== turned into a safe-call

compiler/backend/src/org/jetbrains/kotlin/codegen/intrinsics/IntrinsicMethods.java

@@ -118,7 +118,6 @@ public class IntrinsicMethods {
         declareIntrinsicFunction("Cloneable", "clone", 0, CLONE);
 
         intrinsicsMap.registerIntrinsic(BUILT_INS_PACKAGE_FQ_NAME, KOTLIN_ANY_FQ_NAME, "toString", 0, TO_STRING);
-        intrinsicsMap.registerIntrinsic(BUILT_INS_PACKAGE_FQ_NAME, KOTLIN_ANY_FQ_NAME, "equals", 1, EQUALS);
         intrinsicsMap.registerIntrinsic(BUILT_INS_PACKAGE_FQ_NAME, KOTLIN_ANY_FQ_NAME, "identityEquals", 1, IDENTITY_EQUALS);
         intrinsicsMap.registerIntrinsic(BUILT_INS_PACKAGE_FQ_NAME, KOTLIN_STRING_FQ_NAME, "plus", 1, STRING_PLUS);
         intrinsicsMap.registerIntrinsic(BUILT_INS_PACKAGE_FQ_NAME, null, "arrayOfNulls", 1, new NewArray());

compiler/frontend/src/org/jetbrains/kotlin/psi/JetPsiFactory.kt

@@ -54,6 +54,10 @@ public class JetPsiFactory(private val project: Project) {
         return createParameterList("($text int x)").getParameters().first().getValOrVarNode()!!
     }
 
+    public fun createSafeCallNode(): ASTNode {
+        return (createExpression("a?.b") as JetSafeQualifiedExpression).getOperationTokenNode()
+    }
+
     public fun createExpression(text: String): JetExpression {
         return createProperty("val x = $text").getInitializer()!!
     }

compiler/frontend/src/org/jetbrains/kotlin/resolve/TypeResolver.kt

@@ -35,6 +35,7 @@ import org.jetbrains.kotlin.context.LazinessToken
 import org.jetbrains.kotlin.resolve.lazy.LazyEntity
 import org.jetbrains.kotlin.resolve.lazy.ForceResolveUtil
 import org.jetbrains.kotlin.utils.addToStdlib.firstIsInstanceOrNull
+import org.jetbrains.kotlin.psi.debugText.getDebugText
 
 public class TypeResolver(
         private val annotationResolver: AnnotationResolver,
@@ -237,7 +238,7 @@ public class TypeResolver(
                 c.trace.report(UNSUPPORTED.on(element, "Self-types are not supported yet"))
             }
         })
-        return result ?: type(ErrorUtils.createErrorType(typeElement?.getText() ?: "No type element"))
+        return result ?: type(ErrorUtils.createErrorType(typeElement?.getDebugText() ?: "No type element"))
     }
 
     private fun getScopeForTypeParameter(c: TypeResolutionContext, typeParameterDescriptor: TypeParameterDescriptor): JetScope {

compiler/frontend/src/org/jetbrains/kotlin/types/expressions/BasicExpressionTypingVisitor.java

@@ -932,7 +932,6 @@ public class BasicExpressionTypingVisitor extends ExpressionTypingVisitor {
             ExpressionTypingUtils.getTypeInfoOrNullType(left, context, facade);
             return JetTypeInfo.create(components.builtIns.getBooleanType(), dataFlowInfo);
         }
-        ExpressionReceiver receiver = ExpressionTypingUtils.safeGetExpressionReceiver(facade, left, context);
 
         JetTypeInfo leftTypeInfo = getTypeInfoOrNullType(left, context, facade);
 
@@ -946,16 +945,30 @@ public class BasicExpressionTypingVisitor extends ExpressionTypingVisitor {
                 context.trace, "trace to resolve 'equals(Any?)' interpreting as of type Any? an expression:", right);
         traceInterpretingRightAsNullableAny.record(EXPRESSION_TYPE, right, components.builtIns.getNullableAnyType());
 
