WrongConstant lint on definition instead of usage of constant using shift [378128668]

Fixed

Bug

Status Update

No update yet.

Description

ju...@google.com

created issue #1

Nov 8, 2024 08:20PM

Seeing this when trying to update AndroidX to lint 31.8.0-alpha08 from 31.8.0-alpha06. Assuming this is related to b/370778975.

When an incorrect constant is used for an IntDef, and the constant was defined using the int shift operator, the lint error is appearing on the constant definition instead of the usage.

Repro example:

import androidx.annotation.IntDef;

public class TestFlags {
    public static final int SHIFT_FLAG = 1 << 1;

    @IntDef(flag = true, value = { 0 })
    public @interface FlagDef {}

    @FlagDef int flags = SHIFT_FLAG;
}

Instead of a lint error appearing on the flags = SHIFT_FLAG line, it instead appears on the definition of SHIFT_FLAG:

  TestFlags.java:22: Error: Must be one or more of: 0 [WrongConstant]
      public static final int SHIFT_FLAG = 1 << 1;
                                           ~
  TestFlags.java:22: Error: Must be one or more of: 0 [WrongConstant]
      public static final int SHIFT_FLAG = 1 << 1;
                                                ~

Comments

js...@google.com <js...@google.com> #2Nov 8, 2024 08:27PM

Thank you for the report and the code causing the issue. I have landed a reproduction which shows that the code thrown an ArrayIndexOutOfBoundsException from the last bitSet.toByteArray()[0] when not processed by R8.

ju...@google.com <ju...@google.com> #3Nov 8, 2024 08:31PM

Project: r8
Branch: main
Author: Søren Gjesse <sgjesse@google.com>
Link: https://r8-review.googlesource.com/100168

Add reproduction of issue 391417819

Expand for full commit details

Add reproduction of issue 391417819 
 
Bug: b/391417819 
Change-Id: I37eb909c100104fadeb895bf5d930f4f54e94ba0

Files:

A src/test/java/com/android/tools/r8/B391417819Repro.java

Hash: bf9b1962052bf91689120a09deded518e37862a2
Date: Wed Jan 22 09:41:15 2025

js...@google.com <js...@google.com> #4Nov 8, 2024 09:21PM

deleted

js...@google.com <js...@google.com> Nov 13, 2024 07:08PM

Accepted by js...@google.com.

js...@google.com <js...@google.com> Nov 17, 2024 07:11PM

Marked as fixed.

an...@google.com <an...@google.com> #5Nov 22, 2024 12:04AM

I'm really sorry, please use the source code below:

public class R8Test {

    public byte[] toBytes(boolean on) {
        byte[] bytes = new byte[3];
        bytes[0] = 1;
        BitSet bits = new BitSet(8);
        byte[] byteArray = bits.toByteArray();
        if (byteArray != null && byteArray.length >= 1) {
            bytes[1] = bits.toByteArray()[0];
        }

        BitSet bitSet = new BitSet(8);
        byte[] byteArray2 = bits.toByteArray();
        if (byteArray2 != null && byteArray2.length >= 1) {
            bytes[2] = bitSet.toByteArray()[0];
        }
        return bytes;
    }
}

pr...@google.com <pr...@google.com> #6Dec 11, 2024 06:27PM

Thank you for the update. Most likely the initial source code will still be sufficient to fix the issue.