Add better explanation for '#define CK_DLL_EXP'

diff --git a/src/check.h.in b/src/check.h.in
index ac86d9bbea2d79ca6562e5eb3fa22821161e881d..0c6aa2c738583294f77e1e0a017304bb59d7da33 100644 (file)
--- a/src/check.h.in
+++ b/src/check.h.in
@@ -93,6 +93,15 @@ CK_CPPSTART
  * Used for MSVC to create the export attribute
  * CK_DLL_EXP is defined during the compilation of the library
  * on the command line.
+ *
+ * This definition is only used when building or linking to
+ * the shared library, i.e. libcheck.so. When building the library
+ * the value must be "_declspec(dllexport)".
+ * When linking with the library, the value must be "_declspec(dllimport)"
+ *
+ * This is only used with Microsoft Visual C. In other systems
+ * the value is empty. In MSVC the value is empty when linking with
+ * a static library.
  */
 #ifndef CK_DLL_EXP
 #define CK_DLL_EXP