1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- A D A . E X C E P T I O N S . E X C E P T I O N _ P R O P A G A T I O N -- 6-- -- 7-- B o d y -- 8-- -- 9-- Copyright (C) 1992-2020, Free Software Foundation, Inc. -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. -- 17-- -- 18-- As a special exception under Section 7 of GPL version 3, you are granted -- 19-- additional permissions described in the GCC Runtime Library Exception, -- 20-- version 3.1, as published by the Free Software Foundation. -- 21-- -- 22-- You should have received a copy of the GNU General Public License and -- 23-- a copy of the GCC Runtime Library Exception along with this program; -- 24-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- 25-- <http://www.gnu.org/licenses/>. -- 26-- -- 27-- GNAT was originally developed by the GNAT team at New York University. -- 28-- Extensive contributions were provided by Ada Core Technologies Inc. -- 29-- -- 30------------------------------------------------------------------------------ 31 32-- This is the version using the GCC EH mechanism, which could rely on 33-- different underlying unwinding engines, for example DWARF or ARM unwind 34-- info based. Here is a sketch of the most prominent data structures 35-- involved: 36 37-- (s-excmac.ads) 38-- GNAT_GCC_Exception: 39-- *-----------------------------------* 40-- o-->| (s-excmac.ads) | 41-- | | Header : <gcc occurrence type> | 42-- | | - Class | 43-- | | ... | Constraint_Error: 44-- | |-----------------------------------* Program_Error: 45-- | | (a-except.ads) | Foreign_Exception: 46-- | | Occurrence : Exception_Occurrence | 47-- | | | (s-stalib. ads) 48-- | | - Id : Exception_Id --------------> Exception_Data 49-- o------ - Machine_Occurrence | *------------------------* 50-- | - Msg | | Not_Handled_By_Others | 51-- | - Traceback | | Lang | 52-- | ... | | Foreign_Data --o | 53-- *-----------------------------------* | Full_Name | | 54-- || | ... | | 55-- || foreign rtti blob *----------------|-------* 56-- || *---------------* | 57-- || | ... ... |<-------------------------o 58-- || *---------------* 59-- || 60-- Setup_Current_Excep() 61-- || 62-- || Latch into ATCB or 63-- || environment Current Exception Buffer: 64-- || 65-- vv 66-- <> : Exception_Occurrence 67-- *---------------------------* 68-- | ... ... ... ... ... ... * --- Get_Current_Excep() ----> 69-- *---------------------------* 70 71-- On "raise" events, the runtime allocates a new GNAT_GCC_Exception 72-- instance and eventually calls into libgcc's Unwind_RaiseException. 73-- This part handles the object through the header part only. 74 75-- During execution, Get_Current_Excep provides a pointer to the 76-- Exception_Occurrence being raised or last raised by the current task. 77 78-- This is actually the address of a statically allocated 79-- Exception_Occurrence attached to the current ATCB or to the environment 80-- thread into which an occurrence being raised is synchronized at critical 81-- points during the raise process, via Setup_Current_Excep. 82 83with Ada.Unchecked_Conversion; 84with Ada.Unchecked_Deallocation; 85 86with System.Storage_Elements; use System.Storage_Elements; 87with System.Exceptions.Machine; use System.Exceptions.Machine; 88 89separate (Ada.Exceptions) 90package body Exception_Propagation is 91 92 use Exception_Traces; 93 94 Foreign_Exception : aliased System.Standard_Library.Exception_Data; 95 pragma Import (Ada, Foreign_Exception, 96 "system__exceptions__foreign_exception"); 97 -- Id for foreign exceptions 98 99 -------------------------------------------------------------- 100 -- GNAT Specific Entities To Deal With The GCC EH Circuitry -- 101 -------------------------------------------------------------- 102 103 -- Phase identifiers (Unwind Actions) 104 105 type Unwind_Action is new Integer; 106 pragma