src/com/facebook/buck/android/ProGuardObfuscateStep.java - buck - Git at Google

 /*
  * Copyright 2012-present Facebook, Inc.
  *
  * 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.facebook.buck.android;

 import com.facebook.buck.rules.BuildableContext;
 import com.facebook.buck.shell.ShellStep;
 import com.facebook.buck.step.AbstractExecutionStep;
 import com.facebook.buck.step.ExecutionContext;
 import com.facebook.buck.step.Step;
 import com.facebook.buck.step.fs.TouchStep;
 import com.facebook.buck.zip.CustomZipOutputStream;
 import com.facebook.buck.zip.ZipOutputStreams;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Joiner;
 import com.google.common.base.Objects;
 import com.google.common.base.Optional;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Iterables;
 import com.google.common.io.Files;

 import java.io.File;
 import java.io.IOException;
 import java.nio.file.Path;
 import java.util.Map;
 import java.util.Set;
 import java.util.zip.ZipEntry;

 public final class ProGuardObfuscateStep extends ShellStep {

   static enum SdkProguardType {
     DEFAULT,
     OPTIMIZED,
     NONE,
   }

   private final Map<Path, Path> inputAndOutputEntries;
   private final Path pathToProGuardCommandLineArgsFile;
   private final Optional<Path> proguardJarOverride;
   private final String proguardMaxHeapSize;

   /**
    * Create steps that write out ProGuard's command line arguments to a text file and then run
    * ProGuard using those arguments. We write the arguments to a file to avoid blowing out
    * exec()'s ARG_MAX limit.
    *
    * @param steps Where to append the generated steps.
    */
   public static void create(
       Optional<Path> proguardJarOverride,
       String proguardMaxHeapSize,
       Path generatedProGuardConfig,
       Set<Path> customProguardConfigs,
       SdkProguardType sdkProguardConfig,
       Optional<Integer> optimizationPasses,
       Map<Path, Path> inputAndOutputEntries,
       Set<Path> additionalLibraryJarsForProguard,
       Path proguardDirectory,
       BuildableContext buildableContext,
       ImmutableList.Builder<Step> steps) {

     Path pathToProGuardCommandLineArgsFile = proguardDirectory.resolve("command-line.txt");

     CommandLineHelperStep commandLineHelperStep = new CommandLineHelperStep(
         generatedProGuardConfig,
         customProguardConfigs,
         sdkProguardConfig,
         optimizationPasses,
         inputAndOutputEntries,
         additionalLibraryJarsForProguard,
         proguardDirectory,
         pathToProGuardCommandLineArgsFile);

     ProGuardObfuscateStep proGuardStep = new ProGuardObfuscateStep(
         inputAndOutputEntries,
         pathToProGuardCommandLineArgsFile,
         proguardJarOverride,
         proguardMaxHeapSize);

     buildableContext.recordArtifact(commandLineHelperStep.getConfigurationTxt());
     buildableContext.recordArtifact(commandLineHelperStep.getMappingTxt());

     steps.add(
         commandLineHelperStep,
         proGuardStep,
         // Some proguard configs can propagate the "-dontobfuscate" flag which disables
         // obfuscation and prevents the mapping.txt file from being generated.  So touch it
         // here to guarantee it's around when we go to cache this rule.
         new TouchStep(commandLineHelperStep.getMappingTxt()));
   }

   /**
    * @param inputAndOutputEntries Map of input/output pairs to proguard. The key represents an
    *     input jar (-injars); the value an output jar (-outjars).
    * @param pathToProGuardCommandLineArgsFile Path to file containing arguments to ProGuard.
    */
   private ProGuardObfuscateStep(
       Map<Path, Path> inputAndOutputEntries,
       Path pathToProGuardCommandLineArgsFile,
       Optional<Path> proguardJarOverride,
       String proguardMaxHeapSize) {
     this.inputAndOutputEntries = ImmutableMap.copyOf(inputAndOutputEntries);
     this.pathToProGuardCommandLineArgsFile = pathToProGuardCommandLineArgsFile;
     this.proguardJarOverride = proguardJarOverride;
     this.proguardMaxHeapSize = proguardMaxHeapSize;
   }

