1 //===- StringTableBuilder.h - String table building utility -----*- 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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef LLVM_MC_STRINGTABLEBUILDER_H 10 #define LLVM_MC_STRINGTABLEBUILDER_H 11 12 #include "llvm/ADT/CachedHashString.h" 13 #include "llvm/ADT/DenseMap.h" 14 #include "llvm/ADT/StringRef.h" 15 #include <cstddef> 16 #include <cstdint> 17 18 namespace llvm { 19 20 class raw_ostream; 21 22 /// Utility for building string tables with deduplicated suffixes. 23 class StringTableBuilder { 24 public: 25 enum Kind { ELF, WinCOFF, MachO, RAW, DWARF, XCOFF }; 26 27 private: 28 DenseMap<CachedHashStringRef, size_t> StringIndexMap; 29 size_t Size = 0; 30 Kind K; 31 unsigned Alignment; 32 bool Finalized = false; 33 34 void finalizeStringTable(bool Optimize); 35 void initSize(); 36 37 public: 38 StringTableBuilder(Kind K, unsigned Alignment = 1); 39 ~StringTableBuilder(); 40 41 /// Add a string to the builder. Returns the position of S in the 42 /// table. The position will be changed if finalize is used. 43 /// Can only be used before the table is finalized. 44 size_t add(CachedHashStringRef S); add(StringRef S)45 size_t add(StringRef S) { return add(CachedHashStringRef(S)); } 46 47 /// Analyze the strings and build the final table. No more strings can 48 /// be added after this point. 49 void finalize(); 50 51 /// Finalize the string table without reording it. In this mode, offsets 52 /// returned by add will still be valid. 53 void finalizeInOrder(); 54 55 /// Get the offest of a string in the string table. Can only be used 56 /// after the table is finalized. 57 size_t getOffset(CachedHashStringRef S) const; getOffset(StringRef S)58 size_t getOffset(StringRef S) const { 59 return getOffset(CachedHashStringRef(S)); 60 } 61 getSize()62 size_t getSize() const { return Size; } 63 void clear(); 64 65 void write(raw_ostream &OS) const; 66 void write(uint8_t *Buf) const; 67 68 private: isFinalized()69 bool isFinalized() const { return Finalized; } 70 }; 71 72 } // end namespace llvm 73 74 #endif // LLVM_MC_STRINGTABLEBUILDER_H 75