Allow CMAKE_SYSTEM_VERSION to be set without CMAKE_SYSTEM_NAME

Teach CMakeDetermineSystem to check for a CMAKE_SYSTEM_VERSION setting
even when CMAKE_SYSTEM_NAME is not set.  This will allow builds on the
host OS to target other versions of the OS without full cross-compiling.
This commit is contained in:
Gilles Khouzam 2015-09-23 14:27:07 -07:00 committed by Brad King
parent 7068860941
commit b31ac171a4
2 changed files with 10 additions and 1 deletions

View File

@ -12,6 +12,13 @@ then ``CMAKE_SYSTEM_VERSION`` is by default set to the same value as the
:variable:`CMAKE_HOST_SYSTEM_VERSION` variable so that the build targets
the host system version.
In the case of a host build then ``CMAKE_SYSTEM_VERSION`` may be set
explicitly when first configuring a new build tree in order to enable
targeting the build for a different version of the host operating system
than is actually running on the host. This is allowed and not considered
cross compiling so long as the binaries built for the specified OS version
can still run on the host.
System Version for Cross Compiling
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

View File

@ -123,7 +123,9 @@ elseif(CMAKE_VS_WINCE_VERSION)
set(PRESET_CMAKE_SYSTEM_NAME TRUE)
else()
set(CMAKE_SYSTEM_NAME "${CMAKE_HOST_SYSTEM_NAME}")
if(NOT DEFINED CMAKE_SYSTEM_VERSION)
set(CMAKE_SYSTEM_VERSION "${CMAKE_HOST_SYSTEM_VERSION}")
endif()
set(CMAKE_SYSTEM_PROCESSOR "${CMAKE_HOST_SYSTEM_PROCESSOR}")
set(CMAKE_CROSSCOMPILING FALSE)
set(PRESET_CMAKE_SYSTEM_NAME FALSE)