[Runtimes][CMake] Refactor FindSwiftCore to put focus on targets...

...instead of platforms.

Notable changes/flags:
* Append to variables controlling paths and names, to allow for user
  configuration
* add `SwiftCore_USE_STATIC_LIBS` to generate static archives
* use PlatformInfo variables to get the platform and arch subfolders
  (where appropriate)
* add include guards to ensure PlatformInfo and FindSwiftCore are
    included once in a project
* search for the appropriate static or import library under Windows

Addresses rdar://152838903

Author: edymtt

Runtimes/Supplemental/cmake/modules/FindSwiftCore.cmake

@@ -37,6 +37,8 @@ The module may set the following variables if `SwiftCore_DIR` is not set.
 
 #]=======================================================================]
 
+include_guard(GLOBAL)
+
 # If the SwiftCore_DIR_FLAG is specified, look there instead. The cmake-generated
 # config file is more accurate, but requires that the SDK has one available.
 if(SwiftCore_DIR)
@@ -51,113 +53,112 @@ if(SwiftCore_DIR)
 endif()
 
 include(FindPackageHandleStandardArgs)
+include(PlatformInfo)
+
+# 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
+# it "immediately")
+if(NOT DEFINED SwiftCore_USE_STATIC_LIBS)
+  set(SwiftCore_USE_STATIC_LIBS OFF)
+  if(NOT BUILD_SHARED_LIBS AND NOT APPLE)
+    set(SwiftCore_USE_STATIC_LIBS ON)
+  endif()
+endif()
 
