FIR: introduce & use SELECTOR_BY_QUALIFIED positioning strategy

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

@@ -42,6 +42,7 @@ enum class PositioningStrategy(private val strategy: String) {
     IF_EXPRESSION("IF_EXPRESSION"),
     VARIANCE_MODIFIER("VARIANCE_MODIFIER"),
     LATEINIT_MODIFIER("LATEINIT_MODIFIER"),
+    SELECTOR_BY_QUALIFIED("SELECTOR_BY_QUALIFIED"),
 
     ;
 

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

@@ -388,7 +388,7 @@ object DIAGNOSTICS_LIST : DiagnosticList() {
     }
 
     val FUNCTION_CONTRACTS by object : DiagnosticGroup("Function contracts") {
-        val ERROR_IN_CONTRACT_DESCRIPTION by error<FirSourceElement, KtElement> {
+        val ERROR_IN_CONTRACT_DESCRIPTION by error<FirSourceElement, KtElement>(PositioningStrategy.SELECTOR_BY_QUALIFIED) {
             parameter<String>("reason")
         }
     }
@@ -401,7 +401,7 @@ object DIAGNOSTICS_LIST : DiagnosticList() {
         val REDUNDANT_SINGLE_EXPRESSION_STRING_TEMPLATE by warning<FirSourceElement, PsiElement>()
         val CAN_BE_VAL by warning<FirSourceElement, KtDeclaration>(PositioningStrategy.VAL_OR_VAR_NODE)
         val CAN_BE_REPLACED_WITH_OPERATOR_ASSIGNMENT by warning<FirSourceElement, KtExpression>(PositioningStrategy.OPERATOR)
-        val REDUNDANT_CALL_OF_CONVERSION_METHOD by warning<FirSourceElement, PsiElement>()
+        val REDUNDANT_CALL_OF_CONVERSION_METHOD by warning<FirSourceElement, PsiElement>(PositioningStrategy.SELECTOR_BY_QUALIFIED)
         val ARRAY_EQUALITY_OPERATOR_CAN_BE_REPLACED_WITH_EQUALS by warning<FirSourceElement, KtExpression>(PositioningStrategy.OPERATOR)
         val EMPTY_RANGE by warning<FirSourceElement, PsiElement>()
         val REDUNDANT_SETTER_PARAMETER_TYPE by warning<FirSourceElement, PsiElement>()
@@ -409,7 +409,7 @@ object DIAGNOSTICS_LIST : DiagnosticList() {
         val ASSIGNED_VALUE_IS_NEVER_READ by warning<FirSourceElement, PsiElement>()
         val VARIABLE_INITIALIZER_IS_REDUNDANT by warning<FirSourceElement, PsiElement>()
         val VARIABLE_NEVER_READ by warning<FirSourceElement, KtNamedDeclaration>(PositioningStrategy.DECLARATION_NAME)
-        val USELESS_CALL_ON_NOT_NULL by warning<FirSourceElement, PsiElement>()
+        val USELESS_CALL_ON_NOT_NULL by warning<FirSourceElement, PsiElement>(PositioningStrategy.SELECTOR_BY_QUALIFIED)
     }
 }
 

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

@@ -244,7 +244,7 @@ object FirErrors {
     val INVALID_IF_AS_EXPRESSION by error0<FirSourceElement, KtIfExpression>(SourceElementPositioningStrategies.IF_EXPRESSION)
 
     // Function contracts
-    val ERROR_IN_CONTRACT_DESCRIPTION by error1<FirSourceElement, KtElement, String>()
+    val ERROR_IN_CONTRACT_DESCRIPTION by error1<FirSourceElement, KtElement, String>(SourceElementPositioningStrategies.SELECTOR_BY_QUALIFIED)
 
