//===- Archive.h - ar archive file format -----------------------*- 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 declares the ar archive file format class.
 
//
 
//===----------------------------------------------------------------------===//
 
 
 
#ifndef LLVM_OBJECT_ARCHIVE_H
 
#define LLVM_OBJECT_ARCHIVE_H
 
 
 
#include "llvm/ADT/StringRef.h"
 
#include "llvm/ADT/fallible_iterator.h"
 
#include "llvm/ADT/iterator_range.h"
 
#include "llvm/Object/Binary.h"
 
#include "llvm/Support/Chrono.h"
 
#include "llvm/Support/Error.h"
 
#include "llvm/Support/FileSystem.h"
 
#include "llvm/Support/MemoryBuffer.h"
 
#include <cassert>
 
#include <cstdint>
 
#include <memory>
 
#include <string>
 
#include <vector>
 
 
 
namespace llvm {
 
namespace object {
 
 
 
const char ArchiveMagic[] = "!<arch>\n";
 
const char ThinArchiveMagic[] = "!<thin>\n";
 
const char BigArchiveMagic[] = "<bigaf>\n";
 
 
 
class Archive;
 
 
 
class AbstractArchiveMemberHeader {
 
protected:
 
  AbstractArchiveMemberHeader(const Archive *Parent) : Parent(Parent){};
 
 
 
public:
 
  friend class Archive;
 
  virtual std::unique_ptr<AbstractArchiveMemberHeader> clone() const = 0;
 
  virtual ~AbstractArchiveMemberHeader() = default;
 
 
 
  /// Get the name without looking up long names.
 
  virtual Expected<StringRef> getRawName() const = 0;
 
  virtual StringRef getRawAccessMode() const = 0;
 
  virtual StringRef getRawLastModified() const = 0;
 
  virtual StringRef getRawUID() const = 0;
 
  virtual StringRef getRawGID() const = 0;
 
 
 
  /// Get the name looking up long names.
 
  virtual Expected<StringRef> getName(uint64_t Size) const = 0;
 
  virtual Expected<uint64_t> getSize() const = 0;
 
  virtual uint64_t getOffset() const = 0;
 
 
 
  /// Get next file member location.
 
  virtual Expected<const char *> getNextChildLoc() const = 0;
 
  virtual Expected<bool> isThin() const = 0;
 
 
 
  Expected<sys::fs::perms> getAccessMode() const;
 
  Expected<sys::TimePoint<std::chrono::seconds>> getLastModified() const;
 
  Expected<unsigned> getUID() const;
 
  Expected<unsigned> getGID() const;
 
 
 
  /// Returns the size in bytes of the format-defined member header of the
 
  /// concrete archive type.
 
  virtual uint64_t getSizeOf() const = 0;
 
 
 
  const Archive *Parent;
 
};
 
 
 
template <typename T>
 
class CommonArchiveMemberHeader : public AbstractArchiveMemberHeader {
 
public:
 
  CommonArchiveMemberHeader(const Archive *Parent, const T *RawHeaderPtr)
 
      : AbstractArchiveMemberHeader(Parent), ArMemHdr(RawHeaderPtr){};
 
  StringRef getRawAccessMode() const override;
 
  StringRef getRawLastModified() const override;
 
  StringRef getRawUID() const override;
 
  StringRef getRawGID() const override;
 
 
 
  uint64_t getOffset() const override;
 
  uint64_t getSizeOf() const override { return sizeof(T); }
 
 
 
  T const *ArMemHdr;
 
};
 
 
 
struct UnixArMemHdrType {
 
  char Name[16];
 
  char LastModified[12];
 
  char UID[6];
 
  char GID[6];
 
  char AccessMode[8];
 
  char Size[10]; ///< Size of data, not including header or padding.
 
  char Terminator[2];
 
};
 
 
 
class ArchiveMemberHeader : public CommonArchiveMemberHeader<UnixArMemHdrType> {
 
public:
 
  ArchiveMemberHeader(const Archive *Parent, const char *RawHeaderPtr,
 
                      uint64_t Size, Error *Err);
 