Convention (C, Unwind_Action); 107 108 UA_SEARCH_PHASE : constant Unwind_Action := 1; 109 UA_CLEANUP_PHASE : constant Unwind_Action := 2; 110 UA_HANDLER_FRAME : constant Unwind_Action := 4; 111 UA_FORCE_UNWIND : constant Unwind_Action := 8; 112 UA_END_OF_STACK : constant Unwind_Action := 16; -- GCC extension 113 114 pragma Unreferenced 115 (UA_HANDLER_FRAME, 116 UA_FORCE_UNWIND, 117 UA_END_OF_STACK); 118 119 procedure GNAT_GCC_Exception_Cleanup 120 (Reason : Unwind_Reason_Code; 121 Excep : not null GNAT_GCC_Exception_Access); 122 pragma Convention (C, GNAT_GCC_Exception_Cleanup); 123 -- Procedure called when a GNAT GCC exception is free. 124 125 procedure Propagate_GCC_Exception 126 (GCC_Exception : not null GCC_Exception_Access); 127 pragma No_Return (Propagate_GCC_Exception); 128 -- Propagate a GCC exception 129 130 procedure Reraise_GCC_Exception 131 (GCC_Exception : not null GCC_Exception_Access); 132 pragma No_Return (Reraise_GCC_Exception); 133 pragma Export (C, Reraise_GCC_Exception, "__gnat_reraise_zcx"); 134 -- Called to implement raise without exception, ie reraise. Called 135 -- directly from gigi. 136 137 function Setup_Current_Excep 138 (GCC_Exception : not null GCC_Exception_Access; 139 Phase : Unwind_Action) return EOA; 140 pragma Export (C, Setup_Current_Excep, "__gnat_setup_current_excep"); 141 -- Acknowledge GCC_Exception as the current exception object being 142 -- raised, which could be an Ada or a foreign exception object. Return 143 -- a pointer to the embedded Ada occurrence for an Ada exception object, 144 -- to the current exception buffer otherwise. 145 -- 146 -- Synchronize the current exception buffer as needed for possible 147 -- accesses through Get_Current_Except.all afterwards, depending on the 148 -- Phase bits, received either from the personality routine, from a 149 -- forced_unwind cleanup handler, or just before the start of propagation 150 -- for an Ada exception (Phase 0 in this case). 151 152 procedure Unhandled_Except_Handler 153 (GCC_Exception : not null GCC_Exception_Access); 154 pragma No_Return (Unhandled_Except_Handler); 155 pragma Export (C, Unhandled_Except_Handler, 156 "__gnat_unhandled_except_handler"); 157 -- Called for handle unhandled exceptions, ie the last chance handler 158 -- on platforms (such as SEH) that never returns after throwing an 159 -- exception. Called directly by gigi. 160 161 function CleanupUnwind_Handler 162 (UW_Version : Integer; 163 UW_Phases : Unwind_Action; 164 UW_Eclass : Exception_Class; 165 UW_Exception : not null GCC_Exception_Access; 166 UW_Context : System.Address; 167 UW_Argument : System.Address) return Unwind_Reason_Code; 168 pragma Import (C, CleanupUnwind_Handler, 169 "__gnat_cleanupunwind_handler"); 170 -- Hook called at each step of the forced unwinding we perform to trigger 171 -- cleanups found during the propagation of an unhandled exception. 172 173 -- GCC runtime functions used. These are C non-void functions, actually, 174 -- but we ignore the return values. See raise.c as to why we are using 175 -- __gnat stubs for these. 176 177 procedure Unwind_RaiseException 178 (UW_Exception : not null GCC_Exception_Access); 179 pragma Import (C, Unwind_RaiseException, "__gnat_Unwind_RaiseException"); 180 181 procedure Unwind_ForcedUnwind 182 (UW_Exception : not null GCC_Exception_Access; 183 UW_Handler : System.Address; 184 UW_Argument : System.Address); 185 pragma Import (C, Unwind_ForcedUnwind, "__gnat_Unwind_ForcedUnwind"); 186 187 procedure Set_Exception_Parameter 188 (Excep : EOA; 189 GCC_Exception : not null GCC_Exception_Access); 190 pragma Export 191 (C, Set_Exception_Parameter, "__gnat_set_exception_parameter"); 192 -- Called inserted by gigi to set the exception choice parameter from the 193 -- gcc occurrence. 194 195 procedure Set_Foreign_Occurrence (Excep : EOA; Mo : System.Address); 196 -- Utility routine to initialize occurrence Excep from a foreign exception 197 -- whose machine occurrence is Mo. The message is empty, the backtrace 198 -- is empty too and the exception identity is Foreign_Exception. 199 200 -- Hooks called when entering/leaving an exception handler for a 201 -- given occurrence. The calls are generated by gigi in 202 -- Exception_Handler_to_gnu_gcc. 203 204 -- Begin_Handler_v1, called when entering an exception handler, 205 -- claims responsibility for the handler to release the 206 -- GCC_Exception occurrence. End_Handler_v1, called when 207 -- leaving the handler, releases the occurrence, unless the 208 -- occurrence is propagating further up, or the handler is 209 -- dynamically nested in the context of another handler that 210 -- claimed responsibility for releasing that occurrence. 211 212 -- Responsibility is claimed by changing the Cleanup field to 213 -- Claimed_Cleanup, which enables claimed exceptions to be 214 -- recognized, and avoids accidental releases even by foreign 215 -- handlers. 216 217 function Begin_Handler_v1 218 (GCC_Exception : not null GCC_Exception_Access) 219 return System.Address; 220 pragma Export (C, Begin_Handler_v1, "__gnat_begin_handler_v1"); 221 -- Called when entering an exception handler. Claim 222 -- responsibility for releasing GCC_Exception, by setting the 223 -- cleanup/release function to Claimed_Cleanup, and return the 224 -- address of the previous cleanup/release function. 225 226 procedure End_Handler_v1 227 (GCC_Exception : not null GCC_Exception_Access; 228 Saved_Cleanup : System.Address; 229 Propagating_Exception : GCC_Exception_Access); 230 pragma Export (C, End_Handler_v1, "__gnat_end_handler_v1"); 231 -- Called when leaving an exception handler. Restore the 232 -- Saved_Cleanup in the GCC_Exception occurrence, and then release 233 -- it, unless it remains claimed by an enclosing handler, or 234 -- GCC_Exception and Propagating_Exception are the same 235 -- occurrence. Propagating_Exception could be either an 236 -- occurrence (re)raised within the handler of GCC_Exception, when 237 -- we're executing as an exceptional cleanup, or null, if we're 238 -- completing the handler of GCC_Exception normally. 239 240 procedure Claimed_Cleanup 241 (Reason : Unwind_Reason_Code; 242 GCC_Exception : not null GCC_Exception_Access); 243 pragma Export (C, Claimed_Cleanup, "__gnat_claimed_cleanup"); 244 -- A do-nothing placeholder installed as GCC_Exception.Cleanup 245 -- while handling GCC_Exception, to claim responsibility for 246 -- releasing it, and to stop it from being accidentally released. 247 248 -- The following are version 0 implementations of the version 1 249 -- hooks above. They remain in place for compatibility with the 250 -- output of compilers that still use version 0, such as those 251 -- used during bootstrap. They are interoperable with the v1 252 -- hooks, except that the older versions may malfunction when 253 -- handling foreign exceptions passed to Reraise_Occurrence. 254 255 procedure Begin_Handler (GCC_Exception : not null GCC_Exception_Access); 256 pragma Export (C, Begin_Handler, "__gnat_begin_handler"); 257 -- Called when entering an exception handler translated by an old 258 -- compiler. It does nothing. 