Revert "build: remove SWIFT_NEED_EXPLICIT_LIBDISPATCH (NFC)"

This reverts commit 18570c7 because it
breaks building on platforms that do not want or need libdispatch.

Author: davezarzycki

CMakeLists.txt

@@ -465,7 +465,10 @@ option(SWIFT_BUILD_SOURCEKIT "Build SourceKit" TRUE)
 option(SWIFT_ENABLE_SOURCEKIT_TESTS "Enable running SourceKit tests" ${SWIFT_BUILD_SOURCEKIT})
 
 if(SWIFT_BUILD_SYNTAXPARSERLIB OR SWIFT_BUILD_SOURCEKIT)
-  if(NOT CMAKE_SYSTEM_NAME STREQUAL Darwin)
+  if(CMAKE_SYSTEM_NAME STREQUAL Darwin)
+    set(SWIFT_NEED_EXPLICIT_LIBDISPATCH FALSE)
+  else()
+    set(SWIFT_NEED_EXPLICIT_LIBDISPATCH TRUE)
     if(NOT EXISTS "${SWIFT_PATH_TO_LIBDISPATCH_SOURCE}")
       message(SEND_ERROR "SyntaxParserLib and SourceKit require libdispatch on non-Darwin hosts.  Please specify SWIFT_PATH_TO_LIBDISPATCH_SOURCE")
     endif()
@@ -951,7 +954,7 @@ if (LLVM_ENABLE_DOXYGEN)
   message(STATUS "Doxygen: enabled")
 endif()
 
-if(NOT CMAKE_SYSTEM_NAME STREQUAL Darwin)
+if(SWIFT_NEED_EXPLICIT_LIBDISPATCH)
   if(CMAKE_C_COMPILER_ID STREQUAL Clang AND
      CMAKE_C_COMPILER_VERSION VERSION_GREATER 3.8
      OR LLVM_USE_SANITIZER)

tools/SourceKit/lib/Support/CMakeLists.txt

@@ -11,9 +11,7 @@ target_link_libraries(SourceKitSupport PRIVATE
   swiftSyntax
   clangBasic
   clangRewrite)
-if(NOT CMAKE_SYSTEM_NAME STREQUAL Darwin)
-  target_link_libraries(SourceKitSupport INTERFACE
-    dispatch
-    BlocksRuntime)
+if(SWIFT_NEED_EXPLICIT_LIBDISPATCH)
+  target_link_libraries(SourceKitSupport INTERFACE dispatch BlocksRuntime)
 endif()
 

tools/SourceKit/tools/complete-test/CMakeLists.txt

@@ -7,10 +7,8 @@ if(SWIFT_SOURCEKIT_USE_INPROC_LIBRARY)
 else()
   target_link_libraries(complete-test PRIVATE sourcekitd)
 endif()
-if(NOT CMAKE_SYSTEM_NAME STREQUAL Darwin)
-  target_link_libraries(complete-test PRIVATE
-    dispatch
-    BlocksRuntime)
+if(SWIFT_NEED_EXPLICIT_LIBDISPATCH)
+  target_link_libraries(complete-test PRIVATE dispatch BlocksRuntime)
 endif()
 
 if(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")

tools/SourceKit/tools/sourcekitd-repl/CMakeLists.txt

@@ -12,10 +12,8 @@ if(HAVE_UNICODE_LIBEDIT)
   else()
     target_link_libraries(sourcekitd-repl PRIVATE sourcekitd)
   endif()
-  if(NOT CMAKE_SYSTEM_NAME STREQUAL Darwin)
-    target_link_libraries(sourcekitd-repl PRIVATE
-      dispatch
-      BlocksRuntime)
+  if(SWIFT_NEED_EXPLICIT_LIBDISPATCH)
+    target_link_libraries(sourcekitd-repl PRIVATE dispatch BlocksRuntime)
   endif()
 
   if(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")

tools/SourceKit/tools/sourcekitd-test/CMakeLists.txt

@@ -17,10 +17,8 @@ if(SWIFT_SOURCEKIT_USE_INPROC_LIBRARY)
 else()
   target_link_libraries(sourcekitd-test PRIVATE sourcekitd)
 endif()
-if(NOT CMAKE_SYSTEM_NAME STREQUAL Darwin)
-  target_link_libraries(sourcekitd-test PRIVATE
-    dispatch
-    BlocksRuntime)
+if(SWIFT_NEED_EXPLICIT_LIBDISPATCH)
+  target_link_libraries(sourcekitd-test PRIVATE dispatch BlocksRuntime)
 endif()
 
 add_dependencies(sourcekitd-test sourcekitdTestOptionsTableGen)

tools/libSwiftSyntaxParser/CMakeLists.txt

@@ -45,9 +45,8 @@ endif()
 
 set_property(TARGET libSwiftSyntaxParser APPEND_STRING PROPERTY
   COMPILE_FLAGS " -fblocks")
-if(NOT CMAKE_SYSTEM_NAME STREQUAL Darwin)
-  target_link_libraries(libSwiftSyntaxParser PRIVATE
-    BlocksRuntime)
+if(SWIFT_NEED_EXPLICIT_LIBDISPATCH)
+  target_link_libraries(libSwiftSyntaxParser PRIVATE BlocksRuntime)
 endif()
 
 add_dependencies(parser-lib libSwiftSyntaxParser)

tools/swift-syntax-parser-test/CMakeLists.txt

@@ -27,7 +27,6 @@ endif()
 
 set_property(TARGET swift-syntax-parser-test APPEND_STRING PROPERTY
   COMPILE_FLAGS " -fblocks")
-if(NOT CMAKE_SYSTEM_NAME STREQUAL Darwin)
-  target_link_libraries(swift-syntax-parser-test PRIVATE
-    BlocksRuntime)
+if(SWIFT_NEED_EXPLICIT_LIBDISPATCH)
+  target_link_libraries(swift-syntax-parser-test PRIVATE BlocksRuntime)
 endif()

unittests/SyntaxParser/CMakeLists.txt

@@ -24,7 +24,6 @@ endif()
 
 set_property(TARGET SwiftSyntaxParserTests APPEND_STRING PROPERTY
   COMPILE_FLAGS " -fblocks")
-if(NOT CMAKE_SYSTEM_NAME STREQUAL Darwin)
-  target_link_libraries(SwiftSyntaxParserTests PRIVATE
-    BlocksRuntime)
+if(SWIFT_NEED_EXPLICIT_LIBDISPATCH)
+  target_link_libraries(SwiftSyntaxParserTests PRIVATE BlocksRuntime)
 endif()