Replace calls to GetLinkInformation with calls to a method to get only
the target closure, not the link languages etc. The replaced calls
are used while evaluating generator expressions only. This makes
transitive generator expression evaluation independent from
the languages of a target. In a follow-up topic, it will be possible
to make the languages depend on generator expression evaluation, via
evaluation of the SOURCES and INTERFACE_SOURCES target properties.
Because the order of entries is not the same as the final link line,
the order of debug output is different in the RunCMake.CompatibleInterface
test, because the BOOL_PROP7 target property is evaluated first. Adjust
the test to account for that new order.
If the dependent target sets the property to boolean false, ensure
that that appears in the debug report. Previously, the report
output contained whether the property was consistent among dependencies,
displaying 'TRUE', instead of the content of the property, which may
be 'FALSE'.
Return a std::pair from the consistentProperty method. This makes
it possible to make the return value for string types easier to
reason about. The return value of consistentProperty was previously
set to an empty static string to emulate a 'true' value for the caller
in commit 816b4a8a (cmTarget: Make consistentProperty
return consistent content., 2013-10-22). The pair makes the
consistency result properly typed.
Stephen Kelly