llvm-project/lld/wasm/SymbolTable.h

70 lines
2.1 KiB
C++

//===- SymbolTable.h --------------------------------------------*- C++ -*-===//
//
// The LLVM Linker
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLD_WASM_SYMBOL_TABLE_H
#define LLD_WASM_SYMBOL_TABLE_H
#include "InputFiles.h"
#include "Symbols.h"
#include "llvm/ADT/CachedHashString.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/Support/raw_ostream.h"
using llvm::object::WasmSymbol;
namespace lld {
namespace wasm {
class InputSegment;
// SymbolTable is a bucket of all known symbols, including defined,
// undefined, or lazy symbols (the last one is symbols in archive
// files whose archive members are not yet loaded).
//
// We put all symbols of all files to a SymbolTable, and the
// SymbolTable selects the "best" symbols if there are name
// conflicts. For example, obviously, a defined symbol is better than
// an undefined symbol. Or, if there's a conflict between a lazy and a
// undefined, it'll read an archive member to read a real definition
// to replace the lazy symbol. The logic is implemented in the
// add*() functions, which are called by input files as they are parsed.
// There is one add* function per symbol type.
class SymbolTable {
public:
void addFile(InputFile *File);
std::vector<ObjFile *> ObjectFiles;
std::vector<Symbol *> SyntheticSymbols;
void reportDuplicate(Symbol *Existing, InputFile *NewFile);
void reportRemainingUndefines();
Symbol *find(StringRef Name);
Symbol *addDefined(InputFile *F, const WasmSymbol *Sym,
const InputSegment *Segment = nullptr);
Symbol *addUndefined(InputFile *F, const WasmSymbol *Sym);
Symbol *addUndefinedFunction(StringRef Name);
Symbol *addDefinedGlobal(StringRef Name);
void addLazy(ArchiveFile *F, const Archive::Symbol *Sym);
private:
std::pair<Symbol *, bool> insert(StringRef Name);
llvm::DenseMap<llvm::CachedHashStringRef, Symbol *> SymMap;
};
extern SymbolTable *Symtab;
} // namespace wasm
} // namespace lld
#endif