| 1 | /* Perform an inferior function call, for GDB, the GNU debugger. |
| 2 | |
| 3 | Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, |
| 4 | 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, |
| 5 | 2008, 2009 Free Software Foundation, Inc. |
| 6 | |
| 7 | This file is part of GDB. |
| 8 | |
| 9 | This program is free software; you can redistribute it and/or modify |
| 10 | it under the terms of the GNU General Public License as published by |
| 11 | the Free Software Foundation; either version 3 of the License, or |
| 12 | (at your option) any later version. |
| 13 | |
| 14 | This program is distributed in the hope that it will be useful, |
| 15 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | GNU General Public License for more details. |
| 18 | |
| 19 | You should have received a copy of the GNU General Public License |
| 20 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 21 | |
| 22 | #include "defs.h" |
| 23 | #include "breakpoint.h" |
| 24 | #include "target.h" |
| 25 | #include "regcache.h" |
| 26 | #include "inferior.h" |
| 27 | #include "gdb_assert.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 "gdb_string.h" |
| 35 | #include "infcall.h" |
| 36 | #include "dummy-frame.h" |
| 37 | #include "ada-lang.h" |
| 38 | #include "gdbthread.h" |
| 39 | |
| 40 | /* NOTE: cagney/2003-04-16: What's the future of this code? |
| 41 | |
| 42 | GDB needs an asynchronous expression evaluator, that means an |
| 43 | asynchronous inferior function call implementation, and that in |
| 44 | turn means restructuring the code so that it is event driven. */ |
| 45 | |
| 46 | /* How you should pass arguments to a function depends on whether it |
| 47 | was defined in K&R style or prototype style. If you define a |
| 48 | function using the K&R syntax that takes a `float' argument, then |
| 49 | callers must pass that argument as a `double'. If you define the |
| 50 | function using the prototype syntax, then you must pass the |
| 51 | argument as a `float', with no promotion. |
| 52 | |
| 53 | Unfortunately, on certain older platforms, the debug info doesn't |
| 54 | indicate reliably how each function was defined. A function type's |
| 55 | TYPE_FLAG_PROTOTYPED flag may be clear, even if the function was |
| 56 | defined in prototype style. When calling a function whose |
| 57 | TYPE_FLAG_PROTOTYPED flag is clear, GDB consults this flag to |
| 58 | decide what to do. |
| 59 | |
| 60 | For modern targets, it is proper to assume that, if the prototype |
| 61 | flag is clear, that can be trusted: `float' arguments should be |
| 62 | promoted to `double'. For some older targets, if the prototype |
| 63 | flag is clear, that doesn't tell us anything. The default is to |
| 64 | trust the debug information; the user can override this behavior |
| 65 | with "set coerce-float-to-double 0". */ |
| 66 | |
| 67 | static int coerce_float_to_double_p = 1; |
| 68 | static void |
| 69 | show_coerce_float_to_double_p (struct ui_file *file, int from_tty, |
| 70 | struct cmd_list_element *c, const char *value) |
| 71 | { |
| 72 | fprintf_filtered (file, _("\ |
| 73 | Coercion of floats to doubles when calling functions is %s.\n"), |
| 74 | value); |
| 75 | } |
| 76 | |
| 77 | /* This boolean tells what gdb should do if a signal is received while |
| 78 | in a function called from gdb (call dummy). If set, gdb unwinds |
| 79 | the stack and restore the context to what as it was before the |
| 80 | call. |
| 81 | |
| 82 | The default is to stop in the frame where the signal was received. */ |
| 83 | |
| 84 | int unwind_on_signal_p = 0; |
| 85 | static void |
| 86 | show_unwind_on_signal_p (struct ui_file *file, int from_tty, |
| 87 | struct cmd_list_element *c, const char *value) |
| 88 | { |
| 89 | fprintf_filtered (file, _("\ |
| 90 | Unwinding of stack if a signal is received while in a call dummy is %s.\n"), |
| 91 | value); |
| 92 | } |
| 93 | |
| 94 | |
| 95 | /* Perform the standard coercions that are specified |
| 96 | for arguments to be passed to C or Ada functions. |
| 97 | |
| 98 | If PARAM_TYPE is non-NULL, it is the expected parameter type. |
| 99 | IS_PROTOTYPED is non-zero if the function declaration is prototyped. |
| 100 | SP is the stack pointer were additional data can be pushed (updating |
| 101 | its value as needed). */ |
| 102 | |
| 103 | static struct value * |
| 104 | value_arg_coerce (struct gdbarch *gdbarch, struct value *arg, |
| 105 | struct type *param_type, int is_prototyped, CORE_ADDR *sp) |
| 106 | { |
| 107 | const struct builtin_type *builtin = builtin_type (gdbarch); |
| 108 | struct type *arg_type = check_typedef (value_type (arg)); |
