1 /* Handle exceptional things in C++.
2 Copyright (C) 1989, 92-95, 1996 Free Software Foundation, Inc.
3 Contributed by Michael Tiemann <tiemann@cygnus.com>
4 Rewritten by Mike Stump <mrs@cygnus.com>, based upon an
5 initial re-implementation courtesy Tad Hunt.
7 This file is part of GNU CC.
9 GNU CC 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 2, or (at your option)
14 GNU CC 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.
19 You should have received a copy of the GNU General Public License
20 along with GNU CC; see the file COPYING. If not, write to
21 the Free Software Foundation, 59 Temple Place - Suite 330,
22 Boston, MA 02111-1307, USA. */
36 rtx expand_builtin_return_addr PROTO((enum built_in_function, int, rtx));
38 /* holds the fndecl for __builtin_return_address () */
39 tree builtin_return_address_fndecl;
41 /* A couple of backend routines from m88k.c */
43 /* used to cache a call to __builtin_return_address () */
44 static tree BuiltinReturnAddress;
53 expand_asm (build_string (strlen (str)+1, str));
58 /* This is the startup, and finish stuff per exception table. */
60 /* XXX - Tad: exception handling section */
61 #ifndef EXCEPT_SECTION_ASM_OP
62 #define EXCEPT_SECTION_ASM_OP "section\t.gcc_except_table,\"a\",@progbits"
65 #ifdef EXCEPT_SECTION_ASM_OP
69 void *exception_handler;
71 #endif /* EXCEPT_SECTION_ASM_OP */
73 #ifdef EXCEPT_SECTION_ASM_OP
75 /* on machines which support it, the exception table lives in another section,
76 but it needs a label so we can reference it... This sets up that
78 asm (EXCEPT_SECTION_ASM_OP);
79 exception_table __EXCEPTION_TABLE__[1] = { (void*)0, (void*)0, (void*)0 };
80 asm (TEXT_SECTION_ASM_OP);
82 #endif /* EXCEPT_SECTION_ASM_OP */
84 #ifdef EXCEPT_SECTION_ASM_OP
86 /* we need to know where the end of the exception table is... so this
89 asm (EXCEPT_SECTION_ASM_OP);
90 exception_table __EXCEPTION_END__[1] = { (void*)-1, (void*)-1, (void*)-1 };
91 asm (TEXT_SECTION_ASM_OP);
93 #endif /* EXCEPT_SECTION_ASM_OP */
98 #include "insn-flags.h"
101 /* ======================================================================
102 Briefly the algorithm works like this:
104 When a constructor or start of a try block is encountered,
105 push_eh_entry (&eh_stack) is called. Push_eh_entry () creates a
106 new entry in the unwind protection stack and returns a label to
107 output to start the protection for that block.
109 When a destructor or end try block is encountered, pop_eh_entry
110 (&eh_stack) is called. Pop_eh_entry () returns the eh_entry it
111 created when push_eh_entry () was called. The eh_entry structure
112 contains three things at this point. The start protect label,
113 the end protect label, and the exception handler label. The end
114 protect label should be output before the call to the destructor
115 (if any). If it was a destructor, then its parse tree is stored
116 in the finalization variable in the eh_entry structure. Otherwise
117 the finalization variable is set to NULL to reflect the fact that
118 is the the end of a try block. Next, this modified eh_entry node
119 is enqueued in the finalizations queue by calling
120 enqueue_eh_entry (&queue,entry).
122 +---------------------------------------------------------------+
123 |XXX: Will need modification to deal with partially |
124 | constructed arrays of objects |
126 | Basically, this consists of keeping track of how many |
127 | of the objects have been constructed already (this |
128 | should be in a register though, so that shouldn't be a |
130 +---------------------------------------------------------------+
132 When a catch block is encountered, there is a lot of work to be
135 Since we don't want to generate the catch block inline with the
136 regular flow of the function, we need to have some way of doing
137 so. Luckily, we can use sequences to defer the catch sections.
138 When the start of a catch block is encountered, we start the
139 sequence. After the catch block is generated, we end the
142 Next we must insure that when the catch block is executed, all
143 finalizations for the matching try block have been completed. If
144 any of those finalizations throw an exception, we must call
145 terminate according to the ARM (section r.15.6.1). What this
146 means is that we need to dequeue and emit finalizations for each
147 entry in the eh_queue until we get to an entry with a NULL
148 finalization field. For any of the finalization entries, if it
149 is not a call to terminate (), we must protect it by giving it
150 another start label, end label, and exception handler label,
151 setting its finalization tree to be a call to terminate (), and
152 enqueue'ing this new eh_entry to be output at an outer level.
