Re: [Boost-build] Future development

From: Bill Hoffman (bill.hoffman_at_[hidden])
Date: 2007-10-16 22:19:13

David Abrahams wrote:

>> I have talked about adding a cmake --build option
>> that would do the build directly from cmake before on this list.
>> Perhaps if we did that and gave it a group of settings, it would work
>> more like bjam.  
> 
> Depends on a lot of detail you've left out.  I don't know what "gave
> it a group of settings" means, for example.

I mean create some sort of config file in the cmake language that can 
specify things similar to the ones in the user-config.jam file, and
make it more declarative than the ctest -S script currently is.

> 
>> But, if someone wants to try something today with a cmake release, a
>> ctest script can be used to drive the build right now.
>>
>> I am thinking this is more like an interface to the build system
>> rather than part of it.  
> 
> Not sure what that means.

I am not sure either...  (:

I guess I was trying to say that cmake can build a single 
compiler/settings directory well now. The ability to build more than one 
configuration in one run of cmake would be adding extra stuff to CMake 
that it really does not belong there, and that an interface on top of 
cmake, a python script, cmake script, or something else is what is 
needed.  Basically, you want a higher level interface to cmake that can 
build for multiple compilers all with one command.

> IIUC you run ccmake or CMakeSetup for each member of the
> compiler/project cross-product, right?  If it were just once for each
> compiler, it *might* be acceptable, if suboptimal.  If it's once for
> each compiler for each project, it's totally unacceptable.
> 

Depends on what you mean by a project?   The cmake stuff that Doug has 
done has cmake files for all the projects in boost.  You would run cmake 
at the top of the boost tree, and then be able to build all the projects 
at once, or each project by itself.  However, you could run cmake for 
each project if you wanted to only build a small part of boost, and in 
that case cmake would be run once for each project.  So, I think the 
answer is that it would be one ccmake for each compiler set for all of 
boost.

>> mkdir gcc-3.4; cd gcc-3.4; ccmake ..  make cd ..;mkdir gcc-4.2; ccmake
>> ..  make cd ..;mkdir msvc-6.5; ccmake ..  make
>>
>> After that initial configuration is done, if I change something, 
> 
> like what?  Change a source file?

Change a source file or a cmake input file.  If an input to cmake 
changes, then cmake will automatically re-run itself, if a source file 
changes then it will get rebuilt, but you don't have to specify the 
configuration options more than once per build tree, only the first time.

-Bill