| 109 | struct type *type |
| 110 | = param_type ? check_typedef (param_type) : arg_type; |
| 111 | |
| 112 | /* Perform any Ada-specific coercion first. */ |
| 113 | if (current_language->la_language == language_ada) |
| 114 | arg = ada_convert_actual (arg, type, sp); |
| 115 | |
| 116 | /* Force the value to the target if we will need its address. At |
| 117 | this point, we could allocate arguments on the stack instead of |
| 118 | calling malloc if we knew that their addresses would not be |
| 119 | saved by the called function. */ |
| 120 | arg = value_coerce_to_target (arg); |
| 121 | |
| 122 | switch (TYPE_CODE (type)) |
| 123 | { |
| 124 | case TYPE_CODE_REF: |
| 125 | { |
| 126 | struct value *new_value; |
| 127 | |
| 128 | if (TYPE_CODE (arg_type) == TYPE_CODE_REF) |
| 129 | return value_cast_pointers (type, arg); |
| 130 | |
| 131 | /* Cast the value to the reference's target type, and then |
| 132 | convert it back to a reference. This will issue an error |
| 133 | if the value was not previously in memory - in some cases |
| 134 | we should clearly be allowing this, but how? */ |
| 135 | new_value = value_cast (TYPE_TARGET_TYPE (type), arg); |
| 136 | new_value = value_ref (new_value); |
| 137 | return new_value; |
| 138 | } |
| 139 | case TYPE_CODE_INT: |
| 140 | case TYPE_CODE_CHAR: |
| 141 | case TYPE_CODE_BOOL: |
| 142 | case TYPE_CODE_ENUM: |
| 143 | /* If we don't have a prototype, coerce to integer type if necessary. */ |
| 144 | if (!is_prototyped) |
| 145 | { |
| 146 | if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_int)) |
| 147 | type = builtin->builtin_int; |
| 148 | } |
| 149 | /* Currently all target ABIs require at least the width of an integer |
| 150 | type for an argument. We may have to conditionalize the following |
| 151 | type coercion for future targets. */ |
| 152 | if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_int)) |
| 153 | type = builtin->builtin_int; |
| 154 | break; |
| 155 | case TYPE_CODE_FLT: |
| 156 | if (!is_prototyped && coerce_float_to_double_p) |
| 157 | { |
| 158 | if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_double)) |
| 159 | type = builtin->builtin_double; |
| 160 | else if (TYPE_LENGTH (type) > TYPE_LENGTH (builtin->builtin_double)) |
| 161 | type = builtin->builtin_long_double; |
| 162 | } |
| 163 | break; |
| 164 | case TYPE_CODE_FUNC: |
| 165 | type = lookup_pointer_type (type); |
| 166 | break; |
| 167 | case TYPE_CODE_ARRAY: |
| 168 | /* Arrays are coerced to pointers to their first element, unless |
| 169 | they are vectors, in which case we want to leave them alone, |
| 170 | because they are passed by value. */ |
| 171 | if (current_language->c_style_arrays) |
| 172 | if (!TYPE_VECTOR (type)) |
| 173 | type = lookup_pointer_type (TYPE_TARGET_TYPE (type)); |
| 174 | break; |
| 175 | case TYPE_CODE_UNDEF: |
| 176 | case TYPE_CODE_PTR: |
| 177 | case TYPE_CODE_STRUCT: |
| 178 | case TYPE_CODE_UNION: |
| 179 | case TYPE_CODE_VOID: |
| 180 | case TYPE_CODE_SET: |
| 181 | case TYPE_CODE_RANGE: |
| 182 | case TYPE_CODE_STRING: |
| 183 | case TYPE_CODE_BITSTRING: |
| 184 | case TYPE_CODE_ERROR: |
| 185 | case TYPE_CODE_MEMBERPTR: |
| 186 | case TYPE_CODE_METHODPTR: |
| 187 | case TYPE_CODE_METHOD: |
| 188 | case TYPE_CODE_COMPLEX: |
| 189 | default: |
| 190 | break; |
| 191 | } |
| 192 | |
| 193 | return value_cast (type, arg); |
| 194 | } |
| 195 | |
| 196 | /* Determine a function's address and its return type from its value. |
| 197 | Calls error() if the function is not valid for calling. */ |
| 198 | |
| 199 | CORE_ADDR |
| 200 | find_function_addr (struct value *function, struct type **retval_type) |
| 201 | { |
| 202 | struct type *ftype = check_typedef (value_type (function)); |
| 203 | enum type_code code = TYPE_CODE (ftype); |
| 204 | struct type *value_type = NULL; |
| 205 | CORE_ADDR funaddr; |
| 206 | |
| 207 | /* If it's a member function, just look at the function |
| 208 | part of it. */ |
| 209 | |
| 210 | /* Determine address to call. */ |
| 211 | if (code == TYPE_CODE_FUNC || code == TYPE_CODE_METHOD) |
| 212 | { |
| 213 | funaddr = VALUE_ADDRESS (function); |
| 214 | value_type = TYPE_TARGET_TYPE (ftype); |
| 215 | } |
| 216 | else if (code == TYPE_CODE_PTR) |
| 217 | { |
| 218 | funaddr = value_as_address (function); |
| 219 | ftype = check_typedef (TYPE_TARGET_TYPE (ftype)); |
| 220 | if (TYPE_CODE (ftype) == TYPE_CODE_FUNC |
| 221 | || TYPE_CODE (ftype) == TYPE_CODE_METHOD) |
| 222 | { |
| 223 | funaddr = gdbarch_convert_from_func_ptr_addr (current_gdbarch, |
| 224 | funaddr, |
| 225 | ¤t_target); |
| 226 | value_type = TYPE_TARGET_TYPE (ftype); |
| 227 | } |
