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 for throw. */
171 static tree FirstExceptionMatch;
173 /* Used to cache a call to __unwind_function. */
176 /* Holds a ready to emit call to "terminate". */
177 static tree TerminateFunctionCall;
179 static tree empty_fndecl;
181 /* ====================================================================== */
184 /* ========================================================================= */
188 /* local globals - these local globals are for storing data necessary for
189 generating the exception table and code in the correct order.
191 ========================================================================= */
193 /* Holds the pc for doing "throw" */
194 static tree saved_pc;
195 /* Holds the type of the thing being thrown. */
196 static tree saved_throw_type;
197 /* Holds the value being thrown. */
198 static tree saved_throw_value;
199 /* Holds the cleanup for the value being thrown. */
200 static tree saved_cleanup;
201 /* Indicates if we are in a catch clause. */
202 static tree saved_in_catch;
204 extern int throw_used;
205 extern rtx catch_clauses;
207 /* ========================================================================= */
209 /* Cheesyness to save some typing. Returns the return value rtx. */
212 do_function_call (func, params, return_type)
213 tree func, params, return_type;
216 func_call = build_function_call (func, params);
217 expand_call (func_call, NULL_RTX, 0);
218 if (return_type != NULL_TREE)
219 return hard_function_value (return_type, func_call);
223 /* ========================================================================= */
225 /* sets up all the global eh stuff that needs to be initialized at the
226 start of compilation.
229 - Setting up all the function call trees. */
232 init_exception_processing ()
234 extern tree define_function ();
235 tree unexpected_fndecl, terminate_fndecl;
236 tree set_unexpected_fndecl, set_terminate_fndecl;
237 tree catch_match_fndecl;
238 tree find_first_exception_match_fndecl;
244 tree PFV = build_pointer_type (build_function_type
245 (void_type_node, void_list_node));
247 /* Arg list for the build_function_type call for set_terminate and
249 tree pfvlist = tree_cons (NULL_TREE, PFV, void_list_node);
251 /* void (*pfvtype (void (*) ()))() */
252 tree pfvtype = build_function_type (PFV, pfvlist);
255 tree vtype = build_function_type (void_type_node, void_list_node);
257 set_terminate_fndecl = auto_function (get_identifier ("set_terminate"),
258 pfvtype, NOT_BUILT_IN);
259 set_unexpected_fndecl = auto_function (get_identifier ("set_unexpected"),
260 pfvtype, NOT_BUILT_IN);
261 unexpected_fndecl = auto_function (get_identifier ("unexpected"),
262 vtype, NOT_BUILT_IN);
263 terminate_fndecl = auto_function (get_identifier ("terminate"),
264 vtype, NOT_BUILT_IN);
266 push_lang_context (lang_name_c);
269 = builtin_function (flag_rtti
270 ? "__throw_type_match_rtti"
271 : "__throw_type_match",
272 build_function_type (ptr_type_node,
273 tree_cons (NULL_TREE, ptr_type_node,
274 tree_cons (NULL_TREE, ptr_type_node,
275 tree_cons (NULL_TREE, ptr_type_node,
277 NOT_BUILT_IN, NULL_PTR);
278 find_first_exception_match_fndecl
279 = builtin_function ("__find_first_exception_table_match",
280 build_function_type (ptr_type_node,
281 tree_cons (NULL_TREE, ptr_type_node,
283 NOT_BUILT_IN, NULL_PTR);
285 = builtin_function ("__unwind_function",
286 build_function_type (void_type_node,
287 tree_cons (NULL_TREE, ptr_type_node,
289 NOT_BUILT_IN, NULL_PTR);
291 = builtin_function ("__empty",
292 build_function_type (void_type_node, void_list_node),
293 NOT_BUILT_IN, NULL_PTR);
294 DECL_EXTERNAL (empty_fndecl) = 1;
295 TREE_PUBLIC (empty_fndecl) = 1;
297 Unexpected = default_conversion (unexpected_fndecl);
298 Terminate = default_conversion (terminate_fndecl);
299 SetTerminate = default_conversion (set_terminate_fndecl);
