title: How to compile 64Bit DLL in Eclipse CDT (using Windows SDK)?
body: <p>What I want to be done: Create a 64bit DLL on win7 that interacts with the Windows API including the OLE32.dll. </p>
  
  <p>What I have got:</p>
  
  <p>I am currently stuck. I download Visual Studio 2015 Community Edition. I tried to create a DLL there and on creation it generated everything but no dll. The program did not complain, everything was setup as in the tutorial but no dll file. </p>
  
  <p>So I skipped this and downloaded Eclipse CDT. I set up using the Visual C toolchain and after minor issues I had my DLL generated. So I used Java to fire it up but it complained (I use JNA for integration) and it seams that I have a 32bit DLL.</p>
  
  <p>So I searched the web and read and did stuff but I am totally lost. Since the Visual Studio 2010 Express edition came without a 64bit compiler I am not even sure if the Community edition of Visual Studio supports 64bit dlls this time.</p>
  
  <p>I also have the Windows SDK v7.1 installed. I link to a library file ole32.dll. It contains the method CoCreateInstance which I require. I have to add this manually in order for the compiler to pick it up. If I switch to the 64bit dll version the compiler complains about the CoCreateInstance method can not be linked.</p>
  
  <p>So basically I am lost here. A source on the web gave a work around for the 2010 Express being not able to create x64 DLL and it turned out that the hint was getting windows SDK since it it comes along with a compiler.</p>
  
  <p>Also I noticed that CDT uses Visual Studio 10 files so I guess it is using this compiler.</p>
  
  <p>I set to both compiler and linker the /machine:64 option. But the linker still complains that the obj file from the compiler is 32bit.</p>
  
  <p>Any Ideas?</p>
  
  <p>[Update]</p>
  
  <p>The Compiler prints the following line so basically it is not able to compile 64bit version. Any idea how to replace it? As said it uses the Visual Studio 10 folder but I also have a Visual Studio 12 and 14 folder as well. </p>
  
  <blockquote>
    <p>cl : Command line warning D9002 : ignoring unknown option '/machine:x64'</p>
  </blockquote>