[KT] Add support for package-info.java file in the Kotlin frontend.

Koltin does not have the notion of package-info files where you can define annotation on a package. We let the `package-info.java` files present in the source  go to the Kotlin frontend. We parse them with the `JdtParser` and initialize correctly the `PackageInfoCache`.

PiperOrigin-RevId: 570850258

build_defs/internal_do_not_use/j2cl_java_library.bzl

@@ -1,9 +1,9 @@
 """J2CL library rules."""
 
-load(":provider.bzl", "J2clInfo", "J2ktInfo")
 load(":j2cl_common.bzl", "J2CL_TOOLCHAIN_ATTRS", "j2cl_common", "split_srcs")
-load(":j2kt_common.bzl", "j2kt_common")
 load(":j2cl_js_common.bzl", "J2CL_JS_ATTRS", "JS_PROVIDER_NAME", "j2cl_js_provider")
+load(":j2kt_common.bzl", "j2kt_common")
+load(":provider.bzl", "J2clInfo", "J2ktInfo")
 
 def _impl_j2cl_library(ctx):
     if ctx.attr.j2kt_web_experiment_enabled:
@@ -21,7 +21,11 @@ def _impl_j2cl_library(ctx):
             javac_opts = ctx.attr.javacopts,
         )
 
-        srcs = js_srcs
+        # Pass the package-info.java files as srcs so Kotlin frontend can correctly resolved
+        # JsPackage annotations.
+        # TODO(dramaix): extract package-info from src-jar of the jvm compilation to include
+        # generated package-info.java files.
+        srcs = js_srcs + [f for f in jvm_srcs if f.basename == "package-info.java"]
         kt_common_srcs = j2kt_provider._private_.transpile_kt_out
 
     else:

transpiler/java/com/google/j2cl/transpiler/BazelJ2clBuilder.java

@@ -158,8 +158,9 @@ private J2clTranspilerOptions createOptions(Output output, Problems problems) {
     ImmutableList<FileInfo> allKotlinSources =
         allSources.stream().filter(p -> p.sourcePath().endsWith(".kt")).collect(toImmutableList());
 
-    // TODO(dramaix): add support for transpiling java and kotlin simultaneously.
-    if (!allJavaSources.isEmpty() && !allKotlinSources.isEmpty()) {
+    // For now, only package-info.java files are allowed with Kotlin sources.
+    if (allJavaSources.stream().anyMatch(f -> !f.sourcePath().endsWith("package-info.java"))
+        && !allKotlinSources.isEmpty()) {
       throw new AssertionError(
           "Transpilation of Java and Kotlin files together is not supported yet.");
     }
@@ -175,7 +176,11 @@ private J2clTranspilerOptions createOptions(Output output, Problems problems) {
         .forEach(f -> output.copyFile(f.sourcePath(), f.targetPath()));
 
     return J2clTranspilerOptions.newBuilder()
-        .setSources(allKotlinSources.isEmpty() ? allJavaSources : allKotlinSources)
+        .setSources(
+            ImmutableList.<FileInfo>builder()
+                .addAll(allJavaSources)
+                .addAll(allKotlinSources)
+                .build())
         .setNativeSources(allNativeSources)
         .setClasspaths(getPathEntries(this.classPath))
         .setOutput(output)

transpiler/java/com/google/j2cl/transpiler/frontend/jdt/CompilationUnitBuilder.java

@@ -19,12 +19,14 @@
 import static com.google.common.base.Preconditions.checkState;
 import static com.google.common.collect.ImmutableList.toImmutableList;
 import static com.google.common.collect.MoreCollectors.onlyElement;
+import static com.google.j2cl.transpiler.frontend.jdt.JdtAnnotationUtils.isNullMarked;
+import static com.google.j2cl.transpiler.frontend.jdt.JsInteropAnnotationUtils.getJsNamespace;
+import static com.google.j2cl.transpiler.frontend.jdt.KtInteropAnnotationUtils.getKtObjectiveCName;
 import static java.util.Arrays.stream;
 import static java.util.Map.Entry.comparingByKey;
 import static java.util.stream.Collectors.toCollection;
 import static java.util.stream.Collectors.toList;
 