-        Call call = CallMaker.makeCallWithExpressions(expression, receiver, null, operationSign, Collections.singletonList(right));
+        // Nothing? has no members, and `equals()` would be unresolved on it
+        JetType leftType = leftTypeInfo.getType();
+        if (leftType != null && KotlinBuiltIns.isNothingOrNullableNothing(leftType)) {
+            traceInterpretingRightAsNullableAny.record(EXPRESSION_TYPE, left, components.builtIns.getNullableAnyType());
+        }
+
         ExpressionTypingContext newContext = context.replaceBindingTrace(traceInterpretingRightAsNullableAny);
+        ExpressionReceiver receiver = ExpressionTypingUtils.safeGetExpressionReceiver(facade, left, newContext);
+        Call call = CallMaker.makeCallWithExpressions(
+                expression,
+                receiver,
+                // semantically, a call to `==` is a safe call
+                new JetPsiFactory(expression.getProject()).createSafeCallNode(),
+                operationSign,
+                Collections.singletonList(right)
+        );
         OverloadResolutionResults<FunctionDescriptor> resolutionResults =
                 components.callResolver.resolveCallWithGivenName(newContext, call, operationSign, OperatorConventions.EQUALS);
 
         traceInterpretingRightAsNullableAny.commit(new TraceEntryFilter() {
             @Override
             public boolean accept(@Nullable WritableSlice<?, ?> slice, Object key) {
-                // the type of the right expression isn't 'Any?' actually
+                // the type of the right (and sometimes left) expression isn't 'Any?' actually
-                if (key == right && slice == EXPRESSION_TYPE) return false;
+                if ((key == right || key == left) && slice == EXPRESSION_TYPE) return false;
 
                 // a hack due to KT-678
                 // without this line an smartcast is reported on the receiver (if it was previously checked for not-null)
@@ -1154,6 +1167,9 @@ public class BasicExpressionTypingVisitor extends ExpressionTypingVisitor {
         else if (nullability == Nullability.NOT_NULL) {
             expressionIsAlways = !equality;
         }
+        else if (nullability == Nullability.IMPOSSIBLE) {
+            expressionIsAlways = false;
+        }
         else return;
 
         context.trace.report(SENSELESS_COMPARISON.on(expression, expression, expressionIsAlways));

compiler/testData/builtin-classes.txt

@@ -1,7 +1,6 @@
 package-fragment kotlin
 
 public fun </*0*/ reified T> arrayOfNulls(/*0*/ size: kotlin.Int): kotlin.Array<T?>
-public fun kotlin.Any?.equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
 public fun kotlin.Any?.identityEquals(/*0*/ other: kotlin.Any?): kotlin.Boolean
 public fun kotlin.String?.plus(/*0*/ other: kotlin.Any?): kotlin.String
 public fun kotlin.Any?.toString(): kotlin.String

compiler/testData/cfg/conventions/equals.values

@@ -4,12 +4,12 @@ fun foo(a: Int, b: Int) {
     }
 }
 ---------------------
-                      <v0>: Int                      NEW: magic[FAKE_INITIALIZER](a: Int) -> <v0>
+                      <v0>: Int        NEW: magic[FAKE_INITIALIZER](a: Int) -> <v0>
-                      <v1>: Int                      NEW: magic[FAKE_INITIALIZER](b: Int) -> <v1>
+                      <v1>: Int        NEW: magic[FAKE_INITIALIZER](b: Int) -> <v1>
-a                     <v2>: OR{{<: Any}, {<: Any}}   NEW: r(a) -> <v2>                           
+a                     <v2>: OR{*, *}   NEW: r(a) -> <v2>
-b                     <v3>: *                        NEW: r(b) -> <v3>                           
+b                     <v3>: *          NEW: r(b) -> <v3>
-a == b                <v4>: Boolean                  NEW: call(a == b, equals|<v2>, <v3>) -> <v4>
+a == b                <v4>: Boolean    NEW: call(a == b, equals|<v2>, <v3>) -> <v4>
 { }                   !<v5>: *
-if (a == b) { }       <v6>: *                        NEW: merge(if (a == b) { }|!<v5>) -> <v6>
+if (a == b) { }       <v6>: *          NEW: merge(if (a == b) { }|!<v5>) -> <v6>
-{ if (a == b) { } }   <v6>: *                        COPY
+{ if (a == b) { } }   <v6>: *          COPY
 =====================

