Split ProGuard file into two halves

This changeset splits the proguard.cfg into two halves:

(1) All the general Android settings go into
    $ANDROID_SDK/proguard/proguard-android.txt.

    This defines shrinking rules like keep custom views, etc. The
    crucial point is that this information is maintained and updated
    by Tools updates, so whenever new APIs are added to Android, or
    whenever bugs are found in the configuration such as flags needed
    to work with Dalvik, we can make the updates - we don't have old
    snapshots living on in projects.

(2) Any project specific settings go to proguard-project.txt in the
    project.

(3) The proguard.config property in project.properties now refers to a
    *path* of configuration files, which are all passed to ProGuard in
    the given order. The code which processes this setting will
    substitute android.sdk.home and user.home variables, so the path
    does not have to be hardcoded to point to the project-android.txt
    file.

    The default project templates have been updated to include a
    commented out configuration setting up proguard as described
    above.

The default proguard file name was changed from proguard.cfg to
proguard-project.txt such that it can be directly opened in Eclipse
and to make it clear it's an editable text file.

Lint was updated to find the Proguard file via the proguard.config
property as well as via the old and new default names for projects not
enabled with ProGuard.

A subsequent CL will add a lint check which identifies projects
containing the old setup (full local configuration) and offer to
replace it with the new setup.

Change-Id: I44b4c97a160114c2382f02f843c95486a0dc9d6b

3 files changed, 51 insertions, 7 deletions

diff --git a/files/ant/build.xml b/files/ant/build.xml
index 622d558..e47c3fe 100644
--- a/files/ant/build.xml
+++ b/files/ant/build.xml
@@ -766,13 +766,24 @@
                     </firstmatchmapper>
                 </pathconvert>
 
+                <!-- Turn the path property ${proguard.config} from an A:B:C property
+                     into a series of includes: -include A -include B -include C
+                     suitable for processing by the ProGuard task. Note - this does
+                     not include the leading '-include "' or the closing '"'; those
+                     are added under the <proguard> call below.
+                -->
+                <path id="proguard.configpath">
+                    <pathelement path="${proguard.config}"/>
+                </path>
+                <pathconvert pathsep='" -include "' property="proguard.configcmd" refid="proguard.configpath"/>
+
                 <mkdir   dir="${obfuscate.absolute.dir}" />
                 <delete file="${preobfuscate.jar.file}"/>
                 <delete file="${obfuscated.jar.file}"/>
                 <jar basedir="${out.classes.absolute.dir}"
                     destfile="${preobfuscate.jar.file}" />
                 <proguard>
-                    @${proguard.config}
+                    -include      "${proguard.configcmd}"
                     -injars       ${project.jars}
                     -outjars      "${obfuscated.jar.file}"
                     -libraryjars  ${android.libraryjars}
diff --git a/files/proguard.cfg b/files/proguard-android.txt
index 53f41fe..b3d2fe1 100644
--- a/files/proguard.cfg
+++ b/files/proguard-android.txt
@@ -1,16 +1,29 @@
--optimizationpasses 5
+# This is a configuration file for ProGuard.
+# http://proguard.sourceforge.net/index.html#manual/usage.html
+
 -dontusemixedcaseclassnames
 -dontskipnonpubliclibraryclasses
 -verbose
--optimizations !code/simplification/arithmetic,!code/simplification/cast,!field/*,!class/merging/*
--allowaccessmodification
--keepattributes *Annotation*
-
 
-# dex does not like code run through proguard optimize and preverify steps.
+# Optimization is turned off by default. Dex does not like code run
+# through the ProGuard optimize and preverify steps (and performs some
+# of these optimizations on its own).
 -dontoptimize
 -dontpreverify
 
+# If you want to enable optimization, you should include the
+# following:
+# -optimizations !code/simplification/arithmetic,!code/simplification/cast,!field/*,!class/merging/*
+# -optimizationpasses 5
+# -allowaccessmodification
+#
+# Note that you cannot just include these flags in your own
+# configuration file; if you are including this file, optimization
+# will be turned off. You'll need to either edit this file, or
+# duplicate the contents of this file and remove the include of this
+# file from your project's proguard.config path property.
+
+-keepattributes *Annotation*
 -keep public class * extends android.app.Activity
 -keep public class * extends android.app.Application
 -keep public class * extends android.app.Service
diff --git a/files/proguard-project.txt b/files/proguard-project.txt
new file mode 100644
index 0000000..f2fe155
--- /dev/null
+++ b/files/proguard-project.txt
@@ -0,0 +1,20 @@
+# To enable ProGuard in your project, edit project.properties
+# to define the proguard.config property as described in that file.
+#
+# Add project specific ProGuard rules here.
+# By default, the flags in this file are appended to flags specified
+# in ${sdk.dir}/tools/proguard/proguard-android.txt
+# You can edit the include path and order by changing the ProGuard
+# include property in project.properties.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# Add any project specific keep options here:
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}