Test application for profiling, CMake params for debug symbols (pytorch#28406)

Summary:
Reason:
To have one-step build for test android application based on the current code state that is ready for profiling with simpleperf, systrace etc. to profile performance inside the application.

## Parameters to control debug symbols stripping
Introducing  /CMakeLists parameter `ANDROID_DEBUG_SYMBOLS` to be able not to strip symbols for pytorch (not add linker flag `-s`)
which is checked in `scripts/build_android.sh`

On gradle side stripping happens by default, and to prevent it we have to specify
```
android {
  packagingOptions {
       doNotStrip "**/*.so"
  }
}
```
which is now controlled by new gradle property `nativeLibsDoNotStrip `

## Test_App
`android/test_app` - android app with one MainActivity that does inference in cycle

`android/build_test_app.sh` - script to build libtorch with debug symbols for specified android abis and adds `NDK_DEBUG=1` and `-PnativeLibsDoNotStrip=true` to keep all debug symbols for profiling.
Script assembles all debug flavors:
```
└─ $ find . -type f -name *apk
./test_app/app/build/outputs/apk/mobilenetQuant/debug/test_app-mobilenetQuant-debug.apk
./test_app/app/build/outputs/apk/resnet/debug/test_app-resnet-debug.apk
```

## Different build configurations

Module for inference can be set in `android/test_app/app/build.gradle` as a BuildConfig parameters:
```
    productFlavors {
        mobilenetQuant {
            dimension "model"
            applicationIdSuffix ".mobilenetQuant"
            buildConfigField ("String", "MODULE_ASSET_NAME", buildConfigProps('MODULE_ASSET_NAME_MOBILENET_QUANT'))
            addManifestPlaceholders([APP_NAME: "PyMobileNetQuant"])
            buildConfigField ("String", "LOGCAT_TAG", "\"pytorch-mobilenet\"")
        }
        resnet {
            dimension "model"
            applicationIdSuffix ".resnet"
            buildConfigField ("String", "MODULE_ASSET_NAME", buildConfigProps('MODULE_ASSET_NAME_RESNET18'))
            addManifestPlaceholders([APP_NAME: "PyResnet"])
            buildConfigField ("String", "LOGCAT_TAG", "\"pytorch-resnet\"")
        }
```

In that case we can setup several apps on the same device for comparison, to separate packages `applicationIdSuffix`: 'org.pytorch.testapp.mobilenetQuant' and different application names and logcat tags as `manifestPlaceholder` and another BuildConfig parameter:
```
─ $ adb shell pm list packages | grep pytorch
package:org.pytorch.testapp.mobilenetQuant
package:org.pytorch.testapp.resnet
```

In future we can add another BuildConfig params e.g. single/multi threads and other configuration for profiling.

At the moment 2 flavors - for resnet18 and for mobilenetQuantized
which can be installed on connected device:

```
cd android
```
```
gradle test_app:installMobilenetQuantDebug
```
```
gradle test_app:installResnetDebug
```

## Testing:
```
cd android
sh build_test_app.sh
adb install -r test_app/app/build/outputs/apk/mobilenetQuant/debug/test_app-mobilenetQuant-debug.apk
```

```
cd $ANDROID_NDK
python simpleperf/run_simpleperf_on_device.py record --app org.pytorch.testapp.mobilenetQuant -g --duration 10 -o /data/local/tmp/perf.data
adb pull /data/local/tmp/perf.data
python simpleperf/report_html.py
```

Simpleperf report has all symbols:
![Screenshot 2019-10-22 11 06 21](https://user-images.githubusercontent.com/6638825/67315740-0bc50100-f4bc-11e9-8f9e-2499be13d63e.png)
Pull Request resolved: pytorch#28406

Differential Revision: D18386622

Pulled By: IvanKobzarev

fbshipit-source-id: 3a751192bbc4bc3c6d7f126b0b55086b4d586e7a

Author: IvanKobzarev

CMakeLists.txt

@@ -495,7 +495,7 @@ if(CMAKE_COMPILER_IS_GNUCXX AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 7.0.0
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-stringop-overflow")
 endif()
 
