diff --git a/makefile b/makefile
index b35cdea..5dba41c 100644
--- a/makefile
+++ b/makefile
@@ -1,4 +1,12 @@
 STD=c++17
+OS := $(shell uname)
+ifeq ($(OS), Darwin)
+	CXXFLAGS=-std=$(STD) -c -O3 -fno-exceptions -fPIC -stdlib=libc++ -static-libstdc++ -l:libc++abi.a -static-libgcc
+else
+	CXXFLAGS=-std=$(STD) -c -O3 -fno-exceptions -fPIC
+endif
+CPPFLAGS=-I .
+
 
 NASAL_HEADER=\
 	src/ast_dumper.h\
@@ -53,15 +61,14 @@ NASAL_OBJECT=\
 	build/repl.o\
 	build/main.o
 
-OS := $(shell uname)
 
 # for test
 nasal: $(NASAL_OBJECT) | build
 	@if [ OS = "Darwin" ]; then\
-        $(CXX) $(NASAL_OBJECT) -O3 -o nasal -ldl -lpthread -static -lstdc++;\
+		$(CXX) $(NASAL_OBJECT) -O3 -o nasal -ldl -lpthread -stdlib=libc++ -static-libstdc++;\
 	else\
-	    $(CXX) $(NASAL_OBJECT) -O3 -o nasal -ldl -lpthread;\
-    fi
+		$(CXX) $(NASAL_OBJECT) -O3 -o nasal -ldl -lpthread;\
+	fi
 
 nasal.exe: $(NASAL_OBJECT) | build
 	$(CXX) $(NASAL_OBJECT) -O3 -o nasal.exe
@@ -70,39 +77,19 @@ build:
 	@ if [ ! -d build ]; then mkdir build; fi
 
 build/main.o: $(NASAL_HEADER) src/main.cpp | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/main.cpp -fno-exceptions -fPIC -o build/main.o -I -static -lstdc++ .;\
-	else\
-	    $(CXX) -std=$(STD) -c -O3 src/main.cpp -fno-exceptions -fPIC -o build/main.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/main.cpp -o build/main.o
 
 build/nasal_misc.o: src/nasal.h src/nasal_misc.cpp | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/nasal_misc.cpp -fno-exceptions -fPIC -o build/nasal_misc.o -I -static -lstdc++ .;\
-	else\
-	    $(CXX) -std=$(STD) -c -O3 src/nasal_misc.cpp -fno-exceptions -fPIC -o build/nasal_misc.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/nasal_misc.cpp -o build/nasal_misc.o
 
 build/repl.o: src/nasal.h src/repl.h src/repl.cpp | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/repl.cpp -fno-exceptions -fPIC -o build/repl.o -I -static -lstdc++ .;\
-	else\
-	    $(CXX) -std=$(STD) -c -O3 src/repl.cpp -fno-exceptions -fPIC -o build/repl.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/repl.cpp -o build/repl.o
 
 build/nasal_err.o: src/nasal.h src/repl.h src/nasal_err.h src/nasal_err.cpp | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/nasal_err.cpp -fno-exceptions -fPIC -o build/nasal_err.o -I -static -lstdc++ .;\
-	else\
-	    $(CXX) -std=$(STD) -c -O3 src/nasal_err.cpp -fno-exceptions -fPIC -o build/nasal_err.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/nasal_err.cpp -o build/nasal_err.o
 
 build/nasal_gc.o: src/nasal.h src/nasal_gc.h src/nasal_gc.cpp | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/nasal_gc.cpp -fno-exceptions -fPIC -o build/nasal_gc.o -I -static -lstdc++ .;\
-	else\
-	    $(CXX) -std=$(STD) -c -O3 src/nasal_gc.cpp -fno-exceptions -fPIC -o build/nasal_gc.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/nasal_gc.cpp -o build/nasal_gc.o
 
 build/nasal_import.o: \
 	src/nasal.h\
@@ -110,130 +97,78 @@ build/nasal_import.o: \
 	src/nasal_lexer.h\
 	src/nasal_parse.h\
 	src/nasal_import.h src/nasal_import.cpp | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/nasal_import.cpp -fno-exceptions -fPIC -o build/nasal_import.o -I -static -lstdc++ .;\
-	else\
-	    $(CXX) -std=$(STD) -c -O3 src/nasal_import.cpp -fno-exceptions -fPIC -o build/nasal_import.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/nasal_import.cpp -o build/nasal_import.o
 
 build/nasal_lexer.o: \
 	src/nasal.h\
 	src/repl.h\
 	src/nasal_err.h\
 	src/nasal_lexer.h src/nasal_lexer.cpp | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/nasal_lexer.cpp -fno-exceptions -fPIC -o build/nasal_lexer.o -I -static -lstdc++ .;\
-	else\
-	    $(CXX) -std=$(STD) -c -O3 src/nasal_lexer.cpp -fno-exceptions -fPIC -o build/nasal_lexer.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/nasal_lexer.cpp -o build/nasal_lexer.o
 
