diff options
| -rw-r--r-- | libcxxabi/src/private_typeinfo.cpp | 211 |
1 files changed, 172 insertions, 39 deletions
diff --git a/libcxxabi/src/private_typeinfo.cpp b/libcxxabi/src/private_typeinfo.cpp index 7b3ab5bc24e..eb8974940c0 100644 --- a/libcxxabi/src/private_typeinfo.cpp +++ b/libcxxabi/src/private_typeinfo.cpp @@ -132,7 +132,29 @@ int __class_type_info::search2(__dynamic_cast_info* info, const void* dynamic_ptr, int path_below) const { - if (this == info->dst_type) +#ifdef DEBUG +std::cout << "__class_type_info::search2\n"; +#endif + if (this == info->static_type) + { + if (dynamic_ptr == info->static_ptr) + { + // It is possible to get here more than once. Record the + // "most public" path to here + if (info->above_dst_ptr) + { + if (info->path_dst_ptr_to_static_ptr != public_path) + info->path_dst_ptr_to_static_ptr = path_below; + } + else // not above a dst_type + { + if (info->path_dynamic_ptr_to_static_ptr != public_path) + info->path_dynamic_ptr_to_static_ptr = path_below; + } + info->found_static_ptr = true; + } + } + else if (this == info->dst_type) { if (dynamic_ptr == info->dst_ptr_not_leading_to_static_ptr) { @@ -144,16 +166,14 @@ __class_type_info::search2(__dynamic_cast_info* info, const void* dynamic_ptr, info->path_dynamic_ptr_to_dst_ptr = path_below; info->dst_ptr_not_leading_to_static_ptr = dynamic_ptr; info->number_to_dst_ptr += 1; + // If there exists another dst with a private path to + // (static_ptr, static_type), then the cast from + // (dynamic_ptr, dynamic_type) to dst_type is now ambiguous. + if (info->number_to_static_ptr == 1 && + info->path_dst_ptr_to_static_ptr == not_public_path) + return 0; } } - else if (this == info->static_type && dynamic_ptr == info->static_ptr) - { - if (info->above_dst_ptr) - info->path_dst_ptr_to_static_ptr = path_below; - else if (info->path_dynamic_ptr_to_static_ptr != public_path) - info->path_dynamic_ptr_to_static_ptr = path_below; - info->found_static_ptr = true; - } return 1; } @@ -200,6 +220,29 @@ int __si_class_type_info::search2(__dynamic_cast_info* info, const void* dynamic_ptr, int path_below) const { +#ifdef DEBUG +std::cout << "__si_class_type_info::search2\n"; +#endif + if (this == info->static_type) + { + if (dynamic_ptr == info->static_ptr) + { + // It is possible to get here more than once. Record the + // "most public" path to here + if (info->above_dst_ptr) + { + if (info->path_dst_ptr_to_static_ptr != public_path) + info->path_dst_ptr_to_static_ptr = path_below; + } + else // not above a dst_type + { + if (info->path_dynamic_ptr_to_static_ptr != public_path) + info->path_dynamic_ptr_to_static_ptr = path_below; + } + info->found_static_ptr = true; + } + return 1; + } if (this == info->dst_type) { if (dynamic_ptr == info->dst_ptr_leading_to_static_ptr || @@ -219,22 +262,29 @@ __si_class_type_info::search2(__dynamic_cast_info* info, const void* dynamic_ptr info->found_static_ptr = false; info->dst_ptr_leading_to_static_ptr = dynamic_ptr; info->number_to_static_ptr += 1; - return info->number_to_static_ptr == 1; + // If more than one dst_type points to (static_ptr, static_type) + // then the cast is ambiguous so abort search. + if (info->number_to_static_ptr != 1) + return 0; + // If the path above to (static_ptr, static_type) isn't public + // and if other dst_type's have been found, even if they + // don't point to (static_ptr, static_type), then upcast + // from (dynamic_ptr, dynamic_type) to dst_type is ambiguous. + if (info->path_dst_ptr_to_static_ptr != public_path && + info->number_to_dst_ptr != 0) + return 0; + } + else + { + info->dst_ptr_not_leading_to_static_ptr = dynamic_ptr; + info->number_to_dst_ptr += 1; + // If there exists another dst with a private path to + // (static_ptr, static_type), then the cast from + // (dynamic_ptr, dynamic_type) to dst_type is now ambiguous. + if (info->number_to_static_ptr == 1 && + info->path_dst_ptr_to_static_ptr == not_public_path) + return 0; } - info->dst_ptr_not_leading_to_static_ptr = dynamic_ptr; - info->number_to_dst_ptr += 1; - } - return 1; - } - else if (this == info->static_type) - { - if (dynamic_ptr == info->static_ptr) - { - if (info->above_dst_ptr) - info->path_dst_ptr_to_static_ptr = path_below; - else if (info->path_dynamic_ptr_to_static_ptr != public_path) - info->path_dynamic_ptr_to_static_ptr = path_below; - info->found_static_ptr = true; } return 1; } @@ -278,7 +328,8 @@ __vmi_class_type_info::search1(__dynamic_cast_info* info, const void* dynamic_pt } return 1; } - for (Iter p = __base_info, e = __base_info + __base_count; p < e; ++p) + const Iter e = __base_info + __base_count; + for (Iter p = __base_info; p < e; ++p) { int r = p->search1(info, dynamic_ptr, path_below); if (r == 0) @@ -296,59 +347,138 @@ int __vmi_class_type_info::search2(__dynamic_cast_info* info, const void* dynamic_ptr, int path_below) const { +#ifdef DEBUG +std::cout << "__vmi_class_type_info::search2\n"; +#endif typedef const __base_class_type_info* Iter; + if (this == info->static_type) + { + if (dynamic_ptr == info->static_ptr) + { + // It is possible to get here more than once. Record the + // "most public" path to here + if (info->above_dst_ptr) + { + if (info->path_dst_ptr_to_static_ptr != public_path) + info->path_dst_ptr_to_static_ptr = path_below; + } + else // not above a dst_type + { + if (info->path_dynamic_ptr_to_static_ptr != public_path) + info->path_dynamic_ptr_to_static_ptr = path_below; + } + info->found_static_ptr = true; + } + return 1; + } if (this == info->dst_type) { + // If we've been here before if (dynamic_ptr == info->dst_ptr_leading_to_static_ptr || dynamic_ptr == info->dst_ptr_not_leading_to_static_ptr) { + // Then make a note if we can get here publicly if (path_below == public_path) info->path_dynamic_ptr_to_dst_ptr = public_path; } - else + else // We have haven't been here before { + // Record the access path that got us here info->path_dynamic_ptr_to_dst_ptr = path_below; - for (Iter p = __base_info, e = __base_info + __base_count; p < e; ++p) + // Explore each base above + const Iter e = __base_info + __base_count; + for (Iter p = __base_info; p < e; ++p) { + // Let above nodes know that they are above a dst_type node info->above_dst_ptr = true; // Only a dst_type can abort the search, and one can't be // above here. So it is safe to ignore return. (void)p->search2(info, dynamic_ptr, public_path); info->above_dst_ptr = false; + // If we found (static_ptr, static_type) if (info->found_static_ptr) { info->found_static_ptr = false; info->dst_ptr_leading_to_static_ptr = dynamic_ptr; info->number_to_static_ptr += 1; + // If more than one dst_type points to (static_ptr, static_type) + // then the cast is ambiguous so abort search. if (info->number_to_static_ptr != 1) return 0; + // If the path above to (static_ptr, static_type) isn't public + // and if other dst_type's have been found, even if they + // don't point to (static_ptr, static_type), then upcast + // from (dynamic_ptr, dynamic_type) to dst_type is ambiguous. + if (info->path_dst_ptr_to_static_ptr != public_path && + info->number_to_dst_ptr != 0) + return 0; } else { info->dst_ptr_not_leading_to_static_ptr = dynamic_ptr; info->number_to_dst_ptr += 1; + // If there exists another dst with a private path to + // (static_ptr, static_type), then the cast from + // (dynamic_ptr, dynamic_type) to dst_type is now ambiguous. + if (info->number_to_static_ptr == 1 && + info->path_dst_ptr_to_static_ptr == not_public_path) + return 0; } } } return 1; } - else if (this == info->static_type) + const Iter e = __base_info + __base_count; + // If you find a dst_type and __non_diamond_repeat_mask is not set, then + // there is only one dst_type under here. + // If you find a static_type and __diamond_shaped_mask is not set, then + // the static_type is the base of only one object. + if ((__flags & __diamond_shaped_mask) || info->number_to_static_ptr == 1) { - if (dynamic_ptr == info->static_ptr) + for (Iter p = __base_info; p < e; ++p) { - if (info->above_dst_ptr) - info->path_dst_ptr_to_static_ptr = path_below; - else if (info->path_dynamic_ptr_to_static_ptr != public_path) - info->path_dynamic_ptr_to_static_ptr = path_below; - info->found_static_ptr = true; + if (p->search2(info, dynamic_ptr, path_below) == 0) + return 0; } - return 1; } - for (Iter p = __base_info, e = __base_info + __base_count; p < e; ++p) + else if (__flags & __non_diamond_repeat_mask) { - int r = p->search2(info, dynamic_ptr, path_below); - if (r == 0) - return 0; + // There are no nodes with multiple parents above this node. + for (Iter p = __base_info; p < e; ++p) + { + if (p->search2(info, dynamic_ptr, path_below) == 0) + return 0; + // If we just found a dst_type with a public path to (static_ptr, static_type), + // then the only reason to continue the search is to make sure sure + // no other dst_type points to (static_ptr, static_type). + // If !diamond, then we don't need to search here. + if (info->number_to_static_ptr == 1 && + info->path_dst_ptr_to_static_ptr == public_path) + break; + } + } + else + { + // There are no repeated types above this node. + // There are no nodes with multiple parents above this node. + // no dst_type has been found to (static_ptr, static_type) or + // if it has been found, it has a public path. + for (Iter p = __base_info; p < e; ++p) + { + if (p->search2(info, dynamic_ptr, path_below) == 0) + return 0; + // If we just found a dst_type with a public path to (static_ptr, static_type), + // then the only reason to continue the search is to make sure sure + // no other dst_type points to (static_ptr, static_type). + // If !diamond, then we don't need to search here. + // if we just found a dst_type with a private path to (static_ptr, static_type), + // then we're only looking for a path to (static_ptr, static_type) + // and to check for other dst_types. + // If !diamond & !repeat, then there is not a pointer to (static_ptr, static_type) + // and not a dst_type under here. + if (info->number_to_static_ptr == 1) + break; + } } return 1; } @@ -386,6 +516,9 @@ int __base_class_type_info::search2(__dynamic_cast_info* info, const void* dynamic_ptr, int path_below) const { +#ifdef DEBUG +std::cout << "__base_class_type_info::search2\n"; +#endif ptrdiff_t offset_to_base = __offset_flags >> __offset_shift; if (__offset_flags & __virtual_mask) { |
