bazel-skylib/rules/select_file.bzl

41 lines
1.1 KiB
Python

"""
select_file() build rule implementation.
Selects a single file from the outputs of some target by given relative path.
"""
def _impl(ctx):
if ctx.attr.subpath and len(ctx.attr.subpath) == 0:
fail("Subpath can not be empty.")
out = None
canonical = ctx.attr.subpath.replace("\\", "/")
for file_ in ctx.attr.srcs.files.to_list():
if file_.path.replace("\\", "/").endswith(canonical):
out = file_
break
if not out:
files_str = ",\n".join([
str(f.path)
for f in ctx.attr.srcs.files.to_list()
])
fail("Can not find specified file in [%s]" % files_str)
return [DefaultInfo(files = depset([out]))]
select_file = rule(
implementation = _impl,
doc = "Selects a single file from the outputs of some target \
by given relative path",
attrs = {
"srcs": attr.label(
allow_files = True,
mandatory = True,
doc = "The target producing the file among other outputs",
),
"subpath": attr.string(
mandatory = True,
doc = "Relative path to the file",
),
},
)