153 Finally, after all that is done, we can get around to outputting
154 the catch block which basically wraps all the "catch (...) {...}"
155 statements in a big if/then/else construct that matches the
156 correct block to call.
158 ===================================================================== */
160 extern rtx emit_insn PROTO((rtx));
161 extern rtx gen_nop PROTO(());
163 /* local globals for function calls
164 ====================================================================== */
166 /* used to cache "terminate ()", "unexpected ()", "set_terminate ()", and
167 "set_unexpected ()" after default_conversion. (lib-except.c) */
168 static tree Terminate, Unexpected, SetTerminate, SetUnexpected, CatchMatch;
170 /* used to cache __find_first_exception_table_match ()
171 for throw (lib-except.c) */
172 static tree FirstExceptionMatch;
174 /* used to cache a call to __unwind_function () (lib-except.c) */
177 /* holds a ready to emit call to "terminate ()". */
178 static tree TerminateFunctionCall;
180 static tree empty_fndecl;
182 /* ====================================================================== */
185 /* ========================================================================= */
189 /* local globals - these local globals are for storing data necessary for
190 generating the exception table and code in the correct order.
192 ========================================================================= */
194 /* Holds the pc for doing "throw" */
195 static tree saved_pc;
196 /* Holds the type of the thing being thrown. */
197 static tree saved_throw_type;
198 /* Holds the value being thrown. */
199 static tree saved_throw_value;
200 /* Holds the cleanup for the value being thrown. */
201 static tree saved_cleanup;
202 /* Indicates if we are in a catch clause. */
203 static tree saved_in_catch;
205 extern int throw_used;
206 extern rtx catch_clauses;
208 /* ========================================================================= */
210 /* Cheesyness to save some typing. Returns the return value rtx. */
213 do_function_call (func, params, return_type)
214 tree func, params, return_type;
217 func_call = build_function_call (func, params);
218 expand_call (func_call, NULL_RTX, 0);
219 if (return_type != NULL_TREE)
220 return hard_function_value (return_type, func_call);
224 /* ========================================================================= */
226 extern tree auto_function PROTO((tree, tree, enum built_in_function));
228 /* sets up all the global eh stuff that needs to be initialized at the
229 start of compilation.
232 - Setting up all the function call trees. */
235 init_exception_processing ()
237 extern tree define_function ();
238 tree unexpected_fndecl, terminate_fndecl;
239 tree set_unexpected_fndecl, set_terminate_fndecl;
240 tree catch_match_fndecl;
241 tree find_first_exception_match_fndecl;
247 tree PFV = build_pointer_type (build_function_type
248 (void_type_node, void_list_node));
250 /* arg list for the build_function_type call for set_terminate () and
252 tree pfvlist = tree_cons (NULL_TREE, PFV, void_list_node);
254 /* void (*pfvtype (void (*) ()))() */
255 tree pfvtype = build_function_type (PFV, pfvlist);
258 tree vtype = build_function_type (void_type_node, void_list_node);
260 set_terminate_fndecl = auto_function (get_identifier ("set_terminate"),
261 pfvtype, NOT_BUILT_IN);
262 set_unexpected_fndecl = auto_function (get_identifier ("set_unexpected"),
263 pfvtype, NOT_BUILT_IN);
264 unexpected_fndecl = auto_function (get_identifier ("unexpected"),
265 vtype, NOT_BUILT_IN);
266 terminate_fndecl = auto_function (get_identifier ("terminate"),
267 vtype, NOT_BUILT_IN);
269 push_lang_context (lang_name_c);
272 builtin_function (flag_rtti
273 ? "__throw_type_match_rtti"
274 : "__throw_type_match",
275 build_function_type (ptr_type_node,
276 tree_cons (NULL_TREE, ptr_type_node,
277 tree_cons (NULL_TREE, ptr_type_node,
278 tree_cons (NULL_TREE, ptr_type_node,
280 NOT_BUILT_IN, NULL_PTR);
281 find_first_exception_match_fndecl =
282 builtin_function ("__find_first_exception_table_match",
283 build_function_type (ptr_type_node,
284 tree_cons (NULL_TREE, ptr_type_node,
286 NOT_BUILT_IN, NULL_PTR);
288 builtin_function ("__unwind_function",
