K1: Fix regression with callable references as last statements in lambda
^KT-55729 Fixed
diff --git a/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosisCompilerTestFE10TestdataTestGenerated.java b/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosisCompilerTestFE10TestdataTestGenerated.java
index 0de9586..c70815d 100644
--- a/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosisCompilerTestFE10TestdataTestGenerated.java
+++ b/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosisCompilerTestFE10TestdataTestGenerated.java
@@ -14902,6 +14902,12 @@
}
@Test
+ @TestMetadata("conversionLastStatementInLambda.kt")
+ public void testConversionLastStatementInLambda() throws Exception {
+ runTest("compiler/testData/diagnostics/tests/inference/callableReferences/conversionLastStatementInLambda.kt");
+ }
+
+ @Test
@TestMetadata("kt55931.kt")
public void testKt55931() throws Exception {
runTest("compiler/testData/diagnostics/tests/inference/callableReferences/kt55931.kt");
diff --git a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsTestGenerated.java b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsTestGenerated.java
index db1a284..2ee36fb 100644
--- a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsTestGenerated.java
+++ b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsTestGenerated.java
@@ -14908,6 +14908,12 @@
}
@Test
+ @TestMetadata("conversionLastStatementInLambda.kt")
+ public void testConversionLastStatementInLambda() throws Exception {
+ runTest("compiler/testData/diagnostics/tests/inference/callableReferences/conversionLastStatementInLambda.kt");
+ }
+
+ @Test
@TestMetadata("kt55931.kt")
public void testKt55931() throws Exception {
runTest("compiler/testData/diagnostics/tests/inference/callableReferences/kt55931.kt");
diff --git a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsWithLightTreeTestGenerated.java b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsWithLightTreeTestGenerated.java
index 089d91a..66b6ecd 100644
--- a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsWithLightTreeTestGenerated.java
+++ b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsWithLightTreeTestGenerated.java
@@ -14902,6 +14902,12 @@
}
@Test
+ @TestMetadata("conversionLastStatementInLambda.kt")
+ public void testConversionLastStatementInLambda() throws Exception {
+ runTest("compiler/testData/diagnostics/tests/inference/callableReferences/conversionLastStatementInLambda.kt");
+ }
+
+ @Test
@TestMetadata("kt55931.kt")
public void testKt55931() throws Exception {
runTest("compiler/testData/diagnostics/tests/inference/callableReferences/kt55931.kt");
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/types/expressions/ExpressionTypingServices.java b/compiler/frontend/src/org/jetbrains/kotlin/types/expressions/ExpressionTypingServices.java
index a1165fa..9db2b94 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/types/expressions/ExpressionTypingServices.java
+++ b/compiler/frontend/src/org/jetbrains/kotlin/types/expressions/ExpressionTypingServices.java
@@ -28,9 +28,9 @@
import org.jetbrains.kotlin.resolve.calls.tower.KotlinResolutionCallbacksImpl;
import org.jetbrains.kotlin.resolve.calls.tower.LambdaContextInfo;
import org.jetbrains.kotlin.resolve.scopes.*;
+import org.jetbrains.kotlin.types.KotlinType;
import org.jetbrains.kotlin.types.error.ErrorTypeKind;
import org.jetbrains.kotlin.types.error.ErrorUtils;
-import org.jetbrains.kotlin.types.KotlinType;
import org.jetbrains.kotlin.types.expressions.typeInfoFactory.TypeInfoFactoryKt;
import org.jetbrains.kotlin.util.slicedMap.WritableSlice;
@@ -382,7 +382,51 @@
)
);
- if (context.expectedType == NO_EXPECTED_TYPE && statementExpression instanceof KtCallableReferenceExpression) {
+ // This part is necessary for properly handling the case of calls like `foo { ::bar }`.
+ // In NI, `::bar` shouldn't be eagerly resolved, but introduced as a postponed atom to the general inference system.
+ // The correct definition for the case would be satisfaction of three conditions:
+ // (1) lastStatement is KtCallableReferenceExpression
+ // (2) expected type is not Unit/NO_EXPECTED_TYPE
+ // (3) lastStatement.parent.parent [statement -> block -> function literal] is a lambda that is handled by NI
+ //
+ // When the conditions are met, `createCallArgument` at `org.jetbrains.kotlin.resolve.calls.tower.KotlinResolutionCallbacksImpl.analyzeAndGetLambdaReturnArguments`
+ // we just pick that last statement in the lambda.
+ //
+ // But due to a bug in initial implementation `createDontCareTypeInfoForNILambda` (third condition), it was checking that
+ // "lastStatement has a NI lambda among one of the parents".
+ //
+ // That immediately leads to incorrectly treatment of cases like:
+ // foo {
+ // val x = if (b) {
+ // ::baz <-- the problem is here
+ // } else {
+ // ....
+ // }
+ // println()
+ // }
+ //
+ // The problem with the `::baz` is that it should not be processed as a postponed atom for the call, but it has been.
+ // At the same time, it's being ignored by the NI (because it's not the last statement), thus left unresolved.
+ // The bugs are described at KT-52270 and KT-55931.
+ //
+ // During attempt to fix KT-52270, instead of fixing the third condition (that is actually broken), the second one has been changed to
+ // "expected type is NO_EXPECTED_TYPE".
+ // That helped to the main use case from the issue, but still didn't help with KT-55931.
+ //
+ // But the actual problem is that brought another regression bug (KT-55729) because after that we started
+ // resolving last-statement callable references with expected type eagerly as regular top-level references (without conversions).
