project: Manage VERSION variables

Teach the project() command to set variables

  {PROJECT,<PROJECT-NAME>}_VERSION{,_MAJOR,_MINOR,_PATCH,_TWEAK}

holding the project version number and its components.  Add project()
command option "VERSION" to specify the version explicitly, and default
to the empty string when it is not given.

Since this clears variables when no VERSION is given, this may change
behavior for existing projects that set the version variables themselves
prior to calling project().  Add policy CMP0048 for compatibility.

Suggested-by: Alex Neundorf <neundorf@kde.org>

1 files changed, 12 insertions, 0 deletions

diff --git a/Tests/RunCMake/project/CMP0048-WARN-stderr.txt b/Tests/RunCMake/project/CMP0048-WARN-stderr.txt
new file mode 100644
index 0000000..6d29ad2
--- /dev/null
+++ b/Tests/RunCMake/project/CMP0048-WARN-stderr.txt
@@ -0,0 +1,12 @@
+CMake Warning \(dev\) at CMP0048-WARN.cmake:3 \(project\):
+  Policy CMP0048 is not set: project\(\) command manages VERSION variables.
+  Run "cmake --help-policy CMP0048" for policy details.  Use the cmake_policy
+  command to set the policy and suppress this warning.
+
+  The following variable\(s\) would be set to empty:
+
+    PROJECT_VERSION
+    MyProject_VERSION_TWEAK
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
+This warning is for project developers.  Use -Wno-dev to suppress it.