<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/120973>120973</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [DebugInfo] DW_AT_object_pointer not attached to method declarations
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          Michael137
      </td>
    </tr>
</table>

<pre>
    [DWARF's `DW_AT_object_pointer`](https://dwarfstd.org/issues/050711.2.html) indicates which `DW_TAG_formal_parameter` corresponds to the function object that the method is being called on.

One motivator for this attribute from the original proposal is that it can be used to determine whether a C++ method is static or not. LLDB does need to distinguish static vs. non-static methods, but can't rely on `DW_AT_object_pointer` at the moment because Clang does not emit it on the declaration DIE (only on the definition). GCC emits it on both. See https://godbolt.org/z/3TWjTfWon

So LLDB currently relies on the existence of a `DW_TAG_formal_parameter` called `this` which is a pointer type. With C++23, we can't rely on either of these being true because of the `deducing this` feature: https://godbolt.org/z/h4jeT54G5 (though there's a bug in both Clang and GCC here where we don't emit the `DW_AT_object_pointer` for an explicit object parameter, will raise a separate issue for it)

This issue proposes adding the `DW_AT_object_pointer` to declarations too.
</pre>
<img width="1" height="1" alt="" src="http://email.email.llvm.org/o/eJyEVM1u2zgQfhr6MoggUZYdHXxw4nVQoIsFtgZyDChxJDKgOAY5Spp9-gUppc3-tL3YsEea-eb7GRWjHT3iQTR3ojlt1MyGwuF32xuFrqr3m470W6qeHo9_noXcRxC78vT4dLw8UfeMPT9dyXrGIHalaE5C3hrmaxT1UcizkGf9qsIQWRcURiHPNsYZo5Dnsin3VVXIwvDkhGzBem17xRjh1djerGMux4engcKk3NNVBTXhMgl6CgHjlbyOwARsEIbZ92zJw4IL2CjOhQnZkAYboUPrR-iVc6iBfCHKoyiPf3iEidi-KKYAAwVgYyMo5mC7mRGGQFPuRMGO1isH10BXisqlpnmOZeiVhw5hjqgTJJ2gTtYjvBpkgwEU3At5J-TdB0SRFdseKIAnLuDz59MdaMIIHtc2NrL142yjeX_4JRbgyd-sP5dmUch76OYMQ8g9Q0D3BuR_Ihe880MTeoYOezVHhHun_LiCIAacbF6PfH5YY-9UUJno06ffQMhb8sukpTxYb1NVyLaAh_v73CCuHTpiU8AXRPinS0bSHTleTfKXkOf68vh8GR7JLxp9oYWbfg4BPbu3tJ_F-D4Xv9rI6HsEGkD9yjyLAcSuTEKnfxbLJdFh5Qf47YoFPFo277LJOnH8iv-hGG3Wl4YEJeJqMw4zfiN1qaWRGvXc5_o6e0DFc0BRH39Jitk-46XZPjSJdjY0jya1DZiDqaCbR7ALy6uMyussQnooGTF9ImhaFsjarrh-ZJKUB-UBv16d7ZOKS7q-E5o4sc5BUDYiKIiYaoyQs57ftyxkuwh5SdFaKkuIMILSeiHkp0Bypr6ZL8Weio0-1LqtW7XBQ7Wvt-1u3zTlxhxua31btV212-6Gtt52bTW0vSq7ao9dU3bNxh5kKbeVlHXVyGa7L1q5a_uuKfd9o6qq2oltiZOyrnDuZUoabDLqQyXLdl9vnOrQxXw3pfT4uuwkpExnNBzSSzfdPEaxLZ2NHL-3YcsuH9wTdvP4yQ8kmhP839Y5f4pZ9WY5Buvd-EjDZg7u8C_fWDZzV_Q0CXlOY9evm2ug1P7jGV63eTnIvwMAAP__UFcIFw">