Add -C (change directory) option to bjam

[Jeremiah Willcock]

GNU Make has a very useful command line flag -C (or --directory) that changes the directory to its argument before starting make. This is different than changing it in your shell because Make's change is local to its process (and its subprocesses) and does not change the outside user environment. One example of where this is useful is if I am working in boost/graph, and would like to re-run the Boost.Graph test suite. With -C, all I would need to do is:

bjam -C ../../libs/graph/test

and the tests would be run as though I changed into that directory, ran bjam, and then changed back. I believe that this feature would be very convenient. More documentation is available at ​http://www.gnu.org/software/make/manual/make.html#Options-Summary.

[Steven Watanabe]

Doesn't

bjam ../../libs/graph/test

work?

[Jeremiah Willcock]

Yes -- I didn't notice that. It isn't in bjam --help, but it is likely to be in the documentation somewhere.

[Steven Watanabe]

This is just part of the syntax for specifying which targets to build. In addition to what is specified at http://www.boost.org/boost-build2/doc/html/bbv2/reference/definitions.html#bbv2.reference.ids, a path to a directory is interpreted to mean the project in that directory.

[Vladimir Prus]

Is there anything still to do here? Can this issue be closed?

[Jeremiah Willcock]

It can as far as I'm concerned -- the functionality exists in bjam, and there's no reason to add another syntax for it.

[Daniel James]

It would be useful for building documentation, as the documentation is built under the current directory. But perhaps the proper solution to that would be to fix the boostbook tool so that there's more control over where the documentation is built.

[Vladimir Prus]

Daniel, I suspect that it is indeed better to address doc location is some other, better way. Can you file an issue telling what is bad about the current arrangement?

[Daniel James]

Sure. it's #3240.