[java decompiler] supporting `package-info`

GitOrigin-RevId: e20e9b802600dec52700065a7a29799c73c1dc49

src/org/jetbrains/java/decompiler/main/ClassWriter.java

@@ -249,13 +249,6 @@ public class ClassWriter {
         }
       }
 
-      if (cl.hasModifier(CodeConstants.ACC_MODULE)) {
-        StructModuleAttribute moduleAttribute = cl.getAttribute(StructGeneralAttribute.ATTRIBUTE_MODULE);
-        if (moduleAttribute != null) {
-          writeModuleInfoBody(buffer, moduleAttribute);
-        }
-      }
-
       buffer.appendIndent(indent).append('}');
 
       if (node.type != ClassNode.CLASS_ANONYMOUS) {
@@ -269,10 +262,10 @@ public class ClassWriter {
     DecompilerContext.getLogger().endWriteClass();
   }
 
+  @SuppressWarnings("SpellCheckingInspection")
   private static boolean isSyntheticRecordMethod(StructClass cl, StructMethod mt, TextBuffer code) {
     if (cl.getRecordComponents() != null) {
       String name = mt.getName(), descriptor = mt.getDescriptor();
-      //noinspection SpellCheckingInspection
       if (name.equals("equals") && descriptor.equals("(Ljava/lang/Object;)Z") ||
           name.equals("hashCode") && descriptor.equals("()I") ||
           name.equals("toString") && descriptor.equals("()Ljava/lang/String;")) {
@@ -285,6 +278,30 @@ public class ClassWriter {
     return false;
   }
 
+  public static void packageInfoToJava(StructClass cl, TextBuffer buffer) {
+    appendAnnotations(buffer, 0, cl, -1);
+
+    int index = cl.qualifiedName.lastIndexOf('/');
+    String packageName = cl.qualifiedName.substring(0, index).replace('/', '.');
+    buffer.append("package ").append(packageName).append(';').appendLineSeparator().appendLineSeparator();
+  }
+
+  public static void moduleInfoToJava(StructClass cl, TextBuffer buffer) {
+    appendAnnotations(buffer, 0, cl, -1);
+
+    StructModuleAttribute moduleAttribute = cl.getAttribute(StructGeneralAttribute.ATTRIBUTE_MODULE);
+
+    if ((moduleAttribute.moduleFlags & CodeConstants.ACC_OPEN) != 0) {
+      buffer.append("open ");
+    }
+
+    buffer.append("module ").append(moduleAttribute.moduleName).append(" {").appendLineSeparator();
+
+    writeModuleInfoBody(buffer, moduleAttribute);
+
+    buffer.append('}').appendLineSeparator();
+  }
+
   private static void writeModuleInfoBody(TextBuffer buffer, StructModuleAttribute moduleAttribute) {
     boolean newLineNeeded = false;
 
@@ -368,7 +385,6 @@ public class ClassWriter {
     boolean isEnum = DecompilerContext.getOption(IFernflowerPreferences.DECOMPILE_ENUM) && (flags & CodeConstants.ACC_ENUM) != 0;
     boolean isInterface = (flags & CodeConstants.ACC_INTERFACE) != 0;
     boolean isAnnotation = (flags & CodeConstants.ACC_ANNOTATION) != 0;
-    boolean isModuleInfo = (flags & CodeConstants.ACC_MODULE) != 0 && cl.hasAttribute(StructGeneralAttribute.ATTRIBUTE_MODULE);
 
     if (isDeprecated) {
       appendDeprecation(buffer, indent);
@@ -414,24 +430,10 @@ public class ClassWriter {
     else if (components != null) {
       buffer.append("record ");
     }
-    else if (isModuleInfo) {
-      StructModuleAttribute moduleAttribute = cl.getAttribute(StructGeneralAttribute.ATTRIBUTE_MODULE);
-
-      if ((moduleAttribute.moduleFlags & CodeConstants.ACC_OPEN) != 0) {
-        buffer.append("open ");
-      }
-
-      buffer.append("module ");
-      buffer.append(moduleAttribute.moduleName);
-    }
     else {
       buffer.append("class ");
     }
-
-    // Handled above
-    if (!isModuleInfo) {
     buffer.append(node.simpleName);
-    }
 
     GenericClassDescriptor descriptor = getGenericClassDescriptor(cl);
     if (descriptor != null && !descriptor.fparameters.isEmpty()) {

src/org/jetbrains/java/decompiler/main/ClassesProcessor.java

@@ -302,15 +302,32 @@ public class ClassesProcessor implements CodeConstants {
       return;
     }
 
+    boolean packageInfo = cl.isSynthetic() && "package-info".equals(root.simpleName);
+    boolean moduleInfo = cl.hasModifier(CodeConstants.ACC_MODULE) && cl.hasAttribute(StructGeneralAttribute.ATTRIBUTE_MODULE);
+
     DecompilerContext.getLogger().startReadingClass(cl.qualifiedName);
     try {
       ImportCollector importCollector = new ImportCollector(root);
       DecompilerContext.startClass(importCollector);
 
+      if (packageInfo) {
+        ClassWriter.packageInfoToJava(cl, buffer);
+
+        importCollector.writeImports(buffer, false);
+      }
+      else if (moduleInfo) {
+        TextBuffer moduleBuffer = new TextBuffer(AVERAGE_CLASS_SIZE);
+        ClassWriter.moduleInfoToJava(cl, moduleBuffer);
+
+        importCollector.writeImports(buffer, true);
+
+        buffer.append(moduleBuffer);
+      }
+      else {
         new LambdaProcessor().processClass(root);
 
