1 /* Handle exceptional things in C++.
2 Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3 2000, 2001 Free Software Foundation, Inc.
4 Contributed by Michael Tiemann <tiemann@cygnus.com>
5 Rewritten by Mike Stump <mrs@cygnus.com>, based upon an
6 initial re-implementation courtesy Tad Hunt.
8 This file is part of GNU CC.
10 GNU CC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 2, or (at your option)
15 GNU CC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GNU CC; see the file COPYING. If not, write to
22 the Free Software Foundation, 59 Temple Place - Suite 330,
23 Boston, MA 02111-1307, USA. */
37 #include "tree-inline.h"
39 static void push_eh_cleanup PARAMS ((tree));
40 static tree prepare_eh_type PARAMS ((tree));
41 static tree build_eh_type_type PARAMS ((tree));
42 static tree do_begin_catch PARAMS ((void));
43 static int dtor_nothrow PARAMS ((tree));
44 static tree do_end_catch PARAMS ((tree));
45 static void push_eh_cleanup PARAMS ((tree));
46 static bool decl_is_java_type PARAMS ((tree decl, int err));
47 static void initialize_handler_parm PARAMS ((tree, tree));
48 static tree do_allocate_exception PARAMS ((tree));
49 static tree stabilize_throw_expr PARAMS ((tree, tree *));
50 static tree wrap_cleanups_r PARAMS ((tree *, int *, void *));
51 static int complete_ptr_ref_or_void_ptr_p PARAMS ((tree, tree));
52 static bool is_admissible_throw_operand PARAMS ((tree));
53 static int can_convert_eh PARAMS ((tree, tree));
54 static void check_handlers_1 PARAMS ((tree, tree));
55 static tree cp_protect_cleanup_actions PARAMS ((void));
57 /* Sets up all the global eh stuff that needs to be initialized at the
58 start of compilation. */
61 init_exception_processing ()
65 /* void std::terminate (); */
66 push_namespace (std_identifier);
67 tmp = build_function_type (void_type_node, void_list_node);
68 terminate_node = build_cp_library_fn_ptr ("terminate", tmp);
69 TREE_THIS_VOLATILE (terminate_node) = 1;
70 TREE_NOTHROW (terminate_node) = 1;
73 /* void __cxa_call_unexpected(void *); */
74 tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
75 tmp = build_function_type (void_type_node, tmp);
77 = push_throw_library_fn (get_identifier ("__cxa_call_unexpected"), tmp);
79 eh_personality_libfunc = init_one_libfunc (USING_SJLJ_EXCEPTIONS
80 ? "__gxx_personality_sj0"
81 : "__gxx_personality_v0");
83 lang_eh_runtime_type = build_eh_type_type;
84 lang_protect_cleanup_actions = &cp_protect_cleanup_actions;
87 /* Returns an expression to be executed if an unhandled exception is
88 propagated out of a cleanup region. */
91 cp_protect_cleanup_actions ()
95 When the destruction of an object during stack unwinding exits
96 using an exception ... void terminate(); is called. */
97 return build_call (terminate_node, NULL_TREE);
101 prepare_eh_type (type)
104 if (type == NULL_TREE)
106 if (type == error_mark_node)
107 return error_mark_node;
109 /* peel back references, so they match. */
110 if (TREE_CODE (type) == REFERENCE_TYPE)
111 type = TREE_TYPE (type);
113 /* Peel off cv qualifiers. */
114 type = TYPE_MAIN_VARIANT (type);
119 /* Build the address of a typeinfo decl for use in the runtime
120 matching field of the exception model. */
123 build_eh_type_type (type)
128 if (type == NULL_TREE || type == error_mark_node)
131 if (decl_is_java_type (type, 0))
132 exp = build_java_class_ref (TREE_TYPE (type));
134 exp = get_tinfo_decl (type);
137 exp = build1 (ADDR_EXPR, ptr_type_node, exp);
145 return build (EXC_PTR_EXPR, ptr_type_node);
148 /* Build up a call to __cxa_begin_catch, to tell the runtime that the
149 exception has been handled. */
156 fn = get_identifier ("__cxa_begin_catch");
157 if (IDENTIFIER_GLOBAL_VALUE (fn))
158 fn = IDENTIFIER_GLOBAL_VALUE (fn);
161 /* Declare void* __cxa_begin_catch (void *). */
162 tree tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
163 fn = push_library_fn (fn, build_function_type (ptr_type_node, tmp));
