Mark incompatibilities related to the declaration signature as STRONG

compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/ExpectedActualDeclarationChecker.kt

@@ -306,13 +306,13 @@ object ExpectedActualDeclarationChecker : DeclarationChecker {
         sealed class Incompatible(val reason: String?, val kind: IncompatibilityKind = IncompatibilityKind.WEAK) : Compatibility() {
             // Callables
 
-            object ParameterShape : Incompatible("parameter shapes are different (extension vs non-extension)")
+            object ParameterShape : Incompatible("parameter shapes are different (extension vs non-extension)", IncompatibilityKind.STRONG)
 
             object ParameterCount : Incompatible("number of value parameters is different", IncompatibilityKind.STRONG)
-            object TypeParameterCount : Incompatible("number of type parameters is different")
+            object TypeParameterCount : Incompatible("number of type parameters is different", IncompatibilityKind.STRONG)
 
             object ParameterTypes : Incompatible("parameter types are different", IncompatibilityKind.STRONG)
-            object ReturnType : Incompatible("return type is different")
+            object ReturnType : Incompatible("return type is different", IncompatibilityKind.STRONG)
 
             object ParameterNames : Incompatible("parameter names are different")
             object TypeParameterNames : Incompatible("names of type parameters are different")

compiler/testData/diagnostics/tests/multiplatform/headerClass/expectDeclarationWithStrongIncompatibilities.kt

@@ -8,6 +8,9 @@ expect fun foo2<!JVM:NO_ACTUAL_FOR_EXPECT!>(x: Int)<!>
 
 expect class NoArgConstructor()
 
+expect fun foo3(): <!JVM:NO_ACTUAL_FOR_EXPECT!>Int<!>
+expect fun foo4<!JVM:NO_ACTUAL_FOR_EXPECT!>()<!>: Int
+
 // MODULE: m2-jvm(m1-common)
 
 // FILE: jvm.kt
@@ -20,6 +23,9 @@ fun foo1(x: String) {}
 fun foo2(x: Int, y: Int) {}
 fun foo2(x: String) {}
 
+actual fun foo3(): <!ACTUAL_WITHOUT_EXPECT!>String<!> = ""
+fun foo4(x: Int): String = ""
+
 actual class NoArgConstructor {
     actual constructor()
     actual constructor<!ACTUAL_WITHOUT_EXPECT!>(x: Int)<!>

compiler/testData/diagnostics/tests/multiplatform/headerClass/expectDeclarationWithStrongIncompatibilities.txt

@@ -3,6 +3,8 @@ package
 
 public expect fun foo1(/*0*/ x: kotlin.Int): kotlin.Unit
 public expect fun foo2(/*0*/ x: kotlin.Int): kotlin.Unit
+public expect fun foo3(): kotlin.Int
+public expect fun foo4(): kotlin.Int
 
 public final expect class NoArgConstructor {
     public constructor NoArgConstructor()
@@ -20,6 +22,8 @@ public fun foo1(/*0*/ x: kotlin.Int, /*1*/ y: kotlin.Int): kotlin.Unit
 public fun foo1(/*0*/ x: kotlin.String): kotlin.Unit
 public fun foo2(/*0*/ x: kotlin.Int, /*1*/ y: kotlin.Int): kotlin.Unit
 public fun foo2(/*0*/ x: kotlin.String): kotlin.Unit
+public actual fun foo3(): kotlin.String
+public fun foo4(/*0*/ x: kotlin.Int): kotlin.String
 
 public final actual class NoArgConstructor {
     public constructor NoArgConstructor()

compiler/testData/diagnostics/tests/multiplatform/headerClass/expectDeclarationWithWeakIncompatibilities.kt

@@ -6,18 +6,23 @@
 expect class Foo1
 expect class Foo2
 
-expect fun foo1(): Int
 expect fun foo2(): Int
-expect fun foo3<!JVM:NO_ACTUAL_FOR_EXPECT!>()<!>: Int
+
+expect val s: String
+
+expect open class <!JVM:PACKAGE_OR_CLASSIFIER_REDECLARATION!>Foo3<!>
 
 // MODULE: m2-jvm(m1-common)
 
 // FILE: jvm.kt
 
-<!DECLARATION_WITH_INCOMPATIBLE_EXPECT!>interface<!> Foo1
+<!ACTUAL_WITHOUT_EXPECT!>interface<!> Foo1
 actual <!ACTUAL_WITHOUT_EXPECT!>interface<!> Foo2
 
-actual fun foo1(): <!ACTUAL_WITHOUT_EXPECT!>String<!> = ""
+actual <!ACTUAL_WITHOUT_EXPECT!>var<!> s: String = "value"
 
 fun <!ACTUAL_MISSING!>foo2<!>(): Int = 0
-fun foo3(x: Int): String = ""
+
+actual class <!PACKAGE_OR_CLASSIFIER_REDECLARATION, ACTUAL_WITHOUT_EXPECT!>Foo3<!>
+
+class <!PACKAGE_OR_CLASSIFIER_REDECLARATION, ACTUAL_WITHOUT_EXPECT!>Foo3<!>

compiler/testData/diagnostics/tests/multiplatform/headerClass/expectDeclarationWithWeakIncompatibilities.txt

