[libnma] version: calculate NMA_API_VERSION based on the version number

[Thomas Haller <thaller src gnome org>]

commit e07506ed85c2a8905ef6cb6ddef6ff90223e86dd
Author: Thomas Haller <thaller redhat com>
Date:   Fri Mar 6 19:20:50 2020 +0100

    version: calculate NMA_API_VERSION based on the version number
    
    The concept of NMA_VERSION_CUR_STABLE and NMA_VERSION_NEXT_STABLE is
    flawed. Only the current API version of the source matters.
    
    If the current checkout is still in development (from master branch,
    odd numbers, e.g. 1.8.29+), then this is already aspiring the upcoming
    API (e.g. 1.8.30). Hence, also for such development version, it should
    pretend to be already the to-be-released version.
    
    For releases (tagged, with even numbers, like 1.8.28), obviously the
    version is exactly the API version.
    
    Since we have a versioning scheme based on odd/even numbers, we can
    calculate the current/upcoming API version. Do that.
    
    This also allows us to skip bumping the NMA_VERSION_CUR_STABLE
    and NMA_VERSION_NEXT_STABLE macros. That was easy for forget, resulting
    in a broken release. While the release process was documented to bump
    these two defines, it's easy to forget.
    
    The same is done by libnm, which also follows the odd/even versioning
    scheme.

 src/nma-version.h.in | 33 ++++++++++++++++++++++++++-------
 1 file changed, 26 insertions(+), 7 deletions(-)
---
diff --git a/src/nma-version.h.in b/src/nma-version.h.in
index 1ba9382e..53378844 100644
--- a/src/nma-version.h.in
+++ b/src/nma-version.h.in
@@ -62,26 +62,41 @@
 #define NMA_VERSION_1_8_26 (NMA_ENCODE_VERSION (1, 8, 26))
 #define NMA_VERSION_1_8_28 (NMA_ENCODE_VERSION (1, 8, 28))
 
-#define NMA_VERSION_CUR_STABLE  NMA_VERSION_1_8_26
-#define NMA_VERSION_NEXT_STABLE NMA_VERSION_1_8_28
+/* For releases, NMA_API_VERSION is equal to NMA_VERSION.
+ *
+ * For development builds, NMA_API_VERSION is the next
+ * stable API after NMA_VERSION. When you run a development
+ * version, you are already using the future API, even if
+ * it is not yet release. Hence, the currently used API
+ * version is the future one.  */
+#define NMA_API_VERSION \
+    (((NMA_MINOR_VERSION % 2) == 1) \
+        ? NMA_ENCODE_VERSION (NMA_MAJOR_VERSION, NMA_MINOR_VERSION + 1, 0                               ) \
+        : NMA_ENCODE_VERSION (NMA_MAJOR_VERSION, NMA_MINOR_VERSION    , ((NMA_MICRO_VERSION + 1) / 2) * 2))
+
+/* deprecated. */
+#define NMA_VERSION_CUR_STABLE  NMA_API_VERSION
+
+/* deprecated. */
+#define NMA_VERSION_NEXT_STABLE NMA_API_VERSION
 
 #define NMA_VERSION NMA_ENCODE_VERSION (NMA_MAJOR_VERSION, NMA_MINOR_VERSION, NMA_MICRO_VERSION)
 
-/* Deprecation / Availability macros */
+/*****************************************************************************/
 
 #if !defined (NMA_VERSION_MIN_REQUIRED) || (NMA_VERSION_MIN_REQUIRED == 0)
 # undef NMA_VERSION_MIN_REQUIRED
-# define NMA_VERSION_MIN_REQUIRED (NMA_VERSION_CUR_STABLE)
+# define NMA_VERSION_MIN_REQUIRED (NMA_API_VERSION)
 #endif
 
 #if !defined (NMA_VERSION_MAX_ALLOWED) || (NMA_VERSION_MAX_ALLOWED == 0)
 # undef NMA_VERSION_MAX_ALLOWED
-# define NMA_VERSION_MAX_ALLOWED (NMA_VERSION_NEXT_STABLE)
+# define NMA_VERSION_MAX_ALLOWED (NMA_API_VERSION)
 #endif
 
 /* sanity checks */
-#if NMA_VERSION_MIN_REQUIRED > NMA_VERSION_NEXT_STABLE
-#error "NMA_VERSION_MIN_REQUIRED must be <= NMA_VERSION_NEXT_STABLE"
+#if NMA_VERSION_MIN_REQUIRED > NMA_API_VERSION
+#error "NMA_VERSION_MIN_REQUIRED must be <= NMA_API_VERSION"
 #endif
 #if NMA_VERSION_MAX_ALLOWED < NMA_VERSION_MIN_REQUIRED
 #error "NMA_VERSION_MAX_ALLOWED must be >= NMA_VERSION_MIN_REQUIRED"
@@ -90,6 +105,10 @@
 #error "NMA_VERSION_MIN_REQUIRED must be >= NMA_VERSION_1_2"
 #endif
 
+/*****************************************************************************/
+
+/* Deprecation / Availability macros */
+
 #if NMA_VERSION_MIN_REQUIRED >= NMA_VERSION_1_2
 # define NMA_DEPRECATED_IN_1_2           G_DEPRECATED
 # define NMA_DEPRECATED_IN_1_2_FOR(f)    G_DEPRECATED_FOR(f)