generation of makefiles from build output?

[Mark Galeck]

Hello,

I am working on a project which has more than 100M lines of code, more than 
100K 
files and, more than 1000 makefiles. Makefiles apparently have bugs (may build 
too little or too much), are slow, messy, and violate "Paul's rules" and common 
decency on a routine basis.  I am asked to "do something".  

Well, seems that because of the size of the problem, fixing existing code is 
not 
an option.  

I have an idea - get the full build output from scratch, and write Perl scripts 
to process that output into well designed makefiles. It seems it should be 
possible to figure out, based on output, what the shell commands are that are 
used, what the arguments are, which arguments are options, which are files, 
which are generated from other shell commands, and so forth...  and figure out 
the makefiles from that.  

Has anybody heard of this kind of thing being tried on a large project? Is it 
hopeless? Do I not see some fundamental obstacle which makes it not possible in 
practice? Perhaps somebody already wrote some scripts to do this kind of thing? 

Thank you for any advice,

Mark  

PS.  Larry Wall says good programmers are lazy. I am not good (not in Larry's 
intended meaning), but at least, I am really lazy (in his intended meaning) :)