1 /* Handle exceptional things in C++.
2 Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3 2000, 2001, 2002, 2003, 2004, 2005 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 GCC.
10 GCC 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 GCC 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 GCC; see the file COPYING. If not, write to
22 the Free Software Foundation, 59 Temple Place - Suite 330,
23 Boston, MA 02111-1307, USA. */
28 #include "coretypes.h"
39 #include "tree-inline.h"
40 #include "tree-iterator.h"
42 static void push_eh_cleanup (tree
);
43 static tree
prepare_eh_type (tree
);
44 static tree
build_eh_type_type (tree
);
45 static tree
do_begin_catch (void);
46 static int dtor_nothrow (tree
);
47 static tree
do_end_catch (tree
);
48 static bool decl_is_java_type (tree decl
, int err
);
49 static void initialize_handler_parm (tree
, tree
);
50 static tree
do_allocate_exception (tree
);
51 static tree
wrap_cleanups_r (tree
*, int *, void *);
52 static int complete_ptr_ref_or_void_ptr_p (tree
, tree
);
53 static bool is_admissible_throw_operand (tree
);
54 static int can_convert_eh (tree
, tree
);
55 static tree
cp_protect_cleanup_actions (void);
57 /* Sets up all the global eh stuff that needs to be initialized at the
58 start of compilation. */
61 init_exception_processing (void)
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 (void)
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 (tree type
)
103 if (type
== NULL_TREE
)
105 if (type
== error_mark_node
)
106 return error_mark_node
;
108 /* peel back references, so they match. */
109 type
= non_reference (type
);
111 /* Peel off cv qualifiers. */
112 type
= TYPE_MAIN_VARIANT (type
);
117 /* Return the type info for TYPE as used by EH machinery. */
119 eh_type_info (tree type
)
123 if (type
== NULL_TREE
|| type
== error_mark_node
)
126 if (decl_is_java_type (type
, 0))
127 exp
= build_java_class_ref (TREE_TYPE (type
));
129 exp
= get_tinfo_decl (type
);
134 /* Build the address of a typeinfo decl for use in the runtime
135 matching field of the exception model. */
138 build_eh_type_type (tree type
)
140 tree exp
= eh_type_info (type
);
147 return convert (ptr_type_node
, build_address (exp
));
153 return build0 (EXC_PTR_EXPR
, ptr_type_node
);
156 /* Build up a call to __cxa_begin_catch, to tell the runtime that the
157 exception has been handled. */
160 do_begin_catch (void)
164 fn
= get_identifier ("__cxa_begin_catch");
165 if (!get_global_value_if_present (fn
, &fn
))
167 /* Declare void* __cxa_begin_catch (void *). */
168 tree tmp
= tree_cons (NULL_TREE
, ptr_type_node
, void_list_node
);
169 fn
= push_library_fn (fn
, build_function_type (ptr_type_node
, tmp
));
172 return build_function_call (fn
, tree_cons (NULL_TREE
, build_exc_ptr (),
176 /* Returns nonzero if cleaning up an exception of type TYPE (which can be
177 NULL_TREE for a ... handler) will not throw an exception. */
180 dtor_nothrow (tree type
)
182 if (type
== NULL_TREE
)
185 if (!CLASS_TYPE_P (type
))
188 if (CLASSTYPE_LAZY_DESTRUCTOR (type
))
189 lazily_declare_fn (sfk_destructor
, type
);
191 return TREE_NOTHROW (CLASSTYPE_DESTRUCTORS (type
));
194 /* Build up a call to __cxa_end_catch, to destroy the exception object
195 for the current catch block if no others are currently using it. */
