include(CheckLibraryExists)
include(CheckTypeSize)
include(CheckCXXSourceCompiles)
include(TestBigEndian)
include(TestFloatFormat)

# Check if the size of numeric types are suitable.

check_type_size("short" SIZEOF_SHORT)
if(NOT ${SIZEOF_SHORT} EQUAL 2)
  message(FATAL_ERROR "TagLib requires that short is 16-bit wide.")
endif()

check_type_size("int" SIZEOF_INT)
if(NOT ${SIZEOF_INT} EQUAL 4)
  message(FATAL_ERROR "TagLib requires that int is 32-bit wide.")
endif()

check_type_size("long long" SIZEOF_LONGLONG)
if(NOT ${SIZEOF_LONGLONG} EQUAL 8)
  message(FATAL_ERROR "TagLib requires that long long is 64-bit wide.")
endif()

check_type_size("wchar_t" SIZEOF_WCHAR_T)
if(${SIZEOF_WCHAR_T} LESS 2)
  message(FATAL_ERROR "TagLib requires that wchar_t is sufficient to store a UTF-16 char.")
endif()

check_type_size("float" SIZEOF_FLOAT)
if(NOT ${SIZEOF_FLOAT} EQUAL 4)
  message(FATAL_ERROR "TagLib requires that float is 32-bit wide.")
endif()

check_type_size("double" SIZEOF_DOUBLE)
if(NOT ${SIZEOF_DOUBLE} EQUAL 8)
  message(FATAL_ERROR "TagLib requires that double is 64-bit wide.")
endif()

# Determine the CPU byte order.

test_big_endian(IS_BIG_ENDIAN)

if(NOT IS_BIG_ENDIAN)
  set(SYSTEM_BYTEORDER 1)
else()
  set(SYSTEM_BYTEORDER 2)
endif()

# Check if the format of floating point types are suitable.

test_float_format(FP_IEEE754)
if(${FP_IEEE754} EQUAL 1)
  set(FLOAT_BYTEORDER 1)
elseif(${FP_IEEE754} EQUAL 2)
  set(FLOAT_BYTEORDER 2)
else()
  message(FATAL_ERROR "TagLib requires that floating point types are IEEE754 compliant.")
endif()

# Determine which kind of atomic operations your compiler supports.

check_cxx_source_compiles("
  #include <atomic>
  int main() {
    std::atomic<unsigned int> x;
    x.fetch_add(1);
    x.fetch_sub(1);
    return 0;
  }
" HAVE_STD_ATOMIC)

if(NOT HAVE_STD_ATOMIC)
  check_cxx_source_compiles("
    #include <boost/atomic.hpp>
    int main() {
      boost::atomic<unsigned int> x(1);
      x.fetch_add(1);
      x.fetch_sub(1);
      return 0;
    }
  " HAVE_BOOST_ATOMIC)

  if(NOT HAVE_BOOST_ATOMIC)
    check_cxx_source_compiles("
      int main() {
        volatile int x;
        __sync_add_and_fetch(&x, 1);
        int y = __sync_sub_and_fetch(&x, 1);
        return 0;
      }
    " HAVE_GCC_ATOMIC)

    if(NOT HAVE_GCC_ATOMIC)
      check_cxx_source_compiles("
        #include <libkern/OSAtomic.h>
        int main() {
          volatile int32_t x;
          OSAtomicIncrement32Barrier(&x);
          int32_t y = OSAtomicDecrement32Barrier(&x);
          return 0;
        }
      " HAVE_MAC_ATOMIC)

      if(NOT HAVE_MAC_ATOMIC)
        check_cxx_source_compiles("
          #include <windows.h>
          int main() {
            volatile LONG x;
            InterlockedIncrement(&x);
            LONG y = InterlockedDecrement(&x);
            return 0;
          }
        " HAVE_WIN_ATOMIC)

        if(NOT HAVE_WIN_ATOMIC)
          check_cxx_source_compiles("
            #include <ia64intrin.h>
            int main() {
              volatile int x;
              __sync_add_and_fetch(&x, 1);
              int y = __sync_sub_and_fetch(&x, 1);
              return 0;
            }
          " HAVE_IA64_ATOMIC)
        endif()
      endif()
    endif()
  endif()
endif()

# Determine which kind of byte swap functions your compiler supports.

# GCC's __builtin_bswap* should be checked individually
# because some of them can be missing depends on the GCC version.
check_cxx_source_compiles("
  int main() {
    __builtin_bswap16(0);
    return 0;
  }
" HAVE_GCC_BYTESWAP_16)

check_cxx_source_compiles("
  int main() {
    __builtin_bswap32(0);
    return 0;
  }
" HAVE_GCC_BYTESWAP_32)

check_cxx_source_compiles("
  int main() {
    __builtin_bswap64(0);
    return 0;
  }
" HAVE_GCC_BYTESWAP_64)

if(NOT HAVE_GCC_BYTESWAP_16 OR NOT HAVE_GCC_BYTESWAP_32 OR NOT HAVE_GCC_BYTESWAP_64)
  check_cxx_source_compiles("
    #include <byteswap.h>
    int main() {
      __bswap_16(0);
      __bswap_32(0);
      __bswap_64(0);
      return 0;
    }
  " HAVE_GLIBC_BYTESWAP)

  if(NOT HAVE_GLIBC_BYTESWAP)
    check_cxx_source_compiles("
      #include <stdlib.h>
      int main() {
        _byteswap_ushort(0);
        _byteswap_ulong(0);
        _byteswap_uint64(0);
        return 0;
      }
    " HAVE_MSC_BYTESWAP)

    if(NOT HAVE_MSC_BYTESWAP)
      check_cxx_source_compiles("
        #include <libkern/OSByteOrder.h>
        int main() {
          OSSwapInt16(0);
          OSSwapInt32(0);
          OSSwapInt64(0);
          return 0;
        }
      " HAVE_MAC_BYTESWAP)

      if(NOT HAVE_MAC_BYTESWAP)
        check_cxx_source_compiles("
          #include <sys/endian.h>
          int main() {
            swap16(0);
            swap32(0);
            swap64(0);
            return 0;
          }
        " HAVE_OPENBSD_BYTESWAP)
      endif()
    endif()
  endif()
endif()

# Determine whether your compiler supports some safer version of vsprintf.

check_cxx_source_compiles("
  #include <cstdio>
  #include <cstdarg>
  int main() {
    char buf[20];
    va_list args;
    vsnprintf(buf, 20, \"%d\", args);
    return 0;
  }
" HAVE_VSNPRINTF)

if(NOT HAVE_VSNPRINTF)
  check_cxx_source_compiles("
    #include <cstdio>
    #include <cstdarg>
    int main() {
      char buf[20];
      va_list args;
      vsprintf_s(buf, \"%d\", args);
      return 0;
    }
  " HAVE_VSPRINTF_S)
endif()

# Check for libz using the cmake supplied FindZLIB.cmake

if(NOT ZLIB_SOURCE)
  find_package(ZLIB)
  if(ZLIB_FOUND)
    set(HAVE_ZLIB 1)
  else()
    set(HAVE_ZLIB 0)
  endif()
endif()

if(BUILD_TESTS)
  find_package(CppUnit)
  if(NOT CppUnit_FOUND)
    message(STATUS "CppUnit not found, disabling tests.")
    set(BUILD_TESTS OFF)
  endif()
endif()