| 228 | } |
| 229 | else if (code == TYPE_CODE_INT) |
| 230 | { |
| 231 | /* Handle the case of functions lacking debugging info. |
| 232 | Their values are characters since their addresses are char */ |
| 233 | if (TYPE_LENGTH (ftype) == 1) |
| 234 | funaddr = value_as_address (value_addr (function)); |
| 235 | else |
| 236 | { |
| 237 | /* Handle function descriptors lacking debug info. */ |
| 238 | int found_descriptor = 0; |
| 239 | if (VALUE_LVAL (function) == lval_memory) |
| 240 | { |
| 241 | CORE_ADDR nfunaddr; |
| 242 | funaddr = value_as_address (value_addr (function)); |
| 243 | nfunaddr = funaddr; |
| 244 | funaddr = gdbarch_convert_from_func_ptr_addr (current_gdbarch, |
| 245 | funaddr, |
| 246 | ¤t_target); |
| 247 | if (funaddr != nfunaddr) |
| 248 | found_descriptor = 1; |
| 249 | } |
| 250 | if (!found_descriptor) |
| 251 | /* Handle integer used as address of a function. */ |
| 252 | funaddr = (CORE_ADDR) value_as_long (function); |
| 253 | } |
| 254 | } |
| 255 | else |
| 256 | error (_("Invalid data type for function to be called.")); |
| 257 | |
| 258 | if (retval_type != NULL) |
| 259 | *retval_type = value_type; |
| 260 | return funaddr + gdbarch_deprecated_function_start_offset (current_gdbarch); |
| 261 | } |
| 262 | |
| 263 | /* Call breakpoint_auto_delete on the current contents of the bpstat |
| 264 | of the current thread. */ |
| 265 | |
| 266 | static void |
| 267 | breakpoint_auto_delete_contents (void *arg) |
| 268 | { |
| 269 | if (!ptid_equal (inferior_ptid, null_ptid)) |
| 270 | breakpoint_auto_delete (inferior_thread ()->stop_bpstat); |
| 271 | } |
| 272 | |
| 273 | /* For CALL_DUMMY_ON_STACK, push a breakpoint sequence that the called |
| 274 | function returns to. */ |
| 275 | |
| 276 | static CORE_ADDR |
| 277 | push_dummy_code (struct gdbarch *gdbarch, |
| 278 | CORE_ADDR sp, CORE_ADDR funaddr, |
| 279 | struct value **args, int nargs, |
| 280 | struct type *value_type, |
| 281 | CORE_ADDR *real_pc, CORE_ADDR *bp_addr, |
| 282 | struct regcache *regcache) |
| 283 | { |
| 284 | gdb_assert (gdbarch_push_dummy_code_p (gdbarch)); |
| 285 | |
| 286 | return gdbarch_push_dummy_code (gdbarch, sp, funaddr, |
| 287 | args, nargs, value_type, real_pc, bp_addr, |
| 288 | regcache); |
| 289 | } |
| 290 | |
| 291 | /* All this stuff with a dummy frame may seem unnecessarily complicated |
| 292 | (why not just save registers in GDB?). The purpose of pushing a dummy |
| 293 | frame which looks just like a real frame is so that if you call a |
| 294 | function and then hit a breakpoint (get a signal, etc), "backtrace" |
| 295 | will look right. Whether the backtrace needs to actually show the |
| 296 | stack at the time the inferior function was called is debatable, but |
| 297 | it certainly needs to not display garbage. So if you are contemplating |
| 298 | making dummy frames be different from normal frames, consider that. */ |
| 299 | |
| 300 | /* Perform a function call in the inferior. |
| 301 | ARGS is a vector of values of arguments (NARGS of them). |
| 302 | FUNCTION is a value, the function to be called. |
| 303 | Returns a value representing what the function returned. |
| 304 | May fail to return, if a breakpoint or signal is hit |
| 305 | during the execution of the function. |
| 306 | |
| 307 | ARGS is modified to contain coerced values. */ |
| 308 | |
| 309 | struct value * |
| 310 | call_function_by_hand (struct value *function, int nargs, struct value **args) |
| 311 | { |
| 312 | CORE_ADDR sp; |
| 313 | struct type *values_type, *target_values_type; |
| 314 | unsigned char struct_return = 0, lang_struct_return = 0; |
| 315 | CORE_ADDR struct_addr = 0; |
| 316 | struct regcache *retbuf; |
| 317 | struct cleanup *retbuf_cleanup; |
| 318 | struct inferior_status *inf_status; |
| 319 | struct cleanup *inf_status_cleanup; |
| 320 | CORE_ADDR funaddr; |
| 321 | CORE_ADDR real_pc; |
| 322 | struct type *ftype = check_typedef (value_type (function)); |
| 323 | CORE_ADDR bp_addr; |
| 324 | struct regcache *caller_regcache; |
| 325 | struct cleanup *caller_regcache_cleanup; |
| 326 | struct frame_id dummy_id; |
| 327 | struct cleanup *args_cleanup; |
| 328 | struct frame_info *frame; |
| 329 | struct gdbarch *gdbarch; |
| 330 | |
| 331 | if (TYPE_CODE (ftype) == TYPE_CODE_PTR) |
| 332 | ftype = check_typedef (TYPE_TARGET_TYPE (ftype)); |
| 333 | |
| 334 | if (!target_has_execution) |
| 335 | noprocess (); |
| 336 | |
| 337 | frame = get_current_frame (); |
| 338 | gdbarch = get_frame_arch (frame); |
| 339 | |
| 340 | if (!gdbarch_push_dummy_call_p (gdbarch)) |
| 341 | error (_("This target does not support function calls.")); |