-if(ANDROID)
+if(ANDROID AND (NOT ANDROID_DEBUG_SYMBOLS))
   if(CMAKE_COMPILER_IS_GNUCXX)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -s")
   else()

android/.gitignore

@@ -6,11 +6,5 @@ gradle/wrapper
 .idea/*
 .externalNativeBuild
 build
-pytorch_android/src/main/cpp/libtorch_include/x86/**
-pytorch_android/src/main/cpp/libtorch_include/x86_64/**
-pytorch_android/src/main/cpp/libtorch_include/armeabi-v7a/**
-pytorch_android/src/main/cpp/libtorch_include/arm64-v8a/**
-pytorch_android/src/main/jniLibs/x86/**
-pytorch_android/src/main/jniLibs/x86_64/**
-pytorch_android/src/main/jniLibs/armeabi-v7a/**
-pytorch_android/src/main/jniLibs/arm64-v8a/**
+pytorch_android/src/main/cpp/libtorch_include/**
+pytorch_android/src/main/jniLibs/**

android/build_test_app.sh

@@ -0,0 +1,100 @@
+#!/bin/bash
+set -eux
+
+PYTORCH_DIR="$(cd $(dirname $0)/..; pwd -P)"
+
+PYTORCH_ANDROID_DIR=$PYTORCH_DIR/android
+WORK_DIR=$PYTORCH_DIR
+
+echo "PYTORCH_DIR:$PYTORCH_DIR"
+echo "WORK_DIR:$WORK_DIR"
+
+echo "ANDROID_HOME:$ANDROID_HOME"
+if [ ! -z "$ANDROID_HOME" ]; then
+  echo "ANDROID_HOME not set; please set it to Android sdk directory"
+fi
+
+if [ ! -d $ANDROID_HOME ]; then
+  echo "ANDROID_HOME not a directory; did you install it under $ANDROID_HOME?"
+  exit 1
+fi
+
+GRADLE_PATH=gradle
+GRADLE_NOT_FOUND_MSG="Unable to find gradle, please add it to PATH or set GRADLE_HOME"
+
+if [ ! -x "$(command -v gradle)" ]; then
+  if [ -z "$GRADLE_HOME" ]; then
+    echo GRADLE_NOT_FOUND_MSG
+    exit 1
+  fi
+  GRADLE_PATH=$GRADLE_HOME/bin/gradle
+  if [ ! -f "$GRADLE_PATH" ]; then
+    echo GRADLE_NOT_FOUND_MSG
+    exit 1
+  fi
+fi
+echo "GRADLE_PATH:$GRADLE_PATH"
+
+ABIS_LIST="armeabi-v7a,arm64-v8a,x86,x86_64"
+CUSTOM_ABIS_LIST=false
+if [ $# -gt 0 ]; then
+  ABIS_LIST=$1
+  CUSTOM_ABIS_LIST=true
+fi
+
+echo "ABIS_LIST:$ABIS_LIST"
+
+LIB_DIR=$PYTORCH_ANDROID_DIR/pytorch_android/src/main/jniLibs
+INCLUDE_DIR=$PYTORCH_ANDROID_DIR/pytorch_android/src/main/cpp/libtorch_include
+mkdir -p $LIB_DIR
+rm $LIB_DIR/*
+mkdir -p $INCLUDE_DIR
+
+for abi in $(echo $ABIS_LIST | tr ',' '\n')
+do
+echo "abi:$abi"
+
+OUT_DIR=$WORK_DIR/build_android_$abi
+
+rm -rf $OUT_DIR
+mkdir -p $OUT_DIR
+
+pushd $PYTORCH_DIR
+python $PYTORCH_DIR/setup.py clean
+
+ANDROID_ABI=$abi BUILD_PYTORCH_MOBILE=1 VERBOSE=1 ANDROID_DEBUG_SYMBOLS=1 $PYTORCH_DIR/scripts/build_android.sh -DANDROID_CCACHE=$(which ccache)
+
+cp -R $PYTORCH_DIR/build_android/install/lib $OUT_DIR/
+cp -R $PYTORCH_DIR/build_android/install/include $OUT_DIR/
+
+echo "$abi build output lib,include copied to $OUT_DIR"
+
+LIB_LINK_PATH=$LIB_DIR/$abi
+INCLUDE_LINK_PATH=$INCLUDE_DIR/$abi
+
+rm -f $LIB_LINK_PATH
+rm -f $INCLUDE_LINK_PATH
+
+ln -s $OUT_DIR/lib $LIB_LINK_PATH
+ln -s $OUT_DIR/include $INCLUDE_LINK_PATH
+
+done
+
+# To set proxy for gradle add following lines to ./gradle/gradle.properties:
+# systemProp.http.proxyHost=...
+# systemProp.http.proxyPort=8080
+# systemProp.https.proxyHost=...
+# systemProp.https.proxyPort=8080
+
+if [ "$CUSTOM_ABIS_LIST" = true ]; then
+  NDK_DEBUG=1 $GRADLE_PATH -PnativeLibsDoNotStrip=true -PABI_FILTERS=$ABIS_LIST -p $PYTORCH_ANDROID_DIR clean test_app:assembleDebug
+else
+  NDK_DEBUG=1 $GRADLE_PATH -PnativeLibsDoNotStrip=true -p $PYTORCH_ANDROID_DIR clean test_app:assembleDebug
+fi
+
+find $PYTORCH_ANDROID_DIR -type f -name *apk
+
+find $PYTORCH_ANDROID_DIR -type f -name *apk | xargs echo "To install apk run: $ANDROID_HOME/platform-tools/adb install -r "
+
+popd
+

