From 9e48ef85eafc60687fb97171ab7776a7bb0006fc Mon Sep 17 00:00:00 2001
From: Victor Petukhov <victor.petukhov@jetbrains.com>
Date: Wed, 7 Jul 2021 14:19:55 +0300
Subject: [PATCH] Add tests for inferring self types from Java

---
 .../basicInferenceForImplicitSelfType.fir.kt  |  1 -
 .../basicInferenceForImplicitSelfType.kt      |  1 -
 .../basicInferenceForImplicitSelfType.fir.kt  | 31 +++++++++++++++++--
 .../basicInferenceForImplicitSelfType.kt      | 25 +++++++++++++++
 .../basicInferenceForImplicitSelfType.txt     | 11 +++++++
 .../recursiveTypeWithTwoTypeParams.fir.kt     | 17 ++++++++--
 .../recursiveTypeWithTwoTypeParams.kt         | 13 ++++++++
 .../writerAppenderExampleRecursive.fir.kt     | 25 +++++++++++++++
 .../writerAppenderExampleRecursive.kt         | 25 +++++++++++++++
 .../writerAppenderExampleRecursive.txt        | 24 ++++++++++++++
 .../kotlin/types/AbstractTypeChecker.kt       |  8 +++--
 11 files changed, 171 insertions(+), 10 deletions(-)

diff --git a/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/disabledInferenceOnSelfTypes/basicInferenceForImplicitSelfType.fir.kt b/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/disabledInferenceOnSelfTypes/basicInferenceForImplicitSelfType.fir.kt
index eee33a37eb3..25789449fad 100644
--- a/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/disabledInferenceOnSelfTypes/basicInferenceForImplicitSelfType.fir.kt
+++ b/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/disabledInferenceOnSelfTypes/basicInferenceForImplicitSelfType.fir.kt
@@ -2,7 +2,6 @@
 
 class Builder<B : Builder<B>> {
     fun <T : B> test(): T = TODO()
-
     fun foo() {}
 }
 
diff --git a/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/disabledInferenceOnSelfTypes/basicInferenceForImplicitSelfType.kt b/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/disabledInferenceOnSelfTypes/basicInferenceForImplicitSelfType.kt
index 321714c2e49..a0e2f3e65bb 100644
--- a/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/disabledInferenceOnSelfTypes/basicInferenceForImplicitSelfType.kt
+++ b/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/disabledInferenceOnSelfTypes/basicInferenceForImplicitSelfType.kt
@@ -2,7 +2,6 @@
 
 class Builder<B : Builder<B>> {
     fun <T : B> test(): T = TODO()
-
     fun foo() {}
 }
 
diff --git a/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/basicInferenceForImplicitSelfType.fir.kt b/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/basicInferenceForImplicitSelfType.fir.kt
index a5837fe1b92..ae1910abaa0 100644
--- a/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/basicInferenceForImplicitSelfType.fir.kt
+++ b/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/basicInferenceForImplicitSelfType.fir.kt
@@ -1,5 +1,14 @@
 // !LANGUAGE: +TypeInferenceOnCallsWithSelfTypes
 
+// FILE: JavaBuilder.java
+public class JavaBuilder<B extends JavaBuilder<B>> {
+    <T extends B> T test() {
+        return null;
+    }
+    void foo() { }
+}
+
+// FILE: main.kt
 class Builder<B : Builder<B>> {
     fun <T : B> test(): T = TODO()
 
@@ -7,7 +16,7 @@ class Builder<B : Builder<B>> {
 }
 
 fun testStar(builder: Builder<*>) {
-    builder.test()
+    <!DEBUG_INFO_EXPRESSION_TYPE("Builder<*>")!>builder.test()<!>
 
     builder
         .test()
@@ -15,9 +24,25 @@ fun testStar(builder: Builder<*>) {
 }
 
 fun <K : Builder<K>> testTypeParam(builder: Builder<K>) {
-    builder.test()
+    <!DEBUG_INFO_EXPRESSION_TYPE("K")!>builder.test()<!>
 
     builder
         .test()
         .foo()
-}
\ No newline at end of file
+}
+
+fun testStarJava(builder: JavaBuilder<*>) {
+    <!DEBUG_INFO_EXPRESSION_TYPE("Builder<*>")!>builder.test()<!>
+
+    builder
+        .test()
+        .foo()
+}
+
+fun <K : JavaBuilder<K>> testTypeParamJava(builder: JavaBuilder<K>) {
+    <!DEBUG_INFO_EXPRESSION_TYPE("K")!>builder.test()<!>
+
+    builder
+        .test()
+        .foo()
+}
diff --git a/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/basicInferenceForImplicitSelfType.kt b/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/basicInferenceForImplicitSelfType.kt
index 9d4dcd671f3..dba9e266066 100644
--- a/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/basicInferenceForImplicitSelfType.kt
+++ b/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/basicInferenceForImplicitSelfType.kt
@@ -1,5 +1,14 @@
 // !LANGUAGE: +TypeInferenceOnCallsWithSelfTypes
 
