/* Copyright (c) 2008-2011, Avian Contributors

   Permission to use, copy, modify, and/or distribute this software
   for any purpose with or without fee is hereby granted, provided
   that the above copyright notice and this permission notice appear
   in all copies.

   There is NO WARRANTY for this software.  See license.txt for
   details. */

#ifndef COMMON_H
#define COMMON_H

#ifndef __STDC_CONSTANT_MACROS
#  define __STDC_CONSTANT_MACROS
#endif

#include "stdlib.h"
#include "stdarg.h"
#include "stddef.h"
#include "string.h"
#include "stdio.h"
#include "types.h"
#include "math.h"

#ifdef _MSC_VER

// don't complain about using 'this' in member initializers:
#  pragma warning(disable:4355)

typedef char int8_t;
typedef unsigned char uint8_t;
typedef short int16_t;
typedef unsigned short uint16_t;
typedef int int32_t;
typedef unsigned int uint32_t;
typedef __int64 int64_t;
typedef unsigned __int64 uint64_t;

#  define not !
#  define or ||
#  define and &&
#  define xor ^

#  define LIKELY(v) v
#  define UNLIKELY(v) v

#  define UNUSED

#  define NO_RETURN __declspec(noreturn)

#  define PACKED

#  define PLATFORM_WINDOWS

#  ifdef _M_IX86
typedef int32_t intptr_t;
typedef uint32_t uintptr_t;
#    define UINT64_C(x) x##LL
#    define ARCH_x86_32
#  elif defined _M_X64
typedef int64_t intptr_t;
typedef uint64_t uintptr_t;
#    define UINT64_C(x) x##L
#    define ARCH_x86_64
#  else
#    error "unsupported architecture"
#  endif

namespace vm {

typedef intptr_t intptr_alias_t;

} // namespace vm

#else // not _MSC_VER

#  include "stdint.h"

#  define LIKELY(v) __builtin_expect((v) != 0, true)
#  define UNLIKELY(v) __builtin_expect((v) != 0, false)

#  define UNUSED __attribute__((unused))

#  define NO_RETURN __attribute__((noreturn))

#  define PACKED __attribute__((packed))

#  ifdef __MINGW32__
#    define PLATFORM_WINDOWS
#  endif

#  ifdef __i386__
#    define ARCH_x86_32
#  elif defined __x86_64__
#    define ARCH_x86_64
#  elif (defined __POWERPC__) || (defined __powerpc__)
#    define ARCH_powerpc
#  elif defined __arm__
#    define ARCH_arm
#  else
#    error "unsupported architecture"
#  endif

namespace vm {

typedef intptr_t __attribute__((__may_alias__)) intptr_alias_t;

} // namespace vm

#endif // not _MSC_VER

#undef JNIEXPORT
#ifdef PLATFORM_WINDOWS
#  define JNIEXPORT __declspec(dllexport)
#  define PATH_SEPARATOR ';'
#else // not PLATFORM_WINDOWS
#  define JNIEXPORT __attribute__ ((visibility("default"))) \
  __attribute__ ((used))
#  define PATH_SEPARATOR ':'
#endif // not PLATFORM_WINDOWS

#if (defined ARCH_x86_32) || (defined ARCH_powerpc) || (defined ARCH_arm)
#  define LD "ld"
#  if (defined _MSC_VER) || ((defined __MINGW32__) && __GNUC__ >= 4)
#    define LLD "I64d"
#  else
#    define LLD "lld"
#  endif
#  ifdef __APPLE__
#    define ULD "lu"
#    define LX "lx"
#  else
#    define LX "x"
#    define ULD "u"
#  endif
#elif defined ARCH_x86_64
#  define LD "ld"
#  define LX "lx"
#  if (defined _MSC_VER) || (defined __MINGW32__)
#    define LLD "I64d"
#    define ULD "I64x"
#  else
#    define LLD "ld"
#    define ULD "lu"
#  endif
#else
#  error "Unsupported architecture"
#endif

#ifdef PLATFORM_WINDOWS
#  define SO_PREFIX ""
#else
#  define SO_PREFIX "lib"
#endif

#ifdef __APPLE__
#  define SO_SUFFIX ".dylib"
#elif defined PLATFORM_WINDOWS
#  define SO_SUFFIX ".dll"
#else
#  define SO_SUFFIX ".so"
#endif

#define MACRO_XY(X, Y) X##Y
#define MACRO_MakeNameXY(FX, LINE) MACRO_XY(FX, LINE)
#define MAKE_NAME(FX) MACRO_MakeNameXY(FX, __LINE__)