289 build_function_type (void_type_node,
290 tree_cons (NULL_TREE, ptr_type_node,
292 NOT_BUILT_IN, NULL_PTR);
294 builtin_function ("__empty",
295 build_function_type (void_type_node, void_list_node),
296 NOT_BUILT_IN, NULL_PTR);
297 DECL_EXTERNAL (empty_fndecl) = 1;
298 TREE_PUBLIC (empty_fndecl) = 1;
300 Unexpected = default_conversion (unexpected_fndecl);
301 Terminate = default_conversion (terminate_fndecl);
302 SetTerminate = default_conversion (set_terminate_fndecl);
303 SetUnexpected = default_conversion (set_unexpected_fndecl);
304 CatchMatch = default_conversion (catch_match_fndecl);
305 FirstExceptionMatch = default_conversion (find_first_exception_match_fndecl);
306 Unwind = default_conversion (unwind_fndecl);
307 BuiltinReturnAddress = default_conversion (builtin_return_address_fndecl);
309 TerminateFunctionCall = build_function_call (Terminate, NULL_TREE);
313 declspecs = tree_cons (NULL_TREE, get_identifier ("void"), NULL_TREE);
314 d = build_parse_node (INDIRECT_REF, get_identifier ("__eh_pc"));
315 d = start_decl (d, declspecs, 0, NULL_TREE);
317 cp_finish_decl (d, NULL_TREE, NULL_TREE, 1, 0);
318 saved_pc = lookup_name (get_identifier ("__eh_pc"), 0);
320 declspecs = tree_cons (NULL_TREE, get_identifier ("void"), NULL_TREE);
321 d = build_parse_node (INDIRECT_REF, get_identifier ("__eh_type"));
322 d = start_decl (d, declspecs, 0, NULL_TREE);
324 cp_finish_decl (d, NULL_TREE, NULL_TREE, 1, 0);
325 saved_throw_type = lookup_name (get_identifier ("__eh_type"), 0);
327 declspecs = tree_cons (NULL_TREE, get_identifier ("void"), NULL_TREE);
328 d = build_parse_node (INDIRECT_REF, get_identifier ("__eh_value"));
329 d = start_decl (d, declspecs, 0, NULL_TREE);
331 cp_finish_decl (d, NULL_TREE, NULL_TREE, 1, 0);
332 saved_throw_value = lookup_name (get_identifier ("__eh_value"), 0);
334 declspecs = tree_cons (NULL_TREE, get_identifier ("void"), NULL_TREE);
335 d = build_parse_node (INDIRECT_REF, get_identifier ("__eh_cleanup"));
336 d = build_parse_node (CALL_EXPR, d, void_list_node, NULL_TREE);
337 d = start_decl (d, declspecs, 0, NULL_TREE);
339 cp_finish_decl (d, NULL_TREE, NULL_TREE, 1, 0);
340 saved_cleanup = lookup_name (get_identifier ("__eh_cleanup"), 0);
342 declspecs = tree_cons (NULL_TREE, get_identifier ("bool"), NULL_TREE);
343 d = get_identifier ("__eh_in_catch");
344 d = start_decl (d, declspecs, 0, NULL_TREE);
346 cp_finish_decl (d, NULL_TREE, NULL_TREE, 1, 0);
347 saved_in_catch = lookup_name (get_identifier ("__eh_in_catch"), 0);
350 /* Build a type value for use at runtime for a type that is matched
351 against by the exception handling system. */
354 build_eh_type_type (type)
360 if (type == error_mark_node)
361 return error_mark_node;
363 /* peel back references, so they match. */
364 if (TREE_CODE (type) == REFERENCE_TYPE)
365 type = TREE_TYPE (type);
367 /* Peel off cv qualifiers. */
368 type = TYPE_MAIN_VARIANT (type);
372 return build1 (ADDR_EXPR, ptr_type_node, get_typeid (type));
375 typestring = build_overload_name (type, 1, 1);
376 exp = combine_strings (build_string (strlen (typestring)+1, typestring));
377 return build1 (ADDR_EXPR, ptr_type_node, exp);
380 /* Build a type value for use at runtime for a exp that is thrown or
381 matched against by the exception handling system. */
389 exp = build_typeid (exp);
390 return build1 (ADDR_EXPR, ptr_type_node, exp);
392 return build_eh_type_type (TREE_TYPE (exp));
395 /* This routine creates the cleanup for the exception handling object. */
400 /* All cleanups must last longer than normal. */
401 int yes = suspend_momentary ();
403 /* Arrange to do a dynamically scoped cleanup upon exit from this region. */
404 tree cleanup = build_function_call (saved_cleanup, NULL_TREE);
405 cleanup = build (COMPOUND_EXPR, void_type_node, cleanup,
406 build_modify_expr (saved_in_catch, NOP_EXPR,
407 build_modify_expr (saved_throw_type, NOP_EXPR, integer_zero_node)));
408 expand_decl_cleanup (NULL_TREE, cleanup);
410 resume_momentary (yes);
414 /* call this to start a catch block. Typename is the typename, and identifier
415 is the variable to place the object in or NULL if the variable doesn't
416 matter. If typename is NULL, that means its a "catch (...)" or catch
417 everything. In that case we don't need to do any type checking.
