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