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 { 26 ELF, 27 WinCOFF, 28 MachO, 29 MachO64, 30 MachOLinked, 31 MachO64Linked, 32 RAW, 33 DWARF, 34 XCOFF 35 }; 36 37 private: 38 DenseMap<CachedHashStringRef, size_t> StringIndexMap; 39 size_t Size = 0; 40 Kind K; 41 unsigned Alignment; 42 bool Finalized = false; 43 44 void finalizeStringTable(bool Optimize); 45 void initSize(); 46 47 public: 48 StringTableBuilder(Kind K, unsigned Alignment = 1); 49 ~StringTableBuilder(); 50 51 /// Add a string to the builder. Returns the position of S in the 52 /// table. The position will be changed if finalize is used. 53 /// Can only be used before the table is finalized. 54 size_t add(CachedHashStringRef S); add(StringRef S)55 size_t add(StringRef S) { return add(CachedHashStringRef(S)); } 56 57 /// Analyze the strings and build the final table. No more strings can 58 /// be added after this point. 59 void finalize(); 60 61 /// Finalize the string table without reording it. In this mode, offsets 62 /// returned by add will still be valid. 63 void finalizeInOrder(); 64 65 /// Get the offest of a string in the string table. Can only be used 66 /// after the table is finalized. 67 size_t getOffset(CachedHashStringRef S) const; getOffset(StringRef S)68 size_t getOffset(StringRef S) const { 69 return getOffset(CachedHashStringRef(S)); 70 } 71 72 /// Check if a string is contained in the string table. Since this class 73 /// doesn't store the string values, this function can be used to check if 74 /// storage needs to be done prior to adding the string. contains(StringRef S)75 bool contains(StringRef S) const { 76 return contains(CachedHashStringRef(S)); 77 } contains(CachedHashStringRef S)78 bool contains(CachedHashStringRef S) const { 79 return StringIndexMap.count(S); 80 } 81 getSize()82 size_t getSize() const { return Size; } 83 void clear(); 84 85 void write(raw_ostream &OS) const; 86 void write(uint8_t *Buf) const; 87 88 private: isFinalized()89 bool isFinalized() const { return Finalized; } 90 }; 91 92 } // end namespace llvm 93 94 #endif // LLVM_MC_STRINGTABLEBUILDER_H 95