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The existing LayoutCompilerTest only covered compiled layouts generated from text XML files. It did not cover layouts that were extracted from the APK. This is an important area to cover. This test works by calling `pm compile --compile-layouts` on the test APK, and then directly loads the `compiled_view.dex` file. From there, it pulls out the compiled layouts and executes their inflater. This makes sure the generated DEX files validate and execute without error. Bug: 111895153 Change-Id: Ifc6719c2f438474b5474def02422ef68eee800b2
View Compiler
This directory contains an experimental compiler for layout files.
It will take a layout XML file and produce a CompiledLayout.java file with a specialized layout inflation function.
To use it, let's assume you had a layout in my_layout.xml and your app was in
the Java language package com.example.myapp. Run the following command:
viewcompiler my_layout.xml --package com.example.myapp --out CompiledView.java
This will produce a CompiledView.java, which can then be compiled into your
Android app. Then to use it, in places where you would have inflated
R.layouts.my_layout, instead call CompiledView.inflate.
Precompiling views like this generally improves the time needed to inflate them.
This tool is still in its early stages and has a number of limitations.
- Currently only one layout can be compiled at a time.
mergeandincludenodes are not supported.- View compilation is a manual process that requires code changes in the application.
- This only works for apps that do not use a custom layout inflater.
- Other limitations yet to be discovered.
DexBuilder Tests
The DexBuilder has several low-level end to end tests to verify generated DEX code validates, runs, and has the correct behavior. There are, unfortunately, a number of pieces that must be added to generate new tests. Here are the components:
dex_testcase_generator- Written in C++ usingDexBuilder. This runs as a build step produce the DEX files that will be tested on device. See thegenrulenamedgenerate_dex_testcasesinAndroid.bp. These files are then copied over to the device by TradeFed when running tests.DexBuilderTest- This is a Java Language test harness that loads the generated DEX files and exercises methods in the file.
To add a new DEX file test, follow these steps:
- Modify
dex_testcase_generatorto produce the DEX file. - Add the filename to the
outlist of thegenerate_dex_testcasesrule inAndroid.bp. - Add a new
pushoption toAndroidTest.xmlto copy the DEX file to the device. - Modify
DexBuilderTest.javato load and exercise the new test.
In each case, you should be able to cargo-cult the existing test cases.
In general, you can probably get by without adding a new generated DEX file, and instead add more methods to the files that are already generated. In this case, you can skip all of steps 2 and 3 above, and simplify steps 1 and 4.