2946cd7010
to reflect the new license. We understand that people may be surprised that we're moving the header entirely to discuss the new license. We checked this carefully with the Foundation's lawyer and we believe this is the correct approach. Essentially, all code in the project is now made available by the LLVM project under our new license, so you will see that the license headers include that license only. Some of our contributors have contributed code under our old license, and accordingly, we have retained a copy of our old license notice in the top-level files in each project and repository. llvm-svn: 351636
96 lines
2.8 KiB
C++
96 lines
2.8 KiB
C++
//===- Core/SymbolTable.h - Main Symbol Table -----------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLD_CORE_SYMBOL_TABLE_H
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#define LLD_CORE_SYMBOL_TABLE_H
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#include "lld/Common/LLVM.h"
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#include "llvm/ADT/DenseSet.h"
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#include "llvm/Support/DJB.h"
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#include <cstring>
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#include <map>
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#include <vector>
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namespace lld {
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class AbsoluteAtom;
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class Atom;
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class DefinedAtom;
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class LinkingContext;
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class ResolverOptions;
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class SharedLibraryAtom;
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class UndefinedAtom;
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/// The SymbolTable class is responsible for coalescing atoms.
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///
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/// All atoms coalescable by-name or by-content should be added.
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/// The method replacement() can be used to find the replacement atom
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/// if an atom has been coalesced away.
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class SymbolTable {
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public:
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/// add atom to symbol table
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bool add(const DefinedAtom &);
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/// add atom to symbol table
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bool add(const UndefinedAtom &);
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/// add atom to symbol table
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bool add(const SharedLibraryAtom &);
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/// add atom to symbol table
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bool add(const AbsoluteAtom &);
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/// returns atom in symbol table for specified name (or nullptr)
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const Atom *findByName(StringRef sym);
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/// returns vector of remaining UndefinedAtoms
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std::vector<const UndefinedAtom *> undefines();
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/// if atom has been coalesced away, return replacement, else return atom
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const Atom *replacement(const Atom *);
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/// if atom has been coalesced away, return true
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bool isCoalescedAway(const Atom *);
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private:
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typedef llvm::DenseMap<const Atom *, const Atom *> AtomToAtom;
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struct StringRefMappingInfo {
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static StringRef getEmptyKey() { return StringRef(); }
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static StringRef getTombstoneKey() { return StringRef(" ", 1); }
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static unsigned getHashValue(StringRef const val) {
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return llvm::djbHash(val, 0);
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}
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static bool isEqual(StringRef const lhs, StringRef const rhs) {
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return lhs.equals(rhs);
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}
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};
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typedef llvm::DenseMap<StringRef, const Atom *,
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StringRefMappingInfo> NameToAtom;
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struct AtomMappingInfo {
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static const DefinedAtom * getEmptyKey() { return nullptr; }
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static const DefinedAtom * getTombstoneKey() { return (DefinedAtom*)(-1); }
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static unsigned getHashValue(const DefinedAtom * const Val);
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static bool isEqual(const DefinedAtom * const LHS,
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const DefinedAtom * const RHS);
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};
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typedef llvm::DenseSet<const DefinedAtom*, AtomMappingInfo> AtomContentSet;
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bool addByName(const Atom &);
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bool addByContent(const DefinedAtom &);
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AtomToAtom _replacedAtoms;
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NameToAtom _nameTable;
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AtomContentSet _contentTable;
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};
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} // namespace lld
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#endif // LLD_CORE_SYMBOL_TABLE_H
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