418 (ie: it ends up as the "else" clause rather than an "else if" clause) */
421 expand_start_catch_block (declspecs, declarator)
422 tree declspecs, declarator;
425 tree decl = NULL_TREE;
431 /* Create a binding level for the parm. */
432 expand_start_bindings (0);
434 false_label_rtx = gen_label_rtx ();
435 push_label_entry (&false_label_stack, false_label_rtx, NULL_TREE);
440 rtx call_rtx, return_value_rtx;
443 decl = grokdeclarator (declarator, declspecs, CATCHPARM, 1,
444 NULL_TREE, NULL_TREE);
446 if (decl == NULL_TREE)
448 error ("invalid catch parameter");
450 /* This is cheap, but we want to maintain the data structures. */
451 expand_eh_region_start ();
455 /* Make sure we mark the catch param as used, otherwise we'll get
456 a warning about an unused ((anonymous)). */
457 TREE_USED (decl) = 1;
459 /* Figure out the type that the initializer is. */
460 init_type = TREE_TYPE (decl);
461 if (TREE_CODE (init_type) != REFERENCE_TYPE
462 && TREE_CODE (init_type) != POINTER_TYPE)
463 init_type = build_reference_type (init_type);
465 exp = saved_throw_value;
466 exp = tree_cons (NULL_TREE,
467 build_eh_type_type (TREE_TYPE (decl)),
468 tree_cons (NULL_TREE,
470 tree_cons (NULL_TREE, exp, NULL_TREE)));
471 exp = build_function_call (CatchMatch, exp);
472 call_rtx = expand_call (exp, NULL_RTX, 0);
473 assemble_external (TREE_OPERAND (CatchMatch, 0));
475 return_value_rtx = hard_function_value (ptr_type_node, exp);
477 /* did the throw type match function return TRUE? */
478 emit_cmp_insn (return_value_rtx, const0_rtx, EQ, NULL_RTX,
479 GET_MODE (return_value_rtx), 0, 0);
481 /* if it returned FALSE, jump over the catch block, else fall into it */
482 emit_jump_insn (gen_beq (false_label_rtx));
486 init = convert_from_reference (save_expr (make_tree (init_type, call_rtx)));
488 /* Do we need the below two lines? */
489 /* Let `cp_finish_decl' know that this initializer is ok. */
490 DECL_INITIAL (decl) = init;
491 decl = pushdecl (decl);
492 cp_finish_decl (decl, init, NULL_TREE, 0, LOOKUP_ONLYCONVERTING);
498 /* Fall into the catch all section. */
501 emit_move_insn (DECL_RTL (saved_in_catch), const1_rtx);
503 /* Because we are reordered out of line, we arrange
504 to rethrow in the outer context, should we encounter
505 an exception in the catch handler.
507 Matches the end in expand_end_catch_block (). */
508 expand_eh_region_start ();
510 emit_line_note (input_filename, lineno);
515 /* Call this to end a catch block. Its responsible for emitting the
516 code to handle jumping back to the correct place, and for emitting
517 the label to jump to if this catch block didn't match. */
519 void expand_end_catch_block ()
521 rtx start_region_label_rtx;
522 rtx end_region_label_rtx;
528 /* Fall to outside the try statement when done executing handler and
529 we fall off end of handler. This is jump Lresume in the
531 expand_goto (top_label_entry (&caught_return_label_stack));
533 t = make_node (RTL_EXPR);
534 TREE_TYPE (t) = void_type_node;
535 RTL_EXPR_RTL (t) = const0_rtx;
536 TREE_SIDE_EFFECTS (t) = 1;
537 start_sequence_for_rtl_expr (t);
538 expand_internal_throw (DECL_RTL (top_label_entry (&caught_return_label_stack)));
539 RTL_EXPR_SEQUENCE (t) = get_insns ();
542 /* Matches the start in expand_start_catch_block (). */
543 expand_eh_region_end (t);
545 expand_leftover_cleanups ();
547 /* Cleanup the EH parameter. */
549 expand_end_bindings (decls, decls != NULL_TREE, 0);
551 /* label we emit to jump to if this catch block didn't match. */
552 /* This the closing } in the `if (eq) {' of the documentation. */
553 emit_label (pop_label_entry (&false_label_stack));
556 /* unwind the stack. */
559 do_unwind (inner_throw_label)
560 rtx inner_throw_label;
562 #if defined (SPARC_STACK_ALIGN) /* was sparc */
563 /* This doesn't work for the flat model sparc, I bet. */
569 /* call to __builtin_return_address () */
570 params = tree_cons (NULL_TREE, integer_zero_node, NULL_TREE);
571 fcall = build_function_call (BuiltinReturnAddress, params);
572 return_val_rtx = expand_expr (fcall, NULL_RTX, Pmode, 0);
573 /* In the return, the new pc is pc+8, as the value coming in is
574 really the address of the call insn, not the next insn. */
575 temp = gen_reg_rtx (Pmode);
576 emit_move_insn (temp, inner_throw_label);
577 emit_move_insn (return_val_rtx, plus_constant (temp, -8));
578 emit_insn (gen_rtx (USE, VOIDmode, gen_rtx (REG, SImode, 31)));
579 easy_expand_asm ("ret");
580 easy_expand_asm ("restore");
583 #if defined (ARM_FRAME_RTX) /* was __arm */
584 if (flag_omit_frame_pointer)
585 sorry ("this implementation of exception handling requires a frame pointer");
587 emit_move_insn (stack_pointer_rtx,
588 gen_rtx (MEM, Pmode, plus_constant (hard_frame_pointer_rtx, -8)));
589 emit_move_insn (hard_frame_pointer_rtx,
590 gen_rtx (MEM, Pmode, plus_constant (hard_frame_pointer_rtx, -12)));
592 #if defined (TARGET_88000) /* was m88k */
593 rtx temp_frame = frame_pointer_rtx;
595 temp_frame = memory_address (Pmode, temp_frame);
596 temp_frame = copy_to_reg (gen_rtx (MEM, Pmode, temp_frame));
598 /* hopefully this will successfully pop the frame! */
599 emit_move_insn (frame_pointer_rtx, temp_frame);
600 emit_move_insn (stack_pointer_rtx, frame_pointer_rtx);
601 emit_move_insn (arg_pointer_rtx, frame_pointer_rtx);
602 emit_insn (gen_add2_insn (stack_pointer_rtx, gen_rtx (CONST_INT, VOIDmode,
603 (HOST_WIDE_INT)m88k_debugger_offset (stack_pointer_rtx, 0))));
606 emit_insn (gen_add2_insn (arg_pointer_rtx, gen_rtx (CONST_INT, VOIDmode,
607 -(HOST_WIDE_INT)m88k_debugger_offset (arg_pointer_rtx, 0))));
609 emit_move_insn (stack_pointer_rtx, arg_pointer_rtx);
611 emit_insn (gen_add2_insn (stack_pointer_rtx, gen_rtx (CONST_INT, VOIDmode,
612 (HOST_WIDE_INT)m88k_debugger_offset (arg_pointer_rtx, 0))));
615 #if ! defined (TARGET_88000) && ! defined (ARM_FRAME_RTX) && ! defined (SPARC_STACK_ALIGN)
621 /* I would like to do this here, but the move below doesn't seem to work. */
622 /* call to __builtin_return_address () */
623 params = tree_cons (NULL_TREE, integer_zero_node, NULL_TREE);
624 fcall = build_function_call (BuiltinReturnAddress, params);
625 return_val_rtx = expand_expr (fcall, NULL_RTX, Pmode, 0);
627 emit_move_insn (return_val_rtx, inner_throw_label);
628 /* So, for now, just pass throw label to stack unwinder. */
630 params = tree_cons (NULL_TREE, make_tree (ptr_type_node,
631 inner_throw_label), NULL_TREE);
633 do_function_call (Unwind, params, NULL_TREE);
634 assemble_external (TREE_OPERAND (Unwind, 0));
640 /* is called from expand_exception_blocks () to generate the code in a function
641 to "throw" if anything in the function needs to perform a throw.
