[jnigen] Exclude invalid Dart identifiers by default

pkgs/jnigen/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.12.2-wip
+
+- Now excludes invalid identifiers by default.
+
 ## 0.12.1
 
 - Support implementing generic functions in interfaces.

pkgs/jnigen/lib/src/bindings/excluder.dart

@@ -11,6 +11,21 @@ extension on ClassMember {
   bool get isPrivate => !isPublic;
 }
 
+// TODO(https://github.com/dart-lang/native/issues/1164): Kotlin compiler
+// appends the method name with a dash and a hash code when arguments contain
+// inline classes. This is because inline classes do not have any runtime type
+// and the typical operator overloading supported by JVM cannot work for them.
+//
+// Once we support inline classes, we can relax the following constraints.
+final _validDartIdentifier = RegExp(r'^[a-zA-Z_$][a-zA-Z0-9_$]*$');
+
+extension on String {
+  bool get isInvalidDartIdentifier =>
+      !_validDartIdentifier.hasMatch(this) &&
+      this != '<init>' &&
+      this != '<clinit>';
+}
+
 class Excluder extends Visitor<Classes, void> {
   final Config config;
 
@@ -24,6 +39,11 @@ class Excluder extends Visitor<Classes, void> {
       if (excluded) {
         log.fine('Excluded class ${classDecl.binaryName}');
       }
+      if (classDecl.name.isInvalidDartIdentifier) {
+        log.warning('Excluded class ${classDecl.binaryName}: the name is not a'
+            ' valid Dart identifer');
+        return true;
+      }
       return excluded;
     });
     final classExcluder = _ClassExcluder(config);
@@ -51,6 +71,12 @@ class _ClassExcluder extends Visitor<ClassDecl, void> {
       if (excluded) {
         log.fine('Excluded method ${node.binaryName}#${method.name}');
       }
+      if (method.name.isInvalidDartIdentifier) {
+        log.warning(
+            'Excluded method ${node.binaryName}#${method.name}: the name is not'
+            ' a valid Dart identifer');
+        return false;
+      }
       return !excluded;
     }).toList();
     node.fields = node.fields.where((field) {
@@ -59,6 +85,12 @@ class _ClassExcluder extends Visitor<ClassDecl, void> {
       if (excluded) {
         log.fine('Excluded field ${node.binaryName}#${field.name}');
       }
+      if (field.name.isInvalidDartIdentifier) {
+        log.warning(
+            'Excluded field ${node.binaryName}#${field.name}: the name is not'
+            ' a valid Dart identifer');
+        return false;
+      }
       return !excluded;
     }).toList();
   }

pkgs/jnigen/pubspec.yaml

@@ -4,7 +4,7 @@
 
 name: jnigen
 description: A Dart bindings generator for Java and Kotlin that uses JNI under the hood to interop with Java virtual machine.
-version: 0.12.1
+version: 0.12.2-wip
 repository: https://github.com/dart-lang/native/tree/main/pkgs/jnigen
 
 environment: