Fix type parameter bound check in expect-actual checker

Also make TypeParameterUpperBounds a "strong" incompatibility, meaning
that non-actual members from platform module are _not_ going to be
matched to the expected members if this incompatibility exists between
them, and therefore NO_ACTUAL_FOR_EXPECT will be reported on the
expected declaration, instead of ACTUAL_MISSING on the platform member.
This is needed because the difference in type parameter upper bounds can
have effect on the function signature on the platform (e.g. on JVM,
Array<T> -> T[], but Array<T> -> Comparable[] if T : Comparable<T>), and
it would be incorrect to report ACTUAL_MISSING on the member that has
nothing to do with the expected declaration that happens to coincide
with it in everything except type parameter bounds

 #KT-21864 Fixed

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

@@ -382,7 +382,7 @@ object ExpectedActualDeclarationChecker : DeclarationChecker {
             object Modality : Incompatible("modality is different")
             object Visibility : Incompatible("visibility is different")
 
-            object TypeParameterUpperBounds : Incompatible("upper bounds of type parameters are different")
+            object TypeParameterUpperBounds : Incompatible("upper bounds of type parameters are different", IncompatibilityKind.STRONG)
             object TypeParameterVariance : Incompatible("declaration-site variances of type parameters are different")
             object TypeParameterReified : Incompatible("some type parameter is reified in one declaration and non-reified in the other")
 
@@ -523,8 +523,14 @@ object ExpectedActualDeclarationChecker : DeclarationChecker {
         platformModule: ModuleDescriptor,
         substitutor: Substitutor
     ): Compatibility {
-        if (!areCompatibleTypeLists(a.map { substitutor(it.defaultType) }, b.map { it.defaultType }, platformModule))
-            return Incompatible.TypeParameterUpperBounds
+        for (i in a.indices) {
+            val aBounds = a[i].upperBounds
+            val bBounds = b[i].upperBounds
+            if (aBounds.size != bBounds.size || !areCompatibleTypeLists(aBounds.map(substitutor), bBounds, platformModule)) {
+                return Incompatible.TypeParameterUpperBounds
+            }
+        }
+
         if (!equalsBy(a, b, TypeParameterDescriptor::getVariance)) return Incompatible.TypeParameterVariance
 
         // Removing "reified" from an expected function's type parameter is fine

compiler/testData/diagnostics/tests/multiplatform/generic/functionTypeParameterBounds.kt

@@ -0,0 +1,12 @@
+// !LANGUAGE: +MultiPlatformProjects
+// MODULE: m1-common
+// FILE: common.kt
+
+expect fun <T : Comparable<T>> Array<out T>.sort(): Unit
+
+// MODULE: m2-jvm(m1-common)
+// FILE: jvm.kt
+
+actual fun <T : Comparable<T>> Array<out T>.sort(): Unit {}
+
+fun <T> Array<out T>.sort(): Unit {}

compiler/testData/diagnostics/tests/multiplatform/generic/functionTypeParameterBounds.txt

@@ -0,0 +1,11 @@
+// -- Module: <m1-common> --
+package
+
+public expect fun </*0*/ T : kotlin.Comparable<T>> kotlin.Array<out T>.sort(): kotlin.Unit
+
+
+// -- Module: <m2-jvm> --
+package
+
+public fun </*0*/ T> kotlin.Array<out T>.sort(): kotlin.Unit
+public actual fun </*0*/ T : kotlin.Comparable<T>> kotlin.Array<out T>.sort(): kotlin.Unit

compiler/testData/diagnostics/tests/multiplatform/generic/genericMemberBounds.kt

@@ -0,0 +1,25 @@
+// !LANGUAGE: +MultiPlatformProjects
+// MODULE: m1-common
+// FILE: common.kt
+
+expect class A {
+    fun <T : Any> foo(): Unit
+
+    fun <S : Comparable<S>> bar(): List<S>
+}
+
+// MODULE: m2-jvm(m1-common)
+// FILE: jvm.kt
+
+actual typealias A = JavaA
+
+// FILE: JavaA.java
+import java.util.List;
+
+public class JavaA {
+    public <T> void foo() {}
+
+    public <S extends Comparable<S>> List<S> bar() {
+        return null;
+    }
+}

compiler/testData/diagnostics/tests/multiplatform/generic/genericMemberBounds.txt