166 return build_function_call (fn, tree_cons (NULL_TREE, build_exc_ptr (),
170 /* Returns nonzero if cleaning up an exception of type TYPE (which can be
171 NULL_TREE for a ... handler) will not throw an exception. */
177 if (type == NULL_TREE)
180 if (! TYPE_HAS_DESTRUCTOR (type))
183 return TREE_NOTHROW (CLASSTYPE_DESTRUCTORS (type));
186 /* Build up a call to __cxa_end_catch, to destroy the exception object
187 for the current catch block if no others are currently using it. */
195 fn = get_identifier ("__cxa_end_catch");
196 if (IDENTIFIER_GLOBAL_VALUE (fn))
197 fn = IDENTIFIER_GLOBAL_VALUE (fn);
200 /* Declare void __cxa_end_catch (). */
201 fn = push_void_library_fn (fn, void_list_node);
202 /* This can throw if the destructor for the exception throws. */
203 TREE_NOTHROW (fn) = 0;
206 cleanup = build_function_call (fn, NULL_TREE);
207 TREE_NOTHROW (cleanup) = dtor_nothrow (type);
212 /* This routine creates the cleanup for the current exception. */
215 push_eh_cleanup (type)
218 finish_decl_cleanup (NULL_TREE, do_end_catch (type));
221 /* Return nonzero value if DECL is a Java type suitable for catch or
225 decl_is_java_type (decl, err)
229 bool r = (TREE_CODE (decl) == POINTER_TYPE
230 && TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE
231 && TYPE_FOR_JAVA (TREE_TYPE (decl)));
235 if (TREE_CODE (decl) == REFERENCE_TYPE
236 && TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE
237 && TYPE_FOR_JAVA (TREE_TYPE (decl)))
239 /* Can't throw a reference. */
240 error ("type `%T' is disallowed in Java `throw' or `catch'",
247 = IDENTIFIER_GLOBAL_VALUE (get_identifier ("jthrowable"));
249 if (jthrow_node == NULL_TREE)
251 ("call to Java `catch' or `throw' with `jthrowable' undefined");
253 jthrow_node = TREE_TYPE (TREE_TYPE (jthrow_node));
255 if (! DERIVED_FROM_P (jthrow_node, TREE_TYPE (decl)))
257 /* Thrown object must be a Throwable. */
258 error ("type `%T' is not derived from `java::lang::Throwable'",
267 /* Select the personality routine to be used for exception handling,
268 or issue an error if we need two different ones in the same
270 ??? At present eh_personality_libfunc is set to
271 __gxx_personality_(sj|v)0 in init_exception_processing - should it
272 be done here instead? */
274 choose_personality_routine (lang)
290 if (lang != lang_cplusplus)
295 if (lang != lang_java)
300 ; /* proceed to language selection */
311 eh_personality_libfunc = init_one_libfunc (USING_SJLJ_EXCEPTIONS
312 ? "__gcj_personality_sj0"
313 : "__gcj_personality_v0");
322 error ("mixing C++ and Java catches in a single translation unit");
326 /* Initialize the catch parameter DECL. */
329 initialize_handler_parm (decl, exp)
336 /* Make sure we mark the catch param as used, otherwise we'll get a
337 warning about an unused ((anonymous)). */
338 TREE_USED (decl) = 1;
340 /* Figure out the type that the initializer is. Pointers are returned
341 adjusted by value from __cxa_begin_catch. Others are returned by
343 init_type = TREE_TYPE (decl);
344 if (! TYPE_PTR_P (init_type)
345 && TREE_CODE (init_type) != REFERENCE_TYPE)
346 init_type = build_reference_type (init_type);
348 choose_personality_routine (decl_is_java_type (init_type, 0)
349 ? lang_java : lang_cplusplus);
351 /* Since pointers are passed by value, initialize a reference to
352 pointer catch parm with the address of the temporary. */
353 if (TREE_CODE (init_type) == REFERENCE_TYPE
354 && TYPE_PTR_P (TREE_TYPE (init_type)))
355 exp = build_unary_op (ADDR_EXPR, exp, 1);
357 exp = ocp_convert (init_type, exp, CONV_IMPLICIT|CONV_FORCE_TEMP, 0);
359 init = convert_from_reference (exp);
361 /* If the constructor for the catch parm exits via an exception, we
362 must call terminate. See eh23.C. */
363 if (TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (decl)))
365 /* Generate the copy constructor call directly so we can wrap it.
