feat: add support for 'package-info' (#1967)

jadx-core/src/main/java/jadx/api/impl/SimpleCodeWriter.java

@@ -249,7 +249,6 @@ public class SimpleCodeWriter implements ICodeWriter {
 
 	@Override
 	public String getCodeStr() {
-		removeFirstEmptyLine();
 		return buf.toString();
 	}
 

jadx-core/src/main/java/jadx/core/codegen/ClassGen.java

@@ -96,16 +96,29 @@ public class ClassGen {
 	}
 
 	public ICodeInfo makeClass() throws CodegenException {
+		if (cls.contains(AFlag.PACKAGE_INFO)) {
+			return makePackageInfo();
+		}
 		ICodeWriter clsBody = cls.root().makeCodeWriter();
 		addClassCode(clsBody);
 
 		ICodeWriter clsCode = cls.root().makeCodeWriter();
+		addPackage(clsCode);
+		clsCode.newLine();
+		addImports(clsCode);
+		clsCode.add(clsBody);
+		return clsCode.finish();
+	}
+
+	private void addPackage(ICodeWriter clsCode) {
 		if (cls.getPackage().isEmpty()) {
 			clsCode.add("// default package");
 		} else {
 			clsCode.add("package ").add(cls.getPackage()).add(';');
 		}
-		clsCode.newLine();
+	}
+
+	private void addImports(ICodeWriter clsCode) {
 		int importsCount = imports.size();
 		if (importsCount != 0) {
 			List<ClassInfo> sortedImports = new ArrayList<>(imports);
@@ -122,8 +135,17 @@ public class ClassGen {
 			clsCode.newLine();
 			imports.clear();
 		}
-		clsCode.add(clsBody);
-		return clsCode.finish();
+	}
+
+	private ICodeInfo makePackageInfo() {
+		ICodeWriter code = cls.root().makeCodeWriter();
+		annotationGen.addForClass(code);
+		code.newLine();
+		code.attachDefinition(cls);
+		addPackage(code);
+		code.newLine();
+		addImports(code);
+		return code.finish();
 	}
 
 	public void addClassCode(ICodeWriter code) throws CodegenException {

jadx-core/src/main/java/jadx/core/dex/attributes/AFlag.java

@@ -44,6 +44,8 @@ public enum AFlag {
 	THIS,
 	SUPER,
 
+	PACKAGE_INFO,
+
 	/**
 	 * Mark Android resources class
 	 */

jadx-core/src/main/java/jadx/core/dex/nodes/ClassNode.java

@@ -127,6 +127,7 @@ public class ClassNode extends NotificationAttrNode
 			}
 			initStaticValues(fields);
 			processAttributes(this);
+			processSpecialClasses(this);
 			buildCache();
 
 			// TODO: implement module attribute parsing
@@ -167,6 +168,15 @@ public class ClassNode extends NotificationAttrNode
 		this.interfaces = interfaces;
 	}
 
+	private static void processSpecialClasses(ClassNode cls) {
+		AccessInfo flags = cls.getAccessFlags();
+		if (flags.isSynthetic() && flags.isInterface() && flags.isAbstract()
+				&& cls.getName().equals("package-info")) {
+			cls.add(AFlag.PACKAGE_INFO);
+			cls.add(AFlag.DONT_RENAME);
+		}
+	}
+
 	private static void processAttributes(ClassNode cls) {
 		// move AnnotationDefault from cls to methods (dex specific)
 		AnnotationDefaultClassAttr defAttr = cls.get(JadxAttrType.ANNOTATION_DEFAULT_CLASS);

jadx-core/src/main/java/jadx/core/dex/visitors/ClassModifier.java

@@ -50,6 +50,9 @@ public class ClassModifier extends AbstractVisitor {
 
 	@Override
 	public boolean visit(ClassNode cls) throws JadxException {
+		if (cls.contains(AFlag.PACKAGE_INFO)) {
+			return false;
+		}
 		for (ClassNode inner : cls.getInnerClasses()) {
 			visit(inner);
 		}

