docs: proguard help update

    buildTypes {

        release {

            minifyEnabled true

            proguardFiles getDefaultProguardFile('proguard-android.txt'), \

            'proguard-rules.txt'

            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'

        }

    }

}

    buildTypes {

        release {

            minifyEnabled true

            proguardFiles getDefaultProguardFile('proguard-android.txt'), \

                          'proguard-rules.txt'

            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'

        }

    }

}

<p><code>getDefaultProguardFile('proguard-android.txt')</code> obtains the default ProGuard

settings from the Android SDK installation. Android Studio adds the module-specific rules file

<code>proguard-rules.txt</code> at the root of the module, where you can add custom ProGuard

<code>proguard-rules.pro</code> at the root of the module, where you can add custom ProGuard

rules.</p>

<h3 id="configureSigning">Configure signing settings</h3>

      <h2>In this document</h2>

      <ol>

        <li><a href="#enabling">Enabling ProGuard</a></li>

        <li><a href="#enabling-gradle">Enabling ProGuard (Gradle Builds)</a></li>

        <li><a href="#enabling">Enabling ProGuard (Ant Builds)</a></li>

        <li><a href="#configuring">Configuring ProGuard</a></li>

    </div>

  </div>

  <p>The ProGuard tool shrinks, optimizes, and obfuscates your code by removing unused code and

  <p>The <a href="http://proguard.sourceforge.net">ProGuard</a> tool shrinks, optimizes, and

  obfuscates your code by removing unused code and

  renaming classes, fields, and methods with semantically obscure names. The result is a smaller

  sized <code>.apk</code> file that is more difficult to reverse engineer. Because ProGuard makes your

  application harder to reverse engineer, it is important that you use it

  <p>This document describes how to enable and configure ProGuard as well as use the

  <code>retrace</code> tool to decode obfuscated stack traces.</p>

  <h2 id="enabling">Enabling ProGuard</h2>

 <h2 id="enabling-gradle">Enabling ProGuard (Gradle Builds)</h2>

  <p>When you create a project in Android Studio or with the Gradle build system, the

  <code>minifyEnabled</code> property in the <code>build.gradle</code> file enables and disables

  ProGuard for release builds. The <code>minifyEnabled</code> property is part of the

  <code>buildTypes</code> <code>release</code> block that controls the settings applied to

  release builds. Set the <code>minifyEnabled</code> property to <code>true</code> to enable

  ProGuard, as shown in this example. </p>

  <pre class="no-pretty-print">

  android {

   ...

    buildTypes {

        release {

            minifyEnabled true

            proguardFiles getDefaultProguardFile('proguard-android.txt'),

            'proguard-rules.pro'

        }

    }

  }

  </pre>

  <p>The <code>getDefaultProguardFile('proguard-android.txt')</code> method obtains the default

  ProGuard settings from the Android SDK <code>tools/proguard/</code> folder. The

  <code>proguard-android-optimize.txt</code> file is also available in this Android SDK

  folder with the same rules but with optimizations enabled. ProGuard optimizations perform

  analysis at the bytecode level, inside and across methods to help make your app smaller and run

  faster. Android Studio adds the <code>proguard-rules.pro</code> file at the root of the module,

  so you can also easily add custom ProGuard rules specific to the current module. </p>

  <p>You can also add ProGuard files to the <code>getDefaultProguardFile</code>

  directive for all release builds or as part of the <code>productFlavor</code> settings in the

  <code>build.gradle</code> file to customize the settings applied to build variants. This example

  adds the <code>proguard-rules-new.pro</code> to the <code>proguardFiles</code>

  directive and the <code>other-rules.pro</code> file to the <code>flavor2</code> product flavor. </p>

<pre class="no-pretty-print">

    android {

   ...

    buildTypes {

        release {

            minifyEnabled true

            proguardFiles getDefaultProguardFile('proguard-android.txt'),

            'proguard-rules.pro', 'proguard-rules-new.pro'

        }

    }

   productFlavors {

        flavor1 {

        }

        flavor2 {

            proguardFile 'other-rules.pro'

        }

    }

 }

  </pre>

  <h2 id="enabling">Enabling ProGuard (Ant Builds)</h2>

  <p>When you create an Android project, a <code>proguard.cfg</code> file is automatically

  generated in the root directory of the project. This file defines how ProGuard optimizes and

  obfuscates your code, so it is very important that you understand how to customize it for your

  needs. The default configuration file only covers general cases, so you most likely have to edit

  it for your own needs. See the following section about <a href="#configuring">Configuring ProGuard</a> for information on 

  customizing the ProGuard configuration file.</p>

  it for your own needs. See the following section about <a href="#configuring">Configuring

  ProGuard</a> for information on customizing the ProGuard configuration file.</p>

  <p>To enable ProGuard so that it runs as part of an Ant or Eclipse build, set the

  <code>proguard.config</code> property in the <code>&lt;project_root&gt;/project.properties</code>

  file. The path can be an absolute path or a path relative to the project's root.</p>

<p class="note"><strong>Note:</strong> When using Android Studio, you must add Proguard

to your <code>gradle.build</code> file's build types. For more information, see the

<a href="http://tools.android.com/tech-docs/new-build-system/user-guide#TOC-Running-ProGuard"

>Gradle Plugin User Guide</a>.

