-OBJROOT?=$(shell /bin/pwd)
-
-SDKROOT ?= macosx.internal
-
-# SDKROOT may be passed as a shorthand like "iphoneos.internal". We
-# must resolve these to a full path and override SDKROOT.
-
-SDKROOT_RESOLVED := $(shell xcrun -sdk $(SDKROOT) -show-sdk-path)
-ifeq ($(strip $(SDKROOT)_$(SDKROOT_RESOLVED)),/_)
-SDKROOT_RESOLVED := /
+ifndef SRCROOT
+export SRCROOT := $(shell /bin/pwd)
+endif
+ifndef OBJROOT
+export OBJROOT = $(SRCROOT)/BUILD/obj
+endif
+ifndef DSTROOT
+export DSTROOT = $(SRCROOT)/BUILD/dst
+endif
+ifndef SYMROOT
+export SYMROOT = $(SRCROOT)/BUILD/sym