CMake/Help/prop_tgt/COMPATIBLE_INTERFACE_NUMBER...

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cmTarget: Add interface for compatible numeric properties When using the boost MPL library, one can set a define to increase the limit of how many variadic elements should be supported. The default for BOOST_MPL_LIMIT_VECTOR_SIZE is 20: http://www.boost.org/doc/libs/1_36_0/libs/mpl/doc/refmanual/limit-vector-size.html If the foo library requires that to be set to 30, and the independent bar library requires it to be set to 40, consumers of both need to set it to 40. add_library(foo INTERFACE) set_property(TARGET foo PROPERTY INTERFACE_boost_mpl_vector_size 30) set_property(TARGET foo PROPERTY COMPATIBLE_INTERFACE_NUMBER_MAX boost_mpl_vector_size) target_compile_definitions(foo INTERFACE BOOST_MPL_LIMIT_VECTOR_SIZE=$<TARGET_PROPERTY:boost_mpl_vector_size>) add_library(bar INTERFACE) set_property(TARGET bar PROPERTY INTERFACE_boost_mpl_vector_size 40) # Technically the next two lines are redundant, but as foo and bar are # independent, they both set these interfaces. set_property(TARGET bar PROPERTY COMPATIBLE_INTERFACE_NUMBER_MAX boost_mpl_vector_size) target_compile_definitions(bar INTERFACE BOOST_MPL_LIMIT_VECTOR_SIZE=$<TARGET_PROPERTY:boost_mpl_vector_size>) add_executable(user) target_link_libraries(user foo bar) Because the TARGET_PROPERTY reads the boost_mpl_vector_size property from the HEAD of the dependency graph (the user target), and because that property appears in the COMPATIBLE_INTERFACE_NUMBER_MAX of the dependencies of the user target, the maximum value for it is chosen for the compile definition, ie, 40. There are also use-cases for choosing the minimum value of a number. In Qt, deprecated API can be disabled by version. Setting the definition QT_DISABLE_DEPRECATED_BEFORE=0 disables no deprecated API. Setting it to 0x501000 disables API which was deprecated before Qt 5.1 etc. If two dependencies require the use of API which was deprecated in different Qt versions, then COMPATIBLE_INTERFACE_NUMBER_MIN can be used to ensure that both can compile.
2013-10-22 21:51:36 +04:00
COMPATIBLE_INTERFACE_NUMBER_MAX
-------------------------------
Properties whose maximum value from the link interface will be used.
The ``COMPATIBLE_INTERFACE_NUMBER_MAX`` property may contain a list of
properties for this target whose maximum value may be read at generate
time when evaluated in the ``INTERFACE`` variant of the property in all
linked dependees. For example, if a property ``FOO`` appears in the list,
then for each dependee, the ``INTERFACE_FOO`` property content in all of
its dependencies will be compared with each other and with the ``FOO``
property in the depender. When reading the ``FOO`` property at generate
time, the maximum value will be returned. If the property is not set,
then it is ignored.
Note that for each dependee, the set of properties specified in this
property must not intersect with the set specified in any of the other
:ref:`Compatible Interface Properties`.