title: Xcode 4.6 (4H127), clang warns 'illegal character encoding in string literal' for ISO-8859-1 encoded o-umlaut (0xF6)
body: <p>This code compiled in the previous release of Xcode.  I updated Xcode, and now compilation fails.  I'm guessing there is something wrong with my code.  The question mark in the code below is o-umlaut (ö) encoded according to ISO-8859-1 (0xF6)--we used to call this upper (or extended) ASCII.  I'm guessing the compilation error has something to do with moving to UTF-8 input encoding for clang??</p>
  
  <pre><code>$ xcrun -sdk macosx10.8 -run clang -v
  Apple LLVM version 4.2 (clang-425.0.24) (based on LLVM 3.2svn)
  Target: x86_64-apple-darwin12.2.0
  
  $ cat test.c
  #include &lt;stdio.h&gt;
  int main( int argc, char** argv )
  {
      fprintf( stderr, "?\n" );
      return 0;
  }
  
  $ xcrun -sdk macosx10.8 -run clang -o test test.c 
  test.c:4:23: warning: illegal character encoding in string literal [-Winvalid-source-encoding]
      fprintf( stderr, "&lt;F6&gt;\n" );
                        ^~~~
  1 warning generated.
  </code></pre>