Re-implement variables in the blaze query language. Instead of using a mutable global context of variable bindings, pass around immutable local contexts.

The motivation is so we can safely evaluate all blaze query expressions concurrently under the hood. A global context is hostile to this goal.

--
MOS_MIGRATED_REVID=127324600

1 files changed, 2 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/query2/engine/LoadFilesFunction.java b/src/main/java/com/google/devtools/build/lib/query2/engine/LoadFilesFunction.java
index 1566f2166c..6b6866ebd6 100644
--- a/src/main/java/com/google/devtools/build/lib/query2/engine/LoadFilesFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/query2/engine/LoadFilesFunction.java
@@ -39,12 +39,14 @@ class LoadFilesFunction implements QueryEnvironment.QueryFunction {
   @Override
   public <T> void eval(
       final QueryEnvironment<T> env,
+      VariableContext<T> context,
       final QueryExpression expression,
       List<QueryEnvironment.Argument> args,
       final Callback<T> callback)
       throws QueryException, InterruptedException {
     env.eval(
         args.get(0).getExpression(),
+        context,
         new Callback<T>() {
           @Override
           public void process(Iterable<T> partialResult)