diff --git a/clang/lib/Driver/ToolChain.cpp b/clang/lib/Driver/ToolChain.cpp
--- a/clang/lib/Driver/ToolChain.cpp
+++ b/clang/lib/Driver/ToolChain.cpp
@@ -398,6 +398,8 @@
     return "sunos";
   case llvm::Triple::AIX:
     return "aix";
+  case llvm::Triple::Darwin:
+    return "darwin";
   default:
     return getOS();
   }
diff --git a/clang/test/Driver/darwin-print-file-name.c b/clang/test/Driver/darwin-print-file-name.c
new file mode 100644
--- /dev/null
+++ b/clang/test/Driver/darwin-print-file-name.c
@@ -0,0 +1,6 @@
+// Regression test. Previously Clang just returned the library name instead
+// of the full path.
+// RUN: %clang -print-file-name=libclang_rt.osx.a --target=x86_64-apple-darwin20.3.0 \
+// RUN:        -resource-dir=%S/Inputs/resource_dir \
+// RUN:      | FileCheck --check-prefix=PRINT-RUNTIME-DIR %s
+// PRINT-RUNTIME-DIR: lib{{/|\\}}darwin{{/|\\}}libclang_rt.osx.a
\ No newline at end of file
diff --git a/clang/test/Driver/darwin-print-runtime-dir.c b/clang/test/Driver/darwin-print-runtime-dir.c
new file mode 100644
--- /dev/null
+++ b/clang/test/Driver/darwin-print-runtime-dir.c
@@ -0,0 +1,6 @@
+// Regression test. Previously the output included the OS version number
+// which was not correct.
+// RUN: %clang -print-runtime-dir --target=x86_64-apple-darwin20.3.0 \
+// RUN:        -resource-dir=%S/Inputs/resource_dir \
+// RUN:      | FileCheck --check-prefix=PRINT-RUNTIME-DIR %s
+// PRINT-RUNTIME-DIR: lib{{/|\\}}darwin{{$}}
\ No newline at end of file