clang-tools  8.0.0
BitcodeWriter.h
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1 //===-- BitcodeWriter.h - ClangDoc Bitcode Writer --------------*- 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 implements a writer for serializing the clang-doc internal
11 // representation to LLVM bitcode. The writer takes in a stream and emits the
12 // generated bitcode to that stream.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_DOC_BITCODEWRITER_H
17 #define LLVM_CLANG_TOOLS_EXTRA_CLANG_DOC_BITCODEWRITER_H
18 
19 #include "Representation.h"
20 #include "clang/AST/AST.h"
21 #include "llvm/ADT/DenseMap.h"
22 #include "llvm/ADT/SmallVector.h"
23 #include "llvm/ADT/StringRef.h"
24 #include "llvm/Bitcode/BitstreamWriter.h"
25 #include <initializer_list>
26 #include <vector>
27 
28 namespace clang {
29 namespace doc {
30 
31 // Current version number of clang-doc bitcode.
32 // Should be bumped when removing or changing BlockIds, RecordIds, or
33 // BitCodeConstants, though they can be added without breaking it.
34 static const unsigned VersionNumber = 2;
35 
37  static constexpr unsigned RecordSize = 32U;
38  static constexpr unsigned SignatureBitSize = 8U;
39  static constexpr unsigned SubblockIDSize = 4U;
40  static constexpr unsigned BoolSize = 1U;
41  static constexpr unsigned IntSize = 16U;
42  static constexpr unsigned StringLengthSize = 16U;
43  static constexpr unsigned FilenameLengthSize = 16U;
44  static constexpr unsigned LineNumberSize = 16U;
45  static constexpr unsigned ReferenceTypeSize = 8U;
46  static constexpr unsigned USRLengthSize = 6U;
47  static constexpr unsigned USRBitLengthSize = 8U;
48  static constexpr char Signature[4] = {'D', 'O', 'C', 'S'};
49  static constexpr int USRHashSize = 20;
50 };
51 
52 // New Ids need to be added to both the enum here and the relevant IdNameMap in
53 // the implementation file.
54 enum BlockId {
55  BI_VERSION_BLOCK_ID = llvm::bitc::FIRST_APPLICATION_BLOCKID,
67 };
68 
69 // New Ids need to be added to the enum here, and to the relevant IdNameMap and
70 // initialization list in the implementation file.
71 enum RecordId {
72  VERSION = 1,
112 };
113 
114 static constexpr unsigned BlockIdCount = BI_LAST - BI_FIRST;
115 static constexpr unsigned RecordIdCount = RI_LAST - RI_FIRST;
116 
117 // Identifiers for differentiating between subblocks
118 enum class FieldId {
119  F_default,
120  F_namespace,
121  F_parent,
122  F_vparent,
123  F_type,
126 };
127 
129 public:
130  ClangDocBitcodeWriter(llvm::BitstreamWriter &Stream) : Stream(Stream) {
131  emitHeader();
132  emitBlockInfoBlock();
133  emitVersionBlock();
134  }
135 
136  // Write a specific info to a bitcode stream.
137  bool dispatchInfoForWrite(Info *I);
138 
139  // Block emission of different info types.
140  void emitBlock(const NamespaceInfo &I);
141  void emitBlock(const RecordInfo &I);
142  void emitBlock(const FunctionInfo &I);
143  void emitBlock(const EnumInfo &I);
144  void emitBlock(const TypeInfo &B);
145  void emitBlock(const FieldTypeInfo &B);
146  void emitBlock(const MemberTypeInfo &B);
147  void emitBlock(const CommentInfo &B);
148  void emitBlock(const Reference &B, FieldId F);
149 
150 private:
151  class AbbreviationMap {
152  llvm::DenseMap<unsigned, unsigned> Abbrevs;
153 
154  public:
155  AbbreviationMap() : Abbrevs(RecordIdCount) {}
156 
157  void add(RecordId RID, unsigned AbbrevID);
158  unsigned get(RecordId RID) const;
159  };
160 
161  class StreamSubBlockGuard {
162  llvm::BitstreamWriter &Stream;
163 
164  public:
165  StreamSubBlockGuard(llvm::BitstreamWriter &Stream_, BlockId ID)
166  : Stream(Stream_) {
167  // NOTE: SubBlockIDSize could theoretically be calculated on the fly,
168  // based on the initialization list of records in each block.
