Only add -fPIC flags for compilers known to require it.

Commit 083c9269 (Try to ensure that -fPIC is used in CMake
builds, 2015-05-11) added a raw -fPIC to the INTERFACE_COMPILE_OPTIONS
of Qt5::Core, which affects all consuming compilers.

Use the qmake variable $$QMAKE_CXXFLAGS_APP instead, which at least
currently contains only the -fPIC variable or harmlessly expands to
nothing.  If the content of that qmake variable changes in the
future, a $$QMAKE_CXXFLAGS_APP_PIC variable should be extracted in
qmake and used here.

Don't use the POSITION_INDEPENDENT_CODE feature of CMake.  That adds
the -fPIE flag for executables, which is explicitly what qglobal.h
forbids since commit 3eca75de (Make qglobal.h complain if you
use -fPIE, 2015-05-11).  The current behavior of that CMake feature is
tracked here:

 http://public.kitware.com/Bug/view.php?id=15570

Change-Id: I5c5bcc40fe4b310b55a681a3505f45c50adfa054
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
Reviewed-by: Simon Hausmann <simon.hausmann@theqtcompany.com>

0 files changed, 0 insertions, 0 deletions