[WebAssembly] Define __WASM_EXCEPTIONS__ for -fwasm-exceptions (#92604) When using other specific exception options in Clang, such as `-fseh-exceptions` or `-fsjlj-exceptions`, Clang defines a corresponding preprocessor such as `-D__USING_SJLJ_EXCEPTIONS__`. Emscripten does that in our own build system: https://github.com/emscripten-core/emscripten/blob/7dcd7f40749918e141dc33397d2f4311dd80637a/tools/system_libs.py#L1577-L1578 But to make Wasm EH usable in non-Emscripten toolchain, this has to be defined somewhere else. This PR makes Wasm EH consistent with other exception scheme by letting it defined by Clang depending on the exception option. We have been using `__USING_WASM_EXCEPTIONS__` in our current library code, but this changes it to `__WASM_EXCEPTIONS__` for its conciseness, and I will update other parts of LLVM as follow-ups. This does not break anything currently working, because we have not been defining anything in Clang so far.
Welcome to the LLVM project!
This repository contains the source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and run-time environments.
The LLVM project has multiple components. The core of the project is itself called “LLVM”. This contains all of the tools, libraries, and header files needed to process intermediate representations and convert them into object files. Tools include an assembler, disassembler, bitcode analyzer, and bitcode optimizer.
C-like languages use the Clang frontend. This component compiles C, C++, Objective-C, and Objective-C++ code into LLVM bitcode -- and from there into object files, using LLVM.
Other components include: the libc++ C++ standard library, the LLD linker, and more.
Consult the Getting Started with LLVM page for information on building and running LLVM.
For information on how to contribute to the LLVM project, please take a look at the Contributing to LLVM guide.
Join the LLVM Discourse forums, Discord chat, LLVM Office Hours or Regular sync-ups.
The LLVM project has adopted a code of conduct for participants to all modes of communication within the project.