Add support for RxJava's nullability annotations.

compiler/testData/foreignAnnotations/annotations/io/reactivex/annotations/NonNull.java

@@ -0,0 +1,29 @@
+/**
+ * Copyright (c) 2016-present, RxJava Contributors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
+ * compliance with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is
+ * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
+ * the License for the specific language governing permissions and limitations under the License.
+ */
+
+package io.reactivex.annotations;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import static java.lang.annotation.ElementType.*;
+import static java.lang.annotation.RetentionPolicy.CLASS;
+
+/**
+ * Indicates that a field/parameter/variable/return type is never null.
+ */
+@Documented
+@Target(value = {FIELD, METHOD, PARAMETER, LOCAL_VARIABLE})
+@Retention(value = CLASS)
+public @interface NonNull { }

compiler/testData/foreignAnnotations/annotations/io/reactivex/annotations/Nullable.java

@@ -0,0 +1,32 @@
+/**
+ * Copyright (c) 2016-present, RxJava Contributors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
+ * compliance with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is
+ * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
+ * the License for the specific language governing permissions and limitations under the License.
+ */
+
+package io.reactivex.annotations;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import static java.lang.annotation.ElementType.FIELD;
+import static java.lang.annotation.ElementType.LOCAL_VARIABLE;
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.PARAMETER;
+import static java.lang.annotation.RetentionPolicy.CLASS;
+
+/**
+ * Indicates that a field/parameter/variable/return type may be null.
+ */
+@Documented
+@Target(value = {FIELD, METHOD, PARAMETER, LOCAL_VARIABLE})
+@Retention(value = CLASS)
+public @interface Nullable { }

compiler/testData/foreignAnnotations/tests/rxjava.kt

@@ -0,0 +1,42 @@
+// !DIAGNOSTICS: -UNUSED_VARIABLE -UNUSED_PARAMETER
+// FILE: A.java
+
+import io.reactivex.annotations.*;
+
+public class A<T> {
+    @Nullable public String field = null;
+
+    @Nullable
+    public String foo(@NonNull String x, @Nullable CharSequence y) {
+        return "";
+    }
+
+    @NonNull
+    public String bar() {
+        return "";
+    }
+
+    @Nullable
+    public T baz(@NonNull T x) { return x; }
+}
+
+// FILE: main.kt
+
+fun main(a: A<String>, a1: A<String?>) {
+    a.foo("", null)?.length
+    a.foo("", null)<!UNSAFE_CALL!>.<!>length
+    a.foo(<!NULL_FOR_NONNULL_TYPE!>null<!>, "")<!UNSAFE_CALL!>.<!>length
+
+    a.bar().length
+    a.bar()<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>.length
+
+    a.field?.length
+    a.field<!UNSAFE_CALL!>.<!>length
+
+    a.baz("")<!UNSAFE_CALL!>.<!>length
+    a.baz("")?.length
+    a.baz(<!NULL_FOR_NONNULL_TYPE!>null<!>)<!UNSAFE_CALL!>.<!>length
+
+    a1.baz("")!!.length
+    a1.baz(<!NULL_FOR_NONNULL_TYPE!>null<!>)!!.length
+}

compiler/testData/foreignAnnotations/tests/rxjava.txt

@@ -0,0 +1,14 @@
+package
+
+public fun main(/*0*/ a: A<kotlin.String>, /*1*/ a1: A<kotlin.String?>): kotlin.Unit
+
+public open class A</*0*/ T : kotlin.Any!> {
+    public constructor A</*0*/ T : kotlin.Any!>()
+    @io.reactivex.annotations.Nullable public final var field: kotlin.String?
+    @io.reactivex.annotations.NonNull public open fun bar(): kotlin.String
+    @io.reactivex.annotations.Nullable public open fun baz(/*0*/ @io.reactivex.annotations.NonNull x: T): T?
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    @io.reactivex.annotations.Nullable public open fun foo(/*0*/ @io.reactivex.annotations.NonNull x: kotlin.String, /*1*/ @io.reactivex.annotations.Nullable y: kotlin.CharSequence?): kotlin.String?
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

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

@@ -77,4 +77,10 @@ public class ForeignAnnotationsTestGenerated extends AbstractForeignAnnotationsT
         String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/foreignAnnotations/tests/lombokSimple.kt");
         doTest(fileName);
     }
+
+    @TestMetadata("rxjava.kt")
+    public void testRxjava() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/foreignAnnotations/tests/rxjava.kt");
+        doTest(fileName);
+    }
 }

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/JvmAnnotationNames.kt

@@ -28,7 +28,8 @@ val NULLABLE_ANNOTATIONS = listOf(
         FqName("javax.annotation.CheckForNull"),
         FqName("edu.umd.cs.findbugs.annotations.CheckForNull"),
         FqName("edu.umd.cs.findbugs.annotations.Nullable"),
-        FqName("edu.umd.cs.findbugs.annotations.PossiblyNull")
+        FqName("edu.umd.cs.findbugs.annotations.PossiblyNull"),
+        FqName("io.reactivex.annotations.Nullable")
 )
 
 val JAVAX_NONNULL_ANNOTATION = FqName("javax.annotation.Nonnull")
@@ -40,7 +41,8 @@ val NOT_NULL_ANNOTATIONS = listOf(
         FqName("com.android.annotations.NonNull"),
         FqName("org.eclipse.jdt.annotation.NonNull"),
         FqName("org.checkerframework.checker.nullness.qual.NonNull"),
-        FqName("lombok.NonNull")
+        FqName("lombok.NonNull"),
+        FqName("io.reactivex.annotations.NonNull")
 )
 
 val READ_ONLY_ANNOTATIONS = listOf(

core/descriptors/src/org/jetbrains/kotlin/renderer/DescriptorRenderer.kt

@@ -238,7 +238,9 @@ object ExcludedTypeAnnotations {
             FqName("edu.umd.cs.findbugs.annotations.CheckForNull"),
             FqName("edu.umd.cs.findbugs.annotations.Nullable"),
             FqName("edu.umd.cs.findbugs.annotations.PossiblyNull"),
-            FqName("lombok.NonNull")
+            FqName("lombok.NonNull"),
+            FqName("io.reactivex.annotations.Nullable"),
+            FqName("io.reactivex.annotations.NonNull")
     )
 
     val internalAnnotationsForResolve = setOf(