commit b10dfb99c537d8ff190f5c9585e5f112691d1fc5
author Robert Griesemer <gri@golang.org> Thu Oct 23 09:39:20 2014 -0700
committer Robert Griesemer <gri@golang.org> Thu Oct 23 09:39:20 2014 -0700
tree 6013ab82ca8e9939e99be9c69a6d840450ced7f0
parent b916c559e7c49356c21f5e3ae6f2bdf7bd169896

go/types: don't mark external package objects as used

Also removes a potential race condition regarding the
used flag of Var objects when type-checking packages
concurrently.

Implementation: Rather than marking all used dot-imported
objects and then deduce which corresponding package was used,
now we consider all dot-imported packages as unused and remove
each package from the unused packages map as objects are used.

Now only objects that can be marked as used have a used field
(variables, labels, and packages).

As a result, the code became cleaner and simpler.

Fixes golang/go#8969.

LGTM=adonovan
R=adonovan
CC=golang-codereviews
https://golang.org/cl/163740043