300 SetUnexpected = default_conversion (set_unexpected_fndecl);
301 CatchMatch = default_conversion (catch_match_fndecl);
302 FirstExceptionMatch = default_conversion (find_first_exception_match_fndecl);
303 Unwind = default_conversion (unwind_fndecl);
304 BuiltinReturnAddress = default_conversion (builtin_return_address_fndecl);
306 TerminateFunctionCall = build_function_call (Terminate, NULL_TREE);
310 declspecs = tree_cons (NULL_TREE, get_identifier ("void"), NULL_TREE);
311 d = build_parse_node (INDIRECT_REF, get_identifier ("__eh_pc"));
312 d = start_decl (d, declspecs, 0);
314 cp_finish_decl (d, NULL_TREE, NULL_TREE, 1, 0);
315 saved_pc = lookup_name (get_identifier ("__eh_pc"), 0);
317 declspecs = tree_cons (NULL_TREE, get_identifier ("void"), NULL_TREE);
318 d = build_parse_node (INDIRECT_REF, get_identifier ("__eh_type"));
319 d = start_decl (d, declspecs, 0);
321 cp_finish_decl (d, NULL_TREE, NULL_TREE, 1, 0);
322 saved_throw_type = lookup_name (get_identifier ("__eh_type"), 0);
324 declspecs = tree_cons (NULL_TREE, get_identifier ("void"), NULL_TREE);
325 d = build_parse_node (INDIRECT_REF, get_identifier ("__eh_value"));
326 d = start_decl (d, declspecs, 0);
328 cp_finish_decl (d, NULL_TREE, NULL_TREE, 1, 0);
329 saved_throw_value = lookup_name (get_identifier ("__eh_value"), 0);
331 declspecs = tree_cons (NULL_TREE, get_identifier ("void"), NULL_TREE);
332 d = build_parse_node (INDIRECT_REF, get_identifier ("__eh_cleanup"));
333 d = make_call_declarator (d, void_list_node, NULL_TREE, NULL_TREE);
334 d = start_decl (d, declspecs, 0);
336 cp_finish_decl (d, NULL_TREE, NULL_TREE, 1, 0);
337 saved_cleanup = lookup_name (get_identifier ("__eh_cleanup"), 0);
339 declspecs = tree_cons (NULL_TREE, get_identifier ("bool"), NULL_TREE);
340 d = get_identifier ("__eh_in_catch");
341 d = start_decl (d, declspecs, 0);
343 cp_finish_decl (d, NULL_TREE, NULL_TREE, 1, 0);
344 saved_in_catch = lookup_name (get_identifier ("__eh_in_catch"), 0);
346 /* If we use setjmp/longjmp EH, arrange for all cleanup actions to
347 be protected with __terminate. */
348 protect_cleanup_actions_with_terminate = 1;
351 /* Build a type value for use at runtime for a type that is matched
352 against by the exception handling system. */
355 build_eh_type_type (type)
361 if (type == error_mark_node)
362 return error_mark_node;
364 /* peel back references, so they match. */
365 if (TREE_CODE (type) == REFERENCE_TYPE)
366 type = TREE_TYPE (type);
368 /* Peel off cv qualifiers. */
369 type = TYPE_MAIN_VARIANT (type);
373 return build1 (ADDR_EXPR, ptr_type_node, get_typeid (type));
376 typestring = build_overload_name (type, 1, 1);
377 exp = combine_strings (build_string (strlen (typestring)+1, typestring));
378 return build1 (ADDR_EXPR, ptr_type_node, exp);
381 /* Build a type value for use at runtime for a exp that is thrown or
382 matched against by the exception handling system. */
390 exp = build_typeid (exp);
391 return build1 (ADDR_EXPR, ptr_type_node, exp);
393 return build_eh_type_type (TREE_TYPE (exp));
396 /* This routine creates the cleanup for the exception handling object. */
401 /* All cleanups must last longer than normal. */
402 int yes = suspend_momentary ();
404 /* Arrange to do a dynamically scoped cleanup upon exit from this region. */
405 tree cleanup = build_function_call (saved_cleanup, NULL_TREE);
406 cleanup = build (COMPOUND_EXPR, void_type_node, cleanup,
407 build_modify_expr (saved_in_catch, NOP_EXPR,
408 build_modify_expr (saved_throw_type, NOP_EXPR, integer_zero_node)));
409 expand_decl_cleanup (NULL_TREE, cleanup);
411 resume_momentary (yes);
415 /* call this to start a catch block. Typename is the typename, and identifier
416 is the variable to place the object in or NULL if the variable doesn't
417 matter. If typename is NULL, that means its a "catch (...)" or catch
418 everything. In that case we don't need to do any type checking.