jadx-core/src/main/java/jadx/core/dex/visitors/rename/RenameVisitor.java

@@ -81,6 +81,9 @@ public class RenameVisitor extends AbstractVisitor {
 	}
 
 	private static void checkClassName(IAliasProvider aliasProvider, ClassNode cls, JadxArgs args) {
+		if (cls.contains(AFlag.DONT_RENAME)) {
+			return;
+		}
 		ClassInfo classInfo = cls.getClassInfo();
 		String clsName = classInfo.getAliasShortName();
 

jadx-core/src/test/java/jadx/tests/api/compiler/TestCompiler.java

@@ -20,6 +20,7 @@ import javax.tools.ToolProvider;
 
 import org.jetbrains.annotations.NotNull;
 
+import jadx.api.impl.SimpleCodeWriter;
 import jadx.core.dex.nodes.ClassNode;
 import jadx.core.utils.files.FileUtils;
 import jadx.tests.api.IntegrationTest;
@@ -80,12 +81,16 @@ public class TestCompiler implements Closeable {
 		arguments.add(javaVerStr);
 		arguments.addAll(options.getArguments());
 
-		DiagnosticListener<? super JavaFileObject> diagnostic =
-				diagObj -> System.out.println("Compiler diagnostic: " + diagObj);
+		SimpleCodeWriter output = new SimpleCodeWriter();
+		DiagnosticListener<JavaFileObject> diagnostic = diagObj -> {
+			String msg = "Compiler diagnostic: " + diagObj;
+			output.startLine(msg);
+			System.out.println(msg);
+		};
 		Writer out = new PrintWriter(System.out);
 		CompilationTask compilerTask = compiler.getTask(out, fileManager, diagnostic, arguments, null, jfObjects);
 		if (Boolean.FALSE.equals(compilerTask.call())) {
-			throw new RuntimeException("Compilation failed");
+			throw new RuntimeException("Compilation failed: " + output);
 		}
 	}
 

jadx-core/src/test/java/jadx/tests/integration/code/TestArrayAccessReorder.java

@@ -32,7 +32,6 @@ public class TestArrayAccessReorder extends IntegrationTest {
 	@Test
 	public void test() {
 		noDebugInfo();
-		getArgs().setRawCFGOutput(true);
 		assertThat(getClassNode(TestCls.class))
 				.code()
 				.containsOne("i++");

jadx-core/src/test/java/jadx/tests/integration/special/TestPackageInfoSupport.java

@@ -0,0 +1,32 @@
+package jadx.tests.integration.special;
+
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+import jadx.core.dex.nodes.ClassNode;
+import jadx.tests.api.SmaliTest;
+
+import static jadx.tests.api.utils.assertj.JadxAssertions.assertThat;
+
+public class TestPackageInfoSupport extends SmaliTest {
+
+	@Test
+	public void test() {
+		disableCompilation();
+		List<ClassNode> classes = loadFromSmaliFiles();
+		assertThat(searchCls(classes, "special.pkg1.package-info"))
+				.satisfies(cls -> assertThat(cls.getAlias()).isEqualTo("package-info")) // shouldn't be renamed
+				.code()
+				.containsLines(
+						"@Deprecated",
+						"package special.pkg1;");
+		assertThat(searchCls(classes, "special.pkg2.package-info"))
+				.code()
+				.containsLines(
+						"@ApiStatus.Internal",
+						"package special.pkg2;",
+						"",
+						"import org.jetbrains.annotations.ApiStatus;");
+	}
+}

jadx-core/src/test/smali/special/TestPackageInfoSupport/pkg1.smali

@@ -0,0 +1,6 @@
+.class interface abstract synthetic Lspecial/pkg1/package-info;
+.super Ljava/lang/Object;
+.source "package-info.java"
+
+.annotation runtime Ljava/lang/Deprecated;
+.end annotation

jadx-core/src/test/smali/special/TestPackageInfoSupport/pkg2.smali

@@ -0,0 +1,5 @@
+.class interface abstract synthetic Lspecial/pkg2/package-info;
+.super Ljava/lang/Object;
+
+.annotation runtime Lorg/jetbrains/annotations/ApiStatus$Internal;
+.end annotation