     // Extended checkers
     val REDUNDANT_VISIBILITY_MODIFIER by warning0<FirSourceElement, KtModifierListOwner>(SourceElementPositioningStrategies.VISIBILITY_MODIFIER)
@@ -254,7 +254,7 @@ object FirErrors {
     val REDUNDANT_SINGLE_EXPRESSION_STRING_TEMPLATE by warning0<FirSourceElement, PsiElement>()
     val CAN_BE_VAL by warning0<FirSourceElement, KtDeclaration>(SourceElementPositioningStrategies.VAL_OR_VAR_NODE)
     val CAN_BE_REPLACED_WITH_OPERATOR_ASSIGNMENT by warning0<FirSourceElement, KtExpression>(SourceElementPositioningStrategies.OPERATOR)
-    val REDUNDANT_CALL_OF_CONVERSION_METHOD by warning0<FirSourceElement, PsiElement>()
+    val REDUNDANT_CALL_OF_CONVERSION_METHOD by warning0<FirSourceElement, PsiElement>(SourceElementPositioningStrategies.SELECTOR_BY_QUALIFIED)
     val ARRAY_EQUALITY_OPERATOR_CAN_BE_REPLACED_WITH_EQUALS by warning0<FirSourceElement, KtExpression>(SourceElementPositioningStrategies.OPERATOR)
     val EMPTY_RANGE by warning0<FirSourceElement, PsiElement>()
     val REDUNDANT_SETTER_PARAMETER_TYPE by warning0<FirSourceElement, PsiElement>()
@@ -262,6 +262,6 @@ object FirErrors {
     val ASSIGNED_VALUE_IS_NEVER_READ by warning0<FirSourceElement, PsiElement>()
     val VARIABLE_INITIALIZER_IS_REDUNDANT by warning0<FirSourceElement, PsiElement>()
     val VARIABLE_NEVER_READ by warning0<FirSourceElement, KtNamedDeclaration>(SourceElementPositioningStrategies.DECLARATION_NAME)
-    val USELESS_CALL_ON_NOT_NULL by warning0<FirSourceElement, PsiElement>()
+    val USELESS_CALL_ON_NOT_NULL by warning0<FirSourceElement, PsiElement>(SourceElementPositioningStrategies.SELECTOR_BY_QUALIFIED)
 
 }

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

@@ -335,6 +335,24 @@ object LightTreePositioningStrategies {
         }
     }
 
+    val SELECTOR_BY_QUALIFIED: LightTreePositioningStrategy = object : LightTreePositioningStrategy() {
+        override fun mark(
+            node: LighterASTNode,
+            startOffset: Int,
+            endOffset: Int,
+            tree: FlyweightCapableTreeStructure<LighterASTNode>
+        ): List<TextRange> {
+            if (node.tokenType != KtNodeTypes.DOT_QUALIFIED_EXPRESSION && node.tokenType != KtNodeTypes.SAFE_ACCESS_EXPRESSION) {
+                return super.mark(node, startOffset, endOffset, tree)
+            }
+            val selector = tree.selector(node)
+            if (selector != null) {
+                return markElement(selector, startOffset, endOffset, tree, node)
+            }
+            return super.mark(node, startOffset, endOffset, tree)
+        }
+    }
+
     val WHEN_EXPRESSION = object : LightTreePositioningStrategy() {
         override fun mark(
             node: LighterASTNode,
@@ -448,6 +466,25 @@ private fun FlyweightCapableTreeStructure<LighterASTNode>.defaultValue(node: Lig
     return null
 }
 
+private fun FlyweightCapableTreeStructure<LighterASTNode>.selector(node: LighterASTNode): LighterASTNode? {
+    val childrenRef = Ref<Array<LighterASTNode?>>()
+    getChildren(node, childrenRef)
+    val children = childrenRef.get() ?: return null
+    var dotFound = false
+    for (child in children) {
+        if (child == null) continue
+        if (child.tokenType == KtTokens.DOT) {
+            dotFound = true
+            continue
+        }
+        if (dotFound && (child.tokenType == KtNodeTypes.CALL_EXPRESSION || child.tokenType == KtNodeTypes.REFERENCE_EXPRESSION)) {
+            return child
+        }
+    }
+    return null
+
+}
+
 fun FlyweightCapableTreeStructure<LighterASTNode>.findChildByType(node: LighterASTNode, type: IElementType): LighterASTNode? {
     val childrenRef = Ref<Array<LighterASTNode?>>()
     getChildren(node, childrenRef)

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

@@ -103,6 +103,11 @@ object SourceElementPositioningStrategies {
         PositioningStrategies.DOT_BY_SELECTOR
     )
 
+    val SELECTOR_BY_QUALIFIED = SourceElementPositioningStrategy(
+        LightTreePositioningStrategies.SELECTOR_BY_QUALIFIED,
+        PositioningStrategies.SELECTOR_BY_QUALIFIED
+    )
+
     val WHEN_EXPRESSION = SourceElementPositioningStrategy(
         LightTreePositioningStrategies.WHEN_EXPRESSION,
         PositioningStrategies.WHEN_EXPRESSION

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/PositioningStrategies.kt

@@ -725,4 +725,15 @@ object PositioningStrategies {
             return super.mark(element)
         }
     }
+
+    val SELECTOR_BY_QUALIFIED: PositioningStrategy<PsiElement> = object : PositioningStrategy<PsiElement>() {
+        override fun mark(element: PsiElement): List<TextRange> {
+            if (element is KtQualifiedExpression) {
+                when (val selectorExpression = element.selectorExpression) {
+                    is KtCallExpression, is KtReferenceExpression -> return mark(selectorExpression)
+                }
+            }
+            return super.mark(element)
+        }
+    }
 }