Core: specify the threading package that is in use

This is required for the non-Darwin targets as `SWIFT_THREADING_DARWIN`
does not enable any additional code. However, that macro is used in
other places that are not yet integrated. This was identified by
building for Windows.

Author: compnerd

Runtimes/Core/CMakeLists.txt

@@ -100,6 +100,7 @@ option(SwiftCore_ENABLE_RUNTIME_LEAK_CHECKER "" OFF)
 option(SwiftCore_ENABLE_INTERNAL_CHECKS "" OFF)
 
 defaulted_set(SwiftCore_OBJECT_FORMAT STRING "Object format: ELF COFF")
+defaulted_set(SwiftCore_THREADING_PACKAGE STRING "Threading Package: C11 Linux PThreads Win32")
 
 # TODO: Most of these should be attached to specific targets rather than applied
 #       globally. They can be applied as part of the library interface if they
@@ -118,6 +119,7 @@ add_compile_definitions(
   $<$<BOOL:${SwiftCore_ENABLE_UNICODE_DATA}>:-DSWIFT_STDLIB_ENABLE_UNICODE_DATA> # Stubs
   $<$<BOOL:${SwiftCore_ENABLE_ENVIRONMENT}>:-DSWIFT_STDLIB_HAS_ENVIRON> # Concurrency, runtime, shims, platform overlay
   $<$<BOOL:${SwiftCore_ENABLE_BACKDEPLOYMENT_SUPPORT}>:-DSWIFT_STDLIB_SUPPORT_BACK_DEPLOYMENT> # Concurrency, Compatibility override, magic symbols
+  $<$<COMPILE_LANGUAGE:C,CXX>:-DSWIFT_THREADING_${SwiftCore_THREADING_PACKAGE}>
   $<$<COMPILE_LANGUAGE:C,CXX>:-DSWIFT_RUNTIME_ENABLE_LEAK_CHECKER=$<BOOL:${SwiftCore_ENABLE_RUNTIME_LEAK_CHECKER}>>
   $<$<COMPILE_LANGUAGE:C,CXX>:-DSWIFT_RUNTIME_CLOBBER_FREED_OBJECTS=$<BOOL:${SwiftCore_ENABLE_CLOBBER_FREED_OBJECTS}>>)
 

Runtimes/Core/cmake/modules/DefaultSettings.cmake

@@ -39,12 +39,20 @@ if(APPLE)
   set(SwiftCore_ENABLE_REFLECTION_default ON)
   set(SwiftCore_ENABLE_RUNTIME_OS_VERSIONING ON)
   set(SwiftCore_ENABLE_OVERRIDABLE_RETAIN_RELEASE ON)
+  set(SwiftCore_THREADING_PACKAGE "DARWIN")
 elseif(CMAKE_SYSTEM_NAME STREQUAL "WASM")
   set(SwiftCore_OBJECT_FORMAT_default "elf")
+  set(SwiftCore_THREADING_PACKAGE "NONE")
 elseif(LINUX OR ANDROID OR BSD)
   set(SwiftCore_OBJECT_FORMAT_default "elf")
+  if(LINUX)
+    set(SwiftCore_THREADING_PACKAGE "LINUX")
+  else()
+    set(SwiftCore_THREADING_PACKAGE "PTHREADS")
+  endif()
 elseif(WIN32)
   set(SwiftCore_OBJECT_FORMAT_default "coff")
+  set(SwiftCore_THREADING_PACKAGE "WIN32")
 endif()
 
 include("${SwiftCore_VENDOR_MODULE_DIR}/DefaultSettings.cmake" OPTIONAL)