compiler/testData/cfg/conventions/notEqual.values

@@ -3,12 +3,12 @@ fun neq(a: Int, b: Int) {
     if (a != b) {}
 }
 ---------------------
-                     <v0>: Int                      NEW: magic[FAKE_INITIALIZER](a: Int) -> <v0>
+                     <v0>: Int        NEW: magic[FAKE_INITIALIZER](a: Int) -> <v0>
-                     <v1>: Int                      NEW: magic[FAKE_INITIALIZER](b: Int) -> <v1>
+                     <v1>: Int        NEW: magic[FAKE_INITIALIZER](b: Int) -> <v1>
-a                    <v2>: OR{{<: Any}, {<: Any}}   NEW: r(a) -> <v2>                           
+a                    <v2>: OR{*, *}   NEW: r(a) -> <v2>
-b                    <v3>: *                        NEW: r(b) -> <v3>                           
+b                    <v3>: *          NEW: r(b) -> <v3>
-a != b               <v4>: Boolean                  NEW: call(a != b, equals|<v2>, <v3>) -> <v4>
+a != b               <v4>: Boolean    NEW: call(a != b, equals|<v2>, <v3>) -> <v4>
 {}                   !<v5>: *
-if (a != b) {}       <v6>: *                        NEW: merge(if (a != b) {}|!<v5>) -> <v6>    
+if (a != b) {}       <v6>: *          NEW: merge(if (a != b) {}|!<v5>) -> <v6>
-{ if (a != b) {} }   <v6>: *                        COPY                                        
+{ if (a != b) {} }   <v6>: *          COPY
 =====================

compiler/testData/cfg/tailCalls/sum.values

@@ -4,23 +4,23 @@ tailRecursive fun sum(x: Long, sum: Long): Long {
     return sum(x - 1, sum + x)
 }
 ---------------------
-                                                                 <v0>: Long                     NEW: magic[FAKE_INITIALIZER](x: Long) -> <v0>            
+                                                                 <v0>: Long          NEW: magic[FAKE_INITIALIZER](x: Long) -> <v0>
-                                                                 <v1>: Long                     NEW: magic[FAKE_INITIALIZER](sum: Long) -> <v1>          
+                                                                 <v1>: Long          NEW: magic[FAKE_INITIALIZER](sum: Long) -> <v1>
-x                                                                <v2>: OR{{<: Any}, {<: Any}}   NEW: r(x) -> <v2>                                        
+x                                                                <v2>: OR{*, *}      NEW: r(x) -> <v2>
-0                                                                <v3>: {<: Number}              NEW: r(0) -> <v3>                                        
+0                                                                <v3>: {<: Number}   NEW: r(0) -> <v3>
-toLong()                                                         <v4>: *                        NEW: call(toLong(), toLong|<v3>) -> <v4>                 
+toLong()                                                         <v4>: *             NEW: call(toLong(), toLong|<v3>) -> <v4>
-0.toLong()                                                       <v4>: *                        COPY                                                     
+0.toLong()                                                       <v4>: *             COPY
-x == 0.toLong()                                                  <v5>: Boolean                  NEW: call(x == 0.toLong(), equals|<v2>, <v4>) -> <v5>    
+x == 0.toLong()                                                  <v5>: Boolean       NEW: call(x == 0.toLong(), equals|<v2>, <v4>) -> <v5>
-sum                                                              <v6>: Long                     NEW: r(sum) -> <v6>                                      
+sum                                                              <v6>: Long          NEW: r(sum) -> <v6>
 return sum                                                       !<v7>: *
-if (x == 0.toLong()) return sum                                  <v8>: *                        NEW: merge(if (x == 0.toLong()) return sum|!<v7>) -> <v8>
+if (x == 0.toLong()) return sum                                  <v8>: *             NEW: merge(if (x == 0.toLong()) return sum|!<v7>) -> <v8>
-x                                                                <v9>: Long                     NEW: r(x) -> <v9>                                        
+x                                                                <v9>: Long          NEW: r(x) -> <v9>
-1                                                                <v10>: Int                     NEW: r(1) -> <v10>                                       
+1                                                                <v10>: Int          NEW: r(1) -> <v10>
-x - 1                                                            <v11>: Long                    NEW: call(x - 1, minus|<v9>, <v10>) -> <v11>             
+x - 1                                                            <v11>: Long         NEW: call(x - 1, minus|<v9>, <v10>) -> <v11>
-sum                                                              <v12>: Long                    NEW: r(sum) -> <v12>                                     
+sum                                                              <v12>: Long         NEW: r(sum) -> <v12>
-x                                                                <v13>: Long                    NEW: r(x) -> <v13>                                       
+x                                                                <v13>: Long         NEW: r(x) -> <v13>
-sum + x                                                          <v14>: Long                    NEW: call(sum + x, plus|<v12>, <v13>) -> <v14>           
+sum + x                                                          <v14>: Long         NEW: call(sum + x, plus|<v12>, <v13>) -> <v14>
-sum(x - 1, sum + x)                                              <v15>: Long                    NEW: call(sum(x - 1, sum + x), sum|<v11>, <v14>) -> <v15>
+sum(x - 1, sum + x)                                              <v15>: Long         NEW: call(sum(x - 1, sum + x), sum|<v11>, <v14>) -> <v15>
 return sum(x - 1, sum + x)                                       !<v16>: *
-{ if (x == 0.toLong()) return sum return sum(x - 1, sum + x) }   !<v16>: *                      COPY                                                     
+{ if (x == 0.toLong()) return sum return sum(x - 1, sum + x) }   !<v16>: *           COPY
 =====================

