Shorthand for including an output file of a genrule directory as a src

If you have a genrule that creates a directory with several files, it’s a bit of a pain to write another genrule rule for each (expected) output, just to be able to pass it to *_library (java, python, etc). It would be nice to allow you to somehow specify this in the sources - maybe via flavors (although it is a bit hackish)? e.g.

genrule(
    name='gen_my_thing',
    out='things',
    cmd='$(exe :my_custom_generator) $SRCDIR $OUT',
    srcs=glob(['File1.java', 'File2.java']),
)

java_library(
    name='lib',
    srcs=[
        ':gen_my_thing#lib_output/File1Out.java',
        ':gen_my_thing#lib_output/File2Out.java',
    ]
)

[njlr]

Yes, that works.

For those who stumble on this, try something like:

def extract(x):
  genrule(
    name = x,
    out = x,
    cmd = 'cp $(location :make)/install/include/' + x ' $OUT',
  )
  return ':' + x

headers = [
  'generated_header.h',
]

prebuilt_cxx_library(
  name = 'my-lib',
  exported_headers = dict({ (x, extract(x)) for x in headers }),
  # etc... 

[Coneko]

You need to know the names of the files in advance and write them in the build files.

You can do that using a python loop if you wish, but you cannot list files in the output directory.

The same limitation exists with the new syntax.