Only define _XOPEN_SOURCE in configurecompiler.cmake (for consistency) (

#110092)

* Only define _XOPEN_SOURCE in configurecompiler.cmake (for consistency)

* Apply _DARWIN_C_SOURCE universally for all Apple platforms

eng/native/configurecompiler.cmake

@@ -301,14 +301,19 @@ elseif(CLR_CMAKE_HOST_SUNOS)
   set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fstack-protector")
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fstack-protector")
   add_definitions(-D__EXTENSIONS__ -D_XPG4_2 -D_POSIX_PTHREAD_SEMANTICS -D_REENTRANT)
-elseif(CLR_CMAKE_HOST_OSX AND NOT CLR_CMAKE_HOST_MACCATALYST AND NOT CLR_CMAKE_HOST_IOS AND NOT CLR_CMAKE_HOST_TVOS)
+elseif(CLR_CMAKE_HOST_APPLE)
+  # enable support for X/Open and POSIX APIs, like the <ucontext.h> header file
   add_definitions(-D_XOPEN_SOURCE)
-
-  # the new linker in Xcode 15 (ld_new/ld_prime) deprecated the -bind_at_load flag for macOS which causes a warning
-  # that fails the build since we build with -Werror. Only pass the flag if we need it, i.e. older linkers.
-  check_linker_flag(C "-Wl,-bind_at_load,-fatal_warnings" LINKER_SUPPORTS_BIND_AT_LOAD_FLAG)
-  if(LINKER_SUPPORTS_BIND_AT_LOAD_FLAG)
-    add_linker_flag("-Wl,-bind_at_load")
+  # enable support for Darwin extension APIs, like pthread_getthreadid_np
+  add_definitions(-D_DARWIN_C_SOURCE)
+
+  if(CLR_CMAKE_HOST_OSX)
+    # the new linker in Xcode 15 (ld_new/ld_prime) deprecated the -bind_at_load flag for macOS which causes a warning
+    # that fails the build since we build with -Werror. Only pass the flag if we need it, i.e. older linkers.
+    check_linker_flag(C "-Wl,-bind_at_load,-fatal_warnings" LINKER_SUPPORTS_BIND_AT_LOAD_FLAG)
+    if(LINKER_SUPPORTS_BIND_AT_LOAD_FLAG)
+      add_linker_flag("-Wl,-bind_at_load")
+    endif()
   endif()
 elseif(CLR_CMAKE_HOST_HAIKU)
   add_compile_options($<$<COMPILE_LANGUAGE:ASM>:-Wa,--noexecstack>)

src/coreclr/nativeaot/CMakeLists.txt

@@ -20,7 +20,6 @@ if(CLR_CMAKE_HOST_UNIX)
   add_compile_options(-nostdlib)
 
   if(CLR_CMAKE_TARGET_APPLE)
-    add_definitions(-D_XOPEN_SOURCE)
     add_definitions(-DFEATURE_OBJCMARSHAL)
   endif(CLR_CMAKE_TARGET_APPLE)
 

src/native/libs/System.Native/CMakeLists.txt

@@ -4,10 +4,6 @@ if (NOT CLR_CMAKE_TARGET_MACCATALYST AND NOT CLR_CMAKE_TARGET_IOS AND NOT CLR_CM
     add_definitions(-DHAS_CONSOLE_SIGNALS)
 endif ()
 
-if (CLR_CMAKE_TARGET_OSX)
-    add_definitions(-D_DARWIN_C_SOURCE)
-endif ()
-
 set(NATIVE_SOURCES
     pal_errno.c
     pal_interfaceaddresses.c