1 files changed, 71 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/constraints/Environment.java b/src/main/java/com/google/devtools/build/lib/analysis/constraints/Environment.java
new file mode 100644
index 0000000000..912ed723fe
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/analysis/constraints/Environment.java
@@ -0,0 +1,71 @@
+// Copyright 2015 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.analysis.constraints;
+
+import com.google.common.collect.ImmutableList;
+import com.google.devtools.build.lib.actions.Artifact;
+import com.google.devtools.build.lib.analysis.ConfiguredTarget;
+import com.google.devtools.build.lib.analysis.FileProvider;
+import com.google.devtools.build.lib.analysis.FilesToRunProvider;
+import com.google.devtools.build.lib.analysis.RuleConfiguredTargetBuilder;
+import com.google.devtools.build.lib.analysis.RuleContext;
+import com.google.devtools.build.lib.analysis.RunfilesProvider;
+import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
+import com.google.devtools.build.lib.collect.nestedset.Order;
+import com.google.devtools.build.lib.packages.EnvironmentGroup;
+import com.google.devtools.build.lib.packages.Package;
+import com.google.devtools.build.lib.rules.RuleConfiguredTargetFactory;
+import com.google.devtools.build.lib.syntax.Label;
+
+/**
+ * Implementation for the environment rule.
+ */
+public class Environment implements RuleConfiguredTargetFactory {
+
+  @Override
+  public ConfiguredTarget create(RuleContext ruleContext) {
+
+    // The main analysis work to do here is to simply fill in SupportedEnvironmentsProvider to
+    // pass the environment itself to depending rules.
+    //
+    // This will likely expand when we add support for environments fulfilling other environments.
+    Label label = ruleContext.getLabel();
+    Package pkg = ruleContext.getRule().getPackage();
+
+    EnvironmentGroup group = null;
+    for (EnvironmentGroup pkgGroup : pkg.getTargets(EnvironmentGroup.class)) {
+      if (pkgGroup.getEnvironments().contains(label)) {
+        group = pkgGroup;
+        break;
+      }
+    }
+
+    if (group == null) {
+      ruleContext.ruleError("no matching environment group from the same package");
+      return null;
+    }
+
+    return new RuleConfiguredTargetBuilder(ruleContext)
+        .addProvider(SupportedEnvironmentsProvider.class,
+            new SupportedEnvironments(
+                new EnvironmentCollection.Builder().put(group, label).build()))
+        .addProvider(RunfilesProvider.class, RunfilesProvider.EMPTY)
+        .add(FileProvider.class, new FileProvider(ruleContext.getLabel(),
+            NestedSetBuilder.<Artifact>emptySet(Order.STABLE_ORDER)))
+        .add(FilesToRunProvider.class, new FilesToRunProvider(ruleContext.getLabel(),
+            ImmutableList.<Artifact>of(), null, null))
+        .build();
+  }
+}