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, 7 insertions, 4 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/query2/engine/SomeFunction.java b/src/main/java/com/google/devtools/build/lib/query2/engine/SomeFunction.java
index d6885e44f6..8560992f93 100644
--- a/src/main/java/com/google/devtools/build/lib/query2/engine/SomeFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/query2/engine/SomeFunction.java
@@ -49,11 +49,14 @@ class SomeFunction implements QueryFunction {
   }
 
   @Override
-  public <T> void eval(QueryEnvironment<T> env, QueryExpression expression,
-      List<Argument> args, final Callback<T> callback)
-      throws QueryException, InterruptedException {
+  public <T> void eval(
+      QueryEnvironment<T> env,
+      VariableContext<T> context,
+      QueryExpression expression,
+      List<Argument> args,
+      final Callback<T> callback) throws QueryException, InterruptedException {
     final AtomicBoolean someFound = new AtomicBoolean(false);
-    env.eval(args.get(0).getExpression(), new Callback<T>() {
+    env.eval(args.get(0).getExpression(), context, new Callback<T>() {
       @Override
       public void process(Iterable<T> partialResult) throws QueryException, InterruptedException {
         if (someFound.get() || Iterables.isEmpty(partialResult)) {