[K2] Disappeared UNSUPPORTED_FEATURE (2)

Added a check for the enabled context receivers feature flag for declaration.

^KT-59913

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/CommonDeclarationCheckers.kt

@@ -37,6 +37,7 @@ object CommonDeclarationCheckers : DeclarationCheckers() {
             FirExpectConsistencyChecker,
             FirOptionalExpectationDeclarationChecker,
             FirMissingDependencySupertypeChecker.ForDeclarations,
+            FirContextReceiversDeclarationChecker,
         )
 
     override val classLikeCheckers: Set<FirClassLikeChecker>

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirContextReceiversDeclarationChecker.kt

@@ -0,0 +1,69 @@
+/*
+ * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.fir.analysis.checkers.declaration
+
+import com.intellij.lang.LighterASTNode
+import org.jetbrains.kotlin.KtFakeSourceElementKind
+import org.jetbrains.kotlin.KtLightSourceElement
+import org.jetbrains.kotlin.KtNodeTypes.CONTEXT_RECEIVER_LIST
+import org.jetbrains.kotlin.KtSourceElement
+import org.jetbrains.kotlin.config.LanguageFeature
+import org.jetbrains.kotlin.diagnostics.DiagnosticReporter
+import org.jetbrains.kotlin.diagnostics.reportOn
+import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
+import org.jetbrains.kotlin.fir.declarations.*
+import org.jetbrains.kotlin.toKtLightSourceElement
+import org.jetbrains.kotlin.util.getChildren
+
+object FirContextReceiversDeclarationChecker : FirBasicDeclarationChecker() {
+    override fun check(declaration: FirDeclaration, context: CheckerContext, reporter: DiagnosticReporter) {
+        if (context.languageVersionSettings.supportsFeature(LanguageFeature.ContextReceivers)) return
+        if (declaration.source?.kind is KtFakeSourceElementKind) return
+        if (!declaration.hasContextReceiver()) return
+        val source = declaration.source?.findContextReceiverListSource() ?: return
+
+        reporter.reportOn(
+            source,
+            FirErrors.UNSUPPORTED_FEATURE,
+            LanguageFeature.ContextReceivers to context.languageVersionSettings,
+            context
+        )
+    }
+
+    private fun FirDeclaration.hasContextReceiver(): Boolean {
+        val contextReceivers = when (this) {
+            is FirCallableDeclaration -> contextReceivers
+            is FirRegularClass -> contextReceivers
+            is FirScript -> contextReceivers
+            else -> emptyList()
+        }
+        return contextReceivers.isNotEmpty()
+    }
+
+
+    private fun KtSourceElement.findContextReceiverListSource(): KtLightSourceElement? {
+        var contextReceiverList: LighterASTNode? = null
+        var contextReceiverListOffset = startOffset
+
+        val nodes = lighterASTNode.getChildren(treeStructure)
+        for (node in nodes) {
+            if (node.tokenType == CONTEXT_RECEIVER_LIST) {
+                contextReceiverList = node
+                break
+            } else {
+                contextReceiverListOffset += node.endOffset - node.startOffset
+            }
+        }
+        if (contextReceiverList == null) return null
+
+        return contextReceiverList.toKtLightSourceElement(
+            treeStructure,
+            startOffset = contextReceiverListOffset,
+            endOffset = contextReceiverListOffset + contextReceiverList.textLength,
+        )
+    }
+}

compiler/testData/diagnostics/tests/extensions/contextReceivers/labelsFromClassNameForbidden.fir.kt

@@ -3,11 +3,11 @@ fun List<Int>.f() {
     this@List.size
 }
 
-context(String)
+<!UNSUPPORTED_FEATURE!>context(String)<!>
 fun Int.f() {
     this@String.length
     this@Int.toDouble()
 }
 
-context(String)
+<!UNSUPPORTED_FEATURE!>context(String)<!>
 val p: String get() = this@String

compiler/testData/diagnostics/tests/extensions/contextReceivers/unsupported.fir.kt

