<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/72413>72413</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [compiler-rt] lots of "warning: unknown warning option '-Werror=builtin-declaration-mismatch'" messages
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          ms178
      </td>
    </tr>
</table>

<pre>
    Compiling llvm-git with 0a0e06f29145213e90de88ca39f7b505ce092a4a leads to the following new warnings in compiler-rt:

```
[747/6672] Building ASM object projects/compiler-rt/lib/builtins/CMakeFiles/clang_rt.builtins-i386.dir/i386/floatundisf.S.o
warning: unknown warning option '-Werror=builtin-declaration-mismatch'; did you mean '-Werror=missing-declarations'? [-Wunknown-warning-option]
1 warning generated.
[748/6672] Building ASM object projects/compiler-rt/lib/builtins/CMakeFiles/clang_rt.builtins-i386.dir/i386/muldi3.S.o
warning: unknown warning option '-Werror=builtin-declaration-mismatch'; did you mean '-Werror=missing-declarations'? [-Wunknown-warning-option]
1 warning generated.
[749/6672] Building ASM object projects/compiler-rt/lib/builtins/CMakeFiles/clang_rt.builtins-i386.dir/i386/ashrdi3.S.o
warning: unknown warning option '-Werror=builtin-declaration-mismatch'; did you mean '-Werror=missing-declarations'? [-Wunknown-warning-option]
1 warning generated.
[750/6672] Building ASM object projects/compiler-rt/lib/builtins/CMakeFiles/clang_rt.builtins-i386.dir/i386/floatdidf.S.o
warning: unknown warning option '-Werror=builtin-declaration-mismatch'; did you mean '-Werror=missing-declarations'? [-Wunknown-warning-option]
1 warning generated.
[751/6672] Building ASM object projects/compiler-rt/lib/builtins/CMakeFiles/clang_rt.builtins-i386.dir/i386/floatdisf.S.o
warning: unknown warning option '-Werror=builtin-declaration-mismatch'; did you mean '-Werror=missing-declarations'? [-Wunknown-warning-option]
1 warning generated.
[752/6672] Building ASM object projects/compiler-rt/lib/builtins/CMakeFiles/clang_rt.builtins-i386.dir/i386/floatundidf.S.o
warning: unknown warning option '-Werror=builtin-declaration-mismatch'; did you mean '-Werror=missing-declarations'? [-Wunknown-warning-option]
1 warning generated.
[753/6672] Building ASM object projects/compiler-rt/lib/builtins/CMakeFiles/clang_rt.builtins-i386.dir/i386/lshrdi3.S.o
warning: unknown warning option '-Werror=builtin-declaration-mismatch'; did you mean '-Werror=missing-declarations'? [-Wunknown-warning-option]
1 warning generated.
[754/6672] Building ASM object projects/compiler-rt/lib/builtins/CMakeFiles/clang_rt.builtins-i386.dir/i386/moddi3.S.o
warning: unknown warning option '-Werror=builtin-declaration-mismatch'; did you mean '-Werror=missing-declarations'? [-Wunknown-warning-option]
1 warning generated.
[755/6672] Building ASM object projects/compiler-rt/lib/builtins/CMakeFiles/clang_rt.builtins-i386.dir/i386/udivdi3.S.o
warning: unknown warning option '-Werror=builtin-declaration-mismatch'; did you mean '-Werror=missing-declarations'? [-Wunknown-warning-option]
1 warning generated.
[757/6672] Building ASM object projects/compiler-rt/lib/builtins/CMakeFiles/clang_rt.builtins-i386.dir/i386/ashldi3.S.o
warning: unknown warning option '-Werror=builtin-declaration-mismatch'; did you mean '-Werror=missing-declarations'? [-Wunknown-warning-option]
1 warning generated.
[766/6672] Building ASM object projects/compiler-rt/lib/builtins/CMakeFiles/clang_rt.builtins-i386.dir/i386/divdi3.S.o
warning: unknown warning option '-Werror=builtin-declaration-mismatch'; did you mean '-Werror=missing-declarations'? [-Wunknown-warning-option]
1 warning generated.
[768/6672] Building ASM object projects/compiler-rt/lib/builtins/CMakeFiles/clang_rt.builtins-i386.dir/i386/umoddi3.S.o
warning: unknown warning option '-Werror=builtin-declaration-mismatch'; did you mean '-Werror=missing-declarations'? [-Wunknown-warning-option]
1 warning generated.
[770/6672] Building ASM object projects/compiler-rt/lib/builtins/CMakeFiles/clang_rt.builtins-i386.dir/i386/floatdixf.S.o
warning: unknown warning option '-Werror=builtin-declaration-mismatch'; did you mean '-Werror=missing-declarations'? [-Wunknown-warning-option]
1 warning generated.
[790/6672] Building ASM object projects/compiler-rt/lib/builtins/CMakeFiles/clang_rt.builtins-i386.dir/i386/floatundixf.S.o
warning: unknown warning option '-Werror=builtin-declaration-mismatch'; did you mean '-Werror=missing-declarations'? [-Wunknown-warning-option]
1 warning generated.
[929/6672] Building ASM object projects/compiler-rt/lib/builtins/CMakeFiles/clang_rt.builtins-x86_64.dir/x86_64/floatundidf.S.o
warning: unknown warning option '-Werror=builtin-declaration-mismatch'; did you mean '-Werror=missing-declarations'? [-Wunknown-warning-option]
1 warning generated.
[930/6672] Building ASM object projects/compiler-rt/lib/builtins/CMakeFiles/clang_rt.builtins-x86_64.dir/x86_64/floatundisf.S.o
warning: unknown warning option '-Werror=builtin-declaration-mismatch'; did you mean '-Werror=missing-declarations'? [-Wunknown-warning-option]
1 warning generated.
[942/6672] Building ASM object projects/compiler-rt/lib/builtins/CMakeFiles/clang_rt.builtins-x86_64.dir/x86_64/floatundixf.S.o
warning: unknown warning option '-Werror=builtin-declaration-mismatch'; did you mean '-Werror=missing-declarations'? [-Wunknown-warning-option]

