Clang 21: in-class initializer for static data member is not a constant expression

[ppenzin]

ChakraCore Version

master

Steps to reproduce

Get clang 21 or newer (I used current LLVM 'main') on Linux and build via CMake.

Proof of concept

(this is a build bug, there's no JS code to execute)

Exception or Error

lib/Runtime/Library/IntlEngineInterfaceExtensionObject.cpp:2260:42: error: in-class initializer for static data member is not a constant expression
 2260 |         static const UNumberFormatFields UnsetField = static_cast<UNumberFormatFields>(0xFFFFFFFF);
      |                                          ^            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/Runtime/Library/IntlEngineInterfaceExtensionObject.cpp:2260:55: note: integer value 4294967295 is outside the valid range of values [0, 15] for the enumeration type 'UNumberFormatFields'
 2260 |         static const UNumberFormatFields UnsetField = static_cast<UNumberFormatFields>(0xFFFFFFFF);
      |                                                       ^
1 error generated.
[10/184] Building CXX object lib/Runti...y.dir/JavascriptBuiltInFunctions.cpp.o
ninja: build stopped: subcommand failed.

Additional Context

This is new check introduced in version 21 described in llvm/llvm-project#163517. We are not bound to hit this in regular distro build soon, because packages (especially Ubuntu) have rather old version of Clang.

[ppenzin]

As an aside, we might want to add a 'build bug' template that wouldn't require POC code.

[ShortDevelopment]

As an aside, we might want to add a 'build bug' template that wouldn't require POC code.

That's the second one 😉 .github/ISSUE_TEMPLATE/02-build-issue.yml

[ppenzin]

Yeah, found that as well 😄