<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/122435>122435</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [MinGW] [libunwind] undefined __gxx_personality_seh0 when build libunwind with LTO+Exceptions
        </td>
    </tr>

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

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

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

<pre>
    See #121819 for background context

This may become a problem in the future, but for now it won't actually happen unless libunwind does switch to using `-fexceptions` to compile the whole library

To build a libunwind that reproduces this problem, we need to hack the build system:
```
-DLIBUNWIND_ENABLE_SHARED=OFF
-DCXX_SUPPORTS_FNO_EXCEPTIONS_FLAG=OFF
-DCMAKE_C_FLAGS=“-flto=thin”
-DCMAKE_CXX_FLAGS=“-flto=thin”
```

Then use `-flto=thin` to compile any source and link them with libunwind.a:

```
x86_64-w64-mingw32-clang -flto=thin test.c --static

lld-link: error: undefined symbol: __gxx_personality_seh0
>>> referenced by llvm-project/libunwind/src/libunwind.cpp
>>>               libunwind.a(libunwind.cpp.obj)
```

[report.zip](https://github.com/user-attachments/files/18374405/report.zip) (lld reproduce)
</pre>
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