Over on Vince Slyngstad's website 'so much stuff' - specifically in
the PDP-8 section - there's
a page on the writing of a C compiler, for a subset of C. The PDP-8 is rightly described as not a great fit for C - and the same is commonly said of the 6502.
So this might be interesting to a would-be writer of a C compiler for the 6502.
In particular, there's an intermediate target for a VM, the resulting code then being peephole optimised, and then the result of that being translated to native target code.