419 (ie: it ends up as the "else" clause rather than an "else if" clause) */
422 expand_start_catch_block (declspecs, declarator)
423 tree declspecs, declarator;
426 tree decl = NULL_TREE;
429 if (processing_template_decl)
433 decl = grokdeclarator (declarator, declspecs, CATCHPARM,
436 decl = build_min_nt (DECL_STMT, copy_to_permanent (declarator),
437 copy_to_permanent (declspecs),
447 /* Create a binding level for the parm. */
449 expand_start_bindings (0);
451 false_label_rtx = gen_label_rtx ();
452 push_label_entry (&false_label_stack, false_label_rtx, NULL_TREE);
454 emit_line_note (input_filename, lineno);
459 rtx call_rtx, return_value_rtx;
462 decl = grokdeclarator (declarator, declspecs, CATCHPARM, 1, NULL_TREE);
464 if (decl == NULL_TREE)
466 error ("invalid catch parameter");
468 /* This is cheap, but we want to maintain the data
471 expand_eh_region_start ();
476 /* Make sure we mark the catch param as used, otherwise we'll get
477 a warning about an unused ((anonymous)). */
478 TREE_USED (decl) = 1;
480 /* Figure out the type that the initializer is. */
481 init_type = TREE_TYPE (decl);
482 if (TREE_CODE (init_type) != REFERENCE_TYPE
483 && TREE_CODE (init_type) != POINTER_TYPE)
484 init_type = build_reference_type (init_type);
486 exp = saved_throw_value;
487 exp = tree_cons (NULL_TREE,
488 build_eh_type_type (TREE_TYPE (decl)),
489 tree_cons (NULL_TREE,
491 tree_cons (NULL_TREE, exp, NULL_TREE)));
492 exp = build_function_call (CatchMatch, exp);
493 call_rtx = expand_call (exp, NULL_RTX, 0);
494 assemble_external (TREE_OPERAND (CatchMatch, 0));
496 return_value_rtx = hard_function_value (ptr_type_node, exp);
498 /* did the throw type match function return TRUE? */
499 emit_cmp_insn (return_value_rtx, const0_rtx, EQ, NULL_RTX,
500 GET_MODE (return_value_rtx), 0, 0);
502 /* if it returned FALSE, jump over the catch block, else fall into it */
503 emit_jump_insn (gen_beq (false_label_rtx));
507 init = convert_from_reference (save_expr (make_tree (init_type, call_rtx)));
509 /* Do we need the below two lines? */
510 /* Let `cp_finish_decl' know that this initializer is ok. */
511 DECL_INITIAL (decl) = init;
512 decl = pushdecl (decl);
513 cp_finish_decl (decl, init, NULL_TREE, 0, LOOKUP_ONLYCONVERTING);
519 /* Fall into the catch all section. */
522 emit_move_insn (DECL_RTL (saved_in_catch), const1_rtx);
524 /* If we are not doing setjmp/longjmp EH, because we are reordered
525 out of line, we arrange to rethrow in the outer context so as to
526 skip through the terminate region we are nested in, should we
527 encounter an exception in the catch handler.
