diff --git a/build.gradle b/build.gradle
index 86ba02f..0f782b2 100644
--- a/build.gradle
+++ b/build.gradle
@@ -514,7 +514,7 @@
     classifier = null
     version = null
     manifest {
-        attributes 'Main-Class': 'com.android.tools.r8.R8'
+        attributes 'Main-Class': 'com.android.tools.r8.SwissArmyKnife'
     }
     // In order to build without dependencies, pass the exclude_deps property using:
     // gradle -Pexclude_deps R8
@@ -527,164 +527,27 @@
 }
 
 task D8(type: ShadowJar) {
-    from consolidatedLicense.outputs.files
-    exclude { path ->
-      path.getRelativePath().getPathString().startsWith("META-INF")
-    }
+    from R8.outputs.files
     baseName 'd8'
-    classifier = null
-    version = null
     manifest {
         attributes 'Main-Class': 'com.android.tools.r8.D8'
     }
-    // In order to build without dependencies, pass the exclude_deps property using:
-    // gradle -Pexclude_deps D8
-    if (!project.hasProperty('exclude_deps')) {
-        from repackageSources.outputs.files
-        from repackageDeps.outputs.files
-    } else {
-        from sourceSets.main.output
-    }
 }
 
-task CompatDx(type: Jar) {
-    from sourceSets.main.output
+task CompatDx(type: ShadowJar) {
+    from R8.outputs.files
     baseName 'compatdx'
     manifest {
       attributes 'Main-Class': 'com.android.tools.r8.compatdx.CompatDx'
     }
-    // In order to build without dependencies, pass the exclude_deps property using:
-    // gradle -Pexclude_deps CompatDx
-    if (!project.hasProperty('exclude_deps')) {
-        // Also include dependencies
-        from { configurations.compile.collect { it.isDirectory() ? it : zipTree(it) } }
-    }
 }
 
-task DexFileMerger(type: Jar) {
-    from sourceSets.main.output
-    baseName 'dexfilemerger'
-    manifest {
-      attributes 'Main-Class': 'com.android.tools.r8.dexfilemerger.DexFileMerger'
-    }
-    // In order to build without dependencies, pass the exclude_deps property using:
-    // gradle -Pexclude_deps CompatDx
-    if (!project.hasProperty('exclude_deps')) {
-        // Also include dependencies
-        from { configurations.compile.collect { it.isDirectory() ? it : zipTree(it) } }
-    }
-}
-
-task DexSplitter(type: Jar) {
-    from sourceSets.main.output
-    baseName 'dexsplitter'
-    manifest {
-      attributes 'Main-Class': 'com.android.tools.r8.dexsplitter.DexSplitter'
-    }
-    // In order to build without dependencies, pass the exclude_deps property using:
-    // gradle -Pexclude_deps CompatDx
-    if (!project.hasProperty('exclude_deps')) {
-        // Also include dependencies
-        from { configurations.compile.collect { it.isDirectory() ? it : zipTree(it) } }
-    }
-}
-
-task CompatProguard(type: Jar) {
-    from sourceSets.main.output
+task CompatProguard(type: ShadowJar) {
+    from R8.outputs.files
     baseName 'compatproguard'
     manifest {
         attributes 'Main-Class': 'com.android.tools.r8.compatproguard.CompatProguard'
     }
-    // In order to build without dependencies, pass the exclude_deps property using:
-    // gradle -Pexclude_deps CompatProguard
