JS: improve name clash checker to handle complicated cases

See KT-18010

compiler/testData/diagnostics/testsWithJsStdLib/name/bridgeClash.kt

@@ -0,0 +1,18 @@
+interface I {
+    fun foo()
+}
+
+interface J {
+    @JsName("bar")
+    fun foo()
+}
+
+interface K : I, J {
+    override fun foo()
+}
+
+interface L : K {
+    <!JS_NAME_CLASH!>override fun foo()<!>
+
+    <!JS_NAME_CLASH!>fun bar()<!>
+}

compiler/testData/diagnostics/testsWithJsStdLib/name/bridgeClash.txt

@@ -0,0 +1,30 @@
+package
+
+public interface I {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface J {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    @kotlin.js.JsName(name = "bar") public abstract fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface K : I, J {
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract override /*2*/ fun foo(): kotlin.Unit
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface L : K {
+    public abstract fun bar(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract override /*1*/ fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/testsWithJsStdLib/name/nameSwapInOverride.kt

@@ -0,0 +1,21 @@
+interface I {
+    @JsName("bar")
+    fun foo()
+
+    @JsName("foo")
+    fun bar()
+}
+
+interface J {
+    fun foo()
+
+    fun bar()
+}
+
+class A : I, J {
+    // Duplicate diagnostics are expected here, since `bar()` function gets both `foo` and `bar` names and clashes with both
+    // names of `foo()` function.
+    <!JS_NAME_CLASH, JS_NAME_CLASH!>override fun bar()<!> {}
+
+    <!JS_NAME_CLASH, JS_NAME_CLASH!>override fun foo()<!> {}
+}

compiler/testData/diagnostics/testsWithJsStdLib/name/nameSwapInOverride.txt

@@ -0,0 +1,26 @@
+package
+
+public final class A : I, J {
+    public constructor A()
+    public open override /*2*/ fun bar(): kotlin.Unit
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*2*/ fun foo(): kotlin.Unit
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface I {
+    @kotlin.js.JsName(name = "foo") public abstract fun bar(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    @kotlin.js.JsName(name = "bar") public abstract fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface J {
+    public abstract fun bar(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestWithJsStdLibGenerated.java

@@ -467,6 +467,12 @@ public class DiagnosticsTestWithJsStdLibGenerated extends AbstractDiagnosticsTes
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/diagnostics/testsWithJsStdLib/name"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.ANY, true);
         }
 
+        @TestMetadata("bridgeClash.kt")
+        public void testBridgeClash() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/testsWithJsStdLib/name/bridgeClash.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("classAndFunction.kt")
         public void testClassAndFunction() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/testsWithJsStdLib/name/classAndFunction.kt");
@@ -587,6 +593,12 @@ public class DiagnosticsTestWithJsStdLibGenerated extends AbstractDiagnosticsTes
             doTest(fileName);
         }
 
+        @TestMetadata("nameSwapInOverride.kt")
+        public void testNameSwapInOverride() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/testsWithJsStdLib/name/nameSwapInOverride.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("overrideOverloadedNativeFunction.kt")
         public void testOverrideOverloadedNativeFunction() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/testsWithJsStdLib/name/overrideOverloadedNativeFunction.kt");

js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsNameClashChecker.kt

@@ -20,6 +20,7 @@ import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.diagnostics.DiagnosticSink
 import org.jetbrains.kotlin.diagnostics.Errors
 import org.jetbrains.kotlin.js.naming.NameSuggestion
+import org.jetbrains.kotlin.js.naming.SuggestedName
 import org.jetbrains.kotlin.js.translate.utils.AnnotationsUtils
 import org.jetbrains.kotlin.psi.KtDeclaration
 import org.jetbrains.kotlin.resolve.BindingContext
@@ -40,7 +41,7 @@ class JsNameClashChecker : SimpleDeclarationChecker {
     private val nameSuggestion = NameSuggestion()
     private val scopes = mutableMapOf<DeclarationDescriptor, MutableMap<String, DeclarationDescriptor>>()
     private val clashedFakeOverrides = mutableMapOf<DeclarationDescriptor, Pair<DeclarationDescriptor, DeclarationDescriptor>>()
-    private val clashedDescriptors = mutableSetOf<DeclarationDescriptor>()
+    private val clashedDescriptors = mutableSetOf<Pair<DeclarationDescriptor, String>>()
 
     override fun check(
             declaration: KtDeclaration,
@@ -61,28 +62,29 @@ class JsNameClashChecker : SimpleDeclarationChecker {
     ) {
         if (descriptor is ConstructorDescriptor && descriptor.isPrimary) return
 
