1 //===-- llvm/CodeGen/ByteStreamer.h - ByteStreamer class --------*- C++ -*-===//
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
7 //===----------------------------------------------------------------------===//
9 // This file contains a class that can take bytes that would normally be
10 // streamed via the AsmPrinter.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_BYTESTREAMER_H
15 #define LLVM_LIB_CODEGEN_ASMPRINTER_BYTESTREAMER_H
18 #include "llvm/CodeGen/AsmPrinter.h"
19 #include "llvm/MC/MCStreamer.h"
20 #include "llvm/Support/LEB128.h"
26 ~ByteStreamer() = default;
27 ByteStreamer(const ByteStreamer&) = default;
28 ByteStreamer() = default;
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 = "",
35 unsigned PadTo = 0) = 0;
38 class APByteStreamer final : public ByteStreamer {
43 APByteStreamer(AsmPrinter &Asm) : AP(Asm) {}
44 void EmitInt8(uint8_t Byte, const Twine &Comment) override {
45 AP.OutStreamer->AddComment(Comment);
48 void emitSLEB128(uint64_t DWord, const Twine &Comment) override {
49 AP.OutStreamer->AddComment(Comment);
50 AP.emitSLEB128(DWord);
52 void emitULEB128(uint64_t DWord, const Twine &Comment,
53 unsigned PadTo) override {
54 AP.OutStreamer->AddComment(Comment);
55 AP.emitULEB128(DWord, nullptr, PadTo);
59 class HashingByteStreamer final : public ByteStreamer {
63 HashingByteStreamer(DIEHash &H) : Hash(H) {}
64 void EmitInt8(uint8_t Byte, const Twine &Comment) override {
67 void emitSLEB128(uint64_t DWord, const Twine &Comment) override {
68 Hash.addSLEB128(DWord);
70 void emitULEB128(uint64_t DWord, const Twine &Comment,
71 unsigned PadTo) override {
72 Hash.addULEB128(DWord);
76 class BufferByteStreamer final : public ByteStreamer {
78 SmallVectorImpl<char> &Buffer;
79 std::vector<std::string> &Comments;
82 /// Only verbose textual output needs comments. This will be set to
83 /// true for that case, and false otherwise. If false, comments passed in to
84 /// the emit methods will be ignored.
85 const bool GenerateComments;
87 BufferByteStreamer(SmallVectorImpl<char> &Buffer,
88 std::vector<std::string> &Comments, bool GenerateComments)
89 : Buffer(Buffer), Comments(Comments), GenerateComments(GenerateComments) {
91 void EmitInt8(uint8_t Byte, const Twine &Comment) override {
92 Buffer.push_back(Byte);
94 Comments.push_back(Comment.str());
96 void emitSLEB128(uint64_t DWord, const Twine &Comment) override {
97 raw_svector_ostream OSE(Buffer);
98 unsigned Length = encodeSLEB128(DWord, OSE);
99 if (GenerateComments) {
100 Comments.push_back(Comment.str());
101 // Add some empty comments to keep the Buffer and Comments vectors aligned
103 for (size_t i = 1; i < Length; ++i)
104 Comments.push_back("");
108 void emitULEB128(uint64_t DWord, const Twine &Comment,
109 unsigned PadTo) override {
110 raw_svector_ostream OSE(Buffer);
111 unsigned Length = encodeULEB128(DWord, OSE, PadTo);
112 if (GenerateComments) {
113 Comments.push_back(Comment.str());
114 // Add some empty comments to keep the Buffer and Comments vectors aligned
116 for (size_t i = 1; i < Length; ++i)
117 Comments.push_back("");