1 files changed, 120 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/rules/java/Jvm.java b/src/main/java/com/google/devtools/build/lib/rules/java/Jvm.java
new file mode 100644
index 0000000000..eda736026a
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/rules/java/Jvm.java
@@ -0,0 +1,120 @@
+// Copyright 2014 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.rules.java;
+
+import com.google.common.base.Preconditions;
+import com.google.common.collect.ImmutableMap.Builder;
+import com.google.common.collect.Multimap;
+import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
+import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
+import com.google.devtools.build.lib.syntax.Label;
+import com.google.devtools.build.lib.syntax.SkylarkCallable;
+import com.google.devtools.build.lib.syntax.SkylarkModule;
+import com.google.devtools.build.lib.vfs.PathFragment;
+
+/**
+ * This class represents a Java virtual machine with a host system and a path.
+ * If the JVM comes from the client, it can optionally also contain a label
+ * pointing to a target that contains all the necessary files.
+ */
+@SkylarkModule(name = "jvm",
+    doc = "A configuration fragment representing the Java virtual machine.")
+@Immutable
+public final class Jvm extends BuildConfiguration.Fragment {
+  private final PathFragment javaHome;
+  private final Label jvmLabel;
+
+  /**
+   * Creates a Jvm instance. Either the {@code javaHome} parameter is absolute,
+   * or the {@code jvmLabel} parameter must be non-null. This restriction might
+   * be lifted in the future. Only the {@code jvmLabel} is optional.
+   */
+  public Jvm(PathFragment javaHome, Label jvmLabel) {
+    Preconditions.checkArgument(javaHome.isAbsolute() ^ (jvmLabel != null));
+    this.javaHome = javaHome;
+    this.jvmLabel = jvmLabel;
+  }
+
+  @Override
+  public String getName() {
+    return "Jvm";
+  }
+
+  @Override
+  public void addImplicitLabels(Multimap<String, Label> implicitLabels) {
+    if (jvmLabel != null) {
+      implicitLabels.put(getName(), jvmLabel);
+    }
+  }
+
+  /**
+   * Returns a path fragment that determines the path to the installation
+   * directory. It is either absolute or relative to the execution root.
+   */
+  public PathFragment getJavaHome() {
+    return javaHome;
+  }
+
+  /**
+   * Returns the path to the javac binary.
+   */
+  public PathFragment getJavacExecutable() {
+    return getJavaHome().getRelative("bin/javac");
+  }
+
+  /**
+   * Returns the path to the jar binary.
+   */
+  public PathFragment getJarExecutable() {
+    return getJavaHome().getRelative("bin/jar");
+  }
+
+  /**
+   * Returns the path to the java binary.
+   */
+  @SkylarkCallable(name = "java_executable", structField = true,
+      doc = "The the java executable, i.e. bin/java relative to the Java home.")
+  public PathFragment getJavaExecutable() {
+    return getJavaHome().getRelative("bin/java");
+  }
+
+  /**
+   * Returns a label. Adding this label to the dependencies of an action that
+   * depends on this JVM is sufficient to ensure that all the required files are
+   * present. Can be <code>null</code>, in which case nothing needs to be added
+   * to the dependencies of an action. We rely on convention to make sure that
+   * this case works, since we can't know which JVMs are installed on the build host.
+   */
+  public Label getJvmLabel() {
+    return jvmLabel;
+  }
+
+  /**
+   * Returns a string that uniquely identifies the JVM for the life time of this
+   * Blaze instance. This value is intended for analysis caching, so it need not
+   * reflect changes in the individual files making up the JVM.
+   */
+  @Override
+  public String cacheKey() {
+    return javaHome.getSafePathString();
+  }
+
+  @Override
+  public void addGlobalMakeVariables(Builder<String, String> globalMakeEnvBuilder) {
+    globalMakeEnvBuilder.put("JAVABASE", getJavaHome().getPathString());
+    globalMakeEnvBuilder.put("JAVA", getJavaExecutable().getPathString());
+    globalMakeEnvBuilder.put("JAVAC", getJavacExecutable().getPathString());
+  }
+}