minor native Makefile cleanup

com.oracle.truffle.r.native/Makefile

@@ -21,13 +21,12 @@
 # questions.
 #
 
-# If GNUR_HOME is defined we take that as a pre-built, immutable, entity
-
 .PHONY: all clean 
 
 export TOPDIR = $(CURDIR)
 export FASTR_R_HOME=$(abspath $(TOPDIR)/..)
 export FASTR_LIB_DIR=$(FASTR_R_HOME)/lib
+export FASTR_NATIVE_DIR = $(TOPDIR)
 export R_VERSION = 3.1.3
 export GNUR_HOME = $(TOPDIR)/gnur/R-$(R_VERSION)
 

com.oracle.truffle.r.native/fficall/src/common/Makefile

@@ -24,7 +24,7 @@
 # This builds the GNUR files that are compiled directly, and local overrides
 
 ifneq ($(MAKECMDGOALS),clean)
-include $(TOPDIR)/platform.mk
+include $(FASTR_NATIVE_DIR)/platform.mk
 endif
 
 .PHONY: all clean
@@ -50,7 +50,7 @@ F_SOURCES = $(wildcard *.f)
 F_OBJECTS := $(patsubst %.f,$(OBJ)/%.o,$(F_SOURCES))
 
 JNI_INCLUDES = -I $(JAVA_HOME)/include -I $(JAVA_HOME)/include/$(JDK_OS_DIR)
-FFI_INCLUDES = -I$(TOPDIR)/include -I$(TOPDIR)/include/R_ext
+FFI_INCLUDES = -I$(FASTR_NATIVE_DIR)/include -I$(FASTR_NATIVE_DIR)/include/R_ext
 INCLUDES := -I $(abspath ../include) $(JNI_INCLUDES) $(FFI_INCLUDES)
 
 include ../include/gnurheaders.mk
@@ -81,7 +81,7 @@ $(OBJ)/%.o: $(GNUR_APPL_SRC)/%.c
 $(OBJ)/%.o: $(GNUR_MAIN_SRC)/%.c
 	$(CC) $(CFLAGS) $(INCLUDES) $(GNUR_HEADER_DEFS) $(SUPPRESS_WARNINGS) -c $< -o $@
 
-$(OBJ)/%.o: %.c $(TOPDIR)/include/Rinternals.h
+$(OBJ)/%.o: %.c $(FASTR_NATIVE_DIR)/include/Rinternals.h
 	$(CC) $(CFLAGS) $(INCLUDES) $(GNUR_HEADER_DEFS) $(SUPPRESS_WARNINGS) -c $< -o $@
 
 $(OBJ)/%.o: %.f