   @Override
   public String getShortName() {
     return "proguard_obfuscation";
   }

   @Override
   protected ImmutableList<String> getShellCommandInternal(ExecutionContext context) {
     // Run ProGuard as a standalone executable JAR file.
     Path proguardJar;
     if (proguardJarOverride.isPresent()) {
       proguardJar =
           context.getProjectFilesystem().getPathForRelativePath(proguardJarOverride.get());
     } else {
       AndroidPlatformTarget androidPlatformTarget = context.getAndroidPlatformTarget();
       proguardJar = androidPlatformTarget.getProguardJar();
     }

     ImmutableList.Builder<String> args = ImmutableList.builder();
     args.add("java")
         .add("-Xmx" + proguardMaxHeapSize)
         .add("-jar").add(proguardJar.toString())
         .add("@" + pathToProGuardCommandLineArgsFile);
     return args.build();
   }

   @Override
   public int execute(ExecutionContext context) throws InterruptedException {
     int exitCode = super.execute(context);

     // proguard has a peculiar behaviour when multiple -injars/outjars pairs are specified in which
     // any -injars that would have been fully stripped away will not produce their matching -outjars
     // as requested (so the file won't exist).  Our build steps are not sophisticated enough to
     // account for this and remove those entries from the classes to dex so we hack things here to
     // ensure that the files exist but are empty.
     if (exitCode == 0) {
       exitCode = ensureAllOutputsExist(context);
     }

     return exitCode;
   }

   private int ensureAllOutputsExist(ExecutionContext context) {
     for (Path outputJar : inputAndOutputEntries.values()) {
       File outputJarFile = outputJar.toFile();
       if (!outputJarFile.exists()) {
         try {
           createEmptyZip(outputJarFile);
         } catch (IOException e) {
           context.logError(e, "Error creating empty zip file at: %s.", outputJarFile);
           return 1;
         }
       }
     }
     return 0;
   }

   @VisibleForTesting
   static void createEmptyZip(File file) throws IOException {
     Files.createParentDirs(file);
     CustomZipOutputStream out = ZipOutputStreams.newOutputStream(file);
     // Sun's java 6 runtime doesn't allow us to create a truly empty zip, but this should be enough
     // to pass through dx/split-zip without any issue.
     // ...and Sun's java 7 runtime doesn't let us use an empty string for the zip entry name.
     out.putNextEntry(new ZipEntry("proguard_no_result"));
     out.close();
   }

   @Override
   public boolean equals(Object obj) {
     if (this == obj) {
       return true;
     } else if (!(obj instanceof ProGuardObfuscateStep)) {
       return false;
     }

     ProGuardObfuscateStep that = (ProGuardObfuscateStep) obj;
     return Objects.equal(this.inputAndOutputEntries, that.inputAndOutputEntries) &&
         Objects.equal(this.pathToProGuardCommandLineArgsFile,
             that.pathToProGuardCommandLineArgsFile);
   }

   @Override
   public int hashCode() {
     return Objects.hashCode(inputAndOutputEntries, pathToProGuardCommandLineArgsFile);
   }

   /**
    * Helper class to run as a step before ProGuardObfuscateStep to write out the
    * command-line parameters to a file.  The ProGuardObfuscateStep references
    * this file when it runs using ProGuard's '@' syntax.  This allows for longer
    * command-lines than would otherwise be supported.
    */
   @VisibleForTesting
   static class CommandLineHelperStep extends AbstractExecutionStep {

     private final Path generatedProGuardConfig;
     private final Set<Path> customProguardConfigs;
     private final Map<Path, Path> inputAndOutputEntries;
     private final ImmutableSet<Path> additionalLibraryJarsForProguard;
     private final SdkProguardType sdkProguardConfig;
     private final Optional<Integer> optimizationPasses;
     private final Path proguardDirectory;
     private final Path pathToProGuardCommandLineArgsFile;

