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