```

CachyOS also ships with a brand new gcc-version 13.2.1 20231110.
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzcmc-PqzYQx_8ac7FA_oHtcOCw2YjbUw97eMcngw24z9iRbZK3_30FYduoqrSXammRIgjCnsx88tXYM5YxmsFpXQN2BuySyTmNPtRTxOKUtV69169-uhpr3ACtvU35YBK8mzRCJJFGvCcVLhnBVFdI6dOpk7TqRcsQ6zSqiCwltFqqCJOHadSw99b6-2LN6Tu8y-CMGyI0Dnbr7-iQhwToC0AXgD6uHG2fxyM7i1IA0nAuCGAXeJ6NVYvJl7dv0Le_6y7Ba_DLPQLSPBsmjTUtIE07G5uMW16_fpM_dWOsXsda6YYfIRUfA3JDT7xQJgDSLF8BaXrrZZqdMrEv3gr_cGqLBNAXOLufzt_dR3DQX5PxDgIi8u86BB8AvWzmc6U7K4NcBuSTiZNM3QiIAPQMlVHw3c9w0vJvkycTo3HD8-S4TmogYOf8--ZAvjmQPxwA7PJwFf_p2aCdDjJpVTyRPe1HdpqtMvSIUKv9oMo4hmNSZWjnJKCMOmIKYHh3rodMrYz8BxatYyqW7kfWHje_ljtuBbw6KFS2H9RZmdtBqe5YD8g4HnTbyvl-VA8rVb5jgTUfNq2K_WuBX0fcWVV7c132rEckW5Ev6wn8OvEfvNzYPh6OXhFU9Mt0-wndI1ayVflllewndP-nmeGf-9rr9VV24_tvb1Da6GEczTU-2u0StkE6tbbNh67LbzrEJSZMC1JgSBChGGNUZKqmqqKVzHSNBUKIC1bhbKwxY0pXAvWKdYwrxEtNsCgJU4zzE0KZqTcjDHNWladC9ERpInpctqLjvQQl0pM0trD2NhU-DJmJcda1ICWmmZWttnE9RyBk8XJ9CciikSzU6-FBOw8RlMiamOJfVpJJdj2AeJYKu0DrU4S-h4CQf_m_JQROOkY56JjNwdZjStcI6AsgDSDNYNI4t0Xnp0Ww9vZxyzdVLyvUEtui2DX2PwIAAP__e11lYw">