[cfe-dev] Keeping AST data for includes

[Vladimir Kirillov]

Hi Douglas!

On 08:26 Tue 02 Nov, Douglas Gregor wrote:
> On Nov 2, 2010, at 6:52 AM, Vladimir Kirillov wrote:
> 
> > Hello, cfe-dev!
> > 
> > While processing big source code trees with ASTFrontendAction and custom
> > ASTConsumer, same include files are getting hit and parsed all over and
> > over again.
> > Is there any technique (except precompiled header) to prevent such
> > actions? Like keeping header-related AST data and referencing it within
> > next files' AST?
> 
> That's what precompiled headers do. 
> 
> If you want each header to have an independent, stored AST, then
> you're in trouble, since every #include can affect every #include
> that follows it, and the dependencies between those #includes are
> very fine-grained.

Yes, I am aware of that.

However I thought about some declaration cache, which can be referenced
if the same SourceLocation is hit while the same preprocessor state
conditions are met.. Is it possible atm?