//===- COFF.h - COFF object file implementation -----------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file declares the COFFObjectFile class.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_OBJECT_COFF_H
#define LLVM_OBJECT_COFF_H

#include "llvm/Object/ObjectFile.h"
#include "llvm/Support/COFF.h"
#include "llvm/Support/Endian.h"

namespace llvm {
template <typename T> class ArrayRef;

namespace object {
class ImportDirectoryEntryRef;
class ExportDirectoryEntryRef;
typedef content_iterator<ImportDirectoryEntryRef> import_directory_iterator;
typedef content_iterator<ExportDirectoryEntryRef> export_directory_iterator;

/// The DOS compatible header at the front of all PE/COFF executables.
struct dos_header {
  support::ulittle16_t Magic;
  support::ulittle16_t UsedBytesInTheLastPage;
  support::ulittle16_t FileSizeInPages;
  support::ulittle16_t NumberOfRelocationItems;
  support::ulittle16_t HeaderSizeInParagraphs;
  support::ulittle16_t MinimumExtraParagraphs;
  support::ulittle16_t MaximumExtraParagraphs;
  support::ulittle16_t InitialRelativeSS;
  support::ulittle16_t InitialSP;
  support::ulittle16_t Checksum;
  support::ulittle16_t InitialIP;
  support::ulittle16_t InitialRelativeCS;
  support::ulittle16_t AddressOfRelocationTable;
  support::ulittle16_t OverlayNumber;
  support::ulittle16_t Reserved[4];
  support::ulittle16_t OEMid;
  support::ulittle16_t OEMinfo;
  support::ulittle16_t Reserved2[10];
  support::ulittle32_t AddressOfNewExeHeader;
};

struct coff_file_header {
  support::ulittle16_t Machine;
  support::ulittle16_t NumberOfSections;
  support::ulittle32_t TimeDateStamp;
  support::ulittle32_t PointerToSymbolTable;
  support::ulittle32_t NumberOfSymbols;
  support::ulittle16_t SizeOfOptionalHeader;
  support::ulittle16_t Characteristics;

  bool isImportLibrary() const { return NumberOfSections == 0xffff; }
};

/// The 32-bit PE header that follows the COFF header.
struct pe32_header {
  support::ulittle16_t Magic;
  uint8_t MajorLinkerVersion;
  uint8_t MinorLinkerVersion;
  support::ulittle32_t SizeOfCode;
  support::ulittle32_t SizeOfInitializedData;
  support::ulittle32_t SizeOfUninitializedData;
  support::ulittle32_t AddressOfEntryPoint;
  support::ulittle32_t BaseOfCode;
  support::ulittle32_t BaseOfData;
  support::ulittle32_t ImageBase;
  support::ulittle32_t SectionAlignment;
  support::ulittle32_t FileAlignment;
  support::ulittle16_t MajorOperatingSystemVersion;
  support::ulittle16_t MinorOperatingSystemVersion;
  support::ulittle16_t MajorImageVersion;
  support::ulittle16_t MinorImageVersion;
  support::ulittle16_t MajorSubsystemVersion;
  support::ulittle16_t MinorSubsystemVersion;
  support::ulittle32_t Win32VersionValue;
  support::ulittle32_t SizeOfImage;
  support::ulittle32_t SizeOfHeaders;
  support::ulittle32_t CheckSum;
  support::ulittle16_t Subsystem;
  support::ulittle16_t DLLCharacteristics;
  support::ulittle32_t SizeOfStackReserve;
  support::ulittle32_t SizeOfStackCommit;
  support::ulittle32_t SizeOfHeapReserve;
  support::ulittle32_t SizeOfHeapCommit;
  support::ulittle32_t LoaderFlags;
  support::ulittle32_t NumberOfRvaAndSize;
};

