Allow users to customize CXX, CXXFLAGS, and LDFLAGS normally

src/makefile.unix

@@ -2,8 +2,6 @@
 # Distributed under the MIT/X11 software license, see the accompanying
 # file license.txt or http://www.opensource.org/licenses/mit-license.php.
 
-CXX=g++
-
 USE_UPNP:=0
 
 DEFS=-DNOPCH
@@ -80,7 +78,8 @@ LIBS+= \
 
 
 DEBUGFLAGS=-g
-CXXFLAGS=-O2 -Wno-invalid-offsetof -Wformat $(DEBUGFLAGS) $(DEFS) $(HARDENING)
+CXXFLAGS=-O2
+xCXXFLAGS=-pthread -Wno-invalid-offsetof -Wformat $(DEBUGFLAGS) $(DEFS) $(HARDENING) $(CXXFLAGS)
 HEADERS = \
     base58.h \
     bignum.h \
@@ -125,24 +124,24 @@ all: bitcoind
 -include obj/test/*.P
 
 obj/nogui/%.o: %.cpp
-	$(CXX) -c $(CXXFLAGS) -MMD -o $@ $<
+	$(CXX) -c $(xCXXFLAGS) -MMD -o $@ $<
 	@cp $(@:%.o=%.d) $(@:%.o=%.P); \
 	  sed -e 's/#.*//' -e 's/^[^:]*: *//' -e 's/ *\\$$//' \
 	      -e '/^$$/ d' -e 's/$$/ :/' < $(@:%.o=%.d) >> $(@:%.o=%.P); \
 	  rm -f $(@:%.o=%.d)
 
 bitcoind: $(OBJS:obj/%=obj/nogui/%)
-	$(CXX) $(CXXFLAGS) -o $@ $^ $(LIBS)
+	$(CXX) $(xCXXFLAGS) -o $@ $^ $(LDFLAGS) $(LIBS)
 
 obj/test/%.o: test/%.cpp
-	$(CXX) -c $(CXXFLAGS) -MMD -o $@ $<
+	$(CXX) -c $(xCXXFLAGS) -MMD -o $@ $<
 	@cp $(@:%.o=%.d) $(@:%.o=%.P); \
 	  sed -e 's/#.*//' -e 's/^[^:]*: *//' -e 's/ *\\$$//' \
 	      -e '/^$$/ d' -e 's/$$/ :/' < $(@:%.o=%.d) >> $(@:%.o=%.P); \
 	  rm -f $(@:%.o=%.d)
 
 test_bitcoin: obj/test/test_bitcoin.o $(filter-out obj/nogui/init.o,$(OBJS:obj/%=obj/nogui/%))
-	$(CXX) $(CXXFLAGS) -o $@ $(LIBPATHS) $^ -Wl,-Bstatic -lboost_unit_test_framework $(LIBS)
+	$(CXX) $(xCXXFLAGS) -o $@ $(LIBPATHS) $^ -Wl,-Bstatic -lboost_unit_test_framework $(LDFLAGS) $(LIBS)
 
 clean:
 	-rm -f bitcoind test_bitcoin