CMP0113ΒΆ
New in version 3.19.
Makefile Generators do not repeat custom commands from target dependencies.
Consider a chain of custom commands split across two dependent targets:
add_custom_command(OUTPUT output-not-created
COMMAND ... DEPENDS ...)
set_property(SOURCE output-not-created PROPERTY SYMBOLIC 1)
add_custom_command(OUTPUT output-created
COMMAND ... DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/output-not-created)
add_custom_target(first DEPENDS output-not-created)
add_custom_target(second DEPENDS output-created)
add_dependencies(second first)
In CMake 3.18 and lower, the Makefile generators put a copy of both custom
commands in the Makefile for target second
even though its dependency on
target first
ensures that the first custom command runs before the second.
Running make second
would cause the first custom command to run once in
the first
target and then again in the second
target.
CMake 3.19 and above prefer to not duplicate custom commands in a target that
are already generated in other targets on which the target depends (directly or
indirectly). This policy provides compatibility for projects that have not
been updated to expect the new behavior. In particular, projects that relied
on the duplicate execution or that did not properly set the SYMBOLIC
source file property may be affected.
The OLD
behavior for this policy is to duplicate custom commands in
dependent targets. The NEW
behavior of this policy is to not duplicate
custom commands in dependent targets.
This policy was introduced in CMake version 3.19. Unlike many policies,
CMake version 3.22.6 does not warn when this policy is not set and
simply uses OLD
behavior.
Note
The OLD
behavior of a policy is
deprecated by definition
and may be removed in a future version of CMake.