Makefiles don't track file changes properly

[johnousterhout]

The Makefile for ArachnePerfTest doesn't have enough dependencies to properly track changes to files. The problem is that it builds directly from a source file such as ArachneCreateTest.cc to the binary, such as ArachneCreateTest; there is no mention of the .o file in the Makefile. This causes a problem in the following scenario:

• I modify a file in the Arachne library, and rebuild ArachnePerfTest.
• I then copy in a replacement for ArachnePerfTest.cc, which has a modification time between that of the old version of the file and ArachnePerfTest (e.g., I made the change on a different machine, but forgot to sync the file over to my build machine before I did the first rebuild above).
• Make won't rebuild ArachnePerfTest, because it has a creation time later than the new ArachnePerfTest.cc.

However, if you fleshed out the Makefile, so that ArachnePerfTest depends on ArachnePerfTest.o, which in turn depends on ArachnePerfTest.cc, then updating ArachnePerfTest.cc will result in a proper rebuild, since ArachnePerfTest.o will be out of date.

It's probably worth taking time to make "real" Makefiles for all of the modules, which have the proper Makefile structure.

-John-