Include JS class names in the auto-generated transpiled Java class na…

…mes to make deobfuscation of `class.getName()` output possible.

Most classes will have unique names, as for the most part Closure Compiler will assign them to variables or global-shared-object properties sharing a common namespace. In case there is ambiguity, a unique ID is still added as a suffix after the JS class name.

PiperOrigin-RevId: 702881060

jre/java/javaemul/internal/nativebootstrap/Util.impl.java.js

@@ -160,9 +160,21 @@ class Util {
    */
   static $getGeneratedClassName_(ctor) {
     const propName = '$$generatedClassName';
-    return ctor.prototype.hasOwnProperty(propName) ?
-        ctor.prototype[propName] :
-        ctor.prototype[propName] = 'Class$obf_' + ++Util.$nextUniqId_;
+    if (ctor.prototype.hasOwnProperty(propName)) {
+      return ctor.prototype[propName];
+    }
+
+    // Use the constructor "name", which should be the result of the variable
+    // name JSCompiler assigned the class/function to. This allows for manual
+    // deobfuscation of the class name.
+    const constructorName = ctor.name;
+    const nextUniqId = Util.$nextUniqIdByName_.get(constructorName) ?? 0;
+    Util.$nextUniqIdByName_.set(constructorName, nextUniqId + 1);
+    const generatedClassName =
+        'Class$obf_' + constructorName + '_' + nextUniqId;
+
+    ctor.prototype[propName] = generatedClassName;
+    return generatedClassName;
   }
 
   /**
@@ -289,9 +301,9 @@ class Util {
 
 
 /**
- * @private {number}
+ * @private @const {!Map<string, number>}
  */
-Util.$nextUniqId_ = 1000;
+Util.$nextUniqIdByName_ = new Map();
 
 /**
  * @type {number}

junit/generator/javatests/com/google/j2cl/junit/integration/stacktrace/data/KotlinThrowsInJsFunction.stacktrace_j2cl.txt

@@ -1,6 +1,6 @@
 java.lang.RuntimeException: __the_message__!
     at com.google.j2cl.junit.integration.stacktrace.data.KotlinThrowsInJsFunction$MyFunctionImpl.run(KotlinThrowsInJsFunction.kt:50)
-    at lambda(jre/java/jre.js/javaemul/internal/nativebootstrap/Util.impl.java.js:196:31)
+    at lambda(jre/java/jre.js/javaemul/internal/nativebootstrap/Util.impl.java.js:208:31)
     at com.google.j2cl.junit.integration.stacktrace.data.KotlinThrowsInJsFunction.executesFunction(KotlinThrowsInJsFunction.kt:55)
     at com.google.j2cl.junit.integration.stacktrace.data.KotlinThrowsInJsFunction$1.run(KotlinThrowsInJsFunction.kt:41)
     at com.google.j2cl.junit.integration.stacktrace.data.KotlinThrowsInJsFunction.executesFunction(KotlinThrowsInJsFunction.kt:55)

junit/generator/javatests/com/google/j2cl/junit/integration/stacktrace/data/KotlinThrowsInJsFunction.stacktrace_j2cl_compiled.txt

@@ -1,6 +1,6 @@
 java.lang.RuntimeException: __the_message__!
     at com.google.j2cl.junit.integration.stacktrace.data.KotlinThrowsInJsFunction$MyFunctionImpl.run(KotlinThrowsInJsFunction.kt:50)
-    at apply(<blaze-out>/jre/java/jre.js/javaemul/internal/nativebootstrap/Util.impl.java.js:196:31)
+    at apply(<blaze-out>/jre/java/jre.js/javaemul/internal/nativebootstrap/Util.impl.java.js:208:31)
     at com.google.j2cl.junit.integration.stacktrace.data.KotlinThrowsInJsFunction.executesFunction(KotlinThrowsInJsFunction.kt:55)
     at com.google.j2cl.junit.integration.stacktrace.data.KotlinThrowsInJsFunction$1.run(KotlinThrowsInJsFunction.kt:41)
     at com.google.j2cl.junit.integration.stacktrace.data.KotlinThrowsInJsFunction.executesFunction(KotlinThrowsInJsFunction.kt:55)

junit/generator/javatests/com/google/j2cl/junit/integration/stacktrace/data/ThrowsInJsFunction.stacktrace_j2cl.txt

@@ -1,6 +1,6 @@
 java.lang.RuntimeException: __the_message__!
     at com.google.j2cl.junit.integration.stacktrace.data.ThrowsInJsFunction$MyFunctionImpl.run(ThrowsInJsFunction.java:55)
-    at lambda(jre/java/jre.js/javaemul/internal/nativebootstrap/Util.impl.java.js:196:31)
+    at lambda(jre/java/jre.js/javaemul/internal/nativebootstrap/Util.impl.java.js:208:31)
     at com.google.j2cl.junit.integration.stacktrace.data.ThrowsInJsFunction.executesFunction(ThrowsInJsFunction.java:60)
     at com.google.j2cl.junit.integration.stacktrace.data.ThrowsInJsFunction$1.run(ThrowsInJsFunction.java:46)
     at com.google.j2cl.junit.integration.stacktrace.data.ThrowsInJsFunction.executesFunction(ThrowsInJsFunction.java:60)

junit/generator/javatests/com/google/j2cl/junit/integration/stacktrace/data/ThrowsInJsFunction.stacktrace_j2cl_compiled.txt

@@ -1,6 +1,6 @@
 java.lang.RuntimeException: __the_message__!
     at com.google.j2cl.junit.integration.stacktrace.data.ThrowsInJsFunction$MyFunctionImpl.run(ThrowsInJsFunction.java:55)
-    at apply(<blaze-out>/jre/java/jre.js/javaemul/internal/nativebootstrap/Util.impl.java.js:196:31)
+    at apply(<blaze-out>/jre/java/jre.js/javaemul/internal/nativebootstrap/Util.impl.java.js:208:31)
     at com.google.j2cl.junit.integration.stacktrace.data.ThrowsInJsFunction.executesFunction(ThrowsInJsFunction.java:60)
     at com.google.j2cl.junit.integration.stacktrace.data.ThrowsInJsFunction$1.run(ThrowsInJsFunction.java:46)
     at com.google.j2cl.junit.integration.stacktrace.data.ThrowsInJsFunction.executesFunction(ThrowsInJsFunction.java:60)

transpiler/javatests/com/google/j2cl/integration/java/classliteralstripped/Main.java

@@ -150,7 +150,10 @@ private static void testNative() {
   }
 
   private static void assertClassName(String name, String canonicalName, String simpleName) {
-    assertTrue("Name should have the pattern XXX_Class$obf_1XXX", name.contains("Class$obf_10"));
+    assertTrue(
+        "Name should have the pattern Class$obf_XXX_# or Class$obf_####, but did not match: "
+            + name,
+        name.matches("^Class\\$obf_(.*_\\d+|[1-9]\\d{3,})$"));
     assertTrue(name.endsWith(simpleName));
     assertEquals(name, canonicalName);
   }