1 //===- DebugSubsectionRecord.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/DebugSubsectionRecord.h" 10 #include "llvm/DebugInfo/CodeView/CodeView.h" 11 #include "llvm/DebugInfo/CodeView/DebugSubsection.h" 12 #include "llvm/Support/BinaryStreamReader.h" 13 #include "llvm/Support/BinaryStreamWriter.h" 14 #include "llvm/Support/Error.h" 15 #include "llvm/Support/MathExtras.h" 16 #include <cassert> 17 #include <cstdint> 18 19 using namespace llvm; 20 using namespace llvm::codeview; 21 22 DebugSubsectionRecord::DebugSubsectionRecord() = default; 23 24 DebugSubsectionRecord::DebugSubsectionRecord(DebugSubsectionKind Kind, 25 BinaryStreamRef Data) 26 : Kind(Kind), Data(Data) {} 27 28 Error DebugSubsectionRecord::initialize(BinaryStreamRef Stream, 29 DebugSubsectionRecord &Info) { 30 const DebugSubsectionHeader *Header; 31 BinaryStreamReader Reader(Stream); 32 if (auto EC = Reader.readObject(Header)) 33 return EC; 34 35 DebugSubsectionKind Kind = 36 static_cast<DebugSubsectionKind>(uint32_t(Header->Kind)); 37 if (auto EC = Reader.readStreamRef(Info.Data, Header->Length)) 38 return EC; 39 Info.Kind = Kind; 40 return Error::success(); 41 } 42 43 uint32_t DebugSubsectionRecord::getRecordLength() const { 44 return sizeof(DebugSubsectionHeader) + Data.getLength(); 45 } 46 47 DebugSubsectionKind DebugSubsectionRecord::kind() const { return Kind; } 48 49 BinaryStreamRef DebugSubsectionRecord::getRecordData() const { return Data; } 50 51 DebugSubsectionRecordBuilder::DebugSubsectionRecordBuilder( 52 std::shared_ptr<DebugSubsection> Subsection) 53 : Subsection(std::move(Subsection)) {} 54 55 DebugSubsectionRecordBuilder::DebugSubsectionRecordBuilder( 56 const DebugSubsectionRecord &Contents) 57 : Contents(Contents) {} 58 59 uint32_t DebugSubsectionRecordBuilder::calculateSerializedLength() const { 60 uint32_t DataSize = Subsection ? Subsection->calculateSerializedSize() 61 : Contents.getRecordData().getLength(); 62 // The length of the entire subsection is always padded to 4 bytes, 63 // regardless of the container kind. 64 return sizeof(DebugSubsectionHeader) + alignTo(DataSize, 4); 65 } 66 67 Error DebugSubsectionRecordBuilder::commit(BinaryStreamWriter &Writer, 68 CodeViewContainer Container) const { 69 assert(Writer.getOffset() % alignOf(Container) == 0 && 70 "Debug Subsection not properly aligned"); 71 72 DebugSubsectionHeader Header; 73 Header.Kind = uint32_t(Subsection ? Subsection->kind() : Contents.kind()); 74 // The value written into the Header's Length field is only padded to the 75 // container's alignment 76 uint32_t DataSize = Subsection ? Subsection->calculateSerializedSize() 77 : Contents.getRecordData().getLength(); 78 Header.Length = alignTo(DataSize, alignOf(Container)); 79 80 if (auto EC = Writer.writeObject(Header)) 81 return EC; 82 if (Subsection) { 83 if (auto EC = Subsection->commit(Writer)) 84 return EC; 85 } else { 86 if (auto EC = Writer.writeStreamRef(Contents.getRecordData())) 87 return EC; 88 } 89 if (auto EC = Writer.padToAlignment(4)) 90 return EC; 91 92 return Error::success(); 93 } 94