1 files changed, 184 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/actions/CommandLine.java b/src/main/java/com/google/devtools/build/lib/actions/CommandLine.java
new file mode 100644
index 0000000000..dcf1006ec5
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+++ b/src/main/java/com/google/devtools/build/lib/actions/CommandLine.java
@@ -0,0 +1,184 @@
+// Copyright 2014 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.actions;
+
+import com.google.common.base.Joiner;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.Iterables;
+import com.google.devtools.build.lib.actions.Artifact.ArtifactExpander;
+import com.google.devtools.build.lib.collect.CollectionUtils;
+import com.google.devtools.build.lib.skyframe.serialization.ObjectCodec;
+import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
+import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec.Strategy;
+import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec.VisibleForSerialization;
+import com.google.devtools.build.lib.util.Fingerprint;
+
+/** A representation of a list of arguments. */
+@AutoCodec(strategy = Strategy.POLYMORPHIC)
+public abstract class CommandLine {
+  public static final ObjectCodec<CommandLine> CODEC = new CommandLine_AutoCodec();
+
+  @AutoCodec
+  @VisibleForSerialization
+  static class EmptyCommandLine extends CommandLine {
+    public static final ObjectCodec<EmptyCommandLine> CODEC =
+        new CommandLine_EmptyCommandLine_AutoCodec();
+
+    @Override
+    public Iterable<String> arguments() throws CommandLineExpansionException {
+      return ImmutableList.of();
+    }
+  }
+
+  public static final CommandLine EMPTY = new EmptyCommandLine();
+
+  /** Returns the command line. */
+  public abstract Iterable<String> arguments() throws CommandLineExpansionException;
+
+  /**
+   * Returns the evaluated command line with enclosed artifacts expanded by {@code artifactExpander}
+   * at execution time.
+   *
+   * <p>By default, this method just delegates to {@link #arguments()}, without performing any
+   * artifact expansion. Subclasses should override this method if they contain TreeArtifacts and
+   * need to expand them for proper argument evaluation.
+   */
+  public Iterable<String> arguments(ArtifactExpander artifactExpander)
+      throws CommandLineExpansionException {
+    return arguments();
+  }
+
+  public void addToFingerprint(ActionKeyContext actionKeyContext, Fingerprint fingerprint)
+      throws CommandLineExpansionException {
+    for (String s : arguments()) {
+      fingerprint.addString(s);
+    }
+  }
+
+  @AutoCodec
+  @VisibleForSerialization
+  static class ArgumentCommandLine extends CommandLine {
+    public static final ObjectCodec<ArgumentCommandLine> CODEC =
+        new CommandLine_ArgumentCommandLine_AutoCodec();
+
+    private Iterable<String> args;
+
+    ArgumentCommandLine(Iterable<String> args) {
+      this.args = args;
+    }
+
+    @Override
+    public Iterable<String> arguments() throws CommandLineExpansionException {
+      return args;
+    }
+  }
+
+  /** Returns a {@link CommandLine} backed by a copy of the given list of arguments. */
+  public static CommandLine of(Iterable<String> arguments) {
+    final Iterable<String> immutableArguments = CollectionUtils.makeImmutable(arguments);
+    return new ArgumentCommandLine(immutableArguments);
+  }
+
+  @AutoCodec
+  @VisibleForSerialization
+  static class ConcatenatedCommandLine extends CommandLine {
+    public static final ObjectCodec<ConcatenatedCommandLine> CODEC =
+        new CommandLine_ConcatenatedCommandLine_AutoCodec();
+
+    private ImmutableList<String> executableArgs;
+    private CommandLine commandLine;
+
+    @VisibleForSerialization
+    ConcatenatedCommandLine(ImmutableList<String> executableArgs, CommandLine commandLine) {
+      this.executableArgs = executableArgs;
+      this.commandLine = commandLine;
+    }
+
+    @Override
+    public Iterable<String> arguments() throws CommandLineExpansionException {
+      return Iterables.concat(executableArgs, commandLine.arguments());
+    }
+
+    @Override
+    public Iterable<String> arguments(ArtifactExpander artifactExpander)
+        throws CommandLineExpansionException {
+      return Iterables.concat(executableArgs, commandLine.arguments(artifactExpander));
+    }
+  }
+
+  /**
+   * Returns a {@link CommandLine} that is constructed by prepending the {@code executableArgs} to
+   * {@code commandLine}.
+   */
+  public static CommandLine concat(
+      final ImmutableList<String> executableArgs, final CommandLine commandLine) {
+    if (executableArgs.isEmpty()) {
+      return commandLine;
+    }
+    return new ConcatenatedCommandLine(executableArgs, commandLine);
+  }
+
+  @AutoCodec
+  @VisibleForSerialization
+  static class ReverseConcatenatedCommandLine extends CommandLine {
+    public static final ObjectCodec<ReverseConcatenatedCommandLine> CODEC =
+        new CommandLine_ReverseConcatenatedCommandLine_AutoCodec();
+
+    private ImmutableList<String> executableArgs;
+    private CommandLine commandLine;
+
+    @VisibleForSerialization
+    ReverseConcatenatedCommandLine(ImmutableList<String> executableArgs, CommandLine commandLine) {
+      this.executableArgs = executableArgs;
+      this.commandLine = commandLine;
+    }
+
+    @Override
+    public Iterable<String> arguments() throws CommandLineExpansionException {
+      return Iterables.concat(commandLine.arguments(), executableArgs);
+    }
+
+    @Override
+    public Iterable<String> arguments(ArtifactExpander artifactExpander)
+        throws CommandLineExpansionException {
+      return Iterables.concat(commandLine.arguments(artifactExpander), executableArgs);
+    }
+  }
+
+  /**
+   * Returns a {@link CommandLine} that is constructed by appending the {@code args} to {@code
+   * commandLine}.
+   */
+  public static CommandLine concat(
+      final CommandLine commandLine, final ImmutableList<String> args) {
+    if (args.isEmpty()) {
+      return commandLine;
+    }
+    return new ReverseConcatenatedCommandLine(args, commandLine);
+  }
+
+  /**
+   * This helps when debugging Blaze code that uses {@link CommandLine}s, as you can see their
+   * content directly in the variable inspector.
+   */
+  @Override
+  public String toString() {
+    try {
+      return Joiner.on(' ').join(arguments());
+    } catch (CommandLineExpansionException e) {
+      return "Error in expanding command line";
+    }
+  }
+}