Re: [Boost-build] How best to combine "using xxx", toolset invocation, and conditions?

Subject: Re: [Boost-build] How best to combine "using xxx", toolset invocation, and conditions?
From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2013-12-24 11:25:16

AMDG

On 12/24/2013 03:54 AM, Jess Peterson wrote:
> Thank you for the explanation.  There is a bug in gcc.jam, since if I have
> a project-config.jam file with:
> 
>   using gcc ;
>   using gcc : mingw : /opt/mxe/usr/bin/i686-pc-mingw32-g++ ;
> 
> and a Jamroot with:
> 
>   exe hello : hello.cpp ;
> 
> and invoke with "b2 toolset=gcc-mingw", then I get both compilers added to
> CONFIG_COMMAND
> 
>     "g++" "/opt/mxe/usr/bin/i686-pc-mingw32-g++"    -o
> "bin/gcc-mingw-4.4.7/debug/hello" -Wl,--start-group -Wl,--start-group
> "bin/gcc-mingw-4.4.7/debug/hello.o"  -Wl,-Bstatic -Wl,-Bstatic
>  -Wl,-Bdynamic -Wl,-Bdynamic  -Wl,--end-group -Wl,--end-group -g
> 
> It turns out that choosing "mingw" as my toolset version was not a
> fortunate choice since there is special treatment in gcc.jam that sets the
> flavor to mingw if the target machine has a mingw in it.   Any other name
> works as expected.
> 
> Flavor is not used to find a toolset so toolset=gcc-mingw does not work no
> matter what is chosen as a version.  Also flavor adds a tag at the end of
> the condition (<toolset>gcc-version-flavor) and produces a build at
> .../gcc-flavor-version/... so it is a little confusing.
> 

The order of subfeatures doesn't matter.
Boost.Build sorts them alphabetically.

> ---------------------------
> 
> As an aside, when I made my little test case above, I first put the using
> lines in the Jamroot and invoked with --ignore-config.  The first thing
> that happened is that it found a project-config.jam from a directory far
> above my little test directory, so I added an empty project-config.jam.
>  The next thing is that the using lines are ignored if they are in the
> Jamroot file.  I am not sure why this happens, but I moved the using lines
> to the local project-config.jam.
> 
> Shouldn't using Jamroot, instead of Jamfile, make the current directory the
> root of the project so b2 should not look higher for a project-config.jam?
> 

Yes.

> Shouldn't --ignore-config make it not look for a project-config.jam as well
> as site-config.jam and user-config.jam?
> 

Yes.

> Is there any documentation on project-config.jam and what it normally
> contains?
> 

It's no different from user-config.jam, except that it's
intended to be local to the project.

In Christ,
Steven Watanabe