     /**
      * @param generatedProGuardConfig Proguard configuration as produced by aapt.
      * @param customProguardConfigs Main rule and its dependencies proguard configurations.
      * @param sdkProguardConfig Which proguard config from the Android SDK to use.
      * @param inputAndOutputEntries Map of input/output pairs to proguard.  The key represents an
      *     input jar (-injars); the value an output jar (-outjars).
      * @param additionalLibraryJarsForProguard Libraries that are not operated upon by proguard but
      *     needed to resolve symbols.
      * @param proguardDirectory Output directory for various proguard-generated meta artifacts.
      * @param pathToProGuardCommandLineArgsFile Path to file containing arguments to ProGuard.
      */
     private CommandLineHelperStep(
         Path generatedProGuardConfig,
         Set<Path> customProguardConfigs,
         SdkProguardType sdkProguardConfig,
         Optional<Integer> optimizationPasses,
         Map<Path, Path> inputAndOutputEntries,
         Set<Path> additionalLibraryJarsForProguard,
         Path proguardDirectory,
         Path pathToProGuardCommandLineArgsFile) {
       super("write_proguard_command_line_parameters");
       this.generatedProGuardConfig = generatedProGuardConfig;
       this.customProguardConfigs = ImmutableSet.copyOf(customProguardConfigs);
       this.sdkProguardConfig = sdkProguardConfig;
       this.optimizationPasses = optimizationPasses;
       this.inputAndOutputEntries = ImmutableMap.copyOf(inputAndOutputEntries);
       this.additionalLibraryJarsForProguard = ImmutableSet.copyOf(additionalLibraryJarsForProguard);
       this.proguardDirectory = proguardDirectory;
       this.pathToProGuardCommandLineArgsFile = pathToProGuardCommandLineArgsFile;
     }

     @Override
     public int execute(ExecutionContext context) {
       String proGuardArguments = Joiner.on('\n').join(getParameters(context));
       try {
         context.getProjectFilesystem().writeContentsToPath(
             proGuardArguments,
             pathToProGuardCommandLineArgsFile);
       } catch (IOException e) {
         context.logError(e,
             "Error writing ProGuard arguments to file: %s.",
             pathToProGuardCommandLineArgsFile);
         return 1;
       }

       return 0;
     }

     /** @return the list of arguments to pass to ProGuard. */
     @VisibleForTesting
     ImmutableList<String> getParameters(ExecutionContext context) {
       ImmutableList.Builder<String> args = ImmutableList.builder();
       AndroidPlatformTarget androidPlatformTarget = context.getAndroidPlatformTarget();

       // Relative paths should be interpreted relative to project directory root, not the
       // written parameters file.
       args.add("-basedirectory")
           .add(context.getProjectDirectoryRoot().toAbsolutePath().toString());

       // -include
       switch (sdkProguardConfig) {
         case OPTIMIZED:
           args.add("-include")
               .add(androidPlatformTarget.getOptimizedProguardConfig().toString());
           if (optimizationPasses.isPresent()) {
             args.add("-optimizationpasses").add(optimizationPasses.get().toString());
           }
           break;
         case DEFAULT:
           args.add("-include").add(androidPlatformTarget.getProguardConfig().toString());
           break;
         case NONE:
           break;
         default:
           throw new RuntimeException("Illegal value for sdkProguardConfig: " + sdkProguardConfig);
       }
       for (Path proguardConfig : customProguardConfigs) {
         args.add("-include").add(proguardConfig.toString());
       }
       args.add("-include").add(generatedProGuardConfig.toString());

       // -injars and -outjars paired together for each input.
       for (Map.Entry<Path, Path> inputOutputEntry : inputAndOutputEntries.entrySet()) {
         args.add("-injars").add(inputOutputEntry.getKey().toString());
         args.add("-outjars").add(inputOutputEntry.getValue().toString());
       }