198 do_end_catch (tree type
)
202 fn
= get_identifier ("__cxa_end_catch");
203 if (!get_global_value_if_present (fn
, &fn
))
205 /* Declare void __cxa_end_catch (). */
206 fn
= push_void_library_fn (fn
, void_list_node
);
207 /* This can throw if the destructor for the exception throws. */
208 TREE_NOTHROW (fn
) = 0;
211 cleanup
= build_function_call (fn
, NULL_TREE
);
212 TREE_NOTHROW (cleanup
) = dtor_nothrow (type
);
217 /* This routine creates the cleanup for the current exception. */
220 push_eh_cleanup (tree 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 (tree decl
, int err
)
231 bool r
= (TREE_CODE (decl
) == POINTER_TYPE
232 && TREE_CODE (TREE_TYPE (decl
)) == RECORD_TYPE
233 && TYPE_FOR_JAVA (TREE_TYPE (decl
)));
237 if (TREE_CODE (decl
) == REFERENCE_TYPE
238 && TREE_CODE (TREE_TYPE (decl
)) == RECORD_TYPE
239 && TYPE_FOR_JAVA (TREE_TYPE (decl
)))
241 /* Can't throw a reference. */
242 error ("type %qT is disallowed in Java %<throw%> or %<catch%>",
249 = IDENTIFIER_GLOBAL_VALUE (get_identifier ("jthrowable"));
251 if (jthrow_node
== NULL_TREE
)
253 ("call to Java %<catch%> or %<throw%> with %<jthrowable%> undefined");
255 jthrow_node
= TREE_TYPE (TREE_TYPE (jthrow_node
));
257 if (! DERIVED_FROM_P (jthrow_node
, TREE_TYPE (decl
)))
259 /* Thrown object must be a Throwable. */
260 error ("type %qT is not derived from %<java::lang::Throwable%>",
269 /* Select the personality routine to be used for exception handling,
270 or issue an error if we need two different ones in the same
272 ??? At present eh_personality_libfunc is set to
273 __gxx_personality_(sj|v)0 in init_exception_processing - should it
274 be done here instead? */
276 choose_personality_routine (enum languages lang
)
291 if (lang
!= lang_cplusplus
)
296 if (lang
!= lang_java
)
301 ; /* Proceed to language selection. */
312 eh_personality_libfunc
= init_one_libfunc (USING_SJLJ_EXCEPTIONS
313 ? "__gcj_personality_sj0"
314 : "__gcj_personality_v0");
323 error ("mixing C++ and Java catches in a single translation unit");
327 /* Initialize the catch parameter DECL. */
330 initialize_handler_parm (tree decl
, tree exp
)
335 /* Make sure we mark the catch param as used, otherwise we'll get a
336 warning about an unused ((anonymous)). */
337 TREE_USED (decl
) = 1;
339 /* Figure out the type that the initializer is. Pointers are returned
340 adjusted by value from __cxa_begin_catch. Others are returned by
342 init_type
= TREE_TYPE (decl
);
343 if (!POINTER_TYPE_P (init_type
))
344 init_type
= build_reference_type (init_type
);
346 choose_personality_routine (decl_is_java_type (init_type
, 0)
347 ? lang_java
: lang_cplusplus
);
349 /* Since pointers are passed by value, initialize a reference to
350 pointer catch parm with the address of the temporary. */
351 if (TREE_CODE (init_type
) == REFERENCE_TYPE
352 && TYPE_PTR_P (TREE_TYPE (init_type
)))
353 exp
= build_unary_op (ADDR_EXPR
, exp
, 1);
355 exp
= ocp_convert (init_type
, exp
, CONV_IMPLICIT
|CONV_FORCE_TEMP
, 0);
357 init
= convert_from_reference (exp
);
359 /* If the constructor for the catch parm exits via an exception, we
360 must call terminate. See eh23.C. */
361 if (TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (decl
)))
363 /* Generate the copy constructor call directly so we can wrap it.