compiler/testData/diagnostics/tests/delegatedProperty/absentErrorAboutInitializer.kt

@@ -1,8 +1,9 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 val a: Int by Delegate()
 
 class Delegate {
   fun get(t: Any?, p: PropertyMetadata): Int {
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
     return 1
   }
 }

compiler/testData/diagnostics/tests/delegatedProperty/absentErrorAboutType.kt

@@ -1,8 +1,9 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 val a by Delegate()
 
 class Delegate {
   fun get(t: Any?, p: PropertyMetadata): Int {
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
     return 1
   }
 }

compiler/testData/diagnostics/tests/delegatedProperty/abstractDelegatedProperty.kt

@@ -1,10 +1,11 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 abstract class A {
     abstract val a: Int <!ABSTRACT_DELEGATED_PROPERTY!>by Delegate()<!>
 }
 
 class Delegate {
   fun get(t: Any?, p: PropertyMetadata): Int {
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
     return 1
   }
 }

compiler/testData/diagnostics/tests/delegatedProperty/backingField.kt

@@ -1,3 +1,5 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 class B {
     val a: Int by Delegate()
 
@@ -6,7 +8,6 @@ class B {
 
 class Delegate {
   fun get(t: Any?, p: PropertyMetadata): Int {
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
     return 1
   }
 }

compiler/testData/diagnostics/tests/delegatedProperty/delegatedPropertyOverridedInTrait.kt

@@ -1,3 +1,5 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 trait A {
     val prop: Int
 }
@@ -12,7 +14,6 @@ fun foo() {
 
 class Delegate {
   fun get(t: Any?, p: PropertyMetadata): Int {
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
     return 1
   }
 }

compiler/testData/diagnostics/tests/delegatedProperty/delegatedPropertyOverridedInTraitTypeMismatch.kt

@@ -1,3 +1,5 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 trait A {
     val prop: Int
 }
@@ -12,7 +14,6 @@ fun foo() {
 
 class Delegate {
     fun get(t: Any?, p: PropertyMetadata): String {
-        t.equals(p) // to avoid UNUSED_PARAMETER warning
         return ""
     }
 }

compiler/testData/diagnostics/tests/delegatedProperty/genericGetter.kt

@@ -1,8 +1,9 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 val a: Int by A(1)
 
-class A<T: Any>(<!UNUSED_PARAMETER!>i<!>: T) {
+class A<T: Any>(i: T) {
   fun get(t: Any?, p: PropertyMetadata): T {
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
     throw Exception()
   }
 }

compiler/testData/diagnostics/tests/delegatedProperty/getterWithSubtype.kt

@@ -1,3 +1,5 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 open class Base
 class Derived: Base()
 
@@ -5,7 +7,6 @@ val a: Base by A()
 
 class A {
   fun get(t: Any?, p: PropertyMetadata): Derived {
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
     return Derived()
   }
 }

compiler/testData/diagnostics/tests/delegatedProperty/inTrait.kt

@@ -1,10 +1,11 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 trait T {
   val a: Int <!DELEGATED_PROPERTY_IN_TRAIT!>by Delegate()<!>
 }
 
 class Delegate {
   fun get(t: Any?, p: PropertyMetadata): Int {
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
     return 1
   }
 }

compiler/testData/diagnostics/tests/delegatedProperty/incompleteTypeInference.kt

@@ -1,3 +1,5 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 class A
 
 class D {
@@ -8,7 +10,6 @@ val cTopLevel: Int by <!DELEGATE_SPECIAL_FUNCTION_MISSING!>IncorrectThis<A>()<!>
 
 class IncorrectThis<T> {
     fun get<R>(t: Any?, p: PropertyMetadata): Int {
-        t.equals(p) // to avoid UNUSED_PARAMETER warning
         return 1
     }
 }

