--- /dev/null
+// Copyright (C) 1994, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2007, 2009
+// Free Software Foundation
+//
+// This file is part of GCC.
+//
+// GCC is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// GCC is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+// <http://www.gnu.org/licenses/>.
+
+#include "tinfo.h"
+
+namespace __cxxabiv1 {
+
+__vmi_class_type_info::
+~__vmi_class_type_info ()
+{}
+
+__class_type_info::__sub_kind __vmi_class_type_info::
+__do_find_public_src (ptrdiff_t src2dst,
+ const void *obj_ptr,
+ const __class_type_info *src_type,
+ const void *src_ptr) const
+{
+ if (obj_ptr == src_ptr && *this == *src_type)
+ return __contained_public;
+
+ for (std::size_t i = __base_count; i--;)
+ {
+ if (!__base_info[i].__is_public_p ())
+ continue; // Not public, can't be here.
+
+ const void *base = obj_ptr;
+ ptrdiff_t offset = __base_info[i].__offset ();
+ bool is_virtual = __base_info[i].__is_virtual_p ();
+
+ if (is_virtual)
+ {
+ if (src2dst == -3)
+ continue; // Not a virtual base, so can't be here.
+ }
+ base = convert_to_base (base, is_virtual, offset);
+
+ __sub_kind base_kind = __base_info[i].__base_type->__do_find_public_src
+ (src2dst, base, src_type, src_ptr);
+ if (contained_p (base_kind))
+ {
+ if (is_virtual)
+ base_kind = __sub_kind (base_kind | __contained_virtual_mask);
+ return base_kind;
+ }
+ }
+
+ return __not_contained;
+}
+
+// This is a big hairy function. Although the run-time behaviour of
+// dynamic_cast is simple to describe, it gives rise to some non-obvious
+// behaviour. We also desire to determine as early as possible any definite
+// answer we can get. Because it is unknown what the run-time ratio of
+// succeeding to failing dynamic casts is, we do not know in which direction
+// to bias any optimizations. To that end we make no particular effort towards
+// early fail answers or early success answers. Instead we try to minimize
+// work by filling in things lazily (when we know we need the information),
+// and opportunisticly take early success or failure results.
+bool __vmi_class_type_info::
+__do_dyncast (ptrdiff_t src2dst,
+ __sub_kind access_path,
+ const __class_type_info *dst_type,
+ const void *obj_ptr,
+ const __class_type_info *src_type,
+ const void *src_ptr,
+ __dyncast_result &__restrict result) const
+{
+ if (result.whole_details & __flags_unknown_mask)
+ result.whole_details = __flags;
+
+ if (obj_ptr == src_ptr && *this == *src_type)
+ {
+ // The src object we started from. Indicate how we are accessible from
+ // the most derived object.
+ result.whole2src = access_path;
+ return false;
+ }
+ if (*this == *dst_type)
+ {
+ result.dst_ptr = obj_ptr;
+ result.whole2dst = access_path;
+ if (src2dst >= 0)
+ result.dst2src = adjust_pointer <void> (obj_ptr, src2dst) == src_ptr
+ ? __contained_public : __not_contained;
+ else if (src2dst == -2)
+ result.dst2src = __not_contained;
+ return false;
+ }
+
+ bool result_ambig = false;
+ for (std::size_t i = __base_count; i--;)
+ {
+ __dyncast_result result2 (result.whole_details);
+ void const *base = obj_ptr;
+ __sub_kind base_access = access_path;
+ ptrdiff_t offset = __base_info[i].__offset ();
+ bool is_virtual = __base_info[i].__is_virtual_p ();
+
+ if (is_virtual)
+ base_access = __sub_kind (base_access | __contained_virtual_mask);
+ base = convert_to_base (base, is_virtual, offset);
+
+ if (!__base_info[i].__is_public_p ())
+ {
+ if (src2dst == -2 &&
+ !(result.whole_details
+ & (__non_diamond_repeat_mask | __diamond_shaped_mask)))
+ // The hierarchy has no duplicate bases (which might ambiguate
+ // things) and where we started is not a public base of what we
+ // want (so it cannot be a downcast). There is nothing of interest
+ // hiding in a non-public base.