643 expands "throw" as the following pseudo code:
646 eh = find_first_exception_match (saved_pc);
647 if (!eh) goto gotta_rethrow_it;
651 saved_pc = __builtin_return_address (0);
652 pop_to_previous_level ();
656 expand_builtin_throw ()
661 rtx gotta_rethrow_it;
662 rtx gotta_call_terminate;
673 params = void_list_node;
674 t = build_parse_node (CALL_EXPR, get_identifier ("__throw"), params, NULL_TREE);
675 start_function (decl_tree_cons (NULL_TREE, get_identifier ("static"),
677 t, NULL_TREE, NULL_TREE, 0);
682 expand_start_bindings (0);
684 gotta_rethrow_it = gen_label_rtx ();
685 gotta_call_terminate = gen_label_rtx ();
686 top_of_loop = gen_label_rtx ();
687 unwind_first = gen_label_rtx ();
689 /* These two can be frontend specific. If wanted, they can go in
691 /* Do we have a valid object we are throwing? */
692 emit_cmp_insn (DECL_RTL (saved_throw_type), const0_rtx, EQ, NULL_RTX,
693 GET_MODE (DECL_RTL (saved_throw_type)), 0, 0);
694 emit_jump_insn (gen_beq (gotta_call_terminate));
696 emit_jump (unwind_first);
698 emit_label (top_of_loop);
700 /* search for an exception handler for the saved_pc */
701 return_val_rtx = do_function_call (FirstExceptionMatch,
702 tree_cons (NULL_TREE, saved_pc, NULL_TREE),
704 assemble_external (TREE_OPERAND (FirstExceptionMatch, 0));
706 /* did we find one? */
707 emit_cmp_insn (return_val_rtx, const0_rtx, EQ, NULL_RTX,
708 GET_MODE (return_val_rtx), 0, 0);
710 /* if not, jump to gotta_rethrow_it */
711 emit_jump_insn (gen_beq (gotta_rethrow_it));
713 /* we found it, so jump to it */
714 emit_indirect_jump (return_val_rtx);
716 /* code to deal with unwinding and looking for it again */
717 emit_label (gotta_rethrow_it);
719 /* call to __builtin_return_address () */
720 #if defined (ARM_FRAME_RTX) /* was __arm */
721 /* This should be moved into arm.h:RETURN_ADDR_RTX */
722 /* This replaces a 'call' to __builtin_return_address */
723 return_val_rtx = gen_reg_rtx (Pmode);
724 emit_move_insn (return_val_rtx, gen_rtx (MEM, Pmode, plus_constant (hard_frame_pointer_rtx, -4)));
726 params = tree_cons (NULL_TREE, integer_zero_node, NULL_TREE);
727 fcall = build_function_call (BuiltinReturnAddress, params);
728 return_val_rtx = expand_expr (fcall, NULL_RTX, Pmode, 0);
731 /* did __builtin_return_address () return a valid address? */
732 emit_cmp_insn (return_val_rtx, const0_rtx, EQ, NULL_RTX,
733 GET_MODE (return_val_rtx), 0, 0);
735 emit_jump_insn (gen_beq (gotta_call_terminate));
737 return_val_rtx = eh_outer_context (return_val_rtx);
740 emit_move_insn (eh_saved_pc_rtx, return_val_rtx);
742 do_unwind (gen_rtx (LABEL_REF, Pmode, top_of_loop));
743 emit_jump (top_of_loop);
745 /* no it didn't --> therefore we need to call terminate */
746 emit_label (gotta_call_terminate);
747 do_function_call (Terminate, NULL_TREE, NULL_TREE);
748 assemble_external (TREE_OPERAND (Terminate, 0));
751 rtx ret_val, return_val_rtx;
752 emit_label (unwind_first);
753 ret_val = expand_builtin_return_addr (BUILT_IN_RETURN_ADDRESS,
754 0, hard_frame_pointer_rtx);
756 /* Set it up so that we continue inside, at the top of the loop. */
757 emit_move_insn (ret_val, gen_rtx (LABEL_REF, Pmode, top_of_loop));
758 #ifdef RETURN_ADDR_OFFSET
759 return_val_rtx = plus_constant (ret_val, -RETURN_ADDR_OFFSET);
760 if (return_val_rtx != ret_val)
761 emit_move_insn (ret_val, return_val_rtx);
764 /* Fall into epilogue to unwind prologue. */
767 expand_end_bindings (getdecls (), 1, 0);
771 finish_function (lineno, 0, 0);
