--- Makefile.orig	2020-04-08 07:26:52 UTC
+++ Makefile
@@ -3,9 +3,11 @@ DIR_SRC := ./src
 DIR_OBJ := ./obj
 
 PREFIX ?= /usr/local
+DESTDIR ?=
 BINDIR ?= $(PREFIX)/bin
 INCLUDE_DIRS ?=
 LIBRARY_DIRS ?=
+STRIP_CMD ?= strip
 
 SRC := $(wildcard ${DIR_SRC}/*.cpp)
 OBJ := $(patsubst %.cpp,${DIR_OBJ}/%.o,$(notdir ${SRC}))
@@ -15,13 +17,14 @@ TARGET := fastp
 BIN_TARGET := ${TARGET}
 
 CXX ?= g++
-CXXFLAGS := -std=c++11 -g -O3 -I${DIR_INC} $(foreach includedir,$(INCLUDE_DIRS),-I$(includedir)) ${CXXFLAGS}
+CXXFLAGS ?= -g -O3
+CXXFLAGS += -std=c++11 -I${DIR_INC} $(foreach includedir,$(INCLUDE_DIRS),-I$(includedir))
 LIBS := -lz -lpthread
-LD_FLAGS := $(foreach librarydir,$(LIBRARY_DIRS),-L$(librarydir)) $(LIBS) $(LD_FLAGS)
+LDFLAGS += $(foreach librarydir,$(LIBRARY_DIRS),-L$(librarydir)) $(LIBS)
 
 
 ${BIN_TARGET}:${OBJ}
-	$(CXX) $(OBJ) -o $@ $(LD_FLAGS)
+	$(CXX) $(OBJ) -o $@ $(LDFLAGS)
 
 ${DIR_OBJ}/%.o:${DIR_SRC}/%.cpp make_obj_dir
 	$(CXX) -c $< -o $@ $(CXXFLAGS)
@@ -38,5 +41,8 @@ make_obj_dir:
 	fi
 
 install:
-	install $(TARGET) $(BINDIR)/$(TARGET)
+	install $(TARGET) $(DESTDIR)$(BINDIR)/$(TARGET)
 	@echo "Installed."
+
+install-strip: install
+	$(STRIP_CMD) $(DESTDIR)$(BINDIR)/$(TARGET)