         // add simple class names to implicit import
-      addClassnameToImport(root, importCollector);
+        addClassNameToImport(root, importCollector);
 
         // build wrappers for all nested classes (that's where actual processing takes place)
         initWrappers(root);
@@ -322,21 +339,13 @@ public class ClassesProcessor implements CodeConstants {
         TextBuffer classBuffer = new TextBuffer(AVERAGE_CLASS_SIZE);
         new ClassWriter().classToJava(root, classBuffer, 0, null);
 
-      int index = cl.qualifiedName.lastIndexOf("/");
+        int index = cl.qualifiedName.lastIndexOf('/');
         if (index >= 0) {
           String packageName = cl.qualifiedName.substring(0, index).replace('/', '.');
-
-        buffer.append("package ");
-        buffer.append(packageName);
-        buffer.append(";");
-        buffer.appendLineSeparator();
-        buffer.appendLineSeparator();
+          buffer.append("package ").append(packageName).append(';').appendLineSeparator().appendLineSeparator();
         }
 
-      int import_lines_written = importCollector.writeImports(buffer);
-      if (import_lines_written > 0) {
-        buffer.appendLineSeparator();
-      }
+        importCollector.writeImports(buffer, true);
 
         int offsetLines = buffer.countLines();
 
@@ -354,6 +363,7 @@ public class ClassesProcessor implements CodeConstants {
           }
         }
       }
+    }
     finally {
       destroyWrappers(root);
       DecompilerContext.getLogger().endReadingClass();
@@ -375,13 +385,13 @@ public class ClassesProcessor implements CodeConstants {
     }
   }
 
-  private static void addClassnameToImport(ClassNode node, ImportCollector imp) {
+  private static void addClassNameToImport(ClassNode node, ImportCollector imp) {
     if (node.simpleName != null && node.simpleName.length() > 0) {
       imp.getShortName(node.type == ClassNode.CLASS_ROOT ? node.classStruct.qualifiedName : node.simpleName, false);
     }
 
     for (ClassNode nd : node.nested) {
-      addClassnameToImport(nd, imp);
+      addClassNameToImport(nd, imp);
     }
   }
 

src/org/jetbrains/java/decompiler/main/collectors/ImportCollector.java

@@ -1,4 +1,4 @@
-// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+// Copyright 2000-2021 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package org.jetbrains.java.decompiler.main.collectors;
 
 import org.jetbrains.java.decompiler.main.ClassesProcessor.ClassNode;
@@ -150,21 +150,14 @@ public class ImportCollector {
     return result == null ? shortName : result;
   }
 
-  public int writeImports(TextBuffer buffer) {
-    int importLinesWritten = 0;
-
+  public void writeImports(TextBuffer buffer, boolean addSeparator) {
     List<String> imports = packImports();
-
-    for (String s : imports) {
-      buffer.append("import ");
-      buffer.append(s);
-      buffer.append(';');
+    for (String line : imports) {
+      buffer.append("import ").append(line).append(';').appendLineSeparator();
+    }
+    if (addSeparator && !imports.isEmpty()) {
       buffer.appendLineSeparator();
-
-      importLinesWritten++;
     }
-
-    return importLinesWritten;
   }
 
   private List<String> packImports() {

test/org/jetbrains/java/decompiler/SingleClassesTest.java

@@ -115,9 +115,9 @@ public class SingleClassesTest {
   @Test public void testSynchronizedUnprotected() { doTest("pkg/TestSynchronizedUnprotected"); }
   @Test public void testInterfaceSuper() { doTest("pkg/TestInterfaceSuper"); }
   @Test public void testFieldSingleAccess() { doTest("pkg/TestFieldSingleAccess"); }
+  @Test public void testPackageInfo() { doTest("pkg/package-info"); }
 
   // TODO: fix all below
-  //@Test public void testPackageInfo() { doTest("pkg/package-info"); }
   //@Test public void testSwitchOnStrings() { doTest("pkg/TestSwitchOnStrings");}
   //@Test public void testUnionType() { doTest("pkg/TestUnionType"); }
   //@Test public void testInnerClassConstructor2() { doTest("pkg/TestInner2"); }

testData/results/module-info.dec

@@ -1,4 +1,6 @@
-@Deprecated
+import pkg.test1.TestModuleAnno;
+
+@TestModuleAnno("...")
 module sample.module {
    requires java.base;
 
@@ -15,4 +17,3 @@ module sample.module {
    provides sample.pkg1.TestService with
       sample.pkg1.TestServiceImpl;
 }
-

testData/results/package-info.dec

@@ -1,2 +1,4 @@
-@jdk.Exported
+@PkgAnno("...")
 package pkg;
+
+import ext.PkgAnno;

testData/src/ext/PkgAnno.java

@@ -0,0 +1,8 @@
+package ext;
+
+import java.lang.annotation.*;
+
+@Target(ElementType.PACKAGE)
+public @interface PkgAnno {
+  String value();
+}

testData/src/java9/sample.module/TestModuleAnno.java

@@ -0,0 +1,8 @@
+package pkg.test1;
+
+import java.lang.annotation.*;
+
+@Target(ElementType.MODULE)
+public @interface TestModuleAnno {
+  String value();
+}

testData/src/java9/sample.module/module-info.java

@@ -1,4 +1,6 @@
-@Deprecated
+import pkg.test1.TestModuleAnno;
+
+@TestModuleAnno("...")
 module sample.module {
   requires java.base;
 

testData/src/pkg/package-info.java

@@ -1,2 +1,4 @@
-@jdk.Exported
+@PkgAnno("...")
 package pkg;
+
+import ext.PkgAnno;