build: rebuild objects that depend on modified headers

sandbox/Makefile

@@ -10,6 +10,7 @@ DIR_LIST := memblock vm base queue btree util
 INCLUDE_DIRS := $(foreach dir,$(DIR_LIST),-I$(dir)/include)
 SRC := $(foreach dir,$(DIR_LIST),$(wildcard $(dir)/*.c))
 OBJ := $(addprefix $(BUILD_DIR)/,$(SRC:.c=.o))
+DEPS := $(OBJ:.o=.d)
 
 CFLAGS := $(INCLUDE_DIRS) -g
 
@@ -22,12 +23,14 @@ $(BUILD_DIR)/$(EXEC_NAME): $(OBJ)
 	@mkdir -p $(@D)
 
 	@printf "    \033[1;36mHOSTLD\033[0m \033[1mbuild/sandbox/\033[35m$(EXEC_NAME)\n"
-	@$(CC) $^ -o $@ $(CFLAGS) $(LDFLAGS)
+	@$(CC) $(OBJ) -o $@ $(CFLAGS) $(LDFLAGS)
+
+-include $(DEPS)
 
 $(BUILD_DIR)/%.o: %.c
 	@printf "    \033[1;32mHOSTCC\033[0m \033[35msandbox\033[0m/$<\n"
 	@mkdir -p $(@D)
 
-	@$(CC) $< -o $@ -c $(CFLAGS)
+	@$(CC) $< -o $@ -c $(CFLAGS) -MMD
 
 .PHONY: all