-    if (!project.hasProperty('exclude_deps')) {
-        // Also include dependencies
-        from { configurations.compile.collect { it.isDirectory() ? it : zipTree(it) } }
-    }
-}
-
-task D8Logger(type: Jar) {
-    from sourceSets.main.output
-    baseName 'd8logger'
-    manifest {
-      attributes 'Main-Class': 'com.android.tools.r8.D8Logger'
-    }
-    // In order to build without dependencies, pass the exclude_deps property using:
-    // gradle -Pexclude_deps D8Logger
-    if (!project.hasProperty('exclude_deps')) {
-        // Also include dependencies
-        from { configurations.compile.collect { it.isDirectory() ? it : zipTree(it) } }
-    }
-}
-
-task disasm(type: Jar) {
-    from sourceSets.main.output
-    baseName 'disasm'
-    manifest {
-        attributes 'Main-Class': 'com.android.tools.r8.Disassemble'
-    }
-    // In order to build without dependencies, pass the exclude_deps property using:
-    // gradle -Pexclude_deps D8
-    if (!project.hasProperty('exclude_deps')) {
-        // Also include dependencies
-        from { configurations.compile.collect { it.isDirectory() ? it : zipTree(it) } }
-    }
-}
-
-task bisect(type: Jar) {
-    from sourceSets.main.output
-    baseName 'bisect'
-    manifest {
-      attributes 'Main-Class': 'com.android.tools.r8.bisect.Bisect'
-    }
-    // In order to build without dependencies, pass the exclude_deps property using:
-    // gradle -Pexclude_deps R8
-    if (!project.hasProperty('exclude_deps')) {
-        // Also include dependencies
-        from { configurations.compile.collect { it.isDirectory() ? it : zipTree(it) } }
-    }
-}
-
-task DexSegments(type: Jar) {
-    from sourceSets.main.output
-    baseName 'dexsegments'
-    manifest {
-      attributes 'Main-Class': 'com.android.tools.r8.DexSegments'
-    }
-    // In order to build without dependencies, pass the exclude_deps property using:
-    // gradle -Pexclude_deps DexSegments
-    if (!project.hasProperty('exclude_deps')) {
-        // Also include dependencies
-        from { configurations.compile.collect { it.isDirectory() ? it : zipTree(it) } }
-    }
-}
-
-task maindex(type: Jar) {
-    from sourceSets.main.output
-    baseName 'maindex'
-    manifest {
-      attributes 'Main-Class': 'com.android.tools.r8.GenerateMainDexList'
-    }
-    // In order to build without dependencies, pass the exclude_deps property using:
-    // gradle -Pexclude_deps maindex
-    if (!project.hasProperty('exclude_deps')) {
-        // Also include dependencies
-        from { configurations.compile.collect { it.isDirectory() ? it : zipTree(it) } }
-    }
-}
-
-task ExtractMarker(type: Jar) {
-    from sourceSets.main.output
-    baseName 'extractmarker'
-    manifest {
-      attributes 'Main-Class': 'com.android.tools.r8.ExtractMarker'
-    }
-    // In order to build without dependencies, pass the exclude_deps property using:
-    // gradle -Pexclude_deps ExtractMarker
-    if (!project.hasProperty('exclude_deps')) {
-        // Also include dependencies
-        from { configurations.compile.collect { it.isDirectory() ? it : zipTree(it) } }
-    }
 }
 