 
 
  std::unique_ptr<AbstractArchiveMemberHeader> clone() const override {
 
    return std::make_unique<ArchiveMemberHeader>(*this);
 
  }
 
 
 
  Expected<StringRef> getRawName() const override;
 
 
 
  Expected<StringRef> getName(uint64_t Size) const override;
 
  Expected<uint64_t> getSize() const override;
 
  Expected<const char *> getNextChildLoc() const override;
 
  Expected<bool> isThin() const override;
 
};
 
 
 
// File Member Header
 
struct BigArMemHdrType {
 
  char Size[20];       // File member size in decimal
 
  char NextOffset[20]; // Next member offset in decimal
 
  char PrevOffset[20]; // Previous member offset in decimal
 
  char LastModified[12];
 
  char UID[12];
 
  char GID[12];
 
  char AccessMode[12];
 
  char NameLen[4]; // File member name length in decimal
 
  union {
 
    char Name[2]; // Start of member name
 
    char Terminator[2];
 
  };
 
};
 
 
 
// Define file member header of AIX big archive.
 
class BigArchiveMemberHeader
 
    : public CommonArchiveMemberHeader<BigArMemHdrType> {
 
 
 
public:
 
  BigArchiveMemberHeader(Archive const *Parent, const char *RawHeaderPtr,
 
                         uint64_t Size, Error *Err);
 
  std::unique_ptr<AbstractArchiveMemberHeader> clone() const override {
 
    return std::make_unique<BigArchiveMemberHeader>(*this);
 
  }
 
 
 
  Expected<StringRef> getRawName() const override;
 
  Expected<uint64_t> getRawNameSize() const;
 
 
 
  Expected<StringRef> getName(uint64_t Size) const override;
 
  Expected<uint64_t> getSize() const override;
 
  Expected<const char *> getNextChildLoc() const override;
 
  Expected<uint64_t> getNextOffset() const;
 
  Expected<bool> isThin() const override { return false; }
 
};
 
 
 
class Archive : public Binary {
 
  virtual void anchor();
 
 
 
public:
 
  class Child {
 
    friend Archive;
 
    friend AbstractArchiveMemberHeader;
 
 
 
    const Archive *Parent;
 
    std::unique_ptr<AbstractArchiveMemberHeader> Header;
 
    /// Includes header but not padding byte.
 
    StringRef Data;
 
    /// Offset from Data to the start of the file.
 
    uint16_t StartOfFile;
 
 
 
    Expected<bool> isThinMember() const;
 
 
 
  public:
 
    Child(const Archive *Parent, const char *Start, Error *Err);
 
    Child(const Archive *Parent, StringRef Data, uint16_t StartOfFile);
 
 
 
    Child(const Child &C)
 
        : Parent(C.Parent), Data(C.Data), StartOfFile(C.StartOfFile) {
 
      if (C.Header)
 
        Header = C.Header->clone();
 
    }
 
 
 
    Child(Child &&C) {
 
      Parent = std::move(C.Parent);
 
      Header = std::move(C.Header);
 
      Data = C.Data;
 
      StartOfFile = C.StartOfFile;
 
    }
 
 
 
    Child &operator=(Child &&C) noexcept {
 
      if (&C == this)
 
        return *this;
 
 
 
      Parent = std::move(C.Parent);
 
      Header = std::move(C.Header);
 
      Data = C.Data;
 
      StartOfFile = C.StartOfFile;
 
 
 
      return *this;
 
    }
 
 
 
    Child &operator=(const Child &C) {
 
      if (&C == this)
 
        return *this;
 
 
 
      Parent = C.Parent;
 
      if (C.Header)
 
        Header = C.Header->clone();
 
      Data = C.Data;
 
      StartOfFile = C.StartOfFile;
 
 
 
      return *this;
 
    }
 
 
 
    bool operator==(const Child &other) const {
 
      assert(!Parent || !other.Parent || Parent == other.Parent);
 
      return Data.begin() == other.Data.begin();
 
