Don't compile configure.exe with clang-cl.exe if cl.exe is available

Sometimes clang-cl.exe is on PATH and would get picked up by the
build. That is often by mistake, but it will inreasingly happen
as clang-cl becomes more popular. Unfortunately, configure.bat is
too early to detect which MSVC version it's set to compile
against, so the -fms-compatibility-version option will often be
wrong. One such case is when trying to build for MSVC
2013. Microsoft headers for VS2013 are unsuitable for our use in
Qt with clang-cl.

Instead, use cl.exe. It's a much better-known quantity and is
always on PATH if trying to build with clang-cl, as the latter
needs the former to fall back to if necessary.

This does not affect the build of Qt libraries and tools.

Task-number: QTBUG-51534
Change-Id: I149e0540c00745fe8119fffd146287662436c4b9
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>

0 files changed, 0 insertions, 0 deletions