//===- 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::little16_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;
  }
};

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;
};

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

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

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];
};

class COFFObjectFile : public ObjectFile {
private:
  friend class ImportDirectoryEntryRef;
  friend class ExportDirectoryEntryRef;
  const coff_file_header *COFFHeader;
  const pe32_header      *PE32Header;
  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;

        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;

        error_code        initSymbolTablePtr();
        error_code        initImportTablePtr();
        error_code        initExportTablePtr();

protected:
  virtual error_code getSymbolNext(DataRefImpl Symb, SymbolRef &Res) const;
  virtual error_code getSymbolName(DataRefImpl Symb, StringRef &Res) const;
  virtual error_code getSymbolFileOffset(DataRefImpl Symb, uint64_t &Res) const;
  virtual error_code getSymbolAddress(DataRefImpl Symb, uint64_t &Res) const;
  virtual error_code getSymbolSize(DataRefImpl Symb, uint64_t &Res) const;
  virtual error_code getSymbolFlags(DataRefImpl Symb, uint32_t &Res) const;
  virtual error_code getSymbolType(DataRefImpl Symb, SymbolRef::Type &Res) const;
  virtual error_code getSymbolSection(DataRefImpl Symb,
                                      section_iterator &Res) const;
  virtual error_code getSymbolValue(DataRefImpl Symb, uint64_t &Val) const;

  virtual error_code getSectionNext(DataRefImpl Sec, SectionRef &Res) const;
  virtual error_code getSectionName(DataRefImpl Sec, StringRef &Res) const;
  virtual error_code getSectionAddress(DataRefImpl Sec, uint64_t &Res) const;
  virtual error_code getSectionSize(DataRefImpl Sec, uint64_t &Res) const;
  virtual error_code getSectionContents(DataRefImpl Sec, StringRef &Res) const;
  virtual error_code getSectionAlignment(DataRefImpl Sec, uint64_t &Res) const;
  virtual error_code isSectionText(DataRefImpl Sec, bool &Res) const;
  virtual error_code isSectionData(DataRefImpl Sec, bool &Res) const;
  virtual error_code isSectionBSS(DataRefImpl Sec, bool &Res) const;
  virtual error_code isSectionVirtual(DataRefImpl Sec, bool &Res) const;
  virtual error_code isSectionZeroInit(DataRefImpl Sec, bool &Res) const;
  virtual error_code isSectionReadOnlyData(DataRefImpl Sec, bool &Res) const;
  virtual error_code isSectionRequiredForExecution(DataRefImpl Sec,
                                                   bool &Res) const;
  virtual error_code sectionContainsSymbol(DataRefImpl Sec, DataRefImpl Symb,
                                           bool &Result) const;
  virtual relocation_iterator section_rel_begin(DataRefImpl Sec) const;
  virtual relocation_iterator section_rel_end(DataRefImpl Sec) const;

  virtual error_code getRelocationNext(DataRefImpl Rel,
                                       RelocationRef &Res) const;
  virtual error_code getRelocationAddress(DataRefImpl Rel,
                                          uint64_t &Res) const;
  virtual error_code getRelocationOffset(DataRefImpl Rel,
                                         uint64_t &Res) const;
  virtual symbol_iterator getRelocationSymbol(DataRefImpl Rel) const;
  virtual error_code getRelocationType(DataRefImpl Rel,
                                       uint64_t &Res) const;
  virtual error_code getRelocationTypeName(DataRefImpl Rel,
                                           SmallVectorImpl<char> &Result) const;
  virtual error_code getRelocationValueString(DataRefImpl Rel,
                                           SmallVectorImpl<char> &Result) const;

  virtual error_code getLibraryNext(DataRefImpl LibData,
                                    LibraryRef &Result) const;
  virtual error_code getLibraryPath(DataRefImpl LibData,
                                    StringRef &Result) const;

public:
  COFFObjectFile(MemoryBuffer *Object, error_code &ec);
  virtual symbol_iterator begin_symbols() const;
  virtual symbol_iterator end_symbols() const;
  virtual symbol_iterator begin_dynamic_symbols() const;
  virtual symbol_iterator end_dynamic_symbols() const;
  virtual library_iterator begin_libraries_needed() const;
  virtual library_iterator end_libraries_needed() const;
  virtual section_iterator begin_sections() const;
  virtual section_iterator end_sections() const;

  const coff_section *getCOFFSection(section_iterator &It) const;
  const coff_symbol *getCOFFSymbol(symbol_iterator &It) const;
  const coff_relocation *getCOFFRelocation(relocation_iterator &It) const;

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

  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;

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

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

  error_code getRvaPtr(uint32_t Rva, uintptr_t &Res) const;
  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(0) {}
  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;
  error_code getNext(ImportDirectoryEntryRef &Result) const;
  error_code getName(StringRef &Result) const;

  error_code
  getImportTableEntry(const import_directory_table_entry *&Result) const;

  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(0) {}
  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;
  error_code getNext(ExportDirectoryEntryRef &Result) const;

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