 task bspatch(type: Jar) {
@@ -694,7 +557,7 @@
         attributes 'Main-Class': 'com.android.tools.r8.dex.BSPatch'
     }
     // In order to build without dependencies, pass the exclude_deps property using:
-    // gradle -Pexclude_deps maindex
+    // gradle -Pexclude_deps bspatch
     if (!project.hasProperty('exclude_deps')) {
         // Also include dependencies
         from {
@@ -703,20 +566,6 @@
     }
 }
 
-task jardiff(type: Jar) {
-    from sourceSets.main.output
-    baseName 'jardiff'
-    manifest {
-      attributes 'Main-Class': 'com.android.tools.r8.JarDiff'
-    }
-    // In order to build without dependencies, pass the exclude_deps property using:
-    // gradle -Pexclude_deps jardiff
-    if (!project.hasProperty('exclude_deps')) {
-        // Also include dependencies
-        from { configurations.compile.collect { it.isDirectory() ? it : zipTree(it) } }
-    }
-}
-
 task sourceJar(type: Jar, dependsOn: classes) {
     classifier = 'src'
     from sourceSets.main.allSource
diff --git a/src/main/java/com/android/tools/r8/SwissArmyKnife.java b/src/main/java/com/android/tools/r8/SwissArmyKnife.java
new file mode 100644
index 0000000..0e35847
--- /dev/null
+++ b/src/main/java/com/android/tools/r8/SwissArmyKnife.java
@@ -0,0 +1,83 @@
+// Copyright (c) 2018, the R8 project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+package com.android.tools.r8;
+
+import com.android.tools.r8.bisect.Bisect;
+import com.android.tools.r8.compatdx.CompatDx;
+import com.android.tools.r8.compatproguard.CompatProguard;
+import com.android.tools.r8.dexfilemerger.DexFileMerger;
+import com.android.tools.r8.dexsplitter.DexSplitter;
+import java.util.Arrays;
+
+/**
+ * Common entry point to everything in the R8 project.
+ *
+ * <p>This class is used as the main class in {@code r8.jar}. It checks the first command-line
+ * argument to find the tool to run, or runs {@link R8} if the first argument is not a recognized
+ * tool name.
+ *
+ * <p>The set of tools recognized by this class is defined by a switch statement in {@link
+ * SwissArmyKnife#main(String[])}.
+ */
+public class SwissArmyKnife {
+
+  public static void main(String[] args) throws Exception {
+    if (args.length == 0) {
+      runDefault(args);
+      return;
+    }
+    switch (args[0]) {
+      case "r8":
+        R8.main(shift(args));
+        break;
+      case "d8":
+        D8.main(shift(args));
+        break;
+      case "compatdx":
+        CompatDx.main(shift(args));
+        break;
+      case "dexfilemerger":
+        DexFileMerger.main(shift(args));
+        break;
+      case "dexsplitter":
+        DexSplitter.main(shift(args));
+        break;
+      case "compatproguard":
+        CompatProguard.main(shift(args));
+        break;
+      case "d8logger":
+        D8Logger.main(shift(args));
+        break;
+      case "disasm":
+        Disassemble.main(shift(args));
+        break;
+      case "bisect":
+        Bisect.main(shift(args));
+        break;
+      case "dexsegments":
+        DexSegments.main(shift(args));
+        break;
+      case "maindex":
+        GenerateMainDexList.main(shift(args));
+        break;
+      case "extractmarker":
+        ExtractMarker.main(shift(args));
+        break;
+      case "jardiff":
+        JarDiff.main(shift(args));
+        break;
+      default:
+        runDefault(args);
+        break;
+    }
+  }
+
+  private static void runDefault(String[] args) {
+    R8.main(args);
+  }
+
+  private static String[] shift(String[] args) {
+    return Arrays.copyOfRange(args, 1, args.length);
+  }
+}
diff --git a/tools/archive.py b/tools/archive.py
index 76df65e..07f138a 100755
--- a/tools/archive.py
+++ b/tools/archive.py
@@ -3,22 +3,25 @@
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
-import gradle
 import create_maven_release
-import d8
+import gradle
 import os
-import r8
+import shutil
 import subprocess
 import sys
+import toolhelper
 import utils
-import shutil
 import zipfile
 
 ARCHIVE_BUCKET = 'r8-releases'
 
+def GetToolVersion(jar_path):
+  output = subprocess.check_output(['java', '-jar', jar_path, '--version'])
+  return output.splitlines()[0].strip()
+
 def GetVersion():
-  r8_version = r8.run(['--version'], build = False).splitlines()[0].strip()
-  d8_version = d8.run(['--version'], build = False).splitlines()[0].strip()
+  r8_version = GetToolVersion(utils.R8_JAR)
+  d8_version = GetToolVersion(utils.D8_JAR)
   # The version printed is "D8 vVERSION_NUMBER" and "R8 vVERSION_NUMBER"
   # Sanity check that versions match.
   if d8_version.split()[1] != r8_version.split()[1]:
diff --git a/tools/bisect.py b/tools/bisect.py
index c8d1501..74c880e 100755
--- a/tools/bisect.py
+++ b/tools/bisect.py
@@ -3,33 +3,8 @@
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
-import gradle
-import os
-import subprocess
 import sys
-import utils
-
-JAR = os.path.join(utils.REPO_ROOT, 'build', 'libs', 'bisect.jar')
-
-def run(args, build, debug):
-  if build:
-    gradle.RunGradle(['bisect'])
-  cmd = ['java']
-  if debug:
-    cmd.append('-ea')
-  cmd.extend(['-jar', JAR])
-  cmd.extend(args)
-  subprocess.check_call(cmd)
-
-def main():
-  build = True
-  args = []
-  for arg in sys.argv[1:]:
-    if arg in ("--build", "--no-build"):
-      build = arg == "--build"
-    else:
-      args.append(arg)
-  run(args, build, True)
+import toolhelper
 
