ci: add automatic header file deps to Makefile

.gitignore

@@ -1,3 +1,4 @@
 .clangd
 *.o
 bin/swarm
+obj/

Makefile

@@ -6,19 +6,16 @@ OBJ_DIR = ./obj
 
 HEADERS   = $(wildcard $(INC_DIR)/*.hpp)
 SRC_FILES = $(wildcard $(SRC_DIR)/*.cpp)
+DEP_FILES = $(OBJ_FILES:.o=.d)
 OBJ_FILES = $(addprefix $(OBJ_DIR)/,$(notdir $(SRC_FILES:.cpp=.o)))
 
-CXXFLAGS += -Wall -std=c++20 -O2
+CXXFLAGS += -Wall -std=c++20 -O2 -I $(INC_DIR)
 
 all: bin/swarm
 
-$(OBJ_DIR)/%.o: src/%.cpp
-	$(CXX) -I $(INC_DIR) $(CXXFLAGS) -c -o $@ $^
-
 bin/swarm: $(OBJ_FILES)
-	@mkdir -p $(OBJ_DIR)
 	@mkdir -p bin
-	$(CXX) -I $(INC_DIR) $(CXXFLAGS) -o $@ $^
+	$(CXX) $(CXXFLAGS) -o $@ $^
 
 .PHONY: debug
 debug: CXXFLAGS += -O0 -g
@@ -28,3 +25,9 @@ debug: clean bin/swarm
 clean:
 	$(RM) obj/*.o
 	$(RM) bin/swarm
+
+-include $(DEP_FILES)
+
+$(OBJ_DIR)/%.o : src/%.cpp
+	mkdir -p $(@D)
+	$(CXX) $(CXXFLAGS) -MMD -c $< -o $@