Index: cfe/trunk/include/clang/Driver/Options.td
===================================================================
--- cfe/trunk/include/clang/Driver/Options.td
+++ cfe/trunk/include/clang/Driver/Options.td
@@ -1688,6 +1688,8 @@
   HelpText<"Additional arguments to forward to LLVM's option processing">;
 def mmacosx_version_min_EQ : Joined<["-"], "mmacosx-version-min=">,
   Group<m_Group>, HelpText<"Set Mac OS X deployment target">;
+def mmacos_version_min_EQ : Joined<["-"], "mmacos-version-min=">,
+  Group<m_Group>, Alias<mmacosx_version_min_EQ>;
 def mms_bitfields : Flag<["-"], "mms-bitfields">, Group<m_Group>, Flags<[CC1Option]>,
   HelpText<"Set the default structure layout to be compatible with the Microsoft compiler standard">;
 def mno_ms_bitfields : Flag<["-"], "mno-ms-bitfields">, Group<m_Group>,
Index: cfe/trunk/test/Driver/darwin-version.c
===================================================================
--- cfe/trunk/test/Driver/darwin-version.c
+++ cfe/trunk/test/Driver/darwin-version.c
@@ -29,9 +29,13 @@
 // RUN:   FileCheck --check-prefix=CHECK-VERSION-OSX10 %s
 // RUN: %clang -target x86_64-apple-macosx -mmacosx-version-min=10.10 -c %s -### 2>&1 | \
 // RUN:   FileCheck --check-prefix=CHECK-VERSION-OSX10 %s
+// RUN: %clang -target x86_64-apple-macosx -mmacos-version-min=10.10 -c %s -### 2>&1 | \
+// RUN:   FileCheck --check-prefix=CHECK-VERSION-OSX10 %s
 // CHECK-VERSION-OSX10: "x86_64-apple-macosx10.10.0"
 // RUN: %clang -target x86_64-apple-macosx -mmacosx-version-min= -c %s -### 2>&1 | \
 // RUN:   FileCheck --check-prefix=CHECK-VERSION-MISSING %s
+// RUN: %clang -target x86_64-apple-macosx -mmacos-version-min= -c %s -### 2>&1 | \
+// RUN:   FileCheck --check-prefix=CHECK-VERSION-MISSING %s
 // CHECK-VERSION-MISSING: invalid version number
 // RUN: %clang -target armv7k-apple-darwin -mwatchos-version-min=2.0 -c %s -### 2>&1 | \
 // RUN:   FileCheck --check-prefix=CHECK-VERSION-WATCHOS20 %s