Process 'repo_mapping' attribute from WORKSPACE rules. 'repo_mapping' is a way to remap references to repositories within an external repository by another name. This CL only adds the mappings to the Package object, but it does not actually enable the reassignments.

Example usage (in a WORKSPACE file):
local_repository(
  name = ?a?,
  path = ?../a?,
  repo_mapping = {?@x? : ?@y?}
)

This change also creates a new SkyKey which represents the mappings. This is to prevent all packages from depending on the external package, and instead depending just on the mappings. i.e. a change to the WORKSPACE file that does not touch the mappings shouldn't cause a reload of the package.

RELNOTES:None
PiperOrigin-RevId: 199187963

1 files changed, 63 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/RepositoryMappingFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/RepositoryMappingFunction.java
new file mode 100644
index 0000000000..51e697ae84
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/RepositoryMappingFunction.java
@@ -0,0 +1,63 @@
+// Copyright 2018 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.skyframe;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.devtools.build.lib.cmdline.Label;
+import com.google.devtools.build.lib.cmdline.RepositoryName;
+import com.google.devtools.build.lib.packages.BuildFileContainsErrorsException;
+import com.google.devtools.build.lib.packages.Package;
+import com.google.devtools.build.skyframe.SkyFunction;
+import com.google.devtools.build.skyframe.SkyFunctionException;
+import com.google.devtools.build.skyframe.SkyKey;
+import com.google.devtools.build.skyframe.SkyValue;
+import javax.annotation.Nullable;
+
+/** {@link SkyFunction} for {@link RepositoryMappingValue}s. */
+public class RepositoryMappingFunction implements SkyFunction {
+
+  @Nullable
+  @Override
+  public SkyValue compute(SkyKey skyKey, Environment env)
+      throws SkyFunctionException, InterruptedException {
+    SkyKey externalPackageKey = PackageValue.key(Label.EXTERNAL_PACKAGE_IDENTIFIER);
+    PackageValue externalPackageValue = (PackageValue) env.getValue(externalPackageKey);
+    if (env.valuesMissing()) {
+      return null;
+    }
+    Package externalPackage = externalPackageValue.getPackage();
+    if (externalPackage.containsErrors()) {
+      throw new RepositoryMappingFunctionException();
+    }
+
+    ImmutableMap<RepositoryName, RepositoryName> mapping =
+        externalPackage.getRepositoryMapping((RepositoryName) skyKey.argument());
+    return RepositoryMappingValue.withMapping(mapping);
+  }
+
+  @Nullable
+  @Override
+  public String extractTag(SkyKey skyKey) {
+    return null;
+  }
+
+  private class RepositoryMappingFunctionException extends SkyFunctionException {
+    RepositoryMappingFunctionException() {
+      super(
+          new BuildFileContainsErrorsException(Label.EXTERNAL_PACKAGE_IDENTIFIER),
+          Transience.PERSISTENT);
+    }
+  }
+}