364 See also expand_default_init. */
365 init
= ocp_convert (TREE_TYPE (decl
), init
,
366 CONV_IMPLICIT
|CONV_FORCE_TEMP
, 0);
367 init
= build1 (MUST_NOT_THROW_EXPR
, TREE_TYPE (init
), init
);
370 /* Let `cp_finish_decl' know that this initializer is ok. */
371 DECL_INITIAL (decl
) = error_mark_node
;
372 decl
= pushdecl (decl
);
375 cp_finish_decl (decl
, init
, NULL_TREE
,
376 LOOKUP_ONLYCONVERTING
|DIRECT_BIND
);
379 /* Call this to start a catch block. DECL is the catch parameter. */
382 expand_start_catch_block (tree decl
)
384 tree exp
= NULL_TREE
;
391 /* Make sure this declaration is reasonable. */
392 if (decl
&& !complete_ptr_ref_or_void_ptr_p (TREE_TYPE (decl
), NULL_TREE
))
396 type
= prepare_eh_type (TREE_TYPE (decl
));
405 if (decl_is_java_type (type
, 1))
407 /* Java only passes object via pointer and doesn't require
408 adjusting. The java object is immediately before the
409 generic exception header. */
410 init
= build_exc_ptr ();
411 init
= build1 (NOP_EXPR
, build_pointer_type (type
), init
);
412 init
= build2 (MINUS_EXPR
, TREE_TYPE (init
), init
,
413 TYPE_SIZE_UNIT (TREE_TYPE (init
)));
414 init
= build_indirect_ref (init
, NULL
);
419 /* C++ requires that we call __cxa_begin_catch to get the
420 pointer to the actual object. */
421 init
= do_begin_catch ();
424 exp
= create_temporary_var (ptr_type_node
);
425 DECL_REGISTER (exp
) = 1;
426 cp_finish_decl (exp
, init
, NULL_TREE
, LOOKUP_ONLYCONVERTING
);
427 finish_expr_stmt (build_modify_expr (exp
, INIT_EXPR
, init
));
430 finish_expr_stmt (do_begin_catch ());
432 /* C++ requires that we call __cxa_end_catch at the end of
433 processing the exception. */
435 push_eh_cleanup (type
);
438 initialize_handler_parm (decl
, exp
);
444 /* Call this to end a catch block. Its responsible for emitting the
445 code to handle jumping back to the correct place, and for emitting
446 the label to jump to if this catch block didn't match. */
449 expand_end_catch_block (void)
454 /* The exception being handled is rethrown if control reaches the end of
455 a handler of the function-try-block of a constructor or destructor. */
456 if (in_function_try_handler
457 && (DECL_CONSTRUCTOR_P (current_function_decl
)
458 || DECL_DESTRUCTOR_P (current_function_decl
)))
459 finish_expr_stmt (build_throw (NULL_TREE
));
463 begin_eh_spec_block (void)
465 tree r
= build_stmt (EH_SPEC_BLOCK
, NULL_TREE
, NULL_TREE
);
467 EH_SPEC_STMTS (r
) = push_stmt_list ();
472 finish_eh_spec_block (tree raw_raises
, tree eh_spec_block
)
476 EH_SPEC_STMTS (eh_spec_block
) = pop_stmt_list (EH_SPEC_STMTS (eh_spec_block
));
478 /* Strip cv quals, etc, from the specification types. */
479 for (raises
= NULL_TREE
;
480 raw_raises
&& TREE_VALUE (raw_raises
);
481 raw_raises
= TREE_CHAIN (raw_raises
))
483 tree type
= prepare_eh_type (TREE_VALUE (raw_raises
));
484 tree tinfo
= eh_type_info (type
);
487 raises
= tree_cons (NULL_TREE
, type
, raises
);
490 EH_SPEC_RAISES (eh_spec_block
) = raises
;
493 /* Return a pointer to a buffer for an exception object of type TYPE. */
496 do_allocate_exception (tree type
)
500 fn
= get_identifier ("__cxa_allocate_exception");
501 if (!get_global_value_if_present (fn
, &fn
))
503 /* Declare void *__cxa_allocate_exception(size_t). */
504 tree tmp
= tree_cons (NULL_TREE
, size_type_node
, void_list_node
);
505 fn
= push_library_fn (fn
, build_function_type (ptr_type_node
, tmp
));
508 return build_function_call (fn
, tree_cons (NULL_TREE
, size_in_bytes (type
),
512 /* Call __cxa_free_exception from a cleanup. This is never invoked
513 directly, but see the comment for stabilize_throw_expr. */
516 do_free_exception (tree ptr
)
520 fn
= get_identifier ("__cxa_free_exception");
521 if (!get_global_value_if_present (fn
, &fn
))
523 /* Declare void __cxa_free_exception (void *). */
524 fn
= push_void_library_fn (fn
, tree_cons (NULL_TREE
, ptr_type_node
,
528 return build_function_call (fn
, tree_cons (NULL_TREE
, ptr
, NULL_TREE
));
531 /* Wrap all cleanups for TARGET_EXPRs in MUST_NOT_THROW_EXPR.
