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c++windowsclangclang-cl

Differences between clang versions on windows

I've heard about clang-cl as a "microsoft-flavoured" version of clang but looking at my configuration I'm observing the following:

  • I've got an executable clang in my msys2 directories
  • I've got an executable clang-cl in my msys2 directories
  • I've got an executable clang in my visual-studio build tools directories
  • I've got an executable clang-cl in my visual-studio build tools directories

What are the differences between these versions? (Ultimately I'd like to see if it's worth the effort to add support for clang-cl in my compilation framework)

Additional data: Calling each of them with -v gives me Target: x86_64-w64-windows-gnu for the first one and Target: x86_64-pc-windows-msvc for all the others.

Solution

  • clang[++] vs clang-cl normally only affects the style of command-line arguments. clang[++] is GCC-like and is the primary interface. clang-cl is MSVC-like (MSVC = cl.exe).

    Apparently in MSYS2 Clang it also switches it from MinGW-compatible mode to MSVC-compatible (see --target below).

    You can use both clang[++] and clang-cl to compile MSVC-compatible programs. (Though the former requires knowing what flags to pass, which aren't obvious.) I doubt it makes sense to use clang-cl to compile non-MSVC-comatible programs (such as MinGW-compatible or not for Windows at all).

    The official build of Clang vs MSYS2 Clang affects the default --target=... (using MSVC ABI and libraries vs MinGW ABI and libraries). This can be seen in clang --version.

    Clang installed by Visual Studio, like the one from Clang's official installer, uses MSVC-compatible --target by default. I don't know if there's any difference between them.

    if it's worth the effort to add support for clang-cl in my compilation framework

    If you support MSVC (cl.exe), then supporting clang-cl is trivial, because the flags are (mostly?) the same.