BitstreamRemarkParser.h revision 360784 
1//===-- BitstreamRemarkParser.h - Bitstream parser --------------*- 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 provides an implementation of the remark parser using the LLVM
10// Bitstream format.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_REMARKS_BITSTREAM_REMARK_PARSER_H
15#define LLVM_REMARKS_BITSTREAM_REMARK_PARSER_H
16
17#include "llvm/ADT/StringRef.h"
18#include "llvm/Bitstream/BitstreamReader.h"
19#include "llvm/Remarks/BitstreamRemarkContainer.h"
20#include "llvm/Remarks/Remark.h"
21#include "llvm/Remarks/RemarkParser.h"
22#include "llvm/Support/Error.h"
23#include <array>
24
25namespace llvm {
26namespace remarks {
27
28/// Helper to parse a META_BLOCK for a bitstream remark container.
29struct BitstreamMetaParserHelper {
30  /// The Bitstream reader.
31  BitstreamCursor &Stream;
32  /// Reference to the storage for the block info.
33  BitstreamBlockInfo &BlockInfo;
34  /// The parsed content: depending on the container type, some fields might be
35  /// empty.
36  Optional<uint64_t> ContainerVersion;
37  Optional<uint8_t> ContainerType;
38  Optional<StringRef> StrTabBuf;
39  Optional<StringRef> ExternalFilePath;
40  Optional<uint64_t> RemarkVersion;
41
42  /// Continue parsing with \p Stream. \p Stream is expected to contain a
43  /// ENTER_SUBBLOCK to the META_BLOCK at the current position.
44  /// \p Stream is expected to have a BLOCKINFO_BLOCK set.
45  BitstreamMetaParserHelper(BitstreamCursor &Stream,
46                            BitstreamBlockInfo &BlockInfo);
47
48  /// Parse the META_BLOCK and fill the available entries.
49  /// This helper does not check for the validity of the fields.
50  Error parse();
51};
52
53/// Helper to parse a REMARK_BLOCK for a bitstream remark container.
54struct BitstreamRemarkParserHelper {
55  /// The Bitstream reader.
56  BitstreamCursor &Stream;
57  /// The parsed content: depending on the remark, some fields might be empty.
58  Optional<uint8_t> Type;
59  Optional<uint64_t> RemarkNameIdx;
60  Optional<uint64_t> PassNameIdx;
61  Optional<uint64_t> FunctionNameIdx;
62  Optional<uint64_t> SourceFileNameIdx;
63  Optional<uint32_t> SourceLine;
64  Optional<uint32_t> SourceColumn;
65  Optional<uint64_t> Hotness;
66  struct Argument {
67    Optional<uint64_t> KeyIdx;
68    Optional<uint64_t> ValueIdx;
69    Optional<uint64_t> SourceFileNameIdx;
70    Optional<uint32_t> SourceLine;
71    Optional<uint32_t> SourceColumn;
72  };
73  Optional<ArrayRef<Argument>> Args;
74  /// Avoid re-allocating a vector every time.
75  SmallVector<Argument, 8> TmpArgs;
76
77  /// Continue parsing with \p Stream. \p Stream is expected to contain a
78  /// ENTER_SUBBLOCK to the REMARK_BLOCK at the current position.
79  /// \p Stream is expected to have a BLOCKINFO_BLOCK set and to have already
80  /// parsed the META_BLOCK.
81  BitstreamRemarkParserHelper(BitstreamCursor &Stream);
82
83  /// Parse the REMARK_BLOCK and fill the available entries.
84  /// This helper does not check for the validity of the fields.
85  Error parse();
86};
87
88/// Helper to parse any bitstream remark container.
89struct BitstreamParserHelper {
90  /// The Bitstream reader.
91  BitstreamCursor Stream;
92  /// The block info block.
93  BitstreamBlockInfo BlockInfo;
94  /// Start parsing at \p Buffer.
95  BitstreamParserHelper(StringRef Buffer);
96  /// Parse the magic number.
97  Expected<std::array<char, 4>> parseMagic();
98  /// Parse the block info block containing all the abbrevs.
99  /// This needs to be called before calling any other parsing function.
100  Error parseBlockInfoBlock();
101  /// Return true if the next block is a META_BLOCK. This function does not move
102  /// the cursor.
103  Expected<bool> isMetaBlock();
104  /// Return true if the next block is a REMARK_BLOCK. This function does not
105  /// move the cursor.
106  Expected<bool> isRemarkBlock();
107  /// Return true if the parser reached the end of the stream.
108  bool atEndOfStream() { return Stream.AtEndOfStream(); }
109  /// Jump to the end of the stream, skipping everything.
110  void skipToEnd() { return Stream.skipToEnd(); }
111};
112
113} // end namespace remarks
114} // end namespace llvm
115
116#endif /* LLVM_REMARKS_BITSTREAM_REMARK_PARSER_H */
117