532 Called from build_throw via walk_tree_without_duplicates. */
535 wrap_cleanups_r (tree
*tp
, int *walk_subtrees ATTRIBUTE_UNUSED
,
536 void *data ATTRIBUTE_UNUSED
)
541 /* Don't walk into types. */
547 if (TREE_CODE (exp
) != TARGET_EXPR
)
550 cleanup
= TARGET_EXPR_CLEANUP (exp
);
553 cleanup
= build1 (MUST_NOT_THROW_EXPR
, void_type_node
, cleanup
);
554 TARGET_EXPR_CLEANUP (exp
) = cleanup
;
557 /* Keep iterating. */
561 /* Build a throw expression. */
564 build_throw (tree exp
)
568 if (exp
== error_mark_node
)
571 if (processing_template_decl
)
573 current_function_returns_abnormally
= 1;
574 return build_min (THROW_EXPR
, void_type_node
, exp
);
577 if (exp
== null_node
)
578 warning ("throwing NULL, which has integral, not pointer type");
580 if (exp
!= NULL_TREE
)
582 if (!is_admissible_throw_operand (exp
))
583 return error_mark_node
;
587 return error_mark_node
;
589 if (exp
&& decl_is_java_type (TREE_TYPE (exp
), 1))
591 tree fn
= get_identifier ("_Jv_Throw");
592 if (!get_global_value_if_present (fn
, &fn
))
594 /* Declare void _Jv_Throw (void *). */
595 tree tmp
= tree_cons (NULL_TREE
, ptr_type_node
, void_list_node
);
596 tmp
= build_function_type (ptr_type_node
, tmp
);
597 fn
= push_throw_library_fn (fn
, tmp
);
599 else if (really_overloaded_fn (fn
))
601 error ("%qD should never be overloaded", fn
);
602 return error_mark_node
;
604 fn
= OVL_CURRENT (fn
);
605 exp
= build_function_call (fn
, tree_cons (NULL_TREE
, exp
, NULL_TREE
));
613 tree temp_expr
, allocate_expr
;
616 /* The CLEANUP_TYPE is the internal type of a destructor. */
619 tmp
= void_list_node
;
620 tmp
= tree_cons (NULL_TREE
, ptr_type_node
, tmp
);
621 tmp
= build_function_type (void_type_node
, tmp
);
622 cleanup_type
= build_pointer_type (tmp
);
625 fn
= get_identifier ("__cxa_throw");
626 if (!get_global_value_if_present (fn
, &fn
))
628 /* Declare void __cxa_throw (void*, void*, void (*)(void*)). */
629 /* ??? Second argument is supposed to be "std::type_info*". */
630 tmp
= void_list_node
;
631 tmp
= tree_cons (NULL_TREE
, cleanup_type
, tmp
);
632 tmp
= tree_cons (NULL_TREE
, ptr_type_node
, tmp
);
633 tmp
= tree_cons (NULL_TREE
, ptr_type_node
, tmp
);
634 tmp
= build_function_type (void_type_node
, tmp
);
635 fn
= push_throw_library_fn (fn
, tmp
);
638 /* throw expression */
639 /* First, decay it. */
640 exp
= decay_conversion (exp
);
642 /* OK, this is kind of wacky. The standard says that we call
643 terminate when the exception handling mechanism, after
644 completing evaluation of the expression to be thrown but
645 before the exception is caught (_except.throw_), calls a
646 user function that exits via an uncaught exception.
648 So we have to protect the actual initialization of the
649 exception object with terminate(), but evaluate the
650 expression first. Since there could be temps in the
651 expression, we need to handle that, too. We also expand
652 the call to __cxa_allocate_exception first (which doesn't
653 matter, since it can't throw). */
655 /* Allocate the space for the exception. */
656 allocate_expr
= do_allocate_exception (TREE_TYPE (exp
));
657 allocate_expr
= get_target_expr (allocate_expr
);
658 ptr
= TARGET_EXPR_SLOT (allocate_expr
);
659 object
= build1 (NOP_EXPR
, build_pointer_type (TREE_TYPE (exp
)), ptr
);
660 object
= build_indirect_ref (object
, NULL
);
662 elided
= (TREE_CODE (exp
) == TARGET_EXPR
);
664 /* And initialize the exception object. */
665 exp
= build_init (object
, exp
, LOOKUP_ONLYCONVERTING
);
666 if (exp
== error_mark_node
)
668 error (" in thrown expression");
669 return error_mark_node
;
672 /* Pre-evaluate the thrown expression first, since if we allocated
673 the space first we would have to deal with cleaning it up if
674 evaluating this expression throws.
