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. */
179 if (type == NULL_TREE)
182 if (! TYPE_HAS_DESTRUCTOR (type))
185 fn = lookup_member (type, dtor_identifier, 0, 0);
186 fn = TREE_VALUE (fn);
187 return TREE_NOTHROW (fn);
190 /* Build up a call to __cxa_end_catch, to destroy the exception object
191 for the current catch block if no others are currently using it. */
199 fn = get_identifier ("__cxa_end_catch");
200 if (IDENTIFIER_GLOBAL_VALUE (fn))
201 fn = IDENTIFIER_GLOBAL_VALUE (fn);
204 /* Declare void __cxa_end_catch (). */
205 fn = push_void_library_fn (fn, void_list_node);
206 /* This can throw if the destructor for the exception throws. */
207 TREE_NOTHROW (fn) = 0;
210 cleanup = build_function_call (fn, NULL_TREE);
211 TREE_NOTHROW (cleanup) = dtor_nothrow (type);
216 /* This routine creates the cleanup for the current exception. */
219 push_eh_cleanup (type)
222 finish_decl_cleanup (NULL_TREE, do_end_catch (type));
225 /* Return nonzero value if DECL is a Java type suitable for catch or
229 decl_is_java_type (decl, err)
233 bool r = (TREE_CODE (decl) == POINTER_TYPE
234 && TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE
235 && TYPE_FOR_JAVA (TREE_TYPE (decl)));
239 if (TREE_CODE (decl) == REFERENCE_TYPE
240 && TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE
241 && TYPE_FOR_JAVA (TREE_TYPE (decl)))
243 /* Can't throw a reference. */
244 error ("type `%T' is disallowed in Java `throw' or `catch'",
251 = IDENTIFIER_GLOBAL_VALUE (get_identifier ("jthrowable"));
253 if (jthrow_node == NULL_TREE)
255 ("call to Java `catch' or `throw' with `jthrowable' undefined");
257 jthrow_node = TREE_TYPE (TREE_TYPE (jthrow_node));
259 if (! DERIVED_FROM_P (jthrow_node, TREE_TYPE (decl)))
261 /* Thrown object must be a Throwable. */
262 error ("type `%T' is not derived from `java::lang::Throwable'",
271 /* Select the personality routine to be used for exception handling,
272 or issue an error if we need two different ones in the same
274 ??? At present eh_personality_libfunc is set to
275 __gxx_personality_(sj|v)0 in init_exception_processing - should it
276 be done here instead? */
278 choose_personality_routine (lang)
294 if (lang != lang_cplusplus)
299 if (lang != lang_java)
304 ; /* proceed to language selection */
315 eh_personality_libfunc = init_one_libfunc (USING_SJLJ_EXCEPTIONS
316 ? "__gcj_personality_sj0"
317 : "__gcj_personality_v0");
326 error ("mixing C++ and Java catches in a single translation unit");
330 /* Initialize the catch parameter DECL. */
333 initialize_handler_parm (decl, exp)
340 /* Make sure we mark the catch param as used, otherwise we'll get a
341 warning about an unused ((anonymous)). */
342 TREE_USED (decl) = 1;
344 /* Figure out the type that the initializer is. Pointers are returned
345 adjusted by value from __cxa_begin_catch. Others are returned by
347 init_type = TREE_TYPE (decl);
348 if (! TYPE_PTR_P (init_type)
349 && TREE_CODE (init_type) != REFERENCE_TYPE)
350 init_type = build_reference_type (init_type);
352 choose_personality_routine (decl_is_java_type (init_type, 0)
353 ? lang_java : lang_cplusplus);
355 /* Since pointers are passed by value, initialize a reference to
356 pointer catch parm with the address of the temporary. */
357 if (TREE_CODE (init_type) == REFERENCE_TYPE
358 && TYPE_PTR_P (TREE_TYPE (init_type)))
359 exp = build_unary_op (ADDR_EXPR, exp, 1);
361 exp = ocp_convert (init_type, exp, CONV_IMPLICIT|CONV_FORCE_TEMP, 0);
363 init = convert_from_reference (exp);
365 /* If the constructor for the catch parm exits via an exception, we
366 must call terminate. See eh23.C. */
367 if (TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (decl)))
369 /* Generate the copy constructor call directly so we can wrap it.
