2 files changed, 106 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/whitelisting/BUILD b/src/main/java/com/google/devtools/build/lib/analysis/whitelisting/BUILD
new file mode 100644
index 0000000000..b31e3c224b
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/analysis/whitelisting/BUILD
@@ -0,0 +1,26 @@
+# Description:
+#   Whitelisting mechanism for rolling out and deprecating pieces of Bazel functionality.
+
+package(
+    default_visibility = ["//src:__subpackages__"],
+)
+
+filegroup(
+    name = "srcs",
+    srcs = glob(["**"]),
+)
+
+java_library(
+    name = "whitelisting",
+    srcs = glob(["*.java"]),
+    deps = [
+        "//src/main/java/com/google/devtools/build/lib:build-base",
+        "//src/main/java/com/google/devtools/build/lib:packages-internal",
+        "//src/main/java/com/google/devtools/build/lib:preconditions",
+        "//src/main/java/com/google/devtools/build/lib/cmdline",
+        "//src/main/java/com/google/devtools/common/options",
+        "//third_party:auto_value",
+        "//third_party:guava",
+        "//third_party:jsr305",
+    ],
+)
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/whitelisting/Whitelist.java b/src/main/java/com/google/devtools/build/lib/analysis/whitelisting/Whitelist.java
new file mode 100644
index 0000000000..0da6e4d362
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/analysis/whitelisting/Whitelist.java
@@ -0,0 +1,80 @@
+// Copyright 2017 The Bazel Authors. 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.whitelisting;
+
+import static com.google.devtools.build.lib.packages.Attribute.ConfigurationTransition.HOST;
+import static com.google.devtools.build.lib.packages.Attribute.attr;
+import static com.google.devtools.build.lib.packages.BuildType.LABEL;
+
+import com.google.common.collect.ImmutableList;
+import com.google.devtools.build.lib.analysis.PackageSpecificationProvider;
+import com.google.devtools.build.lib.analysis.RuleConfiguredTarget.Mode;
+import com.google.devtools.build.lib.analysis.RuleContext;
+import com.google.devtools.build.lib.analysis.TransitiveInfoCollection;
+import com.google.devtools.build.lib.cmdline.Label;
+import com.google.devtools.build.lib.packages.Attribute;
+import com.google.devtools.build.lib.util.Preconditions;
+
+/**
+ * Class used for implementing whitelists using package groups.
+ *
+ * <p>To use add an attribute {@link getAttributeFromWhitelistName(String,Label) to the rule class
+ * which needs the whitelisting mechanism and use {@link isAvailable(RuleContext,String)} to check
+ * during analysis if a rule is present
+ */
+public final class Whitelist {
+
+  private Whitelist() {}
+
+  /**
+   * Returns an Attribute.Builder that can be used to add an implicit attribute to a rule containing
+   * a package group whitelist.
+   *
+   * @param whitelistName The name of the whitelist. This has to comply with attribute naming
+   *     standards and will be used as a suffix for the attribute name.
+   * @param packageGroupWhitelist Label for the package group with the whitelist.
+   */
+  public static Attribute.Builder<Label> getAttributeFromWhitelistName(
+      String whitelistName, Label packageGroupWhitelist) {
+    String attributeName = getAttributeNameFromWhitelistName(whitelistName);
+    return attr(attributeName, LABEL)
+        .value(packageGroupWhitelist)
+        .cfg(HOST)
+        .mandatoryNativeProviders(ImmutableList.of(PackageSpecificationProvider.class));
+  }
+
+  /**
+   * Returns whether the rule in the given RuleContext is in a whitelist.
+   *
+   * @param ruleContext The context in which this check is being executed.
+   * @param whitelistName The name of the whitelist being used.
+   */
+  public static boolean isAvailable(RuleContext ruleContext, String whitelistName) {
+    String attributeName = getAttributeNameFromWhitelistName(whitelistName);
+    Preconditions.checkArgument(ruleContext.isAttrDefined(attributeName, LABEL));
+    TransitiveInfoCollection packageGroup = ruleContext.getPrerequisite(attributeName, Mode.HOST);
+    Label label = ruleContext.getLabel();
+    return packageGroup
+        .getProvider(PackageSpecificationProvider.class)
+        .getPackageSpecifications()
+        .toList()
+        .stream()
+        .anyMatch(p -> p.containsPackage(label.getPackageIdentifier()));
+  }
+
+  private static String getAttributeNameFromWhitelistName(String whitelistName) {
+    return String.format("$whitelist_%s", whitelistName);
+  }
+}