/// The 64-bit PE header that follows the COFF header.
struct pe32plus_header {
  support::ulittle16_t Magic;
  uint8_t MajorLinkerVersion;
  uint8_t MinorLinkerVersion;
  support::ulittle32_t SizeOfCode;
  support::ulittle32_t SizeOfInitializedData;
  support::ulittle32_t SizeOfUninitializedData;
  support::ulittle32_t AddressOfEntryPoint;
  support::ulittle32_t BaseOfCode;
  support::ulittle64_t ImageBase;
  support::ulittle32_t SectionAlignment;
  support::ulittle32_t FileAlignment;
  support::ulittle16_t MajorOperatingSystemVersion;
  support::ulittle16_t MinorOperatingSystemVersion;
  support::ulittle16_t MajorImageVersion;
  support::ulittle16_t MinorImageVersion;
  support::ulittle16_t MajorSubsystemVersion;
  support::ulittle16_t MinorSubsystemVersion;
  support::ulittle32_t Win32VersionValue;
  support::ulittle32_t SizeOfImage;
  support::ulittle32_t SizeOfHeaders;
  support::ulittle32_t CheckSum;
  support::ulittle16_t Subsystem;
  support::ulittle16_t DLLCharacteristics;
  support::ulittle64_t SizeOfStackReserve;
  support::ulittle64_t SizeOfStackCommit;
  support::ulittle64_t SizeOfHeapReserve;
  support::ulittle64_t SizeOfHeapCommit;
  support::ulittle32_t LoaderFlags;
  support::ulittle32_t NumberOfRvaAndSize;
};

struct data_directory {
  support::ulittle32_t RelativeVirtualAddress;
  support::ulittle32_t Size;
};

struct import_directory_table_entry {
  support::ulittle32_t ImportLookupTableRVA;
  support::ulittle32_t TimeDateStamp;
  support::ulittle32_t ForwarderChain;
  support::ulittle32_t NameRVA;
  support::ulittle32_t ImportAddressTableRVA;
};

struct import_lookup_table_entry32 {
  support::ulittle32_t data;

  bool isOrdinal() const { return data & 0x80000000; }

  uint16_t getOrdinal() const {
    assert(isOrdinal() && "ILT entry is not an ordinal!");
    return data & 0xFFFF;
  }

  uint32_t getHintNameRVA() const {
    assert(!isOrdinal() && "ILT entry is not a Hint/Name RVA!");
    return data;
  }
};

struct export_directory_table_entry {
  support::ulittle32_t ExportFlags;
  support::ulittle32_t TimeDateStamp;
  support::ulittle16_t MajorVersion;
  support::ulittle16_t MinorVersion;
  support::ulittle32_t NameRVA;
  support::ulittle32_t OrdinalBase;
  support::ulittle32_t AddressTableEntries;
  support::ulittle32_t NumberOfNamePointers;
  support::ulittle32_t ExportAddressTableRVA;
  support::ulittle32_t NamePointerRVA;
  support::ulittle32_t OrdinalTableRVA;
};

union export_address_table_entry {
  support::ulittle32_t ExportRVA;
  support::ulittle32_t ForwarderRVA;
};

typedef support::ulittle32_t export_name_pointer_table_entry;
typedef support::ulittle16_t export_ordinal_table_entry;

struct coff_symbol {
  struct StringTableOffset {
    support::ulittle32_t Zeroes;
    support::ulittle32_t Offset;
  };

  union {
    char ShortName[8];
    StringTableOffset Offset;
  } Name;

  support::ulittle32_t Value;
  support::ulittle16_t SectionNumber;

  support::ulittle16_t Type;

  support::ulittle8_t StorageClass;
  support::ulittle8_t NumberOfAuxSymbols;

  uint8_t getBaseType() const { return Type & 0x0F; }

  uint8_t getComplexType() const { return (Type & 0xF0) >> 4; }

  bool isFunctionDefinition() const {
    return StorageClass == COFF::IMAGE_SYM_CLASS_EXTERNAL &&
           getBaseType() == COFF::IMAGE_SYM_TYPE_NULL &&
           getComplexType() == COFF::IMAGE_SYM_DTYPE_FUNCTION &&
           !COFF::isReservedSectionNumber(SectionNumber);
  }

  bool isFunctionLineInfo() const {
    return StorageClass == COFF::IMAGE_SYM_CLASS_FUNCTION;
  }

  bool isWeakExternal() const {
    return StorageClass == COFF::IMAGE_SYM_CLASS_WEAK_EXTERNAL ||
           (StorageClass == COFF::IMAGE_SYM_CLASS_EXTERNAL &&
            SectionNumber == COFF::IMAGE_SYM_UNDEFINED && Value == 0);
  }

