1 //===-- llvm/Bitcode/BitcodeWriter.h - Bitcode writers ----*- 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 // This header defines interfaces to write LLVM bitcode files/streams. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_BITCODE_BITCODEWRITER_H 15 #define LLVM_BITCODE_BITCODEWRITER_H 16 17 #include "llvm/IR/ModuleSummaryIndex.h" 18 #include "llvm/MC/StringTableBuilder.h" 19 #include <string> 20 21 namespace llvm { 22 class BitstreamWriter; 23 class Module; 24 class raw_ostream; 25 26 class BitcodeWriter { 27 SmallVectorImpl<char> &Buffer; 28 std::unique_ptr<BitstreamWriter> Stream; 29 30 StringTableBuilder StrtabBuilder{StringTableBuilder::RAW}; 31 bool WroteStrtab = false; 32 33 void writeBlob(unsigned Block, unsigned Record, StringRef Blob); 34 35 public: 36 /// Create a BitcodeWriter that writes to Buffer. 37 BitcodeWriter(SmallVectorImpl<char> &Buffer); 38 39 ~BitcodeWriter(); 40 41 /// Write the bitcode file's string table. This must be called exactly once 42 /// after all modules have been written. 43 void writeStrtab(); 44 45 /// Copy the string table for another module into this bitcode file. This 46 /// should be called after copying the module itself into the bitcode file. 47 void copyStrtab(StringRef Strtab); 48 49 /// Write the specified module to the buffer specified at construction time. 50 /// 51 /// If \c ShouldPreserveUseListOrder, encode the use-list order for each \a 52 /// Value in \c M. These will be reconstructed exactly when \a M is 53 /// deserialized. 54 /// 55 /// If \c Index is supplied, the bitcode will contain the summary index 56 /// (currently for use in ThinLTO optimization). 57 /// 58 /// \p GenerateHash enables hashing the Module and including the hash in the 59 /// bitcode (currently for use in ThinLTO incremental build). 60 /// 61 /// If \p ModHash is non-null, when GenerateHash is true, the resulting 62 /// hash is written into ModHash. When GenerateHash is false, that value 63 /// is used as the hash instead of computing from the generated bitcode. 64 /// Can be used to produce the same module hash for a minimized bitcode 65 /// used just for the thin link as in the regular full bitcode that will 66 /// be used in the backend. 67 void writeModule(const Module *M, bool ShouldPreserveUseListOrder = false, 68 const ModuleSummaryIndex *Index = nullptr, 69 bool GenerateHash = false, ModuleHash *ModHash = nullptr); 70 71 void writeIndex( 72 const ModuleSummaryIndex *Index, 73 const std::map<std::string, GVSummaryMapTy> *ModuleToSummariesForIndex); 74 }; 75 76 /// \brief Write the specified module to the specified raw output stream. 77 /// 78 /// For streams where it matters, the given stream should be in "binary" 79 /// mode. 80 /// 81 /// If \c ShouldPreserveUseListOrder, encode the use-list order for each \a 82 /// Value in \c M. These will be reconstructed exactly when \a M is 83 /// deserialized. 84 /// 85 /// If \c Index is supplied, the bitcode will contain the summary index 86 /// (currently for use in ThinLTO optimization). 87 /// 88 /// \p GenerateHash enables hashing the Module and including the hash in the 89 /// bitcode (currently for use in ThinLTO incremental build). 90 /// 91 /// If \p ModHash is non-null, when GenerateHash is true, the resulting 92 /// hash is written into ModHash. When GenerateHash is false, that value 93 /// is used as the hash instead of computing from the generated bitcode. 94 /// Can be used to produce the same module hash for a minimized bitcode 95 /// used just for the thin link as in the regular full bitcode that will 96 /// be used in the backend. 97 void WriteBitcodeToFile(const Module *M, raw_ostream &Out, 98 bool ShouldPreserveUseListOrder = false, 99 const ModuleSummaryIndex *Index = nullptr, 100 bool GenerateHash = false, 101 ModuleHash *ModHash = nullptr); 102 103 /// Write the specified module summary index to the given raw output stream, 104 /// where it will be written in a new bitcode block. This is used when 105 /// writing the combined index file for ThinLTO. When writing a subset of the 106 /// index for a distributed backend, provide the \p ModuleToSummariesForIndex 107 /// map. 108 void WriteIndexToFile(const ModuleSummaryIndex &Index, raw_ostream &Out, 109 const std::map<std::string, GVSummaryMapTy> 110 *ModuleToSummariesForIndex = nullptr); 111 } // End llvm namespace 112 113 #endif 114
