FIR checker: differentiate unsafe infix/operator calls from UNSAFE_CALL

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

@@ -15,6 +15,7 @@ import org.jetbrains.kotlin.fir.PrivateForInline
 import org.jetbrains.kotlin.fir.declarations.FirCallableDeclaration
 import org.jetbrains.kotlin.fir.declarations.FirClass
 import org.jetbrains.kotlin.fir.declarations.FirMemberDeclaration
+import org.jetbrains.kotlin.fir.expressions.FirExpression
 import org.jetbrains.kotlin.fir.expressions.WhenMissingCase
 import org.jetbrains.kotlin.fir.symbols.AbstractFirBasedSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.*
@@ -62,7 +63,7 @@ val DIAGNOSTICS_LIST = DiagnosticListBuilder.buildDiagnosticList {
         val SUPER_IS_NOT_AN_EXPRESSION by error<FirSourceElement, PsiElement>()
         val SUPER_NOT_AVAILABLE by error<FirSourceElement, PsiElement>()
         val ABSTRACT_SUPER_CALL by error<FirSourceElement, PsiElement>()
-        val INSTANCE_ACCESS_BEFORE_SUPER_CALL by error<FirSourceElement, PsiElement>() {
+        val INSTANCE_ACCESS_BEFORE_SUPER_CALL by error<FirSourceElement, PsiElement> {
             parameter<String>("target")
         }
     }
@@ -73,7 +74,7 @@ val DIAGNOSTICS_LIST = DiagnosticListBuilder.buildDiagnosticList {
         val RECURSION_IN_SUPERTYPES by error<FirSourceElement, PsiElement>()
         val NOT_A_SUPERTYPE by error<FirSourceElement, PsiElement>()
         val SUPERCLASS_NOT_ACCESSIBLE_FROM_INTERFACE by error<FirSourceElement, PsiElement>()
-        val QUALIFIED_SUPERTYPE_EXTENDED_BY_OTHER_SUPERTYPE by error<FirSourceElement, PsiElement>() {
+        val QUALIFIED_SUPERTYPE_EXTENDED_BY_OTHER_SUPERTYPE by error<FirSourceElement, PsiElement> {
             parameter<FirClass<*>>("otherSuperType")
         }
         val SUPERTYPE_INITIALIZED_IN_INTERFACE by error<FirSourceElement, PsiElement>()
@@ -155,7 +156,7 @@ val DIAGNOSTICS_LIST = DiagnosticListBuilder.buildDiagnosticList {
         val INAPPLICABLE_CANDIDATE by error<FirSourceElement, PsiElement> {
             parameter<AbstractFirBasedSymbol<*>>("candidate")
         }
-        val INAPPLICABLE_LATEINIT_MODIFIER by error<FirSourceElement, PsiElement>() {
+        val INAPPLICABLE_LATEINIT_MODIFIER by error<FirSourceElement, PsiElement> {
             parameter<String>("reason")
         }
     }
@@ -331,7 +332,7 @@ val DIAGNOSTICS_LIST = DiagnosticListBuilder.buildDiagnosticList {
             parameter<Collection<AbstractFirBasedSymbol<*>>>("candidates")
         }
 
-        val COMPONENT_FUNCTION_ON_NULLABLE by error<FirSourceElement, KtExpression>() {
+        val COMPONENT_FUNCTION_ON_NULLABLE by error<FirSourceElement, KtExpression> {
             parameter<Name>("componentFunctionName")
         }
 
@@ -357,11 +358,19 @@ val DIAGNOSTICS_LIST = DiagnosticListBuilder.buildDiagnosticList {
         val UNSAFE_CALL by error<FirSourceElement, PsiElement>(PositioningStrategy.DOT_BY_SELECTOR) {
             parameter<ConeKotlinType>("receiverType")
         }
-        val UNSAFE_IMPLICIT_INVOKE_CALL by error<FirSourceElement, PsiElement>() {
+        val UNSAFE_IMPLICIT_INVOKE_CALL by error<FirSourceElement, PsiElement> {
             parameter<ConeKotlinType>("receiverType")
         }
-        // TODO: val UNSAFE_INFIX_CALL by ...
+        val UNSAFE_INFIX_CALL by error<FirSourceElement, KtExpression> {
-        // TODO: val UNSAFE_OPERATOR_CALL by ...
+            parameter<FirExpression>("lhs")
+            parameter<String>("operator")
+            parameter<FirExpression>("rhs")
+        }
+        val UNSAFE_OPERATOR_CALL by error<FirSourceElement, KtExpression> {
+            parameter<FirExpression>("lhs")
+            parameter<String>("operator")
+            parameter<FirExpression>("rhs")
+        }
         // TODO: val UNEXPECTED_SAFE_CALL by ...
     }
 

