Implement recovery for incomplete expression before declaration

It's needed when declarations are parsed as a part of previous expression
(see tests)

Currently we apply this kind of recovery in a conservative way,
only when declaration starts at the next line, and while
the condition could be relaxed, there's no need to do this

 #KT-4948 Fixed
 #KT-7118 Fixed

compiler/frontend/src/org/jetbrains/kotlin/parsing/KotlinExpressionParsing.java

@@ -21,6 +21,7 @@ import com.intellij.lang.PsiBuilder;
 import com.intellij.psi.tree.IElementType;
 import com.intellij.psi.tree.TokenSet;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 import org.jetbrains.kotlin.KtNodeType;
 import org.jetbrains.kotlin.KtNodeTypes;
 import org.jetbrains.kotlin.lexer.KtToken;
@@ -42,6 +43,9 @@ public class KotlinExpressionParsing extends AbstractKotlinParsing {
 
     private static final ImmutableMap<String, KtToken> KEYWORD_TEXTS = tokenSetToMap(KEYWORDS);
 
+    private static final IElementType[] LOCAL_DECLARATION_FIRST =
+            new IElementType[] {CLASS_KEYWORD, INTERFACE_KEYWORD, FUN_KEYWORD, VAL_KEYWORD, VAR_KEYWORD, TYPE_ALIAS_KEYWORD};
+
     private static ImmutableMap<String, KtToken> tokenSetToMap(TokenSet tokens) {
         ImmutableMap.Builder<String, KtToken> builder = ImmutableMap.builder();
         for (IElementType token : tokens.getTypes()) {
@@ -298,8 +302,6 @@ public class KotlinExpressionParsing extends AbstractKotlinParsing {
      * see the precedence table
      */
     private void parseBinaryExpression(Precedence precedence) {
-        //        System.out.println(precedence.name() + " at " + myBuilder.getTokenText());
-
         PsiBuilder.Marker expression = mark();
 
         precedence.parseHigherPrecedence(this);
@@ -331,10 +333,8 @@ public class KotlinExpressionParsing extends AbstractKotlinParsing {
      * operation? prefixExpression
      */
     private void parsePrefixExpression() {
-        //        System.out.println("pre at "  + myBuilder.getTokenText());
-
         if (at(AT)) {
-            if (!parseLocalDeclaration()) {
+            if (!parseLocalDeclaration(/* rollbackIfDefinitelyNotExpression = */ false)) {
                 PsiBuilder.Marker expression = mark();
                 myKotlinParsing.parseAnnotations(DEFAULT);
                 parsePrefixExpression();
@@ -454,7 +454,7 @@ public class KotlinExpressionParsing extends AbstractKotlinParsing {
                     expression = mark();
                 }
 
-                parseCallExpression();
+                parseSelectorCallExpression();
 
                 if (firstExpressionParsed) {
                     expression.done(expressionType);
@@ -515,7 +515,7 @@ public class KotlinExpressionParsing extends AbstractKotlinParsing {
     /*
      * atomicExpression typeParameters? valueParameters? functionLiteral*
      */
-    private void parseCallExpression() {
+    private void parseSelectorCallExpression() {
         PsiBuilder.Marker mark = mark();
         parseAtomicExpression();
         if (!myBuilder.newlineBeforeCurrentToken() && parseCallSuffix()) {
@@ -624,8 +624,6 @@ public class KotlinExpressionParsing extends AbstractKotlinParsing {
      *   ;
      */
     private boolean parseAtomicExpression() {
-        //        System.out.println("atom at "  + myBuilder.getTokenText());
-
         boolean ok = true;
 
         if (at(LPAR)) {
@@ -670,9 +668,9 @@ public class KotlinExpressionParsing extends AbstractKotlinParsing {
         else if (at(DO_KEYWORD)) {
             parseDoWhile();
         }
-        else if (atSet(CLASS_KEYWORD, INTERFACE_KEYWORD, FUN_KEYWORD, VAL_KEYWORD,
-                       VAR_KEYWORD, TYPE_ALIAS_KEYWORD)) {
-            parseLocalDeclaration();
+        else if (atSet(LOCAL_DECLARATION_FIRST) &&
+                    parseLocalDeclaration(/* rollbackIfDefinitelyNotExpression = */ myBuilder.newlineBeforeCurrentToken())) {
+            // declaration was parsed, do nothing
         }
         else if (at(IDENTIFIER)) {
             parseSimpleNameExpression();
@@ -1018,12 +1016,12 @@ public class KotlinExpressionParsing extends AbstractKotlinParsing {
     /*
      * modifiers declarationRest
      */
-    private boolean parseLocalDeclaration() {
+    private boolean parseLocalDeclaration(boolean rollbackIfDefinitelyNotExpression) {
         PsiBuilder.Marker decl = mark();
         KotlinParsing.ModifierDetector detector = new KotlinParsing.ModifierDetector();
         myKotlinParsing.parseModifierList(detector, DEFAULT, TokenSet.EMPTY);
 
