CMP0037ΒΆ
Target names should not be reserved and should match a validity pattern.
CMake 2.8.12 and lower allowed creating targets using add_library(),
add_executable() and add_custom_target() with unrestricted
choice for the target name. Newer cmake features such
as cmake-generator-expressions(7) and some
diagnostics expect target names to match a restricted pattern.
Target names may contain upper and lower case letters, numbers, the underscore
character (_), dot(.), plus(+) and minus(-).
As a special case, ALIAS and IMPORTED targets may contain
two consecutive colons.
Target names reserved by one or more CMake generators are not allowed.
Among others these include all, clean, help, and install.
Target names associated with optional features, such as test and
package, may also be reserved. CMake 3.10 and below always reserve them.
CMake 3.11 and above reserve them only when the corresponding feature is
enabled (e.g. by including the CTest or CPack modules).
The OLD behavior for this policy is to allow creating targets with
reserved names or which do not match the validity pattern.
The NEW behavior for this policy is to report an error
if an add_* command is used with an invalid target name.
This policy was introduced in CMake version 3.0. CMake version
3.23.2 warns when the policy is not set and uses OLD behavior. Use
the cmake_policy() command to set it to OLD or NEW explicitly.
Note
The OLD behavior of a policy is
deprecated by definition
and may be removed in a future version of CMake.