New in version 3.18.
CMake provides different algorithms for selecting which sources are grouped together into a bucket. Selection is decided by this property, which has the following acceptable values:
When in this mode CMake determines which files are grouped together. The
UNITY_BUILD_BATCH_SIZEproperty controls the upper limit on how many sources can be combined per unity source file.
add_library(example_library source1.cxx source2.cxx source3.cxx source4.cxx) set_target_properties(example_library PROPERTIES UNITY_BUILD_MODE BATCH UNITY_BUILD_BATCH_SIZE 2 )
When in this mode each target explicitly specifies how to group source files. Each source file that has the same
UNITY_GROUPvalue will be grouped together. Any sources that don't have this property will be compiled individually. The
UNITY_BUILD_BATCH_SIZEproperty is ignored when using this mode.
add_library(example_library source1.cxx source2.cxx source3.cxx source4.cxx) set_target_properties(example_library PROPERTIES UNITY_BUILD_MODE GROUP ) set_source_files_properties(source1.cxx source2.cxx source3.cxx PROPERTIES UNITY_GROUP "bucket1" ) set_source_files_properties(source4.cxx PROPERTIES UNITY_GROUP "bucket2" )
If no explicit
UNITY_BUILD_MODE has been specified, CMake will