Replace hardcoded version number with macro

src/internal.h

@@ -33,8 +33,6 @@
  #include "glfw_config.h"
 #endif
 
-#define _GLFW_VERSION_NUMBER "3.2.0"
-
 #if defined(GLFW_INCLUDE_GLCOREARB) || \
     defined(GLFW_INCLUDE_ES1)       || \
     defined(GLFW_INCLUDE_ES2)       || \
@@ -134,6 +132,13 @@ typedef int GLFWbool;
 // Helper macros
 //========================================================================
 
+// Constructs a version number string from the public header macros
+#define _GLFW_CONCAT_VERSION(m, n, r) #m "." #n "." #r
+#define _GLFW_MAKE_VERSION(m, n, r) _GLFW_CONCAT_VERSION(m, n, r)
+#define _GLFW_VERSION_NUMBER _GLFW_MAKE_VERSION(GLFW_VERSION_MAJOR, \
+                                                GLFW_VERSION_MINOR, \
+                                                GLFW_VERSION_REVISION)
+
 // Checks for whether the library has been initialized
 #define _GLFW_REQUIRE_INIT()                         \
     if (!_glfwInitialized)                           \