776 expand_start_eh_spec ()
778 expand_eh_region_start ();
782 expand_end_eh_spec (raises)
785 tree expr, second_try;
786 rtx check = gen_label_rtx ();
788 rtx ret = gen_reg_rtx (Pmode);
789 rtx flag = gen_reg_rtx (TYPE_MODE (integer_type_node));
790 rtx end = gen_label_rtx ();
792 expr = make_node (RTL_EXPR);
793 TREE_TYPE (expr) = void_type_node;
794 RTL_EXPR_RTL (expr) = const0_rtx;
795 TREE_SIDE_EFFECTS (expr) = 1;
796 start_sequence_for_rtl_expr (expr);
797 cont = gen_label_rtx ();
798 emit_move_insn (ret, gen_rtx (LABEL_REF, Pmode, cont));
801 jumpif (make_tree (integer_type_node, flag), end);
802 do_function_call (Terminate, NULL_TREE, NULL_TREE);
803 assemble_external (TREE_OPERAND (Terminate, 0));
805 RTL_EXPR_SEQUENCE (expr) = get_insns ();
810 expr = make_node (RTL_EXPR);
811 TREE_TYPE (expr) = void_type_node;
812 RTL_EXPR_RTL (expr) = const0_rtx;
813 TREE_SIDE_EFFECTS (expr) = 1;
814 start_sequence_for_rtl_expr (expr);
816 cont = gen_label_rtx ();
817 emit_move_insn (ret, gen_rtx (LABEL_REF, Pmode, cont));
820 jumpif (make_tree (integer_type_node, flag), end);
821 expand_eh_region_start ();
822 do_function_call (Unexpected, NULL_TREE, NULL_TREE);
823 assemble_external (TREE_OPERAND (Unexpected, 0));
825 expand_eh_region_end (second_try);
828 emit_move_insn (flag, const1_rtx);
829 cont = gen_label_rtx ();
833 tree match_type = TREE_VALUE (raises);
837 /* check TREE_VALUE (raises) here */
838 exp = saved_throw_value;
839 exp = tree_cons (NULL_TREE,
840 build_eh_type_type (match_type),
841 tree_cons (NULL_TREE,
843 tree_cons (NULL_TREE, exp, NULL_TREE)));
844 exp = build_function_call (CatchMatch, exp);
845 assemble_external (TREE_OPERAND (CatchMatch, 0));
850 raises = TREE_CHAIN (raises);
852 emit_move_insn (flag, const0_rtx);
854 emit_indirect_jump (ret);
857 RTL_EXPR_SEQUENCE (expr) = get_insns ();
860 expand_eh_region_end (expr);
863 /* This is called to expand all the toplevel exception handling
864 finalization for a function. It should only be called once per
868 expand_exception_blocks ()
872 rtx eh_spec_insns = NULL_RTX;
876 funcend = gen_label_rtx ();
878 /* expand_null_return (); */
882 /* Add all the catch clauses here. */
883 emit_insns (catch_clauses);
884 catch_clauses = NULL_RTX;
886 expand_leftover_cleanups ();
888 insns = get_insns ();
891 /* Do this after we expand leftover cleanups, so that the expand_eh_region_end
892 that expand_end_eh_spec does will match the right expand_eh_region_start,
893 and make sure it comes out before the terminate protected region. */
894 if (TYPE_RAISES_EXCEPTIONS (TREE_TYPE (current_function_decl)))
901 expand_start_eh_spec ();
902 eh_spec_insns = get_insns ();
907 expand_end_eh_spec (TYPE_RAISES_EXCEPTIONS (TREE_TYPE (current_function_decl)));
908 push_to_sequence (insns);
910 /* Now expand any new ones. */
911 expand_leftover_cleanups ();
913 insns = get_insns ();
919 /* Is this necessary? */
920 assemble_external (TREE_OPERAND (Terminate, 0));
922 expand_eh_region_start ();
924 expand_eh_region_end (TerminateFunctionCall);
925 expand_leftover_cleanups ();
929 /* Mark the end of the stack unwinder. */
935 unwind_insns = get_insns ();
939 insns = unwind_insns;
944 emit_label (funcend);
946 /* Only if we had previous insns do we want to emit the jump around
947 them. If there weren't any, then insns will remain NULL_RTX. */
949 insns = get_insns ();
954 emit_insns_after (eh_spec_insns, get_insns ());
957 store_after_parms (eh_spec_insns);
966 static int counter = 0;