+// FILE: JavaBuilder.java
+public class JavaBuilder<B extends JavaBuilder<B>> {
+    <T extends B> T test() {
+        return null;
+    }
+    void foo() { }
+}
+
+// FILE: main.kt
 class Builder<B : Builder<B>> {
     fun <T : B> test(): T = TODO()
 
@@ -21,3 +30,19 @@ fun <K : Builder<K>> testTypeParam(builder: Builder<K>) {
         .test()
         .foo()
 }
+
+fun testStarJava(builder: JavaBuilder<*>) {
+    <!DEBUG_INFO_EXPRESSION_TYPE("(JavaBuilder<*>..JavaBuilder<*>?)")!>builder.test()<!>
+
+    builder
+        .test()
+        .foo()
+}
+
+fun <K : JavaBuilder<K>> testTypeParamJava(builder: JavaBuilder<K>) {
+    <!DEBUG_INFO_EXPRESSION_TYPE("(K..K?)")!>builder.test()<!>
+
+    builder
+        .test()
+        .foo()
+}
diff --git a/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/basicInferenceForImplicitSelfType.txt b/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/basicInferenceForImplicitSelfType.txt
index 37b74c7fc6f..a649ecfa7d8 100644
--- a/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/basicInferenceForImplicitSelfType.txt
+++ b/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/basicInferenceForImplicitSelfType.txt
@@ -1,7 +1,9 @@
 package
 
 public fun testStar(/*0*/ builder: Builder<*>): kotlin.Unit
+public fun testStarJava(/*0*/ builder: JavaBuilder<*>): kotlin.Unit
 public fun </*0*/ K : Builder<K>> testTypeParam(/*0*/ builder: Builder<K>): kotlin.Unit
+public fun </*0*/ K : JavaBuilder<K>> testTypeParamJava(/*0*/ builder: JavaBuilder<K>): kotlin.Unit
 
 public final class Builder</*0*/ B : Builder<B>> {
     public constructor Builder</*0*/ B : Builder<B>>()
@@ -12,3 +14,12 @@ public final class Builder</*0*/ B : Builder<B>> {
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 }
 
+public open class JavaBuilder</*0*/ B : JavaBuilder<B!>!> {
+    public constructor JavaBuilder</*0*/ B : JavaBuilder<B!>!>()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public/*package*/ open fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public/*package*/ open fun </*0*/ T : B!> test(): T!
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
diff --git a/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/recursiveTypeWithTwoTypeParams.fir.kt b/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/recursiveTypeWithTwoTypeParams.fir.kt
index 5d339b162dd..a816d2089fd 100644
--- a/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/recursiveTypeWithTwoTypeParams.fir.kt
+++ b/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/recursiveTypeWithTwoTypeParams.fir.kt
@@ -1,10 +1,23 @@
 // !LANGUAGE: +TypeInferenceOnCallsWithSelfTypes
 
+// FILE: JavaBodySpec.java
+public interface JavaBodySpec<B, S extends JavaBodySpec<B, S>> {
+    default <T extends S> T isEqualTo(B expected) {
+        return null;
+    }
+}
+
+// FILE: main.kt
 interface BodySpec<B, S : BodySpec<B, S>> {
     fun <T : S> isEqualTo(expected: B): T
 }
 
 fun test(b: BodySpec<String, *>) {
     val x = b.isEqualTo("")
-    x
-}
\ No newline at end of file
+    <!DEBUG_INFO_EXPRESSION_TYPE("BodySpec<*, *>")!>x<!>
+}
+
+fun testJava(b: JavaBodySpec<String, *>) {
+    val x = b.isEqualTo("")
+    <!DEBUG_INFO_EXPRESSION_TYPE("BodySpec<*, *>")!>x<!>
+}
diff --git a/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/recursiveTypeWithTwoTypeParams.kt b/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/recursiveTypeWithTwoTypeParams.kt
index e81db1d2289..31661ec2b46 100644
--- a/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/recursiveTypeWithTwoTypeParams.kt
+++ b/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/recursiveTypeWithTwoTypeParams.kt
@@ -1,5 +1,13 @@
 // !LANGUAGE: +TypeInferenceOnCallsWithSelfTypes
 
