--- libmalloc/libmalloc-409.81.2/xcodeconfig/libmalloc.xcconfig
+++ libmalloc/libmalloc-317.121.1/xcodeconfig/libmalloc.xcconfig
@@ -24,11 +24,9 @@
 SYSTEM_HEADER_SEARCH_PATHS = $(SYSTEM_FRAMEWORK_HEADERS) $(SDKROOT)/$(SDK_INSTALL_HEADERS_ROOT)/usr/local/include $(SDKROOT)/$(SDK_INSTALL_HEADERS_ROOT)/usr/include
 SYSTEM_FRAMEWORK_SEARCH_PATHS = $(SDKROOT)/$(SDK_INSTALL_HEADERS_ROOT)/System/Library/Frameworks
 
-GCC_PREPROCESSOR_DEFINITIONS = _FORTIFY_SOURCE=0 NDEBUG $(OSATOMIC_PREPROCESSOR_DEFINITIONS) $(PLATFORM_PREPROCESSOR_DEFINITIONS) $(DRIVERKIT_PREPROCESSOR_DEFINITIONS)
+GCC_PREPROCESSOR_DEFINITIONS = _FORTIFY_SOURCE=0 NDEBUG $(OSATOMIC_PREPROCESSOR_DEFINITIONS) $(PLATFORM_PREPROCESSOR_DEFINITIONS)
 OSATOMIC_PREPROCESSOR_DEFINITIONS = OSATOMIC_USE_INLINED=1 OS_UNFAIR_LOCK_INLINE=1
 OSATOMIC_PREPROCESSOR_DEFINITIONS_NOINLINE = OSATOMIC_DEPRECATED=0 OSATOMIC_USE_INLINED=0 OS_UNFAIR_LOCK_INLINE=0
-DRIVERKIT_PREPROCESSOR_DEFINITIONS = MALLOC_TARGET_DK_OSX=0
-DRIVERKIT_PREPROCESSOR_DEFINITIONS[sdk=driverkit.macosx*] = MALLOC_TARGET_DK_OSX=1
 
 GCC_NO_COMMON_BLOCKS = YES
 ENABLE_STRICT_OBJC_MSGSEND = YES
@@ -91,8 +89,29 @@
 
 INTERPOSE_LDFLAGS = -Wl,-interposable_list,$(SRCROOT)/xcodeconfig/interposable.list
 
+ORDER_FILE = $(SDKROOT)/$(APPLE_INTERNAL_DIR)/OrderFiles/$(PRODUCT_NAME).order
+ORDER_FILE[sdk=*simulator*] =
+ORDER_FILE[sdk=driverkit*] =
+
 DYLIB_CURRENT_VERSION = $(CURRENT_PROJECT_VERSION)
 
+// #ifndef __OPEN_SOURCE__
+CR_LDFLAGS = -lCrashReporterClient
+// on architectures with OSAtomic & os_unfair_lock dyld resolvers we cannot
+// inline and need to callout to libplatform symbols rdar://problem/30155088
+OSATOMIC_PREPROCESSOR_DEFINITIONS[arch=armv7] = $(OSATOMIC_PREPROCESSOR_DEFINITIONS_NOINLINE)
+OSATOMIC_PREPROCESSOR_DEFINITIONS[arch=armv7k] = $(OSATOMIC_PREPROCESSOR_DEFINITIONS_NOINLINE)
+OSATOMIC_PREPROCESSOR_DEFINITIONS[arch=arm64] = $(OSATOMIC_PREPROCESSOR_DEFINITIONS_NOINLINE)
+ARMV81_CFLAGS = -mcpu=monsoon
+
+MALLOC_RESOLVER_SOURCE_FILE_NAMES				= resolver.c
+
+COPY_HEADERS_RUN_UNIFDEF = YES
+COPY_HEADERS_UNIFDEF_FLAGS = $(COPY_HEADERS_UNIFDEF_FLAGS_$(RC_HIDE_HARDWARE_FALL_2018_IOS))
+COPY_HEADERS_UNIFDEF_FLAGS_ = -URC_HIDE_HARDWARE_FALL_2018_IOS
+COPY_HEADERS_UNIFDEF_FLAGS_1 = -DRC_HIDE_HARDWARE_FALL_2018_IOS
+
+// #endif __OPEN_SOURCE__
 
 SUPPORTS_TEXT_BASED_API = YES
 TAPI_VERIFY_MODE = Pedantic