259 260 procedure End_Handler (GCC_Exception : GCC_Exception_Access); 261 pragma Export (C, End_Handler, "__gnat_end_handler"); 262 -- Called when leaving an exception handler translated by an old 263 -- compiler. It releases GCC_Exception, unless it is null. It is 264 -- only ever null when the handler has a 'raise;' translated by a 265 -- v0-using compiler. The artificial handler variable passed to 266 -- End_Handler was set to null to tell End_Handler to refrain from 267 -- releasing the reraised exception. In v1 safer ways are used to 268 -- accomplish that. 269 270 -------------------------------------------------------------------- 271 -- Accessors to Basic Components of a GNAT Exception Data Pointer -- 272 -------------------------------------------------------------------- 273 274 -- As of today, these are only used by the C implementation of the GCC 275 -- propagation personality routine to avoid having to rely on a C 276 -- counterpart of the whole exception_data structure, which is both 277 -- painful and error prone. These subprograms could be moved to a more 278 -- widely visible location if need be. 279 280 function Is_Handled_By_Others (E : Exception_Data_Ptr) return Boolean; 281 pragma Export (C, Is_Handled_By_Others, "__gnat_is_handled_by_others"); 282 pragma Warnings (Off, Is_Handled_By_Others); 283 284 function Language_For (E : Exception_Data_Ptr) return Character; 285 pragma Export (C, Language_For, "__gnat_language_for"); 286 287 function Foreign_Data_For (E : Exception_Data_Ptr) return Address; 288 pragma Export (C, Foreign_Data_For, "__gnat_foreign_data_for"); 289 290 function EID_For (GNAT_Exception : not null GNAT_GCC_Exception_Access) 291 return Exception_Id; 292 pragma Export (C, EID_For, "__gnat_eid_for"); 293 294 --------------------------------------------------------------------------- 295 -- Objects to materialize "others" and "all others" in the GCC EH tables -- 296 --------------------------------------------------------------------------- 297 298 -- Currently, these only have their address taken and compared so there is 299 -- no real point having whole exception data blocks allocated. Note that 300 -- there are corresponding declarations in gigi (trans.c) which must be 301 -- kept properly synchronized. 302 303 Others_Value : constant Character := 'O'; 304 pragma Export (C, Others_Value, "__gnat_others_value"); 305 306 All_Others_Value : constant Character := 'A'; 307 pragma Export (C, All_Others_Value, "__gnat_all_others_value"); 308 309 Unhandled_Others_Value : constant Character := 'U'; 310 pragma Export (C, Unhandled_Others_Value, "__gnat_unhandled_others_value"); 311 -- Special choice (emitted by gigi) to catch and notify unhandled 312 -- exceptions on targets which always handle exceptions (such as SEH). 313 -- The handler will simply call Unhandled_Except_Handler. 314 315 ------------------------- 316 -- Allocate_Occurrence -- 317 ------------------------- 318 319 function Allocate_Occurrence return EOA is 320 Res : GNAT_GCC_Exception_Access; 321 322 begin 323 Res := New_Occurrence; 324 Res.Header.Cleanup := GNAT_GCC_Exception_Cleanup'Address; 325 Res.Occurrence.Machine_Occurrence := Res.all'Address; 326 327 return Res.Occurrence'Access; 328 end Allocate_Occurrence; 329 330 -------------------------------- 331 -- GNAT_GCC_Exception_Cleanup -- 332 -------------------------------- 333 334 procedure GNAT_GCC_Exception_Cleanup 335 (Reason : Unwind_Reason_Code; 336 Excep : not null GNAT_GCC_Exception_Access) 337 is 338 pragma Unreferenced (Reason); 339 340 procedure Free is new Unchecked_Deallocation 341 (GNAT_GCC_Exception, GNAT_GCC_Exception_Access); 342 343 Copy : GNAT_GCC_Exception_Access := Excep; 344 345 begin 346 -- Simply free the memory 347 348 Free (Copy); 349 end GNAT_GCC_Exception_Cleanup; 350 351 ---------------------------- 352 -- Set_Foreign_Occurrence -- 353 ---------------------------- 354 355 procedure Set_Foreign_Occurrence (Excep : EOA; Mo : System.Address) is 356 begin 357 Excep.all := ( 358 Id => Foreign_Exception'Access, 359 Machine_Occurrence => Mo, 360 Msg => <>, 361 Msg_Length => 0, 362 Exception_Raised => True, 363 Pid => Local_Partition_ID, 364 Num_Tracebacks => 0, 365 Tracebacks => <>); 366 end Set_Foreign_Occurrence; 367 368 ------------------------- 369 -- Setup_Current_Excep -- 370 ------------------------- 371 372 function Setup_Current_Excep 373 (GCC_Exception : not null GCC_Exception_Access; 374 Phase : Unwind_Action) return EOA 375 is 376 Excep : constant EOA := Get_Current_Excep.all; 377 378 begin 379 380 if GCC_Exception.Class = GNAT_Exception_Class then 381 382 -- Ada exception : latch the occurrence data in the Current 383 -- Exception Buffer if needed and return a pointer to the original 384 -- Ada exception object. This particular object was specifically 385 -- allocated for this raise and is thus more precise than the fixed 386 -- Current Exception Buffer address. 