title: thread_local member variable construction
body: <p>I'm facing some strange behavior with thread_local and not sure whether I'm doing something wrong or it's a GCC bug.
  I have the following minimal repro scenario:</p>
  
  <pre><code>#include &lt;iostream&gt;
  
  using namespace std;
  
  struct bar {
      struct foo {
          foo () {
              cerr &lt;&lt; "foo" &lt;&lt; endl;
          }
          int i = 42;
      };
  
      static thread_local foo FOO;
  };
  
  static thread_local bar::foo FREE_FOO;
  thread_local bar::foo bar::FOO;
  
  int main() {
      bar b;
      cerr &lt;&lt; "main" &lt;&lt; endl;
      // cerr &lt;&lt; FREE_FOO.i &lt;&lt; endl;
      cerr &lt;&lt; b.FOO.i &lt;&lt; endl;
      return 0;
  }
  </code></pre>
  
  <p>With the commented line above the output looks like this:</p>
  
  <pre><code>main
  0
  </code></pre>
  
  <p><a href="http://ideone.com/63GJjQ" rel="nofollow">Ideone</a></p>
  
  <p>With it uncommented, it becomes this:</p>
  
  <pre><code>main
  foo
  foo
  42
  42
  </code></pre>
  
  <p><a href="http://ideone.com/ZcFJ02" rel="nofollow">Ideone</a></p>
  
  <p>Am I just missing something stupid here?</p>
  
  <pre><code>$ gcc -v
  Using built-in specs.
  COLLECT_GCC=gcc
  COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.8/lto-wrapper
  Target: x86_64-linux-gnu
  Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.8.1-10ubuntu9' --with-bugurl=file:///usr/share/doc/gcc-4.8/README.Bugs --enable-languages=c,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.8 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.8 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --enable-plugin --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64 --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-4.8-amd64 --with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
  Thread model: posix
  gcc version 4.8.1 (Ubuntu/Linaro 4.8.1-10ubuntu9) 
  </code></pre>
  
  <p><strong>Update:</strong></p>
  
  <p>This provides unexpected results as well:</p>
  
  <pre><code>#include &lt;iostream&gt;
  
  using namespace std;
  
  template&lt;class T&gt;
  struct bar {
      struct foo {
          foo () {
              cerr &lt;&lt; "bar::foo" &lt;&lt; endl;
          }
          int i = 42;
      };
  
      void baz() {
          cerr &lt;&lt; bar::FOO.i &lt;&lt; endl;
      }
  
      static thread_local foo FOO;
  };
  
  struct far {
      struct foo {
          foo () {
              cerr &lt;&lt; "far::foo" &lt;&lt; endl;
          }
          int i = 42;
      };
  
      void baz() {
          cerr &lt;&lt; far::FOO.i &lt;&lt; endl;
      }
  
      static thread_local foo FOO;
  };
  
  template&lt;class T&gt; thread_local typename bar&lt;T&gt;::foo bar&lt;T&gt;::FOO;
  thread_local typename far::foo far::FOO;
  
  int main() {
      cerr &lt;&lt; "main" &lt;&lt; endl;
      bar&lt;int&gt; b;
      b.baz();
  
      far f;
      f.baz();
      return 0;
  }
  </code></pre>
  
  <p>Result:</p>
  
  <pre><code>main
  0
  far::foo
  bar::foo
  42
  </code></pre>