include/llvm/DebugInfo/CodeView/DebugSubsectionRecord.h

   1 //===- DebugSubsectionRecord.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_DEBUGSUBSECTIONRECORD_H
  10 #define LLVM_DEBUGINFO_CODEVIEW_DEBUGSUBSECTIONRECORD_H
  11
  12 #include "llvm/DebugInfo/CodeView/CodeView.h"
  13 #include "llvm/Support/BinaryStreamArray.h"
  14 #include "llvm/Support/BinaryStreamRef.h"
  15 #include "llvm/Support/Endian.h"
  16 #include "llvm/Support/Error.h"
  17 #include "llvm/Support/MathExtras.h"
  18 #include <cstdint>
  19 #include <memory>
  20
  21 namespace llvm {
  22
  23 class BinaryStreamWriter;
  24
  25 namespace codeview {
  26
  27 class DebugSubsection;
  28
  29 // Corresponds to the `CV_DebugSSubsectionHeader_t` structure.
  30 struct DebugSubsectionHeader {
  31   support::ulittle32_t Kind;   // codeview::DebugSubsectionKind enum
  32   support::ulittle32_t Length; // number of bytes occupied by this record.
  33 };
  34
  35 class DebugSubsectionRecord {
  36 public:
  37   DebugSubsectionRecord();
  38   DebugSubsectionRecord(DebugSubsectionKind Kind, BinaryStreamRef Data,
  39                         CodeViewContainer Container);
  40
  41   static Error initialize(BinaryStreamRef Stream, DebugSubsectionRecord &Info,
  42                           CodeViewContainer Container);
  43
  44   uint32_t getRecordLength() const;
  45   DebugSubsectionKind kind() const;
  46   BinaryStreamRef getRecordData() const;
  47
  48 private:
  49   CodeViewContainer Container = CodeViewContainer::ObjectFile;
  50   DebugSubsectionKind Kind = DebugSubsectionKind::None;
  51   BinaryStreamRef Data;
  52 };
  53
  54 class DebugSubsectionRecordBuilder {
  55 public:
  56   DebugSubsectionRecordBuilder(std::shared_ptr<DebugSubsection> Subsection,
  57                                CodeViewContainer Container);
  58
  59   /// Use this to copy existing subsections directly from source to destination.
  60   /// For example, line table subsections in an object file only need to be
  61   /// relocated before being copied into the PDB.
  62   DebugSubsectionRecordBuilder(const DebugSubsectionRecord &Contents,
  63                                CodeViewContainer Container);
  64
  65   uint32_t calculateSerializedLength();
  66   Error commit(BinaryStreamWriter &Writer) const;
  67
  68 private:
  69   /// The subsection to build. Will be null if Contents is non-empty.
  70   std::shared_ptr<DebugSubsection> Subsection;
  71
  72   /// The bytes of the subsection. Only non-empty if Subsection is null.
  73   DebugSubsectionRecord Contents;
  74
  75   CodeViewContainer Container;
  76 };
  77
  78 } // end namespace codeview
  79
  80 template <> struct VarStreamArrayExtractor<codeview::DebugSubsectionRecord> {
  81   Error operator()(BinaryStreamRef Stream, uint32_t &Length,
  82                    codeview::DebugSubsectionRecord &Info) {
  83     // FIXME: We need to pass the container type through to this function.  In
  84     // practice this isn't super important since the subsection header describes
  85     // its length and we can just skip it.  It's more important when writing.
  86     if (auto EC = codeview::DebugSubsectionRecord::initialize(
  87             Stream, Info, codeview::CodeViewContainer::Pdb))
  88       return EC;
  89     Length = alignTo(Info.getRecordLength(), 4);
  90     return Error::success();
  91   }
  92 };
  93
  94 namespace codeview {
  95
  96 using DebugSubsectionArray = VarStreamArray<DebugSubsectionRecord>;
  97
  98 } // end namespace codeview
  99
 100 } // end namespace llvm
 101
 102 #endif // LLVM_DEBUGINFO_CODEVIEW_DEBUGSUBSECTIONRECORD_H