529 If we are doing setjmp/longjmp EH, we need to skip through the EH
530 object cleanup region. This isn't quite right, as we really need
531 to clean the object up, but we cannot do that until we track
534 Matches the end in expand_end_catch_block. */
535 expand_eh_region_start ();
537 emit_line_note (input_filename, lineno);
542 /* Call this to end a catch block. Its responsible for emitting the
543 code to handle jumping back to the correct place, and for emitting
544 the label to jump to if this catch block didn't match. */
547 expand_end_catch_block ()
549 rtx start_region_label_rtx;
550 rtx end_region_label_rtx;
556 t = make_node (RTL_EXPR);
557 TREE_TYPE (t) = void_type_node;
558 RTL_EXPR_RTL (t) = const0_rtx;
559 TREE_SIDE_EFFECTS (t) = 1;
560 start_sequence_for_rtl_expr (t);
562 if (exceptions_via_longjmp)
564 /* If we are doing setjmp/longjmp EH, we need to skip through
565 the EH object cleanup region. This isn't quite right, as we
566 really need to clean the object up, but we cannot do that
567 until we track multiple EH objects. */
569 emit_library_call (sjpopnthrow_libfunc, 0, VOIDmode, 0);
574 /* If we are not doing setjmp/longjmp EH, we need an extra
575 region around the whole catch block to skip through the
576 terminate region we are nested in. */
578 expand_internal_throw (DECL_RTL (top_label_entry (&caught_return_label_stack)));
581 RTL_EXPR_SEQUENCE (t) = get_insns ();
584 /* Matches the start in expand_start_catch_block. */
585 expand_eh_region_end (t);
587 /* Fall to outside the try statement when done executing handler and
588 we fall off end of handler. This is jump Lresume in the
590 expand_goto (top_label_entry (&caught_return_label_stack));
592 expand_leftover_cleanups ();
594 /* Cleanup the EH parameter. */
595 expand_end_bindings (getdecls (), kept_level_p (), 0);
596 poplevel (kept_level_p (), 1, 0);
598 /* label we emit to jump to if this catch block didn't match. */
599 /* This the closing } in the `if (eq) {' of the documentation. */
600 emit_label (pop_label_entry (&false_label_stack));
603 /* unwind the stack. */
606 do_unwind (inner_throw_label)
607 rtx inner_throw_label;
609 #if defined (SPARC_STACK_ALIGN) /* was sparc */
610 /* This doesn't work for the flat model sparc, I bet. */
616 /* Call to __builtin_return_address. */
617 params = tree_cons (NULL_TREE, integer_zero_node, NULL_TREE);
618 fcall = build_function_call (BuiltinReturnAddress, params);
619 return_val_rtx = expand_expr (fcall, NULL_RTX, Pmode, 0);
620 /* In the return, the new pc is pc+8, as the value coming in is
621 really the address of the call insn, not the next insn. */
622 temp = gen_reg_rtx (Pmode);
623 emit_move_insn (temp, inner_throw_label);
624 emit_move_insn (return_val_rtx, plus_constant (temp, -8));
625 emit_insn (gen_rtx (USE, VOIDmode, gen_rtx (REG, SImode, 31)));
626 easy_expand_asm ("ret");
627 easy_expand_asm ("restore");
630 #if defined (ARM_FRAME_RTX) /* was __arm */
631 if (flag_omit_frame_pointer)
632 sorry ("this implementation of exception handling requires a frame pointer");
634 emit_move_insn (stack_pointer_rtx,
635 gen_rtx (MEM, Pmode, plus_constant (hard_frame_pointer_rtx, -8)));
636 emit_move_insn (hard_frame_pointer_rtx,
637 gen_rtx (MEM, Pmode, plus_constant (hard_frame_pointer_rtx, -12)));
639 #if defined (TARGET_88000) /* was m88k */
640 rtx temp_frame = frame_pointer_rtx;
642 temp_frame = memory_address (Pmode, temp_frame);
643 temp_frame = copy_to_reg (gen_rtx (MEM, Pmode, temp_frame));
645 /* hopefully this will successfully pop the frame! */
646 emit_move_insn (frame_pointer_rtx, temp_frame);
647 emit_move_insn (stack_pointer_rtx, frame_pointer_rtx);
648 emit_move_insn (arg_pointer_rtx, frame_pointer_rtx);
649 emit_insn (gen_add2_insn (stack_pointer_rtx, gen_rtx (CONST_INT, VOIDmode,
650 (HOST_WIDE_INT)m88k_debugger_offset (stack_pointer_rtx, 0))));
653 emit_insn (gen_add2_insn (arg_pointer_rtx, gen_rtx (CONST_INT, VOIDmode,
654 -(HOST_WIDE_INT)m88k_debugger_offset (arg_pointer_rtx, 0))));
656 emit_move_insn (stack_pointer_rtx, arg_pointer_rtx);
658 emit_insn (gen_add2_insn (stack_pointer_rtx, gen_rtx (CONST_INT, VOIDmode,
659 (HOST_WIDE_INT)m88k_debugger_offset (arg_pointer_rtx, 0))));
662 #if ! defined (TARGET_88000) && ! defined (ARM_FRAME_RTX) && ! defined (SPARC_STACK_ALIGN)
668 /* I would like to do this here, but the move below doesn't seem to work. */
669 /* Call to __builtin_return_address. */
670 params = tree_cons (NULL_TREE, integer_zero_node, NULL_TREE);
671 fcall = build_function_call (BuiltinReturnAddress, params);
672 return_val_rtx = expand_expr (fcall, NULL_RTX, Pmode, 0);
674 emit_move_insn (return_val_rtx, inner_throw_label);
675 /* So, for now, just pass throw label to stack unwinder. */
677 params = tree_cons (NULL_TREE, make_tree (ptr_type_node,
678 inner_throw_label), NULL_TREE);
680 do_function_call (Unwind, params, NULL_TREE);
681 assemble_external (TREE_OPERAND (Unwind, 0));
687 /* Is called from expand_exception_blocks to generate the code in a function
688 to "throw" if anything in the function needs to perform a throw.
