Change moon_version() to use a constant expression

kernel/src/config.cpp

@@ -4,37 +4,36 @@
 #define STRINGIZE(x) #x
 #define STRINGIZE_VALUE_OF(x) STRINGIZE(x)
 
+#ifndef MOON_MAJOR
+#define MOON_MAJOR 0
+#endif
+
+#ifndef MOON_MINOR
+#define MOON_MINOR 3
+#endif
+
+#ifndef _MOON_SUFFIX
+#define MOON_SUFFIX ""
+#else
+#define MOON_SUFFIX STRINGIZE_VALUE_OF(_MOON_SUFFIX);
+#endif
+
 int __moon_version_major()
 {
-#ifndef MOON_MAJOR
-    return 0;
-#else
     return MOON_MAJOR;
-#endif
 }
 
 int __moon_version_minor()
 {
-#ifndef MOON_MINOR
-    return 3;
-#else
     return MOON_MINOR;
-#endif
 }
 
 const char* __moon_version_suffix()
 {
-#ifndef _MOON_SUFFIX
-    return "";
-#else
-    return STRINGIZE_VALUE_OF(_MOON_SUFFIX);
-#endif
+    return MOON_SUFFIX;
 }
 
 const char* moon_version()
 {
-    static char version[64];
-    snprintf(version, sizeof(version), "%d.%d%s", __moon_version_major(), __moon_version_minor(),
-             __moon_version_suffix()); // FIXME: this string is constant each build and should only be calculated once
-    return version;
+    return STRINGIZE_VALUE_OF(MOON_MAJOR) "." STRINGIZE_VALUE_OF(MOON_MINOR) MOON_SUFFIX;
 }