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Admit expression keys for computed member calls #3019

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Merged
rogeralsing merged 1 commit into from
Jun 1, 2026
Merged

Admit expression keys for computed member calls #3019

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35 changes: 31 additions & 4 deletions src/Asynkron.JsEngine/Execution/UnifiedBytecode/UnifiedBytecodeCompiler.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -5403,25 +5403,27 @@ private static bool TryAppendComputedMemberCallTargetPreparation(
}
}

var keyIndex = callTargetIndexInProgram - 1;
var keyStartIndex = FindComputedCallKeyStart(expressionProgram, callTargetIndexInProgram);
if (!TryAppendNamedReceiverOperations(
expressionProgram,
activationSlots,
unified,
Comment on lines +5406 to 5410
stringConstants,
keyIndex,
keyStartIndex,
allowDeepChain: false,
out reason))
{
return false;
}

if (!TryAppendComputedPropertyKeyLoad(
expressionProgram.GetOperation(keyIndex),
if (!TryAppendComputedPropertyKeySpan(
expressionProgram,
activationSlots,
unified,
literalConstants,
stringConstants,
startInclusive: keyStartIndex,
endExclusive: callTargetIndexInProgram,
out reason))
{
return false;
Expand All @@ -5445,6 +5447,31 @@ private static bool TryAppendComputedMemberCallTargetPreparation(
out reason);
}

private static int FindComputedCallKeyStart(
ExpressionProgram expressionProgram,
int callTargetIndexInProgram)
{
var stringConstants = expressionProgram.StringConstants.AsSpan();
var keyStartIndex = 1;
while (keyStartIndex < callTargetIndexInProgram &&
IsPlainNamedPropertyRead(expressionProgram.GetOperation(keyStartIndex), stringConstants))
{
keyStartIndex++;
}

return keyStartIndex;
}

private static bool IsPlainNamedPropertyRead(
PackedExpressionOp operation,
ReadOnlySpan<string> stringConstants)
{
return operation.Kind == ExpressionOpKind.GetNamedProperty &&
!operation.IsOptional &&
!operation.ShortCircuitOnNullishTarget &&
!operation.GetString(stringConstants).IsPrivateName();
}

private static bool TryAppendNamedSuperCallTargetPreparation(
ExpressionProgram expressionProgram,
UnifiedBytecodeSlotLayout slotLayout,
Expand Down
25 changes: 21 additions & 4 deletions src/Asynkron.JsEngine/Execution/UnifiedBytecode/UnifiedBytecodeProductionEligibility.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -2730,18 +2730,20 @@ private static bool TryIsFirstBoundaryCallTargetPreparationCandidate(
if (computedCallTargetIndex >= 2)
{
var computedCallTarget = program.GetOperation(computedCallTargetIndex);
var keyIndex = computedCallTargetIndex - 1;
var keyStartIndex = FindComputedCallKeyStart(program, computedCallTargetIndex, stringConstants);
return !computedCallTarget.IsOptional &&
!computedCallTarget.ShortCircuitOnNullishTarget &&
IsSupportedNamedReceiverChain(
Comment on lines 2732 to 2736
program,
identifierConstants,
stringConstants,
activationSlots,
keyIndex,
keyStartIndex,
allowDeepChain: false) &&
IsSimpleComputedPropertyKey(
program.GetOperation(keyIndex),
IsSupportedComputedPropertyKeySpan(
program,
startInclusive: keyStartIndex,
endExclusive: computedCallTargetIndex,
identifierConstants,
activationSlots) &&
HasSimpleCallArguments(
Expand All @@ -2755,6 +2757,21 @@ private static bool TryIsFirstBoundaryCallTargetPreparationCandidate(
return false;
}

private static int FindComputedCallKeyStart(
ExpressionProgram program,
int computedCallTargetIndex,
ReadOnlySpan<string> stringConstants)
{
var keyStartIndex = 1;
while (keyStartIndex < computedCallTargetIndex &&
IsPlainNamedPropertyRead(program.GetOperation(keyStartIndex), stringConstants))
{
keyStartIndex++;
}

return keyStartIndex;
}

private static bool IsFirstBoundaryDirectEvalCallCandidate(
ExpressionProgram program,
ReadOnlySpan<IdentifierOperand> identifierConstants,
Expand Down
2 changes: 1 addition & 1 deletion tests/Asynkron.JsEngine.Tests/UnifiedBytecodeProductionEligibilityTests.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -2446,7 +2446,7 @@ function invokeComputedExpressionKey(box, left, right) {
}
""",
"invokeComputedExpressionKey",
(int)UnifiedBytecodeProductionDeclineCode.CallDependency)]
(int)UnifiedBytecodeProductionDeclineCode.None)]
[InlineData(
"""
function invokeDeepComputedCallee(root, key, value) {
Expand Down
26 changes: 26 additions & 0 deletions tests/Asynkron.JsEngine.Tests/UnifiedBytecodeProductionInvocationTests.cs
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Expand Up @@ -1994,6 +1994,32 @@ static record => record.Message.Contains(
StringComparison.Ordinal));
}

[Fact(Timeout = 5000)]
public async Task ComputedMemberCallWithExpressionKey_UsesUnifiedBytecodeProductionFastPathAndPreservesThis()
{
await using var engine = CreateEngine();
var result = await engine.Evaluate("""
var box = {
offset: 1,
read(value) {
return value + this.offset;
}
};

function invoke(box, left, right, value) {
return box[left + right](value);
}

invoke(box, "re", "ad", 41);
""");

Assert.Equal(42d, result);
Assert.Contains(CurrentLogger!.Collector.Snapshot(),
static record => record.Message.Contains(
"unified-bytecode-production-fast-path func=invoke argc=4",
StringComparison.Ordinal));
}

[Fact(Timeout = 5000)]
public async Task ComputedMemberCall_NullishReceiverThrowsBeforeKeyCoercion()
{
Expand Down