Linker response files for the MinGW and Unix makefile generators are
controlled by the variable QMAKE_LINK_OBJECT_MAX. This variable holds a
number. If the number of object files passed to the linker exceeds this
number, a linker response file containing object file paths is created.
This heuristic is extremely imprecise. It doesn't take into account the
length of object file names nor the length of $$OBJECTS_DIR.
Also, when using a static Qt, a big part of the linker command line are
libraries. A relatively small example can fail to link with "The
command line is too long" on Windows, even with the object files being
in a response file.
The MinGW makefile generator already reads the variable
QMAKE_RESPONSEFILE_THRESHOLD for compiler response files. Re-use this
variable for the linker response file of the Unix and MinGW makefile
generators.
If QMAKE_RESPONSEFILE_THRESHOLD is set, use it to determine whether to
create a response file. QMAKE_LINK_OBJECT_MAX is then ignored. The
response file contains objects and libraries.
If QMAKE_RESPONSEFILE_THRESHOLD is not set, use QMAKE_LINK_OBJECT_MAX to
determine whether to create a response file. The response file contains
only object files.
QMAKE_LINK_OBJECT_SCRIPT is used in both cases to specify a common base
name of all linker response files.
Pick-to: 6.2 6.3
Task-number: QTBUG-100559
Change-Id: I3c78354fa5ebb1a86438ec804679e0ee776c3f49
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Kai Koehne <kai.koehne@qt.io>
1d3b190425