  bool isFileRecord() const {
    return StorageClass == COFF::IMAGE_SYM_CLASS_FILE;
  }

  bool isSectionDefinition() const {
    // C++/CLI creates external ABS symbols for non-const appdomain globals.
    // These are also followed by an auxiliary section definition.
    bool isAppdomainGlobal = StorageClass == COFF::IMAGE_SYM_CLASS_EXTERNAL &&
                             SectionNumber == COFF::IMAGE_SYM_ABSOLUTE;
    bool isOrdinarySection =
        StorageClass == COFF::IMAGE_SYM_CLASS_STATIC && Value == 0;
    return isAppdomainGlobal || isOrdinarySection;
  }

  bool isCLRToken() const {
    return StorageClass == COFF::IMAGE_SYM_CLASS_CLR_TOKEN;
  }
};

struct coff_section {
  char Name[8];
  support::ulittle32_t VirtualSize;
  support::ulittle32_t VirtualAddress;
  support::ulittle32_t SizeOfRawData;
  support::ulittle32_t PointerToRawData;
  support::ulittle32_t PointerToRelocations;
  support::ulittle32_t PointerToLinenumbers;
  support::ulittle16_t NumberOfRelocations;
  support::ulittle16_t NumberOfLinenumbers;
  support::ulittle32_t Characteristics;

  // Returns true if the actual number of relocations is stored in
  // VirtualAddress field of the first relocation table entry.
  bool hasExtendedRelocations() const {
    return Characteristics & COFF::IMAGE_SCN_LNK_NRELOC_OVFL &&
        NumberOfRelocations == UINT16_MAX;
  };
};

struct coff_relocation {
  support::ulittle32_t VirtualAddress;
  support::ulittle32_t SymbolTableIndex;
  support::ulittle16_t Type;
};

struct coff_aux_function_definition {
  support::ulittle32_t TagIndex;
  support::ulittle32_t TotalSize;
  support::ulittle32_t PointerToLinenumber;
  support::ulittle32_t PointerToNextFunction;
  char Unused[2];
};

struct coff_aux_bf_and_ef_symbol {
  char Unused1[4];
  support::ulittle16_t Linenumber;
  char Unused2[6];
  support::ulittle32_t PointerToNextFunction;
  char Unused3[2];
};

struct coff_aux_weak_external {
  support::ulittle32_t TagIndex;
  support::ulittle32_t Characteristics;
  char Unused[10];
};

struct coff_aux_file {
  char FileName[18];
};

struct coff_aux_section_definition {
  support::ulittle32_t Length;
  support::ulittle16_t NumberOfRelocations;
  support::ulittle16_t NumberOfLinenumbers;
  support::ulittle32_t CheckSum;
  support::ulittle16_t Number;
  support::ulittle8_t Selection;
  char Unused[3];
};

struct coff_aux_clr_token {
  support::ulittle8_t AuxType;
  support::ulittle8_t Reserved;
  support::ulittle32_t SymbolTableIndex;
  char Unused[12];
};

struct coff_load_configuration32 {
  support::ulittle32_t Characteristics;
  support::ulittle32_t TimeDateStamp;
  support::ulittle16_t MajorVersion;
  support::ulittle16_t MinorVersion;
  support::ulittle32_t GlobalFlagsClear;
  support::ulittle32_t GlobalFlagsSet;
  support::ulittle32_t CriticalSectionDefaultTimeout;
  support::ulittle32_t DeCommitFreeBlockThreshold;
  support::ulittle32_t DeCommitTotalFreeThreshold;
  support::ulittle32_t LockPrefixTable;
  support::ulittle32_t MaximumAllocationSize;
  support::ulittle32_t VirtualMemoryThreshold;
  support::ulittle32_t ProcessAffinityMask;
  support::ulittle32_t ProcessHeapFlags;
  support::ulittle16_t CSDVersion;
  uint16_t Reserved;
  support::ulittle32_t EditList;
  support::ulittle32_t SecurityCookie;
  support::ulittle32_t SEHandlerTable;
  support::ulittle32_t SEHandlerCount;
};

struct coff_runtime_function_x64 {
  support::ulittle32_t BeginAddress;
  support::ulittle32_t EndAddress;
  support::ulittle32_t UnwindInformation;
};