-import com.google.common.base.Predicate;
 import com.google.common.base.Predicates;
 import com.google.common.collect.ComparisonChain;
 import com.google.common.collect.Iterables;
@@ -102,11 +104,9 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
-import java.util.Optional;
 import javax.annotation.Nullable;
 import org.eclipse.jdt.core.dom.ASTNode;
 import org.eclipse.jdt.core.dom.AbstractTypeDeclaration;
-import org.eclipse.jdt.core.dom.Annotation;
 import org.eclipse.jdt.core.dom.AnnotationTypeMemberDeclaration;
 import org.eclipse.jdt.core.dom.AnonymousClassDeclaration;
 import org.eclipse.jdt.core.dom.ArrayType;
@@ -117,7 +117,6 @@
 import org.eclipse.jdt.core.dom.EnumDeclaration;
 import org.eclipse.jdt.core.dom.ExpressionMethodReference;
 import org.eclipse.jdt.core.dom.FieldDeclaration;
-import org.eclipse.jdt.core.dom.IAnnotationBinding;
 import org.eclipse.jdt.core.dom.IBinding;
 import org.eclipse.jdt.core.dom.IMethodBinding;
 import org.eclipse.jdt.core.dom.ITypeBinding;
@@ -126,6 +125,7 @@
 import org.eclipse.jdt.core.dom.LambdaExpression;
 import org.eclipse.jdt.core.dom.MethodDeclaration;
 import org.eclipse.jdt.core.dom.Name;
+import org.eclipse.jdt.core.dom.PackageDeclaration;
 import org.eclipse.jdt.core.dom.SimpleName;
 import org.eclipse.jdt.core.dom.SingleVariableDeclaration;
 import org.eclipse.jdt.core.dom.SuperMethodInvocation;
@@ -148,19 +148,17 @@ private CompilationUnit convert(
       this.jdtCompilationUnit = jdtCompilationUnit;
 
       setCurrentSourceFile(sourceFilePath);
+      PackageDeclaration packageDeclaration = jdtCompilationUnit.getPackage();
       String packageName =
-          jdtCompilationUnit.getPackage() == null
-              ? ""
-              : jdtCompilationUnit.getPackage().getName().getFullyQualifiedName();
+          packageDeclaration == null ? "" : packageDeclaration.getName().getFullyQualifiedName();
       setCurrentCompilationUnit(CompilationUnit.createForFile(sourceFilePath, packageName));
       // Records information about package-info files supplied as source code.
-      if (getCurrentSourceFile().endsWith("package-info.java")
-          && jdtCompilationUnit.getPackage() != null) {
+      if (getCurrentSourceFile().endsWith("package-info.java") && packageDeclaration != null) {
         setPackagePropertiesFromSource(
             packageName,
-            getPackageJsNamespace(jdtCompilationUnit),
-            getObjectiveCName(jdtCompilationUnit),
-            isNullMarked(jdtCompilationUnit));
+            getJsNamespace(packageDeclaration),
+            getKtObjectiveCName(packageDeclaration),
+            isNullMarked(packageDeclaration));
       }
       for (Object object : jdtCompilationUnit.types()) {
         AbstractTypeDeclaration abstractTypeDeclaration = (AbstractTypeDeclaration) object;
@@ -169,49 +167,6 @@ private CompilationUnit convert(
 
       return getCurrentCompilationUnit();
     }
-
-    @Nullable
-    private IAnnotationBinding getAnnotationBinding(
-        org.eclipse.jdt.core.dom.CompilationUnit jdtCompilationUnit,
-        Predicate<IAnnotationBinding> whichAnnotation) {
-      List<Annotation> packageAnnotations =
-          JdtEnvironment.asTypedList(jdtCompilationUnit.getPackage().annotations());
-      if (packageAnnotations == null) {
-        return null;
-      }
-
-      Optional<IAnnotationBinding> annotationBinding =
-          packageAnnotations.stream()
-              .map(Annotation::resolveAnnotationBinding)
-              .filter(whichAnnotation)
-              .findFirst();
-
-      return annotationBinding.orElse(null);
-    }
-
-    @Nullable
-    private String getObjectiveCName(org.eclipse.jdt.core.dom.CompilationUnit jdtCompilationUnit) {
-      IAnnotationBinding annotationBinding =
-          getAnnotationBinding(jdtCompilationUnit, KtInteropAnnotationUtils::isKtObjectiveCName);
-      return annotationBinding != null
-          ? KtInteropAnnotationUtils.getKtObjectiveCName(annotationBinding)
-          : null;
-    }
-
-    @Nullable
-    private String getPackageJsNamespace(
-        org.eclipse.jdt.core.dom.CompilationUnit jdtCompilationUnit) {
-      IAnnotationBinding annotationBinding =
-          getAnnotationBinding(jdtCompilationUnit, JsInteropAnnotationUtils::isJsPackageAnnotation);
-      return annotationBinding != null
-          ? JsInteropAnnotationUtils.getJsNamespace(annotationBinding)
-          : null;
-    }
-
-    private boolean isNullMarked(org.eclipse.jdt.core.dom.CompilationUnit jdtCompilationUnit) {
-      return JdtEnvironment.isNullMarked(jdtCompilationUnit.getPackage());
-    }
-
     private Type convert(AbstractTypeDeclaration typeDeclaration) {
       switch (typeDeclaration.getNodeType()) {
         case ASTNode.ANNOTATION_TYPE_DECLARATION:

transpiler/java/com/google/j2cl/transpiler/frontend/jdt/JdtAnnotationUtils.java

@@ -18,12 +18,18 @@
 import static com.google.j2cl.transpiler.frontend.jdt.KtInteropAnnotationUtils.getSuppressWarningsAnnotation;
 import static java.util.Arrays.stream;
 
+import com.google.common.base.Predicate;
 import com.google.common.base.VerifyException;
+import com.google.j2cl.transpiler.frontend.common.Nullability;
 import java.lang.reflect.Field;
 import java.util.Arrays;
+import java.util.List;
+import java.util.Optional;
 import javax.annotation.Nullable;
+import org.eclipse.jdt.core.dom.Annotation;
 import org.eclipse.jdt.core.dom.IAnnotationBinding;
 import org.eclipse.jdt.core.dom.IBinding;
+import org.eclipse.jdt.core.dom.PackageDeclaration;
 import org.eclipse.jdt.internal.compiler.impl.BooleanConstant;
 import org.eclipse.jdt.internal.compiler.impl.IntConstant;
 import org.eclipse.jdt.internal.compiler.impl.StringConstant;
@@ -130,6 +136,23 @@ private static AnnotationBinding getAnnotationBinding(IAnnotationBinding annotat
     }
   }
 
+  public static IAnnotationBinding getAnnotationBinding(
+      PackageDeclaration packageDeclaration, Predicate<IAnnotationBinding> whichAnnotation) {
+    List<Annotation> packageAnnotations =
+        JdtEnvironment.asTypedList(packageDeclaration.annotations());
+    if (packageAnnotations == null) {
+      return null;
+    }
+
+    Optional<IAnnotationBinding> annotationBinding =
+        packageAnnotations.stream()
+            .map(Annotation::resolveAnnotationBinding)
+            .filter(whichAnnotation)
+            .findFirst();
+
+    return annotationBinding.orElse(null);
+  }
+
   public static boolean isWarningSuppressed(
       IAnnotationBinding[] annotationBindings, String warning) {
     IAnnotationBinding annotationBinding = getSuppressWarningsAnnotation(annotationBindings);
@@ -141,5 +164,12 @@ public static boolean isWarningSuppressed(
     return stream(suppressions).anyMatch(warning::equals);
   }
 
+  public static boolean isNullMarked(PackageDeclaration packageDeclaration) {
+    return getAnnotationBinding(
+            packageDeclaration,
+            (a) -> Nullability.isNullMarkedAnnotation(a.getAnnotationType().getQualifiedName()))
+        != null;
+  }
+
   private JdtAnnotationUtils() {}
 }

transpiler/java/com/google/j2cl/transpiler/frontend/jdt/JdtEnvironment.java

@@ -60,7 +60,6 @@
 import java.util.function.Supplier;
 import java.util.stream.Stream;
 import javax.annotation.Nullable;
-import org.eclipse.jdt.core.dom.Annotation;
 import org.eclipse.jdt.core.dom.Assignment;
 import org.eclipse.jdt.core.dom.BodyDeclaration;
 import org.eclipse.jdt.core.dom.IAnnotationBinding;
@@ -70,7 +69,6 @@
 import org.eclipse.jdt.core.dom.IVariableBinding;
 import org.eclipse.jdt.core.dom.InfixExpression;
 import org.eclipse.jdt.core.dom.Modifier;
-import org.eclipse.jdt.core.dom.PackageDeclaration;
 import org.eclipse.jdt.core.dom.PostfixExpression;
 import org.eclipse.jdt.core.dom.PrefixExpression;
 
@@ -1258,18 +1256,6 @@ public TypeDeclaration createDeclarationForType(final ITypeBinding typeBinding)
     return typeDeclaration;
   }
 