 if(APPLE)
+  list(APPEND SwiftCore_INCLUDE_DIR_HINTS
+    "${CMAKE_OSX_SYSROOT}/usr/lib/swift")
+  list(APPEND SwiftCore_LIBRARY_HINTS
+    "${CMAKE_OSX_SYSROOT}/usr/lib/swift")
   # When building for Apple platforms, SwiftCore always comes from within the
   # SDK as a tbd for a shared library in the shared cache.
-  find_path(SwiftCore_INCLUDE_DIR
-      "Swift.swiftmodule"
-    HINTS
-      "${CMAKE_OSX_SYSROOT}/usr/lib/swift")
-  find_library(SwiftCore_IMPLIB
-    NAMES "libswiftCore.tbd"
-    HINTS
-      "${CMAKE_OSX_SYSROOT}/usr/lib/swift")
-  add_library(swiftCore SHARED IMPORTED GLOBAL)
-  set_target_properties(swiftCore PROPERTIES
-    IMPORTED_IMPLIB "${SwiftCore_IMPLIB}"
-    INTERFACE_INCLUDE_DIRECTORIES "${SwiftCore_INCLUDE_DIR}")
-  find_package_handle_standard_args(SwiftCore DEFAULT_MSG
-    SwiftCore_IMPLIB SwiftCore_INCLUDE_DIR)
+  list(APPEND SwiftCore_NAMES libswiftCore.tbd)
 elseif(LINUX)
-  if (NOT BUILD_SHARED_LIBS)
-    find_path(SwiftCore_INCLUDE_DIR
-      "Swift.swiftmodule"
-      HINTS
-        "${Swift_SDKROOT}/usr/lib/swift_static/linux-static")
-    find_library(SwiftCore_LIBRARY
-      NAMES "libswiftCore.a"
-      HINTS "${Swift_SDKROOT}/usr/lib/swift_static/linux-static")
-    add_library(swiftCore STATIC IMPORTED GLOBAL)
+  if (SwiftCore_USE_STATIC_LIBS)
+    list(APPEND SwiftCore_INCLUDE_DIR_HINTS
+      "${Swift_SDKROOT}/usr/lib/swift_static/linux-static")
+    list(APPEND SwiftCore_LIBRARY_HINTS
+      "${Swift_SDKROOT}/usr/lib/swift_static/linux-static")
+    list(APPEND SwiftCore_NAMES libswiftCore.a)
   else()
-    find_path(SwiftCore_INCLUDE_DIR
-      "Swift.swiftmodule"
-      HINTS
-        "${Swift_SDKROOT}/usr/lib/swift/linux")
-    find_library(SwiftCore_LIBRARY
-      NAMES "libswiftCore.so"
-      HINTS "${Swift_SDKROOT}/usr/lib/swift/linux")
-    add_library(swiftCore SHARED IMPORTED GLOBAL)
+    list(APPEND SwiftCore_INCLUDE_DIR_HINTS
+      "${Swift_SDKROOT}/usr/lib/swift/linux")
+    list(APPEND SwiftCore_LIBRARY_HINTS
+      "${Swift_SDKROOT}/usr/lib/swift/linux")
+    list(APPEND SwiftCore_NAMES libswiftCore.so)
   endif()
-  set_target_properties(swiftCore PROPERTIES
-    IMPORTED_LOCATION "${SwiftCore_LIBRARY}"
-    INTERFACE_INCLUDE_DIRECTORIES "${SwiftCore_INCLUDE_DIR}")
-  find_package_handle_standard_args(SwiftCore DEFAULT_MSG
-    SwiftCore_LIBRARY SwiftCore_INCLUDE_DIR)
 elseif(WIN32)
-  find_path(SwiftCore_INCLUDE_DIR
-    "Swift.swiftmodule"
-    HINTS
-      "${Swift_SDKROOT}/usr/lib/swift/windows"
-      "$ENV{SDKROOT}/usr/lib/swift/windows")
-  find_library(SwiftCore_LIBRARY
-    NAMES "libswiftCore.lib"
-    HINTS
-      "${Swift_SDKROOT}/usr/lib/swift/${SwiftCore_PLATFORM_SUBDIR}/${SwiftCore_ARCH_SUBDIR}"
-      "${Swift_SDKROOT}/usr/lib/swift"
-      "$ENV{SDKROOT}/usr/lib/swift/${SwiftCore_PLATFORM_SUBDIR}/${SwiftCore_ARCH_SUBDIR}"
-      "$ENV{SDKROOT}/usr/lib/swift")
-
-  add_library(swiftCore SHARED IMPORTED GLOBAL)
-  set_target_properties(swiftCore PROPERTIES
-    IMPORTED_IMPLIB "${SwiftCore_LIBRARY}"
-    INTERFACE_INCLUDE_DIRECTORIES "${SwiftCore_INCLUDE_DIR}")
-  find_package_handle_standard_args(SwiftCore DEFAULT_MSG
-    SwiftCore_LIBRARY SwiftCore_INCLUDE_DIR)
+  list(APPEND SwiftCore_INCLUDE_DIR_HINTS
+    "${Swift_SDKROOT}/usr/lib/swift/windows"
+    "$ENV{SDKROOT}/usr/lib/swift/windows")
+  list(APPEND SwiftCore_LIBRARY_HINTS
+    "${Swift_SDKROOT}/usr/lib/swift/${${PROJECT_NAME}_PLATFORM_SUBDIR}/${${PROJECT_NAME}_ARCH_SUBDIR}"
+    "${Swift_SDKROOT}/usr/lib/swift"
+    "$ENV{SDKROOT}/usr/lib/swift/${${PROJECT_NAME}_PLATFORM_SUBDIR}/${${PROJECT_NAME}_ARCH_SUBDIR}"
+    "$ENV{SDKROOT}/usr/lib/swift")
+  if (SwiftCore_USE_STATIC_LIBS)
+    list(APPEND SwiftCore_NAMES libswiftCore.lib)
+  else()
+    list(APPEND SwiftCore_NAMES swiftCore.lib)
+  endif()
 elseif(ANDROID)
-  if(BUILD_SHARED_LIBS)
-    find_path(SwiftCore_INCLUDE_DIR
