cmake_minimum_required: Optionally set policies with version range

Teach `cmake_minimum_required` and `cmake_policy(VERSION)` to support a
version range of the form `<min>[...<max>]`.  Define this to mean that
version `<min>` is required, but known policies up to those introduced
by `<max>` will be set to `NEW`.  This will allow projects to easily
specify a range of versions for which they have been updated.

1 files changed, 56 insertions, 0 deletions

diff --git a/Tests/RunCMake/cmake_minimum_required/RangeBad-stderr.txt b/Tests/RunCMake/cmake_minimum_required/RangeBad-stderr.txt
new file mode 100644
index 0000000..b2c62fb
--- /dev/null
+++ b/Tests/RunCMake/cmake_minimum_required/RangeBad-stderr.txt
@@ -0,0 +1,56 @@
+^CMake Error at RangeBad.cmake:1 \(cmake_minimum_required\):
+  cmake_minimum_required VERSION "3.11..." does not have a version on both
+  sides of "...".
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
++
+CMake Error at RangeBad.cmake:2 \(cmake_minimum_required\):
+  cmake_minimum_required VERSION "...3.11" does not have a version on both
+  sides of "...".
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
++
+CMake Error at RangeBad.cmake:3 \(cmake_minimum_required\):
+  cmake_minimum_required VERSION "..." does not have a version on both sides
+  of "...".
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
++
+CMake Error at RangeBad.cmake:4 \(cmake_minimum_required\):
+  Invalid policy max version value "4".  A numeric
+  major.minor\[.patch\[.tweak\]\] must be given.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
++
+CMake Error at RangeBad.cmake:5 \(cmake_minimum_required\):
+  Policy VERSION range "3.11...3.10" specifies a larger minimum than maximum.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
++
+CMake Error at RangeBad.cmake:6 \(cmake_policy\):
+  cmake_policy VERSION "3.11..." does not have a version on both sides of
+  "...".
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
++
+CMake Error at RangeBad.cmake:7 \(cmake_policy\):
+  cmake_policy VERSION "...3.11" does not have a version on both sides of
+  "...".
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
++
+CMake Error at RangeBad.cmake:8 \(cmake_policy\):
+  cmake_policy VERSION "..." does not have a version on both sides of "...".
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
++
+CMake Error at RangeBad.cmake:9 \(cmake_policy\):
+  Invalid policy max version value "4".  A numeric
+  major.minor\[.patch\[.tweak\]\] must be given.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
++
+CMake Error at RangeBad.cmake:10 \(cmake_policy\):
+  Policy VERSION range "3.11...3.10" specifies a larger minimum than maximum.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)$