tree 803a2275982ce67dff4251e5a41a1c8dfd186cf8
parent 26c86f88be0ddd9d59f4fd3f3afdd769af4ecefc
author Laszlo Csomor <laszlocsomor@google.com> 1527604870 -0700
committer Copybara-Service <copybara-piper@google.com> 1527604934 -0700

shell toolchain: genrule now uses it

genrule() now uses the shell toolchain (as well as
the ShellConfiguration config fragment) to look up
the shell interpreter's path.

Also the CommandHelper no longer looks up the
shell interpreter's path itself. Instead its ctor
takes the path as an argument. This allows
supporting rules that already use the shell
toolchain and rules that still only consider the
configuration fragment.

With these changes genrule() is now able to use
the shell interpreter registered as a toolchain,
even if there's no `--shell_executable` flag
specified (or its value is empty).

Subsequent commits will migrate more and more
rules to depend on the shell toolchain.

This commit takes us closer to:

1. be able to detect the local shell interpreter's
   location, especially when it's not the default
   /bin/bash

2. be able to define different shell toolchains
   (different interpreter paths) for remote builds

3. gracefully fail the build if the machine has no
   shell installed but the action graph included a
   shell action

See https://github.com/bazelbuild/bazel/issues/4319

Change-Id: I0674c7e2d5917643d87b48b19a1cb43e606ad2f7

Closes #5282.

Change-Id: I0674c7e2d5917643d87b48b19a1cb43e606ad2f7
PiperOrigin-RevId: 198394021