Rename preprocessor macro __VALGRIND__ to __VALGRIND_MAJOR__ and add
comments.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11105 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/include/valgrind.h b/include/valgrind.h
index 65993fb..43e3657 100644
--- a/include/valgrind.h
+++ b/include/valgrind.h
@@ -79,8 +79,16 @@
/* ------------------------------------------------------------------ */
/* Specify Valgrind's version number, so that user code can
- conditionally compile based on our version number. */
-#define __VALGRIND__ 3
+ conditionally compile based on our version number. Note that these
+ were introduced at version 3.6 and so do not exist in version 3.5
+ or earlier. The recommended way to use them to check for "version
+ X.Y or later" is (eg)
+
+#if defined(__VALGRIND_MAJOR__) && defined(__VALGRIND_MINOR__) \
+ && (__VALGRIND_MAJOR__ > 3 \
+ || (__VALGRIND_MAJOR__ == 3 && __VALGRIND_MINOR__ >= 6))
+*/
+#define __VALGRIND_MAJOR__ 3
#define __VALGRIND_MINOR__ 6