define the XBT_IMPORT_NO_PUBLIC macro for imported but not exported type

[simgrid.git] / include / xbt / misc.h

diff --git a/include/xbt/misc.h b/include/xbt/misc.h
index 7e339d6..256f4ec 100644 (file)
--- a/include/xbt/misc.h
+++ b/include/xbt/misc.h
@@ -56,25 +56,57 @@
 #    define XBT_INLINE  inline
 #endif
 
+/* 
+ * Function calling convention (not used for now) 
+ */
+ 
+#ifdef _WIN32
+#  ifndef _XBT_CALL
+#    define _XBT_CALL __cdecl
+#   endif
+#else 
+#  define _XBT_CALL
+#endif
+
 /* Handle import/export stuff
- * Rational: 
- *   * If you compile the DLL you must pass the right value of XBT_PUBLIC in the project: -DXBT_PUBLIC=__dllspec(ddlexport)
- *   * If you do a static compilation, you must define this macro to empty: -DXBT_PUBLIC=
+ * 
+ * Rational of XBT_PUBLIC: 
+ *   * If you build the DLL you must pass the right value of XBT_PUBLIC in the project : to do this you must define the DLL_EXPORT macro
+ *   * If you do a static compilation, you must define the macro DLL_STATIC
  *   * If you link your code against the DLL, this file defines the macro to '__declspec(dllimport)' for you
  *   * If you compile under unix, this file defines the macro to 'extern', even if it's not mandatory with modern compilers
+ * 
+ * Rational of XBT_PUBLIC_NO_IMPORT:
+ *   * This is for symbols which must be exported in the DLL, but not imported from it. 
+ *     This is obviously useful for initialized globals (which cannot be extern or similar).
+ *     This is also used in the log mecanism where a macro creates the variable automatically.
+ *      When the macro is called from within SimGrid, the symbol must be exported, but when called 
+ *      from within the client code, it must not try to retrieve the symbol from the DLL since it's not in there.
  */
-#ifndef XBT_PUBLIC
-#  ifdef _WIN32
-#   define XBT_PUBLIC __declspec(dllimport)
-#  else 
-#   define XBT_PUBLIC extern
-#  endif /* _WIN32 */
-#endif /* !XBT_PUBLIC */
-
-/* Function calling convention (not used for now) */
-#if !defined (_XBT_CALL)
-#define _XBT_CALL
+
+
+#ifdef DLL_EXPORT
+#  define XBT_PUBLIC(type)                       __declspec(dllexport) type
+#  define XBT_PUBLIC_NO_IMPORT(type)  __declspec(dllexport) type
+#  define XBT_IMPORT_NO_PUBLIC(type)  type 
+#else
+#  ifdef DLL_STATIC
+#    define XBT_PUBLIC(type)              type
+#    define XBT_PUBLIC_NO_IMPORT(type) type
+#   define XBT_IMPORT_NO_PUBLIC(type)  type 
+#  else
+#    ifdef _WIN32
+#      define XBT_PUBLIC(type)              __declspec(dllimport) type
+#      define XBT_PUBLIC_NO_IMPORT(type) type
+#      define XBT_IMPORT_NO_PUBLIC(type) __declspec(dllimport) type
+#       else
+#      define XBT_PUBLIC(type)              extern type
+#      define XBT_PUBLIC_NO_IMPORT(type) type
+#      define XBT_IMPORT_NO_PUBLIC(type) type
+#    endif
+#  endif
 #endif
+   
 
 
 
@@ -110,10 +142,14 @@
 
 SG_BEGIN_DECL()
 
-XBT_PUBLIC const char *xbt_procname(void);
+XBT_PUBLIC(const char *)xbt_procname(void);
 
 #define XBT_BACKTRACE_SIZE 10 /* FIXME: better place? Do document */
    
 SG_END_DECL()
 
 #endif /* XBT_MISC_H */
+
+
+
+