676 The case where EXP the initializer is a call to a constructor or a
677 function returning a class is a bit of a grey area in the
678 standard; it's unclear whether or not it should be allowed to
679 throw. We used to say no, as that allowed us to optimize this
680 case without worrying about deallocating the exception object if
681 it does. But that conflicted with expectations (PR 13944) and the
682 EDG compiler; now we wrap the initialization in a TRY_CATCH_EXPR
683 to call do_free_exception rather than in a MUST_NOT_THROW_EXPR,
686 Note that we don't check the return value from stabilize_init
687 because it will only return false in cases where elided is true,
688 and therefore we don't need to work around the failure to
690 temp_expr
= NULL_TREE
;
691 stabilize_init (exp
, &temp_expr
);
694 exp
= build2 (TRY_CATCH_EXPR
, void_type_node
, exp
,
695 do_free_exception (ptr
));
697 exp
= build1 (MUST_NOT_THROW_EXPR
, void_type_node
, exp
);
699 /* Prepend the allocation. */
700 exp
= build2 (COMPOUND_EXPR
, TREE_TYPE (exp
), allocate_expr
, exp
);
703 /* Prepend the calculation of the throw expression. Also, force
704 any cleanups from the expression to be evaluated here so that
705 we don't have to do them during unwinding. But first wrap
706 them in MUST_NOT_THROW_EXPR, since they are run after the
707 exception object is initialized. */
708 walk_tree_without_duplicates (&temp_expr
, wrap_cleanups_r
, 0);
709 exp
= build2 (COMPOUND_EXPR
, TREE_TYPE (exp
), temp_expr
, exp
);
710 exp
= build1 (CLEANUP_POINT_EXPR
, TREE_TYPE (exp
), exp
);
713 throw_type
= build_eh_type_type (prepare_eh_type (TREE_TYPE (object
)));
715 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TREE_TYPE (object
)))
717 cleanup
= lookup_fnfields (TYPE_BINFO (TREE_TYPE (object
)),
718 complete_dtor_identifier
, 0);
719 cleanup
= BASELINK_FUNCTIONS (cleanup
);
721 cxx_mark_addressable (cleanup
);
722 /* Pretend it's a normal function. */
723 cleanup
= build1 (ADDR_EXPR
, cleanup_type
, cleanup
);
726 cleanup
= build_int_cst (cleanup_type
, 0);
728 tmp
= tree_cons (NULL_TREE
, cleanup
, NULL_TREE
);
729 tmp
= tree_cons (NULL_TREE
, throw_type
, tmp
);
730 tmp
= tree_cons (NULL_TREE
, ptr
, tmp
);
731 /* ??? Indicate that this function call throws throw_type. */
732 tmp
= build_function_call (fn
, tmp
);
734 /* Tack on the initialization stuff. */
735 exp
= build2 (COMPOUND_EXPR
, TREE_TYPE (tmp
), exp
, tmp
);
739 /* Rethrow current exception. */
741 tree fn
= get_identifier ("__cxa_rethrow");
742 if (!get_global_value_if_present (fn
, &fn
))
744 /* Declare void __cxa_rethrow (void). */
745 fn
= push_throw_library_fn
746 (fn
, build_function_type (void_type_node
, void_list_node
));
749 /* ??? Indicate that this function call allows exceptions of the type
750 of the enclosing catch block (if known). */
751 exp
= build_function_call (fn
, NULL_TREE
);
754 exp
= build1 (THROW_EXPR
, void_type_node
, exp
);
759 /* Make sure TYPE is complete, pointer to complete, reference to
760 complete, or pointer to cv void. Issue diagnostic on failure.