compiler/testData/diagnostics/tests/delegatedProperty/localVariable.kt

@@ -1,12 +1,13 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_VARIABLE
+
 class Local {
   fun foo() {
-    val <!UNUSED_VARIABLE!>a<!>: Int <!LOCAL_VARIABLE_WITH_DELEGATE!>by Delegate()<!>
+    val a: Int <!LOCAL_VARIABLE_WITH_DELEGATE!>by Delegate()<!>
   }
 }
 
 class Delegate {
   fun get(t: Any?, p: PropertyMetadata): Int {
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
     return 1
   }
 }

compiler/testData/diagnostics/tests/delegatedProperty/missedSetter.kt

@@ -1,8 +1,9 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 var a: Int by <!DELEGATE_SPECIAL_FUNCTION_MISSING!>A()<!>
 
 class A {
     fun get(t: Any?, p: PropertyMetadata): Int {
-      t.equals(p) // to avoid UNUSED_PARAMETER warning
       return 1
     }
 }

compiler/testData/diagnostics/tests/delegatedProperty/propertyDefferedType.kt

@@ -1,10 +1,9 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 class B {
     val c by Delegate(<!UNRESOLVED_REFERENCE!>ag<!>)
 }
 
 class Delegate<T: Any>(val init: T) {
-  fun get(t: Any?, p: PropertyMetadata): Int {
+  fun get(t: Any?, p: PropertyMetadata): Int = null!!
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
-    throw Exception()
-  }
 }

compiler/testData/diagnostics/tests/delegatedProperty/propertyDelegatedAmbiguity.kt

@@ -1,16 +1,13 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 val a: Int by <!DELEGATE_SPECIAL_FUNCTION_AMBIGUITY!>Delegate()<!>
 
 class Delegate {
     fun get(t: Any?, p: PropertyMetadata): Int {
-        t.equals(p) // to avoid UNUSED_PARAMETER warning
         return 1
     }
 
-    fun propertyDelegated(p: PropertyMetadata) {
+    fun propertyDelegated(p: PropertyMetadata) {}
-        p.equals(p)
-    }
 
-    fun propertyDelegated(p: PropertyMetadata, s: String = "") {
+    fun propertyDelegated(p: PropertyMetadata, s: String = "") {}
-        p.equals(s)
-    }
 }

compiler/testData/diagnostics/tests/delegatedProperty/propertyDelegatedIncomplete.kt

@@ -1,12 +1,11 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 val a: Int by  <!DELEGATE_PD_METHOD_NONE_APPLICABLE!>Delegate()<!>
 
 class Delegate {
     fun get(t: Any?, p: PropertyMetadata): Int {
-        t.equals(p) // to avoid UNUSED_PARAMETER warning
         return 1
     }
 
-    fun propertyDelegated<T>(p: PropertyMetadata) {
+    fun propertyDelegated<T>(p: PropertyMetadata) {}
-        p.equals(p)
-    }
 }

compiler/testData/diagnostics/tests/delegatedProperty/propertyDelegatedMissing.kt

@@ -1,8 +1,9 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 val a: Int by Delegate()
 
 class Delegate {
     fun get(t: Any?, p: PropertyMetadata): Int {
-        t.equals(p) // to avoid UNUSED_PARAMETER warning
         return 1
     }
 }

compiler/testData/diagnostics/tests/delegatedProperty/propertyDelegatedPrivate.kt

@@ -1,12 +1,11 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 val a: Int by <!DELEGATE_PD_METHOD_NONE_APPLICABLE!>Delegate()<!>
 
 class Delegate {
     fun get(t: Any?, p: PropertyMetadata): Int {
-        t.equals(p) // to avoid UNUSED_PARAMETER warning
         return 1
     }
 
-    private fun propertyDelegated(p: PropertyMetadata) {
+    private fun propertyDelegated(p: PropertyMetadata) {}
-        p.equals(p)
-    }
 }

compiler/testData/diagnostics/tests/delegatedProperty/propertyDelegatedWrongArguments.kt

@@ -1,22 +1,17 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 val a: Int by <!DELEGATE_PD_METHOD_NONE_APPLICABLE!>Delegate()<!>
 
 class Delegate {
     fun get(t: Any?, p: PropertyMetadata): Int {
-        t.equals(p) // to avoid UNUSED_PARAMETER warning
         return 1
     }
 
     fun propertyDelegated() {}
 
-    fun propertyDelegated(a: Int) {
+    fun propertyDelegated(a: Int) {}
-        a.equals(a)
-    }
 