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

@@ -15,6 +15,7 @@ import org.jetbrains.kotlin.fir.analysis.diagnostics.SourceElementPositioningStr
 import org.jetbrains.kotlin.fir.declarations.FirCallableDeclaration
 import org.jetbrains.kotlin.fir.declarations.FirClass
 import org.jetbrains.kotlin.fir.declarations.FirMemberDeclaration
+import org.jetbrains.kotlin.fir.expressions.FirExpression
 import org.jetbrains.kotlin.fir.expressions.WhenMissingCase
 import org.jetbrains.kotlin.fir.symbols.AbstractFirBasedSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirClassLikeSymbol
@@ -231,6 +232,8 @@ object FirErrors {
     // Nullability
     val UNSAFE_CALL by error1<FirSourceElement, PsiElement, ConeKotlinType>(SourceElementPositioningStrategies.DOT_BY_SELECTOR)
     val UNSAFE_IMPLICIT_INVOKE_CALL by error1<FirSourceElement, PsiElement, ConeKotlinType>()
+    val UNSAFE_INFIX_CALL by error3<FirSourceElement, KtExpression, FirExpression, String, FirExpression>()
+    val UNSAFE_OPERATOR_CALL by error3<FirSourceElement, KtExpression, FirExpression, String, FirExpression>()
 
     // When expressions
     val NO_ELSE_IN_WHEN by error1<FirSourceElement, KtWhenExpression, List<WhenMissingCase>>(SourceElementPositioningStrategies.WHEN_EXPRESSION)

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

@@ -9,6 +9,7 @@ import org.jetbrains.kotlin.diagnostics.rendering.DefaultErrorMessages
 import org.jetbrains.kotlin.diagnostics.rendering.DiagnosticFactoryToRendererMap
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirDiagnosticRenderers.AMBIGUOUS_CALLS
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirDiagnosticRenderers.DECLARATION_NAME
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirDiagnosticRenderers.FIR
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirDiagnosticRenderers.FQ_NAMES_IN_TYPES
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirDiagnosticRenderers.NAME
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirDiagnosticRenderers.NULLABLE_STRING
@@ -158,6 +159,8 @@ import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.UNRESOLVED_LABEL
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.UNRESOLVED_REFERENCE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.UNSAFE_CALL
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.UNSAFE_IMPLICIT_INVOKE_CALL
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.UNSAFE_INFIX_CALL
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.UNSAFE_OPERATOR_CALL
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.UNUSED_VARIABLE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.UPPER_BOUND_VIOLATED
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.USELESS_VARARG_ON_PARAMETER
@@ -512,6 +515,21 @@ class FirDefaultErrorMessages : DefaultErrorMessages.Extension {
                 "Reference has a nullable type ''{0}'', use explicit \"?.invoke\" to make a function-like call instead.",
                 RENDER_TYPE
             )
+            map.put(
+                UNSAFE_INFIX_CALL,
+                "Infix call corresponds to a dot-qualified call ''{0}.{1}({2})'' which is not allowed on a nullable receiver ''{0}''. " +
+                        "Use ''?.''-qualified call instead",
+                FIR,
+                TO_STRING,
+                FIR
+            )
+            map.put(
+                UNSAFE_OPERATOR_CALL,
+                "Operator call corresponds to a dot-qualified call ''{0}.{1}({2})'' which is not allowed on a nullable receiver ''{0}''. ",
+                FIR,
+                TO_STRING,
+                FIR
+            )
 
             // When expressions
             map.put(NO_ELSE_IN_WHEN, "''when'' expression must be exhaustive, add necessary {0}", WHEN_MISSING_CASES)

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

@@ -5,12 +5,18 @@
 
 package org.jetbrains.kotlin.fir.analysis.diagnostics
 
+import org.jetbrains.kotlin.KtNodeTypes
 import org.jetbrains.kotlin.fir.FirFakeSourceElementKind
 import org.jetbrains.kotlin.fir.FirSourceElement
+import org.jetbrains.kotlin.fir.analysis.getChild
+import org.jetbrains.kotlin.fir.declarations.FirSimpleFunction
+import org.jetbrains.kotlin.fir.declarations.isInfix
+import org.jetbrains.kotlin.fir.declarations.isOperator
 import org.jetbrains.kotlin.fir.diagnostics.*
 import org.jetbrains.kotlin.fir.resolve.calls.InapplicableWrongReceiver
 import org.jetbrains.kotlin.fir.resolve.diagnostics.*
 import org.jetbrains.kotlin.fir.types.*
+import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.resolve.calls.tower.isSuccess
 import org.jetbrains.kotlin.utils.addToStdlib.safeAs
 