370 See also expand_default_init. */
371 init = ocp_convert (TREE_TYPE (decl), init,
372 CONV_IMPLICIT|CONV_FORCE_TEMP, 0);
373 init = build1 (MUST_NOT_THROW_EXPR, TREE_TYPE (init), init);
376 /* Let `cp_finish_decl' know that this initializer is ok. */
377 DECL_INITIAL (decl) = error_mark_node;
378 decl = pushdecl (decl);
381 cp_finish_decl (decl, init, NULL_TREE,
382 LOOKUP_ONLYCONVERTING|DIRECT_BIND);
385 /* Call this to start a catch block. DECL is the catch parameter. */
388 expand_start_catch_block (decl)
391 tree exp = NULL_TREE;
398 /* Make sure this declaration is reasonable. */
399 if (decl && !complete_ptr_ref_or_void_ptr_p (TREE_TYPE (decl), NULL_TREE))
403 type = prepare_eh_type (TREE_TYPE (decl));
412 if (decl_is_java_type (type, 1))
414 /* Java only passes object via pointer and doesn't require
415 adjusting. The java object is immediately before the
416 generic exception header. */
417 init = build_exc_ptr ();
418 init = build1 (NOP_EXPR, build_pointer_type (type), init);
419 init = build (MINUS_EXPR, TREE_TYPE (init), init,
420 TYPE_SIZE_UNIT (TREE_TYPE (init)));
421 init = build_indirect_ref (init, NULL);
426 /* C++ requires that we call __cxa_begin_catch to get the
427 pointer to the actual object. */
428 init = do_begin_catch ();
431 exp = create_temporary_var (ptr_type_node);
432 DECL_REGISTER (exp) = 1;
433 cp_finish_decl (exp, init, NULL_TREE, LOOKUP_ONLYCONVERTING);
434 finish_expr_stmt (build_modify_expr (exp, INIT_EXPR, init));
437 finish_expr_stmt (do_begin_catch ());
439 /* C++ requires that we call __cxa_end_catch at the end of
440 processing the exception. */
442 push_eh_cleanup (type);
445 initialize_handler_parm (decl, exp);
451 /* Call this to end a catch block. Its responsible for emitting the
452 code to handle jumping back to the correct place, and for emitting
453 the label to jump to if this catch block didn't match. */
456 expand_end_catch_block ()
461 /* The exception being handled is rethrown if control reaches the end of
462 a handler of the function-try-block of a constructor or destructor. */
463 if (in_function_try_handler
464 && (DECL_CONSTRUCTOR_P (current_function_decl)
465 || DECL_DESTRUCTOR_P (current_function_decl)))
466 finish_expr_stmt (build_throw (NULL_TREE));
470 begin_eh_spec_block ()
472 tree r = build_stmt (EH_SPEC_BLOCK, NULL_TREE, NULL_TREE);
478 finish_eh_spec_block (raw_raises, eh_spec_block)
484 RECHAIN_STMTS (eh_spec_block, EH_SPEC_STMTS (eh_spec_block));
486 /* Strip cv quals, etc, from the specification types. */
487 for (raises = NULL_TREE;
488 raw_raises && TREE_VALUE (raw_raises);
489 raw_raises = TREE_CHAIN (raw_raises))
490 raises = tree_cons (NULL_TREE, prepare_eh_type (TREE_VALUE (raw_raises)),
493 EH_SPEC_RAISES (eh_spec_block) = raises;
496 /* Return a pointer to a buffer for an exception object of type TYPE. */
499 do_allocate_exception (type)
504 fn = get_identifier ("__cxa_allocate_exception");
505 if (IDENTIFIER_GLOBAL_VALUE (fn))
506 fn = IDENTIFIER_GLOBAL_VALUE (fn);
509 /* Declare void *__cxa_allocate_exception(size_t). */
510 tree tmp = tree_cons (NULL_TREE, c_size_type_node, void_list_node);
511 fn = push_library_fn (fn, build_function_type (ptr_type_node, tmp));
514 return build_function_call (fn, tree_cons (NULL_TREE, size_in_bytes (type),
519 /* Call __cxa_free_exception from a cleanup. This is never invoked
520 directly, but see the comment for stabilize_throw_expr. */
523 do_free_exception (ptr)
528 fn = get_identifier ("__cxa_free_exception");
529 if (IDENTIFIER_GLOBAL_VALUE (fn))
530 fn = IDENTIFIER_GLOBAL_VALUE (fn);
533 /* Declare void __cxa_free_exception (void *). */
534 fn = push_void_library_fn (fn, tree_cons (NULL_TREE, ptr_type_node,
538 return build_function_call (fn, tree_cons (NULL_TREE, ptr, NULL_TREE));
542 /* Wrap all cleanups for TARGET_EXPRs in MUST_NOT_THROW_EXPR.
