prototype code for identifying wow64 in cygwin uname

iswow64process2_aarch64.exe

iswow64process2_armv7.exe

iswow64process2_i686.exe

iswow64process2_x86_64.exe

wow64ident.c

#include <windows.h>
#include <stdio.h>
#include <stdbool.h>

static BOOL
IsWow64Process2 (HANDLE hProcess, USHORT *pProcessMachine, USHORT *pNativeMachine)
{
  typedef BOOL (WINAPI * IsWow64Process2_t) (HANDLE, USHORT *, USHORT *);
  static IsWow64Process2_t pIsWow64Process2 = NULL;
  static bool bIsWow64Process2Inited = false;

  if (!bIsWow64Process2Inited)
  {
    pIsWow64Process2 = (IsWow64Process2_t) GetProcAddress (
						GetModuleHandle("KERNEL32"),
						"IsWow64Process2");
    bIsWow64Process2Inited = true;
  }
  if (pIsWow64Process2)
    return pIsWow64Process2 (hProcess, pProcessMachine, pNativeMachine);

  SetLastError (ERROR_PROC_NOT_FOUND);
  return FALSE;
}

extern const IMAGE_DOS_HEADER
dosheader __asm__ ("__image_base__");

static USHORT
current_module_machine (void)
{
  PIMAGE_NT_HEADERS ntheader = (PIMAGE_NT_HEADERS)((PBYTE) &dosheader
						   + dosheader.e_lfanew);
  return ntheader->FileHeader.Machine;
}

int
main (void)
{
  USHORT emulated, hosted;
  if (!IsWow64Process2 (GetCurrentProcess (), &emulated, &hosted))
    {
#if defined (__x86_64__)
      hosted = IMAGE_FILE_MACHINE_AMD64;
#elif defined (__i386__)
      BOOL wow64 = FALSE;
      IsWow64Process (GetCurrentProcess (), &wow64);
      hosted = wow64 ? IMAGE_FILE_MACHINE_AMD64 : IMAGE_FILE_MACHINE_I386;
#else
      /* this should not happen */
      hosted = IMAGE_FILE_MACHINE_UNKNOWN;
#endif
    }
  if (hosted != current_module_machine ())
    {
      switch (hosted)
       {
	 case IMAGE_FILE_MACHINE_AMD64:
	   /* special case for backwards compatibility */
	   if (current_module_machine () == IMAGE_FILE_MACHINE_I386)
	       printf ("-WOW64");
	   else
	       printf ("-x64");
	   break;
	 case IMAGE_FILE_MACHINE_I386:
	   printf ("-x86");
	   break;
	 case IMAGE_FILE_MACHINE_ARMNT:
	   printf ("-ARM");
	   break;
	 case IMAGE_FILE_MACHINE_ARM64:
	   printf ("-ARM64");
	   break;
	 default:
	   printf ("-%#06x", hosted);
	   break;
       }
    }
  printf ("\n");
  return 0;
}