Add a new tool to check the deps of aar_import. This is the first cl of a

series. The following CLs will integrate this into bazel.

RELNOTES:n/a.
PiperOrigin-RevId: 184706507

1 files changed, 124 insertions, 0 deletions

diff --git a/src/java_tools/import_deps_checker/java/com/google/devtools/build/importdeps/AbstractClassEntryState.java b/src/java_tools/import_deps_checker/java/com/google/devtools/build/importdeps/AbstractClassEntryState.java
new file mode 100644
index 0000000000..209bf83fcb
--- /dev/null
+++ b/src/java_tools/import_deps_checker/java/com/google/devtools/build/importdeps/AbstractClassEntryState.java
@@ -0,0 +1,124 @@
+// 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.importdeps;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+import com.google.auto.value.AutoValue;
+import com.google.common.collect.ImmutableList;
+import java.util.Optional;
+
+/**
+ * The state for a class entry used in {@link ClassCache}. A state can be
+ *
+ * <ul>
+ *   <li>EXISTING: this class exists.
+ *   <li>INCOMPLETE: this class exists, but at least one of its ancestor is missing.
+ *   <li>MISSING: this class is missing on the classpath.
+ * </ul>
+ */
+public abstract class AbstractClassEntryState {
+
+  public boolean isMissingState() {
+    return this instanceof MissingState;
+  }
+
+  public MissingState asMissingState() {
+    throw new IllegalStateException("Not a missing state " + this);
+  }
+
+  public boolean isExistingState() {
+    return this instanceof ExistingState;
+  }
+
+  public ExistingState asExistingState() {
+    throw new IllegalStateException("Not an existing state " + this);
+  }
+
+  public boolean isIncompleteState() {
+    return this instanceof IncompleteState;
+  }
+
+  public IncompleteState asIncompleteState() {
+    throw new IllegalStateException("Not an incomplete state " + this);
+  }
+
+  public abstract Optional<ClassInfo> classInfo();
+
+  /** A state to indicate that a class exists. */
+  @AutoValue
+  public abstract static class ExistingState extends AbstractClassEntryState {
+
+    public static ExistingState create(ClassInfo classInfo) {
+      return new AutoValue_AbstractClassEntryState_ExistingState(Optional.of(classInfo));
+    }
+
+    @Override
+    public ExistingState asExistingState() {
+      return this;
+    }
+  }
+
+  /** A state to indicate that a class is missing. */
+  public static final class MissingState extends AbstractClassEntryState {
+
+    private static final MissingState SINGLETON = new MissingState();
+
+    public static MissingState singleton() {
+      return SINGLETON;
+    }
+
+    private MissingState() {}
+
+    @Override
+    public MissingState asMissingState() {
+      return this;
+    }
+
+    @Override
+    public Optional<ClassInfo> classInfo() {
+      return Optional.empty();
+    }
+  }
+
+  /**
+   * A state to indicate that a class is incomplete, that is, some ancesotor is missing on the
+   * classpath.
+   */
+  @AutoValue
+  public abstract static class IncompleteState extends AbstractClassEntryState {
+
+    public static IncompleteState create(
+        ClassInfo classInfo, ImmutableList<String> resolutionFailurePath) {
+      checkArgument(
+          !resolutionFailurePath.isEmpty(),
+          "The resolution path should contain at least one element, the missing ancestor. %s",
+          resolutionFailurePath);
+      return new AutoValue_AbstractClassEntryState_IncompleteState(
+          Optional.of(classInfo), resolutionFailurePath);
+    }
+
+    public abstract ImmutableList<String> getResolutionFailurePath();
+
+    public String getMissingAncestor() {
+      ImmutableList<String> path = getResolutionFailurePath();
+      return path.get(path.size() - 1);
+    }
+
+    @Override
+    public IncompleteState asIncompleteState() {
+      return this;
+    }
+  }
+}