761 Return the zero on failure and nonzero on success. FROM can be
762 the expr or decl from whence TYPE came, if available. */
765 complete_ptr_ref_or_void_ptr_p (tree type
, tree from
)
769 /* Check complete. */
770 type
= complete_type_or_else (type
, from
);
774 /* Or a pointer or ref to one, or cv void *. */
775 is_ptr
= TREE_CODE (type
) == POINTER_TYPE
;
776 if (is_ptr
|| TREE_CODE (type
) == REFERENCE_TYPE
)
778 tree core
= TREE_TYPE (type
);
780 if (is_ptr
&& VOID_TYPE_P (core
))
782 else if (!complete_type_or_else (core
, from
))
788 /* Return truth-value if EXPRESSION is admissible in throw-expression,
789 i.e. if it is not of incomplete type or a pointer/reference to such
790 a type or of an abstract class type. */
793 is_admissible_throw_operand (tree expr
)
795 tree type
= TREE_TYPE (expr
);
797 /* 15.1/4 [...] The type of the throw-expression shall not be an
798 incomplete type, or a pointer or a reference to an incomplete
799 type, other than void*, const void*, volatile void*, or
800 const volatile void*. Except for these restriction and the
801 restrictions on type matching mentioned in 15.3, the operand
802 of throw is treated exactly as a function argument in a call
803 (5.2.2) or the operand of a return statement. */
804 if (!complete_ptr_ref_or_void_ptr_p (type
, expr
))
807 /* 10.4/3 An abstract class shall not be used as a parameter type,
808 as a function return type or as type of an explicit
810 else if (CLASS_TYPE_P (type
) && CLASSTYPE_PURE_VIRTUALS (type
))
812 error ("expression %qE of abstract class type %qT cannot "
813 "be used in throw-expression", expr
, type
);
820 /* Returns nonzero if FN is a declaration of a standard C library
821 function which is known not to throw.
823 [lib.res.on.exception.handling]: None of the functions from the
824 Standard C library shall report an error by throwing an
825 exception, unless it calls a program-supplied function that
826 throws an exception. */
831 nothrow_libfn_p (tree fn
)
836 && DECL_EXTERNAL (fn
)
837 && DECL_NAMESPACE_SCOPE_P (fn
)
838 && DECL_EXTERN_C_P (fn
))
841 /* Can't be a C library function. */
844 /* Being a C library function, DECL_ASSEMBLER_NAME == DECL_NAME
845 unless the system headers are playing rename tricks, and if
846 they are, we don't want to be confused by them. */
848 return !!libc_name_p (IDENTIFIER_POINTER (id
), IDENTIFIER_LENGTH (id
));
851 /* Returns nonzero if an exception of type FROM will be caught by a
852 handler for type TO, as per [except.handle]. */
855 can_convert_eh (tree to
, tree from
)
857 to
= non_reference (to
);
858 from
= non_reference (from
);
860 if (TREE_CODE (to
) == POINTER_TYPE
&& TREE_CODE (from
) == POINTER_TYPE
)
863 from
= TREE_TYPE (from
);
865 if (! at_least_as_qualified_p (to
, from
))
868 if (TREE_CODE (to
) == VOID_TYPE
)
871 /* Else fall through. */
874 if (CLASS_TYPE_P (to
) && CLASS_TYPE_P (from
)
875 && PUBLICLY_UNIQUELY_DERIVED_P (to
, from
))
881 /* Check whether any of the handlers in I are shadowed by another handler
882 accepting TYPE. Note that the shadowing may not be complete; even if
883 an exception of type B would be caught by a handler for A, there could
884 be a derived class C for which A is an ambiguous base but B is not, so
885 the handler for B would catch an exception of type C. */
888 check_handlers_1 (tree master
, tree_stmt_iterator i
)
890 tree type
= TREE_TYPE (master
);
892 for (; !tsi_end_p (i
); tsi_next (&i
))
894 tree handler
= tsi_stmt (i
);
895 if (TREE_TYPE (handler
) && can_convert_eh (type
, TREE_TYPE (handler
)))
897 warning ("%Hexception of type %qT will be caught",
898 EXPR_LOCUS (handler
), TREE_TYPE (handler
));
899 warning ("%H by earlier handler for %qT",
900 EXPR_LOCUS (master
), type
);
906 /* Given a STATEMENT_LIST of HANDLERs, make sure that they're OK. */
909 check_handlers (tree handlers
)
911 tree_stmt_iterator i
;
913 /* If we don't have a STATEMENT_LIST, then we've just got one
914 handler, and thus nothing to warn about. */
915 if (TREE_CODE (handlers
) != STATEMENT_LIST
)
918 i
= tsi_start (handlers
);
922 tree handler
= tsi_stmt (i
);
925 /* No more handlers; nothing to shadow. */
928 if (TREE_TYPE (handler
) == NULL_TREE
)
929 pedwarn ("%H%<...%> handler must be the last handler for"
930 " its try block", EXPR_LOCUS (handler
));
932 check_handlers_1 (handler
, i
);