| //===- Core/SymbolTable.h - Main Symbol Table -----------------------------===// |
| // |
| // The LLVM Linker |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLD_CORE_SYMBOL_TABLE_H |
| #define LLD_CORE_SYMBOL_TABLE_H |
| |
| #include "lld/Core/LLVM.h" |
| #include "llvm/ADT/DenseSet.h" |
| #include "llvm/ADT/StringExtras.h" |
| #include <cstring> |
| #include <map> |
| #include <vector> |
| |
| namespace lld { |
| |
| class AbsoluteAtom; |
| class Atom; |
| class DefinedAtom; |
| class LinkingContext; |
| class ResolverOptions; |
| class SharedLibraryAtom; |
| class UndefinedAtom; |
| |
| /// \brief The SymbolTable class is responsible for coalescing atoms. |
| /// |
| /// All atoms coalescable by-name or by-content should be added. |
| /// The method replacement() can be used to find the replacement atom |
| /// if an atom has been coalesced away. |
| class SymbolTable { |
| public: |
| explicit SymbolTable(LinkingContext &); |
| |
| /// @brief add atom to symbol table |
| bool add(const DefinedAtom &); |
| |
| /// @brief add atom to symbol table |
| bool add(const UndefinedAtom &); |
| |
| /// @brief add atom to symbol table |
| bool add(const SharedLibraryAtom &); |
| |
| /// @brief add atom to symbol table |
| bool add(const AbsoluteAtom &); |
| |
| /// @brief checks if name is in symbol table and if so atom is not |
| /// UndefinedAtom |
| bool isDefined(StringRef sym); |
| |
| /// @brief returns atom in symbol table for specified name (or nullptr) |
| const Atom *findByName(StringRef sym); |
| |
| /// @brief returns vector of remaining UndefinedAtoms |
| std::vector<const UndefinedAtom *> undefines(); |
| |
| /// returns vector of tentative definitions |
| std::vector<StringRef> tentativeDefinitions(); |
| |
| /// @brief add atom to replacement table |
| void addReplacement(const Atom *replaced, const Atom *replacement); |
| |
| /// @brief if atom has been coalesced away, return replacement, else return atom |
| const Atom *replacement(const Atom *); |
| |
| /// @brief if atom has been coalesced away, return true |
| bool isCoalescedAway(const Atom *); |
| |
| /// @brief Find a group atom. |
| const Atom *findGroup(StringRef name); |
| |
| /// @brief Add a group atom and returns true/false depending on whether the |
| /// previously existed. |
| bool addGroup(const DefinedAtom &da); |
| |
| private: |
| typedef llvm::DenseMap<const Atom *, const Atom *> AtomToAtom; |
| |
| struct StringRefMappingInfo { |
| static StringRef getEmptyKey() { return StringRef(); } |
| static StringRef getTombstoneKey() { return StringRef(" ", 1); } |
| static unsigned getHashValue(StringRef const val) { |
| return llvm::HashString(val); |
| } |
| static bool isEqual(StringRef const lhs, StringRef const rhs) { |
| return lhs.equals(rhs); |
| } |
| }; |
| typedef llvm::DenseMap<StringRef, const Atom *, |
| StringRefMappingInfo> NameToAtom; |
| |
| struct AtomMappingInfo { |
| static const DefinedAtom * getEmptyKey() { return nullptr; } |
| static const DefinedAtom * getTombstoneKey() { return (DefinedAtom*)(-1); } |
| static unsigned getHashValue(const DefinedAtom * const Val); |
| static bool isEqual(const DefinedAtom * const LHS, |
| const DefinedAtom * const RHS); |
| }; |
| typedef llvm::DenseSet<const DefinedAtom*, AtomMappingInfo> AtomContentSet; |
| |
| bool addByName(const Atom &); |
| bool addByContent(const DefinedAtom &); |
| |
| LinkingContext &_ctx; |
| AtomToAtom _replacedAtoms; |
| NameToAtom _nameTable; |
| NameToAtom _groupTable; |
| AtomContentSet _contentTable; |
| }; |
| |
| } // namespace lld |
| |
| #endif // LLD_CORE_SYMBOL_TABLE_H |