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From: Jeff Garland (jeff_at_[hidden])
Date: 2006-04-21 22:21:00

Rene Rivera wrote:
> Walter Landry wrote:
>> Rene Rivera <grafik.list_at_[hidden]> wrote:
>>> As I allude to in the intro to the section of the SoC wiki
>>> page, I personally think writing great libraries isn't just about
>>> writing the code for those libraries. The tools one uses, and the
>>> documentation one creates is much of the time more important. If just
>>> for the plain reason that having good tools allows one to concentrate
>>> more on the libraries. As a mentor for Computer Science students I would
>>> think that the development process is the key point of SoC. The
>>> resulting code is just an excuse to get students acclimated to working
>>> in Open Source development process. (Yes I'm intentionally framing this
>>> only within the SoC.)
>> You could use this rationale to have boost work on compilers, linkers,
>> operating systems, and hardware.
> Yes I could. And don't think none of those are not of interest to me :-)
> And some number in the Boost community actively work on such things.
>> There are other groups that
>> concentrate on making good build tools.
> True, and we;ve thought about switching and/or collaborating with such
> groups. For example Scons.


>> Boost does not exist because
>> people wanted better build tools.
> True, it exists to make better C++ libraries. But you can't have
> libraries without tools.
>> If you are interested in build tools, then by all means join those
>> other groups. You can even use Boost as a testbed. But I don't think
>> it is good to have boosters work on it to the point where it distracts
>> away from Boost's raison d'etre: making good C++ libraries.
> Why do you think it distracts away from the libraries? If some of us
> have the time and inclination to make some of the tools Boost developers
> need better doesn't that benefit everyone? We get to work on things that
> interest us, and sometimes have our own needs for, and Boost and other
> developers get better tools.
> Yes, I'm entirely open to using other groups efforts, and I am genuinely
> interested in the tool you pointed us to. If I could only get some
> reasonable documentation for it I could then evaluate it.

Let me preface by saying that I don't read the Boost.Build list, so I
haven't paid much attention to what has and hasn't been considered over
the last few years. But frankly, it seems to me that the
bjam/ decision was made 5 years (or more) ago and never
really revisited since. And that's fine, from my vantage --
has mostly just worked -- it does what I need and then some. Sure, new
folks are sometimes confused, but that's really due to a lack of binary
packaging and some mediocre documentation -- not some fundamental issue
with Boost.Build.

As I recall during the original build system discussions I was a
proponent of a very different approach. That is, instead of trying to
create a cross-platform fully ported 'build system', you use a 'make
file generator' tool. In this approach, the developer specifies
something very much like the current Jamfiles -- a list of files to
compile, and various options. Then a tool applies platform-compiler
specific settings and generates a platform specific 'make files' that
can use platform specific tools.

The makefile generation approach has different advantages and
disadvantages than the current system. For example, the big advantage
of generated makefiles for 'single platform users' is that they use
whatever the native build system is -- Makefiles on *nix --
solution/project files on windows. The nice effect being that no
training is necessary to explain how things work. The downside is that
for Boost library developers on multiple platforms it's harder because
instead of having to understand one system, you have to deal with
different build systems. And it also complicates packaging because you
either deliver all the makefiles for every platform, make the user
generate them, or have platform specific distributions. But if you want
to run the debugger on Windows, there's no substitute for having a
native project file.

At the time that the Boost.Build approach was pursued, there weren't
many good options in the makefile generation space (basically Imake).
Now, however, there is MPC -- Make Project Creator -- which is another
open source product that serves as the build system for another widely
ported C++ project: ACE/TAO. Kevin Heifner of OCI posted about this
tool a couple months back:

MPC is a serious tool with complete and professionally done docs
( MPC is
heavily used for both open source and industrial C++ projects on more
platforms/compilers than Boost currently supports. It's what I use for
my own personal projects and I've also used it successfully on large
industrial C++ projects. MPC could be a very different direction for
Boost. Kevin didn't try to sell it as a replacement for bjam, only as
an augmentation, but I believe we could adopt MPC and dump Boost.Build.

But even after saying all that, I seriously doubt we can consider going
away from Boost.Build. All change comes with a price -- people have to
study it, learn it, write docs, rewrite regression test scripts, etc.
It probably takes as much or more effort away from library development
to switch the build system than as it does to keep improving the current
system. So my advice would be for folks that have issues with
Boost.Build is to get them documented and work with the team on getting
them resolved. 98% of the issues I see are documentation and not


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