| 342 | |
| 343 | /* Create a cleanup chain that contains the retbuf (buffer |
| 344 | containing the register values). This chain is create BEFORE the |
| 345 | inf_status chain so that the inferior status can cleaned up |
| 346 | (restored or discarded) without having the retbuf freed. */ |
| 347 | retbuf = regcache_xmalloc (gdbarch); |
| 348 | retbuf_cleanup = make_cleanup_regcache_xfree (retbuf); |
| 349 | |
| 350 | /* A cleanup for the inferior status. Create this AFTER the retbuf |
| 351 | so that this can be discarded or applied without interfering with |
| 352 | the regbuf. */ |
| 353 | inf_status = save_inferior_status (1); |
| 354 | inf_status_cleanup = make_cleanup_restore_inferior_status (inf_status); |
| 355 | |
| 356 | /* Save the caller's registers so that they can be restored once the |
| 357 | callee returns. To allow nested calls the registers are (further |
| 358 | down) pushed onto a dummy frame stack. Include a cleanup (which |
| 359 | is tossed once the regcache has been pushed). */ |
| 360 | caller_regcache = frame_save_as_regcache (frame); |
| 361 | caller_regcache_cleanup = make_cleanup_regcache_xfree (caller_regcache); |
| 362 | |
| 363 | /* Ensure that the initial SP is correctly aligned. */ |
| 364 | { |
| 365 | CORE_ADDR old_sp = get_frame_sp (frame); |
| 366 | if (gdbarch_frame_align_p (gdbarch)) |
| 367 | { |
| 368 | sp = gdbarch_frame_align (gdbarch, old_sp); |
| 369 | /* NOTE: cagney/2003-08-13: Skip the "red zone". For some |
| 370 | ABIs, a function can use memory beyond the inner most stack |
| 371 | address. AMD64 called that region the "red zone". Skip at |
| 372 | least the "red zone" size before allocating any space on |
| 373 | the stack. */ |
| 374 | if (gdbarch_inner_than (gdbarch, 1, 2)) |
| 375 | sp -= gdbarch_frame_red_zone_size (gdbarch); |
| 376 | else |
| 377 | sp += gdbarch_frame_red_zone_size (gdbarch); |
| 378 | /* Still aligned? */ |
| 379 | gdb_assert (sp == gdbarch_frame_align (gdbarch, sp)); |
| 380 | /* NOTE: cagney/2002-09-18: |
| 381 | |
| 382 | On a RISC architecture, a void parameterless generic dummy |
| 383 | frame (i.e., no parameters, no result) typically does not |
| 384 | need to push anything the stack and hence can leave SP and |
| 385 | FP. Similarly, a frameless (possibly leaf) function does |
| 386 | not push anything on the stack and, hence, that too can |
| 387 | leave FP and SP unchanged. As a consequence, a sequence of |
| 388 | void parameterless generic dummy frame calls to frameless |
| 389 | functions will create a sequence of effectively identical |
| 390 | frames (SP, FP and TOS and PC the same). This, not |
| 391 | suprisingly, results in what appears to be a stack in an |
| 392 | infinite loop --- when GDB tries to find a generic dummy |
| 393 | frame on the internal dummy frame stack, it will always |
| 394 | find the first one. |
| 395 | |
| 396 | To avoid this problem, the code below always grows the |
| 397 | stack. That way, two dummy frames can never be identical. |
| 398 | It does burn a few bytes of stack but that is a small price |
| 399 | to pay :-). */ |
| 400 | if (sp == old_sp) |
| 401 | { |
| 402 | if (gdbarch_inner_than (gdbarch, 1, 2)) |
| 403 | /* Stack grows down. */ |
| 404 | sp = gdbarch_frame_align (gdbarch, old_sp - 1); |
| 405 | else |
| 406 | /* Stack grows up. */ |
| 407 | sp = gdbarch_frame_align (gdbarch, old_sp + 1); |
| 408 | } |
| 409 | gdb_assert ((gdbarch_inner_than (gdbarch, 1, 2) |
| 410 | && sp <= old_sp) |
| 411 | || (gdbarch_inner_than (gdbarch, 2, 1) |
| 412 | && sp >= old_sp)); |
| 413 | } |
| 414 | else |
| 415 | /* FIXME: cagney/2002-09-18: Hey, you loose! |
| 416 | |
| 417 | Who knows how badly aligned the SP is! |
| 418 | |
| 419 | If the generic dummy frame ends up empty (because nothing is |
| 420 | pushed) GDB won't be able to correctly perform back traces. |
| 421 | If a target is having trouble with backtraces, first thing to |
| 422 | do is add FRAME_ALIGN() to the architecture vector. If that |
| 423 | fails, try dummy_id(). |
| 424 | |
| 425 | If the ABI specifies a "Red Zone" (see the doco) the code |
| 426 | below will quietly trash it. */ |
| 427 | sp = old_sp; |
| 428 | } |
| 429 | |
| 430 | funaddr = find_function_addr (function, &values_type); |
| 431 | if (!values_type) |
| 432 | values_type = builtin_type (gdbarch)->builtin_int; |
| 433 | |
| 434 | CHECK_TYPEDEF (values_type); |
| 435 | |
| 436 | /* Are we returning a value using a structure return (passing a |
| 437 | hidden argument pointing to storage) or a normal value return? |
| 438 | There are two cases: language-mandated structure return and |