690 expands "throw" as the following pseudo code:
693 eh = find_first_exception_match (saved_pc);
694 if (!eh) goto gotta_rethrow_it;
698 saved_pc = __builtin_return_address (0);
699 pop_to_previous_level ();
703 expand_builtin_throw ()
708 rtx gotta_rethrow_it;
709 rtx gotta_call_terminate;
720 params = void_list_node;
721 t = make_call_declarator (get_identifier ("__throw"), params, NULL_TREE,
723 start_function (decl_tree_cons (NULL_TREE, get_identifier ("static"),
730 expand_start_bindings (0);
732 gotta_rethrow_it = gen_label_rtx ();
733 gotta_call_terminate = gen_label_rtx ();
734 top_of_loop = gen_label_rtx ();
735 unwind_first = gen_label_rtx ();
737 /* These two can be frontend specific. If wanted, they can go in
739 /* Do we have a valid object we are throwing? */
740 emit_cmp_insn (DECL_RTL (saved_throw_type), const0_rtx, EQ, NULL_RTX,
741 GET_MODE (DECL_RTL (saved_throw_type)), 0, 0);
742 emit_jump_insn (gen_beq (gotta_call_terminate));
744 emit_jump (unwind_first);
746 emit_label (top_of_loop);
748 /* search for an exception handler for the saved_pc */
749 return_val_rtx = do_function_call (FirstExceptionMatch,
750 tree_cons (NULL_TREE, saved_pc, NULL_TREE),
752 assemble_external (TREE_OPERAND (FirstExceptionMatch, 0));
754 /* did we find one? */
755 emit_cmp_insn (return_val_rtx, const0_rtx, EQ, NULL_RTX,
756 GET_MODE (return_val_rtx), 0, 0);
758 /* if not, jump to gotta_rethrow_it */
759 emit_jump_insn (gen_beq (gotta_rethrow_it));
761 /* we found it, so jump to it */
762 emit_indirect_jump (return_val_rtx);
764 /* code to deal with unwinding and looking for it again */
765 emit_label (gotta_rethrow_it);
767 /* Call to __builtin_return_address. */
768 #if defined (ARM_FRAME_RTX) /* was __arm */
769 /* This should be moved into arm.h:RETURN_ADDR_RTX */
770 /* This replaces a 'call' to __builtin_return_address */
771 return_val_rtx = gen_reg_rtx (Pmode);
772 emit_move_insn (return_val_rtx, gen_rtx (MEM, Pmode, plus_constant (hard_frame_pointer_rtx, -4)));
774 params = tree_cons (NULL_TREE, integer_zero_node, NULL_TREE);
775 fcall = build_function_call (BuiltinReturnAddress, params);
776 return_val_rtx = expand_expr (fcall, NULL_RTX, Pmode, 0);
779 /* Did __builtin_return_address return a valid address? */
780 emit_cmp_insn (return_val_rtx, const0_rtx, EQ, NULL_RTX,
781 GET_MODE (return_val_rtx), 0, 0);
783 emit_jump_insn (gen_beq (gotta_call_terminate));
785 return_val_rtx = eh_outer_context (return_val_rtx);
788 emit_move_insn (eh_saved_pc_rtx, return_val_rtx);
790 do_unwind (gen_rtx (LABEL_REF, Pmode, top_of_loop));
791 emit_jump (top_of_loop);
793 /* no it didn't --> therefore we need to call terminate */
794 emit_label (gotta_call_terminate);
795 do_function_call (Terminate, NULL_TREE, NULL_TREE);
796 assemble_external (TREE_OPERAND (Terminate, 0));
799 rtx ret_val, return_val_rtx;
800 emit_label (unwind_first);
801 ret_val = expand_builtin_return_addr (BUILT_IN_RETURN_ADDRESS,
802 0, hard_frame_pointer_rtx);
804 /* Set it up so that we continue inside, at the top of the loop. */
805 emit_move_insn (ret_val, gen_rtx (LABEL_REF, Pmode, top_of_loop));
806 #ifdef RETURN_ADDR_OFFSET
807 return_val_rtx = plus_constant (ret_val, -RETURN_ADDR_OFFSET);
808 if (return_val_rtx != ret_val)
809 emit_move_insn (ret_val, return_val_rtx);
812 /* Fall into epilogue to unwind prologue. */
815 expand_end_bindings (getdecls (), 1, 0);
819 finish_function (lineno, 0, 0);