543 Called from build_throw via walk_tree_without_duplicates. */
546 wrap_cleanups_r (tp, walk_subtrees, data)
548 int *walk_subtrees ATTRIBUTE_UNUSED;
549 void *data ATTRIBUTE_UNUSED;
554 /* Don't walk into types. */
560 if (TREE_CODE (exp) != TARGET_EXPR)
563 cleanup = TARGET_EXPR_CLEANUP (exp);
566 cleanup = build1 (MUST_NOT_THROW_EXPR, TREE_TYPE (cleanup), cleanup);
567 TARGET_EXPR_CLEANUP (exp) = cleanup;
570 /* Keep iterating. */
574 /* Like stabilize_expr, but specifically for a thrown expression. When
575 throwing a temporary class object, we want to construct it directly into
576 the thrown exception, so we look past the TARGET_EXPR and stabilize the
577 arguments of the call instead.
579 The case where EXP is a call to a function returning a class is a bit of
580 a grey area in the standard; it's unclear whether or not it should be
581 allowed to throw. I'm going to say no, as that allows us to optimize
582 this case without worrying about deallocating the exception object if it
583 does. The alternatives would be either not optimizing this case, or
584 wrapping the initialization in a TRY_CATCH_EXPR to call do_free_exception
585 rather than in a MUST_NOT_THROW_EXPR, for this case only. */
588 stabilize_throw_expr (exp, initp)
594 if (TREE_CODE (exp) == TARGET_EXPR
595 && TREE_CODE (TARGET_EXPR_INITIAL (exp)) == AGGR_INIT_EXPR
596 && flag_elide_constructors)
598 tree aggr_init = AGGR_INIT_EXPR_CHECK (TARGET_EXPR_INITIAL (exp));
599 tree args = TREE_OPERAND (aggr_init, 1);
600 tree newargs = NULL_TREE;
603 init_expr = void_zero_node;
604 for (; args; args = TREE_CHAIN (args))
607 tree newarg = stabilize_expr (TREE_VALUE (args), &arg_init_expr);
609 if (arg_init_expr != void_zero_node)
610 init_expr = build (COMPOUND_EXPR, void_type_node, arg_init_expr, init_expr);
611 *p = tree_cons (NULL_TREE, newarg, NULL_TREE);
612 p = &TREE_CHAIN (*p);
614 TREE_OPERAND (aggr_init, 1) = newargs;
618 exp = stabilize_expr (exp, &init_expr);
625 /* Build a throw expression. */
633 if (exp == error_mark_node)
636 if (processing_template_decl)
637 return build_min (THROW_EXPR, void_type_node, exp);
639 if (exp == null_node)
640 warning ("throwing NULL, which has integral, not pointer type");
642 if (exp != NULL_TREE)
644 if (!is_admissible_throw_operand (exp))
645 return error_mark_node;
649 return error_mark_node;
651 if (exp && decl_is_java_type (TREE_TYPE (exp), 1))
653 tree fn = get_identifier ("_Jv_Throw");
654 if (IDENTIFIER_GLOBAL_VALUE (fn))
655 fn = IDENTIFIER_GLOBAL_VALUE (fn);
658 /* Declare void _Jv_Throw (void *). */
659 tree tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
660 tmp = build_function_type (ptr_type_node, tmp);
661 fn = push_throw_library_fn (fn, tmp);
664 exp = build_function_call (fn, tree_cons (NULL_TREE, exp, NULL_TREE));
672 tree temp_expr, allocate_expr;
674 fn = get_identifier ("__cxa_throw");
675 if (IDENTIFIER_GLOBAL_VALUE (fn))
676 fn = IDENTIFIER_GLOBAL_VALUE (fn);
679 /* The CLEANUP_TYPE is the internal type of a destructor. */
680 if (cleanup_type == NULL_TREE)
682 tmp = void_list_node;
683 tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
684 tmp = build_function_type (void_type_node, tmp);
685 cleanup_type = build_pointer_type (tmp);
688 /* Declare void __cxa_throw (void*, void*, void (*)(void*)). */
689 /* ??? Second argument is supposed to be "std::type_info*". */
690 tmp = void_list_node;
691 tmp = tree_cons (NULL_TREE, cleanup_type, tmp);
692 tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
693 tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
694 tmp = build_function_type (void_type_node, tmp);
695 fn = push_throw_library_fn (fn, tmp);
698 /* throw expression */
699 /* First, decay it. */
700 exp = decay_conversion (exp);
702 /* OK, this is kind of wacky. The standard says that we call
703 terminate when the exception handling mechanism, after
704 completing evaluation of the expression to be thrown but
705 before the exception is caught (_except.throw_), calls a
706 user function that exits via an uncaught exception.
