1//===-- BitcodeReader.h - ClangDoc Bitcode Reader --------------*- 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 implements a reader for parsing the clang-doc internal
10// representation from LLVM bitcode. The reader takes in a stream of bits and
11// generates the set of infos that it represents.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_DOC_BITCODEREADER_H
16#define LLVM_CLANG_TOOLS_EXTRA_CLANG_DOC_BITCODEREADER_H
17
18#include "BitcodeWriter.h"
19#include "Representation.h"
20#include "clang/AST/AST.h"
21#include "llvm/ADT/SmallVector.h"
22#include "llvm/Bitstream/BitstreamReader.h"
23#include "llvm/Support/Error.h"
24#include <optional>
25
26namespace clang {
27namespace doc {
28
29// Class to read bitstream into an InfoSet collection
30class ClangDocBitcodeReader {
31public:
32 ClangDocBitcodeReader(llvm::BitstreamCursor &Stream) : Stream(Stream) {}
33
34 // Main entry point, calls readBlock to read each block in the given stream.
35 llvm::Expected<std::vector<std::unique_ptr<Info>>> readBitcode();
36
37private:
38 enum class Cursor { BadBlock = 1, Record, BlockEnd, BlockBegin };
39
40 // Top level parsing
41 llvm::Error validateStream();
42 llvm::Error readVersion();
43 llvm::Error readBlockInfoBlock();
44
45 // Read a block of records into a single Info struct, calls readRecord on each
46 // record found.
47 template <typename T> llvm::Error readBlock(unsigned ID, T I);
48
49 // Step through a block of records to find the next data field.
50 template <typename T> llvm::Error readSubBlock(unsigned ID, T I);
51
52 // Read record data into the given Info data field, calling the appropriate
53 // parseRecord functions to parse and store the data.
54 template <typename T> llvm::Error readRecord(unsigned ID, T I);
55
56 // Allocate the relevant type of info and add read data to the object.
57 template <typename T>
58 llvm::Expected<std::unique_ptr<Info>> createInfo(unsigned ID);
59
60 // Helper function to step through blocks to find and dispatch the next record
61 // or block to be read.
62 Cursor skipUntilRecordOrBlock(unsigned &BlockOrRecordID);
63
64 // Helper function to set up the appropriate type of Info.
65 llvm::Expected<std::unique_ptr<Info>> readBlockToInfo(unsigned ID);
66
67 llvm::BitstreamCursor &Stream;
68 std::optional<llvm::BitstreamBlockInfo> BlockInfo;
69 FieldId CurrentReferenceField;
70};
71
72} // namespace doc
73} // namespace clang
74
75#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_DOC_BITCODEREADER_H
76

source code of clang-tools-extra/clang-doc/BitcodeReader.h