824 expand_start_eh_spec ()
826 expand_eh_region_start ();
830 expand_end_eh_spec (raises)
833 tree expr, second_try;
834 rtx check = gen_label_rtx ();
836 rtx ret = gen_reg_rtx (Pmode);
837 rtx flag = gen_reg_rtx (TYPE_MODE (integer_type_node));
838 rtx end = gen_label_rtx ();
840 expr = make_node (RTL_EXPR);
841 TREE_TYPE (expr) = void_type_node;
842 RTL_EXPR_RTL (expr) = const0_rtx;
843 TREE_SIDE_EFFECTS (expr) = 1;
844 start_sequence_for_rtl_expr (expr);
845 cont = gen_label_rtx ();
846 emit_move_insn (ret, gen_rtx (LABEL_REF, Pmode, cont));
849 jumpif (make_tree (integer_type_node, flag), end);
850 do_function_call (Terminate, NULL_TREE, NULL_TREE);
851 assemble_external (TREE_OPERAND (Terminate, 0));
853 RTL_EXPR_SEQUENCE (expr) = get_insns ();
858 expr = make_node (RTL_EXPR);
859 TREE_TYPE (expr) = void_type_node;
860 RTL_EXPR_RTL (expr) = const0_rtx;
861 TREE_SIDE_EFFECTS (expr) = 1;
862 start_sequence_for_rtl_expr (expr);
864 cont = gen_label_rtx ();
865 emit_move_insn (ret, gen_rtx (LABEL_REF, Pmode, cont));
868 jumpif (make_tree (integer_type_node, flag), end);
869 expand_eh_region_start ();
870 do_function_call (Unexpected, NULL_TREE, NULL_TREE);
871 assemble_external (TREE_OPERAND (Unexpected, 0));
874 expand_eh_region_end (second_try);
877 emit_move_insn (flag, const1_rtx);
878 cont = gen_label_rtx ();
882 tree match_type = TREE_VALUE (raises);
886 /* check TREE_VALUE (raises) here */
887 exp = saved_throw_value;
888 exp = tree_cons (NULL_TREE,
889 build_eh_type_type (match_type),
890 tree_cons (NULL_TREE,
892 tree_cons (NULL_TREE, exp, NULL_TREE)));
893 exp = build_function_call (CatchMatch, exp);
894 assemble_external (TREE_OPERAND (CatchMatch, 0));
899 raises = TREE_CHAIN (raises);
901 emit_move_insn (flag, const0_rtx);
903 emit_indirect_jump (ret);
906 RTL_EXPR_SEQUENCE (expr) = get_insns ();
909 expand_eh_region_end (expr);
912 /* This is called to expand all the toplevel exception handling
913 finalization for a function. It should only be called once per
917 expand_exception_blocks ()
924 funcend = gen_label_rtx ();
928 /* Add all the catch clauses here. */
929 emit_insns (catch_clauses);
930 catch_clauses = NULL_RTX;
932 expand_leftover_cleanups ();
934 insns = get_insns ();
938 /* Do this after we expand leftover cleanups, so that the
939 expand_eh_region_end that expand_end_eh_spec does will match the
940 right expand_eh_region_start, and make sure it comes out before
941 the terminate protected region. */
942 if (TYPE_RAISES_EXCEPTIONS (TREE_TYPE (current_function_decl)))
944 expand_end_eh_spec (TYPE_RAISES_EXCEPTIONS (TREE_TYPE (current_function_decl)));
945 push_to_sequence (insns);
947 /* Now expand any new ones. */
948 expand_leftover_cleanups ();
950 insns = get_insns ();
959 /* We cannot protect n regions this way if we must flow into the
960 EH region through the top of the region, as we have to with
961 the setjmp/longjmp approach. */
962 if (exceptions_via_longjmp == 0)
964 /* Is this necessary? */
965 assemble_external (TREE_OPERAND (Terminate, 0));
967 expand_eh_region_start ();
972 if (exceptions_via_longjmp == 0)
973 expand_eh_region_end (TerminateFunctionCall);
975 expand_leftover_cleanups ();
978 emit_label (funcend);
980 /* Only if we had previous insns do we want to emit the jump around
981 them. If there weren't any, then insns will remain NULL_RTX. */
983 insns = get_insns ();
992 static int counter = 0;