-  public static boolean isNullMarked(PackageDeclaration packageDeclaration) {
-    List<Annotation> packageAnnotations =
-        JdtEnvironment.asTypedList(packageDeclaration.annotations());
-
-    if (packageAnnotations == null) {
-      return false;
-    }
-
-    return hasNullMarkedAnnotation(
-        packageAnnotations.stream().map(Annotation::resolveAnnotationBinding));
-  }
-
   private boolean isNullMarked(ITypeBinding typeBinding, PackageInfoCache packageInfoCache) {
     return hasNullMarkedAnnotation(typeBinding)
         || packageInfoCache.isNullMarked(

transpiler/java/com/google/j2cl/transpiler/frontend/jdt/JsInteropAnnotationUtils.java

@@ -28,13 +28,15 @@
 import static com.google.j2cl.transpiler.frontend.common.FrontendConstants.JS_PROPERTY_ANNOTATION_NAME;
 import static com.google.j2cl.transpiler.frontend.common.FrontendConstants.JS_TYPE_ANNOTATION_NAME;
 import static com.google.j2cl.transpiler.frontend.common.FrontendConstants.SUPPRESS_WARNINGS_ANNOTATION_NAME;
+import static com.google.j2cl.transpiler.frontend.jdt.JdtAnnotationUtils.getAnnotationBinding;
 import static java.util.Arrays.stream;
 
 import java.util.Optional;
 import org.eclipse.jdt.core.dom.IAnnotationBinding;
 import org.eclipse.jdt.core.dom.IBinding;
 import org.eclipse.jdt.core.dom.IMethodBinding;
 import org.eclipse.jdt.core.dom.ITypeBinding;
+import org.eclipse.jdt.core.dom.PackageDeclaration;
 
 /** Utility methods to get information about Js Interop annotations. */
 public class JsInteropAnnotationUtils {
@@ -120,6 +122,12 @@ public static boolean isUnusableByJsSuppressed(IBinding binding) {
     return stream(suppressions).anyMatch("unusable-by-js"::equals);
   }
 
+  public static String getJsNamespace(PackageDeclaration packageDeclaration) {
+    IAnnotationBinding annotationBinding =
+        getAnnotationBinding(packageDeclaration, JsInteropAnnotationUtils::isJsPackageAnnotation);
+    return JsInteropAnnotationUtils.getJsNamespace(annotationBinding);
+  }
+
   /** The namespace specified on a package, type, method or field. */
   public static String getJsNamespace(ITypeBinding typeBinding) {
     return getJsNamespace(getJsTypeOrJsEnumAnnotation(typeBinding));

transpiler/java/com/google/j2cl/transpiler/frontend/jdt/KtInteropAnnotationUtils.java

@@ -25,9 +25,11 @@
 import static com.google.j2cl.transpiler.frontend.common.FrontendConstants.KT_THROWS_ANNOTATION_NAME;
 import static com.google.j2cl.transpiler.frontend.common.FrontendConstants.SUPPRESS_WARNINGS_ANNOTATION_NAME;
 import static com.google.j2cl.transpiler.frontend.jdt.JdtAnnotationUtils.findAnnotationBindingByName;
+import static com.google.j2cl.transpiler.frontend.jdt.JdtAnnotationUtils.getAnnotationBinding;
 import static com.google.j2cl.transpiler.frontend.jdt.JdtAnnotationUtils.getStringAttribute;
 
 import org.eclipse.jdt.core.dom.IAnnotationBinding;
+import org.eclipse.jdt.core.dom.PackageDeclaration;
 
 /** Utility methods to get information about Kotlin Interop annotations. */
 public class KtInteropAnnotationUtils {
@@ -55,6 +57,11 @@ public static String getKtObjectiveCName(IAnnotationBinding annotationBinding) {
     return getStringAttribute(annotationBinding, "value");
   }
 
+  public static String getKtObjectiveCName(PackageDeclaration packageDeclaration) {
+    return getKtObjectiveCName(
+        getAnnotationBinding(packageDeclaration, KtInteropAnnotationUtils::isKtObjectiveCName));
+  }
+
   public static boolean isKtObjectiveCName(IAnnotationBinding annotationBinding) {
     return annotationBinding.getAnnotationType().getQualifiedName().equals(KT_OBJECTIVE_C_NAME);
   }

transpiler/java/com/google/j2cl/transpiler/frontend/kotlin/BUILD

@@ -11,9 +11,11 @@ kt_jvm_library(
     srcs = glob(["*.kt"]),
     deps = [
         "//third_party:guava",
+        "//third_party:jdt-core",
         "//third_party:kotlin_compiler",
         "//transpiler/java/com/google/j2cl/common",
         "//transpiler/java/com/google/j2cl/transpiler/ast",
         "//transpiler/java/com/google/j2cl/transpiler/frontend/common",
+        "//transpiler/java/com/google/j2cl/transpiler/frontend/jdt",
     ],
 )