Added in version 3.21.
A boolean variable indicating whether the named project was called in a top
level CMakeLists.txt
file.
To obtain the value from the most recent call to project()
in
the current directory scope or above, see the
PROJECT_IS_TOP_LEVEL
variable.
The variable value will be true in:
the top-level directory of the project
the top-level directory of an external project added by
ExternalProject
a directory added by add_subdirectory()
that does not also contain
a project()
call
a directory added by FetchContent_MakeAvailable()
,
if the fetched content does not contain a project()
call
The variable value will be false in:
a directory added by add_subdirectory()
that also contains
a project()
call
a directory added by FetchContent_MakeAvailable()
,
if the fetched content contains a project()
call