Custom source configuration

[Yvan Barthélemy]

I am new to autoconf and I would want to do the following uses :

- I have made a m4 macro to check the Qt environment of a user. Now I  
would like to check the sources in order to correctly set compiler and  
linker flags. Is that sort of thing (source scanning) already  
performed somewhere ?
If done, where is it done, and can I use that process ?
If not done, how can I perform this wheck my self from scratch (aka.  
what would be the better strategy to perform this ?) ?

- The previous use was mostly been thought to be performed at  
configure time, but it maybe be interesting to perform this at  
autoreconf time. For example, I would want to generate myself all code  
with Qt uic, and Qt moc, and distribute the generated code rather than  
asking the user to do it again (assuming there is no difference in the  
generated code when generated on different environment).
Same questions as above : how can I do that sort of thing in the  
autoconf process (it might or might not need to perform source  
analysis).

Thanks
Yvan