llvm/lib/DebugInfo/CodeView/SimpleTypeSerializer.cpp

   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, llvm::endianness::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"