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Re: Incremental build systems, infamake

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On 07/25/11 07:25 PM, Joshua Maurice wrote:

<snip>

> An incrementally correct build system - is a build system which can
> only produce incrementally correct builds. That is, there is no source
> code changes which a developer may do, inadvertently or purposefully,
> which can result in the build system doing an incrementally incorrect
> build.
>
> The key part to realize about this requirement is that the build
> system scripts, such as makefiles, are themselves source code under
> this model. At least, I claim that they ought to be considered as
> source code for the purposes of determining if your incremental build
> system is incrementally correct.
>
> Now, at this point, there is a blurring of lines between build system
> tool and build system. When the makefiles are both source code and
> build system, it becomes hard to distinguish between them. I'm merely
> trying to say that I want a tool in which it is exceptionally hard, if
> not impossible short of maliciousness, to "break" the build system
> such that it might produce an incrementally incorrect build.

Makefiles aren't source code and build system, the make utility is the 
build system.

> Now, why do I want this? I hate waiting for hours each day doing a
> build. Yes, I know that the source code base in question has other
> problems if it takes that long to build, but unfortunately I am not
> the king of the company, and so I have to make due. Besides, even
> spending 10 minutes on a full clean rebuild is 10 minutes
> (potentially) wasted, if another better solution exists. And even more
> importantly, 4 hours spent tracking down a bug which was simply the
> result of a broken incremental build is 4 hours wasted.

Wouldn't the time spent working on a build tool be better spent cleaning 
up the code and the existing system?

> I claim that it's not that hard. However, as far as I can tell, very
> few people have attempted such a thing. In the C++ world at least,
> most ended with something that was "good enough" that caught 95% of
> the cases. A good example AFAIK is the Recursive Make Considered
> Harmful solution, found here:
>      http://miller.emu.id.au/pmiller/books/rmch/

Flat makefiles rule!

> It's good, but it still misses cases. Depending on the exact details
> of implementation, it won't do a rebuild if you change compiler or
> linker options, such as a new preprocessor define. It won't relink an
> executable if you delete one of its associated cpp source files. It
> won't recompile an object file if you introduce a new header file
> which hides a previously included header file on the include path.

Good old make will cover all of those cases.  All you need is a make 
that maintains state.

I work for myself, so wasted time is my money wasted.  I've found the 
most effective way to minimise build times is to design the code and 
makefile(s) to build fast.  That normally means more, smaller files and 
a single flat makefile.  These combine to get the best performance out 
of a distributed or parallel make.

If the build still isn't fast enough, I just throw more hardware at it.

-- 
Ian Collins

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Thread

Incremental build systems, infamake Joshua Maurice <joshuamaurice@gmail.com> - 2011-07-25 00:25 -0700
  Re: Incremental build systems, infamake Ian Collins <ian-news@hotmail.com> - 2011-07-25 21:00 +1200
    Re: Incremental build systems, infamake Joshua Maurice <joshuamaurice@gmail.com> - 2011-07-25 02:11 -0700
      Re: Incremental build systems, infamake Ian Collins <ian-news@hotmail.com> - 2011-07-25 21:33 +1200
        Re: Incremental build systems, infamake Joshua Maurice <joshuamaurice@gmail.com> - 2011-07-25 02:38 -0700
          Re: Incremental build systems, infamake Ian Collins <ian-news@hotmail.com> - 2011-07-25 21:55 +1200
          Re: Incremental build systems, infamake Joshua Maurice <joshuamaurice@gmail.com> - 2011-07-25 03:04 -0700
            Re: Incremental build systems, infamake Ian Collins <ian-news@hotmail.com> - 2011-07-25 22:22 +1200
              Re: Incremental build systems, infamake Joshua Maurice <joshuamaurice@gmail.com> - 2011-07-25 03:25 -0700
                Re: Incremental build systems, infamake Ian Collins <ian-news@hotmail.com> - 2011-07-25 23:41 +1200
            Re: Incremental build systems, infamake Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-07-26 16:11 +0000
              Re: Incremental build systems, infamake Joshua Maurice <joshuamaurice@gmail.com> - 2011-07-26 15:19 -0700
                Re: Incremental build systems, infamake Joshua Maurice <joshuamaurice@gmail.com> - 2011-07-26 15:28 -0700
                Re: Incremental build systems, infamake Joshua Maurice <joshuamaurice@gmail.com> - 2011-07-26 15:49 -0700
  Re: Incremental build systems, infamake Nobody <nobody@nowhere.com> - 2011-07-25 12:52 +0100
    Re: Incremental build systems, infamake Joshua Maurice <joshuamaurice@gmail.com> - 2011-07-25 13:34 -0700
      Re: Incremental build systems, infamake Nobody <nobody@nowhere.com> - 2011-07-27 19:49 +0100
        Re: Incremental build systems, infamake Joshua Maurice <joshuamaurice@gmail.com> - 2011-07-29 03:58 -0700
  Re: Incremental build systems, infamake Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-07-26 15:04 +0000

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