Merge pull request #63839 from zoecarver/cxx-interop-helper-header

[cxx-interop] Provide a support header for common attributes, etc.

Author: zoecarver

lib/ClangImporter/CMakeLists.txt

@@ -42,3 +42,23 @@ add_dependencies(swiftClangImporter
   ${CLANG_TABLEGEN_TARGETS})
 
 set_swift_llvm_is_available(swiftClangImporter)
+
+# Mark - copy "swift-interop-support.h" into the local include directory and install it
+# into the compiler toolchain.
+set(SWIFTINC_DIR
+    "${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/include/swift")
+
+add_custom_command(
+    OUTPUT "${SWIFTINC_DIR}/swift-interop-support.h"
+    COMMAND "${CMAKE_COMMAND}" "-E" "copy" "${CMAKE_CURRENT_SOURCE_DIR}/swift-interop-support.h" "${SWIFTINC_DIR}")
+
+add_custom_target("copy_cxxInterop_support_header"
+    DEPENDS "${SWIFTINC_DIR}/swift-interop-support.h"
+    COMMENT "Copying C++ interop support header to ${SWIFTINC_DIR}")
+
+swift_install_in_component(FILES "${CMAKE_CURRENT_SOURCE_DIR}/swift-interop-support.h"
+                           DESTINATION "include/swift"
+                           COMPONENT compiler)
+
+add_dependencies(swiftClangImporter
+  "copy_cxxInterop_support_header")

lib/ClangImporter/swift-interop-support.h

@@ -0,0 +1,31 @@
+//===--- swift-interop-support.h - C++ and Swift Interop --------*- C++ -*-===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+//
+// This file provides common utilities and annotations that are useful for C++
+// codebases that interoperate with Swift.
+//
+//===----------------------------------------------------------------------===//
+#ifndef SWIFT_CLANGIMPORTER_SWIFT_INTEROP_SUPPORT_H
+#define SWIFT_CLANGIMPORTER_SWIFT_INTEROP_SUPPORT_H
+
+#define SELF_CONTAINED __attribute__((swift_attr("import_owned")))
+#define SAFE_TO_IMPORT __attribute__((swift_attr("import_unsafe")))
+
+#define _CXX_INTEROP_STRINGIFY(_x) #_x
+#define SWIFT_REFERENCE_TYPE(_retain, _release)                                \
+  __attribute__((swift_attr("import_reference")))                              \
+  __attribute__((swift_attr(_CXX_INTEROP_STRINGIFY(retain:_retain))))          \
+  __attribute__((swift_attr(_CXX_INTEROP_STRINGIFY(release:_release))))
+
+#define SWIFT_NAME(_name) __attribute__((swift_name(#_name)))
+
+#endif // SWIFT_CLANGIMPORTER_SWIFT_INTEROP_SUPPORT_H