scons 如何缓存扫描 C 代码的依赖项？
问题的上下文是我想在其他语言中使用相同的技术。
现在我必须做这样的事情：
env.Depends(target = 'lib/PROG1.so', dependency = getDependencies('src/PROG1.xxx'))
其中getDependencies() 返回依赖项列表。但这将在每次运行时扫描依赖项。我想缓存这些结果，并且仅在源文件更改时重新扫描。
【问题讨论】：
标签： scons
如果您使用Depends()，您可能做错了什么...
（这通常意味着您没有指定目标或源，或者您的构建器的扫描仪缺少文件）
SCons 的构建器定义了扫描源代码以查找包含的文件并保存该信息的扫描器。
此外，您还可以向所有构建器指定他们构建的目标的来源。
通常，只有在文件发生更改时才会重新扫描文件。
SCons 的一些命令行标志可能会影响源文件的扫描（来自手册页：https://scons.org/doc/production/HTML/scons-man.html）
--implicit-cache
Cache implicit dependencies. This causes scons to use the implicit (scanned) dependencies from the last time it was run instead of scanning the files for implicit dependencies. This can significantly speed up SCons, but with the following limitations:
scons will not detect changes to implicit dependency search paths (e.g. CPPPATH, LIBPATH) that would ordinarily cause different versions of same-named files to be used.
scons will miss changes in the implicit dependencies in cases where a new implicit dependency is added earlier in the implicit dependency search path (e.g. CPPPATH, LIBPATH) than a current implicit dependency with the same name.
--implicit-deps-changed
Forces SCons to ignore the cached implicit dependencies. This causes the implicit dependencies to be rescanned and recached. This implies --implicit-cache.
--implicit-deps-unchanged
Force SCons to ignore changes in the implicit dependencies. This causes cached implicit dependencies to always be used. This implies --implicit-cache.
或者你的意思是别的什么？
【讨论】：