<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=http://email.email.llvm.org/c/eJzdVttu3DYQ_Rruy2AFkro_6GEvcuvWaYLGDdCnBUVREmtKXJBUbP99Se2uaydBgKJIG5cakRxeRjPDQ-g0un2srmG2AvhsjJgc_Fhv9oBo0TaYNITGLSa07WiHRcZ4l4sSN13SsCyOC5oWOUe0BN1BY9jEB0AZHpmcfAPMhnGnW_YI99IN4AYBnVZK38uph2aWqgWux5FNLYo3CO8RvtQZPsuijnetNOcNiGZegLcn_bSAj-xOwHq_e7P5uT5sf7u-2R9uf39Xo3i_F83c-6mbmw9vDvUvm-1NfXj369uf6t3tez_NlIIoQvRKqY_jC2Pr0_ci3-N66mQPi6kvOniqb318L6IKEU8gJ3CzmaCXH4X9JAnCGG2-Hrz3bdCj8E0_sb6f9KNUXrnX5s4eGRdn39dHo_8Q3AVVNv5UrqwJ9cjcEPaKSRgZBoJvejr4mKxjk7MRPx69ByT1VXgB1QXa7NEmQ3WKSoKKDaqv0HaHyk3AiT_THaJbLySHQTywVnA5MgWd0syFoC6mT_4DAEkB5TsIBT-QCD8vR28II7pbZjqO8w6TU3Nck6fxglyEnsefjPtyMY7SGuV_X_6rNJeoTFBZLvm-CnJJs3g46incxcHfoUlDK3vp7L_vJ81fNx6-XF4LSi7Z_-5hkpT_R5i8bvBczuS7Bk_2DX852QvsdEmSpaVIWEJz8hwhOOfkXBXPxgX3WGpiTELnG_1wljpayldIxTWi-egJ2hLlwkziiNIToRof4e17YIYPSk7zA8zHljnRvmBenslRTOkaB_FcLYJrcEb6VT_sdkBIRCAwlUXBUbwojfbGjThqE6wFxmLZKE5kJYKdYt4XEkcY9LTM-uXCeCD5ra0WAU7uvB3s7EnhaeOqreK2jEu2YrMbtKn-AtdqNqoanDvawIXoVUCPD3BuIg-dCzn7DHTS2llY30lj_6yGKqZd3rIiLZvEN01ZZoKQpOEdZiwRLVsp1ghlK5RuUbpf_fNPyirkFocnTzNSRgkrSk6ztKNFkfCkQQkWng-rKNiJtOlXplpMeiZp_aSS1l-Hp0lmrewnIS4eOumUqAJ1PRPLJZMh7VbPhi90krmAfudJt_38boCSThimVovj1eL1n_R5eaU>53535</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            LLVM build error on sources that contains hexadecimal float literal
        </td>
    </tr>

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

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

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

<pre>
    I use current HEAD (db01b123d012df2f0e6acf7e90bf4ba63382587c) of branch `main` as of today with the following build command:

```
mkdir build && cd build
cmake -DCMAKE_BUILD_TYPE=Debug -DLLVM_ENABLE_PROJECTS=all ../llvm
cmake --build . --config Debug
```

