<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/101921>101921</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [multi-version] clang don't check the incorrect input prefix for target feature
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            clang
      </td>
    </tr>

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

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

<pre>
    * test: https://gcc.godbolt.org/z/1Yhd8dvvY
```
__attribute__ ((target("++sve2")))
void foo_handwritten_sve (float dest[N], unsigned int index[N], float src[Length], int n)
{
   ...
}
```

* For above **__attribute__ ((target("++sve2")))**, gcc will report `[error ](error: pragma or attribute 'target("++sve2")' is not valid)`, while clang doesn't report any warning , and treat it as **__attribute__ ((target("+sve2")))**
   > btw: **__attribute__ ((target("sve2")))** is also not allowed by gcc
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJycU0GP8yYQ_TX4MlqLjO3EOfiQNM2p6v07RRjGNi2BCMbObn99hZNsq2pbrSohGwZm3nszeiolO3qiTjRH0ZwKNfMUYrcMZhiKPpiPTuABmBKL6gAT8y2J6iDwLPA8al2OwfTBcRniKPD8h8Dz5sdkWrMsP4Q8CXkQW_lc6_FyUczR9jPT5QICW4EtqzgSr3sUeBR4TAvhetg_15q7BGtgCOEyKW_u0TKTv6SFcpnBBcVgMs_m-KtoTgJ_gtmv4gxYz2C9ofe_XT4yUtSiOf5CfuTpeZEf-09QsTs-NgBQluUrePpS3fOLBziHCKoPK7kc-J-619xMatQa7tY5iHQLkSFDNkeKMURYebfrPg_pFtV4VZAJvCBB4O6_0XZgE_jAsChnTQ5tZca9T9YRaKf8CCZQ8rnSi4TyH3BX0Vs_Qn6svAGOpBgsg0rfl_4vul99F9XP0PM9i_teya_rZYnKpbDqVM6FOxnoP3JvC9NVZl_tVUHdZofYVrJp2mLqqN8aVD1Wg9FbU0usN62qcF_3WtWahsJ2KLGWrWxkLbFqS93IRm8MojZ7qbeDqCVdlXWlc8s1-6SwKc3UbeRmj5vCqZ5cWu2HuPY5E29ORexywls_j0nU0tnE6a8SbNmtnr3Oju3bQjHZ4EVz-hzVY1B6Iv078ERgvQ4xks5GuM0Mt0iDfYchRHh0DgZSPEcq5ui6fxjd8jT3pQ5XgefM4fl7u8XwG2kWeF41pWz_h6ylwz8DAAD__7oCTgw">