# ============================================================
# Makefile — 编译和运行 C 项目
# 用法:
#   make         编译生成可执行文件
#   make run     编译并运行
#   make clean   删除编译产物
#   make help    查看帮助
# ============================================================

# ---------- 编译器与参数 ----------
CC       = gcc
CFLAGS   = -Wall -Wextra -O2 -std=c99
LDFLAGS  =
RM       = rm -f

# ---------- 项目结构 ----------
TARGET   = app
SRCS     = main.c
OBJS     = $(SRCS:.c=.o)

# ---------- 默认目标：编译 ----------
$(TARGET): $(OBJS)
	$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS)

%.o: %.c
	$(CC) $(CFLAGS) -c $< -o $@

# ---------- 运行 ----------
run: $(TARGET)
	./$(TARGET)

# ---------- 清理 ----------
clean:
	$(RM) $(OBJS) $(TARGET)

# ---------- 帮助 ----------
help:
	@echo "用法:"
	@echo "  make         编译"
	@echo "  make run     编译 + 运行"
	@echo "  make clean   清理"
	@echo "  make help    显示本帮助"

# 标记为伪目标，避免与同名文件冲突
.PHONY: all run clean help