+ continue;
+ base_access = __sub_kind (base_access & ~__contained_public_mask);
+ }
+
+ bool result2_ambig
+ = __base_info[i].__base_type->__do_dyncast (src2dst, base_access,
+ dst_type, base,
+ src_type, src_ptr, result2);
+ result.whole2src = __sub_kind (result.whole2src | result2.whole2src);
+ if (result2.dst2src == __contained_public
+ || result2.dst2src == __contained_ambig)
+ {
+ result.dst_ptr = result2.dst_ptr;
+ result.whole2dst = result2.whole2dst;
+ result.dst2src = result2.dst2src;
+ // Found a downcast which can't be bettered or an ambiguous downcast
+ // which can't be disambiguated
+ return result2_ambig;
+ }
+
+ if (!result_ambig && !result.dst_ptr)
+ {
+ // Not found anything yet.
+ result.dst_ptr = result2.dst_ptr;
+ result.whole2dst = result2.whole2dst;
+ result_ambig = result2_ambig;
+ if (result.dst_ptr && result.whole2src != __unknown
+ && !(__flags & __non_diamond_repeat_mask))
+ // Found dst and src and we don't have repeated bases.
+ return result_ambig;
+ }
+ else if (result.dst_ptr && result.dst_ptr == result2.dst_ptr)
+ {
+ // Found at same address, must be via virtual. Pick the most
+ // accessible path.
+ result.whole2dst =
+ __sub_kind (result.whole2dst | result2.whole2dst);
+ }
+ else if ((result.dst_ptr != 0 && result2.dst_ptr != 0)
+ || (result.dst_ptr != 0 && result2_ambig)
+ || (result2.dst_ptr != 0 && result_ambig))
+ {
+ // Found two different DST_TYPE bases, or a valid one and a set of
+ // ambiguous ones, must disambiguate. See whether SRC_PTR is
+ // contained publicly within one of the non-ambiguous choices. If it
+ // is in only one, then that's the choice. If it is in both, then
+ // we're ambiguous and fail. If it is in neither, we're ambiguous,
+ // but don't yet fail as we might later find a third base which does
+ // contain SRC_PTR.
+
+ __sub_kind new_sub_kind = result2.dst2src;
+ __sub_kind old_sub_kind = result.dst2src;
+
+ if (contained_p (result.whole2src)
+ && (!virtual_p (result.whole2src)
+ || !(result.whole_details & __diamond_shaped_mask)))
+ {
+ // We already found SRC_PTR as a base of most derived, and
+ // either it was non-virtual, or the whole hierarchy is
+ // not-diamond shaped. Therefore if it is in either choice, it
+ // can only be in one of them, and we will already know.
+ if (old_sub_kind == __unknown)
+ old_sub_kind = __not_contained;
+ if (new_sub_kind == __unknown)
+ new_sub_kind = __not_contained;
+ }
+ else
+ {
+ if (old_sub_kind >= __not_contained)
+ ;// already calculated
+ else if (contained_p (new_sub_kind)
+ && (!virtual_p (new_sub_kind)
+ || !(__flags & __diamond_shaped_mask)))
+ // Already found inside the other choice, and it was
+ // non-virtual or we are not diamond shaped.
+ old_sub_kind = __not_contained;
+ else
+ old_sub_kind = dst_type->__find_public_src
+ (src2dst, result.dst_ptr, src_type, src_ptr);
+
+ if (new_sub_kind >= __not_contained)
+ ;// already calculated
+ else if (contained_p (old_sub_kind)
+ && (!virtual_p (old_sub_kind)
+ || !(__flags & __diamond_shaped_mask)))
+ // Already found inside the other choice, and it was
+ // non-virtual or we are not diamond shaped.
+ new_sub_kind = __not_contained;
+ else
+ new_sub_kind = dst_type->__find_public_src
+ (src2dst, result2.dst_ptr, src_type, src_ptr);
+ }
+
+ // Neither sub_kind can be contained_ambig -- we bail out early
+ // when we find those.
+ if (contained_p (__sub_kind (new_sub_kind ^ old_sub_kind)))
+ {
+ // Only on one choice, not ambiguous.
+ if (contained_p (new_sub_kind))
+ {
+ // Only in new.
