The source location for a call that's inside a macro body will,
by default, point into the macro definition itself. The original
logic was causing macro invocations to be overwritten, as I
explain here:
https://github.com/ROCm-Developer-Tools/HIP/issues/207#issuecomment-337521851
The existing PPCallbacks code is correctly rewriting macro
definitions, so the practical effect of this change is that AST
rewrites on code that's expanded from macros are no-ops.
It might be a performance optimisation to put a short-circiut at
the top of the AST callbacks to abort when faced with code that
was expanded from macros.
It might yet prove wise to do absolutely everything at lex-time...
[ROCm/clr commit: f7e65c5334]
Chris Kitching
cf50b4f97a