+// FILE: JavaBodySpec.java
+public interface JavaBodySpec<B, S extends JavaBodySpec<B, S>> {
+    default <T extends S> T isEqualTo(B expected) {
+        return null;
+    }
+}
+
+// FILE: main.kt
 interface BodySpec<B, S : BodySpec<B, S>> {
     fun <T : S> isEqualTo(expected: B): T
 }
@@ -8,3 +16,8 @@ fun test(b: BodySpec<String, *>) {
     val x = b.isEqualTo("")
     <!DEBUG_INFO_EXPRESSION_TYPE("BodySpec<*, *>")!>x<!>
 }
+
+fun testJava(b: JavaBodySpec<String, *>) {
+    val x = b.isEqualTo("")
+    <!DEBUG_INFO_EXPRESSION_TYPE("(JavaBodySpec<*, *>..JavaBodySpec<*, *>?)")!>x<!>
+}
diff --git a/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/writerAppenderExampleRecursive.fir.kt b/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/writerAppenderExampleRecursive.fir.kt
index 6375ab9f202..3722e2e66b7 100644
--- a/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/writerAppenderExampleRecursive.fir.kt
+++ b/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/writerAppenderExampleRecursive.fir.kt
@@ -1,5 +1,23 @@
 // !LANGUAGE: +TypeInferenceOnCallsWithSelfTypes
 
+// FILE: JavaWriterAppender.java
+public class JavaWriterAppender {
+    interface Builder2<K extends Builder2<K>> {}
+
+    class Builder1<B extends Builder1<B>> {
+        B asBuilder() { return null; }
+    }
+
+    <B extends Builder1<B>> B newBuilder() {
+        return null;
+    }
+
+    <B extends Builder1<B> & Builder2<B>> B intersectTwoSelfTypes() {
+        return null;
+    }
+}
+
+// FILE: main.kt
 fun test() {
     <!DEBUG_INFO_EXPRESSION_TYPE("WriterAppender.Builder1<*>")!>WriterAppender.newBuilder()<!>
     <!DEBUG_INFO_EXPRESSION_TYPE("WriterAppender.Builder1<out WriterAppender.Builder1<*>>")!>WriterAppender.Builder1()<!>
@@ -7,6 +25,13 @@ fun test() {
     <!DEBUG_INFO_EXPRESSION_TYPE("{Builder1<*> & Builder2<*>}")!>WriterAppender.intersectTwoSelfTypes()<!>
 }
 
+fun testJava(appender: JavaWriterAppender) {
+    <!DEBUG_INFO_EXPRESSION_TYPE("WriterAppender.Builder1<*>")!>appender.newBuilder()<!>
+    <!DEBUG_INFO_EXPRESSION_TYPE("WriterAppender.Builder1<out WriterAppender.Builder1<*>>")!>appender.Builder1()<!>
+
+    <!DEBUG_INFO_EXPRESSION_TYPE("{Builder1<*> & Builder2<*>}")!>appender.intersectTwoSelfTypes()<!>
+}
+
 object WriterAppender {
     interface Builder2<K : Builder2<K>>
 
diff --git a/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/writerAppenderExampleRecursive.kt b/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/writerAppenderExampleRecursive.kt
index 6375ab9f202..0d6c208ad9e 100644
--- a/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/writerAppenderExampleRecursive.kt
+++ b/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/writerAppenderExampleRecursive.kt
@@ -1,5 +1,23 @@
 // !LANGUAGE: +TypeInferenceOnCallsWithSelfTypes
 
+// FILE: JavaWriterAppender.java
+public class JavaWriterAppender {
+    interface Builder2<K extends Builder2<K>> {}
+
+    class Builder1<B extends Builder1<B>> {
+        B asBuilder() { return null; }
+    }
+
+    <B extends Builder1<B>> B newBuilder() {
+        return null;
+    }
+
+    <B extends Builder1<B> & Builder2<B>> B intersectTwoSelfTypes() {
+        return null;
+    }
+}
+
+// FILE: main.kt
 fun test() {
     <!DEBUG_INFO_EXPRESSION_TYPE("WriterAppender.Builder1<*>")!>WriterAppender.newBuilder()<!>
     <!DEBUG_INFO_EXPRESSION_TYPE("WriterAppender.Builder1<out WriterAppender.Builder1<*>>")!>WriterAppender.Builder1()<!>
@@ -7,6 +25,13 @@ fun test() {
     <!DEBUG_INFO_EXPRESSION_TYPE("{Builder1<*> & Builder2<*>}")!>WriterAppender.intersectTwoSelfTypes()<!>
 }
 
