Add support for nullability annotations in androidx package.

compiler/testData/foreignAnnotations/tests/androidx.kt

@@ -0,0 +1,43 @@
+// !DIAGNOSTICS: -UNUSED_VARIABLE -UNUSED_PARAMETER
+// FILE: A.java
+
+import androidx.annotation.*;
+
+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/androidx.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!>()
+    @androidx.annotation.Nullable public final var field: kotlin.String?
+    @androidx.annotation.NonNull public open fun bar(): kotlin.String
+    @androidx.annotation.Nullable public open fun baz(/*0*/ @androidx.annotation.NonNull x: T): T?
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    @androidx.annotation.Nullable public open fun foo(/*0*/ @androidx.annotation.NonNull x: kotlin.String, /*1*/ @androidx.annotation.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/javac/JavacForeignAnnotationsTestGenerated.java

@@ -25,9 +25,15 @@ public class JavacForeignAnnotationsTestGenerated extends AbstractJavacForeignAn
         KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/foreignAnnotations/tests"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.ANY, true);
     }
 
-    @TestMetadata("android.kt")
+    @TestMetadata("android_support.kt")
-    public void testAndroid() throws Exception {
+    public void testAndroidSupport() throws Exception {
-        String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/foreignAnnotations/tests/android.kt");
+        String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/foreignAnnotations/tests/android_support.kt");
+        doTest(fileName);
+    }
+
+    @TestMetadata("androidx.kt")
+    public void testAndroidSupport() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/foreignAnnotations/tests/androidx.kt");
         doTest(fileName);
     }
 

core/descriptors.jvm/src/org/jetbrains/kotlin/load/java/JvmAnnotationNames.kt

@@ -20,6 +20,7 @@ import org.jetbrains.kotlin.name.FqName
 
 val NULLABLE_ANNOTATIONS = listOf(
         JvmAnnotationNames.JETBRAINS_NULLABLE_ANNOTATION,
+        FqName("androidx.annotation.Nullable"),
         FqName("android.support.annotation.Nullable"),
         FqName("com.android.annotations.Nullable"),
         FqName("org.eclipse.jdt.annotation.Nullable"),
@@ -38,6 +39,7 @@ val JAVAX_CHECKFORNULL_ANNOTATION = FqName("javax.annotation.CheckForNull")
 val NOT_NULL_ANNOTATIONS = listOf(
         JvmAnnotationNames.JETBRAINS_NOT_NULL_ANNOTATION,
         FqName("edu.umd.cs.findbugs.annotations.NonNull"),
+        FqName("androidx.annotation.NonNull"),
         FqName("android.support.annotation.NonNull"),
         FqName("com.android.annotations.NonNull"),
         FqName("org.eclipse.jdt.annotation.NonNull"),

third-party/annotations/androidx/annotation/NonNull.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * 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 androidx.annotation;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import static java.lang.annotation.ElementType.FIELD;
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.PARAMETER;
+import static java.lang.annotation.RetentionPolicy.CLASS;
+
+/**
+ * Denotes that a parameter, field or method return value can never be null.
+ * <p>
+ * This is a marker annotation and it has no specific attributes.
+ */
+@Retention(CLASS)
+@Target({METHOD, PARAMETER, FIELD})
+public @interface NonNull {
+}

third-party/annotations/androidx/annotation/Nullable.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * 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 androidx.annotation;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import static java.lang.annotation.ElementType.FIELD;
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.PARAMETER;
+import static java.lang.annotation.RetentionPolicy.CLASS;
+
+/**
+ * Denotes that a parameter, field or method return value can be null.
+ * <p>
+ * When decorating a method call parameter, this denotes that the parameter can
+ * legitimately be null and the method will gracefully deal with it. Typically
+ * used on optional parameters.
+ * <p>
+ * When decorating a method, this denotes the method might legitimately return
+ * null.
+ * <p>
+ * This is a marker annotation and it has no specific attributes.
+ */
+@Retention(CLASS)
+@Target({METHOD, PARAMETER, FIELD})
+public @interface Nullable {
+}