Do not pass VC-specific 'pragma message' in gc.h to other compilers (Win64)

* include/gc.h: Pass pragma message (to identify missing predefined
symbols for Win64) only if _MSC_VER (as it is specific to VC); report
the message only on first gc.h inclusion; adjust related comment.

Conflicts:

    include/gc.h

diff --git a/include/gc.h b/include/gc.h
index ada78ca0b6f5937a9babd2110a42a92fe73aec2c..abb097f07922ff2dee06e68771db01a68bf33f87 100644 (file)
--- a/include/gc.h
+++ b/include/gc.h
@@ -28,14 +28,14 @@
  * problems.
  */
 
-// help debug mixed up preproc symbols
-#if (defined(WIN64) && !defined(_WIN64))
-#pragma message("Warning: Expecting _WIN64 for x64 targets! Notice the leading underscore!")
-#endif
-
 #ifndef GC_H
 #define GC_H
 
+/* Help debug mixed up preprocessor symbols.    */
+#if (defined(WIN64) && !defined(_WIN64)) && defined(_MSC_VER)
+#pragma message("Warning: Expecting _WIN64 for x64 targets! Notice the leading underscore!")
+#endif
+
 #include "gc_version.h"
         /* Define version numbers here to allow test on build machine   */
         /* for cross-builds.  Note that this defines the header         */