-      "Swift.swiftmodule"
-      NO_CMAKE_FIND_ROOT_PATH
-      HINTS
-        "${Swift_SDKROOT}/usr/lib/swift/android"
-        "$ENV{SDKROOT}/usr/lib/swift/android")
-    find_library(SwiftCore_LIBRARY
-      NO_CMAKE_FIND_ROOT_PATH
-      NAMES "libswiftCore.so"
-      HINTS
-        "${Swift_SDKROOT}/usr/lib/swift/android/${SwiftCore_ARCH_SUBDIR}"
-        "${Swift_SDKROOT}/usr/lib/swift"
-        "$ENV{SDKROOT}/usr/lib/swift/android/${SwiftCore_ARCH_SUBDIR}"
-        "$ENV{SDKROOT}/usr/lib/swift")
-
-    add_library(swiftCore SHARED IMPORTED GLOBAL)
+  if (SwiftCore_USE_STATIC_LIBS)
+    list(APPEND SwiftCore_INCLUDE_DIR_HINTS
+      "${Swift_SDKROOT}/usr/lib/swift_static/android"
+      "$ENV{SDKROOT}/usr/lib/swift_static/android")
+    list(APPEND SwiftCore_LIBRARY_HINTS
+      "${Swift_SDKROOT}/usr/lib/swift_static/android/${${PROJECT_NAME}_ARCH_SUBDIR}"
+      "${Swift_SDKROOT}/usr/lib/swift_static"
+      "$ENV{SDKROOT}/usr/lib/swift_static/android/${${PROJECT_NAME}_ARCH_SUBDIR}"
+      "$ENV{SDKROOT}/usr/lib/swift_static")
+    list(APPEND SwiftCore_NAMES libswiftCore.a)
   else()
-    find_path(SwiftCore_INCLUDE_DIR
-      "Swift.swiftmodule"
-      NO_CMAKE_FIND_ROOT_PATH
-      HINTS
-        "${Swift_SDKROOT}/usr/lib/swift_static/android"
-        "$ENV{SDKROOT}/usr/lib/swift_static/android")
-    find_library(SwiftCore_LIBRARY
-      NO_CMAKE_FIND_ROOT_PATH
-      NAMES "libswiftCore.a"
-      HINTS
-        "${Swift_SDKROOT}/usr/lib/swift_static/android/${SwiftCore_ARCH_SUBDIR}"
-        "${Swift_SDKROOT}/usr/lib/swift_static"
-        "$ENV{SDKROOT}/usr/lib/swift_static/android/${SwiftCore_ARCH_SUBDIR}"
-        "$ENV{SDKROOT}/usr/lib/swift_static")
-
-    add_library(swiftCore STATIC IMPORTED GLOBAL)
+    list(APPEND SwiftCore_INCLUDE_DIR_HINTS
+      "${Swift_SDKROOT}/usr/lib/swift/android"
+      "$ENV{SDKROOT}/usr/lib/swift/android")
+    list(APPEND SwiftCore_LIBRARY_HINTS
+      "${Swift_SDKROOT}/usr/lib/swift/android/${${PROJECT_NAME}_ARCH_SUBDIR}"
+      "${Swift_SDKROOT}/usr/lib/swift"
+      "$ENV{SDKROOT}/usr/lib/swift/android/${${PROJECT_NAME}_ARCH_SUBDIR}"
+      "$ENV{SDKROOT}/usr/lib/swift")
+    list(APPEND SwiftCore_NAMES libswiftCore.so)
   endif()
-
-  set_target_properties(swiftCore PROPERTIES
-    IMPORTED_LOCATION "${SwiftCore_LIBRARY}"
-    INTERFACE_INCLUDE_DIRECTORIES "${SwiftCore_INCLUDE_DIR}")
-  find_package_handle_standard_args(SwiftCore DEFAULT_MSG
-    SwiftCore_LIBRARY SwiftCore_INCLUDE_DIR)
 else()
   message(FATAL_ERROR "FindSwiftCore.cmake module search not implemented for targeted platform\n"
   " Build Core for your platform and set `SwiftCore_DIR` to"
   " the directory containing SwiftCoreConfig.cmake\n")
 endif()
+
+find_path(SwiftCore_INCLUDE_DIR
+  "Swift.swiftmodule"
+  NO_CMAKE_FIND_ROOT_PATH
+  HINTS
+    ${SwiftCore_INCLUDE_DIR_HINTS})
+find_library(SwiftCore_LIBRARY
+  NAMES
+    ${SwiftCore_NAMES}
+  NO_CMAKE_FIND_ROOT_PATH
+  HINTS
+    ${SwiftCore_LIBRARY_HINTS})
+
+if(SwiftCore_USE_STATIC_LIBS)
+  add_library(swiftCore STATIC IMPORTED GLOBAL)
+else()
+  add_library(swiftCore SHARED IMPORTED GLOBAL)
+endif()
+
+set_target_properties(swiftCore PROPERTIES
+  INTERFACE_INCLUDE_DIRECTORIES "${SwiftCore_INCLUDE_DIR}")
+
+if(LINUX OR ANDROID)
+  set_target_properties(swiftCore PROPERTIES
+    IMPORTED_LOCATION "${SwiftCore_LIBRARY}")
+else()
+  set_target_properties(swiftCore PROPERTIES
+    IMPORTED_IMPLIB "${SwiftCore_LIBRARY}")
+endif()
+
+find_package_handle_standard_args(SwiftCore DEFAULT_MSG
+  SwiftCore_LIBRARY SwiftCore_INCLUDE_DIR)

Runtimes/Supplemental/cmake/modules/PlatformInfo.cmake

@@ -1,3 +1,5 @@
+include_guard(GLOBAL)
+
 if(NOT ${PROJECT_NAME}_SIZEOF_POINTER)
   set(${PROJECT_NAME}_SIZEOF_POINTER "${CMAKE_SIZEOF_VOID_P}" CACHE STRING "Size of a pointer in bytes")
   message(CONFIGURE_LOG "Stdlib Pointer size: ${CMAKE_SIZEOF_VOID_P}")