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).

3 files changed, 21 insertions, 1 deletions

diff --git a/Tests/RunCMake/CMP0019/CMP0019-NEW-stderr.txt b/Tests/RunCMake/CMP0019/CMP0019-NEW-stderr.txt
new file mode 100644
index 0000000..66a58fb
--- /dev/null
+++ b/Tests/RunCMake/CMP0019/CMP0019-NEW-stderr.txt
@@ -0,0 +1,6 @@
+^CMake Deprecation Warning at CMakeLists.txt:1 \(cmake_minimum_required\):
+  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.$
diff --git a/Tests/RunCMake/CMP0019/CMP0019-OLD-stderr.txt b/Tests/RunCMake/CMP0019/CMP0019-OLD-stderr.txt
index 048762d..a446211 100644
--- a/Tests/RunCMake/CMP0019/CMP0019-OLD-stderr.txt
+++ b/Tests/RunCMake/CMP0019/CMP0019-OLD-stderr.txt
@@ -1,4 +1,11 @@
-^CMake Deprecation Warning at CMP0019-OLD.cmake:[0-9]+ \(cmake_policy\):
+^CMake Deprecation Warning at CMakeLists.txt:1 \(cmake_minimum_required\):
+  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.
++
+CMake Deprecation Warning at CMP0019-OLD.cmake:[0-9]+ \(cmake_policy\):
   The OLD behavior for policy CMP0019 will be removed from a future version
   of CMake.
 
diff --git a/Tests/RunCMake/CMP0019/CMP0019-WARN-stderr.txt b/Tests/RunCMake/CMP0019/CMP0019-WARN-stderr.txt
index 1e4b47d..f7b9c0e 100644
--- a/Tests/RunCMake/CMP0019/CMP0019-WARN-stderr.txt
+++ b/Tests/RunCMake/CMP0019/CMP0019-WARN-stderr.txt
@@ -1,3 +1,10 @@
+^CMake Deprecation Warning at CMakeLists.txt:1 \(cmake_minimum_required\):
+  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.
++
 CMake Warning \(dev\) in CMakeLists.txt:
   Policy CMP0019 is not set: Do not re-expand variables in include and link
   information.  Run "cmake --help-policy CMP0019" for policy details.  Use