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diff --git a/Help/command/block.rst b/Help/command/block.rst new file mode 100644 index 0000000..9d37deb --- /dev/null +++ b/Help/command/block.rst @@ -0,0 +1,75 @@ +block +----- + +.. versionadded:: 3.25 + +Evaluate a group of commands with a dedicated variable and/or policy scope. + +.. code-block:: cmake + + block([SCOPE_FOR (POLICIES|VARIABLES)] [PROPAGATE <var-name>...]) + <commands> + endblock() + +All commands between ``block()`` and the matching :command:`endblock` are +recorded without being invoked. Once the :command:`endblock` is evaluated, the +recorded list of commands is invoked inside the requested scopes, and, finally, +the scopes created by ``block()`` command are removed. + +``SCOPE_FOR`` + Specify which scopes must be created. + + ``POLICIES`` + Create a new policy scope. This is equivalent to + :command:`cmake_policy(PUSH)`. + + ``VARIABLES`` + Create a new variable scope. + + If ``SCOPE_FOR`` is not specified, this is equivalent to: + + .. code-block:: cmake + + block(SCOPE_FOR VARIABLES POLICIES) + +``PROPAGATE`` + When a variable scope is created by :command:`block` command, this option + set or unset the specified variables in the parent scope. This is equivalent + to :command:`set(PARENT_SCOPE)` or :command:`unset(PARENT_SCOPE)` commands. + + .. code-block:: cmake + + set(VAR1 "INIT1") + set(VAR2 "INIT2") + + block(PROPAGATE VAR1 VAR2) + set(VAR1 "VALUE1") + unset(VAR2) + endblock() + + # here, VAR1 holds value VALUE1 and VAR2 is unset + + This option is only allowed when a variable scope is created. An error will + be raised in the other cases. + +When the ``block`` is local to a :command:`foreach` or :command:`while` +command, the commands :command:`break` and :command:`continue` can be used +inside this block. + +.. code-block:: cmake + + while(TRUE) + block() + ... + # the break() command will terminate the while() command + break() + endblock() + endwhile() + + +See Also +^^^^^^^^ + + * :command:`endblock` + * :command:`return` + * :command:`cmake_policy` |