366 See also expand_default_init. */
367 init = ocp_convert (TREE_TYPE (decl), init,
368 CONV_IMPLICIT|CONV_FORCE_TEMP, 0);
369 init = build1 (MUST_NOT_THROW_EXPR, TREE_TYPE (init), init);
372 /* Let `cp_finish_decl' know that this initializer is ok. */
373 DECL_INITIAL (decl) = error_mark_node;
374 decl = pushdecl (decl);
377 cp_finish_decl (decl, init, NULL_TREE,
378 LOOKUP_ONLYCONVERTING|DIRECT_BIND);
381 /* Call this to start a catch block. DECL is the catch parameter. */
384 expand_start_catch_block (decl)
387 tree exp = NULL_TREE;
394 /* Make sure this declaration is reasonable. */
395 if (decl && !complete_ptr_ref_or_void_ptr_p (TREE_TYPE (decl), NULL_TREE))
399 type = prepare_eh_type (TREE_TYPE (decl));
408 if (decl_is_java_type (type, 1))
410 /* Java only passes object via pointer and doesn't require
411 adjusting. The java object is immediately before the
412 generic exception header. */
413 init = build_exc_ptr ();
414 init = build1 (NOP_EXPR, build_pointer_type (type), init);
415 init = build (MINUS_EXPR, TREE_TYPE (init), init,
416 TYPE_SIZE_UNIT (TREE_TYPE (init)));
417 init = build_indirect_ref (init, NULL);
422 /* C++ requires that we call __cxa_begin_catch to get the
423 pointer to the actual object. */
424 init = do_begin_catch ();
427 exp = create_temporary_var (ptr_type_node);
428 DECL_REGISTER (exp) = 1;
429 cp_finish_decl (exp, init, NULL_TREE, LOOKUP_ONLYCONVERTING);
430 finish_expr_stmt (build_modify_expr (exp, INIT_EXPR, init));
433 finish_expr_stmt (do_begin_catch ());
435 /* C++ requires that we call __cxa_end_catch at the end of
436 processing the exception. */
438 push_eh_cleanup (type);
441 initialize_handler_parm (decl, exp);
447 /* Call this to end a catch block. Its responsible for emitting the
448 code to handle jumping back to the correct place, and for emitting
449 the label to jump to if this catch block didn't match. */
452 expand_end_catch_block ()
457 /* The exception being handled is rethrown if control reaches the end of
458 a handler of the function-try-block of a constructor or destructor. */
459 if (in_function_try_handler
460 && (DECL_CONSTRUCTOR_P (current_function_decl)
461 || DECL_DESTRUCTOR_P (current_function_decl)))
462 finish_expr_stmt (build_throw (NULL_TREE));
466 begin_eh_spec_block ()
468 tree r = build_stmt (EH_SPEC_BLOCK, NULL_TREE, NULL_TREE);
474 finish_eh_spec_block (raw_raises, eh_spec_block)
480 RECHAIN_STMTS (eh_spec_block, EH_SPEC_STMTS (eh_spec_block));
482 /* Strip cv quals, etc, from the specification types. */
483 for (raises = NULL_TREE;
484 raw_raises && TREE_VALUE (raw_raises);
485 raw_raises = TREE_CHAIN (raw_raises))
486 raises = tree_cons (NULL_TREE, prepare_eh_type (TREE_VALUE (raw_raises)),
489 EH_SPEC_RAISES (eh_spec_block) = raises;
492 /* Return a pointer to a buffer for an exception object of type TYPE. */
495 do_allocate_exception (type)
500 fn = get_identifier ("__cxa_allocate_exception");
501 if (IDENTIFIER_GLOBAL_VALUE (fn))
502 fn = IDENTIFIER_GLOBAL_VALUE (fn);
505 /* Declare void *__cxa_allocate_exception(size_t). */
506 tree tmp = tree_cons (NULL_TREE, c_size_type_node, void_list_node);
507 fn = push_library_fn (fn, build_function_type (ptr_type_node, tmp));
510 return build_function_call (fn, tree_cons (NULL_TREE, size_in_bytes (type),
515 /* Call __cxa_free_exception from a cleanup. This is never invoked
516 directly, but see the comment for stabilize_throw_expr. */
519 do_free_exception (ptr)
524 fn = get_identifier ("__cxa_free_exception");
525 if (IDENTIFIER_GLOBAL_VALUE (fn))
526 fn = IDENTIFIER_GLOBAL_VALUE (fn);
529 /* Declare void __cxa_free_exception (void *). */
530 fn = push_void_library_fn (fn, tree_cons (NULL_TREE, ptr_type_node,
534 return build_function_call (fn, tree_cons (NULL_TREE, ptr, NULL_TREE));
538 /* Wrap all cleanups for TARGET_EXPRs in MUST_NOT_THROW_EXPR.
