Hi, Alexandre did not like the needed changes required to add support for this but I figured I would throw it out for debate anyway in case anyone else can make him change his mind (duck). The issue is he does not like needing a single header per-program or per dll. After doing some research it seems to me that even MSVC does not support multiple PCH files per project so I don't know how it could be fixed in gcc to do it Microsoft has not figured it out.
problem: ccache works great for speeding up compiles but seems to still have issue with some header changes. Also the ReactOS guys really want to add pch support to the Wine dlls that are shared so the job falls to me to sell it to Wine.
Solution: Below are the benchmarks from my box and a patch. Simply patch your tree and then ./configure and cd to the regedit folder and do a 'time make','make clean','make pch', and 'time make' if you want to see the speedup on your box. I expect we could get a 2x speedup in fresh compiles of Wine with pch support
Regedit compile without pch
real 0m5.632s user 0m5.000s sys 0m0.524s
Regedit compile with pch
real 0m2.797s user 0m2.352s sys 0m0.428s
-- Steven Edwards - ReactOS and Wine developer
"There is one thing stronger than all the armies in the world, and that is an idea whose time has come." - Victor Hugo