<html>
    <head>
      <base href="http://llvm.org/bugs/" />
    </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 --- - Redefinition of identical typedefs fails"
   href="http://llvm.org/bugs/show_bug.cgi?id=18564">18564</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Redefinition of identical typedefs fails
          </td>
        </tr>

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

        <tr>
          <th>Version</th>
          <td>3.3
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>PC
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>Linux
          </td>
        </tr>

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

        <tr>
          <th>Severity</th>
          <td>normal
          </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>fluffmail@f-m.fm
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvmbugs@cs.uiuc.edu
          </td>
        </tr>

        <tr>
          <th>Classification</th>
          <td>Unclassified
          </td>
        </tr></table>
      <p>
        <div>
        <pre>From C11 ยง6.7(3): "a typedef name may be redefined to denote the same type as
it currently does, provided that type is not a variably modified type."

So we should be able to redundantly duplicate the same typedef into a file with
no problem. But clang seems to have trouble identifying that duplicated
typedefs are duplicates. Sample code:

-------------
typedef struct {
    int a;
    double b;
} ab;

typedef struct {
    int a;
    double b;
} ab;

int main(){}

------------

Result:

<span class="quote">> clang --std=c11 bug.c</span >

bug.c:9:3: error: typedef redefinition with different types ('struct ab' vs
'struct ab')
} ab;
  ^
bug.c:4:3: note: previous definition is here
} ab;
  ^
1 error generated.

------------</pre>
        </div>
      </p>
      <hr>
      <span>You are receiving this mail because:</span>
      
      <ul>
          <li>You are on the CC list for the bug.</li>
      </ul>
    </body>
</html>