1 //===-- StringTableBuilder.h - String table building utility ------*- C++ -*-=// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef LLVM_MC_STRINGTABLEBUILDER_H 11 #define LLVM_MC_STRINGTABLEBUILDER_H 12 13 #include "llvm/ADT/SmallString.h" 14 #include "llvm/ADT/DenseMap.h" 15 #include <cassert> 16 17 namespace llvm { 18 19 /// \brief Utility for building string tables with deduplicated suffixes. 20 class StringTableBuilder { 21 public: 22 enum Kind { ELF, WinCOFF, MachO, RAW }; 23 24 private: 25 SmallString<256> StringTable; 26 DenseMap<CachedHash<StringRef>, size_t> StringIndexMap; 27 size_t Size = 0; 28 Kind K; 29 unsigned Alignment; 30 31 void finalizeStringTable(bool Optimize); 32 33 public: 34 StringTableBuilder(Kind K, unsigned Alignment = 1); 35 36 /// \brief Add a string to the builder. Returns the position of S in the 37 /// table. The position will be changed if finalize is used. 38 /// Can only be used before the table is finalized. 39 size_t add(StringRef S); 40 41 /// \brief Analyze the strings and build the final table. No more strings can 42 /// be added after this point. 43 void finalize(); 44 45 /// Finalize the string table without reording it. In this mode, offsets 46 /// returned by add will still be valid. 47 void finalizeInOrder(); 48 49 /// \brief Retrieve the string table data. Can only be used after the table 50 /// is finalized. 51 StringRef data() const { 52 assert(isFinalized()); 53 return StringTable; 54 } 55 56 /// \brief Get the offest of a string in the string table. Can only be used 57 /// after the table is finalized. 58 size_t getOffset(StringRef S) const; 59 60 const DenseMap<CachedHash<StringRef>, size_t> &getMap() const { 61 return StringIndexMap; 62 } 63 64 size_t getSize() const { return Size; } 65 void clear(); 66 67 private: 68 bool isFinalized() const { 69 return !StringTable.empty(); 70 } 71 }; 72 73 } // end llvm namespace 74 75 #endif 76
