title: Disabling -Werror for -Wimplicit-interface
body: <p>What is the right flag or order of flags to disable treating particular warning as error in GCC? I want to do that for <code>-Wimplicit-interface</code>.</p>
  
  <pre><code>&gt;cat test.f90 
   call s
  end
  
  &gt; gfortran -c -Werror -Wimplicit-interface -Wno-error=implicit-interface test.f90 -o test.o
  test.f90:1.7:
  
   call s
         1
  Warning: Procedure 's' called with an implicit interface at (1)
  
  &gt;ls test*
  test.f90
  </code></pre>
  
  <p>No <code>test.o</code> was generated.</p>
  
  <p>Without <code>-Werror</code> it works</p>
  
  <pre><code>&gt; gfortran -c -Wimplicit-interface -Wno-error=implicit-interface test.f90 -o test.o
  test.f90:1.7:
  
   call s
         1
  Warning: Procedure 's' called with an implicit interface at (1)
  &gt; ls test*
  test.f90  test.o
  </code></pre>
  
  <p>GCC version is <code>gcc version 4.9.2 20141030 (Cray Inc.) (GCC)</code>.</p>