539 Called from build_throw via walk_tree_without_duplicates. */
542 wrap_cleanups_r (tp, walk_subtrees, data)
544 int *walk_subtrees ATTRIBUTE_UNUSED;
545 void *data ATTRIBUTE_UNUSED;
550 /* Don't walk into types. */
556 if (TREE_CODE (exp) != TARGET_EXPR)
559 cleanup = TARGET_EXPR_CLEANUP (exp);
562 cleanup = build1 (MUST_NOT_THROW_EXPR, TREE_TYPE (cleanup), cleanup);
563 TARGET_EXPR_CLEANUP (exp) = cleanup;
566 /* Keep iterating. */
570 /* Like stabilize_expr, but specifically for a thrown expression. When
571 throwing a temporary class object, we want to construct it directly into
572 the thrown exception, so we look past the TARGET_EXPR and stabilize the
573 arguments of the call instead.
575 The case where EXP is a call to a function returning a class is a bit of
576 a grey area in the standard; it's unclear whether or not it should be
577 allowed to throw. I'm going to say no, as that allows us to optimize
578 this case without worrying about deallocating the exception object if it
579 does. The alternatives would be either not optimizing this case, or
580 wrapping the initialization in a TRY_CATCH_EXPR to call do_free_exception
581 rather than in a MUST_NOT_THROW_EXPR, for this case only. */
584 stabilize_throw_expr (exp, initp)
590 if (TREE_CODE (exp) == TARGET_EXPR
591 && TREE_CODE (TARGET_EXPR_INITIAL (exp)) == AGGR_INIT_EXPR
592 && flag_elide_constructors)
594 tree aggr_init = AGGR_INIT_EXPR_CHECK (TARGET_EXPR_INITIAL (exp));
595 tree args = TREE_OPERAND (aggr_init, 1);
596 tree newargs = NULL_TREE;
599 init_expr = void_zero_node;
600 for (; args; args = TREE_CHAIN (args))
603 tree newarg = stabilize_expr (TREE_VALUE (args), &arg_init_expr);
605 if (arg_init_expr != void_zero_node)
606 init_expr = build (COMPOUND_EXPR, void_type_node, arg_init_expr, init_expr);
607 *p = tree_cons (NULL_TREE, newarg, NULL_TREE);
608 p = &TREE_CHAIN (*p);
610 TREE_OPERAND (aggr_init, 1) = newargs;
614 exp = stabilize_expr (exp, &init_expr);
621 /* Build a throw expression. */
629 if (exp == error_mark_node)
632 if (processing_template_decl)
633 return build_min (THROW_EXPR, void_type_node, exp);
635 if (exp == null_node)
636 warning ("throwing NULL, which has integral, not pointer type");
638 if (exp != NULL_TREE)
640 if (!is_admissible_throw_operand (exp))
641 return error_mark_node;
645 return error_mark_node;
647 if (exp && decl_is_java_type (TREE_TYPE (exp), 1))
649 tree fn = get_identifier ("_Jv_Throw");
650 if (IDENTIFIER_GLOBAL_VALUE (fn))
651 fn = IDENTIFIER_GLOBAL_VALUE (fn);
654 /* Declare void _Jv_Throw (void *). */
655 tree tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
656 tmp = build_function_type (ptr_type_node, tmp);
657 fn = push_throw_library_fn (fn, tmp);
660 exp = build_function_call (fn, tree_cons (NULL_TREE, exp, NULL_TREE));
668 tree temp_expr, allocate_expr;
670 fn = get_identifier ("__cxa_throw");
671 if (IDENTIFIER_GLOBAL_VALUE (fn))
672 fn = IDENTIFIER_GLOBAL_VALUE (fn);
675 /* The CLEANUP_TYPE is the internal type of a destructor. */
676 if (cleanup_type == NULL_TREE)
678 tmp = void_list_node;
679 tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
680 tmp = build_function_type (void_type_node, tmp);
681 cleanup_type = build_pointer_type (tmp);
684 /* Declare void __cxa_throw (void*, void*, void (*)(void*)). */
685 /* ??? Second argument is supposed to be "std::type_info*". */
686 tmp = void_list_node;
687 tmp = tree_cons (NULL_TREE, cleanup_type, tmp);
688 tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
689 tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
690 tmp = build_function_type (void_type_node, tmp);
691 fn = push_throw_library_fn (fn, tmp);
694 /* throw expression */
695 /* First, decay it. */
696 exp = decay_conversion (exp);
698 /* OK, this is kind of wacky. The standard says that we call
699 terminate when the exception handling mechanism, after
700 completing evaluation of the expression to be thrown but
701 before the exception is caught (_except.throw_), calls a
702 user function that exits via an uncaught exception.