       // -libraryjars
       Iterable<Path> bootclasspathPaths = androidPlatformTarget.getBootclasspathEntries();
       Iterable<Path> libraryJars = Iterables.concat(bootclasspathPaths,
           additionalLibraryJarsForProguard);
       args.add("-libraryjars").add(Joiner.on(':').join(libraryJars));

       // -dump
       args.add("-printmapping").add(getMappingTxt().toString());
       args.add("-printconfiguration").add(getConfigurationTxt().toString());

       return args.build();
     }

     public Path getConfigurationTxt() {
       return proguardDirectory.resolve("configuration.txt");
     }

     public Path getMappingTxt() {
       return proguardDirectory.resolve("mapping.txt");
     }

     @Override
     public boolean equals(Object obj) {
       if (!(obj instanceof CommandLineHelperStep)) {
         return false;
       }
       CommandLineHelperStep that = (CommandLineHelperStep) obj;

       return
           Objects.equal(sdkProguardConfig, that.sdkProguardConfig) &&
           Objects.equal(additionalLibraryJarsForProguard,
               that.additionalLibraryJarsForProguard) &&
           Objects.equal(customProguardConfigs, that.customProguardConfigs) &&
           Objects.equal(generatedProGuardConfig, that.generatedProGuardConfig) &&
           Objects.equal(inputAndOutputEntries, that.inputAndOutputEntries) &&
           Objects.equal(proguardDirectory, that.proguardDirectory) &&
           Objects.equal(pathToProGuardCommandLineArgsFile, that.pathToProGuardCommandLineArgsFile);
     }

     @Override
     public int hashCode() {
       return Objects.hashCode(
           sdkProguardConfig,
           additionalLibraryJarsForProguard,
           customProguardConfigs,
           generatedProGuardConfig,
           inputAndOutputEntries,
           proguardDirectory,
           pathToProGuardCommandLineArgsFile);
     }
   }
 }
	/*
	* Copyright 2012-present Facebook, Inc.
	*
	* 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.facebook.buck.android;

	import com.facebook.buck.rules.BuildableContext;
	import com.facebook.buck.shell.ShellStep;
	import com.facebook.buck.step.AbstractExecutionStep;
	import com.facebook.buck.step.ExecutionContext;
	import com.facebook.buck.step.Step;
	import com.facebook.buck.step.fs.TouchStep;
	import com.facebook.buck.zip.CustomZipOutputStream;
	import com.facebook.buck.zip.ZipOutputStreams;
	import com.google.common.annotations.VisibleForTesting;
	import com.google.common.base.Joiner;
	import com.google.common.base.Objects;
	import com.google.common.base.Optional;
	import com.google.common.collect.ImmutableList;
	import com.google.common.collect.ImmutableMap;
	import com.google.common.collect.ImmutableSet;
	import com.google.common.collect.Iterables;
	import com.google.common.io.Files;

	import java.io.File;
	import java.io.IOException;
	import java.nio.file.Path;
	import java.util.Map;
	import java.util.Set;
	import java.util.zip.ZipEntry;

	public final class ProGuardObfuscateStep extends ShellStep {

	static enum SdkProguardType {
	DEFAULT,
	OPTIMIZED,
	NONE,
	}

	private final Map<Path, Path> inputAndOutputEntries;
	private final Path pathToProGuardCommandLineArgsFile;
	private final Optional<Path> proguardJarOverride;
	private final String proguardMaxHeapSize;

	/**
	* Create steps that write out ProGuard's command line arguments to a text file and then run
	* ProGuard using those arguments. We write the arguments to a file to avoid blowing out
	* exec()'s ARG_MAX limit.
	*
	* @param steps Where to append the generated steps.
	*/
	public static void create(
	Optional<Path> proguardJarOverride,
	String proguardMaxHeapSize,
	Path generatedProGuardConfig,
	Set<Path> customProguardConfigs,
	SdkProguardType sdkProguardConfig,
	Optional<Integer> optimizationPasses,
	Map<Path, Path> inputAndOutputEntries,
	Set<Path> additionalLibraryJarsForProguard,
	Path proguardDirectory,
	BuildableContext buildableContext,
	ImmutableList.Builder<Step> steps) {