@@ -58,7 +64,6 @@ private fun mapInapplicableCandidateError(
     source: FirSourceElement,
 ): FirDiagnostic<*> {
     // TODO: Need to distinguish SMARTCAST_IMPOSSIBLE
-    // TODO: handle other UNSAFE_* variants: infix, operator
     val rootCause = diagnostic.candidate.diagnostics.find { it.applicability == diagnostic.applicability }
     if (rootCause != null &&
         rootCause is InapplicableWrongReceiver &&
@@ -68,6 +73,24 @@ private fun mapInapplicableCandidateError(
         if (diagnostic.candidate.callInfo.isImplicitInvoke) {
             return FirErrors.UNSAFE_IMPLICIT_INVOKE_CALL.on(source, rootCause.actualType!!)
         }
+
+        val candidateFunction = diagnostic.candidate.symbol.fir as? FirSimpleFunction
+        val candidateFunctionName = candidateFunction?.name
+        val left = diagnostic.candidate.callInfo.explicitReceiver
+        val right = diagnostic.candidate.callInfo.argumentList.arguments.singleOrNull()
+        if (left != null && right != null &&
+            source.elementType == KtNodeTypes.OPERATION_REFERENCE &&
+            (candidateFunction?.isOperator == true || candidateFunction?.isInfix == true)
+        ) {
+            val operationToken = source.getChild(KtTokens.IDENTIFIER)
+            if (candidateFunction.isInfix && operationToken?.elementType == KtTokens.IDENTIFIER) {
+                return FirErrors.UNSAFE_INFIX_CALL.on(source, left, candidateFunctionName!!.asString(), right)
+            }
+            if (candidateFunction.isOperator && operationToken == null) {
+                return FirErrors.UNSAFE_OPERATOR_CALL.on(source, left, candidateFunctionName!!.asString(), right)
+            }
+        }
+
         return FirErrors.UNSAFE_CALL.on(source, rootCause.actualType!!)
     }
     return FirErrors.INAPPLICABLE_CANDIDATE.on(source, diagnostic.candidate.symbol)

compiler/testData/diagnostics/tests/nullabilityAndSmartCasts/InfixCallNullability.fir.kt

@@ -18,15 +18,15 @@ fun test(x : Int?, a : A?) {
 
     a<!UNSAFE_CALL!>.<!>plus(1)
     a?.plus(1)
-    a <!UNSAFE_CALL!>plus<!> 1
+    a <!UNSAFE_INFIX_CALL!>plus<!> 1
-    a <!UNSAFE_CALL!>+<!> 1
+    a <!UNSAFE_OPERATOR_CALL!>+<!> 1
     <!UNSAFE_CALL!>-<!>a
     a<!UNSAFE_CALL!>.<!>unaryMinus()
     a?.unaryMinus()
 
     a<!UNSAFE_CALL!>.<!>div(1)
-    a <!UNSAFE_CALL!>/<!> 1
+    a <!UNSAFE_OPERATOR_CALL!>/<!> 1
-    a <!UNSAFE_CALL!>div<!> 1
+    a <!UNSAFE_INFIX_CALL!>div<!> 1
     a?.div(1)
 
     a.times(1)
@@ -34,8 +34,8 @@ fun test(x : Int?, a : A?) {
     a times 1
     a?.times(1)
 
-    1 <!UNSAFE_CALL!>in<!> a
+    1 <!UNSAFE_OPERATOR_CALL!>in<!> a
-    a <!UNSAFE_CALL!>contains<!> 1
+    a <!UNSAFE_INFIX_CALL!>contains<!> 1
     a<!UNSAFE_CALL!>.<!>contains(1)
     a?.contains(1)
 }

compiler/testData/diagnostics/tests/regressions/kt282.fir.kt

@@ -14,6 +14,6 @@ fun f(): Unit {
     val i : Int? = null
     i <!NONE_APPLICABLE!>+<!> 1
     set + 1
-    1 <!UNSAFE_CALL!>in<!> set
+    1 <!UNSAFE_OPERATOR_CALL!>in<!> set
     1 in 2
 }

compiler/testData/diagnostics/tests/smartCasts/publicVals/open.fir.kt

@@ -7,5 +7,5 @@ infix fun Int.bar(i: Int) = i
 fun test() {
     val p = A()
     // For open value properties, smart casts should not work
-    if (p.foo is Int) p.foo <!UNSAFE_CALL!>bar<!> 11
+    if (p.foo is Int) p.foo <!UNSAFE_INFIX_CALL!>bar<!> 11
 }