What's in the Android Toolbox

A look into the Android build tools. How are Android apps built? What's new in the Android build tools?

1. What’s in the Android Toolbox? Bryan Herbst (@bryancherbst)
2. What tools?
3. $ sdkmanager --list
4. $ sdkmanager --list Tools
5. $ sdkmanager --list Tools Platform-Tools
6. $ sdkmanager --list Tools Platform-Tools Build-Tools
7. SDK tools
8. $ ls $ANDROID_HOME/tools
9. $ ls $ANDROID_HOME/tools android emulator monitor
10. $ ls $ANDROID_HOME/platform-tools
11. $ ls $ANDROID_HOME/platform-tools adb fastboot systrace
12. $ ls $ANDROID_HOME/build-tools/27.0.3
13. $ ls $ANDROID_HOME/build-tools/27.0.3 aapt apksigner dx
14. What’s in an APK?
15. APK ≈ JAR ≈ Zip
16. APK META_INF/ APK metadata
17. APK META_INF/ lib/ Native libs
18. APK META_INF/ lib/ res/ Static resources (PNGs, XML layouts, etc.)
19. APK META_INF/ lib/ res/ assets/ Static assets (fonts, HTML, etc.)
20. APK META_INF/ lib/ res/ assets/ AndroidManifest.xml Hey, this looks familiar!
21. APK META_INF/ lib/ res/ assets/ AndroidManifest.xml classes.dex Your code
22. APK META_INF/ lib/ res/ assets/ AndroidManifest.xml classes.dex resources.arsc Compiled resources (strings, dimens, etc.)
23. Dex?
24. Code (.c, etc) Machine code
25. Code (.c, etc) Machine code (arm) Machine code (x86) Machine code (mips)
26. Java
27. Java (.java) Bytecode (.class) Machine code
28. Java (.java) Bytecode (.class) Machine code Ahead-of-time
29. Java (.java) Bytecode (.class) Machine code Just in time
30. Android
31. Ahead-of-time Java (.java) Bytecode (.class) Machine code Dex Bytecode (.dex)
32. Just-in-time Java (.java) Bytecode (.class) Machine code Dex Bytecode (.dex) Dalvik
33. Ahead-of-time Java (.java) Bytecode (.class) Machine code Dex Bytecode (.dex) ART
34. Ahead-of-time (on-device) Java (.java) Bytecode (.class) Machine code Dex Bytecode (.dex) ART
35. Ahead-of-time (on-device) (with JIT) Java (.java) Bytecode (.class) Machine code Dex Bytecode (.dex) ART
36. Compile Transform Package
37. Compile Transform Package .java à .class
38. Compile Transform Package .classà .dex
39. Compile Transform Package everything à .apk
40. Shift from generic tools to Android-specific tools
41. incrementality parallelism
42. Gradle The orchestrator
43. By default Gradle does nothing
44. Plugins add functionality
45. apply plugin: 'com.android.application' Android functionality
46. apply plugin: 'com.android.application' apply plugin: 'java' Java functionality
47. apply plugin: 'com.android.application' apply plugin: 'java' apply plugin: 'kotlin' Kotlin functionality
48. Plugins can extend the DSL
49. Plugins can add dependency configurations
50. Plugins can add tasks
51. Android Plugin 3.x & Gradle 4.x
52. compile Configurations
53. compile testCompile Configurations
54. compile testCompile debugCompile Configurations
55. compile testCompile debugCompile apk Configurations
56. compile testCompile debugCompile apk provided Configurations
57. compile testCompile debugCompile apk provided Configurations
58. api Available at compile time and runtime Configurations
59. api implementation Available at compile time, Only available to consumers at runtime Configurations
60. api implementation compileOnly Only available at compile time Configurations
61. api implementation compileOnly runtimeOnly Only available at runtime Configurations
62. Lib B Lib A App compile ':libB'
63. Lib B Lib A App compile ':libB'
64. Lib B Lib A App compile ':libB'
65. Lib B Lib A App compile ':libB'
66. Lib B Lib A App implemenation ':libB'
67. Lib B Lib A App implemenation ':libB'
68. Lib B Lib A App implemenation ':libB'
69. And so much more
70. Compile .java à .class
71. Before we compile…
72. Code Generation Dagger Butterknife Databinding
73. buildConfigField "String", "FOO", '"bar"'
74. resValue "string", "FOO", "bar"
75. Compile javac / kotlinc
76. Transforms .class à .dex
77. Java 8 bytecode Java 6/7 bytecode
78. Java 8 bytecode Java 6/7 bytecode Bytecode Optimized bytecode
79. Java 8 bytecode Java 6/7 bytecode Bytecode Optimized bytecode Java bytecode Dex bytecode
80. import com.android.build.api.transform.Transform
81. import com.android.build.api.transform.Transform class RetrolambdaTransform : Transform { }
82. app/build ├── generated ├── intermediates │ ├── classes │ └── transforms │ ├── dex[...] │ ├── mergeJavaRes │ ├── profilers-transform │ └── proguard └── outputs └── apk
83. DX and D8 The dexing duo
84. DX is the current dexing tool
85. $ javac Main.java $ dx --dex --output=. Main.class
86. dexdump lets you disassemble dex files
87. $ dexdump –d classes.dex
88. [000148] Main.main(String) 0000: sget-object v0, System;.out:PrintStream; 0002: const-string v1, "Hello World" 0004: invoke-virtual {v0, v1}, println:(String)V 0007: return-void
89. [000148] Main.main(String) 0000: sget-object v0, System;.out:PrintStream; 0002: const-string v1, "Hello World" 0004: invoke-virtual {v0, v1}, println:(String)V 0007: return-void