 if __name__ == '__main__':
-  sys.exit(main())
+  sys.exit(toolhelper.run('bisect', sys.argv[1:]))
diff --git a/tools/compatdx.py b/tools/compatdx.py
index 25a59db..c4cb320 100755
--- a/tools/compatdx.py
+++ b/tools/compatdx.py
@@ -3,42 +3,8 @@
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
-import gradle
-import os
-import subprocess
 import sys
-import utils
-
-def run(args, build = True, debug = True, profile = False, track_memory_file=None):
-  if build:
-    gradle.RunGradle(['CompatDX'])
-  cmd = []
-  if track_memory_file:
-    cmd.extend(['tools/track_memory.sh', track_memory_file])
-  cmd.append('java')
-  if debug:
-    cmd.append('-ea')
-  if profile:
-    cmd.append('-agentlib:hprof=cpu=samples,interval=1,depth=8')
-  cmd.extend(['-jar', utils.COMPATDX_JAR])
-  cmd.extend(args)
-  subprocess.check_call(cmd)
-
-def main():
-  build = True
-  args = []
-  for arg in sys.argv[1:]:
-    if arg in ("--build", "--no-build"):
-      build = arg == "--build"
-    else:
-      args.append(arg)
-  try:
-    run(args, build)
-  except subprocess.CalledProcessError as e:
-    # In case anything relevant was printed to stdout, normally this is already
-    # on stderr.
-    print(e.output)
-    return e.returncode
+import toolhelper
 
 if __name__ == '__main__':
-  sys.exit(main())
+  sys.exit(toolhelper.run('compatdx', sys.argv[1:]))
diff --git a/tools/compatproguard.py b/tools/compatproguard.py
new file mode 100755
index 0000000..10542e3
--- /dev/null
+++ b/tools/compatproguard.py
@@ -0,0 +1,10 @@
+#!/usr/bin/env python
+# Copyright (c) 2018, the R8 project authors. Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+import sys
+import toolhelper
+
+if __name__ == '__main__':
+  sys.exit(toolhelper.run('compatproguard', sys.argv[1:]))
diff --git a/tools/d8.py b/tools/d8.py
index bf97845..18a4a67 100755
--- a/tools/d8.py
+++ b/tools/d8.py
@@ -3,46 +3,8 @@
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
-import gradle
-import os
-import subprocess
 import sys
-import utils
-
-def run(args, build=True, debug=True, profile=False,
-        track_memory_file=None):
-  if build:
-    gradle.RunGradle(['D8'])
-  cmd = []
-  if track_memory_file:
-    cmd.extend(['tools/track_memory.sh', track_memory_file])
-  cmd.append('java')
-  if debug:
-    cmd.append('-ea')
-  if profile:
-    cmd.append('-agentlib:hprof=cpu=samples,interval=1,depth=8')
-  cmd.extend(['-jar', utils.D8_JAR])
-  cmd.extend(args)
-  utils.PrintCmd(cmd)
-  result = subprocess.check_output(cmd)
-  print(result)
-  return result
-
-def main():
-  build = True
-  args = []
-  for arg in sys.argv[1:]:
-    if arg in ("--build", "--no-build"):
-      build = arg == "--build"
-    else:
-      args.append(arg)
-  try:
-    run(args, build)
-  except subprocess.CalledProcessError as e:
-    # In case anything relevant was printed to stdout, normally this is already
-    # on stderr.
-    print(e.output)
-    return e.returncode
+import toolhelper
 
