title: Conditional commands in Qt .pro file
body: <p>I have doubts about my Qt .pro file... I had seen another post about a similar question <a href="https://stackoverflow.com/questions/5140895/lupdate-and-conditional-includes-in-a-pro-file">in this link</a>, but i used the contains() function and didn't work.</p>
  
  <p>In the my case, i have a file called mainconfig.h where i define some project configurations flags, i really create defines there, like: "#define MY_CONFIG_DEFINE". Those flags define what menu options will be shown etc. My problem is: all files are always compiled, even when i don't use its because i defined some flag in "mainconfig.h" file. I would like to avoid compile some files than i will not use, defining some variables in my .pro file and doing conditional commands, including only the files than i want to.</p>
  
  <p>Can someone help me?</p>
  
  <p>I tried this in my .pro file:</p>
  
  <pre><code>    # This variable defines the current project ADRIANO_PROJECT = PROJECT_TYPE_1
      ADRIANO_PROJECT = PROJECT_TYPE_1
  
      (...) 
  
      FORMS += ui/form1.ui \ 
      contains(ADRIANO_PROJECT, PROJECT_TYPE_1) {
              ui/myform1.ui \
              ui/myform2.ui \ 
      }
               ui/form2.ui \
               ui/form3.ui
  
      (...)
  
      # This is only a example, ok?
  </code></pre>
  
  <p>Sorry my english and thanks.</p>