R8 removes enum class values, despite usage from generated code [339085669]

WAI

Bug

Status Update

No update yet.

Description

cc...@google.com

created issue #1

May 6, 2024 10:04PM

In tweaking proguard rules in androidx microbenchmarks, I noticed that some of our generated moshi code references to a values array are failing to resolve, and crashing at runtime:

> ./gradlew benchmark:benchmark-benchmark:installRelease && adb shell am instrument -w -r -e debug false -e newRunListenerMode true -e class 'androidx.benchmark.benchmark.TrivialJavaBenchmark' -e androidx.benchmark.output.enable true -e listener androidx.benchmark.junit4.InstrumentationResultsRunListener androidx.benchmark.benchmark.test/androidx.benchmark.junit4.AndroidBenchmarkRunner

Time: 9.563
There were 2 failures:
1) increment(androidx.benchmark.benchmark.TrivialJavaBenchmark)
java.lang.ExceptionInInitializerError
	at androidx.benchmark.junit4.BenchmarkRule$applyInternal$$inlined$Statement$1.evaluate(SourceFile:123)
	at androidx.test.rule.GrantPermissionRule$RequestPermissionStatement.evaluate(Unknown Source:11)
	at org.junit.rules.RunRules.evaluate(Unknown Source:2)
...
	at androidx.test.runner.AndroidJUnitRunner.onStart(SourceFile:134)
	at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:2402)
Caused by: java.lang.RuntimeException: java.lang.NoSuchMethodException: androidx.benchmark.json.BenchmarkData$TestResult$ProfilerOutput$Type.values []
	at java.lang.Enum.enumValues(Enum.java:315)
...
	at androidx.benchmark.ResultWriter.<clinit>(SourceFile:20)
	... 31 more
Caused by: java.lang.NoSuchMethodException: androidx.benchmark.json.BenchmarkData$TestResult$ProfilerOutput$Type.values []
	at java.lang.Class.getMethod(Class.java:2937)
	at java.lang.Class.getDeclaredMethod(Class.java:2914)
	at java.lang.Enum.enumValues(Enum.java:312)
	... 64 more

# also repros with
#    ./gradlew benchmark:benchmark-benchmark:cC -P android.testInstrumentationRunnerArguments.class=androidx.benchmark.benchmark.TrivialJavaBenchmark
# but above makes crash stack clearer

Repro AndroidX CL, which just enables R8 in a trivial sample benchmark, and tweaks proguard rules to get it (almost) running: https://android-review.git.corp.google.com/c/platform/frameworks/support/+/3073538

Comments

cc...@google.com <cc...@google.com> #2May 6, 2024 10:22PM

Any suggestions on where such an interface might live? I don't think it makes sense for the interface to be in the drawerlayout artifact if you're specifically going to use the interface to *not* use DrawerLayout.

ap...@google.com <ap...@google.com> #3May 6, 2024 10:53PM

androidx.customview would be a good candidate. This is used by all of the widget libraries.

ch...@google.com <ch...@google.com> #4May 7, 2024 07:34AM

Reassigned to ch...@google.com.

Project: platform/frameworks/support
Branch: androidx-master-dev

commit 3ed3fb003fa6c1244f923202859a616225b5b2fa
Author: Ian Lake <ilake@google.com>
Date: Fri Feb 14 11:17:46 2020

Create an interface for layouts that can be opened

Create a common interface that represents layouts
that have two states: open and closed. This allows
higher level libraries to rely on the interface,
rather than concrete implementations such as
DrawerLayout, making them more resilient to
changes in the current recommended implementation.

Fixes: 129979320
Test: ./gradlew checkApi
Change-Id: I0f2a1414977825aa053c6555261f2b7d4417bd19

M customview/customview/api/1.1.0-alpha02.txt
M customview/customview/api/current.txt
M customview/customview/api/public_plus_experimental_1.1.0-alpha02.txt
M customview/customview/api/public_plus_experimental_current.txt
M customview/customview/api/restricted_1.1.0-alpha02.txt
M customview/customview/api/restricted_current.txt
A customview/customview/src/main/java/androidx/customview/widget/Openable.java
M drawerlayout/drawerlayout/api/1.1.0-alpha03.txt
M drawerlayout/drawerlayout/api/current.txt
M drawerlayout/drawerlayout/api/public_plus_experimental_1.1.0-alpha03.txt
M drawerlayout/drawerlayout/api/public_plus_experimental_current.txt
M drawerlayout/drawerlayout/api/restricted_1.1.0-alpha03.txt
M drawerlayout/drawerlayout/api/restricted_current.txt
M drawerlayout/drawerlayout/build.gradle
M drawerlayout/drawerlayout/src/main/java/androidx/drawerlayout/widget/DrawerLayout.java
M jetifier/jetifier/migration.config
M slidingpanelayout/slidingpanelayout/api/1.1.0-alpha01.txt
M slidingpanelayout/slidingpanelayout/api/current.txt
M slidingpanelayout/slidingpanelayout/api/public_plus_experimental_1.1.0-alpha01.txt
M slidingpanelayout/slidingpanelayout/api/public_plus_experimental_current.txt
M slidingpanelayout/slidingpanelayout/api/restricted_1.1.0-alpha01.txt
M slidingpanelayout/slidingpanelayout/api/restricted_current.txt
M slidingpanelayout/slidingpanelayout/src/main/java/androidx/slidingpanelayout/widget/SlidingPaneLayout.java

https://android-review.googlesource.com/940787

cc...@google.com <cc...@google.com> #5May 7, 2024 10:44PM

Confirm that adding proguard-android-optimize.txt or those rules directly works around the issue.

I was missing it since I generally try to avoid proguard-android-optimize.txt since it is too inclusive in some cases.

Why are standard rules for enums necessary?

ze...@google.com <ze...@google.com> #6May 8, 2024 04:44AM

The Java standard library has implemented various parts of the enum by use of reflection within the runtime, so maintaining that behavior has required these rules in both Proguard and R8.

cc...@google.com <cc...@google.com> #7May 9, 2024 04:58PM

Is it possible for R8 to figure out which enum classes are potentially fed to such stl methods? If so, and the stl behavior is consistent (and stl using values to implement class.enumConstants seems reasonable), it would be nice to avoid this necessary configuration (even if studio gives it to you by default in the very stale proguard-android-optimize list).

Either that, or could make enum value/valueOf minification opt-in.

ze...@google.com <ze...@google.com> #8May 13, 2024 06:12AM

Unfortunately, we have not been able to come up with a safe/sound analysis that can determine when the rules are not needed. Conversely, we have no way of safely keeping the enums that is less conservative than the rules. There are clients that do not have these rules as they manually ensure that they have no usages of enums that would break. Thus we can't make the rules part of the compiler and we can't safely determine when they are needed. We are not happy with that situation, but we currently have no better alternatives.

cc...@google.com <cc...@google.com> #9May 13, 2024 11:40PM

Fair enough, feel free to close as WAI. Understand that the cost to migrate the default is non-zero, with minimal benefit.

ch...@google.com <ch...@google.com> May 14, 2024 07:31AM

Status: Won't Fix (Intended Behavior)

pr...@google.com <pr...@google.com> #10May 14, 2024 05:22PM

The following release(s) address this bug.It is possible this bug has only been partially addressed:

androidx.benchmark:benchmark-junit4:1.3.0-alpha05