    }
 
 
 
    const Archive *getParent() const { return Parent; }
 
    Expected<Child> getNext() const;
 
 
 
    Expected<StringRef> getName() const;
 
    Expected<std::string> getFullName() const;
 
    Expected<StringRef> getRawName() const { return Header->getRawName(); }
 
 
 
    Expected<sys::TimePoint<std::chrono::seconds>> getLastModified() const {
 
      return Header->getLastModified();
 
    }
 
 
 
    StringRef getRawLastModified() const {
 
      return Header->getRawLastModified();
 
    }
 
 
 
    Expected<unsigned> getUID() const { return Header->getUID(); }
 
    Expected<unsigned> getGID() const { return Header->getGID(); }
 
 
 
    Expected<sys::fs::perms> getAccessMode() const {
 
      return Header->getAccessMode();
 
    }
 
 
 
    /// \return the size of the archive member without the header or padding.
 
    Expected<uint64_t> getSize() const;
 
    /// \return the size in the archive header for this member.
 
    Expected<uint64_t> getRawSize() const;
 
 
 
    Expected<StringRef> getBuffer() const;
 
    uint64_t getChildOffset() const;
 
    uint64_t getDataOffset() const { return getChildOffset() + StartOfFile; }
 
 
 
    Expected<MemoryBufferRef> getMemoryBufferRef() const;
 
 
 
    Expected<std::unique_ptr<Binary>>
 
    getAsBinary(LLVMContext *Context = nullptr) const;
 
  };
 
 
 
  class ChildFallibleIterator {
 
    Child C;
 
 
 
  public:
 
    ChildFallibleIterator() : C(Child(nullptr, nullptr, nullptr)) {}
 
    ChildFallibleIterator(const Child &C) : C(C) {}
 
 
 
    const Child *operator->() const { return &C; }
 
    const Child &operator*() const { return C; }
 
 
 
    bool operator==(const ChildFallibleIterator &other) const {
 
      // Ignore errors here: If an error occurred during increment then getNext
 
      // will have been set to child_end(), and the following comparison should
 
      // do the right thing.
 
      return C == other.C;
 
    }
 
 
 
    bool operator!=(const ChildFallibleIterator &other) const {
 
      return !(*this == other);
 
    }
 
 
 
    Error inc() {
 
      auto NextChild = C.getNext();
 
      if (!NextChild)
 
        return NextChild.takeError();
 
      C = std::move(*NextChild);
 
      return Error::success();
 
    }
 
  };
 
 
 
  using child_iterator = fallible_iterator<ChildFallibleIterator>;
 
 
 
  class Symbol {
 
    const Archive *Parent;
 
    uint32_t SymbolIndex;
 
    uint32_t StringIndex; // Extra index to the string.
 
 
 
  public:
 
    Symbol(const Archive *p, uint32_t symi, uint32_t stri)
 
        : Parent(p), SymbolIndex(symi), StringIndex(stri) {}
 
 
 
    bool operator==(const Symbol &other) const {
 
      return (Parent == other.Parent) && (SymbolIndex == other.SymbolIndex);
 
    }
 
 
 
    StringRef getName() const;
 
    Expected<Child> getMember() const;
 
    Symbol getNext() const;
 
  };
 
 
 
  class symbol_iterator {
 
    Symbol symbol;
 
 
 
  public:
 
    symbol_iterator(const Symbol &s) : symbol(s) {}
 
 
 
    const Symbol *operator->() const { return &symbol; }
 
    const Symbol &operator*() const { return symbol; }
 
 
 
    bool operator==(const symbol_iterator &other) const {
 
      return symbol == other.symbol;
 
    }
 
 
 
    bool operator!=(const symbol_iterator &other) const {
 
      return !(*this == other);
 
    }
 
 
 
    symbol_iterator &operator++() { // Preincrement
 
      symbol = symbol.getNext();
 
      return *this;
 
    }
 
  };
 
 
 
