31d5885842
This diff adds support for weak definitions, though it doesn't handle weak symbols in dylibs quite correctly -- we need to emit binding opcodes for them in the weak binding section rather than the lazy binding section. What *is* covered in this diff: 1. Reading the weak flag from symbol table / export trie, and writing it to the export trie 2. Refining the symbol table's rules for choosing one symbol definition over another. Wrote a few dozen test cases to make sure we were matching ld64's behavior. We can now link basic C++ programs. Reviewed By: #lld-macho, compnerd Differential Revision: https://reviews.llvm.org/D83532
58 lines
1.6 KiB
C++
58 lines
1.6 KiB
C++
//===- SymbolTable.h --------------------------------------------*- C++ -*-===//
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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_MACHO_SYMBOL_TABLE_H
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#define LLD_MACHO_SYMBOL_TABLE_H
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#include "lld/Common/LLVM.h"
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#include "llvm/ADT/CachedHashString.h"
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#include "llvm/ADT/DenseMap.h"
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#include "llvm/Object/Archive.h"
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namespace lld {
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namespace macho {
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class ArchiveFile;
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class DylibFile;
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class InputSection;
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class Symbol;
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/*
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* Note that the SymbolTable handles name collisions by calling
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* replaceSymbol(), which does an in-place update of the Symbol via `placement
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* new`. Therefore, there is no need to update any relocations that hold
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* pointers the "old" Symbol -- they will automatically point to the new one.
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*/
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class SymbolTable {
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public:
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Symbol *addDefined(StringRef name, InputSection *isec, uint32_t value,
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bool isWeakDef);
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Symbol *addUndefined(StringRef name);
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Symbol *addDylib(StringRef name, DylibFile *file, bool isWeakDef);
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Symbol *addLazy(StringRef name, ArchiveFile *file,
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const llvm::object::Archive::Symbol &sym);
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ArrayRef<Symbol *> getSymbols() const { return symVector; }
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Symbol *find(StringRef name);
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private:
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std::pair<Symbol *, bool> insert(StringRef name);
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llvm::DenseMap<llvm::CachedHashStringRef, int> symMap;
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std::vector<Symbol *> symVector;
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};
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extern SymbolTable *symtab;
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} // namespace macho
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} // namespace lld
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#endif
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