+ result.dst_ptr = result2.dst_ptr;
+ result.whole2dst = result2.whole2dst;
+ result_ambig = false;
+ old_sub_kind = new_sub_kind;
+ }
+ result.dst2src = old_sub_kind;
+ if (public_p (result.dst2src))
+ return false; // Can't be an ambiguating downcast for later discovery.
+ if (!virtual_p (result.dst2src))
+ return false; // Found non-virtually can't be bettered
+ }
+ else if (contained_p (__sub_kind (new_sub_kind & old_sub_kind)))
+ {
+ // In both.
+ result.dst_ptr = NULL;
+ result.dst2src = __contained_ambig;
+ return true; // Fail.
+ }
+ else
+ {
+ // In neither publicly, ambiguous for the moment, but keep
+ // looking. It is possible that it was private in one or
+ // both and therefore we should fail, but that's just tough.
+ result.dst_ptr = NULL;
+ result.dst2src = __not_contained;
+ result_ambig = true;
+ }
+ }
+
+ if (result.whole2src == __contained_private)
+ // We found SRC_PTR as a private non-virtual base, therefore all
+ // cross casts will fail. We have already found a down cast, if
+ // there is one.
+ return result_ambig;
+ }
+
+ return result_ambig;
+}
+
+bool __vmi_class_type_info::
+__do_upcast (const __class_type_info *dst, const void *obj_ptr,
+ __upcast_result &__restrict result) const
+{
+ if (__class_type_info::__do_upcast (dst, obj_ptr, result))
+ return true;
+
+ int src_details = result.src_details;
+ if (src_details & __flags_unknown_mask)
+ src_details = __flags;
+
+ for (std::size_t i = __base_count; i--;)
+ {
+ __upcast_result result2 (src_details);
+ const void *base = obj_ptr;
+ ptrdiff_t offset = __base_info[i].__offset ();
+ bool is_virtual = __base_info[i].__is_virtual_p ();
+ bool is_public = __base_info[i].__is_public_p ();
+
+ if (!is_public && !(src_details & __non_diamond_repeat_mask))
+ // original cannot have an ambiguous base, so skip private bases
+ continue;
+
+ if (base)
+ base = convert_to_base (base, is_virtual, offset);
+
+ if (__base_info[i].__base_type->__do_upcast (dst, base, result2))
+ {
+ if (result2.base_type == nonvirtual_base_type && is_virtual)
+ result2.base_type = __base_info[i].__base_type;
+ if (contained_p (result2.part2dst) && !is_public)
+ result2.part2dst = __sub_kind (result2.part2dst & ~__contained_public_mask);
+
+ if (!result.base_type)
+ {
+ result = result2;
+ if (!contained_p (result.part2dst))
+ return true; // found ambiguously
+
+ if (result.part2dst & __contained_public_mask)
+ {
+ if (!(__flags & __non_diamond_repeat_mask))
+ return true; // cannot have an ambiguous other base
+ }
+ else
+ {
+ if (!virtual_p (result.part2dst))
+ return true; // cannot have another path
+ if (!(__flags & __diamond_shaped_mask))
+ return true; // cannot have a more accessible path
+ }
+ }
+ else if (result.dst_ptr != result2.dst_ptr)
+ {
+ // Found an ambiguity.
+ result.dst_ptr = NULL;
+ result.part2dst = __contained_ambig;
+ return true;
+ }
+ else if (result.dst_ptr)
+ {
+ // Ok, found real object via a virtual path.
+ result.part2dst
+ = __sub_kind (result.part2dst | result2.part2dst);
+ }
+ else
+ {
+ // Dealing with a null pointer, need to check vbase
+ // containing each of the two choices.
+ if (result2.base_type == nonvirtual_base_type
+ || result.base_type == nonvirtual_base_type
+ || !(*result2.base_type == *result.base_type))
+ {
+ // Already ambiguous, not virtual or via different virtuals.
+ // Cannot match.
+ result.part2dst = __contained_ambig;
+ return true;
+ }
+ result.part2dst
+ = __sub_kind (result.part2dst | result2.part2dst);
+ }
+ }
+ }
+ return result.part2dst != __unknown;
+}
+
+}
projects / msp430-gcc.git / blobdiff