Bug 281216 – [musl] Missing roundevenf and roundeven Function Support on Non-glibc Platforms

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[Pablo Saavedra]

While building WPEWebKit 2.46.1 for musl-based systems, compilation errors occur due to the absence of the `roundevenf` and `roundeven` functions. These functions are not available on platforms that do not use glibc, including musl [1]. This issue impacts platforms such as musl-based distributions, Android, FreeBSD, and others that do not provide the `roundeven` and the `roundevenf` functions, as it is not part of the standard C libraries in these environments. 

The build failure occurs in the `MathCommon.cpp` file in JavaScriptCore, specifically at:

```
2024-10-10T07:04:15.8564050Z | /home/bot/yocto-webkit-scarthgap/builds/raspberrypi3-mesa-wpe-musl/tmp/work/cortexa7t2hf-neon-vfpv4-poky-linux-musleabi/wpewebkit/2.46.1/wpewebkit-2.46.1/Source/JavaScriptCore/runtime/MathCommon.cpp:638:83: error: 'roundevenf' was not declared in this scope; did you mean 'roundf'?
2024-10-10T07:04:15.8566368Z |   638 | JSC_DEFINE_NOEXCEPT_JIT_OPERATION(f32_roundeven, float, (float operand)) { return roundevenf(operand); }
2024-10-10T07:04:15.8567237Z |       |                                                                                   ^~~~~~~~~~
2024-10-10T07:04:15.8567826Z |       |                                                                                   roundf
2024-10-10T07:04:15.8570085Z | /home/bot/yocto-webkit-scarthgap/builds/raspberrypi3-mesa-wpe-musl/tmp/work/cortexa7t2hf-neon-vfpv4-poky-linux-musleabi/wpewebkit/2.46.1/wpewebkit-2.46.1/Source/JavaScriptCore/runtime/MathCommon.cpp: In function 'double JSC::Math::f64_roundeven(double)':
2024-10-10T07:04:15.8573709Z | /home/bot/yocto-webkit-scarthgap/builds/raspberrypi3-mesa-wpe-musl/tmp/work/cortexa7t2hf-neon-vfpv4-poky-linux-musleabi/wpewebkit/2.46.1/wpewebkit-2.46.1/Source/JavaScriptCore/runtime/MathCommon.cpp:639:85: error: 'roundeven' was not declared in this scope; did you mean 'f64_roundeven'?
2024-10-10T07:04:15.8576102Z |   639 | JSC_DEFINE_NOEXCEPT_JIT_OPERATION(f64_roundeven, double, (double operand)) { return roundeven(operand); }
2024-10-10T07:04:15.8576970Z |       |                                                                                     ^~~~~~~~~
2024-10-10T07:04:15.8577574Z |       |                                                                                     f64_roundeven
```

This issue blocks the compilation of WPEWebKit for musl and requires either a fallback to `roundf` and similar alternatives or a platform-specific implementation of the `roundevenf` and `roundeven` functions for non-glibc platforms.


[1] https://www.gnu.org/software/gnulib/manual/gnulib.html

[Pablo Saavedra]

Pull request: https://github.com/WebKit/WebKit/pull/34972

[Angelos Oikonomopoulos]

Oops, thanks for fixing this!

[EWS]

Committed 285058@main (cbd68e2d4822): <https://commits.webkit.org/285058@main>

Reviewed commits have been landed. Closing PR #34972 and removing active labels.

[Radar WebKit Bug Importer]

<rdar://problem/137791968>