On Mon, Apr 26, 2010 at 3:11 AM, Hambridge, Philip J (ODP) <[email protected]> wrote: ... > I’ve started to wonder about reducing the start-up time by placing all > source dependencies in a per-directory .d file generated at the archive link > stage and including this instead of including all the source .d files. A > quick test verifies that this significantly reduces the start-up time due to > make having to open far less files. I’ve yet to figure out quite what the > implications are for ensuring the per-directory .d file gets updated > correctly. > > Before I go any further, has anyone else done anything like this? If so, > were there any pitfalls?
I haven't tried it, but the pitfall that made me shy away from it was that if a build fails, you don't have the updated dependencies from the most recent (incomplete) build for the files that did get built. I.e., the build fails and the fix involves changing a header file that was #included in sources that _did_ build successfully. Will those get rebuilt after you change the header? Even if this was in a fresh tree? Then again, maybe that's only a problem if you try to update the per-directory .d file at the end of the build instead of during the start. That is, don't try to generate the per-directory file as part of building the archive library, but rather have make build it from the existing .d files using rules and re-exec. Philip Guenther _______________________________________________ Help-make mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-make
