CMake: Force build tools when cross-compiling for Windows ARM64HEADdev

TLDR: We need force cross-build the compilation of WebEngine tools
when cross-compiling for Windows ARM64, to ensure that native
development on Windows ARM64 hosts can use the WebEngine tools.

Long version:

We have two packaging configurations for Windows ARM64.

1) we cross-compile 'Windows On Arm' Qt on an x64 Windows host.
   This configuration includes the WoA WebEngine libraries, but not
   the tools.

2) we build Windows on Arm Qt on a native arm64 windows host. This
   currently lacks the WebEngine libraries and tools, because it takes
   too much time to build them on native arm hosts in the CI.

When installing WoA on a Windows host using the Qt online
installer, there are three possible scenarios:

a) Running the x64 installer on an x64 Windows host, to be
   able to cross-build projects targeting Windows on Arm.

   This will install an x64 MSVC host qt, and an arm64 WoA target Qt
   from case '1' above.
   The x64 qt includes the WebEngine libraries and tools, and the WoA
   qt only includes the libraries, but not the tools.

   For WoA project builds, the build system will use the
   x64 host tools. This works fine.

b) Running the x64 installer on an arm64 Windows host.

   This is very similar to the 'a' case, except it involves emulation
   of the x64 host tools.

   This will install an x64 MSVC host qt, and an arm64 WoA target Qt.
   The x64 qt includes the WebEngine libraries and tools, and the WoA
   qt only includes the libraries, but not the tools.

   For WoA project builds, the build system will use the
   x64 host tools using /emulation/. This works fine, as long as x64
   emulation is available and enabled.

c) Running the arm64 installer on an arm64 Windows host.

   This will install the native arm64 WoA Qt from case '2' above.
   The arm64 qt includes arm libraries and tools from case '2', but
   that lacks the WebEngine libraries and tools.

   So the installer will also install the cross-compiled arm64
   WebEngine libraries from case '1', but not the WebEngine tools
   (e.g. dict conversion tool).

To ensure that scenario 'c' also gets WebEngine tools, we need to
force build (cross-compile) the tools in scenario '1'.

This patch achieves that by passing -DQT_FORCE_BUILD_TOOLS=ON ,
similar how we do it for yocto builds.

Pick-to: 6.9 6.10
Task-number: QTBUG-138859
Change-Id: I8270731a4afef7ab9af8df63326fb838e02968e8
Reviewed-by: Michal Klocek <michal.klocek@qt.io>
Reviewed-by: Alexey Edelev <alexey.edelev@qt.io>

0 files changed, 0 insertions, 0 deletions