 if __name__ == '__main__':
-  sys.exit(main())
+  sys.exit(toolhelper.run('d8', sys.argv[1:]))
diff --git a/tools/d8logger.py b/tools/d8logger.py
new file mode 100755
index 0000000..9fb3508
--- /dev/null
+++ b/tools/d8logger.py
@@ -0,0 +1,10 @@
+#!/usr/bin/env python
+# Copyright (c) 2018, the R8 project authors. Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+import sys
+import toolhelper
+
+if __name__ == '__main__':
+  sys.exit(toolhelper.run('d8logger', sys.argv[1:]))
diff --git a/tools/dexfilemerger.py b/tools/dexfilemerger.py
new file mode 100755
index 0000000..7bdfc22
--- /dev/null
+++ b/tools/dexfilemerger.py
@@ -0,0 +1,10 @@
+#!/usr/bin/env python
+# Copyright (c) 2018, the R8 project authors. Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+import sys
+import toolhelper
+
+if __name__ == '__main__':
+  sys.exit(toolhelper.run('dexfilemerger', sys.argv[1:]))
diff --git a/tools/dexsegments.py b/tools/dexsegments.py
new file mode 100755
index 0000000..f984063
--- /dev/null
+++ b/tools/dexsegments.py
@@ -0,0 +1,10 @@
+#!/usr/bin/env python
+# Copyright (c) 2018, the R8 project authors. Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+import sys
+import toolhelper
+
+if __name__ == '__main__':
+  sys.exit(toolhelper.run('dexsegments', sys.argv[1:]))
diff --git a/tools/dexsplitter.py b/tools/dexsplitter.py
new file mode 100755
index 0000000..415b149
--- /dev/null
+++ b/tools/dexsplitter.py
@@ -0,0 +1,10 @@
+#!/usr/bin/env python
+# Copyright (c) 2018, the R8 project authors. Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+import sys
+import toolhelper
+
+if __name__ == '__main__':
+  sys.exit(toolhelper.run('dexsplitter', sys.argv[1:]))
diff --git a/tools/disasm.py b/tools/disasm.py
new file mode 100755
index 0000000..0d2599a
--- /dev/null
+++ b/tools/disasm.py
@@ -0,0 +1,10 @@
+#!/usr/bin/env python
+# Copyright (c) 2018, the R8 project authors. Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+import sys
+import toolhelper
+
+if __name__ == '__main__':
+  sys.exit(toolhelper.run('disasm', sys.argv[1:]))
diff --git a/tools/extractmarker.py b/tools/extractmarker.py
new file mode 100755
index 0000000..36a9c88
--- /dev/null
+++ b/tools/extractmarker.py
@@ -0,0 +1,10 @@
+#!/usr/bin/env python
+# Copyright (c) 2018, the R8 project authors. Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+import sys
+import toolhelper
+
+if __name__ == '__main__':
+  sys.exit(toolhelper.run('extractmarker', sys.argv[1:]))
diff --git a/tools/jardiff.py b/tools/jardiff.py
new file mode 100755
index 0000000..894131c
--- /dev/null
+++ b/tools/jardiff.py
@@ -0,0 +1,10 @@
+#!/usr/bin/env python
+# Copyright (c) 2018, the R8 project authors. Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+import sys
+import toolhelper
+
+if __name__ == '__main__':
+  sys.exit(toolhelper.run('jardiff', sys.argv[1:]))
diff --git a/tools/maindex.py b/tools/maindex.py
new file mode 100755
index 0000000..ff5329a
--- /dev/null
+++ b/tools/maindex.py
@@ -0,0 +1,10 @@
+#!/usr/bin/env python
+# Copyright (c) 2018, the R8 project authors. Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+import sys
+import toolhelper
+
+if __name__ == '__main__':
+  sys.exit(toolhelper.run('maindex', sys.argv[1:]))
diff --git a/tools/r8.py b/tools/r8.py
index 3ae4da7..60c60a0 100755
--- a/tools/r8.py
+++ b/tools/r8.py
@@ -3,46 +3,8 @@
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
-import gradle
-import os
-import subprocess
 import sys
-import utils
-
-def run(args, build=True, debug=True, profile=False,
-        track_memory_file=None):
-  if build:
-    gradle.RunGradle(['r8'])
-  cmd = []
-  if track_memory_file:
-    cmd.extend(['tools/track_memory.sh', track_memory_file])
-  cmd.append('java')
-  if debug:
-    cmd.append('-ea')
-  if profile:
-    cmd.append('-agentlib:hprof=cpu=samples,interval=1,depth=8')
-  cmd.extend(['-jar', utils.R8_JAR])
-  cmd.extend(args)
-  utils.PrintCmd(cmd)
-  result = subprocess.check_output(cmd)
-  print(result)
-  return result
-
-def main():
-  build = True
-  args = []
-  for arg in sys.argv[1:]:
-    if arg in ("--build", "--no-build"):
-      build = arg == "--build"
-    else:
-      args.append(arg)
-  try:
-    run(args, build)
-  except subprocess.CalledProcessError as e:
-    # In case anything relevant was printed to stdout, normally this is already
-    # on stderr.
-    print(e.output)
-    return e.returncode
+import toolhelper
 
 if __name__ == '__main__':
-  sys.exit(main())
+  sys.exit(toolhelper.run('r8', sys.argv[1:]))
diff --git a/tools/run-d8-on-gmscore.py b/tools/run-d8-on-gmscore.py
index 63865d0..b1bdc6e 100755
--- a/tools/run-d8-on-gmscore.py
+++ b/tools/run-d8-on-gmscore.py
@@ -3,11 +3,11 @@
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
-import d8
 import gmscore_data
 import optparse
 import os
 import sys
+import toolhelper
 
 def ParseOptions():
   result = optparse.OptionParser()
@@ -70,8 +70,13 @@
     with open(options.dump_args_file, 'w') as args_file:
       args_file.writelines([arg + os.linesep for arg in args])
   else:
-    d8.run(args, not options.no_build, not options.no_debug, options.profile,
-           options.track_memory_to_file)
+    toolhelper.run(
+        'd8',
+        args,
+        build=not options.no_build,
+        debug=not options.no_debug,
+        profile=options.profile,
+        track_memory_to_file=options.track_memory_to_file)
 
 if __name__ == '__main__':
   sys.exit(main())
diff --git a/tools/run_on_app.py b/tools/run_on_app.py
index b9bcc60..571d96d 100755
--- a/tools/run_on_app.py
+++ b/tools/run_on_app.py
@@ -10,10 +10,9 @@
 import sys
 import time
 
-import d8
 import gmail_data
 import gmscore_data
-import r8
+import toolhelper
 import utils
 import youtube_data
 
@@ -191,22 +190,20 @@
       if options.print_memoryuse and not options.track_memory_to_file:
         options.track_memory_to_file = os.path.join(temp,
             utils.MEMORY_USE_TMP_FILE)
-      if options.compiler == 'd8':
-        d8.run(args, not options.no_build, not options.no_debug,
-            options.profile, options.track_memory_to_file)
-      else:
-        if app_provided_pg_conf:
-          # Ensure that output of -printmapping and -printseeds go to the output
-          # location and not where the app Proguard configuration places them.
-          if outdir.endswith('.zip') or outdir.endswith('.jar'):
-            pg_outdir = os.path.dirname(outdir)
-          else:
-            pg_outdir = outdir
-          additional_pg_conf = GenerateAdditionalProguardConfiguration(
-              temp, os.path.abspath(pg_outdir))
-          args.extend(['--pg-conf', additional_pg_conf])
-        r8.run(args, not options.no_build, not options.no_debug,
-            options.profile, options.track_memory_to_file)
+      if options.compiler == 'r8' and app_provided_pg_conf:
+        # Ensure that output of -printmapping and -printseeds go to the output
+        # location and not where the app Proguard configuration places them.
+        if outdir.endswith('.zip') or outdir.endswith('.jar'):
+          pg_outdir = os.path.dirname(outdir)
+        else:
+          pg_outdir = outdir
+        additional_pg_conf = GenerateAdditionalProguardConfiguration(
+            temp, os.path.abspath(pg_outdir))
+        args.extend(['--pg-conf', additional_pg_conf])
+      toolhelper.run(options.compiler, args, build=not options.no_build,
+                     debug=not options.no_debug,
+                     profile=options.profile,
+                     track_memory_to_file=options.track_memory_to_file)
       if options.print_memoryuse:
         print('{}(MemoryUse): {}'
             .format(options.print_memoryuse,
diff --git a/tools/toolhelper.py b/tools/toolhelper.py
new file mode 100644
index 0000000..a7f509c
--- /dev/null
+++ b/tools/toolhelper.py
@@ -0,0 +1,38 @@
+# Copyright (c) 2018, the R8 project authors. Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+import gradle
+import os
+import subprocess
+import sys
+import utils
+
+def run(tool, args, build=None, debug=True,
+        profile=False, track_memory_file=None):
+  if build is None:
+    build, args = extract_build_from_args(args)
+  if build:
+    gradle.RunGradle(['r8'])
+  cmd = []
+  if track_memory_file:
+    cmd.extend(['tools/track_memory.sh', track_memory_file])
+  cmd.append('java')
+  if debug:
+    cmd.append('-ea')
+  if profile:
+    cmd.append('-agentlib:hprof=cpu=samples,interval=1,depth=8')
+  cmd.extend(['-jar', utils.R8_JAR, tool])
+  cmd.extend(args)
+  utils.PrintCmd(cmd)
+  return subprocess.call(cmd)
+
+def extract_build_from_args(input_args):
+  build = True
+  args = []
+  for arg in input_args:
+    if arg in ("--build", "--no-build"):
+      build = arg == "--build"
+    else:
+      args.append(arg)
+  return build, args