1 files changed, 17 insertions, 0 deletions
diff --git a/include/clang/Frontend/CodeGenOptions.h b/include/clang/Frontend/CodeGenOptions.h
index 22d5d3d16ee2..71730a21dbe2 100644
--- a/include/clang/Frontend/CodeGenOptions.h
+++ b/include/clang/Frontend/CodeGenOptions.h
@@ -69,6 +69,23 @@ public:
     LocalExecTLSModel
   };
 
+  /// Clang versions with different platform ABI conformance.
+  enum class ClangABI {
+    /// Attempt to be ABI-compatible with code generated by Clang 3.8.x
+    /// (SVN r257626). This causes <1 x long long> to be passed in an
+    /// integer register instead of an SSE register on x64_64.
+    Ver3_8,
+
+    /// Attempt to be ABI-compatible with code generated by Clang 4.0.x
+    /// (SVN r291814). This causes move operations to be ignored when
+    /// determining whether a class type can be passed or returned directly.
+    Ver4,
+
+    /// Conform to the underlying platform's C and C++ ABIs as closely
+    /// as we can.
+    Latest
+  };
+
   enum StructReturnConventionKind {
     SRCK_Default,  // No special option was passed.
     SRCK_OnStack,  // Small structs on the stack (-fpcc-struct-return).