-        val suggested = nameSuggestion.suggest(descriptor)!!
-        if (suggested.stable && suggested.scope is ClassOrPackageFragmentDescriptor && presentsInGeneratedCode(suggested.descriptor)) {
-            val scope = getScope(suggested.scope)
-            val name = suggested.names.last()
-            val existing = scope[name]
-            if (existing != null &&
-                existing != descriptor &&
-                existing.isActual == descriptor.isActual &&
-                existing.isExpect == descriptor.isExpect &&
-                !bindingContext.isCommonDiagnosticReported(declaration)
-            ) {
-                diagnosticHolder.report(ErrorsJs.JS_NAME_CLASH.on(declaration, name, existing))
-                val existingDeclaration = existing.findPsi()
-                if (clashedDescriptors.add(existing) && existingDeclaration is KtDeclaration && existingDeclaration != declaration) {
-                    diagnosticHolder.report(ErrorsJs.JS_NAME_CLASH.on(existingDeclaration, name, descriptor))
+        for (suggested in nameSuggestion.suggestAllPossibleNames(descriptor)) {
+            if (suggested.stable && suggested.scope is ClassOrPackageFragmentDescriptor && presentsInGeneratedCode(suggested.descriptor)) {
+                val scope = getScope(suggested.scope)
+                val name = suggested.names.last()
+                val existing = scope[name]
+                if (existing != null &&
+                    existing != descriptor &&
+                    existing.isActual == descriptor.isActual &&
+                    existing.isExpect == descriptor.isExpect &&
+                    !bindingContext.isCommonDiagnosticReported(declaration)
+                ) {
+                    diagnosticHolder.report(ErrorsJs.JS_NAME_CLASH.on(declaration, name, existing))
+                    val existingDeclaration = existing.findPsi()
+                    if (clashedDescriptors.add(existing to name) && existingDeclaration is KtDeclaration &&
+                        existingDeclaration != declaration) {
+                        diagnosticHolder.report(ErrorsJs.JS_NAME_CLASH.on(existingDeclaration, name, descriptor))
+                    }
                 }
             }
         }
 
-        val fqnDescriptor = suggested.descriptor
-        if (fqnDescriptor is ClassDescriptor) {
-            val fakeOverrides = fqnDescriptor.defaultType.memberScope.getContributedDescriptors().asSequence()
+        if (descriptor is ClassDescriptor) {
+            val fakeOverrides = descriptor.unsubstitutedMemberScope.getContributedDescriptors().asSequence()
                     .mapNotNull { it as? CallableMemberDescriptor }
                     .filter { it.kind == CallableMemberDescriptor.Kind.FAKE_OVERRIDE }
             for (override in fakeOverrides) {
@@ -105,6 +107,25 @@ class JsNameClashChecker : SimpleDeclarationChecker {
         }
     }
 
+    private fun NameSuggestion.suggestAllPossibleNames(descriptor: DeclarationDescriptor): Collection<SuggestedName> =
+            if (descriptor is CallableMemberDescriptor) {
+                val primary = suggest(descriptor)
+                if (primary != null) {
+                    val overriddenNames = descriptor.overriddenDescriptors.flatMap {
+                        suggestAllPossibleNames(it).map { overridden ->
+                            SuggestedName(overridden.names, overridden.stable, primary.descriptor, primary.scope)
+                        }
+                    }
+                    (overriddenNames + primary).distinctBy { it.names }
+                }
+                else {
+                    emptyList()
+                }
+            }
+            else {
+                listOfNotNull(suggest(descriptor))
+            }
+
     private fun BindingContext.isCommonDiagnosticReported(declaration: KtDeclaration): Boolean {
         return diagnostics.forElement(declaration).any { it.factory in COMMON_DIAGNOSTICS }
     }
@@ -149,10 +170,11 @@ class JsNameClashChecker : SimpleDeclarationChecker {
             }
         }
 
-        val fqn = nameSuggestion.suggest(descriptor) ?: return
-        if (fqn.stable && presentsInGeneratedCode(fqn.descriptor)) {
-            target[fqn.names.last()] = fqn.descriptor
-            (fqn.descriptor as? CallableMemberDescriptor)?.let { checkOverrideClashes(it, target) }
+        for (fqn in nameSuggestion.suggestAllPossibleNames(descriptor)) {
+            if (fqn.stable && presentsInGeneratedCode(fqn.descriptor)) {
+                target[fqn.names.last()] = fqn.descriptor
+                (fqn.descriptor as? CallableMemberDescriptor)?.let { checkOverrideClashes(it, target) }
+            }
         }
     }