| 439 | target ABI structure return. The variable STRUCT_RETURN only |
| 440 | describes the latter. The language version is handled by passing |
| 441 | the return location as the first parameter to the function, |
| 442 | even preceding "this". This is different from the target |
| 443 | ABI version, which is target-specific; for instance, on ia64 |
| 444 | the first argument is passed in out0 but the hidden structure |
| 445 | return pointer would normally be passed in r8. */ |
| 446 | |
| 447 | if (language_pass_by_reference (values_type)) |
| 448 | { |
| 449 | lang_struct_return = 1; |
| 450 | |
| 451 | /* Tell the target specific argument pushing routine not to |
| 452 | expect a value. */ |
| 453 | target_values_type = builtin_type_void; |
| 454 | } |
| 455 | else |
| 456 | { |
| 457 | struct_return = using_struct_return (value_type (function), values_type); |
| 458 | target_values_type = values_type; |
| 459 | } |
| 460 | |
| 461 | /* Determine the location of the breakpoint (and possibly other |
| 462 | stuff) that the called function will return to. The SPARC, for a |
| 463 | function returning a structure or union, needs to make space for |
| 464 | not just the breakpoint but also an extra word containing the |
| 465 | size (?) of the structure being passed. */ |
| 466 | |
| 467 | /* The actual breakpoint (at BP_ADDR) is inserted separatly so there |
| 468 | is no need to write that out. */ |
| 469 | |
| 470 | switch (gdbarch_call_dummy_location (gdbarch)) |
| 471 | { |
| 472 | case ON_STACK: |
| 473 | sp = push_dummy_code (gdbarch, sp, funaddr, |
| 474 | args, nargs, target_values_type, |
| 475 | &real_pc, &bp_addr, get_current_regcache ()); |
| 476 | break; |
| 477 | case AT_ENTRY_POINT: |
| 478 | { |
| 479 | CORE_ADDR dummy_addr; |
| 480 | |
| 481 | real_pc = funaddr; |
| 482 | dummy_addr = entry_point_address (); |
| 483 | /* Make certain that the address points at real code, and not a |
| 484 | function descriptor. */ |
| 485 | dummy_addr = gdbarch_convert_from_func_ptr_addr (gdbarch, |
| 486 | dummy_addr, |
| 487 | ¤t_target); |
| 488 | /* A call dummy always consists of just a single breakpoint, so |
| 489 | its address is the same as the address of the dummy. */ |
| 490 | bp_addr = dummy_addr; |
| 491 | break; |
| 492 | } |
| 493 | case AT_SYMBOL: |
| 494 | /* Some executables define a symbol __CALL_DUMMY_ADDRESS whose |
| 495 | address is the location where the breakpoint should be |
| 496 | placed. Once all targets are using the overhauled frame code |
| 497 | this can be deleted - ON_STACK is a better option. */ |
| 498 | { |
| 499 | struct minimal_symbol *sym; |
| 500 | CORE_ADDR dummy_addr; |
| 501 | |
| 502 | sym = lookup_minimal_symbol ("__CALL_DUMMY_ADDRESS", NULL, NULL); |
| 503 | real_pc = funaddr; |
| 504 | if (sym) |
| 505 | dummy_addr = SYMBOL_VALUE_ADDRESS (sym); |
| 506 | else |
| 507 | dummy_addr = entry_point_address (); |
| 508 | /* Make certain that the address points at real code, and not |
| 509 | a function descriptor. */ |
| 510 | dummy_addr = gdbarch_convert_from_func_ptr_addr (gdbarch, |
| 511 | dummy_addr, |
| 512 | ¤t_target); |
| 513 | /* A call dummy always consists of just a single breakpoint, |
| 514 | so it's address is the same as the address of the dummy. */ |
| 515 | bp_addr = dummy_addr; |
| 516 | break; |
| 517 | } |
| 518 | default: |
| 519 | internal_error (__FILE__, __LINE__, _("bad switch")); |
| 520 | } |
| 521 | |
| 522 | if (nargs < TYPE_NFIELDS (ftype)) |
| 523 | error (_("Too few arguments in function call.")); |
| 524 | |
| 525 | { |
| 526 | int i; |
| 527 | for (i = nargs - 1; i >= 0; i--) |
| 528 | { |
| 529 | int prototyped; |
| 530 | struct type *param_type; |
| 531 | |
| 532 | /* FIXME drow/2002-05-31: Should just always mark methods as |
| 533 | prototyped. Can we respect TYPE_VARARGS? Probably not. */ |
| 534 | if (TYPE_CODE (ftype) == TYPE_CODE_METHOD) |
| 535 | prototyped = 1; |
| 536 | else if (i < TYPE_NFIELDS (ftype)) |
| 537 | prototyped = TYPE_PROTOTYPED (ftype); |
| 538 | else |
| 539 | prototyped = 0; |
| 540 | |
| 541 | if (i < TYPE_NFIELDS (ftype)) |
| 542 | param_type = TYPE_FIELD_TYPE (ftype, i); |
| 543 | else |
| 544 | param_type = NULL; |
| 545 | |
| 546 | args[i] = value_arg_coerce (gdbarch, args[i], |
| 547 | param_type, prototyped, &sp); |
| 548 | |
| 549 | if (param_type != NULL && language_pass_by_reference (param_type)) |
| 550 | args[i] = value_addr (args[i]); |
| 551 | } |
| 552 | } |
| 553 | |
| 554 | /* Reserve space for the return structure to be written on the |
| 555 | stack, if necessary. Make certain that the value is correctly |
| 556 | aligned. */ |
| 557 | |
| 558 | if (struct_return || lang_struct_return) |