-        IElementType declType = parseLocalDeclarationRest(detector.isEnumDetected());
+        IElementType declType = parseLocalDeclarationRest(detector.isEnumDetected(), rollbackIfDefinitelyNotExpression);
 
         if (declType != null) {
             // we do not attach preceding comments (non-doc) to local variables because they are likely commenting a few statements below
@@ -1220,7 +1218,7 @@ public class KotlinExpressionParsing extends AbstractKotlinParsing {
      *  ;
      */
     private void parseStatement(boolean isScriptTopLevel) {
-        if (!parseLocalDeclaration()) {
+        if (!parseLocalDeclaration(/* rollbackIfDefinitelyNotExpression = */false)) {
             if (!atSet(EXPRESSION_FIRST)) {
                 errorAndAdvance("Expecting a statement");
             }
@@ -1245,9 +1243,17 @@ public class KotlinExpressionParsing extends AbstractKotlinParsing {
      *   : object
      *   ;
      */
-    private IElementType parseLocalDeclarationRest(boolean isEnum) {
+    @Nullable
+    private IElementType parseLocalDeclarationRest(boolean isEnum, boolean failIfDefinitelyNotExpression) {
         IElementType keywordToken = tt();
         IElementType declType = null;
+
+        if (failIfDefinitelyNotExpression) {
+            if (keywordToken != FUN_KEYWORD) return null;
+
+            return myKotlinParsing.parseFunction(/* failIfIdentifierExists = */ true);
+        }
+
         if (keywordToken == CLASS_KEYWORD ||  keywordToken == INTERFACE_KEYWORD) {
             declType = myKotlinParsing.parseClass(isEnum);
         }

compiler/frontend/src/org/jetbrains/kotlin/parsing/KotlinParsing.java

@@ -21,6 +21,7 @@ import com.intellij.lang.WhitespacesBinders;
 import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.psi.tree.IElementType;
 import com.intellij.psi.tree.TokenSet;
+import org.jetbrains.annotations.Contract;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.kotlin.lexer.KtKeywordToken;
@@ -1444,6 +1445,11 @@ public class KotlinParsing extends AbstractKotlinParsing {
         return accessorKind;
     }
 
+    @NotNull
+    IElementType parseFunction() {
+        return parseFunction(false);
+    }
+
     /*
      * function
      *   : modifiers "fun" typeParameters?
@@ -1454,7 +1460,8 @@ public class KotlinParsing extends AbstractKotlinParsing {
      *       functionBody?
      *   ;
      */
-    IElementType parseFunction() {
+    @Contract("false -> !null")
+    IElementType parseFunction(boolean failIfIdentifierExists) {
         assert _at(FUN_KEYWORD);
 
         advance(); // FUN_KEYWORD
@@ -1476,6 +1483,11 @@ public class KotlinParsing extends AbstractKotlinParsing {
         TokenSet functionNameFollow = TokenSet.create(LT, LPAR, RPAR, COLON, EQ);
         boolean receiverFound = parseReceiverType("function", functionNameFollow);
 
+        if (at(IDENTIFIER) && failIfIdentifierExists) {
+            myBuilder.restoreJoiningComplexTokensState();
+            return null;
+        }
+
         // function as expression has no name
         parseFunctionOrPropertyName(receiverFound, "function", functionNameFollow, /*nameRequired = */ false);
 
@@ -1598,15 +1610,15 @@ public class KotlinParsing extends AbstractKotlinParsing {
     /*
      * IDENTIFIER
      */
-    private void parseFunctionOrPropertyName(boolean receiverFound, String title, TokenSet nameFollow, boolean nameRequired) {
-        if (!nameRequired && atSet(nameFollow)) return; // no name
+    private boolean parseFunctionOrPropertyName(boolean receiverFound, String title, TokenSet nameFollow, boolean nameRequired) {
+        if (!nameRequired && atSet(nameFollow)) return true; // no name
 
