[PATCH v3 2/5] include/hw/boards: cope with dev/rc versions in deprecation checks

["Daniel P. Berrangé" <berrange@redhat.com>]

When VERSION is set to a development snapshot (micro >= 50), or a release
candidate (micro >= 90) we have an off-by-1 in determining deprecation
and deletion thresholds for versioned machine types. In such cases we need
to use the next major/minor version in threshold checks.

This adapts the deprecation macros to do "next version" prediction when
seeing a dev/rc version number.

This ensures users of release candidates get an accurate view of machines
that will be deprecated/deleted in the final release.

This requires hardcoding our current release policy of 3 releases per
year, with a major bump at the start of each year, and that dev/rc
versions have micro >= 50.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 include/hw/boards.h | 33 ++++++++++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/include/hw/boards.h b/include/hw/boards.h
index 74a8e96b2e..a6784fe984 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -650,11 +650,42 @@ struct MachineState {
     " years old are subject to deletion after " \
     stringify(MACHINE_VER_DELETION_MAJOR) " years"
 
-#define _MACHINE_VER_IS_EXPIRED_IMPL(cutoff, major, minor) \
+#define _MACHINE_VER_IS_CURRENT_EXPIRED(cutoff, major, minor) \
     (((QEMU_VERSION_MAJOR - major) > cutoff) || \
      (((QEMU_VERSION_MAJOR - major) == cutoff) && \
       (QEMU_VERSION_MINOR - minor) >= 0))
 
+#define _MACHINE_VER_IS_NEXT_MINOR_EXPIRED(cutoff, major, minor) \
+    (((QEMU_VERSION_MAJOR - major) > cutoff) || \
+     (((QEMU_VERSION_MAJOR - major) == cutoff) && \
+      ((QEMU_VERSION_MINOR + 1) - minor) >= 0))
+
+#define _MACHINE_VER_IS_NEXT_MAJOR_EXPIRED(cutoff, major, minor) \
+    ((((QEMU_VERSION_MAJOR + 1) - major) > cutoff) ||            \
+     ((((QEMU_VERSION_MAJOR + 1) - major) == cutoff) &&          \
+      (0 - minor) >= 0))
+
+/*
+ * - The first check applies to formal releases
+ * - The second check applies to dev snapshots / release candidates
+ *   where the next major version is the same.
+ *   e.g. 9.0.50, 9.1.50, 9.0.90, 9.1.90
+ * - The third check applies to dev snapshots / release candidates
+ *   where the next major version will change.
+ *   e.g. 9.2.50, 9.2.90
+ *
+ * NB: this assumes we do 3 minor releases per year, before bumping major,
+ * and dev snapshots / release candidates are numbered with micro >= 50
+ * If this ever changes the logic below will need modifying....
+ */
+#define _MACHINE_VER_IS_EXPIRED_IMPL(cutoff, major, minor) \
+    ((QEMU_VERSION_MICRO < 50 && \
+      _MACHINE_VER_IS_CURRENT_EXPIRED(cutoff, major, minor)) || \
+     (QEMU_VERSION_MICRO >= 50 && QEMU_VERSION_MINOR < 2 && \
+      _MACHINE_VER_IS_NEXT_MINOR_EXPIRED(cutoff, major, minor)) || \
+     (QEMU_VERSION_MICRO >= 50 && QEMU_VERSION_MINOR == 2 && \
+      _MACHINE_VER_IS_NEXT_MAJOR_EXPIRED(cutoff, major, minor)))
+
 #define _MACHINE_VER_IS_EXPIRED2(cutoff, major, minor) \
     _MACHINE_VER_IS_EXPIRED_IMPL(cutoff, major, minor)
 #define _MACHINE_VER_IS_EXPIRED3(cutoff, major, minor, micro) \
-- 
2.49.0