Replace Transitions.configurationHook with equivalent rule class transitions.

This removes the last dynamic dependency on the static configuration
transition table.

PiperOrigin-RevId: 161162272

1 files changed, 45 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/config/ComposingRuleTransitionFactory.java b/src/main/java/com/google/devtools/build/lib/analysis/config/ComposingRuleTransitionFactory.java
new file mode 100644
index 0000000000..3cc2ff71f4
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/analysis/config/ComposingRuleTransitionFactory.java
@@ -0,0 +1,45 @@
+// 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.config;
+
+import com.google.devtools.build.lib.packages.Attribute;
+import com.google.devtools.build.lib.packages.Rule;
+import com.google.devtools.build.lib.packages.RuleTransitionFactory;
+
+/**
+ * A {@link RuleTransitionFactory} that composes other {@link RuleTransitionFactory}s.
+ */
+public class ComposingRuleTransitionFactory implements RuleTransitionFactory {
+
+  private final RuleTransitionFactory rtf1;
+  private final RuleTransitionFactory rtf2;
+
+  /**
+   * Creates a factory that applies the given factories in-order ({@code rtf1} first,
+   * {@code rtf2} second).
+   */
+  public ComposingRuleTransitionFactory(RuleTransitionFactory rtf1, RuleTransitionFactory rtf2) {
+    this.rtf1 = rtf1;
+    this.rtf2 = rtf2;
+  }
+
+  @Override
+  public Attribute.Transition buildTransitionFor(Rule rule) {
+    return new ComposingPatchTransition(
+        (PatchTransition) rtf1.buildTransitionFor(rule),
+        (PatchTransition) rtf2.buildTransitionFor(rule));
+  }
+}