         TokenSet recoverySet = TokenSet.orSet(nameFollow, TokenSet.create(LBRACE, RBRACE), TOP_LEVEL_DECLARATION_FIRST);
         if (!receiverFound) {
-            expect(IDENTIFIER, "Expecting " + title + " name or receiver type", recoverySet);
+            return expect(IDENTIFIER, "Expecting " + title + " name or receiver type", recoverySet);
         }
         else {
-            expect(IDENTIFIER, "Expecting " + title + " name", recoverySet);
+            return expect(IDENTIFIER, "Expecting " + title + " name", recoverySet);
         }
     }
 

compiler/testData/diagnostics/tests/declarationChecks/namedFunAsLastExpressionInBlock.kt

@@ -12,18 +12,18 @@ fun test() {
     val x1 =
         if (1 == 1)
             // TODO: Diagnostic content could be better
-            <!EXPECTED_TYPE_MISMATCH(\(\) -> Int)!>fun named4(): Int {return 1}<!>
-        else
-            <!EXPECTED_TYPE_MISMATCH!>fun named5() = 1<!>
+            <!SYNTAX!><!>fun named4(): Int {return 1}
+        <!SYNTAX!>else<!>
+            fun named5() = 1
 
     val x2 =
             if (1 == 1) {
-                <!EXPECTED_TYPE_MISMATCH!>fun named6(): Int {
+                fun named6(): Int {
                     return 1
-                }<!>
+                }
             }
             else
-                <!EXPECTED_TYPE_MISMATCH!>fun named7() = 1<!>
+                <!SYNTAX!><!>fun named7() = 1
 
     val x3 = when (1) {
         0 -> <!EXPECTED_TYPE_MISMATCH!>fun named8(): Int {return 1}<!>

compiler/testData/diagnostics/tests/incompleteCode/diagnosticWithSyntaxError/declarationAfterDotSelectorExpected.kt

@@ -0,0 +1,29 @@
+// !DIAGNOSTICS: -UNUSED_VARIABLE
+
+fun foo(x: Any) {
+    x.<!SYNTAX!><!>
+    val foo = 1
+
+    x.<!SYNTAX!><!>
+    fun bar() = 2
+
+    x.
+    <!ILLEGAL_SELECTOR!>fun String.() = 3<!>
+
+    var a = 24.<!SYNTAX!><!>
+    var b = 42.0
+}
+
+class A {
+    val z = "a".<!SYNTAX!><!>
+    val x = 4
+
+    val y = "b".<!SYNTAX!><!>
+    fun baz() = 5
+
+    val q = "c".
+    <!ILLEGAL_SELECTOR!>fun String.() = 6<!>
+
+    var a = 24.<!SYNTAX!><!>
+    var b = 42.0
+}

compiler/testData/diagnostics/tests/incompleteCode/diagnosticWithSyntaxError/declarationAfterDotSelectorExpected.txt

@@ -0,0 +1,18 @@
+package
+
+public fun foo(/*0*/ x: kotlin.Any): kotlin.Unit
+
+public final class A {
+    public constructor A()
+    public final var a: [ERROR : Type for 24.]
+    public final var b: kotlin.Double
+    public final val q: [ERROR : Type for "c".
+    fun String.() = 6]
+    public final val x: kotlin.Int = 4
+    public final val y: [ERROR : Type for "b".]
+    public final val z: [ERROR : Type for "a".]
+    public final fun baz(): kotlin.Int
+    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/tests/incompleteCode/diagnosticWithSyntaxError/declarationAfterIncompleteElvis.kt

@@ -0,0 +1,22 @@
+// !DIAGNOSTICS: -UNUSED_VARIABLE
+fun foo(x: Any?) {
+    x ?:<!SYNTAX!><!>
+    val foo = 1
+
+    x ?:<!SYNTAX!><!>
+    fun bar() = 2
+
+    val res: String.() -> Int = null ?:
+    fun String.() = 3
+}
+
+class A {
+    val z = null ?:<!SYNTAX!><!>
+    val x = 4
+
+    val y = null ?:<!SYNTAX!><!>
+    fun baz() = 5
+
+    val q = null ?:
+    fun String.() = 6
+}

compiler/testData/diagnostics/tests/incompleteCode/diagnosticWithSyntaxError/declarationAfterIncompleteElvis.txt

