Ensure crosscompiling with make works in Mac OS X
diff --git a/library/Makefile b/library/Makefile
index b1ef8d3..857e977 100644
--- a/library/Makefile
+++ b/library/Makefile
@@ -37,27 +37,29 @@
 SOEXT_X509=so.0
 SOEXT_CRYPTO=so.2
 
-DLEXT ?= so
-
 # Set AR_DASH= (empty string) to use an ar implentation that does not accept
 # the - prefix for command line options (e.g. llvm-ar)
 AR_DASH ?= -
 
+ARFLAGS = $(AR_DASH)src
 ifdef APPLE_BUILD
+ifneq ($(APPLE_BUILD),0)
 ARFLAGS = $(AR_DASH)Src
 RLFLAGS = -no_warning_for_no_symbols -c
 RL ?= ranlib
-else
-ARFLAGS = $(AR_DASH)src
+endif
 endif
 
+DLEXT ?= so
 ifdef WINDOWS_BUILD
 # Windows shared library extension:
 DLEXT = dll
 else ifdef APPLE_BUILD
+ifneq ($(APPLE_BUILD),0)
 # Mac OS X shared library extension:
 DLEXT = dylib
 endif
+endif
 
 OBJS_CRYPTO=	aes.o		aesni.o		arc4.o		\
 		asn1parse.o	asn1write.o	base64.o	\
@@ -109,9 +111,11 @@
 	echo "  AR    $@"
 	$(AR) $(ARFLAGS) $@ $(OBJS_TLS)
 ifdef APPLE_BUILD
+ifneq ($(APPLE_BUILD),0)
 	echo "  RL    $@"
 	$(RL) $(RLFLAGS) $@
 endif
+endif
 
 libmbedtls.$(SOEXT_TLS): $(OBJS_TLS) libmbedx509.so
 	echo "  LD    $@"
@@ -134,9 +138,11 @@
 	echo "  AR    $@"
 	$(AR) $(ARFLAGS) $@ $(OBJS_X509)
 ifdef APPLE_BUILD
+ifneq ($(APPLE_BUILD),0)
 	echo "  RL    $@"
 	$(RL) $(RLFLAGS) $@
 endif
+endif
 
 libmbedx509.$(SOEXT_X509): $(OBJS_X509) libmbedcrypto.so
 	echo "  LD    $@"
@@ -159,9 +165,11 @@
 	echo "  AR    $@"
 	$(AR) $(ARFLAGS) $@ $(OBJS_CRYPTO)
 ifdef APPLE_BUILD
+ifneq ($(APPLE_BUILD),0)
 	echo "  RL    $@"
 	$(RL) $(RLFLAGS) $@
 endif
+endif
 
 libmbedcrypto.$(SOEXT_CRYPTO): $(OBJS_CRYPTO)
 	echo "  LD    $@"