| 559 | { |
| 560 | int len = TYPE_LENGTH (values_type); |
| 561 | if (gdbarch_inner_than (gdbarch, 1, 2)) |
| 562 | { |
| 563 | /* Stack grows downward. Align STRUCT_ADDR and SP after |
| 564 | making space for the return value. */ |
| 565 | sp -= len; |
| 566 | if (gdbarch_frame_align_p (gdbarch)) |
| 567 | sp = gdbarch_frame_align (gdbarch, sp); |
| 568 | struct_addr = sp; |
| 569 | } |
| 570 | else |
| 571 | { |
| 572 | /* Stack grows upward. Align the frame, allocate space, and |
| 573 | then again, re-align the frame??? */ |
| 574 | if (gdbarch_frame_align_p (gdbarch)) |
| 575 | sp = gdbarch_frame_align (gdbarch, sp); |
| 576 | struct_addr = sp; |
| 577 | sp += len; |
| 578 | if (gdbarch_frame_align_p (gdbarch)) |
| 579 | sp = gdbarch_frame_align (gdbarch, sp); |
| 580 | } |
| 581 | } |
| 582 | |
| 583 | if (lang_struct_return) |
| 584 | { |
| 585 | struct value **new_args; |
| 586 | |
| 587 | /* Add the new argument to the front of the argument list. */ |
| 588 | new_args = xmalloc (sizeof (struct value *) * (nargs + 1)); |
| 589 | new_args[0] = value_from_pointer (lookup_pointer_type (values_type), |
| 590 | struct_addr); |
| 591 | memcpy (&new_args[1], &args[0], sizeof (struct value *) * nargs); |
| 592 | args = new_args; |
| 593 | nargs++; |
| 594 | args_cleanup = make_cleanup (xfree, args); |
| 595 | } |
| 596 | else |
| 597 | args_cleanup = make_cleanup (null_cleanup, NULL); |
| 598 | |
| 599 | /* Create the dummy stack frame. Pass in the call dummy address as, |
| 600 | presumably, the ABI code knows where, in the call dummy, the |
| 601 | return address should be pointed. */ |
| 602 | sp = gdbarch_push_dummy_call (gdbarch, function, get_current_regcache (), |
| 603 | bp_addr, nargs, args, |
| 604 | sp, struct_return, struct_addr); |
| 605 | |
| 606 | do_cleanups (args_cleanup); |
| 607 | |
| 608 | /* Set up a frame ID for the dummy frame so we can pass it to |
| 609 | set_momentary_breakpoint. We need to give the breakpoint a frame |
| 610 | ID so that the breakpoint code can correctly re-identify the |
| 611 | dummy breakpoint. */ |
| 612 | /* Sanity. The exact same SP value is returned by PUSH_DUMMY_CALL, |
| 613 | saved as the dummy-frame TOS, and used by dummy_id to form |
| 614 | the frame ID's stack address. */ |
| 615 | dummy_id = frame_id_build (sp, bp_addr); |
| 616 | |
| 617 | /* Create a momentary breakpoint at the return address of the |
| 618 | inferior. That way it breaks when it returns. */ |
| 619 | |
| 620 | { |
| 621 | struct breakpoint *bpt; |
| 622 | struct symtab_and_line sal; |
| 623 | init_sal (&sal); /* initialize to zeroes */ |
| 624 | sal.pc = bp_addr; |
| 625 | sal.section = find_pc_overlay (sal.pc); |
| 626 | /* Sanity. The exact same SP value is returned by |
| 627 | PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by |
| 628 | dummy_id to form the frame ID's stack address. */ |
| 629 | bpt = set_momentary_breakpoint (sal, dummy_id, bp_call_dummy); |
| 630 | bpt->disposition = disp_del; |
| 631 | } |
| 632 | |
| 633 | /* Everything's ready, push all the info needed to restore the |
| 634 | caller (and identify the dummy-frame) onto the dummy-frame |
| 635 | stack. */ |
| 636 | dummy_frame_push (caller_regcache, &dummy_id); |
| 637 | discard_cleanups (caller_regcache_cleanup); |
| 638 | |
| 639 | /* - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - |
| 640 | If you're looking to implement asynchronous dummy-frames, then |
| 641 | just below is the place to chop this function in two.. */ |
| 642 | |
| 643 | /* Now proceed, having reached the desired place. */ |
| 644 | clear_proceed_status (); |
| 645 | |
| 646 | /* Execute a "stack dummy", a piece of code stored in the stack by |
| 647 | the debugger to be executed in the inferior. |
| 648 | |
| 649 | The dummy's frame is automatically popped whenever that break is |
| 650 | hit. If that is the first time the program stops, |
| 651 | call_function_by_hand returns to its caller with that frame |
| 652 | already gone and sets RC to 0. |
| 653 | |
| 654 | Otherwise, set RC to a non-zero value. If the called function |
| 655 | receives a random signal, we do not allow the user to continue |
| 656 | executing it as this may not work. The dummy frame is poped and |
| 657 | we return 1. If we hit a breakpoint, we leave the frame in place |
| 658 | and return 2 (the frame will eventually be popped when we do hit |
| 659 | the dummy end breakpoint). */ |
| 660 | |
| 661 | { |
| 662 | struct cleanup *old_cleanups = make_cleanup (null_cleanup, 0); |
| 663 | struct cleanup *old_cleanups2; |
| 664 | int saved_async = 0; |
| 665 | struct thread_info *tp = inferior_thread (); |
