[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: how to include dependencies only if includes changed
From: |
Allan Odgaard |
Subject: |
Re: how to include dependencies only if includes changed |
Date: |
Tue, 10 Nov 2009 02:12:24 +0100 |
On 9 Nov 2009, at 19:25, Mark Galeck (CW) wrote:
[...] I am dealing with a code base of over 8 million lines, more
than 1000 .c files, each depending on around 500 .h files. The
dependencies, all of them, take about 1 minute to "-include", even
if you are just rebuilding one .o file.
The time should be relative to number of total .h files (and I guess
number of included files).
I have a much smaller project (~200 sources + ~250 headers) but I
noticed that the implicit rules of make can really slow things down:
% time make
make: Nothing to be done for `all'.
real 0m0.318s
% time make -r
make: Nothing to be done for `all'.
real 0m0.090s
Don’t know if you rely on the implicit rules, if not, definitely test
how much time they eat. If you do use them, you may be able to just
copy those you use and disable the rest.