1 files changed, 72 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/query2/engine/TargetLiteral.java b/src/main/java/com/google/devtools/build/lib/query2/engine/TargetLiteral.java
new file mode 100644
index 0000000000..b6a57cc5a5
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+++ b/src/main/java/com/google/devtools/build/lib/query2/engine/TargetLiteral.java
@@ -0,0 +1,72 @@
+// Copyright 2014 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package com.google.devtools.build.lib.query2.engine;
+
+import com.google.common.base.Preconditions;
+
+import java.util.Collection;
+import java.util.Set;
+
+/**
+ * A literal set of targets, using 'blaze build' syntax.  Or, a reference to a
+ * variable name.  (The syntax of the string "pattern" determines which.)
+ *
+ * TODO(bazel-team): Perhaps we should distinguish NAME from WORD in the parser,
+ * based on the characters in it?  Also, perhaps we should not allow NAMEs to
+ * be quoted like WORDs can be.
+ *
+ * <pre>expr ::= NAME | WORD</pre>
+ */
+final class TargetLiteral extends QueryExpression {
+
+  private final String pattern;
+
+  TargetLiteral(String pattern) {
+    this.pattern = Preconditions.checkNotNull(pattern);
+  }
+
+  public boolean isVariableReference() {
+    return LetExpression.isValidVarReference(pattern);
+  }
+
+  @Override
+  public <T> Set<T> eval(QueryEnvironment<T> env) throws QueryException {
+    if (isVariableReference()) {
+      String varName = LetExpression.getNameFromReference(pattern);
+      Set<T> value = env.getVariable(varName);
+      if (value == null) {
+        throw new QueryException(this, "undefined variable '" + varName + "'");
+      }
+      return env.getVariable(varName);
+    }
+
+    return env.getTargetsMatchingPattern(this, pattern);
+  }
+
+  @Override
+  public void collectTargetPatterns(Collection<String> literals) {
+    if (!isVariableReference()) {
+      literals.add(pattern);
+    }
+  }
+
+  @Override
+  public String toString() {
+    // Keep predicate consistent with Lexer.scanWord!
+    boolean needsQuoting = Lexer.isReservedWord(pattern)
+                        || pattern.isEmpty()
+                        || "$-*".indexOf(pattern.charAt(0)) != -1;
+    return needsQuoting ? ("\"" + pattern + "\"") : pattern;
+  }
+}