90. D8 is the next-gen dexing tool
91. Faster compilation!
92. Faster compilation! Smaller dex files!
93. Faster compilation! Smaller dex files! R8 integration!
94. gradle.properties android.enableD8=true
95. Default in Studio + Gradle Plugin 3.1
96. Desugar Artificial Java sweetener
97. Retrolambda
98. Retrolambda
99. Retrolambda Jack
100. Retrolambda Jack
101. Retrolambda Jack Desugar
102. Retrolambda Jack Desugar D8
103. Jack and Jill Dead tools
104. Shrink + Obfsucate ProGuard and R8
105. Activity Class A Class B
106. Activity Class A Class B
107. Activity Class A
108. A B
109. ProGuard The old guard
110. ProGuard is an open-source Java shrinker, obfuscation, and optimization tool
111. minifyEnabled true proguardFiles 'proguard-rules.pro'
112. -keep class com.model.ImportantData { *; }
113. -keep class * extends android.view.View { <init>(...); }
114. AAPT automatically generates ProGuard rules for Activities
115. AAPT automatically generates ProGuard rules for Views
116. AAPT automatically generates ProGuard rules for Services
117. AAPT automatically generates ProGuard rules for ContentProviders
118. AAPT automatically generates ProGuard rules for BroadcastReceivers
119. ProGuard is an open-source Java shrinker, obfuscation, and optimization tool
120. ProGuard is an open-source Java shrinker, obfuscation, and optimization tool
121. Activity Drawable Class A
122. Drawable Class A
123. R8 The new (pro)guard
124. R8 The new (pro)guard And D8
125. R8 does full program Shrinking, obfuscation, and optimization
126. Better incremental builds!
127. Better incremental builds! New DSL!
128. Not available yet :(
129. Package Making the APK
130. A A P T
131. Android Asset Packaging Tool
132. AAPT packages, reads, and updates APKs
133. AAPT also…
134. AAPT also… Processes resources
135. AAPT also… Processes resources Generates R class
136. AAPT also… Processes resources Generates R class Compiles resources
137. AAPT2 Android Asset Packaging Tool 2
138. AAPT2 is enabled by default as of plugin 3.0.0
139. AAPT2 split linking and compilation
140. AAPT2 is more restrictive
141. <manifest> <application> <activity> <intent-filter /> <action android:name= "ACTION_NAME" /> </activity> </application> </manifest>
142. <manifest> <application> <activity> <intent-filter /> <action android:name= "ACTION_NAME" /> </activity> </application> </manifest>
143. APK Signing
144. V1 signatures use jarsigner
145. V2 signatures use apksigner
146. Whole-file signature https://source.android.com/security/apksigning/v2
147. Gradle Plugin 2.2+ defaults to v2 signatures
148. Zipalign
149. Zipalign aligns APKs on 4-byte boundaries
150. Memory CPU
151. Memory CPU Data
152. Memory CPU Data
153. Memory CPU
154. Memory CPU Data
155. Memory CPU Data
156. Memory CPU Data
157. Memory CPU Data
158. Memory CPU Data
159. V1 signature: After signing V2 signature: Before signing
160. apkzlib
161. Packing tools aapt apksigner zipalign
162. Packing tools aapt apksigner zipalign Gradle Android Plugin apkzlib
163. Post-build
164. ART Android Runtime
165. Ahead-of-time (on-device) (with JIT) Java (.java) Bytecode (.class) Machine code Dex Bytecode (.dex)
166. Compiled APK (.dex)
167. Compiled APK (.dex) optimize (dex2oat) Optimized APK (.dex, .oat)
168. Compiled APK (.dex) optimize (dex2oat) Optimized APK (.dex, .oat) JIT Profile
169. Compiled APK (.dex) optimize (dex2oat) Optimized APK (.dex, .oat) JIT Profile optimize (dex2oat) Optimized .oat
170. Compiled APK (.dex) optimize (dex2oat) Optimized APK (.dex, .oat) JIT Profile optimize (dex2oat) Optimized .oat
171. Compiled APK (.dex) optimize (dex2oat) Optimized APK (.dex, .oat) JIT Profile optimize (dex2oat) Optimized .oat Android 5.0
172. Compiled APK (.dex) optimize (dex2oat) Optimized APK (.dex, .oat) JIT Profile optimize (dex2oat) Optimized .oat Android 7.0
173. State of the ART
174. State of the ART Interpreted (.dex)
175. State of the ART Interpreted (.dex) JIT Compiled (in memory)
176. State of the ART Interpreted (.dex) JIT Compiled (in memory) AOT compiled (.oat)
177. Tools: android.googlesource.com/platform/tools/base ART, APK Signing: source.android.com/ R8 + D8: r8.googlesource.com
178. https://goo.gl/cMsvmf @bryancherbst