CMP0009 — CMake 3.28.3 Documentation

# CMP0009

FILE GLOB_RECURSE calls should not follow symlinks by default.

In CMake 2.6.1 and below, `file(GLOB_RECURSE)` calls would follow through symlinks, sometimes coming up with unexpectedly large result sets because of symlinks to top level directories that contain hundreds of thousands of files.

This policy determines whether or not to follow symlinks encountered during a `file(GLOB_RECURSE)` call. The `OLD` behavior for this policy is to follow the symlinks. The `NEW` behavior for this policy is not to follow the symlinks by default, but only if `FOLLOW_SYMLINKS` is given as an additional argument to the `FILE` command.

This policy was introduced in CMake version 2.6.2. CMake version 3.28.3 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.