This is a simple implementation of build logging or accumulative build methodology (I'm not quite sure which describes it best).
I have heard some confusion with ccache, but ccache is implemented on the lower level and is language specific.

The idea is to check upon whether contents of a file and the compilation flags has changed from one run to another.

It appear to be not too difficult to do in a simple makefile, rather then trying to reinvent the wheel in a different language!

So far it's a very immature project, but once I'm done with the testing I hope it will be useful to many users!

I need to consider renaming it, perhaps, because there exists a command in Solaris with the same name.
However this is not a command, but only a makefile template. Of course it may be turned into one somewhat.

I needed a way of storing all build output for one of my hardware design (read: Verilog) projects and one of the problem that I faced with
make was forcing remake when flags for the preprocessor have changed and yet I wanted to store outputs for each of run.

This however doesn't mean that the hashmake template is Verilog-specific. One may wish to use it for build logging purposes or any other
imaginable paradigm. Of course, in many cases, some consideration needs to be taken whether a revision control system may be more appropriate.

• Testing
  • testing with different projects
• Reusability
  • generalisation of code to make it usable as a part of existing code (plugged into real-world makefiles)
  • attempt to fit around autotools
    A simple solution would be to just add 'move-build' target if you just need to store the builds, but that doesn't help to
    solve checks on preprocessor flags, which needs to be done much earlier!
• Scripts
  • find builds made with specific flags
  • run or view specific builds
  • integrate with revision control tools (i.e. grep for git commit id)
    There is no use for taking care of what the commit/revision id is when building the code, since that doesn't explicitly mean
    that the particular file was changed. However it would be usefull to be able to find a build made in between specific commits
    to the repository or, in other words, builds which had been made on a given code revision.