-    fun propertyDelegated(a: String) {
+    fun propertyDelegated(a: String) {}
-        a.equals(a)
-    }
 
-    fun propertyDelegated(p: PropertyMetadata, a: Int) {
+    fun propertyDelegated(p: PropertyMetadata, a: Int) {}
-        p.equals(a)
-    }
 }

compiler/testData/diagnostics/tests/delegatedProperty/publicDelegatedProperty.kt

@@ -1,8 +1,9 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 <!PUBLIC_MEMBER_SHOULD_SPECIFY_TYPE!>public val a<!> by Delegate()
 
 class Delegate {
   fun get(t: Any?, p: PropertyMetadata): Int {
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
     return 1
   }
 }

compiler/testData/diagnostics/tests/delegatedProperty/recursiveType.kt

@@ -1,3 +1,5 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 val a by <!TYPECHECKER_HAS_RUN_INTO_RECURSIVE_PROBLEM!>a<!>
 
 val b by Delegate(<!TYPECHECKER_HAS_RUN_INTO_RECURSIVE_PROBLEM!>b<!>)
@@ -5,9 +7,8 @@ val b by Delegate(<!TYPECHECKER_HAS_RUN_INTO_RECURSIVE_PROBLEM!>b<!>)
 val c by <!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>d<!>
 val d by <!TYPECHECKER_HAS_RUN_INTO_RECURSIVE_PROBLEM!>c<!>
 
-class Delegate(<!UNUSED_PARAMETER!>i<!>: Int) {
+class Delegate(i: Int) {
   fun get(t: Any?, p: PropertyMetadata): Int {
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
     return 1
   }
 }

compiler/testData/diagnostics/tests/delegatedProperty/redundantGetter.kt

@@ -1,9 +1,10 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 val a: Int by Delegate()
   <!ACCESSOR_FOR_DELEGATED_PROPERTY!>get() = 1<!>
 
 class Delegate {
   fun get(t: Any?, p: PropertyMetadata): Int {
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
     return 1
   }
 }

compiler/testData/diagnostics/tests/delegatedProperty/redundantSetter.kt

@@ -1,14 +1,13 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 var a: Int by Delegate()
   <!ACCESSOR_FOR_DELEGATED_PROPERTY!>get() = 1<!>
   <!ACCESSOR_FOR_DELEGATED_PROPERTY!>set(i) {}<!>
 
 class Delegate {
   fun get(t: Any?, p: PropertyMetadata): Int {
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
     return 1
   }
 
-  fun set(t: Any?, p: PropertyMetadata, i: Int) {
+  fun set(t: Any?, p: PropertyMetadata, i: Int) {}
-    t.equals(p) || i.equals(null)  // to avoid UNUSED_PARAMETER warning
-  }
 }

compiler/testData/diagnostics/tests/delegatedProperty/setterThisTypeMismatch.kt

@@ -1,3 +1,5 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 class D {
   var c: Int by <!DELEGATE_SPECIAL_FUNCTION_NONE_APPLICABLE!>Delegate()<!>
 }
@@ -8,11 +10,7 @@ class A
 
 class Delegate {
   fun get(t: Any?, p: PropertyMetadata): Int {
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
     return 1
   }
-  fun set(t: A, p: PropertyMetadata, i: Int) {
+  fun set(t: A, p: PropertyMetadata, i: Int) {}
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
-    i.equals(null)
-  }
 }

compiler/testData/diagnostics/tests/delegatedProperty/setterWithSupertype.kt

@@ -1,3 +1,5 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 open class Base
 class Derived: Base()
 
@@ -5,13 +7,9 @@ var a: Derived by A()
 
 class A {
   fun get(t: Any?, p: PropertyMetadata): Derived {
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
     return Derived()
   }
 
-  fun set(t: Any?, p: PropertyMetadata, i: Base) {
+  fun set(t: Any?, p: PropertyMetadata, i: Base) {}
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
-    i.equals(null) // to avoid UNUSED_PARAMETER warning
-  }
 }
 

compiler/testData/diagnostics/tests/delegatedProperty/thisInDelegate.kt

@@ -1,12 +1,13 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 val Int.a by Delegate(<!NO_THIS!>this<!>)
 
 class A {
   val Int.a by Delegate(<!TYPE_MISMATCH!>this<!>)
 }
 
-class Delegate(<!UNUSED_PARAMETER!>i<!>: Int) {
+class Delegate(i: Int) {
   fun get(t: Any?, p: PropertyMetadata): Int {
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
     return 1
   }
 }