#define RESOURCE(type, name, release)                                   \
  class MAKE_NAME(Resource_) {                                          \
  public:                                                               \
    MAKE_NAME(Resource_)(type name): name(name) { }                     \
    ~MAKE_NAME(Resource_)() { release; }                                \
                                                                        \
  private:                                                              \
    type name;                                                          \
  } MAKE_NAME(resource_)(name);

inline void* operator new(size_t, void* p) throw() { return p; }

namespace vm {

inline intptr_alias_t&
alias(void* p, unsigned offset)
{
  return *reinterpret_cast<intptr_alias_t*>(static_cast<uint8_t*>(p) + offset);
}

#ifdef _MSC_VER

template <class T>
class RuntimeArray {
 public:
  RuntimeArray(unsigned size):
    body(static_cast<T*>(malloc(size * sizeof(T))))
  { }

  ~RuntimeArray() {
    free(body);
  }

  T* body;
};

#  define RUNTIME_ARRAY(type, name, size) RuntimeArray<type> name(size);
#  define RUNTIME_ARRAY_BODY(name) name.body

inline int
vsnprintf(char* dst, size_t size, const char* format, va_list a)
{
  return vsnprintf_s(dst, size, _TRUNCATE, format, a);
}

inline int
snprintf(char* dst, size_t size, const char* format, ...)
{
  va_list a;
  va_start(a, format);
  int r = vsnprintf(dst, size, format, a);
  va_end(a);
  return r;
}

inline FILE*
fopen(const char* name, const char* mode)
{
  FILE* file;
  if (fopen_s(&file, name, mode) == 0) {
    return file;
  } else {
    return 0;
  }
}

#else // not _MSC_VER

#  define RUNTIME_ARRAY(type, name, size) type name[size];
#  define RUNTIME_ARRAY_BODY(name) name

inline int
vsnprintf(char* dst, size_t size, const char* format, va_list a)
{
  return ::vsnprintf(dst, size, format, a);
}

inline int
snprintf(char* dst, size_t size, const char* format, ...)
{
  va_list a;
  va_start(a, format);
  int r = vsnprintf(dst, size, format, a);
  va_end(a);
  return r;
}

inline FILE*
fopen(const char* name, const char* mode)
{
  return ::fopen(name, mode);
}

#endif // not _MSC_VER

const unsigned BytesPerWord = sizeof(uintptr_t);
const unsigned BitsPerWord = BytesPerWord * 8;

const uintptr_t PointerMask
= ((~static_cast<uintptr_t>(0)) / BytesPerWord) * BytesPerWord;

const unsigned LikelyPageSizeInBytes = 4 * 1024;

inline unsigned
max(unsigned a, unsigned b)
{
  return (a > b ? a : b);
}

inline unsigned
min(unsigned a, unsigned b)
{
  return (a < b ? a : b);
}

inline unsigned
avg(unsigned a, unsigned b)
{
  return (a + b) / 2;
}

inline unsigned
pad(unsigned n, unsigned alignment)
{
  return (n + (alignment - 1)) & ~(alignment - 1);
}

inline unsigned
pad(unsigned n)
{
  return pad(n, BytesPerWord);
}

inline uintptr_t
padWord(uintptr_t n, uintptr_t alignment)
{
  return (n + (alignment - 1)) & ~(alignment - 1);
}

inline uintptr_t
padWord(uintptr_t n)
{
  return padWord(n, BytesPerWord);
}

inline unsigned
ceiling(unsigned n, unsigned d)
{
  return (n + d - 1) / d;
}

inline bool
powerOfTwo(unsigned n)
{
  for (; n > 2; n >>= 1) if (n & 1) return false;
  return true;
}

inline unsigned
nextPowerOfTwo(unsigned n)
{
  unsigned r = 1;
  while (r < n) r <<= 1;
  return r;
}

inline unsigned
log(unsigned n)
{
  unsigned r = 0;
  for (unsigned i = 1; i < n; ++r) i <<= 1;
  return r;
}

template <class T>
inline unsigned
wordOf(unsigned i)
{
  return i / (sizeof(T) * 8);
}

inline unsigned
wordOf(unsigned i)
{
  return wordOf<uintptr_t>(i);
}

template <class T>
inline unsigned
bitOf(unsigned i)
{
  return i % (sizeof(T) * 8);
}