android/gradle.properties

@@ -22,3 +22,8 @@ ANDROID_MAVEN_GRADLE_PLUGIN_VERSION=2.1
 # Gradle internals
 org.gradle.internal.repository.max.retries=1
 org.gradle.jvmargs=-XX:MaxMetaspaceSize=1024m
+
+android.useAndroidX=true
+android.enableJetifier=true
+
+nativeLibsDoNotStrip=false

android/pytorch_android/build.gradle

@@ -42,6 +42,9 @@ android {
         } else {
             pickFirst '**/libfbjni.so'
         }
+        if (nativeLibsDoNotStrip) {
+            doNotStrip "**/*.so"
+        }
     }
 
     useLibrary 'android.test.runner'

android/settings.gradle

@@ -1,6 +1,8 @@
-include ':app', ':pytorch_android', ':fbjni', ':pytorch_android_torchvision', ':pytorch_host'
+include ':app', ':pytorch_android', ':fbjni', ':pytorch_android_torchvision', ':pytorch_host', ':test_app'
 
 project(':fbjni').projectDir = file('libs/fbjni_local')
 project(':pytorch_android_torchvision').projectDir = file('pytorch_android_torchvision')
 
 project(':pytorch_host').projectDir = file('pytorch_android/host')
+project(':test_app').projectDir = file('test_app/app')
+

android/test_app/.gitignore

@@ -0,0 +1,9 @@
+local.properties
+**/*.iml
+.gradle
+gradlew*
+gradle/wrapper
+.idea/*
+.DS_Store
+build
+.externalNativeBuild

android/test_app/app/build.gradle

@@ -0,0 +1,61 @@
+apply plugin: 'com.android.application'
+
+repositories {
+    jcenter()
+}
+
+def props = new Properties()
+file("../gradle.properties").withInputStream { props.load(it) }
+
+def buildConfigProps = { k -> "\"${props.get(k)}\"" }
+
+android {
+    compileSdkVersion 28
+    buildToolsVersion "29.0.2"
+    defaultConfig {
+        applicationId "org.pytorch.testapp"
+        minSdkVersion 21
+        targetSdkVersion 28
+        versionCode 1
+        versionName "1.0"
+        ndk {
+            abiFilters ABI_FILTERS.split(",")
+        }
+        buildConfigField ("String", "MODULE_ASSET_NAME", buildConfigProps('MODULE_ASSET_NAME'))
+        buildConfigField ("String", "LOGCAT_TAG", "@string/app_name")
+        addManifestPlaceholders([APP_NAME: "@string/app_name"])
+    }
+    buildTypes {
+        debug {
+            minifyEnabled false
+        }
+    }
+    flavorDimensions "model"
+    productFlavors {
+        mobNet2Quant {
+            dimension "model"
+            applicationIdSuffix ".mobNet2Quant"
+            buildConfigField ("String", "MODULE_ASSET_NAME", buildConfigProps('MODULE_ASSET_NAME_MOBNET2_QUANT'))
+            addManifestPlaceholders([APP_NAME: "PyMobNet2Quant"])
+            buildConfigField ("String", "LOGCAT_TAG", "\"pytorch-mobnet2q\"")
+        }
+        resnet18 {
+            dimension "model"
+            applicationIdSuffix ".resneti18"
+            buildConfigField ("String", "MODULE_ASSET_NAME", buildConfigProps('MODULE_ASSET_NAME_RESNET18'))
+            addManifestPlaceholders([APP_NAME: "PyResNet18"])
+            buildConfigField ("String", "LOGCAT_TAG", "\"pytorch-resnet18\"")
+        }
+    }
+    packagingOptions {
+        pickFirst '**/libfbjni.so'
+        doNotStrip '**.so'
+    }
+}
+
+dependencies {
+    implementation 'androidx.appcompat:appcompat:1.1.0'
+
+    implementation project(':pytorch_android')
+    implementation project(':pytorch_android_torchvision')
+}

android/test_app/app/src/main/AndroidManifest.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="org.pytorch.testapp">
+
+    <application
+        android:allowBackup="true"
+        android:label="${APP_NAME}"
+        android:supportsRtl="true"
+        android:theme="@style/AppTheme">
+
+        <activity android:name=".MainActivity">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+</manifest>

android/test_app/app/src/main/assets/.gitignore

@@ -0,0 +1,3 @@
+*
+*/
+!.gitignore