@@ -0,0 +1,24 @@
+// -- Module: <m1-common> --
+package
+
+public final expect class A {
+    public final expect fun </*0*/ S : kotlin.Comparable<S>> bar(): kotlin.collections.List<S>
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public final expect fun </*0*/ T : kotlin.Any> foo(): kotlin.Unit
+    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 open class JavaA {
+    public constructor JavaA()
+    public open fun </*0*/ S : kotlin.Comparable<S!>!> bar(): kotlin.collections.(Mutable)List<S!>!
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open fun </*0*/ T : kotlin.Any!> foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+public actual typealias A = JavaA

compiler/testData/diagnostics/tests/multiplatform/generic/typeParameterBoundsDifferentOrderActualMissing.kt

@@ -0,0 +1,13 @@
+// !LANGUAGE: +MultiPlatformProjects
+// MODULE: m1-common
+// FILE: common.kt
+
+interface A
+interface B
+
+expect fun <!JVM:NO_ACTUAL_FOR_EXPECT!><T><!> List<T>.foo() where T : A, T : B
+
+// MODULE: m2-jvm(m1-common)
+// FILE: jvm.kt
+
+fun <T> List<T>.foo() where T : B, T : A {}

compiler/testData/diagnostics/tests/multiplatform/generic/typeParameterBoundsDifferentOrderActualMissing.txt

@@ -0,0 +1,34 @@
+// -- Module: <m1-common> --
+package
+
+public expect fun </*0*/ T : A> kotlin.collections.List<T>.foo(): kotlin.Unit where T : B
+
+public interface A {
+    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 interface B {
+    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 fun </*0*/ T : B> kotlin.collections.List<T>.foo(): kotlin.Unit where T : A
+
+public interface A {
+    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 interface B {
+    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/multiplatform/incompatibleCallables/output.txt

@@ -50,6 +50,24 @@ The following declaration is incompatible because number of type parameters is d
 
 expect fun <T> f7()
            ^
+compiler/testData/multiplatform/incompatibleCallables/common.kt:19:12: error: expected function 'f11' has no actual declaration in module
+The following declaration is incompatible because upper bounds of type parameters are different:
+    public actual fun <T : Annotation> f11(): Unit
+
+expect fun <T : Number> f11()
+           ^
+compiler/testData/multiplatform/incompatibleCallables/common.kt:20:12: error: expected function 'f12' has no actual declaration in module
+The following declaration is incompatible because upper bounds of type parameters are different:
+    public actual fun <U : MutableList<out String>> f12(): Unit
+
+expect fun <U : MutableList<String>> f12()
+           ^
+compiler/testData/multiplatform/incompatibleCallables/common.kt:21:12: error: expected function 'f13' has no actual declaration in module
+The following declaration is incompatible because upper bounds of type parameters are different:
+    public actual fun <A, B : Comparable<B>> f13(): Unit
+
+expect fun <A, B : Comparable<A>> f13()
+           ^
 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
@@ -122,6 +140,24 @@ The following declaration is incompatible because visibility is different:
 
 internal actual fun f10() {}
 ^
+compiler/testData/multiplatform/incompatibleCallables/jvm.kt:19:12: error: actual function 'f11' has no corresponding expected declaration
+The following declaration is incompatible because upper bounds of type parameters are different:
+    public expect fun <T : Number> f11(): Unit
+
+actual fun <T : Annotation> f11() {}
+           ^
+compiler/testData/multiplatform/incompatibleCallables/jvm.kt:20:12: error: actual function 'f12' has no corresponding expected declaration
+The following declaration is incompatible because upper bounds of type parameters are different:
+    public expect fun <U : MutableList<String>> f12(): Unit
+
+actual fun <U : MutableList<out String>> f12() {}
+           ^
+compiler/testData/multiplatform/incompatibleCallables/jvm.kt:21:12: error: actual function 'f13' has no corresponding expected declaration
+The following declaration is incompatible because upper bounds of type parameters are different:
+    public expect fun <A, B : Comparable<A>> f13(): Unit
+
+actual fun <A, B : Comparable<B>> f13() {}
+           ^
 compiler/testData/multiplatform/incompatibleCallables/jvm.kt:23:19: error: actual function 'f14' has no corresponding expected declaration
 The following declaration is incompatible because some type parameter is reified in one declaration and non-reified in the other:
     public expect inline fun <X> f14(): Unit

compiler/testData/multiplatform/incompatibleClasses/output.txt

@@ -11,6 +11,18 @@ The following declaration is incompatible because number of type parameters is d
 
