a couple of cases.
1. On Windows, DLLs are never directly linked to, so they are considered
unused and cause a warning. There used to be special code in
exe-target-class and lib-target-class to supress that warning, but this
failed for unit-test, for example, since main target class for unit test
is not related with exe-target-class. And making yet another main target
class looks ugly.
2. A target specified via project-wide <source> or <library> property is
added to sources for all targets, and cause a warning when it's not used.
However, there are valid cases to ignore such sources. For example
obj a : a.cpp : <optimization>off ;
need to comsume any libraries.
It was not clear how to fix both problems. Further, the only case when I found
the warning to be usefull is when declaring new toolsets, and it that case it
does not add much information compared to --debug-generators output. So, let's
just kill the feature for now.
[SVN r22927]
The used 'CALLER_MODULE' to determine the project where the main target
is to be declared, which did not work if the rule is called from another
module.
Thanks to Zbynek Winkler for the bug report.
* build/project.jam (current): New rule
* test/wrapper.py: New test
* other files: Use 'project.current'.
[SVN r22569]