704 So we have to protect the actual initialization of the
705 exception object with terminate(), but evaluate the
706 expression first. Since there could be temps in the
707 expression, we need to handle that, too. We also expand
708 the call to __cxa_allocate_exception first (which doesn't
709 matter, since it can't throw). */
711 /* Pre-evaluate the thrown expression first, since if we allocated
712 the space first we would have to deal with cleaning it up if
713 evaluating this expression throws. */
714 exp = stabilize_throw_expr (exp, &temp_expr);
716 /* Allocate the space for the exception. */
717 allocate_expr = do_allocate_exception (TREE_TYPE (exp));
718 allocate_expr = get_target_expr (allocate_expr);
719 ptr = TARGET_EXPR_SLOT (allocate_expr);
720 object = build1 (NOP_EXPR, build_pointer_type (TREE_TYPE (exp)), ptr);
721 object = build_indirect_ref (object, NULL);
723 /* And initialize the exception object. */
724 exp = build_init (object, exp, LOOKUP_ONLYCONVERTING);
725 if (exp == error_mark_node)
727 error (" in thrown expression");
728 return error_mark_node;
731 exp = build1 (MUST_NOT_THROW_EXPR, TREE_TYPE (exp), exp);
732 /* Prepend the allocation. */
733 exp = build (COMPOUND_EXPR, TREE_TYPE (exp), allocate_expr, exp);
734 if (temp_expr != void_zero_node)
736 /* Prepend the calculation of the throw expression. Also, force
737 any cleanups from the expression to be evaluated here so that
738 we don't have to do them during unwinding. But first wrap
739 them in MUST_NOT_THROW_EXPR, since they are run after the
740 exception object is initialized. */
741 walk_tree_without_duplicates (&temp_expr, wrap_cleanups_r, 0);
742 exp = build (COMPOUND_EXPR, TREE_TYPE (exp), temp_expr, exp);
743 exp = build1 (CLEANUP_POINT_EXPR, TREE_TYPE (exp), exp);
746 throw_type = build_eh_type_type (prepare_eh_type (TREE_TYPE (object)));
748 if (TYPE_HAS_DESTRUCTOR (TREE_TYPE (object)))
750 cleanup = lookup_fnfields (TYPE_BINFO (TREE_TYPE (object)),
751 complete_dtor_identifier, 0);
752 cleanup = BASELINK_FUNCTIONS (cleanup);
754 cxx_mark_addressable (cleanup);
755 /* Pretend it's a normal function. */
756 cleanup = build1 (ADDR_EXPR, cleanup_type, cleanup);
760 cleanup = build_int_2 (0, 0);
761 TREE_TYPE (cleanup) = cleanup_type;
764 tmp = tree_cons (NULL_TREE, cleanup, NULL_TREE);
765 tmp = tree_cons (NULL_TREE, throw_type, tmp);
766 tmp = tree_cons (NULL_TREE, ptr, tmp);
767 /* ??? Indicate that this function call throws throw_type. */
768 tmp = build_function_call (fn, tmp);
770 /* Tack on the initialization stuff. */
771 exp = build (COMPOUND_EXPR, TREE_TYPE (tmp), exp, tmp);
775 /* Rethrow current exception. */
777 tree fn = get_identifier ("__cxa_rethrow");
778 if (IDENTIFIER_GLOBAL_VALUE (fn))
779 fn = IDENTIFIER_GLOBAL_VALUE (fn);
782 /* Declare void __cxa_rethrow (void). */
783 fn = push_throw_library_fn
784 (fn, build_function_type (void_type_node, void_list_node));
787 /* ??? Indicate that this function call allows exceptions of the type
788 of the enclosing catch block (if known). */
789 exp = build_function_call (fn, NULL_TREE);
792 exp = build1 (THROW_EXPR, void_type_node, exp);
797 /* Make sure TYPE is complete, pointer to complete, reference to
798 complete, or pointer to cv void. Issue diagnostic on failure.