@@ -1,9 +1,8 @@
 // -- Module: <m1-common> --
 package
 
-public expect fun foo1(): kotlin.Int
+public expect val s: kotlin.String
 public expect fun foo2(): kotlin.Int
-public expect fun foo3(): kotlin.Int
 
 public final expect class Foo1 {
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
@@ -17,13 +16,18 @@ public final expect class Foo2 {
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 }
 
+public open expect class Foo3 {
+    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
+}
+
 
 // -- Module: <m2-jvm> --
 package
 
-public actual fun foo1(): kotlin.String
+public actual var s: kotlin.String
 public fun foo2(): kotlin.Int
-public fun foo3(/*0*/ x: kotlin.Int): kotlin.String
 
 public interface Foo1 {
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
@@ -36,3 +40,17 @@ public actual interface Foo2 {
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 }
+
+public final actual class Foo3 {
+    public constructor Foo3()
+    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
+}
+
+public final class Foo3 {
+    public constructor Foo3()
+    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/multiplatform/headerClass/modalityCheckForExplicitAndImplicitOverride.kt

@@ -23,7 +23,7 @@ open class Open {
 }
 
 actual open class Foo1 : Open() {
-    override val <!DECLARATION_WITH_INCOMPATIBLE_EXPECT!>x<!> = super.x
+    override val <!ACTUAL_WITHOUT_EXPECT!>x<!> = super.x
 }
 
 actual open class <!NO_ACTUAL_CLASS_MEMBER_FOR_EXPECTED_CLASS!>Foo2<!> : Open()

compiler/testData/multiplatform/classScopes/functionIncorrectSignature/output.txt

@@ -5,6 +5,15 @@ Output:
 -- JVM --
 Exit code: COMPILATION_ERROR
 Output:
+compiler/testData/multiplatform/classScopes/functionIncorrectSignature/jvm.kt:1:14: error: actual class 'Foo' has no corresponding members for expected class members:
+
+    public final expect fun function(b: ByteArray): Int
+
+    The following declaration is incompatible because return type is different:
+        public final actual fun function(b: ByteArray): Long
+
+actual class Foo {
+             ^
 compiler/testData/multiplatform/classScopes/functionIncorrectSignature/jvm.kt:2:40: error: actual function 'function' has no corresponding expected declaration
 The following declaration is incompatible because return type is different:
     public final expect fun function(b: ByteArray): Int

compiler/testData/multiplatform/incompatibleCallables/output.txt

@@ -8,6 +8,12 @@ expect fun f21(c: suspend Unit.() -> Unit)
 -- JVM --
 Exit code: COMPILATION_ERROR
 Output:
+compiler/testData/multiplatform/incompatibleCallables/common.kt:1:12: error: expected function 'f1' has no actual declaration in module
+The following declaration is incompatible because return type is different:
+    public actual fun f1(): String
+
+expect fun f1()
+           ^
 compiler/testData/multiplatform/incompatibleCallables/common.kt:5:14: error: expected function 'f3' has no actual declaration in module
 The following declaration is incompatible because parameter types are different:
     public actual fun f3(name: Double): Unit
@@ -20,12 +26,30 @@ The following declaration is incompatible because parameter types are different:
 
 expect fun String.f3ext()
                        ^
+compiler/testData/multiplatform/incompatibleCallables/common.kt:8:14: error: expected function 'f4' has no actual declaration in module
+The following declaration is incompatible because parameter shapes are different (extension vs non-extension):
+    public actual fun String.f4(): Unit
+
+expect fun f4(name: String)
+             ^
+compiler/testData/multiplatform/incompatibleCallables/common.kt:10:12: error: expected function 'f5' has no actual declaration in module
+The following declaration is incompatible because parameter shapes are different (extension vs non-extension):
+    public actual fun f5(name: String): Unit
+
+expect fun String.f5()
+           ^
 compiler/testData/multiplatform/incompatibleCallables/common.kt:12:14: error: expected function 'f6' has no actual declaration in module
 The following declaration is incompatible because number of value parameters is different:
     public actual fun f6(p2: Int): Unit
 
 expect fun f6(p1: String, p2: Int)
              ^
+compiler/testData/multiplatform/incompatibleCallables/common.kt:14:12: error: expected function 'f7' has no actual declaration in module
+The following declaration is incompatible because number of type parameters is different:
+    public actual fun <K, V> f7(): Unit
+
+expect fun <T> f7()
+           ^
 compiler/testData/multiplatform/incompatibleCallables/common.kt:32:15: error: expected function 'f21' has no actual declaration in module
 The following declaration is incompatible because parameter types are different:
     public actual fun f21(c: Unit.() -> Unit): Unit

compiler/testData/multiplatform/incompatibleClasses/output.txt

@@ -5,6 +5,12 @@ Output:
 -- JVM --
 Exit code: COMPILATION_ERROR
 Output:
+compiler/testData/multiplatform/incompatibleClasses/common.kt:14:16: error: expected class 'C1' has no actual declaration in module
+The following declaration is incompatible because number of type parameters is different:
+    public final actual class C1<A, Extra>
+
+expect class C1<A>
+               ^
 compiler/testData/multiplatform/incompatibleClasses/jvm.kt:1:8: error: actual interface 'PClass' has no corresponding expected declaration
 The following declaration is incompatible because class kinds are different (class, interface, object, enum, annotation):
     public final expect class PClass