708 So we have to protect the actual initialization of the
709 exception object with terminate(), but evaluate the
710 expression first. Since there could be temps in the
711 expression, we need to handle that, too. We also expand
712 the call to __cxa_allocate_exception first (which doesn't
713 matter, since it can't throw). */
715 /* Pre-evaluate the thrown expression first, since if we allocated
716 the space first we would have to deal with cleaning it up if
717 evaluating this expression throws. */
718 exp = stabilize_throw_expr (exp, &temp_expr);
720 /* Allocate the space for the exception. */
721 allocate_expr = do_allocate_exception (TREE_TYPE (exp));
722 allocate_expr = get_target_expr (allocate_expr);
723 ptr = TARGET_EXPR_SLOT (allocate_expr);
724 object = build1 (NOP_EXPR, build_pointer_type (TREE_TYPE (exp)), ptr);
725 object = build_indirect_ref (object, NULL);
727 /* And initialize the exception object. */
728 exp = build_init (object, exp, LOOKUP_ONLYCONVERTING);
729 if (exp == error_mark_node)
731 error (" in thrown expression");
732 return error_mark_node;
735 exp = build1 (MUST_NOT_THROW_EXPR, TREE_TYPE (exp), exp);
736 /* Prepend the allocation. */
737 exp = build (COMPOUND_EXPR, TREE_TYPE (exp), allocate_expr, exp);
738 if (temp_expr != void_zero_node)
740 /* Prepend the calculation of the throw expression. Also, force
741 any cleanups from the expression to be evaluated here so that
742 we don't have to do them during unwinding. But first wrap
743 them in MUST_NOT_THROW_EXPR, since they are run after the
744 exception object is initialized. */
745 walk_tree_without_duplicates (&temp_expr, wrap_cleanups_r, 0);
746 exp = build (COMPOUND_EXPR, TREE_TYPE (exp), temp_expr, exp);
747 exp = build1 (CLEANUP_POINT_EXPR, TREE_TYPE (exp), exp);
750 throw_type = build_eh_type_type (prepare_eh_type (TREE_TYPE (object)));
752 if (TYPE_HAS_DESTRUCTOR (TREE_TYPE (object)))
754 cleanup = lookup_fnfields (TYPE_BINFO (TREE_TYPE (object)),
755 complete_dtor_identifier, 0);
756 cleanup = TREE_VALUE (cleanup);
758 cxx_mark_addressable (cleanup);
759 /* Pretend it's a normal function. */
760 cleanup = build1 (ADDR_EXPR, cleanup_type, cleanup);
764 cleanup = build_int_2 (0, 0);
765 TREE_TYPE (cleanup) = cleanup_type;
768 tmp = tree_cons (NULL_TREE, cleanup, NULL_TREE);
769 tmp = tree_cons (NULL_TREE, throw_type, tmp);
770 tmp = tree_cons (NULL_TREE, ptr, tmp);
771 /* ??? Indicate that this function call throws throw_type. */
772 tmp = build_function_call (fn, tmp);
774 /* Tack on the initialization stuff. */
775 exp = build (COMPOUND_EXPR, TREE_TYPE (tmp), exp, tmp);
779 /* Rethrow current exception. */
781 tree fn = get_identifier ("__cxa_rethrow");
782 if (IDENTIFIER_GLOBAL_VALUE (fn))
783 fn = IDENTIFIER_GLOBAL_VALUE (fn);
786 /* Declare void __cxa_rethrow (void). */
787 fn = push_throw_library_fn
788 (fn, build_function_type (void_type_node, void_list_node));
791 /* ??? Indicate that this function call allows exceptions of the type
792 of the enclosing catch block (if known). */
793 exp = build_function_call (fn, NULL_TREE);
796 exp = build1 (THROW_EXPR, void_type_node, exp);
801 /* Make sure TYPE is complete, pointer to complete, reference to
802 complete, or pointer to cv void. Issue diagnostic on failure.
