This is xnu-8019. See this file in:
# -*- mode: makefile;-*-
#
# Copyright (C) 2021 Apple Inc. All rights reserved.
#
# MakeInc.san contains global definitions for building,
# linking and installing sanitizer runtime support.
#

#
# Generates rule to build symbolset file from specific export file.
#
#     $(1) - Kext name (without .symbolset suffix)
#     $(2) - Exports name (without .exports suffix)

define san_symbolset_template

SYMBOL_SET_BUILD_$(1) := $$(OBJPATH)/config/$(1).symbolset

# Our external dependency on config/allsymbols from config hierarchy config_all is hardcoded in the toplevel Makefile!
$$(SYMBOL_SET_BUILD_$(1)): $$(SRCROOT)/config/$(2).exports $$(OBJPATH)/config/allsymbols $$(KEXT_CREATE_SYMBOL_SET)
	@$$(LOG_SYMBOLSET) "$(1)$$(Color0) ($$(ColorLF)$$(CURRENT_ARCH_CONFIG_LC), $$(CURRENT_KERNEL_CONFIG_LC) $$(Color0))"
	$$(_v)$$(KEXT_CREATE_SYMBOL_SET)			\
		$$(ARCH_FLAGS_$$(CURRENT_ARCH_CONFIG))	\
		-import $$(OBJPATH)/config/allsymbols		\
		-export $$<		                \
		-output $$@ $(_vstdout)

endef

#
# Generate rule to build System.kext plugin for give sanitizer.
#
#     $(1) - Name of the kext plugin
#     $(2) - Name of the kext variant binary (Kasan_kasan, Kcov, ...)
#

define san_kext_dstroot_rule_template

DSTROOT_KEXT_$(2) := $$(DSTROOT_SYSTEM_KEXT_PATH)/$(1)/$(2)

$$(DSTROOT_KEXT_$(2)): $$(DSTROOT_SYSTEM_KEXT_PATH)/$(1)/% : $$(SYMROOT_SYSTEM_KEXT_PATH)/$(1)/%
	$$(_v)$$(MKDIR) $$(@D)
	@$$(LOG_INSTALLVARIANT) "$$(Color0)symbolset $$(ColorF)$$(@F)$$(Color0) ($$(ColorLF)$$(CURRENT_KERNEL_CONFIG_LC)$$(Color0))"
	$$(_v)$$(INSTALL) $$(EXEC_INSTALL_FLAGS) $$< $$@

endef

#
# Generate rule to build System.kext plugin in SYMROOT
#
#     $(1) - Name of the kext plugin
#     $(2) - Name of the kext variant binary (Kasan_kasan, Kcov, ...)
#     $(3) - build configs to get symbolset binaries from corresponding OBJDIR
#

define san_kext_symroot_rule_template

SYMROOT_KEXT_$(2) := $$(SYMROOT_SYSTEM_KEXT_PATH)/$(1)/$(2)

$$(SYMROOT_KEXT_$(2)): $$(addsuffix /config/$(2).symbolset, \
		$$(addprefix $$(OBJROOT)/,$$(foreach bc,$(3),$$(call function_convert_build_config_to_objdir,$$(bc)))))
	@$$(LOG_INSTALLSYM) "$$(Color0)symbolset $$(ColorF)$(2)$$(Color0) ($$(ColorLF)$$(CURRENT_KERNEL_CONFIG_LC)$$(Color0))"
	$$(_v)$$(MKDIR) $$(@D)
	$$(_v)$$(LIPO) -create `(echo $$^ | xargs -L 1 lipo -detailed_info) | \
		awk '/is architecture/ {s[$$$$6]=$$$$3} END {for (a in s) {print s[a]}}'` -output $$@ $$(_vstdout)

endef