967 int old_interface_unknown = interface_unknown;
972 push_cp_function_context (NULL_TREE);
973 push_to_top_level ();
975 /* No need to mangle this. */
976 push_lang_context (lang_name_c);
978 interface_unknown = 1;
980 params = void_list_node;
981 /* tcf stands for throw clean funciton. */
982 sprintf (name, "__tcf_%d", counter++);
983 t = build_parse_node (CALL_EXPR, get_identifier (name), params, NULL_TREE);
984 start_function (decl_tree_cons (NULL_TREE, get_identifier ("static"),
986 t, NULL_TREE, NULL_TREE, 0);
991 expand_start_bindings (0);
992 emit_line_note (input_filename, lineno);
994 interface_unknown = old_interface_unknown;
998 return current_function_decl;
1004 expand_end_bindings (getdecls (), 1, 0);
1008 finish_function (lineno, 0, 0);
1010 pop_from_top_level ();
1011 pop_cp_function_context (NULL_TREE);
1014 /* Expand a throw statement. This follows the following
1017 1. Allocate space to save the current PC onto the stack.
1018 2. Generate and emit a label and save its address into the
1019 newly allocated stack space since we can't save the pc directly.
1020 3. If this is the first call to throw in this function:
1021 generate a label for the throw block
1022 4. jump to the throw block label. */
1036 tree cleanup = empty_fndecl, e;
1038 /* throw expression */
1039 /* First, decay it. */
1040 exp = decay_conversion (exp);
1042 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
1044 throw_type = build_eh_type (exp);
1045 exp = build_reinterpret_cast (ptr_type_node, exp);
1052 /* Make a copy of the thrown object. WP 15.1.5 */
1053 exp = build_new (NULL_TREE, TREE_TYPE (exp),
1054 build_tree_list (NULL_TREE, exp),
1057 if (exp == error_mark_node)
1058 error (" in thrown expression");
1060 object = build_indirect_ref (exp, NULL_PTR);
1061 throw_type = build_eh_type (object);
1064 object = build_reinterpret_cast (TREE_TYPE (exp), saved_throw_value);
1065 object = build_indirect_ref (object, NULL_PTR);
1066 cleanup = maybe_build_cleanup_and_delete (object);
1068 expand_expr (cleanup, const0_rtx, VOIDmode, 0);
1069 cleanup_insns = get_insns ();
1072 if (cleanup && cleanup_insns)
1074 cleanup = start_anon_func ();
1076 expand_expr (maybe_build_cleanup_and_delete (object),
1077 const0_rtx, VOIDmode, 0);
1081 mark_addressable (cleanup);
1085 cleanup = empty_fndecl;
1089 if (cleanup == empty_fndecl)
1090 assemble_external (empty_fndecl);
1092 e = build_modify_expr (saved_throw_type, NOP_EXPR, throw_type);
1093 expand_expr (e, const0_rtx, VOIDmode, 0);
1095 e = build_modify_expr (saved_throw_value, NOP_EXPR, exp);
1096 e = build1 (CLEANUP_POINT_EXPR, TREE_TYPE (e), e);
1097 expand_expr (e, const0_rtx, VOIDmode, 0);
1099 cleanup = build_unary_op (ADDR_EXPR, cleanup, 0);
1100 cleanup = build_modify_expr (saved_cleanup, NOP_EXPR, cleanup);
1101 expand_expr (cleanup, const0_rtx, VOIDmode, 0);
1105 /* rethrow current exception */
1106 /* This part is easy, as we don't have to do anything else. */
1109 /* This is the label that represents where in the code we were, when
1110 we got an exception. This needs to be updated when we rethrow an
1111 exception, so that the matching routine knows to search out. */
1112 label = gen_label_rtx ();
1115 expand_internal_throw (label);
1118 /* Build a throw expression. */
1124 if (e != error_mark_node)
1126 if (current_template_parms)
1127 return build_min (THROW_EXPR, void_type_node, e);
1128 e = build1 (THROW_EXPR, void_type_node, e);
1129 TREE_SIDE_EFFECTS (e) = 1;