1 //===- Core/SharedLibraryAtom.h - A Shared Library Atom -------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef LLD_CORE_SHARED_LIBRARY_ATOM_H 10 #define LLD_CORE_SHARED_LIBRARY_ATOM_H 11 12 #include "lld/Core/Atom.h" 13 14 namespace lld { 15 16 /// A SharedLibraryAtom has no content. 17 /// It exists to represent a symbol which will be bound at runtime. 18 class SharedLibraryAtom : public Atom { 19 public: 20 enum class Type : uint32_t { 21 Unknown, 22 Code, 23 Data, 24 }; 25 26 /// Returns shared library name used to load it at runtime. 27 /// On Darwin it is the LC_DYLIB_LOAD dylib name. 28 virtual StringRef loadName() const = 0; 29 30 /// Returns if shared library symbol can be missing at runtime and if 31 /// so the loader should silently resolve address of symbol to be nullptr. 32 virtual bool canBeNullAtRuntime() const = 0; 33 34 virtual Type type() const = 0; 35 36 virtual uint64_t size() const = 0; 37 classof(const Atom * a)38 static bool classof(const Atom *a) { 39 return a->definition() == definitionSharedLibrary; 40 } 41 classof(const SharedLibraryAtom *)42 static inline bool classof(const SharedLibraryAtom *) { return true; } 43 44 protected: SharedLibraryAtom()45 SharedLibraryAtom() : Atom(definitionSharedLibrary) {} 46 47 ~SharedLibraryAtom() override = default; 48 }; 49 50 } // namespace lld 51 52 #endif // LLD_CORE_SHARED_LIBRARY_ATOM_H 53