799 Return the zero on failure and non-zero on success. FROM can be
800 the expr or decl from whence TYPE came, if available. */
803 complete_ptr_ref_or_void_ptr_p (type, from)
809 /* Check complete. */
810 type = complete_type_or_else (type, from);
814 /* Or a pointer or ref to one, or cv void *. */
815 is_ptr = TREE_CODE (type) == POINTER_TYPE;
816 if (is_ptr || TREE_CODE (type) == REFERENCE_TYPE)
818 tree core = TREE_TYPE (type);
820 if (is_ptr && VOID_TYPE_P (core))
822 else if (!complete_type_or_else (core, from))
828 /* Return truth-value if EXPRESSION is admissible in throw-expression,
829 i.e. if it is not of incomplete type or a pointer/reference to such
830 a type or of an abstract class type. */
833 is_admissible_throw_operand (expr)
836 tree type = TREE_TYPE (expr);
838 /* 15.1/4 [...] The type of the throw-expression shall not be an
839 incomplete type, or a pointer or a reference to an incomplete
840 type, other than void*, const void*, volatile void*, or
841 const volatile void*. Except for these restriction and the
842 restrictions on type matching mentioned in 15.3, the operand
843 of throw is treated exactly as a function argument in a call
844 (5.2.2) or the operand of a return statement. */
845 if (!complete_ptr_ref_or_void_ptr_p (type, expr))
848 /* 10.4/3 An abstract class shall not be used as a parameter type,
849 as a function return type or as type of an explicit
851 else if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type))
853 error ("expression '%E' of abstract class type '%T' cannot be used in throw-expression", expr, type);
860 /* Returns nonzero if FN is a declaration of a standard C library
861 function which is known not to throw.
863 [lib.res.on.exception.handling]: None of the functions from the
864 Standard C library shall report an error by throwing an
865 exception, unless it calls a program-supplied function that
866 throws an exception. */
877 && DECL_EXTERNAL (fn)
878 && DECL_NAMESPACE_SCOPE_P (fn)
879 && DECL_EXTERN_C_P (fn))
882 /* Can't be a C library function. */
885 id = DECL_ASSEMBLER_NAME (fn);
886 return !!libc_name_p (IDENTIFIER_POINTER (id), IDENTIFIER_LENGTH (id));
889 /* Returns nonzero if an exception of type FROM will be caught by a
890 handler for type TO, as per [except.handle]. */
893 can_convert_eh (to, from)
896 if (TREE_CODE (to) == REFERENCE_TYPE)
898 if (TREE_CODE (from) == REFERENCE_TYPE)
899 from = TREE_TYPE (from);
901 if (TREE_CODE (to) == POINTER_TYPE && TREE_CODE (from) == POINTER_TYPE)
904 from = TREE_TYPE (from);
906 if (! at_least_as_qualified_p (to, from))
909 if (TREE_CODE (to) == VOID_TYPE)
912 /* else fall through */
915 if (CLASS_TYPE_P (to) && CLASS_TYPE_P (from)
916 && PUBLICLY_UNIQUELY_DERIVED_P (to, from))
922 /* Check whether any of HANDLERS are shadowed by another handler accepting
923 TYPE. Note that the shadowing may not be complete; even if an exception
924 of type B would be caught by a handler for A, there could be a derived
925 class C for which A is an ambiguous base but B is not, so the handler
926 for B would catch an exception of type C. */
929 check_handlers_1 (master, handlers)
933 tree type = TREE_TYPE (master);
936 for (handler = handlers; handler; handler = TREE_CHAIN (handler))
937 if (TREE_TYPE (handler)
938 && can_convert_eh (type, TREE_TYPE (handler)))
940 lineno = STMT_LINENO (handler);
941 warning ("exception of type `%T' will be caught",
942 TREE_TYPE (handler));
943 lineno = STMT_LINENO (master);
944 warning (" by earlier handler for `%T'", type);
949 /* Given a chain of HANDLERs, make sure that they're OK. */
952 check_handlers (handlers)
956 int save_line = lineno;
957 for (handler = handlers; handler; handler = TREE_CHAIN (handler))
959 if (TREE_CHAIN (handler) == NULL_TREE)
960 /* No more handlers; nothing to shadow. */;
961 else if (TREE_TYPE (handler) == NULL_TREE)
963 lineno = STMT_LINENO (handler);
965 ("`...' handler must be the last handler for its try block");
968 check_handlers_1 (handler, TREE_CHAIN (handler));