build: add exports targets

Now that we can build the Swift content as a library, we can do export
targets.  This enables us to have CMake determine more information about
the target, track dependencies across projects, and manage the flags
across the trees without the special variables to specify the source and
build trees.

Author: compnerd

CMakeLists.txt

@@ -276,3 +276,5 @@ add_subdirectory(src)
 if(BUILD_TESTING)
   add_subdirectory(tests)
 endif()
+
+add_subdirectory(cmake/modules)

cmake/modules/CMakeLists.txt

@@ -0,0 +1,7 @@
+
+set(DISPATCH_EXPORTS_FILE ${CMAKE_CURRENT_BINARY_DIR}/dispatchExports.cmake)
+configure_file(dispatchConfig.cmake.in
+  ${CMAKE_CURRENT_BINARY_DIR}/dispatchConfig.cmake)
+
+get_property(DISPATCH_EXPORTS GLOBAL PROPERTY DISPATCH_EXPORTS)
+export(TARGETS ${DISPATCH_EXPORTS} FILE ${DISPATCH_EXPORTS_FILE})

cmake/modules/dispatchConfig.cmake.in

@@ -0,0 +1,7 @@
+
+set(DISPATCH_HAS_SWIFT_SDK_OVERLAY @ENABLE_SWIFT@)
+
+if(NOT TARGET dispatch)
+  include(@DISPATCH_EXPORTS_FILE@)
+endif()
+

src/BlocksRuntime/CMakeLists.txt

@@ -28,7 +28,9 @@ if(INSTALL_PRIVATE_HEADERS)
   install(FILES Block_private.h
           DESTINATION ${INSTALL_BLOCK_HEADERS_DIR})
 endif()
+set_property(GLOBAL APPEND PROPERTY DISPATCH_EXPORTS dispatch)
 install(TARGETS BlocksRuntime
+        EXPORT dispatchExports
         ARCHIVE DESTINATION ${INSTALL_TARGET_DIR}
         LIBRARY DESTINATION ${INSTALL_TARGET_DIR}
         RUNTIME DESTINATION bin)

src/CMakeLists.txt

@@ -159,7 +159,9 @@ if(ENABLE_SWIFT)
   add_subdirectory(swift)
 endif()
 
+set_property(GLOBAL APPEND PROPERTY DISPATCH_EXPORTS dispatch)
 install(TARGETS dispatch
+        EXPORT dispatchExports
         ARCHIVE DESTINATION ${INSTALL_TARGET_DIR}
         LIBRARY DESTINATION ${INSTALL_TARGET_DIR}
         RUNTIME DESTINATION bin)

src/swift/CMakeLists.txt

@@ -47,9 +47,11 @@ install(FILES
   ${CMAKE_CURRENT_BINARY_DIR}/swift/Dispatch.swiftdoc
   DESTINATION ${INSTALL_TARGET_DIR}/${swift_arch})
 install(TARGETS swiftDispatch
+  EXPORT dispatchExports
   ARCHIVE DESTINATION ${INSTALL_TARGET_DIR}
   LIBRARY DESTINATION ${INSTALL_TARGET_DIR}
   RUNTIME DESTINATION bin)
+set_property(GLOBAL APPEND PROPERTY DISPATCH_EXPORTS swiftDispatch)
 if(NOT BUILD_SHARED_LIBS)
   install(TARGETS DispatchStubs
     DESTINATION ${INSTALL_TARGET_DIR})