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

#ifndef liblldb_AuxVector_H_
#define liblldb_AuxVector_H_

// C Includes
// C++ Includes
#include <vector>

// Other libraries and framework includes
#include "lldb/lldb-forward.h"

namespace lldb_private {
class DataExtractor;
}

/// @class AuxVector
/// @brief Represents a processes auxiliary vector.
///
/// When a process is loaded on Linux a vector of values is placed onto the
/// stack communicating operating system specific information.  On construction
/// this class locates and parses this information and provides a simple
/// read-only interface to the entries found.
class AuxVector {

public:
  AuxVector(lldb_private::Process *process);

  struct Entry {
    uint64_t type;
    uint64_t value;

    Entry() : type(0), value(0) {}
  };

  /// Constants describing the type of entry.
  /// On Linux, running "LD_SHOW_AUXV=1 ./executable" will spew AUX information.
  enum EntryType {
    AT_NULL = 0,      ///< End of auxv.
    AT_IGNORE = 1,    ///< Ignore entry.
    AT_EXECFD = 2,    ///< File descriptor of program.
    AT_PHDR = 3,      ///< Program headers.
    AT_PHENT = 4,     ///< Size of program header.
    AT_PHNUM = 5,     ///< Number of program headers.
    AT_PAGESZ = 6,    ///< Page size.
    AT_BASE = 7,      ///< Interpreter base address.
    AT_FLAGS = 8,     ///< Flags.
    AT_ENTRY = 9,     ///< Program entry point.
    AT_NOTELF = 10,   ///< Set if program is not an ELF.
    AT_UID = 11,      ///< UID.
    AT_EUID = 12,     ///< Effective UID.
    AT_GID = 13,      ///< GID.
    AT_EGID = 14,     ///< Effective GID.
    AT_CLKTCK = 17,   ///< Clock frequency (e.g. times(2)).
    AT_PLATFORM = 15, ///< String identifying platform.
    AT_HWCAP = 16,    ///< Machine dependent hints about processor capabilities.
    AT_FPUCW = 18,    ///< Used FPU control word.
    AT_DCACHEBSIZE = 19,   ///< Data cache block size.
    AT_ICACHEBSIZE = 20,   ///< Instruction cache block size.
    AT_UCACHEBSIZE = 21,   ///< Unified cache block size.
    AT_IGNOREPPC = 22,     ///< Entry should be ignored.
    AT_SECURE = 23,        ///< Boolean, was exec setuid-like?
    AT_BASE_PLATFORM = 24, ///< String identifying real platforms.
    AT_RANDOM = 25,        ///< Address of 16 random bytes.
    AT_EXECFN = 31,        ///< Filename of executable.
    AT_SYSINFO = 32, ///< Pointer to the global system page used for system
                     ///calls and other nice things.
    AT_SYSINFO_EHDR = 33,
    AT_L1I_CACHESHAPE = 34, ///< Shapes of the caches.
    AT_L1D_CACHESHAPE = 35,
    AT_L2_CACHESHAPE = 36,
    AT_L3_CACHESHAPE = 37,
  };

private:
  typedef std::vector<Entry> EntryVector;

public:
  typedef EntryVector::const_iterator iterator;

  iterator begin() const { return m_auxv.begin(); }
  iterator end() const { return m_auxv.end(); }

  iterator FindEntry(EntryType type) const;

  static const char *GetEntryName(const Entry &entry) {
    return GetEntryName(static_cast<EntryType>(entry.type));
  }

  static const char *GetEntryName(EntryType type);

  void DumpToLog(lldb_private::Log *log) const;

private:
  lldb_private::Process *m_process;
  EntryVector m_auxv;

  lldb::DataBufferSP GetAuxvData();

  void ParseAuxv(lldb_private::DataExtractor &data);
};

#endif