class COFFObjectFile : public ObjectFile {
private:
  friend class ImportDirectoryEntryRef;
  friend class ExportDirectoryEntryRef;
  const coff_file_header *COFFHeader;
  const pe32_header *PE32Header;
  const pe32plus_header *PE32PlusHeader;
  const data_directory *DataDirectory;
  const coff_section *SectionTable;
  const coff_symbol *SymbolTable;
  const char *StringTable;
  uint32_t StringTableSize;
  const import_directory_table_entry *ImportDirectory;
  uint32_t NumberOfImportDirectory;
  const export_directory_table_entry *ExportDirectory;

  std::error_code getString(uint32_t offset, StringRef &Res) const;

  const coff_symbol *toSymb(DataRefImpl Symb) const;
  const coff_section *toSec(DataRefImpl Sec) const;
  const coff_relocation *toRel(DataRefImpl Rel) const;

  std::error_code initSymbolTablePtr();
  std::error_code initImportTablePtr();
  std::error_code initExportTablePtr();

protected:
  void moveSymbolNext(DataRefImpl &Symb) const override;
  std::error_code getSymbolName(DataRefImpl Symb,
                                StringRef &Res) const override;
  std::error_code getSymbolAddress(DataRefImpl Symb,
                                   uint64_t &Res) const override;
  std::error_code getSymbolSize(DataRefImpl Symb, uint64_t &Res) const override;
  uint32_t getSymbolFlags(DataRefImpl Symb) const override;
  std::error_code getSymbolType(DataRefImpl Symb,
                                SymbolRef::Type &Res) const override;
  std::error_code getSymbolSection(DataRefImpl Symb,
                                   section_iterator &Res) const override;
  void moveSectionNext(DataRefImpl &Sec) const override;
  std::error_code getSectionName(DataRefImpl Sec,
                                 StringRef &Res) const override;
  std::error_code getSectionAddress(DataRefImpl Sec,
                                    uint64_t &Res) const override;
  std::error_code getSectionSize(DataRefImpl Sec, uint64_t &Res) const override;
  std::error_code getSectionContents(DataRefImpl Sec,
                                     StringRef &Res) const override;
  std::error_code getSectionAlignment(DataRefImpl Sec,
                                      uint64_t &Res) const override;
  std::error_code isSectionText(DataRefImpl Sec, bool &Res) const override;
  std::error_code isSectionData(DataRefImpl Sec, bool &Res) const override;
  std::error_code isSectionBSS(DataRefImpl Sec, bool &Res) const override;
  std::error_code isSectionVirtual(DataRefImpl Sec, bool &Res) const override;
  std::error_code isSectionZeroInit(DataRefImpl Sec, bool &Res) const override;
  std::error_code isSectionReadOnlyData(DataRefImpl Sec,
                                        bool &Res) const override;
  std::error_code isSectionRequiredForExecution(DataRefImpl Sec,
                                                bool &Res) const override;
  std::error_code sectionContainsSymbol(DataRefImpl Sec, DataRefImpl Symb,
                                        bool &Result) const override;
  relocation_iterator section_rel_begin(DataRefImpl Sec) const override;
  relocation_iterator section_rel_end(DataRefImpl Sec) const override;

  void moveRelocationNext(DataRefImpl &Rel) const override;
  std::error_code getRelocationAddress(DataRefImpl Rel,
                                       uint64_t &Res) const override;
  std::error_code getRelocationOffset(DataRefImpl Rel,
                                      uint64_t &Res) const override;
  symbol_iterator getRelocationSymbol(DataRefImpl Rel) const override;
  std::error_code getRelocationType(DataRefImpl Rel,
                                    uint64_t &Res) const override;
  std::error_code
  getRelocationTypeName(DataRefImpl Rel,
                        SmallVectorImpl<char> &Result) const override;
  std::error_code
  getRelocationValueString(DataRefImpl Rel,
                           SmallVectorImpl<char> &Result) const override;

  std::error_code getLibraryNext(DataRefImpl LibData,
                                 LibraryRef &Result) const override;
  std::error_code getLibraryPath(DataRefImpl LibData,
                                 StringRef &Result) const override;

