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      <base href="https://bugs.llvm.org/">
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    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - clang-cl with /P and /Brepro fails with a cryptic error message"
   href="https://bugs.llvm.org/show_bug.cgi?id=42066">42066</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>clang-cl with /P and /Brepro fails with a cryptic error message
          </td>
        </tr>

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

        <tr>
          <th>Version</th>
          <td>unspecified
          </td>
        </tr>

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

        <tr>
          <th>OS</th>
          <td>Windows NT
          </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>C++
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>brucedawson@chromium.org
          </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>Bug <a class="bz_bug_link 
          bz_status_RESOLVED  bz_closed"
   title="RESOLVED FIXED - clang-cl handles /E and /P (preprocess only) incorrectly with PCH files"
   href="show_bug.cgi?id=38508">https://bugs.llvm.org/show_bug.cgi?id=38508</a> reported a host of errors when
preprocessing a file in the context of the Chromium build. Most of those errors
were fixed but one remains. I started with the repro steps from the previous
bug but I managed to reduce it greatly.

c:\src\chromium3\src\out\release>type test.cpp
int x;

c:\src\chromium3\src\out\release>..\..\third_party\llvm-build\Release+Asserts\bin\clang-cl.exe
/P /Brepro /c test.cpp
clang-cl: warning: argument unused during compilation:
'-mno-incremental-linker-compatible' [-Wunused-command-line-argument]

That's it. I don't know *why* /Brepro triggers this error message, but it does.

Preprocessing files is a valuable investigative technique so getting this to
work again would be great.</pre>
        </div>
      </p>


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