  Archive(MemoryBufferRef Source, Error &Err);
 
  static Expected<std::unique_ptr<Archive>> create(MemoryBufferRef Source);
 
 
 
  /// Size field is 10 decimal digits long
 
  static const uint64_t MaxMemberSize = 9999999999;
 
 
 
  enum Kind { K_GNU, K_GNU64, K_BSD, K_DARWIN, K_DARWIN64, K_COFF, K_AIXBIG };
 
 
 
  Kind kind() const { return (Kind)Format; }
 
  bool isThin() const { return IsThin; }
 
  static object::Archive::Kind getDefaultKindForHost();
 
 
 
  child_iterator child_begin(Error &Err, bool SkipInternal = true) const;
 
  child_iterator child_end() const;
 
  iterator_range<child_iterator> children(Error &Err,
 
                                          bool SkipInternal = true) const {
 
    return make_range(child_begin(Err, SkipInternal), child_end());
 
  }
 
 
 
  symbol_iterator symbol_begin() const;
 
  symbol_iterator symbol_end() const;
 
  iterator_range<symbol_iterator> symbols() const {
 
    return make_range(symbol_begin(), symbol_end());
 
  }
 
 
 
  static bool classof(Binary const *v) { return v->isArchive(); }
 
 
 
  // check if a symbol is in the archive
 
  Expected<std::optional<Child>> findSym(StringRef name) const;
 
 
 
  virtual bool isEmpty() const;
 
  bool hasSymbolTable() const;
 
  StringRef getSymbolTable() const { return SymbolTable; }
 
  StringRef getStringTable() const { return StringTable; }
 
  uint32_t getNumberOfSymbols() const;
 
  virtual uint64_t getFirstChildOffset() const { return getArchiveMagicLen(); }
 
 
 
  std::vector<std::unique_ptr<MemoryBuffer>> takeThinBuffers() {
 
    return std::move(ThinBuffers);
 
  }
 
 
 
  std::unique_ptr<AbstractArchiveMemberHeader>
 
  createArchiveMemberHeader(const char *RawHeaderPtr, uint64_t Size,
 
                            Error *Err) const;
 
 
 
protected:
 
  uint64_t getArchiveMagicLen() const;
 
  void setFirstRegular(const Child &C);
 
 
 
  StringRef SymbolTable;
 
  StringRef StringTable;
 
 
 
private:
 
  StringRef FirstRegularData;
 
  uint16_t FirstRegularStartOfFile = -1;
 
 
 
  unsigned Format : 3;
 
  unsigned IsThin : 1;
 
  mutable std::vector<std::unique_ptr<MemoryBuffer>> ThinBuffers;
 
};
 
 
 
class BigArchive : public Archive {
 
public:
 
  /// Fixed-Length Header.
 
  struct FixLenHdr {
 
    char Magic[sizeof(BigArchiveMagic) - 1]; ///< Big archive magic string.
 
    char MemOffset[20];                      ///< Offset to member table.
 
    char GlobSymOffset[20];                  ///< Offset to global symbol table.
 
    char
 
        GlobSym64Offset[20]; ///< Offset global symbol table for 64-bit objects.
 
    char FirstChildOffset[20]; ///< Offset to first archive member.
 
    char LastChildOffset[20];  ///< Offset to last archive member.
 
    char FreeOffset[20];       ///< Offset to first mem on free list.
 
  };
 
 
 
  const FixLenHdr *ArFixLenHdr;
 
  uint64_t FirstChildOffset = 0;
 
  uint64_t LastChildOffset = 0;
 
 
 
public:
 
  BigArchive(MemoryBufferRef Source, Error &Err);
 
  uint64_t getFirstChildOffset() const override { return FirstChildOffset; }
 
  uint64_t getLastChildOffset() const { return LastChildOffset; }
 
  bool isEmpty() const override {
 
    return Data.getBufferSize() == sizeof(FixLenHdr);
 
  };
 
};
 
 
 
} // end namespace object
 
} // end namespace llvm
 
 
 
#endif // LLVM_OBJECT_ARCHIVE_H