169  Stream.EnterSubblock(ID, BitCodeConstants::SubblockIDSize);
170  }
171 
172  StreamSubBlockGuard(const StreamSubBlockGuard &) = delete;
173  StreamSubBlockGuard &operator=(const StreamSubBlockGuard &) = delete;
174 
175  ~StreamSubBlockGuard() { Stream.ExitBlock(); }
176  };
177 
178  // Emission of validation and overview blocks.
179  void emitHeader();
180  void emitVersionBlock();
181  void emitRecordID(RecordId ID);
182  void emitBlockID(BlockId ID);
183  void emitBlockInfoBlock();
184  void emitBlockInfo(BlockId BID, const std::vector<RecordId> &RIDs);
185 
186  // Emission of individual record types.
187  void emitRecord(StringRef Str, RecordId ID);
188  void emitRecord(const SymbolID &Str, RecordId ID);
189  void emitRecord(const Location &Loc, RecordId ID);
190  void emitRecord(const Reference &Ref, RecordId ID);
191  void emitRecord(bool Value, RecordId ID);
192  void emitRecord(int Value, RecordId ID);
193  void emitRecord(unsigned Value, RecordId ID);
194  bool prepRecordData(RecordId ID, bool ShouldEmit = true);
195 
196  // Emission of appropriate abbreviation type.
197  void emitAbbrev(RecordId ID, BlockId Block);
198 
199  // Static size is the maximum length of the block/record names we're pushing
200  // to this + 1. Longest is currently `MemberTypeBlock` at 15 chars.
201  SmallVector<uint32_t, BitCodeConstants::RecordSize> Record;
202  llvm::BitstreamWriter &Stream;
203  AbbreviationMap Abbrevs;
204 };
205 
206 } // namespace doc
207 } // namespace clang
208 
209 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_DOC_BITCODEWRITER_H
SourceLocation Loc
&#39;#&#39; location in the include directive
static constexpr unsigned SignatureBitSize
Definition: BitcodeWriter.h:38
static const unsigned VersionNumber
Definition: BitcodeWriter.h:34
static constexpr unsigned SubblockIDSize
Definition: BitcodeWriter.h:39
static constexpr unsigned BlockIdCount
ClangDocBitcodeWriter(llvm::BitstreamWriter &Stream)
llvm::SmallVector< uint64_t, 1024 > Record
static constexpr unsigned BoolSize
Definition: BitcodeWriter.h:40
static constexpr unsigned LineNumberSize
Definition: BitcodeWriter.h:44
static constexpr char Signature[4]
Definition: BitcodeWriter.h:48
static constexpr unsigned RecordSize
Definition: BitcodeWriter.h:37
static constexpr int USRHashSize
Definition: BitcodeWriter.h:49
static constexpr unsigned ReferenceTypeSize
Definition: BitcodeWriter.h:45
A base struct for Infos.
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
static constexpr unsigned IntSize
Definition: BitcodeWriter.h:41
static constexpr unsigned USRBitLengthSize
Definition: BitcodeWriter.h:47
static constexpr unsigned USRLengthSize
Definition: BitcodeWriter.h:46
static constexpr unsigned StringLengthSize
Definition: BitcodeWriter.h:42
std::array< uint8_t, 20 > SymbolID
static constexpr unsigned FilenameLengthSize
Definition: BitcodeWriter.h:43
static constexpr unsigned RecordIdCount