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Diffstat (limited to 'Help/prop_tgt/UNITY_BUILD_BATCH_SIZE.rst')
| -rw-r--r-- | Help/prop_tgt/UNITY_BUILD_BATCH_SIZE.rst | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/Help/prop_tgt/UNITY_BUILD_BATCH_SIZE.rst b/Help/prop_tgt/UNITY_BUILD_BATCH_SIZE.rst new file mode 100644 index 000000000..44ffe2784 --- /dev/null +++ b/Help/prop_tgt/UNITY_BUILD_BATCH_SIZE.rst @@ -0,0 +1,23 @@ +UNITY_BUILD_BATCH_SIZE +---------------------- + +Specifies the maximum number of source files that can be combined into any one +unity source file when unity builds are enabled by the :prop_tgt:`UNITY_BUILD` +target property. The original source files will be distributed across as many +unity source files as necessary to honor this limit. + +The initial value for this property is taken from the +:variable:`CMAKE_UNITY_BUILD_BATCH_SIZE` variable when the target is created. +If that variable has not been set, the initial value will be 8. + +The batch size needs to be selected carefully. If set too high, the size of +the combined source files could result in the compiler using excessive memory +or hitting other similar limits. In extreme cases, this can even result in +build failure. On the other hand, if the batch size is too low, there will be +little gain in build performance. + +Although strongly discouraged, the batch size may be set to a value of 0 to +combine all the sources for the target into a single unity file, regardless of +how many sources are involved. This runs the risk of creating an excessively +large unity source file and negatively impacting the build performance, so +a value of 0 is not generally recommended. |