[FE] KT-50878 Prohibit using contextual declarations without -Xcontext-receivers

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/Errors.java

@@ -1299,6 +1299,7 @@ public interface Errors {
     DiagnosticFactory1<KtElement, String> NO_CONTEXT_RECEIVER = DiagnosticFactory1.create(ERROR);
     DiagnosticFactory1<KtElement, String> MULTIPLE_ARGUMENTS_APPLICABLE_FOR_CONTEXT_RECEIVER = DiagnosticFactory1.create(ERROR);
     DiagnosticFactory0<KtElement> AMBIGUOUS_CALL_WITH_IMPLICIT_CONTEXT_RECEIVER = DiagnosticFactory0.create(ERROR);
+    DiagnosticFactory0<KtElement> UNSUPPORTED_CONTEXTUAL_DECLARATION_CALL = DiagnosticFactory0.create(ERROR);
 
     // Error sets
     ImmutableSet<? extends DiagnosticFactory<?>> UNRESOLVED_REFERENCE_DIAGNOSTICS = ImmutableSet.of(

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/DefaultErrorMessages.java

@@ -1109,6 +1109,7 @@ public class DefaultErrorMessages {
         MAP.put(NO_CONTEXT_RECEIVER, "No required context receiver found: {0}", TO_STRING);
         MAP.put(MULTIPLE_ARGUMENTS_APPLICABLE_FOR_CONTEXT_RECEIVER, "Multiple arguments applicable for context receiver: {0}", TO_STRING);
         MAP.put(AMBIGUOUS_CALL_WITH_IMPLICIT_CONTEXT_RECEIVER, "With implicit context receiver, call is ambiguous. Specify the receiver explicitly");
+        MAP.put(UNSUPPORTED_CONTEXTUAL_DECLARATION_CALL, "To use contextual declarations, specify the `-Xcontext-receivers` compiler option");
 
         MAP.setImmutable();
 

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/DiagnosticReporterByTrackingStrategy.kt

@@ -132,6 +132,10 @@ class DiagnosticReporterByTrackingStrategy(
                 val callElement = psiKotlinCall.psiCall.callElement
                 trace.report(AMBIGUOUS_CALL_WITH_IMPLICIT_CONTEXT_RECEIVER.on(callElement))
             }
+            UnsupportedContextualDeclarationCall::class.java -> {
+                val callElement = psiKotlinCall.psiCall.callElement
+                trace.report(UNSUPPORTED_CONTEXTUAL_DECLARATION_CALL.on(callElement))
+            }
         }
     }
 

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/components/ResolutionParts.kt

@@ -19,10 +19,7 @@ import org.jetbrains.kotlin.resolve.calls.inference.model.*
 import org.jetbrains.kotlin.resolve.calls.model.*
 import org.jetbrains.kotlin.resolve.calls.smartcasts.getReceiverValueWithSmartCast
 import org.jetbrains.kotlin.resolve.calls.tasks.ExplicitReceiverKind.*
-import org.jetbrains.kotlin.resolve.calls.tower.ContextReceiverAmbiguity
-import org.jetbrains.kotlin.resolve.calls.tower.InfixCallNoInfixModifier
-import org.jetbrains.kotlin.resolve.calls.tower.InvokeConventionCallNoOperatorModifier
-import org.jetbrains.kotlin.resolve.calls.tower.VisibilityError
+import org.jetbrains.kotlin.resolve.calls.tower.*
 import org.jetbrains.kotlin.resolve.descriptorUtil.isInsideInterface
 import org.jetbrains.kotlin.resolve.scopes.LexicalScope
 import org.jetbrains.kotlin.resolve.scopes.receivers.ReceiverValueWithSmartCastInfo
@@ -857,6 +854,10 @@ internal object ErrorDescriptorResolutionPart : ResolutionPart() {
 internal object CheckContextReceiversResolutionPart : ResolutionPart() {
     override fun ResolutionCandidate.process(workIndex: Int) {
         if (candidateDescriptor.contextReceiverParameters.isEmpty()) return
+        if (!callComponents.languageVersionSettings.supportsFeature(LanguageFeature.ContextReceivers)) {
+            addDiagnostic(UnsupportedContextualDeclarationCall())
+            return
+        }
         val parentLexicalScopes = scopeTower.lexicalScope.parentsWithSelf.filterIsInstance<LexicalScope>()
         val implicitReceiversGroups = mutableListOf<List<ReceiverValueWithSmartCastInfo>>()
         for (scope in parentLexicalScopes) {

