GNU make - 只依赖于文件存在而不是修改时间
GNU make - depend only on file existence and not modification time
我想要一个 makefile，其中我有一个任务 a 只能 运行 如果文件 b 存在，但不需要重新 运行 如果b 已更新。我该怎么做？
你想要一个 order-only prerequisite:
Occasionally, however, you have a situation where you want to impose a specific ordering on the rules to be invoked without forcing the target to be updated if one of those rules is executed. In that case, you want to define order-only prerequisites.
请注意，并非所有版本的 make 都支持此功能。
我想要一个 makefile，其中我有一个任务 a 只能 运行 如果文件 b 存在，但不需要重新 运行 如果b 已更新。我该怎么做？
你想要一个 order-only prerequisite:
Occasionally, however, you have a situation where you want to impose a specific ordering on the rules to be invoked without forcing the target to be updated if one of those rules is executed. In that case, you want to define order-only prerequisites.
请注意，并非所有版本的 make 都支持此功能。