387 388 declare 389 GNAT_Occurrence : constant GNAT_GCC_Exception_Access := 390 To_GNAT_GCC_Exception (GCC_Exception); 391 begin 392 393 -- When reaching here during SEARCH_PHASE, no need to 394 -- replicate the copy performed at the propagation start. 395 396 if Phase /= UA_SEARCH_PHASE then 397 Excep.all := GNAT_Occurrence.Occurrence; 398 end if; 399 return GNAT_Occurrence.Occurrence'Access; 400 end; 401 402 else 403 404 -- Foreign exception (caught by Ada handler, reaching here from 405 -- personality routine) : The original exception object doesn't hold 406 -- an Ada occurrence info. Set the foreign data pointer in the 407 -- Current Exception Buffer and return the address of the latter. 408 409 Set_Foreign_Occurrence (Excep, GCC_Exception.all'Address); 410 411 return Excep; 412 end if; 413 end Setup_Current_Excep; 414 415 ---------------------- 416 -- Begin_Handler_v1 -- 417 ---------------------- 418 419 function Begin_Handler_v1 420 (GCC_Exception : not null GCC_Exception_Access) 421 return System.Address is 422 Saved_Cleanup : constant System.Address := GCC_Exception.Cleanup; 423 begin 424 -- Claim responsibility for releasing this exception, and stop 425 -- others from releasing it. 426 GCC_Exception.Cleanup := Claimed_Cleanup'Address; 427 return Saved_Cleanup; 428 end Begin_Handler_v1; 429 430 -------------------- 431 -- End_Handler_v1 -- 432 -------------------- 433 434 procedure End_Handler_v1 435 (GCC_Exception : not null GCC_Exception_Access; 436 Saved_Cleanup : System.Address; 437 Propagating_Exception : GCC_Exception_Access) is 438 begin 439 GCC_Exception.Cleanup := Saved_Cleanup; 440 -- Restore the Saved_Cleanup, so that it is either used to 441 -- release GCC_Exception below, or transferred to the next 442 -- handler of the Propagating_Exception occurrence. The 443 -- following test ensures that an occurrence is only released 444 -- once, even after reraises. 445 -- 446 -- The idea is that the GCC_Exception is not to be released 447 -- unless it had an unclaimed Cleanup when the handler started 448 -- (see Begin_Handler_v1 above), but if we propagate across its 449 -- handler a reraise of the same exception, we transfer to the 450 -- Propagating_Exception the responsibility for running the 451 -- Saved_Cleanup when its handler completes. 452 -- 453 -- This ownership transfer mechanism ensures safety, as in 454 -- single release and no dangling pointers, because there is no 455 -- way to hold on to the Machine_Occurrence of an 456 -- Exception_Occurrence: the only situations in which another 457 -- Exception_Occurrence gets the same Machine_Occurrence are 458 -- through Reraise_Occurrence, and plain reraise, and so we 459 -- have the following possibilities: 460 -- 461 -- - Reraise_Occurrence is handled within the running handler, 462 -- and so when completing the dynamically nested handler, we 463 -- must NOT release the exception. A Claimed_Cleanup upon 464 -- entry of the nested handler, installed when entering the 465 -- enclosing handler, ensures the exception will not be 466 -- released by the nested handler, but rather by the enclosing 467 -- handler. 468 -- 469 -- - Reraise_Occurrence/reraise escapes the running handler, 470 -- and we run as an exceptional cleanup for GCC_Exception. The 471 -- Saved_Cleanup was reinstalled, but since we're propagating 472 -- the same machine occurrence, we do not release it. Instead, 473 -- we transfer responsibility for releasing it to the eventual 474 -- handler of the propagating exception. 475 -- 476 -- - An unrelated exception propagates through the running 477 -- handler. We restored GCC_Exception.Saved_Cleanup above. 478 -- Since we're propagating a different exception, we proceed to 479 -- release GCC_Exception, unless Saved_Cleanup was 480 -- Claimed_Cleanup, because then we know we're not in the 481 -- outermost handler for GCC_Exception. 482 -- 483 -- - The handler completes normally, so it reinstalls the 484 -- Saved_Cleanup and runs it, unless it was Claimed_Cleanup. 485 -- If Saved_Cleanup is null, Unwind_DeleteException (currently) 486 -- has no effect, so we could skip it, but if it is ever 487 -- changed to do more in this case, we're ready for that, 488 -- calling it exactly once. 489 if Saved_Cleanup /= Claimed_Cleanup'Address 490 and then 491 Propagating_Exception /= GCC_Exception 492 then 493 declare 494 Current : constant EOA := Get_Current_Excep.all; 495 Cur_Occ : constant GCC_Exception_Access 496 := To_GCC_Exception (Current.Machine_Occurrence); 497 begin 498 -- If we are releasing the Machine_Occurrence of the current 499 -- exception, reset the access to it, so that it is no 500 -- longer accessible. 501 if Cur_Occ = GCC_Exception then 502 Current.Machine_Occurrence := System.Null_Address; 503 end if; 504 end; 505 Unwind_DeleteException (GCC_Exception); 506 end if; 507 end End_Handler_v1; 508 509 --------------------- 510 -- Claimed_Cleanup -- 511 --------------------- 512 513 procedure Claimed_Cleanup 514 (Reason : Unwind_Reason_Code; 515 GCC_Exception : not null GCC_Exception_Access) is 516 pragma Unreferenced (Reason); 517 pragma Unreferenced (GCC_Exception); 518 begin 519 -- This procedure should never run. If it does, it's either a 520 -- version 0 handler or a foreign handler, attempting to 521 -- release an exception while a version 1 handler that claimed 522 -- responsibility for releasing the exception remains still 523 -- active. This placeholder stops GCC_Exception from being 524 -- released by them. 525 526 -- We could get away with just Null_Address instead, with 527 -- nearly the same effect, but with this placeholder we can 528 -- detect and report unexpected releases, and we can tell apart 529 -- a GCC_Exception without a Cleanup, from one with another 530 -- active handler, so as to still call Unwind_DeleteException 531 -- exactly once: currently, Unwind_DeleteException does nothing 532 -- when the Cleanup is null, but should it ever be changed to 533 -- do more, we'll still be safe. 534 null; 535 end Claimed_Cleanup; 536 537 ------------------- 538 -- Begin_Handler -- 539 ------------------- 540 541 procedure Begin_Handler (GCC_Exception : not null GCC_Exception_Access) is 542 pragma Unreferenced (GCC_Exception); 543 begin 544 null; 545 end Begin_Handler; 546 547 ----------------- 548 -- End_Handler -- 549 ----------------- 550 551 procedure End_Handler (GCC_Exception : GCC_Exception_Access) is 552 begin 553 if GCC_Exception /= null then 554 555 -- The exception might have been reraised, in this case the cleanup 556 -- mustn't be called. 557 558 Unwind_DeleteException (GCC_Exception); 559 end if; 560 end End_Handler; 561 562 ----------------------------- 563 -- Reraise_GCC_Exception -- 564 ----------------------------- 565 566 procedure Reraise_GCC_Exception 567 (GCC_Exception : not null GCC_Exception_Access) 568 is 569 begin 570 -- Simply propagate it 571 572 Propagate_GCC_Exception (GCC_Exception); 573 end Reraise_GCC_Exception; 574 575 ----------------------------- 576 -- Propagate_GCC_Exception -- 577 ----------------------------- 578 579 -- Call Unwind_RaiseException to actually throw, taking care of handling 580 -- the two phase scheme it implements. 