> 9. Without a C compiler, we're stuck with, wedded to, and beholden to libclang.
> I wouldn't be surprised that the eventual cost of adapting ourselves to
> libclang will exceed the cost of doing our own C compiler.
This is a really insightful point. I had to learn this the hard way :)
We might follow your lead on this, as we have done with so many other great ideas implemented in D.
Ironically, Vexu started from the other side as you, with the preprocessor mostly done, but the backend left to-do: https://github.com/Vexu/arocc
One thing that might make libclang worth the cost, however, is its ability to compile C++ code as well. On Zig's end of things, all we have to do is provide libcxx, libcxxabi, libunwind, compiler-rt, and linking, and then libclang is really pulling a lot of weight by compiling C++ code into object files. Sadly this ability is just too useful in practice to ignore. For example, LLVM itself is C++ so if Zig wants to be able to bootstrap itself, it needs this capability.
Still, I think your maneuver here is the best long-term approach to tackle this problem, and I imagine as time goes on we'll start to migrate towards D's solution here. Maybe someday the Zig distribution that does not have LLVM extensions enabled will be the more popular one.
I'll be watching the evolution of this new feature in D with great interest!