compiler/testData/diagnostics/tests/delegatedProperty/thisOfAnyType.kt

@@ -1,3 +1,5 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 class A {
   var a: Int by Delegate()
 }
@@ -6,11 +8,7 @@ var aTopLevel: Int by Delegate()
 
 class Delegate {
   fun get(t: Any?, p: PropertyMetadata): Int {
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
     return 1
   }
-  fun set(t: Any?, p: PropertyMetadata, a: Int) {
+  fun set(t: Any?, p: PropertyMetadata, a: Int) {}
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
-    a.equals(null)
-  }
 }

compiler/testData/diagnostics/tests/delegatedProperty/typeMismatchForGetReturnType.kt

@@ -1,8 +1,9 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 val c: Int by <!DELEGATE_SPECIAL_FUNCTION_RETURN_TYPE_MISMATCH!>Delegate()<!>
 
 class Delegate {
   fun get(t: Any?, p: PropertyMetadata): String {
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
     return ""
   }
 }

compiler/testData/diagnostics/tests/delegatedProperty/typeMismatchForSetParameter.kt

@@ -1,3 +1,5 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 class A {
   var a: Int by <!DELEGATE_SPECIAL_FUNCTION_NONE_APPLICABLE!>Delegate()<!>
 }
@@ -6,11 +8,7 @@ var aTopLevel: Int by <!DELEGATE_SPECIAL_FUNCTION_NONE_APPLICABLE!>Delegate()<!>
 
 class Delegate {
   fun get(t: Any?, p: PropertyMetadata): Int {
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
     return 1
   }
-  fun set(t: Any?, p: PropertyMetadata, i: String) {
+  fun set(t: Any?, p: PropertyMetadata, i: String) {}
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
-    i.equals(null)
-  }
 }

compiler/testData/diagnostics/tests/delegatedProperty/wrongCountOfParametersInGet.kt

@@ -1,3 +1,5 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 class A {
   val a: Int by <!DELEGATE_SPECIAL_FUNCTION_NONE_APPLICABLE!>Delegate()<!>
 }
@@ -6,7 +8,6 @@ val aTopLevel: Int by <!DELEGATE_SPECIAL_FUNCTION_NONE_APPLICABLE!>Delegate()<!>
 
 class Delegate {
   fun get(t: Any?, p: PropertyMetadata, a: Int): Int {
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
     return a
   }
 }

compiler/testData/diagnostics/tests/delegatedProperty/wrongCountOfParametersInSet.kt

@@ -1,3 +1,5 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 class A {
   var a: Int by <!DELEGATE_SPECIAL_FUNCTION_NONE_APPLICABLE!>Delegate()<!>
 }
@@ -6,12 +8,8 @@ var aTopLevel: Int by <!DELEGATE_SPECIAL_FUNCTION_NONE_APPLICABLE!>Delegate()<!>
 
 class Delegate {
   fun get(t: Any?, p: PropertyMetadata): Int {
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
     return 1
   }
 
-  fun set(t: Any?, p: PropertyMetadata, a: Int, c: Int) {
+  fun set(t: Any?, p: PropertyMetadata, a: Int, c: Int) {}
-    t.equals(p) // to avoid UNUSED_PARAMETER warning
-    c.equals(a)
-  }
 }

compiler/testData/diagnostics/tests/delegatedProperty/wrongSetterReturnType.kt

@@ -1,13 +1,13 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
 var b: Int by Delegate()
 
 class Delegate {
     fun get(t: Any?, p: PropertyMetadata): Int {
-      t.equals(p) // to avoid UNUSED_PARAMETER warning
       return 1
     }
 
     fun set(t: Any?, p: PropertyMetadata, i: Int): Int {
-      t.equals(p) // to avoid UNUSED_PARAMETER warning
       return i
     }
 }

compiler/testData/diagnostics/tests/extensions/ExtensionFunctions.kt

@@ -63,7 +63,7 @@ import outer.*
 
             command.foo
 
-            command.equals(null)
+            command<!UNSAFE_CALL!>.<!>equals(null)
             command?.equals(null)
             command.equals1(null)
             command?.equals1(null)

compiler/testData/diagnostics/tests/multimodule/duplicateClass/collectionMethodStub.txt