+ // So, conversions stopped working there since 1.8.0
+ //
+ // While it might be tempting to revert the incorrect fix for KT-52270, and fix the third condition, we can't do it easily
+ // because it should be a language feature (since it allows new green code), that can't be released in 1.8.10.
+ // So, we're just trying to _partially_ revert the change, by allowing skipping reference not only in case of NO_EXPECTED_TYPE
+ // but also in case we have non-trivial expected type AND lastStatement.parent.parent is function literal.
+ //
+ // That would mean that everything will work just the same as in 1.8.0, but the single case of
+ // `expectSomeSpecificFunctionTypeReturnedFromLambda { ::functionNeededAConversion }` (that was been working in 1.7.20).
+ //
+ // On the KT-55931, currently we don't have plans to fix it until K2 (where it already seems to be fixed).
+ if (isCallableReferenceShouldBeAttemptedToBeProcessedByNI(statementExpression, context, isUnitExpectedType)) {
KotlinTypeInfo typeInfo = createDontCareTypeInfoForNILambda(statementExpression, context);
if (typeInfo != null) return typeInfo;
}
@@ -430,6 +474,19 @@
return result;
}
+ private static boolean isCallableReferenceShouldBeAttemptedToBeProcessedByNI(
+ @NotNull KtExpression statementExpression,
+ @NotNull ExpressionTypingContext context,
+ boolean isUnitExpectedType
+ ) {
+ if (!(statementExpression instanceof KtCallableReferenceExpression)) return false;
+ if (context.expectedType == NO_EXPECTED_TYPE) return true;
+ // This is condition we added after 1.8.0 to fix KT-55729 (see the comment above its single usage)
+ if (!isUnitExpectedType && statementExpression.getParent().getParent() instanceof KtFunctionLiteral) return true;
+
+ return false;
+ }
+
@Nullable
private static KotlinTypeInfo createDontCareTypeInfoForNILambda(
@NotNull KtExpression statementExpression,
diff --git a/compiler/testData/diagnostics/tests/inference/callableReferences/conversionLastStatementInLambda.fir.kt b/compiler/testData/diagnostics/tests/inference/callableReferences/conversionLastStatementInLambda.fir.kt
new file mode 100644
index 0000000..dd04c86
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/inference/callableReferences/conversionLastStatementInLambda.fir.kt
@@ -0,0 +1,33 @@
+// SKIP_TXT
+// ISSUE: KT-55729
+
+fun main(b: Boolean) {
+ callWithLambda {
+ // Unit conversion should work (for K2 see KT-55936)
+ ::<!UNRESOLVED_REFERENCE!>test1<!>
+ }
+
+ callWithLambda {
+ // Unit conversion should work (for K2 see KT-55936)
+ <!ARGUMENT_TYPE_MISMATCH!>if (b) ::test1 else ::test2<!>
+ }
+
+ callWithLambda {
+ // That hasn't been working ever in K1 nor K2
+ <!ARGUMENT_TYPE_MISMATCH!>if (b) {
+ ::test1
+ } else {
+ ::test2
+ }<!>
+ }
+
+ callWithLambda {
+ // That hasn't been working ever in K1 nor K2
+ (::<!UNRESOLVED_REFERENCE!>test1<!>)
+ }
+}
+
+fun test1(): String = ""
+fun test2(): String = ""
+
+fun callWithLambda(action: () -> () -> Unit) {}
diff --git a/compiler/testData/diagnostics/tests/inference/callableReferences/conversionLastStatementInLambda.kt b/compiler/testData/diagnostics/tests/inference/callableReferences/conversionLastStatementInLambda.kt
new file mode 100644
index 0000000..4ec14aa
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/inference/callableReferences/conversionLastStatementInLambda.kt
@@ -0,0 +1,33 @@
+// SKIP_TXT
+// ISSUE: KT-55729
+
+fun main(b: Boolean) {
+ callWithLambda {
+ // Unit conversion should work (for K2 see KT-55936)
+ ::test1
+ }
+
+ callWithLambda {
+ // Unit conversion should work (for K2 see KT-55936)
+ if (b) ::test1 else ::test2
+ }
+
+ callWithLambda {
+ // That hasn't been working ever in K1 nor K2
+ if (b) <!TYPE_MISMATCH!>{
+ <!TYPE_MISMATCH!>::<!TYPE_MISMATCH!>test1<!><!>
+ }<!> else <!TYPE_MISMATCH!>{
+ <!TYPE_MISMATCH!>::<!TYPE_MISMATCH!>test2<!><!>
+ }<!>
+ }
+
+ callWithLambda {
+ // That hasn't been working ever in K1 nor K2
+ (<!TYPE_MISMATCH, TYPE_MISMATCH!>::<!TYPE_MISMATCH!>test1<!><!>)
+ }
+}
+
+fun test1(): String = ""
+fun test2(): String = ""
+
+fun callWithLambda(action: () -> () -> Unit) {}
diff --git a/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java b/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java
index 8babc63..1d3d756 100644
--- a/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java
+++ b/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java
@@ -14908,6 +14908,12 @@
}
@Test
+ @TestMetadata("conversionLastStatementInLambda.kt")
+ public void testConversionLastStatementInLambda() throws Exception {
+ runTest("compiler/testData/diagnostics/tests/inference/callableReferences/conversionLastStatementInLambda.kt");
+ }
+
+ @Test
@TestMetadata("kt55931.kt")
public void testKt55931() throws Exception {
runTest("compiler/testData/diagnostics/tests/inference/callableReferences/kt55931.kt");
