/usr/include/libreoffice/sal/ is in libreoffice-dev-common 1:6.0.3-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/libreoffice/sal/alloca.h
/usr/include/libreoffice/sal/config.h
/usr/include/libreoffice/sal/detail/
/usr/include/libreoffice/sal/detail/log.h
/usr/include/libreoffice/sal/log.hxx
/usr/include/libreoffice/sal/macros.h
/usr/include/libreoffice/sal/main.h
/usr/include/libreoffice/sal/mathconf.h
/usr/include/libreoffice/sal/saldllapi.h
/usr/include/libreoffice/sal/types.h
/usr/include/libreoffice/salhelper/condition.hxx
/usr/include/libreoffice/salhelper/dynload.hxx
/usr/include/libreoffice/salhelper/linkhelper.hxx
/usr/include/libreoffice/salhelper/refobj.hxx
/usr/include/libreoffice/salhelper/salhelperdllapi.h
/usr/include/libreoffice/salhelper/simplereferenceobject.hxx
/usr/include/libreoffice/salhelper/singletonref.hxx
/usr/include/libreoffice/salhelper/thread.hxx
/usr/include/libreoffice/salhelper/timer.hxx