<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/129366>129366</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            llvm-objcopy --redefine-syms Does Not Update Symbols in PE/COFF (.dll) Files
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            new issue
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          Harishmcw
      </td>
    </tr>
</table>

<pre>
    Hi Developers,

When using llvm-objcopy on a PE/COFF .dll file to rename symbols using the --redefine-syms option, the command executes successfully, and the timestamp of the file updates. However, when inspecting the modified .dll, the symbols remain unchanged.

Command Executed:

`llvm-objcopy --redefine-syms objcopy.def openblas.dll`

Definition File (objcopy.def):

```
lsame_ scipy_lsame_
xerbla_ scipy_xerbla_
isamax_ scipy_isamax_
isamin_ scipy_isamin_
ismax_ scipy_ismax_
```
Please confirm whether --redefine-syms is expected to work on PE/COFF .dll files. If not, should it be documented as unsupported? Otherwise, if this is a bug, a fix would be greatly appreciated.
</pre>
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