+fun testJava(appender: JavaWriterAppender) {
+    <!DEBUG_INFO_EXPRESSION_TYPE("(JavaWriterAppender.Builder1<*>..JavaWriterAppender.Builder1<*>?)")!>appender.newBuilder()<!>
+    <!DEBUG_INFO_EXPRESSION_TYPE("JavaWriterAppender.Builder1<out (JavaWriterAppender.Builder1<*>..JavaWriterAppender.Builder1<*>?)>")!>appender.Builder1()<!>
+
+    <!DEBUG_INFO_EXPRESSION_TYPE("({Builder1<*> & Builder2<*>}..{Builder1<*>? & Builder2<*>?}?)")!>appender.intersectTwoSelfTypes()<!>
+}
+
 object WriterAppender {
     interface Builder2<K : Builder2<K>>
 
diff --git a/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/writerAppenderExampleRecursive.txt b/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/writerAppenderExampleRecursive.txt
index fe013b5adc8..a23ac5e853c 100644
--- a/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/writerAppenderExampleRecursive.txt
+++ b/compiler/testData/diagnostics/tests/inference/recursiveTypes/selfTypes/enabledInferenceOnSelfTypes/writerAppenderExampleRecursive.txt
@@ -1,6 +1,30 @@
 package
 
 public fun test(): kotlin.Unit
+public fun testJava(/*0*/ appender: JavaWriterAppender): kotlin.Unit
+
+public open class JavaWriterAppender {
+    public constructor JavaWriterAppender()
+    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/*package*/ open fun </*0*/ B : JavaWriterAppender.Builder1<B!>!> intersectTwoSelfTypes(): B! where B : JavaWriterAppender.Builder2<B!>!
+    public/*package*/ open fun </*0*/ B : JavaWriterAppender.Builder1<B!>!> newBuilder(): B!
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+    public/*package*/ open inner class Builder1</*0*/ B : JavaWriterAppender.Builder1<B!>!> {
+        public/*package*/ constructor Builder1</*0*/ B : JavaWriterAppender.Builder1<B!>!>()
+        public/*package*/ open fun asBuilder(): 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
+    }
+
+    public/*package*/ interface Builder2</*0*/ K : JavaWriterAppender.Builder2<K!>!> {
+        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 object WriterAppender {
     private constructor WriterAppender()
diff --git a/core/compiler.common/src/org/jetbrains/kotlin/types/AbstractTypeChecker.kt b/core/compiler.common/src/org/jetbrains/kotlin/types/AbstractTypeChecker.kt
index f8a362f3e5d..0f68bdf036e 100644
--- a/core/compiler.common/src/org/jetbrains/kotlin/types/AbstractTypeChecker.kt
+++ b/core/compiler.common/src/org/jetbrains/kotlin/types/AbstractTypeChecker.kt
@@ -546,13 +546,15 @@ object AbstractTypeChecker {
         targetType: KotlinTypeMarker
     ): TypeParameterMarker? {
         for (i in 0 until baseType.argumentsCount()) {
-            val typeArgument = baseType.getArgument(i).takeIf { !it.isStarProjection() } ?: continue
+            val typeArgument = baseType.getArgument(i).takeIf { !it.isStarProjection() }?.getType() ?: continue
+            val areBothTypesCaptured =
+                typeArgument.lowerBoundIfFlexible().isCapturedType() && targetType.lowerBoundIfFlexible().isCapturedType()
 
-            if (typeArgument.getType() == targetType) {
+            if (typeArgument == targetType || (areBothTypesCaptured && typeArgument.typeConstructor() == targetType.typeConstructor())) {
                 return baseType.typeConstructor().getParameter(i)
             }
 
-            getTypeParameterForArgumentInBaseIfItEqualToTarget(typeArgument.getType(), targetType)?.let { return it }
+            getTypeParameterForArgumentInBaseIfItEqualToTarget(typeArgument, targetType)?.let { return it }
         }
 
         return null