1 //===- SimpleTypeSerializer.cpp -----------------------------------------===//
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 #include "llvm/DebugInfo/CodeView/SimpleTypeSerializer.h"
10 #include "llvm/DebugInfo/CodeView/CVRecord.h"
11 #include "llvm/DebugInfo/CodeView/RecordSerialization.h"
12 #include "llvm/DebugInfo/CodeView/TypeRecordMapping.h"
13 #include "llvm/Support/BinaryStreamWriter.h"
14 
15 using namespace llvm;
16 using namespace llvm::codeview;
17 
18 static void addPadding(BinaryStreamWriter &Writer) {
19   uint32_t Align = Writer.getOffset() % 4;
20   if (Align == 0)
21     return;
22 
23   int PaddingBytes = 4 - Align;
24   while (PaddingBytes > 0) {
25     uint8_t Pad = static_cast<uint8_t>(LF_PAD0 + PaddingBytes);
26     cantFail(Writer.writeInteger(Pad));
27     --PaddingBytes;
28   }
29 }
30 
31 SimpleTypeSerializer::SimpleTypeSerializer() : ScratchBuffer(MaxRecordLength) {}
32 
33 SimpleTypeSerializer::~SimpleTypeSerializer() = default;
34 
35 template <typename T>
36 ArrayRef<uint8_t> SimpleTypeSerializer::serialize(T &Record) {
37   BinaryStreamWriter Writer(ScratchBuffer, support::little);
38   TypeRecordMapping Mapping(Writer);
39 
40   // Write the record prefix first with a dummy length but real kind.
41   RecordPrefix DummyPrefix(uint16_t(Record.getKind()));
42   cantFail(Writer.writeObject(DummyPrefix));
43 
44   RecordPrefix *Prefix = reinterpret_cast<RecordPrefix *>(ScratchBuffer.data());
45   CVType CVT(Prefix, sizeof(RecordPrefix));
46 
47   cantFail(Mapping.visitTypeBegin(CVT));
48   cantFail(Mapping.visitKnownRecord(CVT, Record));
49   cantFail(Mapping.visitTypeEnd(CVT));
50 
51   addPadding(Writer);
52 
53   // Update the size and kind after serialization.
54   Prefix->RecordKind = CVT.kind();
55   Prefix->RecordLen = Writer.getOffset() - sizeof(uint16_t);
56 
57   return {ScratchBuffer.data(), static_cast<size_t>(Writer.getOffset())};
58 }
59 
60 // Explicitly instantiate the member function for each known type so that we can
61 // implement this in the cpp file.
62 #define TYPE_RECORD(EnumName, EnumVal, Name)                                   \
63   template ArrayRef<uint8_t> llvm::codeview::SimpleTypeSerializer::serialize(  \
64       Name##Record &Record);
65 #define TYPE_RECORD_ALIAS(EnumName, EnumVal, Name, AliasName)
66 #define MEMBER_RECORD(EnumName, EnumVal, Name)
67 #define MEMBER_RECORD_ALIAS(EnumName, EnumVal, Name, AliasName)
68 #include "llvm/DebugInfo/CodeView/CodeViewTypes.def"
69