581 582 procedure Propagate_GCC_Exception 583 (GCC_Exception : not null GCC_Exception_Access) 584 is 585 -- Acknowledge the current exception info now, before unwinding 586 -- starts so it is available even from C++ handlers involved before 587 -- our personality routine. 588 589 Excep : constant EOA := 590 Setup_Current_Excep (GCC_Exception, Phase => 0); 591 592 begin 593 -- Perform a standard raise first. If a regular handler is found, it 594 -- will be entered after all the intermediate cleanups have run. If 595 -- there is no regular handler, it will return. 596 597 Unwind_RaiseException (GCC_Exception); 598 599 -- If we get here we know the exception is not handled, as otherwise 600 -- Unwind_RaiseException arranges for the handler to be entered. Take 601 -- the necessary steps to enable the debugger to gain control while the 602 -- stack is still intact. 603 604 Notify_Unhandled_Exception (Excep); 605 606 -- Now, un a forced unwind to trigger cleanups. Control should not 607 -- resume there, if there are cleanups and in any cases as the 608 -- unwinding hook calls Unhandled_Exception_Terminate when end of 609 -- stack is reached. 610 611 Unwind_ForcedUnwind 612 (GCC_Exception, 613 CleanupUnwind_Handler'Address, 614 System.Null_Address); 615 616 -- We get here in case of error. The debugger has been notified before 617 -- the second step above. 618 619 Unhandled_Except_Handler (GCC_Exception); 620 end Propagate_GCC_Exception; 621 622 ------------------------- 623 -- Propagate_Exception -- 624 ------------------------- 625 626 procedure Propagate_Exception (Excep : Exception_Occurrence) is 627 begin 628 Propagate_GCC_Exception (To_GCC_Exception (Excep.Machine_Occurrence)); 629 end Propagate_Exception; 630 631 ----------------------------- 632 -- Set_Exception_Parameter -- 633 ----------------------------- 634 635 procedure Set_Exception_Parameter 636 (Excep : EOA; 637 GCC_Exception : not null GCC_Exception_Access) 638 is 639 begin 640 -- Setup the exception occurrence 641 642 if GCC_Exception.Class = GNAT_Exception_Class then 643 644 -- From the GCC exception 645 646 declare 647 GNAT_Occurrence : constant GNAT_GCC_Exception_Access := 648 To_GNAT_GCC_Exception (GCC_Exception); 649 begin 650 Save_Occurrence (Excep.all, GNAT_Occurrence.Occurrence); 651 end; 652 653 else 654 -- A default one 655 656 Set_Foreign_Occurrence (Excep, GCC_Exception.all'Address); 657 end if; 658 end Set_Exception_Parameter; 659 660 ------------------------------ 661 -- Unhandled_Except_Handler -- 662 ------------------------------ 663 664 procedure Unhandled_Except_Handler 665 (GCC_Exception : not null GCC_Exception_Access) 666 is 667 Excep : EOA; 668 begin 669 Excep := Setup_Current_Excep (GCC_Exception, Phase => UA_CLEANUP_PHASE); 670 Unhandled_Exception_Terminate (Excep); 671 end Unhandled_Except_Handler; 672 673 ------------- 674 -- EID_For -- 675 ------------- 676 677 function EID_For 678 (GNAT_Exception : not null GNAT_GCC_Exception_Access) return Exception_Id 679 is 680 begin 681 return GNAT_Exception.Occurrence.Id; 682 end EID_For; 683 684 ---------------------- 685 -- Foreign_Data_For -- 686 ---------------------- 687 688 function Foreign_Data_For 689 (E : SSL.Exception_Data_Ptr) return Address 690 is 691 begin 692 return E.Foreign_Data; 693 end Foreign_Data_For; 694 695 -------------------------- 696 -- Is_Handled_By_Others -- 697 -------------------------- 698 699 function Is_Handled_By_Others (E : SSL.Exception_Data_Ptr) return Boolean is 700 begin 701 return not E.all.Not_Handled_By_Others; 702 end Is_Handled_By_Others; 703 704 ------------------ 705 -- Language_For -- 706 ------------------ 707 708 function Language_For (E : SSL.Exception_Data_Ptr) return Character is 709 begin 710 return E.all.Lang; 711 end Language_For; 712 713end Exception_Propagation; 714