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/tower/ImplicitScopeTower.kt

@@ -120,6 +120,12 @@ class ContextReceiverAmbiguity : ResolutionDiagnostic(RESOLVED_WITH_ERROR) {
     }
 }
 
+class UnsupportedContextualDeclarationCall : ResolutionDiagnostic(RESOLVED_WITH_ERROR) {
+    override fun report(reporter: DiagnosticReporter) {
+        reporter.onCall(this)
+    }
+}
+
 // todo error for this access from nested class
 class VisibilityError(val invisibleMember: DeclarationDescriptorWithVisibility) : ResolutionDiagnostic(RUNTIME_ERROR) {
     override fun report(reporter: DiagnosticReporter) {

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

@@ -5,6 +5,17 @@ fun f(g: context(Any) () -> Unit, value: Any): context(A) () -> Unit {
     return value as (context(A) () -> Unit)
 }
 
+fun f(g: () -> Unit, value: Any) : () -> Unit {
+    return g
+}
+
+context(Any)
+fun sameAsFWithoutNonContextualCounterpart(g: () -> Unit, value: Any) : () -> Unit {
+    return g
+}
+
+context(Any) val p get() = 42
+
 context(String, Int)
 class A {
     context(Any)
@@ -12,4 +23,17 @@ class A {
 
     context(String, Int)
     fun m() {}
-}
+}
+
+fun useWithContextReceivers() {
+    with(42) {
+        with("") {
+            <!OVERLOAD_RESOLUTION_AMBIGUITY!>f<!>({}, 42)
+            sameAsFWithoutNonContextualCounterpart({}, 42)
+            p
+            val a = A()
+            a.p
+            a.m()
+        }
+    }
+}

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

@@ -5,6 +5,17 @@ fun f(g: <!UNSUPPORTED_FEATURE!>context(Any)<!> () -> Unit, value: Any): <!UNSUP
     return value as (<!UNSUPPORTED_FEATURE!>context(A)<!> () -> Unit)
 }
 
+fun f(g: () -> Unit, value: Any) : () -> Unit {
+    return g
+}
+
+<!UNSUPPORTED_FEATURE!>context(Any)<!>
+fun sameAsFWithoutNonContextualCounterpart(g: () -> Unit, value: Any) : () -> Unit {
+    return g
+}
+
+<!UNSUPPORTED_FEATURE!>context(Any)<!> val p get() = 42
+
 <!UNSUPPORTED_FEATURE!>context(String, Int)<!>
 class A {
     <!UNSUPPORTED_FEATURE!>context(Any)<!>
@@ -12,4 +23,17 @@ class A {
 
     <!UNSUPPORTED_FEATURE!>context(String, Int)<!>
     fun m() {}
+}
+
+fun useWithContextReceivers() {
+    with(42) {
+        with("") {
+            f({}, 42)
+            <!UNSUPPORTED_CONTEXTUAL_DECLARATION_CALL!>sameAsFWithoutNonContextualCounterpart({}, 42)<!>
+            <!UNSUPPORTED_CONTEXTUAL_DECLARATION_CALL!>p<!>
+            val a = <!UNSUPPORTED_CONTEXTUAL_DECLARATION_CALL!>A()<!>
+            a.<!UNSUPPORTED_CONTEXTUAL_DECLARATION_CALL!>p<!>
+            a.<!UNSUPPORTED_CONTEXTUAL_DECLARATION_CALL!>m()<!>
+        }
+    }
 }

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

@@ -1,6 +1,10 @@
 package
 
+context(kotlin.Any) public val p: kotlin.Int
+public fun f(/*0*/ g: () -> kotlin.Unit, /*1*/ value: kotlin.Any): () -> kotlin.Unit
 context(kotlin.Any) public fun f(/*0*/ g: context(kotlin.Any) () -> kotlin.Unit, /*1*/ value: kotlin.Any): context(A) () -> kotlin.Unit
+context(kotlin.Any) public fun sameAsFWithoutNonContextualCounterpart(/*0*/ g: () -> kotlin.Unit, /*1*/ value: kotlin.Any): () -> kotlin.Unit
+public fun useWithContextReceivers(): kotlin.Unit
 
 context(kotlin.String, kotlin.Int) public final class A {
     public constructor A()