tree 0874e6b8cca8cb3e160815de3ebc2b118d25f724
parent 64e833cc5e4062197424d24d6539baf38defbb50
author brandjon <brandjon@google.com> 1550863096 -0800
committer Copybara-Service <copybara-worker@google.com> 1550863231 -0800

Expose PyRuntimeProvider to Starlark as PyRuntimeInfo

This creates a top-level symbol `PyRuntimeInfo` representing the provider created by the `py_runtime` rule and consumed by `py_binary` and `py_test`.

PyRuntimeProvider is refactored to not implement TransitiveInfoProvider, and to now be split into separate classes for the provider instance vs provider type. Fakes are created for Stardoc and friends.

Tests are added for the API of `PyRuntimeInfo` and for the ability to sandwich a Starlark rule between a py_runtime and its consuming py_binary.

As drive-by cleanups, the provider is now instantiated in Java code via factory methods instead of its constructor, and the isHermetic method is renamed to isInBuild to be consistent with the terminology in the design doc for #7375. Rule documentation is also updated.

Work toward #7375.

RELNOTES: (Python rules) PyRuntimeInfo is exposed to Starlark, making it possible for Starlark rules to depend on or imitate `py_runtime`. The `files` attribute of `py_runtime` is no longer mandatory.
PiperOrigin-RevId: 235224774