@@ -0,0 +1,15 @@
+package
+
+public fun foo(/*0*/ x: kotlin.Any?): kotlin.Unit
+
+public final class A {
+    public constructor A()
+    public final val q: kotlin.String.() -> kotlin.Int
+    public final val x: kotlin.Int = 4
+    public final val y: [ERROR : Type for null ?:]
+    public final val z: [ERROR : Type for null ?:]
+    public final fun baz(): kotlin.Int
+    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/tests/incompleteCode/variableDeclarationInSelector.kt

@@ -1,4 +1,4 @@
 fun foo(s: String) {
-    s.
-    <!DECLARATION_IN_ILLEGAL_CONTEXT, ILLEGAL_SELECTOR!>val b = 42<!>
-}
+    s.<!SYNTAX!><!>
+    val <!UNUSED_VARIABLE!>b<!> = 42
+}

compiler/testData/psi/recovery/DeclarationAfterDotSelectorExpected.kt

@@ -0,0 +1,27 @@
+fun foo(x: Any) {
+    x.
+    val foo = 1
+
+    x.
+    fun bar() = 2
+
+    x.
+    fun String.() = 3
+
+    var a = 24.
+    var b = 42.0
+}
+
+class A {
+    val z = "a".
+    val x = 4
+
+    val y = "b".
+    fun baz() = 5
+
+    val q = "c".
+    fun String.() = 6
+
+    var a = 24.
+    var b = 42.0
+}