@@ -1,6 +1,6 @@
 // !DIAGNOSTICS: -UNCHECKED_CAST
 
-context(Any)
+<!UNSUPPORTED_FEATURE!>context(Any)<!>
 fun f(g: <!UNSUPPORTED_FEATURE!>context(Any) () -> Unit<!>, value: Any): <!UNSUPPORTED_FEATURE!>context(A) () -> Unit<!> {
     return value as <!UNSUPPORTED_FEATURE!>(context(A) () -> Unit)<!>
 }
@@ -9,19 +9,25 @@ fun f(g: () -> Unit, value: Any) : () -> Unit {
     return g
 }
 
-context(Any)
+<!UNSUPPORTED_FEATURE!>context(Any)<!>
 fun sameAsFWithoutNonContextualCounterpart(g: () -> Unit, value: Any) : () -> Unit {
     return g
 }
 
-context(Any) val p get() = 42
+<!UNSUPPORTED_FEATURE!>context(Any)<!> val p get() = 42
 
-context(String, Int)
+<!UNSUPPORTED_FEATURE!>context(String, Int)<!>
+class D constructor(){}
+
+<!UNSUPPORTED_FEATURE!>context(String, Int)<!>
+class C(){}
+
+<!UNSUPPORTED_FEATURE!>context(String, Int)<!>
 class A {
-    context(Any)
+    <!UNSUPPORTED_FEATURE!>context(Any)<!>
     val p: Any get() = 42
 
-    context(String, Int)
+    <!UNSUPPORTED_FEATURE!>context(String, Int)<!>
     fun m() {}
 }
 

compiler/testData/diagnostics/tests/extensions/contextReceivers/unsupported.kt

@@ -16,6 +16,12 @@ fun sameAsFWithoutNonContextualCounterpart(g: () -> Unit, value: Any) : () -> Un
 
 <!UNSUPPORTED_FEATURE!>context(Any)<!> val p get() = 42
 
+<!UNSUPPORTED_FEATURE!>context(String, Int)<!>
+class D constructor(){}
+
+<!UNSUPPORTED_FEATURE!>context(String, Int)<!>
+class C(){}
+
 <!UNSUPPORTED_FEATURE!>context(String, Int)<!>
 class A {
     <!UNSUPPORTED_FEATURE!>context(Any)<!>

compiler/testData/diagnostics/tests/extensions/contextReceivers/unsupported.txt

@@ -14,3 +14,18 @@ context(kotlin.String, kotlin.Int) public final class A {
     context(kotlin.String, kotlin.Int) public final fun m(): kotlin.Unit
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 }
+
+context(kotlin.String, kotlin.Int) public final class C {
+    public constructor C()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+context(kotlin.String, kotlin.Int) public final class D {
+    public constructor D()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+

compiler/testData/diagnostics/testsWithJvmBackend/contextReceivers/kt59590WithContextReceiver.fir.diag.txt

@@ -2,6 +2,8 @@
     context(O) val INSTANCE: O? defined in O
     val INSTANCE: O defined in O
 
+/kt59590WithContextReceiver.fir.kt:5:5: error: The feature "context receivers" is experimental and should be enabled explicitly
+
 /kt59590WithContextReceiver.fir.kt:5:5: error: Platform declaration clash: The following declarations have the same JVM signature (INSTANCELO;):
     context(O) val INSTANCE: O? defined in O
     val INSTANCE: O defined in O

compiler/testData/diagnostics/testsWithJvmBackend/contextReceivers/kt59590WithContextReceiver.fir.kt

@@ -2,7 +2,7 @@
 // !RENDER_ALL_DIAGNOSTICS_FULL_TEXT
 
 <!CONFLICTING_JVM_DECLARATIONS!>object O {
-    <!CONFLICTING_JVM_DECLARATIONS!>context(O)
+    <!CONFLICTING_JVM_DECLARATIONS!><!UNSUPPORTED_FEATURE!>context(O)<!>
     @JvmField
     val INSTANCE: O? = null<!>
-}<!>
+}<!>