build: use the exported target instead of reconstructing paths

Use the exported target from swift rather than recreate the paths locally.  This
almost works to replace the use of the paths.  Unfortunately, swiftrt is not
currently exported.

Author: compnerd

CMakeLists.txt

@@ -44,38 +44,32 @@ dispatch_common_warnings()
 option(ENABLE_DISPATCH_INIT_CONSTRUCTOR "enable libdispatch_init as a constructor" ON)
 set(USE_LIBDISPATCH_INIT_CONSTRUCTOR ${ENABLE_DISPATCH_INIT_CONSTRUCTOR})
 
+# NOTE(abdulras) this is the CMake supported way to control whether we generate
+# shared or static libraries.  This impacts the behaviour of `add_library` in
+# what type of library it generates.
+option(BUILD_SHARED_LIBS "build shared libraries" ON)
+
 option(ENABLE_SWIFT "enable libdispatch swift overlay" OFF)
 if(ENABLE_SWIFT)
   if(NOT CMAKE_SWIFT_COMPILER)
     message(FATAL_ERROR "CMAKE_SWIFT_COMPILER must be defined to enable swift")
   endif()
 
-  get_filename_component(SWIFT_TOOLCHAIN ${CMAKE_SWIFT_COMPILER} DIRECTORY)
-  get_filename_component(SWIFT_TOOLCHAIN ${SWIFT_TOOLCHAIN} DIRECTORY)
-
-  string(TOLOWER ${CMAKE_SYSTEM_NAME} SWIFT_OS)
-  get_swift_host_arch(SWIFT_HOST_ARCH)
+  find_package(Swift REQUIRED CONFIG)
 
-  set(SWIFT_RUNTIME_LIBDIR ${SWIFT_TOOLCHAIN}/${SWIFT_LIBDIR}/swift/${SWIFT_OS}/${SWIFT_HOST_ARCH})
-
-  add_library(swiftCore
-              SHARED IMPORTED GLOBAL)
-  set_target_properties(swiftCore
-                        PROPERTIES
-                          IMPORTED_LOCATION
-                            ${SWIFT_RUNTIME_LIBDIR}/${CMAKE_SHARED_LIBRARY_PREFIX}swiftCore${CMAKE_SHARED_LIBRARY_SUFFIX})
+  string(TOLOWER ${CMAKE_SYSTEM_NAME} swift_os)
+  get_swift_host_arch(swift_arch)
 
-  add_library(swiftSwiftOnoneSupport
-              SHARED IMPORTED GLOBAL)
-  set_target_properties(swiftSwiftOnoneSupport
-                        PROPERTIES
-                          IMPORTED_LOCATION
-                           ${SWIFT_RUNTIME_LIBDIR}/${CMAKE_SHARED_LIBRARY_PREFIX}swiftSwiftOnoneSupport${CMAKE_SHARED_LIBRARY_SUFFIX})
+  if(BUILD_SHARED_LIBS)
+    set(swift_dir swift)
+  else()
+    set(swift_dir swift_static)
+  endif()
 
-  set(INSTALL_TARGET_DIR "${INSTALL_LIBDIR}/swift/${SWIFT_OS}" CACHE PATH "Path where the libraries will be installed")
-  set(INSTALL_DISPATCH_HEADERS_DIR "${INSTALL_LIBDIR}/swift/dispatch" CACHE PATH "Path where the headers will be installed for libdispatch")
-  set(INSTALL_BLOCK_HEADERS_DIR "${INSTALL_LIBDIR}/swift/Block" CACHE PATH "Path where the headers will be installed for the blocks runtime")
-  set(INSTALL_OS_HEADERS_DIR "${INSTALL_LIBDIR}/swift/os" CACHE PATH "Path where the os/ headers will be installed")
+  set(INSTALL_TARGET_DIR "${INSTALL_LIBDIR}/${swift_dir}/${swift_os}" CACHE PATH "Path where the libraries will be installed")
+  set(INSTALL_DISPATCH_HEADERS_DIR "${INSTALL_LIBDIR}/${swift_dir}/dispatch" CACHE PATH "Path where the headers will be installed for libdispatch")
+  set(INSTALL_BLOCK_HEADERS_DIR "${INSTALL_LIBDIR}/${swift_dir}/Block" CACHE PATH "Path where the headers will be installed for the blocks runtime")
+  set(INSTALL_OS_HEADERS_DIR "${INSTALL_LIBDIR}/${swift_dir}/os" CACHE PATH "Path where the os/ headers will be installed")
 endif()
 
