[FIR] Make UNSAFE_INFIX_CALL and UNSAFE_OPERATOR_CALL parameter nullable

This fixes an NPE in the IDE in presence of a syntax error when the
argument expression has no source.

#KT-64062 Fixed

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDataClassConverters.kt

@@ -4045,7 +4045,7 @@ internal val KT_DIAGNOSTIC_CONVERTER = KtDiagnosticConverterBuilder.buildConvert
             firSymbolBuilder.typeBuilder.buildKtType(firDiagnostic.a),
             firDiagnostic.b.source!!.psi as KtExpression,
             firDiagnostic.c,
-            firDiagnostic.d.source!!.psi as KtExpression,
+            firDiagnostic.d?.source?.psi as? KtExpression,
             firDiagnostic as KtPsiDiagnostic,
             token,
         )
@@ -4055,7 +4055,7 @@ internal val KT_DIAGNOSTIC_CONVERTER = KtDiagnosticConverterBuilder.buildConvert
             firSymbolBuilder.typeBuilder.buildKtType(firDiagnostic.a),
             firDiagnostic.b.source!!.psi as KtExpression,
             firDiagnostic.c,
-            firDiagnostic.d.source!!.psi as KtExpression,
+            firDiagnostic.d?.source?.psi as? KtExpression,
             firDiagnostic as KtPsiDiagnostic,
             token,
         )

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDiagnostics.kt

@@ -2822,7 +2822,7 @@ sealed interface KtFirDiagnostic<PSI : PsiElement> : KtDiagnosticWithPsi<PSI> {
         val receiverType: KtType
         val receiverExpression: KtExpression
         val operator: String
-        val argumentExpression: KtExpression
+        val argumentExpression: KtExpression?
     }
 
     interface UnsafeOperatorCall : KtFirDiagnostic<KtExpression> {
@@ -2830,7 +2830,7 @@ sealed interface KtFirDiagnostic<PSI : PsiElement> : KtDiagnosticWithPsi<PSI> {
         val receiverType: KtType
         val receiverExpression: KtExpression
         val operator: String
-        val argumentExpression: KtExpression
+        val argumentExpression: KtExpression?
     }
 
     interface IteratorOnNullable : KtFirDiagnostic<KtExpression> {

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDiagnosticsImpl.kt

@@ -3396,7 +3396,7 @@ internal class UnsafeInfixCallImpl(
     override val receiverType: KtType,
     override val receiverExpression: KtExpression,
     override val operator: String,
-    override val argumentExpression: KtExpression,
+    override val argumentExpression: KtExpression?,
     firDiagnostic: KtPsiDiagnostic,
     token: KtLifetimeToken,
 ) : KtAbstractFirDiagnostic<KtExpression>(firDiagnostic, token), KtFirDiagnostic.UnsafeInfixCall
@@ -3405,7 +3405,7 @@ internal class UnsafeOperatorCallImpl(
     override val receiverType: KtType,
     override val receiverExpression: KtExpression,
     override val operator: String,
-    override val argumentExpression: KtExpression,
+    override val argumentExpression: KtExpression?,
     firDiagnostic: KtPsiDiagnostic,
     token: KtLifetimeToken,
 ) : KtAbstractFirDiagnostic<KtExpression>(firDiagnostic, token), KtFirDiagnostic.UnsafeOperatorCall

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosticCompilerTestFE10TestdataTestGenerated.java

@@ -26348,6 +26348,12 @@ public class DiagnosticCompilerTestFE10TestdataTestGenerated extends AbstractDia
                 runTest("compiler/testData/diagnostics/tests/nullableTypes/takingNullabilityFromExplicitTypeArgmentsInsteadOfUsingFlexibleTypes.kt");
             }
 
+            @Test
+            @TestMetadata("unsafeCallOnOperatorRedCode.kt")
+            public void testUnsafeCallOnOperatorRedCode() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/nullableTypes/unsafeCallOnOperatorRedCode.kt");
+            }
+
             @Test
             @TestMetadata("uselessElvis.kt")
             public void testUselessElvis() throws Exception {

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated.java

@@ -26348,6 +26348,12 @@ public class LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated
                 runTest("compiler/testData/diagnostics/tests/nullableTypes/takingNullabilityFromExplicitTypeArgmentsInsteadOfUsingFlexibleTypes.kt");
             }
 
+            @Test
+            @TestMetadata("unsafeCallOnOperatorRedCode.kt")
+            public void testUnsafeCallOnOperatorRedCode() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/nullableTypes/unsafeCallOnOperatorRedCode.kt");
+            }
+
             @Test
             @TestMetadata("uselessElvis.kt")
             public void testUselessElvis() throws Exception {

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirLightTreeOldFrontendDiagnosticsTestGenerated.java

@@ -24270,6 +24270,12 @@ public class FirLightTreeOldFrontendDiagnosticsTestGenerated extends AbstractFir
                 runTest("compiler/testData/diagnostics/tests/nullableTypes/takingNullabilityFromExplicitTypeArgmentsInsteadOfUsingFlexibleTypes.kt");
             }
 
+            @Test
+            @TestMetadata("unsafeCallOnOperatorRedCode.kt")
+            public void testUnsafeCallOnOperatorRedCode() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/nullableTypes/unsafeCallOnOperatorRedCode.kt");
+            }
+
             @Test
             @TestMetadata("uselessElvis.kt")
             public void testUselessElvis() throws Exception {

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirPsiOldFrontendDiagnosticsTestGenerated.java

