Merge pull request #84388 from edymtt/edymtt/split-find-swiftdarwin-from-find-swiftoverlay

Runtimes: provide a dedicated find module for Darwin overlay

Author: edymtt

Runtimes/Supplemental/cmake/modules/FindSwiftDarwin.cmake

@@ -0,0 +1,70 @@
+#[=======================================================================[.rst:
+FindSwiftDarwin
+------------
+
+Find swiftDarwin in the underlying SDK (the only way we obtain such overlay).
+
+Imported Targets
+^^^^^^^^^^^^^^^^
+
+The following :prop_tgt:`IMPORTED` TARGETS may be defined:
+
+ ``swiftDarwin``
+
+#]=======================================================================]
+
+include_guard(GLOBAL)
+
+# This was loosely modelled after other find modules
+# (namely FindGLEW), where the equivalent parameter
+# is not stored in cache (possibly because we want
+# the project importing it to be able to use
+# it "immediately")
+if(NOT DEFINED SwiftDarwin_USE_STATIC_LIBS)
+  set(SwiftDarwin_USE_STATIC_LIBS OFF)
+endif()
+
+include(FindPackageHandleStandardArgs)
+include(PlatformInfo)
+
+if(NOT APPLE)
+  message(WARNING "Darwin is only produced on Apple platforms, so not attempting to search it here.")
+  return()
+endif()
+
+# Look in the SDK
+list(APPEND swiftDarwin_INCLUDE_DIR_HINTS
+  "${CMAKE_OSX_SYSROOT}/usr/lib/swift")
+list(APPEND swiftDarwin_LIBRARY_HINTS
+  "${CMAKE_OSX_SYSROOT}/usr/lib/swift")
+# When building for Apple platforms, swiftDarwin always comes from within the
+# SDK as a tbd for a shared library in the shared cache.
+list(APPEND swiftDarwin_NAMES libswiftDarwin.tbd)
+set(swiftDarwin_MODULE_NAME "Darwin.swiftmodule")
+
+find_path(swiftDarwin_INCLUDE_DIR
+  ${swiftDarwin_MODULE_NAME}
+  NO_CMAKE_FIND_ROOT_PATH
+  HINTS
+    ${swiftDarwin_INCLUDE_DIR_HINTS})
+find_library(swiftDarwin_LIBRARY
+  NAMES
+    ${swiftDarwin_NAMES}
+  NO_CMAKE_FIND_ROOT_PATH
+  HINTS
+    ${swiftDarwin_LIBRARY_HINTS})
+
+if(SwiftDarwin_USE_STATIC_LIBS)
+  add_library(swiftDarwin STATIC IMPORTED GLOBAL)
+else()
+  add_library(swiftDarwin SHARED IMPORTED GLOBAL)
+endif()
+
+target_include_directories(swiftDarwin INTERFACE
+  "${swiftDarwin_INCLUDE_DIR}")
+
+set_target_properties(swiftDarwin PROPERTIES
+  IMPORTED_IMPLIB "${swiftDarwin_LIBRARY}")
+
+find_package_handle_standard_args(SwiftDarwin DEFAULT_MSG
+  "swiftDarwin_LIBRARY" "swiftDarwin_INCLUDE_DIR")

Runtimes/Supplemental/cmake/modules/FindSwiftOverlay.cmake

@@ -55,16 +55,9 @@ include(FindPackageHandleStandardArgs)
 include(PlatformInfo)
 
 if(APPLE)
-  list(APPEND OVERLAY_TARGET_NAMES "swiftDarwin")
-  # Look in the SDK
-  list(APPEND swiftDarwin_INCLUDE_DIR_HINTS
-    "${CMAKE_OSX_SYSROOT}/usr/lib/swift")
-  list(APPEND swiftDarwin_LIBRARY_HINTS
-    "${CMAKE_OSX_SYSROOT}/usr/lib/swift")
-  # When building for Apple platforms, swiftDarwin always comes from within the
-  # SDK as a tbd for a shared library in the shared cache.
-  list(APPEND swiftDarwin_NAMES libswiftDarwin.tbd)
-  set(swiftDarwin_MODULE_NAME "Darwin.swiftmodule")
+  # Darwin has its own dedicated find module,
+  # so that we can use it together with the CMake config file
+  # generated by the Overlay build system
 
   list(APPEND swift_Builtin_float_INCLUDE_DIR_HINTS
     "${CMAKE_OSX_SYSROOT}/usr/lib/swift")