title: strange compilation error about pthreadtypes.h: 'section' attribute
body: <p>I met a very strange error during compile my code using clang.</p>
  
  <p>here is my command</p>
  
  <pre><code>$clang -c -emit-llvm -I/OP-TEE/op-tee-os/optee_os/lib/libutee/include/ -I/OP-TEE/op-tee-os/optee_os/lib/libutils/ext/include/ test_function_call_ta.c
  </code></pre>
  
  <p>and here is the error:</p>
  
  <pre><code>In file included from /usr/include/stdlib.h:314:
  In file included from /usr/include/x86_64-linux-gnu/sys/types.h:270:
  /usr/include/x86_64-linux-gnu/bits/pthreadtypes.h:200:5: error: 'section' attribute only applies to functions, methods,
        properties, and global variables
    } __data;
      ^
  /opensource_projects/OP-TEE/op-tee-os/optee_os/lib/libutils/ext/include/compiler.h:51:17: note: expanded
        from macro '__data'
  #define __data          __section(".data")
                          ^
  /opensource_projects/OP-TEE/op-tee-os/optee_os/lib/libutils/ext/include/compiler.h:50:37: note: expanded
        from macro '__section'
  #define __section(x)    __attribute__((section(x)))
  </code></pre>
  
  <p>I was wondering why this error is happening, because I did not use any section attributes in the source code.</p>
  
  <p>Thanks in advance!</p>