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1//===- SymbolTable.h --------------------------------------------*- C++ -*-===//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-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef LLD_ELF_SYMBOL_TABLE_H10#define LLD_ELF_SYMBOL_TABLE_H11 12#include "Symbols.h"13#include "llvm/ADT/CachedHashString.h"14#include "llvm/ADT/DenseMap.h"15#include "llvm/Support/Compiler.h"16 17namespace lld::elf {18struct Ctx;19class InputFile;20class SharedFile;21 22struct ArmCmseEntryFunction {23 Symbol *acleSeSym;24 Symbol *sym;25};26 27// SymbolTable is a bucket of all known symbols, including defined,28// undefined, or lazy symbols (the last one is symbols in archive29// files whose archive members are not yet loaded).30//31// We put all symbols of all files to a SymbolTable, and the32// SymbolTable selects the "best" symbols if there are name33// conflicts. For example, obviously, a defined symbol is better than34// an undefined symbol. Or, if there's a conflict between a lazy and a35// undefined, it'll read an archive member to read a real definition36// to replace the lazy symbol. The logic is implemented in the37// add*() functions, which are called by input files as they are parsed. There38// is one add* function per symbol type.39class SymbolTable {40public:41 SymbolTable(Ctx &ctx) : ctx(ctx) {}42 ArrayRef<Symbol *> getSymbols() const { return symVector; }43 44 void wrap(Symbol *sym, Symbol *real, Symbol *wrap);45 46 Symbol *insert(StringRef name);47 48 template <typename T> Symbol *addSymbol(const T &newSym) {49 Symbol *sym = insert(newSym.getName());50 sym->resolve(ctx, newSym);51 return sym;52 }53 Symbol *addAndCheckDuplicate(Ctx &, const Defined &newSym);54 55 void scanVersionScript();56 57 Symbol *find(StringRef name);58 59 void handleDynamicList();60 61 Symbol *addUnusedUndefined(StringRef name,62 uint8_t binding = llvm::ELF::STB_GLOBAL);63 64 // Set of .so files to not link the same shared object file more than once.65 llvm::DenseMap<llvm::CachedHashStringRef, SharedFile *> soNames;66 67 // Comdat groups define "link once" sections. If two comdat groups have the68 // same name, only one of them is linked, and the other is ignored. This map69 // is used to uniquify them.70 llvm::DenseMap<llvm::CachedHashStringRef, const InputFile *> comdatGroups;71 72 // The Map of __acle_se_<sym>, <sym> pairs found in the input objects.73 // Key is the <sym> name.74 llvm::SmallMapVector<StringRef, ArmCmseEntryFunction, 1> cmseSymMap;75 76 // Map of symbols defined in the Arm CMSE import library. The linker must77 // preserve the addresses in the output objects.78 llvm::StringMap<Defined *> cmseImportLib;79 80 // True if <sym> from the input Arm CMSE import library is written to the81 // output Arm CMSE import library.82 llvm::StringMap<bool> inCMSEOutImpLib;83 84private:85 SmallVector<Symbol *, 0> findByVersion(SymbolVersion ver);86 SmallVector<Symbol *, 0> findAllByVersion(SymbolVersion ver,87 bool includeNonDefault);88 89 llvm::StringMap<SmallVector<Symbol *, 0>> &getDemangledSyms();90 bool assignExactVersion(SymbolVersion ver, uint16_t versionId,91 StringRef versionName, bool includeNonDefault);92 void assignWildcardVersion(SymbolVersion ver, uint16_t versionId,93 bool includeNonDefault);94 95 Ctx &ctx;96 97 // Global symbols and a map from symbol name to the index. The order is not98 // defined. We can use an arbitrary order, but it has to be deterministic even99 // when cross linking.100 llvm::DenseMap<llvm::CachedHashStringRef, int> symMap;101 SmallVector<Symbol *, 0> symVector;102 103 // A map from demangled symbol names to their symbol objects.104 // This mapping is 1:N because two symbols with different versions105 // can have the same name. We use this map to handle "extern C++ {}"106 // directive in version scripts.107 std::optional<llvm::StringMap<SmallVector<Symbol *, 0>>> demangledSyms;108};109 110} // namespace lld::elf111 112#endif113