 build/nasal_ast.o: \
 	src/nasal.h\
 	src/nasal_err.h\
 	src/nasal_ast.h src/nasal_ast.cpp | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/nasal_ast.cpp -fno-exceptions -fPIC -o build/nasal_ast.o -I -static -lstdc++ .;\
-	else\
-	    $(CXX) -std=$(STD) -c -O3 src/nasal_ast.cpp -fno-exceptions -fPIC -o build/nasal_ast.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/nasal_ast.cpp -o build/nasal_ast.o
 
 build/nasal_builtin.o: \
 	src/nasal.h\
 	src/nasal_gc.h\
 	src/nasal_builtin.h src/nasal_builtin.cpp | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/nasal_builtin.cpp -fno-exceptions -fPIC -o build/nasal_builtin.o -I -static -lstdc++ .;\
-	else\
-	    $(CXX) -std=$(STD) -c -O3 src/nasal_builtin.cpp -fno-exceptions -fPIC -o build/nasal_builtin.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/nasal_builtin.cpp -o build/nasal_builtin.o
 
 build/coroutine.o: \
 	src/nasal.h\
 	src/nasal_gc.h\
 	src/coroutine.h src/coroutine.cpp | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/coroutine.cpp -fno-exceptions -fPIC -o build/coroutine.o -I -static -lstdc++ .;\
-	else\
-        $(CXX) -std=$(STD) -c -O3 src/coroutine.cpp -fno-exceptions -fPIC -o build/coroutine.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/coroutine.cpp -o build/coroutine.o
 
 build/bits_lib.o: \
 	src/nasal.h\
 	src/nasal_gc.h\
 	src/bits_lib.h src/bits_lib.cpp | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/bits_lib.cpp -fno-exceptions -fPIC -o build/bits_lib.o -I -static -lstdc++ .;\
-	else\
-        $(CXX) -std=$(STD) -c -O3 src/bits_lib.cpp -fno-exceptions -fPIC -o build/bits_lib.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/bits_lib.cpp -o build/bits_lib.o
 
 
 build/math_lib.o: \
 	src/nasal.h\
 	src/nasal_gc.h\
 	src/math_lib.h src/math_lib.cpp | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/math_lib.cpp -fno-exceptions -fPIC -o build/math_lib.o -I -static -lstdc++ .;\
-	else\
-	    $(CXX) -std=$(STD) -c -O3 src/math_lib.cpp -fno-exceptions -fPIC -o build/math_lib.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/math_lib.cpp -o build/math_lib.o
 
 build/io_lib.o: \
 	src/nasal.h\
 	src/nasal_gc.h\
 	src/io_lib.h src/io_lib.cpp | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/io_lib.cpp -fno-exceptions -fPIC -o build/io_lib.o -I -static -lstdc++ .;\
-	else\
-	    $(CXX) -std=$(STD) -c -O3 src/io_lib.cpp -fno-exceptions -fPIC -o build/io_lib.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/io_lib.cpp -o build/io_lib.o
 
 build/dylib_lib.o: \
 	src/nasal.h\
 	src/nasal_gc.h\
 	src/dylib_lib.h src/dylib_lib.cpp | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/dylib_lib.cpp -fno-exceptions -fPIC -o build/dylib_lib.o -I -static -lstdc++ .;\
-	else\
-	    $(CXX) -std=$(STD) -c -O3 src/dylib_lib.cpp -fno-exceptions -fPIC -o build/dylib_lib.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/dylib_lib.cpp -o build/dylib_lib.o
 
 build/unix_lib.o: \
 	src/nasal.h\
 	src/nasal_gc.h\
 	src/unix_lib.h src/unix_lib.cpp | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/unix_lib.cpp -fno-exceptions -fPIC -o build/unix_lib.o -I -static -lstdc++ .;\
-	else\
-	    $(CXX) -std=$(STD) -c -O3 src/unix_lib.cpp -fno-exceptions -fPIC -o build/unix_lib.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/unix_lib.cpp -o build/unix_lib.o
 
 build/fg_props.o: \
 	src/nasal.h\
 	src/nasal_gc.h\
 	src/fg_props.h src/fg_props.cpp | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/fg_props.cpp -fno-exceptions -fPIC -o build/fg_props.o -I -static -lstdc++ .;\
-	else\
-	    $(CXX) -std=$(STD) -c -O3 src/fg_props.cpp -fno-exceptions -fPIC -o build/fg_props.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/fg_props.cpp -o build/fg_props.o
 
 build/nasal_codegen.o: $(NASAL_HEADER) src/nasal_codegen.h src/nasal_codegen.cpp | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/nasal_codegen.cpp -fno-exceptions -fPIC -o build/nasal_codegen.o -I -static -lstdc++ .;\
-	else\
-	    $(CXX) -std=$(STD) -c -O3 src/nasal_codegen.cpp -fno-exceptions -fPIC -o build/nasal_codegen.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/nasal_codegen.cpp -o build/nasal_codegen.o
 