  <p>If you left the <code>proguard.cfg</code> file in its default location (the project's root

  directory), you can specify its location like this:</p>

<p>If you left the <code>proguard.cfg</code> file in its default location (the project's root directory),

you can specify its location like this:</p>

<pre class="no-pretty-print">

proguard.config=proguard.cfg

</pre>

<p>

You can also move the the file to anywhere you want, and specify the absolute path to it:

</p>

<pre class="no-pretty-print">

proguard.config=/path/to/proguard.cfg

</pre>

  <p>When you build your application in release mode, either by running <code>ant release</code> or

  by using the <em>Export Wizard</em> in Eclipse, the build system automatically checks to see if

  the <code>proguard.config</code> property is set. If it is, ProGuard automatically processes

  <h2 id="configuring">Configuring ProGuard</h2>

  <p>For some situations, the default configurations in the <code>proguard.cfg</code> file will

  suffice. However, many situations are hard for ProGuard to analyze correctly and it might remove code

  that it thinks is not used, but your application actually needs. Some examples include:</p>

  <p>For some situations, the default configurations in the ProGuard configuration file will

  suffice. However, many situations are hard for ProGuard to analyze correctly and it might remove

  code that it thinks is not used, but your application actually needs. Some examples include:</p>

  <ul>

    <li>a class that is referenced only in the <code>AndroidManifest.xml</code> file</li>

    <li>dynamically referenced fields and methods</li>

  </ul>

  <p>The default <code>proguard.cfg</code> file tries to cover general cases, but you might

  <p>The default ProGuard configuration file tries to cover general cases, but you might

  encounter exceptions such as <code>ClassNotFoundException</code>, which happens when ProGuard

  strips away an entire class that your application calls.</p>

  <p>You can fix errors when ProGuard strips away your code by adding a <code>-keep</code> line in

  the <code>proguard.cfg</code> file. For example:</p>

  the ProGuard configuration file. For example:</p>

  <pre>

-keep public class <MyClass>

</pre>

  <p>When your obfuscated code outputs a stack trace, the method names are obfuscated, which makes

  debugging hard, if not impossible. Fortunately, whenever ProGuard runs, it outputs a

  <code>&lt;project_root&gt;/bin/proguard/mapping.txt</code> file, which shows you the original

  class, method, and field names mapped to their obfuscated names.</p>

  <code>mapping.txt</code> file, which shows you the original class, method, and field names

  mapped to their obfuscated names.</p>

  <p>The <code>retrace.bat</code> script on Windows or the <code>retrace.sh</code> script on Linux

  or Mac OS X can convert an obfuscated stack trace to a readable one. It is located in the

  <code>&lt;sdk_root&gt;/tools/proguard/</code> directory. The syntax for executing the 

  or Mac OS X can convert an obfuscated stack trace to a readable one. It is located

  in the <code>&lt;sdk_root&gt;/tools/proguard/</code> directory. The syntax for executing the

  <code>retrace</code> tool is:</p>

  <pre>retrace.bat|retrace.sh [-verbose] mapping.txt [&lt;stacktrace_file&gt;]</pre>

  <p>For example:</p>

  By retaining a copy of the <code>mapping.txt</code> file for each release build,

  you ensure that you can debug a problem if a user encounters a bug and submits an obfuscated stack trace.

  A project's <code>mapping.txt</code> file is overwritten every time you do a release build, so you must be

  careful about saving the versions that you need.</p>

  careful about saving the versions that you need. For Eclipse, this file is stored in

  <code>&lt;project_root&gt;/bin/proguard/</code>. For Android Studio, this file is stored in

  the app <code>build/outs/</code> folder. </p>

  <p>For example, say you publish an application and continue developing new features of

  the application for a new version. You then do a release build using ProGuard soon after. The

  on the user's device is gone. There are other situations where your <code>mapping.txt</code> file can be overwritten, so

  ensure that you save a copy for every release that you anticipate you have to debug.</p>

  <p>How you save the <code>mapping.txt</code> file is your decision. For example, you can rename them to

  include a version or build number, or you can version control them along with your source

  code.</p>

  <p>How you save the <code>mapping.txt</code> files is your decision. For example, you can rename

  the files to include a version or build number, or you can version control them along with your

  source code.</p>