compiler/testData/psi/recovery/DeclarationAfterDotSelectorExpected.txt

@@ -0,0 +1,231 @@
+JetFile: DeclarationAfterDotSelectorExpected.kt
+  PACKAGE_DIRECTIVE
+    <empty list>
+  IMPORT_LIST
+    <empty list>
+  FUN
+    PsiElement(fun)('fun')
+    PsiWhiteSpace(' ')
+    PsiElement(IDENTIFIER)('foo')
+    VALUE_PARAMETER_LIST
+      PsiElement(LPAR)('(')
+      VALUE_PARAMETER
+        PsiElement(IDENTIFIER)('x')
+        PsiElement(COLON)(':')
+        PsiWhiteSpace(' ')
+        TYPE_REFERENCE
+          USER_TYPE
+            REFERENCE_EXPRESSION
+              PsiElement(IDENTIFIER)('Any')
+      PsiElement(RPAR)(')')
+    PsiWhiteSpace(' ')
+    BLOCK
+      PsiElement(LBRACE)('{')
+      PsiWhiteSpace('\n    ')
+      DOT_QUALIFIED_EXPRESSION
+        REFERENCE_EXPRESSION
+          PsiElement(IDENTIFIER)('x')
+        PsiElement(DOT)('.')
+        PsiErrorElement:Expecting an element
+          <empty list>
+      PsiWhiteSpace('\n    ')
+      PROPERTY
+        PsiElement(val)('val')
+        PsiWhiteSpace(' ')
+        PsiElement(IDENTIFIER)('foo')
+        PsiWhiteSpace(' ')
+        PsiElement(EQ)('=')
+        PsiWhiteSpace(' ')
+        INTEGER_CONSTANT
+          PsiElement(INTEGER_LITERAL)('1')
+      PsiWhiteSpace('\n\n    ')
+      DOT_QUALIFIED_EXPRESSION
+        REFERENCE_EXPRESSION
+          PsiElement(IDENTIFIER)('x')
+        PsiElement(DOT)('.')
+        PsiErrorElement:Expecting an element
+          <empty list>
+      PsiWhiteSpace('\n    ')
+      FUN
+        PsiElement(fun)('fun')
+        PsiWhiteSpace(' ')
+        PsiElement(IDENTIFIER)('bar')
+        VALUE_PARAMETER_LIST
+          PsiElement(LPAR)('(')
+          PsiElement(RPAR)(')')
+        PsiWhiteSpace(' ')
+        PsiElement(EQ)('=')
+        PsiWhiteSpace(' ')
+        INTEGER_CONSTANT
+          PsiElement(INTEGER_LITERAL)('2')
+      PsiWhiteSpace('\n\n    ')
+      DOT_QUALIFIED_EXPRESSION
+        REFERENCE_EXPRESSION
+          PsiElement(IDENTIFIER)('x')
+        PsiElement(DOT)('.')
+        PsiWhiteSpace('\n    ')
+        FUN
+          PsiElement(fun)('fun')
+          PsiWhiteSpace(' ')
+          TYPE_REFERENCE
+            USER_TYPE
+              REFERENCE_EXPRESSION
+                PsiElement(IDENTIFIER)('String')
+          PsiElement(DOT)('.')
+          VALUE_PARAMETER_LIST
+            PsiElement(LPAR)('(')
+            PsiElement(RPAR)(')')
+          PsiWhiteSpace(' ')
+          PsiElement(EQ)('=')
+          PsiWhiteSpace(' ')
+          INTEGER_CONSTANT
+            PsiElement(INTEGER_LITERAL)('3')
+      PsiWhiteSpace('\n\n    ')
+      PROPERTY
+        PsiElement(var)('var')
+        PsiWhiteSpace(' ')
+        PsiElement(IDENTIFIER)('a')
+        PsiWhiteSpace(' ')
+        PsiElement(EQ)('=')
+        PsiWhiteSpace(' ')
+        DOT_QUALIFIED_EXPRESSION
+          INTEGER_CONSTANT
+            PsiElement(INTEGER_LITERAL)('24')
+          PsiElement(DOT)('.')
+          PsiErrorElement:Expecting an element
+            <empty list>
+      PsiWhiteSpace('\n    ')
+      PROPERTY
+        PsiElement(var)('var')
+        PsiWhiteSpace(' ')
+        PsiElement(IDENTIFIER)('b')
+        PsiWhiteSpace(' ')
+        PsiElement(EQ)('=')
+        PsiWhiteSpace(' ')
+        FLOAT_CONSTANT
+          PsiElement(FLOAT_CONSTANT)('42.0')
+      PsiWhiteSpace('\n')
+      PsiElement(RBRACE)('}')
+  PsiWhiteSpace('\n\n')
+  CLASS
+    PsiElement(class)('class')
+    PsiWhiteSpace(' ')
+    PsiElement(IDENTIFIER)('A')
+    PsiWhiteSpace(' ')
+    CLASS_BODY
+      PsiElement(LBRACE)('{')
+      PsiWhiteSpace('\n    ')
+      PROPERTY
+        PsiElement(val)('val')