	Path pathToProGuardCommandLineArgsFile = proguardDirectory.resolve("command-line.txt");

	CommandLineHelperStep commandLineHelperStep = new CommandLineHelperStep(
	generatedProGuardConfig,
	customProguardConfigs,
	sdkProguardConfig,
	optimizationPasses,
	inputAndOutputEntries,
	additionalLibraryJarsForProguard,
	proguardDirectory,
	pathToProGuardCommandLineArgsFile);

	ProGuardObfuscateStep proGuardStep = new ProGuardObfuscateStep(
	inputAndOutputEntries,
	pathToProGuardCommandLineArgsFile,
	proguardJarOverride,
	proguardMaxHeapSize);

	buildableContext.recordArtifact(commandLineHelperStep.getConfigurationTxt());
	buildableContext.recordArtifact(commandLineHelperStep.getMappingTxt());

	steps.add(
	commandLineHelperStep,
	proGuardStep,
	// Some proguard configs can propagate the "-dontobfuscate" flag which disables
	// obfuscation and prevents the mapping.txt file from being generated. So touch it
	// here to guarantee it's around when we go to cache this rule.
	new TouchStep(commandLineHelperStep.getMappingTxt()));
	}

	/**
	* @param inputAndOutputEntries Map of input/output pairs to proguard. The key represents an
	* input jar (-injars); the value an output jar (-outjars).
	* @param pathToProGuardCommandLineArgsFile Path to file containing arguments to ProGuard.
	*/
	private ProGuardObfuscateStep(
	Map<Path, Path> inputAndOutputEntries,
	Path pathToProGuardCommandLineArgsFile,
	Optional<Path> proguardJarOverride,
	String proguardMaxHeapSize) {
	this.inputAndOutputEntries = ImmutableMap.copyOf(inputAndOutputEntries);
	this.pathToProGuardCommandLineArgsFile = pathToProGuardCommandLineArgsFile;
	this.proguardJarOverride = proguardJarOverride;
	this.proguardMaxHeapSize = proguardMaxHeapSize;
	}

	@Override
	public String getShortName() {
	return "proguard_obfuscation";
	}

	@Override
	protected ImmutableList<String> getShellCommandInternal(ExecutionContext context) {
	// Run ProGuard as a standalone executable JAR file.
	Path proguardJar;
	if (proguardJarOverride.isPresent()) {
	proguardJar =
	context.getProjectFilesystem().getPathForRelativePath(proguardJarOverride.get());
	} else {
	AndroidPlatformTarget androidPlatformTarget = context.getAndroidPlatformTarget();
	proguardJar = androidPlatformTarget.getProguardJar();
	}

	ImmutableList.Builder<String> args = ImmutableList.builder();
	args.add("java")
	.add("-Xmx" + proguardMaxHeapSize)
	.add("-jar").add(proguardJar.toString())
	.add("@" + pathToProGuardCommandLineArgsFile);
	return args.build();
	}

	@Override
	public int execute(ExecutionContext context) throws InterruptedException {
	int exitCode = super.execute(context);

	// proguard has a peculiar behaviour when multiple -injars/outjars pairs are specified in which
	// any -injars that would have been fully stripped away will not produce their matching -outjars
	// as requested (so the file won't exist). Our build steps are not sophisticated enough to
	// account for this and remove those entries from the classes to dex so we hack things here to
	// ensure that the files exist but are empty.
	if (exitCode == 0) {
	exitCode = ensureAllOutputsExist(context);
	}

	return exitCode;
	}

	private int ensureAllOutputsExist(ExecutionContext context) {
	for (Path outputJar : inputAndOutputEntries.values()) {
	File outputJarFile = outputJar.toFile();
	if (!outputJarFile.exists()) {
	try {
	createEmptyZip(outputJarFile);
	} catch (IOException e) {
	context.logError(e, "Error creating empty zip file at: %s.", outputJarFile);
	return 1;
	}
	}
	}
	return 0;
	}

