| // Copyright 2018 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef SRC_DEVELOPER_DEBUG_ZXDB_EXPR_FOUND_MEMBER_H_ |
| #define SRC_DEVELOPER_DEBUG_ZXDB_EXPR_FOUND_MEMBER_H_ |
| |
| #include <stdint.h> |
| |
| #include "src/developer/debug/zxdb/symbols/data_member.h" |
| #include "src/developer/debug/zxdb/symbols/inheritance_path.h" |
| #include "src/lib/fxl/memory/ref_ptr.h" |
| |
| namespace zxdb { |
| |
| // The result of finding a member in a collection. |
| // |
| // This class consists of a DataMember and how to find it from a given class. |
| // |
| // To actually resolve the value when the data_member is not static, the containing object needs to |
| // be known. Typically one would have an object, find a member on it (producing a FoundMember), and |
| // then use that object and the FoundMember to resolve its value. |
| // |
| // If the data member is static data_member()->is_external() will be set. |
| class FoundMember { |
| public: |
| FoundMember(); |
| |
| // Constructs from a data member on a class with no inheritance. This means the DataMember must be |
| // a direct member of the collection it's referring to. |
| // |
| // The collection can be null for static data members. |
| FoundMember(const Collection* collection, const DataMember* data_member); |
| |
| // Constructs from a data member and an object path. |
| FoundMember(InheritancePath path, const DataMember* data_member); |
| |
| ~FoundMember(); |
| |
| bool is_null() const { return !data_member_; } |
| |
| // The inheritance path is used to find the member data only for nonstatic members. |
| // |
| // Static members will have data_member()->is_external() set and the expression will not depend on |
| // the object. In this case, the object_path() will be empty. |
| // |
| // This path can contain synthetic items not strictly in the inheritance tree in the case of |
| // anonymous structs or unions. An InheritedFrom object will be synthesized to represent the |
| // offset of the anonymous struct/union in its enclosing collection. |
| const InheritancePath& object_path() const { return object_path_; } |
| |
| // Variable member of the object_var_ that this class represents. Can be null to represent |
| // "not found". Check is_null(). |
| // |
| // NOTE: that this DataMember isn't necessarily a member of the original object that was queried. |
| // It could be on a base class. In this case, the offset specified on the DataMember data member |
| // will be incorrect since it refers to the offset within its enclosing class. Therefore, one |
| // should always use the data_member_offset_ below. |
| const DataMember* data_member() const { return data_member_.get(); } |
| fxl::RefPtr<DataMember> data_member_ref() const { return data_member_; } |
| |
| // Helper to extract the offset of the data member in the class. This can fail if there is virtual |
| // inheritance or the data member is static (in both cases the data member isn't at a fixed |
| // offset from the collection). |
| std::optional<uint32_t> GetDataMemberOffset() const; |
| |
| private: |
| // See documentation above. |
| InheritancePath object_path_; |
| fxl::RefPtr<DataMember> data_member_; |
| }; |
| |
| } // namespace zxdb |
| |
| #endif // SRC_DEVELOPER_DEBUG_ZXDB_EXPR_FOUND_MEMBER_H_ |