 expect class C1<A>
                ^
+compiler/testData/multiplatform/incompatibleClasses/common.kt:16:16: error: expected class 'C3' has no actual declaration in module
+The following declaration is incompatible because upper bounds of type parameters are different:
+    public final actual class C3<D, E : D?>
+
+expect class C3<D, E : D>
+               ^
+compiler/testData/multiplatform/incompatibleClasses/common.kt:18:16: error: expected class 'C4' has no actual declaration in module
+The following declaration is incompatible because upper bounds of type parameters are different:
+    public typealias C4<F>  = C4Impl<F>
+
+expect class C4<F>
+               ^
 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
@@ -83,6 +95,18 @@ The following declaration is incompatible because declaration-site variances of
 
 actual class C2<out B>
                ^
+compiler/testData/multiplatform/incompatibleClasses/jvm.kt:16:16: error: actual class 'C3' has no corresponding expected declaration
+The following declaration is incompatible because upper bounds of type parameters are different:
+    public final expect class C3<D, E : D>
+
+actual class C3<D, E : D?>
+               ^
+compiler/testData/multiplatform/incompatibleClasses/jvm.kt:18:20: error: actual typealias 'C4' has no corresponding expected declaration
+The following declaration is incompatible because upper bounds of type parameters are different:
+    public final expect class C4<F>
+
+actual typealias C4<F> = C4Impl<F>
+                   ^
 compiler/testData/multiplatform/incompatibleClasses/jvm.kt:21:39: error: actual class 'ExtendsNumber' has no corresponding expected declaration
 The following declaration is incompatible because some supertypes are missing in the actual declaration:
     public abstract expect class ExtendsNumber : Number

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

@@ -14290,11 +14290,29 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                     KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/diagnostics/tests/multiplatform/generic"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.ANY, true);
                 }
 
+                @TestMetadata("functionTypeParameterBounds.kt")
+                public void testFunctionTypeParameterBounds() throws Exception {
+                    String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/multiplatform/generic/functionTypeParameterBounds.kt");
+                    doTest(fileName);
+                }
+
+                @TestMetadata("genericMemberBounds.kt")
+                public void testGenericMemberBounds() throws Exception {
+                    String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/multiplatform/generic/genericMemberBounds.kt");
+                    doTest(fileName);
+                }
+
                 @TestMetadata("membersInGenericClass.kt")
                 public void testMembersInGenericClass() throws Exception {
                     String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/multiplatform/generic/membersInGenericClass.kt");
                     doTest(fileName);
                 }
+
+                @TestMetadata("typeParameterBoundsDifferentOrderActualMissing.kt")
+                public void testTypeParameterBoundsDifferentOrderActualMissing() throws Exception {
+                    String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/multiplatform/generic/typeParameterBoundsDifferentOrderActualMissing.kt");
+                    doTest(fileName);
+                }
             }
 
             @TestMetadata("compiler/testData/diagnostics/tests/multiplatform/headerClass")

compiler/tests/org/jetbrains/kotlin/checkers/javac/DiagnosticsUsingJavacTestGenerated.java

@@ -14290,11 +14290,29 @@ public class DiagnosticsUsingJavacTestGenerated extends AbstractDiagnosticsUsing
                     KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/diagnostics/tests/multiplatform/generic"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.ANY, true);
                 }
 
+                @TestMetadata("functionTypeParameterBounds.kt")
+                public void testFunctionTypeParameterBounds() throws Exception {
+                    String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/multiplatform/generic/functionTypeParameterBounds.kt");
+                    doTest(fileName);
+                }
+
+                @TestMetadata("genericMemberBounds.kt")
+                public void testGenericMemberBounds() throws Exception {
+                    String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/multiplatform/generic/genericMemberBounds.kt");
+                    doTest(fileName);
+                }
+
                 @TestMetadata("membersInGenericClass.kt")
                 public void testMembersInGenericClass() throws Exception {
                     String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/multiplatform/generic/membersInGenericClass.kt");
                     doTest(fileName);
                 }
+
+                @TestMetadata("typeParameterBoundsDifferentOrderActualMissing.kt")
+                public void testTypeParameterBoundsDifferentOrderActualMissing() throws Exception {
+                    String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/multiplatform/generic/typeParameterBoundsDifferentOrderActualMissing.kt");
+                    doTest(fileName);
+                }
             }
 
             @TestMetadata("compiler/testData/diagnostics/tests/multiplatform/headerClass")