	@VisibleForTesting
	static void createEmptyZip(File file) throws IOException {
	Files.createParentDirs(file);
	CustomZipOutputStream out = ZipOutputStreams.newOutputStream(file);
	// Sun's java 6 runtime doesn't allow us to create a truly empty zip, but this should be enough
	// to pass through dx/split-zip without any issue.
	// ...and Sun's java 7 runtime doesn't let us use an empty string for the zip entry name.
	out.putNextEntry(new ZipEntry("proguard_no_result"));
	out.close();
	}

	@Override
	public boolean equals(Object obj) {
	if (this == obj) {
	return true;
	} else if (!(obj instanceof ProGuardObfuscateStep)) {
	return false;
	}

	ProGuardObfuscateStep that = (ProGuardObfuscateStep) obj;
	return Objects.equal(this.inputAndOutputEntries, that.inputAndOutputEntries) &&
	Objects.equal(this.pathToProGuardCommandLineArgsFile,
	that.pathToProGuardCommandLineArgsFile);
	}

	@Override
	public int hashCode() {
	return Objects.hashCode(inputAndOutputEntries, pathToProGuardCommandLineArgsFile);
	}

	/**
	* Helper class to run as a step before ProGuardObfuscateStep to write out the
	* command-line parameters to a file. The ProGuardObfuscateStep references
	* this file when it runs using ProGuard's '@' syntax. This allows for longer
	* command-lines than would otherwise be supported.
	*/
	@VisibleForTesting
	static class CommandLineHelperStep extends AbstractExecutionStep {

	private final Path generatedProGuardConfig;
	private final Set<Path> customProguardConfigs;
	private final Map<Path, Path> inputAndOutputEntries;
	private final ImmutableSet<Path> additionalLibraryJarsForProguard;
	private final SdkProguardType sdkProguardConfig;
	private final Optional<Integer> optimizationPasses;
	private final Path proguardDirectory;
	private final Path pathToProGuardCommandLineArgsFile;

	/**
	* @param generatedProGuardConfig Proguard configuration as produced by aapt.
	* @param customProguardConfigs Main rule and its dependencies proguard configurations.
	* @param sdkProguardConfig Which proguard config from the Android SDK to use.
	* @param inputAndOutputEntries Map of input/output pairs to proguard. The key represents an
	* input jar (-injars); the value an output jar (-outjars).
	* @param additionalLibraryJarsForProguard Libraries that are not operated upon by proguard but
	* needed to resolve symbols.
	* @param proguardDirectory Output directory for various proguard-generated meta artifacts.
	* @param pathToProGuardCommandLineArgsFile Path to file containing arguments to ProGuard.
	*/
	private CommandLineHelperStep(
	Path generatedProGuardConfig,
	Set<Path> customProguardConfigs,
	SdkProguardType sdkProguardConfig,
	Optional<Integer> optimizationPasses,
	Map<Path, Path> inputAndOutputEntries,
	Set<Path> additionalLibraryJarsForProguard,
	Path proguardDirectory,
	Path pathToProGuardCommandLineArgsFile) {
	super("write_proguard_command_line_parameters");
	this.generatedProGuardConfig = generatedProGuardConfig;
	this.customProguardConfigs = ImmutableSet.copyOf(customProguardConfigs);
	this.sdkProguardConfig = sdkProguardConfig;
	this.optimizationPasses = optimizationPasses;
	this.inputAndOutputEntries = ImmutableMap.copyOf(inputAndOutputEntries);
	this.additionalLibraryJarsForProguard = ImmutableSet.copyOf(additionalLibraryJarsForProguard);
	this.proguardDirectory = proguardDirectory;
	this.pathToProGuardCommandLineArgsFile = pathToProGuardCommandLineArgsFile;
	}

