[Clang] Add macros for noescape and lifetime annotations (swiftlang#10644)

rdar://149691819
(cherry picked from commit ac356e7)

Author: egorzhdan

clang/lib/Headers/CMakeLists.txt

@@ -290,6 +290,9 @@ set(files
 # TO_UPSTREAM(BoundsSafety)
 list(APPEND files ptrcheck.h)
 
+# TO_UPSTREAM(Lifetimebound)
+list(APPEND files lifetimebound.h)
+
 set(cuda_wrapper_files
   cuda_wrappers/algorithm
   cuda_wrappers/cmath

clang/lib/Headers/lifetimebound.h

@@ -0,0 +1,19 @@
+/*===---- lifetimebound.h - Lifetime attributes -----------------------------===
+ *
+ * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+ * See https://llvm.org/LICENSE.txt for license information.
+ * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+ *
+ *===------------------------------------------------------------------------===
+ */
+
+#ifndef __LIFETIMEBOUND_H
+#define __LIFETIMEBOUND_H
+
+#define __lifetimebound __attribute__((lifetimebound))
+
+#define __lifetime_capture_by(X) __attribute__((lifetime_capture_by(X)))
+
+#define __noescape __attribute__((noescape))
+
+#endif /* __LIFETIMEBOUND_H */

clang/lib/Headers/module.modulemap

@@ -334,4 +334,11 @@ module ptrcheck {
   header "ptrcheck.h"
   export *
 }
-/* TO_UPSTREAM(BoundsSafety) OFF */
+/* TO_UPSTREAM(BoundsSafety) OFF */
+
+/* TO_UPSTREAM(Lifetimebound) ON */
+module lifetimebound {
+  header "lifetimebound.h"
+  export *
+}
+/* TO_UPSTREAM(Lifetimebound) OFF */

clang/test/Headers/lifetimebound.cpp

@@ -0,0 +1,18 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+// expected-no-diagnostics
+
+// Verify that we can include <lifetimebound.h>
+#include <lifetimebound.h>
+
+struct has_lifetimebound_method {
+  const char* get_ptr(char* ptr __lifetimebound) const;
+};
+
+struct has_lifetime_capture_by_method {
+  void take_ptr(char* ptr __lifetime_capture_by(this));
+  void take_ptr(has_lifetimebound_method a, char* ptr __lifetime_capture_by(a));
+};
+
+struct has_noescape_method {
+  void takes_noescape(char* ptr __noescape);
+};