| 666 | |
| 667 | /* If all error()s out of proceed ended up calling normal_stop |
| 668 | (and perhaps they should; it already does in the special case |
| 669 | of error out of resume()), then we wouldn't need this. */ |
| 670 | make_cleanup (breakpoint_auto_delete_contents, NULL); |
| 671 | |
| 672 | disable_watchpoints_before_interactive_call_start (); |
| 673 | tp->proceed_to_finish = 1; /* We want stop_registers, please... */ |
| 674 | |
| 675 | if (target_can_async_p ()) |
| 676 | saved_async = target_async_mask (0); |
| 677 | |
| 678 | old_cleanups2 = make_cleanup_restore_integer (&suppress_resume_observer); |
| 679 | suppress_resume_observer = 1; |
| 680 | make_cleanup_restore_integer (&suppress_stop_observer); |
| 681 | suppress_stop_observer = 1; |
| 682 | proceed (real_pc, TARGET_SIGNAL_0, 0); |
| 683 | do_cleanups (old_cleanups2); |
| 684 | |
| 685 | if (saved_async) |
| 686 | target_async_mask (saved_async); |
| 687 | |
| 688 | enable_watchpoints_after_interactive_call_stop (); |
| 689 | |
| 690 | discard_cleanups (old_cleanups); |
| 691 | } |
| 692 | |
| 693 | if (! target_has_execution) |
| 694 | { |
| 695 | /* If we try to restore the inferior status (via the cleanup), |
| 696 | we'll crash as the inferior is no longer running. */ |
| 697 | discard_cleanups (inf_status_cleanup); |
| 698 | discard_inferior_status (inf_status); |
| 699 | error (_("\ |
| 700 | The program being debugged exited while in a function called from GDB.")); |
| 701 | } |
| 702 | |
| 703 | if (stopped_by_random_signal || !stop_stack_dummy) |
| 704 | { |
| 705 | /* Find the name of the function we're about to complain about. */ |
| 706 | const char *name = NULL; |
| 707 | { |
| 708 | struct symbol *symbol = find_pc_function (funaddr); |
| 709 | if (symbol) |
| 710 | name = SYMBOL_PRINT_NAME (symbol); |
| 711 | else |
| 712 | { |
| 713 | /* Try the minimal symbols. */ |
| 714 | struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (funaddr); |
| 715 | if (msymbol) |
| 716 | name = SYMBOL_PRINT_NAME (msymbol); |
| 717 | } |
| 718 | if (name == NULL) |
| 719 | { |
| 720 | /* Can't use a cleanup here. It is discarded, instead use |
| 721 | an alloca. */ |
| 722 | char *tmp = xstrprintf ("at %s", hex_string (funaddr)); |
| 723 | char *a = alloca (strlen (tmp) + 1); |
| 724 | strcpy (a, tmp); |
| 725 | xfree (tmp); |
| 726 | name = a; |
| 727 | } |
| 728 | } |
| 729 | if (stopped_by_random_signal) |
| 730 | { |
| 731 | /* We stopped inside the FUNCTION because of a random |
| 732 | signal. Further execution of the FUNCTION is not |
| 733 | allowed. */ |
| 734 | |
| 735 | if (unwind_on_signal_p) |
| 736 | { |
| 737 | /* The user wants the context restored. */ |
| 738 | |
| 739 | /* We must get back to the frame we were before the |
| 740 | dummy call. */ |
| 741 | frame_pop (get_current_frame ()); |
| 742 | |
| 743 | /* FIXME: Insert a bunch of wrap_here; name can be very |
| 744 | long if it's a C++ name with arguments and stuff. */ |
| 745 | error (_("\ |
| 746 | The program being debugged was signaled while in a function called from GDB.\n\ |
| 747 | GDB has restored the context to what it was before the call.\n\ |
| 748 | To change this behavior use \"set unwindonsignal off\".\n\ |
| 749 | Evaluation of the expression containing the function (%s) will be abandoned."), |
| 750 | name); |
| 751 | } |
| 752 | else |
| 753 | { |
| 754 | /* The user wants to stay in the frame where we stopped |
| 755 | (default).*/ |
| 756 | /* If we restored the inferior status (via the cleanup), |
| 757 | we would print a spurious error message (Unable to |
| 758 | restore previously selected frame), would write the |
| 759 | registers from the inf_status (which is wrong), and |
| 760 | would do other wrong things. */ |
| 761 | discard_cleanups (inf_status_cleanup); |
| 762 | discard_inferior_status (inf_status); |
| 763 | /* FIXME: Insert a bunch of wrap_here; name can be very |
| 764 | long if it's a C++ name with arguments and stuff. */ |
| 765 | error (_("\ |
| 766 | The program being debugged was signaled while in a function called from GDB.\n\ |
| 767 | GDB remains in the frame where the signal was received.\n\ |
| 768 | To change this behavior use \"set unwindonsignal on\".\n\ |
| 769 | Evaluation of the expression containing the function (%s) will be abandoned."), |
| 770 | name); |
| 771 | } |
| 772 | } |
| 773 | |
| 774 | if (!stop_stack_dummy) |
| 775 | { |
| 776 | /* We hit a breakpoint inside the FUNCTION. */ |
| 777 | /* If we restored the inferior status (via the cleanup), we |
| 778 | would print a spurious error message (Unable to restore |