+        PsiWhiteSpace(' ')
+        PsiElement(IDENTIFIER)('z')
+        PsiWhiteSpace(' ')
+        PsiElement(EQ)('=')
+        PsiWhiteSpace(' ')
+        DOT_QUALIFIED_EXPRESSION
+          STRING_TEMPLATE
+            PsiElement(OPEN_QUOTE)('"')
+            LITERAL_STRING_TEMPLATE_ENTRY
+              PsiElement(REGULAR_STRING_PART)('a')
+            PsiElement(CLOSING_QUOTE)('"')
+          PsiElement(DOT)('.')
+          PsiErrorElement:Expecting an element
+            <empty list>
+      PsiWhiteSpace('\n    ')
+      PROPERTY
+        PsiElement(val)('val')
+        PsiWhiteSpace(' ')
+        PsiElement(IDENTIFIER)('x')
+        PsiWhiteSpace(' ')
+        PsiElement(EQ)('=')
+        PsiWhiteSpace(' ')
+        INTEGER_CONSTANT
+          PsiElement(INTEGER_LITERAL)('4')
+      PsiWhiteSpace('\n\n    ')
+      PROPERTY
+        PsiElement(val)('val')
+        PsiWhiteSpace(' ')
+        PsiElement(IDENTIFIER)('y')
+        PsiWhiteSpace(' ')
+        PsiElement(EQ)('=')
+        PsiWhiteSpace(' ')
+        DOT_QUALIFIED_EXPRESSION
+          STRING_TEMPLATE
+            PsiElement(OPEN_QUOTE)('"')
+            LITERAL_STRING_TEMPLATE_ENTRY
+              PsiElement(REGULAR_STRING_PART)('b')
+            PsiElement(CLOSING_QUOTE)('"')
+          PsiElement(DOT)('.')
+          PsiErrorElement:Expecting an element
+            <empty list>
+      PsiWhiteSpace('\n    ')
+      FUN
+        PsiElement(fun)('fun')
+        PsiWhiteSpace(' ')
+        PsiElement(IDENTIFIER)('baz')
+        VALUE_PARAMETER_LIST
+          PsiElement(LPAR)('(')
+          PsiElement(RPAR)(')')
+        PsiWhiteSpace(' ')
+        PsiElement(EQ)('=')
+        PsiWhiteSpace(' ')
+        INTEGER_CONSTANT
+          PsiElement(INTEGER_LITERAL)('5')
+      PsiWhiteSpace('\n\n    ')
+      PROPERTY
+        PsiElement(val)('val')
+        PsiWhiteSpace(' ')
+        PsiElement(IDENTIFIER)('q')
+        PsiWhiteSpace(' ')
+        PsiElement(EQ)('=')
+        PsiWhiteSpace(' ')
+        DOT_QUALIFIED_EXPRESSION
+          STRING_TEMPLATE
+            PsiElement(OPEN_QUOTE)('"')
+            LITERAL_STRING_TEMPLATE_ENTRY
+              PsiElement(REGULAR_STRING_PART)('c')
+            PsiElement(CLOSING_QUOTE)('"')
+          PsiElement(DOT)('.')
+          PsiWhiteSpace('\n    ')
+          FUN
+            PsiElement(fun)('fun')
+            PsiWhiteSpace(' ')
+            TYPE_REFERENCE
+              USER_TYPE
+                REFERENCE_EXPRESSION
+                  PsiElement(IDENTIFIER)('String')
+            PsiElement(DOT)('.')
+            VALUE_PARAMETER_LIST
+              PsiElement(LPAR)('(')
+              PsiElement(RPAR)(')')
+            PsiWhiteSpace(' ')
+            PsiElement(EQ)('=')
+            PsiWhiteSpace(' ')
+            INTEGER_CONSTANT
+              PsiElement(INTEGER_LITERAL)('6')
+      PsiWhiteSpace('\n\n    ')
+      PROPERTY
+        PsiElement(var)('var')
+        PsiWhiteSpace(' ')
+        PsiElement(IDENTIFIER)('a')
+        PsiWhiteSpace(' ')
+        PsiElement(EQ)('=')
+        PsiWhiteSpace(' ')
+        DOT_QUALIFIED_EXPRESSION
+          INTEGER_CONSTANT
+            PsiElement(INTEGER_LITERAL)('24')
+          PsiElement(DOT)('.')
+          PsiErrorElement:Expecting an element
+            <empty list>
+      PsiWhiteSpace('\n    ')
+      PROPERTY
+        PsiElement(var)('var')
+        PsiWhiteSpace(' ')
+        PsiElement(IDENTIFIER)('b')
+        PsiWhiteSpace(' ')
+        PsiElement(EQ)('=')
+        PsiWhiteSpace(' ')
+        FLOAT_CONSTANT
+          PsiElement(FLOAT_CONSTANT)('42.0')
+      PsiWhiteSpace('\n')
+      PsiElement(RBRACE)('}')