 build/nasal_opcode.o: \
 	src/nasal.h\
 	src/nasal_builtin.h\
 	src/nasal_opcode.h src/nasal_opcode.cpp | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/nasal_opcode.cpp -fno-exceptions -fPIC -o build/nasal_opcode.o -I -static -lstdc++ .;\
-	else\
-	    $(CXX) -std=$(STD) -c -O3 src/nasal_opcode.cpp -fno-exceptions -fPIC -o build/nasal_opcode.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/nasal_opcode.cpp -o build/nasal_opcode.o
 
 build/nasal_parse.o: \
 	src/nasal.h\
@@ -241,11 +176,7 @@ build/nasal_parse.o: \
 	src/nasal_lexer.h\
 	src/nasal_err.h\
 	src/nasal_parse.h src/nasal_parse.cpp src/nasal_ast.h | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/nasal_parse.cpp -fno-exceptions -fPIC -o build/nasal_parse.o -I -static -lstdc++ .;\
-	else\
-	    $(CXX) -std=$(STD) -c -O3 src/nasal_parse.cpp -fno-exceptions -fPIC -o build/nasal_parse.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/nasal_parse.cpp -o build/nasal_parse.o
 
 build/optimizer.o: \
 	src/nasal.h\
@@ -253,11 +184,7 @@ build/optimizer.o: \
 	src/nasal_ast.h\
 	src/ast_visitor.h\
 	src/optimizer.h src/optimizer.cpp src/nasal_ast.h | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/optimizer.cpp -fno-exceptions -fPIC -o build/optimizer.o -I -static -lstdc++ .;\
-	else\
-	    $(CXX) -std=$(STD) -c -O3 src/optimizer.cpp -fno-exceptions -fPIC -o build/optimizer.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/optimizer.cpp -o build/optimizer.o
 
 build/symbol_finder.o: \
 	src/nasal.h\
@@ -265,22 +192,14 @@ build/symbol_finder.o: \
 	src/nasal_ast.h\
 	src/ast_visitor.h\
 	src/symbol_finder.h src/symbol_finder.cpp src/nasal_ast.h | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/symbol_finder.cpp -fno-exceptions -fPIC -o build/symbol_finder.o -I -static -lstdc++ .;\
-	else\
-	    $(CXX) -std=$(STD) -c -O3 src/symbol_finder.cpp -fno-exceptions -fPIC -o build/symbol_finder.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/symbol_finder.cpp -o build/symbol_finder.o
 
 build/ast_visitor.o: \
 	src/nasal.h\
 	src/nasal_err.h\
 	src/nasal_ast.h\
 	src/ast_visitor.h src/ast_visitor.cpp | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/ast_visitor.cpp -fno-exceptions -fPIC -o build/ast_visitor.o -I -static -lstdc++ .;\
-	else\
-	    $(CXX) -std=$(STD) -c -O3 src/ast_visitor.cpp -fno-exceptions -fPIC -o build/ast_visitor.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/ast_visitor.cpp -o build/ast_visitor.o
 
 build/ast_dumper.o: \
 	src/nasal.h\
@@ -288,25 +207,13 @@ build/ast_dumper.o: \
 	src/nasal_ast.h\
 	src/ast_visitor.h\
 	src/ast_dumper.h src/ast_dumper.cpp | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/ast_dumper.cpp -fno-exceptions -fPIC -o build/ast_dumper.o -I -static -lstdc++ .;\
-	else\
-	    $(CXX) -std=$(STD) -c -O3 src/ast_dumper.cpp -fno-exceptions -fPIC -o build/ast_dumper.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/ast_dumper.cpp -o build/ast_dumper.o
 
 build/nasal_vm.o: $(NASAL_HEADER) src/nasal_vm.h src/nasal_vm.cpp | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/nasal_vm.cpp -fno-exceptions -fPIC -o build/nasal_vm.o -I -static -lstdc++ .;\
-	else\
-	    $(CXX) -std=$(STD) -c -O3 src/nasal_vm.cpp -fno-exceptions -fPIC -o build/nasal_vm.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/nasal_vm.cpp -o build/nasal_vm.o
 
 build/nasal_dbg.o: $(NASAL_HEADER) src/nasal_dbg.h src/nasal_dbg.cpp | build
-	@if [ OS = "Darwin" ]; then\
-        $(CXX) -std=$(STD) -c -O3 src/nasal_dbg.cpp -fno-exceptions -fPIC -o build/nasal_dbg.o -I -static -lstdc++ .;\
-	else\
-	    $(CXX) -std=$(STD) -c -O3 src/nasal_dbg.cpp -fno-exceptions -fPIC -o build/nasal_dbg.o -I .;\
-    fi
+	$(CXX) $(CXXFLAGS) src/nasal_dbg.cpp -o build/nasal_dbg.o
 
 .PHONY: clean
 clean: