build: remove outdated TODO, limit build, install

The DispatchStubs are now used only for the ObjC codepath and no longer
need to be included in the regular build. Simply remove the extra
library unless Objective-C support is enabled.

Author: compnerd

src/CMakeLists.txt

@@ -82,9 +82,6 @@ if(ENABLE_DTRACE)
 endif()
 
 if(HAVE_OBJC)
-  # TODO(compnerd) split DispatchStubs.cc into a separate component for the ObjC
-  # registration and a separate component for the swift compiler's emission of a
-  # call to the ObjC autorelease elision entry point.
   target_sources(dispatch PRIVATE
     data.m
     object.m

src/swift/CMakeLists.txt

@@ -1,9 +1,11 @@
-add_library(DispatchStubs STATIC
-  DispatchStubs.cc)
-target_include_directories(DispatchStubs PRIVATE
-  ${PROJECT_SOURCE_DIR})
-set_target_properties(DispatchStubs PROPERTIES
-  POSITION_INDEPENDENT_CODE YES)
+if(HAVE_OBJC)
+  add_library(DispatchStubs STATIC
+    DispatchStubs.cc)
+  target_include_directories(DispatchStubs PRIVATE
+    ${PROJECT_SOURCE_DIR})
+  set_target_properties(DispatchStubs PROPERTIES
+    POSITION_INDEPENDENT_CODE YES)
+endif()
 
 add_library(swiftDispatch
   Block.swift
@@ -27,7 +29,7 @@ set_target_properties(swiftDispatch PROPERTIES
   Swift_MODULE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/swift
   INTERFACE_INCLUDE_DIRECTORIES ${CMAKE_CURRENT_BINARY_DIR}/swift)
 target_link_libraries(swiftDispatch PRIVATE
-  DispatchStubs
+  $<$<BOOL:${HAVE_OBJC}>:DispatchStubs>
   BlocksRuntime::BlocksRuntime)
 target_link_libraries(swiftDispatch PUBLIC
   dispatch)
@@ -36,6 +38,7 @@ if(NOT DARWIN AND NOT WIN32)
   set_target_properties(swiftDispatch PROPERTIES INSTALL_RPATH "$ORIGIN")
 endif()
 
+set_property(GLOBAL APPEND PROPERTY DISPATCH_EXPORTS swiftDispatch)
 install(TARGETS swiftDispatch
   EXPORT dispatchExports
   ARCHIVE DESTINATION "${Dispatch_INSTALL_LIBDIR}"
@@ -53,11 +56,10 @@ INSTALL(FILES $<TARGET_PROPERTY:swiftDispatch,Swift_MODULE_DIRECTORY>/$<TARGET_P
 INSTALL(FILES $<TARGET_PROPERTY:swiftDispatch,Swift_MODULE_DIRECTORY>/$<TARGET_PROPERTY:swiftDispatch,Swift_MODULE_NAME>.swiftsourceinfo
   DESTINATION ${Dispatch_INSTALL_SWIFTMODULEDIR}/$<TARGET_PROPERTY:swiftDispatch,Swift_MODULE_NAME>.swiftmodule
   RENAME ${Dispatch_MODULE_TRIPLE}.swiftsourceinfo)
-if(NOT BUILD_SHARED_LIBS)
+
+if(NOT BUILD_SHARED_LIBS AND HAVE_OBJC)
   set_property(GLOBAL APPEND PROPERTY DISPATCH_EXPORTS DispatchStubs)
   install(TARGETS DispatchStubs
     EXPORT dispatchExports
     DESTINATION ${Dispatch_INSTALL_LIBDIR})
 endif()
-
-set_property(GLOBAL APPEND PROPERTY DISPATCH_EXPORTS swiftDispatch)