tree dd1abbffaebf8a6bd88ce2494bc6cb0f26eae897
parent 184b454594c865150bfc2df274a6ace4a49e0043
author ulfjack <ulfjack@google.com> 1563783007 -0700
committer Copybara-Service <copybara-worker@google.com> 1563783074 -0700

Use chaining to reduce duplicate toolchain vars

The idea is that all actions generated the same CcCompilationHelper
share a set of toolchain variables (especially those passed in as
extra variables), which significantly reduces memory consumption in
cases where Bazel generates more than one actions for a single
configured target.

AFAICT, there does not seem to be a mechanism that allows the extra
variables to vary based on the specific action generated (i.e., based on
the source or output file for that action).

Note that we can't share copts in the case where per_file_copts is set.
Ideally, we'd share copts as well, unless specifically overridden.

PiperOrigin-RevId: 259276353