Comment by delphLonepaw

2 years ago

LLVM just works well on the front that clang uses, after that, llvm itself is a wild beast full of worms, which is becoming more and more painful to work with if you are a language creator/mantainer, A lot of untested paths, and hidden bugs that zig has hit before... many times.

It will NOT reimplement everything, if you read the proposal, it's in favour of changing the LLVM dependency (the libs) not dropping LLVM IR generation, this will come with performance regression since now will be up to the team to get the correct IR, and making decisions LLVM IR generation does already in LLVM

The problem is that clang is being dropped, which means, unless we have a new C++ front made in zig (a-la AroCC for C) we are gonna suffer quite a bit for projects using C++ with zig.

> unless we have a new C++ front made in zig

Writing a C++ compiler is several order of magnitude more complicated than writing a C, Java, Go or Zig compiler. There's a very good reason there are only 3 in existence despite how ubiquitous C++ is (and even then, it takes years for them to keep up with the latest standards). C++'s grammar is type 0, there's isn't even an EBNF definition of it because it's pratically impossible to write a complete one. Clang only succeeded thanks to massive investments from the biggest players in the industry, and GCC/MSVC simply grew alongside the language. All other C++ compilers died a horrible death a long time ago.

  • Out of curiosity, does Intel's icc compiler see much use? It looks like it uses LLVM these days, but its frontend presumably still needs to handle all of C++'s complexity.

    • ICC is deprecated and will no longer see a release, but it uses the EDG front-end. Its replacement, ICX (the oneAPI compiler), uses clang as its front-end.

      There are essentially only four extant C++ front-end implementations: GCC, Clang, MSVC, and EDG. All other C++ compilers are based on one of these four implementations, or have since gone extinct. (Except maybe Green Hills, but I can't recall anymore if their front-end is still in-house.)

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