inline unsigned
bitOf(unsigned i)
{
  return bitOf<uintptr_t>(i);
}

template <class T>
inline unsigned
indexOf(unsigned word, unsigned bit)
{
  return (word * (sizeof(T) * 8)) + bit;
}

inline unsigned
indexOf(unsigned word, unsigned bit)
{
  return indexOf<uintptr_t>(word, bit);
}

template <class T>
inline void
markBit(T* map, unsigned i)
{
  map[wordOf<T>(i)] |= static_cast<T>(1) << bitOf<T>(i);
}

template <class T>
inline void
clearBit(T* map, unsigned i)
{
  map[wordOf<T>(i)] &= ~(static_cast<T>(1) << bitOf<T>(i));
}

template <class T>
inline unsigned
getBit(T* map, unsigned i)
{
  return (map[wordOf<T>(i)] & (static_cast<T>(1) << bitOf<T>(i)))
    >> bitOf<T>(i);
}

// todo: the following (clearBits, setBits, and getBits) could be made
// more efficient by operating on a word at a time instead of a bit at
// a time:

template <class T>
inline void
clearBits(T* map, unsigned bitsPerRecord, unsigned index)
{
  for (unsigned i = index, limit = index + bitsPerRecord; i < limit; ++i) {
    clearBit<T>(map, i);
  }
}

template <class T>
inline void
setBits(T* map, unsigned bitsPerRecord, int index, unsigned v)
{
  for (int i = index + bitsPerRecord - 1; i >= index; --i) {
    if (v & 1) markBit<T>(map, i); else clearBit<T>(map, i);
    v >>= 1;
  }
}

template <class T>
inline unsigned
getBits(T* map, unsigned bitsPerRecord, unsigned index)
{
  unsigned v = 0;
  for (unsigned i = index, limit = index + bitsPerRecord; i < limit; ++i) {
    v <<= 1;
    v |= getBit<T>(map, i);
  }
  return v;
}

template <class T>
inline T&
cast(void* p, unsigned offset)
{
  return *reinterpret_cast<T*>(static_cast<uint8_t*>(p) + offset);
}

template <class T>
inline T*
mask(T* p)
{
  return reinterpret_cast<T*>(reinterpret_cast<uintptr_t>(p) & PointerMask);
}

inline uint32_t
hash(const char* s)
{
  uint32_t h = 0;
  for (unsigned i = 0; s[i]; ++i) {
    h = (h * 31) + s[i];
  }
  return h;  
}

inline uint32_t
hash(const uint8_t* s, unsigned length)
{
  uint32_t h = 0;
  for (unsigned i = 0; i < length; ++i) {
    h = (h * 31) + s[i];
  }
  return h;
}

inline uint32_t
hash(const int8_t* s, unsigned length)
{
  return hash(reinterpret_cast<const uint8_t*>(s), length);
}

inline uint32_t
hash(const uint16_t* s, unsigned length)
{
  uint32_t h = 0;
  for (unsigned i = 0; i < length; ++i) {
    h = (h * 31) + s[i];
  }
  return h;
}

inline uint32_t
floatToBits(float f)
{
  uint32_t bits; memcpy(&bits, &f, 4);
  return bits;
}

inline uint64_t
doubleToBits(double d)
{
  uint64_t bits; memcpy(&bits, &d, 8);
  return bits;
}

inline double
bitsToDouble(uint64_t bits)
{
  double d; memcpy(&d, &bits, 8);
  return d;
}

inline float
bitsToFloat(uint32_t bits)
{
  float f; memcpy(&f, &bits, 4);
  return f;
}

inline int
difference(void* a, void* b)
{
  return reinterpret_cast<intptr_t>(a) - reinterpret_cast<intptr_t>(b);
}

template <class T>
inline void*
voidPointer(T function)
{
  void* p;
  memcpy(&p, &function, sizeof(void*));
  return p;
}

inline void
replace(char a, char b, char* c)
{
  for (; *c; ++c) if (*c == a) *c = b;
}

inline void
replace(char a, char b, char* dst, const char* src)
{
  unsigned i = 0;
  for (; src[i]; ++ i) {
    dst[i] = src[i] == a ? b : src[i];
  }
  dst[i] = 0;
}

inline bool
equal(const void* a, unsigned al, const void* b, unsigned bl)
{
  if (al == bl) {
    return memcmp(a, b, al) == 0;
  } else {
    return false;
  }
}

class Machine;
class Thread;

struct Object { };

typedef Object* object;

} // namespace vm

#endif//COMMON_H