[bla2]

Looks like this is using clang++ instead of clang-cl, which sets almost all of these flags automatically.

[martell]

Exactly, In fact clang, clang++ and clang-cl are all the same program. The frontend just behaves differently based on the file name.

Disclaimer: I am a LLVM Engineer working on a mingw-w64 standalone clang :)

[jessermeyer]

Why is Clang so much slower than cl at compiling? On OS X / unix Clang seems so much faster.

[martell]

By cl do you mean MSVC cl or are you asking about clang vs clang-cl ?

[jessermeyer]

MSVC cl compiles much faster than clang / clang-cl.

[dxf]

Yes, this is something that is being worked on.

[jessermeyer]

Can you point to an official discussion / svn commit chain that demonstrates this?

[Leandros]

Unfortunately, clang-cl only supports a very limited subset of CL's flags. And if you want to talk to clang directly you have to go through an extra layer of indirection by using -Xclang -flag. By using clang directly you get the whole power of clang without arbitrary limitations (and as a bonus you can now compiler your software on mac and linux).

[bla2]

What's missing?