| 779 | previously selected frame), would write the registers |
| 780 | from the inf_status (which is wrong), and would do other |
| 781 | wrong things. */ |
| 782 | discard_cleanups (inf_status_cleanup); |
| 783 | discard_inferior_status (inf_status); |
| 784 | /* The following error message used to say "The expression |
| 785 | which contained the function call has been discarded." |
| 786 | It is a hard concept to explain in a few words. Ideally, |
| 787 | GDB would be able to resume evaluation of the expression |
| 788 | when the function finally is done executing. Perhaps |
| 789 | someday this will be implemented (it would not be easy). */ |
| 790 | /* FIXME: Insert a bunch of wrap_here; name can be very long if it's |
| 791 | a C++ name with arguments and stuff. */ |
| 792 | error (_("\ |
| 793 | The program being debugged stopped while in a function called from GDB.\n\ |
| 794 | When the function (%s) is done executing, GDB will silently\n\ |
| 795 | stop (instead of continuing to evaluate the expression containing\n\ |
| 796 | the function call)."), name); |
| 797 | } |
| 798 | |
| 799 | /* The above code errors out, so ... */ |
| 800 | internal_error (__FILE__, __LINE__, _("... should not be here")); |
| 801 | } |
| 802 | |
| 803 | /* If we get here the called FUNCTION run to completion. */ |
| 804 | |
| 805 | /* On normal return, the stack dummy has been popped already. */ |
| 806 | regcache_cpy_no_passthrough (retbuf, stop_registers); |
| 807 | |
| 808 | /* Restore the inferior status, via its cleanup. At this stage, |
| 809 | leave the RETBUF alone. */ |
| 810 | do_cleanups (inf_status_cleanup); |
| 811 | |
| 812 | /* Figure out the value returned by the function. */ |
| 813 | { |
| 814 | struct value *retval = NULL; |
| 815 | |
| 816 | if (lang_struct_return) |
| 817 | retval = value_at (values_type, struct_addr); |
| 818 | else if (TYPE_CODE (target_values_type) == TYPE_CODE_VOID) |
| 819 | { |
| 820 | /* If the function returns void, don't bother fetching the |
| 821 | return value. */ |
| 822 | retval = allocate_value (values_type); |
| 823 | } |
| 824 | else |
| 825 | { |
| 826 | switch (gdbarch_return_value (gdbarch, value_type (function), |
| 827 | target_values_type, NULL, NULL, NULL)) |
| 828 | { |
| 829 | case RETURN_VALUE_REGISTER_CONVENTION: |
| 830 | case RETURN_VALUE_ABI_RETURNS_ADDRESS: |
| 831 | case RETURN_VALUE_ABI_PRESERVES_ADDRESS: |
| 832 | retval = allocate_value (values_type); |
| 833 | gdbarch_return_value (gdbarch, value_type (function), values_type, |
| 834 | retbuf, value_contents_raw (retval), NULL); |
| 835 | break; |
| 836 | case RETURN_VALUE_STRUCT_CONVENTION: |
| 837 | retval = value_at (values_type, struct_addr); |
| 838 | break; |
| 839 | } |
| 840 | } |
| 841 | |
| 842 | do_cleanups (retbuf_cleanup); |
| 843 | |
| 844 | gdb_assert(retval); |
| 845 | return retval; |
| 846 | } |
| 847 | } |
| 848 | \f |
| 849 | |
| 850 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
| 851 | void _initialize_infcall (void); |
| 852 | |
| 853 | void |
| 854 | _initialize_infcall (void) |
| 855 | { |
| 856 | add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure, |
| 857 | &coerce_float_to_double_p, _("\ |
| 858 | Set coercion of floats to doubles when calling functions."), _("\ |
| 859 | Show coercion of floats to doubles when calling functions"), _("\ |
| 860 | Variables of type float should generally be converted to doubles before\n\ |
| 861 | calling an unprototyped function, and left alone when calling a prototyped\n\ |
| 862 | function. However, some older debug info formats do not provide enough\n\ |
| 863 | information to determine that a function is prototyped. If this flag is\n\ |
| 864 | set, GDB will perform the conversion for a function it considers\n\ |
| 865 | unprototyped.\n\ |
| 866 | The default is to perform the conversion.\n"), |
| 867 | NULL, |
| 868 | show_coerce_float_to_double_p, |
| 869 | &setlist, &showlist); |
| 870 | |
| 871 | add_setshow_boolean_cmd ("unwindonsignal", no_class, |
| 872 | &unwind_on_signal_p, _("\ |
| 873 | Set unwinding of stack if a signal is received while in a call dummy."), _("\ |
| 874 | Show unwinding of stack if a signal is received while in a call dummy."), _("\ |
| 875 | The unwindonsignal lets the user determine what gdb should do if a signal\n\ |
| 876 | is received while in a function called from gdb (call dummy). If set, gdb\n\ |
| 877 | unwinds the stack and restore the context to what as it was before the call.\n\ |
| 878 | The default is to stop in the frame where the signal was received."), |
| 879 | NULL, |
| 880 | show_unwind_on_signal_p, |
| 881 | &setlist, &showlist); |
| 882 | } |