1 //===- SymbolSerializer.h ---------------------------------------*- 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 #ifndef LLVM_DEBUGINFO_CODEVIEW_SYMBOLSERIALIZER_H
10 #define LLVM_DEBUGINFO_CODEVIEW_SYMBOLSERIALIZER_H
11 
12 #include "llvm/ADT/Optional.h"
13 #include "llvm/DebugInfo/CodeView/CVRecord.h"
14 #include "llvm/DebugInfo/CodeView/CodeView.h"
15 #include "llvm/DebugInfo/CodeView/RecordSerialization.h"
16 #include "llvm/DebugInfo/CodeView/SymbolRecordMapping.h"
17 #include "llvm/DebugInfo/CodeView/SymbolVisitorCallbacks.h"
18 #include "llvm/Support/Allocator.h"
19 #include "llvm/Support/BinaryByteStream.h"
20 #include "llvm/Support/BinaryStreamWriter.h"
21 #include "llvm/Support/Endian.h"
22 #include "llvm/Support/Error.h"
23 #include <array>
24 #include <cstdint>
25 
26 namespace llvm {
27 namespace codeview {
28 
29 class SymbolSerializer : public SymbolVisitorCallbacks {
30   BumpPtrAllocator &Storage;
31   // Since this is a fixed size buffer, use a stack allocated buffer.  This
32   // yields measurable performance increase over the repeated heap allocations
33   // when serializing many independent records via writeOneSymbol.
34   std::array<uint8_t, MaxRecordLength> RecordBuffer;
35   MutableBinaryByteStream Stream;
36   BinaryStreamWriter Writer;
37   SymbolRecordMapping Mapping;
38   Optional<SymbolKind> CurrentSymbol;
39 
40   Error writeRecordPrefix(SymbolKind Kind) {
41     RecordPrefix Prefix;
42     Prefix.RecordKind = Kind;
43     Prefix.RecordLen = 0;
44     if (auto EC = Writer.writeObject(Prefix))
45       return EC;
46     return Error::success();
47   }
48 
49 public:
50   SymbolSerializer(BumpPtrAllocator &Storage, CodeViewContainer Container);
51 
52   template <typename SymType>
53   static CVSymbol writeOneSymbol(SymType &Sym, BumpPtrAllocator &Storage,
54                                  CodeViewContainer Container) {
55     RecordPrefix Prefix{uint16_t(Sym.Kind)};
56     CVSymbol Result(&Prefix, sizeof(Prefix));
57     SymbolSerializer Serializer(Storage, Container);
58     consumeError(Serializer.visitSymbolBegin(Result));
59     consumeError(Serializer.visitKnownRecord(Result, Sym));
60     consumeError(Serializer.visitSymbolEnd(Result));
61     return Result;
62   }
63 
64   Error visitSymbolBegin(CVSymbol &Record) override;
65   Error visitSymbolEnd(CVSymbol &Record) override;
66 
67 #define SYMBOL_RECORD(EnumName, EnumVal, Name)                                 \
68   Error visitKnownRecord(CVSymbol &CVR, Name &Record) override {               \
69     return visitKnownRecordImpl(CVR, Record);                                  \
70   }
71 #define SYMBOL_RECORD_ALIAS(EnumName, EnumVal, Name, AliasName)
72 #include "llvm/DebugInfo/CodeView/CodeViewSymbols.def"
73 
74 private:
75   template <typename RecordKind>
76   Error visitKnownRecordImpl(CVSymbol &CVR, RecordKind &Record) {
77     return Mapping.visitKnownRecord(CVR, Record);
78   }
79 };
80 
81 } // end namespace codeview
82 } // end namespace llvm
83 
84 #endif // LLVM_DEBUGINFO_CODEVIEW_SYMBOLSERIALIZER_H
85