From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Thread: 103376,206547e68a60b0e7 X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news3.google.com!newsfeed2.dallas1.level3.net!news.level3.com!bos-service1.raytheon.com!cyclone.swbell.net!cyclone-sf.pbi.net!216.218.192.242!news.he.net!xara.net!gxn.net!194.159.246.34.MISMATCH!peer-uk.news.demon.net!kibo.news.demon.net!news.demon.co.uk!demon!not-for-mail From: Simon Wright Newsgroups: comp.lang.ada Subject: Re: How to cache output of the compiler aka ccache Date: 18 Mar 2005 19:22:00 +0000 Organization: Pushface Sender: simon@smaug.pushface.org Message-ID: References: <1111085641.211767.56950@f14g2000cwb.googlegroups.com> <877jk65a2f.fsf@insalien.org> NNTP-Posting-Host: pogner.demon.co.uk Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: news.demon.co.uk 1111173817 24420 62.49.19.209 (18 Mar 2005 19:23:37 GMT) X-Complaints-To: abuse@demon.net NNTP-Posting-Date: Fri, 18 Mar 2005 19:23:37 +0000 (UTC) User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.1 Xref: g2news1.google.com comp.lang.ada:9606 Date: 2005-03-18T19:22:00+00:00 List-Id: Ludovic Brenta writes: > and "gnatmake -m" does minimal > recompilation. This really speeds things up. We absolutely rely on this; the handwritten code is in separate proper bodies, 99% of specs and package bodies are generated, and the only way to change them is to change the model and re-generate. One thing to watch out for is that when deciding whether a unit needs to be recompiled GNAT first checks the timestamp of each dependency; it the timestamp is different it checks the contents of the dependency and only recompiles if there's a semantic difference. So recreating lots of identical source will mean that the dependencies have to be at least parsed. This can take quite a time (I think mainly the overhead of opening/closing the files). We had an interesting bug with 3.16a1 on Windows where compilations ran slower if the compiler had been installed in the winter months (outside daylight saving time) -- a feature involving the Windows installer, I think; the timestamps in the library were all one hour out. -- Simon Wright 100% Ada, no bugs.