 if(NOT ENABLE_SWIFT)
@@ -87,11 +81,6 @@ endif()
 
 option(ENABLE_DTRACE "enable dtrace support" "")
 
-# NOTE(abdulras) this is the CMake supported way to control whether we generate
-# shared or static libraries.  This impacts the behaviour of `add_library` in
-# what type of library it generates.
-option(BUILD_SHARED_LIBS "build shared libraries" ON)
-
 option(ENABLE_TESTING "build libdispatch tests" ON)
 
 option(USE_LLD_LINKER "use the lld linker" FALSE)

src/CMakeLists.txt

@@ -112,11 +112,16 @@ if(ENABLE_SWIFT)
                       ${swift_optimization_flags}
                     DEPENDS
                       ${PROJECT_SOURCE_DIR}/dispatch/module.modulemap)
+
+  get_filename_component(swift_toolchain ${CMAKE_SWIFT_COMPILER} DIRECTORY)
+  get_filename_component(swift_toolchain ${swift_toolchain} DIRECTORY)
+  set(swift_runtime_libdir ${swift_toolchain}/lib/${swift_dir}/${swift_os}/${swift_arch})
+
   target_sources(dispatch
                  PRIVATE
                    swift/DispatchStubs.cc
                    ${CMAKE_CURRENT_BINARY_DIR}/swiftDispatch.o
-                   ${SWIFT_RUNTIME_LIBDIR}/swiftrt.o)
+                   ${swift_runtime_libdir}/swiftrt.o)
   if(CMAKE_BUILD_TYPE MATCHES Debug)
     target_link_libraries(dispatch
                           PRIVATE

tests/CMakeLists.txt

@@ -59,8 +59,8 @@ endif()
 if(ENABLE_SWIFT)
   target_link_libraries(bsdtestharness
                         PRIVATE
-                          swiftCore
-                          swiftSwiftOnoneSupport)
+                          swiftCore-${swift_os}-${swift_arch}
+                          swiftSwiftOnoneSupport-${swift_os}-${swift_arch})
 endif()
 
 function(add_unit_test name)
@@ -83,7 +83,10 @@ function(add_unit_test name)
     # For testing in swift.org CI system; make deadlines lenient by default
     # to reduce probability of test failures due to machine load.
     target_compile_options(${name} PRIVATE -DLENIENT_DEADLINES=1)
-    target_link_libraries(${name} PRIVATE swiftCore swiftSwiftOnoneSupport)
+    target_link_libraries(${name}
+                          PRIVATE
+                            swiftCore-${swift_os}-${swift_arch}
+                            swiftSwiftOnoneSupport-${swift_os}-${swift_arch})
   endif()
   target_include_directories(${name}
                              SYSTEM BEFORE PRIVATE
@@ -114,8 +117,8 @@ function(add_unit_test name)
   if(ENABLE_SWIFT)
     target_link_libraries(${name}
                           PRIVATE
-                            swiftCore
-                            swiftSwiftOnoneSupport)
+                            swiftCore-${swift_os}-${swift_arch}
+                            swiftSwiftOnoneSupport-${swift_os}-${swift_arch})
   endif()
   target_link_libraries(${name} PRIVATE bsdtests)
   add_test(NAME ${name}