<html>
    <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 - transferring the warning on designated_init on a non-struct to an error?"
   href="https://bugs.llvm.org/show_bug.cgi?id=42223">42223</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>transferring the warning on designated_init on a non-struct to an error?
          </td>
        </tr>

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

        <tr>
          <th>Version</th>
          <td>trunk
          </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>enhancement
          </td>
        </tr>

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

        <tr>
          <th>Component</th>
          <td>C++
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>zhonghao@pku.org.cn
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>blitzrakete@gmail.com, dgregor@apple.com, erik.pilkington@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
          </td>
        </tr></table>
      <p>
        <div>
        <pre>My clang is 9.0.0, and the code is:

struct S {
 int a;
 union {
 int b;
 int c;
 };
} __attribute__((designated_init));

static struct S s = {
 .a = 0,
 .b = 0,
};

union U {
 int a;
 struct {
 int b;
 int c;
 } __attribute__((designated_init));
};

static union U u = {
 .b = 0,
 .c = 0,
};

clang produces the warnings:

<source>:7:18: warning: unknown attribute 'designated_init' ignored
[-Wunknown-attributes]

} __attribute__((designated_init));

                 ^

<source>:19:19: warning: unknown attribute 'designated_init' ignored
[-Wunknown-attributes]

 } __attribute__((designated_init));

                  ^

2 warnings generated.

Compiler returned: 0

Meanwhile, gcc rejects it:

<source>:25:1: error: too many initializers for 'U'

   25 | };

      | ^

Compiler returned: 1

The code comes from a gcc bug reprt:

<a href="https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59855">https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59855</a>

Some discussions seem to be useful.</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>