//===-- LVCodeViewReader.h --------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines the LVCodeViewReader class, which is used to describe a
// debug information (COFF) reader.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_DEBUGINFO_LOGICALVIEW_READERS_CODEVIEWREADER_H
#define LLVM_DEBUGINFO_LOGICALVIEW_READERS_CODEVIEWREADER_H

#include "llvm/DebugInfo/CodeView/AppendingTypeTableBuilder.h"
#include "llvm/DebugInfo/CodeView/DebugInlineeLinesSubsection.h"
#include "llvm/DebugInfo/CodeView/DebugLinesSubsection.h"
#include "llvm/DebugInfo/CodeView/DebugStringTableSubsection.h"
#include "llvm/DebugInfo/CodeView/TypeRecord.h"
#include "llvm/DebugInfo/LogicalView/Readers/LVBinaryReader.h"
#include "llvm/DebugInfo/LogicalView/Readers/LVCodeViewVisitor.h"
#include "llvm/DebugInfo/PDB/Native/NativeSession.h"
#include "llvm/DebugInfo/PDB/PDB.h"
#include "llvm/Support/BinaryByteStream.h"
#include "llvm/Support/BinaryItemStream.h"
#include "llvm/Support/BinaryStreamArray.h"

namespace llvm {
template <> struct BinaryItemTraits<codeview::CVType> {
  static size_t length(const codeview::CVType &Item) { return Item.length(); }
  static ArrayRef<uint8_t> bytes(const codeview::CVType &Item) {
    return Item.data();
  }
};

namespace codeview {
class LazyRandomTypeCollection;
}
namespace object {
struct coff_section;
}
namespace pdb {
class SymbolGroup;
}
namespace logicalview {

class LVElement;
class LVLine;
class LVScope;
class LVScopeCompileUnit;
class LVSymbol;
class LVType;
class LVTypeVisitor;
class LVSymbolVisitor;
class LVSymbolVisitorDelegate;

using LVNames = SmallVector<StringRef, 16>;

// The ELF reader uses the DWARF constants to create the logical elements.
// The DW_TAG_* and DW_AT_* are used to select the logical object and to
// set specific attributes, such as name, type, etc.
// As the CodeView constants are different to the DWARF constants, the
// CodeView reader will map them to the DWARF ones.

class LVCodeViewReader final : public LVBinaryReader {
  friend class LVTypeVisitor;
  friend class LVSymbolVisitor;
  friend class LVSymbolVisitorDelegate;

  using LVModules = std::vector<LVScope *>;
  LVModules Modules;

  // Encapsulates access to the input file and any dependent type server,
  // including any precompiled header object.
  llvm::pdb::InputFile Input;
  std::shared_ptr<llvm::pdb::InputFile> TypeServer;
  std::shared_ptr<LazyRandomTypeCollection> PrecompHeader;

  // Persistance data when loading a type server.
  ErrorOr<std::unique_ptr<MemoryBuffer>> BuffOrErr = nullptr;
  std::unique_ptr<MemoryBuffer> MemBuffer;
  std::unique_ptr<llvm::pdb::IPDBSession> Session;
  std::unique_ptr<llvm::pdb::NativeSession> PdbSession;

  // Persistance data when loading a precompiled header.
  BumpPtrAllocator BuilderAllocator;
  std::unique_ptr<AppendingTypeTableBuilder> Builder;
  std::unique_ptr<BinaryItemStream<CVType>> ItemStream;
  std::unique_ptr<BinaryStreamReader> ReaderPrecomp;
  std::vector<CVType> TypeArray;
  CVTypeArray TypeStream;
  CVTypeArray CVTypesPrecomp;

  // Persistance data when loading an executable file.
  std::unique_ptr<MemoryBuffer> BinaryBuffer;
  std::unique_ptr<llvm::object::Binary> BinaryExecutable;

  Error loadTargetInfo(const object::ObjectFile &Obj);
  Error loadTargetInfo(const llvm::pdb::PDBFile &Pdb);

  void mapRangeAddress(const object::ObjectFile &Obj,
                       const object::SectionRef &Section,
                       bool IsComdat) override;

  llvm::object::COFFObjectFile &getObj() { return Input.obj(); }
  llvm::pdb::PDBFile &getPdb() { return Input.pdb(); }
  bool isObj() const { return Input.isObj(); }
  bool isPdb() const { return Input.isPdb(); }
  StringRef getFileName() { return Input.getFilePath(); }

  // Pathname to executable image.
  std::string ExePath;

  LVOffset CurrentOffset = 0;
  int32_t CurrentModule = -1;

  using RelocMapTy = DenseMap<const llvm::object::coff_section *,
                              std::vector<llvm::object::RelocationRef>>;
  RelocMapTy RelocMap;

  // Object files have only one type stream that contains both types and ids.
  // Precompiled header objects don't contain an IPI stream. Use the TPI.
  LazyRandomTypeCollection &types() {
    return TypeServer ? TypeServer->types()
                      : (PrecompHeader ? *PrecompHeader : Input.types());
  }
  LazyRandomTypeCollection &ids() {
    return TypeServer ? TypeServer->ids()
                      : (PrecompHeader ? *PrecompHeader : Input.ids());
  }