compiler/testData/psi/recovery/DeclarationAfterIncompleteElvis.kt

@@ -0,0 +1,21 @@
+fun foo(x: Any?) {
+    x ?:
+    val foo = 1
+
+    x ?:
+    fun bar() = 2
+
+    x ?:
+    fun String.() = 3
+}
+
+class A {
+    val z = null ?:
+    val x = 4
+
+    val y = null ?:
+    fun baz() = 5
+
+    val q = null ?:
+    fun String.() = 6
+}

compiler/testData/psi/recovery/DeclarationAfterIncompleteElvis.txt

@@ -0,0 +1,188 @@
+JetFile: DeclarationAfterIncompleteElvis.kt
+  PACKAGE_DIRECTIVE
+    <empty list>
+  IMPORT_LIST
+    <empty list>
+  FUN
+    PsiElement(fun)('fun')
+    PsiWhiteSpace(' ')
+    PsiElement(IDENTIFIER)('foo')
+    VALUE_PARAMETER_LIST
+      PsiElement(LPAR)('(')
+      VALUE_PARAMETER
+        PsiElement(IDENTIFIER)('x')
+        PsiElement(COLON)(':')
+        PsiWhiteSpace(' ')
+        TYPE_REFERENCE
+          NULLABLE_TYPE
+            USER_TYPE
+              REFERENCE_EXPRESSION
+                PsiElement(IDENTIFIER)('Any')
+            PsiElement(QUEST)('?')
+      PsiElement(RPAR)(')')
+    PsiWhiteSpace(' ')
+    BLOCK
+      PsiElement(LBRACE)('{')
+      PsiWhiteSpace('\n    ')
+      BINARY_EXPRESSION
+        REFERENCE_EXPRESSION
+          PsiElement(IDENTIFIER)('x')
+        PsiWhiteSpace(' ')
+        OPERATION_REFERENCE
+          PsiElement(ELVIS)('?:')
+        PsiErrorElement:Expecting an element
+          <empty list>
+      PsiWhiteSpace('\n    ')
+      PROPERTY
+        PsiElement(val)('val')
+        PsiWhiteSpace(' ')
+        PsiElement(IDENTIFIER)('foo')
+        PsiWhiteSpace(' ')
+        PsiElement(EQ)('=')
+        PsiWhiteSpace(' ')
+        INTEGER_CONSTANT
+          PsiElement(INTEGER_LITERAL)('1')
+      PsiWhiteSpace('\n\n    ')
+      BINARY_EXPRESSION
+        REFERENCE_EXPRESSION
+          PsiElement(IDENTIFIER)('x')
+        PsiWhiteSpace(' ')
+        OPERATION_REFERENCE
+          PsiElement(ELVIS)('?:')
+        PsiErrorElement:Expecting an element
+          <empty list>
+      PsiWhiteSpace('\n    ')
+      FUN
+        PsiElement(fun)('fun')
+        PsiWhiteSpace(' ')
+        PsiElement(IDENTIFIER)('bar')
+        VALUE_PARAMETER_LIST
+          PsiElement(LPAR)('(')
+          PsiElement(RPAR)(')')
+        PsiWhiteSpace(' ')
+        PsiElement(EQ)('=')
+        PsiWhiteSpace(' ')
+        INTEGER_CONSTANT
+          PsiElement(INTEGER_LITERAL)('2')
+      PsiWhiteSpace('\n\n    ')
+      BINARY_EXPRESSION
+        REFERENCE_EXPRESSION
+          PsiElement(IDENTIFIER)('x')
+        PsiWhiteSpace(' ')
+        OPERATION_REFERENCE
+          PsiElement(ELVIS)('?:')
+        PsiWhiteSpace('\n    ')
+        FUN
+          PsiElement(fun)('fun')
+          PsiWhiteSpace(' ')
+          TYPE_REFERENCE
+            USER_TYPE
+              REFERENCE_EXPRESSION
+                PsiElement(IDENTIFIER)('String')
+          PsiElement(DOT)('.')
+          VALUE_PARAMETER_LIST
+            PsiElement(LPAR)('(')
+            PsiElement(RPAR)(')')
+          PsiWhiteSpace(' ')
+          PsiElement(EQ)('=')
+          PsiWhiteSpace(' ')
+          INTEGER_CONSTANT
+            PsiElement(INTEGER_LITERAL)('3')
+      PsiWhiteSpace('\n')
+      PsiElement(RBRACE)('}')
+  PsiWhiteSpace('\n\n')
+  CLASS
+    PsiElement(class)('class')
+    PsiWhiteSpace(' ')
+    PsiElement(IDENTIFIER)('A')
+    PsiWhiteSpace(' ')
+    CLASS_BODY
+      PsiElement(LBRACE)('{')
+      PsiWhiteSpace('\n    ')
+      PROPERTY
+        PsiElement(val)('val')
+        PsiWhiteSpace(' ')
+        PsiElement(IDENTIFIER)('z')
+        PsiWhiteSpace(' ')
+        PsiElement(EQ)('=')
+        PsiWhiteSpace(' ')
+        BINARY_EXPRESSION
+          NULL
+            PsiElement(null)('null')
+          PsiWhiteSpace(' ')
+          OPERATION_REFERENCE
+            PsiElement(ELVIS)('?:')
+          PsiErrorElement:Expecting an element
+            <empty list>
+      PsiWhiteSpace('\n    ')
+      PROPERTY
+        PsiElement(val)('val')
+        PsiWhiteSpace(' ')
+        PsiElement(IDENTIFIER)('x')
+        PsiWhiteSpace(' ')
+        PsiElement(EQ)('=')
+        PsiWhiteSpace(' ')
+        INTEGER_CONSTANT
+          PsiElement(INTEGER_LITERAL)('4')
+      PsiWhiteSpace('\n\n    ')
+      PROPERTY
+        PsiElement(val)('val')
+        PsiWhiteSpace(' ')
+        PsiElement(IDENTIFIER)('y')
+        PsiWhiteSpace(' ')
+        PsiElement(EQ)('=')
+        PsiWhiteSpace(' ')
+        BINARY_EXPRESSION
+          NULL
+            PsiElement(null)('null')
+          PsiWhiteSpace(' ')
+          OPERATION_REFERENCE
+            PsiElement(ELVIS)('?:')
+          PsiErrorElement:Expecting an element
+            <empty list>
+      PsiWhiteSpace('\n    ')
+      FUN
+        PsiElement(fun)('fun')
+        PsiWhiteSpace(' ')
+        PsiElement(IDENTIFIER)('baz')
+        VALUE_PARAMETER_LIST
+          PsiElement(LPAR)('(')
+          PsiElement(RPAR)(')')
+        PsiWhiteSpace(' ')
+        PsiElement(EQ)('=')
+        PsiWhiteSpace(' ')
+        INTEGER_CONSTANT
+          PsiElement(INTEGER_LITERAL)('5')
+      PsiWhiteSpace('\n\n    ')
+      PROPERTY
+        PsiElement(val)('val')
+        PsiWhiteSpace(' ')
+        PsiElement(IDENTIFIER)('q')
+        PsiWhiteSpace(' ')
+        PsiElement(EQ)('=')
+        PsiWhiteSpace(' ')
+        BINARY_EXPRESSION
+          NULL
+            PsiElement(null)('null')
+          PsiWhiteSpace(' ')
+          OPERATION_REFERENCE
+            PsiElement(ELVIS)('?:')
+          PsiWhiteSpace('\n    ')
+          FUN
+            PsiElement(fun)('fun')
+            PsiWhiteSpace(' ')
+            TYPE_REFERENCE
+              USER_TYPE
+                REFERENCE_EXPRESSION
+                  PsiElement(IDENTIFIER)('String')
+            PsiElement(DOT)('.')
+            VALUE_PARAMETER_LIST
+              PsiElement(LPAR)('(')
+              PsiElement(RPAR)(')')
+            PsiWhiteSpace(' ')
+            PsiElement(EQ)('=')
+            PsiWhiteSpace(' ')
+            INTEGER_CONSTANT
+              PsiElement(INTEGER_LITERAL)('6')
+      PsiWhiteSpace('\n')
+      PsiElement(RBRACE)('}')