The build command then in turn gives the following error:

```
/home/gnaggnoyil/workspace/llvm-project/libc/src/math/generic/common_constants.cpp:15:5: 警告：use of C++17 hexadecimal floating constant
   15 |     0x1.0000000000000p+0, 0x1.fc07f01fc07f0p-1, 0x1.f81f81f81f820p-1,
      |     ^~~~~~~~~~~~~~~~~~
/home/gnaggnoyil/workspace/llvm-project/libc/src/math/generic/common_constants.cpp:15:5: 错误：exponent has no digits
/home/gnaggnoyil/workspace/llvm-project/libc/src/math/generic/common_constants.cpp:15:27: 警告：use of C++17 hexadecimal floating constant
   15 |     0x1.0000000000000p+0, 0x1.fc07f01fc07f0p-1, 0x1.f81f81f81f820p-1,
      |                           ^~~~~~~~~~~~~~~~~~
/home/gnaggnoyil/workspace/llvm-project/libc/src/math/generic/common_constants.cpp:15:27: 错误：exponent has no digits
/home/gnaggnoyil/workspace/llvm-project/libc/src/math/generic/common_constants.cpp:15:49: 警告：use of C++17 hexadecimal floating constant
   15 |     0x1.0000000000000p+0, 0x1.fc07f01fc07f0p-1, 0x1.f81f81f81f820p-1,
      |                                                 ^~~~~~~~~~~~~~~~~~
/home/gnaggnoyil/workspace/llvm-project/libc/src/math/generic/common_constants.cpp:15:49: 错误：exponent has no digits
/home/gnaggnoyil/workspace/llvm-project/libc/src/math/generic/common_constants.cpp:16:5: 警告：use of C++17 hexadecimal floating constant
   16 |     0x1.f44659e4a4271p-1, 0x1.f07c1f07c1f08p-1, 0x1.ecc07b301ecc0p-1,
      |     ^~~~~~~~~~~~~~~~~~

......
```

I'm using cmake 3.22 with my OS archlinux updated as of today (2022-02-02). I tried GCC 11.1 and GCC 10.3 and both reported the same error. Clang 13.0 on the other hand does not report such error.
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzdVktv3DYQ_jXcy2AFinofdNiHNnXrNEHjBMhpQVGUxJgSBZKK7X8fUrvr2kkQoIe0cakRyeFjNDP8CH21ah7KK5gNBzZrzUcLv1WbPSCSNzUO65BEDQ5J05IW85SyNuMFrtu4pmkU5STJM4ZIAaqFWtOR9YBSPFAxugao8eNWNfQB7oTtwfYcWiWluhNjB_UsZANMDQMdGxRtEN4jfKlTfJZFHW4boc8bEEmdAGtO-mkBG-gth_V-93rzR3Xcvr-63h9vPr6tULTf83ru3NT19YfXx-rPzfa6Or79683v1e7mnZumUkIQIHKQ8vPwzNj69L3A9ZgaW9HBYuq7Dp7qGxffs6h8xCOIEeysR-jEZ26-SgLXWukfB-9869XAXdONtOtG9SCkU-6UvjUTZfzs-3rS6hNn1quidqdyMNrXA7W938tHroUf8L6p8ehiMpaO1gRsmpwHYeIq_wKqcrTZo02KqgQVIco3qDqg7Q4VG48Td6Y7RLZOwgx6fk8bzsRAJbRSUeuDupg--Q8AYQIo24Ev-D4M8NMyOUMYkd0y0zKctTg8NdM6fBzPw4uQ8_ijcVcuxlFSoeyfy3-V5gIVMSqKJd8HL5c08_tJjf4u9u4OjQoa0Qlr_n0_Sfay8fD98lJQcsn-Lw-TuPg_wuRlg-dyJr80eNKf-MtJn2GnjeM0KXhMY5KFTxGCMxaeq_zJOGcOS3WEQ9_5ST-cpQ6W8gNScYVINjiCtkS5MJMoIOREqIYHePMOqGa9FON8D_PUUMubZ8zLMTmCCVljL46rBXAFVgu36tVuB2EYhOCZyqLgIFqUWjnjmk9Ke2uesRg68BNZCWAnqfMljAIMalxm3XKuHZDc1kZxDyd73g5mdqTwtHHVlFFTRAVdWWElLz0jO_OlZYG3ZtSs2cKSqPWHah2XNN8eOUhhuaZyNWtZ9tZOxnMocvCoc4mZ68BB7kLqvgGrMGbmxnWSyD2rviwSV7K0iJocJznL8oZgTnFGEtawhGQrSWsuTYmSLUr2K1H6jGL_ZEkaFkFM84KRNGlJnscsrlGMuWPBMvAfDpTuVrpcfHD80bhJKYy7BI-T1BjRjZxf7NPZ9kqXf9-91eJxubj7BZBwYsQ">