public:
  COFFObjectFile(std::unique_ptr<MemoryBuffer> Object, std::error_code &EC);
  basic_symbol_iterator symbol_begin_impl() const override;
  basic_symbol_iterator symbol_end_impl() const override;
  library_iterator needed_library_begin() const override;
  library_iterator needed_library_end() const override;
  section_iterator section_begin() const override;
  section_iterator section_end() const override;

  const coff_section *getCOFFSection(const SectionRef &Section) const;
  const coff_symbol *getCOFFSymbol(const SymbolRef &Symbol) const;
  const coff_relocation *getCOFFRelocation(const RelocationRef &Reloc) const;

  uint8_t getBytesInAddress() const override;
  StringRef getFileFormatName() const override;
  unsigned getArch() const override;
  StringRef getLoadName() const override;

  import_directory_iterator import_directory_begin() const;
  import_directory_iterator import_directory_end() const;
  export_directory_iterator export_directory_begin() const;
  export_directory_iterator export_directory_end() const;

  std::error_code getHeader(const coff_file_header *&Res) const;
  std::error_code getCOFFHeader(const coff_file_header *&Res) const;
  std::error_code getPE32Header(const pe32_header *&Res) const;
  std::error_code getPE32PlusHeader(const pe32plus_header *&Res) const;
  std::error_code getDataDirectory(uint32_t index,
                                   const data_directory *&Res) const;
  std::error_code getSection(int32_t index, const coff_section *&Res) const;
  std::error_code getSymbol(uint32_t index, const coff_symbol *&Res) const;
  template <typename T>
  std::error_code getAuxSymbol(uint32_t index, const T *&Res) const {
    const coff_symbol *s;
    std::error_code ec = getSymbol(index, s);
    Res = reinterpret_cast<const T *>(s);
    return ec;
  }
  std::error_code getSymbolName(const coff_symbol *symbol,
                                StringRef &Res) const;
  ArrayRef<uint8_t> getSymbolAuxData(const coff_symbol *symbol) const;

  std::error_code getSectionName(const coff_section *Sec, StringRef &Res) const;
  std::error_code getSectionContents(const coff_section *Sec,
                                     ArrayRef<uint8_t> &Res) const;

  std::error_code getVaPtr(uint64_t VA, uintptr_t &Res) const;
  std::error_code getRvaPtr(uint32_t Rva, uintptr_t &Res) const;
  std::error_code getHintName(uint32_t Rva, uint16_t &Hint,
                              StringRef &Name) const;

  static inline bool classof(const Binary *v) { return v->isCOFF(); }
};

// The iterator for the import directory table.
class ImportDirectoryEntryRef {
public:
  ImportDirectoryEntryRef() : OwningObject(nullptr) {}
  ImportDirectoryEntryRef(const import_directory_table_entry *Table, uint32_t I,
                          const COFFObjectFile *Owner)
      : ImportTable(Table), Index(I), OwningObject(Owner) {}

  bool operator==(const ImportDirectoryEntryRef &Other) const;
  void moveNext();
  std::error_code getName(StringRef &Result) const;

  std::error_code
  getImportTableEntry(const import_directory_table_entry *&Result) const;

  std::error_code
  getImportLookupEntry(const import_lookup_table_entry32 *&Result) const;

private:
  const import_directory_table_entry *ImportTable;
  uint32_t Index;
  const COFFObjectFile *OwningObject;
};

// The iterator for the export directory table entry.
class ExportDirectoryEntryRef {
public:
  ExportDirectoryEntryRef() : OwningObject(nullptr) {}
  ExportDirectoryEntryRef(const export_directory_table_entry *Table, uint32_t I,
                          const COFFObjectFile *Owner)
      : ExportTable(Table), Index(I), OwningObject(Owner) {}

  bool operator==(const ExportDirectoryEntryRef &Other) const;
  void moveNext();

  std::error_code getDllName(StringRef &Result) const;
  std::error_code getOrdinalBase(uint32_t &Result) const;
  std::error_code getOrdinal(uint32_t &Result) const;
  std::error_code getExportRVA(uint32_t &Result) const;
  std::error_code getSymbolName(StringRef &Result) const;

private:
  const export_directory_table_entry *ExportTable;
  uint32_t Index;
  const COFFObjectFile *OwningObject;
};
} // end namespace object
} // end namespace llvm

#endif