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

@@ -8723,6 +8723,18 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                     doTest(fileName);
                 }
 
+                @TestMetadata("declarationAfterDotSelectorExpected.kt")
+                public void testDeclarationAfterDotSelectorExpected() throws Exception {
+                    String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/incompleteCode/diagnosticWithSyntaxError/declarationAfterDotSelectorExpected.kt");
+                    doTest(fileName);
+                }
+
+                @TestMetadata("declarationAfterIncompleteElvis.kt")
+                public void testDeclarationAfterIncompleteElvis() throws Exception {
+                    String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/incompleteCode/diagnosticWithSyntaxError/declarationAfterIncompleteElvis.kt");
+                    doTest(fileName);
+                }
+
                 @TestMetadata("funEquals.kt")
                 public void testFunEquals() throws Exception {
                     String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/incompleteCode/diagnosticWithSyntaxError/funEquals.kt");

compiler/tests/org/jetbrains/kotlin/parsing/ParsingTestGenerated.java

@@ -1992,6 +1992,18 @@ public class ParsingTestGenerated extends AbstractParsingTest {
                 doParsingTest(fileName);
             }
 
+            @TestMetadata("DeclarationAfterDotSelectorExpected.kt")
+            public void testDeclarationAfterDotSelectorExpected() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/psi/recovery/DeclarationAfterDotSelectorExpected.kt");
+                doParsingTest(fileName);
+            }
+
+            @TestMetadata("DeclarationAfterIncompleteElvis.kt")
+            public void testDeclarationAfterIncompleteElvis() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/psi/recovery/DeclarationAfterIncompleteElvis.kt");
+                doParsingTest(fileName);
+            }
+
             @TestMetadata("DoWhileWithEmptyCondition.kt")
             public void testDoWhileWithEmptyCondition() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/psi/recovery/DoWhileWithEmptyCondition.kt");