Before this patch we enabled AUTOMOC, AUTORCC, AUTOUIC for all targets
that did not opt out.
Aside from being wasteful from a performance point of view,
this also caused issues when trying to build qtimageformats which
does not depend on Widgets which is the package that exposes uic.
To avoid this, enable only AUTOMOC for all targets by default, and
UIC and RCC can be opted in via the ENABLE_AUTOGEN_TOOLS option.
To facilitate this some refactoring had to be done, like moving some
common setup for all autogen tools into a separate call, and making
sure that extend_target understands the autogen options, because some
ui files are only added conditionally.
Also the conversion script has been adapted to output the
ENABLE_AUTOGEN_TOOLS option whenever a .pro file contains at least
one FORMS += foo assignment.
Note that we don't really use AUTORCC while building Qt, so nothing
opts into that at the moment.
Task-number: QTBUG-75875
Change-Id: I889c4980e9fb1b74ba361abed4044737f8842ea4
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
0425ee0610