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 "llvm/Support/Alignment.h" 16 #include <cstddef> 17 #include <cstdint> 18 19 namespace llvm { 20 21 class raw_ostream; 22 23 /// Utility for building string tables with deduplicated suffixes. 24 class StringTableBuilder { 25 public: 26 enum Kind { 27 ELF, 28 WinCOFF, 29 MachO, 30 MachO64, 31 MachOLinked, 32 MachO64Linked, 33 RAW, 34 DWARF, 35 XCOFF, 36 DXContainer 37 }; 38 39 private: 40 DenseMap<CachedHashStringRef, size_t> StringIndexMap; 41 size_t Size = 0; 42 Kind K; 43 Align Alignment; 44 bool Finalized = false; 45 46 void finalizeStringTable(bool Optimize); 47 void initSize(); 48 49 public: 50 StringTableBuilder(Kind K, Align Alignment = Align(1)); 51 ~StringTableBuilder(); 52 53 /// Add a string to the builder. Returns the position of S in the 54 /// table. The position will be changed if finalize is used. 55 /// Can only be used before the table is finalized. 56 size_t add(CachedHashStringRef S); add(StringRef S)57 size_t add(StringRef S) { return add(CachedHashStringRef(S)); } 58 59 /// Analyze the strings and build the final table. No more strings can 60 /// be added after this point. 61 void finalize(); 62 63 /// Finalize the string table without reording it. In this mode, offsets 64 /// returned by add will still be valid. 65 void finalizeInOrder(); 66 67 /// Get the offest of a string in the string table. Can only be used 68 /// after the table is finalized. 69 size_t getOffset(CachedHashStringRef S) const; getOffset(StringRef S)70 size_t getOffset(StringRef S) const { 71 return getOffset(CachedHashStringRef(S)); 72 } 73 74 /// Check if a string is contained in the string table. Since this class 75 /// doesn't store the string values, this function can be used to check if 76 /// storage needs to be done prior to adding the string. contains(StringRef S)77 bool contains(StringRef S) const { return contains(CachedHashStringRef(S)); } contains(CachedHashStringRef S)78 bool contains(CachedHashStringRef S) const { return StringIndexMap.count(S); } 79 getSize()80 size_t getSize() const { return Size; } 81 void clear(); 82 83 void write(raw_ostream &OS) const; 84 void write(uint8_t *Buf) const; 85 isFinalized()86 bool isFinalized() const { return Finalized; } 87 }; 88 89 } // end namespace llvm 90 91 #endif // LLVM_MC_STRINGTABLEBUILDER_H 92