803 Return the zero on failure and non-zero on success. FROM can be
804 the expr or decl from whence TYPE came, if available. */
807 complete_ptr_ref_or_void_ptr_p (type, from)
813 /* Check complete. */
814 type = complete_type_or_else (type, from);
818 /* Or a pointer or ref to one, or cv void *. */
819 is_ptr = TREE_CODE (type) == POINTER_TYPE;
820 if (is_ptr || TREE_CODE (type) == REFERENCE_TYPE)
822 tree core = TREE_TYPE (type);
824 if (is_ptr && VOID_TYPE_P (core))
826 else if (!complete_type_or_else (core, from))
832 /* Return truth-value if EXPRESSION is admissible in throw-expression,
833 i.e. if it is not of incomplete type or a pointer/reference to such
834 a type or of an abstract class type. */
837 is_admissible_throw_operand (expr)
840 tree type = TREE_TYPE (expr);
842 /* 15.1/4 [...] The type of the throw-expression shall not be an
843 incomplete type, or a pointer or a reference to an incomplete
844 type, other than void*, const void*, volatile void*, or
845 const volatile void*. Except for these restriction and the
846 restrictions on type matching mentioned in 15.3, the operand
847 of throw is treated exactly as a function argument in a call
848 (5.2.2) or the operand of a return statement. */
849 if (!complete_ptr_ref_or_void_ptr_p (type, expr))
852 /* 10.4/3 An abstract class shall not be used as a parameter type,
853 as a function return type or as type of an explicit
855 else if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type))
857 error ("expression '%E' of abstract class type '%T' cannot be used in throw-expression", expr, type);
864 /* Returns nonzero if FN is a declaration of a standard C library
865 function which is known not to throw.
867 [lib.res.on.exception.handling]: None of the functions from the
868 Standard C library shall report an error by throwing an
869 exception, unless it calls a program-supplied function that
870 throws an exception. */
881 && DECL_EXTERNAL (fn)
882 && DECL_NAMESPACE_SCOPE_P (fn)
883 && DECL_EXTERN_C_P (fn))
886 /* Can't be a C library function. */
889 id = DECL_ASSEMBLER_NAME (fn);
890 return !!libc_name_p (IDENTIFIER_POINTER (id), IDENTIFIER_LENGTH (id));
893 /* Returns nonzero if an exception of type FROM will be caught by a
894 handler for type TO, as per [except.handle]. */
897 can_convert_eh (to, from)
900 if (TREE_CODE (to) == REFERENCE_TYPE)
902 if (TREE_CODE (from) == REFERENCE_TYPE)
903 from = TREE_TYPE (from);
905 if (TREE_CODE (to) == POINTER_TYPE && TREE_CODE (from) == POINTER_TYPE)
908 from = TREE_TYPE (from);
910 if (! at_least_as_qualified_p (to, from))
913 if (TREE_CODE (to) == VOID_TYPE)
916 /* else fall through */
919 if (CLASS_TYPE_P (to) && CLASS_TYPE_P (from)
920 && PUBLICLY_UNIQUELY_DERIVED_P (to, from))
926 /* Check whether any of HANDLERS are shadowed by another handler accepting
927 TYPE. Note that the shadowing may not be complete; even if an exception
928 of type B would be caught by a handler for A, there could be a derived
929 class C for which A is an ambiguous base but B is not, so the handler
930 for B would catch an exception of type C. */
933 check_handlers_1 (master, handlers)
937 tree type = TREE_TYPE (master);
940 for (handler = handlers; handler; handler = TREE_CHAIN (handler))
941 if (TREE_TYPE (handler)
942 && can_convert_eh (type, TREE_TYPE (handler)))
944 lineno = STMT_LINENO (handler);
945 warning ("exception of type `%T' will be caught",
946 TREE_TYPE (handler));
947 lineno = STMT_LINENO (master);
948 warning (" by earlier handler for `%T'", type);
953 /* Given a chain of HANDLERs, make sure that they're OK. */
956 check_handlers (handlers)
960 int save_line = lineno;
961 for (handler = handlers; handler; handler = TREE_CHAIN (handler))
963 if (TREE_CHAIN (handler) == NULL_TREE)
964 /* No more handlers; nothing to shadow. */;
965 else if (TREE_TYPE (handler) == NULL_TREE)
967 lineno = STMT_LINENO (handler);
969 ("`...' handler must be the last handler for its try block");
972 check_handlers_1 (handler, TREE_CHAIN (handler));