993 int old_interface_unknown = interface_unknown;
998 push_cp_function_context (NULL_TREE);
999 push_to_top_level ();
1001 /* No need to mangle this. */
1002 push_lang_context (lang_name_c);
1004 interface_unknown = 1;
1006 params = void_list_node;
1007 /* tcf stands for throw clean funciton. */
1008 sprintf (name, "__tcf_%d", counter++);
1009 t = make_call_declarator (get_identifier (name), params, NULL_TREE,
1011 start_function (decl_tree_cons (NULL_TREE, get_identifier ("static"),
1014 store_parm_decls ();
1018 expand_start_bindings (0);
1019 emit_line_note (input_filename, lineno);
1021 interface_unknown = old_interface_unknown;
1023 pop_lang_context ();
1025 return current_function_decl;
1031 expand_end_bindings (getdecls (), 1, 0);
1035 finish_function (lineno, 0, 0);
1037 pop_from_top_level ();
1038 pop_cp_function_context (NULL_TREE);
1041 /* Expand a throw statement. This follows the following
1044 1. Allocate space to save the current PC onto the stack.
1045 2. Generate and emit a label and save its address into the
1046 newly allocated stack space since we can't save the pc directly.
1047 3. If this is the first call to throw in this function:
1048 generate a label for the throw block
1049 4. jump to the throw block label. */
1063 tree cleanup = empty_fndecl, e;
1065 /* throw expression */
1066 /* First, decay it. */
1067 exp = decay_conversion (exp);
1069 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
1071 throw_type = build_eh_type (exp);
1072 exp = build_reinterpret_cast (ptr_type_node, exp);
1078 /* Make a copy of the thrown object. WP 15.1.5 */
1079 exp = build_new (NULL_TREE, TREE_TYPE (exp),
1080 build_tree_list (NULL_TREE, exp),
1083 if (exp == error_mark_node)
1084 error (" in thrown expression");
1086 object = build_indirect_ref (exp, NULL_PTR);
1087 throw_type = build_eh_type (object);
1090 object = build_reinterpret_cast (TREE_TYPE (exp), saved_throw_value);
1091 object = build_indirect_ref (object, NULL_PTR);
1092 cleanup = maybe_build_cleanup_and_delete (object);
1097 cleanup = start_anon_func ();
1099 expand_expr (maybe_build_cleanup_and_delete (object),
1100 const0_rtx, VOIDmode, 0);
1104 mark_addressable (cleanup);
1108 cleanup = empty_fndecl;
1112 if (cleanup == empty_fndecl)
1113 assemble_external (empty_fndecl);
1115 e = build_modify_expr (saved_throw_type, NOP_EXPR, throw_type);
1116 expand_expr (e, const0_rtx, VOIDmode, 0);
1118 e = build_modify_expr (saved_throw_value, NOP_EXPR, exp);
1119 e = build1 (CLEANUP_POINT_EXPR, TREE_TYPE (e), e);
1120 expand_expr (e, const0_rtx, VOIDmode, 0);
1122 cleanup = build_unary_op (ADDR_EXPR, cleanup, 0);
1123 cleanup = build_modify_expr (saved_cleanup, NOP_EXPR, cleanup);
1124 expand_expr (cleanup, const0_rtx, VOIDmode, 0);
1128 /* rethrow current exception */
1129 /* This part is easy, as we don't have to do anything else. */
1132 if (exceptions_via_longjmp)
1136 /* This is the label that represents where in the code we were, when
1137 we got an exception. This needs to be updated when we rethrow an
1138 exception, so that the matching routine knows to search out. */
1139 label = gen_label_rtx ();
1142 expand_internal_throw (label);
1146 /* Build a throw expression. */
1152 if (e != error_mark_node)
1154 if (processing_template_decl)
1155 return build_min (THROW_EXPR, void_type_node, e);
1156 e = build1 (THROW_EXPR, void_type_node, e);
1157 TREE_SIDE_EFFECTS (e) = 1;