@@ -24276,6 +24276,12 @@ public class FirPsiOldFrontendDiagnosticsTestGenerated extends AbstractFirPsiDia
                 runTest("compiler/testData/diagnostics/tests/nullableTypes/takingNullabilityFromExplicitTypeArgmentsInsteadOfUsingFlexibleTypes.kt");
             }
 
+            @Test
+            @TestMetadata("unsafeCallOnOperatorRedCode.kt")
+            public void testUnsafeCallOnOperatorRedCode() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/nullableTypes/unsafeCallOnOperatorRedCode.kt");
+            }
+
             @Test
             @TestMetadata("uselessElvis.kt")
             public void testUselessElvis() throws Exception {

compiler/fir/checkers/checkers-component-generator/src/org/jetbrains/kotlin/fir/checkers/generator/diagnostics/FirDiagnosticsList.kt

@@ -1405,13 +1405,13 @@ object DIAGNOSTICS_LIST : DiagnosticList("FirErrors") {
             parameter<ConeKotlinType>("receiverType")
             parameter<FirExpression>("receiverExpression")
             parameter<String>("operator")
-            parameter<FirExpression>("argumentExpression")
+            parameter<FirExpression?>("argumentExpression")
         }
         val UNSAFE_OPERATOR_CALL by error<KtExpression>(PositioningStrategy.REFERENCE_BY_QUALIFIED) {
             parameter<ConeKotlinType>("receiverType")
             parameter<FirExpression>("receiverExpression")
             parameter<String>("operator")
-            parameter<FirExpression>("argumentExpression")
+            parameter<FirExpression?>("argumentExpression")
         }
         val ITERATOR_ON_NULLABLE by error<KtExpression>()
         val UNNECESSARY_SAFE_CALL by warning<PsiElement>(PositioningStrategy.SAFE_ACCESS) {

compiler/fir/checkers/gen/org/jetbrains/kotlin/fir/analysis/diagnostics/FirErrors.kt

@@ -707,8 +707,8 @@ object FirErrors {
     // Nullability
     val UNSAFE_CALL by error2<PsiElement, ConeKotlinType, FirExpression?>(SourceElementPositioningStrategies.DOT_BY_QUALIFIED)
     val UNSAFE_IMPLICIT_INVOKE_CALL by error1<PsiElement, ConeKotlinType>(SourceElementPositioningStrategies.REFERENCE_BY_QUALIFIED)
-    val UNSAFE_INFIX_CALL by error4<KtExpression, ConeKotlinType, FirExpression, String, FirExpression>(SourceElementPositioningStrategies.REFERENCE_BY_QUALIFIED)
+    val UNSAFE_INFIX_CALL by error4<KtExpression, ConeKotlinType, FirExpression, String, FirExpression?>(SourceElementPositioningStrategies.REFERENCE_BY_QUALIFIED)
-    val UNSAFE_OPERATOR_CALL by error4<KtExpression, ConeKotlinType, FirExpression, String, FirExpression>(SourceElementPositioningStrategies.REFERENCE_BY_QUALIFIED)
+    val UNSAFE_OPERATOR_CALL by error4<KtExpression, ConeKotlinType, FirExpression, String, FirExpression?>(SourceElementPositioningStrategies.REFERENCE_BY_QUALIFIED)
     val ITERATOR_ON_NULLABLE by error0<KtExpression>()
     val UNNECESSARY_SAFE_CALL by warning1<PsiElement, ConeKotlinType>(SourceElementPositioningStrategies.SAFE_ACCESS)
     val SAFE_CALL_WILL_CHANGE_NULLABILITY by warning0<KtSafeQualifiedExpression>(SourceElementPositioningStrategies.CALL_ELEMENT_WITH_DOT)

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/diagnostics/coneDiagnosticToFirDiagnostic.kt

@@ -240,7 +240,7 @@ private fun mapUnsafeCallError(
                 rootCause.actualType,
                 receiverExpression,
                 candidateFunctionName!!.asString(),
-                singleArgument,
+                singleArgument.takeIf { it.source != null },
             )
         } else {
             FirErrors.UNSAFE_OPERATOR_CALL.createOn(
@@ -248,7 +248,7 @@ private fun mapUnsafeCallError(
                 rootCause.actualType,
                 receiverExpression,
                 candidateFunctionName!!.asString(),
-                singleArgument,
+                singleArgument.takeIf { it.source != null },
             )
         }
     }

compiler/testData/diagnostics/tests/nullableTypes/unsafeCallOnOperatorRedCode.fir.kt

@@ -0,0 +1,3 @@
+fun add(a: Int?, b: Int?): Int {
+    return a<!UNSAFE_OPERATOR_CALL!>+<!><!SYNTAX!><!>
+}

compiler/testData/diagnostics/tests/nullableTypes/unsafeCallOnOperatorRedCode.kt

@@ -0,0 +1,3 @@
+fun add(a: Int?, b: Int?): Int {
+    return a<!NONE_APPLICABLE!>+<!><!SYNTAX!><!>
+}

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java

@@ -26348,6 +26348,12 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                 runTest("compiler/testData/diagnostics/tests/nullableTypes/takingNullabilityFromExplicitTypeArgmentsInsteadOfUsingFlexibleTypes.kt");
             }
 
+            @Test
+            @TestMetadata("unsafeCallOnOperatorRedCode.kt")
+            public void testUnsafeCallOnOperatorRedCode() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/nullableTypes/unsafeCallOnOperatorRedCode.kt");
+            }
+
             @Test
             @TestMetadata("uselessElvis.kt")
             public void testUselessElvis() throws Exception {