@@ -12,7 +12,6 @@ internal final class C : kotlin.MutableIterator<kotlin.Int> {
 
 package kotlin {
     public fun </*0*/ reified T> arrayOfNulls(/*0*/ size: kotlin.Int): kotlin.Array<T?>
-    public fun kotlin.Any?.equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     public fun kotlin.Any?.identityEquals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     public fun kotlin.String?.plus(/*0*/ other: kotlin.Any?): kotlin.String
     public fun kotlin.Any?.toString(): kotlin.String

compiler/testData/diagnostics/tests/regressions/kt127.kt

@@ -2,7 +2,6 @@
 
 class Foo() {}
 
-fun Any.equals(<!UNUSED_PARAMETER!>other<!> : Any?) : Boolean = true
 fun Any?.equals1(<!UNUSED_PARAMETER!>other<!> : Any?) : Boolean = true
 
 fun main(args: Array<String>) {
@@ -14,5 +13,6 @@ fun main(args: Array<String>) {
     //   .equals(null) => 1; // must be resolved
     //   ?.equals(null) => 1 // same here
     // }
-    command.equals(null)
+    command.equals1(null)
+    command?.equals(null)
 }

compiler/testData/diagnostics/tests/regressions/kt127.txt

@@ -1,7 +1,6 @@
 package
 
 internal fun main(/*0*/ args: kotlin.Array<kotlin.String>): kotlin.Unit
-internal fun kotlin.Any.equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
 internal fun kotlin.Any?.equals1(/*0*/ other: kotlin.Any?): kotlin.Boolean
 
 internal final class Foo {

compiler/testData/diagnostics/tests/regressions/kt860.txt

@@ -2,7 +2,6 @@ package
 
 package kotlin {
     public fun </*0*/ reified T> arrayOfNulls(/*0*/ size: kotlin.Int): kotlin.Array<T?>
-    public fun kotlin.Any?.equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     public fun kotlin.Any?.identityEquals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     public fun kotlin.String?.plus(/*0*/ other: kotlin.Any?): kotlin.String
     public fun kotlin.Any?.toString(): kotlin.String

compiler/tests/org/jetbrains/kotlin/codegen/FunctionGenTest.java

@@ -30,7 +30,7 @@ public class FunctionGenTest extends CodegenTestCase {
     }
 
     public void testAnyEqualsNullable() throws InvocationTargetException, IllegalAccessException {
-        loadText("fun foo(x: Any?) = x.equals(\"lala\")");
+        loadText("fun foo(x: Any?) = x?.equals(\"lala\")");
         Method foo = generateFunction();
         assertTrue((Boolean) foo.invoke(null, "lala"));
         assertFalse((Boolean) foo.invoke(null, "mama"));

core/builtins/native/kotlin/Library.kt

@@ -22,13 +22,6 @@ package kotlin
  */
 public fun Any?.identityEquals(other: Any?): Boolean // = this === other
 
-/**
- * Returns true if the receiver and the [other] object are "equal" to each other, or if they are
- * both null.
- * @see Any.equals
- */
-public fun Any?.equals(other: Any?): Boolean
-
 /**
  * Returns a string representation of the object. Can be called with a null receiver, in which case
  * it returns the string "null".

idea/testData/checker/ExtensionFunctions.kt

@@ -58,7 +58,7 @@ fun Int.foo() = this
 
             command.foo
 
-            command.equals(null)
+            command<error descr="[UNSAFE_CALL] Only safe (?.) or non-null asserted (!!.) calls are allowed on a nullable receiver of type Command?">.</error>equals(null)
             command?.equals(null)
             command.equals1(null)
             command?.equals1(null)

idea/testData/unifier/equivalence/expressions/conventions/equals.kt

@@ -1,5 +1,6 @@
 val a = <selection>1 == 2</selection>
 val b = 1.equals(2)
+val b1 = 1?.equals(2)
 val c = 2.equals(1)
 val d = 1 === 2
 val e = 1 != 2

idea/testData/unifier/equivalence/expressions/conventions/equals.kt.match

@@ -1,3 +1,3 @@
 1 == 2
 
-1.equals(2)
+1?.equals(2)

js/js.translator/testData/expression/equals/cases/explicitEqualsMethodForPrimitives.kt

@@ -7,7 +7,7 @@ fun box(): Boolean {
     if (!(a equals 2.0)) return false
     val c = "a"
     if (!("a" equals c)) return false
-    if (!(null equals null)) return false
+    if (!((null : Any?)?.equals(null) ?: true)) return false
     val d = 5.6
     if (!(d.toShort() equals 5.toShort())) return false
     if (!(d.toByte() equals 5.toByte())) return false