_PATTERNS --------------- .. versionadded:: 4.5 Patterns specification for instantiating the rule ````. The ``_PATTERNS`` property may be set to a :ref:`semicolon-separated list ` of patterns using the syntax ``PATTERN=VALUE`` or ``PATTERN=``. More precisely, each item must match the regular expression ``(^[A-Z][A-Z0-9_]+)=(.*)$``. CMake will automatically drop any patterns which do not match against this regular expression. The list is ordered, so a pattern can use in its definition a previously defined pattern. In the following example, ``OUTPUT_DIR=/some/path;OUTPUT_FILE=/my_file``, when the pattern ```` is expanded, the pattern ```` is already known. Related properties: * :prop_fs:`RULE_PATTERNS` to specify patterns for a file set. Related commands: * :command:`add_custom_rule` for custom rule specification.