Status Update
Comments
xi...@google.com <xi...@google.com>
tn...@google.com <tn...@google.com>
me...@google.com <me...@google.com>
tn...@google.com <tn...@google.com> #2
Thank you for the report and reproduction. I can reproduce on a Android TV emulator.
an...@google.com <an...@google.com> #3
Status of current findings.
This is related to the SplitReturnRewriter
added in
Not running this code pass on java.lang.Object androidx.collection.LruCache.remove(java.lang.Object)
works around the issue. I used the following patch:
diff --git a/src/main/java/com/android/tools/r8/ir/conversion/passes/SplitReturnRewriter.java b/src/main/java/com/android/tools/r8/ir/conversion/passes/SplitReturnRewriter.java
index 157d26c66a..63e0f76064 100644
--- a/src/main/java/com/android/tools/r8/ir/conversion/passes/SplitReturnRewriter.java
+++ b/src/main/java/com/android/tools/r8/ir/conversion/passes/SplitReturnRewriter.java
@@ -43,6 +43,10 @@ public class SplitReturnRewriter extends CodeRewriterPass<AppInfo> {
@Override
protected CodeRewriterResult rewriteCode(IRCode code) {
+ if (code.context().toSourceString().equals(
+ "java.lang.Object androidx.collection.LruCache.remove(java.lang.Object)")) {
+ return CodeRewriterResult.NO_CHANGE;
+ }
int color = colorExceptionHandlers(code);
AffectedValues affectedValues = new AffectedValues();
boolean changed = false;
Comparing the DEX with and without this patch shows one instruction diff in void androidx.leanback.widget.GridLayoutManager$2.addItem(java.lang.Object, int, int, int, int)
where java.lang.Object androidx.collection.LruCache.remove(java.lang.Object)
is inlined into.
Tracing the IR for void androidx.leanback.widget.GridLayoutManager$2.addItem(java.lang.Object, int, int, int, int)
for the two versions shows that they start to deviate in second pass of IR after inserting assume instructions (SSA)
with
block 29, pred-counts: 1, succ-count: 2, filled: true, sealed: false
predecessors: 28
successors: 31 30 (no try/catch successors)
no phis
#143:loadView;1762:addItem: -1: InstanceGet v67 <- v136; field: androidx.collection.LruCache androidx.leanback.widget.ViewsStateBundle.mChildStates
: -1: Assume v140 <- v67; lower bound: @Nullable androidx.collection.LruCache {}
: -1: SafeCheckCast v131 <- v65; java.lang.String
: -1: Invoke-Virtual v132 <- v140, v131; method: java.lang.Object androidx.collection.LruCache.remove(java.lang.String)
: -1: CheckCast v69 <- v132; android.util.SparseArray
#144:loadView;1762:addItem: -1: If v69 EQZ block 31 (fallthrough 30)
vs.
block 29, pred-counts: 1, succ-count: 2, filled: true, sealed: false
predecessors: 28
successors: 31 30 (no try/catch successors)
no phis
#143:loadView;1762:addItem: -1: InstanceGet v67 <- v136; field: androidx.collection.LruCache androidx.leanback.widget.ViewsStateBundle.mChildStates
: -1: Assume v140 <- v67; lower bound: @Nullable androidx.collection.LruCache {}
: -1: SafeCheckCast v131 <- v65; java.lang.String
: -1: Invoke-Virtual v132 <- v140, v131; method: java.lang.Object androidx.collection.LruCache.remove(java.lang.String)
: -1: Assume v141 <- v132; not null
: -1: CheckCast v69 <- v141; android.util.SparseArray
#144:loadView;1762:addItem: -1: If v69 EQZ block 31 (fallthrough 30)
This is from computeDynamicReturnType
concluding a dynamic return type of DynamicTypeWithUpperBound(@NotNull java.lang.Object {})
.
aa...@gmail.com <aa...@gmail.com> #4
Looks like dead code removal in java.lang.Object androidx.collection.LruCache.remove(java.lang.Object)
is causing this.
The method java.lang.Object androidx.collection.LruCache.remove(java.lang.Object)
is processed twice in first round of IR, second time with more precise type for the argument as java.lang.Object androidx.collection.LruCache.remove(java.lang.String)
.
That second processing involves quite a bit of inlining. However before dead code removal the return is still split between null and not null return value:
block 33, pred-counts: 1, succ-count: 2, filled: true, sealed: false
predecessors: 32
successors: 37 34 (no try/catch successors)
no phis
#187:remove;0:remove: -1: If v54 EQZ block 37 (fallthrough 34)
block 34, pred-counts: 1, succ-count: 1, filled: true, sealed: false
predecessors: 33
successors: 35 (no try/catch successors)
no phis
#187:remove;0:remove: -1: Assume v49 <- v54; not null
#188:remove;0:remove: -1: ConstNumber v32(0b0) <- 0 (INT)
: -1: ConstNumber v33(0) <- 0 (@Null NULL)
: -1: Goto block 35
block 35, pred-counts: 1, succ-count: 0, filled: true, sealed: false
predecessors: 34
successors: -
no phis
#188:remove;0:remove: -1: ConstString v90 <- "key"
: -1: Invoke-Static v45, v90; method: void kotlin.jvm.internal.Intrinsics.checkNotNullParameter(java.lang.Object, java.lang.String)
: -1: ConstString v91 <- "oldValue"
: -1: Invoke-Static v49, v91; method: void kotlin.jvm.internal.Intrinsics.checkNotNullParameter(java.lang.Object, java.lang.String)
#191:remove;0:remove: -1: Return v49
block 37, pred-counts: 1, succ-count: 0, filled: true, sealed: false
predecessors: 33
successors: -
no phis
#191:remove;0:remove: -1: Return v54
After dead code removal a single return is left with the non null assumption:
block 34, pred-counts: 1, succ-count: 1, filled: true, sealed: false
predecessors: 32
successors: 35 (no try/catch successors)
no phis
#187:remove;0:remove: -1: Assume v49 <- v54; not null
#188:remove;0:remove: -1: Goto block 35
block 35, pred-counts: 1, succ-count: 0, filled: true, sealed: false
predecessors: 34
successors: -
no phis
#191:remove;0:remove: -1: Return v49
For reference the source of the method is:
public fun remove(key: K): V? {
val previous: V?
lock.synchronized {
previous = map.remove(key)
if (previous != null) {
size -= safeSizeOf(key, previous)
}
}
if (previous != null) {
entryRemoved(false, key, previous, null)
}
return previous
}
with the default implementation of entryRemoved
doing nothing:
protected open fun entryRemoved(evicted: Boolean, key: K, oldValue: V, newValue: V?) {}
Description
DESCRIBE THE ISSUE IN DETAIL:
I need to request use BLE scanning .
ACCESS_FINE_LOCATION
permission in my app on Android versions 30 and below in order toSince I don't need that for versions 31 and above, I include the permission in my manifest with a
maxSdkVersion
:This triggers a violation of lint's
CoarseFineLocation
.