pch support

[Thomas Weidenmueller]

Peter Åstrand wrote:
> Disabling precompiled headers is the first thing I do when starting a
> new project. We are using Visual C++ 2003/7.1, which often fails if you
> are building from a network share (this is more or less unsupported
> though, see
> http://groups.google.com/groups?hl=en&lr=lang_en&ie=UTF-8&oe=UTF-8&selm=umBJLvIYDHA.2632%40TK2MSFTNGP09.phx.gbl).


We've been using PCH with GCC for a long time in ReactOS, it's been
working very well and reliable. Compiling ReactOS is *a lot* faster with
PCH enabled.

I don't really understand what the problem is. Nothing really should
change except that all includes are grouped into one header file. It
works the same with MSVC. The only difference is that dependency
tracking needs to use one minor hack so it works properly with MSVC.
Even ancient versions of GCC don't have a problem with it and should
compile everything properly without any additional hacks (without PCH
support of course).

- Thomas