1 //===-- llvm/CodeGen/ByteStreamer.h - ByteStreamer class --------*- 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 // This file contains a class that can take bytes that would normally be 10 // streamed via the AsmPrinter. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_BYTESTREAMER_H 15 #define LLVM_LIB_CODEGEN_ASMPRINTER_BYTESTREAMER_H 16 17 #include "DIEHash.h" 18 #include "llvm/CodeGen/AsmPrinter.h" 19 #include "llvm/MC/MCStreamer.h" 20 #include "llvm/Support/LEB128.h" 21 #include <string> 22 23 namespace llvm { 24 class ByteStreamer { 25 protected: 26 ~ByteStreamer() = default; 27 ByteStreamer(const ByteStreamer&) = default; 28 ByteStreamer() = default; 29 30 public: 31 // For now we're just handling the calls we need for dwarf emission/hashing. 32 virtual void EmitInt8(uint8_t Byte, const Twine &Comment = "") = 0; 33 virtual void EmitSLEB128(uint64_t DWord, const Twine &Comment = "") = 0; 34 virtual void EmitULEB128(uint64_t DWord, const Twine &Comment = "", unsigned PadTo = 0) = 0; 35 }; 36 37 class APByteStreamer final : public ByteStreamer { 38 private: 39 AsmPrinter &AP; 40 41 public: 42 APByteStreamer(AsmPrinter &Asm) : AP(Asm) {} 43 void EmitInt8(uint8_t Byte, const Twine &Comment) override { 44 AP.OutStreamer->AddComment(Comment); 45 AP.emitInt8(Byte); 46 } 47 void EmitSLEB128(uint64_t DWord, const Twine &Comment) override { 48 AP.OutStreamer->AddComment(Comment); 49 AP.EmitSLEB128(DWord); 50 } 51 void EmitULEB128(uint64_t DWord, const Twine &Comment, unsigned PadTo) override { 52 AP.OutStreamer->AddComment(Comment); 53 AP.EmitULEB128(DWord); 54 } 55 }; 56 57 class HashingByteStreamer final : public ByteStreamer { 58 private: 59 DIEHash &Hash; 60 public: 61 HashingByteStreamer(DIEHash &H) : Hash(H) {} 62 void EmitInt8(uint8_t Byte, const Twine &Comment) override { 63 Hash.update(Byte); 64 } 65 void EmitSLEB128(uint64_t DWord, const Twine &Comment) override { 66 Hash.addSLEB128(DWord); 67 } 68 void EmitULEB128(uint64_t DWord, const Twine &Comment, unsigned PadTo) override { 69 Hash.addULEB128(DWord); 70 } 71 }; 72 73 class BufferByteStreamer final : public ByteStreamer { 74 private: 75 SmallVectorImpl<char> &Buffer; 76 std::vector<std::string> &Comments; 77 78 public: 79 /// Only verbose textual output needs comments. This will be set to 80 /// true for that case, and false otherwise. If false, comments passed in to 81 /// the emit methods will be ignored. 82 const bool GenerateComments; 83 84 BufferByteStreamer(SmallVectorImpl<char> &Buffer, 85 std::vector<std::string> &Comments, bool GenerateComments) 86 : Buffer(Buffer), Comments(Comments), GenerateComments(GenerateComments) { 87 } 88 void EmitInt8(uint8_t Byte, const Twine &Comment) override { 89 Buffer.push_back(Byte); 90 if (GenerateComments) 91 Comments.push_back(Comment.str()); 92 } 93 void EmitSLEB128(uint64_t DWord, const Twine &Comment) override { 94 raw_svector_ostream OSE(Buffer); 95 unsigned Length = encodeSLEB128(DWord, OSE); 96 if (GenerateComments) { 97 Comments.push_back(Comment.str()); 98 // Add some empty comments to keep the Buffer and Comments vectors aligned 99 // with each other. 100 for (size_t i = 1; i < Length; ++i) 101 Comments.push_back(""); 102 103 } 104 } 105 void EmitULEB128(uint64_t DWord, const Twine &Comment, unsigned PadTo) override { 106 raw_svector_ostream OSE(Buffer); 107 unsigned Length = encodeULEB128(DWord, OSE, PadTo); 108 if (GenerateComments) { 109 Comments.push_back(Comment.str()); 110 // Add some empty comments to keep the Buffer and Comments vectors aligned 111 // with each other. 112 for (size_t i = 1; i < Length; ++i) 113 Comments.push_back(""); 114 115 } 116 } 117 }; 118 119 } 120 121 #endif 122