Tag genrules as requiring darwin if they use a mac toolchain.
--
MOS_MIGRATED_REVID=96128887
diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppConfiguration.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppConfiguration.java
index e9d2749..398c276 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppConfiguration.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppConfiguration.java
@@ -82,6 +82,13 @@
@SkylarkModule(name = "cpp", doc = "A configuration fragment for C++")
@Immutable
public class CppConfiguration extends BuildConfiguration.Fragment {
+
+ /**
+ * String indicating a Mac system, for example when used in a crosstool configuration's host or
+ * target system name.
+ */
+ public static final String MAC_SYSTEM_NAME = "x86_64-apple-macosx";
+
/**
* An enumeration of all the tools that comprise a toolchain.
*/
