Package: libc++-23-dev-wasm32 Version: 1:23.1.2-1 Severity: normal X-Debbugs-Cc: [email protected]
Dear Maintainer, * What led up to the situation? Since LLVM 23.1.0, Clang supports separate C++ standard library variants for WebAssembly with and without exception handling. [1][2] [1] [WebAssembly] Clang support for exception-based lookup paths - #185775#185775 https://github.com/llvm/llvm-project/pull/185775 [2] [WebAssembly] Move __cpp_exception to libunwind https://github.com/llvm/llvm-project/pull/185770 The Clang driver selects the appropriate variant depending on whether -fwasm-exceptions is specified. Currently, however, libc++-23-dev-wasm32 is built with: -DLIBCXX_ENABLE_EXCEPTIONS:BOOL=OFF -DLIBCXXABI_ENABLE_EXCEPTIONS:BOOL=OFF -DLIBCXXABI_USE_LLVM_UNWINDER:BOOL=OFF As a result, the Debian WASM libc++ package provides only the non-exception-enabled variant. To make use of the exception-based lookup paths provided by Clang, both the exception-enabled (EH) and non-exception-enabled (non EH) variants of libc++ and libc++abi need to be built and installed in the locations expected by the Clang WebAssembly driver. * What was the outcome of this action? When -fwasm-exceptions is enabled, the Clang driver is already able to select the exception-enabled C++ standard library variant; otherwise it selects the non-exception-enabled variant. However, Debian currently does not provide the exception-enabled variant in libc++-23-dev-wasm32, so C++ applications using WebAssembly exception handling cannot use the corresponding libc++ runtime from the Debian package. Please consider providing both variants in the WASM libc++/libc++abi packages. Best Regards,