  LVLogicalVisitor LogicalVisitor;

  Expected<StringRef>
  getFileNameForFileOffset(uint32_t FileOffset,
                           const llvm::pdb::SymbolGroup *SG = nullptr);
  void printRelocatedField(StringRef Label,
                           const llvm::object::coff_section *CoffSection,
                           uint32_t RelocOffset, uint32_t Offset,
                           StringRef *RelocSym);

  Error printFileNameForOffset(StringRef Label, uint32_t FileOffset,
                               const llvm::pdb::SymbolGroup *SG = nullptr);

  Error loadPrecompiledObject(PrecompRecord &Precomp, CVTypeArray &CVTypesObj);
  Error loadTypeServer(TypeServer2Record &TS);
  Error traverseTypes(llvm::pdb::PDBFile &Pdb, LazyRandomTypeCollection &Types,
                      LazyRandomTypeCollection &Ids);

  Error collectInlineeInfo(DebugInlineeLinesSubsectionRef &Lines,
                           const llvm::pdb::SymbolGroup *SG = nullptr);

  void cacheRelocations();
  Error resolveSymbol(const llvm::object::coff_section *CoffSection,
                      uint64_t Offset, llvm::object::SymbolRef &Sym);
  Error resolveSymbolName(const llvm::object::coff_section *CoffSection,
                          uint64_t Offset, StringRef &Name);
  Error traverseTypeSection(StringRef SectionName,
                            const llvm::object::SectionRef &Section);
  Error traverseSymbolSection(StringRef SectionName,
                              const llvm::object::SectionRef &Section);
  Error traverseInlineeLines(StringRef Subsection);

  DebugChecksumsSubsectionRef CVFileChecksumTable;
  DebugStringTableSubsectionRef CVStringTable;

  Error traverseSymbolsSubsection(StringRef Subsection,
                                  const llvm::object::SectionRef &Section,
                                  StringRef SectionContents);

  /// Given a .debug$S section, find the string table and file checksum table.
  /// This function taken from (COFFDumper.cpp).
  /// TODO: It can be moved to the COFF library.
  Error initializeFileAndStringTables(BinaryStreamReader &Reader);

  Error createLines(const FixedStreamArray<LineNumberEntry> &LineNumbers,
                    LVAddress Addendum, uint32_t Segment, uint32_t Begin,
                    uint32_t Size, uint32_t NameIndex,
                    const llvm::pdb::SymbolGroup *SG = nullptr);
  Error createScopes(llvm::object::COFFObjectFile &Obj);
  Error createScopes(llvm::pdb::PDBFile &Pdb);
  Error processModule();

protected:
  Error createScopes() override;
  void sortScopes() override;

public:
  LVCodeViewReader() = delete;
  LVCodeViewReader(StringRef Filename, StringRef FileFormatName,
                   llvm::object::COFFObjectFile &Obj, ScopedPrinter &W,
                   StringRef ExePath)
      : LVBinaryReader(Filename, FileFormatName, W, LVBinaryType::COFF),
        Input(&Obj), ExePath(ExePath), LogicalVisitor(this, W, Input) {}
  LVCodeViewReader(StringRef Filename, StringRef FileFormatName,
                   llvm::pdb::PDBFile &Pdb, ScopedPrinter &W, StringRef ExePath)
      : LVBinaryReader(Filename, FileFormatName, W, LVBinaryType::COFF),
        Input(&Pdb), ExePath(ExePath), LogicalVisitor(this, W, Input) {}
  LVCodeViewReader(const LVCodeViewReader &) = delete;
  LVCodeViewReader &operator=(const LVCodeViewReader &) = delete;
  ~LVCodeViewReader() = default;

  void getLinkageName(const llvm::object::coff_section *CoffSection,
                      uint32_t RelocOffset, uint32_t Offset,
                      StringRef *RelocSym);

  void addModule(LVScope *Scope) { Modules.push_back(Scope); }
  LVScope *getScopeForModule(uint32_t Modi) {
    return Modi >= Modules.size() ? nullptr : Modules[Modi];
  }

  // Get the string representation for the CodeView symbols.
  static StringRef getSymbolKindName(SymbolKind Kind);
  static std::string formatRegisterId(RegisterId Register, CPUType CPU);

  std::string getRegisterName(LVSmall Opcode,
                              ArrayRef<uint64_t> Operands) override;

  bool isSystemEntry(LVElement *Element, StringRef Name) const override;

  void print(raw_ostream &OS) const;
  void printRecords(raw_ostream &OS) const override {
    LogicalVisitor.printRecords(OS);
  };

#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
  void dump() const { print(dbgs()); }
#endif
};

} // end namespace logicalview
} // end namespace llvm

#endif // LLVM_DEBUGINFO_LOGICALVIEW_READERS_CODEVIEWREADER_H