(minor)

I noticed that for each DR Stratego/J generates 18 Java strategies (DR, once-DR, bagof-DR, bigbagof-DR, …), while (at least in my experience) generally only 1 or 2 of those strategies are used.

It may be useful to have the compiler check which ones are actually used, and generate only those.

Some numbers (of a few days ago) on my project:

• 19 DRs, each used in one way only (17 unused strategies per DR)
• 19 * 17 => 323 unused Java files generated and compiled, on a total of 1387 Java files
• potential benefit: up to 23% faster compilation :-)

(Or does this option already exist somewhere where I didn’t look yet?)

Submitted by Tobi Vollebregt on 12 January 2011 at 12:45

I’m pretty sure it does this already, as long as you don’t use the --library option that disables the dead code elimination. For Spoofax, this option is used as Spoofax programs have multiple entry points…

Aha, interesting.

I tried removing the –library option and tricked the compiler into exporting all necessary strategies by adding a (never executed) main strategy that lists all public strategies. (Might be an idea to automate that at some point; after all this list of strategies is known from the .esv files)

This reduced the number of generated Java files from 1377 to 609 (!), and also halfed the compilation time :-)

One other observation: the aux-DR strategy kept existing for all my DRs, while I never explicitly use it. Calls to this are generated as part of some syntactic construct? (one guess: DR scope?)