Deprecate compatibility with CMake versions older than 2.8.12

Issue a deprecation warning on calls to `cmake_minimum_required` or
`cmake_policy` that set policies based on versions older than 2.8.12.
Note that the effective policy version includes `...<max>` treatment.
This is important in combination with commit ca24b70d31 (Export: Specify
a policy range in exported files, 2020-05-16, v3.18.0-rc1~133^2).

1 files changed, 10 insertions, 1 deletions

diff --git a/Tests/RunCMake/list/GET-CMP0007-WARN-stderr.txt b/Tests/RunCMake/list/GET-CMP0007-WARN-stderr.txt
index a0f8837..9103bd2 100644
--- a/Tests/RunCMake/list/GET-CMP0007-WARN-stderr.txt
+++ b/Tests/RunCMake/list/GET-CMP0007-WARN-stderr.txt
@@ -1,4 +1,13 @@
-^CMake Warning \(dev\) at GET-CMP0007-WARN.cmake:4 \(list\):
+^CMake Deprecation Warning at GET-CMP0007-WARN.cmake:1 \(cmake_policy\):
+  Compatibility with CMake < 2.8.12 will be removed from a future version of
+  CMake.
+
+  Update the VERSION argument <min> value or use a ...<max> suffix to tell
+  CMake that the project does not need compatibility with older versions.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
++
+CMake Warning \(dev\) at GET-CMP0007-WARN.cmake:4 \(list\):
   Policy CMP0007 is not set: list command no longer ignores empty elements.
   Run "cmake --help-policy CMP0007" for policy details.  Use the cmake_policy
   command to set the policy and suppress this warning.  List has value =