You can not define _UNICODE. How did you determine that szExeFile is a WCHAR? Win32::Process::List compiled without errors or warnings for me.

That's why I confused. W::P::L compiled successfully for me too. what I determine the szExeFile's type is using printf as the test code below:

#include "stdafx.h"
#include <windows.h>
#include <tlhelp32.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <perl.h>
#include <EXTERN.h>
#include "XSUB.h"

PerlInterpreter *my_perl;

BOOL GetProcessList( );


int _tmain(int argc, _TCHAR* argv[])
{
    PERL_SYS_INIT3(NULL, NULL, NULL);
    my_perl = perl_alloc();
    perl_construct(my_perl);
    GetProcessList( );

    Sleep(10000);
    perl_destruct(my_perl);
    perl_free(my_perl);
    PERL_SYS_TERM();
    return 0;
}

BOOL GetProcessList( )
{
  HANDLE hProcessSnap;

  PROCESSENTRY32 pe32;



  hProcessSnap = CreateToolhelp32Snapshot( TH32CS_SNAPPROCESS, 0 );

  pe32.dwSize = sizeof( PROCESSENTRY32 );




  while( Process32Next( hProcessSnap, &pe32 ) )
  {
      
    printf("process name is %s \n", pe32.szExeFile);  //just print the
+ first char of name
    printf("process name is %ls \n", pe32.szExeFile); // display name 
+correctly
             
                SV* name_sv = newSV(0);
                sv_setpv((SV*)name_sv, pe32.szExeFile);  //complain he
+re
    

  } ;

  CloseHandle( hProcessSnap );
  return( TRUE );
}
[download]

My question is, I think simply changing WCHAR to SV is wrong. but the fact blow me, W::P::L compiled,and works fine.