); |
| 1379 | |
| 1380 | add_setshow_boolean_cmd ("unwindonsignal", no_class, |
| 1381 | &unwind_on_signal_p, _("\ |
| 1382 | Set unwinding of stack if a signal is received while in a call dummy."), _("\ |
| 1383 | Show unwinding of stack if a signal is received while in a call dummy."), _("\ |
| 1384 | The unwindonsignal lets the user determine what gdb should do if a signal\n\ |
| 1385 | is received while in a function called from gdb (call dummy). If set, gdb\n\ |
| 1386 | unwinds the stack and restore the context to what as it was before the call.\n\ |
| 1387 | The default is to stop in the frame where the signal was received."), |
| 1388 | NULL, |
| 1389 | show_unwind_on_signal_p, |
| 1390 | &setlist, &showlist); |
| 1391 | |
| 1392 | add_setshow_boolean_cmd ("unwind-on-terminating-exception", no_class, |
| 1393 | &unwind_on_terminating_exception_p, _("\ |
| 1394 | Set unwinding of stack if std::terminate is called while in call dummy."), _("\ |
| 1395 | Show unwinding of stack if std::terminate() is called while in a call dummy."), |
| 1396 | _("\ |
| 1397 | The unwind on terminating exception flag lets the user determine\n\ |
| 1398 | what gdb should do if a std::terminate() call is made from the\n\ |
| 1399 | default exception handler. If set, gdb unwinds the stack and restores\n\ |
| 1400 | the context to what it was before the call. If unset, gdb allows the\n\ |
| 1401 | std::terminate call to proceed.\n\ |
| 1402 | The default is to unwind the frame."), |
| 1403 | NULL, |
| 1404 | show_unwind_on_terminating_exception_p, |
| 1405 | &setlist, &showlist); |
| 1406 | |
| 1407 | } |