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    <head>
      <base href="https://bugs.llvm.org/">
    </head>
    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - Should have __has_feature for GCC-compatible __auto_type"
   href="https://bugs.llvm.org/show_bug.cgi?id=32052">32052</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Should have __has_feature for GCC-compatible __auto_type
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>clang
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>3.9
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>All
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>All
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>NEW
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>enhancement
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>P
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>-New Bugs
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>unassignedclangbugs@nondot.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>m-llvm@bodyfour.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvm-bugs@lists.llvm.org
          </td>
        </tr></table>
      <p>
        <div>
        <pre>In 2015 (r252690), clang added support for GCC 4.9's "__auto_type" but as far
as I can tell there is no __has_feature() test to determine if the compiler
version you're using supports it or not.  i.e. the following compiles fine with
the latest Xcode:


#if __has_feature(__auto_type)
#error "has feature"
#endif

#if __has_extension(__auto_type)
#error "has extension"
#endif

#if __has_attribute(__auto_type)
#error "has attribute"
#endif

int main()
{
  __auto_type x = 5;
  return x;
}


Right now I don't have a source clang build handy (I am just using Xcode's
clang) but I grepped around the cfe-3.9.1 code and I couldn't find it there
either.  There is of course __has_feature(cxx_auto_type), but that's for the
C++11 "auto", not the GNU C __auto_type.  Perhaps can you add a
__has_feature(c_auto_type) or __has_feature(gnu_auto_type) in the future?</pre>
        </div>
      </p>


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