	@Override
	public int execute(ExecutionContext context) {
	String proGuardArguments = Joiner.on('\n').join(getParameters(context));
	try {
	context.getProjectFilesystem().writeContentsToPath(
	proGuardArguments,
	pathToProGuardCommandLineArgsFile);
	} catch (IOException e) {
	context.logError(e,
	"Error writing ProGuard arguments to file: %s.",
	pathToProGuardCommandLineArgsFile);
	return 1;
	}

	return 0;
	}

	/** @return the list of arguments to pass to ProGuard. */
	@VisibleForTesting
	ImmutableList<String> getParameters(ExecutionContext context) {
	ImmutableList.Builder<String> args = ImmutableList.builder();
	AndroidPlatformTarget androidPlatformTarget = context.getAndroidPlatformTarget();

	// Relative paths should be interpreted relative to project directory root, not the
	// written parameters file.
	args.add("-basedirectory")
	.add(context.getProjectDirectoryRoot().toAbsolutePath().toString());

	// -include
	switch (sdkProguardConfig) {
	case OPTIMIZED:
	args.add("-include")
	.add(androidPlatformTarget.getOptimizedProguardConfig().toString());
	if (optimizationPasses.isPresent()) {
	args.add("-optimizationpasses").add(optimizationPasses.get().toString());
	}
	break;
	case DEFAULT:
	args.add("-include").add(androidPlatformTarget.getProguardConfig().toString());
	break;
	case NONE:
	break;
	default:
	throw new RuntimeException("Illegal value for sdkProguardConfig: " + sdkProguardConfig);
	}
	for (Path proguardConfig : customProguardConfigs) {
	args.add("-include").add(proguardConfig.toString());
	}
	args.add("-include").add(generatedProGuardConfig.toString());

	// -injars and -outjars paired together for each input.
	for (Map.Entry<Path, Path> inputOutputEntry : inputAndOutputEntries.entrySet()) {
	args.add("-injars").add(inputOutputEntry.getKey().toString());
	args.add("-outjars").add(inputOutputEntry.getValue().toString());
	}

	// -libraryjars
	Iterable<Path> bootclasspathPaths = androidPlatformTarget.getBootclasspathEntries();
	Iterable<Path> libraryJars = Iterables.concat(bootclasspathPaths,
	additionalLibraryJarsForProguard);
	args.add("-libraryjars").add(Joiner.on(':').join(libraryJars));

	// -dump
	args.add("-printmapping").add(getMappingTxt().toString());
	args.add("-printconfiguration").add(getConfigurationTxt().toString());

	return args.build();
	}

	public Path getConfigurationTxt() {
	return proguardDirectory.resolve("configuration.txt");
	}

	public Path getMappingTxt() {
	return proguardDirectory.resolve("mapping.txt");
	}

	@Override
	public boolean equals(Object obj) {
	if (!(obj instanceof CommandLineHelperStep)) {
	return false;
	}
	CommandLineHelperStep that = (CommandLineHelperStep) obj;

	return
	Objects.equal(sdkProguardConfig, that.sdkProguardConfig) &&
	Objects.equal(additionalLibraryJarsForProguard,
	that.additionalLibraryJarsForProguard) &&
	Objects.equal(customProguardConfigs, that.customProguardConfigs) &&
	Objects.equal(generatedProGuardConfig, that.generatedProGuardConfig) &&
	Objects.equal(inputAndOutputEntries, that.inputAndOutputEntries) &&
	Objects.equal(proguardDirectory, that.proguardDirectory) &&
	Objects.equal(pathToProGuardCommandLineArgsFile, that.pathToProGuardCommandLineArgsFile);
	}

	@Override
	public int hashCode() {
	return Objects.hashCode(
	sdkProguardConfig,
	additionalLibraryJarsForProguard,
	customProguardConfigs,
	generatedProGuardConfig,
	inputAndOutputEntries,
	proguardDirectory,
	pathToProGuardCommandLineArgsFile);
	}
	}
	}