<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/64631>64631</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [clang] __attribute__((target_clones)) is accepted even when not supported by the platform (linux-musl)
        </td>
    </tr>

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

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

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

<pre>
    doing

```console
/ # cat main.cc 
static int __attribute__((target_clones("default,avx")))
has_target_clones(void) {
    return 0;
}
int main(void) {
    return has_target_clones();
}
/ # clang++ main.cc -o x
/ # echo $?
0
```

successfully compiles, but then

```console
/ # ldd x
        /lib/ld-musl-x86_64.so.1 (0x7fbb9a2ee000)
        libc.musl-x86_64.so.1 => /lib/ld-musl-x86_64.so.1 (0x7fbb9a2ee000)
Error relocating x: unsupported relocation type 37
```

by contrast, gcc

```console
/ # g++ main.cc  -o x
main.cc:2:1: error: the call requires 'ifunc', which is not supported by this target
    2 | has_target_clones(void) {
      | ^~~~~~~~~~~~~~~~~
```

this is because musl does not support ifunc.

i can perhaps imagine some rationale for why it would successfully compile anyway (despite the musl target not supporting it ever), but this breaks configure tests that [check if it's supported](https://github.com/libvips/libvips/blob/8d5f33174c956623c1b7eb82c43c828c0511cc22/meson.build#L149) (it detects as valid and uses it, generating a broken exe). a compile+executable test would catch it instead, but that is less feasible when cross compiling.

perhaps clang should follow what gcc does?
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJycVcuO8ygTfRqyKXVkg6-LLLo7X1b_O0QYl23-JuChIJfNPPsIO339Wt-0JrIcC6ji1DmHQhLp0SLuWPnEyv1GxjA5v7P44ma6vTjCTef626532o4s27Ps8f6usvVRzpIzeB_lB2BcgJIBTlLbrVKwzlCQQSvQNsDxKEPwuosBj0fGG8abIP2I4aiMs0jLEO9xkNEExp_l-co4Z7y9P0u-SdLxa9TZ6Z7xFlj9tC4CAPAYoreQMXEfZPV-_UhYEsh_ifxupwTjt3xvxRtpR8afGH96I-HBwfXzKlSTA8YLJg7rRPaF2I9sU1QKiYZozA2UO83aJBzP0MUAYUL7c2lM379ByVrGD0Z36d0_nCKZh2tTHatiS26bA-NNdq2HrmslR8yy7I19lrVGd2r7e4jYM_EL_mPaX947Dx6NUzJoO8KViUeIluI8Ox-wf5tzFsJtRhD1H1jrElc2eEnJRjAq9XOavgr4QcH7EBOPnInHPEHEBDx9hAlBSWPA419ReyRgvNZDtIrxOoG4TFpNoAmsC_BeV3eDMGmC1WjvHuTA6udvLfitZWFZzspff3_5_YGlZV9N0KGSkRCSXtA7_AQRlhq2H-M0KGlhRj_JmUCf5KgtArkTgl8UkgZhcB4u0w10gIuLpofvnAzS3i7ylozRI8064MLjAmQt-yOU5AsdAM_ol4bweghSCR7lCyXRBz1GjxCQAkGYZABWPqkJ1QvoAXRgvKZ3-lm5Z7yZQpiJiWQBxg-jDlPstsqdVjOf9UyfvjrjksObvhyEyOtCtWVVcaHyrsau4aoQquGNyso8Vyr1r8MJydltF7XpGRf_y4t2EZA3OkCPAVUgkARnaXQP0vYQCWkB-wwjWvTroZDQefeCFvCKjLdbkK9EMv6EV1QxyM6sxd9ZVzIk1wXQlgLK_p01GZL2BolgQEk6BV4mtKC8I7on1nb8JP2r6EunA5qWPQZnjLvAJaUclVosxMRh0-9E34pWbnCXV23eZEWdVZtpJ-TQihZlyXlVSl62iE2PuWgx74sK5UbveMZF1uQ8y4syq7ZFhog1V3WdSS6GnBUZnqQ2W2POp63z40YTRdxVRSXyjZEdGlouNs4tXmCZTDdJud_4XYp56OJIrMiMpkDvWYIOZrkR105e7n9wZS1SagKpFM7pROMZ7crkNycdYTYyDM6fkvxG23hd-iTj7SZ6s_uTFc359e9h9u7_qALjh6W25Mql9n8CAAD__2I2b2I">